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Linux 5.7.7
[linux/fpc-iii.git] / net / rxrpc / input.c
blob22dec6049e1bb997c19be8813d65d5f8f443d37f
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_count == 0)
95 goto out;
96 if (ktime_before(skb->tstamp,
97 ktime_add_us(call->cong_tstamp,
98 call->peer->srtt_us >> 3)))
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 * Apply a hard ACK by advancing the Tx window.
197 */
198 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
199 struct rxrpc_ack_summary *summary)
200 {
201 struct sk_buff *skb, *list = NULL;
202 bool rot_last = false;
203 int ix;
204 u8 annotation;
205
206 if (call->acks_lowest_nak == call->tx_hard_ack) {
207 call->acks_lowest_nak = to;
208 } else if (before_eq(call->acks_lowest_nak, to)) {
209 summary->new_low_nack = true;
210 call->acks_lowest_nak = to;
211 }
212
213 spin_lock(&call->lock);
214
215 while (before(call->tx_hard_ack, to)) {
216 call->tx_hard_ack++;
217 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
218 skb = call->rxtx_buffer[ix];
219 annotation = call->rxtx_annotations[ix];
220 rxrpc_see_skb(skb, rxrpc_skb_rotated);
221 call->rxtx_buffer[ix] = NULL;
222 call->rxtx_annotations[ix] = 0;
223 skb->next = list;
224 list = skb;
225
226 if (annotation & RXRPC_TX_ANNO_LAST) {
227 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
228 rot_last = true;
229 }
230 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
231 summary->nr_rot_new_acks++;
232 }
233
234 spin_unlock(&call->lock);
235
236 trace_rxrpc_transmit(call, (rot_last ?
237 rxrpc_transmit_rotate_last :
238 rxrpc_transmit_rotate));
239 wake_up(&call->waitq);
240
241 while (list) {
242 skb = list;
243 list = skb->next;
244 skb_mark_not_on_list(skb);
245 rxrpc_free_skb(skb, rxrpc_skb_freed);
246 }
247
248 return rot_last;
249 }
250
251 /*
252 * End the transmission phase of a call.
253 *
254 * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
255 * or a final ACK packet.
256 */
257 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
258 const char *abort_why)
259 {
260 unsigned int state;
261
262 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
263
264 write_lock(&call->state_lock);
265
266 state = call->state;
267 switch (state) {
268 case RXRPC_CALL_CLIENT_SEND_REQUEST:
269 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
270 if (reply_begun)
271 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
272 else
273 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
274 break;
275
276 case RXRPC_CALL_SERVER_AWAIT_ACK:
277 __rxrpc_call_completed(call);
278 rxrpc_notify_socket(call);
279 state = call->state;
280 break;
281
282 default:
283 goto bad_state;
284 }
285
286 write_unlock(&call->state_lock);
287 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
288 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
289 else
290 trace_rxrpc_transmit(call, rxrpc_transmit_end);
291 _leave(" = ok");
292 return true;
293
294 bad_state:
295 write_unlock(&call->state_lock);
296 kdebug("end_tx %s", rxrpc_call_states[call->state]);
297 rxrpc_proto_abort(abort_why, call, call->tx_top);
298 return false;
299 }
300
301 /*
302 * Begin the reply reception phase of a call.
303 */
304 static bool rxrpc_receiving_reply(struct rxrpc_call *call)
305 {
306 struct rxrpc_ack_summary summary = { 0 };
307 unsigned long now, timo;
308 rxrpc_seq_t top = READ_ONCE(call->tx_top);
309
310 if (call->ackr_reason) {
311 spin_lock_bh(&call->lock);
312 call->ackr_reason = 0;
313 spin_unlock_bh(&call->lock);
314 now = jiffies;
315 timo = now + MAX_JIFFY_OFFSET;
316 WRITE_ONCE(call->resend_at, timo);
317 WRITE_ONCE(call->ack_at, timo);
318 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
319 }
320
321 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
322 if (!rxrpc_rotate_tx_window(call, top, &summary)) {
323 rxrpc_proto_abort("TXL", call, top);
324 return false;
325 }
326 }
327 if (!rxrpc_end_tx_phase(call, true, "ETD"))
328 return false;
329 call->tx_phase = false;
330 return true;
331 }
332
333 /*
334 * Scan a data packet to validate its structure and to work out how many
335 * subpackets it contains.
336 *
337 * A jumbo packet is a collection of consecutive packets glued together with
338 * little headers between that indicate how to change the initial header for
339 * each subpacket.
340 *
341 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
342 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
343 * size.
