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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;
David Howells8782def2016-09-30 09:26:12 +010060 if (cwnd >= call->cong_ssthresh &&
David Howells57494342016-09-24 18:05:27 +010061 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;
David Howells8782def2016-09-30 09:26:12 +010085 if (cwnd >= call->cong_ssthresh) {
David Howells57494342016-09-24 18:05:27 +010086 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;
David Howells8782def2016-09-30 09:26:12 +0100164 if (cwnd < call->cong_ssthresh)
David Howells57494342016-09-24 18:05:27 +0100165 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 Howellsfc943f62016-09-22 00:29:32 +0100207 ktime_t now = skb->tstamp;
David Howells8e831342016-09-22 00:29:31 +0100208
David Howellsfc943f62016-09-22 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 Howells31a1b982016-09-24 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 Howells70790db2016-09-23 12:39:22 +0100224 u8 annotation;
David Howells17926a72007-04-26 15:48:28 -0700225
David Howells31a1b982016-09-24 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 12:39:22 +0100245
246 if (annotation & RXRPC_TX_ANNO_LAST)
247 set_bit(RXRPC_CALL_TX_LAST, &call->flags);
David Howells31a1b982016-09-24 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells70790db2016-09-23 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 Howells31a1b982016-09-24 18:05:26 +0100322 struct rxrpc_ack_summary summary = { 0 };
David Howells70790db2016-09-23 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);
David Howellsdf0adc72016-09-26 22:12:49 +0100331 rxrpc_set_timer(call, rxrpc_timer_init_for_reply,
332 ktime_get_real());
David Howellsdd7c1ee2016-09-24 18:05:27 +0100333 }
334
David Howells70790db2016-09-23 12:39:22 +0100335 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags))
David Howells31a1b982016-09-24 18:05:26 +0100336 rxrpc_rotate_tx_window(call, top, &summary);
David Howells70790db2016-09-23 12:39:22 +0100337 if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
338 rxrpc_proto_abort("TXL", call, top);
339 return false;
340 }
341 if (!rxrpc_end_tx_phase(call, true, "ETD"))
342 return false;
343 call->tx_phase = false;
344 return true;
David Howells248f2192016-09-08 11:10:12 +0100345}
346
347/*
348 * Scan a jumbo packet to validate its structure and to work out how many
349 * subpackets it contains.
350 *
351 * A jumbo packet is a collection of consecutive packets glued together with
352 * little headers between that indicate how to change the initial header for
353 * each subpacket.
354 *
355 * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but
356 * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any
357 * size.
358 */
359static bool rxrpc_validate_jumbo(struct sk_buff *skb)
360{
361 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells775e5b72016-09-30 13:26:03 +0100362 unsigned int offset = sizeof(struct rxrpc_wire_header);
David Howells89a80ed2016-09-13 22:36:22 +0100363 unsigned int len = skb->len;
David Howells248f2192016-09-08 11:10:12 +0100364 int nr_jumbo = 1;
365 u8 flags = sp->hdr.flags;
366
367 do {
368 nr_jumbo++;
369 if (len - offset < RXRPC_JUMBO_SUBPKTLEN)
370 goto protocol_error;
371 if (flags & RXRPC_LAST_PACKET)
372 goto protocol_error;
373 offset += RXRPC_JUMBO_DATALEN;
374 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
375 goto protocol_error;
376 offset += sizeof(struct rxrpc_jumbo_header);
377 } while (flags & RXRPC_JUMBO_PACKET);
378
379 sp->nr_jumbo = nr_jumbo;
380 return true;
381
382protocol_error:
383 return false;
384}
385
386/*
387 * Handle reception of a duplicate packet.
388 *
389 * We have to take care to avoid an attack here whereby we're given a series of
390 * jumbograms, each with a sequence number one before the preceding one and
391 * filled up to maximum UDP size. If they never send us the first packet in
392 * the sequence, they can cause us to have to hold on to around 2MiB of kernel
393 * space until the call times out.
394 *
395 * We limit the space usage by only accepting three duplicate jumbo packets per
396 * call. After that, we tell the other side we're no longer accepting jumbos
397 * (that information is encoded in the ACK packet).
398 */
399static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq,
David Howells75e42122016-09-13 22:36:22 +0100400 u8 annotation, bool *_jumbo_bad)
David Howells248f2192016-09-08 11:10:12 +0100401{
402 /* Discard normal packets that are duplicates. */
403 if (annotation == 0)
404 return;
405
406 /* Skip jumbo subpackets that are duplicates. When we've had three or
407 * more partially duplicate jumbo packets, we refuse to take any more
408 * jumbos for this call.
409 */
David Howells75e42122016-09-13 22:36:22 +0100410 if (!*_jumbo_bad) {
411 call->nr_jumbo_bad++;
412 *_jumbo_bad = true;
David Howells248f2192016-09-08 11:10:12 +0100413 }
David Howells17926a72007-04-26 15:48:28 -0700414}
415
416/*
David Howells248f2192016-09-08 11:10:12 +0100417 * Process a DATA packet, adding the packet to the Rx ring.
David Howells17926a72007-04-26 15:48:28 -0700418 */
David Howells248f2192016-09-08 11:10:12 +0100419static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
420 u16 skew)
421{
422 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells775e5b72016-09-30 13:26:03 +0100423 unsigned int offset = sizeof(struct rxrpc_wire_header);
David Howells248f2192016-09-08 11:10:12 +0100424 unsigned int ix;
425 rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
426 rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
David Howells75e42122016-09-13 22:36:22 +0100427 bool immediate_ack = false, jumbo_bad = false, queued;
David Howells248f2192016-09-08 11:10:12 +0100428 u16 len;
429 u8 ack = 0, flags, annotation = 0;
430
431 _enter("{%u,%u},{%u,%u}",
David Howells89a80ed2016-09-13 22:36:22 +0100432 call->rx_hard_ack, call->rx_top, skb->len, seq);
David Howells248f2192016-09-08 11:10:12 +0100433
434 _proto("Rx DATA %%%u { #%u f=%02x }",
435 sp->hdr.serial, seq, sp->hdr.flags);
436
437 if (call->state >= RXRPC_CALL_COMPLETE)
438 return;
439
440 /* Received data implicitly ACKs all of the request packets we sent
441 * when we're acting as a client.
