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KVM: x86: fix empty-body warnings
[linux/fpc-iii.git] / net / rxrpc / input.c
blob9128aa0e40aac8f51a84f10dc0bd0dd5933c1e23
1 /* RxRPC packet reception
2 *
3 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/module.h>
15 #include <linux/net.h>
16 #include <linux/skbuff.h>
17 #include <linux/errqueue.h>
18 #include <linux/udp.h>
19 #include <linux/in.h>
20 #include <linux/in6.h>
21 #include <linux/icmp.h>
22 #include <linux/gfp.h>
23 #include <net/sock.h>
24 #include <net/af_rxrpc.h>
25 #include <net/ip.h>
26 #include <net/udp.h>
27 #include <net/net_namespace.h>
28 #include "ar-internal.h"
29
30 static void rxrpc_proto_abort(const char *why,
31 struct rxrpc_call *call, rxrpc_seq_t seq)
32 {
33 if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
34 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
35 rxrpc_queue_call(call);
36 }
37 }
38
39 /*
40 * Do TCP-style congestion management [RFC 5681].
41 */
42 static void rxrpc_congestion_management(struct rxrpc_call *call,
43 struct sk_buff *skb,
44 struct rxrpc_ack_summary *summary,
45 rxrpc_serial_t acked_serial)
46 {
47 enum rxrpc_congest_change change = rxrpc_cong_no_change;
48 unsigned int cumulative_acks = call->cong_cumul_acks;
49 unsigned int cwnd = call->cong_cwnd;
50 bool resend = false;
51
52 summary->flight_size =
53 (call->tx_top - call->tx_hard_ack) - summary->nr_acks;
54
55 if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
56 summary->retrans_timeo = true;
57 call->cong_ssthresh = max_t(unsigned int,
58 summary->flight_size / 2, 2);
59 cwnd = 1;
60 if (cwnd >= call->cong_ssthresh &&
61 call->cong_mode == RXRPC_CALL_SLOW_START) {
62 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
63 call->cong_tstamp = skb->tstamp;
64 cumulative_acks = 0;
65 }
66 }
67
68 cumulative_acks += summary->nr_new_acks;
69 cumulative_acks += summary->nr_rot_new_acks;
70 if (cumulative_acks > 255)
71 cumulative_acks = 255;
72
73 summary->mode = call->cong_mode;
74 summary->cwnd = call->cong_cwnd;
75 summary->ssthresh = call->cong_ssthresh;
76 summary->cumulative_acks = cumulative_acks;
77 summary->dup_acks = call->cong_dup_acks;
78
79 switch (call->cong_mode) {
80 case RXRPC_CALL_SLOW_START:
81 if (summary->nr_nacks > 0)
82 goto packet_loss_detected;
83 if (summary->cumulative_acks > 0)
84 cwnd += 1;
85 if (cwnd >= call->cong_ssthresh) {
86 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
87 call->cong_tstamp = skb->tstamp;
88 }
89 goto out;
90
91 case RXRPC_CALL_CONGEST_AVOIDANCE:
92 if (summary->nr_nacks > 0)
93 goto packet_loss_detected;
94
95 /* We analyse the number of packets that get ACK'd per RTT
96 * period and increase the window if we managed to fill it.
97 */
98 if (call->peer->rtt_usage == 0)
99 goto out;
100 if (ktime_before(skb->tstamp,
101 ktime_add_ns(call->cong_tstamp,
102 call->peer->rtt)))
103 goto out_no_clear_ca;
104 change = rxrpc_cong_rtt_window_end;
105 call->cong_tstamp = skb->tstamp;
106 if (cumulative_acks >= cwnd)
107 cwnd++;
108 goto out;
109
110 case RXRPC_CALL_PACKET_LOSS:
111 if (summary->nr_nacks == 0)
112 goto resume_normality;
113
114 if (summary->new_low_nack) {
115 change = rxrpc_cong_new_low_nack;
116 call->cong_dup_acks = 1;
117 if (call->cong_extra > 1)
118 call->cong_extra = 1;
119 goto send_extra_data;
120 }
121
122 call->cong_dup_acks++;
123 if (call->cong_dup_acks < 3)
124 goto send_extra_data;
125
126 change = rxrpc_cong_begin_retransmission;
127 call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
128 call->cong_ssthresh = max_t(unsigned int,
129 summary->flight_size / 2, 2);
130 cwnd = call->cong_ssthresh + 3;
131 call->cong_extra = 0;
132 call->cong_dup_acks = 0;
133 resend = true;
134 goto out;
135
136 case RXRPC_CALL_FAST_RETRANSMIT:
137 if (!summary->new_low_nack) {
138 if (summary->nr_new_acks == 0)
139 cwnd += 1;
140 call->cong_dup_acks++;
141 if (call->cong_dup_acks == 2) {
142 change = rxrpc_cong_retransmit_again;
143 call->cong_dup_acks = 0;
144 resend = true;
145 }
146 } else {
147 change = rxrpc_cong_progress;
148 cwnd = call->cong_ssthresh;
149 if (summary->nr_nacks == 0)
150 goto resume_normality;
151 }
152 goto out;
153
154 default:
155 BUG();
156 goto out;
157 }
158
159 resume_normality:
160 change = rxrpc_cong_cleared_nacks;
161 call->cong_dup_acks = 0;
162 call->cong_extra = 0;
163 call->cong_tstamp = skb->tstamp;
164 if (cwnd < call->cong_ssthresh)
165 call->cong_mode = RXRPC_CALL_SLOW_START;
166 else
167 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
168 out:
169 cumulative_acks = 0;
170 out_no_clear_ca:
171 if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1)
172 cwnd = RXRPC_RXTX_BUFF_SIZE - 1;
173 call->cong_cwnd = cwnd;
174 call->cong_cumul_acks = cumulative_acks;
175 trace_rxrpc_congest(call, summary, acked_serial, change);
176 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
177 rxrpc_queue_call(call);
178 return;
179
180 packet_loss_detected:
181 change = rxrpc_cong_saw_nack;
182 call->cong_mode = RXRPC_CALL_PACKET_LOSS;
183 call->cong_dup_acks = 0;
184 goto send_extra_data;
185
186 send_extra_data:
187 /* Send some previously unsent DATA if we have some to advance the ACK
188 * state.
