--- /dev/null
+/* RxRPC packet transmission
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program 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 of the License, or (at your option) any later version.
+ */
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/circ_buf.h>
+#include <linux/export.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Time till packet resend (in jiffies).
+ */
+unsigned rxrpc_resend_timeout = 4 * HZ;
+
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+ struct rxrpc_call *call,
+ struct msghdr *msg, size_t len);
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+ unsigned long *user_call_ID,
+ enum rxrpc_command *command,
+ u32 *abort_code,
+ bool server)
+{
+ struct cmsghdr *cmsg;
+ int len;
+
+ *command = RXRPC_CMD_SEND_DATA;
+
+ if (msg->msg_controllen == 0)
+ return -EINVAL;
+
+ for_each_cmsghdr(cmsg, msg) {
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+ _debug("CMSG %d, %d, %d",
+ cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+ if (cmsg->cmsg_level != SOL_RXRPC)
+ continue;
+
+ switch (cmsg->cmsg_type) {
+ case RXRPC_USER_CALL_ID:
+ if (msg->msg_flags & MSG_CMSG_COMPAT) {
+ if (len != sizeof(u32))
+ return -EINVAL;
+ *user_call_ID = *(u32 *) CMSG_DATA(cmsg);
+ } else {
+ if (len != sizeof(unsigned long))
+ return -EINVAL;
+ *user_call_ID = *(unsigned long *)
+ CMSG_DATA(cmsg);
+ }
+ _debug("User Call ID %lx", *user_call_ID);
+ break;
+
+ case RXRPC_ABORT:
+ if (*command != RXRPC_CMD_SEND_DATA)
+ return -EINVAL;
+ *command = RXRPC_CMD_SEND_ABORT;
+ if (len != sizeof(*abort_code))
+ return -EINVAL;
+ *abort_code = *(unsigned int *) CMSG_DATA(cmsg);
+ _debug("Abort %x", *abort_code);
+ if (*abort_code == 0)
+ return -EINVAL;
+ break;
+
+ case RXRPC_ACCEPT:
+ if (*command != RXRPC_CMD_SEND_DATA)
+ return -EINVAL;
+ *command = RXRPC_CMD_ACCEPT;
+ if (len != 0)
+ return -EINVAL;
+ if (!server)
+ return -EISCONN;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * abort a call, sending an ABORT packet to the peer
+ */
+static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
+{
+ write_lock_bh(&call->state_lock);
+
+ if (call->state <= RXRPC_CALL_COMPLETE) {
+ call->state = RXRPC_CALL_LOCALLY_ABORTED;
+ call->abort_code = abort_code;
+ set_bit(RXRPC_CALL_ABORT, &call->events);
+ del_timer_sync(&call->resend_timer);
+ del_timer_sync(&call->ack_timer);
+ clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+ clear_bit(RXRPC_CALL_ACK, &call->events);
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ rxrpc_queue_call(call);
+ }
+
+ write_unlock_bh(&call->state_lock);
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_client_sendmsg(struct rxrpc_sock *rx, struct rxrpc_transport *trans,
+ struct msghdr *msg, size_t len)
+{
+ struct rxrpc_conn_bundle *bundle;
+ enum rxrpc_command cmd;
+ struct rxrpc_call *call;
+ unsigned long user_call_ID = 0;
+ struct key *key;
+ __be16 service_id;
+ u32 abort_code = 0;
+ int ret;
+
+ _enter("");
+
+ ASSERT(trans != NULL);
+
+ ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+ false);
+ if (ret < 0)
+ return ret;
+
+ bundle = NULL;
+ if (trans) {
+ service_id = rx->service_id;
+ if (msg->msg_name) {
+ DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx,
+ msg->msg_name);
+ service_id = htons(srx->srx_service);
+ }
+ key = rx->key;
+ if (key && !rx->key->payload.data)
+ key = NULL;
+ bundle = rxrpc_get_bundle(rx, trans, key, service_id,
