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 <net/udp.h> 17#include "ar-internal.h" 18 19extern int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len); 20 21static ssize_t do_udp_sendmsg(struct socket *socket, struct msghdr *msg, size_t len) 22{ 23 struct sockaddr *sa = msg->msg_name; 24 struct sock *sk = socket->sk; 25 26 if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6)) { 27 if (sa->sa_family == AF_INET6) { 28 if (sk->sk_family != AF_INET6) { 29 pr_warn("AF_INET6 address on AF_INET socket\n"); 30 return -ENOPROTOOPT; 31 } 32 return udpv6_sendmsg(sk, msg, len); 33 } 34 } 35 return udp_sendmsg(sk, msg, len); 36} 37 38struct rxrpc_abort_buffer { 39 struct rxrpc_wire_header whdr; 40 __be32 abort_code; 41}; 42 43static const char rxrpc_keepalive_string[] = ""; 44 45/* 46 * Increase Tx backoff on transmission failure and clear it on success. 47 */ 48static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret) 49{ 50 if (ret < 0) { 51 u16 tx_backoff = READ_ONCE(call->tx_backoff); 52 53 if (tx_backoff < HZ) 54 WRITE_ONCE(call->tx_backoff, tx_backoff + 1); 55 } else { 56 WRITE_ONCE(call->tx_backoff, 0); 57 } 58} 59 60/* 61 * Arrange for a keepalive ping a certain time after we last transmitted. This 62 * lets the far side know we're still interested in this call and helps keep 63 * the route through any intervening firewall open. 64 * 65 * Receiving a response to the ping will prevent the ->expect_rx_by timer from 66 * expiring. 67 */ 68static void rxrpc_set_keepalive(struct rxrpc_call *call) 69{ 70 unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6; 71 72 keepalive_at += now; 73 WRITE_ONCE(call->keepalive_at, keepalive_at); 74 rxrpc_reduce_call_timer(call, keepalive_at, now, 75 rxrpc_timer_set_for_keepalive); 76} 77 78/* 79 * Fill out an ACK packet. 80 */ 81static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn, 82 struct rxrpc_call *call, 83 struct rxrpc_txbuf *txb, 84 u16 *_rwind) 85{ 86 struct rxrpc_ackinfo ackinfo; 87 unsigned int qsize, sack, wrap, to; 88 rxrpc_seq_t window, wtop; 89 int rsize; 90 u32 mtu, jmax; 91 u8 *ackp = txb->acks; 92 93 call->ackr_nr_unacked = 0; 94 atomic_set(&call->ackr_nr_consumed, 0); 95 rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill); 96 clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags); 97 98 window = call->ackr_window; 99 wtop = call->ackr_wtop; 100 sack = call->ackr_sack_base % RXRPC_SACK_SIZE; 101 txb->ack.firstPacket = htonl(window); 102 txb->ack.nAcks = wtop - window; 103 104 if (after(wtop, window)) { 105 wrap = RXRPC_SACK_SIZE - sack; 106 to = min_t(unsigned int, txb->ack.nAcks, RXRPC_SACK_SIZE); 107 108 if (sack + txb->ack.nAcks <= RXRPC_SACK_SIZE) { 109 memcpy(txb->acks, call->ackr_sack_table + sack, txb->ack.nAcks); 110 } else { 111 memcpy(txb->acks, call->ackr_sack_table + sack, wrap); 112 memcpy(txb->acks + wrap, call->ackr_sack_table, 113 to - wrap); 114 } 115 116 ackp += to; 117 } else if (before(wtop, window)) { 118 pr_warn("ack window backward %x %x", window, wtop); 119 } else if (txb->ack.reason == RXRPC_ACK_DELAY) { 120 txb->ack.reason = RXRPC_ACK_IDLE; 121 } 122 123 mtu = conn->peer->if_mtu; 124 mtu -= conn->peer->hdrsize; 125 jmax = rxrpc_rx_jumbo_max; 126 qsize = (window - 1) - call->rx_consumed; 127 rsize = max_t(int, call->rx_winsize - qsize, 0); 128 *_rwind = rsize; 129 ackinfo.rxMTU = htonl(rxrpc_rx_mtu); 130 ackinfo.maxMTU = htonl(mtu); 131 ackinfo.rwind = htonl(rsize); 132 ackinfo.jumbo_max = htonl(jmax); 133 134 *ackp++ = 0; 135 *ackp++ = 0; 136 *ackp++ = 0; 137 memcpy(ackp, &ackinfo, sizeof(ackinfo)); 138 return txb->ack.nAcks + 3 + sizeof(ackinfo); 139} 140 141/* 142 * Record the beginning of an RTT probe. 