--- /dev/null
+/* SCTP kernel implementation
+ * (C) Copyright IBM Corp. 2001, 2004
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2002 Intel Corp.
+ * Copyright (c) 2002 Nokia Corp.
+ *
+ * This is part of the SCTP Linux Kernel Implementation.
+ *
+ * These are the state functions for the state machine.
+ *
+ * This SCTP implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This SCTP implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ * lksctp developers <linux-sctp@vger.kernel.org>
+ *
+ * Written or modified by:
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Karl Knutson <karl@athena.chicago.il.us>
+ * Mathew Kotowsky <kotowsky@sctp.org>
+ * Sridhar Samudrala <samudrala@us.ibm.com>
+ * Jon Grimm <jgrimm@us.ibm.com>
+ * Hui Huang <hui.huang@nokia.com>
+ * Dajiang Zhang <dajiang.zhang@nokia.com>
+ * Daisy Chang <daisyc@us.ibm.com>
+ * Ardelle Fan <ardelle.fan@intel.com>
+ * Ryan Layer <rmlayer@us.ibm.com>
+ * Kevin Gao <kevin.gao@intel.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/inet_ecn.h>
+#include <linux/skbuff.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+#include <net/sctp/structs.h>
+
+static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ const void *payload,
+ size_t paylen);
+static int sctp_eat_data(const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands);
+static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk);
+static void sctp_send_stale_cookie_err(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_chunk *err_chunk);
+static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
+
+static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
+ sctp_cmd_seq_t *commands,
+ __be16 error, int sk_err,
+ const struct sctp_association *asoc,
+ struct sctp_transport *transport);
+
+static sctp_disposition_t sctp_sf_abort_violation(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ void *arg,
+ sctp_cmd_seq_t *commands,
+ const __u8 *payload,
+ const size_t paylen);
+
+static sctp_disposition_t sctp_sf_violation_chunklen(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg, void *ext,
+ sctp_cmd_seq_t *commands);
+
+static sctp_disposition_t sctp_sf_violation_ctsn(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_disposition_t sctp_sf_violation_chunk(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+static sctp_ierror_t sctp_sf_authenticate(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk);
+
+static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands);
+
+/* Small helper function that checks if the chunk length
+ * is of the appropriate length. The 'required_length' argument
+ * is set to be the size of a specific chunk we are testing.
+ * Return Values: 1 = Valid length
+ * 0 = Invalid length
+ *
+ */
+static inline int
+sctp_chunk_length_valid(struct sctp_chunk *chunk,
+ __u16 required_length)
+{
+ __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
+
+ /* Previously already marked? */
+ if (unlikely(chunk->pdiscard))
+ return 0;
+ if (unlikely(chunk_length < required_length))
+ return 0;
+
+ return 1;
+}
+
+/**********************************************************
+ * These are the state functions for handling chunk events.
+ **********************************************************/
+
+/*
+ * Process the final SHUTDOWN COMPLETE.
+ *
+ * Section: 4 (C) (diagram), 9.2
+ * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
+ * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
+ * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
+ * should stop the T2-shutdown timer and remove all knowledge of the
+ * association (and thus the association enters the CLOSED state).
+ *
+ * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
+ * C) Rules for packet carrying SHUTDOWN COMPLETE:
+ * ...
+ * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
+ * if the Verification Tag field of the packet matches its own tag and
+ * the T bit is not set
+ * OR
+ * it is set to its peer's tag and the T bit is set in the Chunk
+ * Flags.
+ * Otherwise, the receiver MUST silently discard the packet
+ * and take no further action. An endpoint MUST ignore the
+ * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_4_C(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_ulpevent *ev;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* RFC 2960 6.10 Bundling
+ *
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ */
+ if (!chunk->singleton)
+ return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* RFC 2960 10.2 SCTP-to-ULP
+ *
+ * H) SHUTDOWN COMPLETE notification
+ *
+ * When SCTP completes the shutdown procedures (section 9.2) this
+ * notification is passed to the upper layer.
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
+ 0, 0, 0, NULL, GFP_ATOMIC);
+ if (ev)
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+
+ /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
+ * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
+ * not the chunk should be discarded. If the endpoint is in
+ * the SHUTDOWN-ACK-SENT state the endpoint should stop the
+ * T2-shutdown timer and remove all knowledge of the
+ * association (and thus the association enters the CLOSED
+ * state).
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+
+ SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+}
+
+/*
+ * Respond to a normal INIT chunk.
+ * We are the side that is being asked for an association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, B
+ * B) "Z" shall respond immediately with an INIT ACK chunk. The
+ * destination IP address of the INIT ACK MUST be set to the source
+ * IP address of the INIT to which this INIT ACK is responding. In
+ * the response, besides filling in other parameters, "Z" must set the
+ * Verification Tag field to Tag_A, and also provide its own
+ * Verification Tag (Tag_Z) in the Initiate Tag field.
+ *
+ * Verification Tag: Must be 0.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *repl;
+ struct sctp_association *new_asoc;
+ struct sctp_chunk *err_chunk;
+ struct sctp_packet *packet;
+ sctp_unrecognized_param_t *unk_param;
+ int len;
+
+ /* 6.10 Bundling
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ *
+ * IG Section 2.11.2
+ * Furthermore, we require that the receiver of an INIT chunk MUST
+ * enforce these rules by silently discarding an arriving packet
+ * with an INIT chunk that is bundled with other chunks.
+ */
+ if (!chunk->singleton)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* If the packet is an OOTB packet which is temporarily on the
+ * control endpoint, respond with an ABORT.
+ */
+ if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
+ SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+ }
+
+ /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
+ * Tag.
+ */
+ if (chunk->sctp_hdr->vtag != 0)
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the INIT chunk has a valid length.
+ * Normally, this would cause an ABORT with a Protocol Violation
+ * error, but since we don't have an association, we'll
+ * just discard the packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* If the INIT is coming toward a closing socket, we'll send back
+ * and ABORT. Essentially, this catches the race of INIT being
+ * backloged to the socket at the same time as the user isses close().
+ * Since the socket and all its associations are going away, we
+ * can treat this OOTB
+ */
+ if (sctp_sstate(ep->base.sk, CLOSING))
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+
+ /* Verify the INIT chunk before processing it. */
+ err_chunk = NULL;
+ if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
+ (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
+ &err_chunk)) {
+ /* This chunk contains fatal error. It is to be discarded.
+ * Send an ABORT, with causes if there is any.
+ */
+ if (err_chunk) {
+ packet = sctp_abort_pkt_new(net, ep, asoc, arg,
+ (__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t),
+ ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t));
+
+ sctp_chunk_free(err_chunk);
+
+ if (packet) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+ return SCTP_DISPOSITION_CONSUME;
+ } else {
+ return SCTP_DISPOSITION_NOMEM;
+ }
+ } else {
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
+ commands);
+ }
+ }
+
+ /* Grab the INIT header. */
+ chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
+
+ /* Tag the variable length parameters. */
+ chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
+
+ new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
+ if (!new_asoc)
+ goto nomem;
+
+ if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
+ sctp_scope(sctp_source(chunk)),
+ GFP_ATOMIC) < 0)
+ goto nomem_init;
+
+ /* The call, sctp_process_init(), can fail on memory allocation. */
+ if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
+ (sctp_init_chunk_t *)chunk->chunk_hdr,
+ GFP_ATOMIC))
+ goto nomem_init;
+
+ /* B) "Z" shall respond immediately with an INIT ACK chunk. */
+
+ /* If there are errors need to be reported for unknown parameters,
+ * make sure to reserve enough room in the INIT ACK for them.
+ */
+ len = 0;
+ if (err_chunk)
+ len = ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t);
+
+ repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
+ if (!repl)
+ goto nomem_init;
+
+ /* If there are errors need to be reported for unknown parameters,
+ * include them in the outgoing INIT ACK as "Unrecognized parameter"
+ * parameter.
+ */
+ if (err_chunk) {
+ /* Get the "Unrecognized parameter" parameter(s) out of the
+ * ERROR chunk generated by sctp_verify_init(). Since the
+ * error cause code for "unknown parameter" and the
+ * "Unrecognized parameter" type is the same, we can
+ * construct the parameters in INIT ACK by copying the
+ * ERROR causes over.
+ */
+ unk_param = (sctp_unrecognized_param_t *)
+ ((__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t));
+ /* Replace the cause code with the "Unrecognized parameter"
+ * parameter type.
+ */
+ sctp_addto_chunk(repl, len, unk_param);
+ sctp_chunk_free(err_chunk);
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /*
+ * Note: After sending out INIT ACK with the State Cookie parameter,
+ * "Z" MUST NOT allocate any resources, nor keep any states for the
+ * new association. Otherwise, "Z" will be vulnerable to resource
+ * attacks.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+
+nomem_init:
+ sctp_association_free(new_asoc);
+nomem:
+ if (err_chunk)
+ sctp_chunk_free(err_chunk);
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal INIT ACK chunk.
+ * We are the side that is initiating the association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, C
+ * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
+ * timer and leave COOKIE-WAIT state. "A" shall then send the State
+ * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
+ * the T1-cookie timer, and enter the COOKIE-ECHOED state.
+ *
+ * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
+ * DATA chunks, but it MUST be the first chunk in the packet and
+ * until the COOKIE ACK is returned the sender MUST NOT send any
+ * other packets to the peer.
+ *
+ * Verification Tag: 3.3.3
+ * If the value of the Initiate Tag in a received INIT ACK chunk is
+ * found to be 0, the receiver MUST treat it as an error and close the
+ * association by transmitting an ABORT.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_init_chunk_t *initchunk;
+ struct sctp_chunk *err_chunk;
+ struct sctp_packet *packet;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* 6.10 Bundling
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ */
+ if (!chunk->singleton)
+ return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the INIT-ACK chunk has a valid length */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+ /* Grab the INIT header. */
+ chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
+
+ /* Verify the INIT chunk before processing it. */
+ err_chunk = NULL;
+ if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
+ (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
+ &err_chunk)) {
+
+ sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
+
+ /* This chunk contains fatal error. It is to be discarded.
+ * Send an ABORT, with causes. If there are no causes,
+ * then there wasn't enough memory. Just terminate
+ * the association.
+ */
+ if (err_chunk) {
+ packet = sctp_abort_pkt_new(net, ep, asoc, arg,
+ (__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t),
+ ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t));
+
+ sctp_chunk_free(err_chunk);
+
+ if (packet) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+ error = SCTP_ERROR_INV_PARAM;
+ }
+ }
+
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destroy this association just because the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
+ asoc, chunk->transport);
+ }
+
+ /* Tag the variable length parameters. Note that we never
+ * convert the parameters in an INIT chunk.
+ */
+ chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
+
+ initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
+ SCTP_PEER_INIT(initchunk));
+
+ /* Reset init error count upon receipt of INIT-ACK. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
+
+ /* 5.1 C) "A" shall stop the T1-init timer and leave
+ * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
+ * timer, and enter the COOKIE-ECHOED state.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
+
+ /* SCTP-AUTH: genereate the assocition shared keys so that
+ * we can potentially signe the COOKIE-ECHO.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
+
+ /* 5.1 C) "A" shall then send the State Cookie received in the
+ * INIT ACK chunk in a COOKIE ECHO chunk, ...
+ */
+ /* If there is any errors to report, send the ERROR chunk generated
+ * for unknown parameters as well.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
+ SCTP_CHUNK(err_chunk));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Respond to a normal COOKIE ECHO chunk.
+ * We are the side that is being asked for an association.
+ *
+ * Section: 5.1 Normal Establishment of an Association, D
+ * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
+ * with a COOKIE ACK chunk after building a TCB and moving to
+ * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
+ * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
+ * chunk MUST be the first chunk in the packet.
+ *
+ * IMPLEMENTATION NOTE: An implementation may choose to send the
+ * Communication Up notification to the SCTP user upon reception
+ * of a valid COOKIE ECHO chunk.
+ *
+ * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
+ * D) Rules for packet carrying a COOKIE ECHO
+ *
+ * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
+ * Initial Tag received in the INIT ACK.
+ *
+ * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_association *new_asoc;
+ sctp_init_chunk_t *peer_init;
+ struct sctp_chunk *repl;
+ struct sctp_ulpevent *ev, *ai_ev = NULL;
+ int error = 0;
+ struct sctp_chunk *err_chk_p;
+ struct sock *sk;
+
+ /* If the packet is an OOTB packet which is temporarily on the
+ * control endpoint, respond with an ABORT.
+ */
+ if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
+ SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the COOKIE_ECHO chunk has a valid length.
+ * In this case, we check that we have enough for at least a
+ * chunk header. More detailed verification is done
+ * in sctp_unpack_cookie().
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* If the endpoint is not listening or if the number of associations
+ * on the TCP-style socket exceed the max backlog, respond with an
+ * ABORT.
+ */
+ sk = ep->base.sk;
+ if (!sctp_sstate(sk, LISTENING) ||
+ (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+
+ /* "Decode" the chunk. We have no optional parameters so we
+ * are in good shape.
+ */
+ chunk->subh.cookie_hdr =
+ (struct sctp_signed_cookie *)chunk->skb->data;
+ if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t)))
+ goto nomem;
+
+ /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
+ * "Z" will reply with a COOKIE ACK chunk after building a TCB
+ * and moving to the ESTABLISHED state.
+ */
+ new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
+ &err_chk_p);
+
+ /* FIXME:
+ * If the re-build failed, what is the proper error path
+ * from here?
+ *
+ * [We should abort the association. --piggy]
+ */
+ if (!new_asoc) {
+ /* FIXME: Several errors are possible. A bad cookie should
+ * be silently discarded, but think about logging it too.
+ */
+ switch (error) {
+ case -SCTP_IERROR_NOMEM:
+ goto nomem;
+
+ case -SCTP_IERROR_STALE_COOKIE:
+ sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
+ err_chk_p);
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ case -SCTP_IERROR_BAD_SIG:
+ default:
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+ }
+
+
+ /* Delay state machine commands until later.
+ *
+ * Re-build the bind address for the association is done in
+ * the sctp_unpack_cookie() already.
+ */
+ /* This is a brand-new association, so these are not yet side
+ * effects--it is safe to run them here.
+ */
+ peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
+
+ if (!sctp_process_init(new_asoc, chunk,
+ &chunk->subh.cookie_hdr->c.peer_addr,
+ peer_init, GFP_ATOMIC))
+ goto nomem_init;
+
+ /* SCTP-AUTH: Now that we've populate required fields in
+ * sctp_process_init, set up the assocaition shared keys as
+ * necessary so that we can potentially authenticate the ACK
+ */
+ error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
+ if (error)
+ goto nomem_init;
+
+ /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
+ * is supposed to be authenticated and we have to do delayed
+ * authentication. We've just recreated the association using
+ * the information in the cookie and now it's much easier to
+ * do the authentication.
+ */
+ if (chunk->auth_chunk) {
+ struct sctp_chunk auth;
+ sctp_ierror_t ret;
+
+ /* Make sure that we and the peer are AUTH capable */
+ if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
+ sctp_association_free(new_asoc);
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* set-up our fake chunk so that we can process it */
+ auth.skb = chunk->auth_chunk;
+ auth.asoc = chunk->asoc;
+ auth.sctp_hdr = chunk->sctp_hdr;
+ auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
+ sizeof(sctp_chunkhdr_t));
+ skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
+ auth.transport = chunk->transport;
+
+ ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
+ if (ret != SCTP_IERROR_NO_ERROR) {
+ sctp_association_free(new_asoc);
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+ }
+
+ repl = sctp_make_cookie_ack(new_asoc, chunk);
+ if (!repl)
+ goto nomem_init;
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * D) IMPLEMENTATION NOTE: An implementation may choose to
+ * send the Communication Up notification to the SCTP user
+ * upon reception of a valid COOKIE ECHO chunk.
+ */
+ ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
+ new_asoc->c.sinit_num_ostreams,
+ new_asoc->c.sinit_max_instreams,
+ NULL, GFP_ATOMIC);
+ if (!ev)
+ goto nomem_ev;
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaptation Layer Indication parameter , SCTP
+ * delivers this notification to inform the application that of the
+ * peers requested adaptation layer.
+ */
+ if (new_asoc->peer.adaptation_ind) {
+ ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
+ GFP_ATOMIC);
+ if (!ai_ev)
+ goto nomem_aiev;
+ }
+
+ /* Add all the state machine commands now since we've created
+ * everything. This way we don't introduce memory corruptions
+ * during side-effect processing and correclty count established
+ * associations.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
+ SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
+
+ if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+
+ /* This will send the COOKIE ACK */
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /* Queue the ASSOC_CHANGE event */
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Send up the Adaptation Layer Indication event */
+ if (ai_ev)
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ai_ev));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem_aiev:
+ sctp_ulpevent_free(ev);
+nomem_ev:
+ sctp_chunk_free(repl);
+nomem_init:
+ sctp_association_free(new_asoc);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Respond to a normal COOKIE ACK chunk.
