1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC packet reception
4 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
16 #include <linux/in6.h>
17 #include <linux/icmp.h>
18 #include <linux/gfp.h>
20 #include <net/af_rxrpc.h>
23 #include <net/net_namespace.h>
24 #include "ar-internal.h"
26 static void rxrpc_proto_abort(const char *why,
27 struct rxrpc_call *call, rxrpc_seq_t seq)
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);
36 * Do TCP-style congestion management [RFC 5681].
38 static void rxrpc_congestion_management(struct rxrpc_call *call,
40 struct rxrpc_ack_summary *summary,
41 rxrpc_serial_t acked_serial)
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;
48 summary->flight_size =
49 (call->tx_top - call->tx_hard_ack) - summary->nr_acks;
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);
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;
64 cumulative_acks += summary->nr_new_acks;
65 cumulative_acks += summary->nr_rot_new_acks;
66 if (cumulative_acks > 255)
67 cumulative_acks = 255;
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;
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)
81 if (cwnd >= call->cong_ssthresh) {
82 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
83 call->cong_tstamp = skb->tstamp;
87 case RXRPC_CALL_CONGEST_AVOIDANCE:
88 if (summary->nr_nacks > 0)
89 goto packet_loss_detected;
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.
94 if (call->peer->rtt_usage == 0)
96 if (ktime_before(skb->tstamp,
97 ktime_add_ns(call->cong_tstamp,
100 change = rxrpc_cong_rtt_window_end;
101 call->cong_tstamp = skb->tstamp;
102 if (cumulative_acks >= cwnd)
106 case RXRPC_CALL_PACKET_LOSS:
107 if (summary->nr_nacks == 0)
108 goto resume_normality;
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;
118 call->cong_dup_acks++;
119 if (call->cong_dup_acks < 3)
120 goto send_extra_data;
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;
132 case RXRPC_CALL_FAST_RETRANSMIT:
133 if (!summary->new_low_nack) {
134 if (summary->nr_new_acks == 0)
136 call->cong_dup_acks++;
137 if (call->cong_dup_acks == 2) {
138 change = rxrpc_cong_retransmit_again;
139 call->cong_dup_acks = 0;
143 change = rxrpc_cong_progress;
144 cwnd = call->cong_ssthresh;
145 if (summary->nr_nacks == 0)
146 goto 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;
163 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
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);
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;
183 /* Send some previously unsent DATA if we have some to advance the ACK
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) {
190 wake_up(&call->waitq);
192 goto out_no_clear_ca;
196 * Apply a hard ACK by advancing the Tx window.
198 static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
199 struct rxrpc_ack_summary *summary)
201 struct sk_buff *skb, *list = NULL;
202 bool rot_last = false;
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;
213 spin_lock(&call->lock);
215 while (before(call->tx_hard_ack, to)) {
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;
226 if (annotation & RXRPC_TX_ANNO_LAST) {
227 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
230 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
231 summary->nr_rot_new_acks++;
234 spin_unlock(&call->lock);
236 trace_rxrpc_transmit(call, (rot_last ?
237 rxrpc_transmit_rotate_last :
238 rxrpc_transmit_rotate));
239 wake_up(&call->waitq);
244 skb_mark_not_on_list(skb);
245 rxrpc_free_skb(skb, rxrpc_skb_freed);
252 * End the transmission phase of a call.
254 * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
255 * or a final ACK packet.
257 static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
258 const char *abort_why)
262 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
264 write_lock(&call->state_lock);
268 case RXRPC_CALL_CLIENT_SEND_REQUEST:
269 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
271 call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
273 call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
276 case RXRPC_CALL_SERVER_AWAIT_ACK:
277 __rxrpc_call_completed(call);
278 rxrpc_notify_socket(call);
286 write_unlock(&call->state_lock);
287 if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
288 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
290 trace_rxrpc_transmit(call, rxrpc_transmit_end);
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);
302 * Begin the reply reception phase of a call.
