net/rxrpc/output.c

   1 /* RxRPC packet transmission
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells ([email protected])
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/net.h>
  15 #include <linux/gfp.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/export.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include "ar-internal.h"
  21
  22 struct rxrpc_ack_buffer {
  23         struct rxrpc_wire_header whdr;
  24         struct rxrpc_ackpacket ack;
  25         u8 acks[255];
  26         u8 pad[3];
  27         struct rxrpc_ackinfo ackinfo;
  28 };
  29
  30 struct rxrpc_abort_buffer {
  31         struct rxrpc_wire_header whdr;
  32         __be32 abort_code;
  33 };
  34
  35 static const char rxrpc_keepalive_string[] = "";
  36
  37 /*
  38  * Increase Tx backoff on transmission failure and clear it on success.
  39  */
  40 static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
  41 {
  42         if (ret < 0) {
  43                 u16 tx_backoff = READ_ONCE(call->tx_backoff);
  44
  45                 if (tx_backoff < HZ)
  46                         WRITE_ONCE(call->tx_backoff, tx_backoff + 1);
  47         } else {
  48                 WRITE_ONCE(call->tx_backoff, 0);
  49         }
  50 }
  51
  52 /*
  53  * Arrange for a keepalive ping a certain time after we last transmitted.  This
  54  * lets the far side know we're still interested in this call and helps keep
  55  * the route through any intervening firewall open.
  56  *
  57  * Receiving a response to the ping will prevent the ->expect_rx_by timer from
  58  * expiring.
  59  */
  60 static void rxrpc_set_keepalive(struct rxrpc_call *call)
  61 {
  62         unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
  63
  64         keepalive_at += now;
  65         WRITE_ONCE(call->keepalive_at, keepalive_at);
  66         rxrpc_reduce_call_timer(call, keepalive_at, now,
  67                                 rxrpc_timer_set_for_keepalive);
  68 }
  69
  70 /*
  71  * Fill out an ACK packet.
  72  */
  73 static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
  74                                  struct rxrpc_call *call,
  75                                  struct rxrpc_ack_buffer *pkt,
  76                                  rxrpc_seq_t *_hard_ack,
  77                                  rxrpc_seq_t *_top,
  78                                  u8 reason)
  79 {
  80         rxrpc_serial_t serial;
  81         rxrpc_seq_t hard_ack, top, seq;
  82         int ix;
  83         u32 mtu, jmax;
  84         u8 *ackp = pkt->acks;
  85
  86         /* Barrier against rxrpc_input_data(). */
  87         serial = call->ackr_serial;
  88         hard_ack = READ_ONCE(call->rx_hard_ack);
  89         top = smp_load_acquire(&call->rx_top);
  90         *_hard_ack = hard_ack;
  91         *_top = top;
  92
  93         pkt->ack.bufferSpace    = htons(8);
  94         pkt->ack.maxSkew        = htons(call->ackr_skew);
  95         pkt->ack.firstPacket    = htonl(hard_ack + 1);
  96         pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
  97         pkt->ack.serial         = htonl(serial);
  98         pkt->ack.reason         = reason;
  99         pkt->ack.nAcks          = top - hard_ack;
 100
 101         if (reason == RXRPC_ACK_PING)
 102                 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
 103
 104         if (after(top, hard_ack)) {
 105                 seq = hard_ack + 1;
 106                 do {
 107                         ix = seq & RXRPC_RXTX_BUFF_MASK;
 108                         if (call->rxtx_buffer[ix])
 109                                 *ackp++ = RXRPC_ACK_TYPE_ACK;
 110                         else
 111                                 *ackp++ = RXRPC_ACK_TYPE_NACK;
 112                         seq++;
 113                 } while (before_eq(seq, top));
 114         }
 115
 116         mtu = conn->params.peer->if_mtu;
 117         mtu -= conn->params.peer->hdrsize;
 118         jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
 119         pkt->ackinfo.rxMTU      = htonl(rxrpc_rx_mtu);
 120         pkt->ackinfo.maxMTU     = htonl(mtu);
 121         pkt->ackinfo.rwind      = htonl(call->rx_winsize);
 122         pkt->ackinfo.jumbo_max  = htonl(jmax);
 123
 124         *ackp++ = 0;
 125         *ackp++ = 0;
 126         *ackp++ = 0;
 127         return top - hard_ack + 3;
 128 }
 129
 130 /*
 131  * Send an ACK call packet.