+ * We are the side that is being asked for an association.
+ *
+ * RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
+ * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
+ * timer. It may also notify its ULP about the successful
+ * establishment of the association with a Communication Up
+ * notification (see Section 10).
+ *
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_ulpevent *ev;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Verify that the chunk length for the COOKIE-ACK is OK.
+ * If we don't do this, any bundled chunks may be junked.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Reset init error count upon receipt of COOKIE-ACK,
+ * to avoid problems with the managemement of this
+ * counter in stale cookie situations when a transition back
+ * from the COOKIE-ECHOED state to the COOKIE-WAIT
+ * state is performed.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * E) Upon reception of the COOKIE ACK, endpoint "A" will move
+ * from the COOKIE-ECHOED state to the ESTABLISHED state,
+ * stopping the T1-cookie timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
+ SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
+ if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+
+ /* It may also notify its ULP about the successful
+ * establishment of the association with a Communication Up
+ * notification (see Section 10).
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
+ 0, asoc->c.sinit_num_ostreams,
+ asoc->c.sinit_max_instreams,
+ NULL, GFP_ATOMIC);
+
+ if (!ev)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaptation Layer Indication parameter , SCTP
+ * delivers this notification to inform the application that of the
+ * peers requested adaptation layer.
+ */
+ if (asoc->peer.adaptation_ind) {
+ ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
+ if (!ev)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Generate and sendout a heartbeat packet. */
+static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_transport *transport = (struct sctp_transport *) arg;
+ struct sctp_chunk *reply;
+
+ /* Send a heartbeat to our peer. */
+ reply = sctp_make_heartbeat(asoc, transport);
+ if (!reply)
+ return SCTP_DISPOSITION_NOMEM;
+
+ /* Set rto_pending indicating that an RTT measurement
+ * is started with this heartbeat chunk.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
+ SCTP_TRANSPORT(transport));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* Generate a HEARTBEAT packet on the given transport. */
+sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_transport *transport = (struct sctp_transport *) arg;
+
+ if (asoc->overall_error_count >= asoc->max_retrans) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ /* Section 3.3.5.
+ * The Sender-specific Heartbeat Info field should normally include
+ * information about the sender's current time when this HEARTBEAT
+ * chunk is sent and the destination transport address to which this
+ * HEARTBEAT is sent (see Section 8.3).
+ */
+
+ if (transport->param_flags & SPP_HB_ENABLE) {
+ if (SCTP_DISPOSITION_NOMEM ==
+ sctp_sf_heartbeat(ep, asoc, type, arg,
+ commands))
+ return SCTP_DISPOSITION_NOMEM;
+
+ /* Set transport error counter and association error counter
+ * when sending heartbeat.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
+ SCTP_TRANSPORT(transport));
+ }
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
+ SCTP_TRANSPORT(transport));
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
+ SCTP_TRANSPORT(transport));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Process an heartbeat request.
+ *
+ * Section: 8.3 Path Heartbeat
+ * The receiver of the HEARTBEAT should immediately respond with a
+ * HEARTBEAT ACK that contains the Heartbeat Information field copied
+ * from the received HEARTBEAT chunk.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ * When receiving an SCTP packet, the endpoint MUST ensure that the
+ * value in the Verification Tag field of the received SCTP packet
+ * matches its own Tag. If the received Verification Tag value does not
+ * match the receiver's own tag value, the receiver shall silently
+ * discard the packet and shall not process it any further except for
+ * those cases listed in Section 8.5.1 below.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_paramhdr_t *param_hdr;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *reply;
+ size_t paylen = 0;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the HEARTBEAT chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* 8.3 The receiver of the HEARTBEAT should immediately
+ * respond with a HEARTBEAT ACK that contains the Heartbeat
+ * Information field copied from the received HEARTBEAT chunk.
+ */
+ chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
+ param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
+ paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
+
+ if (ntohs(param_hdr->length) > paylen)
+ return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+ param_hdr, commands);
+
+ if (!pskb_pull(chunk->skb, paylen))
+ goto nomem;
+
+ reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
+ if (!reply)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Process the returning HEARTBEAT ACK.
+ *
+ * Section: 8.3 Path Heartbeat
+ * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
+ * should clear the error counter of the destination transport
+ * address to which the HEARTBEAT was sent, and mark the destination
+ * transport address as active if it is not so marked. The endpoint may
+ * optionally report to the upper layer when an inactive destination
+ * address is marked as active due to the reception of the latest
+ * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
+ * clear the association overall error count as well (as defined
+ * in section 8.1).
+ *
+ * The receiver of the HEARTBEAT ACK should also perform an RTT
+ * measurement for that destination transport address using the time
+ * value carried in the HEARTBEAT ACK chunk.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ union sctp_addr from_addr;
+ struct sctp_transport *link;
+ sctp_sender_hb_info_t *hbinfo;
+ unsigned long max_interval;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
+ sizeof(sctp_sender_hb_info_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
+ /* Make sure that the length of the parameter is what we expect */
+ if (ntohs(hbinfo->param_hdr.length) !=
+ sizeof(sctp_sender_hb_info_t)) {
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ from_addr = hbinfo->daddr;
+ link = sctp_assoc_lookup_paddr(asoc, &from_addr);
+
+ /* This should never happen, but lets log it if so. */
+ if (unlikely(!link)) {
+ if (from_addr.sa.sa_family == AF_INET6) {
+ net_warn_ratelimited("%s association %p could not find address %pI6\n",
+ __func__,
+ asoc,
+ &from_addr.v6.sin6_addr);
+ } else {
+ net_warn_ratelimited("%s association %p could not find address %pI4\n",
+ __func__,
+ asoc,
+ &from_addr.v4.sin_addr.s_addr);
+ }
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* Validate the 64-bit random nonce. */
+ if (hbinfo->hb_nonce != link->hb_nonce)
+ return SCTP_DISPOSITION_DISCARD;
+
+ max_interval = link->hbinterval + link->rto;
+
+ /* Check if the timestamp looks valid. */
+ if (time_after(hbinfo->sent_at, jiffies) ||
+ time_after(jiffies, hbinfo->sent_at + max_interval)) {
+ pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
+ "for transport:%p\n", __func__, link);
+
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
+ * the HEARTBEAT should clear the error counter of the
+ * destination transport address to which the HEARTBEAT was
+ * sent and mark the destination transport address as active if
+ * it is not so marked.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* Helper function to send out an abort for the restart
+ * condition.
+ */
+static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
+ struct sctp_chunk *init,
+ sctp_cmd_seq_t *commands)
+{
+ int len;
+ struct sctp_packet *pkt;
+ union sctp_addr_param *addrparm;
+ struct sctp_errhdr *errhdr;
+ struct sctp_endpoint *ep;
+ char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
+ struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
+
+ /* Build the error on the stack. We are way to malloc crazy
+ * throughout the code today.
+ */
+ errhdr = (struct sctp_errhdr *)buffer;
+ addrparm = (union sctp_addr_param *)errhdr->variable;
+
+ /* Copy into a parm format. */
+ len = af->to_addr_param(ssa, addrparm);
+ len += sizeof(sctp_errhdr_t);
+
+ errhdr->cause = SCTP_ERROR_RESTART;
+ errhdr->length = htons(len);
+
+ /* Assign to the control socket. */
+ ep = sctp_sk(net->sctp.ctl_sock)->ep;
+
+ /* Association is NULL since this may be a restart attack and we
+ * want to send back the attacker's vtag.
+ */
+ pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
+
+ if (!pkt)
+ goto out;
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
+
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+
+ /* Discard the rest of the inbound packet. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+
+out:
+ /* Even if there is no memory, treat as a failure so
+ * the packet will get dropped.
+ */
+ return 0;
+}
+
+static bool list_has_sctp_addr(const struct list_head *list,
+ union sctp_addr *ipaddr)
+{
+ struct sctp_transport *addr;
+
+ list_for_each_entry(addr, list, transports) {
+ if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
+ return true;
+ }
+
+ return false;
+}
+/* A restart is occurring, check to make sure no new addresses
+ * are being added as we may be under a takeover attack.
+ */
+static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *init,
+ sctp_cmd_seq_t *commands)
+{
+ struct net *net = sock_net(new_asoc->base.sk);
+ struct sctp_transport *new_addr;
+ int ret = 1;
+
+ /* Implementor's Guide - Section 5.2.2
+ * ...
+ * Before responding the endpoint MUST check to see if the
+ * unexpected INIT adds new addresses to the association. If new
+ * addresses are added to the association, the endpoint MUST respond
+ * with an ABORT..
+ */
+
+ /* Search through all current addresses and make sure
+ * we aren't adding any new ones.
+ */
+ list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
+ transports) {
+ if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
+ &new_addr->ipaddr)) {
+ sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
+ commands);
+ ret = 0;
+ break;
+ }
+ }
+
+ /* Return success if all addresses were found. */
+ return ret;
+}
+
+/* Populate the verification/tie tags based on overlapping INIT
+ * scenario.
+ *
+ * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
+ */
+static void sctp_tietags_populate(struct sctp_association *new_asoc,
+ const struct sctp_association *asoc)
+{
+ switch (asoc->state) {
+
+ /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
+
+ case SCTP_STATE_COOKIE_WAIT:
+ new_asoc->c.my_vtag = asoc->c.my_vtag;
+ new_asoc->c.my_ttag = asoc->c.my_vtag;
+ new_asoc->c.peer_ttag = 0;
+ break;
+
+ case SCTP_STATE_COOKIE_ECHOED:
+ new_asoc->c.my_vtag = asoc->c.my_vtag;
+ new_asoc->c.my_ttag = asoc->c.my_vtag;
+ new_asoc->c.peer_ttag = asoc->c.peer_vtag;
+ break;
+
+ /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
+ * COOKIE-WAIT and SHUTDOWN-ACK-SENT
+ */
+ default:
+ new_asoc->c.my_ttag = asoc->c.my_vtag;
+ new_asoc->c.peer_ttag = asoc->c.peer_vtag;
+ break;
+ }
+
+ /* Other parameters for the endpoint SHOULD be copied from the
+ * existing parameters of the association (e.g. number of
+ * outbound streams) into the INIT ACK and cookie.
+ */
+ new_asoc->rwnd = asoc->rwnd;
+ new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
+ new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
+ new_asoc->c.initial_tsn = asoc->c.initial_tsn;
+}
+
+/*
+ * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
+ * handling action.
+ *
+ * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
+ *
+ * Returns value representing action to be taken. These action values
+ * correspond to Action/Description values in RFC 2960, Table 2.
+ */
+static char sctp_tietags_compare(struct sctp_association *new_asoc,
+ const struct sctp_association *asoc)
+{
+ /* In this case, the peer may have restarted. */
+ if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
+ (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
+ (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
+ (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
+ return 'A';
+
+ /* Collision case B. */
+ if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
+ ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
+ (0 == asoc->c.peer_vtag))) {
+ return 'B';
+ }
+
+ /* Collision case D. */
+ if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
+ (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
+ return 'D';
+
+ /* Collision case C. */
+ if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
+ (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
+ (0 == new_asoc->c.my_ttag) &&
+ (0 == new_asoc->c.peer_ttag))
+ return 'C';
+
+ /* No match to any of the special cases; discard this packet. */
+ return 'E';
+}
+
+/* Common helper routine for both duplicate and simulataneous INIT
+ * chunk handling.
+ */
+static sctp_disposition_t sctp_sf_do_unexpected_init(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg, sctp_cmd_seq_t *commands)
+{
+ sctp_disposition_t retval;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *repl;
+ struct sctp_association *new_asoc;
+ struct sctp_chunk *err_chunk;
+ struct sctp_packet *packet;
+ sctp_unrecognized_param_t *unk_param;
+ int len;
+
+ /* 6.10 Bundling
+ * An endpoint MUST NOT bundle INIT, INIT ACK or
+ * SHUTDOWN COMPLETE with any other chunks.
+ *
+ * IG Section 2.11.2
+ * Furthermore, we require that the receiver of an INIT chunk MUST
+ * enforce these rules by silently discarding an arriving packet
+ * with an INIT chunk that is bundled with other chunks.
+ */
+ if (!chunk->singleton)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
+ * Tag.
+ */
+ if (chunk->sctp_hdr->vtag != 0)
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the INIT chunk has a valid length.
+ * In this case, we generate a protocol violation since we have
+ * an association established.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+ /* Grab the INIT header. */
+ chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
+
+ /* Tag the variable length parameters. */
+ chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
+
+ /* Verify the INIT chunk before processing it. */
+ err_chunk = NULL;
+ if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
+ (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
+ &err_chunk)) {
+ /* This chunk contains fatal error. It is to be discarded.
+ * Send an ABORT, with causes if there is any.
+ */
+ if (err_chunk) {
+ packet = sctp_abort_pkt_new(net, ep, asoc, arg,
+ (__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t),
+ ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t));
+
+ if (packet) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+ retval = SCTP_DISPOSITION_CONSUME;
+ } else {
+ retval = SCTP_DISPOSITION_NOMEM;
+ }
+ goto cleanup;
+ } else {
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
+ commands);
+ }
+ }
+
+ /*
+ * Other parameters for the endpoint SHOULD be copied from the
+ * existing parameters of the association (e.g. number of
+ * outbound streams) into the INIT ACK and cookie.
+ * FIXME: We are copying parameters from the endpoint not the
+ * association.
+ */
+ new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
+ if (!new_asoc)
+ goto nomem;
+
+ if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
+ sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
+ goto nomem;
+
+ /* In the outbound INIT ACK the endpoint MUST copy its current
+ * Verification Tag and Peers Verification tag into a reserved
+ * place (local tie-tag and per tie-tag) within the state cookie.
+ */
+ if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
+ (sctp_init_chunk_t *)chunk->chunk_hdr,
+ GFP_ATOMIC))
+ goto nomem;
+
+ /* Make sure no new addresses are being added during the
+ * restart. Do not do this check for COOKIE-WAIT state,
+ * since there are no peer addresses to check against.
+ * Upon return an ABORT will have been sent if needed.
+ */
+ if (!sctp_state(asoc, COOKIE_WAIT)) {
+ if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
+ commands)) {
+ retval = SCTP_DISPOSITION_CONSUME;
+ goto nomem_retval;
+ }
+ }
+
+ sctp_tietags_populate(new_asoc, asoc);
+
+ /* B) "Z" shall respond immediately with an INIT ACK chunk. */
+
+ /* If there are errors need to be reported for unknown parameters,
+ * make sure to reserve enough room in the INIT ACK for them.
+ */
+ len = 0;
+ if (err_chunk) {
+ len = ntohs(err_chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t);
+ }
+
+ repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
+ if (!repl)
+ goto nomem;
+
+ /* If there are errors need to be reported for unknown parameters,
+ * include them in the outgoing INIT ACK as "Unrecognized parameter"
+ * parameter.
+ */
+ if (err_chunk) {
+ /* Get the "Unrecognized parameter" parameter(s) out of the
+ * ERROR chunk generated by sctp_verify_init(). Since the
+ * error cause code for "unknown parameter" and the
+ * "Unrecognized parameter" type is the same, we can
+ * construct the parameters in INIT ACK by copying the
+ * ERROR causes over.
+ */
+ unk_param = (sctp_unrecognized_param_t *)
+ ((__u8 *)(err_chunk->chunk_hdr) +
+ sizeof(sctp_chunkhdr_t));
+ /* Replace the cause code with the "Unrecognized parameter"
+ * parameter type.
+ */
+ sctp_addto_chunk(repl, len, unk_param);
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /*
+ * Note: After sending out INIT ACK with the State Cookie parameter,
+ * "Z" MUST NOT allocate any resources for this new association.
+ * Otherwise, "Z" will be vulnerable to resource attacks.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+ retval = SCTP_DISPOSITION_CONSUME;
+
+ return retval;
+
+nomem:
+ retval = SCTP_DISPOSITION_NOMEM;
+nomem_retval:
+ if (new_asoc)
+ sctp_association_free(new_asoc);
+cleanup:
+ if (err_chunk)
+ sctp_chunk_free(err_chunk);
+ return retval;
+}
+
+/*
+ * Handle simultaneous INIT.
+ * This means we started an INIT and then we got an INIT request from
+ * our peer.
+ *
+ * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
+ * This usually indicates an initialization collision, i.e., each
+ * endpoint is attempting, at about the same time, to establish an
+ * association with the other endpoint.
