net/rxrpc/output.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* RxRPC packet transmission
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/net.h>
  11 #include <linux/gfp.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/export.h>
  14 #include <net/sock.h>
  15 #include <net/af_rxrpc.h>
  16 #include <net/udp.h>
  17 #include "ar-internal.h"
  18
  19 struct rxrpc_ack_buffer {
  20         struct rxrpc_wire_header whdr;
  21         struct rxrpc_ackpacket ack;
  22         u8 acks[255];
  23         u8 pad[3];
  24         struct rxrpc_ackinfo ackinfo;
  25 };
  26
  27 extern int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
  28
  29 static ssize_t do_udp_sendmsg(struct socket *sk, struct msghdr *msg, size_t len)
  30 {
  31 #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
  32         struct sockaddr *sa = msg->msg_name;
  33
  34         if (sa->sa_family == AF_INET6)
  35                 return udpv6_sendmsg(sk->sk, msg, len);
  36 #endif
  37         return udp_sendmsg(sk->sk, msg, len);
  38 }
  39
  40 struct rxrpc_abort_buffer {
  41         struct rxrpc_wire_header whdr;
  42         __be32 abort_code;
  43 };
  44
  45 static const char rxrpc_keepalive_string[] = "";
  46
  47 /*
  48  * Increase Tx backoff on transmission failure and clear it on success.
  49  */
  50 static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
  51 {
  52         if (ret < 0) {
  53                 u16 tx_backoff = READ_ONCE(call->tx_backoff);
  54
  55                 if (tx_backoff < HZ)
  56                         WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
  57         } else {
  58                 WRITE_ONCE(call->tx_backoff, 0);
  59         }
  60 }
  61
  62 /*
  63  * Arrange for a keepalive ping a certain time after we last transmitted.  This
  64  * lets the far side know we're still interested in this call and helps keep
  65  * the route through any intervening firewall open.
  66  *
  67  * Receiving a response to the ping will prevent the ->expect_rx_by timer from
  68  * expiring.
  69  */
  70 static void rxrpc_set_keepalive(struct rxrpc_call *call)
  71 {
  72         unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
  73
  74         keepalive_at += now;
  75         WRITE_ONCE(call->keepalive_at, keepalive_at);
  76         rxrpc_reduce_call_timer(call, keepalive_at, now,
  77                                 rxrpc_timer_set_for_keepalive);
  78 }
  79
  80 /*
  81  * Fill out an ACK packet.
  82  */
  83 static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
  84                                  struct rxrpc_call *call,
  85                                  struct rxrpc_ack_buffer *pkt,
  86                                  rxrpc_seq_t *_hard_ack,
  87                                  rxrpc_seq_t *_top,
  88                                  u8 reason)
  89 {
  90         rxrpc_serial_t serial;
  91         unsigned int tmp;
  92         rxrpc_seq_t hard_ack, top, seq;
  93         int ix;
  94         u32 mtu, jmax;
  95         u8 *ackp = pkt->acks;
  96
  97         tmp = atomic_xchg(&call->ackr_nr_unacked, 0);
  98         tmp |= atomic_xchg(&call->ackr_nr_consumed, 0);
  99         if (!tmp && (reason == RXRPC_ACK_DELAY ||
 100                      reason == RXRPC_ACK_IDLE)) {
 101                 rxrpc_inc_stat(call->rxnet, stat_tx_ack_skip);
 102                 return 0;
 103         }
 104
 105         rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill);
 106
 107         /* Barrier against rxrpc_input_data(). */
 108         serial = call->ackr_serial;
 109         hard_ack = READ_ONCE(call->rx_hard_ack);
 110         top = smp_load_acquire(&call->rx_top);
 111         *_hard_ack = hard_ack;
 112         *_top = top;
 113
 114         pkt->ack.bufferSpace    = htons(0);
 115         pkt->ack.maxSkew        = htons(0);
 116         pkt->ack.firstPacket    = htonl(hard_ack + 1);
 117         pkt->ack.previousPacket = htonl(call->ackr_highest_seq);
 118         pkt->ack.serial         = htonl(serial);
 119         pkt->ack.reason         = reason;
 120         pkt->ack.nAcks          = top - hard_ack;
 121
 122         if (reason == RXRPC_ACK_PING)
 123                 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
 124
 125         if (after(top, hard_ack)) {
 126                 seq = hard_ack + 1;
 127                 do {
 128                         ix = seq & RXRPC_RXTX_BUFF_MASK;
 129                         if (call->rxtx_buffer[ix])
 130                                 *ackp++ = RXRPC_ACK_TYPE_ACK;
 131                         else
 132                                 *ackp++ = RXRPC_ACK_TYPE_NACK;
 133                         seq++;
 134                 } while (before_eq(seq, top));
 135         }
 136
 137         mtu = conn->params.peer->if_mtu;
 138         mtu -= conn->params.peer->hdrsize;
 139         jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
 140         pkt->ackinfo.rxMTU      = htonl(rxrpc_rx_mtu);
 141         pkt->ackinfo.maxMTU     = htonl(mtu);
 142         pkt->ackinfo.rwind      = htonl(call->rx_winsize);
 143         pkt->ackinfo.jumbo_max  = htonl(jmax);
 144
 145         *ackp++ = 0;
 146         *ackp++ = 0;
 147         *ackp++ = 0;
 148         return top - hard_ack + 3;
 149 }
 150
 151 /*
 152  * Record the beginning of an RTT probe.
