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 "ar-internal.h"
  17
  18 struct rxrpc_ack_buffer {
  19         struct rxrpc_wire_header whdr;
  20         struct rxrpc_ackpacket ack;
  21         u8 acks[255];
  22         u8 pad[3];
  23         struct rxrpc_ackinfo ackinfo;
  24 };
  25
  26 struct rxrpc_abort_buffer {
  27         struct rxrpc_wire_header whdr;
  28         __be32 abort_code;
  29 };
  30
  31 static const char rxrpc_keepalive_string[] = "";
  32
  33 /*
  34  * Increase Tx backoff on transmission failure and clear it on success.
  35  */
  36 static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
  37 {
  38         if (ret < 0) {
  39                 u16 tx_backoff = READ_ONCE(call->tx_backoff);
  40
  41                 if (tx_backoff < HZ)
  42                         WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
  43         } else {
  44                 WRITE_ONCE(call->tx_backoff, 0);
  45         }
  46 }
  47
  48 /*
  49  * Arrange for a keepalive ping a certain time after we last transmitted.  This
  50  * lets the far side know we're still interested in this call and helps keep
  51  * the route through any intervening firewall open.
  52  *
  53  * Receiving a response to the ping will prevent the ->expect_rx_by timer from
  54  * expiring.
  55  */
  56 static void rxrpc_set_keepalive(struct rxrpc_call *call)
  57 {
  58         unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
  59
  60         keepalive_at += now;
  61         WRITE_ONCE(call->keepalive_at, keepalive_at);
  62         rxrpc_reduce_call_timer(call, keepalive_at, now,
  63                                 rxrpc_timer_set_for_keepalive);
  64 }
  65
  66 /*
  67  * Fill out an ACK packet.
  68  */
  69 static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
  70                                  struct rxrpc_call *call,
  71                                  struct rxrpc_ack_buffer *pkt,
  72                                  rxrpc_seq_t *_hard_ack,
  73                                  rxrpc_seq_t *_top,
  74                                  u8 reason)
  75 {
  76         rxrpc_serial_t serial;
  77         rxrpc_seq_t hard_ack, top, seq;
  78         int ix;
  79         u32 mtu, jmax;
  80         u8 *ackp = pkt->acks;
  81
  82         /* Barrier against rxrpc_input_data(). */
  83         serial = call->ackr_serial;
  84         hard_ack = READ_ONCE(call->rx_hard_ack);
  85         top = smp_load_acquire(&call->rx_top);
  86         *_hard_ack = hard_ack;
  87         *_top = top;
  88
  89         pkt->ack.bufferSpace    = htons(8);
  90         pkt->ack.maxSkew        = htons(call->ackr_skew);
  91         pkt->ack.firstPacket    = htonl(hard_ack + 1);
  92         pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
  93         pkt->ack.serial         = htonl(serial);
  94         pkt->ack.reason         = reason;
  95         pkt->ack.nAcks          = top - hard_ack;
  96
  97         if (reason == RXRPC_ACK_PING)
  98                 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
  99
 100         if (after(top, hard_ack)) {
 101                 seq = hard_ack + 1;
 102                 do {
 103                         ix = seq & RXRPC_RXTX_BUFF_MASK;
 104                         if (call->rxtx_buffer[ix])
 105                                 *ackp++ = RXRPC_ACK_TYPE_ACK;
 106                         else
 107                                 *ackp++ = RXRPC_ACK_TYPE_NACK;
 108                         seq++;
 109                 } while (before_eq(seq, top));
 110         }
 111
 112         mtu = conn->params.peer->if_mtu;
 113         mtu -= conn->params.peer->hdrsize;
 114         jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
 115         pkt->ackinfo.rxMTU      = htonl(rxrpc_rx_mtu);
 116         pkt->ackinfo.maxMTU     = htonl(mtu);
 117         pkt->ackinfo.rwind      = htonl(call->rx_winsize);
 118         pkt->ackinfo.jumbo_max  = htonl(jmax);
 119
 120         *ackp++ = 0;
 121         *ackp++ = 0;
 122         *ackp++ = 0;
 123         return top - hard_ack + 3;
 124 }
 125
 126 /*
 127  * Send an ACK call packet.
