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(0);
  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  * Record the beginning of an RTT probe.
 128  */
 129 static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
 130                                  enum rxrpc_rtt_tx_trace why)
 131 {
 132         unsigned long avail = call->rtt_avail;
 133         int rtt_slot = 9;
 134
 135         if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
 136                 goto no_slot;
 137
 138         rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
 139         if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
 140                 goto no_slot;
 141
 142         call->rtt_serial[rtt_slot] = serial;
 143         call->rtt_sent_at[rtt_slot] = ktime_get_real();
 144         smp_wmb(); /* Write data before avail bit */
 145         set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
 146
 147         trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
 148         return rtt_slot;
 149
 150 no_slot:
 151         trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
 152         return -1;
 153 }
 154
 155 /*
 156  * Cancel an RTT probe.
 157  */
 158 static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
 159                                    rxrpc_serial_t serial, int rtt_slot)
 160 {
 161         if (rtt_slot != -1) {
 162                 clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
 163                 smp_wmb(); /* Clear pending bit before setting slot */
 164                 set_bit(rtt_slot, &call->rtt_avail);
 165                 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial);
 166         }
 167 }
 168
 169 /*
 170  * Send an ACK call packet.
 171  */
 172 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
 173                           rxrpc_serial_t *_serial)
 174 {
 175         struct rxrpc_connection *conn;
 176         struct rxrpc_ack_buffer *pkt;
 177         struct msghdr msg;
 178         struct kvec iov[2];
 179         rxrpc_serial_t serial;
 180         rxrpc_seq_t hard_ack, top;
 181         size_t len, n;
 182         int ret, rtt_slot = -1;
 183         u8 reason;
 184
 185         if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 186                 return -ECONNRESET;
 187
 188         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 189         if (!pkt)
 190                 return -ENOMEM;
 191
 192         conn = call->conn;
 193
 194         msg.msg_name    = &call->peer->srx.transport;
 195         msg.msg_namelen = call->peer->srx.transport_len;
 196         msg.msg_control = NULL;
 197         msg.msg_controllen = 0;
 198         msg.msg_flags   = 0;
 199
 200         pkt->whdr.epoch         = htonl(conn->proto.epoch);
 201         pkt->whdr.cid           = htonl(call->cid);
 202         pkt->whdr.callNumber    = htonl(call->call_id);
 203         pkt->whdr.seq           = 0;
 204         pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
 205         pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
 206         pkt->whdr.userStatus    = 0;
 207         pkt->whdr.securityIndex = call->security_ix;
 208         pkt->whdr._rsvd         = 0;
 209         pkt->whdr.serviceId     = htons(call->service_id);
 210
 211         spin_lock_bh(&call->lock);
 212         if (ping) {
 213                 reason = RXRPC_ACK_PING;
 214         } else {
 215                 reason = call->ackr_reason;
 216                 if (!call->ackr_reason) {
 217                         spin_unlock_bh(&call->lock);
 218                         ret = 0;
 219                         goto out;
 220                 }
 221                 call->ackr_reason = 0;
 222         }
 223         n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
 224
 225         spin_unlock_bh(&call->lock);
 226
 227         iov[0].iov_base = pkt;
 228         iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
 229         iov[1].iov_base = &pkt->ackinfo;
 230         iov[1].iov_len  = sizeof(pkt->ackinfo);
 231         len = iov[0].iov_len + iov[1].iov_len;
 232
 233         serial = atomic_inc_return(&conn->serial);
 234         pkt->whdr.serial = htonl(serial);
 235         trace_rxrpc_tx_ack(call->debug_id, serial,
 236                            ntohl(pkt->ack.firstPacket),
 237                            ntohl(pkt->ack.serial),
 238                            pkt->ack.reason, pkt->ack.nAcks);
 239         if (_serial)
