?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize
[linux/fpc-iii.git] / net / rxrpc / input.c
blob157be1ff8697be438a7ee6636e37671169fff3df
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC packet reception
3 *
4 * Copyright (C) 2007, 2016 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 <linux/udp.h>
15 #include <linux/in.h>
16 #include <linux/in6.h>
17 #include <linux/icmp.h>
18 #include <linux/gfp.h>
19 #include <net/sock.h>
20 #include <net/af_rxrpc.h>
21 #include <net/ip.h>
22 #include <net/udp.h>
23 #include <net/net_namespace.h>
24 #include "ar-internal.h"
25
26 static void rxrpc_proto_abort(const char *why,
27 struct rxrpc_call *call, rxrpc_seq_t seq)
28 {
29 if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
30 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
31 rxrpc_queue_call(call);
32 }
33 }
34
35 /*
36 * Do TCP-style congestion management [RFC 5681].
37 */
38 static void rxrpc_congestion_management(struct rxrpc_call *call,
39 struct sk_buff *skb,
40 struct rxrpc_ack_summary *summary,
41 rxrpc_serial_t acked_serial)
42 {
43 enum rxrpc_congest_change change = rxrpc_cong_no_change;
44 unsigned int cumulative_acks = call->cong_cumul_acks;
45 unsigned int cwnd = call->cong_cwnd;
46 bool resend = false;
47
48 summary->flight_size =
49 (call->tx_top - call->tx_hard_ack) - summary->nr_acks;
50
51 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
52 summary->retrans_timeo = true;
53 call->cong_ssthresh = max_t(unsigned int,
54 summary->flight_size / 2, 2);
55 cwnd = 1;
56 if (cwnd >= call->cong_ssthresh &&
57 call->cong_mode == RXRPC_CALL_SLOW_START) {
58 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
59 call->cong_tstamp = skb->tstamp;
60 cumulative_acks = 0;
61 }
62 }
63
64 cumulative_acks += summary->nr_new_acks;
65 cumulative_acks += summary->nr_rot_new_acks;
66 if (cumulative_acks > 255)
67 cumulative_acks = 255;
68
69 summary->mode = call->cong_mode;
70 summary->cwnd = call->cong_cwnd;
71 summary->ssthresh = call->cong_ssthresh;
72 summary->cumulative_acks = cumulative_acks;
73 summary->dup_acks = call->cong_dup_acks;
74
75 switch (call->cong_mode) {
76 case RXRPC_CALL_SLOW_START:
77 if (summary->nr_nacks > 0)
78 goto packet_loss_detected;
79 if (summary->cumulative_acks > 0)
80 cwnd += 1;
81 if (cwnd >= call->cong_ssthresh) {
82 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
83 call->cong_tstamp = skb->tstamp;
84 }
85 goto out;
86
87 case RXRPC_CALL_CONGEST_AVOIDANCE:
88 if (summary->nr_nacks > 0)
89 goto packet_loss_detected;
90
91 /* We analyse the number of packets that get ACK'd per RTT
92 * period and increase the window if we managed to fill it.
93 */
94 if (call->peer->rtt_usage == 0)
95 goto out;
96 if (ktime_before(skb->tstamp,
97 ktime_add_ns(call->cong_tstamp,
98 call->peer->rtt)))
99 goto out_no_clear_ca;
100 change = rxrpc_cong_rtt_window_end;
101 call->cong_tstamp = skb->tstamp;
102 if (cumulative_acks >= cwnd)
103 cwnd++;
104 goto out;
105
106 case RXRPC_CALL_PACKET_LOSS:
107 if (summary->nr_nacks == 0)
108 goto resume_normality;
109
110 if (summary->new_low_nack) {
111 change = rxrpc_cong_new_low_nack;
112 call->cong_dup_acks = 1;
113 if (call->cong_extra > 1)
114 call->cong_extra = 1;
115 goto send_extra_data;
116 }
117
118 call->cong_dup_acks++;
119 if (call->cong_dup_acks < 3)
120 goto send_extra_data;
121
122 change = rxrpc_cong_begin_retransmission;
123 call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
124 call->cong_ssthresh = max_t(unsigned int,
125 summary->flight_size / 2, 2);
126 cwnd = call->cong_ssthresh + 3;
127 call->cong_extra = 0;
128 call->cong_dup_acks = 0;
129 resend = true;
130 goto out;
131
132 case RXRPC_CALL_FAST_RETRANSMIT:
133 if (!summary->new_low_nack) {
134 if (summary->nr_new_acks == 0)
135 cwnd += 1;
136 call->cong_dup_acks++;
137 if (call->cong_dup_acks == 2) {
138 change = rxrpc_cong_retransmit_again;
139 call->cong_dup_acks = 0;
140 resend = true;
141 }
142 } else {
143 change = rxrpc_cong_progress;
144 cwnd = call->cong_ssthresh;
145 if (summary->nr_nacks == 0)
146 goto resume_normality;
147 }
148 goto out;
149
150 default:
151 BUG();
152 goto out;
153 }
154
155 resume_normality:
156 change = rxrpc_cong_cleared_nacks;
157 call->cong_dup_acks = 0;
158 call->cong_extra = 0;
159 call->cong_tstamp = skb->tstamp;
160 if (cwnd < call->cong_ssthresh)
161 call->cong_mode = RXRPC_CALL_SLOW_START;
162 else
163 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
164 out:
165 cumulative_acks = 0;
166 out_no_clear_ca:
167 if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
168 cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
169 call->cong_cwnd = cwnd;
170 call->cong_cumul_acks = cumulative_acks;
171 trace_rxrpc_congest(call, summary, acked_serial, change);
172 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
173 rxrpc_queue_call(call);
174 return;
175
176 packet_loss_detected:
177 change = rxrpc_cong_saw_nack;
178 call->cong_mode = RXRPC_CALL_PACKET_LOSS;
179 call->cong_dup_acks = 0;
180 goto send_extra_data;
181
182 send_extra_data:
183 /* Send some previously unsent DATA if we have some to advance the ACK
184 * state.
