blob: 1461d30583c9bf5eaa938aa934323dc8db854bf4 [file] [log] [blame]
David Howells17926a72007-04-26 15:48:28 -07001/* RxRPC packet reception
2 *
David Howells248f2192016-09-08 11:10:12 +01003 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
David Howells17926a72007-04-26 15:48:28 -07004 * 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
Joe Perches9b6d5392016-06-02 12:08:52 -070012#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
David Howells17926a72007-04-26 15:48:28 -070014#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/gfp.h>
David Howells17926a72007-04-26 15:48:28 -070023#include <net/sock.h>
24#include <net/af_rxrpc.h>
25#include <net/ip.h>
Herbert Xu1781f7f2007-12-11 11:30:32 -080026#include <net/udp.h>
Pavel Emelyanov02833282008-07-05 21:18:48 -070027#include <net/net_namespace.h>
David Howells17926a72007-04-26 15:48:28 -070028#include "ar-internal.h"
29
David Howells248f2192016-09-08 11:10:12 +010030static void rxrpc_proto_abort(const char *why,
31 struct rxrpc_call *call, rxrpc_seq_t seq)
David Howells17926a72007-04-26 15:48:28 -070032{
David Howells248f2192016-09-08 11:10:12 +010033 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);
David Howells17926a72007-04-26 15:48:28 -070036 }
David Howells17926a72007-04-26 15:48:28 -070037}
38
39/*
David Howells57494342016-09-24 18:05:27 +010040 * Do TCP-style congestion management [RFC 5681].
41 */
42static void rxrpc_congestion_management(struct rxrpc_call *call,
43 struct sk_buff *skb,
David Howellsed1e8672016-09-29 22:37:16 +010044 struct rxrpc_ack_summary *summary,
45 rxrpc_serial_t acked_serial)
David Howells57494342016-09-24 18:05:27 +010046{
47 enum rxrpc_congest_change change = rxrpc_cong_no_change;
David Howells57494342016-09-24 18:05:27 +010048 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
159resume_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;
168out:
169 cumulative_acks = 0;
170out_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;
David Howellsed1e8672016-09-29 22:37:16 +0100175 trace_rxrpc_congest(call, summary, acked_serial, change);
David Howells57494342016-09-24 18:05:27 +0100176 if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
177 rxrpc_queue_call(call);
178 return;
179
180packet_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
186send_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/*
David Howells8e831342016-09-22 00:29:31 +0100200 * Ping the other end to fill our RTT cache and to retrieve the rwind
201 * and MTU parameters.
202 */
203static 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);
David Howellsfc943f672016-09-22 00:29:32 +0100207 ktime_t now = skb->tstamp;
David Howells8e831342016-09-22 00:29:31 +0100208
David Howellsfc943f672016-09-22 00:29:32 +0100209 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,
David Howells9c7ad432016-09-23 13:50:40 +0100212 true, true,
213 rxrpc_propose_ack_ping_for_params);
David Howells8e831342016-09-22 00:29:31 +0100214}
215
216/*
David Howells248f2192016-09-08 11:10:12 +0100217 * Apply a hard ACK by advancing the Tx window.
David Howells17926a72007-04-26 15:48:28 -0700218 */
David Howells31a1b9892016-09-24 18:05:26 +0100219static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
220 struct rxrpc_ack_summary *summary)
David Howells17926a72007-04-26 15:48:28 -0700221{
David Howells248f2192016-09-08 11:10:12 +0100222 struct sk_buff *skb, *list = NULL;
223 int ix;
David Howells70790dbe2016-09-23 12:39:22 +0100224 u8 annotation;
David Howells17926a72007-04-26 15:48:28 -0700225
David Howells31a1b9892016-09-24 18:05:26 +0100226 if (call->acks_lowest_nak == call->tx_hard_ack) {
227 call->acks_lowest_nak = to;
228 } else if (before_eq(call->acks_lowest_nak, to)) {
229 summary->new_low_nack = true;
230 call->acks_lowest_nak = to;
231 }
232
David Howells17926a72007-04-26 15:48:28 -0700233 spin_lock(&call->lock);
234
David Howells248f2192016-09-08 11:10:12 +0100235 while (before(call->tx_hard_ack, to)) {
236 call->tx_hard_ack++;
237 ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK;
238 skb = call->rxtx_buffer[ix];
David Howells70790dbe2016-09-23 12:39:22 +0100239 annotation = call->rxtx_annotations[ix];
David Howells71f3ca42016-09-17 10:49:14 +0100240 rxrpc_see_skb(skb, rxrpc_skb_tx_rotated);
David Howells248f2192016-09-08 11:10:12 +0100241 call->rxtx_buffer[ix] = NULL;
242 call->rxtx_annotations[ix] = 0;
243 skb->next = list;
244 list = skb;
David Howells70790dbe2016-09-23 12:39:22 +0100245
246 if (annotation & RXRPC_TX_ANNO_LAST)
247 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
David Howells31a1b9892016-09-24 18:05:26 +0100248 if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
249 summary->nr_rot_new_acks++;
David Howells17926a72007-04-26 15:48:28 -0700250 }
251
252 spin_unlock(&call->lock);
David Howells17926a72007-04-26 15:48:28 -0700253
David Howells70790dbe2016-09-23 12:39:22 +0100254 trace_rxrpc_transmit(call, (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ?
255 rxrpc_transmit_rotate_last :
256 rxrpc_transmit_rotate));
David Howellsbc4abfc2016-09-13 22:36:21 +0100257 wake_up(&call->waitq);
258
David Howells248f2192016-09-08 11:10:12 +0100259 while (list) {
260 skb = list;
261 list = skb->next;
262 skb->next = NULL;
David Howells71f3ca42016-09-17 10:49:14 +0100263 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
David Howells248f2192016-09-08 11:10:12 +0100264 }
David Howells17926a72007-04-26 15:48:28 -0700265}
266
267/*
David Howells248f2192016-09-08 11:10:12 +0100268 * End the transmission phase of a call.
269 *
270 * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
271 * or a final ACK packet.
