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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* RxRPC virtual connection handler, common bits.
3 *
4 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/module.h>
11#include <linux/slab.h>
12#include <linux/net.h>
13#include <linux/skbuff.h>
14#include "ar-internal.h"
15
16/*
17 * Time till a connection expires after last use (in seconds).
18 */
19unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
20unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
21
22static void rxrpc_destroy_connection(struct rcu_head *);
23
24static void rxrpc_connection_timer(struct timer_list *timer)
25{
26 struct rxrpc_connection *conn =
27 container_of(timer, struct rxrpc_connection, timer);
28
29 rxrpc_queue_conn(conn);
30}
31
32/*
33 * allocate a new connection
34 */
35struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
36{
37 struct rxrpc_connection *conn;
38
39 _enter("");
40
41 conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
42 if (conn) {
43 INIT_LIST_HEAD(&conn->cache_link);
44 spin_lock_init(&conn->channel_lock);
45 INIT_LIST_HEAD(&conn->waiting_calls);
46 timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
47 INIT_WORK(&conn->processor, &rxrpc_process_connection);
48 INIT_LIST_HEAD(&conn->proc_link);
49 INIT_LIST_HEAD(&conn->link);
50 skb_queue_head_init(&conn->rx_queue);
51 conn->security = &rxrpc_no_security;
52 spin_lock_init(&conn->state_lock);
53 conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
54 conn->size_align = 4;
55 conn->idle_timestamp = jiffies;
56 }
57
58 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
59 return conn;
60}
61
62/*
63 * Look up a connection in the cache by protocol parameters.
64 *
65 * If successful, a pointer to the connection is returned, but no ref is taken.
66 * NULL is returned if there is no match.
67 *
68 * When searching for a service call, if we find a peer but no connection, we
69 * return that through *_peer in case we need to create a new service call.
70 *
71 * The caller must be holding the RCU read lock.
72 */
73struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
74 struct sk_buff *skb,
75 struct rxrpc_peer **_peer)
76{
77 struct rxrpc_connection *conn;
78 struct rxrpc_conn_proto k;
79 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
80 struct sockaddr_rxrpc srx;
81 struct rxrpc_peer *peer;
82
83 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
84
85 if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
86 goto not_found;
87
88 if (srx.transport.family != local->srx.transport.family &&
89 (srx.transport.family == AF_INET &&
90 local->srx.transport.family != AF_INET6)) {
91 pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
92 srx.transport.family,
93 local->srx.transport.family);
94 goto not_found;
95 }
96
97 k.epoch = sp->hdr.epoch;
98 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
99
100 if (rxrpc_to_server(sp)) {
101 /* We need to look up service connections by the full protocol
102 * parameter set. We look up the peer first as an intermediate
103 * step and then the connection from the peer's tree.
104 */
105 peer = rxrpc_lookup_peer_rcu(local, &srx);
106 if (!peer)
107 goto not_found;
108 *_peer = peer;
109 conn = rxrpc_find_service_conn_rcu(peer, skb);
110 if (!conn || atomic_read(&conn->usage) == 0)
111 goto not_found;
112 _leave(" = %p", conn);
113 return conn;
114 } else {
115 /* Look up client connections by connection ID alone as their
116 * IDs are unique for this machine.
