--- /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.
+ *
+ * This file is part of the SCTP kernel implementation
+ *
+ * These functions work with the state functions in sctp_sm_statefuns.c
+ * to implement the state operations. These functions implement the
+ * steps which require modifying existing data structures.
+ *
+ * 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>
+ * C. Robin <chris@hundredacre.ac.uk>
+ * Jon Grimm <jgrimm@us.ibm.com>
+ * Xingang Guo <xingang.guo@intel.com>
+ * Dajiang Zhang <dajiang.zhang@nokia.com>
+ * Sridhar Samudrala <sri@us.ibm.com>
+ * Daisy Chang <daisyc@us.ibm.com>
+ * Ardelle Fan <ardelle.fan@intel.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/scatterlist.h>
+#include <linux/crypto.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+
+#include <linux/skbuff.h>
+#include <linux/random.h> /* for get_random_bytes */
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
+ __u8 type, __u8 flags, int paylen);
+static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
+ __u8 flags, int paylen);
+static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
+ __u8 type, __u8 flags, int paylen);
+static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *init_chunk,
+ int *cookie_len,
+ const __u8 *raw_addrs, int addrs_len);
+static int sctp_process_param(struct sctp_association *asoc,
+ union sctp_params param,
+ const union sctp_addr *peer_addr,
+ gfp_t gfp);
+static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
+ const void *data);
+static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
+ const void *data);
+
+/* Control chunk destructor */
+static void sctp_control_release_owner(struct sk_buff *skb)
+{
+ /*TODO: do memory release */
+}
+
+static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
+{
+ struct sctp_association *asoc = chunk->asoc;
+ struct sk_buff *skb = chunk->skb;
+
+ /* TODO: properly account for control chunks.
+ * To do it right we'll need:
+ * 1) endpoint if association isn't known.
+ * 2) proper memory accounting.
+ *
+ * For now don't do anything for now.
+ */
+ skb->sk = asoc ? asoc->base.sk : NULL;
+ skb->destructor = sctp_control_release_owner;
+}
+
+/* What was the inbound interface for this chunk? */
+int sctp_chunk_iif(const struct sctp_chunk *chunk)
+{
+ struct sctp_af *af;
+ int iif = 0;
+
+ af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
+ if (af)
+ iif = af->skb_iif(chunk->skb);
+
+ return iif;
+}
+
+/* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 2: The ECN capable field is reserved for future use of
+ * Explicit Congestion Notification.
+ */
+static const struct sctp_paramhdr ecap_param = {
+ SCTP_PARAM_ECN_CAPABLE,
+ cpu_to_be16(sizeof(struct sctp_paramhdr)),
+};
+static const struct sctp_paramhdr prsctp_param = {
+ SCTP_PARAM_FWD_TSN_SUPPORT,
+ cpu_to_be16(sizeof(struct sctp_paramhdr)),
+};
+
+/* A helper to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk.
+ */
+void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
+ size_t paylen)
+{
+ sctp_errhdr_t err;
+ __u16 len;
+
+ /* Cause code constants are now defined in network order. */
+ err.cause = cause_code;
+ len = sizeof(sctp_errhdr_t) + paylen;
+ err.length = htons(len);
+ chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
+}
+
+/* A helper to initialize an op error inside a
+ * provided chunk, as most cause codes will be embedded inside an
+ * abort chunk. Differs from sctp_init_cause in that it won't oops
+ * if there isn't enough space in the op error chunk
+ */
+static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
+ size_t paylen)
+{
+ sctp_errhdr_t err;
+ __u16 len;
+
+ /* Cause code constants are now defined in network order. */
+ err.cause = cause_code;
+ len = sizeof(sctp_errhdr_t) + paylen;
+ err.length = htons(len);
+
+ if (skb_tailroom(chunk->skb) < len)
+ return -ENOSPC;
+ chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
+ sizeof(sctp_errhdr_t),
+ &err);
+ return 0;
+}
+/* 3.3.2 Initiation (INIT) (1)
+ *
+ * This chunk is used to initiate a SCTP association between two
+ * endpoints. The format of the INIT chunk is shown below:
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 1 | Chunk Flags | Chunk Length |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Initiate Tag |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Advertised Receiver Window Credit (a_rwnd) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Number of Outbound Streams | Number of Inbound Streams |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Initial TSN |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * \ \
+ * / Optional/Variable-Length Parameters /
+ * \ \
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *
+ * The INIT chunk contains the following parameters. Unless otherwise
+ * noted, each parameter MUST only be included once in the INIT chunk.
+ *
+ * Fixed Parameters Status
+ * ----------------------------------------------
+ * Initiate Tag Mandatory
+ * Advertised Receiver Window Credit Mandatory
+ * Number of Outbound Streams Mandatory
+ * Number of Inbound Streams Mandatory
+ * Initial TSN Mandatory
+ *
+ * Variable Parameters Status Type Value
+ * -------------------------------------------------------------
+ * IPv4 Address (Note 1) Optional 5
+ * IPv6 Address (Note 1) Optional 6
+ * Cookie Preservative Optional 9
+ * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
+ * Host Name Address (Note 3) Optional 11
+ * Supported Address Types (Note 4) Optional 12
+ */
+struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
+ const struct sctp_bind_addr *bp,
+ gfp_t gfp, int vparam_len)
+{
+ struct net *net = sock_net(asoc->base.sk);
+ struct sctp_endpoint *ep = asoc->ep;
+ sctp_inithdr_t init;
+ union sctp_params addrs;
+ size_t chunksize;
+ struct sctp_chunk *retval = NULL;
+ int num_types, addrs_len = 0;
+ struct sctp_sock *sp;
+ sctp_supported_addrs_param_t sat;
+ __be16 types[2];
+ sctp_adaptation_ind_param_t aiparam;
+ sctp_supported_ext_param_t ext_param;
+ int num_ext = 0;
+ __u8 extensions[3];
+ sctp_paramhdr_t *auth_chunks = NULL,
+ *auth_hmacs = NULL;
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 1: The INIT chunks can contain multiple addresses that
+ * can be IPv4 and/or IPv6 in any combination.
+ */
+ retval = NULL;
+
+ /* Convert the provided bind address list to raw format. */
+ addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
+
+ init.init_tag = htonl(asoc->c.my_vtag);
+ init.a_rwnd = htonl(asoc->rwnd);
+ init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
+ init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
+ init.initial_tsn = htonl(asoc->c.initial_tsn);
+
+ /* How many address types are needed? */
+ sp = sctp_sk(asoc->base.sk);
+ num_types = sp->pf->supported_addrs(sp, types);
+
+ chunksize = sizeof(init) + addrs_len;
+ chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
+ chunksize += sizeof(ecap_param);
+
+ if (net->sctp.prsctp_enable)
+ chunksize += sizeof(prsctp_param);
+
+ /* ADDIP: Section 4.2.7:
+ * An implementation supporting this extension [ADDIP] MUST list
+ * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
+ * INIT-ACK parameters.
+ */
+ if (net->sctp.addip_enable) {
+ extensions[num_ext] = SCTP_CID_ASCONF;
+ extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
+ num_ext += 2;
+ }
+
+ if (sp->adaptation_ind)
+ chunksize += sizeof(aiparam);
+
+ chunksize += vparam_len;
+
+ /* Account for AUTH related parameters */
+ if (ep->auth_enable) {
+ /* Add random parameter length*/
+ chunksize += sizeof(asoc->c.auth_random);
+
+ /* Add HMACS parameter length if any were defined */
+ auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
+ if (auth_hmacs->length)
+ chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
+ else
+ auth_hmacs = NULL;
+
+ /* Add CHUNKS parameter length */
+ auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
+ if (auth_chunks->length)
+ chunksize += WORD_ROUND(ntohs(auth_chunks->length));
+ else
+ auth_chunks = NULL;
+
+ extensions[num_ext] = SCTP_CID_AUTH;
+ num_ext += 1;
+ }
+
+ /* If we have any extensions to report, account for that */
+ if (num_ext)
+ chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
+ num_ext);
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 3: An INIT chunk MUST NOT contain more than one Host
+ * Name address parameter. Moreover, the sender of the INIT
+ * MUST NOT combine any other address types with the Host Name
+ * address in the INIT. The receiver of INIT MUST ignore any
+ * other address types if the Host Name address parameter is
+ * present in the received INIT chunk.
+ *
+ * PLEASE DO NOT FIXME [This version does not support Host Name.]
+ */
+
+ retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize);
+ if (!retval)
+ goto nodata;
+
+ retval->subh.init_hdr =
+ sctp_addto_chunk(retval, sizeof(init), &init);
+ retval->param_hdr.v =
+ sctp_addto_chunk(retval, addrs_len, addrs.v);
+
+ /* RFC 2960 3.3.2 Initiation (INIT) (1)
+ *
+ * Note 4: This parameter, when present, specifies all the
+ * address types the sending endpoint can support. The absence
+ * of this parameter indicates that the sending endpoint can
+ * support any address type.
+ */
+ sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
+ sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
+ sctp_addto_chunk(retval, sizeof(sat), &sat);
+ sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
+
+ sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
+
+ /* Add the supported extensions parameter. Be nice and add this
+ * fist before addiding the parameters for the extensions themselves
+ */
+ if (num_ext) {
+ ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
+ ext_param.param_hdr.length =
+ htons(sizeof(sctp_supported_ext_param_t) + num_ext);
+ sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
+ &ext_param);
+ sctp_addto_param(retval, num_ext, extensions);
+ }
+
+ if (net->sctp.prsctp_enable)
+ sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
+
+ if (sp->adaptation_ind) {
+ aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
+ aiparam.param_hdr.length = htons(sizeof(aiparam));
+ aiparam.adaptation_ind = htonl(sp->adaptation_ind);
+ sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
+ }
+
+ /* Add SCTP-AUTH chunks to the parameter list */
+ if (ep->auth_enable) {
+ sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
+ asoc->c.auth_random);
+ if (auth_hmacs)
+ sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
+ auth_hmacs);
+ if (auth_chunks)
+ sctp_addto_chunk(retval, ntohs(auth_chunks->length),
+ auth_chunks);
+ }
+nodata:
+ kfree(addrs.v);
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ gfp_t gfp, int unkparam_len)
+{
+ sctp_inithdr_t initack;
+ struct sctp_chunk *retval;
+ union sctp_params addrs;
+ struct sctp_sock *sp;
+ int addrs_len;
+ sctp_cookie_param_t *cookie;
+ int cookie_len;
+ size_t chunksize;
+ sctp_adaptation_ind_param_t aiparam;
+ sctp_supported_ext_param_t ext_param;
+ int num_ext = 0;
+ __u8 extensions[3];
+ sctp_paramhdr_t *auth_chunks = NULL,
+ *auth_hmacs = NULL,
+ *auth_random = NULL;
+
+ retval = NULL;
+
+ /* Note: there may be no addresses to embed. */
+ addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
+
+ initack.init_tag = htonl(asoc->c.my_vtag);
+ initack.a_rwnd = htonl(asoc->rwnd);
+ initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
+ initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
+ initack.initial_tsn = htonl(asoc->c.initial_tsn);
+
+ /* FIXME: We really ought to build the cookie right
+ * into the packet instead of allocating more fresh memory.
+ */
+ cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
+ addrs.v, addrs_len);
+ if (!cookie)
+ goto nomem_cookie;
+
+ /* Calculate the total size of allocation, include the reserved
+ * space for reporting unknown parameters if it is specified.
+ */
+ sp = sctp_sk(asoc->base.sk);
+ chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
+
+ /* Tell peer that we'll do ECN only if peer advertised such cap. */
+ if (asoc->peer.ecn_capable)
+ chunksize += sizeof(ecap_param);
+
+ if (asoc->peer.prsctp_capable)
+ chunksize += sizeof(prsctp_param);
+
+ if (asoc->peer.asconf_capable) {
+ extensions[num_ext] = SCTP_CID_ASCONF;
+ extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
+ num_ext += 2;
+ }
+
+ if (sp->adaptation_ind)
+ chunksize += sizeof(aiparam);
+
+ if (asoc->peer.auth_capable) {
+ auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
+ chunksize += ntohs(auth_random->length);
+
+ auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
+ if (auth_hmacs->length)
+ chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
+ else
+ auth_hmacs = NULL;
+
+ auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
+ if (auth_chunks->length)
+ chunksize += WORD_ROUND(ntohs(auth_chunks->length));
+ else
+ auth_chunks = NULL;
+
+ extensions[num_ext] = SCTP_CID_AUTH;
+ num_ext += 1;
+ }
+
+ if (num_ext)
+ chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
+ num_ext);
+
+ /* Now allocate and fill out the chunk. */
+ retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
+ if (!retval)
+ goto nomem_chunk;
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [INIT ACK back to where the INIT came from.]
