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 */
rxrpc_tx_backoff(struct rxrpc_call * call,int ret)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 */
rxrpc_set_keepalive(struct rxrpc_call * call)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 */
rxrpc_fill_out_ack(struct rxrpc_connection * conn,struct rxrpc_call * call,struct rxrpc_ack_buffer * pkt,rxrpc_seq_t * _hard_ack,rxrpc_seq_t * _top,u8 reason)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 * Send an ACK call packet.
128 */
rxrpc_send_ack_packet(struct rxrpc_call * call,bool ping,rxrpc_serial_t * _serial)129 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
130 rxrpc_serial_t *_serial)
131 {
132 struct rxrpc_connection *conn = NULL;
133 struct rxrpc_ack_buffer *pkt;
134 struct msghdr msg;
135 struct kvec iov[2];
136 rxrpc_serial_t serial;
137 rxrpc_seq_t hard_ack, top;
138 size_t len, n;
139 int ret;
140 u8 reason;
141
142 spin_lock_bh(&call->lock);
143 if (call->conn)
144 conn = rxrpc_get_connection_maybe(call->conn);
145 spin_unlock_bh(&call->lock);
146 if (!conn)
147 return -ECONNRESET;
148
149 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
150 if (!pkt) {
151 rxrpc_put_connection(conn);
152 return -ENOMEM;
153 }
154
155 msg.msg_name = &call->peer->srx.transport;
156 msg.msg_namelen = call->peer->srx.transport_len;
157 msg.msg_control = NULL;
158 msg.msg_controllen = 0;
159 msg.msg_flags = 0;
160
161 pkt->whdr.epoch = htonl(conn->proto.epoch);
162 pkt->whdr.cid = htonl(call->cid);
163 pkt->whdr.callNumber = htonl(call->call_id);
164 pkt->whdr.seq = 0;
165 pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
166 pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
167 pkt->whdr.userStatus = 0;
168 pkt->whdr.securityIndex = call->security_ix;
169 pkt->whdr._rsvd = 0;
170 pkt->whdr.serviceId = htons(call->service_id);
171
172 spin_lock_bh(&call->lock);
173 if (ping) {
174 reason = RXRPC_ACK_PING;
175 } else {
176 reason = call->ackr_reason;
177 if (!call->ackr_reason) {
178 spin_unlock_bh(&call->lock);
179 ret = 0;
180 goto out;
181 }
182 call->ackr_reason = 0;
183 }
184 n = rxrpc_fill_out_ack(conn, call, pkt, &hard_ack, &top, reason);
185
186 spin_unlock_bh(&call->lock);
187
188 iov[0].iov_base = pkt;
189 iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
190 iov[1].iov_base = &pkt->ackinfo;
191 iov[1].iov_len = sizeof(pkt->ackinfo);
192 len = iov[0].iov_len + iov[1].iov_len;
193
194 serial = atomic_inc_return(&conn->serial);
195 pkt->whdr.serial = htonl(serial);
196 trace_rxrpc_tx_ack(call->debug_id, serial,
197 ntohl(pkt->ack.firstPacket),
198 ntohl(pkt->ack.serial),
199 pkt->ack.reason, pkt->ack.nAcks);
200 if (_serial)
201 *_serial = serial;
202
203 if (ping) {
204 call->ping_serial = serial;
205 smp_wmb();
206 /* We need to stick a time in before we send the packet in case
207 * the reply gets back before kernel_sendmsg() completes - but
208 * asking UDP to send the packet can take a relatively long
209 * time.