David Howells17926a72007-04-26 15:48:28 -0700272 */
David Howells70790dbe2016-09-23 12:39:22 +0100273static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
274 const char *abort_why)
David Howells17926a72007-04-26 15:48:28 -0700275{
David Howells17926a72007-04-26 15:48:28 -0700276
David Howells70790dbe2016-09-23 12:39:22 +0100277 ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
David Howells248f2192016-09-08 11:10:12 +0100278
279 write_lock(&call->state_lock);
280
281 switch (call->state) {
David Howells70790dbe2016-09-23 12:39:22 +0100282 case RXRPC_CALL_CLIENT_SEND_REQUEST:
David Howells17926a72007-04-26 15:48:28 -0700283 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
David Howells70790dbe2016-09-23 12:39:22 +0100284 if (reply_begun)
285 call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
286 else
287 call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
David Howells17926a72007-04-26 15:48:28 -0700288 break;
David Howells70790dbe2016-09-23 12:39:22 +0100289
David Howells248f2192016-09-08 11:10:12 +0100290 case RXRPC_CALL_SERVER_AWAIT_ACK:
291 __rxrpc_call_completed(call);
292 rxrpc_notify_socket(call);
David Howells17926a72007-04-26 15:48:28 -0700293 break;
David Howells70790dbe2016-09-23 12:39:22 +0100294
295 default:
296 goto bad_state;
David Howells17926a72007-04-26 15:48:28 -0700297 }
David Howells248f2192016-09-08 11:10:12 +0100298
299 write_unlock(&call->state_lock);
David Howells70790dbe2016-09-23 12:39:22 +0100300 if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) {
David Howells0d967962016-09-24 18:05:27 +0100301 rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, false, true,
302 rxrpc_propose_ack_client_tx_end);
David Howells70790dbe2016-09-23 12:39:22 +0100303 trace_rxrpc_transmit(call, rxrpc_transmit_await_reply);
304 } else {
305 trace_rxrpc_transmit(call, rxrpc_transmit_end);
306 }
David Howells248f2192016-09-08 11:10:12 +0100307 _leave(" = ok");
308 return true;
David Howells70790dbe2016-09-23 12:39:22 +0100309
310bad_state:
311 write_unlock(&call->state_lock);
312 kdebug("end_tx %s", rxrpc_call_states[call->state]);
313 rxrpc_proto_abort(abort_why, call, call->tx_top);
314 return false;
315}
316
317/*
318 * Begin the reply reception phase of a call.
319 */
320static bool rxrpc_receiving_reply(struct rxrpc_call *call)
321{
David Howells31a1b9892016-09-24 18:05:26 +0100322 struct rxrpc_ack_summary summary = { 0 };
David Howells70790dbe2016-09-23 12:39:22 +0100323 rxrpc_seq_t top = READ_ONCE(call->tx_top);
324
David Howellsdd7c1ee2016-09-24 18:05:27 +0100325 if (call->ackr_reason) {
326 spin_lock_bh(&call->lock);
327 call->ackr_reason = 0;
328 call->resend_at = call->expire_at;
329 call->ack_at = call->expire_at;
330 spin_unlock_bh(&call->lock);
331 rxrpc_set_timer(call, rxrpc_timer_init_for_reply);
332 }
333
David Howells70790dbe2016-09-23 12:39:22 +0100334 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags))
David Howells31a1b9892016-09-24 18:05:26 +0100335 rxrpc_rotate_tx_window(call, top, &summary);
David Howells70790dbe2016-09-23 12:39:22 +0100336 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
337 rxrpc_proto_abort("TXL", call, top);
338 return false;
339 }
340 if (!rxrpc_end_tx_phase(call, true, "ETD"))
341 return false;
342 call->tx_phase = false;
343 return true;
David Howells248f2192016-09-08 11:10:12 +0100344}
345
346/*
347 * Scan a jumbo packet to validate its structure and to work out how many
348 * subpackets it contains.
349 *
350 * A jumbo packet is a collection of consecutive packets glued together with
351 * little headers between that indicate how to change the initial header for
352 * each subpacket.
353 *
354 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
355 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
356 * size.
357 */
358static bool rxrpc_validate_jumbo(struct sk_buff *skb)
359{
360 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
361 unsigned int offset = sp->offset;
David Howells89a80ed2016-09-13 22:36:22 +0100362 unsigned int len = skb->len;
David Howells248f2192016-09-08 11:10:12 +0100363 int nr_jumbo = 1;
364 u8 flags = sp->hdr.flags;
365
366 do {
367 nr_jumbo++;
368 if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
369 goto protocol_error;
370 if (flags & RXRPC_LAST_PACKET)
371 goto protocol_error;
372 offset += RXRPC_JUMBO_DATALEN;
373 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
374 goto protocol_error;
375 offset += sizeof(struct rxrpc_jumbo_header);
376 } while (flags & RXRPC_JUMBO_PACKET);
377
378 sp->nr_jumbo = nr_jumbo;
379 return true;
380
381protocol_error:
382 return false;
383}
384
385/*
386 * Handle reception of a duplicate packet.
387 *
388 * We have to take care to avoid an attack here whereby we're given a series of
389 * jumbograms, each with a sequence number one before the preceding one and
390 * filled up to maximum UDP size. If they never send us the first packet in
391 * the sequence, they can cause us to have to hold on to around 2MiB of kernel
392 * space until the call times out.
393 *
394 * We limit the space usage by only accepting three duplicate jumbo packets per
395 * call. After that, we tell the other side we're no longer accepting jumbos
396 * (that information is encoded in the ACK packet).
397 */
398static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
David Howells75e42122016-09-13 22:36:22 +0100399 u8 annotation, bool *_jumbo_bad)
David Howells248f2192016-09-08 11:10:12 +0100400{
401 /* Discard normal packets that are duplicates. */
402 if (annotation == 0)
403 return;
404
405 /* Skip jumbo subpackets that are duplicates. When we've had three or
406 * more partially duplicate jumbo packets, we refuse to take any more
407 * jumbos for this call.
408 */
David Howells75e42122016-09-13 22:36:22 +0100409 if (!*_jumbo_bad) {
410 call->nr_jumbo_bad++;
411 *_jumbo_bad = true;
David Howells248f2192016-09-08 11:10:12 +0100412 }
David Howells17926a72007-04-26 15:48:28 -0700413}
414
415/*
David Howells248f2192016-09-08 11:10:12 +0100416 * Process a DATA packet, adding the packet to the Rx ring.