 153  */
 154 static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
 155                                  enum rxrpc_rtt_tx_trace why)
 156 {
 157         unsigned long avail = call->rtt_avail;
 158         int rtt_slot = 9;
 159
 160         if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
 161                 goto no_slot;
 162
 163         rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
 164         if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
 165                 goto no_slot;
 166
 167         call->rtt_serial[rtt_slot] = serial;
 168         call->rtt_sent_at[rtt_slot] = ktime_get_real();
 169         smp_wmb(); /* Write data before avail bit */
 170         set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
 171
 172         trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
 173         return rtt_slot;
 174
 175 no_slot:
 176         trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
 177         return -1;
 178 }
 179
 180 /*
 181  * Cancel an RTT probe.
 182  */
 183 static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
 184                                    rxrpc_serial_t serial, int rtt_slot)
 185 {
 186         if (rtt_slot != -1) {
 187                 clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
 188                 smp_wmb(); /* Clear pending bit before setting slot */
 189                 set_bit(rtt_slot, &call->rtt_avail);
 190                 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial);
 191         }
 192 }
 193
 194 /*
 195  * Send an ACK call packet.
 196  */
 197 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 198                           rxrpc_serial_t *_serial)
 199 {
 200         struct rxrpc_connection *conn;
 201         struct rxrpc_ack_buffer *pkt;
 202         struct msghdr msg;
 203         struct kvec iov[2];
 204         rxrpc_serial_t serial;
 205         rxrpc_seq_t hard_ack, top;
 206         size_t len, n;
 207         int ret, rtt_slot = -1;
 208         u8 reason;
 209
 210         if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 211                 return -ECONNRESET;
 212
 213         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 214         if (!pkt)
 215                 return -ENOMEM;
 216
 217         conn = call->conn;
 218
 219         msg.msg_name    = &call->peer->srx.transport;
 220         msg.msg_namelen = call->peer->srx.transport_len;
 221         msg.msg_control = NULL;
 222         msg.msg_controllen = 0;
 223         msg.msg_flags   = 0;
 224
 225         pkt->whdr.epoch         = htonl(conn->proto.epoch);
 226         pkt->whdr.cid           = htonl(call->cid);
 227         pkt->whdr.callNumber    = htonl(call->call_id);
 228         pkt->whdr.seq           = 0;
 229         pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
 230         pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
 231         pkt->whdr.userStatus    = 0;
 232         pkt->whdr.securityIndex = call->security_ix;
 233         pkt->whdr._rsvd         = 0;
 234         pkt->whdr.serviceId     = htons(call->service_id);
 235
 236         spin_lock_bh(&call->lock);
 237         if (ping) {
 238                 reason = RXRPC_ACK_PING;
 239         } else {
 240                 reason = call->ackr_reason;
 241                 if (!call->ackr_reason) {
 242                         spin_unlock_bh(&call->lock);
 243                         ret = 0;
 244                         goto out;
 245                 }
 246                 call->ackr_reason = 0;
 247         }
 248         n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 249
 250         spin_unlock_bh(&call->lock);
 251         if (n == 0) {
 252                 kfree(pkt);
 253                 return 0;
 254         }
 255
 256         iov[0].iov_base = pkt;
 257         iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
 258         iov[1].iov_base = &pkt->ackinfo;
 259         iov[1].iov_len  = sizeof(pkt->ackinfo);
 260         len = iov[0].iov_len + iov[1].iov_len;
 261
 262         serial = atomic_inc_return(&conn->serial);
 263         pkt->whdr.serial = htonl(serial);
 264         trace_rxrpc_tx_ack(call->debug_id, serial,
 265                            ntohl(pkt->ack.firstPacket),
 266                            ntohl(pkt->ack.serial),
 267                            pkt->ack.reason, pkt->ack.nAcks);
 268         if (_serial)
 269                 *_serial = serial;
 270
 271         if (ping)
 272                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);
 273
 274         rxrpc_inc_stat(call->rxnet, stat_tx_ack_send);
 275
 276         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
 277         ret = do_udp_sendmsg(conn->params.local->socket, &msg, len);