210 */
211 call->ping_time = ktime_get_real();
212 set_bit(RXRPC_CALL_PINGING, &call->flags);
213 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
214 }
215
216 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
217 conn->params.peer->last_tx_at = ktime_get_seconds();
218 if (ret < 0)
219 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
220 rxrpc_tx_point_call_ack);
221 else
222 trace_rxrpc_tx_packet(call->debug_id, &pkt->whdr,
223 rxrpc_tx_point_call_ack);
224 rxrpc_tx_backoff(call, ret);
225
226 if (call->state < RXRPC_CALL_COMPLETE) {
227 if (ret < 0) {
228 if (ping)
229 clear_bit(RXRPC_CALL_PINGING, &call->flags);
230 rxrpc_propose_ACK(call, pkt->ack.reason,
231 ntohl(pkt->ack.serial),
232 false, true,
233 rxrpc_propose_ack_retry_tx);
234 } else {
235 spin_lock_bh(&call->lock);
236 if (after(hard_ack, call->ackr_consumed))
237 call->ackr_consumed = hard_ack;
238 if (after(top, call->ackr_seen))
239 call->ackr_seen = top;
240 spin_unlock_bh(&call->lock);
241 }
242
243 rxrpc_set_keepalive(call);
244 }
245
246 out:
247 rxrpc_put_connection(conn);
248 kfree(pkt);
249 return ret;
250 }
251
252 /*
253 * Send an ABORT call packet.
254 */
rxrpc_send_abort_packet(struct rxrpc_call * call)255 int rxrpc_send_abort_packet(struct rxrpc_call *call)
256 {
257 struct rxrpc_connection *conn = NULL;
258 struct rxrpc_abort_buffer pkt;
259 struct msghdr msg;
260 struct kvec iov[1];
261 rxrpc_serial_t serial;
262 int ret;
263
264 /* Don't bother sending aborts for a client call once the server has
265 * hard-ACK'd all of its request data. After that point, we're not
266 * going to stop the operation proceeding, and whilst we might limit
267 * the reply, it's not worth it if we can send a new call on the same
268 * channel instead, thereby closing off this call.
269 */
270 if (rxrpc_is_client_call(call) &&
271 test_bit(RXRPC_CALL_TX_LAST, &call->flags))
272 return 0;
273
274 spin_lock_bh(&call->lock);
275 if (call->conn)
276 conn = rxrpc_get_connection_maybe(call->conn);
277 spin_unlock_bh(&call->lock);
278 if (!conn)
279 return -ECONNRESET;
280
281 msg.msg_name = &call->peer->srx.transport;
282 msg.msg_namelen = call->peer->srx.transport_len;
283 msg.msg_control = NULL;
284 msg.msg_controllen = 0;
285 msg.msg_flags = 0;
286
287 pkt.whdr.epoch = htonl(conn->proto.epoch);
288 pkt.whdr.cid = htonl(call->cid);
289 pkt.whdr.callNumber = htonl(call->call_id);
290 pkt.whdr.seq = 0;
291 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
292 pkt.whdr.flags = conn->out_clientflag;
293 pkt.whdr.userStatus = 0;
294 pkt.whdr.securityIndex = call->security_ix;
295 pkt.whdr._rsvd = 0;
296 pkt.whdr.serviceId = htons(call->service_id);
297 pkt.abort_code = htonl(call->abort_code);
298
299 iov[0].iov_base = &pkt;
300 iov[0].iov_len = sizeof(pkt);
301
302 serial = atomic_inc_return(&conn->serial);
303 pkt.whdr.serial = htonl(serial);
304
305 ret = kernel_sendmsg(conn->params.local->socket,
306 &msg, iov, 1, sizeof(pkt));
307 conn->params.peer->last_tx_at = ktime_get_seconds();
308 if (ret < 0)
309 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
310 rxrpc_tx_point_call_abort);
311 else
312 trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
313 rxrpc_tx_point_call_abort);
314 rxrpc_tx_backoff(call, ret);
315
316 rxrpc_put_connection(conn);
317 return ret;
318 }
319
320 /*
321 * send a packet through the transport endpoint
322 */
rxrpc_send_data_packet(struct rxrpc_call * call,struct sk_buff * skb,bool retrans)323 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
324 bool retrans)
325 {
326 struct rxrpc_connection *conn = call->conn;
327 struct rxrpc_wire_header whdr;
328 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
329 struct msghdr msg;
330 struct kvec iov[2];
331 rxrpc_serial_t serial;
332 size_t len;
333 int ret, opt;
334
335 _enter(",{%d}", skb->len);
336
337 /* Each transmission of a Tx packet needs a new serial number */
338 serial = atomic_inc_return(&conn->serial);
339
340 whdr.epoch = htonl(conn->proto.epoch);
341 whdr.cid = htonl(call->cid);
342 whdr.callNumber = htonl(call->call_id);