David Howells17926a72007-04-26 15:48:28 -0700417 */
David Howells248f2192016-09-08 11:10:12 +0100418static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
419 u16 skew)
420{
421 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
422 unsigned int offset = sp->offset;
423 unsigned int ix;
424 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
425 rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
David Howells75e42122016-09-13 22:36:22 +0100426 bool immediate_ack = false, jumbo_bad = false, queued;
David Howells248f2192016-09-08 11:10:12 +0100427 u16 len;
428 u8 ack = 0, flags, annotation = 0;
429
430 _enter("{%u,%u},{%u,%u}",
David Howells89a80ed2016-09-13 22:36:22 +0100431 call->rx_hard_ack, call->rx_top, skb->len, seq);
David Howells248f2192016-09-08 11:10:12 +0100432
433 _proto("Rx DATA %%%u { #%u f=%02x }",
434 sp->hdr.serial, seq, sp->hdr.flags);
435
436 if (call->state >= RXRPC_CALL_COMPLETE)
437 return;
438
439 /* Received data implicitly ACKs all of the request packets we sent
440 * when we're acting as a client.
441 */
David Howells70790dbe2016-09-23 12:39:22 +0100442 if ((call->state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
443 call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
444 !rxrpc_receiving_reply(call))
David Howells248f2192016-09-08 11:10:12 +0100445 return;
446
447 call->ackr_prev_seq = seq;
448
449 hard_ack = READ_ONCE(call->rx_hard_ack);
450 if (after(seq, hard_ack + call->rx_winsize)) {
451 ack = RXRPC_ACK_EXCEEDS_WINDOW;
452 ack_serial = serial;
453 goto ack;
454 }
455
456 flags = sp->hdr.flags;
457 if (flags & RXRPC_JUMBO_PACKET) {
David Howells75e42122016-09-13 22:36:22 +0100458 if (call->nr_jumbo_bad > 3) {
David Howells248f2192016-09-08 11:10:12 +0100459 ack = RXRPC_ACK_NOSPACE;
460 ack_serial = serial;
461 goto ack;
462 }
463 annotation = 1;
464 }
465
466next_subpacket:
467 queued = false;
468 ix = seq & RXRPC_RXTX_BUFF_MASK;
David Howells89a80ed2016-09-13 22:36:22 +0100469 len = skb->len;
David Howells248f2192016-09-08 11:10:12 +0100470 if (flags & RXRPC_JUMBO_PACKET)
471 len = RXRPC_JUMBO_DATALEN;
472
473 if (flags & RXRPC_LAST_PACKET) {
David Howells816c9fc2016-09-17 10:49:11 +0100474 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
David Howells248f2192016-09-08 11:10:12 +0100475 seq != call->rx_top)
476 return rxrpc_proto_abort("LSN", call, seq);
477 } else {
478 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
479 after_eq(seq, call->rx_top))
480 return rxrpc_proto_abort("LSA", call, seq);
481 }
482
483 if (before_eq(seq, hard_ack)) {
484 ack = RXRPC_ACK_DUPLICATE;
485 ack_serial = serial;
486 goto skip;
487 }
488
489 if (flags & RXRPC_REQUEST_ACK && !ack) {
490 ack = RXRPC_ACK_REQUESTED;
491 ack_serial = serial;
492 }
493
494 if (call->rxtx_buffer[ix]) {
David Howells75e42122016-09-13 22:36:22 +0100495 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
David Howells248f2192016-09-08 11:10:12 +0100496 if (ack != RXRPC_ACK_DUPLICATE) {
497 ack = RXRPC_ACK_DUPLICATE;
498 ack_serial = serial;
499 }
500 immediate_ack = true;
501 goto skip;
502 }
503
504 /* Queue the packet. We use a couple of memory barriers here as need
505 * to make sure that rx_top is perceived to be set after the buffer
506 * pointer and that the buffer pointer is set after the annotation and
507 * the skb data.
508 *
509 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
510 * and also rxrpc_fill_out_ack().
511 */
David Howells71f3ca42016-09-17 10:49:14 +0100512 rxrpc_get_skb(skb, rxrpc_skb_rx_got);
David Howells248f2192016-09-08 11:10:12 +0100513 call->rxtx_annotations[ix] = annotation;
514 smp_wmb();
515 call->rxtx_buffer[ix] = skb;
David Howellsa7056c52016-09-24 18:05:27 +0100516 if (after(seq, call->rx_top)) {
David Howells248f2192016-09-08 11:10:12 +0100517 smp_store_release(&call->rx_top, seq);
David Howellsa7056c52016-09-24 18:05:27 +0100518 } else if (before(seq, call->rx_top)) {
519 /* Send an immediate ACK if we fill in a hole */
520 if (!ack) {
521 ack = RXRPC_ACK_DELAY;
522 ack_serial = serial;
523 }
524 immediate_ack = true;
525 }
David Howells58dc63c2016-09-17 10:49:13 +0100526 if (flags & RXRPC_LAST_PACKET) {
David Howells816c9fc2016-09-17 10:49:11 +0100527 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
David Howells58dc63c2016-09-17 10:49:13 +0100528 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
529 } else {
530 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
531 }
David Howells248f2192016-09-08 11:10:12 +0100532 queued = true;
533
534 if (after_eq(seq, call->rx_expect_next)) {
535 if (after(seq, call->rx_expect_next)) {
536 _net("OOS %u > %u", seq, call->rx_expect_next);
537 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
538 ack_serial = serial;
539 }
540 call->rx_expect_next = seq + 1;
541 }
542
543skip:
544 offset += len;
545 if (flags & RXRPC_JUMBO_PACKET) {
546 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
547 return rxrpc_proto_abort("XJF", call, seq);
548 offset += sizeof(struct rxrpc_jumbo_header);
549 seq++;
550 serial++;
551 annotation++;
552 if (flags & RXRPC_JUMBO_PACKET)
553 annotation |= RXRPC_RX_ANNO_JLAST;
David Howells75e42122016-09-13 22:36:22 +0100554 if (after(seq, hard_ack + call->rx_winsize)) {
555 ack = RXRPC_ACK_EXCEEDS_WINDOW;
556 ack_serial = serial;
557 if (!jumbo_bad) {
558 call->nr_jumbo_bad++;
559 jumbo_bad = true;
560 }
561 goto ack;
562 }
David Howells248f2192016-09-08 11:10:12 +0100563
564 _proto("Rx DATA Jumbo %%%u", serial);
565 goto next_subpacket;
566 }
567
568 if (queued && flags & RXRPC_LAST_PACKET && !ack) {
569 ack = RXRPC_ACK_DELAY;
570 ack_serial = serial;
571 }
572
573ack:
574 if (ack)
575 rxrpc_propose_ACK(call, ack, skew, ack_serial,
David Howells9c7ad432016-09-23 13:50:40 +0100576 immediate_ack, true,
577 rxrpc_propose_ack_input_data);
David Howells248f2192016-09-08 11:10:12 +0100578
579 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1)
580 rxrpc_notify_socket(call);
581 _leave(" [queued]");
582}
583
584/*
David Howells50235c42016-09-22 00:29:31 +0100585 * Process a requested ACK.