+ *
+ * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
+ * endpoint MUST respond with an INIT ACK using the same parameters it
+ * sent in its original INIT chunk (including its Verification Tag,
+ * unchanged). These original parameters are combined with those from the
+ * newly received INIT chunk. The endpoint shall also generate a State
+ * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
+ * INIT to calculate the State Cookie.
+ *
+ * After that, the endpoint MUST NOT change its state, the T1-init
+ * timer shall be left running and the corresponding TCB MUST NOT be
+ * destroyed. The normal procedures for handling State Cookies when
+ * a TCB exists will resolve the duplicate INITs to a single association.
+ *
+ * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
+ * its Tie-Tags with the Tag information of itself and its peer (see
+ * section 5.2.2 for a description of the Tie-Tags).
+ *
+ * Verification Tag: Not explicit, but an INIT can not have a valid
+ * verification tag, so we skip the check.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* Call helper to do the real work for both simulataneous and
+ * duplicate INIT chunk handling.
+ */
+ return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Handle duplicated INIT messages. These are usually delayed
+ * restransmissions.
+ *
+ * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
+ * COOKIE-ECHOED and COOKIE-WAIT
+ *
+ * Unless otherwise stated, upon reception of an unexpected INIT for
+ * this association, the endpoint shall generate an INIT ACK with a
+ * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
+ * current Verification Tag and peer's Verification Tag into a reserved
+ * place within the state cookie. We shall refer to these locations as
+ * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
+ * containing this INIT ACK MUST carry a Verification Tag value equal to
+ * the Initiation Tag found in the unexpected INIT. And the INIT ACK
+ * MUST contain a new Initiation Tag (randomly generated see Section
+ * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
+ * existing parameters of the association (e.g. number of outbound
+ * streams) into the INIT ACK and cookie.
+ *
+ * After sending out the INIT ACK, the endpoint shall take no further
+ * actions, i.e., the existing association, including its current state,
+ * and the corresponding TCB MUST NOT be changed.
+ *
+ * Note: Only when a TCB exists and the association is not in a COOKIE-
+ * WAIT state are the Tie-Tags populated. For a normal association INIT
+ * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
+ * set to 0 (indicating that no previous TCB existed). The INIT ACK and
+ * State Cookie are populated as specified in section 5.2.1.
+ *
+ * Verification Tag: Not specified, but an INIT has no way of knowing
+ * what the verification tag could be, so we ignore it.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* Call helper to do the real work for both simulataneous and
+ * duplicate INIT chunk handling.
+ */
+ return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
+}
+
+
+/*
+ * Unexpected INIT-ACK handler.
+ *
+ * Section 5.2.3
+ * If an INIT ACK received by an endpoint in any state other than the
+ * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
+ * An unexpected INIT ACK usually indicates the processing of an old or
+ * duplicated INIT chunk.
+*/
+sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg, sctp_cmd_seq_t *commands)
+{
+ /* Per the above section, we'll discard the chunk if we have an
+ * endpoint. If this is an OOTB INIT-ACK, treat it as such.
+ */
+ if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
+ return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
+ else
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+}
+
+/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
+ *
+ * Section 5.2.4
+ * A) In this case, the peer may have restarted.
+ */
+static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_association *new_asoc)
+{
+ sctp_init_chunk_t *peer_init;
+ struct sctp_ulpevent *ev;
+ struct sctp_chunk *repl;
+ struct sctp_chunk *err;
+ sctp_disposition_t disposition;
+
+ /* new_asoc is a brand-new association, so these are not yet
+ * side effects--it is safe to run them here.
+ */
+ peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
+
+ if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
+ GFP_ATOMIC))
+ goto nomem;
+
+ /* Make sure no new addresses are being added during the
+ * restart. Though this is a pretty complicated attack
+ * since you'd have to get inside the cookie.
+ */
+ if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
+ return SCTP_DISPOSITION_CONSUME;
+ }
+
+ /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
+ * the peer has restarted (Action A), it MUST NOT setup a new
+ * association but instead resend the SHUTDOWN ACK and send an ERROR
+ * chunk with a "Cookie Received while Shutting Down" error cause to
+ * its peer.
+ */
+ if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
+ disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
+ SCTP_ST_CHUNK(chunk->chunk_hdr->type),
+ chunk, commands);
+ if (SCTP_DISPOSITION_NOMEM == disposition)
+ goto nomem;
+
+ err = sctp_make_op_error(asoc, chunk,
+ SCTP_ERROR_COOKIE_IN_SHUTDOWN,
+ NULL, 0, 0);
+ if (err)
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err));
+
+ return SCTP_DISPOSITION_CONSUME;
+ }
+
+ /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
+ * data. Consider the optional choice of resending of this data.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
+ sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
+
+ /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
+ * and ASCONF-ACK cache.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+ sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
+
+ repl = sctp_make_cookie_ack(new_asoc, chunk);
+ if (!repl)
+ goto nomem;
+
+ /* Report association restart to upper layer. */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
+ new_asoc->c.sinit_num_ostreams,
+ new_asoc->c.sinit_max_instreams,
+ NULL, GFP_ATOMIC);
+ if (!ev)
+ goto nomem_ev;
+
+ /* Update the content of current association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+ if (sctp_state(asoc, SHUTDOWN_PENDING) &&
+ (sctp_sstate(asoc->base.sk, CLOSING) ||
+ sock_flag(asoc->base.sk, SOCK_DEAD))) {
+ /* if were currently in SHUTDOWN_PENDING, but the socket
+ * has been closed by user, don't transition to ESTABLISHED.
+ * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
+ SCTP_ST_CHUNK(0), NULL,
+ commands);
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ }
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem_ev:
+ sctp_chunk_free(repl);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
+ *
+ * Section 5.2.4
+ * B) In this case, both sides may be attempting to start an association
+ * at about the same time but the peer endpoint started its INIT
+ * after responding to the local endpoint's INIT
+ */
+/* This case represents an initialization collision. */
+static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_association *new_asoc)
+{
+ sctp_init_chunk_t *peer_init;
+ struct sctp_chunk *repl;
+
+ /* new_asoc is a brand-new association, so these are not yet
+ * side effects--it is safe to run them here.
+ */
+ peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
+ if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
+ GFP_ATOMIC))
+ goto nomem;
+
+ /* Update the content of current association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
+
+ repl = sctp_make_cookie_ack(new_asoc, chunk);
+ if (!repl)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * D) IMPLEMENTATION NOTE: An implementation may choose to
+ * send the Communication Up notification to the SCTP user
+ * upon reception of a valid COOKIE ECHO chunk.
+ *
+ * Sadly, this needs to be implemented as a side-effect, because
+ * we are not guaranteed to have set the association id of the real
+ * association and so these notifications need to be delayed until
+ * the association id is allocated.
+ */
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaptation Layer Indication parameter , SCTP
+ * delivers this notification to inform the application that of the
+ * peers requested adaptation layer.
+ *
+ * This also needs to be done as a side effect for the same reason as
+ * above.
+ */
+ if (asoc->peer.adaptation_ind)
+ sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
+ *
+ * Section 5.2.4
+ * C) In this case, the local endpoint's cookie has arrived late.
+ * Before it arrived, the local endpoint sent an INIT and received an
+ * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
+ * but a new tag of its own.
+ */
+/* This case represents an initialization collision. */
+static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_association *new_asoc)
+{
+ /* The cookie should be silently discarded.
+ * The endpoint SHOULD NOT change states and should leave
+ * any timers running.
+ */
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
+ *
+ * Section 5.2.4
+ *
+ * D) When both local and remote tags match the endpoint should always
+ * enter the ESTABLISHED state, if it has not already done so.
+ */
+/* This case represents an initialization collision. */
+static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_association *new_asoc)
+{
+ struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
+ struct sctp_chunk *repl;
+
+ /* Clarification from Implementor's Guide:
+ * D) When both local and remote tags match the endpoint should
+ * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
+ * It should stop any cookie timer that may be running and send
+ * a COOKIE ACK.
+ */
+
+ /* Don't accidentally move back into established state. */
+ if (asoc->state < SCTP_STATE_ESTABLISHED) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_ESTABLISHED));
+ SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
+ SCTP_NULL());
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * D) IMPLEMENTATION NOTE: An implementation may choose
+ * to send the Communication Up notification to the
+ * SCTP user upon reception of a valid COOKIE
+ * ECHO chunk.
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0,
+ SCTP_COMM_UP, 0,
+ asoc->c.sinit_num_ostreams,
+ asoc->c.sinit_max_instreams,
+ NULL, GFP_ATOMIC);
+ if (!ev)
+ goto nomem;
+
+ /* Sockets API Draft Section 5.3.1.6
+ * When a peer sends a Adaptation Layer Indication parameter,
+ * SCTP delivers this notification to inform the application
+ * that of the peers requested adaptation layer.
+ */
+ if (asoc->peer.adaptation_ind) {
+ ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
+ GFP_ATOMIC);
+ if (!ai_ev)
+ goto nomem;
+
+ }
+ }
+
+ repl = sctp_make_cookie_ack(new_asoc, chunk);
+ if (!repl)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+
+ if (ev)
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ if (ai_ev)
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ai_ev));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ if (ai_ev)
+ sctp_ulpevent_free(ai_ev);
+ if (ev)
+ sctp_ulpevent_free(ev);
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
+ * chunk was retransmitted and then delayed in the network.
+ *
+ * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
+ *
+ * Verification Tag: None. Do cookie validation.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_disposition_t retval;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_association *new_asoc;
+ int error = 0;
+ char action;
+ struct sctp_chunk *err_chk_p;
+
+ /* Make sure that the chunk has a valid length from the protocol
+ * perspective. In this case check to make sure we have at least
+ * enough for the chunk header. Cookie length verification is
+ * done later.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* "Decode" the chunk. We have no optional parameters so we
+ * are in good shape.
+ */
+ chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
+ if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t)))
+ goto nomem;
+
+ /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
+ * of a duplicate COOKIE ECHO match the Verification Tags of the
+ * current association, consider the State Cookie valid even if
+ * the lifespan is exceeded.
+ */
+ new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
+ &err_chk_p);
+
+ /* FIXME:
+ * If the re-build failed, what is the proper error path
+ * from here?
+ *
+ * [We should abort the association. --piggy]
+ */
+ if (!new_asoc) {
+ /* FIXME: Several errors are possible. A bad cookie should
+ * be silently discarded, but think about logging it too.
+ */
+ switch (error) {
+ case -SCTP_IERROR_NOMEM:
+ goto nomem;
+
+ case -SCTP_IERROR_STALE_COOKIE:
+ sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
+ err_chk_p);
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ case -SCTP_IERROR_BAD_SIG:
+ default:
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+ }
+
+ /* Compare the tie_tag in cookie with the verification tag of
+ * current association.
+ */
+ action = sctp_tietags_compare(new_asoc, asoc);
+
+ switch (action) {
+ case 'A': /* Association restart. */
+ retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
+ new_asoc);
+ break;
+
+ case 'B': /* Collision case B. */
+ retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
+ new_asoc);
+ break;
+
+ case 'C': /* Collision case C. */
+ retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
+ new_asoc);
+ break;
+
+ case 'D': /* Collision case D. */
+ retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
+ new_asoc);
+ break;
+
+ default: /* Discard packet for all others. */
+ retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ break;
+ }
+
+ /* Delete the tempory new association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ /* Restore association pointer to provide SCTP command interpeter
+ * with a valid context in case it needs to manipulate
+ * the queues */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
+ SCTP_ASOC((struct sctp_association *)asoc));
+
+ return retval;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Process an ABORT. (SHUTDOWN-PENDING state)
+ *
+ * See sctp_sf_do_9_1_abort().
+ */
+sctp_disposition_t sctp_sf_shutdown_pending_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ABORT chunk has a valid length.
+ * Since this is an ABORT chunk, we have to discard it
+ * because of the following text:
+ * RFC 2960, Section 3.3.7
+ * If an endpoint receives an ABORT with a format error or for an
+ * association that doesn't exist, it MUST silently discard it.
+ * Because the length is "invalid", we can't really discard just
+ * as we do not know its true length. So, to be safe, discard the
+ * packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* ADD-IP: Special case for ABORT chunks
+ * F4) One special consideration is that ABORT Chunks arriving
+ * destined to the IP address being deleted MUST be
+ * ignored (see Section 5.3.1 for further details).
+ */
+ if (SCTP_ADDR_DEL ==
+ sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+
+ return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Process an ABORT. (SHUTDOWN-SENT state)
+ *
+ * See sctp_sf_do_9_1_abort().
+ */
+sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ABORT chunk has a valid length.
+ * Since this is an ABORT chunk, we have to discard it
+ * because of the following text:
+ * RFC 2960, Section 3.3.7
+ * If an endpoint receives an ABORT with a format error or for an
+ * association that doesn't exist, it MUST silently discard it.
+ * Because the length is "invalid", we can't really discard just
+ * as we do not know its true length. So, to be safe, discard the
+ * packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* ADD-IP: Special case for ABORT chunks
+ * F4) One special consideration is that ABORT Chunks arriving
+ * destined to the IP address being deleted MUST be
+ * ignored (see Section 5.3.1 for further details).
+ */
+ if (SCTP_ADDR_DEL ==
+ sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+
+ /* Stop the T2-shutdown timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ /* Stop the T5-shutdown guard timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Process an ABORT. (SHUTDOWN-ACK-SENT state)
+ *
+ * See sctp_sf_do_9_1_abort().
+ */
+sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* The same T2 timer, so we should be able to use
+ * common function with the SHUTDOWN-SENT state.
+ */
+ return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Handle an Error received in COOKIE_ECHOED state.
+ *
+ * Only handle the error type of stale COOKIE Error, the other errors will
+ * be ignored.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_errhdr_t *err;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ERROR chunk has a valid length.
+ * The parameter walking depends on this as well.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Process the error here */
+ /* FUTURE FIXME: When PR-SCTP related and other optional
+ * parms are emitted, this will have to change to handle multiple
+ * errors.
+ */
+ sctp_walk_errors(err, chunk->chunk_hdr) {
+ if (SCTP_ERROR_STALE_COOKIE == err->cause)
+ return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
+ arg, commands);
+ }
+
+ /* It is possible to have malformed error causes, and that
+ * will cause us to end the walk early. However, since
+ * we are discarding the packet, there should be no adverse
+ * affects.
+ */
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Handle a Stale COOKIE Error
+ *
+ * Section: 5.2.6 Handle Stale COOKIE Error
+ * If the association is in the COOKIE-ECHOED state, the endpoint may elect
+ * one of the following three alternatives.
+ * ...
+ * 3) Send a new INIT chunk to the endpoint, adding a Cookie
+ * Preservative parameter requesting an extension to the lifetime of
+ * the State Cookie. When calculating the time extension, an
+ * implementation SHOULD use the RTT information measured based on the
+ * previous COOKIE ECHO / ERROR exchange, and should add no more
+ * than 1 second beyond the measured RTT, due to long State Cookie
+ * lifetimes making the endpoint more subject to a replay attack.
+ *
+ * Verification Tag: Not explicit, but safe to ignore.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ time_t stale;
+ sctp_cookie_preserve_param_t bht;
+ sctp_errhdr_t *err;
+ struct sctp_chunk *reply;
+ struct sctp_bind_addr *bp;
+ int attempts = asoc->init_err_counter + 1;
+
+ if (attempts > asoc->max_init_attempts) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ err = (sctp_errhdr_t *)(chunk->skb->data);
+
+ /* When calculating the time extension, an implementation
+ * SHOULD use the RTT information measured based on the
+ * previous COOKIE ECHO / ERROR exchange, and should add no
+ * more than 1 second beyond the measured RTT, due to long
+ * State Cookie lifetimes making the endpoint more subject to
+ * a replay attack.
+ * Measure of Staleness's unit is usec. (1/1000000 sec)
+ * Suggested Cookie Life-span Increment's unit is msec.
+ * (1/1000 sec)
+ * In general, if you use the suggested cookie life, the value
+ * found in the field of measure of staleness should be doubled
+ * to give ample time to retransmit the new cookie and thus
+ * yield a higher probability of success on the reattempt.
+ */
+ stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
+ stale = (stale * 2) / 1000;
+
+ bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
+ bht.param_hdr.length = htons(sizeof(bht));
+ bht.lifespan_increment = htonl(stale);
+
+ /* Build that new INIT chunk. */
+ bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
+ reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
+ if (!reply)
+ goto nomem;
+
+ sctp_addto_chunk(reply, sizeof(bht), &bht);
+
+ /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
+ sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
+
+ /* Stop pending T3-rtx and heartbeat timers */
+ sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
+
+ /* Delete non-primary peer ip addresses since we are transitioning
+ * back to the COOKIE-WAIT state
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
+
+ /* If we've sent any data bundled with COOKIE-ECHO we will need to
+ * resend
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
+ SCTP_TRANSPORT(asoc->peer.primary_path));
+
+ /* Cast away the const modifier, as we want to just
+ * rerun it through as a sideffect.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Process an ABORT.
