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1/* RxRPC packet transmission
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/net.h>
15#include <linux/gfp.h>
16#include <linux/skbuff.h>
17#include <linux/export.h>
18#include <net/sock.h>
19#include <net/af_rxrpc.h>
20#include "ar-internal.h"
21
22struct rxrpc_ack_buffer {
23 struct rxrpc_wire_header whdr;
24 struct rxrpc_ackpacket ack;
25 u8 acks[255];
26 u8 pad[3];
27 struct rxrpc_ackinfo ackinfo;
28};
29
30struct rxrpc_abort_buffer {
31 struct rxrpc_wire_header whdr;
32 __be32 abort_code;
33};
34
35static const char rxrpc_keepalive_string[] = "";
36
37/*
38 * Arrange for a keepalive ping a certain time after we last transmitted. This
39 * lets the far side know we're still interested in this call and helps keep
40 * the route through any intervening firewall open.
41 *
42 * Receiving a response to the ping will prevent the ->expect_rx_by timer from
43 * expiring.
44 */
45static void rxrpc_set_keepalive(struct rxrpc_call *call)
46{
47 unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
48
49 keepalive_at += now;
50 WRITE_ONCE(call->keepalive_at, keepalive_at);
51 rxrpc_reduce_call_timer(call, keepalive_at, now,
52 rxrpc_timer_set_for_keepalive);
53}
54
55/*
56 * Fill out an ACK packet.
57 */
58static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
59 struct rxrpc_call *call,
60 struct rxrpc_ack_buffer *pkt,
61 rxrpc_seq_t *_hard_ack,
62 rxrpc_seq_t *_top,
63 u8 reason)
64{
65 rxrpc_serial_t serial;
66 rxrpc_seq_t hard_ack, top, seq;
67 int ix;
68 u32 mtu, jmax;
69 u8 *ackp = pkt->acks;
70
71 /* Barrier against rxrpc_input_data(). */
72 serial = call->ackr_serial;
73 hard_ack = READ_ONCE(call->rx_hard_ack);
74 top = smp_load_acquire(&call->rx_top);
75 *_hard_ack = hard_ack;
76 *_top = top;
77
78 pkt->ack.bufferSpace = htons(8);
79 pkt->ack.maxSkew = htons(call->ackr_skew);
80 pkt->ack.firstPacket = htonl(hard_ack + 1);
81 pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
82 pkt->ack.serial = htonl(serial);
83 pkt->ack.reason = reason;
84 pkt->ack.nAcks = top - hard_ack;
85
86 if (reason == RXRPC_ACK_PING)
87 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
88
89 if (after(top, hard_ack)) {
90 seq = hard_ack + 1;
91 do {
92 ix = seq & RXRPC_RXTX_BUFF_MASK;
93 if (call->rxtx_buffer[ix])
94 *ackp++ = RXRPC_ACK_TYPE_ACK;
95 else
96 *ackp++ = RXRPC_ACK_TYPE_NACK;
97 seq++;
98 } while (before_eq(seq, top));
99 }
100
101 mtu = conn->params.peer->if_mtu;
102 mtu -= conn->params.peer->hdrsize;
103 jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
104 pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
105 pkt->ackinfo.maxMTU = htonl(mtu);
106 pkt->ackinfo.rwind = htonl(call->rx_winsize);
107 pkt->ackinfo.jumbo_max = htonl(jmax);
108
109 *ackp++ = 0;
110 *ackp++ = 0;
111 *ackp++ = 0;
112 return top - hard_ack + 3;
113}
114
115/*
116 * Send an ACK call packet.
117 */
118int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
119 rxrpc_serial_t *_serial)
120{
121 struct rxrpc_connection *conn = NULL;
122 struct rxrpc_ack_buffer *pkt;
123 struct msghdr msg;
124 struct kvec iov[2];
125 rxrpc_serial_t serial;
126 rxrpc_seq_t hard_ack, top;
127 ktime_t now;
128 size_t len, n;
129 int ret;
130 u8 reason;
131
132 spin_lock_bh(&call->lock);
133 if (call->conn)
134 conn = rxrpc_get_connection_maybe(call->conn);
135 spin_unlock_bh(&call->lock);
136 if (!conn)
137 return -ECONNRESET;
138
139 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
140 if (!pkt) {
141 rxrpc_put_connection(conn);
142 return -ENOMEM;
143 }
144
145 msg.msg_name = &call->peer->srx.transport;
146 msg.msg_namelen = call->peer->srx.transport_len;
147 msg.msg_control = NULL;
148 msg.msg_controllen = 0;
149 msg.msg_flags = 0;
150
151 pkt->whdr.epoch = htonl(conn->proto.epoch);
152 pkt->whdr.cid = htonl(call->cid);
153 pkt->whdr.callNumber = htonl(call->call_id);
154 pkt->whdr.seq = 0;
155 pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
156 pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
157 pkt->whdr.userStatus = 0;
158 pkt->whdr.securityIndex = call->security_ix;
159 pkt->whdr._rsvd = 0;
160 pkt->whdr.serviceId = htons(call->service_id);
161
162 spin_lock_bh(&call->lock);
163 if (ping) {
164 reason = RXRPC_ACK_PING;
165 } else {
166 reason = call->ackr_reason;
167 if (!call->ackr_reason) {
168 spin_unlock_bh(&call->lock);
169 ret = 0;
170 goto out;
171 }
172 call->ackr_reason = 0;
173 }
174 n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
175
176 spin_unlock_bh(&call->lock);
177
178 iov[0].iov_base = pkt;
179 iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
180 iov[1].iov_base = &pkt->ackinfo;
181 iov[1].iov_len = sizeof(pkt->ackinfo);
182 len = iov[0].iov_len + iov[1].iov_len;
183
184 serial = atomic_inc_return(&conn->serial);
185 pkt->whdr.serial = htonl(serial);
186 trace_rxrpc_tx_ack(call, serial,
187 ntohl(pkt->ack.firstPacket),
188 ntohl(pkt->ack.serial),
189 pkt->ack.reason, pkt->ack.nAcks);
190 if (_serial)
191 *_serial = serial;
192
193 if (ping) {
194 call->ping_serial = serial;
195 smp_wmb();
196 /* We need to stick a time in before we send the packet in case
197 * the reply gets back before kernel_sendmsg() completes - but
198 * asking UDP to send the packet can take a relatively long
199 * time, so we update the time after, on the assumption that
200 * the packet transmission is more likely to happen towards the
201 * end of the kernel_sendmsg() call.
