1 /* RxRPC packet reception
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 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/errqueue.h>
16 #include <linux/udp.h>
17 #include <linux/in.h>
18 #include <linux/in6.h>
19 #include <linux/icmp.h>
20 #include <linux/gfp.h>
21 #include <net/sock.h>
22 #include <net/af_rxrpc.h>
23 #include <net/ip.h>
24 #include <net/udp.h>
25 #include <net/net_namespace.h>
26 #include "ar-internal.h"
27
28 const char *rxrpc_pkts[] = {
29 "?00",
30 "DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
31 "?09", "?10", "?11", "?12", "VERSION", "?14", "?15"
32 };
33
34 /*
35 * queue a packet for recvmsg to pass to userspace
36 * - the caller must hold a lock on call->lock
37 * - must not be called with interrupts disabled (sk_filter() disables BH's)
38 * - eats the packet whether successful or not
39 * - there must be just one reference to the packet, which the caller passes to
40 * this function
41 */
rxrpc_queue_rcv_skb(struct rxrpc_call * call,struct sk_buff * skb,bool force,bool terminal)42 int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
43 bool force, bool terminal)
44 {
45 struct rxrpc_skb_priv *sp;
46 struct rxrpc_sock *rx = call->socket;
47 struct sock *sk;
48 int ret;
49
50 _enter(",,%d,%d", force, terminal);
51
52 ASSERT(!irqs_disabled());
53
54 sp = rxrpc_skb(skb);
55 ASSERTCMP(sp->call, ==, call);
56
57 /* if we've already posted the terminal message for a call, then we
58 * don't post any more */
59 if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
60 _debug("already terminated");
61 ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
62 skb->destructor = NULL;
63 sp->call = NULL;
64 rxrpc_put_call(call);
65 rxrpc_free_skb(skb);
66 return 0;
67 }
68
69 sk = &rx->sk;
70
71 if (!force) {
72 /* cast skb->rcvbuf to unsigned... It's pointless, but
73 * reduces number of warnings when compiling with -W
74 * --ANK */
75 // ret = -ENOBUFS;
76 // if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
77 // (unsigned int) sk->sk_rcvbuf)
78 // goto out;
79
80 ret = sk_filter(sk, skb);
81 if (ret < 0)
82 goto out;
83 }
84
85 spin_lock_bh(&sk->sk_receive_queue.lock);
86 if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
87 !test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
88 call->socket->sk.sk_state != RXRPC_CLOSE) {
89 skb->destructor = rxrpc_packet_destructor;
90 skb->dev = NULL;
91 skb->sk = sk;
92 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
93
94 if (terminal) {
95 _debug("<<<< TERMINAL MESSAGE >>>>");
96 set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
97 }
98
99 /* allow interception by a kernel service */
100 if (rx->interceptor) {
101 rx->interceptor(sk, call->user_call_ID, skb);
102 spin_unlock_bh(&sk->sk_receive_queue.lock);
103 } else {
104 _net("post skb %p", skb);
105 __skb_queue_tail(&sk->sk_receive_queue, skb);
106 spin_unlock_bh(&sk->sk_receive_queue.lock);
107
108 if (!sock_flag(sk, SOCK_DEAD))
109 sk->sk_data_ready(sk);
110 }
111 skb = NULL;
112 } else {
113 spin_unlock_bh(&sk->sk_receive_queue.lock);
114 }
115 ret = 0;
116
117 out:
118 /* release the socket buffer */
119 if (skb) {
120 skb->destructor = NULL;
121 sp->call = NULL;
122 rxrpc_put_call(call);
123 rxrpc_free_skb(skb);
124 }
125
126 _leave(" = %d", ret);
127 return ret;
128 }
129
130 /*
131 * process a DATA packet, posting the packet to the appropriate queue
132 * - eats the packet if successful
133 */
rxrpc_fast_process_data(struct rxrpc_call * call,struct sk_buff * skb,u32 seq)134 static int rxrpc_fast_process_data(struct rxrpc_call *call,
135 struct sk_buff *skb, u32 seq)
136 {
137 struct rxrpc_skb_priv *sp;
138 bool terminal;
139 int ret, ackbit, ack;
140