442 */
David Howells70790db2016-09-23 12:39:22 +0100443 if ((call->state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
444 call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
445 !rxrpc_receiving_reply(call))
David Howells248f2192016-09-08 11:10:12 +0100446 return;
447
448 call->ackr_prev_seq = seq;
449
450 hard_ack = READ_ONCE(call->rx_hard_ack);
451 if (after(seq, hard_ack + call->rx_winsize)) {
452 ack = RXRPC_ACK_EXCEEDS_WINDOW;
453 ack_serial = serial;
454 goto ack;
455 }
456
457 flags = sp->hdr.flags;
458 if (flags & RXRPC_JUMBO_PACKET) {
David Howells75e42122016-09-13 22:36:22 +0100459 if (call->nr_jumbo_bad > 3) {
David Howells248f2192016-09-08 11:10:12 +0100460 ack = RXRPC_ACK_NOSPACE;
461 ack_serial = serial;
462 goto ack;
463 }
464 annotation = 1;
465 }
466
467next_subpacket:
468 queued = false;
469 ix = seq & RXRPC_RXTX_BUFF_MASK;
David Howells89a80ed2016-09-13 22:36:22 +0100470 len = skb->len;
David Howells248f2192016-09-08 11:10:12 +0100471 if (flags & RXRPC_JUMBO_PACKET)
472 len = RXRPC_JUMBO_DATALEN;
473
474 if (flags & RXRPC_LAST_PACKET) {
David Howells816c9fc2016-09-17 10:49:11 +0100475 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
David Howells248f2192016-09-08 11:10:12 +0100476 seq != call->rx_top)
477 return rxrpc_proto_abort("LSN", call, seq);
478 } else {
479 if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
480 after_eq(seq, call->rx_top))
481 return rxrpc_proto_abort("LSA", call, seq);
482 }
483
484 if (before_eq(seq, hard_ack)) {
485 ack = RXRPC_ACK_DUPLICATE;
486 ack_serial = serial;
487 goto skip;
488 }
489
490 if (flags & RXRPC_REQUEST_ACK && !ack) {
491 ack = RXRPC_ACK_REQUESTED;
492 ack_serial = serial;
493 }
494
495 if (call->rxtx_buffer[ix]) {
David Howells75e42122016-09-13 22:36:22 +0100496 rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
David Howells248f2192016-09-08 11:10:12 +0100497 if (ack != RXRPC_ACK_DUPLICATE) {
498 ack = RXRPC_ACK_DUPLICATE;
499 ack_serial = serial;
500 }
501 immediate_ack = true;
502 goto skip;
503 }
504
505 /* Queue the packet. We use a couple of memory barriers here as need
506 * to make sure that rx_top is perceived to be set after the buffer
507 * pointer and that the buffer pointer is set after the annotation and
508 * the skb data.
509 *
510 * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window()
511 * and also rxrpc_fill_out_ack().
512 */
David Howells71f3ca42016-09-17 10:49:14 +0100513 rxrpc_get_skb(skb, rxrpc_skb_rx_got);
David Howells248f2192016-09-08 11:10:12 +0100514 call->rxtx_annotations[ix] = annotation;
515 smp_wmb();
516 call->rxtx_buffer[ix] = skb;
David Howellsa7056c52016-09-24 18:05:27 +0100517 if (after(seq, call->rx_top)) {
David Howells248f2192016-09-08 11:10:12 +0100518 smp_store_release(&call->rx_top, seq);
David Howellsa7056c52016-09-24 18:05:27 +0100519 } else if (before(seq, call->rx_top)) {
520 /* Send an immediate ACK if we fill in a hole */
521 if (!ack) {
522 ack = RXRPC_ACK_DELAY;
523 ack_serial = serial;
524 }
525 immediate_ack = true;
526 }
David Howells58dc63c2016-09-17 10:49:13 +0100527 if (flags & RXRPC_LAST_PACKET) {
David Howells816c9fc2016-09-17 10:49:11 +0100528 set_bit(RXRPC_CALL_RX_LAST, &call->flags);
David Howells58dc63c2016-09-17 10:49:13 +0100529 trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
530 } else {
531 trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
532 }
David Howells248f2192016-09-08 11:10:12 +0100533 queued = true;
534
535 if (after_eq(seq, call->rx_expect_next)) {
536 if (after(seq, call->rx_expect_next)) {
537 _net("OOS %u > %u", seq, call->rx_expect_next);
538 ack = RXRPC_ACK_OUT_OF_SEQUENCE;
539 ack_serial = serial;
540 }
541 call->rx_expect_next = seq + 1;
542 }
543
544skip:
545 offset += len;
546 if (flags & RXRPC_JUMBO_PACKET) {
547 if (skb_copy_bits(skb, offset, &flags, 1) < 0)
548 return rxrpc_proto_abort("XJF", call, seq);
549 offset += sizeof(struct rxrpc_jumbo_header);
550 seq++;
551 serial++;
552 annotation++;
553 if (flags & RXRPC_JUMBO_PACKET)
554 annotation |= RXRPC_RX_ANNO_JLAST;
David Howells75e42122016-09-13 22:36:22 +0100555 if (after(seq, hard_ack + call->rx_winsize)) {
556 ack = RXRPC_ACK_EXCEEDS_WINDOW;
557 ack_serial = serial;
558 if (!jumbo_bad) {
559 call->nr_jumbo_bad++;
560 jumbo_bad = true;
561 }
562 goto ack;
563 }
David Howells248f2192016-09-08 11:10:12 +0100564
565 _proto("Rx DATA Jumbo %%%u", serial);
566 goto next_subpacket;
567 }
568
569 if (queued && flags & RXRPC_LAST_PACKET && !ack) {
570 ack = RXRPC_ACK_DELAY;
571 ack_serial = serial;
572 }
573
574ack:
575 if (ack)
576 rxrpc_propose_ACK(call, ack, skew, ack_serial,
David Howells9c7ad432016-09-23 13:50:40 +0100577 immediate_ack, true,
578 rxrpc_propose_ack_input_data);
David Howells248f2192016-09-08 11:10:12 +0100579
580 if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1)
581 rxrpc_notify_socket(call);
582 _leave(" [queued]");
583}
584
585/*
David Howells50235c42016-09-22 00:29:31 +0100586 * Process a requested ACK.