117 */
118 conn = idr_find(&rxrpc_client_conn_ids,
119 sp->hdr.cid >> RXRPC_CIDSHIFT);
120 if (!conn || atomic_read(&conn->usage) == 0) {
121 _debug("no conn");
122 goto not_found;
123 }
124
125 if (conn->proto.epoch != k.epoch ||
126 conn->params.local != local)
127 goto not_found;
128
129 peer = conn->params.peer;
130 switch (srx.transport.family) {
131 case AF_INET:
132 if (peer->srx.transport.sin.sin_port !=
133 srx.transport.sin.sin_port ||
134 peer->srx.transport.sin.sin_addr.s_addr !=
135 srx.transport.sin.sin_addr.s_addr)
136 goto not_found;
137 break;
138#ifdef CONFIG_AF_RXRPC_IPV6
139 case AF_INET6:
140 if (peer->srx.transport.sin6.sin6_port !=
141 srx.transport.sin6.sin6_port ||
142 memcmp(&peer->srx.transport.sin6.sin6_addr,
143 &srx.transport.sin6.sin6_addr,
144 sizeof(struct in6_addr)) != 0)
145 goto not_found;
146 break;
147#endif
148 default:
149 BUG();
150 }
151
152 _leave(" = %p", conn);
153 return conn;
154 }
155
156not_found:
157 _leave(" = NULL");
158 return NULL;
159}
160
161/*
162 * Disconnect a call and clear any channel it occupies when that call
163 * terminates. The caller must hold the channel_lock and must release the
164 * call's ref on the connection.
165 */
166void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
167 struct rxrpc_call *call)
168{
169 struct rxrpc_channel *chan =
170 &conn->channels[call->cid & RXRPC_CHANNELMASK];
171
172 _enter("%d,%x", conn->debug_id, call->cid);
173
174 if (rcu_access_pointer(chan->call) == call) {
175 /* Save the result of the call so that we can repeat it if necessary
176 * through the channel, whilst disposing of the actual call record.
177 */
178 trace_rxrpc_disconnect_call(call);
179 switch (call->completion) {
180 case RXRPC_CALL_SUCCEEDED:
181 chan->last_seq = call->rx_hard_ack;
182 chan->last_type = RXRPC_PACKET_TYPE_ACK;
183 break;
184 case RXRPC_CALL_LOCALLY_ABORTED:
185 chan->last_abort = call->abort_code;
186 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
187 break;
188 default:
189 chan->last_abort = RX_USER_ABORT;
190 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
191 break;
192 }
193
194 /* Sync with rxrpc_conn_retransmit(). */
195 smp_wmb();
196 chan->last_call = chan->call_id;
197 chan->call_id = chan->call_counter;
198
199 rcu_assign_pointer(chan->call, NULL);
200 }
201
202 _leave("");
203}
204
205/*
206 * Disconnect a call and clear any channel it occupies when that call
207 * terminates.
208 */
209void rxrpc_disconnect_call(struct rxrpc_call *call)
210{
211 struct rxrpc_connection *conn = call->conn;
212
213 call->peer->cong_cwnd = call->cong_cwnd;
214
215 if (!hlist_unhashed(&call->error_link)) {
216 spin_lock_bh(&call->peer->lock);
217 hlist_del_rcu(&call->error_link);
218 spin_unlock_bh(&call->peer->lock);
219 }
220
221 if (rxrpc_is_client_call(call))
222 return rxrpc_disconnect_client_call(call);
223
224 spin_lock(&conn->channel_lock);
225 __rxrpc_disconnect_call(conn, call);
226 spin_unlock(&conn->channel_lock);
227
228 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
229 conn->idle_timestamp = jiffies;
230}
231
232/*
233 * Kill off a connection.
234 */
235void rxrpc_kill_connection(struct rxrpc_connection *conn)
236{
237 struct rxrpc_net *rxnet = conn->params.local->rxnet;
238
239 ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
240 !rcu_access_pointer(conn->channels[1].call) &&
241 !rcu_access_pointer(conn->channels[2].call) &&
242 !rcu_access_pointer(conn->channels[3].call));
243 ASSERT(list_empty(&conn->cache_link));
244
245 write_lock(&rxnet->conn_lock);
246 list_del_init(&conn->proc_link);
247 write_unlock(&rxnet->conn_lock);
248
249 /* Drain the Rx queue. Note that even though we've unpublished, an
250 * incoming packet could still be being added to our Rx queue, so we
251 * will need to drain it again in the RCU cleanup handler.
252 */
253 rxrpc_purge_queue(&conn->rx_queue);
254
255 /* Leave final destruction to RCU. The connection processor work item
256 * must carry a ref on the connection to prevent us getting here whilst
257 * it is queued or running.
