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
19 extern int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
20
21 static 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
38 struct rxrpc_abort_buffer {
39 struct rxrpc_wire_header whdr;
40 __be32 abort_code;
41 };
42
43 static const char rxrpc_keepalive_string[] = "";
44
45 /*
46 * Increase Tx backoff on transmission failure and clear it on success.
47 */
48 static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
49 {
50 if (ret < 0) {
51 if (call->tx_backoff < 1000)
52 call->tx_backoff += 100;
53 } else {
54 call->tx_backoff = 0;
55 }
56 }
57
58 /*
59 * Arrange for a keepalive ping a certain time after we last transmitted. This
60 * lets the far side know we're still interested in this call and helps keep
61 * the route through any intervening firewall open.
62 *
63 * Receiving a response to the ping will prevent the ->expect_rx_by timer from
64 * expiring.
65 */
66 static void rxrpc_set_keepalive(struct rxrpc_call *call, ktime_t now)
67 {
68 ktime_t delay = ms_to_ktime(READ_ONCE(call->next_rx_timo) / 6);
69
70 call->keepalive_at = ktime_add(ktime_get_real(), delay);
71 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_keepalive);
72 }
73
74 /*
75 * Fill out an ACK packet.
76 */
77 static void rxrpc_fill_out_ack(struct rxrpc_call *call,
78 struct rxrpc_txbuf *txb,
79 u8 ack_reason,
80 rxrpc_serial_t serial)
81 {
82 struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
83 struct rxrpc_acktrailer *trailer = txb->kvec[2].iov_base + 3;
84 struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);
85 unsigned int qsize, sack, wrap, to;
86 rxrpc_seq_t window, wtop;
87 int rsize;
88 u32 mtu, jmax;
89 u8 *filler = txb->kvec[2].iov_base;
90 u8 *sackp = txb->kvec[1].iov_base;
91
92 rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill);
93
94 window = call->ackr_window;
95 wtop = call->ackr_wtop;
96 sack = call->ackr_sack_base % RXRPC_SACK_SIZE;
97
98 whdr->seq = 0;
99 whdr->type = RXRPC_PACKET_TYPE_ACK;
100 txb->flags |= RXRPC_SLOW_START_OK;
101 ack->bufferSpace = 0;
102 ack->maxSkew = 0;
103 ack->firstPacket = htonl(window);
104 ack->previousPacket = htonl(call->rx_highest_seq);
105 ack->serial = htonl(serial);
106 ack->reason = ack_reason;
107 ack->nAcks = wtop - window;
108 filler[0] = 0;
109 filler[1] = 0;
110 filler[2] = 0;
111
112 if (ack_reason == RXRPC_ACK_PING)
113 txb->flags |= RXRPC_REQUEST_ACK;
114
115 if (after(wtop, window)) {
116 txb->len += ack->nAcks;
117 txb->kvec[1].iov_base = sackp;
118 txb->kvec[1].iov_len = ack->nAcks;
119
120 wrap = RXRPC_SACK_SIZE - sack;
121 to = min_t(unsigned int, ack->nAcks, RXRPC_SACK_SIZE);
122
123 if (sack + ack->nAcks <= RXRPC_SACK_SIZE) {
124 memcpy(sackp, call->ackr_sack_table + sack, ack->nAcks);
125 } else {
126 memcpy(sackp, call->ackr_sack_table + sack, wrap);
127 memcpy(sackp + wrap, call->ackr_sack_table, to - wrap);
128 }
129 } else if (before(wtop, window)) {
130 pr_warn("ack window backward %x %x", window, wtop);
131 } else if (ack->reason == RXRPC_ACK_DELAY) {
132 ack->reason = RXRPC_ACK_IDLE;
133 }
134
135 mtu = call->peer->if_mtu;
136 mtu -= call->peer->hdrsize;
137 jmax = rxrpc_rx_jumbo_max;
138 qsize = (window - 1) - call->rx_consumed;
139 rsize = max_t(int, call->rx_winsize - qsize, 0);
140 txb->ack_rwind = rsize;
141 trailer->maxMTU = htonl(rxrpc_rx_mtu);
142 trailer->ifMTU = htonl(mtu);
143 trailer->rwind = htonl(rsize);
144 trailer->jumbo_max = htonl(jmax);
145 }
146
147 /*
148 * Record the beginning of an RTT probe.