185 */
186 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
187 RXRPC_TX_ANNO_LAST ||
188 summary->nr_acks != call->tx_top - call->tx_hard_ack) {
189 call->cong_extra++;
190 wake_up(&call->waitq);
191 }
192 goto out_no_clear_ca;
193 }
194
195 /*
196 * Ping the other end to fill our RTT cache and to retrieve the rwind
197 * and MTU parameters.
198 */
199 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb)
200 {
201 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
202 ktime_t now = skb->tstamp;
203
204 if (call->peer->rtt_usage < 3 ||
205 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
206 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
207 true, true,
208 rxrpc_propose_ack_ping_for_params);
209 }
210
211 /*
212 * Apply a hard ACK by advancing the Tx window.
213 */
214 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
215 struct rxrpc_ack_summary *summary)
216 {
217 struct sk_buff *skb, *list = NULL;
218 bool rot_last = false;
219 int ix;
220 u8 annotation;
221
222 if (call->acks_lowest_nak == call->tx_hard_ack) {
223 call->acks_lowest_nak = to;
224 } else if (before_eq(call->acks_lowest_nak, to)) {
225 summary->new_low_nack = true;
226 call->acks_lowest_nak = to;
227 }
228
229 spin_lock(&call->lock);
230
231 while (before(call->tx_hard_ack, to)) {
232 call->tx_hard_ack++;
233 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
234 skb = call->rxtx_buffer[ix];
235 annotation = call->rxtx_annotations[ix];
236 rxrpc_see_skb(skb, rxrpc_skb_rotated);
237 call->rxtx_buffer[ix] = NULL;
238 call->rxtx_annotations[ix] = 0;
239 skb->next = list;
240 list = skb;
241
242 if (annotation & RXRPC_TX_ANNO_LAST) {
243 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
244 rot_last = true;
245 }
246 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
247 summary->nr_rot_new_acks++;
248 }
249
250 spin_unlock(&call->lock);
251
252 trace_rxrpc_transmit(call, (rot_last ?
253 rxrpc_transmit_rotate_last :
254 rxrpc_transmit_rotate));
255 wake_up(&call->waitq);
256
257 while (list) {
258 skb = list;
259 list = skb->next;
260 skb_mark_not_on_list(skb);
261 rxrpc_free_skb(skb, rxrpc_skb_freed);
262 }
263
264 return rot_last;
265 }
266
267 /*
268 * End the transmission phase of a call.
269 *
270 * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
271 * or a final ACK packet.
272 */
273 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
274 const char *abort_why)
275 {
276 unsigned int state;
277
278 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
279
280 write_lock(&call->state_lock);
281
282 state = call->state;
283 switch (state) {
284 case RXRPC_CALL_CLIENT_SEND_REQUEST:
285 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
286 if (reply_begun)
287 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
288 else
289 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
290 break;
291
292 case RXRPC_CALL_SERVER_AWAIT_ACK:
293 __rxrpc_call_completed(call);
294 rxrpc_notify_socket(call);
295 state = call->state;
296 break;
297
298 default:
299 goto bad_state;
300 }
301
302 write_unlock(&call->state_lock);
303 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
304 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
305 else
306 trace_rxrpc_transmit(call, rxrpc_transmit_end);
307 _leave(" = ok");
308 return true;
309
310 bad_state:
311 write_unlock(&call->state_lock);
312 kdebug("end_tx %s", rxrpc_call_states[call->state]);
313 rxrpc_proto_abort(abort_why, call, call->tx_top);
314 return false;
315 }
316
317 /*
318 * Begin the reply reception phase of a call.
319 */
320 static bool rxrpc_receiving_reply(struct rxrpc_call *call)
321 {
322 struct rxrpc_ack_summary summary = { 0 };
323 unsigned long now, timo;
324 rxrpc_seq_t top = READ_ONCE(call->tx_top);
325
326 if (call->ackr_reason) {
327 spin_lock_bh(&call->lock);
328 call->ackr_reason = 0;
329 spin_unlock_bh(&call->lock);
330 now = jiffies;
331 timo = now + MAX_JIFFY_OFFSET;
332 WRITE_ONCE(call->resend_at, timo);
333 WRITE_ONCE(call->ack_at, timo);
334 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
335 }
336
337 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
338 if (!rxrpc_rotate_tx_window(call, top, &summary)) {
339 rxrpc_proto_abort("TXL", call, top);
340 return false;
341 }
342 }
343 if (!rxrpc_end_tx_phase(call, true, "ETD"))
344 return false;
345 call->tx_phase = false;
346 return true;
347 }
348
349 /*
350 * Scan a data packet to validate its structure and to work out how many
351 * subpackets it contains.
352 *
353 * A jumbo packet is a collection of consecutive packets glued together with
354 * little headers between that indicate how to change the initial header for
355 * each subpacket.
356 *
357 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
358 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
359 * size.