189 */
190 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
191 RXRPC_TX_ANNO_LAST ||
192 summary->nr_acks != call->tx_top - call->tx_hard_ack) {
193 call->cong_extra++;
194 wake_up(&call->waitq);
195 }
196 goto out_no_clear_ca;
197 }
198
199 /*
200 * Ping the other end to fill our RTT cache and to retrieve the rwind
201 * and MTU parameters.
202 */
203 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb,
204 int skew)
205 {
206 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
207 ktime_t now = skb->tstamp;
208
209 if (call->peer->rtt_usage < 3 ||
210 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
211 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
212 true, true,
213 rxrpc_propose_ack_ping_for_params);
214 }
215
216 /*
217 * Apply a hard ACK by advancing the Tx window.
218 */
219 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
220 struct rxrpc_ack_summary *summary)
221 {
222 struct sk_buff *skb, *list = NULL;
223 bool rot_last = false;
224 int ix;
225 u8 annotation;
226
227 if (call->acks_lowest_nak == call->tx_hard_ack) {
228 call->acks_lowest_nak = to;
229 } else if (before_eq(call->acks_lowest_nak, to)) {
230 summary->new_low_nack = true;
231 call->acks_lowest_nak = to;
232 }
233
234 spin_lock(&call->lock);
235
236 while (before(call->tx_hard_ack, to)) {
237 call->tx_hard_ack++;
238 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
239 skb = call->rxtx_buffer[ix];
240 annotation = call->rxtx_annotations[ix];
241 rxrpc_see_skb(skb, rxrpc_skb_tx_rotated);
242 call->rxtx_buffer[ix] = NULL;
243 call->rxtx_annotations[ix] = 0;
244 skb->next = list;
245 list = skb;
246
247 if (annotation & RXRPC_TX_ANNO_LAST) {
248 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
249 rot_last = true;
250 }
251 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
252 summary->nr_rot_new_acks++;
253 }
254
255 spin_unlock(&call->lock);
256
257 trace_rxrpc_transmit(call, (rot_last ?
258 rxrpc_transmit_rotate_last :
259 rxrpc_transmit_rotate));
260 wake_up(&call->waitq);
261
262 while (list) {
263 skb = list;
264 list = skb->next;
265 skb_mark_not_on_list(skb);
266 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
267 }
268
269 return rot_last;
270 }
271
272 /*
273 * End the transmission phase of a call.
274 *
275 * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
276 * or a final ACK packet.
277 */
278 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
279 const char *abort_why)
280 {
281 unsigned int state;
282
283 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
284
285 write_lock(&call->state_lock);
286
287 state = call->state;
288 switch (state) {
289 case RXRPC_CALL_CLIENT_SEND_REQUEST:
290 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
291 if (reply_begun)
292 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
293 else
294 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
295 break;
296
297 case RXRPC_CALL_SERVER_AWAIT_ACK:
298 __rxrpc_call_completed(call);
299 rxrpc_notify_socket(call);
300 state = call->state;
301 break;
302
303 default:
304 goto bad_state;
305 }
306
307 write_unlock(&call->state_lock);
308 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
309 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
310 else
311 trace_rxrpc_transmit(call, rxrpc_transmit_end);
312 _leave(" = ok");
313 return true;
314
315 bad_state:
316 write_unlock(&call->state_lock);
317 kdebug("end_tx %s", rxrpc_call_states[call->state]);
318 rxrpc_proto_abort(abort_why, call, call->tx_top);
319 return false;
320 }
321
322 /*
323 * Begin the reply reception phase of a call.
324 */
325 static bool rxrpc_receiving_reply(struct rxrpc_call *call)
326 {
327 struct rxrpc_ack_summary summary = { 0 };
328 unsigned long now, timo;
329 rxrpc_seq_t top = READ_ONCE(call->tx_top);
330
331 if (call->ackr_reason) {
332 spin_lock_bh(&call->lock);
333 call->ackr_reason = 0;
334 spin_unlock_bh(&call->lock);
335 now = jiffies;
336 timo = now + MAX_JIFFY_OFFSET;
337 WRITE_ONCE(call->resend_at, timo);
338 WRITE_ONCE(call->ack_at, timo);
339 trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
340 }
341
342 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
343 if (!rxrpc_rotate_tx_window(call, top, &summary)) {
344 rxrpc_proto_abort("TXL", call, top);
345 return false;
346 }
347 }
348 if (!rxrpc_end_tx_phase(call, true, "ETD"))
349 return false;
350 call->tx_phase = false;
351 return true;
352 }
353
354 /*
355 * Scan a jumbo packet to validate its structure and to work out how many
356 * subpackets it contains.
357 *
358 * A jumbo packet is a collection of consecutive packets glued together with
359 * little headers between that indicate how to change the initial header for
360 * each subpacket.
361 *
362 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
363 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
364 * size.