149 */
150 static void rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
151 ktime_t now, enum rxrpc_rtt_tx_trace why)
152 {
153 unsigned long avail = call->rtt_avail;
154 int rtt_slot = 9;
155
156 if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
157 goto no_slot;
158
159 rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
160 if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
161 goto no_slot;
162
163 call->rtt_serial[rtt_slot] = serial;
164 call->rtt_sent_at[rtt_slot] = now;
165 smp_wmb(); /* Write data before avail bit */
166 set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
167
168 trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
169 return;
170
171 no_slot:
172 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
173 }
174
175 /*
176 * Transmit an ACK packet.
177 */
178 static void rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
179 {
180 struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
181 struct rxrpc_connection *conn;
182 struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);
183 struct msghdr msg;
184 ktime_t now;
185 int ret;
186
187 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
188 return;
189
190 conn = call->conn;
191
192 msg.msg_name = &call->peer->srx.transport;
193 msg.msg_namelen = call->peer->srx.transport_len;
194 msg.msg_control = NULL;
195 msg.msg_controllen = 0;
196 msg.msg_flags = MSG_SPLICE_PAGES;
197
198 whdr->flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
199
200 txb->serial = rxrpc_get_next_serial(conn);
201 whdr->serial = htonl(txb->serial);
202 trace_rxrpc_tx_ack(call->debug_id, txb->serial,
203 ntohl(ack->firstPacket),
204 ntohl(ack->serial), ack->reason, ack->nAcks,
205 txb->ack_rwind);
206
207 rxrpc_inc_stat(call->rxnet, stat_tx_ack_send);
208
209 iov_iter_kvec(&msg.msg_iter, WRITE, txb->kvec, txb->nr_kvec, txb->len);
210 rxrpc_local_dont_fragment(conn->local, false);
211 ret = do_udp_sendmsg(conn->local->socket, &msg, txb->len);
212 call->peer->last_tx_at = ktime_get_seconds();
213 if (ret < 0) {
214 trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret,
215 rxrpc_tx_point_call_ack);
216 } else {
217 trace_rxrpc_tx_packet(call->debug_id, whdr,
218 rxrpc_tx_point_call_ack);
219 now = ktime_get_real();
220 if (ack->reason == RXRPC_ACK_PING)
221 rxrpc_begin_rtt_probe(call, txb->serial, now, rxrpc_rtt_tx_ping);
222 if (txb->flags & RXRPC_REQUEST_ACK)
223 call->peer->rtt_last_req = now;
224 rxrpc_set_keepalive(call, now);
225 }
226 rxrpc_tx_backoff(call, ret);
227 }
228
229 /*
230 * Queue an ACK for immediate transmission.
231 */
232 void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason,
233 rxrpc_serial_t serial, enum rxrpc_propose_ack_trace why)
234 {
235 struct rxrpc_txbuf *txb;
236
237 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
238 return;
239
240 rxrpc_inc_stat(call->rxnet, stat_tx_acks[ack_reason]);
241
242 txb = rxrpc_alloc_ack_txbuf(call, call->ackr_wtop - call->ackr_window);
243 if (!txb) {
244 kleave(" = -ENOMEM");
245 return;
246 }
247
248 txb->ack_why = why;
249
250 rxrpc_fill_out_ack(call, txb, ack_reason, serial);
251 call->ackr_nr_unacked = 0;
252 atomic_set(&call->ackr_nr_consumed, 0);
253 clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
254
255 trace_rxrpc_send_ack(call, why, ack_reason, serial);
256 rxrpc_send_ack_packet(call, txb);
257 rxrpc_put_txbuf(txb, rxrpc_txbuf_put_ack_tx);
258 }
259
260 /*
261 * Send an ABORT call packet.