202 */
203 call->ping_time = ktime_get_real();
204 set_bit(RXRPC_CALL_PINGING, &call->flags);
205 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
206 }
207
208 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
209 now = ktime_get_real();
210 if (ping)
211 call->ping_time = now;
212 conn->params.peer->last_tx_at = ktime_get_real();
213 if (ret < 0)
214 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
215 rxrpc_tx_fail_call_ack);
216
217 if (call->state < RXRPC_CALL_COMPLETE) {
218 if (ret < 0) {
219 if (ping)
220 clear_bit(RXRPC_CALL_PINGING, &call->flags);
221 rxrpc_propose_ACK(call, pkt->ack.reason,
222 ntohs(pkt->ack.maxSkew),
223 ntohl(pkt->ack.serial),
224 true, true,
225 rxrpc_propose_ack_retry_tx);
226 } else {
227 spin_lock_bh(&call->lock);
228 if (after(hard_ack, call->ackr_consumed))
229 call->ackr_consumed = hard_ack;
230 if (after(top, call->ackr_seen))
231 call->ackr_seen = top;
232 spin_unlock_bh(&call->lock);
233 }
234
235 rxrpc_set_keepalive(call);
236 }
237
238out:
239 rxrpc_put_connection(conn);
240 kfree(pkt);
241 return ret;
242}
243
244/*
245 * Send an ABORT call packet.
246 */
247int rxrpc_send_abort_packet(struct rxrpc_call *call)
248{
249 struct rxrpc_connection *conn = NULL;
250 struct rxrpc_abort_buffer pkt;
251 struct msghdr msg;
252 struct kvec iov[1];
253 rxrpc_serial_t serial;
254 int ret;
255
256 /* Don't bother sending aborts for a client call once the server has
257 * hard-ACK'd all of its request data. After that point, we're not
258 * going to stop the operation proceeding, and whilst we might limit
259 * the reply, it's not worth it if we can send a new call on the same
260 * channel instead, thereby closing off this call.
261 */
262 if (rxrpc_is_client_call(call) &&
263 test_bit(RXRPC_CALL_TX_LAST, &call->flags))
264 return 0;
265
266 spin_lock_bh(&call->lock);
267 if (call->conn)
268 conn = rxrpc_get_connection_maybe(call->conn);
269 spin_unlock_bh(&call->lock);
270 if (!conn)
271 return -ECONNRESET;
272
273 msg.msg_name = &call->peer->srx.transport;
274 msg.msg_namelen = call->peer->srx.transport_len;
275 msg.msg_control = NULL;
276 msg.msg_controllen = 0;
277 msg.msg_flags = 0;
278
279 pkt.whdr.epoch = htonl(conn->proto.epoch);
280 pkt.whdr.cid = htonl(call->cid);
281 pkt.whdr.callNumber = htonl(call->call_id);
282 pkt.whdr.seq = 0;
283 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
284 pkt.whdr.flags = conn->out_clientflag;
285 pkt.whdr.userStatus = 0;
286 pkt.whdr.securityIndex = call->security_ix;
287 pkt.whdr._rsvd = 0;
288 pkt.whdr.serviceId = htons(call->service_id);
289 pkt.abort_code = htonl(call->abort_code);
290
291 iov[0].iov_base = &pkt;
292 iov[0].iov_len = sizeof(pkt);
293
294 serial = atomic_inc_return(&conn->serial);
295 pkt.whdr.serial = htonl(serial);
296
297 ret = kernel_sendmsg(conn->params.local->socket,
298 &msg, iov, 1, sizeof(pkt));
299 conn->params.peer->last_tx_at = ktime_get_real();
300 if (ret < 0)
301 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
302 rxrpc_tx_fail_call_abort);
303
304
305 rxrpc_put_connection(conn);
306 return ret;
307}
308
309/*
310 * send a packet through the transport endpoint
311 */
312int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
313 bool retrans)
314{
315 struct rxrpc_connection *conn = call->conn;
316 struct rxrpc_wire_header whdr;
317 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
318 struct msghdr msg;
319 struct kvec iov[2];
320 rxrpc_serial_t serial;
321 size_t len;
322 bool lost = false;
323 int ret, opt;
324
325 _enter(",{%d}", skb->len);
326
327 /* Each transmission of a Tx packet needs a new serial number */
328 serial = atomic_inc_return(&conn->serial);
329
330 whdr.epoch = htonl(conn->proto.epoch);
331 whdr.cid = htonl(call->cid);
332 whdr.callNumber = htonl(call->call_id);
333 whdr.seq = htonl(sp->hdr.seq);
334 whdr.serial = htonl(serial);
335 whdr.type = RXRPC_PACKET_TYPE_DATA;
336 whdr.flags = sp->hdr.flags;
337 whdr.userStatus = 0;
338 whdr.securityIndex = call->security_ix;
339 whdr._rsvd = htons(sp->hdr._rsvd);
340 whdr.serviceId = htons(call->service_id);
341
342 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
343 sp->hdr.seq == 1)
344 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
345
346 iov[0].iov_base = &whdr;
347 iov[0].iov_len = sizeof(whdr);
348 iov[1].iov_base = skb->head;
349 iov[1].iov_len = skb->len;
350 len = iov[0].iov_len + iov[1].iov_len;
351
352 msg.msg_name = &call->peer->srx.transport;
353 msg.msg_namelen = call->peer->srx.transport_len;
354 msg.msg_control = NULL;
355 msg.msg_controllen = 0;
356 msg.msg_flags = 0;
357
358 /* If our RTT cache needs working on, request an ACK. Also request
359 * ACKs if a DATA packet appears to have been lost.