+ */
+ retval->transport = chunk->transport;
+
+ retval->subh.init_hdr =
+ sctp_addto_chunk(retval, sizeof(initack), &initack);
+ retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
+ sctp_addto_chunk(retval, cookie_len, cookie);
+ if (asoc->peer.ecn_capable)
+ sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
+ if (num_ext) {
+ ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
+ ext_param.param_hdr.length =
+ htons(sizeof(sctp_supported_ext_param_t) + num_ext);
+ sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
+ &ext_param);
+ sctp_addto_param(retval, num_ext, extensions);
+ }
+ if (asoc->peer.prsctp_capable)
+ sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
+
+ if (sp->adaptation_ind) {
+ aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
+ aiparam.param_hdr.length = htons(sizeof(aiparam));
+ aiparam.adaptation_ind = htonl(sp->adaptation_ind);
+ sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
+ }
+
+ if (asoc->peer.auth_capable) {
+ sctp_addto_chunk(retval, ntohs(auth_random->length),
+ auth_random);
+ if (auth_hmacs)
+ sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
+ auth_hmacs);
+ if (auth_chunks)
+ sctp_addto_chunk(retval, ntohs(auth_chunks->length),
+ auth_chunks);
+ }
+
+ /* We need to remove the const qualifier at this point. */
+ retval->asoc = (struct sctp_association *) asoc;
+
+nomem_chunk:
+ kfree(cookie);
+nomem_cookie:
+ kfree(addrs.v);
+ return retval;
+}
+
+/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
+ *
+ * This chunk is used only during the initialization of an association.
+ * It is sent by the initiator of an association to its peer to complete
+ * the initialization process. This chunk MUST precede any DATA chunk
+ * sent within the association, but MAY be bundled with one or more DATA
+ * chunks in the same packet.
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 10 |Chunk Flags | Length |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * / Cookie /
+ * \ \
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Chunk Flags: 8 bit
+ *
+ * Set to zero on transmit and ignored on receipt.
+ *
+ * Length: 16 bits (unsigned integer)
+ *
+ * Set to the size of the chunk in bytes, including the 4 bytes of
+ * the chunk header and the size of the Cookie.
+ *
+ * Cookie: variable size
+ *
+ * This field must contain the exact cookie received in the
+ * State Cookie parameter from the previous INIT ACK.
+ *
+ * An implementation SHOULD make the cookie as small as possible
+ * to insure interoperability.
+ */
+struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+ void *cookie;
+ int cookie_len;
+
+ cookie = asoc->peer.cookie;
+ cookie_len = asoc->peer.cookie_len;
+
+ /* Build a cookie echo chunk. */
+ retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
+ if (!retval)
+ goto nodata;
+ retval->subh.cookie_hdr =
+ sctp_addto_chunk(retval, cookie_len, cookie);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [COOKIE ECHO back to where the INIT ACK came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+nodata:
+ return retval;
+}
+
+/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
+ *
+ * This chunk is used only during the initialization of an
+ * association. It is used to acknowledge the receipt of a COOKIE
+ * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
+ * within the association, but MAY be bundled with one or more DATA
+ * chunks or SACK chunk in the same SCTP packet.
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 11 |Chunk Flags | Length = 4 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Chunk Flags: 8 bits
+ *
+ * Set to zero on transmit and ignored on receipt.
+ */
+struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+
+ retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [COOKIE ACK back to where the COOKIE ECHO came from.]
+ */
+ if (retval && chunk)
+ retval->transport = chunk->transport;
+
+ return retval;
+}
+
+/*
+ * 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.
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Lowest TSN Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Note: The CWR is considered a Control chunk.
+ */
+struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
+ const __u32 lowest_tsn,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+ sctp_cwrhdr_t cwr;
+
+ cwr.lowest_tsn = htonl(lowest_tsn);
+ retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
+ sizeof(sctp_cwrhdr_t));
+
+ if (!retval)
+ goto nodata;
+
+ retval->subh.ecn_cwr_hdr =
+ sctp_addto_chunk(retval, sizeof(cwr), &cwr);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [Report a reduced congestion window back to where the ECNE
+ * came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+nodata:
+ return retval;
+}
+
+/* Make an ECNE chunk. This is a congestion experienced report. */
+struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
+ const __u32 lowest_tsn)
+{
+ struct sctp_chunk *retval;
+ sctp_ecnehdr_t ecne;
+
+ ecne.lowest_tsn = htonl(lowest_tsn);
+ retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
+ sizeof(sctp_ecnehdr_t));
+ if (!retval)
+ goto nodata;
+ retval->subh.ecne_hdr =
+ sctp_addto_chunk(retval, sizeof(ecne), &ecne);
+
+nodata:
+ return retval;
+}
+
+/* Make a DATA chunk for the given association from the provided
+ * parameters. However, do not populate the data payload.
+ */
+struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
+ const struct sctp_sndrcvinfo *sinfo,
+ int data_len, __u8 flags, __u16 ssn)
+{
+ struct sctp_chunk *retval;
+ struct sctp_datahdr dp;
+ int chunk_len;
+
+ /* We assign the TSN as LATE as possible, not here when
+ * creating the chunk.
+ */
+ dp.tsn = 0;
+ dp.stream = htons(sinfo->sinfo_stream);
+ dp.ppid = sinfo->sinfo_ppid;
+
+ /* Set the flags for an unordered send. */
+ if (sinfo->sinfo_flags & SCTP_UNORDERED) {
+ flags |= SCTP_DATA_UNORDERED;
+ dp.ssn = 0;
+ } else
+ dp.ssn = htons(ssn);
+
+ chunk_len = sizeof(dp) + data_len;
+ retval = sctp_make_data(asoc, flags, chunk_len);
+ if (!retval)
+ goto nodata;
+
+ retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
+ memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
+
+nodata:
+ return retval;
+}
+
+/* Create a selective ackowledgement (SACK) for the given
+ * association. This reports on which TSN's we've seen to date,
+ * including duplicates and gaps.
+ */
+struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
+{
+ struct sctp_chunk *retval;
+ struct sctp_sackhdr sack;
+ int len;
+ __u32 ctsn;
+ __u16 num_gabs, num_dup_tsns;
+ struct sctp_association *aptr = (struct sctp_association *)asoc;
+ struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
+ struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
+ struct sctp_transport *trans;
+
+ memset(gabs, 0, sizeof(gabs));
+ ctsn = sctp_tsnmap_get_ctsn(map);
+
+ pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
+
+ /* How much room is needed in the chunk? */
+ num_gabs = sctp_tsnmap_num_gabs(map, gabs);
+ num_dup_tsns = sctp_tsnmap_num_dups(map);
+
+ /* Initialize the SACK header. */
+ sack.cum_tsn_ack = htonl(ctsn);
+ sack.a_rwnd = htonl(asoc->a_rwnd);
+ sack.num_gap_ack_blocks = htons(num_gabs);
+ sack.num_dup_tsns = htons(num_dup_tsns);
+
+ len = sizeof(sack)
+ + sizeof(struct sctp_gap_ack_block) * num_gabs
+ + sizeof(__u32) * num_dup_tsns;
+
+ /* Create the chunk. */
+ retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len);
+ if (!retval)
+ goto nodata;
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, etc.) to the same destination transport
+ * address from which it received the DATA or control chunk to
+ * which it is replying. This rule should also be followed if
+ * the endpoint is bundling DATA chunks together with the
+ * reply chunk.
+ *
+ * However, when acknowledging multiple DATA chunks received
+ * in packets from different source addresses in a single
+ * SACK, the SACK chunk may be transmitted to one of the
+ * destination transport addresses from which the DATA or
+ * control chunks being acknowledged were received.
+ *
+ * [BUG: We do not implement the following paragraph.
+ * Perhaps we should remember the last transport we used for a
+ * SACK and avoid that (if possible) if we have seen any
+ * duplicates. --piggy]
+ *
+ * When a receiver of a duplicate DATA chunk sends a SACK to a
+ * multi- homed endpoint it MAY be beneficial to vary the
+ * destination address and not use the source address of the
+ * DATA chunk. The reason being that receiving a duplicate
+ * from a multi-homed endpoint might indicate that the return
+ * path (as specified in the source address of the DATA chunk)
+ * for the SACK is broken.
+ *
+ * [Send to the address from which we last received a DATA chunk.]
+ */
+ retval->transport = asoc->peer.last_data_from;
+
+ retval->subh.sack_hdr =
+ sctp_addto_chunk(retval, sizeof(sack), &sack);
+
+ /* Add the gap ack block information. */
+ if (num_gabs)
+ sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
+ gabs);
+
+ /* Add the duplicate TSN information. */
+ if (num_dup_tsns) {
+ aptr->stats.idupchunks += num_dup_tsns;
+ sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
+ sctp_tsnmap_get_dups(map));
+ }
+ /* Once we have a sack generated, check to see what our sack
+ * generation is, if its 0, reset the transports to 0, and reset
+ * the association generation to 1
+ *
+ * The idea is that zero is never used as a valid generation for the
+ * association so no transport will match after a wrap event like this,
+ * Until the next sack
+ */
+ if (++aptr->peer.sack_generation == 0) {
+ list_for_each_entry(trans, &asoc->peer.transport_addr_list,
+ transports)
+ trans->sack_generation = 0;
+ aptr->peer.sack_generation = 1;
+ }
+nodata:
+ return retval;
+}
+
+/* Make a SHUTDOWN chunk. */
+struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+ sctp_shutdownhdr_t shut;
+ __u32 ctsn;
+
+ ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
+ shut.cum_tsn_ack = htonl(ctsn);
+
+ retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
+ sizeof(sctp_shutdownhdr_t));
+ if (!retval)
+ goto nodata;
+
+ retval->subh.shutdown_hdr =
+ sctp_addto_chunk(retval, sizeof(shut), &shut);
+
+ if (chunk)
+ retval->transport = chunk->transport;
+nodata:
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+
+ retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [ACK back to where the SHUTDOWN came from.]
+ */
+ if (retval && chunk)
+ retval->transport = chunk->transport;
+
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_shutdown_complete(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+ __u8 flags = 0;
+
+ /* Set the T-bit if we have no association (vtag will be
+ * reflected)
+ */
+ flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
+
+ retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
+ * came from.]
+ */
+ if (retval && chunk)
+ retval->transport = chunk->transport;
+
+ return retval;
+}
+
+/* Create an ABORT. Note that we set the T bit if we have no
+ * association, except when responding to an INIT (sctpimpguide 2.41).
+ */
+struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ const size_t hint)
+{
+ struct sctp_chunk *retval;
+ __u8 flags = 0;
+
+ /* Set the T-bit if we have no association and 'chunk' is not
+ * an INIT (vtag will be reflected).
+ */
+ if (!asoc) {
+ if (chunk && chunk->chunk_hdr &&
+ chunk->chunk_hdr->type == SCTP_CID_INIT)
+ flags = 0;
+ else
+ flags = SCTP_CHUNK_FLAG_T;
+ }
+
+ retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [ABORT back to where the offender came from.]