+ GFP_KERNEL);
+ if (IS_ERR(bundle))
+ return PTR_ERR(bundle);
+ }
+
+ call = rxrpc_get_client_call(rx, trans, bundle, user_call_ID,
+ abort_code == 0, GFP_KERNEL);
+ if (trans)
+ rxrpc_put_bundle(trans, bundle);
+ if (IS_ERR(call)) {
+ _leave(" = %ld", PTR_ERR(call));
+ return PTR_ERR(call);
+ }
+
+ _debug("CALL %d USR %lx ST %d on CONN %p",
+ call->debug_id, call->user_call_ID, call->state, call->conn);
+
+ if (call->state >= RXRPC_CALL_COMPLETE) {
+ /* it's too late for this call */
+ ret = -ESHUTDOWN;
+ } else if (cmd == RXRPC_CMD_SEND_ABORT) {
+ rxrpc_send_abort(call, abort_code);
+ } else if (cmd != RXRPC_CMD_SEND_DATA) {
+ ret = -EINVAL;
+ } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
+ /* request phase complete for this client call */
+ ret = -EPROTO;
+ } else {
+ ret = rxrpc_send_data(rx, call, msg, len);
+ }
+
+ rxrpc_put_call(call);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/**
+ * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
+ * @call: The call to send data through
+ * @msg: The data to send
+ * @len: The amount of data to send
+ *
+ * Allow a kernel service to send data on a call. The call must be in an state
+ * appropriate to sending data. No control data should be supplied in @msg,
+ * nor should an address be supplied. MSG_MORE should be flagged if there's
+ * more data to come, otherwise this data will end the transmission phase.
+ */
+int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg,
+ size_t len)
+{
+ int ret;
+
+ _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
+
+ ASSERTCMP(msg->msg_name, ==, NULL);
+ ASSERTCMP(msg->msg_control, ==, NULL);
+
+ lock_sock(&call->socket->sk);
+
+ _debug("CALL %d USR %lx ST %d on CONN %p",
+ call->debug_id, call->user_call_ID, call->state, call->conn);
+
+ if (call->state >= RXRPC_CALL_COMPLETE) {
+ ret = -ESHUTDOWN; /* it's too late for this call */
+ } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+ call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+ call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+ ret = -EPROTO; /* request phase complete for this client call */
+ } else {
+ ret = rxrpc_send_data(call->socket, call, msg, len);
+ }
+
+ release_sock(&call->socket->sk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_send_data);
+
+/**
+ * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
+ * @call: The call to be aborted
+ * @abort_code: The abort code to stick into the ABORT packet
+ *
+ * Allow a kernel service to abort a call, if it's still in an abortable state.
+ */
+void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code)
+{
+ _enter("{%d},%d", call->debug_id, abort_code);
+
+ lock_sock(&call->socket->sk);
+
+ _debug("CALL %d USR %lx ST %d on CONN %p",
+ call->debug_id, call->user_call_ID, call->state, call->conn);
+
+ if (call->state < RXRPC_CALL_COMPLETE)
+ rxrpc_send_abort(call, abort_code);
+
+ release_sock(&call->socket->sk);
+ _leave("");
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);
+
+/*
+ * send a message through a server socket
+ * - caller holds the socket locked
+ */
+int rxrpc_server_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+{
+ enum rxrpc_command cmd;
+ struct rxrpc_call *call;
+ unsigned long user_call_ID = 0;
+ u32 abort_code = 0;
+ int ret;
+
+ _enter("");
+
+ ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+ true);
+ if (ret < 0)
+ return ret;
+