262 */
263 int rxrpc_send_abort_packet(struct rxrpc_call *call)
264 {
265 struct rxrpc_connection *conn;
266 struct rxrpc_abort_buffer pkt;
267 struct msghdr msg;
268 struct kvec iov[1];
269 rxrpc_serial_t serial;
270 int ret;
271
272 /* Don't bother sending aborts for a client call once the server has
273 * hard-ACK'd all of its request data. After that point, we're not
274 * going to stop the operation proceeding, and whilst we might limit
275 * the reply, it's not worth it if we can send a new call on the same
276 * channel instead, thereby closing off this call.
277 */
278 if (rxrpc_is_client_call(call) &&
279 test_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags))
280 return 0;
281
282 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
283 return -ECONNRESET;
284
285 conn = call->conn;
286
287 msg.msg_name = &call->peer->srx.transport;
288 msg.msg_namelen = call->peer->srx.transport_len;
289 msg.msg_control = NULL;
290 msg.msg_controllen = 0;
291 msg.msg_flags = 0;
292
293 pkt.whdr.epoch = htonl(conn->proto.epoch);
294 pkt.whdr.cid = htonl(call->cid);
295 pkt.whdr.callNumber = htonl(call->call_id);
296 pkt.whdr.seq = 0;
297 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
298 pkt.whdr.flags = conn->out_clientflag;
299 pkt.whdr.userStatus = 0;
300 pkt.whdr.securityIndex = call->security_ix;
301 pkt.whdr._rsvd = 0;
302 pkt.whdr.serviceId = htons(call->dest_srx.srx_service);
303 pkt.abort_code = htonl(call->abort_code);
304
305 iov[0].iov_base = &pkt;
306 iov[0].iov_len = sizeof(pkt);
307
308 serial = rxrpc_get_next_serial(conn);
309 pkt.whdr.serial = htonl(serial);
310
311 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, sizeof(pkt));
312 ret = do_udp_sendmsg(conn->local->socket, &msg, sizeof(pkt));
313 conn->peer->last_tx_at = ktime_get_seconds();
314 if (ret < 0)
315 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
316 rxrpc_tx_point_call_abort);
317 else
318 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
319 rxrpc_tx_point_call_abort);
320 rxrpc_tx_backoff(call, ret);
321 return ret;
322 }
323
324 /*
325 * Prepare a (sub)packet for transmission.
326 */
327 static void rxrpc_prepare_data_subpacket(struct rxrpc_call *call, struct rxrpc_txbuf *txb,
328 rxrpc_serial_t serial)
329 {
330 struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
331 enum rxrpc_req_ack_trace why;
332 struct rxrpc_connection *conn = call->conn;
333
334 _enter("%x,{%d}", txb->seq, txb->len);
335
336 txb->serial = serial;
337
338 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
339 txb->seq == 1)
340 whdr->userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
341
342 /* If our RTT cache needs working on, request an ACK. Also request
343 * ACKs if a DATA packet appears to have been lost.
344 *
345 * However, we mustn't request an ACK on the last reply packet of a
346 * service call, lest OpenAFS incorrectly send us an ACK with some
347 * soft-ACKs in it and then never follow up with a proper hard ACK.
348 */
349 if (txb->flags & RXRPC_REQUEST_ACK)
350 why = rxrpc_reqack_already_on;
351 else if ((txb->flags & RXRPC_LAST_PACKET) && rxrpc_sending_to_client(txb))
352 why = rxrpc_reqack_no_srv_last;
353 else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events))
354 why = rxrpc_reqack_ack_lost;
355 else if (txb->flags & RXRPC_TXBUF_RESENT)
356 why = rxrpc_reqack_retrans;
357 else if (call->cong_mode == RXRPC_CALL_SLOW_START && call->cong_cwnd <= 2)
358 why = rxrpc_reqack_slow_start;
359 else if (call->tx_winsize <= 2)
360 why = rxrpc_reqack_small_txwin;
361 else if (call->peer->rtt_count < 3 && txb->seq & 1)
362 why = rxrpc_reqack_more_rtt;
363 else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real()))
364 why = rxrpc_reqack_old_rtt;
365 else
366 goto dont_set_request_ack;
367
368 rxrpc_inc_stat(call->rxnet, stat_why_req_ack[why]);
369 trace_rxrpc_req_ack(call->debug_id, txb->seq, why);
370 if (why != rxrpc_reqack_no_srv_last)
371 txb->flags |= RXRPC_REQUEST_ACK;
372 dont_set_request_ack:
373
374 whdr->flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
375 whdr->serial = htonl(txb->serial);
376 whdr->cksum = txb->cksum;
377
378 trace_rxrpc_tx_data(call, txb->seq, txb->serial, txb->flags, false);
379 }
380
381 /*
382 * Prepare a packet for transmission.