360 */
361 if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
362 (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
363 retrans ||
364 call->cong_mode == RXRPC_CALL_SLOW_START ||
365 (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
366 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
367 ktime_get_real())))
368 whdr.flags |= RXRPC_REQUEST_ACK;
369
370 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
371 static int lose;
372 if ((lose++ & 7) == 7) {
373 ret = 0;
374 lost = true;
375 goto done;
376 }
377 }
378
379 _proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
380
381 /* send the packet with the don't fragment bit set if we currently
382 * think it's small enough */
383 if (iov[1].iov_len >= call->peer->maxdata)
384 goto send_fragmentable;
385
386 down_read(&conn->params.local->defrag_sem);
387 /* send the packet by UDP
388 * - returns -EMSGSIZE if UDP would have to fragment the packet
389 * to go out of the interface
390 * - in which case, we'll have processed the ICMP error
391 * message and update the peer record
392 */
393 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
394 conn->params.peer->last_tx_at = ktime_get_real();
395
396 up_read(&conn->params.local->defrag_sem);
397 if (ret < 0)
398 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
399 rxrpc_tx_fail_call_data_nofrag);
400 if (ret == -EMSGSIZE)
401 goto send_fragmentable;
402
403done:
404 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
405 retrans, lost);
406 if (ret >= 0) {
407 ktime_t now = ktime_get_real();
408 skb->tstamp = now;
409 smp_wmb();
410 sp->hdr.serial = serial;
411 if (whdr.flags & RXRPC_REQUEST_ACK) {
412 call->peer->rtt_last_req = now;
413 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
414 if (call->peer->rtt_usage > 1) {
415 unsigned long nowj = jiffies, ack_lost_at;
416
417 ack_lost_at = nsecs_to_jiffies(2 * call->peer->rtt);
418 if (ack_lost_at < 1)
419 ack_lost_at = 1;
420
421 ack_lost_at += nowj;
422 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
423 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
424 rxrpc_timer_set_for_lost_ack);
425 }
426 }
427
428 if (sp->hdr.seq == 1 &&
429 !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
430 &call->flags)) {
431 unsigned long nowj = jiffies, expect_rx_by;
432
433 expect_rx_by = nowj + call->next_rx_timo;
434 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
435 rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
436 rxrpc_timer_set_for_normal);
437 }
438 }
439
440 rxrpc_set_keepalive(call);
441
442 _leave(" = %d [%u]", ret, call->peer->maxdata);
443 return ret;
444
445send_fragmentable:
446 /* attempt to send this message with fragmentation enabled */
447 _debug("send fragment");
448
449 down_write(&conn->params.local->defrag_sem);
450
451 switch (conn->params.local->srx.transport.family) {
452 case AF_INET:
453 opt = IP_PMTUDISC_DONT;
454 ret = kernel_setsockopt(conn->params.local->socket,
455 SOL_IP, IP_MTU_DISCOVER,
456 (char *)&opt, sizeof(opt));
457 if (ret == 0) {
458 ret = kernel_sendmsg(conn->params.local->socket, &msg,
459 iov, 2, len);
460 conn->params.peer->last_tx_at = ktime_get_real();
461
462 opt = IP_PMTUDISC_DO;
463 kernel_setsockopt(conn->params.local->socket, SOL_IP,
464 IP_MTU_DISCOVER,
465 (char *)&opt, sizeof(opt));
466 }
467 break;
468
469#ifdef CONFIG_AF_RXRPC_IPV6
470 case AF_INET6:
471 opt = IPV6_PMTUDISC_DONT;
472 ret = kernel_setsockopt(conn->params.local->socket,
473 SOL_IPV6, IPV6_MTU_DISCOVER,
474 (char *)&opt, sizeof(opt));
475 if (ret == 0) {
476 ret = kernel_sendmsg(conn->params.local->socket, &msg,
477 iov, 2, len);
478 conn->params.peer->last_tx_at = ktime_get_real();
479
480 opt = IPV6_PMTUDISC_DO;
481 kernel_setsockopt(conn->params.local->socket,
482 SOL_IPV6, IPV6_MTU_DISCOVER,
483 (char *)&opt, sizeof(opt));
484 }
485 break;
486#endif
487 }
488
489 if (ret < 0)
490 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