365 */
366 static bool rxrpc_validate_jumbo(struct sk_buff *skb)
367 {
368 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
369 unsigned int offset = sizeof(struct rxrpc_wire_header);
370 unsigned int len = skb->len;
371 int nr_jumbo = 1;
372 u8 flags = sp->hdr.flags;
373
374 do {
375 nr_jumbo++;
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 } while (flags & RXRPC_JUMBO_PACKET);
385
386 sp->nr_jumbo = nr_jumbo;
387 return true;
388
389 protocol_error:
390 return false;
391 }
392
393 /*
394 * Handle reception of a duplicate packet.
395 *
396 * We have to take care to avoid an attack here whereby we're given a series of
397 * jumbograms, each with a sequence number one before the preceding one and
398 * filled up to maximum UDP size. If they never send us the first packet in
399 * the sequence, they can cause us to have to hold on to around 2MiB of kernel
400 * space until the call times out.
401 *
402 * We limit the space usage by only accepting three duplicate jumbo packets per
403 * call. After that, we tell the other side we're no longer accepting jumbos
404 * (that information is encoded in the ACK packet).
405 */
406 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
407 u8 annotation, bool *_jumbo_bad)
408 {
409 /* Discard normal packets that are duplicates. */
410 if (annotation == 0)
411 return;
412
413 /* Skip jumbo subpackets that are duplicates. When we've had three or
414 * more partially duplicate jumbo packets, we refuse to take any more
415 * jumbos for this call.
416 */
417 if (!*_jumbo_bad) {
418 call->nr_jumbo_bad++;
419 *_jumbo_bad = true;
420 }
421 }
422
423 /*
424 * Process a DATA packet, adding the packet to the Rx ring.
425 */
426 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
427 u16 skew)
428 {
429 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
430 enum rxrpc_call_state state;
431 unsigned int offset = sizeof(struct rxrpc_wire_header);
432 unsigned int ix;
433 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
434 rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
435 bool immediate_ack = false, jumbo_bad = false, queued;
436 u16 len;
437 u8 ack = 0, flags, annotation = 0;
438
439 _enter("{%u,%u},{%u,%u}",
440 call->rx_hard_ack, call->rx_top, skb->len, seq);
441
442 _proto("Rx DATA %%%u { #%u f=%02x }",
443 sp->hdr.serial, seq, sp->hdr.flags);
444
445 state = READ_ONCE(call->state);
446 if (state >= RXRPC_CALL_COMPLETE)
447 return;
448
449 if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
450 unsigned long timo = READ_ONCE(call->next_req_timo);
451 unsigned long now, expect_req_by;
452
453 if (timo) {
454 now = jiffies;
455 expect_req_by = now + timo;
456 WRITE_ONCE(call->expect_req_by, expect_req_by);
457 rxrpc_reduce_call_timer(call, expect_req_by, now,
458 rxrpc_timer_set_for_idle);
459 }
460 }
461
462 spin_lock(&call->input_lock);
463
464 /* Received data implicitly ACKs all of the request packets we sent
465 * when we're acting as a client.
466 */
467 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
468 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
469 !rxrpc_receiving_reply(call))
470 goto unlock;
471
472 call->ackr_prev_seq = seq;
473
474 hard_ack = READ_ONCE(call->rx_hard_ack);
475 if (after(seq, hard_ack + call->rx_winsize)) {
476 ack = RXRPC_ACK_EXCEEDS_WINDOW;
477 ack_serial = serial;
478 goto ack;
479 }
480
481 flags = sp->hdr.flags;
482 if (flags & RXRPC_JUMBO_PACKET) {
483 if (call->nr_jumbo_bad > 3) {
484 ack = RXRPC_ACK_NOSPACE;
485 ack_serial = serial;
486 goto ack;
487 }
488 annotation = 1;
489 }
490
491 next_subpacket:
492 queued = false;
493 ix = seq & RXRPC_RXTX_BUFF_MASK;
494 len = skb->len;
495 if (flags & RXRPC_JUMBO_PACKET)
496 len = RXRPC_JUMBO_DATALEN;
497
498 if (flags & RXRPC_LAST_PACKET) {
499 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
500 seq != call->rx_top) {
501 rxrpc_proto_abort("LSN", call, seq);
502 goto unlock;
503 }
504 } else {
505 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
506 after_eq(seq, call->rx_top)) {
507 rxrpc_proto_abort("LSA", call, seq);
508 goto unlock;
509 }
510 }
511
512 trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation);
513 if (before_eq(seq, hard_ack)) {
514 ack = RXRPC_ACK_DUPLICATE;
515 ack_serial = serial;
516 goto skip;
517 }
518
519 if (flags & RXRPC_REQUEST_ACK && !ack) {
520 ack = RXRPC_ACK_REQUESTED;
521 ack_serial = serial;
522 }
523
524 if (call->rxtx_buffer[ix]) {
525 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
526 if (ack != RXRPC_ACK_DUPLICATE) {
527 ack = RXRPC_ACK_DUPLICATE;
528 ack_serial = serial;
529 }
530 immediate_ack = true;
531 goto skip;
532 }
533
534 /* Queue the packet. We use a couple of memory barriers here as need
535 * to make sure that rx_top is perceived to be set after the buffer
536 * pointer and that the buffer pointer is set after the annotation and
537 * the skb data.
538 *
539 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
540 * and also rxrpc_fill_out_ack().