 240                 *_serial = serial;
 241
 242         if (ping)
 243                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);
 244
 245         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 246         conn->params.peer->last_tx_at = ktime_get_seconds();
 247         if (ret < 0)
 248                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 249                                     rxrpc_tx_point_call_ack);
 250         else
 251                 trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
 252                                       rxrpc_tx_point_call_ack);
 253         rxrpc_tx_backoff(call, ret);
 254
 255         if (call->state < RXRPC_CALL_COMPLETE) {
 256                 if (ret < 0) {
 257                         rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 258                         rxrpc_propose_ACK(call, pkt->ack.reason,
 259                                           ntohl(pkt->ack.serial),
 260                                           false, true,
 261                                           rxrpc_propose_ack_retry_tx);
 262                 } else {
 263                         spin_lock_bh(&call->lock);
 264                         if (after(hard_ack, call->ackr_consumed))
 265                                 call->ackr_consumed = hard_ack;
 266                         if (after(top, call->ackr_seen))
 267                                 call->ackr_seen = top;
 268                         spin_unlock_bh(&call->lock);
 269                 }
 270
 271                 rxrpc_set_keepalive(call);
 272         }
 273
 274 out:
 275         kfree(pkt);
 276         return ret;
 277 }
 278
 279 /*
 280  * Send an ABORT call packet.
 281  */
 282 int rxrpc_send_abort_packet(struct rxrpc_call *call)
 283 {
 284         struct rxrpc_connection *conn;
 285         struct rxrpc_abort_buffer pkt;
 286         struct msghdr msg;
 287         struct kvec iov[1];
 288         rxrpc_serial_t serial;
 289         int ret;
 290
 291         /* Don't bother sending aborts for a client call once the server has
 292          * hard-ACK'd all of its request data.  After that point, we're not
 293          * going to stop the operation proceeding, and whilst we might limit
 294          * the reply, it's not worth it if we can send a new call on the same
 295          * channel instead, thereby closing off this call.
 296          */
 297         if (rxrpc_is_client_call(call) &&
 298             test_bit(RXRPC_CALL_TX_LAST, &call->flags))
 299                 return 0;
 300
 301         if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
 302                 return -ECONNRESET;
 303
 304         conn = call->conn;
 305
 306         msg.msg_name    = &call->peer->srx.transport;
 307         msg.msg_namelen = call->peer->srx.transport_len;
 308         msg.msg_control = NULL;
 309         msg.msg_controllen = 0;
 310         msg.msg_flags   = 0;
 311
 312         pkt.whdr.epoch          = htonl(conn->proto.epoch);
 313         pkt.whdr.cid            = htonl(call->cid);
 314         pkt.whdr.callNumber     = htonl(call->call_id);
 315         pkt.whdr.seq            = 0;
 316         pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
 317         pkt.whdr.flags          = conn->out_clientflag;
 318         pkt.whdr.userStatus     = 0;
 319         pkt.whdr.securityIndex  = call->security_ix;
 320         pkt.whdr._rsvd          = 0;
 321         pkt.whdr.serviceId      = htons(call->service_id);
 322         pkt.abort_code          = htonl(call->abort_code);
 323
 324         iov[0].iov_base = &pkt;
 325         iov[0].iov_len  = sizeof(pkt);
 326
 327         serial = atomic_inc_return(&conn->serial);
 328         pkt.whdr.serial = htonl(serial);
 329
 330         ret = kernel_sendmsg(conn->params.local->socket,
 331                              &msg, iov, 1, sizeof(pkt));
 332         conn->params.peer->last_tx_at = ktime_get_seconds();
 333         if (ret < 0)
 334                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 335                                     rxrpc_tx_point_call_abort);
 336         else
 337                 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
 338                                       rxrpc_tx_point_call_abort);
 339         rxrpc_tx_backoff(call, ret);
 340         return ret;
 341 }
 342
 343 /*
 344  * send a packet through the transport endpoint
 345  */