143 */ 144static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial, 145 enum rxrpc_rtt_tx_trace why) 146{ 147 unsigned long avail = call->rtt_avail; 148 int rtt_slot = 9; 149 150 if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK)) 151 goto no_slot; 152 153 rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK); 154 if (!test_and_clear_bit(rtt_slot, &call->rtt_avail)) 155 goto no_slot; 156 157 call->rtt_serial[rtt_slot] = serial; 158 call->rtt_sent_at[rtt_slot] = ktime_get_real(); 159 smp_wmb(); /* Write data before avail bit */ 160 set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 161 162 trace_rxrpc_rtt_tx(call, why, rtt_slot, serial); 163 return rtt_slot; 164 165no_slot: 166 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial); 167 return -1; 168} 169 170/* 171 * Cancel an RTT probe. 172 */ 173static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call, 174 rxrpc_serial_t serial, int rtt_slot) 175{ 176 if (rtt_slot != -1) { 177 clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail); 178 smp_wmb(); /* Clear pending bit before setting slot */ 179 set_bit(rtt_slot, &call->rtt_avail); 180 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial); 181 } 182} 183 184/* 185 * Transmit an ACK packet. 186 */ 187int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb) 188{ 189 struct rxrpc_connection *conn; 190 struct msghdr msg; 191 struct kvec iov[1]; 192 rxrpc_serial_t serial; 193 size_t len, n; 194 int ret, rtt_slot = -1; 195 u16 rwind; 196 197 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) 198 return -ECONNRESET; 199 200 conn = call->conn; 201 202 msg.msg_name = &call->peer->srx.transport; 203 msg.msg_namelen = call->peer->srx.transport_len; 204 msg.msg_control = NULL; 205 msg.msg_controllen = 0; 206 msg.msg_flags = 0; 207 208 if (txb->ack.reason == RXRPC_ACK_PING) 209 txb->wire.flags |= RXRPC_REQUEST_ACK; 210 211 n = rxrpc_fill_out_ack(conn, call, txb, &rwind); 212 if (n == 0) 213 return 0; 214 215 iov[0].iov_base = &txb->wire; 216 iov[0].iov_len = sizeof(txb->wire) + sizeof(txb->ack) + n; 217 len = iov[0].iov_len; 218 219 serial = rxrpc_get_next_serial(conn); 220 txb->wire.serial = htonl(serial); 221 trace_rxrpc_tx_ack(call->debug_id, serial, 222 ntohl(txb->ack.firstPacket), 223 ntohl(txb->ack.serial), txb->ack.reason, txb->ack.nAcks, 224 rwind); 225 226 if (txb->ack.reason == RXRPC_ACK_PING) 227 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping); 228 229 rxrpc_inc_stat(call->rxnet, stat_tx_ack_send); 230 231 /* Grab the highest received seq as late as possible */ 232 txb->ack.previousPacket = htonl(call->rx_highest_seq); 233 234 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len); 235 ret = do_udp_sendmsg(conn->local->socket, &msg, len); 236 call->peer->last_tx_at = ktime_get_seconds(); 237 if (ret < 0) { 238 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 239 rxrpc_tx_point_call_ack); 240 } else { 241 trace_rxrpc_tx_packet(call->debug_id, &txb->wire, 242 rxrpc_tx_point_call_ack); 243 if (txb->wire.flags & RXRPC_REQUEST_ACK) 244 call->peer->rtt_last_req = ktime_get_real(); 245 } 246 rxrpc_tx_backoff(call, ret); 247 248 if (!__rxrpc_call_is_complete(call)) { 249 if (ret < 0) 250 rxrpc_cancel_rtt_probe(call, serial, rtt_slot); 251 rxrpc_set_keepalive(call); 252 } 253 254 return ret; 255} 256 257/* 258 * Send an ABORT call packet. 