258 */
259 call_rcu(&conn->rcu, rxrpc_destroy_connection);
260}
261
262/*
263 * Queue a connection's work processor, getting a ref to pass to the work
264 * queue.
265 */
266bool rxrpc_queue_conn(struct rxrpc_connection *conn)
267{
268 const void *here = __builtin_return_address(0);
269 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
270 if (n == 0)
271 return false;
272 if (rxrpc_queue_work(&conn->processor))
273 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, n + 1, here);
274 else
275 rxrpc_put_connection(conn);
276 return true;
277}
278
279/*
280 * Note the re-emergence of a connection.
281 */
282void rxrpc_see_connection(struct rxrpc_connection *conn)
283{
284 const void *here = __builtin_return_address(0);
285 if (conn) {
286 int n = atomic_read(&conn->usage);
287
288 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
289 }
290}
291
292/*
293 * Get a ref on a connection.
294 */
295void rxrpc_get_connection(struct rxrpc_connection *conn)
296{
297 const void *here = __builtin_return_address(0);
298 int n = atomic_inc_return(&conn->usage);
299
300 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n, here);
301}
302
303/*
304 * Try to get a ref on a connection.
305 */
306struct rxrpc_connection *
307rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
308{
309 const void *here = __builtin_return_address(0);
310
311 if (conn) {
312 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
313 if (n > 0)
314 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n + 1, here);
315 else
316 conn = NULL;
317 }
318 return conn;
319}
320
321/*
322 * Set the service connection reap timer.
323 */
324static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
325 unsigned long reap_at)
326{
327 if (rxnet->live)
328 timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
329}
330
331/*
332 * Release a service connection
333 */
334void rxrpc_put_service_conn(struct rxrpc_connection *conn)
335{
336 const void *here = __builtin_return_address(0);
337 unsigned int debug_id = conn->debug_id;
338 int n;
339
340 n = atomic_dec_return(&conn->usage);
341 trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, n, here);
342 ASSERTCMP(n, >=, 0);
343 if (n == 1)
344 rxrpc_set_service_reap_timer(conn->params.local->rxnet,
345 jiffies + rxrpc_connection_expiry);
346}
347
348/*
349 * destroy a virtual connection
350 */
351static void rxrpc_destroy_connection(struct rcu_head *rcu)
352{
353 struct rxrpc_connection *conn =
354 container_of(rcu, struct rxrpc_connection, rcu);
355
356 _enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
357
358 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
359
360 _net("DESTROY CONN %d", conn->debug_id);
361
362 del_timer_sync(&conn->timer);
363 rxrpc_purge_queue(&conn->rx_queue);
364
365 conn->security->clear(conn);
366 key_put(conn->params.key);
367 key_put(conn->server_key);
368 rxrpc_put_peer(conn->params.peer);
369
370 if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
371 wake_up_var(&conn->params.local->rxnet->nr_conns);
372 rxrpc_put_local(conn->params.local);
373
374 kfree(conn);
375 _leave("");
376}
377
378/*
379 * reap dead service connections
380 */
381void rxrpc_service_connection_reaper(struct work_struct *work)
382{
383 struct rxrpc_connection *conn, *_p;
384 struct rxrpc_net *rxnet =
385 container_of(work, struct rxrpc_net, service_conn_reaper);
386 unsigned long expire_at, earliest, idle_timestamp, now;
387
388 LIST_HEAD(graveyard);
389
390 _enter("");
391
392 now = jiffies;
393 earliest = now + MAX_JIFFY_OFFSET;
394
395 write_lock(&rxnet->conn_lock);
396 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
397 ASSERTCMP(atomic_read(&conn->usage), >, 0);
398 if (likely(atomic_read(&conn->usage) > 1))
399 continue;
400 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
401 continue;
402
403 if (rxnet->live && !conn->params.local->dead) {
404 idle_timestamp = READ_ONCE(conn->idle_timestamp);
405 expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
406 if (conn->params.local->service_closed)
407 expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
408
409 _debug("reap CONN %d { u=%d,t=%ld }",
410 conn->debug_id, atomic_read(&conn->usage),
411 (long)expire_at - (long)now);
412
413 if (time_before(now, expire_at)) {
414 if (time_before(expire_at, earliest))
415 earliest = expire_at;
416 continue;
417 }
418 }
419
420 /* The usage count sits at 1 whilst the object is unused on the
421 * list; we reduce that to 0 to make the object unavailable.