360 */
361 static bool rxrpc_validate_data(struct sk_buff *skb)
362 {
363 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
364 unsigned int offset = sizeof(struct rxrpc_wire_header);
365 unsigned int len = skb->len;
366 u8 flags = sp->hdr.flags;
367
368 for (;;) {
369 if (flags & RXRPC_REQUEST_ACK)
370 __set_bit(sp->nr_subpackets, sp->rx_req_ack);
371 sp->nr_subpackets++;
372
373 if (!(flags & RXRPC_JUMBO_PACKET))
374 break;
375
376 if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
377 goto protocol_error;
378 if (flags & RXRPC_LAST_PACKET)
379 goto protocol_error;
380 offset += RXRPC_JUMBO_DATALEN;
381 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
382 goto protocol_error;
383 offset += sizeof(struct rxrpc_jumbo_header);
384 }
385
386 if (flags & RXRPC_LAST_PACKET)
387 sp->rx_flags |= RXRPC_SKB_INCL_LAST;
388 return true;
389
390 protocol_error:
391 return false;
392 }
393
394 /*
395 * Handle reception of a duplicate packet.
396 *
397 * We have to take care to avoid an attack here whereby we're given a series of
398 * jumbograms, each with a sequence number one before the preceding one and
399 * filled up to maximum UDP size. If they never send us the first packet in
400 * the sequence, they can cause us to have to hold on to around 2MiB of kernel
401 * space until the call times out.
402 *
403 * We limit the space usage by only accepting three duplicate jumbo packets per
404 * call. After that, we tell the other side we're no longer accepting jumbos
405 * (that information is encoded in the ACK packet).
406 */
407 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
408 bool is_jumbo, bool *_jumbo_bad)
409 {
410 /* Discard normal packets that are duplicates. */
411 if (is_jumbo)
412 return;
413
414 /* Skip jumbo subpackets that are duplicates. When we've had three or
415 * more partially duplicate jumbo packets, we refuse to take any more
416 * jumbos for this call.
417 */
418 if (!*_jumbo_bad) {
419 call->nr_jumbo_bad++;
420 *_jumbo_bad = true;
421 }
422 }
423
424 /*
425 * Process a DATA packet, adding the packet to the Rx ring. The caller's
426 * packet ref must be passed on or discarded.
427 */
428 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
429 {
430 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
431 enum rxrpc_call_state state;
432 unsigned int j;
433 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
434 rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
435 bool immediate_ack = false, jumbo_bad = false;
436 u8 ack = 0;
437
438 _enter("{%u,%u},{%u,%u}",
439 call->rx_hard_ack, call->rx_top, skb->len, seq0);
440
441 _proto("Rx DATA %%%u { #%u f=%02x n=%u }",
442 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
443
444 state = READ_ONCE(call->state);
445 if (state >= RXRPC_CALL_COMPLETE) {
446 rxrpc_free_skb(skb, rxrpc_skb_freed);
447 return;
448 }
449
450 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
451 unsigned long timo = READ_ONCE(call->next_req_timo);
452 unsigned long now, expect_req_by;
453
454 if (timo) {
455 now = jiffies;
456 expect_req_by = now + timo;
457 WRITE_ONCE(call->expect_req_by, expect_req_by);
458 rxrpc_reduce_call_timer(call, expect_req_by, now,
459 rxrpc_timer_set_for_idle);
460 }
461 }
462
463 spin_lock(&call->input_lock);
464
465 /* Received data implicitly ACKs all of the request packets we sent
466 * when we're acting as a client.
467 */
468 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
469 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
470 !rxrpc_receiving_reply(call))
471 goto unlock;
472
473 call->ackr_prev_seq = seq0;
474 hard_ack = READ_ONCE(call->rx_hard_ack);
475
476 if (sp->nr_subpackets > 1) {
477 if (call->nr_jumbo_bad > 3) {
478 ack = RXRPC_ACK_NOSPACE;
479 ack_serial = serial;
480 goto ack;
481 }
482 }
483
484 for (j = 0; j < sp->nr_subpackets; j++) {
485 rxrpc_serial_t serial = sp->hdr.serial + j;
486 rxrpc_seq_t seq = seq0 + j;
487 unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
488 bool terminal = (j == sp->nr_subpackets - 1);
489 bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST);
490 u8 flags, annotation = j;
491
492 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
493 j, serial, seq, terminal, last);
494
495 if (last) {
496 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
497 seq != call->rx_top) {
498 rxrpc_proto_abort("LSN", call, seq);
499 goto unlock;
500 }
501 } else {
502 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
503 after_eq(seq, call->rx_top)) {
504 rxrpc_proto_abort("LSA", call, seq);
505 goto unlock;
506 }
507 }
508
509 flags = 0;
510 if (last)
511 flags |= RXRPC_LAST_PACKET;
512 if (!terminal)
513 flags |= RXRPC_JUMBO_PACKET;
514 if (test_bit(j, sp->rx_req_ack))
515 flags |= RXRPC_REQUEST_ACK;
516 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
517
518 if (before_eq(seq, hard_ack)) {
519 ack = RXRPC_ACK_DUPLICATE;
520 ack_serial = serial;
521 continue;
522 }
523
524 if (call->rxtx_buffer[ix]) {
525 rxrpc_input_dup_data(call, seq, sp->nr_subpackets > 1,
526 &jumbo_bad);
527 if (ack != RXRPC_ACK_DUPLICATE) {
528 ack = RXRPC_ACK_DUPLICATE;
529 ack_serial = serial;
530 }
531 immediate_ack = true;
532 continue;
533 }
534
535 if (after(seq, hard_ack + call->rx_winsize)) {
536 ack = RXRPC_ACK_EXCEEDS_WINDOW;
537 ack_serial = serial;
538 if (flags & RXRPC_JUMBO_PACKET) {
539 if (!jumbo_bad) {
540 call->nr_jumbo_bad++;
541 jumbo_bad = true;
542 }
543 }
544
545 goto ack;
546 }
547
548 if (flags & RXRPC_REQUEST_ACK && !ack) {
549 ack = RXRPC_ACK_REQUESTED;
550 ack_serial = serial;
551 }
552
553 /* Queue the packet. We use a couple of memory barriers here as need
554 * to make sure that rx_top is perceived to be set after the buffer
555 * pointer and that the buffer pointer is set after the annotation and
556 * the skb data.