+ */
+ if (retval && chunk)
+ retval->transport = chunk->transport;
+
+ return retval;
+}
+
+/* Helper to create ABORT with a NO_USER_DATA error. */
+struct sctp_chunk *sctp_make_abort_no_data(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk, __u32 tsn)
+{
+ struct sctp_chunk *retval;
+ __be32 payload;
+
+ retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
+ + sizeof(tsn));
+
+ if (!retval)
+ goto no_mem;
+
+ /* Put the tsn back into network byte order. */
+ payload = htonl(tsn);
+ sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
+ sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [ABORT back to where the offender came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+no_mem:
+ return retval;
+}
+
+/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
+struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
+ struct msghdr *msg,
+ size_t paylen)
+{
+ struct sctp_chunk *retval;
+ void *payload = NULL;
+ int err;
+
+ retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
+ if (!retval)
+ goto err_chunk;
+
+ if (paylen) {
+ /* Put the msg_iov together into payload. */
+ payload = kmalloc(paylen, GFP_KERNEL);
+ if (!payload)
+ goto err_payload;
+
+ err = memcpy_from_msg(payload, msg, paylen);
+ if (err < 0)
+ goto err_copy;
+ }
+
+ sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
+ sctp_addto_chunk(retval, paylen, payload);
+
+ if (paylen)
+ kfree(payload);
+
+ return retval;
+
+err_copy:
+ kfree(payload);
+err_payload:
+ sctp_chunk_free(retval);
+ retval = NULL;
+err_chunk:
+ return retval;
+}
+
+/* Append bytes to the end of a parameter. Will panic if chunk is not big
+ * enough.
+ */
+static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
+ const void *data)
+{
+ void *target;
+ int chunklen = ntohs(chunk->chunk_hdr->length);
+
+ target = skb_put(chunk->skb, len);
+
+ if (data)
+ memcpy(target, data, len);
+ else
+ memset(target, 0, len);
+
+ /* Adjust the chunk length field. */
+ chunk->chunk_hdr->length = htons(chunklen + len);
+ chunk->chunk_end = skb_tail_pointer(chunk->skb);
+
+ return target;
+}
+
+/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
+struct sctp_chunk *sctp_make_abort_violation(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ const __u8 *payload,
+ const size_t paylen)
+{
+ struct sctp_chunk *retval;
+ struct sctp_paramhdr phdr;
+
+ retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
+ + sizeof(sctp_paramhdr_t));
+ if (!retval)
+ goto end;
+
+ sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
+ + sizeof(sctp_paramhdr_t));
+
+ phdr.type = htons(chunk->chunk_hdr->type);
+ phdr.length = chunk->chunk_hdr->length;
+ sctp_addto_chunk(retval, paylen, payload);
+ sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
+
+end:
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_violation_paramlen(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ struct sctp_paramhdr *param)
+{
+ struct sctp_chunk *retval;
+ static const char error[] = "The following parameter had invalid length:";
+ size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
+ sizeof(sctp_paramhdr_t);
+
+ retval = sctp_make_abort(asoc, chunk, payload_len);
+ if (!retval)
+ goto nodata;
+
+ sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
+ sizeof(error) + sizeof(sctp_paramhdr_t));
+ sctp_addto_chunk(retval, sizeof(error), error);
+ sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
+
+nodata:
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_violation_max_retrans(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ struct sctp_chunk *retval;
+ static const char error[] = "Association exceeded its max_retans count";
+ size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
+
+ retval = sctp_make_abort(asoc, chunk, payload_len);
+ if (!retval)
+ goto nodata;
+
+ sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
+ sctp_addto_chunk(retval, sizeof(error), error);
+
+nodata:
+ return retval;
+}
+
+/* Make a HEARTBEAT chunk. */
+struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
+ const struct sctp_transport *transport)
+{
+ struct sctp_chunk *retval;
+ sctp_sender_hb_info_t hbinfo;
+
+ retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
+
+ if (!retval)
+ goto nodata;
+
+ hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
+ hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
+ hbinfo.daddr = transport->ipaddr;
+ hbinfo.sent_at = jiffies;
+ hbinfo.hb_nonce = transport->hb_nonce;
+
+ /* Cast away the 'const', as this is just telling the chunk
+ * what transport it belongs to.
+ */
+ retval->transport = (struct sctp_transport *) transport;
+ retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
+ &hbinfo);
+
+nodata:
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ const void *payload, const size_t paylen)
+{
+ struct sctp_chunk *retval;
+
+ retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
+ if (!retval)
+ goto nodata;
+
+ retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, * etc.) to the same destination transport
+ * address from which it * received the DATA or control chunk
+ * to which it is replying.
+ *
+ * [HBACK back to where the HEARTBEAT came from.]
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+nodata:
+ return retval;
+}
+
+/* Create an Operation Error chunk with the specified space reserved.
+ * This routine can be used for containing multiple causes in the chunk.
+ */
+static struct sctp_chunk *sctp_make_op_error_space(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ size_t size)
+{
+ struct sctp_chunk *retval;
+
+ retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
+ sizeof(sctp_errhdr_t) + size);
+ if (!retval)
+ goto nodata;
+
+ /* RFC 2960 6.4 Multi-homed SCTP Endpoints
+ *
+ * An endpoint SHOULD transmit reply chunks (e.g., SACK,
+ * HEARTBEAT ACK, etc.) to the same destination transport
+ * address from which it received the DATA or control chunk
+ * to which it is replying.
+ *
+ */
+ if (chunk)
+ retval->transport = chunk->transport;
+
+nodata:
+ return retval;
+}
+
+/* Create an Operation Error chunk of a fixed size,
+ * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
+ * This is a helper function to allocate an error chunk for
+ * for those invalid parameter codes in which we may not want
+ * to report all the errors, if the incoming chunk is large
+ */
+static inline struct sctp_chunk *sctp_make_op_error_fixed(
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk)
+{
+ size_t size = asoc ? asoc->pathmtu : 0;
+
+ if (!size)
+ size = SCTP_DEFAULT_MAXSEGMENT;
+
+ return sctp_make_op_error_space(asoc, chunk, size);
+}
+
+/* Create an Operation Error chunk. */
+struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
+ const struct sctp_chunk *chunk,
+ __be16 cause_code, const void *payload,
+ size_t paylen, size_t reserve_tail)
+{
+ struct sctp_chunk *retval;
+
+ retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
+ if (!retval)
+ goto nodata;
+
+ sctp_init_cause(retval, cause_code, paylen + reserve_tail);
+ sctp_addto_chunk(retval, paylen, payload);
+ if (reserve_tail)
+ sctp_addto_param(retval, reserve_tail, NULL);
+
+nodata:
+ return retval;
+}
+
+struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
+{
+ struct sctp_chunk *retval;
+ struct sctp_hmac *hmac_desc;
+ struct sctp_authhdr auth_hdr;
+ __u8 *hmac;
+
+ /* Get the first hmac that the peer told us to use */
+ hmac_desc = sctp_auth_asoc_get_hmac(asoc);
+ if (unlikely(!hmac_desc))
+ return NULL;
+
+ retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
+ hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
+ if (!retval)
+ return NULL;
+
+ auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
+ auth_hdr.shkey_id = htons(asoc->active_key_id);
+
+ retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
+ &auth_hdr);
+
+ hmac = skb_put(retval->skb, hmac_desc->hmac_len);
+ memset(hmac, 0, hmac_desc->hmac_len);
+
+ /* Adjust the chunk header to include the empty MAC */
+ retval->chunk_hdr->length =
+ htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
+ retval->chunk_end = skb_tail_pointer(retval->skb);
+
+ return retval;
+}
+
+
+/********************************************************************
+ * 2nd Level Abstractions
+ ********************************************************************/
+
+/* Turn an skb into a chunk.
+ * FIXME: Eventually move the structure directly inside the skb->cb[].
+ *
+ * sctpimpguide-05.txt Section 2.8.2
+ * M1) Each time a new DATA chunk is transmitted
+ * set the 'TSN.Missing.Report' count for that TSN to 0. The
+ * 'TSN.Missing.Report' count will be used to determine missing chunks
+ * and when to fast retransmit.
+ *
+ */
+struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
+ const struct sctp_association *asoc,
+ struct sock *sk)
+{
+ struct sctp_chunk *retval;
+
+ retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
+
+ if (!retval)
+ goto nodata;
+ if (!sk)
+ pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
+
+ INIT_LIST_HEAD(&retval->list);
+ retval->skb = skb;
+ retval->asoc = (struct sctp_association *)asoc;
+ retval->singleton = 1;
+
+ retval->fast_retransmit = SCTP_CAN_FRTX;
+
+ /* Polish the bead hole. */
+ INIT_LIST_HEAD(&retval->transmitted_list);
+ INIT_LIST_HEAD(&retval->frag_list);
+ SCTP_DBG_OBJCNT_INC(chunk);
+ atomic_set(&retval->refcnt, 1);
+
+nodata:
+ return retval;
+}
+
+/* Set chunk->source and dest based on the IP header in chunk->skb. */
+void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
+ union sctp_addr *dest)
+{
+ memcpy(&chunk->source, src, sizeof(union sctp_addr));
+ memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
+}
+
+/* Extract the source address from a chunk. */
+const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
+{
+ /* If we have a known transport, use that. */
+ if (chunk->transport) {
+ return &chunk->transport->ipaddr;
+ } else {
+ /* Otherwise, extract it from the IP header. */
+ return &chunk->source;
+ }
+}
+
+/* Create a new chunk, setting the type and flags headers from the
+ * arguments, reserving enough space for a 'paylen' byte payload.
+ */
+static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
+ __u8 type, __u8 flags, int paylen)
+{
+ struct sctp_chunk *retval;
+ sctp_chunkhdr_t *chunk_hdr;
+ struct sk_buff *skb;
+ struct sock *sk;
+
+ /* No need to allocate LL here, as this is only a chunk. */
+ skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
+ GFP_ATOMIC);
+ if (!skb)
+ goto nodata;
+
+ /* Make room for the chunk header. */
+ chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
+ chunk_hdr->type = type;
+ chunk_hdr->flags = flags;
+ chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
+
+ sk = asoc ? asoc->base.sk : NULL;
+ retval = sctp_chunkify(skb, asoc, sk);
+ if (!retval) {
+ kfree_skb(skb);
+ goto nodata;
+ }
+
+ retval->chunk_hdr = chunk_hdr;
+ retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
+
+ /* Determine if the chunk needs to be authenticated */
+ if (sctp_auth_send_cid(type, asoc))
+ retval->auth = 1;
+
+ return retval;
+nodata:
+ return NULL;
+}
+
+static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
+ __u8 flags, int paylen)
+{
+ return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen);
+}
+
+static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
+ __u8 type, __u8 flags, int paylen)
+{
+ struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen);
+
+ if (chunk)
+ sctp_control_set_owner_w(chunk);
+
+ return chunk;
+}
+
+/* Release the memory occupied by a chunk. */
+static void sctp_chunk_destroy(struct sctp_chunk *chunk)
+{
+ BUG_ON(!list_empty(&chunk->list));
+ list_del_init(&chunk->transmitted_list);
+
+ consume_skb(chunk->skb);
+ consume_skb(chunk->auth_chunk);
+
+ SCTP_DBG_OBJCNT_DEC(chunk);
+ kmem_cache_free(sctp_chunk_cachep, chunk);
+}
+
+/* Possibly, free the chunk. */
+void sctp_chunk_free(struct sctp_chunk *chunk)
+{
+ /* Release our reference on the message tracker. */
+ if (chunk->msg)
+ sctp_datamsg_put(chunk->msg);
+
+ sctp_chunk_put(chunk);
+}
+
+/* Grab a reference to the chunk. */
+void sctp_chunk_hold(struct sctp_chunk *ch)
+{
+ atomic_inc(&ch->refcnt);
+}
+
+/* Release a reference to the chunk. */
+void sctp_chunk_put(struct sctp_chunk *ch)
+{
+ if (atomic_dec_and_test(&ch->refcnt))
+ sctp_chunk_destroy(ch);
+}
+
+/* Append bytes to the end of a chunk. Will panic if chunk is not big
+ * enough.
+ */
+void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
+{
+ void *target;
+ void *padding;
+ int chunklen = ntohs(chunk->chunk_hdr->length);
+ int padlen = WORD_ROUND(chunklen) - chunklen;
+
+ padding = skb_put(chunk->skb, padlen);
+ target = skb_put(chunk->skb, len);
+
+ memset(padding, 0, padlen);
+ memcpy(target, data, len);
+
+ /* Adjust the chunk length field. */
+ chunk->chunk_hdr->length = htons(chunklen + padlen + len);
+ chunk->chunk_end = skb_tail_pointer(chunk->skb);
+
+ return target;
+}
+
+/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
+ * space in the chunk
+ */
+static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
+ int len, const void *data)
+{
+ if (skb_tailroom(chunk->skb) >= len)
+ return sctp_addto_chunk(chunk, len, data);
+ else
+ return NULL;
+}
+
+/* Append bytes from user space to the end of a chunk. Will panic if
+ * chunk is not big enough.