587 */
588static void rxrpc_input_requested_ack(struct rxrpc_call *call,
589 ktime_t resp_time,
590 rxrpc_serial_t orig_serial,
591 rxrpc_serial_t ack_serial)
592{
593 struct rxrpc_skb_priv *sp;
594 struct sk_buff *skb;
595 ktime_t sent_at;
596 int ix;
597
598 for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
599 skb = call->rxtx_buffer[ix];
600 if (!skb)
601 continue;
602
603 sp = rxrpc_skb(skb);
604 if (sp->hdr.serial != orig_serial)
605 continue;
606 smp_rmb();
607 sent_at = skb->tstamp;
608 goto found;
609 }
610 return;
611
612found:
613 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
614 orig_serial, ack_serial, sent_at, resp_time);
615}
616
617/*
David Howells8e831342016-09-22 00:29:31 +0100618 * Process a ping response.
619 */
620static void rxrpc_input_ping_response(struct rxrpc_call *call,
621 ktime_t resp_time,
622 rxrpc_serial_t orig_serial,
623 rxrpc_serial_t ack_serial)
624{
625 rxrpc_serial_t ping_serial;
626 ktime_t ping_time;
627
David Howellsa5af7e12016-10-06 08:11:49 +0100628 ping_time = call->ping_time;
David Howells8e831342016-09-22 00:29:31 +0100629 smp_rmb();
David Howellsa5af7e12016-10-06 08:11:49 +0100630 ping_serial = call->ping_serial;
David Howells8e831342016-09-22 00:29:31 +0100631
632 if (!test_bit(RXRPC_CALL_PINGING, &call->flags) ||
633 before(orig_serial, ping_serial))
634 return;
635 clear_bit(RXRPC_CALL_PINGING, &call->flags);
636 if (after(orig_serial, ping_serial))
637 return;
638
639 rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
640 orig_serial, ack_serial, ping_time, resp_time);
641}
642
643/*
David Howells248f2192016-09-08 11:10:12 +0100644 * Process the extra information that may be appended to an ACK packet
645 */
646static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
647 struct rxrpc_ackinfo *ackinfo)
648{
649 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
650 struct rxrpc_peer *peer;
651 unsigned int mtu;
David Howells01fd0742016-09-13 10:23:01 +0100652 u32 rwind = ntohl(ackinfo->rwind);
David Howells248f2192016-09-08 11:10:12 +0100653
654 _proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
655 sp->hdr.serial,
656 ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
David Howells01fd0742016-09-13 10:23:01 +0100657 rwind, ntohl(ackinfo->jumbo_max));
David Howells248f2192016-09-08 11:10:12 +0100658
David Howells01fd0742016-09-13 10:23:01 +0100659 if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
660 rwind = RXRPC_RXTX_BUFF_SIZE - 1;
661 call->tx_winsize = rwind;
David Howells08511152016-09-30 09:33:27 +0100662 if (call->cong_ssthresh > rwind)
663 call->cong_ssthresh = rwind;
David Howells248f2192016-09-08 11:10:12 +0100664
665 mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
666
667 peer = call->peer;
668 if (mtu < peer->maxdata) {
669 spin_lock_bh(&peer->lock);
670 peer->maxdata = mtu;
671 peer->mtu = mtu + peer->hdrsize;
672 spin_unlock_bh(&peer->lock);
673 _net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
674 }
675}
676
677/*
678 * Process individual soft ACKs.
679 *
680 * Each ACK in the array corresponds to one packet and can be either an ACK or
681 * a NAK. If we get find an explicitly NAK'd packet we resend immediately;
682 * packets that lie beyond the end of the ACK list are scheduled for resend by
683 * the timer on the basis that the peer might just not have processed them at
684 * the time the ACK was sent.