557 *
558 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
559 * and also rxrpc_fill_out_ack().
560 */
561 if (!terminal)
562 rxrpc_get_skb(skb, rxrpc_skb_got);
563 call->rxtx_annotations[ix] = annotation;
564 smp_wmb();
565 call->rxtx_buffer[ix] = skb;
566 if (after(seq, call->rx_top)) {
567 smp_store_release(&call->rx_top, seq);
568 } else if (before(seq, call->rx_top)) {
569 /* Send an immediate ACK if we fill in a hole */
570 if (!ack) {
571 ack = RXRPC_ACK_DELAY;
572 ack_serial = serial;
573 }
574 immediate_ack = true;
575 }
576
577 if (terminal) {
578 /* From this point on, we're not allowed to touch the
579 * packet any longer as its ref now belongs to the Rx
580 * ring.
581 */
582 skb = NULL;
583 }
584
585 if (last) {
586 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
587 if (!ack) {
588 ack = RXRPC_ACK_DELAY;
589 ack_serial = serial;
590 }
591 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
592 } else {
593 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
594 }
595
596 if (after_eq(seq, call->rx_expect_next)) {
597 if (after(seq, call->rx_expect_next)) {
598 _net("OOS %u > %u", seq, call->rx_expect_next);
599 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
600 ack_serial = serial;
601 }
602 call->rx_expect_next = seq + 1;
603 }
604 }
605
606 ack:
607 if (ack)
608 rxrpc_propose_ACK(call, ack, ack_serial,
609 immediate_ack, true,
610 rxrpc_propose_ack_input_data);
611 else
612 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
613 false, true,
614 rxrpc_propose_ack_input_data);
615
616 if (seq0 == READ_ONCE(call->rx_hard_ack) + 1) {
617 trace_rxrpc_notify_socket(call->debug_id, serial);
618 rxrpc_notify_socket(call);
619 }
620
621 unlock:
622 spin_unlock(&call->input_lock);
623 rxrpc_free_skb(skb, rxrpc_skb_freed);
624 _leave(" [queued]");
625 }
626
627 /*
628 * Process a requested ACK.
629 */
630 static void rxrpc_input_requested_ack(struct rxrpc_call *call,
631 ktime_t resp_time,
632 rxrpc_serial_t orig_serial,
633 rxrpc_serial_t ack_serial)
634 {
635 struct rxrpc_skb_priv *sp;
636 struct sk_buff *skb;
637 ktime_t sent_at;
638 int ix;
639
640 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
641 skb = call->rxtx_buffer[ix];
642 if (!skb)
643 continue;
644
645 sent_at = skb->tstamp;
646 smp_rmb(); /* Read timestamp before serial. */
647 sp = rxrpc_skb(skb);
648 if (sp->hdr.serial != orig_serial)
649 continue;
650 goto found;
651 }
652
653 return;
654
655 found:
656 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
657 orig_serial, ack_serial, sent_at, resp_time);
658 }
659
660 /*
661 * Process the response to a ping that we sent to find out if we lost an ACK.
662 *
663 * If we got back a ping response that indicates a lower tx_top than what we
664 * had at the time of the ping transmission, we adjudge all the DATA packets
665 * sent between the response tx_top and the ping-time tx_top to have been lost.
666 */
667 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
668 {
669 rxrpc_seq_t top, bottom, seq;
670 bool resend = false;
671
672 spin_lock_bh(&call->lock);
673
674 bottom = call->tx_hard_ack + 1;
675 top = call->acks_lost_top;
676 if (before(bottom, top)) {
677 for (seq = bottom; before_eq(seq, top); seq++) {
678 int ix = seq & RXRPC_RXTX_BUFF_MASK;
679 u8 annotation = call->rxtx_annotations[ix];
680 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
681
682 if (anno_type != RXRPC_TX_ANNO_UNACK)
683 continue;
684 annotation &= ~RXRPC_TX_ANNO_MASK;
685 annotation |= RXRPC_TX_ANNO_RETRANS;
686 call->rxtx_annotations[ix] = annotation;
687 resend = true;
688 }
689 }
690
691 spin_unlock_bh(&call->lock);
692
693 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
694 rxrpc_queue_call(call);
695 }
696
697 /*
698 * Process a ping response.
699 */
700 static void rxrpc_input_ping_response(struct rxrpc_call *call,
701 ktime_t resp_time,
702 rxrpc_serial_t orig_serial,
703 rxrpc_serial_t ack_serial)
704 {
705 rxrpc_serial_t ping_serial;
706 ktime_t ping_time;
707
708 ping_time = call->ping_time;
709 smp_rmb();
710 ping_serial = READ_ONCE(call->ping_serial);
711
712 if (orig_serial == call->acks_lost_ping)
713 rxrpc_input_check_for_lost_ack(call);
714
715 if (before(orig_serial, ping_serial) ||
716 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
717 return;
718 if (after(orig_serial, ping_serial))
719 return;
720
721 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
722 orig_serial, ack_serial, ping_time, resp_time);
723 }
724
725 /*
726 * Process the extra information that may be appended to an ACK packet
727 */
728 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
729 struct rxrpc_ackinfo *ackinfo)
730 {
731 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
732 struct rxrpc_peer *peer;
733 unsigned int mtu;
734 bool wake = false;
735 u32 rwind = ntohl(ackinfo->rwind);
736
737 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
738 sp->hdr.serial,
739 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
740 rwind, ntohl(ackinfo->jumbo_max));
741
742 if (call->tx_winsize != rwind) {
743 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
744 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
745 if (rwind > call->tx_winsize)
746 wake = true;
747 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
748 ntohl(ackinfo->rwind), wake);
749 call->tx_winsize = rwind;
750 }
751
752 if (call->cong_ssthresh > rwind)
753 call->cong_ssthresh = rwind;
754
755 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
756
757 peer = call->peer;
758 if (mtu < peer->maxdata) {
759 spin_lock_bh(&peer->lock);
760 peer->maxdata = mtu;
761 peer->mtu = mtu + peer->hdrsize;
762 spin_unlock_bh(&peer->lock);
763 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
764 }
765
766 if (wake)
767 wake_up(&call->waitq);
768 }
769
770 /*
771 * Process individual soft ACKs.