 346 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
 347                            bool retrans)
 348 {
 349         struct rxrpc_connection *conn = call->conn;
 350         struct rxrpc_wire_header whdr;
 351         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 352         struct msghdr msg;
 353         struct kvec iov[2];
 354         rxrpc_serial_t serial;
 355         size_t len;
 356         int ret, rtt_slot = -1;
 357
 358         _enter(",{%d}", skb->len);
 359
 360         /* Each transmission of a Tx packet needs a new serial number */
 361         serial = atomic_inc_return(&conn->serial);
 362
 363         whdr.epoch      = htonl(conn->proto.epoch);
 364         whdr.cid        = htonl(call->cid);
 365         whdr.callNumber = htonl(call->call_id);
 366         whdr.seq        = htonl(sp->hdr.seq);
 367         whdr.serial     = htonl(serial);
 368         whdr.type       = RXRPC_PACKET_TYPE_DATA;
 369         whdr.flags      = sp->hdr.flags;
 370         whdr.userStatus = 0;
 371         whdr.securityIndex = call->security_ix;
 372         whdr._rsvd      = htons(sp->hdr._rsvd);
 373         whdr.serviceId  = htons(call->service_id);
 374
 375         if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
 376             sp->hdr.seq == 1)
 377                 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
 378
 379         iov[0].iov_base = &whdr;
 380         iov[0].iov_len = sizeof(whdr);
 381         iov[1].iov_base = skb->head;
 382         iov[1].iov_len = skb->len;
 383         len = iov[0].iov_len + iov[1].iov_len;
 384
 385         msg.msg_name = &call->peer->srx.transport;
 386         msg.msg_namelen = call->peer->srx.transport_len;
 387         msg.msg_control = NULL;
 388         msg.msg_controllen = 0;
 389         msg.msg_flags = 0;
 390
 391         /* If our RTT cache needs working on, request an ACK.  Also request
 392          * ACKs if a DATA packet appears to have been lost.
 393          *
 394          * However, we mustn't request an ACK on the last reply packet of a
 395          * service call, lest OpenAFS incorrectly send us an ACK with some
 396          * soft-ACKs in it and then never follow up with a proper hard ACK.
 397          */
 398         if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
 399              rxrpc_to_server(sp)
 400              ) &&
 401             (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
 402              retrans ||
 403              call->cong_mode == RXRPC_CALL_SLOW_START ||
 404              (call->peer->rtt_count < 3 && sp->hdr.seq & 1) ||
 405              ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
 406                           ktime_get_real())))
 407                 whdr.flags |= RXRPC_REQUEST_ACK;
 408
 409         if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
 410                 static int lose;
 411                 if ((lose++ & 7) == 7) {
 412                         ret = 0;
 413                         trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
 414                                             whdr.flags, retrans, true);
 415                         goto done;
 416                 }
 417         }
 418
 419         trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
 420                             false);
 421
 422         /* send the packet with the don't fragment bit set if we currently
 423          * think it's small enough */
 424         if (iov[1].iov_len >= call->peer->maxdata)
 425                 goto send_fragmentable;
 426
 427         down_read(&conn->params.local->defrag_sem);
 428
 429         sp->hdr.serial = serial;
 430         smp_wmb(); /* Set serial before timestamp */
 431         skb->tstamp = ktime_get_real();
 432         if (whdr.flags & RXRPC_REQUEST_ACK)
 433                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
 434
 435         /* send the packet by UDP
 436          * - returns -EMSGSIZE if UDP would have to fragment the packet
 437          *   to go out of the interface
 438          *   - in which case, we'll have processed the ICMP error
 439          *     message and update the peer record
 440          */
 441         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 442         conn->params.peer->last_tx_at = ktime_get_seconds();
 443
 444         up_read(&conn->params.local->defrag_sem);
 445         if (ret < 0) {