422 */
423 if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
424 continue;
425 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
426
427 if (rxrpc_conn_is_client(conn))
428 BUG();
429 else
430 rxrpc_unpublish_service_conn(conn);
431
432 list_move_tail(&conn->link, &graveyard);
433 }
434 write_unlock(&rxnet->conn_lock);
435
436 if (earliest != now + MAX_JIFFY_OFFSET) {
437 _debug("reschedule reaper %ld", (long)earliest - (long)now);
438 ASSERT(time_after(earliest, now));
439 rxrpc_set_service_reap_timer(rxnet, earliest);
440 }
441
442 while (!list_empty(&graveyard)) {
443 conn = list_entry(graveyard.next, struct rxrpc_connection,
444 link);
445 list_del_init(&conn->link);
446
447 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
448 rxrpc_kill_connection(conn);
449 }
450
451 _leave("");
452}
453
454/*
455 * preemptively destroy all the service connection records rather than
456 * waiting for them to time out
457 */
458void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
459{
460 struct rxrpc_connection *conn, *_p;
461 bool leak = false;
462
463 _enter("");
464
465 atomic_dec(&rxnet->nr_conns);
466 rxrpc_destroy_all_client_connections(rxnet);
467
468 del_timer_sync(&rxnet->service_conn_reap_timer);
469 rxrpc_queue_work(&rxnet->service_conn_reaper);
470 flush_workqueue(rxrpc_workqueue);
471
472 write_lock(&rxnet->conn_lock);
473 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
474 pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
475 conn, atomic_read(&conn->usage));
476 leak = true;
477 }
478 write_unlock(&rxnet->conn_lock);
479 BUG_ON(leak);
480
481 ASSERT(list_empty(&rxnet->conn_proc_list));
482
483 /* We need to wait for the connections to be destroyed by RCU as they
484 * pin things that we still need to get rid of.
485 */
486 wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));
487 _leave("");
488}
1/* RxRPC virtual connection handler, common bits.
2 *
3 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4 * 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
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/net.h>
17#include <linux/skbuff.h>
18#include "ar-internal.h"
19
20/*
21 * Time till a connection expires after last use (in seconds).
22 */
23unsigned int rxrpc_connection_expiry = 10 * 60;
24
25static void rxrpc_connection_reaper(struct work_struct *work);
26
27LIST_HEAD(rxrpc_connections);
28LIST_HEAD(rxrpc_connection_proc_list);
29DEFINE_RWLOCK(rxrpc_connection_lock);
30static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
31
32static void rxrpc_destroy_connection(struct rcu_head *);
33
34/*
35 * allocate a new connection
36 */
37struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
38{
39 struct rxrpc_connection *conn;
40
41 _enter("");
42
43 conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
44 if (conn) {
45 INIT_LIST_HEAD(&conn->cache_link);
46 spin_lock_init(&conn->channel_lock);
47 INIT_LIST_HEAD(&conn->waiting_calls);
48 INIT_WORK(&conn->processor, &rxrpc_process_connection);
49 INIT_LIST_HEAD(&conn->proc_link);
50 INIT_LIST_HEAD(&conn->link);
51 skb_queue_head_init(&conn->rx_queue);
52 conn->security = &rxrpc_no_security;
53 spin_lock_init(&conn->state_lock);
54 conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
55 conn->size_align = 4;
56 conn->idle_timestamp = jiffies;
57 }
58
59 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
60 return conn;
61}
62
63/*
64 * Look up a connection in the cache by protocol parameters.