772 *
773 * Each ACK in the array corresponds to one packet and can be either an ACK or
774 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
775 * packets that lie beyond the end of the ACK list are scheduled for resend by
776 * the timer on the basis that the peer might just not have processed them at
777 * the time the ACK was sent.
778 */
779 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
780 rxrpc_seq_t seq, int nr_acks,
781 struct rxrpc_ack_summary *summary)
782 {
783 int ix;
784 u8 annotation, anno_type;
785
786 for (; nr_acks > 0; nr_acks--, seq++) {
787 ix = seq & RXRPC_RXTX_BUFF_MASK;
788 annotation = call->rxtx_annotations[ix];
789 anno_type = annotation & RXRPC_TX_ANNO_MASK;
790 annotation &= ~RXRPC_TX_ANNO_MASK;
791 switch (*acks++) {
792 case RXRPC_ACK_TYPE_ACK:
793 summary->nr_acks++;
794 if (anno_type == RXRPC_TX_ANNO_ACK)
795 continue;
796 summary->nr_new_acks++;
797 call->rxtx_annotations[ix] =
798 RXRPC_TX_ANNO_ACK | annotation;
799 break;
800 case RXRPC_ACK_TYPE_NACK:
801 if (!summary->nr_nacks &&
802 call->acks_lowest_nak != seq) {
803 call->acks_lowest_nak = seq;
804 summary->new_low_nack = true;
805 }
806 summary->nr_nacks++;
807 if (anno_type == RXRPC_TX_ANNO_NAK)
808 continue;
809 summary->nr_new_nacks++;
810 if (anno_type == RXRPC_TX_ANNO_RETRANS)
811 continue;
812 call->rxtx_annotations[ix] =
813 RXRPC_TX_ANNO_NAK | annotation;
814 break;
815 default:
816 return rxrpc_proto_abort("SFT", call, 0);
817 }
818 }
819 }
820
821 /*
822 * Process an ACK packet.
823 *
824 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
825 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
826 *
827 * A hard-ACK means that a packet has been processed and may be discarded; a
828 * soft-ACK means that the packet may be discarded and retransmission
829 * requested. A phase is complete when all packets are hard-ACK'd.
830 */
831 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
832 {
833 struct rxrpc_ack_summary summary = { 0 };
834 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
835 union {
836 struct rxrpc_ackpacket ack;
837 struct rxrpc_ackinfo info;
838 u8 acks[RXRPC_MAXACKS];
839 } buf;
840 rxrpc_serial_t acked_serial;
841 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
842 int nr_acks, offset, ioffset;
843
844 _enter("");
845
846 offset = sizeof(struct rxrpc_wire_header);
847 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
848 _debug("extraction failure");
849 return rxrpc_proto_abort("XAK", call, 0);
850 }
851 offset += sizeof(buf.ack);
852
853 acked_serial = ntohl(buf.ack.serial);
854 first_soft_ack = ntohl(buf.ack.firstPacket);
855 prev_pkt = ntohl(buf.ack.previousPacket);
856 hard_ack = first_soft_ack - 1;
857 nr_acks = buf.ack.nAcks;
858 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
859 buf.ack.reason : RXRPC_ACK__INVALID);
860
861 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
862 first_soft_ack, prev_pkt,
863 summary.ack_reason, nr_acks);
864
865 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
866 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
867 sp->hdr.serial);
868 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
869 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
870 sp->hdr.serial);
871
872 if (buf.ack.reason == RXRPC_ACK_PING) {
873 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
874 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
875 sp->hdr.serial, true, true,
876 rxrpc_propose_ack_respond_to_ping);
877 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
878 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
879 sp->hdr.serial, true, true,
880 rxrpc_propose_ack_respond_to_ack);
881 }
882
883 /* Discard any out-of-order or duplicate ACKs (outside lock). */
884 if (before(first_soft_ack, call->ackr_first_seq) ||
885 before(prev_pkt, call->ackr_prev_seq))
886 return;
887
888 buf.info.rxMTU = 0;
889 ioffset = offset + nr_acks + 3;
890 if (skb->len >= ioffset + sizeof(buf.info) &&
891 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
892 return rxrpc_proto_abort("XAI", call, 0);
893
894 spin_lock(&call->input_lock);
895
896 /* Discard any out-of-order or duplicate ACKs (inside lock). */
897 if (before(first_soft_ack, call->ackr_first_seq) ||
898 before(prev_pkt, call->ackr_prev_seq))
899 goto out;
900 call->acks_latest_ts = skb->tstamp;
901 call->acks_latest = sp->hdr.serial;
902
903 call->ackr_first_seq = first_soft_ack;
904 call->ackr_prev_seq = prev_pkt;
905
906 /* Parse rwind and mtu sizes if provided. */
907 if (buf.info.rxMTU)
908 rxrpc_input_ackinfo(call, skb, &buf.info);
909
910 if (first_soft_ack == 0) {
911 rxrpc_proto_abort("AK0", call, 0);
912 goto out;
913 }
914
915 /* Ignore ACKs unless we are or have just been transmitting. */
916 switch (READ_ONCE(call->state)) {
917 case RXRPC_CALL_CLIENT_SEND_REQUEST:
918 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
919 case RXRPC_CALL_SERVER_SEND_REPLY:
920 case RXRPC_CALL_SERVER_AWAIT_ACK:
921 break;
922 default:
923 goto out;
924 }
925
926 if (before(hard_ack, call->tx_hard_ack) ||
927 after(hard_ack, call->tx_top)) {
928 rxrpc_proto_abort("AKW", call, 0);
929 goto out;
930 }
931 if (nr_acks > call->tx_top - hard_ack) {
932 rxrpc_proto_abort("AKN", call, 0);
933 goto out;
934 }
935
936 if (after(hard_ack, call->tx_hard_ack)) {
937 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
938 rxrpc_end_tx_phase(call, false, "ETA");
939 goto out;
940 }
941 }
942
943 if (nr_acks > 0) {
944 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
945 rxrpc_proto_abort("XSA", call, 0);
946 goto out;
947 }
948 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
949 &summary);
950 }
951
952 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
953 RXRPC_TX_ANNO_LAST &&
954 summary.nr_acks == call->tx_top - hard_ack &&
955 rxrpc_is_client_call(call))
956 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
957 false, true,
958 rxrpc_propose_ack_ping_for_lost_reply);
959
960 rxrpc_congestion_management(call, skb, &summary, acked_serial);
961 out:
962 spin_unlock(&call->input_lock);
963 }
964
965 /*
966 * Process an ACKALL packet.
