1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* connection-level event handling
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/module.h>
11 #include <linux/net.h>
12 #include <linux/skbuff.h>
13 #include <linux/errqueue.h>
14 #include <net/sock.h>
15 #include <net/af_rxrpc.h>
16 #include <net/ip.h>
17 #include "ar-internal.h"
18
19 /*
20 * Retransmit terminal ACK or ABORT of the previous call.
21 */
rxrpc_conn_retransmit_call(struct rxrpc_connection * conn,struct sk_buff * skb,unsigned int channel)22 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
23 struct sk_buff *skb,
24 unsigned int channel)
25 {
26 struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
27 struct rxrpc_channel *chan;
28 struct msghdr msg;
29 struct kvec iov[3];
30 struct {
31 struct rxrpc_wire_header whdr;
32 union {
33 __be32 abort_code;
34 struct rxrpc_ackpacket ack;
35 };
36 } __attribute__((packed)) pkt;
37 struct rxrpc_ackinfo ack_info;
38 size_t len;
39 int ret, ioc;
40 u32 serial, mtu, call_id, padding;
41
42 _enter("%d", conn->debug_id);
43
44 if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
45 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
46 &pkt.ack, sizeof(pkt.ack)) < 0)
47 return;
48 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
49 return;
50 }
51
52 chan = &conn->channels[channel];
53
54 /* If the last call got moved on whilst we were waiting to run, just
55 * ignore this packet.
56 */
57 call_id = READ_ONCE(chan->last_call);
58 /* Sync with __rxrpc_disconnect_call() */
59 smp_rmb();
60 if (skb && call_id != sp->hdr.callNumber)
61 return;
62
63 msg.msg_name = &conn->params.peer->srx.transport;
64 msg.msg_namelen = conn->params.peer->srx.transport_len;
65 msg.msg_control = NULL;
66 msg.msg_controllen = 0;
67 msg.msg_flags = 0;
68
69 iov[0].iov_base = &pkt;
70 iov[0].iov_len = sizeof(pkt.whdr);
71 iov[1].iov_base = &padding;
72 iov[1].iov_len = 3;
73 iov[2].iov_base = &ack_info;
74 iov[2].iov_len = sizeof(ack_info);
75
76 pkt.whdr.epoch = htonl(conn->proto.epoch);
77 pkt.whdr.cid = htonl(conn->proto.cid | channel);
78 pkt.whdr.callNumber = htonl(call_id);
79 pkt.whdr.seq = 0;
80 pkt.whdr.type = chan->last_type;
81 pkt.whdr.flags = conn->out_clientflag;
82 pkt.whdr.userStatus = 0;
83 pkt.whdr.securityIndex = conn->security_ix;
84 pkt.whdr._rsvd = 0;
85 pkt.whdr.serviceId = htons(conn->service_id);
86
87 len = sizeof(pkt.whdr);
88 switch (chan->last_type) {
89 case RXRPC_PACKET_TYPE_ABORT:
90 pkt.abort_code = htonl(chan->last_abort);
91 iov[0].iov_len += sizeof(pkt.abort_code);
92 len += sizeof(pkt.abort_code);
93 ioc = 1;
94 break;
95
96 case RXRPC_PACKET_TYPE_ACK:
97 mtu = conn->params.peer->if_mtu;
98 mtu -= conn->params.peer->hdrsize;
99 pkt.ack.bufferSpace = 0;
100 pkt.ack.maxSkew = htons(skb ? skb->priority : 0);
101 pkt.ack.firstPacket = htonl(chan->last_seq + 1);
102 pkt.ack.previousPacket = htonl(chan->last_seq);
103 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0);
104 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
105 pkt.ack.nAcks = 0;
106 ack_info.rxMTU = htonl(rxrpc_rx_mtu);
107 ack_info.maxMTU = htonl(mtu);
108 ack_info.rwind = htonl(rxrpc_rx_window_size);
109 ack_info.jumbo_max = htonl(rxrpc_rx_jumbo_max);
110 pkt.whdr.flags |= RXRPC_SLOW_START_OK;
111 padding = 0;
112 iov[0].iov_len += sizeof(pkt.ack);
113 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
114 ioc = 3;
115 break;
116
117 default:
118 return;
119 }
120
121 /* Resync with __rxrpc_disconnect_call() and check that the last call
122 * didn't get advanced whilst we were filling out the packets.