+ * Returns a kernel err value.
+ */
+int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
+ struct iov_iter *from)
+{
+ void *target;
+ ssize_t copied;
+
+ /* Make room in chunk for data. */
+ target = skb_put(chunk->skb, len);
+
+ /* Copy data (whole iovec) into chunk */
+ copied = copy_from_iter(target, len, from);
+ if (copied != len)
+ return -EFAULT;
+
+ /* Adjust the chunk length field. */
+ chunk->chunk_hdr->length =
+ htons(ntohs(chunk->chunk_hdr->length) + len);
+ chunk->chunk_end = skb_tail_pointer(chunk->skb);
+
+ return 0;
+}
+
+/* Helper function to assign a TSN if needed. This assumes that both
+ * the data_hdr and association have already been assigned.
+ */
+void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
+{
+ struct sctp_datamsg *msg;
+ struct sctp_chunk *lchunk;
+ struct sctp_stream *stream;
+ __u16 ssn;
+ __u16 sid;
+
+ if (chunk->has_ssn)
+ return;
+
+ /* All fragments will be on the same stream */
+ sid = ntohs(chunk->subh.data_hdr->stream);
+ stream = &chunk->asoc->ssnmap->out;
+
+ /* Now assign the sequence number to the entire message.
+ * All fragments must have the same stream sequence number.
+ */
+ msg = chunk->msg;
+ list_for_each_entry(lchunk, &msg->chunks, frag_list) {
+ if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
+ ssn = 0;
+ } else {
+ if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
+ ssn = sctp_ssn_next(stream, sid);
+ else
+ ssn = sctp_ssn_peek(stream, sid);
+ }
+
+ lchunk->subh.data_hdr->ssn = htons(ssn);
+ lchunk->has_ssn = 1;
+ }
+}
+
+/* Helper function to assign a TSN if needed. This assumes that both
+ * the data_hdr and association have already been assigned.
+ */
+void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
+{
+ if (!chunk->has_tsn) {
+ /* This is the last possible instant to
+ * assign a TSN.
+ */
+ chunk->subh.data_hdr->tsn =
+ htonl(sctp_association_get_next_tsn(chunk->asoc));
+ chunk->has_tsn = 1;
+ }
+}
+
+/* Create a CLOSED association to use with an incoming packet. */
+struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
+ struct sctp_chunk *chunk,
+ gfp_t gfp)
+{
+ struct sctp_association *asoc;
+ struct sk_buff *skb;
+ sctp_scope_t scope;
+ struct sctp_af *af;
+
+ /* Create the bare association. */
+ scope = sctp_scope(sctp_source(chunk));
+ asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
+ if (!asoc)
+ goto nodata;
+ asoc->temp = 1;
+ skb = chunk->skb;
+ /* Create an entry for the source address of the packet. */
+ af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
+ if (unlikely(!af))
+ goto fail;
+ af->from_skb(&asoc->c.peer_addr, skb, 1);
+nodata:
+ return asoc;
+
+fail:
+ sctp_association_free(asoc);
+ return NULL;
+}
+
+/* Build a cookie representing asoc.
+ * This INCLUDES the param header needed to put the cookie in the INIT ACK.
+ */
+static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ const struct sctp_chunk *init_chunk,
+ int *cookie_len,
+ const __u8 *raw_addrs, int addrs_len)
+{
+ sctp_cookie_param_t *retval;
+ struct sctp_signed_cookie *cookie;
+ struct scatterlist sg;
+ int headersize, bodysize;
+
+ /* Header size is static data prior to the actual cookie, including
+ * any padding.
+ */
+ headersize = sizeof(sctp_paramhdr_t) +
+ (sizeof(struct sctp_signed_cookie) -
+ sizeof(struct sctp_cookie));
+ bodysize = sizeof(struct sctp_cookie)
+ + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
+
+ /* Pad out the cookie to a multiple to make the signature
+ * functions simpler to write.
+ */
+ if (bodysize % SCTP_COOKIE_MULTIPLE)
+ bodysize += SCTP_COOKIE_MULTIPLE
+ - (bodysize % SCTP_COOKIE_MULTIPLE);
+ *cookie_len = headersize + bodysize;
+
+ /* Clear this memory since we are sending this data structure
+ * out on the network.
+ */
+ retval = kzalloc(*cookie_len, GFP_ATOMIC);
+ if (!retval)
+ goto nodata;
+
+ cookie = (struct sctp_signed_cookie *) retval->body;
+
+ /* Set up the parameter header. */
+ retval->p.type = SCTP_PARAM_STATE_COOKIE;
+ retval->p.length = htons(*cookie_len);
+
+ /* Copy the cookie part of the association itself. */
+ cookie->c = asoc->c;
+ /* Save the raw address list length in the cookie. */
+ cookie->c.raw_addr_list_len = addrs_len;
+
+ /* Remember PR-SCTP capability. */
+ cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
+
+ /* Save adaptation indication in the cookie. */
+ cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
+
+ /* Set an expiration time for the cookie. */
+ cookie->c.expiration = ktime_add(asoc->cookie_life,
+ ktime_get());
+
+ /* Copy the peer's init packet. */
+ memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
+ ntohs(init_chunk->chunk_hdr->length));
+
+ /* Copy the raw local address list of the association. */
+ memcpy((__u8 *)&cookie->c.peer_init[0] +
+ ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
+
+ if (sctp_sk(ep->base.sk)->hmac) {
+ struct hash_desc desc;
+
+ /* Sign the message. */
+ sg_init_one(&sg, &cookie->c, bodysize);
+ desc.tfm = sctp_sk(ep->base.sk)->hmac;
+ desc.flags = 0;
+
+ if (crypto_hash_setkey(desc.tfm, ep->secret_key,
+ sizeof(ep->secret_key)) ||
+ crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
+ goto free_cookie;
+ }
+
+ return retval;
+
+free_cookie:
+ kfree(retval);
+nodata:
+ *cookie_len = 0;
+ return NULL;
+}
+
+/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
+struct sctp_association *sctp_unpack_cookie(
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ struct sctp_chunk *chunk, gfp_t gfp,
+ int *error, struct sctp_chunk **errp)
+{
+ struct sctp_association *retval = NULL;
+ struct sctp_signed_cookie *cookie;
+ struct sctp_cookie *bear_cookie;
+ int headersize, bodysize, fixed_size;
+ __u8 *digest = ep->digest;
+ struct scatterlist sg;
+ unsigned int len;
+ sctp_scope_t scope;
+ struct sk_buff *skb = chunk->skb;
+ ktime_t kt;
+ struct hash_desc desc;
+
+ /* Header size is static data prior to the actual cookie, including
+ * any padding.
+ */
+ headersize = sizeof(sctp_chunkhdr_t) +
+ (sizeof(struct sctp_signed_cookie) -
+ sizeof(struct sctp_cookie));
+ bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
+ fixed_size = headersize + sizeof(struct sctp_cookie);
+
+ /* Verify that the chunk looks like it even has a cookie.
+ * There must be enough room for our cookie and our peer's
+ * INIT chunk.
+ */
+ len = ntohs(chunk->chunk_hdr->length);
+ if (len < fixed_size + sizeof(struct sctp_chunkhdr))
+ goto malformed;
+
+ /* Verify that the cookie has been padded out. */
+ if (bodysize % SCTP_COOKIE_MULTIPLE)
+ goto malformed;
+
+ /* Process the cookie. */
+ cookie = chunk->subh.cookie_hdr;
+ bear_cookie = &cookie->c;
+
+ if (!sctp_sk(ep->base.sk)->hmac)
+ goto no_hmac;
+
+ /* Check the signature. */
+ sg_init_one(&sg, bear_cookie, bodysize);
+ desc.tfm = sctp_sk(ep->base.sk)->hmac;
+ desc.flags = 0;
+
+ memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
+ if (crypto_hash_setkey(desc.tfm, ep->secret_key,
+ sizeof(ep->secret_key)) ||
+ crypto_hash_digest(&desc, &sg, bodysize, digest)) {
+ *error = -SCTP_IERROR_NOMEM;
+ goto fail;
+ }
+
+ if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
+ *error = -SCTP_IERROR_BAD_SIG;
+ goto fail;
+ }
+
+no_hmac:
+ /* IG Section 2.35.2:
+ * 3) Compare the port numbers and the verification tag contained
+ * within the COOKIE ECHO chunk to the actual port numbers and the
+ * verification tag within the SCTP common header of the received
+ * packet. If these values do not match the packet MUST be silently
+ * discarded,
+ */
+ if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
+ *error = -SCTP_IERROR_BAD_TAG;
+ goto fail;
+ }
+
+ if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
+ ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
+ *error = -SCTP_IERROR_BAD_PORTS;
+ goto fail;
+ }
+
+ /* Check to see if the cookie is stale. If there is already
+ * an association, there is no need to check cookie's expiration
+ * for init collision case of lost COOKIE ACK.
+ * If skb has been timestamped, then use the stamp, otherwise
+ * use current time. This introduces a small possibility that
+ * that a cookie may be considered expired, but his would only slow
+ * down the new association establishment instead of every packet.
+ */
+ if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
+ kt = skb_get_ktime(skb);
+ else
+ kt = ktime_get();
+
+ if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
+ /*
+ * Section 3.3.10.3 Stale Cookie Error (3)
+ *
+ * Cause of error
+ * ---------------
+ * Stale Cookie Error: Indicates the receipt of a valid State
+ * Cookie that has expired.
+ */
+ len = ntohs(chunk->chunk_hdr->length);
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+ if (*errp) {
+ suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
+ __be32 n = htonl(usecs);
+
+ sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
+ sizeof(n));
+ sctp_addto_chunk(*errp, sizeof(n), &n);
+ *error = -SCTP_IERROR_STALE_COOKIE;
+ } else
+ *error = -SCTP_IERROR_NOMEM;
+
+ goto fail;
+ }
+
+ /* Make a new base association. */
+ scope = sctp_scope(sctp_source(chunk));
+ retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
+ if (!retval) {
+ *error = -SCTP_IERROR_NOMEM;
+ goto fail;
+ }
+
+ /* Set up our peer's port number. */
+ retval->peer.port = ntohs(chunk->sctp_hdr->source);
+
+ /* Populate the association from the cookie. */
+ memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
+
+ if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
+ GFP_ATOMIC) < 0) {
+ *error = -SCTP_IERROR_NOMEM;
+ goto fail;
+ }
+
+ /* Also, add the destination address. */
+ if (list_empty(&retval->base.bind_addr.address_list)) {
+ sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
+ SCTP_ADDR_SRC, GFP_ATOMIC);
+ }
+
+ retval->next_tsn = retval->c.initial_tsn;
+ retval->ctsn_ack_point = retval->next_tsn - 1;
+ retval->addip_serial = retval->c.initial_tsn;
+ retval->adv_peer_ack_point = retval->ctsn_ack_point;
+ retval->peer.prsctp_capable = retval->c.prsctp_capable;
+ retval->peer.adaptation_ind = retval->c.adaptation_ind;
+
+ /* The INIT stuff will be done by the side effects. */
+ return retval;
+
+fail:
+ if (retval)
+ sctp_association_free(retval);
+
+ return NULL;
+
+malformed:
+ /* Yikes! The packet is either corrupt or deliberately
+ * malformed.
+ */
+ *error = -SCTP_IERROR_MALFORMED;
+ goto fail;
+}
+
+/********************************************************************
+ * 3rd Level Abstractions
+ ********************************************************************/
+
+struct __sctp_missing {
+ __be32 num_missing;
+ __be16 type;
+} __packed;
+
+/*
+ * Report a missing mandatory parameter.
+ */
+static int sctp_process_missing_param(const struct sctp_association *asoc,
+ sctp_param_t paramtype,
+ struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ struct __sctp_missing report;
+ __u16 len;
+
+ len = WORD_ROUND(sizeof(report));
+
+ /* Make an ERROR chunk, preparing enough room for
+ * returning multiple unknown parameters.