967 */
968 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
969 {
970 struct rxrpc_ack_summary summary = { 0 };
971 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
972
973 _proto("Rx ACKALL %%%u", sp->hdr.serial);
974
975 spin_lock(&call->input_lock);
976
977 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
978 rxrpc_end_tx_phase(call, false, "ETL");
979
980 spin_unlock(&call->input_lock);
981 }
982
983 /*
984 * Process an ABORT packet directed at a call.
985 */
986 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
987 {
988 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
989 __be32 wtmp;
990 u32 abort_code = RX_CALL_DEAD;
991
992 _enter("");
993
994 if (skb->len >= 4 &&
995 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
996 &wtmp, sizeof(wtmp)) >= 0)
997 abort_code = ntohl(wtmp);
998
999 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
1000
1001 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
1002
1003 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
1004 abort_code, -ECONNABORTED))
1005 rxrpc_notify_socket(call);
1006 }
1007
1008 /*
1009 * Process an incoming call packet.
1010 */
1011 static void rxrpc_input_call_packet(struct rxrpc_call *call,
1012 struct sk_buff *skb)
1013 {
1014 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1015 unsigned long timo;
1016
1017 _enter("%p,%p", call, skb);
1018
1019 timo = READ_ONCE(call->next_rx_timo);
1020 if (timo) {
1021 unsigned long now = jiffies, expect_rx_by;
1022
1023 expect_rx_by = now + timo;
1024 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
1025 rxrpc_reduce_call_timer(call, expect_rx_by, now,
1026 rxrpc_timer_set_for_normal);
1027 }
1028
1029 switch (sp->hdr.type) {
1030 case RXRPC_PACKET_TYPE_DATA:
1031 rxrpc_input_data(call, skb);
1032 goto no_free;
1033
1034 case RXRPC_PACKET_TYPE_ACK:
1035 rxrpc_input_ack(call, skb);
1036 break;
1037
1038 case RXRPC_PACKET_TYPE_BUSY:
1039 _proto("Rx BUSY %%%u", sp->hdr.serial);
1040
1041 /* Just ignore BUSY packets from the server; the retry and
1042 * lifespan timers will take care of business. BUSY packets
1043 * from the client don't make sense.
1044 */
1045 break;
1046
1047 case RXRPC_PACKET_TYPE_ABORT:
1048 rxrpc_input_abort(call, skb);
1049 break;
1050
1051 case RXRPC_PACKET_TYPE_ACKALL:
1052 rxrpc_input_ackall(call, skb);
1053 break;
1054
1055 default:
1056 break;
1057 }
1058
1059 rxrpc_free_skb(skb, rxrpc_skb_freed);
1060 no_free:
1061 _leave("");
1062 }
1063
1064 /*
1065 * Handle a new service call on a channel implicitly completing the preceding
1066 * call on that channel. This does not apply to client conns.
1067 *
1068 * TODO: If callNumber > call_id + 1, renegotiate security.
1069 */
1070 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
1071 struct rxrpc_connection *conn,
1072 struct rxrpc_call *call)
1073 {
1074 switch (READ_ONCE(call->state)) {
1075 case RXRPC_CALL_SERVER_AWAIT_ACK:
1076 rxrpc_call_completed(call);
1077 /* Fall through */
1078 case RXRPC_CALL_COMPLETE:
1079 break;
1080 default:
1081 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
1082 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
1083 rxrpc_queue_call(call);
1084 }
1085 trace_rxrpc_improper_term(call);
1086 break;
1087 }
1088
1089 spin_lock(&rx->incoming_lock);
1090 __rxrpc_disconnect_call(conn, call);
1091 spin_unlock(&rx->incoming_lock);
1092 rxrpc_notify_socket(call);
1093 }
1094
1095 /*
1096 * post connection-level events to the connection
1097 * - this includes challenges, responses, some aborts and call terminal packet
1098 * retransmission.