65 *
66 * If successful, a pointer to the connection is returned, but no ref is taken.
67 * NULL is returned if there is no match.
68 *
69 * The caller must be holding the RCU read lock.
70 */
71struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
72 struct sk_buff *skb)
73{
74 struct rxrpc_connection *conn;
75 struct rxrpc_conn_proto k;
76 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
77 struct sockaddr_rxrpc srx;
78 struct rxrpc_peer *peer;
79
80 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
81
82 if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
83 goto not_found;
84
85 k.epoch = sp->hdr.epoch;
86 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
87
88 /* We may have to handle mixing IPv4 and IPv6 */
89 if (srx.transport.family != local->srx.transport.family) {
90 pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
91 srx.transport.family,
92 local->srx.transport.family);
93 goto not_found;
94 }
95
96 k.epoch = sp->hdr.epoch;
97 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
98
99 if (sp->hdr.flags & RXRPC_CLIENT_INITIATED) {
100 /* We need to look up service connections by the full protocol
101 * parameter set. We look up the peer first as an intermediate
102 * step and then the connection from the peer's tree.
103 */
104 peer = rxrpc_lookup_peer_rcu(local, &srx);
105 if (!peer)
106 goto not_found;
107 conn = rxrpc_find_service_conn_rcu(peer, skb);
108 if (!conn || atomic_read(&conn->usage) == 0)
109 goto not_found;
110 _leave(" = %p", conn);
111 return conn;
112 } else {
113 /* Look up client connections by connection ID alone as their
114 * IDs are unique for this machine.
115 */
116 conn = idr_find(&rxrpc_client_conn_ids,
117 sp->hdr.cid >> RXRPC_CIDSHIFT);
118 if (!conn || atomic_read(&conn->usage) == 0) {
119 _debug("no conn");
120 goto not_found;
121 }
122
123 if (conn->proto.epoch != k.epoch ||
124 conn->params.local != local)
125 goto not_found;
126
127 peer = conn->params.peer;
128 switch (srx.transport.family) {
129 case AF_INET:
130 if (peer->srx.transport.sin.sin_port !=
131 srx.transport.sin.sin_port ||
132 peer->srx.transport.sin.sin_addr.s_addr !=
133 srx.transport.sin.sin_addr.s_addr)
134 goto not_found;
135 break;
136#ifdef CONFIG_AF_RXRPC_IPV6
137 case AF_INET6:
138 if (peer->srx.transport.sin6.sin6_port !=
139 srx.transport.sin6.sin6_port ||
140 memcmp(&peer->srx.transport.sin6.sin6_addr,
141 &srx.transport.sin6.sin6_addr,
142 sizeof(struct in6_addr)) != 0)
143 goto not_found;
144 break;
145#endif
146 default:
147 BUG();
148 }
149
150 _leave(" = %p", conn);
151 return conn;
152 }
153
154not_found:
155 _leave(" = NULL");
156 return NULL;
157}
158
159/*
160 * Disconnect a call and clear any channel it occupies when that call
161 * terminates. The caller must hold the channel_lock and must release the
162 * call's ref on the connection.
163 */
164void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
165 struct rxrpc_call *call)
166{
167 struct rxrpc_channel *chan =
168 &conn->channels[call->cid & RXRPC_CHANNELMASK];
169
170 _enter("%d,%x", conn->debug_id, call->cid);
171
172 if (rcu_access_pointer(chan->call) == call) {
173 /* Save the result of the call so that we can repeat it if necessary
174 * through the channel, whilst disposing of the actual call record.
175 */
176 chan->last_service_id = call->service_id;
177 if (call->abort_code) {
178 chan->last_abort = call->abort_code;
179 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
180 } else {
181 chan->last_seq = call->rx_hard_ack;
182 chan->last_type = RXRPC_PACKET_TYPE_ACK;
183 }
184 /* Sync with rxrpc_conn_retransmit(). */
185 smp_wmb();
186 chan->last_call = chan->call_id;
187 chan->call_id = chan->call_counter;
188
189 rcu_assign_pointer(chan->call, NULL);
190 }
191
192 _leave("");
193}
194
195/*
196 * Disconnect a call and clear any channel it occupies when that call
197 * terminates.