259 */ 260int rxrpc_send_abort_packet(struct rxrpc_call *call) 261{ 262 struct rxrpc_connection *conn; 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_ALL_ACKED, &call->flags)) 277 return 0; 278 279 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) 280 return -ECONNRESET; 281 282 conn = call->conn; 283 284 msg.msg_name = &call->peer->srx.transport; 285 msg.msg_namelen = call->peer->srx.transport_len; 286 msg.msg_control = NULL; 287 msg.msg_controllen = 0; 288 msg.msg_flags = 0; 289 290 pkt.whdr.epoch = htonl(conn->proto.epoch); 291 pkt.whdr.cid = htonl(call->cid); 292 pkt.whdr.callNumber = htonl(call->call_id); 293 pkt.whdr.seq = 0; 294 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT; 295 pkt.whdr.flags = conn->out_clientflag; 296 pkt.whdr.userStatus = 0; 297 pkt.whdr.securityIndex = call->security_ix; 298 pkt.whdr._rsvd = 0; 299 pkt.whdr.serviceId = htons(call->dest_srx.srx_service); 300 pkt.abort_code = htonl(call->abort_code); 301 302 iov[0].iov_base = &pkt; 303 iov[0].iov_len = sizeof(pkt); 304 305 serial = rxrpc_get_next_serial(conn); 306 pkt.whdr.serial = htonl(serial); 307 308 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, sizeof(pkt)); 309 ret = do_udp_sendmsg(conn->local->socket, &msg, sizeof(pkt)); 310 conn->peer->last_tx_at = ktime_get_seconds(); 311 if (ret < 0) 312 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 313 rxrpc_tx_point_call_abort); 314 else 315 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr, 316 rxrpc_tx_point_call_abort); 317 rxrpc_tx_backoff(call, ret); 318 return ret; 319} 320 321/* 322 * send a packet through the transport endpoint 323 */ 324int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb) 325{ 326 enum rxrpc_req_ack_trace why; 327 struct rxrpc_connection *conn = call->conn; 328 struct msghdr msg; 329 struct kvec iov[1]; 330 rxrpc_serial_t serial; 331 size_t len; 332 int ret, rtt_slot = -1; 333 334 _enter("%x,{%d}", txb->seq, txb->len); 335 336 /* Each transmission of a Tx packet needs a new serial number */ 337 serial = rxrpc_get_next_serial(conn); 338 txb->wire.serial = htonl(serial); 339 340 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) && 341 txb->seq == 1) 342 txb->wire.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE; 343 344 iov[0].iov_base = &txb->wire; 345 iov[0].iov_len = sizeof(txb->wire) + txb->len; 346 len = iov[0].iov_len; 347 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len); 348 349 msg.msg_name = &call->peer->srx.transport; 350 msg.msg_namelen = call->peer->srx.transport_len; 351 msg.msg_control = NULL; 352 msg.msg_controllen = 0; 353 msg.msg_flags = 0; 354 355 /* If our RTT cache needs working on, request an ACK. Also request 356 * ACKs if a DATA packet appears to have been lost. 357 * 358 * However, we mustn't request an ACK on the last reply packet of a 359 * service call, lest OpenAFS incorrectly send us an ACK with some 360 * soft-ACKs in it and then never follow up with a proper hard ACK. 361 */ 362 if (txb->wire.flags & RXRPC_REQUEST_ACK) 363 why = rxrpc_reqack_already_on; 364 else if (test_bit(RXRPC_TXBUF_LAST, &txb->flags) && rxrpc_sending_to_client(txb)) 365 why = rxrpc_reqack_no_srv_last; 366 else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events)) 367 why = rxrpc_reqack_ack_lost; 368 else if (test_bit(RXRPC_TXBUF_RESENT, &txb->flags)) 369 why = rxrpc_reqack_retrans; 370 else if (call->cong_mode == RXRPC_CALL_SLOW_START && call->cong_cwnd <= 2) 371 why = rxrpc_reqack_slow_start; 372 else if (call->tx_winsize <= 2) 373 why = rxrpc_reqack_small_txwin; 374 else if (call->peer->rtt_count < 3 && txb->seq & 1) 375 why = rxrpc_reqack_more_rtt; 376 else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real())) 377 why = rxrpc_reqack_old_rtt; 378 else 379 goto dont_set_request_ack; 380 381 rxrpc_inc_stat(call->rxnet, stat_why_req_ack[why]); 382 trace_rxrpc_req_ack(call->debug_id, txb->seq, why); 383 if (why != rxrpc_reqack_no_srv_last) 384 txb->wire.flags |= RXRPC_REQUEST_ACK; 385dont_set_request_ack: 386 387 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { 388 static int lose; 389 if ((lose++ & 7) == 7) { 390 ret = 0; 391 trace_rxrpc_tx_data(call, txb->seq, serial, 392 txb->wire.flags, 393 test_bit(RXRPC_TXBUF_RESENT, &txb->flags), 394 true); 395 goto done; 396 } 397 } 398 399 trace_rxrpc_tx_data(call, txb->seq, serial, txb->wire.flags, 400 test_bit(RXRPC_TXBUF_RESENT, &txb->flags), false); 401 402 /* Track what we've attempted to transmit at least once so that the 403 * retransmission algorithm doesn't try to resend what we haven't sent 404 * yet. However, this can race as we can receive an ACK before we get 405 * to this point. But, OTOH, if we won't get an ACK mentioning this 406 * packet unless the far side received it (though it could have 407 * discarded it anyway and NAK'd it). 408 */ 409 cmpxchg(&call->tx_transmitted, txb->seq - 1, txb->seq); 410 411 /* send the packet with the don't fragment bit set if we currently 412 * think it's small enough */ 413 if (txb->len >= call->peer->maxdata) 414 goto send_fragmentable; 415 416 txb->last_sent = ktime_get_real(); 417 if (txb->wire.flags & RXRPC_REQUEST_ACK) 418 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data); 419 420 /* send the packet by UDP 421 * - returns -EMSGSIZE if UDP would have to fragment the packet 422 * to go out of the interface 423 * - in which case, we'll have processed the ICMP error 424 * message and update the peer record 425 */ 426 rxrpc_inc_stat(call->rxnet, stat_tx_data_send); 427 ret = do_udp_sendmsg(conn->local->socket, &msg, len); 428 conn->peer->last_tx_at = ktime_get_seconds(); 429 430 if (ret < 0) { 431 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail); 432 rxrpc_cancel_rtt_probe(call, serial, rtt_slot); 433 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 434 rxrpc_tx_point_call_data_nofrag); 435 } else { 436 trace_rxrpc_tx_packet(call->debug_id, &txb->wire, 437 rxrpc_tx_point_call_data_nofrag); 438 } 439 440 rxrpc_tx_backoff(call, ret); 441 if (ret == -EMSGSIZE) 442 goto send_fragmentable; 443 444done: 445 if (ret >= 0) { 446 call->tx_last_sent = txb->last_sent; 447 if (txb->wire.flags & RXRPC_REQUEST_ACK) { 448 call->peer->rtt_last_req = txb->last_sent; 449 if (call->peer->rtt_count > 1) { 450 unsigned long nowj = jiffies, ack_lost_at; 451 452 ack_lost_at = rxrpc_get_rto_backoff(call->peer, false); 453 ack_lost_at += nowj; 454 WRITE_ONCE(call->ack_lost_at, ack_lost_at); 455 rxrpc_reduce_call_timer(call, ack_lost_at, nowj, 456 rxrpc_timer_set_for_lost_ack); 457 } 458 } 459 460 if (txb->seq == 1 && 461 !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, 462 &call->flags)) { 463 unsigned long nowj = jiffies, expect_rx_by; 464 465 expect_rx_by = nowj + call->next_rx_timo; 466 WRITE_ONCE(call->expect_rx_by, expect_rx_by); 467 rxrpc_reduce_call_timer(call, expect_rx_by, nowj, 468 rxrpc_timer_set_for_normal); 469 } 470 471 rxrpc_set_keepalive(call); 472 } else { 473 /* Cancel the call if the initial transmission fails, 474 * particularly if that's due to network routing issues that 475 * aren't going away anytime soon. The layer above can arrange 476 * the retransmission. 