685 */
686static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
David Howells31a1b982016-09-24 18:05:26 +0100687 rxrpc_seq_t seq, int nr_acks,
688 struct rxrpc_ack_summary *summary)
David Howells248f2192016-09-08 11:10:12 +0100689{
David Howells248f2192016-09-08 11:10:12 +0100690 int ix;
David Howellsf07373e2016-09-22 00:29:32 +0100691 u8 annotation, anno_type;
David Howells248f2192016-09-08 11:10:12 +0100692
693 for (; nr_acks > 0; nr_acks--, seq++) {
694 ix = seq & RXRPC_RXTX_BUFF_MASK;
David Howellsf07373e2016-09-22 00:29:32 +0100695 annotation = call->rxtx_annotations[ix];
696 anno_type = annotation & RXRPC_TX_ANNO_MASK;
697 annotation &= ~RXRPC_TX_ANNO_MASK;
David Howellsd01dc4c2016-09-17 10:49:12 +0100698 switch (*acks++) {
David Howells248f2192016-09-08 11:10:12 +0100699 case RXRPC_ACK_TYPE_ACK:
David Howells31a1b982016-09-24 18:05:26 +0100700 summary->nr_acks++;
David Howellsf07373e2016-09-22 00:29:32 +0100701 if (anno_type == RXRPC_TX_ANNO_ACK)
702 continue;
David Howells31a1b982016-09-24 18:05:26 +0100703 summary->nr_new_acks++;
David Howellsf07373e2016-09-22 00:29:32 +0100704 call->rxtx_annotations[ix] =
705 RXRPC_TX_ANNO_ACK | annotation;
David Howells248f2192016-09-08 11:10:12 +0100706 break;
707 case RXRPC_ACK_TYPE_NACK:
David Howells31a1b982016-09-24 18:05:26 +0100708 if (!summary->nr_nacks &&
709 call->acks_lowest_nak != seq) {
710 call->acks_lowest_nak = seq;
711 summary->new_low_nack = true;
712 }
713 summary->nr_nacks++;
David Howellsf07373e2016-09-22 00:29:32 +0100714 if (anno_type == RXRPC_TX_ANNO_NAK)
David Howells248f2192016-09-08 11:10:12 +0100715 continue;
David Howells31a1b982016-09-24 18:05:26 +0100716 summary->nr_new_nacks++;
David Howellsbe8aa332016-09-23 12:39:23 +0100717 if (anno_type == RXRPC_TX_ANNO_RETRANS)
718 continue;
David Howellsf07373e2016-09-22 00:29:32 +0100719 call->rxtx_annotations[ix] =
720 RXRPC_TX_ANNO_NAK | annotation;
David Howells248f2192016-09-08 11:10:12 +0100721 break;
722 default:
723 return rxrpc_proto_abort("SFT", call, 0);
724 }
725 }
David Howells248f2192016-09-08 11:10:12 +0100726}
727
728/*
729 * Process an ACK packet.
730 *
731 * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
732 * in the ACK array. Anything before that is hard-ACK'd and may be discarded.
733 *
734 * A hard-ACK means that a packet has been processed and may be discarded; a
735 * soft-ACK means that the packet may be discarded and retransmission
736 * requested. A phase is complete when all packets are hard-ACK'd.
737 */
738static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
739 u16 skew)
740{
David Howells31a1b982016-09-24 18:05:26 +0100741 struct rxrpc_ack_summary summary = { 0 };
David Howells248f2192016-09-08 11:10:12 +0100742 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
743 union {
744 struct rxrpc_ackpacket ack;
745 struct rxrpc_ackinfo info;
746 u8 acks[RXRPC_MAXACKS];
747 } buf;
David Howells8e831342016-09-22 00:29:31 +0100748 rxrpc_serial_t acked_serial;
David Howells248f2192016-09-08 11:10:12 +0100749 rxrpc_seq_t first_soft_ack, hard_ack;
David Howells775e5b72016-09-30 13:26:03 +0100750 int nr_acks, offset, ioffset;
David Howells248f2192016-09-08 11:10:12 +0100751
752 _enter("");
753
David Howells775e5b72016-09-30 13:26:03 +0100754 offset = sizeof(struct rxrpc_wire_header);
755 if (skb_copy_bits(skb, offset, &buf.ack, sizeof(buf.ack)) < 0) {
David Howells248f2192016-09-08 11:10:12 +0100756 _debug("extraction failure");
757 return rxrpc_proto_abort("XAK", call, 0);
758 }
David Howells775e5b72016-09-30 13:26:03 +0100759 offset += sizeof(buf.ack);
David Howells248f2192016-09-08 11:10:12 +0100760
David Howells8e831342016-09-22 00:29:31 +0100761 acked_serial = ntohl(buf.ack.serial);
David Howells248f2192016-09-08 11:10:12 +0100762 first_soft_ack = ntohl(buf.ack.firstPacket);
763 hard_ack = first_soft_ack - 1;
764 nr_acks = buf.ack.nAcks;
David Howells31a1b982016-09-24 18:05:26 +0100765 summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ?
766 buf.ack.reason : RXRPC_ACK__INVALID);
David Howells248f2192016-09-08 11:10:12 +0100767
David Howells31a1b982016-09-24 18:05:26 +0100768 trace_rxrpc_rx_ack(call, first_soft_ack, summary.ack_reason, nr_acks);
David Howellsec71eb92016-09-17 10:49:13 +0100769
David Howells248f2192016-09-08 11:10:12 +0100770 _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
771 sp->hdr.serial,
772 ntohs(buf.ack.maxSkew),
773 first_soft_ack,
774 ntohl(buf.ack.previousPacket),
David Howells8e831342016-09-22 00:29:31 +0100775 acked_serial,
David Howells31a1b982016-09-24 18:05:26 +0100776 rxrpc_ack_names[summary.ack_reason],
David Howells248f2192016-09-08 11:10:12 +0100777 buf.ack.nAcks);
778
David Howells8e831342016-09-22 00:29:31 +0100779 if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
780 rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
781 sp->hdr.serial);
David Howells50235c42016-09-22 00:29:31 +0100782 if (buf.ack.reason == RXRPC_ACK_REQUESTED)
783 rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
784 sp->hdr.serial);
David Howells8e831342016-09-22 00:29:31 +0100785
David Howells248f2192016-09-08 11:10:12 +0100786 if (buf.ack.reason == RXRPC_ACK_PING) {
787 _proto("Rx ACK %%%u PING Request", sp->hdr.serial);
788 rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
David Howells9c7ad432016-09-23 13:50:40 +0100789 skew, sp->hdr.serial, true, true,
790 rxrpc_propose_ack_respond_to_ping);
David Howells248f2192016-09-08 11:10:12 +0100791 } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
792 rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
David Howells9c7ad432016-09-23 13:50:40 +0100793 skew, sp->hdr.serial, true, true,
794 rxrpc_propose_ack_respond_to_ack);