 132  */
 133 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 134                           rxrpc_serial_t *_serial)
 135 {
 136         struct rxrpc_connection *conn = NULL;
 137         struct rxrpc_ack_buffer *pkt;
 138         struct msghdr msg;
 139         struct kvec iov[2];
 140         rxrpc_serial_t serial;
 141         rxrpc_seq_t hard_ack, top;
 142         size_t len, n;
 143         int ret;
 144         u8 reason;
 145
 146         spin_lock_bh(&call->lock);
 147         if (call->conn)
 148                 conn = rxrpc_get_connection_maybe(call->conn);
 149         spin_unlock_bh(&call->lock);
 150         if (!conn)
 151                 return -ECONNRESET;
 152
 153         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 154         if (!pkt) {
 155                 rxrpc_put_connection(conn);
 156                 return -ENOMEM;
 157         }
 158
 159         msg.msg_name    = &call->peer->srx.transport;
 160         msg.msg_namelen = call->peer->srx.transport_len;
 161         msg.msg_control = NULL;
 162         msg.msg_controllen = 0;
 163         msg.msg_flags   = 0;
 164
 165         pkt->whdr.epoch         = htonl(conn->proto.epoch);
 166         pkt->whdr.cid           = htonl(call->cid);
 167         pkt->whdr.callNumber    = htonl(call->call_id);
 168         pkt->whdr.seq           = 0;
 169         pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
 170         pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
 171         pkt->whdr.userStatus    = 0;
 172         pkt->whdr.securityIndex = call->security_ix;
 173         pkt->whdr._rsvd         = 0;
 174         pkt->whdr.serviceId     = htons(call->service_id);
 175
 176         spin_lock_bh(&call->lock);
 177         if (ping) {
 178                 reason = RXRPC_ACK_PING;
 179         } else {
 180                 reason = call->ackr_reason;
 181                 if (!call->ackr_reason) {
 182                         spin_unlock_bh(&call->lock);
 183                         ret = 0;
 184                         goto out;
 185                 }
 186                 call->ackr_reason = 0;
 187         }
 188         n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 189
 190         spin_unlock_bh(&call->lock);
 191
 192         iov[0].iov_base = pkt;
 193         iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
 194         iov[1].iov_base = &pkt->ackinfo;
 195         iov[1].iov_len  = sizeof(pkt->ackinfo);
 196         len = iov[0].iov_len + iov[1].iov_len;
 197
 198         serial = atomic_inc_return(&conn->serial);
 199         pkt->whdr.serial = htonl(serial);
 200         trace_rxrpc_tx_ack(call->debug_id, serial,
 201                            ntohl(pkt->ack.firstPacket),
 202                            ntohl(pkt->ack.serial),
 203                            pkt->ack.reason, pkt->ack.nAcks);
 204         if (_serial)
 205                 *_serial = serial;
 206
 207         if (ping) {
 208                 call->ping_serial = serial;
 209                 smp_wmb();
 210                 /* We need to stick a time in before we send the packet in case
 211                  * the reply gets back before kernel_sendmsg() completes - but
 212                  * asking UDP to send the packet can take a relatively long
 213                  * time.
