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