477 */ 478 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags)) 479 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 480 RX_USER_ABORT, ret); 481 } 482 483 _leave(" = %d [%u]", ret, call->peer->maxdata); 484 return ret; 485 486send_fragmentable: 487 /* attempt to send this message with fragmentation enabled */ 488 _debug("send fragment"); 489 490 txb->last_sent = ktime_get_real(); 491 if (txb->wire.flags & RXRPC_REQUEST_ACK) 492 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data); 493 494 switch (conn->local->srx.transport.family) { 495 case AF_INET6: 496 case AF_INET: 497 rxrpc_local_dont_fragment(conn->local, false); 498 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_frag); 499 ret = do_udp_sendmsg(conn->local->socket, &msg, len); 500 conn->peer->last_tx_at = ktime_get_seconds(); 501 502 rxrpc_local_dont_fragment(conn->local, true); 503 break; 504 505 default: 506 BUG(); 507 } 508 509 if (ret < 0) { 510 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail); 511 rxrpc_cancel_rtt_probe(call, serial, rtt_slot); 512 trace_rxrpc_tx_fail(call->debug_id, serial, ret, 513 rxrpc_tx_point_call_data_frag); 514 } else { 515 trace_rxrpc_tx_packet(call->debug_id, &txb->wire, 516 rxrpc_tx_point_call_data_frag); 517 } 518 rxrpc_tx_backoff(call, ret); 519 goto done; 520} 521 522/* 523 * Transmit a connection-level abort. 524 */ 525void rxrpc_send_conn_abort(struct rxrpc_connection *conn) 526{ 527 struct rxrpc_wire_header whdr; 528 struct msghdr msg; 529 struct kvec iov[2]; 530 __be32 word; 531 size_t len; 532 u32 serial; 533 int ret; 534 535 msg.msg_name = &conn->peer->srx.transport; 536 msg.msg_namelen = conn->peer->srx.transport_len; 537 msg.msg_control = NULL; 538 msg.msg_controllen = 0; 539 msg.msg_flags = 0; 540 541 whdr.epoch = htonl(conn->proto.epoch); 542 whdr.cid = htonl(conn->proto.cid); 543 whdr.callNumber = 0; 544 whdr.seq = 0; 545 whdr.type = RXRPC_PACKET_TYPE_ABORT; 546 whdr.flags = conn->out_clientflag; 547 whdr.userStatus = 0; 548 whdr.securityIndex = conn->security_ix; 549 whdr._rsvd = 0; 550 whdr.serviceId = htons(conn->service_id); 551 552 word = htonl(conn->abort_code); 553 554 iov[0].iov_base = &whdr; 555 iov[0].iov_len = sizeof(whdr); 556 iov[1].iov_base = &word; 557 iov[1].iov_len = sizeof(word); 558 559 len = iov[0].iov_len + iov[1].iov_len; 560 561 serial = rxrpc_get_next_serial(conn); 562 whdr.serial = htonl(serial); 563 564 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len); 565 ret = do_udp_sendmsg(conn->local->socket, &msg, len); 566 if (ret < 0) { 567 trace_rxrpc_tx_fail(conn->debug_id, serial, ret, 568 rxrpc_tx_point_conn_abort); 569 _debug("sendmsg failed: %d", ret); 570 return; 571 } 572 573 trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort); 574 575 conn->peer->last_tx_at = ktime_get_seconds(); 576} 577 578/* 579 * Reject a packet through the local endpoint. 