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