 128  */
 129 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 130                           rxrpc_serial_t *_serial)
 131 {
 132         struct rxrpc_connection *conn = NULL;
 133         struct rxrpc_ack_buffer *pkt;
 134         struct msghdr msg;
 135         struct kvec iov[2];
 136         rxrpc_serial_t serial;
 137         rxrpc_seq_t hard_ack, top;
 138         size_t len, n;
 139         int ret;
 140         u8 reason;
 141
 142         spin_lock_bh(&call->lock);
 143         if (call->conn)
 144                 conn = rxrpc_get_connection_maybe(call->conn);
 145         spin_unlock_bh(&call->lock);
 146         if (!conn)
 147                 return -ECONNRESET;
 148
 149         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 150         if (!pkt) {
 151                 rxrpc_put_connection(conn);
 152                 return -ENOMEM;
 153         }
 154
 155         msg.msg_name    = &call->peer->srx.transport;
 156         msg.msg_namelen = call->peer->srx.transport_len;
 157         msg.msg_control = NULL;
 158         msg.msg_controllen = 0;
 159         msg.msg_flags   = 0;
 160
 161         pkt->whdr.epoch         = htonl(conn->proto.epoch);
 162         pkt->whdr.cid           = htonl(call->cid);
 163         pkt->whdr.callNumber    = htonl(call->call_id);
 164         pkt->whdr.seq           = 0;
 165         pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
 166         pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
 167         pkt->whdr.userStatus    = 0;
 168         pkt->whdr.securityIndex = call->security_ix;
 169         pkt->whdr._rsvd         = 0;
 170         pkt->whdr.serviceId     = htons(call->service_id);
 171
 172         spin_lock_bh(&call->lock);
 173         if (ping) {
 174                 reason = RXRPC_ACK_PING;
 175         } else {
 176                 reason = call->ackr_reason;
 177                 if (!call->ackr_reason) {
 178                         spin_unlock_bh(&call->lock);
 179                         ret = 0;
 180                         goto out;
 181                 }
 182                 call->ackr_reason = 0;
 183         }
 184         n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 185
 186         spin_unlock_bh(&call->lock);
 187
 188         iov[0].iov_base = pkt;
 189         iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
 190         iov[1].iov_base = &pkt->ackinfo;
 191         iov[1].iov_len  = sizeof(pkt->ackinfo);
 192         len = iov[0].iov_len + iov[1].iov_len;
 193
 194         serial = atomic_inc_return(&conn->serial);
 195         pkt->whdr.serial = htonl(serial);
 196         trace_rxrpc_tx_ack(call->debug_id, serial,
 197                            ntohl(pkt->ack.firstPacket),
 198                            ntohl(pkt->ack.serial),
 199                            pkt->ack.reason, pkt->ack.nAcks);
 200         if (_serial)
 201                 *_serial = serial;
 202
 203         if (ping) {
 204                 call->ping_serial = serial;
 205                 smp_wmb();
 206                 /* We need to stick a time in before we send the packet in case
 207                  * the reply gets back before kernel_sendmsg() completes - but
 208                  * asking UDP to send the packet can take a relatively long
 209                  * time.
 210                  */
 211                 call->ping_time = ktime_get_real();
 212                 set_bit(RXRPC_CALL_PINGING, &call->flags);
 213                 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
 214         }
 215
 216         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 217         conn->params.peer->last_tx_at = ktime_get_seconds();
 218         if (ret < 0)
 219                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 220                                     rxrpc_tx_point_call_ack);
 221         else
 222                 trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
 223                                       rxrpc_tx_point_call_ack);
 224         rxrpc_tx_backoff(call, ret);
 225
 226         if (call->state < RXRPC_CALL_COMPLETE) {
 227                 if (ret < 0) {
 228                         if (ping)
 229                                 clear_bit(RXRPC_CALL_PINGING, &call->flags);
 230                         rxrpc_propose_ACK(call, pkt->ack.reason,
 231                                           ntohs(pkt->ack.maxSkew),
 232                                           ntohl(pkt->ack.serial),
 233                                           false, true,
 234                                           rxrpc_propose_ack_retry_tx);
 235                 } else {
 236                         spin_lock_bh(&call->lock);
 237                         if (after(hard_ack, call->ackr_consumed))
 238                                 call->ackr_consumed = hard_ack;
 239                         if (after(top, call->ackr_seen))
 240                                 call->ackr_seen = top;
 241                         spin_unlock_bh(&call->lock);
 242                 }
 243
 244                 rxrpc_set_keepalive(call);
 245         }
 246
 247 out:
 248         rxrpc_put_connection(conn);
 249         kfree(pkt);
 250         return ret;
 251 }
 252
 253 /*
 254  * Send an ABORT call packet.