+ *
+ * Section: 9.1
+ * After checking the Verification Tag, the receiving endpoint shall
+ * remove the association from its record, and shall report the
+ * termination to its upper layer.
+ *
+ * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
+ * B) Rules for packet carrying ABORT:
+ *
+ * - The endpoint shall always fill in the Verification Tag field of the
+ * outbound packet with the destination endpoint's tag value if it
+ * is known.
+ *
+ * - If the ABORT is sent in response to an OOTB packet, the endpoint
+ * MUST follow the procedure described in Section 8.4.
+ *
+ * - The receiver MUST accept the packet if the Verification Tag
+ * matches either its own tag, OR the tag of its peer. Otherwise, the
+ * receiver MUST silently discard the packet and take no further
+ * action.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ABORT chunk has a valid length.
+ * Since this is an ABORT chunk, we have to discard it
+ * because of the following text:
+ * RFC 2960, Section 3.3.7
+ * If an endpoint receives an ABORT with a format error or for an
+ * association that doesn't exist, it MUST silently discard it.
+ * Because the length is "invalid", we can't really discard just
+ * as we do not know its true length. So, to be safe, discard the
+ * packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* ADD-IP: Special case for ABORT chunks
+ * F4) One special consideration is that ABORT Chunks arriving
+ * destined to the IP address being deleted MUST be
+ * ignored (see Section 5.3.1 for further details).
+ */
+ if (SCTP_ADDR_DEL ==
+ sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+
+ return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
+}
+
+static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ unsigned int len;
+ __be16 error = SCTP_ERROR_NO_ERROR;
+
+ /* See if we have an error cause code in the chunk. */
+ len = ntohs(chunk->chunk_hdr->length);
+ if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
+
+ sctp_errhdr_t *err;
+ sctp_walk_errors(err, chunk->chunk_hdr);
+ if ((void *)err != (void *)chunk->chunk_end)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
+ /* ASSOC_FAILED will DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+
+ return SCTP_DISPOSITION_ABORT;
+}
+
+/*
+ * Process an ABORT. (COOKIE-WAIT state)
+ *
+ * See sctp_sf_do_9_1_abort() above.
+ */
+sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ unsigned int len;
+ __be16 error = SCTP_ERROR_NO_ERROR;
+
+ if (!sctp_vtag_verify_either(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ABORT chunk has a valid length.
+ * Since this is an ABORT chunk, we have to discard it
+ * because of the following text:
+ * RFC 2960, Section 3.3.7
+ * If an endpoint receives an ABORT with a format error or for an
+ * association that doesn't exist, it MUST silently discard it.
+ * Because the length is "invalid", we can't really discard just
+ * as we do not know its true length. So, to be safe, discard the
+ * packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* See if we have an error cause code in the chunk. */
+ len = ntohs(chunk->chunk_hdr->length);
+ if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
+ error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
+
+ return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
+ chunk->transport);
+}
+
+/*
+ * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
+ */
+sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
+ ENOPROTOOPT, asoc,
+ (struct sctp_transport *)arg);
+}
+
+/*
+ * Process an ABORT. (COOKIE-ECHOED state)
+ */
+sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* There is a single T1 timer, so we should be able to use
+ * common function with the COOKIE-WAIT state.
+ */
+ return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Stop T1 timer and abort association with "INIT failed".
+ *
+ * This is common code called by several sctp_sf_*_abort() functions above.
+ */
+static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
+ sctp_cmd_seq_t *commands,
+ __be16 error, int sk_err,
+ const struct sctp_association *asoc,
+ struct sctp_transport *transport)
+{
+ pr_debug("%s: ABORT received (INIT)\n", __func__);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
+ /* CMD_INIT_FAILED will DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(error));
+
+ return SCTP_DISPOSITION_ABORT;
+}
+
+/*
+ * sctp_sf_do_9_2_shut
+ *
+ * Section: 9.2
+ * Upon the reception of the SHUTDOWN, the peer endpoint shall
+ * - enter the SHUTDOWN-RECEIVED state,
+ *
+ * - stop accepting new data from its SCTP user
+ *
+ * - verify, by checking the Cumulative TSN Ack field of the chunk,
+ * that all its outstanding DATA chunks have been received by the
+ * SHUTDOWN sender.
+ *
+ * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
+ * send a SHUTDOWN in response to a ULP request. And should discard
+ * subsequent SHUTDOWN chunks.
+ *
+ * If there are still outstanding DATA chunks left, the SHUTDOWN
+ * receiver shall continue to follow normal data transmission
+ * procedures defined in Section 6 until all outstanding DATA chunks
+ * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
+ * new data from its SCTP user.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_shutdownhdr_t *sdh;
+ sctp_disposition_t disposition;
+ struct sctp_ulpevent *ev;
+ __u32 ctsn;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SHUTDOWN chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk,
+ sizeof(struct sctp_shutdown_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Convert the elaborate header. */
+ sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
+ skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
+ chunk->subh.shutdown_hdr = sdh;
+ ctsn = ntohl(sdh->cum_tsn_ack);
+
+ if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
+ pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
+ asoc->ctsn_ack_point);
+
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* If Cumulative TSN Ack beyond the max tsn currently
+ * send, terminating the association and respond to the
+ * sender with an ABORT.
+ */
+ if (!TSN_lt(ctsn, asoc->next_tsn))
+ return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
+
+ /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
+ * When a peer sends a SHUTDOWN, SCTP delivers this notification to
+ * inform the application that it should cease sending data.
+ */
+ ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
+ if (!ev) {
+ disposition = SCTP_DISPOSITION_NOMEM;
+ goto out;
+ }
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Upon the reception of the SHUTDOWN, the peer endpoint shall
+ * - enter the SHUTDOWN-RECEIVED state,
+ * - stop accepting new data from its SCTP user
+ *
+ * [This is implicit in the new state.]
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
+ disposition = SCTP_DISPOSITION_CONSUME;
+
+ if (sctp_outq_is_empty(&asoc->outqueue)) {
+ disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
+ arg, commands);
+ }
+
+ if (SCTP_DISPOSITION_NOMEM == disposition)
+ goto out;
+
+ /* - verify, by checking the Cumulative TSN Ack field of the
+ * chunk, that all its outstanding DATA chunks have been
+ * received by the SHUTDOWN sender.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
+ SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
+
+out:
+ return disposition;
+}
+
+/*
+ * sctp_sf_do_9_2_shut_ctsn
+ *
+ * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
+ * it MUST NOT send a SHUTDOWN in response to a ULP request.
+ * The Cumulative TSN Ack of the received SHUTDOWN chunk
+ * MUST be processed.
+ */
+sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_shutdownhdr_t *sdh;
+ __u32 ctsn;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SHUTDOWN chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk,
+ sizeof(struct sctp_shutdown_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
+ ctsn = ntohl(sdh->cum_tsn_ack);
+
+ if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
+ pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
+ asoc->ctsn_ack_point);
+
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* If Cumulative TSN Ack beyond the max tsn currently
+ * send, terminating the association and respond to the
+ * sender with an ABORT.
+ */
+ if (!TSN_lt(ctsn, asoc->next_tsn))
+ return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
+
+ /* verify, by checking the Cumulative TSN Ack field of the
+ * chunk, that all its outstanding DATA chunks have been
+ * received by the SHUTDOWN sender.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
+ SCTP_BE32(sdh->cum_tsn_ack));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* RFC 2960 9.2
+ * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
+ * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
+ * transport addresses (either in the IP addresses or in the INIT chunk)
+ * that belong to this association, it should discard the INIT chunk and
+ * retransmit the SHUTDOWN ACK chunk.
+ */
+sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
+ struct sctp_chunk *reply;
+
+ /* Make sure that the chunk has a valid length */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Since we are not going to really process this INIT, there
+ * is no point in verifying chunk boundries. Just generate
+ * the SHUTDOWN ACK.
+ */
+ reply = sctp_make_shutdown_ack(asoc, chunk);
+ if (NULL == reply)
+ goto nomem;
+
+ /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
+ * the T2-SHUTDOWN timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
+
+ /* and restart the T2-shutdown timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+ return SCTP_DISPOSITION_CONSUME;
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * sctp_sf_do_ecn_cwr
+ *
+ * Section: Appendix A: Explicit Congestion Notification
+ *
+ * CWR:
+ *
+ * RFC 2481 details a specific bit for a sender to send in the header of
+ * its next outbound TCP segment to indicate to its peer that it has
+ * reduced its congestion window. This is termed the CWR bit. For
+ * SCTP the same indication is made by including the CWR chunk.
+ * This chunk contains one data element, i.e. the TSN number that
+ * was sent in the ECNE chunk. This element represents the lowest
+ * TSN number in the datagram that was originally marked with the
+ * CE bit.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_cwrhdr_t *cwr;
+ struct sctp_chunk *chunk = arg;
+ u32 lowest_tsn;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ cwr = (sctp_cwrhdr_t *) chunk->skb->data;
+ skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
+
+ lowest_tsn = ntohl(cwr->lowest_tsn);
+
+ /* Does this CWR ack the last sent congestion notification? */
+ if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
+ /* Stop sending ECNE. */
+ sctp_add_cmd_sf(commands,
+ SCTP_CMD_ECN_CWR,
+ SCTP_U32(lowest_tsn));
+ }
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * sctp_sf_do_ecne
+ *
+ * Section: Appendix A: Explicit Congestion Notification
+ *
+ * ECN-Echo
+ *
+ * RFC 2481 details a specific bit for a receiver to send back in its
+ * TCP acknowledgements to notify the sender of the Congestion
+ * Experienced (CE) bit having arrived from the network. For SCTP this
+ * same indication is made by including the ECNE chunk. This chunk
+ * contains one data element, i.e. the lowest TSN associated with the IP
+ * datagram marked with the CE bit.....
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_ecne(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_ecnehdr_t *ecne;
+ struct sctp_chunk *chunk = arg;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ ecne = (sctp_ecnehdr_t *) chunk->skb->data;
+ skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
+
+ /* If this is a newer ECNE than the last CWR packet we sent out */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
+ SCTP_U32(ntohl(ecne->lowest_tsn)));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Section: 6.2 Acknowledgement on Reception of DATA Chunks
+ *
+ * The SCTP endpoint MUST always acknowledge the reception of each valid
+ * DATA chunk.
+ *
+ * The guidelines on delayed acknowledgement algorithm specified in
+ * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
+ * acknowledgement SHOULD be generated for at least every second packet
+ * (not every second DATA chunk) received, and SHOULD be generated within
+ * 200 ms of the arrival of any unacknowledged DATA chunk. In some
+ * situations it may be beneficial for an SCTP transmitter to be more
+ * conservative than the algorithms detailed in this document allow.
+ * However, an SCTP transmitter MUST NOT be more aggressive than the
+ * following algorithms allow.
+ *
+ * A SCTP receiver MUST NOT generate more than one SACK for every
+ * incoming packet, other than to update the offered window as the
+ * receiving application consumes new data.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_arg_t force = SCTP_NOFORCE();
+ int error;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ error = sctp_eat_data(asoc, chunk, commands);
+ switch (error) {
+ case SCTP_IERROR_NO_ERROR:
+ break;
+ case SCTP_IERROR_HIGH_TSN:
+ case SCTP_IERROR_BAD_STREAM:
+ SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
+ goto discard_noforce;
+ case SCTP_IERROR_DUP_TSN:
+ case SCTP_IERROR_IGNORE_TSN:
+ SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
+ goto discard_force;
+ case SCTP_IERROR_NO_DATA:
+ goto consume;
+ case SCTP_IERROR_PROTO_VIOLATION:
+ return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
+ (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
+ default:
+ BUG();
+ }
+
+ if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
+ force = SCTP_FORCE();
+
+ if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+ }
+
+ /* If this is the last chunk in a packet, we need to count it
+ * toward sack generation. Note that we need to SACK every
+ * OTHER packet containing data chunks, EVEN IF WE DISCARD
+ * THEM. We elect to NOT generate SACK's if the chunk fails
+ * the verification tag test.
+ *
+ * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
+ *
+ * The SCTP endpoint MUST always acknowledge the reception of
+ * each valid DATA chunk.
+ *
+ * The guidelines on delayed acknowledgement algorithm
+ * specified in Section 4.2 of [RFC2581] SHOULD be followed.
+ * Specifically, an acknowledgement SHOULD be generated for at
+ * least every second packet (not every second DATA chunk)
+ * received, and SHOULD be generated within 200 ms of the
+ * arrival of any unacknowledged DATA chunk. In some
+ * situations it may be beneficial for an SCTP transmitter to
+ * be more conservative than the algorithms detailed in this
+ * document allow. However, an SCTP transmitter MUST NOT be
+ * more aggressive than the following algorithms allow.
+ */
+ if (chunk->end_of_packet)
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
+
+ return SCTP_DISPOSITION_CONSUME;
+
+discard_force:
+ /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
+ *
+ * When a packet arrives with duplicate DATA chunk(s) and with
+ * no new DATA chunk(s), the endpoint MUST immediately send a
+ * SACK with no delay. If a packet arrives with duplicate
+ * DATA chunk(s) bundled with new DATA chunks, the endpoint
+ * MAY immediately send a SACK. Normally receipt of duplicate
+ * DATA chunks will occur when the original SACK chunk was lost
+ * and the peer's RTO has expired. The duplicate TSN number(s)
+ * SHOULD be reported in the SACK as duplicate.
+ */
+ /* In our case, we split the MAY SACK advice up whether or not
+ * the last chunk is a duplicate.'
+ */
+ if (chunk->end_of_packet)
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
+ return SCTP_DISPOSITION_DISCARD;
+
+discard_noforce:
+ if (chunk->end_of_packet)
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
+
+ return SCTP_DISPOSITION_DISCARD;
+consume:
+ return SCTP_DISPOSITION_CONSUME;
+
+}
+
+/*
+ * sctp_sf_eat_data_fast_4_4
+ *
+ * Section: 4 (4)
+ * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
+ * DATA chunks without delay.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ int error;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ error = sctp_eat_data(asoc, chunk, commands);
+ switch (error) {
+ case SCTP_IERROR_NO_ERROR:
+ case SCTP_IERROR_HIGH_TSN:
+ case SCTP_IERROR_DUP_TSN:
+ case SCTP_IERROR_IGNORE_TSN:
+ case SCTP_IERROR_BAD_STREAM:
+ break;
+ case SCTP_IERROR_NO_DATA:
+ goto consume;
+ case SCTP_IERROR_PROTO_VIOLATION:
+ return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
+ (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
+ default:
+ BUG();
+ }
+
+ /* Go a head and force a SACK, since we are shutting down. */
+
+ /* Implementor's Guide.
+ *
+ * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
+ * respond to each received packet containing one or more DATA chunk(s)
+ * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
+ */
+ if (chunk->end_of_packet) {
+ /* We must delay the chunk creation since the cumulative
+ * TSN has not been updated yet.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+ }
+
+consume:
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Section: 6.2 Processing a Received SACK
+ * D) Any time a SACK arrives, the endpoint performs the following:
+ *
+ * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
+ * then drop the SACK. Since Cumulative TSN Ack is monotonically
+ * increasing, a SACK whose Cumulative TSN Ack is less than the
+ * Cumulative TSN Ack Point indicates an out-of-order SACK.
+ *
+ * ii) Set rwnd equal to the newly received a_rwnd minus the number
+ * of bytes still outstanding after processing the Cumulative TSN Ack
+ * and the Gap Ack Blocks.
+ *
+ * iii) If the SACK is missing a TSN that was previously
+ * acknowledged via a Gap Ack Block (e.g., the data receiver
+ * reneged on the data), then mark the corresponding DATA chunk
+ * as available for retransmit: Mark it as missing for fast
+ * retransmit as described in Section 7.2.4 and if no retransmit
+ * timer is running for the destination address to which the DATA
+ * chunk was originally transmitted, then T3-rtx is started for
+ * that destination address.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_sackhdr_t *sackh;
+ __u32 ctsn;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Pull the SACK chunk from the data buffer */
+ sackh = sctp_sm_pull_sack(chunk);
+ /* Was this a bogus SACK? */
+ if (!sackh)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ chunk->subh.sack_hdr = sackh;
+ ctsn = ntohl(sackh->cum_tsn_ack);
+
+ /* i) If Cumulative TSN Ack is less than the Cumulative TSN
+ * Ack Point, then drop the SACK. Since Cumulative TSN
+ * Ack is monotonically increasing, a SACK whose
+ * Cumulative TSN Ack is less than the Cumulative TSN Ack
+ * Point indicates an out-of-order SACK.
