summaryrefslogtreecommitdiff
path: root/net/rxrpc/call_object.c
blob: 18ab13f82f6e197b8b692d0adaff1dc23b56ff05 (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
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
/* RxRPC individual remote procedure call handling
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/circ_buf.h>
#include <linux/spinlock_types.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"

/*
 * Maximum lifetime of a call (in jiffies).
 */
unsigned int rxrpc_max_call_lifetime = 60 * HZ;

const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
	[RXRPC_CALL_UNINITIALISED]		= "Uninit  ",
	[RXRPC_CALL_CLIENT_AWAIT_CONN]		= "ClWtConn",
	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
	[RXRPC_CALL_SERVER_ACCEPTING]		= "SvAccept",
	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
	[RXRPC_CALL_COMPLETE]			= "Complete",
};

const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
	[RXRPC_CALL_SUCCEEDED]			= "Complete",
	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
};

const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
	[rxrpc_call_new_client]		= "NWc",
	[rxrpc_call_new_service]	= "NWs",
	[rxrpc_call_queued]		= "QUE",
	[rxrpc_call_queued_ref]		= "QUR",
	[rxrpc_call_seen]		= "SEE",
	[rxrpc_call_got]		= "GOT",
	[rxrpc_call_got_userid]		= "Gus",
	[rxrpc_call_put]		= "PUT",
	[rxrpc_call_put_userid]		= "Pus",
	[rxrpc_call_put_noqueue]	= "PNQ",
};

struct kmem_cache *rxrpc_call_jar;
LIST_HEAD(rxrpc_calls);
DEFINE_RWLOCK(rxrpc_call_lock);

static void rxrpc_call_timer_expired(unsigned long _call)
{
	struct rxrpc_call *call = (struct rxrpc_call *)_call;

	_enter("%d", call->debug_id);

	if (call->state < RXRPC_CALL_COMPLETE)
		rxrpc_queue_call(call);
}

/*
 * find an extant server call
 * - called in process context with IRQs enabled
 */
struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
					      unsigned long user_call_ID)
{
	struct rxrpc_call *call;
	struct rb_node *p;

	_enter("%p,%lx", rx, user_call_ID);

	read_lock(&rx->call_lock);

	p = rx->calls.rb_node;
	while (p) {
		call = rb_entry(p, struct rxrpc_call, sock_node);

		if (user_call_ID < call->user_call_ID)
			p = p->rb_left;
		else if (user_call_ID > call->user_call_ID)
			p = p->rb_right;
		else
			goto found_extant_call;
	}

	read_unlock(&rx->call_lock);
	_leave(" = NULL");
	return NULL;

found_extant_call:
	rxrpc_get_call(call, rxrpc_call_got);
	read_unlock(&rx->call_lock);
	_leave(" = %p [%d]", call, atomic_read(&call->usage));
	return call;
}

/*
 * allocate a new call
 */
struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
{
	struct rxrpc_call *call;

	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
	if (!call)
		return NULL;

	call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
				    sizeof(struct sk_buff *),
				    gfp);
	if (!call->rxtx_buffer)
		goto nomem;

	call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
	if (!call->rxtx_annotations)
		goto nomem_2;

	setup_timer(&call->timer, rxrpc_call_timer_expired,
		    (unsigned long)call);
	INIT_WORK(&call->processor, &rxrpc_process_call);
	INIT_LIST_HEAD(&call->link);
	INIT_LIST_HEAD(&call->chan_wait_link);
	INIT_LIST_HEAD(&call->accept_link);
	INIT_LIST_HEAD(&call->recvmsg_link);
	INIT_LIST_HEAD(&call->sock_link);
	init_waitqueue_head(&call->waitq);
	spin_lock_init(&call->lock);
	rwlock_init(&call->state_lock);
	atomic_set(&call->usage, 1);
	call->debug_id = atomic_inc_return(&rxrpc_debug_id);

	memset(&call->sock_node, 0xed, sizeof(call->sock_node));

	/* Leave space in the ring to handle a maxed-out jumbo packet */
	call->rx_winsize = RXRPC_RXTX_BUFF_SIZE - 1 - 46;
	call->tx_winsize = 16;
	call->rx_expect_next = 1;
	return call;

nomem_2:
	kfree(call->rxtx_buffer);
nomem:
	kmem_cache_free(rxrpc_call_jar, call);
	return NULL;
}

/*
 * Allocate a new client call.
 */
static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
						  gfp_t gfp)
{
	struct rxrpc_call *call;

	_enter("");

	call = rxrpc_alloc_call(gfp);
	if (!call)
		return ERR_PTR(-ENOMEM);
	call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
	call->service_id = srx->srx_service;

	_leave(" = %p", call);
	return call;
}

/*
 * Initiate the call ack/resend/expiry timer.
 */
static void rxrpc_start_call_timer(struct rxrpc_call *call)
{
	unsigned long expire_at;

	expire_at = jiffies + rxrpc_max_call_lifetime;
	call->expire_at = expire_at;
	call->ack_at = expire_at;
	call->resend_at = expire_at;
	call->timer.expires = expire_at;
	add_timer(&call->timer);
}