141 _enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
142
143 sp = rxrpc_skb(skb);
144 ASSERTCMP(sp->call, ==, NULL);
145
146 spin_lock(&call->lock);
147
148 if (call->state > RXRPC_CALL_COMPLETE)
149 goto discard;
150
151 ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
152 ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
153 ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
154
155 if (seq < call->rx_data_post) {
156 _debug("dup #%u [-%u]", seq, call->rx_data_post);
157 ack = RXRPC_ACK_DUPLICATE;
158 ret = -ENOBUFS;
159 goto discard_and_ack;
160 }
161
162 /* we may already have the packet in the out of sequence queue */
163 ackbit = seq - (call->rx_data_eaten + 1);
164 ASSERTCMP(ackbit, >=, 0);
165 if (__test_and_set_bit(ackbit, call->ackr_window)) {
166 _debug("dup oos #%u [%u,%u]",
167 seq, call->rx_data_eaten, call->rx_data_post);
168 ack = RXRPC_ACK_DUPLICATE;
169 goto discard_and_ack;
170 }
171
172 if (seq >= call->ackr_win_top) {
173 _debug("exceed #%u [%u]", seq, call->ackr_win_top);
174 __clear_bit(ackbit, call->ackr_window);
175 ack = RXRPC_ACK_EXCEEDS_WINDOW;
176 goto discard_and_ack;
177 }
178
179 if (seq == call->rx_data_expect) {
180 clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
181 call->rx_data_expect++;
182 } else if (seq > call->rx_data_expect) {
183 _debug("oos #%u [%u]", seq, call->rx_data_expect);
184 call->rx_data_expect = seq + 1;
185 if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
186 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
187 goto enqueue_and_ack;
188 }
189 goto enqueue_packet;
190 }
191
192 if (seq != call->rx_data_post) {
193 _debug("ahead #%u [%u]", seq, call->rx_data_post);
194 goto enqueue_packet;
195 }
196
197 if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
198 goto protocol_error;
199
200 /* if the packet need security things doing to it, then it goes down
201 * the slow path */
202 if (call->conn->security)
203 goto enqueue_packet;
204
205 sp->call = call;
206 rxrpc_get_call(call);
207 terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
208 !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
209 ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
210 if (ret < 0) {
211 if (ret == -ENOMEM || ret == -ENOBUFS) {
212 __clear_bit(ackbit, call->ackr_window);
213 ack = RXRPC_ACK_NOSPACE;
214 goto discard_and_ack;
215 }
216 goto out;
217 }
218
219 skb = NULL;
220
221 _debug("post #%u", seq);
222 ASSERTCMP(call->rx_data_post, ==, seq);
223 call->rx_data_post++;
224
225 if (sp->hdr.flags & RXRPC_LAST_PACKET)
226 set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
227
228 /* if we've reached an out of sequence packet then we need to drain
229 * that queue into the socket Rx queue now */
230 if (call->rx_data_post == call->rx_first_oos) {
231 _debug("drain rx oos now");
232 read_lock(&call->state_lock);
233 if (call->state < RXRPC_CALL_COMPLETE &&
234 !test_and_set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events))
235 rxrpc_queue_call(call);
236 read_unlock(&call->state_lock);
237 }
238
239 spin_unlock(&call->lock);
240 atomic_inc(&call->ackr_not_idle);
241 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
242 _leave(" = 0 [posted]");
243 return 0;
244
245 protocol_error:
246 ret = -EBADMSG;
247 out:
248 spin_unlock(&call->lock);
249 _leave(" = %d", ret);
250 return ret;
251
252 discard_and_ack:
253 _debug("discard and ACK packet %p", skb);
254 __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
255 discard:
256 spin_unlock(&call->lock);
257 rxrpc_free_skb(skb);
258 _leave(" = 0 [discarded]");
259 return 0;
260
261 enqueue_and_ack:
262 __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
263 enqueue_packet:
264 _net("defer skb %p", skb);
265 spin_unlock(&call->lock);