+ */
+ if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
+ pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
+ asoc->ctsn_ack_point);
+
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* If Cumulative TSN Ack beyond the max tsn currently
+ * send, terminating the association and respond to the
+ * sender with an ABORT.
+ */
+ if (!TSN_lt(ctsn, asoc->next_tsn))
+ return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
+
+ /* Return this SACK for further processing. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
+
+ /* Note: We do the rest of the work on the PROCESS_SACK
+ * sideeffect.
+ */
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Generate an ABORT in response to a packet.
+ *
+ * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
+ *
+ * 8) The receiver should respond to the sender of the OOTB packet with
+ * an ABORT. When sending the ABORT, the receiver of the OOTB packet
+ * MUST fill in the Verification Tag field of the outbound packet
+ * with the value found in the Verification Tag field of the OOTB
+ * packet and set the T-bit in the Chunk Flags to indicate that the
+ * Verification Tag is reflected. After sending this ABORT, the
+ * receiver of the OOTB packet shall discard the OOTB packet and take
+ * no further action.
+ *
+ * Verification Tag:
+ *
+ * The return value is the disposition of the chunk.
+*/
+static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_packet *packet = NULL;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *abort;
+
+ packet = sctp_ootb_pkt_new(net, asoc, chunk);
+
+ if (packet) {
+ /* Make an ABORT. The T bit will be set if the asoc
+ * is NULL.
+ */
+ abort = sctp_make_abort(asoc, chunk, 0);
+ if (!abort) {
+ sctp_ootb_pkt_free(packet);
+ return SCTP_DISPOSITION_NOMEM;
+ }
+
+ /* Reflect vtag if T-Bit is set */
+ if (sctp_test_T_bit(abort))
+ packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+ /* Set the skb to the belonging sock for accounting. */
+ abort->skb->sk = ep->base.sk;
+
+ sctp_packet_append_chunk(packet, abort);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+
+ sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ return SCTP_DISPOSITION_CONSUME;
+ }
+
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
+ * event as ULP notification for each cause included in the chunk.
+ *
+ * API 5.3.1.3 - SCTP_REMOTE_ERROR
+ *
+ * The return value is the disposition of the chunk.
+*/
+sctp_disposition_t sctp_sf_operr_notify(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ sctp_errhdr_t *err;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ERROR chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+ sctp_walk_errors(err, chunk->chunk_hdr);
+ if ((void *)err != (void *)chunk->chunk_end)
+ return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+ (void *)err, commands);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
+ SCTP_CHUNK(chunk));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Process an inbound SHUTDOWN ACK.
+ *
+ * From Section 9.2:
+ * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
+ * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
+ * peer, and remove all record of the association.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *reply;
+ struct sctp_ulpevent *ev;
+
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+ /* 10.2 H) SHUTDOWN COMPLETE notification
+ *
+ * When SCTP completes the shutdown procedures (section 9.2) this
+ * notification is passed to the upper layer.
+ */
+ ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
+ 0, 0, 0, NULL, GFP_ATOMIC);
+ if (!ev)
+ goto nomem;
+
+ /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
+ reply = sctp_make_shutdown_complete(asoc, chunk);
+ if (!reply)
+ goto nomem_chunk;
+
+ /* Do all the commands now (after allocation), so that we
+ * have consistent state if memory allocation failes
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
+
+ /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
+ * stop the T2-shutdown timer,
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+ SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+ /* ...and remove all record of the association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+ return SCTP_DISPOSITION_DELETE_TCB;
+
+nomem_chunk:
+ sctp_ulpevent_free(ev);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
+ *
+ * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
+ * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
+ * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
+ * packet must fill in the Verification Tag field of the outbound
+ * packet with the Verification Tag received in the SHUTDOWN ACK and
+ * set the T-bit in the Chunk Flags to indicate that the Verification
+ * Tag is reflected.
+ *
+ * 8) The receiver should respond to the sender of the OOTB packet with
+ * an ABORT. When sending the ABORT, the receiver of the OOTB packet
+ * MUST fill in the Verification Tag field of the outbound packet
+ * with the value found in the Verification Tag field of the OOTB
+ * packet and set the T-bit in the Chunk Flags to indicate that the
+ * Verification Tag is reflected. After sending this ABORT, the
+ * receiver of the OOTB packet shall discard the OOTB packet and take
+ * no further action.
+ */
+sctp_disposition_t sctp_sf_ootb(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sk_buff *skb = chunk->skb;
+ sctp_chunkhdr_t *ch;
+ sctp_errhdr_t *err;
+ __u8 *ch_end;
+ int ootb_shut_ack = 0;
+ int ootb_cookie_ack = 0;
+
+ SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
+
+ ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
+ do {
+ /* Report violation if the chunk is less then minimal */
+ if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Now that we know we at least have a chunk header,
+ * do things that are type appropriate.
+ */
+ if (SCTP_CID_SHUTDOWN_ACK == ch->type)
+ ootb_shut_ack = 1;
+
+ /* RFC 2960, Section 3.3.7
+ * Moreover, under any circumstances, an endpoint that
+ * receives an ABORT MUST NOT respond to that ABORT by
+ * sending an ABORT of its own.
+ */
+ if (SCTP_CID_ABORT == ch->type)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
+ * or a COOKIE ACK the SCTP Packet should be silently
+ * discarded.
+ */
+
+ if (SCTP_CID_COOKIE_ACK == ch->type)
+ ootb_cookie_ack = 1;
+
+ if (SCTP_CID_ERROR == ch->type) {
+ sctp_walk_errors(err, ch) {
+ if (SCTP_ERROR_STALE_COOKIE == err->cause) {
+ ootb_cookie_ack = 1;
+ break;
+ }
+ }
+ }
+
+ /* Report violation if chunk len overflows */
+ ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
+ if (ch_end > skb_tail_pointer(skb))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ ch = (sctp_chunkhdr_t *) ch_end;
+ } while (ch_end < skb_tail_pointer(skb));
+
+ if (ootb_shut_ack)
+ return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
+ else if (ootb_cookie_ack)
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ else
+ return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Handle an "Out of the blue" SHUTDOWN ACK.
+ *
+ * Section: 8.4 5, sctpimpguide 2.41.
+ *
+ * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
+ * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
+ * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
+ * packet must fill in the Verification Tag field of the outbound
+ * packet with the Verification Tag received in the SHUTDOWN ACK and
+ * set the T-bit in the Chunk Flags to indicate that the Verification
+ * Tag is reflected.
+ *
+ * Inputs
+ * (endpoint, asoc, type, arg, commands)
+ *
+ * Outputs
+ * (sctp_disposition_t)
+ *
+ * The return value is the disposition of the chunk.
+ */
+static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_packet *packet = NULL;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *shut;
+
+ packet = sctp_ootb_pkt_new(net, asoc, chunk);
+
+ if (packet) {
+ /* Make an SHUTDOWN_COMPLETE.
+ * The T bit will be set if the asoc is NULL.
+ */
+ shut = sctp_make_shutdown_complete(asoc, chunk);
+ if (!shut) {
+ sctp_ootb_pkt_free(packet);
+ return SCTP_DISPOSITION_NOMEM;
+ }
+
+ /* Reflect vtag if T-Bit is set */
+ if (sctp_test_T_bit(shut))
+ packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+ /* Set the skb to the belonging sock for accounting. */
+ shut->skb->sk = ep->base.sk;
+
+ sctp_packet_append_chunk(packet, shut);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+
+ /* If the chunk length is invalid, we don't want to process
+ * the reset of the packet.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* We need to discard the rest of the packet to prevent
+ * potential bomming attacks from additional bundled chunks.
+ * This is documented in SCTP Threats ID.
+ */
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
+ *
+ * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
+ * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
+ * procedures in section 8.4 SHOULD be followed, in other words it
+ * should be treated as an Out Of The Blue packet.
+ * [This means that we do NOT check the Verification Tag on these
+ * chunks. --piggy ]
+ *
+ */
+sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ /* Although we do have an association in this case, it corresponds
+ * to a restarted association. So the packet is treated as an OOTB
+ * packet and the state function that handles OOTB SHUTDOWN_ACK is
+ * called with a NULL association.
+ */
+ SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
+
+ return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
+}
+
+/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
+sctp_disposition_t sctp_sf_do_asconf(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *asconf_ack = NULL;
+ struct sctp_paramhdr *err_param = NULL;
+ sctp_addiphdr_t *hdr;
+ __u32 serial;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* ADD-IP: Section 4.1.1
+ * This chunk MUST be sent in an authenticated way by using
+ * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
+ * is received unauthenticated it MUST be silently discarded as
+ * described in [I-D.ietf-tsvwg-sctp-auth].
+ */
+ if (!net->sctp.addip_noauth && !chunk->auth)
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ASCONF ADDIP chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ hdr = (sctp_addiphdr_t *)chunk->skb->data;
+ serial = ntohl(hdr->serial);
+
+ /* Verify the ASCONF chunk before processing it. */
+ if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
+ return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+ (void *)err_param, commands);
+
+ /* ADDIP 5.2 E1) Compare the value of the serial number to the value
+ * the endpoint stored in a new association variable
+ * 'Peer-Serial-Number'.
+ */
+ if (serial == asoc->peer.addip_serial + 1) {
+ /* If this is the first instance of ASCONF in the packet,
+ * we can clean our old ASCONF-ACKs.
+ */
+ if (!chunk->has_asconf)
+ sctp_assoc_clean_asconf_ack_cache(asoc);
+
+ /* ADDIP 5.2 E4) When the Sequence Number matches the next one
+ * expected, process the ASCONF as described below and after
+ * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
+ * the response packet and cache a copy of it (in the event it
+ * later needs to be retransmitted).
+ *
+ * Essentially, do V1-V5.
+ */
+ asconf_ack = sctp_process_asconf((struct sctp_association *)
+ asoc, chunk);
+ if (!asconf_ack)
+ return SCTP_DISPOSITION_NOMEM;
+ } else if (serial < asoc->peer.addip_serial + 1) {
+ /* ADDIP 5.2 E2)
+ * If the value found in the Sequence Number is less than the
+ * ('Peer- Sequence-Number' + 1), simply skip to the next
+ * ASCONF, and include in the outbound response packet
+ * any previously cached ASCONF-ACK response that was
+ * sent and saved that matches the Sequence Number of the
+ * ASCONF. Note: It is possible that no cached ASCONF-ACK
+ * Chunk exists. This will occur when an older ASCONF
+ * arrives out of order. In such a case, the receiver
+ * should skip the ASCONF Chunk and not include ASCONF-ACK
+ * Chunk for that chunk.
+ */
+ asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
+ if (!asconf_ack)
+ return SCTP_DISPOSITION_DISCARD;
+
+ /* Reset the transport so that we select the correct one
+ * this time around. This is to make sure that we don't
+ * accidentally use a stale transport that's been removed.
+ */
+ asconf_ack->transport = NULL;
+ } else {
+ /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
+ * it must be either a stale packet or from an attacker.
+ */
+ return SCTP_DISPOSITION_DISCARD;
+ }
+
+ /* ADDIP 5.2 E6) The destination address of the SCTP packet
+ * containing the ASCONF-ACK Chunks MUST be the source address of
+ * the SCTP packet that held the ASCONF Chunks.
+ *
+ * To do this properly, we'll set the destination address of the chunk
+ * and at the transmit time, will try look up the transport to use.
+ * Since ASCONFs may be bundled, the correct transport may not be
+ * created until we process the entire packet, thus this workaround.
+ */
+ asconf_ack->dest = chunk->source;
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
+ if (asoc->new_transport) {
+ sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
+ ((struct sctp_association *)asoc)->new_transport = NULL;
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * ADDIP Section 4.3 General rules for address manipulation
+ * When building TLV parameters for the ASCONF Chunk that will add or
+ * delete IP addresses the D0 to D13 rules should be applied:
+ */
+sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type, void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *asconf_ack = arg;
+ struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
+ struct sctp_chunk *abort;
+ struct sctp_paramhdr *err_param = NULL;
+ sctp_addiphdr_t *addip_hdr;
+ __u32 sent_serial, rcvd_serial;
+
+ if (!sctp_vtag_verify(asconf_ack, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* ADD-IP, Section 4.1.2:
+ * This chunk MUST be sent in an authenticated way by using
+ * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
+ * is received unauthenticated it MUST be silently discarded as
+ * described in [I-D.ietf-tsvwg-sctp-auth].
+ */
+ if (!net->sctp.addip_noauth && !asconf_ack->auth)
+ return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the ADDIP chunk has a valid length. */
+ if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
+ rcvd_serial = ntohl(addip_hdr->serial);
+
+ /* Verify the ASCONF-ACK chunk before processing it. */
+ if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
+ return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+ (void *)err_param, commands);
+
+ if (last_asconf) {
+ addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
+ sent_serial = ntohl(addip_hdr->serial);
+ } else {
+ sent_serial = asoc->addip_serial - 1;
+ }
+
+ /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
+ * equal to the next serial number to be used but no ASCONF chunk is
+ * outstanding the endpoint MUST ABORT the association. Note that a
+ * sequence number is greater than if it is no more than 2^^31-1
+ * larger than the current sequence number (using serial arithmetic).
+ */
+ if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
+ !(asoc->addip_last_asconf)) {
+ abort = sctp_make_abort(asoc, asconf_ack,
+ sizeof(sctp_errhdr_t));
+ if (abort) {
+ sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(abort));
+ }
+ /* We are going to ABORT, so we might as well stop
+ * processing the rest of the chunks in the packet.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+ sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_ABORT;
+ }
+
+ if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+
+ if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
+ asconf_ack)) {
+ /* Successfully processed ASCONF_ACK. We can
+ * release the next asconf if we have one.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
+ SCTP_NULL());
+ return SCTP_DISPOSITION_CONSUME;
+ }
+
+ abort = sctp_make_abort(asoc, asconf_ack,
+ sizeof(sctp_errhdr_t));
+ if (abort) {
+ sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(abort));
+ }
+ /* We are going to ABORT, so we might as well stop
+ * processing the rest of the chunks in the packet.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_ABORT;
+ }
+
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/*
+ * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
+ *
+ * When a FORWARD TSN chunk arrives, the data receiver MUST first update
+ * its cumulative TSN point to the value carried in the FORWARD TSN
+ * chunk, and then MUST further advance its cumulative TSN point locally
+ * if possible.
+ * After the above processing, the data receiver MUST stop reporting any
+ * missing TSNs earlier than or equal to the new cumulative TSN point.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_fwdtsn_hdr *fwdtsn_hdr;
+ struct sctp_fwdtsn_skip *skip;
+ __u16 len;
+ __u32 tsn;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the FORWARD_TSN chunk has valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
+ chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
+ len = ntohs(chunk->chunk_hdr->length);
+ len -= sizeof(struct sctp_chunkhdr);
+ skb_pull(chunk->skb, len);
+
+ tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
+ pr_debug("%s: TSN 0x%x\n", __func__, tsn);
+
+ /* The TSN is too high--silently discard the chunk and count on it
+ * getting retransmitted later.
+ */
+ if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
+ goto discard_noforce;
+
+ /* Silently discard the chunk if stream-id is not valid */
+ sctp_walk_fwdtsn(skip, chunk) {
+ if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
+ goto discard_noforce;
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
+ if (len > sizeof(struct sctp_fwdtsn_hdr))
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
+ SCTP_CHUNK(chunk));
+
+ /* Count this as receiving DATA. */
+ if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+ }
+
+ /* FIXME: For now send a SACK, but DATA processing may
+ * send another.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
+
+ return SCTP_DISPOSITION_CONSUME;
+
+discard_noforce:
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_fwdtsn_hdr *fwdtsn_hdr;
+ struct sctp_fwdtsn_skip *skip;
+ __u16 len;
+ __u32 tsn;
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the FORWARD_TSN chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
+ chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
+ len = ntohs(chunk->chunk_hdr->length);
+ len -= sizeof(struct sctp_chunkhdr);
+ skb_pull(chunk->skb, len);
+
+ tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
+ pr_debug("%s: TSN 0x%x\n", __func__, tsn);
+
+ /* The TSN is too high--silently discard the chunk and count on it
+ * getting retransmitted later.
+ */
+ if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
+ goto gen_shutdown;
+
+ /* Silently discard the chunk if stream-id is not valid */
+ sctp_walk_fwdtsn(skip, chunk) {
+ if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
+ goto gen_shutdown;
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
+ if (len > sizeof(struct sctp_fwdtsn_hdr))
+ sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
+ SCTP_CHUNK(chunk));
+
+ /* Go a head and force a SACK, since we are shutting down. */
+gen_shutdown:
+ /* Implementor's Guide.