343 whdr.seq = htonl(sp->hdr.seq);
344 whdr.serial = htonl(serial);
345 whdr.type = RXRPC_PACKET_TYPE_DATA;
346 whdr.flags = sp->hdr.flags;
347 whdr.userStatus = 0;
348 whdr.securityIndex = call->security_ix;
349 whdr._rsvd = htons(sp->hdr._rsvd);
350 whdr.serviceId = htons(call->service_id);
351
352 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
353 sp->hdr.seq == 1)
354 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
355
356 iov[0].iov_base = &whdr;
357 iov[0].iov_len = sizeof(whdr);
358 iov[1].iov_base = skb->head;
359 iov[1].iov_len = skb->len;
360 len = iov[0].iov_len + iov[1].iov_len;
361
362 msg.msg_name = &call->peer->srx.transport;
363 msg.msg_namelen = call->peer->srx.transport_len;
364 msg.msg_control = NULL;
365 msg.msg_controllen = 0;
366 msg.msg_flags = 0;
367
368 /* If our RTT cache needs working on, request an ACK. Also request
369 * ACKs if a DATA packet appears to have been lost.
370 *
371 * However, we mustn't request an ACK on the last reply packet of a
372 * service call, lest OpenAFS incorrectly send us an ACK with some
373 * soft-ACKs in it and then never follow up with a proper hard ACK.
374 */
375 if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) ||
376 rxrpc_to_server(sp)
377 ) &&
378 (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
379 retrans ||
380 call->cong_mode == RXRPC_CALL_SLOW_START ||
381 (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
382 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
383 ktime_get_real())))
384 whdr.flags |= RXRPC_REQUEST_ACK;
385
386 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
387 static int lose;
388 if ((lose++ & 7) == 7) {
389 ret = 0;
390 trace_rxrpc_tx_data(call, sp->hdr.seq, serial,
391 whdr.flags, retrans, true);
392 goto done;
393 }
394 }
395
396 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags, retrans,
397 false);
398
399 /* send the packet with the don't fragment bit set if we currently
400 * think it's small enough */
401 if (iov[1].iov_len >= call->peer->maxdata)
402 goto send_fragmentable;
403
404 down_read(&conn->params.local->defrag_sem);
405
406 sp->hdr.serial = serial;
407 smp_wmb(); /* Set serial before timestamp */
408 skb->tstamp = ktime_get_real();
409
410 /* send the packet by UDP
411 * - returns -EMSGSIZE if UDP would have to fragment the packet
412 * to go out of the interface
413 * - in which case, we'll have processed the ICMP error
414 * message and update the peer record
415 */
416 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
417 conn->params.peer->last_tx_at = ktime_get_seconds();
418
419 up_read(&conn->params.local->defrag_sem);
420 if (ret < 0)
421 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
422 rxrpc_tx_point_call_data_nofrag);
423 else
424 trace_rxrpc_tx_packet(call->debug_id, &whdr,
425 rxrpc_tx_point_call_data_nofrag);
426 rxrpc_tx_backoff(call, ret);
427 if (ret == -EMSGSIZE)
428 goto send_fragmentable;
429
430 done:
431 if (ret >= 0) {
432 if (whdr.flags & RXRPC_REQUEST_ACK) {
433 call->peer->rtt_last_req = skb->tstamp;
434 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
435 if (call->peer->rtt_usage > 1) {
436 unsigned long nowj = jiffies, ack_lost_at;
437
438 ack_lost_at = nsecs_to_jiffies(2 * call->peer->rtt);
439 if (ack_lost_at < 1)
440 ack_lost_at = 1;
441
442 ack_lost_at += nowj;
443 WRITE_ONCE(call->ack_lost_at, ack_lost_at);
444 rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
445 rxrpc_timer_set_for_lost_ack);
446 }
447 }
448
449 if (sp->hdr.seq == 1 &&
450 !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
451 &call->flags)) {
452 unsigned long nowj = jiffies, expect_rx_by;
453
454 expect_rx_by = nowj + call->next_rx_timo;
455 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
456 rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
457 rxrpc_timer_set_for_normal);
458 }
459
460 rxrpc_set_keepalive(call);
461 } else {
462 /* Cancel the call if the initial transmission fails,
463 * particularly if that's due to network routing issues that
464 * aren't going away anytime soon. The layer above can arrange
465 * the retransmission.