 278         call->peer->last_tx_at = ktime_get_seconds();
 279         if (ret < 0)
 280                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 281                                     rxrpc_tx_point_call_ack);
 282         else
 283                 trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
 284                                       rxrpc_tx_point_call_ack);
 285         rxrpc_tx_backoff(call, ret);
 286
 287         if (call->state < RXRPC_CALL_COMPLETE) {
 288                 if (ret < 0) {
 289                         rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 290                         rxrpc_propose_ACK(call, pkt->ack.reason,
 291                                           ntohl(pkt->ack.serial),
 292                                           false, true,
 293                                           rxrpc_propose_ack_retry_tx);
 294                 }
 295
 296                 rxrpc_set_keepalive(call);
 297         }
 298
 299 out:
 300         kfree(pkt);
 301         return ret;
 302 }
 303
 304 /*
 305  * Send an ABORT call packet.
 306  */
 307 int rxrpc_send_abort_packet(struct rxrpc_call *call)
 308 {
 309         struct rxrpc_connection *conn;
 310         struct rxrpc_abort_buffer pkt;
 311         struct msghdr msg;
 312         struct kvec iov[1];
 313         rxrpc_serial_t serial;
 314         int ret;
 315
 316         /* Don't bother sending aborts for a client call once the server has
 317          * hard-ACK'd all of its request data.  After that point, we're not
 318          * going to stop the operation proceeding, and whilst we might limit
 319          * the reply, it's not worth it if we can send a new call on the same
 320          * channel instead, thereby closing off this call.
 321          */
 322         if (rxrpc_is_client_call(call) &&
 323             test_bit(RXRPC_CALL_TX_LAST, &call->flags))
 324                 return 0;
 325
 326         if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 327                 return -ECONNRESET;
 328
 329         conn = call->conn;
 330
 331         msg.msg_name    = &call->peer->srx.transport;
 332         msg.msg_namelen = call->peer->srx.transport_len;
 333         msg.msg_control = NULL;
 334         msg.msg_controllen = 0;
 335         msg.msg_flags   = 0;
 336
 337         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 338         pkt.whdr.cid            = htonl(call->cid);
 339         pkt.whdr.callNumber     = htonl(call->call_id);
 340         pkt.whdr.seq            = 0;
 341         pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
 342         pkt.whdr.flags          = conn->out_clientflag;
 343         pkt.whdr.userStatus     = 0;
 344         pkt.whdr.securityIndex  = call->security_ix;
 345         pkt.whdr._rsvd          = 0;
 346         pkt.whdr.serviceId      = htons(call->service_id);
 347         pkt.abort_code          = htonl(call->abort_code);
 348
 349         iov[0].iov_base = &pkt;
 350         iov[0].iov_len  = sizeof(pkt);
 351
 352         serial = atomic_inc_return(&conn->serial);
 353         pkt.whdr.serial = htonl(serial);
 354
 355         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, sizeof(pkt));
 356         ret = do_udp_sendmsg(conn->params.local->socket, &msg, sizeof(pkt));
 357         conn->params.peer->last_tx_at = ktime_get_seconds();
 358         if (ret < 0)
 359                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 360                                     rxrpc_tx_point_call_abort);
 361         else
 362                 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
 363                                       rxrpc_tx_point_call_abort);
 364         rxrpc_tx_backoff(call, ret);
 365         return ret;
 366 }
 367
 368 /*
 369  * send a packet through the transport endpoint
 370  */
 371 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
 372                            bool retrans)
 373 {
 374         enum rxrpc_req_ack_trace why;
 375         struct rxrpc_connection *conn = call->conn;
 376         struct rxrpc_wire_header whdr;
 377         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 378         struct msghdr msg;
 379         struct kvec iov[2];
 380         rxrpc_serial_t serial;
 381         size_t len;
 382         int ret, rtt_slot = -1;
 383
 384         _enter(",{%d}", skb->len);
 385
 386         if (hlist_unhashed(&call->error_link)) {
 387                 spin_lock_bh(&call->peer->lock);
 388                 hlist_add_head_rcu(&call->error_link, &call->peer->error_targets);
 389                 spin_unlock_bh(&call->peer->lock);
 390         }
 391
 392         /* Each transmission of a Tx packet needs a new serial number */
