summaryrefslogtreecommitdiff
path: root/net/rxrpc/io_thread.c
blob: 9e9dfb2fc559be6c2615ecaf2e675f9e3c73d752 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC packet reception
 *
 * Copyright (C) 2007, 2016, 2022 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "ar-internal.h"

static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
				      struct sockaddr_rxrpc *peer_srx,
				      struct sk_buff *skb);

/*
 * handle data received on the local endpoint
 * - may be called in interrupt context
 *
 * [!] Note that as this is called from the encap_rcv hook, the socket is not
 * held locked by the caller and nothing prevents sk_user_data on the UDP from
 * being cleared in the middle of processing this function.
 *
 * Called with the RCU read lock held from the IP layer via UDP.
 */
int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
{
	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);

	if (unlikely(!local)) {
		kfree_skb(skb);
		return 0;
	}
	if (skb->tstamp == 0)
		skb->tstamp = ktime_get_real();

	skb->mark = RXRPC_SKB_MARK_PACKET;
	rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv);
	skb_queue_tail(&local->rx_queue, skb);
	rxrpc_wake_up_io_thread(local);
	return 0;
}

/*
 * Handle an error received on the local endpoint.
 */
void rxrpc_error_report(struct sock *sk)
{
	struct rxrpc_local *local;
	struct sk_buff *skb;

	rcu_read_lock();
	local = rcu_dereference_sk_user_data(sk);
	if (unlikely(!local)) {
		rcu_read_unlock();
		return;
	}

	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
		skb->mark = RXRPC_SKB_MARK_ERROR;
		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
		skb_queue_tail(&local->rx_queue, skb);
	}

	rxrpc_wake_up_io_thread(local);
	rcu_read_unlock();
}

/*
 * Directly produce an abort from a packet.
 */
bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
			s32 abort_code, int err)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);

	trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
			  abort_code, err);
	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
	skb->priority = abort_code;
	return false;
}

static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
{
	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
}

#define just_discard true

/*
 * Process event packets targeted at a local endpoint.
 */
static bool rxrpc_input_version(struct rxrpc_local *local, struct sk_buff *skb)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	char v;

	_enter("");

	rxrpc_see_skb(skb, rxrpc_skb_see_version);
	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), &v, 1) >= 0) {
		if (v == 0)
			rxrpc_send_version_request(local, &sp->hdr, skb);
	}

	return true;
}

/*
 * Extract the wire header from a packet and translate the byte order.
 */
static bool rxrpc_extract_header(struct rxrpc_skb_priv *sp,
				 struct sk_buff *skb)
{
	struct rxrpc_wire_header whdr;

	/* dig out the RxRPC connection details */
	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
		return rxrpc_bad_message(skb, rxrpc_badmsg_short_hdr);

	memset(sp, 0, sizeof(*sp));
	sp->hdr.epoch		= ntohl(whdr.epoch);
	sp->hdr.cid		= ntohl(whdr.cid);
	sp->hdr.callNumber	= ntohl(whdr.callNumber);
	sp->hdr.seq		= ntohl(whdr.seq);
	sp->hdr.serial		= ntohl(whdr.serial);
	sp->hdr.flags		= whdr.flags;
	sp->hdr.type		= whdr.type;
	sp->hdr.userStatus	= whdr.userStatus;
	sp->hdr.securityIndex	= whdr.securityIndex;
	sp->hdr._rsvd		= ntohs(whdr._rsvd);
	sp->hdr.serviceId	= ntohs(whdr.serviceId);
	return true;
}

/*
 * Extract the abort code from an ABORT packet and stash it in skb->priority.
 */
static bool rxrpc_extract_abort(struct sk_buff *skb)
{
	__be32 wtmp;

	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
			  &wtmp, sizeof(wtmp)) < 0)
		return false;
	skb->priority = ntohl(wtmp);
	return true;
}

/*
 * Process packets received on the local endpoint
 */
static bool rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff **_skb)
{
	struct rxrpc_connection *conn;
	struct sockaddr_rxrpc peer_srx;
	struct rxrpc_skb_priv *sp;
	struct rxrpc_peer *peer = NULL;
	struct sk_buff *skb = *_skb;
	bool ret = false;

	skb_pull(skb, sizeof(struct udphdr));

	sp = rxrpc_skb(skb);

	/* dig out the RxRPC connection details */
	if (!rxrpc_extract_header(sp, skb))
		return just_discard;

	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
		static int lose;
		if ((lose++ & 7) == 7) {
			trace_rxrpc_rx_lose(sp);
			return just_discard;
		}
	}

	trace_rxrpc_rx_packet(sp);

	switch (sp->hdr.type) {
	case RXRPC_PACKET_TYPE_VERSION:
		if (rxrpc_to_client(sp))
			return just_discard;
		return rxrpc_input_version(local, skb);

	case RXRPC_PACKET_TYPE_BUSY:
		if (rxrpc_to_server(sp))
			return just_discard;
		fallthrough;
	case RXRPC_PACKET_TYPE_ACK:
	case RXRPC_PACKET_TYPE_ACKALL:
		if (sp->hdr.callNumber == 0)
			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
		break;
	case RXRPC_PACKET_TYPE_ABORT:
		if (!rxrpc_extract_abort(skb))
			return just_discard; /* Just discard if malformed */
		break;

	case RXRPC_PACKET_TYPE_DATA:
		if (sp->hdr.callNumber == 0)
			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
		if (sp->hdr.seq == 0)
			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_seq);

