packet: on direct_xmit, limit tso and csum to supported devices
[cascardo/linux.git] / net / rxrpc / output.c
index f4bda06..5dab1ff 100644 (file)
 #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 int 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 msghdr *msg,
-                             unsigned long *user_call_ID,
-                             enum rxrpc_command *command,
-                             u32 *abort_code,
-                             bool *_exclusive)
-{
-       struct cmsghdr *cmsg;
-       bool got_user_ID = false;
-       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);
-                       got_user_ID = true;
-                       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;
-                       break;
-
-               case RXRPC_EXCLUSIVE_CALL:
-                       *_exclusive = true;
-                       if (len != 0)
-                               return -EINVAL;
-                       break;
-               default:
-                       return -EINVAL;
-               }
-       }
+struct rxrpc_ack_buffer {
+       struct rxrpc_wire_header whdr;
+       struct rxrpc_ackpacket ack;
+       u8 acks[255];
+       u8 pad[3];
+       struct rxrpc_ackinfo ackinfo;
+};
 
-       if (!got_user_ID)
-               return -EINVAL;
-       _leave(" = 0");
-       return 0;
-}
+struct rxrpc_abort_buffer {
+       struct rxrpc_wire_header whdr;
+       __be32 abort_code;
+};
 
 /*
- * abort a call, sending an ABORT packet to the peer
+ * Fill out an ACK packet.
  */
-static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
+static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
+                                struct rxrpc_ack_buffer *pkt,
+                                rxrpc_seq_t *_hard_ack,
+                                rxrpc_seq_t *_top,
+                                u8 reason)
 {
-       write_lock_bh(&call->state_lock);
-
-       if (call->state <= RXRPC_CALL_COMPLETE) {
-               call->state = RXRPC_CALL_LOCALLY_ABORTED;
-               call->local_abort = abort_code;
-               set_bit(RXRPC_CALL_EV_ABORT, &call->events);
-               del_timer_sync(&call->resend_timer);
-               del_timer_sync(&call->ack_timer);
-               clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
-               clear_bit(RXRPC_CALL_EV_ACK, &call->events);
-               clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
-               rxrpc_queue_call(call);
+       rxrpc_serial_t serial;
+       rxrpc_seq_t hard_ack, top, seq;
+       int ix;
+       u32 mtu, jmax;
+       u8 *ackp = pkt->acks;
+
+       /* Barrier against rxrpc_input_data(). */
+       serial = call->ackr_serial;
+       hard_ack = READ_ONCE(call->rx_hard_ack);
+       top = smp_load_acquire(&call->rx_top);
+       *_hard_ack = hard_ack;
+       *_top = top;
+
+       pkt->ack.bufferSpace    = htons(8);
+       pkt->ack.maxSkew        = htons(call->ackr_skew);
+       pkt->ack.firstPacket    = htonl(hard_ack + 1);
+       pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
+       pkt->ack.serial         = htonl(serial);
+       pkt->ack.reason         = reason;
+       pkt->ack.nAcks          = top - hard_ack;
+
+       if (reason == RXRPC_ACK_PING)
+               pkt->whdr.flags |= RXRPC_REQUEST_ACK;
+
+       if (after(top, hard_ack)) {
+               seq = hard_ack + 1;
+               do {
+                       ix = seq & RXRPC_RXTX_BUFF_MASK;
+                       if (call->rxtx_buffer[ix])
+                               *ackp++ = RXRPC_ACK_TYPE_ACK;
+                       else
+                               *ackp++ = RXRPC_ACK_TYPE_NACK;
+                       seq++;
+               } while (before_eq(seq, top));
        }
 