466 */
467 if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
468 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
469 RX_USER_ABORT, ret);
470 }
471
472 _leave(" = %d [%u]", ret, call->peer->maxdata);
473 return ret;
474
475 send_fragmentable:
476 /* attempt to send this message with fragmentation enabled */
477 _debug("send fragment");
478
479 down_write(&conn->params.local->defrag_sem);
480
481 sp->hdr.serial = serial;
482 smp_wmb(); /* Set serial before timestamp */
483 skb->tstamp = ktime_get_real();
484
485 switch (conn->params.local->srx.transport.family) {
486 case AF_INET:
487 opt = IP_PMTUDISC_DONT;
488 ret = kernel_setsockopt(conn->params.local->socket,
489 SOL_IP, IP_MTU_DISCOVER,
490 (char *)&opt, sizeof(opt));
491 if (ret == 0) {
492 ret = kernel_sendmsg(conn->params.local->socket, &msg,
493 iov, 2, len);
494 conn->params.peer->last_tx_at = ktime_get_seconds();
495
496 opt = IP_PMTUDISC_DO;
497 kernel_setsockopt(conn->params.local->socket, SOL_IP,
498 IP_MTU_DISCOVER,
499 (char *)&opt, sizeof(opt));
500 }
501 break;
502
503 #ifdef CONFIG_AF_RXRPC_IPV6
504 case AF_INET6:
505 opt = IPV6_PMTUDISC_DONT;
506 ret = kernel_setsockopt(conn->params.local->socket,
507 SOL_IPV6, IPV6_MTU_DISCOVER,
508 (char *)&opt, sizeof(opt));
509 if (ret == 0) {
510 ret = kernel_sendmsg(conn->params.local->socket, &msg,
511 iov, 2, len);
512 conn->params.peer->last_tx_at = ktime_get_seconds();
513
514 opt = IPV6_PMTUDISC_DO;
515 kernel_setsockopt(conn->params.local->socket,
516 SOL_IPV6, IPV6_MTU_DISCOVER,
517 (char *)&opt, sizeof(opt));
518 }
519 break;
520 #endif
521
522 default:
523 BUG();
524 }
525
526 if (ret < 0)
527 trace_rxrpc_tx_fail(call->debug_id, serial, ret,
528 rxrpc_tx_point_call_data_frag);
529 else
530 trace_rxrpc_tx_packet(call->debug_id, &whdr,
531 rxrpc_tx_point_call_data_frag);
532 rxrpc_tx_backoff(call, ret);
533
534 up_write(&conn->params.local->defrag_sem);
535 goto done;
536 }
537
538 /*
539 * reject packets through the local endpoint
540 */
rxrpc_reject_packets(struct rxrpc_local * local)541 void rxrpc_reject_packets(struct rxrpc_local *local)
542 {
543 struct sockaddr_rxrpc srx;
544 struct rxrpc_skb_priv *sp;
545 struct rxrpc_wire_header whdr;
546 struct sk_buff *skb;
547 struct msghdr msg;
548 struct kvec iov[2];
549 size_t size;
550 __be32 code;
551 int ret, ioc;
552
553 _enter("%d", local->debug_id);
554
555 iov[0].iov_base = &whdr;
556 iov[0].iov_len = sizeof(whdr);
557 iov[1].iov_base = &code;
558 iov[1].iov_len = sizeof(code);
559
560 msg.msg_name = &srx.transport;
561 msg.msg_control = NULL;
562 msg.msg_controllen = 0;
563 msg.msg_flags = 0;
564
565 memset(&whdr, 0, sizeof(whdr));
566