+ *
+ * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
+ * respond to each received packet containing one or more DATA chunk(s)
+ * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * SCTP-AUTH Section 6.3 Receiving authenticated chukns
+ *
+ * The receiver MUST use the HMAC algorithm indicated in the HMAC
+ * Identifier field. If this algorithm was not specified by the
+ * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
+ * during association setup, the AUTH chunk and all chunks after it MUST
+ * be discarded and an ERROR chunk SHOULD be sent with the error cause
+ * defined in Section 4.1.
+ *
+ * If an endpoint with no shared key receives a Shared Key Identifier
+ * other than 0, it MUST silently discard all authenticated chunks. If
+ * the endpoint has at least one endpoint pair shared key for the peer,
+ * it MUST use the key specified by the Shared Key Identifier if a
+ * key has been configured for that Shared Key Identifier. If no
+ * endpoint pair shared key has been configured for that Shared Key
+ * Identifier, all authenticated chunks MUST be silently discarded.
+ *
+ * Verification Tag: 8.5 Verification Tag [Normal verification]
+ *
+ * The return value is the disposition of the chunk.
+ */
+static sctp_ierror_t sctp_sf_authenticate(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ struct sctp_chunk *chunk)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_hmac *hmac;
+ unsigned int sig_len;
+ __u16 key_id;
+ __u8 *save_digest;
+ __u8 *digest;
+
+ /* Pull in the auth header, so we can do some more verification */
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ chunk->subh.auth_hdr = auth_hdr;
+ skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
+
+ /* Make sure that we support the HMAC algorithm from the auth
+ * chunk.
+ */
+ if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
+ return SCTP_IERROR_AUTH_BAD_HMAC;
+
+ /* Make sure that the provided shared key identifier has been
+ * configured
+ */
+ key_id = ntohs(auth_hdr->shkey_id);
+ if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
+ return SCTP_IERROR_AUTH_BAD_KEYID;
+
+
+ /* Make sure that the length of the signature matches what
+ * we expect.
+ */
+ sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
+ hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
+ if (sig_len != hmac->hmac_len)
+ return SCTP_IERROR_PROTO_VIOLATION;
+
+ /* Now that we've done validation checks, we can compute and
+ * verify the hmac. The steps involved are:
+ * 1. Save the digest from the chunk.
+ * 2. Zero out the digest in the chunk.
+ * 3. Compute the new digest
+ * 4. Compare saved and new digests.
+ */
+ digest = auth_hdr->hmac;
+ skb_pull(chunk->skb, sig_len);
+
+ save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
+ if (!save_digest)
+ goto nomem;
+
+ memset(digest, 0, sig_len);
+
+ sctp_auth_calculate_hmac(asoc, chunk->skb,
+ (struct sctp_auth_chunk *)chunk->chunk_hdr,
+ GFP_ATOMIC);
+
+ /* Discard the packet if the digests do not match */
+ if (memcmp(save_digest, digest, sig_len)) {
+ kfree(save_digest);
+ return SCTP_IERROR_BAD_SIG;
+ }
+
+ kfree(save_digest);
+ chunk->auth = 1;
+
+ return SCTP_IERROR_NO_ERROR;
+nomem:
+ return SCTP_IERROR_NOMEM;
+}
+
+sctp_disposition_t sctp_sf_eat_auth(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_authhdr *auth_hdr;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *err_chunk;
+ sctp_ierror_t error;
+
+ /* Make sure that the peer has AUTH capable */
+ if (!asoc->peer.auth_capable)
+ return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
+
+ if (!sctp_vtag_verify(chunk, asoc)) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
+ SCTP_NULL());
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ }
+
+ /* Make sure that the AUTH chunk has valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
+ error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
+ switch (error) {
+ case SCTP_IERROR_AUTH_BAD_HMAC:
+ /* Generate the ERROR chunk and discard the rest
+ * of the packet
+ */
+ err_chunk = sctp_make_op_error(asoc, chunk,
+ SCTP_ERROR_UNSUP_HMAC,
+ &auth_hdr->hmac_id,
+ sizeof(__u16), 0);
+ if (err_chunk) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err_chunk));
+ }
+ /* Fall Through */
+ case SCTP_IERROR_AUTH_BAD_KEYID:
+ case SCTP_IERROR_BAD_SIG:
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ case SCTP_IERROR_PROTO_VIOLATION:
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ case SCTP_IERROR_NOMEM:
+ return SCTP_DISPOSITION_NOMEM;
+
+ default: /* Prevent gcc warnings */
+ break;
+ }
+
+ if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
+ struct sctp_ulpevent *ev;
+
+ ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
+ SCTP_AUTH_NEWKEY, GFP_ATOMIC);
+
+ if (!ev)
+ return -ENOMEM;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+ SCTP_ULPEVENT(ev));
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Process an unknown chunk.
+ *
+ * Section: 3.2. Also, 2.1 in the implementor's guide.
+ *
+ * Chunk Types are encoded such that the highest-order two bits specify
+ * the action that must be taken if the processing endpoint does not
+ * recognize the Chunk Type.
+ *
+ * 00 - Stop processing this SCTP packet and discard it, do not process
+ * any further chunks within it.
+ *
+ * 01 - Stop processing this SCTP packet and discard it, do not process
+ * any further chunks within it, and report the unrecognized
+ * chunk in an 'Unrecognized Chunk Type'.
+ *
+ * 10 - Skip this chunk and continue processing.
+ *
+ * 11 - Skip this chunk and continue processing, but report in an ERROR
+ * Chunk using the 'Unrecognized Chunk Type' cause of error.
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *unk_chunk = arg;
+ struct sctp_chunk *err_chunk;
+ sctp_chunkhdr_t *hdr;
+
+ pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
+
+ if (!sctp_vtag_verify(unk_chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the chunk has a valid length.
+ * Since we don't know the chunk type, we use a general
+ * chunkhdr structure to make a comparison.
+ */
+ if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ switch (type.chunk & SCTP_CID_ACTION_MASK) {
+ case SCTP_CID_ACTION_DISCARD:
+ /* Discard the packet. */
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ case SCTP_CID_ACTION_DISCARD_ERR:
+ /* Generate an ERROR chunk as response. */
+ hdr = unk_chunk->chunk_hdr;
+ err_chunk = sctp_make_op_error(asoc, unk_chunk,
+ SCTP_ERROR_UNKNOWN_CHUNK, hdr,
+ WORD_ROUND(ntohs(hdr->length)),
+ 0);
+ if (err_chunk) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err_chunk));
+ }
+
+ /* Discard the packet. */
+ sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+ return SCTP_DISPOSITION_CONSUME;
+ case SCTP_CID_ACTION_SKIP:
+ /* Skip the chunk. */
+ return SCTP_DISPOSITION_DISCARD;
+ case SCTP_CID_ACTION_SKIP_ERR:
+ /* Generate an ERROR chunk as response. */
+ hdr = unk_chunk->chunk_hdr;
+ err_chunk = sctp_make_op_error(asoc, unk_chunk,
+ SCTP_ERROR_UNKNOWN_CHUNK, hdr,
+ WORD_ROUND(ntohs(hdr->length)),
+ 0);
+ if (err_chunk) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err_chunk));
+ }
+ /* Skip the chunk. */
+ return SCTP_DISPOSITION_CONSUME;
+ default:
+ break;
+ }
+
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/*
+ * Discard the chunk.
+ *
+ * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
+ * [Too numerous to mention...]
+ * Verification Tag: No verification needed.
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the chunk has a valid length.
+ * Since we don't know the chunk type, we use a general
+ * chunkhdr structure to make a comparison.
+ */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
+
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/*
+ * Discard the whole packet.
+ *
+ * Section: 8.4 2)
+ *
+ * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
+ * silently discard the OOTB packet and take no further action.
+ *
+ * Verification Tag: No verification necessary
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_pdiscard(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+
+/*
+ * The other end is violating protocol.
+ *
+ * Section: Not specified
+ * Verification Tag: Not specified
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (asoc, reply_msg, msg_up, timers, counters)
+ *
+ * We simply tag the chunk as a violation. The state machine will log
+ * the violation and continue.
+ */
+sctp_disposition_t sctp_sf_violation(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ /* Make sure that the chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+
+ return SCTP_DISPOSITION_VIOLATION;
+}
+
+/*
+ * Common function to handle a protocol violation.
+ */
+static sctp_disposition_t sctp_sf_abort_violation(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ void *arg,
+ sctp_cmd_seq_t *commands,
+ const __u8 *payload,
+ const size_t paylen)
+{
+ struct sctp_packet *packet = NULL;
+ struct sctp_chunk *chunk = arg;
+ struct sctp_chunk *abort = NULL;
+
+ /* SCTP-AUTH, Section 6.3:
+ * It should be noted that if the receiver wants to tear
+ * down an association in an authenticated way only, the
+ * handling of malformed packets should not result in
+ * tearing down the association.
+ *
+ * This means that if we only want to abort associations
+ * in an authenticated way (i.e AUTH+ABORT), then we
+ * can't destroy this association just because the packet
+ * was malformed.
+ */
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ goto discard;
+
+ /* Make the abort chunk. */
+ abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
+ if (!abort)
+ goto nomem;
+
+ if (asoc) {
+ /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
+ if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
+ !asoc->peer.i.init_tag) {
+ sctp_initack_chunk_t *initack;
+
+ initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
+ if (!sctp_chunk_length_valid(chunk,
+ sizeof(sctp_initack_chunk_t)))
+ abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
+ else {
+ unsigned int inittag;
+
+ inittag = ntohl(initack->init_hdr.init_tag);
+ sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
+ SCTP_U32(inittag));
+ }
+ }
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+
+ if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNREFUSED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ }
+ } else {
+ packet = sctp_ootb_pkt_new(net, asoc, chunk);
+
+ if (!packet)
+ goto nomem_pkt;
+
+ if (sctp_test_T_bit(abort))
+ packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+ abort->skb->sk = ep->base.sk;
+
+ sctp_packet_append_chunk(packet, abort);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+ }
+
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+
+discard:
+ sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
+ return SCTP_DISPOSITION_ABORT;
+
+nomem_pkt:
+ sctp_chunk_free(abort);
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Handle a protocol violation when the chunk length is invalid.
+ * "Invalid" length is identified as smaller than the minimal length a
+ * given chunk can be. For example, a SACK chunk has invalid length
+ * if its length is set to be smaller than the size of sctp_sack_chunk_t.
+ *
+ * We inform the other end by sending an ABORT with a Protocol Violation
+ * error code.
+ *
+ * Section: Not specified
+ * Verification Tag: Nothing to do
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * Outputs
+ * (reply_msg, msg_up, counters)
+ *
+ * Generate an ABORT chunk and terminate the association.
+ */
+static sctp_disposition_t sctp_sf_violation_chunklen(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ static const char err_str[] = "The following chunk had invalid length:";
+
+ return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
+
+/*
+ * Handle a protocol violation when the parameter length is invalid.
+ * If the length is smaller than the minimum length of a given parameter,
+ * or accumulated length in multi parameters exceeds the end of the chunk,
+ * the length is considered as invalid.
+ */
+static sctp_disposition_t sctp_sf_violation_paramlen(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg, void *ext,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+ struct sctp_paramhdr *param = ext;
+ struct sctp_chunk *abort = NULL;
+
+ if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
+ goto discard;
+
+ /* Make the abort chunk. */
+ abort = sctp_make_violation_paramlen(asoc, chunk, param);
+ if (!abort)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+
+discard:
+ sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
+ return SCTP_DISPOSITION_ABORT;
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Handle a protocol violation when the peer trying to advance the
+ * cumulative tsn ack to a point beyond the max tsn currently sent.
+ *
+ * We inform the other end by sending an ABORT with a Protocol Violation
+ * error code.
+ */
+static sctp_disposition_t sctp_sf_violation_ctsn(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
+
+ return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
+
+/* Handle protocol violation of an invalid chunk bundling. For example,
+ * when we have an association and we receive bundled INIT-ACK, or
+ * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
+ * statement from the specs. Additionally, there might be an attacker
+ * on the path and we may not want to continue this communication.
+ */
+static sctp_disposition_t sctp_sf_violation_chunk(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ static const char err_str[] = "The following chunk violates protocol:";
+
+ if (!asoc)
+ return sctp_sf_violation(net, ep, asoc, type, arg, commands);
+
+ return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
+ sizeof(err_str));
+}
+/***************************************************************************
+ * These are the state functions for handling primitive (Section 10) events.
+ ***************************************************************************/
+/*
+ * sctp_sf_do_prm_asoc
+ *
+ * Section: 10.1 ULP-to-SCTP
+ * B) Associate
+ *
+ * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
+ * outbound stream count)
+ * -> association id [,destination transport addr list] [,outbound stream
+ * count]
+ *
+ * This primitive allows the upper layer to initiate an association to a
+ * specific peer endpoint.
+ *
+ * The peer endpoint shall be specified by one of the transport addresses
+ * which defines the endpoint (see Section 1.4). If the local SCTP
+ * instance has not been initialized, the ASSOCIATE is considered an
+ * error.
+ * [This is not relevant for the kernel implementation since we do all
+ * initialization at boot time. It we hadn't initialized we wouldn't
+ * get anywhere near this code.]
+ *
+ * An association id, which is a local handle to the SCTP association,
+ * will be returned on successful establishment of the association. If
+ * SCTP is not able to open an SCTP association with the peer endpoint,
+ * an error is returned.
+ * [In the kernel implementation, the struct sctp_association needs to
+ * be created BEFORE causing this primitive to run.]
+ *
+ * Other association parameters may be returned, including the
+ * complete destination transport addresses of the peer as well as the
+ * outbound stream count of the local endpoint. One of the transport
+ * address from the returned destination addresses will be selected by
+ * the local endpoint as default primary path for sending SCTP packets
+ * to this peer. The returned "destination transport addr list" can
+ * be used by the ULP to change the default primary path or to force
+ * sending a packet to a specific transport address. [All of this
+ * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
+ * function.]
+ *
+ * Mandatory attributes:
+ *
+ * o local SCTP instance name - obtained from the INITIALIZE operation.
+ * [This is the argument asoc.]
+ * o destination transport addr - specified as one of the transport
+ * addresses of the peer endpoint with which the association is to be
+ * established.
+ * [This is asoc->peer.active_path.]
+ * o outbound stream count - the number of outbound streams the ULP
+ * would like to open towards this peer endpoint.
+ * [BUG: This is not currently implemented.]
+ * Optional attributes:
+ *
+ * None.
+ *
+ * The return value is a disposition.
+ */
+sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *repl;
+ struct sctp_association *my_asoc;
+
+ /* The comment below says that we enter COOKIE-WAIT AFTER
+ * sending the INIT, but that doesn't actually work in our
+ * implementation...
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
+
+ /* RFC 2960 5.1 Normal Establishment of an Association
+ *
+ * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
+ * must provide its Verification Tag (Tag_A) in the Initiate
+ * Tag field. Tag_A SHOULD be a random number in the range of
+ * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
+ */
+
+ repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
+ if (!repl)
+ goto nomem;
+
+ /* Choose transport for INIT. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
+ SCTP_CHUNK(repl));
+
+ /* Cast away the const modifier, as we want to just
+ * rerun it through as a sideffect.
+ */
+ my_asoc = (struct sctp_association *)asoc;
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
+
+ /* After sending the INIT, "A" starts the T1-init timer and
+ * enters the COOKIE-WAIT state.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Process the SEND primitive.
+ *
+ * Section: 10.1 ULP-to-SCTP
+ * E) Send
+ *
+ * Format: SEND(association id, buffer address, byte count [,context]
+ * [,stream id] [,life time] [,destination transport address]
+ * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
+ * -> result
+ *
+ * This is the main method to send user data via SCTP.
+ *
+ * Mandatory attributes:
+ *
+ * o association id - local handle to the SCTP association
+ *
+ * o buffer address - the location where the user message to be
+ * transmitted is stored;
+ *
+ * o byte count - The size of the user data in number of bytes;
+ *
+ * Optional attributes:
+ *
+ * o context - an optional 32 bit integer that will be carried in the
+ * sending failure notification to the ULP if the transportation of
+ * this User Message fails.
+ *
+ * o stream id - to indicate which stream to send the data on. If not
+ * specified, stream 0 will be used.
+ *
+ * o life time - specifies the life time of the user data. The user data
+ * will not be sent by SCTP after the life time expires. This
+ * parameter can be used to avoid efforts to transmit stale
+ * user messages. SCTP notifies the ULP if the data cannot be
+ * initiated to transport (i.e. sent to the destination via SCTP's
+ * send primitive) within the life time variable. However, the
+ * user data will be transmitted if SCTP has attempted to transmit a
+ * chunk before the life time expired.