		/* Unshare the packet so that it can be modified for in-place
		 * decryption.
		 */
		if (sp->hdr.securityIndex != 0) {
			skb = skb_unshare(skb, GFP_ATOMIC);
			if (!skb) {
				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare_nomem);
				*_skb = NULL;
				return just_discard;
			}

			if (skb != *_skb) {
				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare);
				*_skb = skb;
				rxrpc_new_skb(skb, rxrpc_skb_new_unshared);
				sp = rxrpc_skb(skb);
			}
		}
		break;

	case RXRPC_PACKET_TYPE_CHALLENGE:
		if (rxrpc_to_server(sp))
			return just_discard;
		break;
	case RXRPC_PACKET_TYPE_RESPONSE:
		if (rxrpc_to_client(sp))
			return just_discard;
		break;

		/* Packet types 9-11 should just be ignored. */
	case RXRPC_PACKET_TYPE_PARAMS:
	case RXRPC_PACKET_TYPE_10:
	case RXRPC_PACKET_TYPE_11:
		return just_discard;

	default:
		return rxrpc_bad_message(skb, rxrpc_badmsg_unsupported_packet);
	}

	if (sp->hdr.serviceId == 0)
		return rxrpc_bad_message(skb, rxrpc_badmsg_zero_service);

	if (WARN_ON_ONCE(rxrpc_extract_addr_from_skb(&peer_srx, skb) < 0))
		return just_discard; /* Unsupported address type. */

	if (peer_srx.transport.family != local->srx.transport.family &&
	    (peer_srx.transport.family == AF_INET &&
	     local->srx.transport.family != AF_INET6)) {
		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
				    peer_srx.transport.family,
				    local->srx.transport.family);
		return just_discard; /* Wrong address type. */
	}

	if (rxrpc_to_client(sp)) {
		rcu_read_lock();
		conn = rxrpc_find_client_connection_rcu(local, &peer_srx, skb);
		conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
		rcu_read_unlock();
		if (!conn)
			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_conn);

		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
		return ret;
	}

	/* We need to look up service connections by the full protocol
	 * parameter set.  We look up the peer first as an intermediate step
	 * and then the connection from the peer's tree.
	 */
	rcu_read_lock();

	peer = rxrpc_lookup_peer_rcu(local, &peer_srx);
	if (!peer) {
		rcu_read_unlock();
		return rxrpc_new_incoming_call(local, NULL, NULL, &peer_srx, skb);
	}

	conn = rxrpc_find_service_conn_rcu(peer, skb);
	conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
	if (conn) {
		rcu_read_unlock();
		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
		return ret;
	}

	peer = rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input);
	rcu_read_unlock();

	ret = rxrpc_new_incoming_call(local, peer, NULL, &peer_srx, skb);
	rxrpc_put_peer(peer, rxrpc_peer_put_input);
	return ret;
}

/*
 * Deal with a packet that's associated with an extant connection.
 */
static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
				      struct sockaddr_rxrpc *peer_srx,
				      struct sk_buff *skb)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	struct rxrpc_channel *chan;
	struct rxrpc_call *call = NULL;
	unsigned int channel;
	bool ret;

	if (sp->hdr.securityIndex != conn->security_ix)
		return rxrpc_direct_abort(skb, rxrpc_eproto_wrong_security,
					  RXKADINCONSISTENCY, -EBADMSG);

	if (sp->hdr.serviceId != conn->service_id) {
		int old_id;

		if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
			return rxrpc_protocol_error(skb, rxrpc_eproto_reupgrade);

		old_id = cmpxchg(&conn->service_id, conn->orig_service_id,
				 sp->hdr.serviceId);
		if (old_id != conn->orig_service_id &&
		    old_id != sp->hdr.serviceId)
			return rxrpc_protocol_error(skb, rxrpc_eproto_bad_upgrade);
	}

	if (after(sp->hdr.serial, conn->hi_serial))
		conn->hi_serial = sp->hdr.serial;

	/* It's a connection-level packet if the call number is 0. */
	if (sp->hdr.callNumber == 0)
		return rxrpc_input_conn_packet(conn, skb);

	/* Call-bound packets are routed by connection channel. */
	channel = sp->hdr.cid & RXRPC_CHANNELMASK;
	chan = &conn->channels[channel];

	/* Ignore really old calls */
	if (sp->hdr.callNumber < chan->last_call)
		return just_discard;

	if (sp->hdr.callNumber == chan->last_call) {
		if (chan->call ||
		    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
			return just_discard;