 214                  */
 215                 call->ping_time = ktime_get_real();
 216                 set_bit(RXRPC_CALL_PINGING, &call->flags);
 217                 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
 218         }
 219
 220         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 221         conn->params.peer->last_tx_at = ktime_get_seconds();
 222         if (ret < 0)
 223                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 224                                     rxrpc_tx_point_call_ack);
 225         else
 226                 trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
 227                                       rxrpc_tx_point_call_ack);
 228         rxrpc_tx_backoff(call, ret);
 229
 230         if (call->state < RXRPC_CALL_COMPLETE) {
 231                 if (ret < 0) {
 232                         if (ping)
 233                                 clear_bit(RXRPC_CALL_PINGING, &call->flags);
 234                         rxrpc_propose_ACK(call, pkt->ack.reason,
 235                                           ntohs(pkt->ack.maxSkew),
 236                                           ntohl(pkt->ack.serial),
 237                                           false, true,
 238                                           rxrpc_propose_ack_retry_tx);
 239                 } else {
 240                         spin_lock_bh(&call->lock);
 241                         if (after(hard_ack, call->ackr_consumed))
 242                                 call->ackr_consumed = hard_ack;
 243                         if (after(top, call->ackr_seen))
 244                                 call->ackr_seen = top;
 245                         spin_unlock_bh(&call->lock);
 246                 }
 247
 248                 rxrpc_set_keepalive(call);
 249         }
 250
 251 out:
 252         rxrpc_put_connection(conn);
 253         kfree(pkt);
 254         return ret;
 255 }
 256
 257 /*
 258  * Send an ABORT call packet.
 259  */
 260 int rxrpc_send_abort_packet(struct rxrpc_call *call)
 261 {
 262         struct rxrpc_connection *conn = NULL;
 263         struct rxrpc_abort_buffer pkt;
 264         struct msghdr msg;
 265         struct kvec iov[1];
 266         rxrpc_serial_t serial;
 267         int ret;
 268
 269         /* Don't bother sending aborts for a client call once the server has
 270          * hard-ACK'd all of its request data.  After that point, we're not
 271          * going to stop the operation proceeding, and whilst we might limit
 272          * the reply, it's not worth it if we can send a new call on the same
 273          * channel instead, thereby closing off this call.
 274          */
 275         if (rxrpc_is_client_call(call) &&
 276             test_bit(RXRPC_CALL_TX_LAST, &call->flags))
 277                 return 0;
 278
 279         spin_lock_bh(&call->lock);
 280         if (call->conn)
 281                 conn = rxrpc_get_connection_maybe(call->conn);
 282         spin_unlock_bh(&call->lock);
 283         if (!conn)
 284                 return -ECONNRESET;
 285
 286         msg.msg_name    = &call->peer->srx.transport;
 287         msg.msg_namelen = call->peer->srx.transport_len;
 288         msg.msg_control = NULL;
 289         msg.msg_controllen = 0;
 290         msg.msg_flags   = 0;
 291
 292         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 293         pkt.whdr.cid            = htonl(call->cid);
 294         pkt.whdr.callNumber     = htonl(call->call_id);
 295         pkt.whdr.seq            = 0;
 296         pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
 297         pkt.whdr.flags          = conn->out_clientflag;
 298         pkt.whdr.userStatus     = 0;
 299         pkt.whdr.securityIndex  = call->security_ix;
 300         pkt.whdr._rsvd          = 0;
 301         pkt.whdr.serviceId      = htons(call->service_id);
 302         pkt.abort_code          = htonl(call->abort_code);
 303
 304         iov[0].iov_base = &pkt;
 305         iov[0].iov_len  = sizeof(pkt);
 306
 307         serial = atomic_inc_return(&conn->serial);
 308         pkt.whdr.serial = htonl(serial);
 309
 310         ret = kernel_sendmsg(conn->params.local->socket,
 311                              &msg, iov, 1, sizeof(pkt));
 312         conn->params.peer->last_tx_at = ktime_get_seconds();
 313         if (ret < 0)
 314                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 315                                     rxrpc_tx_point_call_abort);
 316         else
 317                 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
 318                                       rxrpc_tx_point_call_abort);
 319         rxrpc_tx_backoff(call, ret);
 320
 321         rxrpc_put_connection(conn);
 322         return ret;
 323 }
 324
 325 /*
 326  * send a packet through the transport endpoint
 327  */
 328 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
 329                            bool retrans)
 330 {
 331         struct rxrpc_connection *conn = call->conn;
 332         struct rxrpc_wire_header whdr;
 333         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 334         struct msghdr msg;
 335         struct kvec iov[2];
 336         rxrpc_serial_t serial;
 337         size_t len;
 338         bool lost = false;
 339         int ret, opt;
 340
 341         _enter(",{%d}", skb->len);
 342
 343         /* Each transmission of a Tx packet needs a new serial number */
 344         serial = atomic_inc_return(&conn->serial);
 345
 346         whdr.epoch      = htonl(conn->proto.epoch);
 347         whdr.cid        = htonl(call->cid);
 348         whdr.callNumber = htonl(call->call_id);
 349         whdr.seq        = htonl(sp->hdr.seq);
 350         whdr.serial     = htonl(serial);