383 */
384 static size_t rxrpc_prepare_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
385 {
386 rxrpc_serial_t serial;
387
388 /* Each transmission of a Tx packet needs a new serial number */
389 serial = rxrpc_get_next_serial(call->conn);
390
391 rxrpc_prepare_data_subpacket(call, txb, serial);
392
393 return txb->len;
394 }
395
396 /*
397 * Set timeouts after transmitting a packet.
398 */
399 static void rxrpc_tstamp_data_packets(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
400 {
401 ktime_t now = ktime_get_real();
402 bool ack_requested = txb->flags & RXRPC_REQUEST_ACK;
403
404 call->tx_last_sent = now;
405 txb->last_sent = now;
406
407 if (ack_requested) {
408 rxrpc_begin_rtt_probe(call, txb->serial, now, rxrpc_rtt_tx_data);
409
410 call->peer->rtt_last_req = now;
411 if (call->peer->rtt_count > 1) {
412 ktime_t delay = rxrpc_get_rto_backoff(call->peer, false);
413
414 call->ack_lost_at = ktime_add(now, delay);
415 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_lost_ack);
416 }
417 }
418
419 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags)) {
420 ktime_t delay = ms_to_ktime(READ_ONCE(call->next_rx_timo));
421
422 call->expect_rx_by = ktime_add(now, delay);
423 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_expect_rx);
424 }
425
426 rxrpc_set_keepalive(call, now);
427 }
428
429 /*
430 * send a packet through the transport endpoint
431 */
432 static int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
433 {
434 struct rxrpc_wire_header *whdr = txb->kvec[0].iov_base;
435 struct rxrpc_connection *conn = call->conn;
436 enum rxrpc_tx_point frag;
437 struct msghdr msg;
438 size_t len;
439 int ret;
440
441 _enter("%x,{%d}", txb->seq, txb->len);
442
443 len = rxrpc_prepare_data_packet(call, txb);
444
445 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
446 static int lose;
447 if ((lose++ & 7) == 7) {
448 ret = 0;
449 trace_rxrpc_tx_data(call, txb->seq, txb->serial,
450 txb->flags, true);
451 goto done;
452 }
453 }
454
455 iov_iter_kvec(&msg.msg_iter, WRITE, txb->kvec, txb->nr_kvec, len);
456
457 msg.msg_name = &call->peer->srx.transport;
458 msg.msg_namelen = call->peer->srx.transport_len;
459 msg.msg_control = NULL;
460 msg.msg_controllen = 0;
461 msg.msg_flags = MSG_SPLICE_PAGES;
462
463 /* Track what we've attempted to transmit at least once so that the
464 * retransmission algorithm doesn't try to resend what we haven't sent
465 * yet.