344 */
345 static bool rxrpc_validate_data(struct sk_buff *skb)
346 {
347 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
348 unsigned int offset = sizeof(struct rxrpc_wire_header);
349 unsigned int len = skb->len;
350 u8 flags = sp->hdr.flags;
351
352 for (;;) {
353 if (flags & RXRPC_REQUEST_ACK)
354 __set_bit(sp->nr_subpackets, sp->rx_req_ack);
355 sp->nr_subpackets++;
356
357 if (!(flags & RXRPC_JUMBO_PACKET))
358 break;
359
360 if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
361 goto protocol_error;
362 if (flags & RXRPC_LAST_PACKET)
363 goto protocol_error;
364 offset += RXRPC_JUMBO_DATALEN;
365 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
366 goto protocol_error;
367 offset += sizeof(struct rxrpc_jumbo_header);
368 }
369
370 if (flags & RXRPC_LAST_PACKET)
371 sp->rx_flags |= RXRPC_SKB_INCL_LAST;
372 return true;
373
374 protocol_error:
375 return false;
376 }
377
378 /*
379 * Handle reception of a duplicate packet.
380 *
381 * We have to take care to avoid an attack here whereby we're given a series of
382 * jumbograms, each with a sequence number one before the preceding one and
383 * filled up to maximum UDP size. If they never send us the first packet in
384 * the sequence, they can cause us to have to hold on to around 2MiB of kernel
385 * space until the call times out.
386 *
387 * We limit the space usage by only accepting three duplicate jumbo packets per
388 * call. After that, we tell the other side we're no longer accepting jumbos
389 * (that information is encoded in the ACK packet).
390 */
391 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
392 bool is_jumbo, bool *_jumbo_bad)
393 {
394 /* Discard normal packets that are duplicates. */
395 if (is_jumbo)
396 return;
397
398 /* Skip jumbo subpackets that are duplicates. When we've had three or
399 * more partially duplicate jumbo packets, we refuse to take any more
400 * jumbos for this call.
401 */
402 if (!*_jumbo_bad) {
403 call->nr_jumbo_bad++;
404 *_jumbo_bad = true;
405 }
406 }
407
408 /*
409 * Process a DATA packet, adding the packet to the Rx ring. The caller's
410 * packet ref must be passed on or discarded.
411 */
412 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
413 {
414 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
415 enum rxrpc_call_state state;
416 unsigned int j, nr_subpackets;
417 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
418 rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack;
419 bool immediate_ack = false, jumbo_bad = false;
420 u8 ack = 0;
421
422 _enter("{%u,%u},{%u,%u}",
423 call->rx_hard_ack, call->rx_top, skb->len, seq0);
424
425 _proto("Rx DATA %%%u { #%u f=%02x n=%u }",
426 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
427
428 state = READ_ONCE(call->state);
429 if (state >= RXRPC_CALL_COMPLETE) {
430 rxrpc_free_skb(skb, rxrpc_skb_freed);
431 return;
432 }
433
434 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
435 unsigned long timo = READ_ONCE(call->next_req_timo);
436 unsigned long now, expect_req_by;
437
438 if (timo) {
439 now = jiffies;
440 expect_req_by = now + timo;
441 WRITE_ONCE(call->expect_req_by, expect_req_by);
442 rxrpc_reduce_call_timer(call, expect_req_by, now,
443 rxrpc_timer_set_for_idle);
444 }
445 }
446
447 spin_lock(&call->input_lock);
448
449 /* Received data implicitly ACKs all of the request packets we sent
450 * when we're acting as a client.
451 */
452 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
453 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
454 !rxrpc_receiving_reply(call))
455 goto unlock;
456
457 call->ackr_prev_seq = seq0;
458 hard_ack = READ_ONCE(call->rx_hard_ack);
459
460 nr_subpackets = sp->nr_subpackets;
461 if (nr_subpackets > 1) {
462 if (call->nr_jumbo_bad > 3) {
463 ack = RXRPC_ACK_NOSPACE;
464 ack_serial = serial;
465 goto ack;
466 }
467 }
468
469 for (j = 0; j < nr_subpackets; j++) {
470 rxrpc_serial_t serial = sp->hdr.serial + j;
471 rxrpc_seq_t seq = seq0 + j;
472 unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK;
473 bool terminal = (j == nr_subpackets - 1);
474 bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST);
475 u8 flags, annotation = j;
476
477 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
478 j, serial, seq, terminal, last);
479
480 if (last) {
481 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
482 seq != call->rx_top) {
483 rxrpc_proto_abort("LSN", call, seq);
484 goto unlock;
485 }
486 } else {
487 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
488 after_eq(seq, call->rx_top)) {
489 rxrpc_proto_abort("LSA", call, seq);
490 goto unlock;
491 }
492 }
493
494 flags = 0;
495 if (last)
496 flags |= RXRPC_LAST_PACKET;
497 if (!terminal)
498 flags |= RXRPC_JUMBO_PACKET;
499 if (test_bit(j, sp->rx_req_ack))
500 flags |= RXRPC_REQUEST_ACK;
501 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
502
503 if (before_eq(seq, hard_ack)) {
504 ack = RXRPC_ACK_DUPLICATE;
505 ack_serial = serial;
506 continue;
507 }
508
509 if (call->rxtx_buffer[ix]) {
510 rxrpc_input_dup_data(call, seq, nr_subpackets > 1,
511 &jumbo_bad);
512 if (ack != RXRPC_ACK_DUPLICATE) {
513 ack = RXRPC_ACK_DUPLICATE;
514 ack_serial = serial;
515 }
516 immediate_ack = true;
517 continue;
518 }
519
520 if (after(seq, hard_ack + call->rx_winsize)) {
521 ack = RXRPC_ACK_EXCEEDS_WINDOW;
522 ack_serial = serial;
523 if (flags & RXRPC_JUMBO_PACKET) {
524 if (!jumbo_bad) {
525 call->nr_jumbo_bad++;
526 jumbo_bad = true;
527 }
528 }
529
530 goto ack;
531 }
532
533 if (flags & RXRPC_REQUEST_ACK && !ack) {
534 ack = RXRPC_ACK_REQUESTED;
535 ack_serial = serial;
536 }
537
538 /* Queue the packet. We use a couple of memory barriers here as need
539 * to make sure that rx_top is perceived to be set after the buffer
540 * pointer and that the buffer pointer is set after the annotation and
541 * the skb data.