 351         whdr.type       = RXRPC_PACKET_TYPE_DATA;
 352         whdr.flags      = sp->hdr.flags;
 353         whdr.userStatus = 0;
 354         whdr.securityIndex = call->security_ix;
 355         whdr._rsvd      = htons(sp->hdr._rsvd);
 356         whdr.serviceId  = htons(call->service_id);
 357
 358         if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
 359             sp->hdr.seq == 1)
 360                 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
 361
 362         iov[0].iov_base = &whdr;
 363         iov[0].iov_len = sizeof(whdr);
 364         iov[1].iov_base = skb->head;
 365         iov[1].iov_len = skb->len;
 366         len = iov[0].iov_len + iov[1].iov_len;
 367
 368         msg.msg_name = &call->peer->srx.transport;
 369         msg.msg_namelen = call->peer->srx.transport_len;
 370         msg.msg_control = NULL;
 371         msg.msg_controllen = 0;
 372         msg.msg_flags = 0;
 373
 374         /* If our RTT cache needs working on, request an ACK.  Also request
 375          * ACKs if a DATA packet appears to have been lost.
 376          *
 377          * However, we mustn't request an ACK on the last reply packet of a
 378          * service call, lest OpenAFS incorrectly send us an ACK with some
 379          * soft-ACKs in it and then never follow up with a proper hard ACK.
 380          */
 381         if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
 382              rxrpc_to_server(sp)
 383              ) &&
 384             (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
 385              retrans ||
 386              call->cong_mode == RXRPC_CALL_SLOW_START ||
 387              (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
 388              ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
 389                           ktime_get_real())))
 390                 whdr.flags |= RXRPC_REQUEST_ACK;
 391
 392         if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
 393                 static int lose;
 394                 if ((lose++ & 7) == 7) {
 395                         ret = 0;
 396                         lost = true;
 397                 }
 398         }
 399
 400         trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
 401                             retrans, lost);
 402         if (lost)
 403                 goto done;
 404
 405         /* send the packet with the don't fragment bit set if we currently
 406          * think it's small enough */
 407         if (iov[1].iov_len >= call->peer->maxdata)
 408                 goto send_fragmentable;
 409
 410         down_read(&conn->params.local->defrag_sem);
 411
 412         sp->hdr.serial = serial;
 413         smp_wmb(); /* Set serial before timestamp */
 414         skb->tstamp = ktime_get_real();
 415
 416         /* send the packet by UDP
 417          * - returns -EMSGSIZE if UDP would have to fragment the packet
 418          *   to go out of the interface
 419          *   - in which case, we'll have processed the ICMP error
 420          *     message and update the peer record
 421          */
 422         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 423         conn->params.peer->last_tx_at = ktime_get_seconds();
 424
 425         up_read(&conn->params.local->defrag_sem);
 426         if (ret < 0)
 427                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 428                                     rxrpc_tx_point_call_data_nofrag);
 429         else
 430                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 431                                       rxrpc_tx_point_call_data_nofrag);
 432         rxrpc_tx_backoff(call, ret);
 433         if (ret == -EMSGSIZE)
 434                 goto send_fragmentable;
 435
 436 done:
 437         if (ret >= 0) {
 438                 if (whdr.flags & RXRPC_REQUEST_ACK) {
 439                         call->peer->rtt_last_req = skb->tstamp;
 440                         trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
 441                         if (call->peer->rtt_usage > 1) {
 442                                 unsigned long nowj = jiffies, ack_lost_at;
 443
 444                                 ack_lost_at = nsecs_to_jiffies(2 * call->peer->rtt);
 445                                 if (ack_lost_at < 1)
 446                                         ack_lost_at = 1;
 447
 448                                 ack_lost_at += nowj;
 449                                 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
 450                                 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
 451                                                         rxrpc_timer_set_for_lost_ack);
 452                         }
 453                 }
 454
 455                 if (sp->hdr.seq == 1 &&
 456                     !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
 457                                       &call->flags)) {
 458                         unsigned long nowj = jiffies, expect_rx_by;
 459
 460                         expect_rx_by = nowj + call->next_rx_timo;
 461                         WRITE_ONCE(call->expect_rx_by, expect_rx_by);
 462                         rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
 463                                                 rxrpc_timer_set_for_normal);
 464                 }
 465
 466                 rxrpc_set_keepalive(call);
 467         } else {
 468                 /* Cancel the call if the initial transmission fails,
 469                  * particularly if that's due to network routing issues that
 470                  * aren't going away anytime soon.  The layer above can arrange
 471                  * the retransmission.
