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 if (hlist_unhashed(&call->error_link)) { 361 spin_lock_bh(&call->peer->lock); 362 hlist_add_head_rcu(&call->error_link, &call->peer->error_targets); 363 spin_unlock_bh(&call->peer->lock); 364 } 365 366 /* Each transmission of a Tx packet needs a new serial number */ 367 serial = atomic_inc_return(&conn->serial); 368 369 whdr.epoch = htonl(conn->proto.epoch); 370 whdr.cid = htonl(call->cid); 371 whdr.callNumber = htonl(call->call_id); 372 whdr.seq = htonl(sp->hdr.seq); 373 whdr.serial = htonl(serial); 374 whdr.type = RXRPC_PACKET_TYPE_DATA; 375 whdr.flags = sp->hdr.flags; 376 whdr.userStatus = 0; 377 whdr.securityIndex = call->security_ix; 378 whdr._rsvd = htons(sp->hdr._rsvd); 379 whdr.serviceId = htons(call->service_id); 380 381 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) && 382 sp->hdr.seq == 1) 383 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE; 384 385 iov[0].iov_base = &whdr; 386 iov[0].iov_len = sizeof(whdr); 387 iov[1].iov_base = skb->head; 388 iov[1].iov_len = skb->len; 389 len = iov[0].iov_len + iov[1].iov_len; 390 391 msg.msg_name = &call->peer->srx.transport; 392 msg.msg_namelen = call->peer->srx.transport_len; 393 msg.msg_control = NULL; 394 msg.msg_controllen = 0; 395 msg.msg_flags = 0; 396 397 /* If our RTT cache needs working on, request an ACK. Also request 398 * ACKs if a DATA packet appears to have been lost. 399 * 400 * However, we mustn't request an ACK on the last reply packet of a 401 * service call, lest OpenAFS incorrectly send us an ACK with some 402 * soft-ACKs in it and then never follow up with a proper hard ACK. 403 */ 404 if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) || 405 rxrpc_to_server(sp) 406 ) && 407 (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) || 408 retrans || 409 call->cong_mode == RXRPC_CALL_SLOW_START || 410 (call->peer->rtt_count < 3 && sp->hdr.seq & 1) || 411 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), 412 ktime_get_real()))) 413 whdr.flags |= RXRPC_REQUEST_ACK; 414 415 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 416 static int lose; 417 if ((lose++ & 7) == 7) { 418 ret = 0; 419 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, 420 whdr.flags, retrans, true); 421 goto done; 422 } 423 } 424 425 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans, 426 false); 427 428 /* send the packet with the don't fragment bit set if we currently 429 * think it's small enough */ 430 if (iov[1].iov_len >= call->peer->maxdata) 431 goto send_fragmentable; 432 433 down_read(&conn->params.local->defrag_sem); 434 435 sp->hdr.serial = serial; 436 smp_wmb(); /* Set serial before timestamp */ 437 skb->tstamp = ktime_get_real(); 438 if (whdr.flags & RXRPC_REQUEST_ACK) 439 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data); 440 441 /* send the packet by UDP 442 * - returns -EMSGSIZE if UDP would have to fragment the packet 443 * to go out of the interface 444 * - in which case, we'll have processed the ICMP error 445 * message and update the peer record 446 */ 447 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len); 448 conn->params.peer->last_tx_at = ktime_get_seconds(); 449 450 up_read(&conn->params.local->defrag_sem); 451 if (ret < 0) { 452 rxrpc_cancel_rtt_probe(call, serial, rtt_slot); 453 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 454 rxrpc_tx_point_call_data_nofrag); 455 } else { 456 trace_rxrpc_tx_packet(call->debug_id, &whdr, 457 rxrpc_tx_point_call_data_nofrag); 458 } 459 460 rxrpc_tx_backoff(call, ret); 461 if (ret == -EMSGSIZE) 462 goto send_fragmentable; 463 464 done: 465 if (ret >= 0) { 466 if (whdr.flags & RXRPC_REQUEST_ACK) { 467 call->peer->rtt_last_req = skb->tstamp; 468 if (call->peer->rtt_count > 1) { 469 unsigned long nowj = jiffies, ack_lost_at; 470 471 ack_lost_at = rxrpc_get_rto_backoff(call->peer, false); 472 ack_lost_at += nowj; 473 WRITE_ONCE(call->ack_lost_at, ack_lost_at); 474 rxrpc_reduce_call_timer(call, ack_lost_at, nowj, 475 rxrpc_timer_set_for_lost_ack); 476 } 477 } 478 479 if (sp->hdr.seq == 1 && 480 !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, 481 &call->flags)) { 482 unsigned long nowj = jiffies, expect_rx_by; 483 484 expect_rx_by = nowj + call->next_rx_timo; 485 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 486 rxrpc_reduce_call_timer(call, expect_rx_by, nowj, 487 rxrpc_timer_set_for_normal); 488 } 489 490 rxrpc_set_keepalive(call); 491 } else { 492 /* Cancel the call if the initial transmission fails, 493 * particularly if that's due to network routing issues that 494 * aren't going away anytime soon. The layer above can arrange 495 * the retransmission. 