542 *
543 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
544 * and also rxrpc_fill_out_ack().
545 */
546 if (!terminal)
547 rxrpc_get_skb(skb, rxrpc_skb_got);
548 call->rxtx_annotations[ix] = annotation;
549 smp_wmb();
550 call->rxtx_buffer[ix] = skb;
551 if (after(seq, call->rx_top)) {
552 smp_store_release(&call->rx_top, seq);
553 } else if (before(seq, call->rx_top)) {
554 /* Send an immediate ACK if we fill in a hole */
555 if (!ack) {
556 ack = RXRPC_ACK_DELAY;
557 ack_serial = serial;
558 }
559 immediate_ack = true;
560 }
561
562 if (terminal) {
563 /* From this point on, we're not allowed to touch the
564 * packet any longer as its ref now belongs to the Rx
565 * ring.
566 */
567 skb = NULL;
568 sp = NULL;
569 }
570
571 if (last) {
572 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
573 if (!ack) {
574 ack = RXRPC_ACK_DELAY;
575 ack_serial = serial;
576 }
577 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
578 } else {
579 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
580 }
581
582 if (after_eq(seq, call->rx_expect_next)) {
583 if (after(seq, call->rx_expect_next)) {
584 _net("OOS %u > %u", seq, call->rx_expect_next);
585 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
586 ack_serial = serial;
587 }
588 call->rx_expect_next = seq + 1;
589 }
590 }
591
592 ack:
593 if (ack)
594 rxrpc_propose_ACK(call, ack, ack_serial,
595 immediate_ack, true,
596 rxrpc_propose_ack_input_data);
597 else
598 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
599 false, true,
600 rxrpc_propose_ack_input_data);
601
602 trace_rxrpc_notify_socket(call->debug_id, serial);
603 rxrpc_notify_socket(call);
604
605 unlock:
606 spin_unlock(&call->input_lock);
607 rxrpc_free_skb(skb, rxrpc_skb_freed);
608 _leave(" [queued]");
609 }
610
611 /*
612 * Process a requested ACK.
613 */
614 static void rxrpc_input_requested_ack(struct rxrpc_call *call,
615 ktime_t resp_time,
616 rxrpc_serial_t orig_serial,
617 rxrpc_serial_t ack_serial)
618 {
619 struct rxrpc_skb_priv *sp;
620 struct sk_buff *skb;
621 ktime_t sent_at;
622 int ix;
623
624 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
625 skb = call->rxtx_buffer[ix];
626 if (!skb)
627 continue;
628
629 sent_at = skb->tstamp;
630 smp_rmb(); /* Read timestamp before serial. */
631 sp = rxrpc_skb(skb);
632 if (sp->hdr.serial != orig_serial)
633 continue;
634 goto found;
635 }
636
637 return;
638
639 found:
640 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
641 orig_serial, ack_serial, sent_at, resp_time);
642 }
643
644 /*
645 * Process the response to a ping that we sent to find out if we lost an ACK.
646 *
647 * If we got back a ping response that indicates a lower tx_top than what we
648 * had at the time of the ping transmission, we adjudge all the DATA packets
649 * sent between the response tx_top and the ping-time tx_top to have been lost.
650 */
651 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
652 {
653 rxrpc_seq_t top, bottom, seq;
654 bool resend = false;
655
656 spin_lock_bh(&call->lock);
657
658 bottom = call->tx_hard_ack + 1;
659 top = call->acks_lost_top;
660 if (before(bottom, top)) {
661 for (seq = bottom; before_eq(seq, top); seq++) {
662 int ix = seq & RXRPC_RXTX_BUFF_MASK;
663 u8 annotation = call->rxtx_annotations[ix];
664 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
665
666 if (anno_type != RXRPC_TX_ANNO_UNACK)
667 continue;
668 annotation &= ~RXRPC_TX_ANNO_MASK;
669 annotation |= RXRPC_TX_ANNO_RETRANS;
670 call->rxtx_annotations[ix] = annotation;
671 resend = true;
672 }
673 }
674
675 spin_unlock_bh(&call->lock);
676
677 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
678 rxrpc_queue_call(call);
679 }
680
681 /*
682 * Process a ping response.