 255  */
 256 int rxrpc_send_abort_packet(struct rxrpc_call *call)
 257 {
 258         struct rxrpc_connection *conn = NULL;
 259         struct rxrpc_abort_buffer pkt;
 260         struct msghdr msg;
 261         struct kvec iov[1];
 262         rxrpc_serial_t serial;
 263         int ret;
 264
 265         /* Don't bother sending aborts for a client call once the server has
 266          * hard-ACK'd all of its request data.  After that point, we're not
 267          * going to stop the operation proceeding, and whilst we might limit
 268          * the reply, it's not worth it if we can send a new call on the same
 269          * channel instead, thereby closing off this call.
 270          */
 271         if (rxrpc_is_client_call(call) &&
 272             test_bit(RXRPC_CALL_TX_LAST, &call->flags))
 273                 return 0;
 274
 275         spin_lock_bh(&call->lock);
 276         if (call->conn)
 277                 conn = rxrpc_get_connection_maybe(call->conn);
 278         spin_unlock_bh(&call->lock);
 279         if (!conn)
 280                 return -ECONNRESET;
 281
 282         msg.msg_name    = &call->peer->srx.transport;
 283         msg.msg_namelen = call->peer->srx.transport_len;
 284         msg.msg_control = NULL;
 285         msg.msg_controllen = 0;
 286         msg.msg_flags   = 0;
 287
 288         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 289         pkt.whdr.cid            = htonl(call->cid);
 290         pkt.whdr.callNumber     = htonl(call->call_id);
 291         pkt.whdr.seq            = 0;
 292         pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
 293         pkt.whdr.flags          = conn->out_clientflag;
 294         pkt.whdr.userStatus     = 0;
 295         pkt.whdr.securityIndex  = call->security_ix;
 296         pkt.whdr._rsvd          = 0;
 297         pkt.whdr.serviceId      = htons(call->service_id);
 298         pkt.abort_code          = htonl(call->abort_code);
 299
 300         iov[0].iov_base = &pkt;
 301         iov[0].iov_len  = sizeof(pkt);
 302
 303         serial = atomic_inc_return(&conn->serial);
 304         pkt.whdr.serial = htonl(serial);
 305
 306         ret = kernel_sendmsg(conn->params.local->socket,
 307                              &msg, iov, 1, sizeof(pkt));
 308         conn->params.peer->last_tx_at = ktime_get_seconds();
 309         if (ret < 0)
 310                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 311                                     rxrpc_tx_point_call_abort);
 312         else
 313                 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
 314                                       rxrpc_tx_point_call_abort);
 315         rxrpc_tx_backoff(call, ret);
 316
 317         rxrpc_put_connection(conn);
 318         return ret;
 319 }
 320
 321 /*
 322  * send a packet through the transport endpoint
 323  */
 324 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
 325                            bool retrans)
 326 {
 327         struct rxrpc_connection *conn = call->conn;
 328         struct rxrpc_wire_header whdr;
 329         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 330         struct msghdr msg;
 331         struct kvec iov[2];
 332         rxrpc_serial_t serial;
 333         size_t len;
 334         int ret, opt;
 335
 336         _enter(",{%d}", skb->len);
 337
 338         /* Each transmission of a Tx packet needs a new serial number */
 339         serial = atomic_inc_return(&conn->serial);
 340
 341         whdr.epoch      = htonl(conn->proto.epoch);
 342         whdr.cid        = htonl(call->cid);
 343         whdr.callNumber = htonl(call->call_id);
 344         whdr.seq        = htonl(sp->hdr.seq);
 345         whdr.serial     = htonl(serial);
 346         whdr.type       = RXRPC_PACKET_TYPE_DATA;
 347         whdr.flags      = sp->hdr.flags;
 348         whdr.userStatus = 0;
 349         whdr.securityIndex = call->security_ix;
 350         whdr._rsvd      = htons(sp->hdr._rsvd);
 351         whdr.serviceId  = htons(call->service_id);
 352
 353         if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
 354             sp->hdr.seq == 1)
 355                 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
 356
 357         iov[0].iov_base = &whdr;
 358         iov[0].iov_len = sizeof(whdr);
 359         iov[1].iov_base = skb->head;
 360         iov[1].iov_len = skb->len;
 361         len = iov[0].iov_len + iov[1].iov_len;
 362
 363         msg.msg_name = &call->peer->srx.transport;
 364         msg.msg_namelen = call->peer->srx.transport_len;
 365         msg.msg_control = NULL;
 366         msg.msg_controllen = 0;
 367         msg.msg_flags = 0;
 368
 369         /* If our RTT cache needs working on, request an ACK.  Also request
