1 /* RxRPC virtual connection handler, common bits.
3 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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"
21 * Time till a connection expires after last use (in seconds).
23 unsigned int rxrpc_connection_expiry = 10 * 60;
25 static void rxrpc_connection_reaper(struct work_struct *work);
27 LIST_HEAD(rxrpc_connections);
28 LIST_HEAD(rxrpc_connection_proc_list);
29 DEFINE_RWLOCK(rxrpc_connection_lock);
30 static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper);
32 static void rxrpc_destroy_connection(struct rcu_head *);
35 * allocate a new connection
37 struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
39 struct rxrpc_connection *conn;
43 conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
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);
56 conn->idle_timestamp = jiffies;
59 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
64 * Look up a connection in the cache by protocol parameters.
66 * If successful, a pointer to the connection is returned, but no ref is taken.
67 * NULL is returned if there is no match.
69 * The caller must be holding the RCU read lock.
71 struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
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;
80 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
82 if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
85 k.epoch = sp->hdr.epoch;
86 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
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",
92 local->srx.transport.family);
96 k.epoch = sp->hdr.epoch;
97 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
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.
104 peer = rxrpc_lookup_peer_rcu(local, &srx);
107 conn = rxrpc_find_service_conn_rcu(peer, skb);
108 if (!conn || atomic_read(&conn->usage) == 0)
110 _leave(" = %p", conn);
113 /* Look up client connections by connection ID alone as their
114 * IDs are unique for this machine.
116 conn = idr_find(&rxrpc_client_conn_ids,
117 sp->hdr.cid >> RXRPC_CIDSHIFT);
118 if (!conn || atomic_read(&conn->usage) == 0) {
123 if (conn->proto.epoch != k.epoch ||
124 conn->params.local != local)
127 peer = conn->params.peer;
128 switch (srx.transport.family) {
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)
136 #ifdef CONFIG_AF_RXRPC_IPV6
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)
150 _leave(" = %p", conn);
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.
164 void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
165 struct rxrpc_call *call)
167 struct rxrpc_channel *chan =
168 &conn->channels[call->cid & RXRPC_CHANNELMASK];
170 _enter("%d,%x", conn->debug_id, call->cid);
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.
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;
181 chan->last_seq = call->rx_hard_ack;
182 chan->last_type = RXRPC_PACKET_TYPE_ACK;
184 /* Sync with rxrpc_conn_retransmit(). */
186 chan->last_call = chan->call_id;
187 chan->call_id = chan->call_counter;
189 rcu_assign_pointer(chan->call, NULL);
196 * Disconnect a call and clear any channel it occupies when that call
199 void rxrpc_disconnect_call(struct rxrpc_call *call)
201 struct rxrpc_connection *conn = call->conn;
203 spin_lock_bh(&conn->params.peer->lock);
204 hlist_del_init(&call->error_link);
205 spin_unlock_bh(&conn->params.peer->lock);
207 if (rxrpc_is_client_call(call))
208 return rxrpc_disconnect_client_call(call);
210 spin_lock(&conn->channel_lock);
211 __rxrpc_disconnect_call(conn, call);
212 spin_unlock(&conn->channel_lock);
214 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
215 conn->idle_timestamp = jiffies;
219 * Kill off a connection.
221 void rxrpc_kill_connection(struct rxrpc_connection *conn)
223 ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
224 !rcu_access_pointer(conn->channels[1].call) &&
225 !rcu_access_pointer(conn->channels[2].call) &&
226 !rcu_access_pointer(conn->channels[3].call));
227 ASSERT(list_empty(&conn->cache_link));
229 write_lock(&rxrpc_connection_lock);
230 list_del_init(&conn->proc_link);
231 write_unlock(&rxrpc_connection_lock);
233 /* Drain the Rx queue. Note that even though we've unpublished, an
234 * incoming packet could still be being added to our Rx queue, so we
235 * will need to drain it again in the RCU cleanup handler.
237 rxrpc_purge_queue(&conn->rx_queue);
239 /* Leave final destruction to RCU. The connection processor work item
240 * must carry a ref on the connection to prevent us getting here whilst
241 * it is queued or running.
243 call_rcu(&conn->rcu, rxrpc_destroy_connection);
247 * Queue a connection's work processor, getting a ref to pass to the work
250 bool rxrpc_queue_conn(struct rxrpc_connection *conn)
252 const void *here = __builtin_return_address(0);
253 int n = __atomic_add_unless(&conn->usage, 1, 0);
256 if (rxrpc_queue_work(&conn->processor))
257 trace_rxrpc_conn(conn, rxrpc_conn_queued, n + 1, here);
259 rxrpc_put_connection(conn);
264 * Note the re-emergence of a connection.