541 */
542 rxrpc_get_skb(skb, rxrpc_skb_rx_got);
543 call->rxtx_annotations[ix] = annotation;
544 smp_wmb();
545 call->rxtx_buffer[ix] = skb;
546 if (after(seq, call->rx_top)) {
547 smp_store_release(&call->rx_top, seq);
548 } else if (before(seq, call->rx_top)) {
549 /* Send an immediate ACK if we fill in a hole */
550 if (!ack) {
551 ack = RXRPC_ACK_DELAY;
552 ack_serial = serial;
553 }
554 immediate_ack = true;
555 }
556 if (flags & RXRPC_LAST_PACKET) {
557 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
558 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
559 } else {
560 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
561 }
562 queued = true;
563
564 if (after_eq(seq, call->rx_expect_next)) {
565 if (after(seq, call->rx_expect_next)) {
566 _net("OOS %u > %u", seq, call->rx_expect_next);
567 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
568 ack_serial = serial;
569 }
570 call->rx_expect_next = seq + 1;
571 }
572
573 skip:
574 offset += len;
575 if (flags & RXRPC_JUMBO_PACKET) {
576 if (skb_copy_bits(skb, offset, &flags, 1) < 0) {
577 rxrpc_proto_abort("XJF", call, seq);
578 goto unlock;
579 }
580 offset += sizeof(struct rxrpc_jumbo_header);
581 seq++;
582 serial++;
583 annotation++;
584 if (flags & RXRPC_JUMBO_PACKET)
585 annotation |= RXRPC_RX_ANNO_JLAST;
586 if (after(seq, hard_ack + call->rx_winsize)) {
587 ack = RXRPC_ACK_EXCEEDS_WINDOW;
588 ack_serial = serial;
589 if (!jumbo_bad) {
590 call->nr_jumbo_bad++;
591 jumbo_bad = true;
592 }
593 goto ack;
594 }
595
596 _proto("Rx DATA Jumbo %%%u", serial);
597 goto next_subpacket;
598 }
599
600 if (queued && flags & RXRPC_LAST_PACKET && !ack) {
601 ack = RXRPC_ACK_DELAY;
602 ack_serial = serial;
603 }
604
605 ack:
606 if (ack)
607 rxrpc_propose_ACK(call, ack, skew, ack_serial,
608 immediate_ack, true,
609 rxrpc_propose_ack_input_data);
610 else
611 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, skew, serial,
612 false, true,
613 rxrpc_propose_ack_input_data);
614
615 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1) {
616 trace_rxrpc_notify_socket(call->debug_id, serial);
617 rxrpc_notify_socket(call);
618 }
619
620 unlock:
621 spin_unlock(&call->input_lock);
622 _leave(" [queued]");
623 }
624
625 /*
626 * Process a requested ACK.
627 */
628 static void rxrpc_input_requested_ack(struct rxrpc_call *call,
629 ktime_t resp_time,
630 rxrpc_serial_t orig_serial,
631 rxrpc_serial_t ack_serial)
632 {
633 struct rxrpc_skb_priv *sp;
634 struct sk_buff *skb;
635 ktime_t sent_at;
636 int ix;
637
638 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
639 skb = call->rxtx_buffer[ix];
640 if (!skb)
641 continue;
642
643 sent_at = skb->tstamp;
644 smp_rmb(); /* Read timestamp before serial. */
645 sp = rxrpc_skb(skb);
646 if (sp->hdr.serial != orig_serial)
647 continue;
648 goto found;
649 }
650
651 return;
652
653 found:
654 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
655 orig_serial, ack_serial, sent_at, resp_time);
656 }
657
658 /*
659 * Process the response to a ping that we sent to find out if we lost an ACK.
660 *
661 * If we got back a ping response that indicates a lower tx_top than what we
662 * had at the time of the ping transmission, we adjudge all the DATA packets
663 * sent between the response tx_top and the ping-time tx_top to have been lost.
664 */
665 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
666 {
667 rxrpc_seq_t top, bottom, seq;
668 bool resend = false;
669
670 spin_lock_bh(&call->lock);
671
672 bottom = call->tx_hard_ack + 1;
673 top = call->acks_lost_top;
674 if (before(bottom, top)) {
675 for (seq = bottom; before_eq(seq, top); seq++) {
676 int ix = seq & RXRPC_RXTX_BUFF_MASK;
677 u8 annotation = call->rxtx_annotations[ix];
678 u8 anno_type = annotation & RXRPC_TX_ANNO_MASK;
679
680 if (anno_type != RXRPC_TX_ANNO_UNACK)
681 continue;
682 annotation &= ~RXRPC_TX_ANNO_MASK;
683 annotation |= RXRPC_TX_ANNO_RETRANS;
684 call->rxtx_annotations[ix] = annotation;
685 resend = true;
686 }
687 }
688
689 spin_unlock_bh(&call->lock);
690
691 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
692 rxrpc_queue_call(call);
693 }
694
695 /*
696 * Process a ping response.