 472                  */
 473                 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
 474                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 475                                                   RX_USER_ABORT, ret);
 476         }
 477
 478         _leave(" = %d [%u]", ret, call->peer->maxdata);
 479         return ret;
 480
 481 send_fragmentable:
 482         /* attempt to send this message with fragmentation enabled */
 483         _debug("send fragment");
 484
 485         down_write(&conn->params.local->defrag_sem);
 486
 487         sp->hdr.serial = serial;
 488         smp_wmb(); /* Set serial before timestamp */
 489         skb->tstamp = ktime_get_real();
 490
 491         switch (conn->params.local->srx.transport.family) {
 492         case AF_INET:
 493                 opt = IP_PMTUDISC_DONT;
 494                 ret = kernel_setsockopt(conn->params.local->socket,
 495                                         SOL_IP, IP_MTU_DISCOVER,
 496                                         (char *)&opt, sizeof(opt));
 497                 if (ret == 0) {
 498                         ret = kernel_sendmsg(conn->params.local->socket, &msg,
 499                                              iov, 2, len);
 500                         conn->params.peer->last_tx_at = ktime_get_seconds();
 501
 502                         opt = IP_PMTUDISC_DO;
 503                         kernel_setsockopt(conn->params.local->socket, SOL_IP,
 504                                           IP_MTU_DISCOVER,
 505                                           (char *)&opt, sizeof(opt));
 506                 }
 507                 break;
 508
 509 #ifdef CONFIG_AF_RXRPC_IPV6
 510         case AF_INET6:
 511                 opt = IPV6_PMTUDISC_DONT;
 512                 ret = kernel_setsockopt(conn->params.local->socket,
 513                                         SOL_IPV6, IPV6_MTU_DISCOVER,
 514                                         (char *)&opt, sizeof(opt));
 515                 if (ret == 0) {
 516                         ret = kernel_sendmsg(conn->params.local->socket, &msg,
 517                                              iov, 2, len);
 518                         conn->params.peer->last_tx_at = ktime_get_seconds();
 519
 520                         opt = IPV6_PMTUDISC_DO;
 521                         kernel_setsockopt(conn->params.local->socket,
 522                                           SOL_IPV6, IPV6_MTU_DISCOVER,
 523                                           (char *)&opt, sizeof(opt));
 524                 }
 525                 break;
 526 #endif
 527         }
 528
 529         if (ret < 0)
 530                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 531                                     rxrpc_tx_point_call_data_frag);
 532         else
 533                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 534                                       rxrpc_tx_point_call_data_frag);
 535         rxrpc_tx_backoff(call, ret);
 536
 537         up_write(&conn->params.local->defrag_sem);
 538         goto done;
 539 }
 540
 541 /*
 542  * reject packets through the local endpoint
 543  */
 544 void rxrpc_reject_packets(struct rxrpc_local *local)
 545 {
 546         struct sockaddr_rxrpc srx;
 547         struct rxrpc_skb_priv *sp;
 548         struct rxrpc_wire_header whdr;
 549         struct sk_buff *skb;
 550         struct msghdr msg;
 551         struct kvec iov[2];
 552         size_t size;
 553         __be32 code;
 554         int ret, ioc;
 555
 556         _enter("%d", local->debug_id);
 557
 558         iov[0].iov_base = &whdr;
 559         iov[0].iov_len = sizeof(whdr);
 560         iov[1].iov_base = &code;
 561         iov[1].iov_len = sizeof(code);
 562
 563         msg.msg_name = &srx.transport;
 564         msg.msg_control = NULL;
 565         msg.msg_controllen = 0;
 566         msg.msg_flags = 0;
 567
 568         memset(&whdr, 0, sizeof(whdr));
 569
 570         while ((skb = skb_dequeue(&local->reject_queue))) {
