aboutsummaryrefslogtreecommitdiffstats
path: root/net/rxrpc/conn_object.c
blob: c0ddba787fd417599696c1d2b0086344844c520b (plain) (blame)
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
/* RxRPC virtual connection handler, common bits.
 *
 * Copyright (C) 2007, 2016 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/module.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include "ar-internal.h"

/*
 * Time till a connection expires after last use (in seconds).
 */
unsigned int rxrpc_connection_expiry = 10 * 60;

static void rxrpc_connection_reaper(struct work_struct *work);

LIST_HEAD(rxrpc_connections);
LIST_HEAD(rxrpc_connection_proc_list);
DEFINE_RWLOCK(rxrpc_connection_lock);
static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);

static void rxrpc_destroy_connection(struct rcu_head *);

/*
 * allocate a new connection
 */
struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
{
	struct rxrpc_connection *conn;

	_enter("");

	conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
	if (conn) {
		INIT_LIST_HEAD(&conn->cache_link);
		spin_lock_init(&conn->channel_lock);
		INIT_LIST_HEAD(&conn->waiting_calls);
		INIT_WORK(&conn->processor, &rxrpc_process_connection);
		INIT_LIST_HEAD(&conn->proc_link);
		INIT_LIST_HEAD(&conn->link);
		skb_queue_head_init(&conn->rx_queue);
		conn->security = &rxrpc_no_security;
		spin_lock_init(&conn->state_lock);
		conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
		conn->size_align = 4;
		conn->header_size = sizeof(struct rxrpc_wire_header);
		conn->idle_timestamp = jiffies;
	}

	_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
	return conn;
}

/*
 * Look up a connection in the cache by protocol parameters.
 *
 * If successful, a pointer to the connection is returned, but no ref is taken.
 * NULL is returned if there is no match.
 *
 * The caller must be holding the RCU read lock.
 */
struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
						   struct sk_buff *skb)
{
	struct rxrpc_connection *conn;
	struct rxrpc_conn_proto k;
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	struct sockaddr_rxrpc srx;
	struct rxrpc_peer *peer;

	_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);

	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
		goto not_found;

	k.epoch	= sp->hdr.epoch;
	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;

	/* We may have to handle mixing IPv4 and IPv6 */
	if (srx.transport.family != local->srx.transport.family) {
		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
				    srx.transport.family,
				    local->srx.transport.family);
		goto not_found;
	}

	k.epoch	= sp->hdr.epoch;
	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;

	if (sp->hdr.flags & RXRPC_CLIENT_INITIATED) {
		/* 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.
		 */
		peer = rxrpc_lookup_peer_rcu(local, &srx);
		if (!peer)
			goto not_found;
		conn = rxrpc_find_service_conn_rcu(peer, skb);
		if (!conn || atomic_read(&conn->usage) == 0)
			goto not_found;
		_leave(" = %p", conn);
		return conn;
	} else {
		/* Look up client connections by connection ID alone as their
		 * IDs are unique for this machine.
		 */
		conn = idr_find(&rxrpc_client_conn_ids,
				sp->hdr.cid >> RXRPC_CIDSHIFT);
		if (!conn || atomic_read(&conn->usage) == 0) {
			_debug("no conn");
			goto not_found;
		}

		if (conn->proto.epoch != k.epoch ||
		    conn->params.local != local)
			goto not_found;

		peer = conn->params.peer;
		switch (srx.transport.family) {
		case AF_INET:
			if (peer->srx.transport.sin.sin_port !=
			    srx.transport.sin.sin_port ||
			    peer->srx.transport.sin.sin_addr.s_addr !=
			    srx.transport.sin.sin_addr.s_addr)
				goto not_found;
			break;
		case AF_INET6:
			if (peer->srx.transport.sin6.sin6_port !=
			    srx.transport.sin6.sin6_port ||
			    memcmp(&peer->srx.transport.sin6.sin6_addr,
				   &srx.transport.sin6.sin6_addr,
				   sizeof(struct in6_addr)) != 0)
				goto not_found;
			break;
		default:
			BUG();
		}

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

not_found:
	_leave(" = NULL");
	return NULL;
}

/*
 * Disconnect a call and clear any channel it occupies when that call
 * terminates.  The caller must hold the channel_lock and must release the
 * call's ref on the connection.
 */
void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
			     struct rxrpc_call *call)
{
	struct rxrpc_channel *chan =
		&conn->channels[call->cid & RXRPC_CHANNELMASK];

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

	if (rcu_access_pointer(chan->call) == call) {
		/* Save the result of the call so that we can repeat it if necessary
		 * through the channel, whilst disposing of the actual call record.
		 */
		chan->last_service_id = call->service_id;
		if (call->abort_code) {
			chan->last_abort = call->abort_code;
			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
		} else {
			chan->last_seq = call->rx_hard_ack;
			chan->last_type = RXRPC_PACKET_TYPE_ACK;
		}
		/* Sync with rxrpc_conn_retransmit(). */
		smp_wmb();
		chan->last_call = chan->call_id;
		chan->call_id = chan->call_counter;

		rcu_assign_pointer(chan->call, NULL);
	}

	_leave("");
}

/*
 * Disconnect a call and clear any channel it occupies when that call
 * terminates.
 */
void rxrpc_disconnect_call(struct rxrpc_call *call)
{
	struct rxrpc_connection *conn = call->conn;

	spin_lock_bh(&conn->params.peer->lock);
	hlist_del_init(&call->error_link);
	spin_unlock_bh(&conn->params.peer->lock);

	if (rxrpc_is_client_call(call))
		return rxrpc_disconnect_client_call(call);

	spin_lock(&conn->channel_lock);
	__rxrpc_disconnect_call(conn, call);
	spin_unlock(&conn->channel_lock);

	call->conn = NULL;
	conn->idle_timestamp = jiffies;
	rxrpc_put_connection(conn);
}