-       write_unlock_bh(&call->state_lock);
-}
-
-/*
- * Create a new client call for sendmsg().
- */
-static struct rxrpc_call *
-rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
-                                 unsigned long user_call_ID, bool exclusive)
-{
-       struct rxrpc_conn_parameters cp;
-       struct rxrpc_call *call;
-       struct key *key;
-
-       DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
-
-       _enter("");
-
-       if (!msg->msg_name)
-               return ERR_PTR(-EDESTADDRREQ);
-
-       key = rx->key;
-       if (key && !rx->key->payload.data[0])
-               key = NULL;
-
-       memset(&cp, 0, sizeof(cp));
-       cp.local                = rx->local;
-       cp.key                  = rx->key;
-       cp.security_level       = rx->min_sec_level;
-       cp.exclusive            = rx->exclusive | exclusive;
-       cp.service_id           = srx->srx_service;
-       call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
-
-       _leave(" = %p\n", call);
-       return call;
+       mtu = call->conn->params.peer->if_mtu;
+       mtu -= call->conn->params.peer->hdrsize;
+       jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
+       pkt->ackinfo.rxMTU      = htonl(rxrpc_rx_mtu);
+       pkt->ackinfo.maxMTU     = htonl(mtu);
+       pkt->ackinfo.rwind      = htonl(call->rx_winsize);
+       pkt->ackinfo.jumbo_max  = htonl(jmax);
+
+       *ackp++ = 0;
+       *ackp++ = 0;
+       *ackp++ = 0;
+       return top - hard_ack + 3;
 }
 
 /*
- * 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
+ * Send an ACK call packet.
  */
-int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
 {
-       enum rxrpc_command cmd;
-       struct rxrpc_call *call;
-       unsigned long user_call_ID = 0;
-       bool exclusive = false;
-       u32 abort_code = 0;
+       struct rxrpc_connection *conn = NULL;
+       struct rxrpc_ack_buffer *pkt;
+       struct msghdr msg;
+       struct kvec iov[2];
+       rxrpc_serial_t serial;
+       rxrpc_seq_t hard_ack, top;
+       size_t len, n;
        int ret;
-
-       _enter("");
-
-       ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
-                                &exclusive);
-       if (ret < 0)
-               return ret;
-
-       if (cmd == RXRPC_CMD_ACCEPT) {
-               if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
-                       return -EINVAL;
-               call = rxrpc_accept_call(rx, user_call_ID);
-               if (IS_ERR(call))
-                       return PTR_ERR(call);
-               rxrpc_put_call(call);
-               return 0;
+       u8 reason;
+
+       spin_lock_bh(&call->lock);
+       if (call->conn)
+               conn = rxrpc_get_connection_maybe(call->conn);
+       spin_unlock_bh(&call->lock);
+       if (!conn)
+               return -ECONNRESET;
+
+       pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+       if (!pkt) {
+               rxrpc_put_connection(conn);
+               return -ENOMEM;
        }
 
-       call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
-       if (!call) {
-               if (cmd != RXRPC_CMD_SEND_DATA)
-                       return -EBADSLT;
-               call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
-                                                        exclusive);
-               if (IS_ERR(call))
-                       return PTR_ERR(call);
+       msg.msg_name    = &call->peer->srx.transport;
+       msg.msg_namelen = call->peer->srx.transport_len;
+       msg.msg_control = NULL;
+       msg.msg_controllen = 0;
+       msg.msg_flags   = 0;
+
+       pkt->whdr.epoch         = htonl(conn->proto.epoch);
+       pkt->whdr.cid           = htonl(call->cid);
+       pkt->whdr.callNumber    = htonl(call->call_id);
+       pkt->whdr.seq           = 0;
+       pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
+       pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
+       pkt->whdr.userStatus    = 0;
+       pkt->whdr.securityIndex = call->security_ix;
+       pkt->whdr._rsvd         = 0;
+       pkt->whdr.serviceId     = htons(call->service_id);
+
+       spin_lock_bh(&call->lock);
+       if (ping) {
+               reason = RXRPC_ACK_PING;
+       } else {
+               reason = call->ackr_reason;
+               if (!call->ackr_reason) {
+                       spin_unlock_bh(&call->lock);
+                       ret = 0;
+                       goto out;
+               }
+               call->ackr_reason = 0;
+       }
+       n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
+
+       spin_unlock_bh(&call->lock);
+
+       iov[0].iov_base = pkt;
+       iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
+       iov[1].iov_base = &pkt->ackinfo;
+       iov[1].iov_len  = sizeof(pkt->ackinfo);
+       len = iov[0].iov_len + iov[1].iov_len;
+
+       serial = atomic_inc_return(&conn->serial);
+       pkt->whdr.serial = htonl(serial);
+       trace_rxrpc_tx_ack(call, serial,
+                          ntohl(pkt->ack.firstPacket),
+                          ntohl(pkt->ack.serial),
+                          pkt->ack.reason, pkt->ack.nAcks);
+
+       if (ping) {
+               call->ping_serial = serial;
+               smp_wmb();
+               /* We need to stick a time in before we send the packet in case
+                * the reply gets back before kernel_sendmsg() completes - but
+                * asking UDP to send the packet can take a relatively long
+                * time, so we update the time after, on the assumption that
+                * the packet transmission is more likely to happen towards the
+                * end of the kernel_sendmsg() call.
+                */
+               call->ping_time = ktime_get_real();
+               set_bit(RXRPC_CALL_PINGING, &call->flags);
+               trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
        }
 