+ */
+ if (!*errp)
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+
+ if (*errp) {
+ report.num_missing = htonl(1);
+ report.type = paramtype;
+ sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
+ sizeof(report));
+ sctp_addto_chunk(*errp, sizeof(report), &report);
+ }
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+/* Report an Invalid Mandatory Parameter. */
+static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
+ struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ /* Invalid Mandatory Parameter Error has no payload. */
+
+ if (!*errp)
+ *errp = sctp_make_op_error_space(asoc, chunk, 0);
+
+ if (*errp)
+ sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
+ struct sctp_paramhdr *param,
+ const struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ /* This is a fatal error. Any accumulated non-fatal errors are
+ * not reported.
+ */
+ if (*errp)
+ sctp_chunk_free(*errp);
+
+ /* Create an error chunk and fill it in with our payload. */
+ *errp = sctp_make_violation_paramlen(asoc, chunk, param);
+
+ return 0;
+}
+
+
+/* Do not attempt to handle the HOST_NAME parm. However, do
+ * send back an indicator to the peer.
+ */
+static int sctp_process_hn_param(const struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ __u16 len = ntohs(param.p->length);
+
+ /* Processing of the HOST_NAME parameter will generate an
+ * ABORT. If we've accumulated any non-fatal errors, they
+ * would be unrecognized parameters and we should not include
+ * them in the ABORT.
+ */
+ if (*errp)
+ sctp_chunk_free(*errp);
+
+ *errp = sctp_make_op_error_space(asoc, chunk, len);
+
+ if (*errp) {
+ sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
+ sctp_addto_chunk(*errp, len, param.v);
+ }
+
+ /* Stop processing this chunk. */
+ return 0;
+}
+
+static int sctp_verify_ext_param(struct net *net, union sctp_params param)
+{
+ __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ int have_auth = 0;
+ int have_asconf = 0;
+ int i;
+
+ for (i = 0; i < num_ext; i++) {
+ switch (param.ext->chunks[i]) {
+ case SCTP_CID_AUTH:
+ have_auth = 1;
+ break;
+ case SCTP_CID_ASCONF:
+ case SCTP_CID_ASCONF_ACK:
+ have_asconf = 1;
+ break;
+ }
+ }
+
+ /* ADD-IP Security: The draft requires us to ABORT or ignore the
+ * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
+ * only if ADD-IP is turned on and we are not backward-compatible
+ * mode.
+ */
+ if (net->sctp.addip_noauth)
+ return 1;
+
+ if (net->sctp.addip_enable && !have_auth && have_asconf)
+ return 0;
+
+ return 1;
+}
+
+static void sctp_process_ext_param(struct sctp_association *asoc,
+ union sctp_params param)
+{
+ struct net *net = sock_net(asoc->base.sk);
+ __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ int i;
+
+ for (i = 0; i < num_ext; i++) {
+ switch (param.ext->chunks[i]) {
+ case SCTP_CID_FWD_TSN:
+ if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
+ asoc->peer.prsctp_capable = 1;
+ break;
+ case SCTP_CID_AUTH:
+ /* if the peer reports AUTH, assume that he
+ * supports AUTH.
+ */
+ if (asoc->ep->auth_enable)
+ asoc->peer.auth_capable = 1;
+ break;
+ case SCTP_CID_ASCONF:
+ case SCTP_CID_ASCONF_ACK:
+ if (net->sctp.addip_enable)
+ asoc->peer.asconf_capable = 1;
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+/* RFC 3.2.1 & the Implementers Guide 2.2.
+ *
+ * The Parameter 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
+ * Parameter Type.
+ *
+ * 00 - Stop processing this parameter; do not process any further
+ * parameters within this chunk
+ *
+ * 01 - Stop processing this parameter, do not process any further
+ * parameters within this chunk, and report the unrecognized
+ * parameter in an 'Unrecognized Parameter' ERROR chunk.
+ *
+ * 10 - Skip this parameter and continue processing.
+ *
+ * 11 - Skip this parameter and continue processing but
+ * report the unrecognized parameter in an
+ * 'Unrecognized Parameter' ERROR chunk.
+ *
+ * Return value:
+ * SCTP_IERROR_NO_ERROR - continue with the chunk
+ * SCTP_IERROR_ERROR - stop and report an error.
+ * SCTP_IERROR_NOMEME - out of memory.
+ */
+static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ int retval = SCTP_IERROR_NO_ERROR;
+
+ switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
+ case SCTP_PARAM_ACTION_DISCARD:
+ retval = SCTP_IERROR_ERROR;
+ break;
+ case SCTP_PARAM_ACTION_SKIP:
+ break;
+ case SCTP_PARAM_ACTION_DISCARD_ERR:
+ retval = SCTP_IERROR_ERROR;
+ /* Fall through */
+ case SCTP_PARAM_ACTION_SKIP_ERR:
+ /* Make an ERROR chunk, preparing enough room for
+ * returning multiple unknown parameters.
+ */
+ if (NULL == *errp)
+ *errp = sctp_make_op_error_fixed(asoc, chunk);
+
+ if (*errp) {
+ if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
+ WORD_ROUND(ntohs(param.p->length))))
+ sctp_addto_chunk_fixed(*errp,
+ WORD_ROUND(ntohs(param.p->length)),
+ param.v);
+ } else {
+ /* If there is no memory for generating the ERROR
+ * report as specified, an ABORT will be triggered
+ * to the peer and the association won't be
+ * established.
+ */
+ retval = SCTP_IERROR_NOMEM;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return retval;
+}
+
+/* Verify variable length parameters
+ * Return values:
+ * SCTP_IERROR_ABORT - trigger an ABORT
+ * SCTP_IERROR_NOMEM - out of memory (abort)
+ * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
+ * SCTP_IERROR_NO_ERROR - continue with the chunk
+ */
+static sctp_ierror_t sctp_verify_param(struct net *net,
+ const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc,
+ union sctp_params param,
+ sctp_cid_t cid,
+ struct sctp_chunk *chunk,
+ struct sctp_chunk **err_chunk)
+{
+ struct sctp_hmac_algo_param *hmacs;
+ int retval = SCTP_IERROR_NO_ERROR;
+ __u16 n_elt, id = 0;
+ int i;
+
+ /* FIXME - This routine is not looking at each parameter per the
+ * chunk type, i.e., unrecognized parameters should be further
+ * identified based on the chunk id.
+ */
+
+ switch (param.p->type) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ case SCTP_PARAM_IPV6_ADDRESS:
+ case SCTP_PARAM_COOKIE_PRESERVATIVE:
+ case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
+ case SCTP_PARAM_STATE_COOKIE:
+ case SCTP_PARAM_HEARTBEAT_INFO:
+ case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
+ case SCTP_PARAM_ECN_CAPABLE:
+ case SCTP_PARAM_ADAPTATION_LAYER_IND:
+ break;
+
+ case SCTP_PARAM_SUPPORTED_EXT:
+ if (!sctp_verify_ext_param(net, param))
+ return SCTP_IERROR_ABORT;
+ break;
+
+ case SCTP_PARAM_SET_PRIMARY:
+ if (net->sctp.addip_enable)
+ break;
+ goto fallthrough;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ /* Tell the peer, we won't support this param. */
+ sctp_process_hn_param(asoc, param, chunk, err_chunk);
+ retval = SCTP_IERROR_ABORT;
+ break;
+
+ case SCTP_PARAM_FWD_TSN_SUPPORT:
+ if (net->sctp.prsctp_enable)
+ break;
+ goto fallthrough;
+
+ case SCTP_PARAM_RANDOM:
+ if (!ep->auth_enable)
+ goto fallthrough;
+
+ /* SCTP-AUTH: Secion 6.1
+ * If the random number is not 32 byte long the association
+ * MUST be aborted. The ABORT chunk SHOULD contain the error
+ * cause 'Protocol Violation'.
+ */
+ if (SCTP_AUTH_RANDOM_LENGTH !=
+ ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
+ sctp_process_inv_paramlength(asoc, param.p,
+ chunk, err_chunk);
+ retval = SCTP_IERROR_ABORT;
+ }
+ break;
+
+ case SCTP_PARAM_CHUNKS:
+ if (!ep->auth_enable)
+ goto fallthrough;
+
+ /* SCTP-AUTH: Section 3.2
+ * The CHUNKS parameter MUST be included once in the INIT or
+ * INIT-ACK chunk if the sender wants to receive authenticated
+ * chunks. Its maximum length is 260 bytes.
+ */
+ if (260 < ntohs(param.p->length)) {
+ sctp_process_inv_paramlength(asoc, param.p,
+ chunk, err_chunk);
+ retval = SCTP_IERROR_ABORT;
+ }
+ break;
+
+ case SCTP_PARAM_HMAC_ALGO:
+ if (!ep->auth_enable)
+ goto fallthrough;
+
+ hmacs = (struct sctp_hmac_algo_param *)param.p;
+ n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
+
+ /* SCTP-AUTH: Section 6.1
+ * The HMAC algorithm based on SHA-1 MUST be supported and
+ * included in the HMAC-ALGO parameter.
+ */
+ for (i = 0; i < n_elt; i++) {
+ id = ntohs(hmacs->hmac_ids[i]);
+
+ if (id == SCTP_AUTH_HMAC_ID_SHA1)
+ break;
+ }
+
+ if (id != SCTP_AUTH_HMAC_ID_SHA1) {
+ sctp_process_inv_paramlength(asoc, param.p, chunk,
+ err_chunk);
+ retval = SCTP_IERROR_ABORT;
+ }
+ break;
+fallthrough:
+ default:
+ pr_debug("%s: unrecognized param:%d for chunk:%d\n",
+ __func__, ntohs(param.p->type), cid);
+
+ retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
+ break;
+ }
+ return retval;
+}
+
+/* Verify the INIT packet before we process it. */
+int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
+ const struct sctp_association *asoc, sctp_cid_t cid,
+ sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
+ struct sctp_chunk **errp)
+{
+ union sctp_params param;
+ bool has_cookie = false;
+ int result;
+
+ /* Check for missing mandatory parameters. Note: Initial TSN is
+ * also mandatory, but is not checked here since the valid range
+ * is 0..2**32-1. RFC4960, section 3.3.3.
+ */
+ if (peer_init->init_hdr.num_outbound_streams == 0 ||
+ peer_init->init_hdr.num_inbound_streams == 0 ||
+ peer_init->init_hdr.init_tag == 0 ||
+ ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
+ return sctp_process_inv_mandatory(asoc, chunk, errp);
+
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+ if (param.p->type == SCTP_PARAM_STATE_COOKIE)
+ has_cookie = true;
+ }
+
+ /* There is a possibility that a parameter length was bad and
+ * in that case we would have stoped walking the parameters.
+ * The current param.p would point at the bad one.
+ * Current consensus on the mailing list is to generate a PROTOCOL
+ * VIOLATION error. We build the ERROR chunk here and let the normal
+ * error handling code build and send the packet.
+ */
+ if (param.v != (void *)chunk->chunk_end)
+ return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
+
+ /* The only missing mandatory param possible today is
+ * the state cookie for an INIT-ACK chunk.
+ */
+ if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
+ return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
+ chunk, errp);
+
+ /* Verify all the variable length parameters */
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+ result = sctp_verify_param(net, ep, asoc, param, cid,
+ chunk, errp);
+ switch (result) {
+ case SCTP_IERROR_ABORT:
+ case SCTP_IERROR_NOMEM:
+ return 0;
+ case SCTP_IERROR_ERROR:
+ return 1;
+ case SCTP_IERROR_NO_ERROR:
+ default:
+ break;
+ }
+
+ } /* for (loop through all parameters) */
+
+ return 1;
+}
+
+/* Unpack the parameters in an INIT packet into an association.
+ * Returns 0 on failure, else success.
+ * FIXME: This is an association method.
+ */
+int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
+ const union sctp_addr *peer_addr,
+ sctp_init_chunk_t *peer_init, gfp_t gfp)
+{
+ struct net *net = sock_net(asoc->base.sk);
+ union sctp_params param;
+ struct sctp_transport *transport;
+ struct list_head *pos, *temp;
+ struct sctp_af *af;
+ union sctp_addr addr;
+ char *cookie;
+ int src_match = 0;
+
+ /* We must include the address that the INIT packet came from.