1099 */
1100 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
1101 struct sk_buff *skb)
1102 {
1103 _enter("%p,%p", conn, skb);
1104
1105 skb_queue_tail(&conn->rx_queue, skb);
1106 rxrpc_queue_conn(conn);
1107 }
1108
1109 /*
1110 * post endpoint-level events to the local endpoint
1111 * - this includes debug and version messages
1112 */
1113 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
1114 struct sk_buff *skb)
1115 {
1116 _enter("%p,%p", local, skb);
1117
1118 if (rxrpc_get_local_maybe(local)) {
1119 skb_queue_tail(&local->event_queue, skb);
1120 rxrpc_queue_local(local);
1121 } else {
1122 rxrpc_free_skb(skb, rxrpc_skb_freed);
1123 }
1124 }
1125
1126 /*
1127 * put a packet up for transport-level abort
1128 */
1129 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
1130 {
1131 CHECK_SLAB_OKAY(&local->usage);
1132
1133 if (rxrpc_get_local_maybe(local)) {
1134 skb_queue_tail(&local->reject_queue, skb);
1135 rxrpc_queue_local(local);
1136 } else {
1137 rxrpc_free_skb(skb, rxrpc_skb_freed);
1138 }
1139 }
1140
1141 /*
1142 * Extract the wire header from a packet and translate the byte order.
1143 */
1144 static noinline
1145 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
1146 {
1147 struct rxrpc_wire_header whdr;
1148
1149 /* dig out the RxRPC connection details */
1150 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
1151 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
1152 tracepoint_string("bad_hdr"));
1153 return -EBADMSG;
1154 }
1155
1156 memset(sp, 0, sizeof(*sp));
1157 sp->hdr.epoch = ntohl(whdr.epoch);
1158 sp->hdr.cid = ntohl(whdr.cid);
1159 sp->hdr.callNumber = ntohl(whdr.callNumber);
1160 sp->hdr.seq = ntohl(whdr.seq);
1161 sp->hdr.serial = ntohl(whdr.serial);
1162 sp->hdr.flags = whdr.flags;
1163 sp->hdr.type = whdr.type;
1164 sp->hdr.userStatus = whdr.userStatus;
1165 sp->hdr.securityIndex = whdr.securityIndex;
1166 sp->hdr._rsvd = ntohs(whdr._rsvd);
1167 sp->hdr.serviceId = ntohs(whdr.serviceId);
1168 return 0;
1169 }
1170
1171 /*
1172 * handle data received on the local endpoint
1173 * - may be called in interrupt context
1174 *
1175 * [!] Note that as this is called from the encap_rcv hook, the socket is not
1176 * held locked by the caller and nothing prevents sk_user_data on the UDP from
1177 * being cleared in the middle of processing this function.
1178 *
1179 * Called with the RCU read lock held from the IP layer via UDP.
1180 */
1181 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
1182 {
1183 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
1184 struct rxrpc_connection *conn;
1185 struct rxrpc_channel *chan;
1186 struct rxrpc_call *call = NULL;
1187 struct rxrpc_skb_priv *sp;
1188 struct rxrpc_peer *peer = NULL;
1189 struct rxrpc_sock *rx = NULL;
1190 unsigned int channel;
1191
1192 _enter("%p", udp_sk);
1193
1194 if (unlikely(!local)) {
1195 kfree_skb(skb);
1196 return 0;
1197 }
1198 if (skb->tstamp == 0)
1199 skb->tstamp = ktime_get_real();
1200
1201 rxrpc_new_skb(skb, rxrpc_skb_received);
1202
1203 skb_pull(skb, sizeof(struct udphdr));
1204
1205 /* The UDP protocol already released all skb resources;
1206 * we are free to add our own data there.
1207 */
1208 sp = rxrpc_skb(skb);
1209
1210 /* dig out the RxRPC connection details */
1211 if (rxrpc_extract_header(sp, skb) < 0)
1212 goto bad_message;
1213
1214 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1215 static int lose;
1216 if ((lose++ & 7) == 7) {
1217 trace_rxrpc_rx_lose(sp);
1218 rxrpc_free_skb(skb, rxrpc_skb_lost);
1219 return 0;
1220 }
1221 }
1222
1223 if (skb->tstamp == 0)
1224 skb->tstamp = ktime_get_real();
1225 trace_rxrpc_rx_packet(sp);
1226
1227 switch (sp->hdr.type) {
1228 case RXRPC_PACKET_TYPE_VERSION:
1229 if (rxrpc_to_client(sp))
1230 goto discard;
1231 rxrpc_post_packet_to_local(local, skb);
1232 goto out;
1233
1234 case RXRPC_PACKET_TYPE_BUSY:
1235 if (rxrpc_to_server(sp))
1236 goto discard;
1237 /* Fall through */
1238 case RXRPC_PACKET_TYPE_ACK:
1239 case RXRPC_PACKET_TYPE_ACKALL:
1240 if (sp->hdr.callNumber == 0)
1241 goto bad_message;
1242 /* Fall through */
1243 case RXRPC_PACKET_TYPE_ABORT:
1244 break;
1245
1246 case RXRPC_PACKET_TYPE_DATA:
1247 if (sp->hdr.callNumber == 0 ||
1248 sp->hdr.seq == 0)
1249 goto bad_message;
1250 if (!rxrpc_validate_data(skb))
1251 goto bad_message;
1252
1253 /* Unshare the packet so that it can be modified for in-place
1254 * decryption.