683 */
684 static void rxrpc_input_ping_response(struct rxrpc_call *call,
685 ktime_t resp_time,
686 rxrpc_serial_t orig_serial,
687 rxrpc_serial_t ack_serial)
688 {
689 rxrpc_serial_t ping_serial;
690 ktime_t ping_time;
691
692 ping_time = call->ping_time;
693 smp_rmb();
694 ping_serial = READ_ONCE(call->ping_serial);
695
696 if (orig_serial == call->acks_lost_ping)
697 rxrpc_input_check_for_lost_ack(call);
698
699 if (before(orig_serial, ping_serial) ||
700 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
701 return;
702 if (after(orig_serial, ping_serial))
703 return;
704
705 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
706 orig_serial, ack_serial, ping_time, resp_time);
707 }
708
709 /*
710 * Process the extra information that may be appended to an ACK packet
711 */
712 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
713 struct rxrpc_ackinfo *ackinfo)
714 {
715 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
716 struct rxrpc_peer *peer;
717 unsigned int mtu;
718 bool wake = false;
719 u32 rwind = ntohl(ackinfo->rwind);
720
721 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
722 sp->hdr.serial,
723 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
724 rwind, ntohl(ackinfo->jumbo_max));
725
726 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
727 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
728 if (call->tx_winsize != rwind) {
729 if (rwind > call->tx_winsize)
730 wake = true;
731 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
732 call->tx_winsize = rwind;
733 }
734
735 if (call->cong_ssthresh > rwind)
736 call->cong_ssthresh = rwind;
737
738 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
739
740 peer = call->peer;
741 if (mtu < peer->maxdata) {
742 spin_lock_bh(&peer->lock);
743 peer->maxdata = mtu;
744 peer->mtu = mtu + peer->hdrsize;
745 spin_unlock_bh(&peer->lock);
746 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
747 }
748
749 if (wake)
750 wake_up(&call->waitq);
751 }
752
753 /*
754 * Process individual soft ACKs.
755 *
756 * Each ACK in the array corresponds to one packet and can be either an ACK or
757 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
758 * packets that lie beyond the end of the ACK list are scheduled for resend by
759 * the timer on the basis that the peer might just not have processed them at
760 * the time the ACK was sent.
761 */
762 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
763 rxrpc_seq_t seq, int nr_acks,
764 struct rxrpc_ack_summary *summary)
765 {
766 int ix;
767 u8 annotation, anno_type;
768
769 for (; nr_acks > 0; nr_acks--, seq++) {
770 ix = seq & RXRPC_RXTX_BUFF_MASK;
771 annotation = call->rxtx_annotations[ix];
772 anno_type = annotation & RXRPC_TX_ANNO_MASK;
773 annotation &= ~RXRPC_TX_ANNO_MASK;
774 switch (*acks++) {
775 case RXRPC_ACK_TYPE_ACK:
776 summary->nr_acks++;
777 if (anno_type == RXRPC_TX_ANNO_ACK)
778 continue;
779 summary->nr_new_acks++;
780 call->rxtx_annotations[ix] =
781 RXRPC_TX_ANNO_ACK | annotation;
782 break;
783 case RXRPC_ACK_TYPE_NACK:
784 if (!summary->nr_nacks &&
785 call->acks_lowest_nak != seq) {
786 call->acks_lowest_nak = seq;
787 summary->new_low_nack = true;
788 }
789 summary->nr_nacks++;
790 if (anno_type == RXRPC_TX_ANNO_NAK)
791 continue;
792 summary->nr_new_nacks++;
793 if (anno_type == RXRPC_TX_ANNO_RETRANS)
794 continue;
795 call->rxtx_annotations[ix] =
796 RXRPC_TX_ANNO_NAK | annotation;
797 break;
798 default:
799 return rxrpc_proto_abort("SFT", call, 0);
800 }
801 }
802 }
803
804 /*
805 * Return true if the ACK is valid - ie. it doesn't appear to have regressed
806 * with respect to the ack state conveyed by preceding ACKs.
807 */
808 static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
809 rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
810 {
811 rxrpc_seq_t base = READ_ONCE(call->ackr_first_seq);
812
813 if (after(first_pkt, base))
814 return true; /* The window advanced */
815
816 if (before(first_pkt, base))
817 return false; /* firstPacket regressed */
818
819 if (after_eq(prev_pkt, call->ackr_prev_seq))
820 return true; /* previousPacket hasn't regressed. */
821
822 /* Some rx implementations put a serial number in previousPacket. */
823 if (after_eq(prev_pkt, base + call->tx_winsize))
824 return false;
825 return true;
826 }
827
828 /*
829 * Process an ACK packet.
830 *
831 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
832 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
833 *
834 * A hard-ACK means that a packet has been processed and may be discarded; a
835 * soft-ACK means that the packet may be discarded and retransmission
836 * requested. A phase is complete when all packets are hard-ACK'd.