 571                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 572                 sp = rxrpc_skb(skb);
 573
 574                 switch (skb->mark) {
 575                 case RXRPC_SKB_MARK_REJECT_BUSY:
 576                         whdr.type = RXRPC_PACKET_TYPE_BUSY;
 577                         size = sizeof(whdr);
 578                         ioc = 1;
 579                         break;
 580                 case RXRPC_SKB_MARK_REJECT_ABORT:
 581                         whdr.type = RXRPC_PACKET_TYPE_ABORT;
 582                         code = htonl(skb->priority);
 583                         size = sizeof(whdr) + sizeof(code);
 584                         ioc = 2;
 585                         break;
 586                 default:
 587                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 588                         continue;
 589                 }
 590
 591                 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
 592                         msg.msg_namelen = srx.transport_len;
 593
 594                         whdr.epoch      = htonl(sp->hdr.epoch);
 595                         whdr.cid        = htonl(sp->hdr.cid);
 596                         whdr.callNumber = htonl(sp->hdr.callNumber);
 597                         whdr.serviceId  = htons(sp->hdr.serviceId);
 598                         whdr.flags      = sp->hdr.flags;
 599                         whdr.flags      ^= RXRPC_CLIENT_INITIATED;
 600                         whdr.flags      &= RXRPC_CLIENT_INITIATED;
 601
 602                         ret = kernel_sendmsg(local->socket, &msg,
 603                                              iov, ioc, size);
 604                         if (ret < 0)
 605                                 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
 606                                                     rxrpc_tx_point_reject);
 607                         else
 608                                 trace_rxrpc_tx_packet(local->debug_id, &whdr,
 609                                                       rxrpc_tx_point_reject);
 610                 }
 611
 612                 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 613         }
 614
 615         _leave("");
 616 }
 617
 618 /*
 619  * Send a VERSION reply to a peer as a keepalive.
 620  */
 621 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
 622 {
 623         struct rxrpc_wire_header whdr;
 624         struct msghdr msg;
 625         struct kvec iov[2];
 626         size_t len;
 627         int ret;
 628
 629         _enter("");
 630
 631         msg.msg_name    = &peer->srx.transport;
 632         msg.msg_namelen = peer->srx.transport_len;
 633         msg.msg_control = NULL;
 634         msg.msg_controllen = 0;
 635         msg.msg_flags   = 0;
 636
 637         whdr.epoch      = htonl(peer->local->rxnet->epoch);
 638         whdr.cid        = 0;
 639         whdr.callNumber = 0;
 640         whdr.seq        = 0;
 641         whdr.serial     = 0;
 642         whdr.type       = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
 643         whdr.flags      = RXRPC_LAST_PACKET;
 644         whdr.userStatus = 0;
 645         whdr.securityIndex = 0;
 646         whdr._rsvd      = 0;
 647         whdr.serviceId  = 0;
 648
 649         iov[0].iov_base = &whdr;
 650         iov[0].iov_len  = sizeof(whdr);
 651         iov[1].iov_base = (char *)rxrpc_keepalive_string;
 652         iov[1].iov_len  = sizeof(rxrpc_keepalive_string);
 653
 654         len = iov[0].iov_len + iov[1].iov_len;
 655
 656         _proto("Tx VERSION (keepalive)");
 657
 658         ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
 659         if (ret < 0)
 660                 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
 661                                     rxrpc_tx_point_version_keepalive);
 662         else
 663                 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
 664                                       rxrpc_tx_point_version_keepalive);
 665
 666         peer->last_tx_at = ktime_get_seconds();
 667         _leave("");
 668 }