491 rxrpc_tx_fail_call_data_frag);
492
493 up_write(&conn->params.local->defrag_sem);
494 goto done;
495}
496
497/*
498 * reject packets through the local endpoint
499 */
500void rxrpc_reject_packets(struct rxrpc_local *local)
501{
502 struct sockaddr_rxrpc srx;
503 struct rxrpc_skb_priv *sp;
504 struct rxrpc_wire_header whdr;
505 struct sk_buff *skb;
506 struct msghdr msg;
507 struct kvec iov[2];
508 size_t size;
509 __be32 code;
510 int ret;
511
512 _enter("%d", local->debug_id);
513
514 iov[0].iov_base = &whdr;
515 iov[0].iov_len = sizeof(whdr);
516 iov[1].iov_base = &code;
517 iov[1].iov_len = sizeof(code);
518 size = sizeof(whdr) + sizeof(code);
519
520 msg.msg_name = &srx.transport;
521 msg.msg_control = NULL;
522 msg.msg_controllen = 0;
523 msg.msg_flags = 0;
524
525 memset(&whdr, 0, sizeof(whdr));
526 whdr.type = RXRPC_PACKET_TYPE_ABORT;
527
528 while ((skb = skb_dequeue(&local->reject_queue))) {
529 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
530 sp = rxrpc_skb(skb);
531
532 if (rxrpc_extract_addr_from_skb(local, &srx, skb) == 0) {
533 msg.msg_namelen = srx.transport_len;
534
535 code = htonl(skb->priority);
536
537 whdr.epoch = htonl(sp->hdr.epoch);
538 whdr.cid = htonl(sp->hdr.cid);
539 whdr.callNumber = htonl(sp->hdr.callNumber);
540 whdr.serviceId = htons(sp->hdr.serviceId);
541 whdr.flags = sp->hdr.flags;
542 whdr.flags ^= RXRPC_CLIENT_INITIATED;
543 whdr.flags &= RXRPC_CLIENT_INITIATED;
544
545 ret = kernel_sendmsg(local->socket, &msg, iov, 2, size);
546 if (ret < 0)
547 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
548 rxrpc_tx_fail_reject);
549 }
550
551 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
552 }
553
554 _leave("");
555}
556
557/*
558 * Send a VERSION reply to a peer as a keepalive.
559 */
560void rxrpc_send_keepalive(struct rxrpc_peer *peer)
561{
562 struct rxrpc_wire_header whdr;
563 struct msghdr msg;
564 struct kvec iov[2];
565 size_t len;
566 int ret;
567
568 _enter("");
569
570 msg.msg_name = &peer->srx.transport;
571 msg.msg_namelen = peer->srx.transport_len;
572 msg.msg_control = NULL;
573 msg.msg_controllen = 0;
574 msg.msg_flags = 0;
575
576 whdr.epoch = htonl(peer->local->rxnet->epoch);
577 whdr.cid = 0;
578 whdr.callNumber = 0;
579 whdr.seq = 0;
580 whdr.serial = 0;
581 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
582 whdr.flags = RXRPC_LAST_PACKET;
583 whdr.userStatus = 0;
584 whdr.securityIndex = 0;
585 whdr._rsvd = 0;
586 whdr.serviceId = 0;
587
588 iov[0].iov_base = &whdr;
589 iov[0].iov_len = sizeof(whdr);
590 iov[1].iov_base = (char *)rxrpc_keepalive_string;
591 iov[1].iov_len = sizeof(rxrpc_keepalive_string);
592
593 len = iov[0].iov_len + iov[1].iov_len;
594
595 _proto("Tx VERSION (keepalive)");
596
597 ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
598 if (ret < 0)
599 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
600 rxrpc_tx_fail_version_keepalive);
601
602 peer->last_tx_at = ktime_get_real();
603 _leave("");
604}
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{
85 struct rxrpc_ackinfo ackinfo;
86 unsigned int qsize;
87 rxrpc_seq_t window, wtop, wrap_point, ix, first;
88 int rsize;
89 u64 wtmp;
90 u32 mtu, jmax;
91 u8 *ackp = txb->acks;
92 u8 sack_buffer[sizeof(call->ackr_sack_table)] __aligned(8);
93
94 atomic_set(&call->ackr_nr_unacked, 0);
95 atomic_set(&call->ackr_nr_consumed, 0);
96 rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill);
97
98 /* Barrier against rxrpc_input_data(). */
99retry:
100 wtmp = atomic64_read_acquire(&call->ackr_window);
101 window = lower_32_bits(wtmp);
102 wtop = upper_32_bits(wtmp);
103 txb->ack.firstPacket = htonl(window);
104 txb->ack.nAcks = 0;
105
106 if (after(wtop, window)) {
107 /* Try to copy the SACK ring locklessly. We can use the copy,
108 * only if the now-current top of the window didn't go past the
109 * previously read base - otherwise we can't know whether we
110 * have old data or new data.