304 static bool rxrpc_receiving_reply(struct rxrpc_call *call)
306 struct rxrpc_ack_summary summary = { 0 };
307 unsigned long now, timo;
308 rxrpc_seq_t top = READ_ONCE(call->tx_top);
310 if (call->ackr_reason) {
311 spin_lock_bh(&call->lock);
312 call->ackr_reason = 0;
313 spin_unlock_bh(&call->lock);
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);
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);
327 if (!rxrpc_end_tx_phase(call, true, "ETD"))
329 call->tx_phase = false;
334 * Scan a data packet to validate its structure and to work out how many
335 * subpackets it contains.
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
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
345 static bool rxrpc_validate_data(struct sk_buff *skb)
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;
353 if (flags & RXRPC_REQUEST_ACK)
354 __set_bit(sp->nr_subpackets, sp->rx_req_ack);
357 if (!(flags & RXRPC_JUMBO_PACKET))
360 if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
362 if (flags & RXRPC_LAST_PACKET)
364 offset += RXRPC_JUMBO_DATALEN;
365 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
367 offset += sizeof(struct rxrpc_jumbo_header);
370 if (flags & RXRPC_LAST_PACKET)
371 sp->rx_flags |= RXRPC_SKB_INCL_LAST;
379 * Handle reception of a duplicate packet.
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.
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).
391 static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
392 bool is_jumbo, bool *_jumbo_bad)
394 /* Discard normal packets that are duplicates. */
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.
403 call->nr_jumbo_bad++;
409 * Process a DATA packet, adding the packet to the Rx ring. The caller's
410 * packet ref must be passed on or discarded.
412 static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
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;
422 _enter("{%u,%u},{%u,%u}",
423 call->rx_hard_ack, call->rx_top, skb->len, seq0);
425 _proto("Rx DATA %%%u { #%u f=%02x n=%u }",
426 sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets);
428 state = READ_ONCE(call->state);
429 if (state >= RXRPC_CALL_COMPLETE) {
430 rxrpc_free_skb(skb, rxrpc_skb_freed);
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;
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);
447 spin_lock(&call->input_lock);
449 /* Received data implicitly ACKs all of the request packets we sent
450 * when we're acting as a client.
452 if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
453 state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
454 !rxrpc_receiving_reply(call))
457 call->ackr_prev_seq = seq0;
458 hard_ack = READ_ONCE(call->rx_hard_ack);
460 nr_subpackets = sp->nr_subpackets;
461 if (nr_subpackets > 1) {
462 if (call->nr_jumbo_bad > 3) {
463 ack = RXRPC_ACK_NOSPACE;
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;
477 _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }",
478 j, serial, seq, terminal, last);
481 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
482 seq != call->rx_top) {
483 rxrpc_proto_abort("LSN", call, seq);
487 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
488 after_eq(seq, call->rx_top)) {
489 rxrpc_proto_abort("LSA", call, seq);
496 flags |= RXRPC_LAST_PACKET;
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);
503 if (before_eq(seq, hard_ack)) {
504 ack = RXRPC_ACK_DUPLICATE;
509 if (call->rxtx_buffer[ix]) {
510 rxrpc_input_dup_data(call, seq, nr_subpackets > 1,
512 if (ack != RXRPC_ACK_DUPLICATE) {
513 ack = RXRPC_ACK_DUPLICATE;
516 immediate_ack = true;
520 if (after(seq, hard_ack + call->rx_winsize)) {
521 ack = RXRPC_ACK_EXCEEDS_WINDOW;
523 if (flags & RXRPC_JUMBO_PACKET) {
525 call->nr_jumbo_bad++;
533 if (flags & RXRPC_REQUEST_ACK && !ack) {
534 ack = RXRPC_ACK_REQUESTED;
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
543 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
544 * and also rxrpc_fill_out_ack().