123 */
124 smp_rmb();
125 if (READ_ONCE(chan->last_call) != call_id)
126 return;
127
128 serial = atomic_inc_return(&conn->serial);
129 pkt.whdr.serial = htonl(serial);
130
131 switch (chan->last_type) {
132 case RXRPC_PACKET_TYPE_ABORT:
133 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
134 break;
135 case RXRPC_PACKET_TYPE_ACK:
136 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
137 ntohl(pkt.ack.firstPacket),
138 ntohl(pkt.ack.serial),
139 pkt.ack.reason, 0);
140 _proto("Tx ACK %%%u [re]", serial);
141 break;
142 }
143
144 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
145 conn->params.peer->last_tx_at = ktime_get_seconds();
146 if (ret < 0)
147 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
148 rxrpc_tx_point_call_final_resend);
149 else
150 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
151 rxrpc_tx_point_call_final_resend);
152
153 _leave("");
154 }
155
156 /*
157 * pass a connection-level abort onto all calls on that connection
158 */
rxrpc_abort_calls(struct rxrpc_connection * conn,enum rxrpc_call_completion compl,rxrpc_serial_t serial)159 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
160 enum rxrpc_call_completion compl,
161 rxrpc_serial_t serial)
162 {
163 struct rxrpc_call *call;
164 int i;
165
166 _enter("{%d},%x", conn->debug_id, conn->abort_code);
167
168 spin_lock(&conn->channel_lock);
169
170 for (i = 0; i < RXRPC_MAXCALLS; i++) {
171 call = rcu_dereference_protected(
172 conn->channels[i].call,
173 lockdep_is_held(&conn->channel_lock));
174 if (call) {
175 if (compl == RXRPC_CALL_LOCALLY_ABORTED)
176 trace_rxrpc_abort(call->debug_id,
177 "CON", call->cid,
178 call->call_id, 0,
179 conn->abort_code,
180 conn->error);
181 else
182 trace_rxrpc_rx_abort(call, serial,
183 conn->abort_code);
184 if (rxrpc_set_call_completion(call, compl,
185 conn->abort_code,
186 conn->error))
187 rxrpc_notify_socket(call);
188 }
189 }
190
191 spin_unlock(&conn->channel_lock);
192 _leave("");
193 }
194
195 /*
196 * generate a connection-level abort
197 */
rxrpc_abort_connection(struct rxrpc_connection * conn,int error,u32 abort_code)198 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
199 int error, u32 abort_code)
200 {
201 struct rxrpc_wire_header whdr;
202 struct msghdr msg;
203 struct kvec iov[2];
204 __be32 word;
205 size_t len;
206 u32 serial;
207 int ret;
208
209 _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
210
211 /* generate a connection-level abort */
212 spin_lock_bh(&conn->state_lock);
213 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
214 spin_unlock_bh(&conn->state_lock);
215 _leave(" = 0 [already dead]");
216 return 0;
217 }
218
219 conn->error = error;
220 conn->abort_code = abort_code;
221 conn->state = RXRPC_CONN_LOCALLY_ABORTED;
222 spin_unlock_bh(&conn->state_lock);
223
224 msg.msg_name = &conn->params.peer->srx.transport;
225 msg.msg_namelen = conn->params.peer->srx.transport_len;
226 msg.msg_control = NULL;
227 msg.msg_controllen = 0;
228 msg.msg_flags = 0;
229
230 whdr.epoch = htonl(conn->proto.epoch);
231 whdr.cid = htonl(conn->proto.cid);
232 whdr.callNumber = 0;
233 whdr.seq = 0;
234 whdr.type = RXRPC_PACKET_TYPE_ABORT;
235 whdr.flags = conn->out_clientflag;
236 whdr.userStatus = 0;
237 whdr.securityIndex = conn->security_ix;
238 whdr._rsvd = 0;
239 whdr.serviceId = htons(conn->service_id);
240
241 word = htonl(conn->abort_code);
242
243 iov[0].iov_base = &whdr;
244 iov[0].iov_len = sizeof(whdr);
245 iov[1].iov_base = &word;
246 iov[1].iov_len = sizeof(word);
247
248 len = iov[0].iov_len + iov[1].iov_len;
249
250 serial = atomic_inc_return(&conn->serial);
251 rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
252 whdr.serial = htonl(serial);
253 _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
254
255 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
256 if (ret < 0) {
257 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
258 rxrpc_tx_point_conn_abort);
259 _debug("sendmsg failed: %d", ret);
260 return -EAGAIN;
261 }
262
263 trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
264
265 conn->params.peer->last_tx_at = ktime_get_seconds();
266
267 _leave(" = 0");
268 return 0;
269 }
270
271 /*
272 * mark a call as being on a now-secured channel
273 * - must be called with BH's disabled.