837 */
838 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
839 {
840 struct rxrpc_ack_summary summary = { 0 };
841 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
842 union {
843 struct rxrpc_ackpacket ack;
844 struct rxrpc_ackinfo info;
845 u8 acks[RXRPC_MAXACKS];
846 } buf;
847 rxrpc_serial_t acked_serial;
848 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
849 int nr_acks, offset, ioffset;
850
851 _enter("");
852
853 offset = sizeof(struct rxrpc_wire_header);
854 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
855 _debug("extraction failure");
856 return rxrpc_proto_abort("XAK", call, 0);
857 }
858 offset += sizeof(buf.ack);
859
860 acked_serial = ntohl(buf.ack.serial);
861 first_soft_ack = ntohl(buf.ack.firstPacket);
862 prev_pkt = ntohl(buf.ack.previousPacket);
863 hard_ack = first_soft_ack - 1;
864 nr_acks = buf.ack.nAcks;
865 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
866 buf.ack.reason : RXRPC_ACK__INVALID);
867
868 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
869 first_soft_ack, prev_pkt,
870 summary.ack_reason, nr_acks);
871
872 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
873 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
874 sp->hdr.serial);
875 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
876 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
877 sp->hdr.serial);
878
879 if (buf.ack.reason == RXRPC_ACK_PING) {
880 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
881 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
882 sp->hdr.serial, true, true,
883 rxrpc_propose_ack_respond_to_ping);
884 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
885 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
886 sp->hdr.serial, true, true,
887 rxrpc_propose_ack_respond_to_ack);
888 }
889
890 /* Discard any out-of-order or duplicate ACKs (outside lock). */
891 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
892 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
893 first_soft_ack, call->ackr_first_seq,
894 prev_pkt, call->ackr_prev_seq);
895 return;
896 }
897
898 buf.info.rxMTU = 0;
899 ioffset = offset + nr_acks + 3;
900 if (skb->len >= ioffset + sizeof(buf.info) &&
901 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
902 return rxrpc_proto_abort("XAI", call, 0);
903
904 spin_lock(&call->input_lock);
905
906 /* Discard any out-of-order or duplicate ACKs (inside lock). */
907 if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
908 trace_rxrpc_rx_discard_ack(call->debug_id, sp->hdr.serial,
909 first_soft_ack, call->ackr_first_seq,
910 prev_pkt, call->ackr_prev_seq);
911 goto out;
912 }
913 call->acks_latest_ts = skb->tstamp;
914
915 call->ackr_first_seq = first_soft_ack;
916 call->ackr_prev_seq = prev_pkt;
917
918 /* Parse rwind and mtu sizes if provided. */
919 if (buf.info.rxMTU)
920 rxrpc_input_ackinfo(call, skb, &buf.info);
921
922 if (first_soft_ack == 0) {
923 rxrpc_proto_abort("AK0", call, 0);
924 goto out;
925 }
926
927 /* Ignore ACKs unless we are or have just been transmitting. */
928 switch (READ_ONCE(call->state)) {
929 case RXRPC_CALL_CLIENT_SEND_REQUEST:
930 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
931 case RXRPC_CALL_SERVER_SEND_REPLY:
932 case RXRPC_CALL_SERVER_AWAIT_ACK:
933 break;
934 default:
935 goto out;
936 }
937
938 if (before(hard_ack, call->tx_hard_ack) ||
939 after(hard_ack, call->tx_top)) {
940 rxrpc_proto_abort("AKW", call, 0);
941 goto out;
942 }
943 if (nr_acks > call->tx_top - hard_ack) {
944 rxrpc_proto_abort("AKN", call, 0);
945 goto out;
946 }
947
948 if (after(hard_ack, call->tx_hard_ack)) {
949 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
950 rxrpc_end_tx_phase(call, false, "ETA");
951 goto out;
952 }
953 }
954
955 if (nr_acks > 0) {
956 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
957 rxrpc_proto_abort("XSA", call, 0);
958 goto out;
959 }
960 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
961 &summary);
962 }
963
964 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
965 RXRPC_TX_ANNO_LAST &&
966 summary.nr_acks == call->tx_top - hard_ack &&
967 rxrpc_is_client_call(call))
968 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
969 false, true,
970 rxrpc_propose_ack_ping_for_lost_reply);
971
972 rxrpc_congestion_management(call, skb, &summary, acked_serial);
973 out:
974 spin_unlock(&call->input_lock);
975 }
976
977 /*
978 * Process an ACKALL packet.
979 */
980 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
981 {
982 struct rxrpc_ack_summary summary = { 0 };
983 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
984
985 _proto("Rx ACKALL %%%u", sp->hdr.serial);
986
987 spin_lock(&call->input_lock);
988
989 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
990 rxrpc_end_tx_phase(call, false, "ETL");
991
992 spin_unlock(&call->input_lock);
993 }
994
995 /*
996 * Process an ABORT packet directed at a call.