466 */
467 if (txb->seq == call->tx_transmitted + 1)
468 call->tx_transmitted = txb->seq;
469
470 /* send the packet with the don't fragment bit set if we currently
471 * think it's small enough */
472 if (txb->len >= call->peer->maxdata) {
473 rxrpc_local_dont_fragment(conn->local, false);
474 frag = rxrpc_tx_point_call_data_frag;
475 } else {
476 rxrpc_local_dont_fragment(conn->local, true);
477 frag = rxrpc_tx_point_call_data_nofrag;
478 }
479
480 retry:
481 /* send the packet by UDP
482 * - returns -EMSGSIZE if UDP would have to fragment the packet
483 * to go out of the interface
484 * - in which case, we'll have processed the ICMP error
485 * message and update the peer record
486 */
487 rxrpc_inc_stat(call->rxnet, stat_tx_data_send);
488 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
489 conn->peer->last_tx_at = ktime_get_seconds();
490
491 if (ret < 0) {
492 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
493 trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret, frag);
494 } else {
495 trace_rxrpc_tx_packet(call->debug_id, whdr, frag);
496 }
497
498 rxrpc_tx_backoff(call, ret);
499 if (ret == -EMSGSIZE && frag == rxrpc_tx_point_call_data_frag) {
500 rxrpc_local_dont_fragment(conn->local, false);
501 frag = rxrpc_tx_point_call_data_frag;
502 goto retry;
503 }
504
505 done:
506 if (ret >= 0) {
507 rxrpc_tstamp_data_packets(call, txb);
508 } else {
509 /* Cancel the call if the initial transmission fails,
510 * particularly if that's due to network routing issues that
511 * aren't going away anytime soon. The layer above can arrange
512 * the retransmission.
513 */
514 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
515 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
516 RX_USER_ABORT, ret);
517 }
518
519 _leave(" = %d [%u]", ret, call->peer->maxdata);
520 return ret;
521 }
522
523 /*
524 * Transmit a connection-level abort.
525 */
526 void rxrpc_send_conn_abort(struct rxrpc_connection *conn)
527 {
528 struct rxrpc_wire_header whdr;
529 struct msghdr msg;
530 struct kvec iov[2];
531 __be32 word;
532 size_t len;
533 u32 serial;
534 int ret;
535
536 msg.msg_name = &conn->peer->srx.transport;
537 msg.msg_namelen = conn->peer->srx.transport_len;
538 msg.msg_control = NULL;
539 msg.msg_controllen = 0;
540 msg.msg_flags = 0;
541
542 whdr.epoch = htonl(conn->proto.epoch);
543 whdr.cid = htonl(conn->proto.cid);
544 whdr.callNumber = 0;
545 whdr.seq = 0;
546 whdr.type = RXRPC_PACKET_TYPE_ABORT;
547 whdr.flags = conn->out_clientflag;
548 whdr.userStatus = 0;
549 whdr.securityIndex = conn->security_ix;
550 whdr._rsvd = 0;
551 whdr.serviceId = htons(conn->service_id);
552
553 word = htonl(conn->abort_code);
554
555 iov[0].iov_base = &whdr;
556 iov[0].iov_len = sizeof(whdr);
557 iov[1].iov_base = &word;
558 iov[1].iov_len = sizeof(word);
559
560 len = iov[0].iov_len + iov[1].iov_len;
561
562 serial = rxrpc_get_next_serial(conn);
563 whdr.serial = htonl(serial);
564
565 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
566 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
567 if (ret < 0) {
568 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
569 rxrpc_tx_point_conn_abort);
570 _debug("sendmsg failed: %d", ret);
571 return;
572 }
573
574 trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
575
576 conn->peer->last_tx_at = ktime_get_seconds();
577 }
578
579 /*
580 * Reject a packet through the local endpoint.