/*
 * Kill off a connection.
 */
void rxrpc_kill_connection(struct rxrpc_connection *conn)
{
	ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
	       !rcu_access_pointer(conn->channels[1].call) &&
	       !rcu_access_pointer(conn->channels[2].call) &&
	       !rcu_access_pointer(conn->channels[3].call));
	ASSERT(list_empty(&conn->cache_link));

	write_lock(&rxrpc_connection_lock);
	list_del_init(&conn->proc_link);
	write_unlock(&rxrpc_connection_lock);

	/* Drain the Rx queue.  Note that even though we've unpublished, an
	 * incoming packet could still be being added to our Rx queue, so we
	 * will need to drain it again in the RCU cleanup handler.
	 */
	rxrpc_purge_queue(&conn->rx_queue);

	/* Leave final destruction to RCU.  The connection processor work item
	 * must carry a ref on the connection to prevent us getting here whilst
	 * it is queued or running.
	 */
	call_rcu(&conn->rcu, rxrpc_destroy_connection);
}

/*
 * release a virtual connection
 */
void __rxrpc_put_connection(struct rxrpc_connection *conn)
{
	rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
}

/*
 * destroy a virtual connection
 */
static void rxrpc_destroy_connection(struct rcu_head *rcu)
{
	struct rxrpc_connection *conn =
		container_of(rcu, struct rxrpc_connection, rcu);

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

	ASSERTCMP(atomic_read(&conn->usage), ==, 0);

	_net("DESTROY CONN %d", conn->debug_id);

	rxrpc_purge_queue(&conn->rx_queue);

	conn->security->clear(conn);
	key_put(conn->params.key);
	key_put(conn->server_key);
	rxrpc_put_peer(conn->params.peer);
	rxrpc_put_local(conn->params.local);

	kfree(conn);
	_leave("");
}

/*
 * reap dead service connections
 */
static void rxrpc_connection_reaper(struct work_struct *work)
{
	struct rxrpc_connection *conn, *_p;
	unsigned long reap_older_than, earliest, idle_timestamp, now;

	LIST_HEAD(graveyard);

	_enter("");

	now = jiffies;
	reap_older_than = now - rxrpc_connection_expiry * HZ;
	earliest = ULONG_MAX;

	write_lock(&rxrpc_connection_lock);
	list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
		ASSERTCMP(atomic_read(&conn->usage), >, 0);
		if (likely(atomic_read(&conn->usage) > 1))
			continue;
		if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
			continue;

		idle_timestamp = READ_ONCE(conn->idle_timestamp);
		_debug("reap CONN %d { u=%d,t=%ld }",
		       conn->debug_id, atomic_read(&conn->usage),
		       (long)reap_older_than - (long)idle_timestamp);

		if (time_after(idle_timestamp, reap_older_than)) {
			if (time_before(idle_timestamp, earliest))
				earliest = idle_timestamp;
			continue;
		}

		/* The usage count sits at 1 whilst the object is unused on the
		 * list; we reduce that to 0 to make the object unavailable.
		 */
		if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
			continue;

		if (rxrpc_conn_is_client(conn))
			BUG();
		else
			rxrpc_unpublish_service_conn(conn);

		list_move_tail(&conn->link, &graveyard);
	}
	write_unlock(&rxrpc_connection_lock);

	if (earliest != ULONG_MAX) {
		_debug("reschedule reaper %ld", (long) earliest - now);
		ASSERT(time_after(earliest, now));
		rxrpc_queue_delayed_work(&rxrpc_connection_reap,
					 earliest - now);
	}

	while (!list_empty(&graveyard)) {
		conn = list_entry(graveyard.next, struct rxrpc_connection,
				  link);
		list_del_init(&conn->link);

		ASSERTCMP(atomic_read(&conn->usage), ==, 0);
		rxrpc_kill_connection(conn);
	}

	_leave("");
}

/*
 * preemptively destroy all the service connection records rather than
 * waiting for them to time out
 */
void __exit rxrpc_destroy_all_connections(void)
{
	struct rxrpc_connection *conn, *_p;
	bool leak = false;

	_enter("");

	rxrpc_destroy_all_client_connections();

	rxrpc_connection_expiry = 0;
	cancel_delayed_work(&rxrpc_connection_reap);
	rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
	flush_workqueue(rxrpc_workqueue);

	write_lock(&rxrpc_connection_lock);
	list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
		pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
		       conn, atomic_read(&conn->usage));
		leak = true;
	}
	write_unlock(&rxrpc_connection_lock);
	BUG_ON(leak);

	ASSERT(list_empty(&rxrpc_connection_proc_list));

	/* Make sure the local and peer records pinned by any dying connections
	 * are released.
	 */
	rcu_barrier();
	rxrpc_destroy_client_conn_ids();

	_leave("");
}