266 skb_queue_tail(&call->rx_queue, skb);
267 atomic_inc(&call->ackr_not_idle);
268 read_lock(&call->state_lock);
269 if (call->state < RXRPC_CALL_DEAD)
270 rxrpc_queue_call(call);
271 read_unlock(&call->state_lock);
272 _leave(" = 0 [queued]");
273 return 0;
274 }
275
276 /*
277 * assume an implicit ACKALL of the transmission phase of a client socket upon
278 * reception of the first reply packet
279 */
rxrpc_assume_implicit_ackall(struct rxrpc_call * call,u32 serial)280 static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
281 {
282 write_lock_bh(&call->state_lock);
283
284 switch (call->state) {
285 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
286 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
287 call->acks_latest = serial;
288
289 _debug("implicit ACKALL %%%u", call->acks_latest);
290 set_bit(RXRPC_CALL_RCVD_ACKALL, &call->events);
291 write_unlock_bh(&call->state_lock);
292
293 if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
294 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
295 clear_bit(RXRPC_CALL_RESEND, &call->events);
296 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
297 }
298 break;
299
300 default:
301 write_unlock_bh(&call->state_lock);
302 break;
303 }
304 }
305
306 /*
307 * post an incoming packet to the nominated call to deal with
308 * - must get rid of the sk_buff, either by freeing it or by queuing it
309 */
rxrpc_fast_process_packet(struct rxrpc_call * call,struct sk_buff * skb)310 void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
311 {
312 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
313 __be32 _abort_code;
314 u32 serial, hi_serial, seq, abort_code;
315
316 _enter("%p,%p", call, skb);
317
318 ASSERT(!irqs_disabled());
319
320 #if 0 // INJECT RX ERROR
321 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
322 static int skip = 0;
323 if (++skip == 3) {
324 printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
325 skip = 0;
326 goto free_packet;
327 }
328 }
329 #endif
330
331 /* track the latest serial number on this connection for ACK packet
332 * information */
333 serial = ntohl(sp->hdr.serial);
334 hi_serial = atomic_read(&call->conn->hi_serial);
335 while (serial > hi_serial)
336 hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
337 serial);
338
339 /* request ACK generation for any ACK or DATA packet that requests
340 * it */
341 if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
342 _proto("ACK Requested on %%%u", serial);
343 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial, false);
344 }
345
346 switch (sp->hdr.type) {
347 case RXRPC_PACKET_TYPE_ABORT:
348 _debug("abort");
349
350 if (skb_copy_bits(skb, 0, &_abort_code,
351 sizeof(_abort_code)) < 0)
352 goto protocol_error;
353
354 abort_code = ntohl(_abort_code);
355 _proto("Rx ABORT %%%u { %x }", serial, abort_code);
356
357 write_lock_bh(&call->state_lock);
358 if (call->state < RXRPC_CALL_COMPLETE) {
359 call->state = RXRPC_CALL_REMOTELY_ABORTED;
360 call->abort_code = abort_code;
361 set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
362 rxrpc_queue_call(call);
363 }
364 goto free_packet_unlock;
365
366 case RXRPC_PACKET_TYPE_BUSY:
367 _proto("Rx BUSY %%%u", serial);
368
369 if (call->conn->out_clientflag)
370 goto protocol_error;
371
372 write_lock_bh(&call->state_lock);
373 switch (call->state) {
374 case RXRPC_CALL_CLIENT_SEND_REQUEST:
375 call->state = RXRPC_CALL_SERVER_BUSY;
376 set_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
377 rxrpc_queue_call(call);
378 case RXRPC_CALL_SERVER_BUSY:
379 goto free_packet_unlock;
380 default:
381 goto protocol_error_locked;
382 }
383
384 default:
385 _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], serial);