266 void rxrpc_see_connection(struct rxrpc_connection *conn)
268 const void *here = __builtin_return_address(0);
270 int n = atomic_read(&conn->usage);
272 trace_rxrpc_conn(conn, rxrpc_conn_seen, n, here);
277 * Get a ref on a connection.
279 void rxrpc_get_connection(struct rxrpc_connection *conn)
281 const void *here = __builtin_return_address(0);
282 int n = atomic_inc_return(&conn->usage);
284 trace_rxrpc_conn(conn, rxrpc_conn_got, n, here);
288 * Try to get a ref on a connection.
290 struct rxrpc_connection *
291 rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
293 const void *here = __builtin_return_address(0);
296 int n = __atomic_add_unless(&conn->usage, 1, 0);
298 trace_rxrpc_conn(conn, rxrpc_conn_got, n + 1, here);
306 * Release a service connection
308 void rxrpc_put_service_conn(struct rxrpc_connection *conn)
310 const void *here = __builtin_return_address(0);
313 n = atomic_dec_return(&conn->usage);
314 trace_rxrpc_conn(conn, rxrpc_conn_put_service, n, here);
317 rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
321 * destroy a virtual connection
323 static void rxrpc_destroy_connection(struct rcu_head *rcu)
325 struct rxrpc_connection *conn =
326 container_of(rcu, struct rxrpc_connection, rcu);
328 _enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
330 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
332 _net("DESTROY CONN %d", conn->debug_id);
334 rxrpc_purge_queue(&conn->rx_queue);
336 conn->security->clear(conn);
337 key_put(conn->params.key);
338 key_put(conn->server_key);
339 rxrpc_put_peer(conn->params.peer);
340 rxrpc_put_local(conn->params.local);
347 * reap dead service connections
349 static void rxrpc_connection_reaper(struct work_struct *work)
351 struct rxrpc_connection *conn, *_p;
352 unsigned long reap_older_than, earliest, idle_timestamp, now;
354 LIST_HEAD(graveyard);
359 reap_older_than = now - rxrpc_connection_expiry * HZ;
360 earliest = ULONG_MAX;
362 write_lock(&rxrpc_connection_lock);
363 list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
364 ASSERTCMP(atomic_read(&conn->usage), >, 0);
365 if (likely(atomic_read(&conn->usage) > 1))
367 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
370 idle_timestamp = READ_ONCE(conn->idle_timestamp);
371 _debug("reap CONN %d { u=%d,t=%ld }",
372 conn->debug_id, atomic_read(&conn->usage),
373 (long)reap_older_than - (long)idle_timestamp);
375 if (time_after(idle_timestamp, reap_older_than)) {
376 if (time_before(idle_timestamp, earliest))
377 earliest = idle_timestamp;
381 /* The usage count sits at 1 whilst the object is unused on the
382 * list; we reduce that to 0 to make the object unavailable.
384 if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
387 if (rxrpc_conn_is_client(conn))
390 rxrpc_unpublish_service_conn(conn);
392 list_move_tail(&conn->link, &graveyard);
394 write_unlock(&rxrpc_connection_lock);
396 if (earliest != ULONG_MAX) {
397 _debug("reschedule reaper %ld", (long) earliest - now);
398 ASSERT(time_after(earliest, now));
399 rxrpc_queue_delayed_work(&rxrpc_connection_reap,
403 while (!list_empty(&graveyard)) {
404 conn = list_entry(graveyard.next, struct rxrpc_connection,
406 list_del_init(&conn->link);
408 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
409 rxrpc_kill_connection(conn);
416 * preemptively destroy all the service connection records rather than
417 * waiting for them to time out
419 void __exit rxrpc_destroy_all_connections(void)
421 struct rxrpc_connection *conn, *_p;
426 rxrpc_destroy_all_client_connections();
428 rxrpc_connection_expiry = 0;
429 cancel_delayed_work(&rxrpc_connection_reap);
430 rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
431 flush_workqueue(rxrpc_workqueue);
433 write_lock(&rxrpc_connection_lock);
434 list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) {
435 pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
436 conn, atomic_read(&conn->usage));
439 write_unlock(&rxrpc_connection_lock);
442 ASSERT(list_empty(&rxrpc_connection_proc_list));
444 /* Make sure the local and peer records pinned by any dying connections
448 rxrpc_destroy_client_conn_ids();