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 __read_mostly rxrpc_connection_expiry = 10 * 60;
24 unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
26 static void rxrpc_destroy_connection(struct rcu_head *);
28 static void rxrpc_connection_timer(struct timer_list *timer)
30 struct rxrpc_connection *conn =
31 container_of(timer, struct rxrpc_connection, timer);
33 rxrpc_queue_conn(conn);
37 * allocate a new connection
39 struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
41 struct rxrpc_connection *conn;
45 conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
47 INIT_LIST_HEAD(&conn->cache_link);
48 spin_lock_init(&conn->channel_lock);
49 INIT_LIST_HEAD(&conn->waiting_calls);
50 timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
51 INIT_WORK(&conn->processor, &rxrpc_process_connection);
52 INIT_LIST_HEAD(&conn->proc_link);
53 INIT_LIST_HEAD(&conn->link);
54 skb_queue_head_init(&conn->rx_queue);
55 conn->security = &rxrpc_no_security;
56 spin_lock_init(&conn->state_lock);
57 conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
59 conn->idle_timestamp = jiffies;
62 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
67 * Look up a connection in the cache by protocol parameters.
69 * If successful, a pointer to the connection is returned, but no ref is taken.
70 * NULL is returned if there is no match.
72 * When searching for a service call, if we find a peer but no connection, we
73 * return that through *_peer in case we need to create a new service call.
75 * The caller must be holding the RCU read lock.
77 struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
79 struct rxrpc_peer **_peer)
81 struct rxrpc_connection *conn;
82 struct rxrpc_conn_proto k;
83 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
84 struct sockaddr_rxrpc srx;
85 struct rxrpc_peer *peer;
87 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
89 if (rxrpc_extract_addr_from_skb(local, &srx, skb) < 0)
92 /* We may have to handle mixing IPv4 and IPv6 */
93 if (srx.transport.family != local->srx.transport.family) {
94 pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
96 local->srx.transport.family);
100 k.epoch = sp->hdr.epoch;
101 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
103 if (rxrpc_to_server(sp)) {
104 /* We need to look up service connections by the full protocol
105 * parameter set. We look up the peer first as an intermediate
106 * step and then the connection from the peer's tree.
108 peer = rxrpc_lookup_peer_rcu(local, &srx);
112 conn = rxrpc_find_service_conn_rcu(peer, skb);
113 if (!conn || atomic_read(&conn->usage) == 0)
115 _leave(" = %p", conn);
118 /* Look up client connections by connection ID alone as their
119 * IDs are unique for this machine.
121 conn = idr_find(&rxrpc_client_conn_ids,
122 sp->hdr.cid >> RXRPC_CIDSHIFT);
123 if (!conn || atomic_read(&conn->usage) == 0) {
128 if (conn->proto.epoch != k.epoch ||
129 conn->params.local != local)
132 peer = conn->params.peer;
133 switch (srx.transport.family) {
135 if (peer->srx.transport.sin.sin_port !=
136 srx.transport.sin.sin_port ||
137 peer->srx.transport.sin.sin_addr.s_addr !=
138 srx.transport.sin.sin_addr.s_addr)
141 #ifdef CONFIG_AF_RXRPC_IPV6
143 if (peer->srx.transport.sin6.sin6_port !=
144 srx.transport.sin6.sin6_port ||
145 memcmp(&peer->srx.transport.sin6.sin6_addr,
146 &srx.transport.sin6.sin6_addr,
147 sizeof(struct in6_addr)) != 0)
155 _leave(" = %p", conn);
165 * Disconnect a call and clear any channel it occupies when that call
166 * terminates. The caller must hold the channel_lock and must release the
167 * call's ref on the connection.
169 void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
170 struct rxrpc_call *call)
172 struct rxrpc_channel *chan =
173 &conn->channels[call->cid & RXRPC_CHANNELMASK];
175 _enter("%d,%x", conn->debug_id, call->cid);
177 if (rcu_access_pointer(chan->call) == call) {
178 /* Save the result of the call so that we can repeat it if necessary
179 * through the channel, whilst disposing of the actual call record.
181 trace_rxrpc_disconnect_call(call);
182 switch (call->completion) {
183 case RXRPC_CALL_SUCCEEDED:
184 chan->last_seq = call->rx_hard_ack;
185 chan->last_type = RXRPC_PACKET_TYPE_ACK;
187 case RXRPC_CALL_LOCALLY_ABORTED:
188 chan->last_abort = call->abort_code;
189 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
192 chan->last_abort = RX_USER_ABORT;
193 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
197 /* Sync with rxrpc_conn_retransmit(). */
199 chan->last_call = chan->call_id;
200 chan->call_id = chan->call_counter;
202 rcu_assign_pointer(chan->call, NULL);
209 * Disconnect a call and clear any channel it occupies when that call
212 void rxrpc_disconnect_call(struct rxrpc_call *call)
214 struct rxrpc_connection *conn = call->conn;
216 call->peer->cong_cwnd = call->cong_cwnd;
218 if (!hlist_unhashed(&call->error_link)) {
219 spin_lock_bh(&call->peer->lock);
220 hlist_del_rcu(&call->error_link);
221 spin_unlock_bh(&call->peer->lock);
224 if (rxrpc_is_client_call(call))
225 return rxrpc_disconnect_client_call(call);
227 spin_lock(&conn->channel_lock);
228 __rxrpc_disconnect_call(conn, call);
229 spin_unlock(&conn->channel_lock);
231 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
232 conn->idle_timestamp = jiffies;
236 * Kill off a connection.