386 goto protocol_error;
387
388 case RXRPC_PACKET_TYPE_DATA:
389 seq = ntohl(sp->hdr.seq);
390
391 _proto("Rx DATA %%%u { #%u }", serial, seq);
392
393 if (seq == 0)
394 goto protocol_error;
395
396 call->ackr_prev_seq = sp->hdr.seq;
397
398 /* received data implicitly ACKs all of the request packets we
399 * sent when we're acting as a client */
400 if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
401 rxrpc_assume_implicit_ackall(call, serial);
402
403 switch (rxrpc_fast_process_data(call, skb, seq)) {
404 case 0:
405 skb = NULL;
406 goto done;
407
408 default:
409 BUG();
410
411 /* data packet received beyond the last packet */
412 case -EBADMSG:
413 goto protocol_error;
414 }
415
416 case RXRPC_PACKET_TYPE_ACKALL:
417 case RXRPC_PACKET_TYPE_ACK:
418 /* ACK processing is done in process context */
419 read_lock_bh(&call->state_lock);
420 if (call->state < RXRPC_CALL_DEAD) {
421 skb_queue_tail(&call->rx_queue, skb);
422 rxrpc_queue_call(call);
423 skb = NULL;
424 }
425 read_unlock_bh(&call->state_lock);
426 goto free_packet;
427 }
428
429 protocol_error:
430 _debug("protocol error");
431 write_lock_bh(&call->state_lock);
432 protocol_error_locked:
433 if (call->state <= RXRPC_CALL_COMPLETE) {
434 call->state = RXRPC_CALL_LOCALLY_ABORTED;
435 call->abort_code = RX_PROTOCOL_ERROR;
436 set_bit(RXRPC_CALL_ABORT, &call->events);
437 rxrpc_queue_call(call);
438 }
439 free_packet_unlock:
440 write_unlock_bh(&call->state_lock);
441 free_packet:
442 rxrpc_free_skb(skb);
443 done:
444 _leave("");
445 }
446
447 /*
448 * split up a jumbo data packet
449 */
rxrpc_process_jumbo_packet(struct rxrpc_call * call,struct sk_buff * jumbo)450 static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
451 struct sk_buff *jumbo)
452 {
453 struct rxrpc_jumbo_header jhdr;
454 struct rxrpc_skb_priv *sp;
455 struct sk_buff *part;
456
457 _enter(",{%u,%u}", jumbo->data_len, jumbo->len);
458
459 sp = rxrpc_skb(jumbo);
460
461 do {
462 sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
463
464 /* make a clone to represent the first subpacket in what's left
465 * of the jumbo packet */
466 part = skb_clone(jumbo, GFP_ATOMIC);
467 if (!part) {
468 /* simply ditch the tail in the event of ENOMEM */
469 pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
470 break;
471 }
472 rxrpc_new_skb(part);
473
474 pskb_trim(part, RXRPC_JUMBO_DATALEN);
475
476 if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
477 goto protocol_error;
478
479 if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
480 goto protocol_error;
481 if (!pskb_pull(jumbo, sizeof(jhdr)))
482 BUG();
483
484 sp->hdr.seq = htonl(ntohl(sp->hdr.seq) + 1);
485 sp->hdr.serial = htonl(ntohl(sp->hdr.serial) + 1);
486 sp->hdr.flags = jhdr.flags;
487 sp->hdr._rsvd = jhdr._rsvd;
488
489 _proto("Rx DATA Jumbo %%%u", ntohl(sp->hdr.serial) - 1);
490
491 rxrpc_fast_process_packet(call, part);
492 part = NULL;
493
494 } while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
495
496 rxrpc_fast_process_packet(call, jumbo);
497 _leave("");
498 return;
499
500 protocol_error:
501 _debug("protocol error");
502 rxrpc_free_skb(part);
503 rxrpc_free_skb(jumbo);
504 write_lock_bh(&call->state_lock);
505 if (call->state <= RXRPC_CALL_COMPLETE) {
506 call->state = RXRPC_CALL_LOCALLY_ABORTED;
507 call->abort_code = RX_PROTOCOL_ERROR;
508 set_bit(RXRPC_CALL_ABORT, &call->events);
509 rxrpc_queue_call(call);
510 }
511 write_unlock_bh(&call->state_lock);
512 _leave("");
513 }
514
515 /*
516 * post an incoming packet to the appropriate call/socket to deal with
517 * - must get rid of the sk_buff, either by freeing it or by queuing it
518 */
rxrpc_post_packet_to_call(struct rxrpc_call * call,struct sk_buff * skb)519 static void rxrpc_post_packet_to_call(struct rxrpc_call *call,
