1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC virtual connection handler, common bits.
4 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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"
17 * Time till a connection expires after last use (in seconds).
19 unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
20 unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
22 static void rxrpc_destroy_connection(struct rcu_head *);
24 static void rxrpc_connection_timer(struct timer_list *timer)
26 struct rxrpc_connection *conn =
27 container_of(timer, struct rxrpc_connection, timer);
29 rxrpc_queue_conn(conn);
33 * allocate a new connection
35 struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp)
37 struct rxrpc_connection *conn;
41 conn = kzalloc(sizeof(struct rxrpc_connection), gfp);
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);
55 conn->idle_timestamp = jiffies;
58 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
63 * Look up a connection in the cache by protocol parameters.
65 * If successful, a pointer to the connection is returned, but no ref is taken.
66 * NULL is returned if there is no match.
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.
71 * The caller must be holding the RCU read lock.
73 struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
75 struct rxrpc_peer **_peer)
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;
83 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
85 if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
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",
93 local->srx.transport.family);
97 k.epoch = sp->hdr.epoch;
98 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
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.
105 peer = rxrpc_lookup_peer_rcu(local, &srx);
109 conn = rxrpc_find_service_conn_rcu(peer, skb);
110 if (!conn || atomic_read(&conn->usage) == 0)
112 _leave(" = %p", conn);
115 /* Look up client connections by connection ID alone as their
116 * IDs are unique for this machine.
118 conn = idr_find(&rxrpc_client_conn_ids,
119 sp->hdr.cid >> RXRPC_CIDSHIFT);
120 if (!conn || atomic_read(&conn->usage) == 0) {
125 if (conn->proto.epoch != k.epoch ||
126 conn->params.local != local)
129 peer = conn->params.peer;
130 switch (srx.transport.family) {
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)
138 #ifdef CONFIG_AF_RXRPC_IPV6
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)
152 _leave(" = %p", conn);
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.
166 void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
167 struct rxrpc_call *call)
169 struct rxrpc_channel *chan =
170 &conn->channels[call->cid & RXRPC_CHANNELMASK];
172 _enter("%d,%x", conn->debug_id, call->cid);
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.
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;
184 case RXRPC_CALL_LOCALLY_ABORTED:
185 chan->last_abort = call->abort_code;
186 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
189 chan->last_abort = RX_USER_ABORT;
190 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
194 /* Sync with rxrpc_conn_retransmit(). */
196 chan->last_call = chan->call_id;
197 chan->call_id = chan->call_counter;
199 rcu_assign_pointer(chan->call, NULL);
206 * Disconnect a call and clear any channel it occupies when that call
209 void rxrpc_disconnect_call(struct rxrpc_call *call)
211 struct rxrpc_connection *conn = call->conn;
213 call->peer->cong_cwnd = call->cong_cwnd;
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);
221 if (rxrpc_is_client_call(call))
222 return rxrpc_disconnect_client_call(call);
224 spin_lock(&conn->channel_lock);
225 __rxrpc_disconnect_call(conn, call);
226 spin_unlock(&conn->channel_lock);
228 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
229 conn->idle_timestamp = jiffies;
233 * Kill off a connection.
235 void rxrpc_kill_connection(struct rxrpc_connection *conn)
237 struct rxrpc_net *rxnet = conn->params.local->rxnet;
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));
245 write_lock(&rxnet->conn_lock);
246 list_del_init(&conn->proc_link);
247 write_unlock(&rxnet->conn_lock);
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.
253 rxrpc_purge_queue(&conn->rx_queue);
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.
259 call_rcu(&conn->rcu, rxrpc_destroy_connection);
263 * Queue a connection's work processor, getting a ref to pass to the work
266 bool rxrpc_queue_conn(struct rxrpc_connection *conn)
268 const void *here = __builtin_return_address(0);
269 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
272 if (rxrpc_queue_work(&conn->processor))
273 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, n + 1, here);
275 rxrpc_put_connection(conn);
280 * Note the re-emergence of a connection.
282 void rxrpc_see_connection(struct rxrpc_connection *conn)
284 const void *here = __builtin_return_address(0);
286 int n = atomic_read(&conn->usage);
288 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
293 * Get a ref on a connection.
295 void rxrpc_get_connection(struct rxrpc_connection *conn)
297 const void *here = __builtin_return_address(0);
298 int n = atomic_inc_return(&conn->usage);
300 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n, here);
304 * Try to get a ref on a connection.
306 struct rxrpc_connection *
307 rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
309 const void *here = __builtin_return_address(0);
312 int n = atomic_fetch_add_unless(&conn->usage, 1, 0);
314 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, n + 1, here);
322 * Set the service connection reap timer.
324 static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
325 unsigned long reap_at)
328 timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
332 * Release a service connection
334 void rxrpc_put_service_conn(struct rxrpc_connection *conn)
336 const void *here = __builtin_return_address(0);
337 unsigned int debug_id = conn->debug_id;
340 n = atomic_dec_return(&conn->usage);
341 trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, n, here);
344 rxrpc_set_service_reap_timer(conn->params.local->rxnet,
345 jiffies + rxrpc_connection_expiry);
349 * destroy a virtual connection
351 static void rxrpc_destroy_connection(struct rcu_head *rcu)
353 struct rxrpc_connection *conn =
354 container_of(rcu, struct rxrpc_connection, rcu);
356 _enter("{%d,u=%d}", conn->debug_id, atomic_read(&conn->usage));
358 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
360 _net("DESTROY CONN %d", conn->debug_id);
362 del_timer_sync(&conn->timer);
363 rxrpc_purge_queue(&conn->rx_queue);
365 conn->security->clear(conn);
366 key_put(conn->params.key);
367 key_put(conn->server_key);
368 rxrpc_put_peer(conn->params.peer);
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);
379 * reap dead service connections
381 void rxrpc_service_connection_reaper(struct work_struct *work)
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;
388 LIST_HEAD(graveyard);
393 earliest = now + MAX_JIFFY_OFFSET;
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))
400 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
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;
409 _debug("reap CONN %d { u=%d,t=%ld }",
410 conn->debug_id, atomic_read(&conn->usage),
411 (long)expire_at - (long)now);
413 if (time_before(now, expire_at)) {
414 if (time_before(expire_at, earliest))
415 earliest = expire_at;
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.
423 if (atomic_cmpxchg(&conn->usage, 1, 0) != 1)
425 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
427 if (rxrpc_conn_is_client(conn))
430 rxrpc_unpublish_service_conn(conn);
432 list_move_tail(&conn->link, &graveyard);
434 write_unlock(&rxnet->conn_lock);
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);
442 while (!list_empty(&graveyard)) {
443 conn = list_entry(graveyard.next, struct rxrpc_connection,
445 list_del_init(&conn->link);
447 ASSERTCMP(atomic_read(&conn->usage), ==, 0);
448 rxrpc_kill_connection(conn);
455 * preemptively destroy all the service connection records rather than
456 * waiting for them to time out
458 void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
460 struct rxrpc_connection *conn, *_p;
465 atomic_dec(&rxnet->nr_conns);
466 rxrpc_destroy_all_client_connections(rxnet);
468 del_timer_sync(&rxnet->service_conn_reap_timer);
469 rxrpc_queue_work(&rxnet->service_conn_reaper);
470 flush_workqueue(rxrpc_workqueue);
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));
478 write_unlock(&rxnet->conn_lock);
481 ASSERT(list_empty(&rxnet->conn_proc_list));
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.
486 wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));