567 while ((skb = skb_dequeue(&local->reject_queue))) {
568 rxrpc_see_skb(skb, rxrpc_skb_seen);
569 sp = rxrpc_skb(skb);
570
571 switch (skb->mark) {
572 case RXRPC_SKB_MARK_REJECT_BUSY:
573 whdr.type = RXRPC_PACKET_TYPE_BUSY;
574 size = sizeof(whdr);
575 ioc = 1;
576 break;
577 case RXRPC_SKB_MARK_REJECT_ABORT:
578 whdr.type = RXRPC_PACKET_TYPE_ABORT;
579 code = htonl(skb->priority);
580 size = sizeof(whdr) + sizeof(code);
581 ioc = 2;
582 break;
583 default:
584 rxrpc_free_skb(skb, rxrpc_skb_freed);
585 continue;
586 }
587
588 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
589 msg.msg_namelen = srx.transport_len;
590
591 whdr.epoch = htonl(sp->hdr.epoch);
592 whdr.cid = htonl(sp->hdr.cid);
593 whdr.callNumber = htonl(sp->hdr.callNumber);
594 whdr.serviceId = htons(sp->hdr.serviceId);
595 whdr.flags = sp->hdr.flags;
596 whdr.flags ^= RXRPC_CLIENT_INITIATED;
597 whdr.flags &= RXRPC_CLIENT_INITIATED;
598
599 ret = kernel_sendmsg(local->socket, &msg,
600 iov, ioc, size);
601 if (ret < 0)
602 trace_rxrpc_tx_fail(local->debug_id, 0, ret,
603 rxrpc_tx_point_reject);
604 else
605 trace_rxrpc_tx_packet(local->debug_id, &whdr,
606 rxrpc_tx_point_reject);
607 }
608
609 rxrpc_free_skb(skb, rxrpc_skb_freed);
610 }
611
612 _leave("");
613 }
614
615 /*
616 * Send a VERSION reply to a peer as a keepalive.
617 */
rxrpc_send_keepalive(struct rxrpc_peer * peer)618 void rxrpc_send_keepalive(struct rxrpc_peer *peer)
619 {
620 struct rxrpc_wire_header whdr;
621 struct msghdr msg;
622 struct kvec iov[2];
623 size_t len;
624 int ret;
625
626 _enter("");
627
628 msg.msg_name = &peer->srx.transport;
629 msg.msg_namelen = peer->srx.transport_len;
630 msg.msg_control = NULL;
631 msg.msg_controllen = 0;
632 msg.msg_flags = 0;
633
634 whdr.epoch = htonl(peer->local->rxnet->epoch);
635 whdr.cid = 0;
636 whdr.callNumber = 0;
637 whdr.seq = 0;
638 whdr.serial = 0;
639 whdr.type = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
640 whdr.flags = RXRPC_LAST_PACKET;
641 whdr.userStatus = 0;
642 whdr.securityIndex = 0;
643 whdr._rsvd = 0;
644 whdr.serviceId = 0;
645
646 iov[0].iov_base = &whdr;
647 iov[0].iov_len = sizeof(whdr);
648 iov[1].iov_base = (char *)rxrpc_keepalive_string;
649 iov[1].iov_len = sizeof(rxrpc_keepalive_string);
650
651 len = iov[0].iov_len + iov[1].iov_len;
652
653 _proto("Tx VERSION (keepalive)");
654
655 ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
656 if (ret < 0)
657 trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
658 rxrpc_tx_point_version_keepalive);
659 else
660 trace_rxrpc_tx_packet(peer->debug_id, &whdr,
661 rxrpc_tx_point_version_keepalive);
662
663 peer->last_tx_at = ktime_get_seconds();
664 _leave("");
665 }
666