496 */ 497 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags)) 498 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 499 RX_USER_ABORT, ret); 500 } 501 502 _leave(" = %d [%u]", ret, call->peer->maxdata); 503 return ret; 504 505 send_fragmentable: 506 /* attempt to send this message with fragmentation enabled */ 507 _debug("send fragment"); 508 509 down_write(&conn->params.local->defrag_sem); 510 511 sp->hdr.serial = serial; 512 smp_wmb(); /* Set serial before timestamp */ 513 skb->tstamp = ktime_get_real(); 514 if (whdr.flags & RXRPC_REQUEST_ACK) 515 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data); 516 517 switch (conn->params.local->srx.transport.family) { 518 case AF_INET6: 519 case AF_INET: 520 ip_sock_set_mtu_discover(conn->params.local->socket->sk, 521 IP_PMTUDISC_DONT); 522 ret = kernel_sendmsg(conn->params.local->socket, &msg, 523 iov, 2, len); 524 conn->params.peer->last_tx_at = ktime_get_seconds(); 525 526 ip_sock_set_mtu_discover(conn->params.local->socket->sk, 527 IP_PMTUDISC_DO); 528 break; 529 530 default: 531 BUG(); 532 } 533 534 if (ret < 0) { 535 rxrpc_cancel_rtt_probe(call, serial, rtt_slot); 536 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 537 rxrpc_tx_point_call_data_frag); 538 } else { 539 trace_rxrpc_tx_packet(call->debug_id, &whdr, 540 rxrpc_tx_point_call_data_frag); 541 } 542 rxrpc_tx_backoff(call, ret); 543 544 up_write(&conn->params.local->defrag_sem); 545 goto done; 546 } 547 548 /* 549 * reject packets through the local endpoint 550 */ 551 void rxrpc_reject_packets(struct rxrpc_local *local) 552 { 553 struct sockaddr_rxrpc srx; 554 struct rxrpc_skb_priv *sp; 555 struct rxrpc_wire_header whdr; 556 struct sk_buff *skb; 557 struct msghdr msg; 558 struct kvec iov[2]; 559 size_t size; 560 __be32 code; 561 int ret, ioc; 562 563 _enter("%d", local->debug_id); 564 565 iov[0].iov_base = &whdr; 566 iov[0].iov_len = sizeof(whdr); 567 iov[1].iov_base = &code; 568 iov[1].iov_len = sizeof(code); 569 570 msg.msg_name = &srx.transport; 571 msg.msg_control = NULL; 572 msg.msg_controllen = 0; 573 msg.msg_flags = 0; 574 575 memset(&whdr, 0, sizeof(whdr)); 576 577 while ((skb = skb_dequeue(&local->reject_queue))) { 578 rxrpc_see_skb(skb, rxrpc_skb_seen); 579 sp = rxrpc_skb(skb); 580 581 switch (skb->mark) { 582 case RXRPC_SKB_MARK_REJECT_BUSY: 583 whdr.type = RXRPC_PACKET_TYPE_BUSY; 584 size = sizeof(whdr); 585 ioc = 1; 586 break; 587 case RXRPC_SKB_MARK_REJECT_ABORT: 588 whdr.type = RXRPC_PACKET_TYPE_ABORT; 589 code = htonl(skb->priority); 590 size = sizeof(whdr) + sizeof(code); 591 ioc = 2; 592 break; 593 default: 594 rxrpc_free_skb(skb, rxrpc_skb_freed); 595 continue; 596 } 597 598 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) { 599 msg.msg_namelen = srx.transport_len; 600 601 whdr.epoch = htonl(sp->hdr.epoch); 602 whdr.cid = htonl(sp->hdr.cid); 603 whdr.callNumber = htonl(sp->hdr.callNumber); 604 whdr.serviceId = htons(sp->hdr.serviceId); 605 whdr.flags = sp->hdr.flags; 606 whdr.flags ^= RXRPC_CLIENT_INITIATED; 607 whdr.flags &= RXRPC_CLIENT_INITIATED; 608 609 ret = kernel_sendmsg(local->socket, &msg, 610 iov, ioc, size); 611 if (ret < 0) 612 trace_rxrpc_tx_fail(local->debug_id, 0, ret, 613 rxrpc_tx_point_reject); 614 else 615 trace_rxrpc_tx_packet(local->debug_id, &whdr, 616 rxrpc_tx_point_reject); 617 } 618 619 rxrpc_free_skb(skb, rxrpc_skb_freed); 620 } 621 622 _leave(""); 623 } 624 625 /* 626 * Send a VERSION reply to a peer as a keepalive. 627 */ 628 void rxrpc_send_keepalive(struct rxrpc_peer *peer) 629 { 630 struct rxrpc_wire_header whdr; 631 struct msghdr msg; 632 struct kvec iov[2]; 633 size_t len; 634 int ret; 635 636 _enter(""); 637 638 msg.msg_name = &peer->srx.transport; 639 msg.msg_namelen = peer->srx.transport_len; 640 msg.msg_control = NULL; 641 msg.msg_controllen = 0; 642 msg.msg_flags = 0; 643 644 whdr.epoch = htonl(peer->local->rxnet->epoch); 645 whdr.cid = 0; 646 whdr.callNumber = 0; 647 whdr.seq = 0; 648 whdr.serial = 0; 649 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */ 650 whdr.flags = RXRPC_LAST_PACKET; 651 whdr.userStatus = 0; 652 whdr.securityIndex = 0; 653 whdr._rsvd = 0; 654 whdr.serviceId = 0; 655 656 iov[0].iov_base = &whdr; 657 iov[0].iov_len = sizeof(whdr); 658 iov[1].iov_base = (char *)rxrpc_keepalive_string; 659 iov[1].iov_len = sizeof(rxrpc_keepalive_string); 660 661 len = iov[0].iov_len + iov[1].iov_len; 662 663 _proto("Tx VERSION (keepalive)"); 664 665 ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len); 666 if (ret < 0) 667 trace_rxrpc_tx_fail(peer->debug_id, 0, ret, 668 rxrpc_tx_point_version_keepalive); 669 else 670 trace_rxrpc_tx_packet(peer->debug_id, &whdr, 671 rxrpc_tx_point_version_keepalive); 672 673 peer->last_tx_at = ktime_get_seconds(); 674 _leave(""); 675 } 676