520 struct sk_buff *skb)
521 {
522 struct rxrpc_skb_priv *sp;
523
524 _enter("%p,%p", call, skb);
525
526 sp = rxrpc_skb(skb);
527
528 _debug("extant call [%d]", call->state);
529
530 read_lock(&call->state_lock);
531 switch (call->state) {
532 case RXRPC_CALL_LOCALLY_ABORTED:
533 if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events)) {
534 rxrpc_queue_call(call);
535 goto free_unlock;
536 }
537 case RXRPC_CALL_REMOTELY_ABORTED:
538 case RXRPC_CALL_NETWORK_ERROR:
539 case RXRPC_CALL_DEAD:
540 goto dead_call;
541 case RXRPC_CALL_COMPLETE:
542 case RXRPC_CALL_CLIENT_FINAL_ACK:
543 /* complete server call */
544 if (call->conn->in_clientflag)
545 goto dead_call;
546 /* resend last packet of a completed call */
547 _debug("final ack again");
548 rxrpc_get_call(call);
549 set_bit(RXRPC_CALL_ACK_FINAL, &call->events);
550 rxrpc_queue_call(call);
551 goto free_unlock;
552 default:
553 break;
554 }
555
556 read_unlock(&call->state_lock);
557 rxrpc_get_call(call);
558
559 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
560 sp->hdr.flags & RXRPC_JUMBO_PACKET)
561 rxrpc_process_jumbo_packet(call, skb);
562 else
563 rxrpc_fast_process_packet(call, skb);
564
565 rxrpc_put_call(call);
566 goto done;
567
568 dead_call:
569 if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
570 skb->priority = RX_CALL_DEAD;
571 rxrpc_reject_packet(call->conn->trans->local, skb);
572 goto unlock;
573 }
574 free_unlock:
575 rxrpc_free_skb(skb);
576 unlock:
577 read_unlock(&call->state_lock);
578 done:
579 _leave("");
580 }
581
582 /*
583 * post connection-level events to the connection
584 * - this includes challenges, responses and some aborts
585 */
rxrpc_post_packet_to_conn(struct rxrpc_connection * conn,struct sk_buff * skb)586 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
587 struct sk_buff *skb)
588 {
589 _enter("%p,%p", conn, skb);
590
591 atomic_inc(&conn->usage);
592 skb_queue_tail(&conn->rx_queue, skb);
593 rxrpc_queue_conn(conn);
594 }
595
596 /*
597 * post endpoint-level events to the local endpoint
598 * - this includes debug and version messages
599 */
rxrpc_post_packet_to_local(struct rxrpc_local * local,struct sk_buff * skb)600 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
601 struct sk_buff *skb)
602 {
603 _enter("%p,%p", local, skb);
604
605 atomic_inc(&local->usage);
606 skb_queue_tail(&local->event_queue, skb);
607 rxrpc_queue_work(&local->event_processor);
608 }
609
rxrpc_conn_from_local(struct rxrpc_local * local,struct sk_buff * skb,struct rxrpc_skb_priv * sp)610 static struct rxrpc_connection *rxrpc_conn_from_local(struct rxrpc_local *local,
611 struct sk_buff *skb,
612 struct rxrpc_skb_priv *sp)
613 {
614 struct rxrpc_peer *peer;
615 struct rxrpc_transport *trans;
616 struct rxrpc_connection *conn;
617
618 peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr,
619 udp_hdr(skb)->source);
620 if (IS_ERR(peer))
621 goto cant_find_conn;
622
623 trans = rxrpc_find_transport(local, peer);
624 rxrpc_put_peer(peer);
625 if (!trans)
626 goto cant_find_conn;
627
628 conn = rxrpc_find_connection(trans, &sp->hdr);
629 rxrpc_put_transport(trans);
630 if (!conn)
631 goto cant_find_conn;
632
633 return conn;
634 cant_find_conn:
635 return NULL;
636 }
637
638 /*
639 * handle data received on the local endpoint
640 * - may be called in interrupt context
641 */
rxrpc_data_ready(struct sock * sk)642 void rxrpc_data_ready(struct sock *sk)
643 {
644 struct rxrpc_skb_priv *sp;
645 struct rxrpc_local *local;
646 struct sk_buff *skb;
647 int ret;
648
649 _enter("%p", sk);
650
651 ASSERT(!irqs_disabled());
652
653 read_lock_bh(&rxrpc_local_lock);
654 local = sk->sk_user_data;
655 if (local && atomic_read(&local->usage) > 0)