David Howells248f2192016-09-08 11:10:12 +0100795 }
796
David Howells775e5b72016-09-30 13:26:03 +0100797 ioffset = offset + nr_acks + 3;
798 if (skb->len >= ioffset + sizeof(buf.info)) {
799 if (skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
David Howells248f2192016-09-08 11:10:12 +0100800 return rxrpc_proto_abort("XAI", call, 0);
801 rxrpc_input_ackinfo(call, skb, &buf.info);
802 }
803
804 if (first_soft_ack == 0)
805 return rxrpc_proto_abort("AK0", call, 0);
806
807 /* Ignore ACKs unless we are or have just been transmitting. */
808 switch (call->state) {
809 case RXRPC_CALL_CLIENT_SEND_REQUEST:
810 case RXRPC_CALL_CLIENT_AWAIT_REPLY:
811 case RXRPC_CALL_SERVER_SEND_REPLY:
812 case RXRPC_CALL_SERVER_AWAIT_ACK:
813 break;
814 default:
815 return;
816 }
817
818 /* Discard any out-of-order or duplicate ACKs. */
David Howells98dafac2016-09-23 14:04:38 +0100819 if (before_eq(sp->hdr.serial, call->acks_latest)) {
David Howells248f2192016-09-08 11:10:12 +0100820 _debug("discard ACK %d <= %d",
821 sp->hdr.serial, call->acks_latest);
822 return;
823 }
David Howells57494342016-09-24 18:05:27 +0100824 call->acks_latest_ts = skb->tstamp;
David Howells248f2192016-09-08 11:10:12 +0100825 call->acks_latest = sp->hdr.serial;
826
David Howells248f2192016-09-08 11:10:12 +0100827 if (before(hard_ack, call->tx_hard_ack) ||
828 after(hard_ack, call->tx_top))
829 return rxrpc_proto_abort("AKW", call, 0);
David Howells70790db2016-09-23 12:39:22 +0100830 if (nr_acks > call->tx_top - hard_ack)
831 return rxrpc_proto_abort("AKN", call, 0);
David Howells248f2192016-09-08 11:10:12 +0100832
833 if (after(hard_ack, call->tx_hard_ack))
David Howells31a1b982016-09-24 18:05:26 +0100834 rxrpc_rotate_tx_window(call, hard_ack, &summary);
David Howells248f2192016-09-08 11:10:12 +0100835
David Howells70790db2016-09-23 12:39:22 +0100836 if (nr_acks > 0) {
David Howells775e5b72016-09-30 13:26:03 +0100837 if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0)
David Howells70790db2016-09-23 12:39:22 +0100838 return rxrpc_proto_abort("XSA", call, 0);
David Howells31a1b982016-09-24 18:05:26 +0100839 rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
840 &summary);
David Howells70790db2016-09-23 12:39:22 +0100841 }
David Howells248f2192016-09-08 11:10:12 +0100842
David Howells70790db2016-09-23 12:39:22 +0100843 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
844 rxrpc_end_tx_phase(call, false, "ETA");
845 return;
846 }
847
David Howells0d967962016-09-24 18:05:27 +0100848 if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] &
849 RXRPC_TX_ANNO_LAST &&
David Howellsa9f312d2016-10-06 08:11:49 +0100850 summary.nr_acks == call->tx_top - hard_ack &&
851 rxrpc_is_client_call(call))
David Howells0d967962016-09-24 18:05:27 +0100852 rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
853 false, true,
854 rxrpc_propose_ack_ping_for_lost_reply);
David Howells57494342016-09-24 18:05:27 +0100855
David Howellsed1e8672016-09-29 22:37:16 +0100856 return rxrpc_congestion_management(call, skb, &summary, acked_serial);
David Howells248f2192016-09-08 11:10:12 +0100857}
858
859/*
860 * Process an ACKALL packet.
861 */
862static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
863{
David Howells31a1b982016-09-24 18:05:26 +0100864 struct rxrpc_ack_summary summary = { 0 };
David Howells248f2192016-09-08 11:10:12 +0100865 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
866
867 _proto("Rx ACKALL %%%u", sp->hdr.serial);
868
David Howells31a1b982016-09-24 18:05:26 +0100869 rxrpc_rotate_tx_window(call, call->tx_top, &summary);
David Howells70790db2016-09-23 12:39:22 +0100870 if (test_bit(RXRPC_CALL_TX_LAST, &call->flags))
871 rxrpc_end_tx_phase(call, false, "ETL");
David Howells248f2192016-09-08 11:10:12 +0100872}
873
874/*
875 * Process an ABORT packet.
876 */
877static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
David Howells17926a72007-04-26 15:48:28 -0700878{
879 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells0d12f8a2016-03-04 15:53:46 +0000880 __be32 wtmp;
David Howells248f2192016-09-08 11:10:12 +0100881 u32 abort_code = RX_CALL_DEAD;
882
883 _enter("");
884
885 if (skb->len >= 4 &&
David Howells775e5b72016-09-30 13:26:03 +0100886 skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
887 &wtmp, sizeof(wtmp)) >= 0)
David Howells248f2192016-09-08 11:10:12 +0100888 abort_code = ntohl(wtmp);
889
890 _proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
891
892 if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
893 abort_code, ECONNABORTED))
894 rxrpc_notify_socket(call);
895}
896
897/*
898 * Process an incoming call packet.
899 */
900static void rxrpc_input_call_packet(struct rxrpc_call *call,
901 struct sk_buff *skb, u16 skew)
902{
903 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
David Howells17926a72007-04-26 15:48:28 -0700904
905 _enter("%p,%p", call, skb);
906
David Howells17926a72007-04-26 15:48:28 -0700907 switch (sp->hdr.type) {
David Howells248f2192016-09-08 11:10:12 +0100908 case RXRPC_PACKET_TYPE_DATA:
909 rxrpc_input_data(call, skb, skew);
910 break;
David Howells17926a72007-04-26 15:48:28 -0700911
David Howells248f2192016-09-08 11:10:12 +0100912 case RXRPC_PACKET_TYPE_ACK:
913 rxrpc_input_ack(call, skb, skew);
914 break;
David Howells17926a72007-04-26 15:48:28 -0700915
916 case RXRPC_PACKET_TYPE_BUSY:
David Howells0d12f8a2016-03-04 15:53:46 +0000917 _proto("Rx BUSY %%%u", sp->hdr.serial);
David Howells17926a72007-04-26 15:48:28 -0700918
David Howells248f2192016-09-08 11:10:12 +0100919 /* Just ignore BUSY packets from the server; the retry and
920 * lifespan timers will take care of business. BUSY packets
921 * from the client don't make sense.