997 */
998 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
999 {
1000 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1001 __be32 wtmp;
1002 u32 abort_code = RX_CALL_DEAD;
1003
1004 _enter("");
1005
1006 if (skb->len >= 4 &&
1007 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1008 &wtmp, sizeof(wtmp)) >= 0)
1009 abort_code = ntohl(wtmp);
1010
1011 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
1012
1013 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
1014
1015 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
1016 abort_code, -ECONNABORTED))
1017 rxrpc_notify_socket(call);
1018 }
1019
1020 /*
1021 * Process an incoming call packet.
1022 */
1023 static void rxrpc_input_call_packet(struct rxrpc_call *call,
1024 struct sk_buff *skb)
1025 {
1026 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1027 unsigned long timo;
1028
1029 _enter("%p,%p", call, skb);
1030
1031 timo = READ_ONCE(call->next_rx_timo);
1032 if (timo) {
1033 unsigned long now = jiffies, expect_rx_by;
1034
1035 expect_rx_by = now + timo;
1036 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
1037 rxrpc_reduce_call_timer(call, expect_rx_by, now,
1038 rxrpc_timer_set_for_normal);
1039 }
1040
1041 switch (sp->hdr.type) {
1042 case RXRPC_PACKET_TYPE_DATA:
1043 rxrpc_input_data(call, skb);
1044 goto no_free;
1045
1046 case RXRPC_PACKET_TYPE_ACK:
1047 rxrpc_input_ack(call, skb);
1048 break;
1049
1050 case RXRPC_PACKET_TYPE_BUSY:
1051 _proto("Rx BUSY %%%u", sp->hdr.serial);
1052
1053 /* Just ignore BUSY packets from the server; the retry and
1054 * lifespan timers will take care of business. BUSY packets
1055 * from the client don't make sense.
1056 */
1057 break;
1058
1059 case RXRPC_PACKET_TYPE_ABORT:
1060 rxrpc_input_abort(call, skb);
1061 break;
1062
1063 case RXRPC_PACKET_TYPE_ACKALL:
1064 rxrpc_input_ackall(call, skb);
1065 break;
1066
1067 default:
1068 break;
1069 }
1070
1071 rxrpc_free_skb(skb, rxrpc_skb_freed);
1072 no_free:
1073 _leave("");
1074 }
1075
1076 /*
1077 * Handle a new service call on a channel implicitly completing the preceding
1078 * call on that channel. This does not apply to client conns.
1079 *
1080 * TODO: If callNumber > call_id + 1, renegotiate security.
1081 */
1082 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
1083 struct rxrpc_connection *conn,
1084 struct rxrpc_call *call)
1085 {
1086 switch (READ_ONCE(call->state)) {
1087 case RXRPC_CALL_SERVER_AWAIT_ACK:
1088 rxrpc_call_completed(call);
1089 /* Fall through */
1090 case RXRPC_CALL_COMPLETE:
1091 break;
1092 default:
1093 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
1094 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
1095 rxrpc_queue_call(call);
1096 }
1097 trace_rxrpc_improper_term(call);
1098 break;
1099 }
1100
1101 spin_lock(&rx->incoming_lock);
1102 __rxrpc_disconnect_call(conn, call);
1103 spin_unlock(&rx->incoming_lock);
1104 rxrpc_notify_socket(call);
1105 }
1106
1107 /*
1108 * post connection-level events to the connection
1109 * - this includes challenges, responses, some aborts and call terminal packet
1110 * retransmission.
1111 */
1112 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
1113 struct sk_buff *skb)
1114 {
1115 _enter("%p,%p", conn, skb);
1116
1117 skb_queue_tail(&conn->rx_queue, skb);
1118 rxrpc_queue_conn(conn);
1119 }
1120
1121 /*
1122 * post endpoint-level events to the local endpoint
1123 * - this includes debug and version messages
1124 */
1125 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
1126 struct sk_buff *skb)
1127 {
1128 _enter("%p,%p", local, skb);
1129
1130 if (rxrpc_get_local_maybe(local)) {
1131 skb_queue_tail(&local->event_queue, skb);
1132 rxrpc_queue_local(local);
1133 } else {
1134 rxrpc_free_skb(skb, rxrpc_skb_freed);
1135 }
1136 }
1137
1138 /*
1139 * put a packet up for transport-level abort
1140 */
1141 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
1142 {
1143 CHECK_SLAB_OKAY(&local->usage);
1144
1145 if (rxrpc_get_local_maybe(local)) {
1146 skb_queue_tail(&local->reject_queue, skb);
1147 rxrpc_queue_local(local);
1148 } else {
1149 rxrpc_free_skb(skb, rxrpc_skb_freed);
1150 }
1151 }
1152
1153 /*
1154 * Extract the wire header from a packet and translate the byte order.