581 */
582 void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
583 {
584 struct rxrpc_wire_header whdr;
585 struct sockaddr_rxrpc srx;
586 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
587 struct msghdr msg;
588 struct kvec iov[2];
589 size_t size;
590 __be32 code;
591 int ret, ioc;
592
593 rxrpc_see_skb(skb, rxrpc_skb_see_reject);
594
595 iov[0].iov_base = &whdr;
596 iov[0].iov_len = sizeof(whdr);
597 iov[1].iov_base = &code;
598 iov[1].iov_len = sizeof(code);
599
600 msg.msg_name = &srx.transport;
601 msg.msg_control = NULL;
602 msg.msg_controllen = 0;
603 msg.msg_flags = 0;
604
605 memset(&whdr, 0, sizeof(whdr));
606
607 switch (skb->mark) {
608 case RXRPC_SKB_MARK_REJECT_BUSY:
609 whdr.type = RXRPC_PACKET_TYPE_BUSY;
610 size = sizeof(whdr);
611 ioc = 1;
612 break;
613 case RXRPC_SKB_MARK_REJECT_ABORT:
614 whdr.type = RXRPC_PACKET_TYPE_ABORT;
615 code = htonl(skb->priority);
616 size = sizeof(whdr) + sizeof(code);
617 ioc = 2;
618 break;
619 default:
620 return;
621 }
622
623 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
624 msg.msg_namelen = srx.transport_len;
625
626 whdr.epoch = htonl(sp->hdr.epoch);
627 whdr.cid = htonl(sp->hdr.cid);
628 whdr.callNumber = htonl(sp->hdr.callNumber);
629 whdr.serviceId = htons(sp->hdr.serviceId);
630 whdr.flags = sp->hdr.flags;
631 whdr.flags ^= RXRPC_CLIENT_INITIATED;
632 whdr.flags &= RXRPC_CLIENT_INITIATED;
633
634 iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size);
635 ret = do_udp_sendmsg(local->socket, &msg, size);
636 if (ret < 0)
637 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
638 rxrpc_tx_point_reject);
639 else
640 trace_rxrpc_tx_packet(local->debug_id, &whdr,
641 rxrpc_tx_point_reject);
642 }
643 }
644
645 /*
646 * Send a VERSION reply to a peer as a keepalive.
647 */
648 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
649 {
650 struct rxrpc_wire_header whdr;
651 struct msghdr msg;
652 struct kvec iov[2];
653 size_t len;
654 int ret;
655
656 _enter("");
657
658 msg.msg_name = &peer->srx.transport;
659 msg.msg_namelen = peer->srx.transport_len;
660 msg.msg_control = NULL;
661 msg.msg_controllen = 0;
662 msg.msg_flags = 0;
663
664 whdr.epoch = htonl(peer->local->rxnet->epoch);
665 whdr.cid = 0;
666 whdr.callNumber = 0;
667 whdr.seq = 0;
668 whdr.serial = 0;
669 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
670 whdr.flags = RXRPC_LAST_PACKET;
671 whdr.userStatus = 0;
672 whdr.securityIndex = 0;
673 whdr._rsvd = 0;
674 whdr.serviceId = 0;
675
676 iov[0].iov_base = &whdr;
677 iov[0].iov_len = sizeof(whdr);
678 iov[1].iov_base = (char *)rxrpc_keepalive_string;
679 iov[1].iov_len = sizeof(rxrpc_keepalive_string);
680
681 len = iov[0].iov_len + iov[1].iov_len;
682
683 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
684 ret = do_udp_sendmsg(peer->local->socket, &msg, len);
685 if (ret < 0)
686 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
687 rxrpc_tx_point_version_keepalive);
688 else
689 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
690 rxrpc_tx_point_version_keepalive);
691
692 peer->last_tx_at = ktime_get_seconds();
693 _leave("");
694 }
695
696 /*
697 * Schedule an instant Tx resend.
698 */
699 static inline void rxrpc_instant_resend(struct rxrpc_call *call,
700 struct rxrpc_txbuf *txb)
701 {
702 if (!__rxrpc_call_is_complete(call))
703 kdebug("resend");
704 }
705
706 /*
707 * Transmit one packet.
708 */
709 void rxrpc_transmit_one(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
710 {
711 int ret;
712
713 ret = rxrpc_send_data_packet(call, txb);
714 if (ret < 0) {
715 switch (ret) {
716 case -ENETUNREACH:
717 case -EHOSTUNREACH:
718 case -ECONNREFUSED:
719 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
720 0, ret);
721 break;
722 default:
723 _debug("need instant resend %d", ret);
724 rxrpc_instant_resend(call, txb);
725 }
726 } else {
727 ktime_t delay = ns_to_ktime(call->peer->rto_us * NSEC_PER_USEC);
728
729 call->resend_at = ktime_add(ktime_get_real(), delay);
730 trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_resend_tx);
731 }
732 }
733
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