-       _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 = -ECONNRESET;
-       } else if (cmd == RXRPC_CMD_SEND_ABORT) {
-               rxrpc_send_abort(call, abort_code);
-               ret = 0;
-       } else if (cmd != RXRPC_CMD_SEND_DATA) {
-               ret = -EINVAL;
-       } else if (!call->in_clientflag &&
-                  call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
-               /* request phase complete for this client call */
-               ret = -EPROTO;
-       } else if (call->in_clientflag &&
-                  call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
-                  call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
-               /* Reply phase not begun or not complete for service call. */
-               ret = -EPROTO;
-       } else {
-               ret = rxrpc_send_data(rx, call, msg, len);
+       ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+       if (ping)
+               call->ping_time = ktime_get_real();
+
+       if (call->state < RXRPC_CALL_COMPLETE) {
+               if (ret < 0) {
+                       if (ping)
+                               clear_bit(RXRPC_CALL_PINGING, &call->flags);
+                       rxrpc_propose_ACK(call, pkt->ack.reason,
+                                         ntohs(pkt->ack.maxSkew),
+                                         ntohl(pkt->ack.serial),
+                                         true, true,
+                                         rxrpc_propose_ack_retry_tx);
+               } else {
+                       spin_lock_bh(&call->lock);
+                       if (after(hard_ack, call->ackr_consumed))
+                               call->ackr_consumed = hard_ack;
+                       if (after(top, call->ackr_seen))
+                               call->ackr_seen = top;
+                       spin_unlock_bh(&call->lock);
+               }
        }
 
-       rxrpc_put_call(call);
-       _leave(" = %d", ret);
+out:
+       rxrpc_put_connection(conn);
+       kfree(pkt);
        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.
+/*
+ * Send an ABORT call packet.
  */
-int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg,
-                          size_t len)
+int rxrpc_send_abort_packet(struct rxrpc_call *call)
 {
+       struct rxrpc_connection *conn = NULL;
+       struct rxrpc_abort_buffer pkt;
+       struct msghdr msg;
+       struct kvec iov[1];
+       rxrpc_serial_t serial;
        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);
+       spin_lock_bh(&call->lock);
+       if (call->conn)
+               conn = rxrpc_get_connection_maybe(call->conn);
+       spin_unlock_bh(&call->lock);
+       if (!conn)
+               return -ECONNRESET;
 