697 */
698 static void rxrpc_input_ping_response(struct rxrpc_call *call,
699 ktime_t resp_time,
700 rxrpc_serial_t orig_serial,
701 rxrpc_serial_t ack_serial)
702 {
703 rxrpc_serial_t ping_serial;
704 ktime_t ping_time;
705
706 ping_time = call->ping_time;
707 smp_rmb();
708 ping_serial = READ_ONCE(call->ping_serial);
709
710 if (orig_serial == call->acks_lost_ping)
711 rxrpc_input_check_for_lost_ack(call);
712
713 if (before(orig_serial, ping_serial) ||
714 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
715 return;
716 if (after(orig_serial, ping_serial))
717 return;
718
719 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
720 orig_serial, ack_serial, ping_time, resp_time);
721 }
722
723 /*
724 * Process the extra information that may be appended to an ACK packet
725 */
726 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
727 struct rxrpc_ackinfo *ackinfo)
728 {
729 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
730 struct rxrpc_peer *peer;
731 unsigned int mtu;
732 bool wake = false;
733 u32 rwind = ntohl(ackinfo->rwind);
734
735 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
736 sp->hdr.serial,
737 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
738 rwind, ntohl(ackinfo->jumbo_max));
739
740 if (call->tx_winsize != rwind) {
741 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
742 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
743 if (rwind > call->tx_winsize)
744 wake = true;
745 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
746 ntohl(ackinfo->rwind), wake);
747 call->tx_winsize = rwind;
748 }
749
750 if (call->cong_ssthresh > rwind)
751 call->cong_ssthresh = rwind;
752
753 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
754
755 peer = call->peer;
756 if (mtu < peer->maxdata) {
757 spin_lock_bh(&peer->lock);
758 peer->maxdata = mtu;
759 peer->mtu = mtu + peer->hdrsize;
760 spin_unlock_bh(&peer->lock);
761 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
762 }
763
764 if (wake)
765 wake_up(&call->waitq);
766 }
767
768 /*
769 * Process individual soft ACKs.
770 *
771 * Each ACK in the array corresponds to one packet and can be either an ACK or
772 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
773 * packets that lie beyond the end of the ACK list are scheduled for resend by
774 * the timer on the basis that the peer might just not have processed them at
775 * the time the ACK was sent.
776 */
777 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
778 rxrpc_seq_t seq, int nr_acks,
779 struct rxrpc_ack_summary *summary)
780 {
781 int ix;
782 u8 annotation, anno_type;
783
784 for (; nr_acks > 0; nr_acks--, seq++) {
785 ix = seq & RXRPC_RXTX_BUFF_MASK;
786 annotation = call->rxtx_annotations[ix];
787 anno_type = annotation & RXRPC_TX_ANNO_MASK;
788 annotation &= ~RXRPC_TX_ANNO_MASK;
789 switch (*acks++) {
790 case RXRPC_ACK_TYPE_ACK:
791 summary->nr_acks++;
792 if (anno_type == RXRPC_TX_ANNO_ACK)
793 continue;
794 summary->nr_new_acks++;
795 call->rxtx_annotations[ix] =
796 RXRPC_TX_ANNO_ACK | annotation;
797 break;
798 case RXRPC_ACK_TYPE_NACK:
799 if (!summary->nr_nacks &&
800 call->acks_lowest_nak != seq) {
801 call->acks_lowest_nak = seq;
802 summary->new_low_nack = true;
803 }
804 summary->nr_nacks++;
805 if (anno_type == RXRPC_TX_ANNO_NAK)
806 continue;
807 summary->nr_new_nacks++;
808 if (anno_type == RXRPC_TX_ANNO_RETRANS)
809 continue;
810 call->rxtx_annotations[ix] =
811 RXRPC_TX_ANNO_NAK | annotation;
812 break;
813 default:
814 return rxrpc_proto_abort("SFT", call, 0);
815 }
816 }
817 }
818
819 /*
820 * Process an ACK packet.
821 *
822 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
823 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
824 *
825 * A hard-ACK means that a packet has been processed and may be discarded; a
826 * soft-ACK means that the packet may be discarded and retransmission
827 * requested. A phase is complete when all packets are hard-ACK'd.
828 */
829 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
830 u16 skew)
831 {
832 struct rxrpc_ack_summary summary = { 0 };
833 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
834 union {
835 struct rxrpc_ackpacket ack;
836 struct rxrpc_ackinfo info;
837 u8 acks[RXRPC_MAXACKS];
838 } buf;
839 rxrpc_serial_t acked_serial;
840 rxrpc_seq_t first_soft_ack, hard_ack;
841 int nr_acks, offset, ioffset;
842
843 _enter("");
844
845 offset = sizeof(struct rxrpc_wire_header);
846 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
847 _debug("extraction failure");
848 return rxrpc_proto_abort("XAK", call, 0);
849 }
850 offset += sizeof(buf.ack);
851
852 acked_serial = ntohl(buf.ack.serial);
853 first_soft_ack = ntohl(buf.ack.firstPacket);
854 hard_ack = first_soft_ack - 1;
855 nr_acks = buf.ack.nAcks;
856 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
857 buf.ack.reason : RXRPC_ACK__INVALID);
858
859 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
860 first_soft_ack, ntohl(buf.ack.previousPacket),
861 summary.ack_reason, nr_acks);
862
863 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
864 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
865 sp->hdr.serial);
866 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
867 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
868 sp->hdr.serial);
869
870 if (buf.ack.reason == RXRPC_ACK_PING) {
871 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
872 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
873 skew, sp->hdr.serial, true, true,
874 rxrpc_propose_ack_respond_to_ping);
875 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
876 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
877 skew, sp->hdr.serial, true, true,
878 rxrpc_propose_ack_respond_to_ack);
879 }
880
