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
do_udp_sendmsg(struct socket * socket,struct msghdr * msg,size_t len)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 */
rxrpc_tx_backoff(struct rxrpc_call * call,int ret)48 static 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 */
rxrpc_set_keepalive(struct rxrpc_call * call)68 static 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 */
rxrpc_fill_out_ack(struct rxrpc_connection * conn,struct rxrpc_call * call,struct rxrpc_txbuf * txb,u16 * _rwind)81 static 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_acktrailer trailer;
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 trailer.maxMTU = htonl(rxrpc_rx_mtu);
130 trailer.ifMTU = htonl(mtu);
131 trailer.rwind = htonl(rsize);
132 trailer.jumbo_max = htonl(jmax);
133
134 *ackp++ = 0;
135 *ackp++ = 0;
136 *ackp++ = 0;
137 memcpy(ackp, &trailer, sizeof(trailer));
138 return txb->ack.nAcks + 3 + sizeof(trailer);
139 }
140
141 /*
142 * Record the beginning of an RTT probe.
143 */
rxrpc_begin_rtt_probe(struct rxrpc_call * call,rxrpc_serial_t serial,enum rxrpc_rtt_tx_trace why)144 static 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
165 no_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 */
rxrpc_cancel_rtt_probe(struct rxrpc_call * call,rxrpc_serial_t serial,int rtt_slot)173 static 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 */
rxrpc_send_ack_packet(struct rxrpc_call * call,struct rxrpc_txbuf * txb)187 int 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 */
rxrpc_send_abort_packet(struct rxrpc_call * call)260 int 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 */
rxrpc_send_data_packet(struct rxrpc_call * call,struct rxrpc_txbuf * txb)324 int 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;
385 dont_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
444 done:
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
486 send_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 */
rxrpc_send_conn_abort(struct rxrpc_connection * conn)525 void 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 */
rxrpc_reject_packet(struct rxrpc_local * local,struct sk_buff * skb)581 void 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 */
rxrpc_send_keepalive(struct rxrpc_peer * peer)647 void 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 */
rxrpc_instant_resend(struct rxrpc_call * call,struct rxrpc_txbuf * txb)698 static 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 */
rxrpc_transmit_one(struct rxrpc_call * call,struct rxrpc_txbuf * txb)708 void 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