-       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);
+       msg.msg_name    = &call->peer->srx.transport;
+       msg.msg_namelen = call->peer->srx.transport_len;
+       msg.msg_control = NULL;
+       msg.msg_controllen = 0;
+       msg.msg_flags   = 0;
+
+       pkt.whdr.epoch          = htonl(conn->proto.epoch);
+       pkt.whdr.cid            = htonl(call->cid);
+       pkt.whdr.callNumber     = htonl(call->call_id);
+       pkt.whdr.seq            = 0;
+       pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
+       pkt.whdr.flags          = conn->out_clientflag;
+       pkt.whdr.userStatus     = 0;
+       pkt.whdr.securityIndex  = call->security_ix;
+       pkt.whdr._rsvd          = 0;
+       pkt.whdr.serviceId      = htons(call->service_id);
+       pkt.abort_code          = htonl(call->abort_code);
+
+       iov[0].iov_base = &pkt;
+       iov[0].iov_len  = sizeof(pkt);
+
+       serial = atomic_inc_return(&conn->serial);
+       pkt.whdr.serial = htonl(serial);
+
+       ret = kernel_sendmsg(conn->params.local->socket,
+                            &msg, iov, 1, sizeof(pkt));
+
+       rxrpc_put_connection(conn);
        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 packet through the transport endpoint
  */
-int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
+int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
+                          bool retrans)
 {
-       struct kvec iov[1];
+       struct rxrpc_connection *conn = call->conn;
+       struct rxrpc_wire_header whdr;
+       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
        struct msghdr msg;
+       struct kvec iov[2];
+       rxrpc_serial_t serial;
+       size_t len;
+       bool lost = false;
        int ret, opt;
 
        _enter(",{%d}", skb->len);
 
-       iov[0].iov_base = skb->head;
-       iov[0].iov_len = skb->len;
+       /* Each transmission of a Tx packet needs a new serial number */
+       serial = atomic_inc_return(&conn->serial);
+
+       whdr.epoch      = htonl(conn->proto.epoch);
+       whdr.cid        = htonl(call->cid);
+       whdr.callNumber = htonl(call->call_id);
+       whdr.seq        = htonl(sp->hdr.seq);
+       whdr.serial     = htonl(serial);
+       whdr.type       = RXRPC_PACKET_TYPE_DATA;
+       whdr.flags      = sp->hdr.flags;
+       whdr.userStatus = 0;
+       whdr.securityIndex = call->security_ix;
+       whdr._rsvd      = htons(sp->hdr._rsvd);
+       whdr.serviceId  = htons(call->service_id);
 
-       msg.msg_name = &conn->params.peer->srx.transport;
-       msg.msg_namelen = conn->params.peer->srx.transport_len;
+       iov[0].iov_base = &whdr;
+       iov[0].iov_len = sizeof(whdr);
+       iov[1].iov_base = skb->head;
+       iov[1].iov_len = skb->len;
+       len = iov[0].iov_len + iov[1].iov_len;
+
+       msg.msg_name = &call->peer->srx.transport;
+       msg.msg_namelen = call->peer->srx.transport_len;
        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_wire_header) < conn->params.peer->maxdata) {
-               down_read(&conn->params.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(conn->params.local->socket, &msg, iov, 1,
-                                    iov[0].iov_len);
+       /* If our RTT cache needs working on, request an ACK.  Also request
+        * ACKs if a DATA packet appears to have been lost.
+        */
+       if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
+           (retrans ||
+            call->cong_mode == RXRPC_CALL_SLOW_START ||
+            (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
+            ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
+                         ktime_get_real())))
+               whdr.flags |= RXRPC_REQUEST_ACK;
+
+       if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+               static int lose;
+               if ((lose++ & 7) == 7) {
+                       ret = 0;
+                       lost = true;
+                       goto done;
+               }
+       }
 
-               up_read(&conn->params.local->defrag_sem);
-               if (ret == -EMSGSIZE)
-                       goto send_fragmentable;
+       _proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
 