547 rxrpc_get_skb(skb, rxrpc_skb_got);
548 call->rxtx_annotations[ix] = annotation;
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 */
556 ack = RXRPC_ACK_DELAY;
559 immediate_ack = true;
563 /* From this point on, we're not allowed to touch the
564 * packet any longer as its ref now belongs to the Rx
572 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
574 ack = RXRPC_ACK_DELAY;
577 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
579 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
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;
588 call->rx_expect_next = seq + 1;
594 rxrpc_propose_ACK(call, ack, ack_serial,
596 rxrpc_propose_ack_input_data);
598 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial,
600 rxrpc_propose_ack_input_data);
602 trace_rxrpc_notify_socket(call->debug_id, serial);
603 rxrpc_notify_socket(call);
606 spin_unlock(&call->input_lock);
607 rxrpc_free_skb(skb, rxrpc_skb_freed);
612 * Process a requested ACK.
614 static void rxrpc_input_requested_ack(struct rxrpc_call *call,
616 rxrpc_serial_t orig_serial,
617 rxrpc_serial_t ack_serial)
619 struct rxrpc_skb_priv *sp;
624 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
625 skb = call->rxtx_buffer[ix];
629 sent_at = skb->tstamp;
630 smp_rmb(); /* Read timestamp before serial. */
632 if (sp->hdr.serial != orig_serial)
640 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
641 orig_serial, ack_serial, sent_at, resp_time);
645 * Process the response to a ping that we sent to find out if we lost an ACK.
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.
651 static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
653 rxrpc_seq_t top, bottom, seq;
656 spin_lock_bh(&call->lock);
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;
666 if (anno_type != RXRPC_TX_ANNO_UNACK)
668 annotation &= ~RXRPC_TX_ANNO_MASK;
669 annotation |= RXRPC_TX_ANNO_RETRANS;
670 call->rxtx_annotations[ix] = annotation;
675 spin_unlock_bh(&call->lock);
677 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
678 rxrpc_queue_call(call);
682 * Process a ping response.
684 static void rxrpc_input_ping_response(struct rxrpc_call *call,
686 rxrpc_serial_t orig_serial,
687 rxrpc_serial_t ack_serial)
689 rxrpc_serial_t ping_serial;
692 ping_time = call->ping_time;
694 ping_serial = READ_ONCE(call->ping_serial);
696 if (orig_serial == call->acks_lost_ping)
697 rxrpc_input_check_for_lost_ack(call);
699 if (before(orig_serial, ping_serial) ||
700 !test_and_clear_bit(RXRPC_CALL_PINGING, &call->flags))
702 if (after(orig_serial, ping_serial))
705 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
706 orig_serial, ack_serial, ping_time, resp_time);
710 * Process the extra information that may be appended to an ACK packet
712 static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
713 struct rxrpc_ackinfo *ackinfo)
715 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
716 struct rxrpc_peer *peer;
719 u32 rwind = ntohl(ackinfo->rwind);
721 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
723 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
724 rwind, ntohl(ackinfo->jumbo_max));
726 if (call->tx_winsize != rwind) {
727 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
728 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
729 if (rwind > call->tx_winsize)
731 trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
732 ntohl(ackinfo->rwind), wake);
733 call->tx_winsize = rwind;
736 if (call->cong_ssthresh > rwind)
737 call->cong_ssthresh = rwind;
739 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
742 if (mtu < peer->maxdata) {
743 spin_lock_bh(&peer->lock);
745 peer->mtu = mtu + peer->hdrsize;
746 spin_unlock_bh(&peer->lock);
747 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
751 wake_up(&call->waitq);
755 * Process individual soft ACKs.
757 * Each ACK in the array corresponds to one packet and can be either an ACK or
758 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
759 * packets that lie beyond the end of the ACK list are scheduled for resend by
760 * the timer on the basis that the peer might just not have processed them at
761 * the time the ACK was sent.