+ *
+ * o destination transport address - specified as one of the destination
+ * transport addresses of the peer endpoint to which this packet
+ * should be sent. Whenever possible, SCTP should use this destination
+ * transport address for sending the packets, instead of the current
+ * primary path.
+ *
+ * o unorder flag - this flag, if present, indicates that the user
+ * would like the data delivered in an unordered fashion to the peer
+ * (i.e., the U flag is set to 1 on all DATA chunks carrying this
+ * message).
+ *
+ * o no-bundle flag - instructs SCTP not to bundle this user data with
+ * other outbound DATA chunks. SCTP MAY still bundle even when
+ * this flag is present, when faced with network congestion.
+ *
+ * o payload protocol-id - A 32 bit unsigned integer that is to be
+ * passed to the peer indicating the type of payload protocol data
+ * being transmitted. This value is passed as opaque data by SCTP.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_datamsg *msg = arg;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Process the SHUTDOWN primitive.
+ *
+ * Section: 10.1:
+ * C) Shutdown
+ *
+ * Format: SHUTDOWN(association id)
+ * -> result
+ *
+ * Gracefully closes an association. Any locally queued user data
+ * will be delivered to the peer. The association will be terminated only
+ * after the peer acknowledges all the SCTP packets sent. A success code
+ * will be returned on successful termination of the association. If
+ * attempting to terminate the association results in a failure, an error
+ * code shall be returned.
+ *
+ * Mandatory attributes:
+ *
+ * o association id - local handle to the SCTP association
+ *
+ * Optional attributes:
+ *
+ * None.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ int disposition;
+
+ /* From 9.2 Shutdown of an Association
+ * Upon receipt of the SHUTDOWN primitive from its upper
+ * layer, the endpoint enters SHUTDOWN-PENDING state and
+ * remains there until all outstanding data has been
+ * acknowledged by its peer. The endpoint accepts no new data
+ * from its upper layer, but retransmits data to the far end
+ * if necessary to fill gaps.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
+
+ disposition = SCTP_DISPOSITION_CONSUME;
+ if (sctp_outq_is_empty(&asoc->outqueue)) {
+ disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
+ arg, commands);
+ }
+ return disposition;
+}
+
+/*
+ * Process the ABORT primitive.
+ *
+ * Section: 10.1:
+ * C) Abort
+ *
+ * Format: Abort(association id [, cause code])
+ * -> result
+ *
+ * Ungracefully closes an association. Any locally queued user data
+ * will be discarded and an ABORT chunk is sent to the peer. A success code
+ * will be returned on successful abortion of the association. If
+ * attempting to abort the association results in a failure, an error
+ * code shall be returned.
+ *
+ * Mandatory attributes:
+ *
+ * o association id - local handle to the SCTP association
+ *
+ * Optional attributes:
+ *
+ * o cause code - reason of the abort to be passed to the peer
+ *
+ * None.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_9_1_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* From 9.1 Abort of an Association
+ * Upon receipt of the ABORT primitive from its upper
+ * layer, the endpoint enters CLOSED state and
+ * discard all outstanding data has been
+ * acknowledged by its peer. The endpoint accepts no new data
+ * from its upper layer, but retransmits data to the far end
+ * if necessary to fill gaps.
+ */
+ struct sctp_chunk *abort = arg;
+ sctp_disposition_t retval;
+
+ retval = SCTP_DISPOSITION_CONSUME;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+
+ /* Even if we can't send the ABORT due to low memory delete the
+ * TCB. This is a departure from our typical NOMEM handling.
+ */
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ /* Delete the established association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_USER_ABORT));
+
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+
+ return retval;
+}
+
+/* We tried an illegal operation on an association which is closed. */
+sctp_disposition_t sctp_sf_error_closed(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* We tried an illegal operation on an association which is shutting
+ * down.
+ */
+sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
+ SCTP_ERROR(-ESHUTDOWN));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * sctp_cookie_wait_prm_shutdown
+ *
+ * Section: 4 Note: 2
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explicitly address this issue, but is the route through the
+ * state table when someone issues a shutdown while in COOKIE_WAIT state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+
+ SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+}
+
+/*
+ * sctp_cookie_echoed_prm_shutdown
+ *
+ * Section: 4 Note: 2
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explcitly address this issue, but is the route through the
+ * state table when someone issues a shutdown while in COOKIE_ECHOED state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg, sctp_cmd_seq_t *commands)
+{
+ /* There is a single T1 timer, so we should be able to use
+ * common function with the COOKIE-WAIT state.
+ */
+ return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * sctp_sf_cookie_wait_prm_abort
+ *
+ * Section: 4 Note: 2
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explicitly address this issue, but is the route through the
+ * state table when someone issues an abort while in COOKIE_WAIT state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *abort = arg;
+ sctp_disposition_t retval;
+
+ /* Stop T1-init timer */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+ retval = SCTP_DISPOSITION_CONSUME;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_CLOSED));
+
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+
+ /* Even if we can't send the ABORT due to low memory delete the
+ * TCB. This is a departure from our typical NOMEM handling.
+ */
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNREFUSED));
+ /* Delete the established association. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_USER_ABORT));
+
+ return retval;
+}
+
+/*
+ * sctp_sf_cookie_echoed_prm_abort
+ *
+ * Section: 4 Note: 3
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explcitly address this issue, but is the route through the
+ * state table when someone issues an abort while in COOKIE_ECHOED state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* There is a single T1 timer, so we should be able to use
+ * common function with the COOKIE-WAIT state.
+ */
+ return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * sctp_sf_shutdown_pending_prm_abort
+ *
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explicitly address this issue, but is the route through the
+ * state table when someone issues an abort while in SHUTDOWN-PENDING state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* Stop the T5-shutdown guard timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * sctp_sf_shutdown_sent_prm_abort
+ *
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explicitly address this issue, but is the route through the
+ * state table when someone issues an abort while in SHUTDOWN-SENT state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* Stop the T2-shutdown timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ /* Stop the T5-shutdown guard timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * sctp_sf_cookie_echoed_prm_abort
+ *
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * The RFC does not explcitly address this issue, but is the route through the
+ * state table when someone issues an abort while in COOKIE_ECHOED state.
+ *
+ * Outputs
+ * (timers)
+ */
+sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ /* The same T2 timer, so we should be able to use
+ * common function with the SHUTDOWN-SENT state.
+ */
+ return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
+}
+
+/*
+ * Process the REQUESTHEARTBEAT primitive
+ *
+ * 10.1 ULP-to-SCTP
+ * J) Request Heartbeat
+ *
+ * Format: REQUESTHEARTBEAT(association id, destination transport address)
+ *
+ * -> result
+ *
+ * Instructs the local endpoint to perform a HeartBeat on the specified
+ * destination transport address of the given association. The returned
+ * result should indicate whether the transmission of the HEARTBEAT
+ * chunk to the destination address is successful.
+ *
+ * Mandatory attributes:
+ *
+ * o association id - local handle to the SCTP association
+ *
+ * o destination transport address - the transport address of the
+ * association on which a heartbeat should be issued.
+ */
+sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
+ (struct sctp_transport *)arg, commands))
+ return SCTP_DISPOSITION_NOMEM;
+
+ /*
+ * RFC 2960 (bis), section 8.3
+ *
+ * D) Request an on-demand HEARTBEAT on a specific destination
+ * transport address of a given association.
+ *
+ * The endpoint should increment the respective error counter of
+ * the destination transport address each time a HEARTBEAT is sent
+ * to that address and not acknowledged within one RTO.
+ *
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
+ SCTP_TRANSPORT(arg));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * ADDIP Section 4.1 ASCONF Chunk Procedures
+ * When an endpoint has an ASCONF signaled change to be sent to the
+ * remote endpoint it should do A1 to A9
+ */
+sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = arg;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Ignore the primitive event
+ *
+ * The return value is the disposition of the primitive.
+ */
+sctp_disposition_t sctp_sf_ignore_primitive(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ pr_debug("%s: primitive type:%d is ignored\n", __func__,
+ type.primitive);
+
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/***************************************************************************
+ * These are the state functions for the OTHER events.
+ ***************************************************************************/
+
+/*
+ * When the SCTP stack has no more user data to send or retransmit, this
+ * notification is given to the user. Also, at the time when a user app
+ * subscribes to this event, if there is no data to be sent or
+ * retransmit, the stack will immediately send up this notification.
+ */
+sctp_disposition_t sctp_sf_do_no_pending_tsn(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_ulpevent *event;
+
+ event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
+ if (!event)
+ return SCTP_DISPOSITION_NOMEM;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Start the shutdown negotiation.
+ *
+ * From Section 9.2:
+ * Once all its outstanding data has been acknowledged, the endpoint
+ * shall send a SHUTDOWN chunk to its peer including in the Cumulative
+ * TSN Ack field the last sequential TSN it has received from the peer.
+ * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
+ * state. If the timer expires, the endpoint must re-send the SHUTDOWN
+ * with the updated last sequential TSN received from its peer.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *reply;
+
+ /* Once all its outstanding data has been acknowledged, the
+ * endpoint shall send a SHUTDOWN chunk to its peer including
+ * in the Cumulative TSN Ack field the last sequential TSN it
+ * has received from the peer.
+ */
+ reply = sctp_make_shutdown(asoc, NULL);
+ if (!reply)
+ goto nomem;
+
+ /* Set the transport for the SHUTDOWN chunk and the timeout for the
+ * T2-shutdown timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
+
+ /* It shall then start the T2-shutdown timer */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ /* RFC 4960 Section 9.2
+ * The sender of the SHUTDOWN MAY also start an overall guard timer
+ * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+
+ if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+
+ /* and enter the SHUTDOWN-SENT state. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
+
+ /* sctp-implguide 2.10 Issues with Heartbeating and failover
+ *
+ * HEARTBEAT ... is discontinued after sending either SHUTDOWN
+ * or SHUTDOWN-ACK.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Generate a SHUTDOWN ACK now that everything is SACK'd.
+ *
+ * From Section 9.2:
+ *
+ * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
+ * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
+ * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
+ * endpoint must re-send the SHUTDOWN ACK.
+ *
+ * The return value is the disposition.
+ */
+sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
+ struct sctp_chunk *reply;
+
+ /* There are 2 ways of getting here:
+ * 1) called in response to a SHUTDOWN chunk
+ * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
+ *
+ * For the case (2), the arg parameter is set to NULL. We need
+ * to check that we have a chunk before accessing it's fields.
+ */
+ if (chunk) {
+ if (!sctp_vtag_verify(chunk, asoc))
+ return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
+
+ /* Make sure that the SHUTDOWN chunk has a valid length. */
+ if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
+ return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
+ commands);
+ }
+
+ /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
+ * shall send a SHUTDOWN ACK ...
+ */
+ reply = sctp_make_shutdown_ack(asoc, chunk);
+ if (!reply)
+ goto nomem;
+
+ /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
+ * the T2-shutdown timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
+
+ /* and start/restart a T2-shutdown timer of its own, */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+
+ if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
+
+ /* Enter the SHUTDOWN-ACK-SENT state. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
+
+ /* sctp-implguide 2.10 Issues with Heartbeating and failover
+ *
+ * HEARTBEAT ... is discontinued after sending either SHUTDOWN
+ * or SHUTDOWN-ACK.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * Ignore the event defined as other
+ *
+ * The return value is the disposition of the event.
+ */
+sctp_disposition_t sctp_sf_ignore_other(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ pr_debug("%s: the event other type:%d is ignored\n",
+ __func__, type.other);
+
+ return SCTP_DISPOSITION_DISCARD;
+}
+
+/************************************************************
+ * These are the state functions for handling timeout events.
+ ************************************************************/
+
+/*
+ * RTX Timeout
+ *
+ * Section: 6.3.3 Handle T3-rtx Expiration
+ *
+ * Whenever the retransmission timer T3-rtx expires for a destination
+ * address, do the following:
+ * [See below]
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_transport *transport = arg;
+
+ SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
+
+ if (asoc->overall_error_count >= asoc->max_retrans) {
+ if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
+ /*
+ * We are here likely because the receiver had its rwnd
+ * closed for a while and we have not been able to
+ * transmit the locally queued data within the maximum
+ * retransmission attempts limit. Start the T5
+ * shutdown guard timer to give the receiver one last
+ * chance and some additional time to recover before
+ * aborting.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+ }
+
+ /* E1) For the destination address for which the timer
+ * expires, adjust its ssthresh with rules defined in Section
+ * 7.2.3 and set the cwnd <- MTU.
+ */
+
+ /* E2) For the destination address for which the timer
+ * expires, set RTO <- RTO * 2 ("back off the timer"). The
+ * maximum value discussed in rule C7 above (RTO.max) may be
+ * used to provide an upper bound to this doubling operation.
+ */
+
+ /* E3) Determine how many of the earliest (i.e., lowest TSN)
+ * outstanding DATA chunks for the address for which the
+ * T3-rtx has expired will fit into a single packet, subject
+ * to the MTU constraint for the path corresponding to the
+ * destination transport address to which the retransmission
+ * is being sent (this may be different from the address for
+ * which the timer expires [see Section 6.4]). Call this
+ * value K. Bundle and retransmit those K DATA chunks in a
+ * single packet to the destination endpoint.
+ *
+ * Note: Any DATA chunks that were sent to the address for
+ * which the T3-rtx timer expired but did not fit in one MTU
+ * (rule E3 above), should be marked for retransmission and
+ * sent as soon as cwnd allows (normally when a SACK arrives).
+ */
+
+ /* Do some failure management (Section 8.2). */
+ sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
+
+ /* NB: Rules E4 and F1 are implicit in R1. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * Generate delayed SACK on timeout
+ *
+ * Section: 6.2 Acknowledgement on Reception of DATA Chunks
+ *
+ * The guidelines on delayed acknowledgement algorithm specified in
+ * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
+ * acknowledgement SHOULD be generated for at least every second packet
+ * (not every second DATA chunk) received, and SHOULD be generated
+ * within 200 ms of the arrival of any unacknowledged DATA chunk. In
+ * some situations it may be beneficial for an SCTP transmitter to be
+ * more conservative than the algorithms detailed in this document
+ * allow. However, an SCTP transmitter MUST NOT be more aggressive than
+ * the following algorithms allow.
+ */
+sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
+ sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * sctp_sf_t1_init_timer_expire
+ *
+ * Section: 4 Note: 2
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * RFC 2960 Section 4 Notes
+ * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
+ * and re-start the T1-init timer without changing state. This MUST
+ * be repeated up to 'Max.Init.Retransmits' times. After that, the
+ * endpoint MUST abort the initialization process and report the
+ * error to SCTP user.
+ *
+ * Outputs
+ * (timers, events)
+ *
+ */
+sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *repl = NULL;
+ struct sctp_bind_addr *bp;
+ int attempts = asoc->init_err_counter + 1;
+
+ pr_debug("%s: timer T1 expired (INIT)\n", __func__);
+
+ SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
+
+ if (attempts <= asoc->max_init_attempts) {
+ bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
+ repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
+ if (!repl)
+ return SCTP_DISPOSITION_NOMEM;
+
+ /* Choose transport for INIT. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
+ SCTP_CHUNK(repl));
+
+ /* Issue a sideeffect to do the needed accounting. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ } else {
+ pr_debug("%s: giving up on INIT, attempts:%d "
+ "max_init_attempts:%d\n", __func__, attempts,
+ asoc->max_init_attempts);
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/*
+ * sctp_sf_t1_cookie_timer_expire
+ *
+ * Section: 4 Note: 2
+ * Verification Tag:
+ * Inputs
+ * (endpoint, asoc)
+ *
+ * RFC 2960 Section 4 Notes
+ * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
+ * COOKIE ECHO and re-start the T1-cookie timer without changing
+ * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
+ * After that, the endpoint MUST abort the initialization process and
+ * report the error to SCTP user.
+ *
+ * Outputs
+ * (timers, events)
+ *
+ */
+sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *repl = NULL;
+ int attempts = asoc->init_err_counter + 1;
+
+ pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
+
+ SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
+
+ if (attempts <= asoc->max_init_attempts) {
+ repl = sctp_make_cookie_echo(asoc, NULL);
+ if (!repl)
+ return SCTP_DISPOSITION_NOMEM;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
+ SCTP_CHUNK(repl));
+ /* Issue a sideeffect to do the needed accounting. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
+ } else {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
+ * with the updated last sequential TSN received from its peer.
+ *
+ * An endpoint should limit the number of retransmissions of the
+ * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
+ * If this threshold is exceeded the endpoint should destroy the TCB and
+ * MUST report the peer endpoint unreachable to the upper layer (and
+ * thus the association enters the CLOSED state). The reception of any
+ * packet from its peer (i.e. as the peer sends all of its queued DATA
+ * chunks) should clear the endpoint's retransmission count and restart
+ * the T2-Shutdown timer, giving its peer ample opportunity to transmit
+ * all of its queued DATA chunks that have not yet been sent.