1255 */
1256 if (sp->hdr.securityIndex != 0) {
1257 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
1258 if (!nskb) {
1259 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
1260 goto out;
1261 }
1262
1263 if (nskb != skb) {
1264 rxrpc_eaten_skb(skb, rxrpc_skb_received);
1265 skb = nskb;
1266 rxrpc_new_skb(skb, rxrpc_skb_unshared);
1267 sp = rxrpc_skb(skb);
1268 }
1269 }
1270 break;
1271
1272 case RXRPC_PACKET_TYPE_CHALLENGE:
1273 if (rxrpc_to_server(sp))
1274 goto discard;
1275 break;
1276 case RXRPC_PACKET_TYPE_RESPONSE:
1277 if (rxrpc_to_client(sp))
1278 goto discard;
1279 break;
1280
1281 /* Packet types 9-11 should just be ignored. */
1282 case RXRPC_PACKET_TYPE_PARAMS:
1283 case RXRPC_PACKET_TYPE_10:
1284 case RXRPC_PACKET_TYPE_11:
1285 goto discard;
1286
1287 default:
1288 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1289 goto bad_message;
1290 }
1291
1292 if (sp->hdr.serviceId == 0)
1293 goto bad_message;
1294
1295 if (rxrpc_to_server(sp)) {
1296 /* Weed out packets to services we're not offering. Packets
1297 * that would begin a call are explicitly rejected and the rest
1298 * are just discarded.
1299 */
1300 rx = rcu_dereference(local->service);
1301 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
1302 sp->hdr.serviceId != rx->second_service)) {
1303 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
1304 sp->hdr.seq == 1)
1305 goto unsupported_service;
1306 goto discard;
1307 }
1308 }
1309
1310 conn = rxrpc_find_connection_rcu(local, skb, &peer);
1311 if (conn) {
1312 if (sp->hdr.securityIndex != conn->security_ix)
1313 goto wrong_security;
1314
1315 if (sp->hdr.serviceId != conn->service_id) {
1316 int old_id;
1317
1318 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
1319 goto reupgrade;
1320 old_id = cmpxchg(&conn->service_id, conn->params.service_id,
1321 sp->hdr.serviceId);
1322
1323 if (old_id != conn->params.service_id &&
1324 old_id != sp->hdr.serviceId)
1325 goto reupgrade;
1326 }
1327
1328 if (sp->hdr.callNumber == 0) {
1329 /* Connection-level packet */
1330 _debug("CONN %p {%d}", conn, conn->debug_id);
1331 rxrpc_post_packet_to_conn(conn, skb);
1332 goto out;
1333 }
1334
1335 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
1336 conn->hi_serial = sp->hdr.serial;
1337
1338 /* Call-bound packets are routed by connection channel. */
1339 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1340 chan = &conn->channels[channel];
1341
1342 /* Ignore really old calls */
1343 if (sp->hdr.callNumber < chan->last_call)
1344 goto discard;
1345
1346 if (sp->hdr.callNumber == chan->last_call) {
1347 if (chan->call ||
1348 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
1349 goto discard;
1350
1351 /* For the previous service call, if completed
1352 * successfully, we discard all further packets.
1353 */
1354 if (rxrpc_conn_is_service(conn) &&
1355 chan->last_type == RXRPC_PACKET_TYPE_ACK)
1356 goto discard;
1357
1358 /* But otherwise we need to retransmit the final packet
1359 * from data cached in the connection record.
1360 */
1361 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
1362 trace_rxrpc_rx_data(chan->call_debug_id,
1363 sp->hdr.seq,
1364 sp->hdr.serial,
1365 sp->hdr.flags, 0);
1366 rxrpc_post_packet_to_conn(conn, skb);
1367 goto out;
1368 }
1369
1370 call = rcu_dereference(chan->call);
1371
1372 if (sp->hdr.callNumber > chan->call_id) {
1373 if (rxrpc_to_client(sp))
1374 goto reject_packet;
1375 if (call)
1376 rxrpc_input_implicit_end_call(rx, conn, call);
1377 call = NULL;
1378 }
1379
1380 if (call) {
1381 if (sp->hdr.serviceId != call->service_id)
1382 call->service_id = sp->hdr.serviceId;
1383 if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
1384 call->rx_serial = sp->hdr.serial;
1385 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
1386 set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
1387 }
1388 }
1389
1390 if (!call || atomic_read(&call->usage) == 0) {
1391 if (rxrpc_to_client(sp) ||
1392 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1393 goto bad_message;
1394 if (sp->hdr.seq != 1)
1395 goto discard;
1396 call = rxrpc_new_incoming_call(local, rx, skb);
1397 if (!call)
1398 goto reject_packet;
1399 rxrpc_send_ping(call, skb);
1400 mutex_unlock(&call->user_mutex);
1401 }
1402
1403 /* Process a call packet; this either discards or passes on the ref
1404 * elsewhere.
1405 */
1406 rxrpc_input_call_packet(call, skb);
1407 goto out;
1408
1409 discard:
1410 rxrpc_free_skb(skb, rxrpc_skb_freed);
1411 out:
1412 trace_rxrpc_rx_done(0, 0);
1413 return 0;
1414
1415 wrong_security:
1416 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1417 RXKADINCONSISTENCY, EBADMSG);
1418 skb->priority = RXKADINCONSISTENCY;
1419 goto post_abort;
1420
1421 unsupported_service:
1422 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1423 RX_INVALID_OPERATION, EOPNOTSUPP);
1424 skb->priority = RX_INVALID_OPERATION;
1425 goto post_abort;
1426
1427 reupgrade:
1428 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1429 RX_PROTOCOL_ERROR, EBADMSG);
1430 goto protocol_error;
1431
1432 bad_message:
1433 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1434 RX_PROTOCOL_ERROR, EBADMSG);
1435 protocol_error:
1436 skb->priority = RX_PROTOCOL_ERROR;
1437 post_abort:
1438 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
1439 reject_packet:
1440 trace_rxrpc_rx_done(skb->mark, skb->priority);
1441 rxrpc_reject_packet(local, skb);
1442 _leave(" [badmsg]");
1443 return 0;
1444 }
Linux with added FPC-III support