 370          * ACKs if a DATA packet appears to have been lost.
 371          *
 372          * However, we mustn't request an ACK on the last reply packet of a
 373          * service call, lest OpenAFS incorrectly send us an ACK with some
 374          * soft-ACKs in it and then never follow up with a proper hard ACK.
 375          */
 376         if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
 377              rxrpc_to_server(sp)
 378              ) &&
 379             (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
 380              retrans ||
 381              call->cong_mode == RXRPC_CALL_SLOW_START ||
 382              (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
 383              ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
 384                           ktime_get_real())))
 385                 whdr.flags |= RXRPC_REQUEST_ACK;
 386
 387         if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
 388                 static int lose;
 389                 if ((lose++ & 7) == 7) {
 390                         ret = 0;
 391                         trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
 392                                             whdr.flags, retrans, true);
 393                         goto done;
 394                 }
 395         }
 396
 397         trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
 398                             false);
 399
 400         /* send the packet with the don't fragment bit set if we currently
 401          * think it's small enough */
 402         if (iov[1].iov_len >= call->peer->maxdata)
 403                 goto send_fragmentable;
 404
 405         down_read(&conn->params.local->defrag_sem);
 406
 407         sp->hdr.serial = serial;
 408         smp_wmb(); /* Set serial before timestamp */
 409         skb->tstamp = ktime_get_real();
 410
 411         /* send the packet by UDP
 412          * - returns -EMSGSIZE if UDP would have to fragment the packet
 413          *   to go out of the interface
 414          *   - in which case, we'll have processed the ICMP error
 415          *     message and update the peer record
 416          */
 417         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 418         conn->params.peer->last_tx_at = ktime_get_seconds();
 419
 420         up_read(&conn->params.local->defrag_sem);
 421         if (ret < 0)
 422                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 423                                     rxrpc_tx_point_call_data_nofrag);
 424         else
 425                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 426                                       rxrpc_tx_point_call_data_nofrag);
 427         rxrpc_tx_backoff(call, ret);
 428         if (ret == -EMSGSIZE)
 429                 goto send_fragmentable;
 430
 431 done:
 432         if (ret >= 0) {
 433                 if (whdr.flags & RXRPC_REQUEST_ACK) {
 434                         call->peer->rtt_last_req = skb->tstamp;
 435                         trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
 436                         if (call->peer->rtt_usage > 1) {
 437                                 unsigned long nowj = jiffies, ack_lost_at;
 438
 439                                 ack_lost_at = nsecs_to_jiffies(2 * call->peer->rtt);
 440                                 if (ack_lost_at < 1)
 441                                         ack_lost_at = 1;
 442
 443                                 ack_lost_at += nowj;
 444                                 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
 445                                 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
 446                                                         rxrpc_timer_set_for_lost_ack);
 447                         }
 448                 }
 449
 450                 if (sp->hdr.seq == 1 &&
 451                     !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
 452                                       &call->flags)) {
 453                         unsigned long nowj = jiffies, expect_rx_by;
 454
 455                         expect_rx_by = nowj + call->next_rx_timo;
 456                         WRITE_ONCE(call->expect_rx_by, expect_rx_by);
 457                         rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
 458                                                 rxrpc_timer_set_for_normal);
 459                 }
 460
 461                 rxrpc_set_keepalive(call);
 462         } else {
 463                 /* Cancel the call if the initial transmission fails,
 464                  * particularly if that's due to network routing issues that
 465                  * aren't going away anytime soon.  The layer above can arrange
 466                  * the retransmission.