881 /* Discard any out-of-order or duplicate ACKs. */
882 if (before_eq(sp->hdr.serial, call->acks_latest))
883 return;
884
885 buf.info.rxMTU = 0;
886 ioffset = offset + nr_acks + 3;
887 if (skb->len >= ioffset + sizeof(buf.info) &&
888 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
889 return rxrpc_proto_abort("XAI", call, 0);
890
891 spin_lock(&call->input_lock);
892
893 /* Discard any out-of-order or duplicate ACKs. */
894 if (before_eq(sp->hdr.serial, call->acks_latest))
895 goto out;
896 call->acks_latest_ts = skb->tstamp;
897 call->acks_latest = sp->hdr.serial;
898
899 /* Parse rwind and mtu sizes if provided. */
900 if (buf.info.rxMTU)
901 rxrpc_input_ackinfo(call, skb, &buf.info);
902
903 if (first_soft_ack == 0) {
904 rxrpc_proto_abort("AK0", call, 0);
905 goto out;
906 }
907
908 /* Ignore ACKs unless we are or have just been transmitting. */
909 switch (READ_ONCE(call->state)) {
910 case RXRPC_CALL_CLIENT_SEND_REQUEST:
911 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
912 case RXRPC_CALL_SERVER_SEND_REPLY:
913 case RXRPC_CALL_SERVER_AWAIT_ACK:
914 break;
915 default:
916 goto out;
917 }
918
919 if (before(hard_ack, call->tx_hard_ack) ||
920 after(hard_ack, call->tx_top)) {
921 rxrpc_proto_abort("AKW", call, 0);
922 goto out;
923 }
924 if (nr_acks > call->tx_top - hard_ack) {
925 rxrpc_proto_abort("AKN", call, 0);
926 goto out;
927 }
928
929 if (after(hard_ack, call->tx_hard_ack)) {
930 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
931 rxrpc_end_tx_phase(call, false, "ETA");
932 goto out;
933 }
934 }
935
936 if (nr_acks > 0) {
937 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
938 rxrpc_proto_abort("XSA", call, 0);
939 goto out;
940 }
941 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
942 &summary);
943 }
944
945 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
946 RXRPC_TX_ANNO_LAST &&
947 summary.nr_acks == call->tx_top - hard_ack &&
948 rxrpc_is_client_call(call))
949 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
950 false, true,
951 rxrpc_propose_ack_ping_for_lost_reply);
952
953 rxrpc_congestion_management(call, skb, &summary, acked_serial);
954 out:
955 spin_unlock(&call->input_lock);
956 }
957
958 /*
959 * Process an ACKALL packet.
960 */
961 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
962 {
963 struct rxrpc_ack_summary summary = { 0 };
964 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
965
966 _proto("Rx ACKALL %%%u", sp->hdr.serial);
967
968 spin_lock(&call->input_lock);
969
970 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
971 rxrpc_end_tx_phase(call, false, "ETL");
972
973 spin_unlock(&call->input_lock);
974 }
975
976 /*
977 * Process an ABORT packet directed at a call.
978 */
979 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
980 {
981 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
982 __be32 wtmp;
983 u32 abort_code = RX_CALL_DEAD;
984
985 _enter("");
986
987 if (skb->len >= 4 &&
988 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
989 &wtmp, sizeof(wtmp)) >= 0)
990 abort_code = ntohl(wtmp);
991
992 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
993
994 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
995
996 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
997 abort_code, -ECONNABORTED))
998 rxrpc_notify_socket(call);
999 }
1000
1001 /*
1002 * Process an incoming call packet.
1003 */
1004 static void rxrpc_input_call_packet(struct rxrpc_call *call,
1005 struct sk_buff *skb, u16 skew)
1006 {
1007 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1008 unsigned long timo;
1009
1010 _enter("%p,%p", call, skb);
1011
1012 timo = READ_ONCE(call->next_rx_timo);
1013 if (timo) {
1014 unsigned long now = jiffies, expect_rx_by;
1015
1016 expect_rx_by = now + timo;
1017 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
1018 rxrpc_reduce_call_timer(call, expect_rx_by, now,
1019 rxrpc_timer_set_for_normal);
1020 }
1021
1022 switch (sp->hdr.type) {
1023 case RXRPC_PACKET_TYPE_DATA:
1024 rxrpc_input_data(call, skb, skew);
1025 break;
1026
1027 case RXRPC_PACKET_TYPE_ACK:
1028 rxrpc_input_ack(call, skb, skew);
1029 break;
1030
1031 case RXRPC_PACKET_TYPE_BUSY:
1032 _proto("Rx BUSY %%%u", sp->hdr.serial);
1033
1034 /* Just ignore BUSY packets from the server; the retry and
1035 * lifespan timers will take care of business. BUSY packets
1036 * from the client don't make sense.
1037 */
1038 break;
1039
1040 case RXRPC_PACKET_TYPE_ABORT:
1041 rxrpc_input_abort(call, skb);
1042 break;
1043
1044 case RXRPC_PACKET_TYPE_ACKALL:
1045 rxrpc_input_ackall(call, skb);
1046 break;
1047
1048 default:
1049 break;
1050 }
1051
1052 _leave("");
1053 }
1054
1055 /*
1056 * Handle a new service call on a channel implicitly completing the preceding
1057 * call on that channel. This does not apply to client conns.
1058 *
1059 * TODO: If callNumber > call_id + 1, renegotiate security.
1060 */
1061 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
1062 struct rxrpc_connection *conn,
1063 struct rxrpc_call *call)
1064 {
1065 switch (READ_ONCE(call->state)) {
1066 case RXRPC_CALL_SERVER_AWAIT_ACK:
1067 rxrpc_call_completed(call);
1068 /* Fall through */
1069 case RXRPC_CALL_COMPLETE:
1070 break;
1071 default:
1072 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
1073 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
1074 rxrpc_queue_call(call);
1075 }
1076 trace_rxrpc_improper_term(call);
1077 break;
1078 }
1079
1080 spin_lock(&rx->incoming_lock);
1081 __rxrpc_disconnect_call(conn, call);
1082 spin_unlock(&rx->incoming_lock);
1083 rxrpc_notify_socket(call);
1084 }
1085
1086 /*
1087 * post connection-level events to the connection
1088 * - this includes challenges, responses, some aborts and call terminal packet
1089 * retransmission.
