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 timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
45 INIT_WORK(&conn->processor, &rxrpc_process_connection);
46 INIT_LIST_HEAD(&conn->proc_link);
47 INIT_LIST_HEAD(&conn->link);
48 skb_queue_head_init(&conn->rx_queue);
49 conn->security = &rxrpc_no_security;
50 spin_lock_init(&conn->state_lock);
51 conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
53 conn->idle_timestamp = jiffies;
56 _leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
61 * Look up a connection in the cache by protocol parameters.
63 * If successful, a pointer to the connection is returned, but no ref is taken.
64 * NULL is returned if there is no match.
66 * When searching for a service call, if we find a peer but no connection, we
67 * return that through *_peer in case we need to create a new service call.
69 * The caller must be holding the RCU read lock.
71 struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *local,
73 struct rxrpc_peer **_peer)
75 struct rxrpc_connection *conn;
76 struct rxrpc_conn_proto k;
77 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
78 struct sockaddr_rxrpc srx;
79 struct rxrpc_peer *peer;
81 _enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
83 if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
86 if (srx.transport.family != local->srx.transport.family &&
87 (srx.transport.family == AF_INET &&
88 local->srx.transport.family != AF_INET6)) {
89 pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
91 local->srx.transport.family);
95 k.epoch = sp->hdr.epoch;
96 k.cid = sp->hdr.cid & RXRPC_CIDMASK;
98 if (rxrpc_to_server(sp)) {
99 /* We need to look up service connections by the full protocol
100 * parameter set. We look up the peer first as an intermediate
101 * step and then the connection from the peer's tree.
103 peer = rxrpc_lookup_peer_rcu(local, &srx);
107 conn = rxrpc_find_service_conn_rcu(peer, skb);
108 if (!conn || refcount_read(&conn->ref) == 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 || refcount_read(&conn->ref) == 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 trace_rxrpc_disconnect_call(call);
177 switch (call->completion) {
178 case RXRPC_CALL_SUCCEEDED:
179 chan->last_seq = call->rx_hard_ack;
180 chan->last_type = RXRPC_PACKET_TYPE_ACK;
182 case RXRPC_CALL_LOCALLY_ABORTED:
183 chan->last_abort = call->abort_code;
184 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
187 chan->last_abort = RX_CALL_DEAD;
188 chan->last_type = RXRPC_PACKET_TYPE_ABORT;
192 /* Sync with rxrpc_conn_retransmit(). */
194 chan->last_call = chan->call_id;
195 chan->call_id = chan->call_counter;
197 rcu_assign_pointer(chan->call, NULL);
204 * Disconnect a call and clear any channel it occupies when that call
207 void rxrpc_disconnect_call(struct rxrpc_call *call)
209 struct rxrpc_connection *conn = call->conn;
211 call->peer->cong_cwnd = call->cong_cwnd;
213 if (!hlist_unhashed(&call->error_link)) {
214 spin_lock_bh(&call->peer->lock);
215 hlist_del_rcu(&call->error_link);
216 spin_unlock_bh(&call->peer->lock);
219 if (rxrpc_is_client_call(call))
220 return rxrpc_disconnect_client_call(conn->bundle, call);
222 spin_lock(&conn->bundle->channel_lock);
223 __rxrpc_disconnect_call(conn, call);
224 spin_unlock(&conn->bundle->channel_lock);
226 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
227 conn->idle_timestamp = jiffies;
231 * Kill off a connection.
233 void rxrpc_kill_connection(struct rxrpc_connection *conn)
235 struct rxrpc_net *rxnet = conn->params.local->rxnet;
237 ASSERT(!rcu_access_pointer(conn->channels[0].call) &&
238 !rcu_access_pointer(conn->channels[1].call) &&
239 !rcu_access_pointer(conn->channels[2].call) &&
240 !rcu_access_pointer(conn->channels[3].call));
241 ASSERT(list_empty(&conn->cache_link));
243 write_lock(&rxnet->conn_lock);
244 list_del_init(&conn->proc_link);
245 write_unlock(&rxnet->conn_lock);
247 /* Drain the Rx queue. Note that even though we've unpublished, an
248 * incoming packet could still be being added to our Rx queue, so we
249 * will need to drain it again in the RCU cleanup handler.
251 rxrpc_purge_queue(&conn->rx_queue);
253 /* Leave final destruction to RCU. The connection processor work item
254 * must carry a ref on the connection to prevent us getting here whilst
255 * it is queued or running.