111 */
112 memcpy(sack_buffer, call->ackr_sack_table, sizeof(sack_buffer));
113 wrap_point = window + RXRPC_SACK_SIZE - 1;
114 wtmp = atomic64_read_acquire(&call->ackr_window);
115 window = lower_32_bits(wtmp);
116 wtop = upper_32_bits(wtmp);
117 if (after(wtop, wrap_point)) {
118 cond_resched();
119 goto retry;
120 }
121
122 /* The buffer is maintained as a ring with an invariant mapping
123 * between bit position and sequence number, so we'll probably
124 * need to rotate it.
125 */
126 txb->ack.nAcks = wtop - window;
127 ix = window % RXRPC_SACK_SIZE;
128 first = sizeof(sack_buffer) - ix;
129
130 if (ix + txb->ack.nAcks <= RXRPC_SACK_SIZE) {
131 memcpy(txb->acks, sack_buffer + ix, txb->ack.nAcks);
132 } else {
133 memcpy(txb->acks, sack_buffer + ix, first);
134 memcpy(txb->acks + first, sack_buffer,
135 txb->ack.nAcks - first);
136 }
137
138 ackp += txb->ack.nAcks;
139 } else if (before(wtop, window)) {
140 pr_warn("ack window backward %x %x", window, wtop);
141 } else if (txb->ack.reason == RXRPC_ACK_DELAY) {
142 txb->ack.reason = RXRPC_ACK_IDLE;
143 }
144
145 mtu = conn->peer->if_mtu;
146 mtu -= conn->peer->hdrsize;
147 jmax = rxrpc_rx_jumbo_max;
148 qsize = (window - 1) - call->rx_consumed;
149 rsize = max_t(int, call->rx_winsize - qsize, 0);
150 ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
151 ackinfo.maxMTU = htonl(mtu);
152 ackinfo.rwind = htonl(rsize);
153 ackinfo.jumbo_max = htonl(jmax);
154
155 *ackp++ = 0;
156 *ackp++ = 0;
157 *ackp++ = 0;
158 memcpy(ackp, &ackinfo, sizeof(ackinfo));
159 return txb->ack.nAcks + 3 + sizeof(ackinfo);
160}
161
162/*
163 * Record the beginning of an RTT probe.
164 */
165static int rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
166 enum rxrpc_rtt_tx_trace why)
167{
168 unsigned long avail = call->rtt_avail;
169 int rtt_slot = 9;
170
171 if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
172 goto no_slot;
173
174 rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
175 if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
176 goto no_slot;
177
178 call->rtt_serial[rtt_slot] = serial;
179 call->rtt_sent_at[rtt_slot] = ktime_get_real();
180 smp_wmb(); /* Write data before avail bit */
181 set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
182
183 trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
184 return rtt_slot;
185
186no_slot:
187 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
188 return -1;
189}
190
191/*
192 * Cancel an RTT probe.
193 */
194static void rxrpc_cancel_rtt_probe(struct rxrpc_call *call,
195 rxrpc_serial_t serial, int rtt_slot)
196{
197 if (rtt_slot != -1) {
198 clear_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
199 smp_wmb(); /* Clear pending bit before setting slot */
200 set_bit(rtt_slot, &call->rtt_avail);
201 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_cancel, rtt_slot, serial);
202 }
203}
204
205/*
206 * Transmit an ACK packet.
207 */
208int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
209{
210 struct rxrpc_connection *conn;
211 struct msghdr msg;
212 struct kvec iov[1];
213 rxrpc_serial_t serial;
214 size_t len, n;
215 int ret, rtt_slot = -1;
216
217 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
218 return -ECONNRESET;
219
220 conn = call->conn;
221
222 msg.msg_name = &call->peer->srx.transport;
223 msg.msg_namelen = call->peer->srx.transport_len;
224 msg.msg_control = NULL;
225 msg.msg_controllen = 0;
226 msg.msg_flags = 0;
227
228 if (txb->ack.reason == RXRPC_ACK_PING)
229 txb->wire.flags |= RXRPC_REQUEST_ACK;
230
231 n = rxrpc_fill_out_ack(conn, call, txb);
232 if (n == 0)
233 return 0;
234
235 iov[0].iov_base = &txb->wire;
236 iov[0].iov_len = sizeof(txb->wire) + sizeof(txb->ack) + n;
237 len = iov[0].iov_len;
238
239 serial = atomic_inc_return(&conn->serial);
240 txb->wire.serial = htonl(serial);
241 trace_rxrpc_tx_ack(call->debug_id, serial,
242 ntohl(txb->ack.firstPacket),
243 ntohl(txb->ack.serial), txb->ack.reason, txb->ack.nAcks);
244
245 if (txb->ack.reason == RXRPC_ACK_PING)
246 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_ping);
247
248 rxrpc_inc_stat(call->rxnet, stat_tx_ack_send);
249
250 /* Grab the highest received seq as late as possible */
251 txb->ack.previousPacket = htonl(call->rx_highest_seq);
252
253 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
254 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
255 call->peer->last_tx_at = ktime_get_seconds();
256 if (ret < 0)
257 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
258 rxrpc_tx_point_call_ack);
259 else
260 trace_rxrpc_tx_packet(call->debug_id, &txb->wire,
261 rxrpc_tx_point_call_ack);
262 rxrpc_tx_backoff(call, ret);
263
264 if (!__rxrpc_call_is_complete(call)) {
265 if (ret < 0)
266 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
267 rxrpc_set_keepalive(call);
268 }
269
270 return ret;
271}
272
273/*
274 * Send an ABORT call packet.