763 static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
764 rxrpc_seq_t seq, int nr_acks,
765 struct rxrpc_ack_summary *summary)
768 u8 annotation, anno_type;
770 for (; nr_acks > 0; nr_acks--, seq++) {
771 ix = seq & RXRPC_RXTX_BUFF_MASK;
772 annotation = call->rxtx_annotations[ix];
773 anno_type = annotation & RXRPC_TX_ANNO_MASK;
774 annotation &= ~RXRPC_TX_ANNO_MASK;
776 case RXRPC_ACK_TYPE_ACK:
778 if (anno_type == RXRPC_TX_ANNO_ACK)
780 summary->nr_new_acks++;
781 call->rxtx_annotations[ix] =
782 RXRPC_TX_ANNO_ACK | annotation;
784 case RXRPC_ACK_TYPE_NACK:
785 if (!summary->nr_nacks &&
786 call->acks_lowest_nak != seq) {
787 call->acks_lowest_nak = seq;
788 summary->new_low_nack = true;
791 if (anno_type == RXRPC_TX_ANNO_NAK)
793 summary->nr_new_nacks++;
794 if (anno_type == RXRPC_TX_ANNO_RETRANS)
796 call->rxtx_annotations[ix] =
797 RXRPC_TX_ANNO_NAK | annotation;
800 return rxrpc_proto_abort("SFT", call, 0);
806 * Process an ACK packet.
808 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
809 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
811 * A hard-ACK means that a packet has been processed and may be discarded; a
812 * soft-ACK means that the packet may be discarded and retransmission
813 * requested. A phase is complete when all packets are hard-ACK'd.
815 static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
817 struct rxrpc_ack_summary summary = { 0 };
818 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
820 struct rxrpc_ackpacket ack;
821 struct rxrpc_ackinfo info;
822 u8 acks[RXRPC_MAXACKS];
824 rxrpc_serial_t acked_serial;
825 rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
826 int nr_acks, offset, ioffset;
830 offset = sizeof(struct rxrpc_wire_header);
831 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
832 _debug("extraction failure");
833 return rxrpc_proto_abort("XAK", call, 0);
835 offset += sizeof(buf.ack);
837 acked_serial = ntohl(buf.ack.serial);
838 first_soft_ack = ntohl(buf.ack.firstPacket);
839 prev_pkt = ntohl(buf.ack.previousPacket);
840 hard_ack = first_soft_ack - 1;
841 nr_acks = buf.ack.nAcks;
842 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
843 buf.ack.reason : RXRPC_ACK__INVALID);
845 trace_rxrpc_rx_ack(call, sp->hdr.serial, acked_serial,
846 first_soft_ack, prev_pkt,
847 summary.ack_reason, nr_acks);
849 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
850 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
852 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
853 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
856 if (buf.ack.reason == RXRPC_ACK_PING) {
857 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
858 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
859 sp->hdr.serial, true, true,
860 rxrpc_propose_ack_respond_to_ping);
861 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
862 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
863 sp->hdr.serial, true, true,
864 rxrpc_propose_ack_respond_to_ack);
867 /* Discard any out-of-order or duplicate ACKs (outside lock). */
868 if (before(first_soft_ack, call->ackr_first_seq) ||
869 before(prev_pkt, call->ackr_prev_seq))
873 ioffset = offset + nr_acks + 3;
874 if (skb->len >= ioffset + sizeof(buf.info) &&
875 skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
876 return rxrpc_proto_abort("XAI", call, 0);
878 spin_lock(&call->input_lock);
880 /* Discard any out-of-order or duplicate ACKs (inside lock). */
881 if (before(first_soft_ack, call->ackr_first_seq) ||
882 before(prev_pkt, call->ackr_prev_seq))
884 call->acks_latest_ts = skb->tstamp;
886 call->ackr_first_seq = first_soft_ack;
887 call->ackr_prev_seq = prev_pkt;
889 /* Parse rwind and mtu sizes if provided. */
891 rxrpc_input_ackinfo(call, skb, &buf.info);
893 if (first_soft_ack == 0) {
894 rxrpc_proto_abort("AK0", call, 0);
898 /* Ignore ACKs unless we are or have just been transmitting. */
899 switch (READ_ONCE(call->state)) {
900 case RXRPC_CALL_CLIENT_SEND_REQUEST:
901 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
902 case RXRPC_CALL_SERVER_SEND_REPLY:
903 case RXRPC_CALL_SERVER_AWAIT_ACK:
909 if (before(hard_ack, call->tx_hard_ack) ||
910 after(hard_ack, call->tx_top)) {
911 rxrpc_proto_abort("AKW", call, 0);
914 if (nr_acks > call->tx_top - hard_ack) {
915 rxrpc_proto_abort("AKN", call, 0);
919 if (after(hard_ack, call->tx_hard_ack)) {
920 if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
921 rxrpc_end_tx_phase(call, false, "ETA");
927 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) {
928 rxrpc_proto_abort("XSA", call, 0);
931 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
935 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
936 RXRPC_TX_ANNO_LAST &&
937 summary.nr_acks == call->tx_top - hard_ack &&
938 rxrpc_is_client_call(call))
939 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
941 rxrpc_propose_ack_ping_for_lost_reply);
943 rxrpc_congestion_management(call, skb, &summary, acked_serial);
945 spin_unlock(&call->input_lock);
949 * Process an ACKALL packet.