+ if (cmd == RXRPC_CMD_ACCEPT) {
+ call = rxrpc_accept_call(rx, user_call_ID);
+ if (IS_ERR(call))
+ return PTR_ERR(call);
+ rxrpc_put_call(call);
+ return 0;
+ }
+
+ call = rxrpc_find_server_call(rx, user_call_ID);
+ if (!call)
+ return -EBADSLT;
+ if (call->state >= RXRPC_CALL_COMPLETE) {
+ ret = -ESHUTDOWN;
+ goto out;
+ }
+
+ switch (cmd) {
+ case RXRPC_CMD_SEND_DATA:
+ if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+ call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+ call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+ /* Tx phase not yet begun for this call */
+ ret = -EPROTO;
+ break;
+ }
+
+ ret = rxrpc_send_data(rx, call, msg, len);
+ break;
+
+ case RXRPC_CMD_SEND_ABORT:
+ rxrpc_send_abort(call, abort_code);
+ break;
+ default:
+ BUG();
+ }
+
+ out:
+ rxrpc_put_call(call);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * send a packet through the transport endpoint
+ */
+int rxrpc_send_packet(struct rxrpc_transport *trans, struct sk_buff *skb)
+{
+ struct kvec iov[1];
+ struct msghdr msg;
+ int ret, opt;
+
+ _enter(",{%d}", skb->len);
+
+ iov[0].iov_base = skb->head;
+ iov[0].iov_len = skb->len;
+
+ msg.msg_name = &trans->peer->srx.transport.sin;
+ msg.msg_namelen = sizeof(trans->peer->srx.transport.sin);
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ /* send the packet with the don't fragment bit set if we currently
+ * think it's small enough */
+ if (skb->len - sizeof(struct rxrpc_header) < trans->peer->maxdata) {
+ down_read(&trans->local->defrag_sem);
+ /* send the packet by UDP
+ * - returns -EMSGSIZE if UDP would have to fragment the packet
+ * to go out of the interface
+ * - in which case, we'll have processed the ICMP error
+ * message and update the peer record
+ */
+ ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
+ iov[0].iov_len);
+
+ up_read(&trans->local->defrag_sem);
+ if (ret == -EMSGSIZE)
+ goto send_fragmentable;
+
+ _leave(" = %d [%u]", ret, trans->peer->maxdata);
+ return ret;
+ }
+
+send_fragmentable:
+ /* attempt to send this message with fragmentation enabled */
+ _debug("send fragment");
+
+ down_write(&trans->local->defrag_sem);
+ opt = IP_PMTUDISC_DONT;
+ ret = kernel_setsockopt(trans->local->socket, SOL_IP, IP_MTU_DISCOVER,
+ (char *) &opt, sizeof(opt));
+ if (ret == 0) {
+ ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
+ iov[0].iov_len);
+
+ opt = IP_PMTUDISC_DO;
+ kernel_setsockopt(trans->local->socket, SOL_IP,
+ IP_MTU_DISCOVER, (char *) &opt, sizeof(opt));
+ }
+
+ up_write(&trans->local->defrag_sem);
+ _leave(" = %d [frag %u]", ret, trans->peer->maxdata);
+ return ret;
+}
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+ struct rxrpc_call *call,
+ long *timeo)
+{
+ DECLARE_WAITQUEUE(myself, current);
+ int ret;
+
+ _enter(",{%d},%ld",
+ CIRC_SPACE(call->acks_head, call->acks_tail, call->acks_winsz),
+ *timeo);
+
+ add_wait_queue(&call->tx_waitq, &myself);
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ ret = 0;
+ if (CIRC_SPACE(call->acks_head, call->acks_tail,
+ call->acks_winsz) > 0)
+ break;
+ if (signal_pending(current)) {
+ ret = sock_intr_errno(*timeo);
+ break;
+ }
+
+ release_sock(&rx->sk);
+ *timeo = schedule_timeout(*timeo);
+ lock_sock(&rx->sk);
+ }
+
+ remove_wait_queue(&call->tx_waitq, &myself);
+ set_current_state(TASK_RUNNING);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * attempt to schedule an instant Tx resend
+ */