274 */
rxrpc_call_is_secure(struct rxrpc_call * call)275 static void rxrpc_call_is_secure(struct rxrpc_call *call)
276 {
277 _enter("%p", call);
278 if (call) {
279 write_lock_bh(&call->state_lock);
280 if (call->state == RXRPC_CALL_SERVER_SECURING) {
281 call->state = RXRPC_CALL_SERVER_ACCEPTING;
282 rxrpc_notify_socket(call);
283 }
284 write_unlock_bh(&call->state_lock);
285 }
286 }
287
288 /*
289 * connection-level Rx packet processor
290 */
rxrpc_process_event(struct rxrpc_connection * conn,struct sk_buff * skb,u32 * _abort_code)291 static int rxrpc_process_event(struct rxrpc_connection *conn,
292 struct sk_buff *skb,
293 u32 *_abort_code)
294 {
295 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
296 __be32 wtmp;
297 u32 abort_code;
298 int loop, ret;
299
300 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
301 _leave(" = -ECONNABORTED [%u]", conn->state);
302 return -ECONNABORTED;
303 }
304
305 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
306
307 switch (sp->hdr.type) {
308 case RXRPC_PACKET_TYPE_DATA:
309 case RXRPC_PACKET_TYPE_ACK:
310 rxrpc_conn_retransmit_call(conn, skb,
311 sp->hdr.cid & RXRPC_CHANNELMASK);
312 return 0;
313
314 case RXRPC_PACKET_TYPE_BUSY:
315 /* Just ignore BUSY packets for now. */
316 return 0;
317
318 case RXRPC_PACKET_TYPE_ABORT:
319 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
320 &wtmp, sizeof(wtmp)) < 0) {
321 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
322 tracepoint_string("bad_abort"));
323 return -EPROTO;
324 }
325 abort_code = ntohl(wtmp);
326 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
327
328 conn->error = -ECONNABORTED;
329 conn->abort_code = abort_code;
330 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
331 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
332 return -ECONNABORTED;
333
334 case RXRPC_PACKET_TYPE_CHALLENGE:
335 return conn->security->respond_to_challenge(conn, skb,
336 _abort_code);
337
338 case RXRPC_PACKET_TYPE_RESPONSE:
339 ret = conn->security->verify_response(conn, skb, _abort_code);
340 if (ret < 0)
341 return ret;
342
343 ret = conn->security->init_connection_security(conn);
344 if (ret < 0)
345 return ret;
346
347 ret = conn->security->prime_packet_security(conn);
348 if (ret < 0)
349 return ret;
350
351 spin_lock(&conn->channel_lock);
352 spin_lock_bh(&conn->state_lock);
353
354 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
355 conn->state = RXRPC_CONN_SERVICE;
356 spin_unlock_bh(&conn->state_lock);
357 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
358 rxrpc_call_is_secure(
359 rcu_dereference_protected(
360 conn->channels[loop].call,
361 lockdep_is_held(&conn->channel_lock)));
362 } else {
363 spin_unlock_bh(&conn->state_lock);
364 }
365
366 spin_unlock(&conn->channel_lock);
367 return 0;
368
369 default:
370 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
371 tracepoint_string("bad_conn_pkt"));
372 return -EPROTO;
373 }
374 }
375
376 /*
377 * set up security and issue a challenge
378 */
rxrpc_secure_connection(struct rxrpc_connection * conn)379 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
380 {
381 u32 abort_code;
382 int ret;
383
384 _enter("{%d}", conn->debug_id);
385
386 ASSERT(conn->security_ix != 0);
387 ASSERT(conn->server_key);
388
389 if (conn->security->issue_challenge(conn) < 0) {
390 abort_code = RX_CALL_DEAD;
391 ret = -ENOMEM;
392 goto abort;
393 }
394
395 _leave("");
396 return;
397
398 abort:
399 _debug("abort %d, %d", ret, abort_code);
400 rxrpc_abort_connection(conn, ret, abort_code);
401 _leave(" [aborted]");
402 }
403
404 /*
405 * Process delayed final ACKs that we haven't subsumed into a subsequent call.