/*
 * set up a call for the given data
 * - called in process context with IRQs enabled
 */
struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
					 struct rxrpc_conn_parameters *cp,
					 struct sockaddr_rxrpc *srx,
					 unsigned long user_call_ID,
					 gfp_t gfp)
{
	struct rxrpc_call *call, *xcall;
	struct rb_node *parent, **pp;
	const void *here = __builtin_return_address(0);
	int ret;

	_enter("%p,%lx", rx, user_call_ID);

	call = rxrpc_alloc_client_call(srx, gfp);
	if (IS_ERR(call)) {
		_leave(" = %ld", PTR_ERR(call));
		return call;
	}

	trace_rxrpc_call(call, 0, atomic_read(&call->usage), here,
			 (const void *)user_call_ID);

	/* Publish the call, even though it is incompletely set up as yet */
	call->user_call_ID = user_call_ID;
	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);

	write_lock(&rx->call_lock);

	pp = &rx->calls.rb_node;
	parent = NULL;
	while (*pp) {
		parent = *pp;
		xcall = rb_entry(parent, struct rxrpc_call, sock_node);

		if (user_call_ID < xcall->user_call_ID)
			pp = &(*pp)->rb_left;
		else if (user_call_ID > xcall->user_call_ID)
			pp = &(*pp)->rb_right;
		else
			goto found_user_ID_now_present;
	}

	rcu_assign_pointer(call->socket, rx);
	rxrpc_get_call(call, rxrpc_call_got_userid);
	rb_link_node(&call->sock_node, parent, pp);
	rb_insert_color(&call->sock_node, &rx->calls);
	list_add(&call->sock_link, &rx->sock_calls);

	write_unlock(&rx->call_lock);

	write_lock(&rxrpc_call_lock);
	list_add_tail(&call->link, &rxrpc_calls);
	write_unlock(&rxrpc_call_lock);

	/* Set up or get a connection record and set the protocol parameters,
	 * including channel number and call ID.
	 */
	ret = rxrpc_connect_call(call, cp, srx, gfp);
	if (ret < 0)
		goto error;

	spin_lock_bh(&call->conn->params.peer->lock);
	hlist_add_head(&call->error_link,
		       &call->conn->params.peer->error_targets);
	spin_unlock_bh(&call->conn->params.peer->lock);

	rxrpc_start_call_timer(call);

	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);

	_leave(" = %p [new]", call);
	return call;

error:
	write_lock(&rx->call_lock);
	rb_erase(&call->sock_node, &rx->calls);
	write_unlock(&rx->call_lock);
	rxrpc_put_call(call, rxrpc_call_put_userid);

	write_lock(&rxrpc_call_lock);
	list_del_init(&call->link);
	write_unlock(&rxrpc_call_lock);

error_out:
	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
				    RX_CALL_DEAD, ret);
	set_bit(RXRPC_CALL_RELEASED, &call->flags);
	rxrpc_put_call(call, rxrpc_call_put);
	_leave(" = %d", ret);
	return ERR_PTR(ret);

	/* We unexpectedly found the user ID in the list after taking
	 * the call_lock.  This shouldn't happen unless the user races
	 * with itself and tries to add the same user ID twice at the
	 * same time in different threads.
	 */
found_user_ID_now_present:
	write_unlock(&rx->call_lock);
	ret = -EEXIST;
	goto error_out;
}

/*
 * Set up an incoming call.  call->conn points to the connection.
 * This is called in BH context and isn't allowed to fail.
 */
void rxrpc_incoming_call(struct rxrpc_sock *rx,
			 struct rxrpc_call *call,
			 struct sk_buff *skb)
{
	struct rxrpc_connection *conn = call->conn;
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	u32 chan;

	_enter(",%d", call->conn->debug_id);

	rcu_assign_pointer(call->socket, rx);
	call->call_id		= sp->hdr.callNumber;
	call->service_id	= sp->hdr.serviceId;
	call->cid		= sp->hdr.cid;
	call->state		= RXRPC_CALL_SERVER_ACCEPTING;
	if (sp->hdr.securityIndex > 0)
		call->state	= RXRPC_CALL_SERVER_SECURING;

	/* Set the channel for this call.  We don't get channel_lock as we're
	 * only defending against the data_ready handler (which we're called
	 * from) and the RESPONSE packet parser (which is only really
	 * interested in call_counter and can cope with a disagreement with the
	 * call pointer).
	 */
	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
	conn->channels[chan].call_counter = call->call_id;
	conn->channels[chan].call_id = call->call_id;
	rcu_assign_pointer(conn->channels[chan].call, call);

	spin_lock(&conn->params.peer->lock);
	hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
	spin_unlock(&conn->params.peer->lock);

	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);

	rxrpc_start_call_timer(call);
	_leave("");
}

/*
 * Queue a call's work processor, getting a ref to pass to the work queue.
 */
bool rxrpc_queue_call(struct rxrpc_call *call)
{
	const void *here = __builtin_return_address(0);
	int n = __atomic_add_unless(&call->usage, 1, 0);
	if (n == 0)
		return false;
	if (rxrpc_queue_work(&call->processor))
		trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
	else
		rxrpc_put_call(call, rxrpc_call_put_noqueue);
	return true;
}