1090 */
1091 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
1092 struct sk_buff *skb)
1093 {
1094 _enter("%p,%p", conn, skb);
1095
1096 skb_queue_tail(&conn->rx_queue, skb);
1097 rxrpc_queue_conn(conn);
1098 }
1099
1100 /*
1101 * post endpoint-level events to the local endpoint
1102 * - this includes debug and version messages
1103 */
1104 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
1105 struct sk_buff *skb)
1106 {
1107 _enter("%p,%p", local, skb);
1108
1109 skb_queue_tail(&local->event_queue, skb);
1110 rxrpc_queue_local(local);
1111 }
1112
1113 /*
1114 * put a packet up for transport-level abort
1115 */
1116 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
1117 {
1118 CHECK_SLAB_OKAY(&local->usage);
1119
1120 skb_queue_tail(&local->reject_queue, skb);
1121 rxrpc_queue_local(local);
1122 }
1123
1124 /*
1125 * Extract the wire header from a packet and translate the byte order.
1126 */
1127 static noinline
1128 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
1129 {
1130 struct rxrpc_wire_header whdr;
1131
1132 /* dig out the RxRPC connection details */
1133 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
1134 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
1135 tracepoint_string("bad_hdr"));
1136 return -EBADMSG;
1137 }
1138
1139 memset(sp, 0, sizeof(*sp));
1140 sp->hdr.epoch = ntohl(whdr.epoch);
1141 sp->hdr.cid = ntohl(whdr.cid);
1142 sp->hdr.callNumber = ntohl(whdr.callNumber);
1143 sp->hdr.seq = ntohl(whdr.seq);
1144 sp->hdr.serial = ntohl(whdr.serial);
1145 sp->hdr.flags = whdr.flags;
1146 sp->hdr.type = whdr.type;
1147 sp->hdr.userStatus = whdr.userStatus;
1148 sp->hdr.securityIndex = whdr.securityIndex;
1149 sp->hdr._rsvd = ntohs(whdr._rsvd);
1150 sp->hdr.serviceId = ntohs(whdr.serviceId);
1151 return 0;
1152 }
1153
1154 /*
1155 * handle data received on the local endpoint
1156 * - may be called in interrupt context
1157 *
1158 * The socket is locked by the caller and this prevents the socket from being
1159 * shut down and the local endpoint from going away, thus sk_user_data will not
1160 * be cleared until this function returns.
1161 *
1162 * Called with the RCU read lock held from the IP layer via UDP.
1163 */
1164 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
1165 {
1166 struct rxrpc_connection *conn;
1167 struct rxrpc_channel *chan;
1168 struct rxrpc_call *call = NULL;
1169 struct rxrpc_skb_priv *sp;
1170 struct rxrpc_local *local = udp_sk->sk_user_data;
1171 struct rxrpc_peer *peer = NULL;
1172 struct rxrpc_sock *rx = NULL;
1173 unsigned int channel;
1174 int skew = 0;
1175
1176 _enter("%p", udp_sk);
1177
1178 if (skb->tstamp == 0)
1179 skb->tstamp = ktime_get_real();
1180
1181 rxrpc_new_skb(skb, rxrpc_skb_rx_received);
1182
1183 skb_pull(skb, sizeof(struct udphdr));
1184
1185 /* The UDP protocol already released all skb resources;
1186 * we are free to add our own data there.
1187 */
1188 sp = rxrpc_skb(skb);
1189
1190 /* dig out the RxRPC connection details */
1191 if (rxrpc_extract_header(sp, skb) < 0)
1192 goto bad_message;
1193
1194 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1195 static int lose;
1196 if ((lose++ & 7) == 7) {
1197 trace_rxrpc_rx_lose(sp);
1198 rxrpc_free_skb(skb, rxrpc_skb_rx_lost);
1199 return 0;
1200 }
1201 }
1202
1203 if (skb->tstamp == 0)
1204 skb->tstamp = ktime_get_real();
1205 trace_rxrpc_rx_packet(sp);
1206
1207 switch (sp->hdr.type) {
1208 case RXRPC_PACKET_TYPE_VERSION:
1209 if (rxrpc_to_client(sp))
1210 goto discard;
1211 rxrpc_post_packet_to_local(local, skb);
1212 goto out;
1213
1214 case RXRPC_PACKET_TYPE_BUSY:
1215 if (rxrpc_to_server(sp))
1216 goto discard;
1217 /* Fall through */
1218 case RXRPC_PACKET_TYPE_ACK:
1219 case RXRPC_PACKET_TYPE_ACKALL:
1220 if (sp->hdr.callNumber == 0)
1221 goto bad_message;
1222 /* Fall through */
1223 case RXRPC_PACKET_TYPE_ABORT:
1224 break;
1225
1226 case RXRPC_PACKET_TYPE_DATA:
1227 if (sp->hdr.callNumber == 0 ||
1228 sp->hdr.seq == 0)
1229 goto bad_message;
1230 if (sp->hdr.flags & RXRPC_JUMBO_PACKET &&
1231 !rxrpc_validate_jumbo(skb))
1232 goto bad_message;
1233 break;
1234
1235 case RXRPC_PACKET_TYPE_CHALLENGE:
1236 if (rxrpc_to_server(sp))
1237 goto discard;
1238 break;
1239 case RXRPC_PACKET_TYPE_RESPONSE:
1240 if (rxrpc_to_client(sp))
1241 goto discard;
1242 break;
1243
1244 /* Packet types 9-11 should just be ignored. */
1245 case RXRPC_PACKET_TYPE_PARAMS:
1246 case RXRPC_PACKET_TYPE_10:
1247 case RXRPC_PACKET_TYPE_11:
1248 goto discard;
1249
1250 default:
1251 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1252 goto bad_message;
1253 }
1254
1255 if (sp->hdr.serviceId == 0)
1256 goto bad_message;
1257
1258 if (rxrpc_to_server(sp)) {
1259 /* Weed out packets to services we're not offering. Packets
1260 * that would begin a call are explicitly rejected and the rest
1261 * are just discarded.