 446                 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 447                 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
 448                                     rxrpc_tx_point_call_data_nofrag);
 449         } else {
 450                 trace_rxrpc_tx_packet(call->debug_id, &whdr,
 451                                       rxrpc_tx_point_call_data_nofrag);
 452         }
 453
 454         rxrpc_tx_backoff(call, ret);
 455         if (ret == -EMSGSIZE)
 456                 goto send_fragmentable;
 457
 458 done:
 459         if (ret >= 0) {
 460                 if (whdr.flags & RXRPC_REQUEST_ACK) {
 461                         call->peer->rtt_last_req = skb->tstamp;
 462                         if (call->peer->rtt_count > 1) {
 463                                 unsigned long nowj = jiffies, ack_lost_at;
 464
 465                                 ack_lost_at = rxrpc_get_rto_backoff(call->peer, retrans);
 466                                 ack_lost_at += nowj;
 467                                 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
 468                                 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
 469                                                         rxrpc_timer_set_for_lost_ack);
 470                         }
 471                 }
 472
 473                 if (sp->hdr.seq == 1 &&
 474                     !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
 475                                       &call->flags)) {
 476                         unsigned long nowj = jiffies, expect_rx_by;
 477
 478                         expect_rx_by = nowj + call->next_rx_timo;
 479                         WRITE_ONCE(call->expect_rx_by, expect_rx_by);
 480                         rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
 481                                                 rxrpc_timer_set_for_normal);
 482                 }
 483
 484                 rxrpc_set_keepalive(call);
 485         } else {
 486                 /* Cancel the call if the initial transmission fails,
 487                  * particularly if that's due to network routing issues that
 488                  * aren't going away anytime soon.  The layer above can arrange
 489                  * the retransmission.
 490                  */
 491                 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
 492                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 493                                                   RX_USER_ABORT, ret);
 494         }
 495
 496         _leave(" = %d [%u]", ret, call->peer->maxdata);
 497         return ret;
 498
 499 send_fragmentable:
 500         /* attempt to send this message with fragmentation enabled */
 501         _debug("send fragment");
 502
 503         down_write(&conn->params.local->defrag_sem);
 504
 505         sp->hdr.serial = serial;
 506         smp_wmb(); /* Set serial before timestamp */
 507         skb->tstamp = ktime_get_real();
 508         if (whdr.flags & RXRPC_REQUEST_ACK)
 509                 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
 510
 511         switch (conn->params.local->srx.transport.family) {
 512         case AF_INET6:
 513         case AF_INET:
 514                 ip_sock_set_mtu_discover(conn->params.local->socket->sk,
 515                                 IP_PMTUDISC_DONT);
 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                 ip_sock_set_mtu_discover(conn->params.local->socket->sk,
 521                                 IP_PMTUDISC_DO);
 522                 break;
 523
 524         default:
 525                 BUG();
 526         }
 527
 528         if (ret < 0) {
 529                 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
 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         }
 536         rxrpc_tx_backoff(call, ret);
 537
 538         up_write(&conn->params.local->defrag_sem);
 539         goto done;
 540 }
 541
 542 /*
 543  * reject packets through the local endpoint
 544  */
 545 void rxrpc_reject_packets(struct rxrpc_local *local)
 546 {
 547         struct sockaddr_rxrpc srx;
 548         struct rxrpc_skb_priv *sp;
 549         struct rxrpc_wire_header whdr;
 550         struct sk_buff *skb;
 551         struct msghdr msg;
 552         struct kvec iov[2];
 553         size_t size;
 554         __be32 code;
 555         int ret, ioc;
 556
 557         _enter("%d", local->debug_id);
 558
 559         iov[0].iov_base = &whdr;