922 */
923 break;
David Howells17926a72007-04-26 15:48:28 -0700924
David Howells248f2192016-09-08 11:10:12 +0100925 case RXRPC_PACKET_TYPE_ABORT:
926 rxrpc_input_abort(call, skb);
927 break;
928
929 case RXRPC_PACKET_TYPE_ACKALL:
930 rxrpc_input_ackall(call, skb);
931 break;
David Howells17926a72007-04-26 15:48:28 -0700932
933 default:
David Howells0d12f8a2016-03-04 15:53:46 +0000934 _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial);
David Howells17926a72007-04-26 15:48:28 -0700935 break;
936 }
937
David Howells17926a72007-04-26 15:48:28 -0700938 _leave("");
939}
940
941/*
David Howellsb3156272016-10-06 08:11:49 +0100942 * Handle a new call on a channel implicitly completing the preceding call on
943 * that channel.
944 *
945 * TODO: If callNumber > call_id + 1, renegotiate security.
946 */
947static void rxrpc_input_implicit_end_call(struct rxrpc_connection *conn,
948 struct rxrpc_call *call)
949{
950 switch (call->state) {
951 case RXRPC_CALL_SERVER_AWAIT_ACK:
952 rxrpc_call_completed(call);
953 break;
954 case RXRPC_CALL_COMPLETE:
955 break;
956 default:
957 if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, ESHUTDOWN)) {
958 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
959 rxrpc_queue_call(call);
960 }
961 break;
962 }
963
964 __rxrpc_disconnect_call(conn, call);
965 rxrpc_notify_socket(call);
966}
967
968/*
David Howells17926a72007-04-26 15:48:28 -0700969 * post connection-level events to the connection
David Howells18bfeba2016-08-23 15:27:25 +0100970 * - this includes challenges, responses, some aborts and call terminal packet
971 * retransmission.
David Howells17926a72007-04-26 15:48:28 -0700972 */
David Howells2e7e9752016-08-09 10:11:48 +0100973static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
David Howells17926a72007-04-26 15:48:28 -0700974 struct sk_buff *skb)
975{
976 _enter("%p,%p", conn, skb);
977
David Howells17926a72007-04-26 15:48:28 -0700978 skb_queue_tail(&conn->rx_queue, skb);
David Howells2e7e9752016-08-09 10:11:48 +0100979 rxrpc_queue_conn(conn);
David Howells17926a72007-04-26 15:48:28 -0700980}
981
David Howells44ba0692015-04-01 16:31:26 +0100982/*
983 * post endpoint-level events to the local endpoint
984 * - this includes debug and version messages
985 */
986static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
987 struct sk_buff *skb)
988{
989 _enter("%p,%p", local, skb);
990
David Howells44ba0692015-04-01 16:31:26 +0100991 skb_queue_tail(&local->event_queue, skb);
David Howells5acbee42016-06-27 10:32:02 +0100992 rxrpc_queue_local(local);
David Howells44ba0692015-04-01 16:31:26 +0100993}
994
David Howells0d12f8a2016-03-04 15:53:46 +0000995/*
David Howells248f2192016-09-08 11:10:12 +0100996 * put a packet up for transport-level abort
997 */
998static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
999{
1000 CHECK_SLAB_OKAY(&local->usage);
1001
1002 skb_queue_tail(&local->reject_queue, skb);
1003 rxrpc_queue_local(local);
1004}
1005
1006/*
David Howells0d12f8a2016-03-04 15:53:46 +00001007 * Extract the wire header from a packet and translate the byte order.
1008 */
1009static noinline
1010int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
1011{
1012 struct rxrpc_wire_header whdr;
1013
1014 /* dig out the RxRPC connection details */
Willem de Bruijn4d0fc732016-04-07 11:44:59 -04001015 if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
David Howells0d12f8a2016-03-04 15:53:46 +00001016 return -EBADMSG;
David Howells0d12f8a2016-03-04 15:53:46 +00001017
1018 memset(sp, 0, sizeof(*sp));
1019 sp->hdr.epoch = ntohl(whdr.epoch);
1020 sp->hdr.cid = ntohl(whdr.cid);
1021 sp->hdr.callNumber = ntohl(whdr.callNumber);
1022 sp->hdr.seq = ntohl(whdr.seq);
1023 sp->hdr.serial = ntohl(whdr.serial);
1024 sp->hdr.flags = whdr.flags;
1025 sp->hdr.type = whdr.type;
1026 sp->hdr.userStatus = whdr.userStatus;
1027 sp->hdr.securityIndex = whdr.securityIndex;
1028 sp->hdr._rsvd = ntohs(whdr._rsvd);
1029 sp->hdr.serviceId = ntohs(whdr.serviceId);
1030 return 0;
1031}
1032
David Howells17926a72007-04-26 15:48:28 -07001033/*
1034 * handle data received on the local endpoint
1035 * - may be called in interrupt context
David Howells4f95dd72016-04-04 14:00:35 +01001036 *
1037 * The socket is locked by the caller and this prevents the socket from being
1038 * shut down and the local endpoint from going away, thus sk_user_data will not
1039 * be cleared until this function returns.