238 void rxrpc_kill_connection(struct rxrpc_connection *conn)
240 struct rxrpc_net *rxnet = conn->params.local->rxnet;
242 ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
243 !rcu_access_pointer(conn->channels[1].call) &&
244 !rcu_access_pointer(conn->channels[2].call) &&
245 !rcu_access_pointer(conn->channels[3].call));
246 ASSERT(list_empty(&conn->cache_link));
248 write_lock(&rxnet->conn_lock);
249 list_del_init(&conn->proc_link);
250 write_unlock(&rxnet->conn_lock);
252 /* Drain the Rx queue. Note that even though we've unpublished, an
253 * incoming packet could still be being added to our Rx queue, so we
254 * will need to drain it again in the RCU cleanup handler.
256 rxrpc_purge_queue(&conn->rx_queue);
258 /* Leave final destruction to RCU. The connection processor work item
259 * must carry a ref on the connection to prevent us getting here whilst
260 * it is queued or running.
262 call_rcu(&conn->rcu, rxrpc_destroy_connection);
266 * Queue a connection's work processor, getting a ref to pass to the work
269 bool rxrpc_queue_conn(struct rxrpc_connection *conn)
271 const void *here = __builtin_return_address(0);
272 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
275 if (rxrpc_queue_work(&conn->processor))
276 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, n + 1, here);
278 rxrpc_put_connection(conn);
283 * Note the re-emergence of a connection.
285 void rxrpc_see_connection(struct rxrpc_connection *conn)
287 const void *here = __builtin_return_address(0);
289 int n = atomic_read(&conn->usage);
291 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
296 * Get a ref on a connection.
298 void rxrpc_get_connection(struct rxrpc_connection *conn)
300 const void *here = __builtin_return_address(0);
301 int n = atomic_inc_return(&conn->usage);
303 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n, here);
307 * Try to get a ref on a connection.
309 struct rxrpc_connection *
310 rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
312 const void *here = __builtin_return_address(0);
315 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
317 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n + 1, here);
325 * Set the service connection reap timer.
327 static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
328 unsigned long reap_at)
331 timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
335 * Release a service connection
337 void rxrpc_put_service_conn(struct rxrpc_connection *conn)
339 const void *here = __builtin_return_address(0);
340 unsigned int debug_id = conn->debug_id;
343 n = atomic_dec_return(&conn->usage);
344 trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, n, here);
347 rxrpc_set_service_reap_timer(conn->params.local->rxnet,
348 jiffies + rxrpc_connection_expiry);
352 * destroy a virtual connection
354 static void rxrpc_destroy_connection(struct rcu_head *rcu)
356 struct rxrpc_connection *conn =
357 container_of(rcu, struct rxrpc_connection, rcu);
359 _enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
361 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
363 _net("DESTROY CONN %d", conn->debug_id);
365 del_timer_sync(&conn->timer);
366 rxrpc_purge_queue(&conn->rx_queue);
368 conn->security->clear(conn);
369 key_put(conn->params.key);
370 key_put(conn->server_key);
371 rxrpc_put_peer(conn->params.peer);
373 if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
374 wake_up_var(&conn->params.local->rxnet->nr_conns);
375 rxrpc_put_local(conn->params.local);
382 * reap dead service connections
384 void rxrpc_service_connection_reaper(struct work_struct *work)
386 struct rxrpc_connection *conn, *_p;
387 struct rxrpc_net *rxnet =
388 container_of(work, struct rxrpc_net, service_conn_reaper);
389 unsigned long expire_at, earliest, idle_timestamp, now;
391 LIST_HEAD(graveyard);
396 earliest = now + MAX_JIFFY_OFFSET;
398 write_lock(&rxnet->conn_lock);
399 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
400 ASSERTCMP(atomic_read(&conn->usage), >, 0);
401 if (likely(atomic_read(&conn->usage) > 1))
403 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
406 if (rxnet->live && !conn->params.local->dead) {
407 idle_timestamp = READ_ONCE(conn->idle_timestamp);
408 expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
409 if (conn->params.local->service_closed)
410 expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
412 _debug("reap CONN %d { u=%d,t=%ld }",
413 conn->debug_id, atomic_read(&conn->usage),
414 (long)expire_at - (long)now);
416 if (time_before(now, expire_at)) {
417 if (time_before(expire_at, earliest))
418 earliest = expire_at;
423 /* The usage count sits at 1 whilst the object is unused on the
424 * list; we reduce that to 0 to make the object unavailable.
426 if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
428 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
430 if (rxrpc_conn_is_client(conn))
433 rxrpc_unpublish_service_conn(conn);
435 list_move_tail(&conn->link, &graveyard);
437 write_unlock(&rxnet->conn_lock);
439 if (earliest != now + MAX_JIFFY_OFFSET) {
440 _debug("reschedule reaper %ld", (long)earliest - (long)now);
441 ASSERT(time_after(earliest, now));
442 rxrpc_set_service_reap_timer(rxnet, earliest);
445 while (!list_empty(&graveyard)) {
446 conn = list_entry(graveyard.next, struct rxrpc_connection,
448 list_del_init(&conn->link);
450 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
451 rxrpc_kill_connection(conn);
458 * preemptively destroy all the service connection records rather than
459 * waiting for them to time out
461 void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
463 struct rxrpc_connection *conn, *_p;
468 atomic_dec(&rxnet->nr_conns);
469 rxrpc_destroy_all_client_connections(rxnet);
471 del_timer_sync(&rxnet->service_conn_reap_timer);
472 rxrpc_queue_work(&rxnet->service_conn_reaper);
473 flush_workqueue(rxrpc_workqueue);
475 write_lock(&rxnet->conn_lock);
476 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
477 pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
478 conn, atomic_read(&conn->usage));
481 write_unlock(&rxnet->conn_lock);
484 ASSERT(list_empty(&rxnet->conn_proc_list));
486 /* We need to wait for the connections to be destroyed by RCU as they
487 * pin things that we still need to get rid of.
489 wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));