 393         serial = atomic_inc_return(&conn->serial);
 394
 395         whdr.epoch      = htonl(conn->proto.epoch);
 396         whdr.cid        = htonl(call->cid);
 397         whdr.callNumber = htonl(call->call_id);
 398         whdr.seq        = htonl(sp->hdr.seq);
 399         whdr.serial     = htonl(serial);
 400         whdr.type       = RXRPC_PACKET_TYPE_DATA;
 401         whdr.flags      = sp->hdr.flags;
 402         whdr.userStatus = 0;
 403         whdr.securityIndex = call->security_ix;
 404         whdr._rsvd      = htons(sp->hdr._rsvd);
 405         whdr.serviceId  = htons(call->service_id);
 406
 407         if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
 408             sp->hdr.seq == 1)
 409                 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
 410
 411         iov[0].iov_base = &whdr;
 412         iov[0].iov_len = sizeof(whdr);
 413         iov[1].iov_base = skb->head;
 414         iov[1].iov_len = skb->len;
 415         len = iov[0].iov_len + iov[1].iov_len;
 416         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
 417
 418         msg.msg_name = &call->peer->srx.transport;
 419         msg.msg_namelen = call->peer->srx.transport_len;
 420         msg.msg_control = NULL;
 421         msg.msg_controllen = 0;
 422         msg.msg_flags = 0;
 423
 424         /* If our RTT cache needs working on, request an ACK.  Also request
 425          * ACKs if a DATA packet appears to have been lost.
 426          *
 427          * However, we mustn't request an ACK on the last reply packet of a
 428          * service call, lest OpenAFS incorrectly send us an ACK with some
 429          * soft-ACKs in it and then never follow up with a proper hard ACK.
 430          */
 431         if (whdr.flags & RXRPC_REQUEST_ACK)
 432                 why = rxrpc_reqack_already_on;
 433         else if ((whdr.flags & RXRPC_LAST_PACKET) && rxrpc_to_client(sp))
 434                 why = rxrpc_reqack_no_srv_last;
 435         else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events))
 436                 why = rxrpc_reqack_ack_lost;
 437         else if (retrans)
 438                 why = rxrpc_reqack_retrans;
 439         else if (call->cong_mode == RXRPC_CALL_SLOW_START && call->cong_cwnd <= 2)
 440                 why = rxrpc_reqack_slow_start;
 441         else if (call->tx_winsize <= 2)
 442                 why = rxrpc_reqack_small_txwin;
 443         else if (call->peer->rtt_count < 3 && sp->hdr.seq & 1)
 444                 why = rxrpc_reqack_more_rtt;
 445         else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real()))
 446                 why = rxrpc_reqack_old_rtt;
 447         else
 448                 goto dont_set_request_ack;
 449
 450         rxrpc_inc_stat(call->rxnet, stat_why_req_ack[why]);
 451         trace_rxrpc_req_ack(call->debug_id, sp->hdr.seq, why);
 452         if (why != rxrpc_reqack_no_srv_last)
 453                 whdr.flags |= RXRPC_REQUEST_ACK;
 454 dont_set_request_ack:
 455
 456         if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
 457                 static int lose;
 458                 if ((lose++ & 7) == 7) {
 459                         ret = 0;
 460                         trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
 461                                             whdr.flags, retrans, true);
 462                         goto done;
 463                 }
 464         }
 465
 466         trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
 467                             false);
 468
 469         /* send the packet with the don't fragment bit set if we currently
 470          * think it's small enough */
 471         if (iov[1].iov_len >= call->peer->maxdata)
 472                 goto send_fragmentable;
 473
 474         down_read(&conn->params.local->defrag_sem);
 475
 476         sp->hdr.serial = serial;
 477         smp_wmb(); /* Set serial before timestamp */
 478         skb->tstamp = ktime_get_real();
 479         if (whdr.flags & RXRPC_REQUEST_ACK)
 480                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
 481
 482         /* send the packet by UDP
 483          * - returns -EMSGSIZE if UDP would have to fragment the packet
 484          *   to go out of the interface
 485          *   - in which case, we'll have processed the ICMP error
 486          *     message and update the peer record
 487          */
 488         rxrpc_inc_stat(call->rxnet, stat_tx_data_send);
 489         ret = do_udp_sendmsg(conn->params.local->socket, &msg, len);
 490         conn->params.peer->last_tx_at = ktime_get_seconds();
 491
 492         up_read(&conn->params.local->defrag_sem);
 493         if (ret < 0) {