 560         iov[0].iov_len = sizeof(whdr);
 561         iov[1].iov_base = &code;
 562         iov[1].iov_len = sizeof(code);
 563
 564         msg.msg_name = &srx.transport;
 565         msg.msg_control = NULL;
 566         msg.msg_controllen = 0;
 567         msg.msg_flags = 0;
 568
 569         memset(&whdr, 0, sizeof(whdr));
 570
 571         while ((skb = skb_dequeue(&local->reject_queue))) {
 572                 rxrpc_see_skb(skb, rxrpc_skb_seen);
 573                 sp = rxrpc_skb(skb);
 574
 575                 switch (skb->mark) {
 576                 case RXRPC_SKB_MARK_REJECT_BUSY:
 577                         whdr.type = RXRPC_PACKET_TYPE_BUSY;
 578                         size = sizeof(whdr);
 579                         ioc = 1;
 580                         break;
 581                 case RXRPC_SKB_MARK_REJECT_ABORT:
 582                         whdr.type = RXRPC_PACKET_TYPE_ABORT;
 583                         code = htonl(skb->priority);
 584                         size = sizeof(whdr) + sizeof(code);
 585                         ioc = 2;
 586                         break;
 587                 default:
 588                         rxrpc_free_skb(skb, rxrpc_skb_freed);
 589                         continue;
 590                 }
 591
 592                 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
 593                         msg.msg_namelen = srx.transport_len;
 594
 595                         whdr.epoch      = htonl(sp->hdr.epoch);
 596                         whdr.cid        = htonl(sp->hdr.cid);
 597                         whdr.callNumber = htonl(sp->hdr.callNumber);
 598                         whdr.serviceId  = htons(sp->hdr.serviceId);
 599                         whdr.flags      = sp->hdr.flags;
 600                         whdr.flags      ^= RXRPC_CLIENT_INITIATED;
 601                         whdr.flags      &= RXRPC_CLIENT_INITIATED;
 602
 603                         ret = kernel_sendmsg(local->socket, &msg,
 604                                              iov, ioc, size);
 605                         if (ret < 0)
 606                                 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
 607                                                     rxrpc_tx_point_reject);
 608                         else
 609                                 trace_rxrpc_tx_packet(local->debug_id, &whdr,
 610                                                       rxrpc_tx_point_reject);
 611                 }
 612
 613                 rxrpc_free_skb(skb, rxrpc_skb_freed);
 614         }
 615
 616         _leave("");
 617 }
 618
 619 /*
 620  * Send a VERSION reply to a peer as a keepalive.
 621  */
 622 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
 623 {
 624         struct rxrpc_wire_header whdr;
 625         struct msghdr msg;
 626         struct kvec iov[2];
 627         size_t len;
 628         int ret;
 629
 630         _enter("");
 631
 632         msg.msg_name    = &peer->srx.transport;
 633         msg.msg_namelen = peer->srx.transport_len;
 634         msg.msg_control = NULL;
 635         msg.msg_controllen = 0;
 636         msg.msg_flags   = 0;
 637
 638         whdr.epoch      = htonl(peer->local->rxnet->epoch);
 639         whdr.cid        = 0;
 640         whdr.callNumber = 0;
 641         whdr.seq        = 0;
 642         whdr.serial     = 0;
 643         whdr.type       = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
 644         whdr.flags      = RXRPC_LAST_PACKET;
 645         whdr.userStatus = 0;
 646         whdr.securityIndex = 0;
 647         whdr._rsvd      = 0;
 648         whdr.serviceId  = 0;
 649
 650         iov[0].iov_base = &whdr;
 651         iov[0].iov_len  = sizeof(whdr);
 652         iov[1].iov_base = (char *)rxrpc_keepalive_string;
 653         iov[1].iov_len  = sizeof(rxrpc_keepalive_string);
 654
 655         len = iov[0].iov_len + iov[1].iov_len;
 656
 657         _proto("Tx VERSION (keepalive)");
 658
 659         ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
 660         if (ret < 0)
 661                 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
 662                                     rxrpc_tx_point_version_keepalive);
 663         else
 664                 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
 665                                       rxrpc_tx_point_version_keepalive);
 666
 667         peer->last_tx_at = ktime_get_seconds();
 668         _leave("");
 669 }