198 */
199void rxrpc_disconnect_call(struct rxrpc_call *call)
200{
201 struct rxrpc_connection *conn = call->conn;
202
203 spin_lock_bh(&conn->params.peer->lock);
204 hlist_del_init(&call->error_link);
205 spin_unlock_bh(&conn->params.peer->lock);
206
207 if (rxrpc_is_client_call(call))
208 return rxrpc_disconnect_client_call(call);
209
210 spin_lock(&conn->channel_lock);
211 __rxrpc_disconnect_call(conn, call);
212 spin_unlock(&conn->channel_lock);
213
214 call->conn = NULL;
215 conn->idle_timestamp = jiffies;
216 rxrpc_put_connection(conn);
217}
218
219/*
220 * Kill off a connection.
221 */
222void rxrpc_kill_connection(struct rxrpc_connection *conn)
223{
224 ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
225 !rcu_access_pointer(conn->channels[1].call) &&
226 !rcu_access_pointer(conn->channels[2].call) &&
227 !rcu_access_pointer(conn->channels[3].call));
228 ASSERT(list_empty(&conn->cache_link));
229
230 write_lock(&rxrpc_connection_lock);
231 list_del_init(&conn->proc_link);
232 write_unlock(&rxrpc_connection_lock);
233
234 /* Drain the Rx queue. Note that even though we've unpublished, an
235 * incoming packet could still be being added to our Rx queue, so we
236 * will need to drain it again in the RCU cleanup handler.
237 */
238 rxrpc_purge_queue(&conn->rx_queue);
239
240 /* Leave final destruction to RCU. The connection processor work item
241 * must carry a ref on the connection to prevent us getting here whilst
242 * it is queued or running.
243 */
244 call_rcu(&conn->rcu, rxrpc_destroy_connection);
245}
246
247/*
248 * Queue a connection's work processor, getting a ref to pass to the work
249 * queue.
250 */
251bool rxrpc_queue_conn(struct rxrpc_connection *conn)
252{
253 const void *here = __builtin_return_address(0);
254 int n = __atomic_add_unless(&conn->usage, 1, 0);
255 if (n == 0)
256 return false;
257 if (rxrpc_queue_work(&conn->processor))
258 trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 1, here);
259 else
260 rxrpc_put_connection(conn);
261 return true;
262}
263
264/*
265 * Note the re-emergence of a connection.
266 */
267void rxrpc_see_connection(struct rxrpc_connection *conn)
268{
269 const void *here = __builtin_return_address(0);
270 if (conn) {
271 int n = atomic_read(&conn->usage);
272
273 trace_rxrpc_conn(conn, rxrpc_conn_seen, n, here);
274 }
275}
276
277/*
278 * Get a ref on a connection.
279 */
280void rxrpc_get_connection(struct rxrpc_connection *conn)
281{
282 const void *here = __builtin_return_address(0);
283 int n = atomic_inc_return(&conn->usage);
284
285 trace_rxrpc_conn(conn, rxrpc_conn_got, n, here);
286}
287
288/*
289 * Try to get a ref on a connection.