586 */
587static void rxrpc_input_requested_ack(struct rxrpc_call *call,
588 ktime_t resp_time,
589 rxrpc_serial_t orig_serial,
590 rxrpc_serial_t ack_serial)
591{
592 struct rxrpc_skb_priv *sp;
593 struct sk_buff *skb;
594 ktime_t sent_at;
595 int ix;
596
597 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
598 skb = call->rxtx_buffer[ix];
599 if (!skb)
600 continue;
601
602 sp = rxrpc_skb(skb);
603 if (sp->hdr.serial != orig_serial)
604 continue;
605 smp_rmb();
606 sent_at = skb->tstamp;
607 goto found;
608 }
609 return;
610
611found:
612 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
613 orig_serial, ack_serial, sent_at, resp_time);
614}
615
616/*
David Howells8e831342016-09-22 00:29:31 +0100617 * Process a ping response.
618 */
619static void rxrpc_input_ping_response(struct rxrpc_call *call,
620 ktime_t resp_time,
621 rxrpc_serial_t orig_serial,
622 rxrpc_serial_t ack_serial)
623{
624 rxrpc_serial_t ping_serial;
625 ktime_t ping_time;
626
627 ping_time = call->ackr_ping_time;
628 smp_rmb();
629 ping_serial = call->ackr_ping;
630
631 if (!test_bit(RXRPC_CALL_PINGING, &call->flags) ||
632 before(orig_serial, ping_serial))
633 return;
634 clear_bit(RXRPC_CALL_PINGING, &call->flags);
635 if (after(orig_serial, ping_serial))
636 return;
637
638 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
639 orig_serial, ack_serial, ping_time, resp_time);
640}
641
642/*
David Howells248f2192016-09-08 11:10:12 +0100643 * Process the extra information that may be appended to an ACK packet
644 */
645static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
646 struct rxrpc_ackinfo *ackinfo)
647{
648 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
649 struct rxrpc_peer *peer;
650 unsigned int mtu;
David Howells01fd0742016-09-13 10:23:01 +0100651 u32 rwind = ntohl(ackinfo->rwind);
David Howells248f2192016-09-08 11:10:12 +0100652
653 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
654 sp->hdr.serial,
655 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
David Howells01fd0742016-09-13 10:23:01 +0100656 rwind, ntohl(ackinfo->jumbo_max));
David Howells248f2192016-09-08 11:10:12 +0100657
David Howells01fd0742016-09-13 10:23:01 +0100658 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
659 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
660 call->tx_winsize = rwind;
David Howells248f2192016-09-08 11:10:12 +0100661
662 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
663
664 peer = call->peer;
665 if (mtu < peer->maxdata) {
666 spin_lock_bh(&peer->lock);
667 peer->maxdata = mtu;
668 peer->mtu = mtu + peer->hdrsize;
669 spin_unlock_bh(&peer->lock);
670 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
671 }
672}
673
674/*
675 * Process individual soft ACKs.
676 *
677 * Each ACK in the array corresponds to one packet and can be either an ACK or
678 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
679 * packets that lie beyond the end of the ACK list are scheduled for resend by
680 * the timer on the basis that the peer might just not have processed them at
681 * the time the ACK was sent.
682 */
683static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
David Howells31a1b9892016-09-24 18:05:26 +0100684 rxrpc_seq_t seq, int nr_acks,
685 struct rxrpc_ack_summary *summary)
David Howells248f2192016-09-08 11:10:12 +0100686{
David Howells248f2192016-09-08 11:10:12 +0100687 int ix;
David Howellsf07373e2016-09-22 00:29:32 +0100688 u8 annotation, anno_type;
David Howells248f2192016-09-08 11:10:12 +0100689
690 for (; nr_acks > 0; nr_acks--, seq++) {
691 ix = seq & RXRPC_RXTX_BUFF_MASK;
David Howellsf07373e2016-09-22 00:29:32 +0100692 annotation = call->rxtx_annotations[ix];
693 anno_type = annotation & RXRPC_TX_ANNO_MASK;
694 annotation &= ~RXRPC_TX_ANNO_MASK;
David Howellsd01dc4c2016-09-17 10:49:12 +0100695 switch (*acks++) {
David Howells248f2192016-09-08 11:10:12 +0100696 case RXRPC_ACK_TYPE_ACK:
David Howells31a1b9892016-09-24 18:05:26 +0100697 summary->nr_acks++;
David Howellsf07373e2016-09-22 00:29:32 +0100698 if (anno_type == RXRPC_TX_ANNO_ACK)
699 continue;
David Howells31a1b9892016-09-24 18:05:26 +0100700 summary->nr_new_acks++;
David Howellsf07373e2016-09-22 00:29:32 +0100701 call->rxtx_annotations[ix] =
702 RXRPC_TX_ANNO_ACK | annotation;
David Howells248f2192016-09-08 11:10:12 +0100703 break;
704 case RXRPC_ACK_TYPE_NACK:
David Howells31a1b9892016-09-24 18:05:26 +0100705 if (!summary->nr_nacks &&
706 call->acks_lowest_nak != seq) {
707 call->acks_lowest_nak = seq;
708 summary->new_low_nack = true;
709 }
710 summary->nr_nacks++;
David Howellsf07373e2016-09-22 00:29:32 +0100711 if (anno_type == RXRPC_TX_ANNO_NAK)
David Howells248f2192016-09-08 11:10:12 +0100712 continue;
David Howells31a1b9892016-09-24 18:05:26 +0100713 summary->nr_new_nacks++;
David Howellsbe8aa332016-09-23 12:39:23 +0100714 if (anno_type == RXRPC_TX_ANNO_RETRANS)
715 continue;
David Howellsf07373e2016-09-22 00:29:32 +0100716 call->rxtx_annotations[ix] =
717 RXRPC_TX_ANNO_NAK | annotation;
David Howells248f2192016-09-08 11:10:12 +0100718 break;
719 default:
720 return rxrpc_proto_abort("SFT", call, 0);
721 }
722 }
David Howells248f2192016-09-08 11:10:12 +0100723}
724
725/*
726 * Process an ACK packet.