/*
 * Queue a call's work processor, passing the callers ref to the work queue.
 */
bool __rxrpc_queue_call(struct rxrpc_call *call)
{
	const void *here = __builtin_return_address(0);
	int n = atomic_read(&call->usage);
	ASSERTCMP(n, >=, 1);
	if (rxrpc_queue_work(&call->processor))
		trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
	else
		rxrpc_put_call(call, rxrpc_call_put_noqueue);
	return true;
}

/*
 * Note the re-emergence of a call.
 */
void rxrpc_see_call(struct rxrpc_call *call)
{
	const void *here = __builtin_return_address(0);
	if (call) {
		int n = atomic_read(&call->usage);

		trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
	}
}

/*
 * Note the addition of a ref on a call.
 */
void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
{
	const void *here = __builtin_return_address(0);
	int n = atomic_inc_return(&call->usage);

	trace_rxrpc_call(call, op, n, here, NULL);
}

/*
 * Detach a call from its owning socket.
 */
void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
{
	struct rxrpc_connection *conn = call->conn;
	bool put = false;
	int i;

	_enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));

	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);

	rxrpc_see_call(call);

	spin_lock_bh(&call->lock);
	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
		BUG();
	spin_unlock_bh(&call->lock);

	del_timer_sync(&call->timer);

	/* Make sure we don't get any more notifications */
	write_lock_bh(&rx->recvmsg_lock);

	if (!list_empty(&call->recvmsg_link)) {
		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
		       call, call->events, call->flags);
		list_del(&call->recvmsg_link);
		put = true;
	}

	/* list_empty() must return false in rxrpc_notify_socket() */
	call->recvmsg_link.next = NULL;
	call->recvmsg_link.prev = NULL;

	write_unlock_bh(&rx->recvmsg_lock);
	if (put)
		rxrpc_put_call(call, rxrpc_call_put);

	write_lock(&rx->call_lock);

	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
		rb_erase(&call->sock_node, &rx->calls);
		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
		rxrpc_put_call(call, rxrpc_call_put_userid);
	}

	list_del(&call->sock_link);
	write_unlock(&rx->call_lock);

	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);

	if (conn)
		rxrpc_disconnect_call(call);

	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
		rxrpc_free_skb(call->rxtx_buffer[i]);
		call->rxtx_buffer[i] = NULL;
	}

	/* We have to release the prealloc backlog ref */
	if (rxrpc_is_service_call(call))
		rxrpc_put_call(call, rxrpc_call_put);
	_leave("");
}

/*
 * release all the calls associated with a socket
 */
void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
{
	struct rxrpc_call *call;

	_enter("%p", rx);

	while (!list_empty(&rx->sock_calls)) {
		call = list_entry(rx->sock_calls.next,
				  struct rxrpc_call, sock_link);
		rxrpc_get_call(call, rxrpc_call_got);
		rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
		rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
		rxrpc_release_call(rx, call);
		rxrpc_put_call(call, rxrpc_call_put);
	}

	_leave("");
}

/*
 * release a call
 */
void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
{
	const void *here = __builtin_return_address(0);
	int n;

	ASSERT(call != NULL);

	n = atomic_dec_return(&call->usage);
	trace_rxrpc_call(call, op, n, here, NULL);
	ASSERTCMP(n, >=, 0);
	if (n == 0) {
		_debug("call %d dead", call->debug_id);
		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);

		write_lock(&rxrpc_call_lock);
		list_del_init(&call->link);
		write_unlock(&rxrpc_call_lock);

		rxrpc_cleanup_call(call);
	}
}

/*
 * Final call destruction under RCU.
 */
static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
{
	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);

	rxrpc_put_peer(call->peer);
	kfree(call->rxtx_buffer);
	kfree(call->rxtx_annotations);
	kmem_cache_free(rxrpc_call_jar, call);
}

/*
 * clean up a call
 */
void rxrpc_cleanup_call(struct rxrpc_call *call)
{
	int i;

	_net("DESTROY CALL %d", call->debug_id);

	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));

	del_timer_sync(&call->timer);

	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
	ASSERTCMP(call->conn, ==, NULL);

	/* Clean up the Rx/Tx buffer */
	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
		rxrpc_free_skb(call->rxtx_buffer[i]);

	rxrpc_free_skb(call->tx_pending);

	call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
}

/*
 * Make sure that all calls are gone.
 */
void __exit rxrpc_destroy_all_calls(void)
{
	struct rxrpc_call *call;

	_enter("");

	if (list_empty(&rxrpc_calls))
		return;

	write_lock(&rxrpc_call_lock);

	while (!list_empty(&rxrpc_calls)) {
		call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
		_debug("Zapping call %p", call);

		rxrpc_see_call(call);
		list_del_init(&call->link);

		pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
		       call, atomic_read(&call->usage),
		       rxrpc_call_states[call->state],
		       call->flags, call->events);

		write_unlock(&rxrpc_call_lock);
		cond_resched();
		write_lock(&rxrpc_call_lock);
	}

	write_unlock(&rxrpc_call_lock);
}