951 static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
953 struct rxrpc_ack_summary summary = { 0 };
954 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
956 _proto("Rx ACKALL %%%u", sp->hdr.serial);
958 spin_lock(&call->input_lock);
960 if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
961 rxrpc_end_tx_phase(call, false, "ETL");
963 spin_unlock(&call->input_lock);
967 * Process an ABORT packet directed at a call.
969 static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
971 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
973 u32 abort_code = RX_CALL_DEAD;
978 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
979 &wtmp, sizeof(wtmp)) >= 0)
980 abort_code = ntohl(wtmp);
982 trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
984 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
986 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
987 abort_code, -ECONNABORTED))
988 rxrpc_notify_socket(call);
992 * Process an incoming call packet.
994 static void rxrpc_input_call_packet(struct rxrpc_call *call,
997 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1000 _enter("%p,%p", call, skb);
1002 timo = READ_ONCE(call->next_rx_timo);
1004 unsigned long now = jiffies, expect_rx_by;
1006 expect_rx_by = now + timo;
1007 WRITE_ONCE(call->expect_rx_by, expect_rx_by);
1008 rxrpc_reduce_call_timer(call, expect_rx_by, now,
1009 rxrpc_timer_set_for_normal);
1012 switch (sp->hdr.type) {
1013 case RXRPC_PACKET_TYPE_DATA:
1014 rxrpc_input_data(call, skb);
1017 case RXRPC_PACKET_TYPE_ACK:
1018 rxrpc_input_ack(call, skb);
1021 case RXRPC_PACKET_TYPE_BUSY:
1022 _proto("Rx BUSY %%%u", sp->hdr.serial);
1024 /* Just ignore BUSY packets from the server; the retry and
1025 * lifespan timers will take care of business. BUSY packets
1026 * from the client don't make sense.
1030 case RXRPC_PACKET_TYPE_ABORT:
1031 rxrpc_input_abort(call, skb);
1034 case RXRPC_PACKET_TYPE_ACKALL:
1035 rxrpc_input_ackall(call, skb);
1042 rxrpc_free_skb(skb, rxrpc_skb_freed);
1048 * Handle a new service call on a channel implicitly completing the preceding
1049 * call on that channel. This does not apply to client conns.
1051 * TODO: If callNumber > call_id + 1, renegotiate security.