406 */
rxrpc_process_delayed_final_acks(struct rxrpc_connection * conn)407 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
408 {
409 unsigned long j = jiffies, next_j;
410 unsigned int channel;
411 bool set;
412
413 again:
414 next_j = j + LONG_MAX;
415 set = false;
416 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
417 struct rxrpc_channel *chan = &conn->channels[channel];
418 unsigned long ack_at;
419
420 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
421 continue;
422
423 smp_rmb(); /* vs rxrpc_disconnect_client_call */
424 ack_at = READ_ONCE(chan->final_ack_at);
425
426 if (time_before(j, ack_at)) {
427 if (time_before(ack_at, next_j)) {
428 next_j = ack_at;
429 set = true;
430 }
431 continue;
432 }
433
434 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
435 &conn->flags))
436 rxrpc_conn_retransmit_call(conn, NULL, channel);
437 }
438
439 j = jiffies;
440 if (time_before_eq(next_j, j))
441 goto again;
442 if (set)
443 rxrpc_reduce_conn_timer(conn, next_j);
444 }
445
446 /*
447 * connection-level event processor
448 */
rxrpc_do_process_connection(struct rxrpc_connection * conn)449 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
450 {
451 struct sk_buff *skb;
452 u32 abort_code = RX_PROTOCOL_ERROR;
453 int ret;
454
455 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
456 rxrpc_secure_connection(conn);
457
458 /* Process delayed ACKs whose time has come. */
459 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
460 rxrpc_process_delayed_final_acks(conn);
461
462 /* go through the conn-level event packets, releasing the ref on this
463 * connection that each one has when we've finished with it */
464 while ((skb = skb_dequeue(&conn->rx_queue))) {
465 rxrpc_see_skb(skb, rxrpc_skb_seen);
466 ret = rxrpc_process_event(conn, skb, &abort_code);
467 switch (ret) {
468 case -EPROTO:
469 case -EKEYEXPIRED:
470 case -EKEYREJECTED:
471 goto protocol_error;
472 case -ENOMEM:
473 case -EAGAIN:
474 goto requeue_and_leave;
475 case -ECONNABORTED:
476 default:
477 rxrpc_free_skb(skb, rxrpc_skb_freed);
478 break;
479 }
480 }
481
482 return;
483
484 requeue_and_leave:
485 skb_queue_head(&conn->rx_queue, skb);
486 return;
487
488 protocol_error:
489 if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
490 goto requeue_and_leave;
491 rxrpc_free_skb(skb, rxrpc_skb_freed);
492 return;
493 }
494
rxrpc_process_connection(struct work_struct * work)495 void rxrpc_process_connection(struct work_struct *work)
496 {
497 struct rxrpc_connection *conn =
498 container_of(work, struct rxrpc_connection, processor);
499
500 rxrpc_see_connection(conn);
501
502 if (__rxrpc_use_local(conn->params.local)) {
503 rxrpc_do_process_connection(conn);
504 rxrpc_unuse_local(conn->params.local);
505 }
506
507 rxrpc_put_connection(conn);
508 _leave("");
509 return;
510 }
511