275 */
276int rxrpc_send_abort_packet(struct rxrpc_call *call)
277{
278 struct rxrpc_connection *conn;
279 struct rxrpc_abort_buffer pkt;
280 struct msghdr msg;
281 struct kvec iov[1];
282 rxrpc_serial_t serial;
283 int ret;
284
285 /* Don't bother sending aborts for a client call once the server has
286 * hard-ACK'd all of its request data. After that point, we're not
287 * going to stop the operation proceeding, and whilst we might limit
288 * the reply, it's not worth it if we can send a new call on the same
289 * channel instead, thereby closing off this call.
290 */
291 if (rxrpc_is_client_call(call) &&
292 test_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags))
293 return 0;
294
295 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
296 return -ECONNRESET;
297
298 conn = call->conn;
299
300 msg.msg_name = &call->peer->srx.transport;
301 msg.msg_namelen = call->peer->srx.transport_len;
302 msg.msg_control = NULL;
303 msg.msg_controllen = 0;
304 msg.msg_flags = 0;
305
306 pkt.whdr.epoch = htonl(conn->proto.epoch);
307 pkt.whdr.cid = htonl(call->cid);
308 pkt.whdr.callNumber = htonl(call->call_id);
309 pkt.whdr.seq = 0;
310 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
311 pkt.whdr.flags = conn->out_clientflag;
312 pkt.whdr.userStatus = 0;
313 pkt.whdr.securityIndex = call->security_ix;
314 pkt.whdr._rsvd = 0;
315 pkt.whdr.serviceId = htons(call->dest_srx.srx_service);
316 pkt.abort_code = htonl(call->abort_code);
317
318 iov[0].iov_base = &pkt;
319 iov[0].iov_len = sizeof(pkt);
320
321 serial = atomic_inc_return(&conn->serial);
322 pkt.whdr.serial = htonl(serial);
323
324 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, sizeof(pkt));
325 ret = do_udp_sendmsg(conn->local->socket, &msg, sizeof(pkt));
326 conn->peer->last_tx_at = ktime_get_seconds();
327 if (ret < 0)
328 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
329 rxrpc_tx_point_call_abort);
330 else
331 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
332 rxrpc_tx_point_call_abort);
333 rxrpc_tx_backoff(call, ret);
334 return ret;
335}
336
337/*
338 * send a packet through the transport endpoint
339 */
340int rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
341{
342 enum rxrpc_req_ack_trace why;
343 struct rxrpc_connection *conn = call->conn;
344 struct msghdr msg;
345 struct kvec iov[1];
346 rxrpc_serial_t serial;
347 size_t len;
348 int ret, rtt_slot = -1;
349
350 _enter("%x,{%d}", txb->seq, txb->len);
351
352 /* Each transmission of a Tx packet needs a new serial number */
353 serial = atomic_inc_return(&conn->serial);
354 txb->wire.serial = htonl(serial);
355
356 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
357 txb->seq == 1)
358 txb->wire.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
359
360 iov[0].iov_base = &txb->wire;
361 iov[0].iov_len = sizeof(txb->wire) + txb->len;
362 len = iov[0].iov_len;
363 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
364
365 msg.msg_name = &call->peer->srx.transport;
366 msg.msg_namelen = call->peer->srx.transport_len;
367 msg.msg_control = NULL;
368 msg.msg_controllen = 0;
369 msg.msg_flags = 0;
370
371 /* If our RTT cache needs working on, request an ACK. Also request
372 * ACKs if a DATA packet appears to have been lost.
373 *
374 * However, we mustn't request an ACK on the last reply packet of a
375 * service call, lest OpenAFS incorrectly send us an ACK with some
376 * soft-ACKs in it and then never follow up with a proper hard ACK.
377 */
378 if (txb->wire.flags & RXRPC_REQUEST_ACK)
379 why = rxrpc_reqack_already_on;
380 else if (test_bit(RXRPC_TXBUF_LAST, &txb->flags) && rxrpc_sending_to_client(txb))
381 why = rxrpc_reqack_no_srv_last;
382 else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events))
383 why = rxrpc_reqack_ack_lost;
384 else if (test_bit(RXRPC_TXBUF_RESENT, &txb->flags))
385 why = rxrpc_reqack_retrans;
386 else if (call->cong_mode == RXRPC_CALL_SLOW_START && call->cong_cwnd <= 2)
387 why = rxrpc_reqack_slow_start;
388 else if (call->tx_winsize <= 2)
389 why = rxrpc_reqack_small_txwin;
390 else if (call->peer->rtt_count < 3 && txb->seq & 1)
391 why = rxrpc_reqack_more_rtt;
392 else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real()))
393 why = rxrpc_reqack_old_rtt;
394 else
395 goto dont_set_request_ack;
396
397 rxrpc_inc_stat(call->rxnet, stat_why_req_ack[why]);
398 trace_rxrpc_req_ack(call->debug_id, txb->seq, why);
399 if (why != rxrpc_reqack_no_srv_last)
400 txb->wire.flags |= RXRPC_REQUEST_ACK;
401dont_set_request_ack:
402
403 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
404 static int lose;
405 if ((lose++ & 7) == 7) {
406 ret = 0;
407 trace_rxrpc_tx_data(call, txb->seq, serial,
408 txb->wire.flags,
409 test_bit(RXRPC_TXBUF_RESENT, &txb->flags),
410 true);
411 goto done;
412 }
413 }
414
415 trace_rxrpc_tx_data(call, txb->seq, serial, txb->wire.flags,
416 test_bit(RXRPC_TXBUF_RESENT, &txb->flags), false);
417
418 /* Track what we've attempted to transmit at least once so that the
419 * retransmission algorithm doesn't try to resend what we haven't sent
420 * yet. However, this can race as we can receive an ACK before we get
421 * to this point. But, OTOH, if we won't get an ACK mentioning this
422 * packet unless the far side received it (though it could have
423 * discarded it anyway and NAK'd it).