1053 static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
1054 struct rxrpc_connection *conn,
1055 struct rxrpc_call *call)
1057 switch (READ_ONCE(call->state)) {
1058 case RXRPC_CALL_SERVER_AWAIT_ACK:
1059 rxrpc_call_completed(call);
1061 case RXRPC_CALL_COMPLETE:
1064 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
1065 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
1066 rxrpc_queue_call(call);
1068 trace_rxrpc_improper_term(call);
1072 spin_lock(&rx->incoming_lock);
1073 __rxrpc_disconnect_call(conn, call);
1074 spin_unlock(&rx->incoming_lock);
1075 rxrpc_notify_socket(call);
1079 * post connection-level events to the connection
1080 * - this includes challenges, responses, some aborts and call terminal packet
1083 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
1084 struct sk_buff *skb)
1086 _enter("%p,%p", conn, skb);
1088 skb_queue_tail(&conn->rx_queue, skb);
1089 rxrpc_queue_conn(conn);
1093 * post endpoint-level events to the local endpoint
1094 * - this includes debug and version messages
1096 static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
1097 struct sk_buff *skb)
1099 _enter("%p,%p", local, skb);
1101 if (rxrpc_get_local_maybe(local)) {
1102 skb_queue_tail(&local->event_queue, skb);
1103 rxrpc_queue_local(local);
1105 rxrpc_free_skb(skb, rxrpc_skb_freed);
1110 * put a packet up for transport-level abort
1112 static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
1114 CHECK_SLAB_OKAY(&local->usage);
1116 if (rxrpc_get_local_maybe(local)) {
1117 skb_queue_tail(&local->reject_queue, skb);
1118 rxrpc_queue_local(local);
1120 rxrpc_free_skb(skb, rxrpc_skb_freed);
1125 * Extract the wire header from a packet and translate the byte order.
1128 int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
1130 struct rxrpc_wire_header whdr;
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"));
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);
1155 * handle data received on the local endpoint
1156 * - may be called in interrupt context
1158 * [!] Note that as this is called from the encap_rcv hook, the socket is not
1159 * held locked by the caller and nothing prevents sk_user_data on the UDP from
1160 * being cleared in the middle of processing this function.
1162 * Called with the RCU read lock held from the IP layer via UDP.
1164 int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
1166 struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
1167 struct rxrpc_connection *conn;
1168 struct rxrpc_channel *chan;
1169 struct rxrpc_call *call = NULL;
1170 struct rxrpc_skb_priv *sp;
1171 struct rxrpc_peer *peer = NULL;
1172 struct rxrpc_sock *rx = NULL;
1173 unsigned int channel;
1175 _enter("%p", udp_sk);
1177 if (unlikely(!local)) {
1181 if (skb->tstamp == 0)
1182 skb->tstamp = ktime_get_real();
1184 rxrpc_new_skb(skb, rxrpc_skb_received);
1186 skb_pull(skb, sizeof(struct udphdr));
1188 /* The UDP protocol already released all skb resources;
1189 * we are free to add our own data there.
1191 sp = rxrpc_skb(skb);
1193 /* dig out the RxRPC connection details */
1194 if (rxrpc_extract_header(sp, skb) < 0)
1197 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1199 if ((lose++ & 7) == 7) {
1200 trace_rxrpc_rx_lose(sp);
1201 rxrpc_free_skb(skb, rxrpc_skb_lost);
1206 if (skb->tstamp == 0)
1207 skb->tstamp = ktime_get_real();
1208 trace_rxrpc_rx_packet(sp);
1210 switch (sp->hdr.type) {
1211 case RXRPC_PACKET_TYPE_VERSION:
1212 if (rxrpc_to_client(sp))
1214 rxrpc_post_packet_to_local(local, skb);
1217 case RXRPC_PACKET_TYPE_BUSY:
1218 if (rxrpc_to_server(sp))
1221 case RXRPC_PACKET_TYPE_ACK:
1222 case RXRPC_PACKET_TYPE_ACKALL:
1223 if (sp->hdr.callNumber == 0)
1226 case RXRPC_PACKET_TYPE_ABORT:
1229 case RXRPC_PACKET_TYPE_DATA:
1230 if (sp->hdr.callNumber == 0 ||
1233 if (!rxrpc_validate_data(skb))
1236 /* Unshare the packet so that it can be modified for in-place
1239 if (sp->hdr.securityIndex != 0) {
1240 struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
1242 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
1247 rxrpc_eaten_skb(skb, rxrpc_skb_received);
1249 rxrpc_new_skb(skb, rxrpc_skb_unshared);
1250 sp = rxrpc_skb(skb);
1255 case RXRPC_PACKET_TYPE_CHALLENGE:
1256 if (rxrpc_to_server(sp))
1259 case RXRPC_PACKET_TYPE_RESPONSE:
1260 if (rxrpc_to_client(sp))
1264 /* Packet types 9-11 should just be ignored. */
1265 case RXRPC_PACKET_TYPE_PARAMS:
1266 case RXRPC_PACKET_TYPE_10:
1267 case RXRPC_PACKET_TYPE_11:
1271 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1275 if (sp->hdr.serviceId == 0)
1278 if (rxrpc_to_server(sp)) {
1279 /* Weed out packets to services we're not offering. Packets
1280 * that would begin a call are explicitly rejected and the rest
1281 * are just discarded.