 467                  */
 468                 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
 469                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 470                                                   RX_USER_ABORT, ret);
 471         }
 472
 473         _leave(" = %d [%u]", ret, call->peer->maxdata);
 474         return ret;
 475
 476 send_fragmentable:
 477         /* attempt to send this message with fragmentation enabled */
 478         _debug("send fragment");
 479
 480         down_write(&conn->params.local->defrag_sem);
 481
 482         sp->hdr.serial = serial;
 483         smp_wmb(); /* Set serial before timestamp */
 484         skb->tstamp = ktime_get_real();
 485
 486         switch (conn->params.local->srx.transport.family) {
 487         case AF_INET:
 488                 opt = IP_PMTUDISC_DONT;
 489                 ret = kernel_setsockopt(conn->params.local->socket,
 490                                         SOL_IP, IP_MTU_DISCOVER,
 491                                         (char *)&opt, sizeof(opt));
 492                 if (ret == 0) {
 493                         ret = kernel_sendmsg(conn->params.local->socket, &msg,
 494                                              iov, 2, len);
 495                         conn->params.peer->last_tx_at = ktime_get_seconds();
 496
 497                         opt = IP_PMTUDISC_DO;
 498                         kernel_setsockopt(conn->params.local->socket, SOL_IP,
 499                                           IP_MTU_DISCOVER,
 500                                           (char *)&opt, sizeof(opt));
 501                 }
 502                 break;
 503
 504 #ifdef CONFIG_AF_RXRPC_IPV6
 505         case AF_INET6:
 506                 opt = IPV6_PMTUDISC_DONT;
 507                 ret = kernel_setsockopt(conn->params.local->socket,
 508                                         SOL_IPV6, IPV6_MTU_DISCOVER,
 509                                         (char *)&opt, sizeof(opt));
 510                 if (ret == 0) {
 511                         ret = kernel_sendmsg(conn->params.local->socket, &msg,
 512                                              iov, 2, len);
 513                         conn->params.peer->last_tx_at = ktime_get_seconds();
 514
 515                         opt = IPV6_PMTUDISC_DO;
 516                         kernel_setsockopt(conn->params.local->socket,
 517                                           SOL_IPV6, IPV6_MTU_DISCOVER,
 518                                           (char *)&opt, sizeof(opt));
 519                 }
 520                 break;
 521 #endif
 522         }
 523
 524         if (ret < 0)
 525                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 526                                     rxrpc_tx_point_call_data_frag);
 527         else
 528                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 529                                       rxrpc_tx_point_call_data_frag);
 530         rxrpc_tx_backoff(call, ret);
 531
 532         up_write(&conn->params.local->defrag_sem);
 533         goto done;
 534 }
 535
 536 /*
 537  * reject packets through the local endpoint
 538  */
 539 void rxrpc_reject_packets(struct rxrpc_local *local)
 540 {
 541         struct sockaddr_rxrpc srx;
 542         struct rxrpc_skb_priv *sp;
 543         struct rxrpc_wire_header whdr;
 544         struct sk_buff *skb;
 545         struct msghdr msg;
 546         struct kvec iov[2];
 547         size_t size;
 548         __be32 code;
 549         int ret, ioc;
 550
 551         _enter("%d", local->debug_id);
 552
 553         iov[0].iov_base = &whdr;
 554         iov[0].iov_len = sizeof(whdr);
 555         iov[1].iov_base = &code;
 556         iov[1].iov_len = sizeof(code);
 557
 558         msg.msg_name = &srx.transport;
 559         msg.msg_control = NULL;
 560         msg.msg_controllen = 0;
 561         msg.msg_flags = 0;
 562
 563         memset(&whdr, 0, sizeof(whdr));
 564
 565         while ((skb = skb_dequeue(&local->reject_queue))) {