580 */ 581void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb) 582{ 583 struct rxrpc_wire_header whdr; 584 struct sockaddr_rxrpc srx; 585 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 586 struct msghdr msg; 587 struct kvec iov[2]; 588 size_t size; 589 __be32 code; 590 int ret, ioc; 591 592 rxrpc_see_skb(skb, rxrpc_skb_see_reject); 593 594 iov[0].iov_base = &whdr; 595 iov[0].iov_len = sizeof(whdr); 596 iov[1].iov_base = &code; 597 iov[1].iov_len = sizeof(code); 598 599 msg.msg_name = &srx.transport; 600 msg.msg_control = NULL; 601 msg.msg_controllen = 0; 602 msg.msg_flags = 0; 603 604 memset(&whdr, 0, sizeof(whdr)); 605 606 switch (skb->mark) { 607 case RXRPC_SKB_MARK_REJECT_BUSY: 608 whdr.type = RXRPC_PACKET_TYPE_BUSY; 609 size = sizeof(whdr); 610 ioc = 1; 611 break; 612 case RXRPC_SKB_MARK_REJECT_ABORT: 613 whdr.type = RXRPC_PACKET_TYPE_ABORT; 614 code = htonl(skb->priority); 615 size = sizeof(whdr) + sizeof(code); 616 ioc = 2; 617 break; 618 default: 619 return; 620 } 621 622 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) { 623 msg.msg_namelen = srx.transport_len; 624 625 whdr.epoch = htonl(sp->hdr.epoch); 626 whdr.cid = htonl(sp->hdr.cid); 627 whdr.callNumber = htonl(sp->hdr.callNumber); 628 whdr.serviceId = htons(sp->hdr.serviceId); 629 whdr.flags = sp->hdr.flags; 630 whdr.flags ^= RXRPC_CLIENT_INITIATED; 631 whdr.flags &= RXRPC_CLIENT_INITIATED; 632 633 iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size); 634 ret = do_udp_sendmsg(local->socket, &msg, size); 635 if (ret < 0) 636 trace_rxrpc_tx_fail(local->debug_id, 0, ret, 637 rxrpc_tx_point_reject); 638 else 639 trace_rxrpc_tx_packet(local->debug_id, &whdr, 640 rxrpc_tx_point_reject); 641 } 642} 643 644/* 645 * Send a VERSION reply to a peer as a keepalive. 646 */ 647void rxrpc_send_keepalive(struct rxrpc_peer *peer) 648{ 649 struct rxrpc_wire_header whdr; 650 struct msghdr msg; 651 struct kvec iov[2]; 652 size_t len; 653 int ret; 654 655 _enter(""); 656 657 msg.msg_name = &peer->srx.transport; 658 msg.msg_namelen = peer->srx.transport_len; 659 msg.msg_control = NULL; 660 msg.msg_controllen = 0; 661 msg.msg_flags = 0; 662 663 whdr.epoch = htonl(peer->local->rxnet->epoch); 664 whdr.cid = 0; 665 whdr.callNumber = 0; 666 whdr.seq = 0; 667 whdr.serial = 0; 668 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */ 669 whdr.flags = RXRPC_LAST_PACKET; 670 whdr.userStatus = 0; 671 whdr.securityIndex = 0; 672 whdr._rsvd = 0; 673 whdr.serviceId = 0; 674 675 iov[0].iov_base = &whdr; 676 iov[0].iov_len = sizeof(whdr); 677 iov[1].iov_base = (char *)rxrpc_keepalive_string; 678 iov[1].iov_len = sizeof(rxrpc_keepalive_string); 679 680 len = iov[0].iov_len + iov[1].iov_len; 681 682 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len); 683 ret = do_udp_sendmsg(peer->local->socket, &msg, len); 684 if (ret < 0) 685 trace_rxrpc_tx_fail(peer->debug_id, 0, ret, 686 rxrpc_tx_point_version_keepalive); 687 else 688 trace_rxrpc_tx_packet(peer->debug_id, &whdr, 689 rxrpc_tx_point_version_keepalive); 690 691 peer->last_tx_at = ktime_get_seconds(); 692 _leave(""); 693} 694 695/* 696 * Schedule an instant Tx resend. 697 */ 698static inline void rxrpc_instant_resend(struct rxrpc_call *call, 699 struct rxrpc_txbuf *txb) 700{ 701 if (!__rxrpc_call_is_complete(call)) 702 kdebug("resend"); 703} 704 705/* 706 * Transmit one packet. 707 */ 708void rxrpc_transmit_one(struct rxrpc_call *call, struct rxrpc_txbuf *txb) 709{ 710 int ret; 711 712 ret = rxrpc_send_data_packet(call, txb); 713 if (ret < 0) { 714 switch (ret) { 715 case -ENETUNREACH: 716 case -EHOSTUNREACH: 717 case -ECONNREFUSED: 718 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 719 0, ret); 720 break; 721 default: 722 _debug("need instant resend %d", ret); 723 rxrpc_instant_resend(call, txb); 724 } 725 } else { 726 unsigned long now = jiffies; 727 unsigned long resend_at = now + call->peer->rto_j; 728 729 WRITE_ONCE(call->resend_at, resend_at); 730 rxrpc_reduce_call_timer(call, resend_at, now, 731 rxrpc_timer_set_for_send); 732 } 733} 734