1283 rx = rcu_dereference(local->service);
1284 if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
1285 sp->hdr.serviceId != rx->second_service)) {
1286 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
1288 goto unsupported_service;
1293 conn = rxrpc_find_connection_rcu(local, skb, &peer);
1295 if (sp->hdr.securityIndex != conn->security_ix)
1296 goto wrong_security;
1298 if (sp->hdr.serviceId != conn->service_id) {
1301 if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
1303 old_id = cmpxchg(&conn->service_id, conn->params.service_id,
1306 if (old_id != conn->params.service_id &&
1307 old_id != sp->hdr.serviceId)
1311 if (sp->hdr.callNumber == 0) {
1312 /* Connection-level packet */
1313 _debug("CONN %p {%d}", conn, conn->debug_id);
1314 rxrpc_post_packet_to_conn(conn, skb);
1318 if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
1319 conn->hi_serial = sp->hdr.serial;
1321 /* Call-bound packets are routed by connection channel. */
1322 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1323 chan = &conn->channels[channel];
1325 /* Ignore really old calls */
1326 if (sp->hdr.callNumber < chan->last_call)
1329 if (sp->hdr.callNumber == chan->last_call) {
1331 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
1334 /* For the previous service call, if completed
1335 * successfully, we discard all further packets.
1337 if (rxrpc_conn_is_service(conn) &&
1338 chan->last_type == RXRPC_PACKET_TYPE_ACK)
1341 /* But otherwise we need to retransmit the final packet
1342 * from data cached in the connection record.
1344 if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
1345 trace_rxrpc_rx_data(chan->call_debug_id,
1349 rxrpc_post_packet_to_conn(conn, skb);
1353 call = rcu_dereference(chan->call);
1355 if (sp->hdr.callNumber > chan->call_id) {
1356 if (rxrpc_to_client(sp))
1359 rxrpc_input_implicit_end_call(rx, conn, call);
1364 if (sp->hdr.serviceId != call->service_id)
1365 call->service_id = sp->hdr.serviceId;
1366 if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
1367 call->rx_serial = sp->hdr.serial;
1368 if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
1369 set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
1373 if (!call || atomic_read(&call->usage) == 0) {
1374 if (rxrpc_to_client(sp) ||
1375 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1377 if (sp->hdr.seq != 1)
1379 call = rxrpc_new_incoming_call(local, rx, skb);
1384 /* Process a call packet; this either discards or passes on the ref
1387 rxrpc_input_call_packet(call, skb);
1391 rxrpc_free_skb(skb, rxrpc_skb_freed);
1393 trace_rxrpc_rx_done(0, 0);
1397 trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1398 RXKADINCONSISTENCY, EBADMSG);
1399 skb->priority = RXKADINCONSISTENCY;
1402 unsupported_service:
1403 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1404 RX_INVALID_OPERATION, EOPNOTSUPP);
1405 skb->priority = RX_INVALID_OPERATION;
1409 trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1410 RX_PROTOCOL_ERROR, EBADMSG);
1411 goto protocol_error;
1414 trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1415 RX_PROTOCOL_ERROR, EBADMSG);
1417 skb->priority = RX_PROTOCOL_ERROR;
1419 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
1421 trace_rxrpc_rx_done(skb->mark, skb->priority);
1422 rxrpc_reject_packet(local, skb);
1423 _leave(" [badmsg]");