1262 */
1263 rx = rcu_dereference(local->service);
1264 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
1265 sp->hdr.serviceId != rx->second_service)) {
1266 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
1267 sp->hdr.seq == 1)
1268 goto unsupported_service;
1269 goto discard;
1270 }
1271 }
1272
1273 conn = rxrpc_find_connection_rcu(local, skb, &peer);
1274 if (conn) {
1275 if (sp->hdr.securityIndex != conn->security_ix)
1276 goto wrong_security;
1277
1278 if (sp->hdr.serviceId != conn->service_id) {
1279 int old_id;
1280
1281 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
1282 goto reupgrade;
1283 old_id = cmpxchg(&conn->service_id, conn->params.service_id,
1284 sp->hdr.serviceId);
1285
1286 if (old_id != conn->params.service_id &&
1287 old_id != sp->hdr.serviceId)
1288 goto reupgrade;
1289 }
1290
1291 if (sp->hdr.callNumber == 0) {
1292 /* Connection-level packet */
1293 _debug("CONN %p {%d}", conn, conn->debug_id);
1294 rxrpc_post_packet_to_conn(conn, skb);
1295 goto out;
1296 }
1297
1298 /* Note the serial number skew here */
1299 skew = (int)sp->hdr.serial - (int)conn->hi_serial;
1300 if (skew >= 0) {
1301 if (skew > 0)
1302 conn->hi_serial = sp->hdr.serial;
1303 } else {
1304 skew = -skew;
1305 skew = min(skew, 65535);
1306 }
1307
1308 /* Call-bound packets are routed by connection channel. */
1309 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1310 chan = &conn->channels[channel];
1311
1312 /* Ignore really old calls */
1313 if (sp->hdr.callNumber < chan->last_call)
1314 goto discard;
1315
1316 if (sp->hdr.callNumber == chan->last_call) {
1317 if (chan->call ||
1318 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
1319 goto discard;
1320
1321 /* For the previous service call, if completed
1322 * successfully, we discard all further packets.
1323 */
1324 if (rxrpc_conn_is_service(conn) &&
1325 chan->last_type == RXRPC_PACKET_TYPE_ACK)
1326 goto discard;
1327
1328 /* But otherwise we need to retransmit the final packet
1329 * from data cached in the connection record.
1330 */
1331 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
1332 trace_rxrpc_rx_data(chan->call_debug_id,
1333 sp->hdr.seq,
1334 sp->hdr.serial,
1335 sp->hdr.flags, 0);
1336 rxrpc_post_packet_to_conn(conn, skb);
1337 goto out;
1338 }
1339
1340 call = rcu_dereference(chan->call);
1341
1342 if (sp->hdr.callNumber > chan->call_id) {
1343 if (rxrpc_to_client(sp))
1344 goto reject_packet;
1345 if (call)
1346 rxrpc_input_implicit_end_call(rx, conn, call);
1347 call = NULL;
1348 }
1349
1350 if (call) {
1351 if (sp->hdr.serviceId != call->service_id)
1352 call->service_id = sp->hdr.serviceId;
1353 if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
1354 call->rx_serial = sp->hdr.serial;
1355 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
1356 set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
1357 }
1358 }
1359
1360 if (!call || atomic_read(&call->usage) == 0) {
1361 if (rxrpc_to_client(sp) ||
1362 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1363 goto bad_message;
1364 if (sp->hdr.seq != 1)
1365 goto discard;
1366 call = rxrpc_new_incoming_call(local, rx, skb);
1367 if (!call)
1368 goto reject_packet;
1369 rxrpc_send_ping(call, skb, skew);
1370 mutex_unlock(&call->user_mutex);
1371 }
1372
1373 rxrpc_input_call_packet(call, skb, skew);
1374 goto discard;
1375
1376 discard:
1377 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
1378 out:
1379 trace_rxrpc_rx_done(0, 0);
1380 return 0;
1381
1382 wrong_security:
1383 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1384 RXKADINCONSISTENCY, EBADMSG);
1385 skb->priority = RXKADINCONSISTENCY;
1386 goto post_abort;
1387
1388 unsupported_service:
1389 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1390 RX_INVALID_OPERATION, EOPNOTSUPP);
1391 skb->priority = RX_INVALID_OPERATION;
1392 goto post_abort;
1393
1394 reupgrade:
1395 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1396 RX_PROTOCOL_ERROR, EBADMSG);
1397 goto protocol_error;
1398
1399 bad_message:
1400 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1401 RX_PROTOCOL_ERROR, EBADMSG);
1402 protocol_error:
1403 skb->priority = RX_PROTOCOL_ERROR;
1404 post_abort:
1405 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
1406 reject_packet:
1407 trace_rxrpc_rx_done(skb->mark, skb->priority);
1408 rxrpc_reject_packet(local, skb);
1409 _leave(" [badmsg]");
1410 return 0;
1411 }
Linux with added FPC-III support