1155 */
1156 static noinline
1157 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
1158 {
1159 struct rxrpc_wire_header whdr;
1160
1161 /* dig out the RxRPC connection details */
1162 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
1163 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
1164 tracepoint_string("bad_hdr"));
1165 return -EBADMSG;
1166 }
1167
1168 memset(sp, 0, sizeof(*sp));
1169 sp->hdr.epoch = ntohl(whdr.epoch);
1170 sp->hdr.cid = ntohl(whdr.cid);
1171 sp->hdr.callNumber = ntohl(whdr.callNumber);
1172 sp->hdr.seq = ntohl(whdr.seq);
1173 sp->hdr.serial = ntohl(whdr.serial);
1174 sp->hdr.flags = whdr.flags;
1175 sp->hdr.type = whdr.type;
1176 sp->hdr.userStatus = whdr.userStatus;
1177 sp->hdr.securityIndex = whdr.securityIndex;
1178 sp->hdr._rsvd = ntohs(whdr._rsvd);
1179 sp->hdr.serviceId = ntohs(whdr.serviceId);
1180 return 0;
1181 }
1182
1183 /*
1184 * handle data received on the local endpoint
1185 * - may be called in interrupt context
1186 *
1187 * [!] Note that as this is called from the encap_rcv hook, the socket is not
1188 * held locked by the caller and nothing prevents sk_user_data on the UDP from
1189 * being cleared in the middle of processing this function.
1190 *
1191 * Called with the RCU read lock held from the IP layer via UDP.
1192 */
1193 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
1194 {
1195 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
1196 struct rxrpc_connection *conn;
1197 struct rxrpc_channel *chan;
1198 struct rxrpc_call *call = NULL;
1199 struct rxrpc_skb_priv *sp;
1200 struct rxrpc_peer *peer = NULL;
1201 struct rxrpc_sock *rx = NULL;
1202 unsigned int channel;
1203
1204 _enter("%p", udp_sk);
1205
1206 if (unlikely(!local)) {
1207 kfree_skb(skb);
1208 return 0;
1209 }
1210 if (skb->tstamp == 0)
1211 skb->tstamp = ktime_get_real();
1212
1213 rxrpc_new_skb(skb, rxrpc_skb_received);
1214
1215 skb_pull(skb, sizeof(struct udphdr));
1216
1217 /* The UDP protocol already released all skb resources;
1218 * we are free to add our own data there.
1219 */
1220 sp = rxrpc_skb(skb);
1221
1222 /* dig out the RxRPC connection details */
1223 if (rxrpc_extract_header(sp, skb) < 0)
1224 goto bad_message;
1225
1226 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1227 static int lose;
1228 if ((lose++ & 7) == 7) {
1229 trace_rxrpc_rx_lose(sp);
1230 rxrpc_free_skb(skb, rxrpc_skb_lost);
1231 return 0;
1232 }
1233 }
1234
1235 if (skb->tstamp == 0)
1236 skb->tstamp = ktime_get_real();
1237 trace_rxrpc_rx_packet(sp);
1238
1239 switch (sp->hdr.type) {
1240 case RXRPC_PACKET_TYPE_VERSION:
1241 if (rxrpc_to_client(sp))
1242 goto discard;
1243 rxrpc_post_packet_to_local(local, skb);
1244 goto out;
1245
1246 case RXRPC_PACKET_TYPE_BUSY:
1247 if (rxrpc_to_server(sp))
1248 goto discard;
1249 /* Fall through */
1250 case RXRPC_PACKET_TYPE_ACK:
1251 case RXRPC_PACKET_TYPE_ACKALL:
1252 if (sp->hdr.callNumber == 0)
1253 goto bad_message;
1254 /* Fall through */
1255 case RXRPC_PACKET_TYPE_ABORT:
1256 break;
1257
1258 case RXRPC_PACKET_TYPE_DATA:
1259 if (sp->hdr.callNumber == 0 ||
1260 sp->hdr.seq == 0)
1261 goto bad_message;
1262 if (!rxrpc_validate_data(skb))
1263 goto bad_message;
1264
1265 /* Unshare the packet so that it can be modified for in-place
1266 * decryption.
1267 */
1268 if (sp->hdr.securityIndex != 0) {
1269 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
1270 if (!nskb) {
1271 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
1272 goto out;
1273 }
1274
1275 if (nskb != skb) {
1276 rxrpc_eaten_skb(skb, rxrpc_skb_received);
1277 skb = nskb;
1278 rxrpc_new_skb(skb, rxrpc_skb_unshared);
1279 sp = rxrpc_skb(skb);
1280 }
1281 }
1282 break;
1283
1284 case RXRPC_PACKET_TYPE_CHALLENGE:
1285 if (rxrpc_to_server(sp))
1286 goto discard;
1287 break;
1288 case RXRPC_PACKET_TYPE_RESPONSE:
1289 if (rxrpc_to_client(sp))
1290 goto discard;
1291 break;
1292
1293 /* Packet types 9-11 should just be ignored. */
1294 case RXRPC_PACKET_TYPE_PARAMS:
1295 case RXRPC_PACKET_TYPE_10:
1296 case RXRPC_PACKET_TYPE_11:
1297 goto discard;
1298
1299 default:
1300 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1301 goto bad_message;
1302 }
1303
1304 if (sp->hdr.serviceId == 0)
1305 goto bad_message;
1306
1307 if (rxrpc_to_server(sp)) {
1308 /* Weed out packets to services we're not offering. Packets
1309 * that would begin a call are explicitly rejected and the rest
1310 * are just discarded.