727 *
728 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
729 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
730 *
731 * A hard-ACK means that a packet has been processed and may be discarded; a
732 * soft-ACK means that the packet may be discarded and retransmission
733 * requested. A phase is complete when all packets are hard-ACK'd.
734 */
735static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
736 u16 skew)
737{
David Howells31a1b9892016-09-24 18:05:26 +0100738 struct rxrpc_ack_summary summary = { 0 };
David Howells248f2192016-09-08 11:10:12 +0100739 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
740 union {
741 struct rxrpc_ackpacket ack;
742 struct rxrpc_ackinfo info;
743 u8 acks[RXRPC_MAXACKS];
744 } buf;
David Howells8e831342016-09-22 00:29:31 +0100745 rxrpc_serial_t acked_serial;
David Howells248f2192016-09-08 11:10:12 +0100746 rxrpc_seq_t first_soft_ack, hard_ack;
747 int nr_acks, offset;
748
749 _enter("");
750
751 if (skb_copy_bits(skb, sp->offset, &buf.ack, sizeof(buf.ack)) < 0) {
752 _debug("extraction failure");
753 return rxrpc_proto_abort("XAK", call, 0);
754 }
755 sp->offset += sizeof(buf.ack);
756
David Howells8e831342016-09-22 00:29:31 +0100757 acked_serial = ntohl(buf.ack.serial);
David Howells248f2192016-09-08 11:10:12 +0100758 first_soft_ack = ntohl(buf.ack.firstPacket);
759 hard_ack = first_soft_ack - 1;
760 nr_acks = buf.ack.nAcks;
David Howells31a1b9892016-09-24 18:05:26 +0100761 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
762 buf.ack.reason : RXRPC_ACK__INVALID);
David Howells248f2192016-09-08 11:10:12 +0100763
David Howells31a1b9892016-09-24 18:05:26 +0100764 trace_rxrpc_rx_ack(call, first_soft_ack, summary.ack_reason, nr_acks);
David Howellsec71eb92016-09-17 10:49:13 +0100765
David Howells248f2192016-09-08 11:10:12 +0100766 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
767 sp->hdr.serial,
768 ntohs(buf.ack.maxSkew),
769 first_soft_ack,
770 ntohl(buf.ack.previousPacket),
David Howells8e831342016-09-22 00:29:31 +0100771 acked_serial,
David Howells31a1b9892016-09-24 18:05:26 +0100772 rxrpc_ack_names[summary.ack_reason],
David Howells248f2192016-09-08 11:10:12 +0100773 buf.ack.nAcks);
774
David Howells8e831342016-09-22 00:29:31 +0100775 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
776 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
777 sp->hdr.serial);
David Howells50235c42016-09-22 00:29:31 +0100778 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
779 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
780 sp->hdr.serial);
David Howells8e831342016-09-22 00:29:31 +0100781
David Howells248f2192016-09-08 11:10:12 +0100782 if (buf.ack.reason == RXRPC_ACK_PING) {
783 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
784 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
David Howells9c7ad432016-09-23 13:50:40 +0100785 skew, sp->hdr.serial, true, true,
786 rxrpc_propose_ack_respond_to_ping);
David Howells248f2192016-09-08 11:10:12 +0100787 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
788 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
David Howells9c7ad432016-09-23 13:50:40 +0100789 skew, sp->hdr.serial, true, true,
790 rxrpc_propose_ack_respond_to_ack);
David Howells248f2192016-09-08 11:10:12 +0100791 }
792
793 offset = sp->offset + nr_acks + 3;
David Howells89a80ed2016-09-13 22:36:22 +0100794 if (skb->len >= offset + sizeof(buf.info)) {
David Howells248f2192016-09-08 11:10:12 +0100795 if (skb_copy_bits(skb, offset, &buf.info, sizeof(buf.info)) < 0)
796 return rxrpc_proto_abort("XAI", call, 0);
797 rxrpc_input_ackinfo(call, skb, &buf.info);
798 }
799
800 if (first_soft_ack == 0)
801 return rxrpc_proto_abort("AK0", call, 0);
802
803 /* Ignore ACKs unless we are or have just been transmitting. */
804 switch (call->state) {
805 case RXRPC_CALL_CLIENT_SEND_REQUEST:
806 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
807 case RXRPC_CALL_SERVER_SEND_REPLY:
808 case RXRPC_CALL_SERVER_AWAIT_ACK:
809 break;
810 default:
811 return;
812 }
813
814 /* Discard any out-of-order or duplicate ACKs. */
David Howells98dafac2016-09-23 14:04:38 +0100815 if (before_eq(sp->hdr.serial, call->acks_latest)) {
David Howells248f2192016-09-08 11:10:12 +0100816 _debug("discard ACK %d <= %d",
817 sp->hdr.serial, call->acks_latest);
818 return;
819 }
David Howells57494342016-09-24 18:05:27 +0100820 call->acks_latest_ts = skb->tstamp;
David Howells248f2192016-09-08 11:10:12 +0100821 call->acks_latest = sp->hdr.serial;
822
David Howells248f2192016-09-08 11:10:12 +0100823 if (before(hard_ack, call->tx_hard_ack) ||
824 after(hard_ack, call->tx_top))
825 return rxrpc_proto_abort("AKW", call, 0);
David Howells70790dbe2016-09-23 12:39:22 +0100826 if (nr_acks > call->tx_top - hard_ack)
827 return rxrpc_proto_abort("AKN", call, 0);
David Howells248f2192016-09-08 11:10:12 +0100828
829 if (after(hard_ack, call->tx_hard_ack))
David Howells31a1b9892016-09-24 18:05:26 +0100830 rxrpc_rotate_tx_window(call, hard_ack, &summary);
David Howells248f2192016-09-08 11:10:12 +0100831
David Howells70790dbe2016-09-23 12:39:22 +0100832 if (nr_acks > 0) {
833 if (skb_copy_bits(skb, sp->offset, buf.acks, nr_acks) < 0)
834 return rxrpc_proto_abort("XSA", call, 0);
David Howells31a1b9892016-09-24 18:05:26 +0100835 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
836 &summary);
David Howells70790dbe2016-09-23 12:39:22 +0100837 }
David Howells248f2192016-09-08 11:10:12 +0100838
David Howells70790dbe2016-09-23 12:39:22 +0100839 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
840 rxrpc_end_tx_phase(call, false, "ETA");
841 return;
842 }
843
David Howells0d967962016-09-24 18:05:27 +0100844 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
845 RXRPC_TX_ANNO_LAST &&
846 summary.nr_acks == call->tx_top - hard_ack)
847 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
848 false, true,
849 rxrpc_propose_ack_ping_for_lost_reply);
David Howells57494342016-09-24 18:05:27 +0100850
David Howellsed1e8672016-09-29 22:37:16 +0100851 return rxrpc_congestion_management(call, skb, &summary, acked_serial);
David Howells248f2192016-09-08 11:10:12 +0100852}
853
854/*
855 * Process an ACKALL packet.