424 */
425 cmpxchg(&call->tx_transmitted, txb->seq - 1, txb->seq);
426
427 /* send the packet with the don't fragment bit set if we currently
428 * think it's small enough */
429 if (txb->len >= call->peer->maxdata)
430 goto send_fragmentable;
431
432 down_read(&conn->local->defrag_sem);
433
434 txb->last_sent = ktime_get_real();
435 if (txb->wire.flags & RXRPC_REQUEST_ACK)
436 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
437
438 /* send the packet by UDP
439 * - returns -EMSGSIZE if UDP would have to fragment the packet
440 * to go out of the interface
441 * - in which case, we'll have processed the ICMP error
442 * message and update the peer record
443 */
444 rxrpc_inc_stat(call->rxnet, stat_tx_data_send);
445 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
446 conn->peer->last_tx_at = ktime_get_seconds();
447
448 up_read(&conn->local->defrag_sem);
449 if (ret < 0) {
450 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
451 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
452 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
453 rxrpc_tx_point_call_data_nofrag);
454 } else {
455 trace_rxrpc_tx_packet(call->debug_id, &txb->wire,
456 rxrpc_tx_point_call_data_nofrag);
457 }
458
459 rxrpc_tx_backoff(call, ret);
460 if (ret == -EMSGSIZE)
461 goto send_fragmentable;
462
463done:
464 if (ret >= 0) {
465 call->tx_last_sent = txb->last_sent;
466 if (txb->wire.flags & RXRPC_REQUEST_ACK) {
467 call->peer->rtt_last_req = txb->last_sent;
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 (txb->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
505send_fragmentable:
506 /* attempt to send this message with fragmentation enabled */
507 _debug("send fragment");
508
509 down_write(&conn->local->defrag_sem);
510
511 txb->last_sent = ktime_get_real();
512 if (txb->wire.flags & RXRPC_REQUEST_ACK)
513 rtt_slot = rxrpc_begin_rtt_probe(call, serial, rxrpc_rtt_tx_data);
514
515 switch (conn->local->srx.transport.family) {
516 case AF_INET6:
517 case AF_INET:
518 ip_sock_set_mtu_discover(conn->local->socket->sk,
519 IP_PMTUDISC_DONT);
520 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_frag);
521 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
522 conn->peer->last_tx_at = ktime_get_seconds();
523
524 ip_sock_set_mtu_discover(conn->local->socket->sk,
525 IP_PMTUDISC_DO);
526 break;
527
528 default:
529 BUG();
530 }
531
532 if (ret < 0) {
533 rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
534 rxrpc_cancel_rtt_probe(call, serial, rtt_slot);
535 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
536 rxrpc_tx_point_call_data_frag);
537 } else {
538 trace_rxrpc_tx_packet(call->debug_id, &txb->wire,
539 rxrpc_tx_point_call_data_frag);
540 }
541 rxrpc_tx_backoff(call, ret);
542
543 up_write(&conn->local->defrag_sem);
544 goto done;
545}
546
547/*
548 * Transmit a connection-level abort.
549 */
550void rxrpc_send_conn_abort(struct rxrpc_connection *conn)
551{
552 struct rxrpc_wire_header whdr;
553 struct msghdr msg;
554 struct kvec iov[2];
555 __be32 word;
556 size_t len;
557 u32 serial;
558 int ret;
559
560 msg.msg_name = &conn->peer->srx.transport;
561 msg.msg_namelen = conn->peer->srx.transport_len;
562 msg.msg_control = NULL;
563 msg.msg_controllen = 0;
564 msg.msg_flags = 0;
565
566 whdr.epoch = htonl(conn->proto.epoch);
567 whdr.cid = htonl(conn->proto.cid);
568 whdr.callNumber = 0;
569 whdr.seq = 0;
570 whdr.type = RXRPC_PACKET_TYPE_ABORT;
571 whdr.flags = conn->out_clientflag;
572 whdr.userStatus = 0;
573 whdr.securityIndex = conn->security_ix;
574 whdr._rsvd = 0;
575 whdr.serviceId = htons(conn->service_id);
576
577 word = htonl(conn->abort_code);
578
579 iov[0].iov_base = &whdr;
580 iov[0].iov_len = sizeof(whdr);
581 iov[1].iov_base = &word;
582 iov[1].iov_len = sizeof(word);
583
584 len = iov[0].iov_len + iov[1].iov_len;
585
586 serial = atomic_inc_return(&conn->serial);
587 whdr.serial = htonl(serial);
588
589 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
590 ret = do_udp_sendmsg(conn->local->socket, &msg, len);
591 if (ret < 0) {
592 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
593 rxrpc_tx_point_conn_abort);
594 _debug("sendmsg failed: %d", ret);
595 return;
596 }
597
598 trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
599
600 conn->peer->last_tx_at = ktime_get_seconds();
601}
602
603/*
604 * Reject a packet through the local endpoint.