 566                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 567                 sp = rxrpc_skb(skb);
 568
 569                 switch (skb->mark) {
 570                 case RXRPC_SKB_MARK_REJECT_BUSY:
 571                         whdr.type = RXRPC_PACKET_TYPE_BUSY;
 572                         size = sizeof(whdr);
 573                         ioc = 1;
 574                         break;
 575                 case RXRPC_SKB_MARK_REJECT_ABORT:
 576                         whdr.type = RXRPC_PACKET_TYPE_ABORT;
 577                         code = htonl(skb->priority);
 578                         size = sizeof(whdr) + sizeof(code);
 579                         ioc = 2;
 580                         break;
 581                 default:
 582                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 583                         continue;
 584                 }
 585
 586                 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
 587                         msg.msg_namelen = srx.transport_len;
 588
 589                         whdr.epoch      = htonl(sp->hdr.epoch);
 590                         whdr.cid        = htonl(sp->hdr.cid);
 591                         whdr.callNumber = htonl(sp->hdr.callNumber);
 592                         whdr.serviceId  = htons(sp->hdr.serviceId);
 593                         whdr.flags      = sp->hdr.flags;
 594                         whdr.flags      ^= RXRPC_CLIENT_INITIATED;
 595                         whdr.flags      &= RXRPC_CLIENT_INITIATED;
 596
 597                         ret = kernel_sendmsg(local->socket, &msg,
 598                                              iov, ioc, size);
 599                         if (ret < 0)
 600                                 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
 601                                                     rxrpc_tx_point_reject);
 602                         else
 603                                 trace_rxrpc_tx_packet(local->debug_id, &whdr,
 604                                                       rxrpc_tx_point_reject);
 605                 }
 606
 607                 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 608         }
 609
 610         _leave("");
 611 }
 612
 613 /*
 614  * Send a VERSION reply to a peer as a keepalive.
 615  */
 616 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
 617 {
 618         struct rxrpc_wire_header whdr;
 619         struct msghdr msg;
 620         struct kvec iov[2];
 621         size_t len;
 622         int ret;
 623
 624         _enter("");
 625
 626         msg.msg_name    = &peer->srx.transport;
 627         msg.msg_namelen = peer->srx.transport_len;
 628         msg.msg_control = NULL;
 629         msg.msg_controllen = 0;
 630         msg.msg_flags   = 0;
 631
 632         whdr.epoch      = htonl(peer->local->rxnet->epoch);
 633         whdr.cid        = 0;
 634         whdr.callNumber = 0;
 635         whdr.seq        = 0;
 636         whdr.serial     = 0;
 637         whdr.type       = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
 638         whdr.flags      = RXRPC_LAST_PACKET;
 639         whdr.userStatus = 0;
 640         whdr.securityIndex = 0;
 641         whdr._rsvd      = 0;
 642         whdr.serviceId  = 0;
 643
 644         iov[0].iov_base = &whdr;
 645         iov[0].iov_len  = sizeof(whdr);
 646         iov[1].iov_base = (char *)rxrpc_keepalive_string;
 647         iov[1].iov_len  = sizeof(rxrpc_keepalive_string);
 648
 649         len = iov[0].iov_len + iov[1].iov_len;
 650
 651         _proto("Tx VERSION (keepalive)");
 652
 653         ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
 654         if (ret < 0)
 655                 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
 656                                     rxrpc_tx_point_version_keepalive);
 657         else
 658                 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
 659                                       rxrpc_tx_point_version_keepalive);
 660
 661         peer->last_tx_at = ktime_get_seconds();
 662         _leave("");
 663 }