+static inline void rxrpc_instant_resend(struct rxrpc_call *call)
+{
+ read_lock_bh(&call->state_lock);
+ if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ if (call->state < RXRPC_CALL_COMPLETE &&
+ !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
+ rxrpc_queue_call(call);
+ }
+ read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * queue a packet for transmission, set the resend timer and attempt
+ * to send the packet immediately
+ */
+static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
+ bool last)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ int ret;
+
+ _net("queue skb %p [%d]", skb, call->acks_head);
+
+ ASSERT(call->acks_window != NULL);
+ call->acks_window[call->acks_head] = (unsigned long) skb;
+ smp_wmb();
+ call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
+
+ if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
+ _debug("________awaiting reply/ACK__________");
+ write_lock_bh(&call->state_lock);
+ switch (call->state) {
+ case RXRPC_CALL_CLIENT_SEND_REQUEST:
+ call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
+ break;
+ case RXRPC_CALL_SERVER_ACK_REQUEST:
+ call->state = RXRPC_CALL_SERVER_SEND_REPLY;
+ if (!last)
+ break;
+ case RXRPC_CALL_SERVER_SEND_REPLY:
+ call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
+ break;
+ default:
+ break;
+ }
+ write_unlock_bh(&call->state_lock);
+ }
+
+ _proto("Tx DATA %%%u { #%u }",
+ ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+
+ sp->need_resend = false;
+ sp->resend_at = jiffies + rxrpc_resend_timeout;
+ if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
+ _debug("run timer");
+ call->resend_timer.expires = sp->resend_at;
+ add_timer(&call->resend_timer);
+ }
+
+ /* attempt to cancel the rx-ACK timer, deferring reply transmission if
+ * we're ACK'ing the request phase of an incoming call */
+ ret = -EAGAIN;
+ if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
+ /* the packet may be freed by rxrpc_process_call() before this
+ * returns */
+ ret = rxrpc_send_packet(call->conn->trans, skb);
+ _net("sent skb %p", skb);
+ } else {
+ _debug("failed to delete ACK timer");
+ }
+
+ if (ret < 0) {
+ _debug("need instant resend %d", ret);
+ sp->need_resend = true;
+ rxrpc_instant_resend(call);
+ }
+
+ _leave("");
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - caller holds the socket locked
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+ struct rxrpc_call *call,
+ struct msghdr *msg, size_t len)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *skb;
+ struct sock *sk = &rx->sk;
+ long timeo;
+ bool more;
+ int ret, copied;
+
+ timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+ /* this should be in poll */
+ clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+ return -EPIPE;
+
+ more = msg->msg_flags & MSG_MORE;
+
+ skb = call->tx_pending;
+ call->tx_pending = NULL;
+
+ copied = 0;
+ do {
+ if (!skb) {
+ size_t size, chunk, max, space;
+
+ _debug("alloc");
+
+ if (CIRC_SPACE(call->acks_head, call->acks_tail,
+ call->acks_winsz) <= 0) {
+ ret = -EAGAIN;
+ if (msg->msg_flags & MSG_DONTWAIT)
+ goto maybe_error;
+ ret = rxrpc_wait_for_tx_window(rx, call,
+ &timeo);
+ if (ret < 0)
+ goto maybe_error;
+ }
+
+ max = call->conn->trans->peer->maxdata;
+ max -= call->conn->security_size;
+ max &= ~(call->conn->size_align - 1UL);
+
+ chunk = max;
+ if (chunk > msg_data_left(msg) && !more)
+ chunk = msg_data_left(msg);
+