605 */
606void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
607{
608 struct rxrpc_wire_header whdr;
609 struct sockaddr_rxrpc srx;
610 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
611 struct msghdr msg;
612 struct kvec iov[2];
613 size_t size;
614 __be32 code;
615 int ret, ioc;
616
617 rxrpc_see_skb(skb, rxrpc_skb_see_reject);
618
619 iov[0].iov_base = &whdr;
620 iov[0].iov_len = sizeof(whdr);
621 iov[1].iov_base = &code;
622 iov[1].iov_len = sizeof(code);
623
624 msg.msg_name = &srx.transport;
625 msg.msg_control = NULL;
626 msg.msg_controllen = 0;
627 msg.msg_flags = 0;
628
629 memset(&whdr, 0, sizeof(whdr));
630
631 switch (skb->mark) {
632 case RXRPC_SKB_MARK_REJECT_BUSY:
633 whdr.type = RXRPC_PACKET_TYPE_BUSY;
634 size = sizeof(whdr);
635 ioc = 1;
636 break;
637 case RXRPC_SKB_MARK_REJECT_ABORT:
638 whdr.type = RXRPC_PACKET_TYPE_ABORT;
639 code = htonl(skb->priority);
640 size = sizeof(whdr) + sizeof(code);
641 ioc = 2;
642 break;
643 default:
644 return;
645 }
646
647 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
648 msg.msg_namelen = srx.transport_len;
649
650 whdr.epoch = htonl(sp->hdr.epoch);
651 whdr.cid = htonl(sp->hdr.cid);
652 whdr.callNumber = htonl(sp->hdr.callNumber);
653 whdr.serviceId = htons(sp->hdr.serviceId);
654 whdr.flags = sp->hdr.flags;
655 whdr.flags ^= RXRPC_CLIENT_INITIATED;
656 whdr.flags &= RXRPC_CLIENT_INITIATED;
657
658 iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size);
659 ret = do_udp_sendmsg(local->socket, &msg, size);
660 if (ret < 0)
661 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
662 rxrpc_tx_point_reject);
663 else
664 trace_rxrpc_tx_packet(local->debug_id, &whdr,
665 rxrpc_tx_point_reject);
666 }
667}
668
669/*
670 * Send a VERSION reply to a peer as a keepalive.
671 */
672void rxrpc_send_keepalive(struct rxrpc_peer *peer)
673{
674 struct rxrpc_wire_header whdr;
675 struct msghdr msg;
676 struct kvec iov[2];
677 size_t len;
678 int ret;
679
680 _enter("");
681
682 msg.msg_name = &peer->srx.transport;
683 msg.msg_namelen = peer->srx.transport_len;
684 msg.msg_control = NULL;
685 msg.msg_controllen = 0;
686 msg.msg_flags = 0;
687
688 whdr.epoch = htonl(peer->local->rxnet->epoch);
689 whdr.cid = 0;
690 whdr.callNumber = 0;
691 whdr.seq = 0;
692 whdr.serial = 0;
693 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
694 whdr.flags = RXRPC_LAST_PACKET;
695 whdr.userStatus = 0;
696 whdr.securityIndex = 0;
697 whdr._rsvd = 0;
698 whdr.serviceId = 0;
699
700 iov[0].iov_base = &whdr;
701 iov[0].iov_len = sizeof(whdr);
702 iov[1].iov_base = (char *)rxrpc_keepalive_string;
703 iov[1].iov_len = sizeof(rxrpc_keepalive_string);
704
705 len = iov[0].iov_len + iov[1].iov_len;
706
707 iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
708 ret = do_udp_sendmsg(peer->local->socket, &msg, len);
709 if (ret < 0)
710 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
711 rxrpc_tx_point_version_keepalive);
712 else
713 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
714 rxrpc_tx_point_version_keepalive);
715
716 peer->last_tx_at = ktime_get_seconds();
717 _leave("");
718}
719
720/*
721 * Schedule an instant Tx resend.
722 */
723static inline void rxrpc_instant_resend(struct rxrpc_call *call,
724 struct rxrpc_txbuf *txb)
725{
726 if (!__rxrpc_call_is_complete(call))
727 kdebug("resend");
728}
729
730/*
731 * Transmit one packet.
732 */
733void rxrpc_transmit_one(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
734{
735 int ret;
736
737 ret = rxrpc_send_data_packet(call, txb);
738 if (ret < 0) {
739 switch (ret) {
740 case -ENETUNREACH:
741 case -EHOSTUNREACH:
742 case -ECONNREFUSED:
743 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
744 0, ret);
745 break;
746 default:
747 _debug("need instant resend %d", ret);
748 rxrpc_instant_resend(call, txb);
749 }
750 } else {
751 unsigned long now = jiffies;
752 unsigned long resend_at = now + call->peer->rto_j;
753
754 WRITE_ONCE(call->resend_at, resend_at);
755 rxrpc_reduce_call_timer(call, resend_at, now,
756 rxrpc_timer_set_for_send);
757 }
758}