-               _leave(" = %d [%u]", ret, conn->params.peer->maxdata);
-               return ret;
+       /* send the packet with the don't fragment bit set if we currently
+        * think it's small enough */
+       if (iov[1].iov_len >= call->peer->maxdata)
+               goto send_fragmentable;
+
+       down_read(&conn->params.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(conn->params.local->socket, &msg, iov, 2, len);
+
+       up_read(&conn->params.local->defrag_sem);
+       if (ret == -EMSGSIZE)
+               goto send_fragmentable;
+
+done:
+       trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
+                           retrans, lost);
+       if (ret >= 0) {
+               ktime_t now = ktime_get_real();
+               skb->tstamp = now;
+               smp_wmb();
+               sp->hdr.serial = serial;
+               if (whdr.flags & RXRPC_REQUEST_ACK) {
+                       call->peer->rtt_last_req = now;
+                       trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
+               }
        }
+       _leave(" = %d [%u]", ret, call->peer->maxdata);
+       return ret;
 
 send_fragmentable:
        /* attempt to send this message with fragmentation enabled */
@@ -358,8 +373,8 @@ send_fragmentable:
                                        SOL_IP, IP_MTU_DISCOVER,
                                        (char *)&opt, sizeof(opt));
                if (ret == 0) {
-                       ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
-                                            iov[0].iov_len);
+                       ret = kernel_sendmsg(conn->params.local->socket, &msg,
+                                            iov, 2, len);
 
                        opt = IP_PMTUDISC_DO;
                        kernel_setsockopt(conn->params.local->socket, SOL_IP,
@@ -367,355 +382,82 @@ send_fragmentable:
                                          (char *)&opt, sizeof(opt));
                }
                break;
-       }
-
-       up_write(&conn->params.local->defrag_sem);
-       _leave(" = %d [frag %u]", ret, conn->params.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, ACCESS_ONCE(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, ACCESS_ONCE(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_EV_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;
+#ifdef CONFIG_AF_RXRPC_IPV6
+       case AF_INET6:
+               opt = IPV6_PMTUDISC_DONT;
+               ret = kernel_setsockopt(conn->params.local->socket,
+                                       SOL_IPV6, IPV6_MTU_DISCOVER,
+                                       (char *)&opt, sizeof(opt));
+               if (ret == 0) {
+                       ret = kernel_sendmsg(conn->params.local->socket, &msg,
+                                            iov, 1, iov[0].iov_len);
 
-       _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;
+                       opt = IPV6_PMTUDISC_DO;
+                       kernel_setsockopt(conn->params.local->socket,
+                                         SOL_IPV6, IPV6_MTU_DISCOVER,
+                                         (char *)&opt, sizeof(opt));
                }
-               write_unlock_bh(&call->state_lock);
-       }
-
-       _proto("Tx DATA %%%u { #%u }", sp->hdr.serial, 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_data_packet(call->conn, 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);
+               break;
+#endif
        }
 
-       _leave("");
-}
-
-/*
- * Convert a host-endian header into a network-endian header.
- */
-static void rxrpc_insert_header(struct sk_buff *skb)
-{
-       struct rxrpc_wire_header whdr;
-       struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
-
-       whdr.epoch      = htonl(sp->hdr.epoch);
-       whdr.cid        = htonl(sp->hdr.cid);
-       whdr.callNumber = htonl(sp->hdr.callNumber);
-       whdr.seq        = htonl(sp->hdr.seq);
-       whdr.serial     = htonl(sp->hdr.serial);
-       whdr.type       = sp->hdr.type;
-       whdr.flags      = sp->hdr.flags;
-       whdr.userStatus = sp->hdr.userStatus;
-       whdr.securityIndex = sp->hdr.securityIndex;
-       whdr._rsvd      = htons(sp->hdr._rsvd);
-       whdr.serviceId  = htons(sp->hdr.serviceId);
-
-       memcpy(skb->head, &whdr, sizeof(whdr));
+       up_write(&conn->params.local->defrag_sem);
+       goto done;
 }
 
 /*
- * send data through a socket
- * - must be called in process context
- * - caller holds the socket locked
+ * reject packets through the local endpoint
  */
-static int rxrpc_send_data(struct rxrpc_sock *rx,
-                          struct rxrpc_call *call,
-                          struct msghdr *msg, size_t len)
+void rxrpc_reject_packets(struct rxrpc_local *local)
 {
+       struct sockaddr_rxrpc srx;
        struct rxrpc_skb_priv *sp;
+       struct rxrpc_wire_header whdr;
        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 */
-       sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
-
-       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,
-                                      ACCESS_ONCE(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->params.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);
+       struct msghdr msg;
+       struct kvec iov[2];
+       size_t size;
+       __be32 code;
 