+ * This is the only address that matters for an INIT packet.
+ * When processing a COOKIE ECHO, we retrieve the from address
+ * of the INIT from the cookie.
+ */
+
+ /* This implementation defaults to making the first transport
+ * added as the primary transport. The source address seems to
+ * be a a better choice than any of the embedded addresses.
+ */
+ if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
+ goto nomem;
+
+ if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
+ src_match = 1;
+
+ /* Process the initialization parameters. */
+ sctp_walk_params(param, peer_init, init_hdr.params) {
+ if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
+ param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
+ af = sctp_get_af_specific(param_type2af(param.p->type));
+ af->from_addr_param(&addr, param.addr,
+ chunk->sctp_hdr->source, 0);
+ if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
+ src_match = 1;
+ }
+
+ if (!sctp_process_param(asoc, param, peer_addr, gfp))
+ goto clean_up;
+ }
+
+ /* source address of chunk may not match any valid address */
+ if (!src_match)
+ goto clean_up;
+
+ /* AUTH: After processing the parameters, make sure that we
+ * have all the required info to potentially do authentications.
+ */
+ if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
+ !asoc->peer.peer_hmacs))
+ asoc->peer.auth_capable = 0;
+
+ /* In a non-backward compatible mode, if the peer claims
+ * support for ADD-IP but not AUTH, the ADD-IP spec states
+ * that we MUST ABORT the association. Section 6. The section
+ * also give us an option to silently ignore the packet, which
+ * is what we'll do here.
+ */
+ if (!net->sctp.addip_noauth &&
+ (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
+ asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
+ SCTP_PARAM_DEL_IP |
+ SCTP_PARAM_SET_PRIMARY);
+ asoc->peer.asconf_capable = 0;
+ goto clean_up;
+ }
+
+ /* Walk list of transports, removing transports in the UNKNOWN state. */
+ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
+ transport = list_entry(pos, struct sctp_transport, transports);
+ if (transport->state == SCTP_UNKNOWN) {
+ sctp_assoc_rm_peer(asoc, transport);
+ }
+ }
+
+ /* The fixed INIT headers are always in network byte
+ * order.
+ */
+ asoc->peer.i.init_tag =
+ ntohl(peer_init->init_hdr.init_tag);
+ asoc->peer.i.a_rwnd =
+ ntohl(peer_init->init_hdr.a_rwnd);
+ asoc->peer.i.num_outbound_streams =
+ ntohs(peer_init->init_hdr.num_outbound_streams);
+ asoc->peer.i.num_inbound_streams =
+ ntohs(peer_init->init_hdr.num_inbound_streams);
+ asoc->peer.i.initial_tsn =
+ ntohl(peer_init->init_hdr.initial_tsn);
+
+ /* Apply the upper bounds for output streams based on peer's
+ * number of inbound streams.
+ */
+ if (asoc->c.sinit_num_ostreams >
+ ntohs(peer_init->init_hdr.num_inbound_streams)) {
+ asoc->c.sinit_num_ostreams =
+ ntohs(peer_init->init_hdr.num_inbound_streams);
+ }
+
+ if (asoc->c.sinit_max_instreams >
+ ntohs(peer_init->init_hdr.num_outbound_streams)) {
+ asoc->c.sinit_max_instreams =
+ ntohs(peer_init->init_hdr.num_outbound_streams);
+ }
+
+ /* Copy Initiation tag from INIT to VT_peer in cookie. */
+ asoc->c.peer_vtag = asoc->peer.i.init_tag;
+
+ /* Peer Rwnd : Current calculated value of the peer's rwnd. */
+ asoc->peer.rwnd = asoc->peer.i.a_rwnd;
+
+ /* Copy cookie in case we need to resend COOKIE-ECHO. */
+ cookie = asoc->peer.cookie;
+ if (cookie) {
+ asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
+ if (!asoc->peer.cookie)
+ goto clean_up;
+ }
+
+ /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
+ * high (for example, implementations MAY use the size of the receiver
+ * advertised window).
+ */
+ list_for_each_entry(transport, &asoc->peer.transport_addr_list,
+ transports) {
+ transport->ssthresh = asoc->peer.i.a_rwnd;
+ }
+
+ /* Set up the TSN tracking pieces. */
+ if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
+ asoc->peer.i.initial_tsn, gfp))
+ goto clean_up;
+
+ /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
+ *
+ * The stream sequence number in all the streams shall start
+ * from 0 when the association is established. Also, when the
+ * stream sequence number reaches the value 65535 the next
+ * stream sequence number shall be set to 0.
+ */
+
+ /* Allocate storage for the negotiated streams if it is not a temporary
+ * association.
+ */
+ if (!asoc->temp) {
+ int error;
+
+ asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
+ asoc->c.sinit_num_ostreams, gfp);
+ if (!asoc->ssnmap)
+ goto clean_up;
+
+ error = sctp_assoc_set_id(asoc, gfp);
+ if (error)
+ goto clean_up;
+ }
+
+ /* 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 the following:
+ * ...
+ * A2) A serial number should be assigned to the Chunk. The serial
+ * number should be a monotonically increasing number. All serial
+ * numbers are defined to be initialized at the start of the
+ * association to the same value as the Initial TSN.
+ */
+ asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
+ return 1;
+
+clean_up:
+ /* Release the transport structures. */
+ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
+ transport = list_entry(pos, struct sctp_transport, transports);
+ if (transport->state != SCTP_ACTIVE)
+ sctp_assoc_rm_peer(asoc, transport);
+ }
+
+nomem:
+ return 0;
+}
+
+
+/* Update asoc with the option described in param.
+ *
+ * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
+ *
+ * asoc is the association to update.
+ * param is the variable length parameter to use for update.
+ * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
+ * If the current packet is an INIT we want to minimize the amount of
+ * work we do. In particular, we should not build transport
+ * structures for the addresses.
+ */
+static int sctp_process_param(struct sctp_association *asoc,
+ union sctp_params param,
+ const union sctp_addr *peer_addr,
+ gfp_t gfp)
+{
+ struct net *net = sock_net(asoc->base.sk);
+ union sctp_addr addr;
+ int i;
+ __u16 sat;
+ int retval = 1;
+ sctp_scope_t scope;
+ time_t stale;
+ struct sctp_af *af;
+ union sctp_addr_param *addr_param;
+ struct sctp_transport *t;
+ struct sctp_endpoint *ep = asoc->ep;
+
+ /* We maintain all INIT parameters in network byte order all the
+ * time. This allows us to not worry about whether the parameters
+ * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
+ */
+ switch (param.p->type) {
+ case SCTP_PARAM_IPV6_ADDRESS:
+ if (PF_INET6 != asoc->base.sk->sk_family)
+ break;
+ goto do_addr_param;
+
+ case SCTP_PARAM_IPV4_ADDRESS:
+ /* v4 addresses are not allowed on v6-only socket */
+ if (ipv6_only_sock(asoc->base.sk))
+ break;
+do_addr_param:
+ af = sctp_get_af_specific(param_type2af(param.p->type));
+ af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
+ scope = sctp_scope(peer_addr);
+ if (sctp_in_scope(net, &addr, scope))
+ if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
+ return 0;
+ break;
+
+ case SCTP_PARAM_COOKIE_PRESERVATIVE:
+ if (!net->sctp.cookie_preserve_enable)
+ break;
+
+ stale = ntohl(param.life->lifespan_increment);
+
+ /* Suggested Cookie Life span increment's unit is msec,
+ * (1/1000sec).
+ */
+ asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
+ break;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
+ break;
+
+ case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
+ /* Turn off the default values first so we'll know which
+ * ones are really set by the peer.
+ */
+ asoc->peer.ipv4_address = 0;
+ asoc->peer.ipv6_address = 0;
+
+ /* Assume that peer supports the address family
+ * by which it sends a packet.
+ */
+ if (peer_addr->sa.sa_family == AF_INET6)
+ asoc->peer.ipv6_address = 1;
+ else if (peer_addr->sa.sa_family == AF_INET)
+ asoc->peer.ipv4_address = 1;
+
+ /* Cycle through address types; avoid divide by 0. */
+ sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ if (sat)
+ sat /= sizeof(__u16);
+
+ for (i = 0; i < sat; ++i) {
+ switch (param.sat->types[i]) {
+ case SCTP_PARAM_IPV4_ADDRESS:
+ asoc->peer.ipv4_address = 1;
+ break;
+
+ case SCTP_PARAM_IPV6_ADDRESS:
+ if (PF_INET6 == asoc->base.sk->sk_family)
+ asoc->peer.ipv6_address = 1;
+ break;
+
+ case SCTP_PARAM_HOST_NAME_ADDRESS:
+ asoc->peer.hostname_address = 1;
+ break;
+
+ default: /* Just ignore anything else. */
+ break;
+ }
+ }
+ break;
+
+ case SCTP_PARAM_STATE_COOKIE:
+ asoc->peer.cookie_len =
+ ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
+ asoc->peer.cookie = param.cookie->body;
+ break;
+
+ case SCTP_PARAM_HEARTBEAT_INFO:
+ /* Would be odd to receive, but it causes no problems. */
+ break;
+
+ case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
+ /* Rejected during verify stage. */
+ break;
+
+ case SCTP_PARAM_ECN_CAPABLE:
+ asoc->peer.ecn_capable = 1;
+ break;
+
+ case SCTP_PARAM_ADAPTATION_LAYER_IND:
+ asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
+ break;
+
+ case SCTP_PARAM_SET_PRIMARY:
+ if (!net->sctp.addip_enable)
+ goto fall_through;
+
+ addr_param = param.v + sizeof(sctp_addip_param_t);
+
+ af = sctp_get_af_specific(param_type2af(addr_param->p.type));
+ if (af == NULL)
+ break;
+
+ af->from_addr_param(&addr, addr_param,
+ htons(asoc->peer.port), 0);
+
+ /* if the address is invalid, we can't process it.
+ * XXX: see spec for what to do.
+ */
+ if (!af->addr_valid(&addr, NULL, NULL))
+ break;
+
+ t = sctp_assoc_lookup_paddr(asoc, &addr);
+ if (!t)
+ break;
+
+ sctp_assoc_set_primary(asoc, t);
+ break;
+
+ case SCTP_PARAM_SUPPORTED_EXT:
+ sctp_process_ext_param(asoc, param);
+ break;
+
+ case SCTP_PARAM_FWD_TSN_SUPPORT:
+ if (net->sctp.prsctp_enable) {
+ asoc->peer.prsctp_capable = 1;
+ break;
+ }
+ /* Fall Through */
+ goto fall_through;
+
+ case SCTP_PARAM_RANDOM:
+ if (!ep->auth_enable)
+ goto fall_through;
+
+ /* Save peer's random parameter */
+ asoc->peer.peer_random = kmemdup(param.p,
+ ntohs(param.p->length), gfp);
+ if (!asoc->peer.peer_random) {
+ retval = 0;
+ break;
+ }
+ break;
+
+ case SCTP_PARAM_HMAC_ALGO:
+ if (!ep->auth_enable)
+ goto fall_through;
+
+ /* Save peer's HMAC list */
+ asoc->peer.peer_hmacs = kmemdup(param.p,
+ ntohs(param.p->length), gfp);
+ if (!asoc->peer.peer_hmacs) {
+ retval = 0;
+ break;
+ }
+
+ /* Set the default HMAC the peer requested*/
+ sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
+ break;
+
+ case SCTP_PARAM_CHUNKS:
+ if (!ep->auth_enable)
+ goto fall_through;
+
+ asoc->peer.peer_chunks = kmemdup(param.p,
+ ntohs(param.p->length), gfp);
+ if (!asoc->peer.peer_chunks)
+ retval = 0;
+ break;
+fall_through:
+ default:
+ /* Any unrecognized parameters should have been caught
+ * and handled by sctp_verify_param() which should be
+ * called prior to this routine. Simply log the error
+ * here.
+ */
+ pr_debug("%s: ignoring param:%d for association:%p.\n",
+ __func__, ntohs(param.p->type), asoc);
+ break;
+ }
+
+ return retval;
+}
+
+/* Select a new verification tag. */
+__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
+{
+ /* I believe that this random number generator complies with RFC1750.
