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