 494                 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 495                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 496                                     rxrpc_tx_point_call_data_nofrag);
 497         } else {
 498                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 499                                       rxrpc_tx_point_call_data_nofrag);
 500         }
 501
 502         rxrpc_tx_backoff(call, ret);
 503         if (ret == -EMSGSIZE)
 504                 goto send_fragmentable;
 505
 506 done:
 507         if (ret >= 0) {
 508                 if (whdr.flags & RXRPC_REQUEST_ACK) {
 509                         call->peer->rtt_last_req = skb->tstamp;
 510                         if (call->peer->rtt_count > 1) {
 511                                 unsigned long nowj = jiffies, ack_lost_at;
 512
 513                                 ack_lost_at = rxrpc_get_rto_backoff(call->peer, false);
 514                                 ack_lost_at += nowj;
 515                                 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
 516                                 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
 517                                                         rxrpc_timer_set_for_lost_ack);
 518                         }
 519                 }
 520
 521                 if (sp->hdr.seq == 1 &&
 522                     !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
 523                                       &call->flags)) {
 524                         unsigned long nowj = jiffies, expect_rx_by;
 525
 526                         expect_rx_by = nowj + call->next_rx_timo;
 527                         WRITE_ONCE(call->expect_rx_by, expect_rx_by);
 528                         rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
 529                                                 rxrpc_timer_set_for_normal);
 530                 }
 531
 532                 rxrpc_set_keepalive(call);
 533         } else {
 534                 /* Cancel the call if the initial transmission fails,
 535                  * particularly if that's due to network routing issues that
 536                  * aren't going away anytime soon.  The layer above can arrange
 537                  * the retransmission.
 538                  */
 539                 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
 540                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 541                                                   RX_USER_ABORT, ret);
 542         }
 543
 544         _leave(" = %d [%u]", ret, call->peer->maxdata);
 545         return ret;
 546
 547 send_fragmentable:
 548         /* attempt to send this message with fragmentation enabled */
 549         _debug("send fragment");
 550
 551         down_write(&conn->params.local->defrag_sem);
 552
 553         sp->hdr.serial = serial;
 554         smp_wmb(); /* Set serial before timestamp */
 555         skb->tstamp = ktime_get_real();
 556         if (whdr.flags & RXRPC_REQUEST_ACK)
 557                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
 558
 559         switch (conn->params.local->srx.transport.family) {
 560         case AF_INET6:
 561         case AF_INET:
 562                 ip_sock_set_mtu_discover(conn->params.local->socket->sk,
 563                                 IP_PMTUDISC_DONT);
 564                 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_frag);
 565                 ret = do_udp_sendmsg(conn->params.local->socket, &msg, len);
 566                 conn->params.peer->last_tx_at = ktime_get_seconds();
 567
 568                 ip_sock_set_mtu_discover(conn->params.local->socket->sk,
 569                                 IP_PMTUDISC_DO);
 570                 break;
 571
 572         default:
 573                 BUG();
 574         }
 575
 576         if (ret < 0) {
 577                 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 578                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 579                                     rxrpc_tx_point_call_data_frag);
 580         } else {
 581                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 582                                       rxrpc_tx_point_call_data_frag);
 583         }
 584         rxrpc_tx_backoff(call, ret);
 585
 586         up_write(&conn->params.local->defrag_sem);
 587         goto done;
 588 }
 589
 590 /*
 591  * reject packets through the local endpoint
 592  */
 593 void rxrpc_reject_packets(struct rxrpc_local *local)
 594 {
 595         struct sockaddr_rxrpc srx;
 596         struct rxrpc_skb_priv *sp;
 597         struct rxrpc_wire_header whdr;
 598         struct sk_buff *skb;
 599         struct msghdr msg;