+ * A tag of 0 is reserved for special cases (e.g. INIT).
+ */
+ __u32 x;
+
+ do {
+ get_random_bytes(&x, sizeof(__u32));
+ } while (x == 0);
+
+ return x;
+}
+
+/* Select an initial TSN to send during startup. */
+__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
+{
+ __u32 retval;
+
+ get_random_bytes(&retval, sizeof(__u32));
+ return retval;
+}
+
+/*
+ * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 0xC1 | Chunk Flags | Chunk Length |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Serial Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Address Parameter |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF Parameter #1 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * \ \
+ * / .... /
+ * \ \
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF Parameter #N |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Address Parameter and other parameter will not be wrapped in this function
+ */
+static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
+ union sctp_addr *addr,
+ int vparam_len)
+{
+ sctp_addiphdr_t asconf;
+ struct sctp_chunk *retval;
+ int length = sizeof(asconf) + vparam_len;
+ union sctp_addr_param addrparam;
+ int addrlen;
+ struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
+
+ addrlen = af->to_addr_param(addr, &addrparam);
+ if (!addrlen)
+ return NULL;
+ length += addrlen;
+
+ /* Create the chunk. */
+ retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length);
+ if (!retval)
+ return NULL;
+
+ asconf.serial = htonl(asoc->addip_serial++);
+
+ retval->subh.addip_hdr =
+ sctp_addto_chunk(retval, sizeof(asconf), &asconf);
+ retval->param_hdr.v =
+ sctp_addto_chunk(retval, addrlen, &addrparam);
+
+ return retval;
+}
+
+/* ADDIP
+ * 3.2.1 Add IP Address
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 0xC001 | Length = Variable |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF-Request Correlation ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Address Parameter |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * 3.2.2 Delete IP Address
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 0xC002 | Length = Variable |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF-Request Correlation ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Address Parameter |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ */
+struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
+ union sctp_addr *laddr,
+ struct sockaddr *addrs,
+ int addrcnt,
+ __be16 flags)
+{
+ sctp_addip_param_t param;
+ struct sctp_chunk *retval;
+ union sctp_addr_param addr_param;
+ union sctp_addr *addr;
+ void *addr_buf;
+ struct sctp_af *af;
+ int paramlen = sizeof(param);
+ int addr_param_len = 0;
+ int totallen = 0;
+ int i;
+ int del_pickup = 0;
+
+ /* Get total length of all the address parameters. */
+ addr_buf = addrs;
+ for (i = 0; i < addrcnt; i++) {
+ addr = addr_buf;
+ af = sctp_get_af_specific(addr->v4.sin_family);
+ addr_param_len = af->to_addr_param(addr, &addr_param);
+
+ totallen += paramlen;
+ totallen += addr_param_len;
+
+ addr_buf += af->sockaddr_len;
+ if (asoc->asconf_addr_del_pending && !del_pickup) {
+ /* reuse the parameter length from the same scope one */
+ totallen += paramlen;
+ totallen += addr_param_len;
+ del_pickup = 1;
+
+ pr_debug("%s: picked same-scope del_pending addr, "
+ "totallen for all addresses is %d\n",
+ __func__, totallen);
+ }
+ }
+
+ /* Create an asconf chunk with the required length. */
+ retval = sctp_make_asconf(asoc, laddr, totallen);
+ if (!retval)
+ return NULL;
+
+ /* Add the address parameters to the asconf chunk. */
+ addr_buf = addrs;
+ for (i = 0; i < addrcnt; i++) {
+ addr = addr_buf;
+ af = sctp_get_af_specific(addr->v4.sin_family);
+ addr_param_len = af->to_addr_param(addr, &addr_param);
+ param.param_hdr.type = flags;
+ param.param_hdr.length = htons(paramlen + addr_param_len);
+ param.crr_id = i;
+
+ sctp_addto_chunk(retval, paramlen, ¶m);
+ sctp_addto_chunk(retval, addr_param_len, &addr_param);
+
+ addr_buf += af->sockaddr_len;
+ }
+ if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
+ addr = asoc->asconf_addr_del_pending;
+ af = sctp_get_af_specific(addr->v4.sin_family);
+ addr_param_len = af->to_addr_param(addr, &addr_param);
+ param.param_hdr.type = SCTP_PARAM_DEL_IP;
+ param.param_hdr.length = htons(paramlen + addr_param_len);
+ param.crr_id = i;
+
+ sctp_addto_chunk(retval, paramlen, ¶m);
+ sctp_addto_chunk(retval, addr_param_len, &addr_param);
+ }
+ return retval;
+}
+
+/* ADDIP
+ * 3.2.4 Set Primary IP Address
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type =0xC004 | Length = Variable |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF-Request Correlation ID |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Address Parameter |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Create an ASCONF chunk with Set Primary IP address parameter.
+ */
+struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
+ union sctp_addr *addr)
+{
+ sctp_addip_param_t param;
+ struct sctp_chunk *retval;
+ int len = sizeof(param);
+ union sctp_addr_param addrparam;
+ int addrlen;
+ struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
+
+ addrlen = af->to_addr_param(addr, &addrparam);
+ if (!addrlen)
+ return NULL;
+ len += addrlen;
+
+ /* Create the chunk and make asconf header. */
+ retval = sctp_make_asconf(asoc, addr, len);
+ if (!retval)
+ return NULL;
+
+ param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
+ param.param_hdr.length = htons(len);
+ param.crr_id = 0;
+
+ sctp_addto_chunk(retval, sizeof(param), ¶m);
+ sctp_addto_chunk(retval, addrlen, &addrparam);
+
+ return retval;
+}
+
+/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type = 0x80 | Chunk Flags | Chunk Length |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Serial Number |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF Parameter Response#1 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * \ \
+ * / .... /
+ * \ \
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | ASCONF Parameter Response#N |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * Create an ASCONF_ACK chunk with enough space for the parameter responses.
+ */
+static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
+ __u32 serial, int vparam_len)
+{
+ sctp_addiphdr_t asconf;
+ struct sctp_chunk *retval;
+ int length = sizeof(asconf) + vparam_len;
+
+ /* Create the chunk. */
+ retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length);
+ if (!retval)
+ return NULL;
+
+ asconf.serial = htonl(serial);
+
+ retval->subh.addip_hdr =
+ sctp_addto_chunk(retval, sizeof(asconf), &asconf);
+
+ return retval;
+}
+
+/* Add response parameters to an ASCONF_ACK chunk. */
+static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
+ __be16 err_code, sctp_addip_param_t *asconf_param)
+{
+ sctp_addip_param_t ack_param;
+ sctp_errhdr_t err_param;
+ int asconf_param_len = 0;
+ int err_param_len = 0;
+ __be16 response_type;
+
+ if (SCTP_ERROR_NO_ERROR == err_code) {
+ response_type = SCTP_PARAM_SUCCESS_REPORT;
+ } else {
+ response_type = SCTP_PARAM_ERR_CAUSE;
+ err_param_len = sizeof(err_param);
+ if (asconf_param)
+ asconf_param_len =
+ ntohs(asconf_param->param_hdr.length);
+ }
+
+ /* Add Success Indication or Error Cause Indication parameter. */
+ ack_param.param_hdr.type = response_type;
+ ack_param.param_hdr.length = htons(sizeof(ack_param) +
+ err_param_len +
+ asconf_param_len);
+ ack_param.crr_id = crr_id;
+ sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
+
+ if (SCTP_ERROR_NO_ERROR == err_code)
+ return;
+
+ /* Add Error Cause parameter. */
+ err_param.cause = err_code;
+ err_param.length = htons(err_param_len + asconf_param_len);
+ sctp_addto_chunk(chunk, err_param_len, &err_param);
+
+ /* Add the failed TLV copied from ASCONF chunk. */
+ if (asconf_param)
+ sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
+}
+
+/* Process a asconf parameter. */
+static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
+ struct sctp_chunk *asconf,
+ sctp_addip_param_t *asconf_param)
+{
+ struct sctp_transport *peer;
+ struct sctp_af *af;
+ union sctp_addr addr;
+ union sctp_addr_param *addr_param;
+
+ addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
+
+ if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
+ asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
+ asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
+ return SCTP_ERROR_UNKNOWN_PARAM;
+
+ switch (addr_param->p.type) {
+ case SCTP_PARAM_IPV6_ADDRESS:
+ if (!asoc->peer.ipv6_address)
+ return SCTP_ERROR_DNS_FAILED;
+ break;
+ case SCTP_PARAM_IPV4_ADDRESS:
+ if (!asoc->peer.ipv4_address)
+ return SCTP_ERROR_DNS_FAILED;
+ break;
+ default:
+ return SCTP_ERROR_DNS_FAILED;
+ }
+
+ af = sctp_get_af_specific(param_type2af(addr_param->p.type));
+ if (unlikely(!af))
+ return SCTP_ERROR_DNS_FAILED;
+
+ af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
+
+ /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
+ * or multicast address.
+ * (note: wildcard is permitted and requires special handling so
+ * make sure we check for that)
+ */
+ if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
+ return SCTP_ERROR_DNS_FAILED;
+
+ switch (asconf_param->param_hdr.type) {
+ case SCTP_PARAM_ADD_IP:
+ /* Section 4.2.1:
+ * If the address 0.0.0.0 or ::0 is provided, the source
+ * address of the packet MUST be added.
+ */
+ if (af->is_any(&addr))
+ memcpy(&addr, &asconf->source, sizeof(addr));
+
+ /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
+ * request and does not have the local resources to add this
+ * new address to the association, it MUST return an Error
+ * Cause TLV set to the new error code 'Operation Refused
+ * Due to Resource Shortage'.
+ */
+
+ peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
+ if (!peer)
+ return SCTP_ERROR_RSRC_LOW;
+
+ /* Start the heartbeat timer. */
+ if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
+ sctp_transport_hold(peer);
+ asoc->new_transport = peer;
+ break;
+ case SCTP_PARAM_DEL_IP:
+ /* ADDIP 4.3 D7) If a request is received to delete the
+ * last remaining IP address of a peer endpoint, the receiver
+ * MUST send an Error Cause TLV with the error cause set to the
+ * new error code 'Request to Delete Last Remaining IP Address'.
+ */
+ if (asoc->peer.transport_count == 1)
+ return SCTP_ERROR_DEL_LAST_IP;
+
+ /* ADDIP 4.3 D8) If a request is received to delete an IP
+ * address which is also the source address of the IP packet
+ * which contained the ASCONF chunk, the receiver MUST reject
+ * this request. To reject the request the receiver MUST send
+ * an Error Cause TLV set to the new error code 'Request to
+ * Delete Source IP Address'
+ */
+ if (sctp_cmp_addr_exact(&asconf->source, &addr))
+ return SCTP_ERROR_DEL_SRC_IP;
+
+ /* Section 4.2.2
+ * If the address 0.0.0.0 or ::0 is provided, all
+ * addresses of the peer except the source address of the
+ * packet MUST be deleted.
+ */
+ if (af->is_any(&addr)) {
+ sctp_assoc_set_primary(asoc, asconf->transport);
+ sctp_assoc_del_nonprimary_peers(asoc,
+ asconf->transport);
+ } else
+ sctp_assoc_del_peer(asoc, &addr);
+ break;
+ case SCTP_PARAM_SET_PRIMARY:
+ /* ADDIP Section 4.2.4
+ * If the address 0.0.0.0 or ::0 is provided, the receiver
+ * MAY mark the source address of the packet as its
+ * primary.