David Howells17926a72007-04-26 15:48:28 -07001040 */
David Howells248f2192016-09-08 11:10:12 +01001041void rxrpc_data_ready(struct sock *udp_sk)
David Howells17926a72007-04-26 15:48:28 -07001042{
David Howells8496af52016-07-01 07:51:50 +01001043 struct rxrpc_connection *conn;
David Howells248f2192016-09-08 11:10:12 +01001044 struct rxrpc_channel *chan;
1045 struct rxrpc_call *call;
David Howells17926a72007-04-26 15:48:28 -07001046 struct rxrpc_skb_priv *sp;
David Howells248f2192016-09-08 11:10:12 +01001047 struct rxrpc_local *local = udp_sk->sk_user_data;
David Howells17926a72007-04-26 15:48:28 -07001048 struct sk_buff *skb;
David Howells248f2192016-09-08 11:10:12 +01001049 unsigned int channel;
David Howells563ea7d2016-08-23 15:27:25 +01001050 int ret, skew;
David Howells17926a72007-04-26 15:48:28 -07001051
David Howells248f2192016-09-08 11:10:12 +01001052 _enter("%p", udp_sk);
David Howells17926a72007-04-26 15:48:28 -07001053
1054 ASSERT(!irqs_disabled());
1055
David Howells248f2192016-09-08 11:10:12 +01001056 skb = skb_recv_datagram(udp_sk, 0, 1, &ret);
David Howells17926a72007-04-26 15:48:28 -07001057 if (!skb) {
David Howells17926a72007-04-26 15:48:28 -07001058 if (ret == -EAGAIN)
1059 return;
1060 _debug("UDP socket error %d", ret);
1061 return;
1062 }
1063
David Howells71f3ca42016-09-17 10:49:14 +01001064 rxrpc_new_skb(skb, rxrpc_skb_rx_received);
David Howells17926a72007-04-26 15:48:28 -07001065
1066 _net("recv skb %p", skb);
1067
1068 /* we'll probably need to checksum it (didn't call sock_recvmsg) */
1069 if (skb_checksum_complete(skb)) {
David Howells71f3ca42016-09-17 10:49:14 +01001070 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
Eric Dumazet02c22342016-04-27 16:44:30 -07001071 __UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
David Howells17926a72007-04-26 15:48:28 -07001072 _leave(" [CSUM failed]");
1073 return;
1074 }
1075
Eric Dumazet02c22342016-04-27 16:44:30 -07001076 __UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
Herbert Xu1781f7f2007-12-11 11:30:32 -08001077
David Howells0d12f8a2016-03-04 15:53:46 +00001078 /* The socket buffer we have is owned by UDP, with UDP's data all over
1079 * it, but we really want our own data there.
1080 */
David Howells17926a72007-04-26 15:48:28 -07001081 skb_orphan(skb);
1082 sp = rxrpc_skb(skb);
David Howells17926a72007-04-26 15:48:28 -07001083
David Howells89b475a2016-09-23 12:39:22 +01001084 /* dig out the RxRPC connection details */
1085 if (rxrpc_extract_header(sp, skb) < 0)
1086 goto bad_message;
1087
David Howells8a681c362016-09-17 10:49:15 +01001088 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
1089 static int lose;
1090 if ((lose++ & 7) == 7) {
David Howells89b475a2016-09-23 12:39:22 +01001091 trace_rxrpc_rx_lose(sp);
David Howells8a681c362016-09-17 10:49:15 +01001092 rxrpc_lose_skb(skb, rxrpc_skb_rx_lost);
1093 return;
1094 }
1095 }
1096
David Howells49e19ec2016-09-08 11:10:12 +01001097 trace_rxrpc_rx_packet(sp);
David Howells17926a72007-04-26 15:48:28 -07001098
1099 _net("Rx RxRPC %s ep=%x call=%x:%x",
1100 sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
David Howells0d12f8a2016-03-04 15:53:46 +00001101 sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
David Howells17926a72007-04-26 15:48:28 -07001102
David Howells351c1e62016-03-04 15:56:06 +00001103 if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
1104 !((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
David Howells17926a72007-04-26 15:48:28 -07001105 _proto("Rx Bad Packet Type %u", sp->hdr.type);
1106 goto bad_message;
1107 }
1108
David Howells248f2192016-09-08 11:10:12 +01001109 switch (sp->hdr.type) {
1110 case RXRPC_PACKET_TYPE_VERSION:
David Howells44ba0692015-04-01 16:31:26 +01001111 rxrpc_post_packet_to_local(local, skb);
1112 goto out;
David Howellsbc6e1ea2016-06-10 22:30:27 +01001113
David Howells248f2192016-09-08 11:10:12 +01001114 case RXRPC_PACKET_TYPE_BUSY:
1115 if (sp->hdr.flags & RXRPC_CLIENT_INITIATED)
1116 goto discard;
1117
1118 case RXRPC_PACKET_TYPE_DATA:
1119 if (sp->hdr.callNumber == 0)
1120 goto bad_message;
1121 if (sp->hdr.flags & RXRPC_JUMBO_PACKET &&
1122 !rxrpc_validate_jumbo(skb))
1123 goto bad_message;
1124 break;
1125 }
David Howells17926a72007-04-26 15:48:28 -07001126
David Howells8496af52016-07-01 07:51:50 +01001127 rcu_read_lock();
1128
David Howells8496af52016-07-01 07:51:50 +01001129 conn = rxrpc_find_connection_rcu(local, skb);
David Howells248f2192016-09-08 11:10:12 +01001130 if (conn) {
1131 if (sp->hdr.securityIndex != conn->security_ix)
1132 goto wrong_security;
David Howells563ea7d2016-08-23 15:27:25 +01001133
David Howells248f2192016-09-08 11:10:12 +01001134 if (sp->hdr.callNumber == 0) {
1135 /* Connection-level packet */
1136 _debug("CONN %p {%d}", conn, conn->debug_id);
1137 rxrpc_post_packet_to_conn(conn, skb);
1138 goto out_unlock;
1139 }
David Howells8496af52016-07-01 07:51:50 +01001140
David Howells248f2192016-09-08 11:10:12 +01001141 /* Note the serial number skew here */
1142 skew = (int)sp->hdr.serial - (int)conn->hi_serial;
1143 if (skew >= 0) {
1144 if (skew > 0)
1145 conn->hi_serial = sp->hdr.serial;
1146 } else {
1147 skew = -skew;
1148 skew = min(skew, 65535);
1149 }
1150
David Howells8496af52016-07-01 07:51:50 +01001151 /* Call-bound packets are routed by connection channel. */
David Howells248f2192016-09-08 11:10:12 +01001152 channel = sp->hdr.cid & RXRPC_CHANNELMASK;
1153 chan = &conn->channels[channel];
Tim Smith77276402014-03-03 23:04:45 +00001154
David Howells18bfeba2016-08-23 15:27:25 +01001155 /* Ignore really old calls */
1156 if (sp->hdr.callNumber < chan->last_call)
1157 goto discard_unlock;
1158
1159 if (sp->hdr.callNumber == chan->last_call) {
David Howells248f2192016-09-08 11:10:12 +01001160 /* For the previous service call, if completed successfully, we
1161 * discard all further packets.