+ */
+sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *reply = NULL;
+
+ pr_debug("%s: timer T2 expired\n", __func__);
+
+ SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
+
+ ((struct sctp_association *)asoc)->shutdown_retries++;
+
+ if (asoc->overall_error_count >= asoc->max_retrans) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_DELETE_TCB;
+ }
+
+ switch (asoc->state) {
+ case SCTP_STATE_SHUTDOWN_SENT:
+ reply = sctp_make_shutdown(asoc, NULL);
+ break;
+
+ case SCTP_STATE_SHUTDOWN_ACK_SENT:
+ reply = sctp_make_shutdown_ack(asoc, NULL);
+ break;
+
+ default:
+ BUG();
+ break;
+ }
+
+ if (!reply)
+ goto nomem;
+
+ /* Do some failure management (Section 8.2).
+ * If we remove the transport an SHUTDOWN was last sent to, don't
+ * do failure management.
+ */
+ if (asoc->shutdown_last_sent_to)
+ sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
+ SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
+
+ /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
+ * the T2-shutdown timer.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
+
+ /* Restart the T2-shutdown timer. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ return SCTP_DISPOSITION_CONSUME;
+
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/*
+ * ADDIP Section 4.1 ASCONF CHunk Procedures
+ * If the T4 RTO timer expires the endpoint should do B1 to B5
+ */
+sctp_disposition_t sctp_sf_t4_timer_expire(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *chunk = asoc->addip_last_asconf;
+ struct sctp_transport *transport = chunk->transport;
+
+ SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
+
+ /* ADDIP 4.1 B1) Increment the error counters and perform path failure
+ * detection on the appropriate destination address as defined in
+ * RFC2960 [5] section 8.1 and 8.2.
+ */
+ if (transport)
+ sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
+ SCTP_TRANSPORT(transport));
+
+ /* Reconfig T4 timer and transport. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
+
+ /* ADDIP 4.1 B2) Increment the association error counters and perform
+ * endpoint failure detection on the association as defined in
+ * RFC2960 [5] section 8.1 and 8.2.
+ * association error counter is incremented in SCTP_CMD_STRIKE.
+ */
+ if (asoc->overall_error_count >= asoc->max_retrans) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_DISPOSITION_ABORT;
+ }
+
+ /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
+ * the ASCONF chunk was sent by doubling the RTO timer value.
+ * This is done in SCTP_CMD_STRIKE.
+ */
+
+ /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
+ * choose an alternate destination address (please refer to RFC2960
+ * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
+ * chunk, it MUST be the same (including its serial number) as the last
+ * ASCONF sent.
+ */
+ sctp_chunk_hold(asoc->addip_last_asconf);
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(asoc->addip_last_asconf));
+
+ /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
+ * destination is selected, then the RTO used will be that of the new
+ * destination address.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
+ SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/* sctpimpguide-05 Section 2.12.2
+ * The sender of the SHUTDOWN MAY also start an overall guard timer
+ * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
+ * At the expiration of this timer the sender SHOULD abort the association
+ * by sending an ABORT chunk.
+ */
+sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ struct sctp_chunk *reply = NULL;
+
+ pr_debug("%s: timer T5 expired\n", __func__);
+
+ SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
+
+ reply = sctp_make_abort(asoc, NULL, 0);
+ if (!reply)
+ goto nomem;
+
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ETIMEDOUT));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_ERROR));
+
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+
+ return SCTP_DISPOSITION_DELETE_TCB;
+nomem:
+ return SCTP_DISPOSITION_NOMEM;
+}
+
+/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
+ * the association is automatically closed by starting the shutdown process.
+ * The work that needs to be done is same as when SHUTDOWN is initiated by
+ * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
+ */
+sctp_disposition_t sctp_sf_autoclose_timer_expire(
+ struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ int disposition;
+
+ SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
+
+ /* From 9.2 Shutdown of an Association
+ * Upon receipt of the SHUTDOWN primitive from its upper
+ * layer, the endpoint enters SHUTDOWN-PENDING state and
+ * remains there until all outstanding data has been
+ * acknowledged by its peer. The endpoint accepts no new data
+ * from its upper layer, but retransmits data to the far end
+ * if necessary to fill gaps.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
+ SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
+
+ disposition = SCTP_DISPOSITION_CONSUME;
+ if (sctp_outq_is_empty(&asoc->outqueue)) {
+ disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
+ arg, commands);
+ }
+ return disposition;
+}
+
+/*****************************************************************************
+ * These are sa state functions which could apply to all types of events.
+ ****************************************************************************/
+
+/*
+ * This table entry is not implemented.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_not_impl(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ return SCTP_DISPOSITION_NOT_IMPL;
+}
+
+/*
+ * This table entry represents a bug.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_bug(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ return SCTP_DISPOSITION_BUG;
+}
+
+/*
+ * This table entry represents the firing of a timer in the wrong state.
+ * Since timer deletion cannot be guaranteed a timer 'may' end up firing
+ * when the association is in the wrong state. This event should
+ * be ignored, so as to prevent any rearming of the timer.
+ *
+ * Inputs
+ * (endpoint, asoc, chunk)
+ *
+ * The return value is the disposition of the chunk.
+ */
+sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const sctp_subtype_t type,
+ void *arg,
+ sctp_cmd_seq_t *commands)
+{
+ pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
+
+ return SCTP_DISPOSITION_CONSUME;
+}
+
+/********************************************************************
+ * 2nd Level Abstractions
+ ********************************************************************/
+
+/* Pull the SACK chunk based on the SACK header. */
+static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
+{
+ struct sctp_sackhdr *sack;
+ unsigned int len;
+ __u16 num_blocks;
+ __u16 num_dup_tsns;
+
+ /* Protect ourselves from reading too far into
+ * the skb from a bogus sender.
+ */
+ sack = (struct sctp_sackhdr *) chunk->skb->data;
+
+ num_blocks = ntohs(sack->num_gap_ack_blocks);
+ num_dup_tsns = ntohs(sack->num_dup_tsns);
+ len = sizeof(struct sctp_sackhdr);
+ len += (num_blocks + num_dup_tsns) * sizeof(__u32);
+ if (len > chunk->skb->len)
+ return NULL;
+
+ skb_pull(chunk->skb, len);
+
+ return sack;
+}
+
+/* Create an ABORT packet to be sent as a response, with the specified
+ * error causes.
+ */
+static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ const void *payload,
+ size_t paylen)
+{
+ struct sctp_packet *packet;
+ struct sctp_chunk *abort;
+
+ packet = sctp_ootb_pkt_new(net, asoc, chunk);
+
+ if (packet) {
+ /* Make an ABORT.
+ * The T bit will be set if the asoc is NULL.
+ */
+ abort = sctp_make_abort(asoc, chunk, paylen);
+ if (!abort) {
+ sctp_ootb_pkt_free(packet);
+ return NULL;
+ }
+
+ /* Reflect vtag if T-Bit is set */
+ if (sctp_test_T_bit(abort))
+ packet->vtag = ntohl(chunk->sctp_hdr->vtag);
+
+ /* Add specified error causes, i.e., payload, to the
+ * end of the chunk.
+ */
+ sctp_addto_chunk(abort, paylen, payload);
+
+ /* Set the skb to the belonging sock for accounting. */
+ abort->skb->sk = ep->base.sk;
+
+ sctp_packet_append_chunk(packet, abort);
+
+ }
+
+ return packet;
+}
+
+/* Allocate a packet for responding in the OOTB conditions. */
+static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_packet *packet;
+ struct sctp_transport *transport;
+ __u16 sport;
+ __u16 dport;
+ __u32 vtag;
+
+ /* Get the source and destination port from the inbound packet. */
+ sport = ntohs(chunk->sctp_hdr->dest);
+ dport = ntohs(chunk->sctp_hdr->source);
+
+ /* The V-tag is going to be the same as the inbound packet if no
+ * association exists, otherwise, use the peer's vtag.
+ */
+ if (asoc) {
+ /* Special case the INIT-ACK as there is no peer's vtag
+ * yet.
+ */
+ switch (chunk->chunk_hdr->type) {
+ case SCTP_CID_INIT_ACK:
+ {
+ sctp_initack_chunk_t *initack;
+
+ initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
+ vtag = ntohl(initack->init_hdr.init_tag);
+ break;
+ }
+ default:
+ vtag = asoc->peer.i.init_tag;
+ break;
+ }
+ } else {
+ /* Special case the INIT and stale COOKIE_ECHO as there is no
+ * vtag yet.
+ */
+ switch (chunk->chunk_hdr->type) {
+ case SCTP_CID_INIT:
+ {
+ sctp_init_chunk_t *init;
+
+ init = (sctp_init_chunk_t *)chunk->chunk_hdr;
+ vtag = ntohl(init->init_hdr.init_tag);
+ break;
+ }
+ default:
+ vtag = ntohl(chunk->sctp_hdr->vtag);
+ break;
+ }
+ }
+
+ /* Make a transport for the bucket, Eliza... */
+ transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
+ if (!transport)
+ goto nomem;
+
+ /* Cache a route for the transport with the chunk's destination as
+ * the source address.
+ */
+ sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
+ sctp_sk(net->sctp.ctl_sock));
+
+ packet = sctp_packet_init(&transport->packet, transport, sport, dport);
+ packet = sctp_packet_config(packet, vtag, 0);
+
+ return packet;
+
+nomem:
+ return NULL;
+}
+
+/* Free the packet allocated earlier for responding in the OOTB condition. */
+void sctp_ootb_pkt_free(struct sctp_packet *packet)
+{
+ sctp_transport_free(packet->transport);
+}
+
+/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
+static void sctp_send_stale_cookie_err(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands,
+ struct sctp_chunk *err_chunk)
+{
+ struct sctp_packet *packet;
+
+ if (err_chunk) {
+ packet = sctp_ootb_pkt_new(net, asoc, chunk);
+ if (packet) {
+ struct sctp_signed_cookie *cookie;
+
+ /* Override the OOTB vtag from the cookie. */
+ cookie = chunk->subh.cookie_hdr;
+ packet->vtag = cookie->c.peer_vtag;
+
+ /* Set the skb to the belonging sock for accounting. */
+ err_chunk->skb->sk = ep->base.sk;
+ sctp_packet_append_chunk(packet, err_chunk);
+ sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
+ SCTP_PACKET(packet));
+ SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
+ } else
+ sctp_chunk_free (err_chunk);
+ }
+}
+
+
+/* Process a data chunk */
+static int sctp_eat_data(const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ sctp_cmd_seq_t *commands)
+{
+ sctp_datahdr_t *data_hdr;
+ struct sctp_chunk *err;
+ size_t datalen;
+ sctp_verb_t deliver;
+ int tmp;
+ __u32 tsn;
+ struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
+ struct sock *sk = asoc->base.sk;
+ struct net *net = sock_net(sk);
+ u16 ssn;
+ u16 sid;
+ u8 ordered = 0;
+
+ data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
+ skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
+
+ tsn = ntohl(data_hdr->tsn);
+ pr_debug("%s: TSN 0x%x\n", __func__, tsn);
+
+ /* ASSERT: Now skb->data is really the user data. */
+
+ /* Process ECN based congestion.
+ *
+ * Since the chunk structure is reused for all chunks within
+ * a packet, we use ecn_ce_done to track if we've already
+ * done CE processing for this packet.
+ *
+ * We need to do ECN processing even if we plan to discard the
+ * chunk later.
+ */
+
+ if (!chunk->ecn_ce_done) {
+ struct sctp_af *af;
+ chunk->ecn_ce_done = 1;
+
+ af = sctp_get_af_specific(
+ ipver2af(ip_hdr(chunk->skb)->version));
+
+ if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
+ /* Do real work as sideffect. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
+ SCTP_U32(tsn));
+ }
+ }
+
+ tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
+ if (tmp < 0) {
+ /* The TSN is too high--silently discard the chunk and
+ * count on it getting retransmitted later.
+ */
+ if (chunk->asoc)
+ chunk->asoc->stats.outofseqtsns++;
+ return SCTP_IERROR_HIGH_TSN;
+ } else if (tmp > 0) {
+ /* This is a duplicate. Record it. */
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
+ return SCTP_IERROR_DUP_TSN;
+ }
+
+ /* This is a new TSN. */
+
+ /* Discard if there is no room in the receive window.
+ * Actually, allow a little bit of overflow (up to a MTU).
+ */
+ datalen = ntohs(chunk->chunk_hdr->length);
+ datalen -= sizeof(sctp_data_chunk_t);
+
+ deliver = SCTP_CMD_CHUNK_ULP;
+
+ /* Think about partial delivery. */
+ if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
+
+ /* Even if we don't accept this chunk there is
+ * memory pressure.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
+ }
+
+ /* Spill over rwnd a little bit. Note: While allowed, this spill over
+ * seems a bit troublesome in that frag_point varies based on
+ * PMTU. In cases, such as loopback, this might be a rather
+ * large spill over.
+ */
+ if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
+ (datalen > asoc->rwnd + asoc->frag_point))) {
+
+ /* If this is the next TSN, consider reneging to make
+ * room. Note: Playing nice with a confused sender. A
+ * malicious sender can still eat up all our buffer
+ * space and in the future we may want to detect and
+ * do more drastic reneging.
+ */
+ if (sctp_tsnmap_has_gap(map) &&
+ (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
+ pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
+ deliver = SCTP_CMD_RENEGE;
+ } else {
+ pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
+ __func__, tsn, datalen, asoc->rwnd);
+
+ return SCTP_IERROR_IGNORE_TSN;
+ }
+ }
+
+ /*
+ * Also try to renege to limit our memory usage in the event that
+ * we are under memory pressure
+ * If we can't renege, don't worry about it, the sk_rmem_schedule
+ * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
+ * memory usage too much
+ */
+ if (*sk->sk_prot_creator->memory_pressure) {
+ if (sctp_tsnmap_has_gap(map) &&
+ (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
+ pr_debug("%s: under pressure, reneging for tsn:%u\n",
+ __func__, tsn);
+ deliver = SCTP_CMD_RENEGE;
+ }
+ }
+
+ /*
+ * Section 3.3.10.9 No User Data (9)
+ *
+ * Cause of error
+ * ---------------
+ * No User Data: This error cause is returned to the originator of a
+ * DATA chunk if a received DATA chunk has no user data.
+ */
+ if (unlikely(0 == datalen)) {
+ err = sctp_make_abort_no_data(asoc, chunk, tsn);
+ if (err) {
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err));
+ }
+ /* We are going to ABORT, so we might as well stop
+ * processing the rest of the chunks in the packet.
+ */
+ sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
+ sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+ SCTP_ERROR(ECONNABORTED));
+ sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+ SCTP_PERR(SCTP_ERROR_NO_DATA));
+ SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+ SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+ return SCTP_IERROR_NO_DATA;
+ }
+
+ chunk->data_accepted = 1;
+
+ /* Note: Some chunks may get overcounted (if we drop) or overcounted
+ * if we renege and the chunk arrives again.
+ */
+ if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
+ SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
+ if (chunk->asoc)
+ chunk->asoc->stats.iuodchunks++;
+ } else {
+ SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
+ if (chunk->asoc)
+ chunk->asoc->stats.iodchunks++;
+ ordered = 1;
+ }
+
+ /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
+ *
+ * If an endpoint receive a DATA chunk with an invalid stream
+ * identifier, it shall acknowledge the reception of the DATA chunk
+ * following the normal procedure, immediately send an ERROR chunk
+ * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
+ * and discard the DATA chunk.
+ */
+ sid = ntohs(data_hdr->stream);
+ if (sid >= asoc->c.sinit_max_instreams) {
+ /* Mark tsn as received even though we drop it */
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
+
+ err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
+ &data_hdr->stream,
+ sizeof(data_hdr->stream),
+ sizeof(u16));
+ if (err)
+ sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+ SCTP_CHUNK(err));
+ return SCTP_IERROR_BAD_STREAM;
+ }
+
+ /* Check to see if the SSN is possible for this TSN.
+ * The biggest gap we can record is 4K wide. Since SSNs wrap
+ * at an unsigned short, there is no way that an SSN can
+ * wrap and for a valid TSN. We can simply check if the current
+ * SSN is smaller then the next expected one. If it is, it wrapped
+ * and is invalid.
+ */
+ ssn = ntohs(data_hdr->ssn);
+ if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
+ return SCTP_IERROR_PROTO_VIOLATION;
+ }
+
+ /* Send the data up to the user. Note: Schedule the
+ * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
+ * chunk needs the updated rwnd.
+ */
+ sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
+
+ return SCTP_IERROR_NO_ERROR;
+}
Code Review / kvmfornfv.git / blobdiff