290 */
291struct rxrpc_connection *
292rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
293{
294 const void *here = __builtin_return_address(0);
295
296 if (conn) {
297 int n = __atomic_add_unless(&conn->usage, 1, 0);
298 if (n > 0)
299 trace_rxrpc_conn(conn, rxrpc_conn_got, n + 1, here);
300 else
301 conn = NULL;
302 }
303 return conn;
304}
305
306/*
307 * Release a service connection
308 */
309void rxrpc_put_service_conn(struct rxrpc_connection *conn)
310{
311 const void *here = __builtin_return_address(0);
312 int n;
313
314 n = atomic_dec_return(&conn->usage);
315 trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here);
316 ASSERTCMP(n, >=, 0);
317 if (n == 0)
318 rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
319}
320
321/*
322 * destroy a virtual connection
323 */
324static void rxrpc_destroy_connection(struct rcu_head *rcu)
325{
326 struct rxrpc_connection *conn =
327 container_of(rcu, struct rxrpc_connection, rcu);
328
329 _enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
330
331 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
332
333 _net("DESTROY CONN %d", conn->debug_id);
334
335 rxrpc_purge_queue(&conn->rx_queue);
336
337 conn->security->clear(conn);
338 key_put(conn->params.key);
339 key_put(conn->server_key);
340 rxrpc_put_peer(conn->params.peer);
341 rxrpc_put_local(conn->params.local);
342
343 kfree(conn);
344 _leave("");
345}
346
347/*
348 * reap dead service connections
349 */
350static void rxrpc_connection_reaper(struct work_struct *work)
351{
352 struct rxrpc_connection *conn, *_p;
353 unsigned long reap_older_than, earliest, idle_timestamp, now;
354
355 LIST_HEAD(graveyard);
356
357 _enter("");
358
359 now = jiffies;
360 reap_older_than = now - rxrpc_connection_expiry * HZ;
361 earliest = ULONG_MAX;
362
363 write_lock(&rxrpc_connection_lock);
364 list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
365 ASSERTCMP(atomic_read(&conn->usage), >, 0);
366 if (likely(atomic_read(&conn->usage) > 1))
367 continue;
368 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
369 continue;
370
371 idle_timestamp = READ_ONCE(conn->idle_timestamp);
372 _debug("reap CONN %d { u=%d,t=%ld }",
373 conn->debug_id, atomic_read(&conn->usage),
374 (long)reap_older_than - (long)idle_timestamp);
375
376 if (time_after(idle_timestamp, reap_older_than)) {
377 if (time_before(idle_timestamp, earliest))
378 earliest = idle_timestamp;
379 continue;
380 }
381
382 /* The usage count sits at 1 whilst the object is unused on the
383 * list; we reduce that to 0 to make the object unavailable.
384 */
385 if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
386 continue;
387
388 if (rxrpc_conn_is_client(conn))
389 BUG();
390 else
391 rxrpc_unpublish_service_conn(conn);
392
393 list_move_tail(&conn->link, &graveyard);
394 }
395 write_unlock(&rxrpc_connection_lock);
396
397 if (earliest != ULONG_MAX) {
398 _debug("reschedule reaper %ld", (long) earliest - now);
399 ASSERT(time_after(earliest, now));
400 rxrpc_queue_delayed_work(&rxrpc_connection_reap,
401 earliest - now);
402 }
403
404 while (!list_empty(&graveyard)) {
405 conn = list_entry(graveyard.next, struct rxrpc_connection,
406 link);
407 list_del_init(&conn->link);
408
409 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
410 rxrpc_kill_connection(conn);
411 }
412
413 _leave("");
414}
415
416/*
417 * preemptively destroy all the service connection records rather than
418 * waiting for them to time out
419 */
420void __exit rxrpc_destroy_all_connections(void)
421{
422 struct rxrpc_connection *conn, *_p;
423 bool leak = false;
424
425 _enter("");
426
427 rxrpc_destroy_all_client_connections();
428
429 rxrpc_connection_expiry = 0;
430 cancel_delayed_work(&rxrpc_connection_reap);
431 rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
432 flush_workqueue(rxrpc_workqueue);
433
434 write_lock(&rxrpc_connection_lock);
435 list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
436 pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
437 conn, atomic_read(&conn->usage));
438 leak = true;
439 }
440 write_unlock(&rxrpc_connection_lock);
441 BUG_ON(leak);
442
443 ASSERT(list_empty(&rxrpc_connection_proc_list));
444
445 /* Make sure the local and peer records pinned by any dying connections
446 * are released.
447 */
448 rcu_barrier();
449 rxrpc_destroy_client_conn_ids();
450
451 _leave("");
452}