+ */
+ if (af->is_any(&addr))
+ memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
+
+ peer = sctp_assoc_lookup_paddr(asoc, &addr);
+ if (!peer)
+ return SCTP_ERROR_DNS_FAILED;
+
+ sctp_assoc_set_primary(asoc, peer);
+ break;
+ }
+
+ return SCTP_ERROR_NO_ERROR;
+}
+
+/* Verify the ASCONF packet before we process it. */
+bool sctp_verify_asconf(const struct sctp_association *asoc,
+ struct sctp_chunk *chunk, bool addr_param_needed,
+ struct sctp_paramhdr **errp)
+{
+ sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
+ union sctp_params param;
+ bool addr_param_seen = false;
+
+ sctp_walk_params(param, addip, addip_hdr.params) {
+ size_t length = ntohs(param.p->length);
+
+ *errp = param.p;
+ switch (param.p->type) {
+ case SCTP_PARAM_ERR_CAUSE:
+ break;
+ case SCTP_PARAM_IPV4_ADDRESS:
+ if (length != sizeof(sctp_ipv4addr_param_t))
+ return false;
+ addr_param_seen = true;
+ break;
+ case SCTP_PARAM_IPV6_ADDRESS:
+ if (length != sizeof(sctp_ipv6addr_param_t))
+ return false;
+ addr_param_seen = true;
+ break;
+ case SCTP_PARAM_ADD_IP:
+ case SCTP_PARAM_DEL_IP:
+ case SCTP_PARAM_SET_PRIMARY:
+ /* In ASCONF chunks, these need to be first. */
+ if (addr_param_needed && !addr_param_seen)
+ return false;
+ length = ntohs(param.addip->param_hdr.length);
+ if (length < sizeof(sctp_addip_param_t) +
+ sizeof(sctp_paramhdr_t))
+ return false;
+ break;
+ case SCTP_PARAM_SUCCESS_REPORT:
+ case SCTP_PARAM_ADAPTATION_LAYER_IND:
+ if (length != sizeof(sctp_addip_param_t))
+ return false;
+ break;
+ default:
+ /* This is unkown to us, reject! */
+ return false;
+ }
+ }
+
+ /* Remaining sanity checks. */
+ if (addr_param_needed && !addr_param_seen)
+ return false;
+ if (!addr_param_needed && addr_param_seen)
+ return false;
+ if (param.v != chunk->chunk_end)
+ return false;
+
+ return true;
+}
+
+/* Process an incoming ASCONF chunk with the next expected serial no. and
+ * return an ASCONF_ACK chunk to be sent in response.
+ */
+struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
+ struct sctp_chunk *asconf)
+{
+ sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
+ bool all_param_pass = true;
+ union sctp_params param;
+ sctp_addiphdr_t *hdr;
+ union sctp_addr_param *addr_param;
+ sctp_addip_param_t *asconf_param;
+ struct sctp_chunk *asconf_ack;
+ __be16 err_code;
+ int length = 0;
+ int chunk_len;
+ __u32 serial;
+
+ chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
+ hdr = (sctp_addiphdr_t *)asconf->skb->data;
+ serial = ntohl(hdr->serial);
+
+ /* Skip the addiphdr and store a pointer to address parameter. */
+ length = sizeof(sctp_addiphdr_t);
+ addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
+ chunk_len -= length;
+
+ /* Skip the address parameter and store a pointer to the first
+ * asconf parameter.
+ */
+ length = ntohs(addr_param->p.length);
+ asconf_param = (void *)addr_param + length;
+ chunk_len -= length;
+
+ /* create an ASCONF_ACK chunk.
+ * Based on the definitions of parameters, we know that the size of
+ * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
+ * parameters.
+ */
+ asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
+ if (!asconf_ack)
+ goto done;
+
+ /* Process the TLVs contained within the ASCONF chunk. */
+ sctp_walk_params(param, addip, addip_hdr.params) {
+ /* Skip preceeding address parameters. */
+ if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
+ param.p->type == SCTP_PARAM_IPV6_ADDRESS)
+ continue;
+
+ err_code = sctp_process_asconf_param(asoc, asconf,
+ param.addip);
+ /* ADDIP 4.1 A7)
+ * If an error response is received for a TLV parameter,
+ * all TLVs with no response before the failed TLV are
+ * considered successful if not reported. All TLVs after
+ * the failed response are considered unsuccessful unless
+ * a specific success indication is present for the parameter.
+ */
+ if (err_code != SCTP_ERROR_NO_ERROR)
+ all_param_pass = false;
+ if (!all_param_pass)
+ sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
+ err_code, param.addip);
+
+ /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
+ * an IP address sends an 'Out of Resource' in its response, it
+ * MUST also fail any subsequent add or delete requests bundled
+ * in the ASCONF.
+ */
+ if (err_code == SCTP_ERROR_RSRC_LOW)
+ goto done;
+ }
+done:
+ asoc->peer.addip_serial++;
+
+ /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
+ * after freeing the reference to old asconf ack if any.
+ */
+ if (asconf_ack) {
+ sctp_chunk_hold(asconf_ack);
+ list_add_tail(&asconf_ack->transmitted_list,
+ &asoc->asconf_ack_list);
+ }
+
+ return asconf_ack;
+}
+
+/* Process a asconf parameter that is successfully acked. */
+static void sctp_asconf_param_success(struct sctp_association *asoc,
+ sctp_addip_param_t *asconf_param)
+{
+ struct sctp_af *af;
+ union sctp_addr addr;
+ struct sctp_bind_addr *bp = &asoc->base.bind_addr;
+ union sctp_addr_param *addr_param;
+ struct sctp_transport *transport;
+ struct sctp_sockaddr_entry *saddr;
+
+ addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
+
+ /* We have checked the packet before, so we do not check again. */
+ af = sctp_get_af_specific(param_type2af(addr_param->p.type));
+ af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
+
+ switch (asconf_param->param_hdr.type) {
+ case SCTP_PARAM_ADD_IP:
+ /* This is always done in BH context with a socket lock
+ * held, so the list can not change.
+ */
+ local_bh_disable();
+ list_for_each_entry(saddr, &bp->address_list, list) {
+ if (sctp_cmp_addr_exact(&saddr->a, &addr))
+ saddr->state = SCTP_ADDR_SRC;
+ }
+ local_bh_enable();
+ list_for_each_entry(transport, &asoc->peer.transport_addr_list,
+ transports) {
+ dst_release(transport->dst);
+ transport->dst = NULL;
+ }
+ break;
+ case SCTP_PARAM_DEL_IP:
+ local_bh_disable();
+ sctp_del_bind_addr(bp, &addr);
+ if (asoc->asconf_addr_del_pending != NULL &&
+ sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
+ kfree(asoc->asconf_addr_del_pending);
+ asoc->asconf_addr_del_pending = NULL;
+ }
+ local_bh_enable();
+ list_for_each_entry(transport, &asoc->peer.transport_addr_list,
+ transports) {
+ dst_release(transport->dst);
+ transport->dst = NULL;
+ }
+ break;
+ default:
+ break;
+ }
+}
+
+/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
+ * for the given asconf parameter. If there is no response for this parameter,
+ * return the error code based on the third argument 'no_err'.
+ * ADDIP 4.1
+ * A7) If an error response is received for a TLV parameter, all TLVs with no
+ * response before the failed TLV are considered successful if not reported.
+ * All TLVs after the failed response are considered unsuccessful unless a
+ * specific success indication is present for the parameter.
+ */
+static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
+ sctp_addip_param_t *asconf_param,
+ int no_err)
+{
+ sctp_addip_param_t *asconf_ack_param;
+ sctp_errhdr_t *err_param;
+ int length;
+ int asconf_ack_len;
+ __be16 err_code;
+
+ if (no_err)
+ err_code = SCTP_ERROR_NO_ERROR;
+ else
+ err_code = SCTP_ERROR_REQ_REFUSED;
+
+ asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
+ sizeof(sctp_chunkhdr_t);
+
+ /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
+ * the first asconf_ack parameter.
+ */
+ length = sizeof(sctp_addiphdr_t);
+ asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
+ length);
+ asconf_ack_len -= length;
+
+ while (asconf_ack_len > 0) {
+ if (asconf_ack_param->crr_id == asconf_param->crr_id) {
+ switch (asconf_ack_param->param_hdr.type) {
+ case SCTP_PARAM_SUCCESS_REPORT:
+ return SCTP_ERROR_NO_ERROR;
+ case SCTP_PARAM_ERR_CAUSE:
+ length = sizeof(sctp_addip_param_t);
+ err_param = (void *)asconf_ack_param + length;
+ asconf_ack_len -= length;
+ if (asconf_ack_len > 0)
+ return err_param->cause;
+ else
+ return SCTP_ERROR_INV_PARAM;
+ break;
+ default:
+ return SCTP_ERROR_INV_PARAM;
+ }
+ }
+
+ length = ntohs(asconf_ack_param->param_hdr.length);
+ asconf_ack_param = (void *)asconf_ack_param + length;
+ asconf_ack_len -= length;
+ }
+
+ return err_code;
+}
+
+/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
+int sctp_process_asconf_ack(struct sctp_association *asoc,
+ struct sctp_chunk *asconf_ack)
+{
+ struct sctp_chunk *asconf = asoc->addip_last_asconf;
+ union sctp_addr_param *addr_param;
+ sctp_addip_param_t *asconf_param;
+ int length = 0;
+ int asconf_len = asconf->skb->len;
+ int all_param_pass = 0;
+ int no_err = 1;
+ int retval = 0;
+ __be16 err_code = SCTP_ERROR_NO_ERROR;
+
+ /* Skip the chunkhdr and addiphdr from the last asconf sent and store
+ * a pointer to address parameter.
+ */
+ length = sizeof(sctp_addip_chunk_t);
+ addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
+ asconf_len -= length;
+
+ /* Skip the address parameter in the last asconf sent and store a
+ * pointer to the first asconf parameter.
+ */
+ length = ntohs(addr_param->p.length);
+ asconf_param = (void *)addr_param + length;
+ asconf_len -= length;
+
+ /* ADDIP 4.1
+ * A8) If there is no response(s) to specific TLV parameter(s), and no
+ * failures are indicated, then all request(s) are considered
+ * successful.
+ */
+ if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
+ all_param_pass = 1;
+
+ /* Process the TLVs contained in the last sent ASCONF chunk. */
+ while (asconf_len > 0) {
+ if (all_param_pass)
+ err_code = SCTP_ERROR_NO_ERROR;
+ else {
+ err_code = sctp_get_asconf_response(asconf_ack,
+ asconf_param,
+ no_err);
+ if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
+ no_err = 0;
+ }
+
+ switch (err_code) {
+ case SCTP_ERROR_NO_ERROR:
+ sctp_asconf_param_success(asoc, asconf_param);
+ break;
+
+ case SCTP_ERROR_RSRC_LOW:
+ retval = 1;
+ break;
+
+ case SCTP_ERROR_UNKNOWN_PARAM:
+ /* Disable sending this type of asconf parameter in
+ * future.
+ */
+ asoc->peer.addip_disabled_mask |=
+ asconf_param->param_hdr.type;
+ break;
+
+ case SCTP_ERROR_REQ_REFUSED:
+ case SCTP_ERROR_DEL_LAST_IP:
+ case SCTP_ERROR_DEL_SRC_IP:
+ default:
+ break;
+ }
+
+ /* Skip the processed asconf parameter and move to the next
+ * one.
+ */
+ length = ntohs(asconf_param->param_hdr.length);
+ asconf_param = (void *)asconf_param + length;
+ asconf_len -= length;
+ }
+
+ if (no_err && asoc->src_out_of_asoc_ok) {
+ asoc->src_out_of_asoc_ok = 0;
+ sctp_transport_immediate_rtx(asoc->peer.primary_path);
+ }
+
+ /* Free the cached last sent asconf chunk. */
+ list_del_init(&asconf->transmitted_list);
+ sctp_chunk_free(asconf);
+ asoc->addip_last_asconf = NULL;
+
+ return retval;
+}
+
+/* Make a FWD TSN chunk. */
+struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
+ __u32 new_cum_tsn, size_t nstreams,
+ struct sctp_fwdtsn_skip *skiplist)
+{
+ struct sctp_chunk *retval = NULL;
+ struct sctp_fwdtsn_hdr ftsn_hdr;
+ struct sctp_fwdtsn_skip skip;
+ size_t hint;
+ int i;
+
+ hint = (nstreams + 1) * sizeof(__u32);
+
+ retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint);
+
+ if (!retval)
+ return NULL;
+
+ ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
+ retval->subh.fwdtsn_hdr =
+ sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
+
+ for (i = 0; i < nstreams; i++) {
+ skip.stream = skiplist[i].stream;
+ skip.ssn = skiplist[i].ssn;
+ sctp_addto_chunk(retval, sizeof(skip), &skip);
+ }
+
+ return retval;
+}
Code Review / kvmfornfv.git / blobdiff