856 */
857static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
858{
David Howells31a1b9892016-09-24 18:05:26 +0100859 struct rxrpc_ack_summary summary = { 0 };
David Howells248f2192016-09-08 11:10:12 +0100860 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
861
862 _proto("Rx ACKALL %%%u", sp->hdr.serial);
863
David Howells31a1b9892016-09-24 18:05:26 +0100864 rxrpc_rotate_tx_window(call, call->tx_top, &summary);
David Howells70790dbe2016-09-23 12:39:22 +0100865 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags))
866 rxrpc_end_tx_phase(call, false, "ETL");
David Howells248f2192016-09-08 11:10:12 +0100867}
868
869/*
870 * Process an ABORT packet.
871 */
872static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
David Howells17926a72007-04-26 15:48:28 -0700873{
874 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells0d12f8a2016-03-04 15:53:46 +0000875 __be32 wtmp;
David Howells248f2192016-09-08 11:10:12 +0100876 u32 abort_code = RX_CALL_DEAD;
877
878 _enter("");
879
880 if (skb->len >= 4 &&
881 skb_copy_bits(skb, sp->offset, &wtmp, sizeof(wtmp)) >= 0)
882 abort_code = ntohl(wtmp);
883
884 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
885
886 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
887 abort_code, ECONNABORTED))
888 rxrpc_notify_socket(call);
889}
890
891/*
892 * Process an incoming call packet.
893 */
894static void rxrpc_input_call_packet(struct rxrpc_call *call,
895 struct sk_buff *skb, u16 skew)
896{
897 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells17926a72007-04-26 15:48:28 -0700898
899 _enter("%p,%p", call, skb);
900
David Howells17926a72007-04-26 15:48:28 -0700901 switch (sp->hdr.type) {
David Howells248f2192016-09-08 11:10:12 +0100902 case RXRPC_PACKET_TYPE_DATA:
903 rxrpc_input_data(call, skb, skew);
904 break;
David Howells17926a72007-04-26 15:48:28 -0700905
David Howells248f2192016-09-08 11:10:12 +0100906 case RXRPC_PACKET_TYPE_ACK:
907 rxrpc_input_ack(call, skb, skew);
908 break;
David Howells17926a72007-04-26 15:48:28 -0700909
910 case RXRPC_PACKET_TYPE_BUSY:
David Howells0d12f8a2016-03-04 15:53:46 +0000911 _proto("Rx BUSY %%%u", sp->hdr.serial);
David Howells17926a72007-04-26 15:48:28 -0700912
David Howells248f2192016-09-08 11:10:12 +0100913 /* Just ignore BUSY packets from the server; the retry and
914 * lifespan timers will take care of business. BUSY packets
915 * from the client don't make sense.
916 */
917 break;
David Howells17926a72007-04-26 15:48:28 -0700918
David Howells248f2192016-09-08 11:10:12 +0100919 case RXRPC_PACKET_TYPE_ABORT:
920 rxrpc_input_abort(call, skb);
921 break;
922
923 case RXRPC_PACKET_TYPE_ACKALL:
924 rxrpc_input_ackall(call, skb);
925 break;
David Howells17926a72007-04-26 15:48:28 -0700926
927 default:
David Howells0d12f8a2016-03-04 15:53:46 +0000928 _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial);
David Howells17926a72007-04-26 15:48:28 -0700929 break;
930 }
931
David Howells17926a72007-04-26 15:48:28 -0700932 _leave("");
933}
934
935/*
936 * post connection-level events to the connection
David Howells18bfeba2016-08-23 15:27:25 +0100937 * - this includes challenges, responses, some aborts and call terminal packet
938 * retransmission.
David Howells17926a72007-04-26 15:48:28 -0700939 */
David Howells2e7e9752016-08-09 10:11:48 +0100940static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
David Howells17926a72007-04-26 15:48:28 -0700941 struct sk_buff *skb)
942{
943 _enter("%p,%p", conn, skb);
944
David Howells17926a72007-04-26 15:48:28 -0700945 skb_queue_tail(&conn->rx_queue, skb);
David Howells2e7e9752016-08-09 10:11:48 +0100946 rxrpc_queue_conn(conn);
David Howells17926a72007-04-26 15:48:28 -0700947}
948
David Howells44ba0692015-04-01 16:31:26 +0100949/*
950 * post endpoint-level events to the local endpoint
951 * - this includes debug and version messages
952 */
953static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
954 struct sk_buff *skb)
955{
956 _enter("%p,%p", local, skb);
957
David Howells44ba0692015-04-01 16:31:26 +0100958 skb_queue_tail(&local->event_queue, skb);
David Howells5acbee42016-06-27 10:32:02 +0100959 rxrpc_queue_local(local);
David Howells44ba0692015-04-01 16:31:26 +0100960}
961
David Howells0d12f8a2016-03-04 15:53:46 +0000962/*
David Howells248f2192016-09-08 11:10:12 +0100963 * put a packet up for transport-level abort
964 */
965static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
966{
967 CHECK_SLAB_OKAY(&local->usage);
968
969 skb_queue_tail(&local->reject_queue, skb);
970 rxrpc_queue_local(local);
971}
972
973/*
David Howells0d12f8a2016-03-04 15:53:46 +0000974 * Extract the wire header from a packet and translate the byte order.