1311 */
1312 rx = rcu_dereference(local->service);
1313 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
1314 sp->hdr.serviceId != rx->second_service)) {
1315 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
1316 sp->hdr.seq == 1)
1317 goto unsupported_service;
1318 goto discard;
1319 }
1320 }
1321
1322 conn = rxrpc_find_connection_rcu(local, skb, &peer);
1323 if (conn) {
1324 if (sp->hdr.securityIndex != conn->security_ix)
1325 goto wrong_security;
1326
1327 if (sp->hdr.serviceId != conn->service_id) {
1328 int old_id;
1329
1330 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
1331 goto reupgrade;
1332 old_id = cmpxchg(&conn->service_id, conn->params.service_id,
1333 sp->hdr.serviceId);
1334
1335 if (old_id != conn->params.service_id &&
1336 old_id != sp->hdr.serviceId)
1337 goto reupgrade;
1338 }
1339
1340 if (sp->hdr.callNumber == 0) {
1341 /* Connection-level packet */
1342 _debug("CONN %p {%d}", conn, conn->debug_id);
1343 rxrpc_post_packet_to_conn(conn, skb);
1344 goto out;
1345 }
1346
1347 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
1348 conn->hi_serial = sp->hdr.serial;
1349
1350 /* Call-bound packets are routed by connection channel. */
1351 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1352 chan = &conn->channels[channel];
1353
1354 /* Ignore really old calls */
1355 if (sp->hdr.callNumber < chan->last_call)
1356 goto discard;
1357
1358 if (sp->hdr.callNumber == chan->last_call) {
1359 if (chan->call ||
1360 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
1361 goto discard;
1362
1363 /* For the previous service call, if completed
1364 * successfully, we discard all further packets.
1365 */
1366 if (rxrpc_conn_is_service(conn) &&
1367 chan->last_type == RXRPC_PACKET_TYPE_ACK)
1368 goto discard;
1369
1370 /* But otherwise we need to retransmit the final packet
1371 * from data cached in the connection record.
1372 */
1373 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
1374 trace_rxrpc_rx_data(chan->call_debug_id,
1375 sp->hdr.seq,
1376 sp->hdr.serial,
1377 sp->hdr.flags, 0);
1378 rxrpc_post_packet_to_conn(conn, skb);
1379 goto out;
1380 }
1381
1382 call = rcu_dereference(chan->call);
1383
1384 if (sp->hdr.callNumber > chan->call_id) {
1385 if (rxrpc_to_client(sp))
1386 goto reject_packet;
1387 if (call)
1388 rxrpc_input_implicit_end_call(rx, conn, call);
1389 call = NULL;
1390 }
1391
1392 if (call) {
1393 if (sp->hdr.serviceId != call->service_id)
1394 call->service_id = sp->hdr.serviceId;
1395 if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
1396 call->rx_serial = sp->hdr.serial;
1397 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
1398 set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
1399 }
1400 }
1401
1402 if (!call || atomic_read(&call->usage) == 0) {
1403 if (rxrpc_to_client(sp) ||
1404 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1405 goto bad_message;
1406 if (sp->hdr.seq != 1)
1407 goto discard;
1408 call = rxrpc_new_incoming_call(local, rx, skb);
1409 if (!call)
1410 goto reject_packet;
1411 }
1412
1413 /* Process a call packet; this either discards or passes on the ref
1414 * elsewhere.
1415 */
1416 rxrpc_input_call_packet(call, skb);
1417 goto out;
1418
1419 discard:
1420 rxrpc_free_skb(skb, rxrpc_skb_freed);
1421 out:
1422 trace_rxrpc_rx_done(0, 0);
1423 return 0;
1424
1425 wrong_security:
1426 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1427 RXKADINCONSISTENCY, EBADMSG);
1428 skb->priority = RXKADINCONSISTENCY;
1429 goto post_abort;
1430
1431 unsupported_service:
1432 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1433 RX_INVALID_OPERATION, EOPNOTSUPP);
1434 skb->priority = RX_INVALID_OPERATION;
1435 goto post_abort;
1436
1437 reupgrade:
1438 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1439 RX_PROTOCOL_ERROR, EBADMSG);
1440 goto protocol_error;
1441
1442 bad_message:
1443 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1444 RX_PROTOCOL_ERROR, EBADMSG);
1445 protocol_error:
1446 skb->priority = RX_PROTOCOL_ERROR;
1447 post_abort:
1448 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
1449 reject_packet:
1450 trace_rxrpc_rx_done(skb->mark, skb->priority);
1451 rxrpc_reject_packet(local, skb);
1452 _leave(" [badmsg]");
1453 return 0;
1454 }
Linux with added FPC-III support