656 rxrpc_get_local(local);
657 else
658 local = NULL;
659 read_unlock_bh(&rxrpc_local_lock);
660 if (!local) {
661 _leave(" [local dead]");
662 return;
663 }
664
665 skb = skb_recv_datagram(sk, 0, 1, &ret);
666 if (!skb) {
667 rxrpc_put_local(local);
668 if (ret == -EAGAIN)
669 return;
670 _debug("UDP socket error %d", ret);
671 return;
672 }
673
674 rxrpc_new_skb(skb);
675
676 _net("recv skb %p", skb);
677
678 /* we'll probably need to checksum it (didn't call sock_recvmsg) */
679 if (skb_checksum_complete(skb)) {
680 rxrpc_free_skb(skb);
681 rxrpc_put_local(local);
682 UDP_INC_STATS_BH(&init_net, UDP_MIB_INERRORS, 0);
683 _leave(" [CSUM failed]");
684 return;
685 }
686
687 UDP_INC_STATS_BH(&init_net, UDP_MIB_INDATAGRAMS, 0);
688
689 /* the socket buffer we have is owned by UDP, with UDP's data all over
690 * it, but we really want our own */
691 skb_orphan(skb);
692 sp = rxrpc_skb(skb);
693 memset(sp, 0, sizeof(*sp));
694
695 _net("Rx UDP packet from %08x:%04hu",
696 ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
697
698 /* dig out the RxRPC connection details */
699 if (skb_copy_bits(skb, sizeof(struct udphdr), &sp->hdr,
700 sizeof(sp->hdr)) < 0)
701 goto bad_message;
702 if (!pskb_pull(skb, sizeof(struct udphdr) + sizeof(sp->hdr)))
703 BUG();
704
705 _net("Rx RxRPC %s ep=%x call=%x:%x",
706 sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
707 ntohl(sp->hdr.epoch),
708 ntohl(sp->hdr.cid),
709 ntohl(sp->hdr.callNumber));
710
711 if (sp->hdr.type == 0 || sp->hdr.type >= RXRPC_N_PACKET_TYPES) {
712 _proto("Rx Bad Packet Type %u", sp->hdr.type);
713 goto bad_message;
714 }
715
716 if (sp->hdr.type == RXRPC_PACKET_TYPE_VERSION) {
717 rxrpc_post_packet_to_local(local, skb);
718 goto out;
719 }
720
721 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
722 (sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
723 goto bad_message;
724
725 if (sp->hdr.callNumber == 0) {
726 /* This is a connection-level packet. These should be
727 * fairly rare, so the extra overhead of looking them up the
728 * old-fashioned way doesn't really hurt */
729 struct rxrpc_connection *conn;
730
731 conn = rxrpc_conn_from_local(local, skb, sp);
732 if (!conn)
733 goto cant_route_call;
734
735 _debug("CONN %p {%d}", conn, conn->debug_id);
736 rxrpc_post_packet_to_conn(conn, skb);
737 rxrpc_put_connection(conn);
738 } else {
739 struct rxrpc_call *call;
740 u8 in_clientflag = 0;
741
742 if (sp->hdr.flags & RXRPC_CLIENT_INITIATED)
743 in_clientflag = RXRPC_CLIENT_INITIATED;
744 call = rxrpc_find_call_hash(in_clientflag, sp->hdr.cid,
745 sp->hdr.callNumber, sp->hdr.epoch,
746 sp->hdr.serviceId, local, AF_INET,
747 (u8 *)&ip_hdr(skb)->saddr);
748 if (call)
749 rxrpc_post_packet_to_call(call, skb);
750 else
751 goto cant_route_call;
752 }
753
754 out:
755 rxrpc_put_local(local);
756 return;
757
758 cant_route_call:
759 _debug("can't route call");
760 if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
761 sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
762 if (sp->hdr.seq == cpu_to_be32(1)) {
763 _debug("first packet");
764 skb_queue_tail(&local->accept_queue, skb);
765 rxrpc_queue_work(&local->acceptor);
766 rxrpc_put_local(local);
767 _leave(" [incoming]");
768 return;
769 }
770 skb->priority = RX_INVALID_OPERATION;
771 } else {
772 skb->priority = RX_CALL_DEAD;
773 }
774
775 if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
776 _debug("reject type %d",sp->hdr.type);
777 rxrpc_reject_packet(local, skb);
778 }
779 rxrpc_put_local(local);
780 _leave(" [no call]");
781 return;
782
783 bad_message:
784 skb->priority = RX_PROTOCOL_ERROR;
785 rxrpc_reject_packet(local, skb);
786 rxrpc_put_local(local);
787 _leave(" [badmsg]");
788 }
789