-                       ASSERTCMP(skb->mark, ==, 0);
+       _enter("%d", local->debug_id);
 
-                       _debug("HS: %u", call->conn->header_size);
-                       skb_reserve(skb, call->conn->header_size);
-                       skb->len += call->conn->header_size;
+       iov[0].iov_base = &whdr;
+       iov[0].iov_len = sizeof(whdr);
+       iov[1].iov_base = &code;
+       iov[1].iov_len = sizeof(code);
+       size = sizeof(whdr) + sizeof(code);
 
-                       sp = rxrpc_skb(skb);
-                       sp->remain = chunk;
-                       if (sp->remain > skb_tailroom(skb))
-                               sp->remain = skb_tailroom(skb);
+       msg.msg_name = &srx.transport;
+       msg.msg_control = NULL;
+       msg.msg_controllen = 0;
+       msg.msg_flags = 0;
 
-                       _net("skb: hr %d, tr %d, hl %d, rm %d",
-                              skb_headroom(skb),
-                              skb_tailroom(skb),
-                              skb_headlen(skb),
-                              sp->remain);
+       memset(&whdr, 0, sizeof(whdr));
+       whdr.type = RXRPC_PACKET_TYPE_ABORT;
 
-                       skb->ip_summed = CHECKSUM_UNNECESSARY;
-               }
-
-               _debug("append");
+       while ((skb = skb_dequeue(&local->reject_queue))) {
+               rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
                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;
-               }
+               if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
+                       msg.msg_namelen = srx.transport_len;
 
-               /* 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_ix) {
-                               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->proto.epoch;
-                       sp->hdr.cid     = call->cid;
-                       sp->hdr.callNumber = call->call_id;
-                       sp->hdr.seq     = seq;
-                       sp->hdr.serial  = 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 = call->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,
-                                           ACCESS_ONCE(call->acks_tail),
-                                           call->acks_winsz) > 1)
-                               sp->hdr.flags |= RXRPC_MORE_PACKETS;
-                       if (more && seq & 1)
-                               sp->hdr.flags |= RXRPC_REQUEST_ACK;
-
-                       ret = conn->security->secure_packet(
-                               call, skb, skb->mark,
-                               skb->head + sizeof(struct rxrpc_wire_header));
-                       if (ret < 0)
-                               goto out;
-
-                       rxrpc_insert_header(skb);
-                       rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
-                       skb = NULL;
-               }
-       } while (msg_data_left(msg) > 0);
+                       code = htonl(skb->priority);
 
-success:
-       ret = copied;
-out:
-       call->tx_pending = skb;
-       _leave(" = %d", ret);
-       return ret;
+                       whdr.epoch      = htonl(sp->hdr.epoch);
+                       whdr.cid        = htonl(sp->hdr.cid);
+                       whdr.callNumber = htonl(sp->hdr.callNumber);
+                       whdr.serviceId  = htons(sp->hdr.serviceId);
+                       whdr.flags      = sp->hdr.flags;
+                       whdr.flags      ^= RXRPC_CLIENT_INITIATED;
+                       whdr.flags      &= RXRPC_CLIENT_INITIATED;
 
-call_aborted:
-       rxrpc_free_skb(skb);
-       if (call->state == RXRPC_CALL_NETWORK_ERROR)
-               ret = call->error_report < RXRPC_LOCAL_ERROR_OFFSET ?
-                       call->error_report :
-                       call->error_report - RXRPC_LOCAL_ERROR_OFFSET;
-       else
-               ret = -ECONNABORTED;
-       _leave(" = %d", ret);
-       return ret;
+                       kernel_sendmsg(local->socket, &msg, iov, 2, size);
+               }
 
-maybe_error:
-       if (copied)
-               goto success;
-       goto out;
+               rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
+       }
 
-efault:
-       ret = -EFAULT;
-       goto out;
+       _leave("");
 }