+ space = chunk + call->conn->size_align;
+ space &= ~(call->conn->size_align - 1UL);
+
+ size = space + call->conn->header_size;
+
+ _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
+
+ /* create a buffer that we can retain until it's ACK'd */
+ skb = sock_alloc_send_skb(
+ sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
+ if (!skb)
+ goto maybe_error;
+
+ rxrpc_new_skb(skb);
+
+ _debug("ALLOC SEND %p", skb);
+
+ ASSERTCMP(skb->mark, ==, 0);
+
+ _debug("HS: %u", call->conn->header_size);
+ skb_reserve(skb, call->conn->header_size);
+ skb->len += call->conn->header_size;
+
+ sp = rxrpc_skb(skb);
+ sp->remain = chunk;
+ if (sp->remain > skb_tailroom(skb))
+ sp->remain = skb_tailroom(skb);
+
+ _net("skb: hr %d, tr %d, hl %d, rm %d",
+ skb_headroom(skb),
+ skb_tailroom(skb),
+ skb_headlen(skb),
+ sp->remain);
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ }
+
+ _debug("append");
+ sp = rxrpc_skb(skb);
+
+ /* append next segment of data to the current buffer */
+ if (msg_data_left(msg) > 0) {
+ int copy = skb_tailroom(skb);
+ ASSERTCMP(copy, >, 0);
+ if (copy > msg_data_left(msg))
+ copy = msg_data_left(msg);
+ if (copy > sp->remain)
+ copy = sp->remain;
+
+ _debug("add");
+ ret = skb_add_data(skb, &msg->msg_iter, copy);
+ _debug("added");
+ if (ret < 0)
+ goto efault;
+ sp->remain -= copy;
+ skb->mark += copy;
+ copied += copy;
+ }
+
+ /* check for the far side aborting the call or a network error
+ * occurring */
+ if (call->state > RXRPC_CALL_COMPLETE)
+ goto call_aborted;
+
+ /* add the packet to the send queue if it's now full */
+ if (sp->remain <= 0 ||
+ (msg_data_left(msg) == 0 && !more)) {
+ struct rxrpc_connection *conn = call->conn;
+ uint32_t seq;
+ size_t pad;
+
+ /* pad out if we're using security */
+ if (conn->security) {
+ pad = conn->security_size + skb->mark;
+ pad = conn->size_align - pad;
+ pad &= conn->size_align - 1;
+ _debug("pad %zu", pad);
+ if (pad)
+ memset(skb_put(skb, pad), 0, pad);
+ }
+
+ seq = atomic_inc_return(&call->sequence);
+
+ sp->hdr.epoch = conn->epoch;
+ sp->hdr.cid = call->cid;
+ sp->hdr.callNumber = call->call_id;
+ sp->hdr.seq = htonl(seq);
+ sp->hdr.serial =
+ htonl(atomic_inc_return(&conn->serial));
+ sp->hdr.type = RXRPC_PACKET_TYPE_DATA;
+ sp->hdr.userStatus = 0;
+ sp->hdr.securityIndex = conn->security_ix;
+ sp->hdr._rsvd = 0;
+ sp->hdr.serviceId = conn->service_id;
+
+ sp->hdr.flags = conn->out_clientflag;
+ if (msg_data_left(msg) == 0 && !more)
+ sp->hdr.flags |= RXRPC_LAST_PACKET;
+ else if (CIRC_SPACE(call->acks_head, call->acks_tail,
+ call->acks_winsz) > 1)
+ sp->hdr.flags |= RXRPC_MORE_PACKETS;
+ if (more && seq & 1)
+ sp->hdr.flags |= RXRPC_REQUEST_ACK;
+
+ ret = rxrpc_secure_packet(
+ call, skb, skb->mark,
+ skb->head + sizeof(struct rxrpc_header));
+ if (ret < 0)
+ goto out;
+
+ memcpy(skb->head, &sp->hdr,
+ sizeof(struct rxrpc_header));
+ rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
+ skb = NULL;
+ }
+ } while (msg_data_left(msg) > 0);
+
+success:
+ ret = copied;
+out:
+ call->tx_pending = skb;
+ _leave(" = %d", ret);
+ return ret;
+
+call_aborted:
+ rxrpc_free_skb(skb);
+ if (call->state == RXRPC_CALL_NETWORK_ERROR)
+ ret = call->conn->trans->peer->net_error;
+ else
+ ret = -ECONNABORTED;
+ _leave(" = %d", ret);
+ return ret;
+
+maybe_error:
+ if (copied)
+ goto success;
+ goto out;
+
+efault:
+ ret = -EFAULT;
+ goto out;
+}
Code Review / kvmfornfv.git / blobdiff