975 */
976static noinline
977int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
978{
979 struct rxrpc_wire_header whdr;
980
981 /* dig out the RxRPC connection details */
Willem de Bruijn4d0fc732016-04-07 11:44:59 -0400982 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
David Howells0d12f8a2016-03-04 15:53:46 +0000983 return -EBADMSG;
David Howells0d12f8a2016-03-04 15:53:46 +0000984
985 memset(sp, 0, sizeof(*sp));
986 sp->hdr.epoch = ntohl(whdr.epoch);
987 sp->hdr.cid = ntohl(whdr.cid);
988 sp->hdr.callNumber = ntohl(whdr.callNumber);
989 sp->hdr.seq = ntohl(whdr.seq);
990 sp->hdr.serial = ntohl(whdr.serial);
991 sp->hdr.flags = whdr.flags;
992 sp->hdr.type = whdr.type;
993 sp->hdr.userStatus = whdr.userStatus;
994 sp->hdr.securityIndex = whdr.securityIndex;
995 sp->hdr._rsvd = ntohs(whdr._rsvd);
996 sp->hdr.serviceId = ntohs(whdr.serviceId);
David Howells248f2192016-09-08 11:10:12 +0100997 sp->offset = sizeof(whdr);
David Howells0d12f8a2016-03-04 15:53:46 +0000998 return 0;
999}
1000
David Howells17926a72007-04-26 15:48:28 -07001001/*
1002 * handle data received on the local endpoint
1003 * - may be called in interrupt context
David Howells4f95dd72016-04-04 14:00:35 +01001004 *
1005 * The socket is locked by the caller and this prevents the socket from being
1006 * shut down and the local endpoint from going away, thus sk_user_data will not
1007 * be cleared until this function returns.
David Howells17926a72007-04-26 15:48:28 -07001008 */
David Howells248f2192016-09-08 11:10:12 +01001009void rxrpc_data_ready(struct sock *udp_sk)
David Howells17926a72007-04-26 15:48:28 -07001010{
David Howells8496af52016-07-01 07:51:50 +01001011 struct rxrpc_connection *conn;
David Howells248f2192016-09-08 11:10:12 +01001012 struct rxrpc_channel *chan;
1013 struct rxrpc_call *call;
David Howells17926a72007-04-26 15:48:28 -07001014 struct rxrpc_skb_priv *sp;
David Howells248f2192016-09-08 11:10:12 +01001015 struct rxrpc_local *local = udp_sk->sk_user_data;
David Howells17926a72007-04-26 15:48:28 -07001016 struct sk_buff *skb;
David Howells248f2192016-09-08 11:10:12 +01001017 unsigned int channel;
David Howells563ea7d2016-08-23 15:27:25 +01001018 int ret, skew;
David Howells17926a72007-04-26 15:48:28 -07001019
David Howells248f2192016-09-08 11:10:12 +01001020 _enter("%p", udp_sk);
David Howells17926a72007-04-26 15:48:28 -07001021
1022 ASSERT(!irqs_disabled());
1023
David Howells248f2192016-09-08 11:10:12 +01001024 skb = skb_recv_datagram(udp_sk, 0, 1, &ret);
David Howells17926a72007-04-26 15:48:28 -07001025 if (!skb) {
David Howells17926a72007-04-26 15:48:28 -07001026 if (ret == -EAGAIN)
1027 return;
1028 _debug("UDP socket error %d", ret);
1029 return;
1030 }
1031
David Howells71f3ca42016-09-17 10:49:14 +01001032 rxrpc_new_skb(skb, rxrpc_skb_rx_received);
David Howells17926a72007-04-26 15:48:28 -07001033
1034 _net("recv skb %p", skb);
1035
1036 /* we'll probably need to checksum it (didn't call sock_recvmsg) */
1037 if (skb_checksum_complete(skb)) {
David Howells71f3ca42016-09-17 10:49:14 +01001038 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
Eric Dumazet02c22342016-04-27 16:44:30 -07001039 __UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
David Howells17926a72007-04-26 15:48:28 -07001040 _leave(" [CSUM failed]");
1041 return;
1042 }
1043
Eric Dumazet02c22342016-04-27 16:44:30 -07001044 __UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
Herbert Xu1781f7f2007-12-11 11:30:32 -08001045
David Howells0d12f8a2016-03-04 15:53:46 +00001046 /* The socket buffer we have is owned by UDP, with UDP's data all over
1047 * it, but we really want our own data there.
1048 */
David Howells17926a72007-04-26 15:48:28 -07001049 skb_orphan(skb);
1050 sp = rxrpc_skb(skb);
David Howells17926a72007-04-26 15:48:28 -07001051
David Howells89b475a2016-09-23 12:39:22 +01001052 /* dig out the RxRPC connection details */
1053 if (rxrpc_extract_header(sp, skb) < 0)
1054 goto bad_message;
1055
David Howells8a681c362016-09-17 10:49:15 +01001056 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1057 static int lose;
1058 if ((lose++ & 7) == 7) {
David Howells89b475a2016-09-23 12:39:22 +01001059 trace_rxrpc_rx_lose(sp);
David Howells8a681c362016-09-17 10:49:15 +01001060 rxrpc_lose_skb(skb, rxrpc_skb_rx_lost);
1061 return;
1062 }
1063 }
1064
David Howells49e19ec2016-09-08 11:10:12 +01001065 trace_rxrpc_rx_packet(sp);
David Howells17926a72007-04-26 15:48:28 -07001066
1067 _net("Rx RxRPC %s ep=%x call=%x:%x",
1068 sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
David Howells0d12f8a2016-03-04 15:53:46 +00001069 sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
David Howells17926a72007-04-26 15:48:28 -07001070
David Howells351c1e62016-03-04 15:56:06 +00001071 if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
1072 !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
David Howells17926a72007-04-26 15:48:28 -07001073 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1074 goto bad_message;
1075 }
1076
David Howells248f2192016-09-08 11:10:12 +01001077 switch (sp->hdr.type) {
1078 case RXRPC_PACKET_TYPE_VERSION:
David Howells44ba0692015-04-01 16:31:26 +01001079 rxrpc_post_packet_to_local(local, skb);
1080 goto out;
David Howellsbc6e1ea2016-06-10 22:30:27 +01001081
David Howells248f2192016-09-08 11:10:12 +01001082 case RXRPC_PACKET_TYPE_BUSY:
1083 if (sp->hdr.flags & RXRPC_CLIENT_INITIATED)
1084 goto discard;
1085
1086 case RXRPC_PACKET_TYPE_DATA:
1087 if (sp->hdr.callNumber == 0)
1088 goto bad_message;
1089 if (sp->hdr.flags & RXRPC_JUMBO_PACKET &&
1090 !rxrpc_validate_jumbo(skb))
1091 goto bad_message;
1092 break;
1093 }
David Howells17926a72007-04-26 15:48:28 -07001094
David Howells8496af52016-07-01 07:51:50 +01001095 rcu_read_lock();
1096
David Howells8496af52016-07-01 07:51:50 +01001097 conn = rxrpc_find_connection_rcu(local, skb);
David Howells248f2192016-09-08 11:10:12 +01001098 if (conn) {
1099 if (sp->hdr.securityIndex != conn->security_ix)
1100 goto wrong_security;
David Howells563ea7d2016-08-23 15:27:25 +01001101
David Howells248f2192016-09-08 11:10:12 +01001102 if (sp->hdr.callNumber == 0) {
1103 /* Connection-level packet */
1104 _debug("CONN %p {%d}", conn, conn->debug_id);
1105 rxrpc_post_packet_to_conn(conn, skb);
1106 goto out_unlock;
1107 }
David Howells8496af52016-07-01 07:51:50 +01001108
David Howells248f2192016-09-08 11:10:12 +01001109 /* Note the serial number skew here */
1110 skew = (int)sp->hdr.serial - (int)conn->hi_serial;
1111 if (skew >= 0) {
1112 if (skew > 0)
1113 conn->hi_serial = sp->hdr.serial;
1114 } else {
1115 skew = -skew;
1116 skew = min(skew, 65535);
1117 }
1118
David Howells8496af52016-07-01 07:51:50 +01001119 /* Call-bound packets are routed by connection channel. */
David Howells248f2192016-09-08 11:10:12 +01001120 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1121 chan = &conn->channels[channel];
Tim Smith77276402014-03-03 23:04:45 +00001122
David Howells18bfeba2016-08-23 15:27:25 +01001123 /* Ignore really old calls */
1124 if (sp->hdr.callNumber < chan->last_call)
1125 goto discard_unlock;
1126
1127 if (sp->hdr.callNumber == chan->last_call) {
David Howells248f2192016-09-08 11:10:12 +01001128 /* For the previous service call, if completed successfully, we
1129 * discard all further packets.
David Howells18bfeba2016-08-23 15:27:25 +01001130 */
David Howells2266ffd2016-08-24 13:06:14 +01001131 if (rxrpc_conn_is_service(conn) &&
David Howells18bfeba2016-08-23 15:27:25 +01001132 (chan->last_type == RXRPC_PACKET_TYPE_ACK ||
1133 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT))
1134 goto discard_unlock;
1135
David Howells248f2192016-09-08 11:10:12 +01001136 /* But otherwise we need to retransmit the final packet from
1137 * data cached in the connection record.
David Howells18bfeba2016-08-23 15:27:25 +01001138 */
1139 rxrpc_post_packet_to_conn(conn, skb);
1140 goto out_unlock;
1141 }
1142
1143 call = rcu_dereference(chan->call);
David Howells248f2192016-09-08 11:10:12 +01001144 } else {
1145 skew = 0;
1146 call = NULL;
Tim Smith77276402014-03-03 23:04:45 +00001147 }
David Howells44ba0692015-04-01 16:31:26 +01001148
David Howells248f2192016-09-08 11:10:12 +01001149 if (!call || atomic_read(&call->usage) == 0) {
1150 if (!(sp->hdr.type & RXRPC_CLIENT_INITIATED) ||
1151 sp->hdr.callNumber == 0 ||
1152 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1153 goto bad_message_unlock;
1154 if (sp->hdr.seq != 1)
1155 goto discard_unlock;
1156 call = rxrpc_new_incoming_call(local, conn, skb);
1157 if (!call) {
1158 rcu_read_unlock();
1159 goto reject_packet;
1160 }
David Howells8e831342016-09-22 00:29:31 +01001161 rxrpc_send_ping(call, skb, skew);
David Howells248f2192016-09-08 11:10:12 +01001162 }
1163
1164 rxrpc_input_call_packet(call, skb, skew);
1165 goto discard_unlock;
1166
David Howells18bfeba2016-08-23 15:27:25 +01001167discard_unlock:
David Howells8496af52016-07-01 07:51:50 +01001168 rcu_read_unlock();
David Howells248f2192016-09-08 11:10:12 +01001169discard:
David Howells71f3ca42016-09-17 10:49:14 +01001170 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
David Howells44ba0692015-04-01 16:31:26 +01001171out:
David Howells49e19ec2016-09-08 11:10:12 +01001172 trace_rxrpc_rx_done(0, 0);
David Howells17926a72007-04-26 15:48:28 -07001173 return;
1174
David Howells248f2192016-09-08 11:10:12 +01001175out_unlock:
David Howells8496af52016-07-01 07:51:50 +01001176 rcu_read_unlock();
David Howells248f2192016-09-08 11:10:12 +01001177 goto out;
David Howells8496af52016-07-01 07:51:50 +01001178
David Howells248f2192016-09-08 11:10:12 +01001179wrong_security:
1180 rcu_read_unlock();
1181 trace_rxrpc_abort("SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1182 RXKADINCONSISTENCY, EBADMSG);
1183 skb->priority = RXKADINCONSISTENCY;
1184 goto post_abort;
David Howells17926a72007-04-26 15:48:28 -07001185
David Howells248f2192016-09-08 11:10:12 +01001186bad_message_unlock:
1187 rcu_read_unlock();
David Howells17926a72007-04-26 15:48:28 -07001188bad_message:
David Howells248f2192016-09-08 11:10:12 +01001189 trace_rxrpc_abort("BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1190 RX_PROTOCOL_ERROR, EBADMSG);
David Howells17926a72007-04-26 15:48:28 -07001191 skb->priority = RX_PROTOCOL_ERROR;
David Howells248f2192016-09-08 11:10:12 +01001192post_abort:
1193 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
David Howells49e19ec2016-09-08 11:10:12 +01001194reject_packet:
1195 trace_rxrpc_rx_done(skb->mark, skb->priority);
David Howells17926a72007-04-26 15:48:28 -07001196 rxrpc_reject_packet(local, skb);
David Howells17926a72007-04-26 15:48:28 -07001197 _leave(" [badmsg]");
1198}