		/* For the previous service call, if completed successfully, we
		 * discard all further packets.
		 */
		if (rxrpc_conn_is_service(conn) &&
		    chan->last_type == RXRPC_PACKET_TYPE_ACK)
			return just_discard;

		/* But otherwise we need to retransmit the final packet from
		 * data cached in the connection record.
		 */
		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
			trace_rxrpc_rx_data(chan->call_debug_id,
					    sp->hdr.seq,
					    sp->hdr.serial,
					    sp->hdr.flags);
		rxrpc_conn_retransmit_call(conn, skb, channel);
		return just_discard;
	}

	call = rxrpc_try_get_call(chan->call, rxrpc_call_get_input);

	if (sp->hdr.callNumber > chan->call_id) {
		if (rxrpc_to_client(sp)) {
			rxrpc_put_call(call, rxrpc_call_put_input);
			return rxrpc_protocol_error(skb,
						    rxrpc_eproto_unexpected_implicit_end);
		}

		if (call) {
			rxrpc_implicit_end_call(call, skb);
			rxrpc_put_call(call, rxrpc_call_put_input);
			call = NULL;
		}
	}

	if (!call) {
		if (rxrpc_to_client(sp))
			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_call);
		return rxrpc_new_incoming_call(conn->local, conn->peer, conn,
					       peer_srx, skb);
	}

	ret = rxrpc_input_call_event(call, skb);
	rxrpc_put_call(call, rxrpc_call_put_input);
	return ret;
}

/*
 * I/O and event handling thread.
 */
int rxrpc_io_thread(void *data)
{
	struct rxrpc_connection *conn;
	struct sk_buff_head rx_queue;
	struct rxrpc_local *local = data;
	struct rxrpc_call *call;
	struct sk_buff *skb;
	bool should_stop;

	complete(&local->io_thread_ready);

	skb_queue_head_init(&rx_queue);

	set_user_nice(current, MIN_NICE);

	for (;;) {
		rxrpc_inc_stat(local->rxnet, stat_io_loop);

		/* Deal with connections that want immediate attention. */
		conn = list_first_entry_or_null(&local->conn_attend_q,
						struct rxrpc_connection,
						attend_link);
		if (conn) {
			spin_lock_bh(&local->lock);
			list_del_init(&conn->attend_link);
			spin_unlock_bh(&local->lock);

			rxrpc_input_conn_event(conn, NULL);
			rxrpc_put_connection(conn, rxrpc_conn_put_poke);
			continue;
		}

		if (test_and_clear_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
				       &local->client_conn_flags))
			rxrpc_discard_expired_client_conns(local);

		/* Deal with calls that want immediate attention. */
		if ((call = list_first_entry_or_null(&local->call_attend_q,
						     struct rxrpc_call,
						     attend_link))) {
			spin_lock_bh(&local->lock);
			list_del_init(&call->attend_link);
			spin_unlock_bh(&local->lock);

			trace_rxrpc_call_poked(call);
			rxrpc_input_call_event(call, NULL);
			rxrpc_put_call(call, rxrpc_call_put_poke);
			continue;
		}

		if (!list_empty(&local->new_client_calls))
			rxrpc_connect_client_calls(local);

		/* Process received packets and errors. */
		if ((skb = __skb_dequeue(&rx_queue))) {
			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
			switch (skb->mark) {
			case RXRPC_SKB_MARK_PACKET:
				skb->priority = 0;
				if (!rxrpc_input_packet(local, &skb))
					rxrpc_reject_packet(local, skb);
				trace_rxrpc_rx_done(skb->mark, skb->priority);
				rxrpc_free_skb(skb, rxrpc_skb_put_input);
				break;
			case RXRPC_SKB_MARK_ERROR:
				rxrpc_input_error(local, skb);
				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
				break;
			case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
				rxrpc_input_conn_event(sp->conn, skb);
				rxrpc_put_connection(sp->conn, rxrpc_conn_put_poke);
				rxrpc_free_skb(skb, rxrpc_skb_put_conn_secured);
				break;
			default:
				WARN_ON_ONCE(1);
				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);
				break;
			}
			continue;
		}

		if (!skb_queue_empty(&local->rx_queue)) {
			spin_lock_irq(&local->rx_queue.lock);
			skb_queue_splice_tail_init(&local->rx_queue, &rx_queue);
			spin_unlock_irq(&local->rx_queue.lock);
			continue;
		}

		set_current_state(TASK_INTERRUPTIBLE);
		should_stop = kthread_should_stop();
		if (!skb_queue_empty(&local->rx_queue) ||
		    !list_empty(&local->call_attend_q) ||
		    !list_empty(&local->conn_attend_q) ||
		    !list_empty(&local->new_client_calls) ||
		    test_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
			     &local->client_conn_flags)) {
			__set_current_state(TASK_RUNNING);
			continue;
		}

		if (should_stop)
			break;
		schedule();
	}

	__set_current_state(TASK_RUNNING);
	rxrpc_see_local(local, rxrpc_local_stop);
	rxrpc_destroy_local(local);
	local->io_thread = NULL;
	rxrpc_see_local(local, rxrpc_local_stopped);
	return 0;
}