David Howells18bfeba2016-08-23 15:27:25 +01001162 */
David Howells2266ffd2016-08-24 13:06:14 +01001163 if (rxrpc_conn_is_service(conn) &&
David Howells18bfeba2016-08-23 15:27:25 +01001164 (chan->last_type == RXRPC_PACKET_TYPE_ACK ||
1165 sp->hdr.type == RXRPC_PACKET_TYPE_ABORT))
1166 goto discard_unlock;
1167
David Howells248f2192016-09-08 11:10:12 +01001168 /* But otherwise we need to retransmit the final packet from
1169 * data cached in the connection record.
David Howells18bfeba2016-08-23 15:27:25 +01001170 */
1171 rxrpc_post_packet_to_conn(conn, skb);
1172 goto out_unlock;
1173 }
1174
1175 call = rcu_dereference(chan->call);
David Howellsb3156272016-10-06 08:11:49 +01001176
1177 if (sp->hdr.callNumber > chan->call_id) {
1178 if (!(sp->hdr.flags & RXRPC_CLIENT_INITIATED)) {
1179 rcu_read_unlock();
1180 goto reject_packet;
1181 }
1182 if (call)
1183 rxrpc_input_implicit_end_call(conn, call);
1184 call = NULL;
1185 }
David Howells248f2192016-09-08 11:10:12 +01001186 } else {
1187 skew = 0;
1188 call = NULL;
Tim Smith77276402014-03-03 23:04:45 +00001189 }
David Howells44ba0692015-04-01 16:31:26 +01001190
David Howells248f2192016-09-08 11:10:12 +01001191 if (!call || atomic_read(&call->usage) == 0) {
1192 if (!(sp->hdr.type & RXRPC_CLIENT_INITIATED) ||
1193 sp->hdr.callNumber == 0 ||
1194 sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
1195 goto bad_message_unlock;
1196 if (sp->hdr.seq != 1)
1197 goto discard_unlock;
1198 call = rxrpc_new_incoming_call(local, conn, skb);
1199 if (!call) {
1200 rcu_read_unlock();
1201 goto reject_packet;
1202 }
David Howells8e831342016-09-22 00:29:31 +01001203 rxrpc_send_ping(call, skb, skew);
David Howells248f2192016-09-08 11:10:12 +01001204 }
1205
1206 rxrpc_input_call_packet(call, skb, skew);
1207 goto discard_unlock;
1208
David Howells18bfeba2016-08-23 15:27:25 +01001209discard_unlock:
David Howells8496af52016-07-01 07:51:50 +01001210 rcu_read_unlock();
David Howells248f2192016-09-08 11:10:12 +01001211discard:
David Howells71f3ca42016-09-17 10:49:14 +01001212 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
David Howells44ba0692015-04-01 16:31:26 +01001213out:
David Howells49e19ec2016-09-08 11:10:12 +01001214 trace_rxrpc_rx_done(0, 0);
David Howells17926a72007-04-26 15:48:28 -07001215 return;
1216
David Howells248f2192016-09-08 11:10:12 +01001217out_unlock:
David Howells8496af52016-07-01 07:51:50 +01001218 rcu_read_unlock();
David Howells248f2192016-09-08 11:10:12 +01001219 goto out;
David Howells8496af52016-07-01 07:51:50 +01001220
David Howells248f2192016-09-08 11:10:12 +01001221wrong_security:
1222 rcu_read_unlock();
1223 trace_rxrpc_abort("SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1224 RXKADINCONSISTENCY, EBADMSG);
1225 skb->priority = RXKADINCONSISTENCY;
1226 goto post_abort;
David Howells17926a72007-04-26 15:48:28 -07001227
David Howells248f2192016-09-08 11:10:12 +01001228bad_message_unlock:
1229 rcu_read_unlock();
David Howells17926a72007-04-26 15:48:28 -07001230bad_message:
David Howells248f2192016-09-08 11:10:12 +01001231 trace_rxrpc_abort("BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
1232 RX_PROTOCOL_ERROR, EBADMSG);
David Howells17926a72007-04-26 15:48:28 -07001233 skb->priority = RX_PROTOCOL_ERROR;
David Howells248f2192016-09-08 11:10:12 +01001234post_abort:
1235 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
David Howells49e19ec2016-09-08 11:10:12 +01001236reject_packet:
1237 trace_rxrpc_rx_done(skb->mark, skb->priority);
David Howells17926a72007-04-26 15:48:28 -07001238 rxrpc_reject_packet(local, skb);
David Howells17926a72007-04-26 15:48:28 -07001239 _leave(" [badmsg]");
1240}