 600         struct kvec iov[2];
 601         size_t size;
 602         __be32 code;
 603         int ret, ioc;
 604
 605         _enter("%d", local->debug_id);
 606
 607         iov[0].iov_base = &whdr;
 608         iov[0].iov_len = sizeof(whdr);
 609         iov[1].iov_base = &code;
 610         iov[1].iov_len = sizeof(code);
 611
 612         msg.msg_name = &srx.transport;
 613         msg.msg_control = NULL;
 614         msg.msg_controllen = 0;
 615         msg.msg_flags = 0;
 616
 617         memset(&whdr, 0, sizeof(whdr));
 618
 619         while ((skb = skb_dequeue(&local->reject_queue))) {
 620                 rxrpc_see_skb(skb, rxrpc_skb_seen);
 621                 sp = rxrpc_skb(skb);
 622
 623                 switch (skb->mark) {
 624                 case RXRPC_SKB_MARK_REJECT_BUSY:
 625                         whdr.type = RXRPC_PACKET_TYPE_BUSY;
 626                         size = sizeof(whdr);
 627                         ioc = 1;
 628                         break;
 629                 case RXRPC_SKB_MARK_REJECT_ABORT:
 630                         whdr.type = RXRPC_PACKET_TYPE_ABORT;
 631                         code = htonl(skb->priority);
 632                         size = sizeof(whdr) + sizeof(code);
 633                         ioc = 2;
 634                         break;
 635                 default:
 636                         rxrpc_free_skb(skb, rxrpc_skb_freed);
 637                         continue;
 638                 }
 639
 640                 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
 641                         msg.msg_namelen = srx.transport_len;
 642
 643                         whdr.epoch      = htonl(sp->hdr.epoch);
 644                         whdr.cid        = htonl(sp->hdr.cid);
 645                         whdr.callNumber = htonl(sp->hdr.callNumber);
 646                         whdr.serviceId  = htons(sp->hdr.serviceId);
 647                         whdr.flags      = sp->hdr.flags;
 648                         whdr.flags      ^= RXRPC_CLIENT_INITIATED;
 649                         whdr.flags      &= RXRPC_CLIENT_INITIATED;
 650
 651                         iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size);
 652                         ret = do_udp_sendmsg(local->socket, &msg, size);
 653                         if (ret < 0)
 654                                 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
 655                                                     rxrpc_tx_point_reject);
 656                         else
 657                                 trace_rxrpc_tx_packet(local->debug_id, &whdr,
 658                                                       rxrpc_tx_point_reject);
 659                 }
 660
 661                 rxrpc_free_skb(skb, rxrpc_skb_freed);
 662         }
 663
 664         _leave("");
 665 }
 666
 667 /*
 668  * Send a VERSION reply to a peer as a keepalive.
 669  */
 670 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
 671 {
 672         struct rxrpc_wire_header whdr;
 673         struct msghdr msg;
 674         struct kvec iov[2];
 675         size_t len;
 676         int ret;
 677
 678         _enter("");
 679
 680         msg.msg_name    = &peer->srx.transport;
 681         msg.msg_namelen = peer->srx.transport_len;
 682         msg.msg_control = NULL;
 683         msg.msg_controllen = 0;
 684         msg.msg_flags   = 0;
 685
 686         whdr.epoch      = htonl(peer->local->rxnet->epoch);
 687         whdr.cid        = 0;
 688         whdr.callNumber = 0;
 689         whdr.seq        = 0;
 690         whdr.serial     = 0;
 691         whdr.type       = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
 692         whdr.flags      = RXRPC_LAST_PACKET;
 693         whdr.userStatus = 0;
 694         whdr.securityIndex = 0;
 695         whdr._rsvd      = 0;
 696         whdr.serviceId  = 0;
 697
 698         iov[0].iov_base = &whdr;
 699         iov[0].iov_len  = sizeof(whdr);
 700         iov[1].iov_base = (char *)rxrpc_keepalive_string;
 701         iov[1].iov_len  = sizeof(rxrpc_keepalive_string);
 702
 703         len = iov[0].iov_len + iov[1].iov_len;
 704
 705         _proto("Tx VERSION (keepalive)");
 706
 707         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
 708         ret = do_udp_sendmsg(peer->local->socket, &msg, len);
 709         if (ret < 0)
 710                 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
 711                                     rxrpc_tx_point_version_keepalive);
 712         else
 713                 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
 714                                       rxrpc_tx_point_version_keepalive);
 715
 716         peer->last_tx_at = ktime_get_seconds();
 717         _leave("");
 718 }