257 call_rcu(&conn->rcu, rxrpc_destroy_connection);
261 * Queue a connection's work processor, getting a ref to pass to the work
264 bool rxrpc_queue_conn(struct rxrpc_connection *conn)
266 const void *here = __builtin_return_address(0);
269 if (!__refcount_inc_not_zero(&conn->ref, &r))
271 if (rxrpc_queue_work(&conn->processor))
272 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_queued, r + 1, here);
274 rxrpc_put_connection(conn);
279 * Note the re-emergence of a connection.
281 void rxrpc_see_connection(struct rxrpc_connection *conn)
283 const void *here = __builtin_return_address(0);
285 int n = refcount_read(&conn->ref);
287 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_seen, n, here);
292 * Get a ref on a connection.
294 struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn)
296 const void *here = __builtin_return_address(0);
299 __refcount_inc(&conn->ref, &r);
300 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r, here);
305 * Try to get a ref on a connection.
307 struct rxrpc_connection *
308 rxrpc_get_connection_maybe(struct rxrpc_connection *conn)
310 const void *here = __builtin_return_address(0);
314 if (__refcount_inc_not_zero(&conn->ref, &r))
315 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_got, r + 1, here);
323 * Set the service connection reap timer.
325 static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
326 unsigned long reap_at)
329 timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
333 * Release a service connection
335 void rxrpc_put_service_conn(struct rxrpc_connection *conn)
337 const void *here = __builtin_return_address(0);
338 unsigned int debug_id = conn->debug_id;
341 __refcount_dec(&conn->ref, &r);
342 trace_rxrpc_conn(debug_id, rxrpc_conn_put_service, r - 1, 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, refcount_read(&conn->ref));
358 ASSERTCMP(refcount_read(&conn->ref), ==, 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_bundle(conn->bundle);
369 rxrpc_put_peer(conn->params.peer);
371 if (atomic_dec_and_test(&conn->params.local->rxnet->nr_conns))
372 wake_up_var(&conn->params.local->rxnet->nr_conns);
373 rxrpc_put_local(conn->params.local);
380 * reap dead service connections
382 void rxrpc_service_connection_reaper(struct work_struct *work)
384 struct rxrpc_connection *conn, *_p;
385 struct rxrpc_net *rxnet =
386 container_of(work, struct rxrpc_net, service_conn_reaper);
387 unsigned long expire_at, earliest, idle_timestamp, now;
389 LIST_HEAD(graveyard);
394 earliest = now + MAX_JIFFY_OFFSET;
396 write_lock(&rxnet->conn_lock);
397 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
398 ASSERTCMP(refcount_read(&conn->ref), >, 0);
399 if (likely(refcount_read(&conn->ref) > 1))
401 if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
404 if (rxnet->live && !conn->params.local->dead) {
405 idle_timestamp = READ_ONCE(conn->idle_timestamp);
406 expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
407 if (conn->params.local->service_closed)
408 expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
410 _debug("reap CONN %d { u=%d,t=%ld }",
411 conn->debug_id, refcount_read(&conn->ref),
412 (long)expire_at - (long)now);
414 if (time_before(now, expire_at)) {
415 if (time_before(expire_at, earliest))
416 earliest = expire_at;
421 /* The usage count sits at 1 whilst the object is unused on the
422 * list; we reduce that to 0 to make the object unavailable.
424 if (!refcount_dec_if_one(&conn->ref))
426 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_reap_service, 0, NULL);
428 if (rxrpc_conn_is_client(conn))
431 rxrpc_unpublish_service_conn(conn);
433 list_move_tail(&conn->link, &graveyard);
435 write_unlock(&rxnet->conn_lock);
437 if (earliest != now + MAX_JIFFY_OFFSET) {
438 _debug("reschedule reaper %ld", (long)earliest - (long)now);
439 ASSERT(time_after(earliest, now));
440 rxrpc_set_service_reap_timer(rxnet, earliest);
443 while (!list_empty(&graveyard)) {
444 conn = list_entry(graveyard.next, struct rxrpc_connection,
446 list_del_init(&conn->link);
448 ASSERTCMP(refcount_read(&conn->ref), ==, 0);
449 rxrpc_kill_connection(conn);
456 * preemptively destroy all the service connection records rather than
457 * waiting for them to time out
459 void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
461 struct rxrpc_connection *conn, *_p;
466 atomic_dec(&rxnet->nr_conns);
467 rxrpc_destroy_all_client_connections(rxnet);
469 del_timer_sync(&rxnet->service_conn_reap_timer);
470 rxrpc_queue_work(&rxnet->service_conn_reaper);
471 flush_workqueue(rxrpc_workqueue);
473 write_lock(&rxnet->conn_lock);
474 list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
475 pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
476 conn, refcount_read(&conn->ref));
479 write_unlock(&rxnet->conn_lock);
482 ASSERT(list_empty(&rxnet->conn_proc_list));
484 /* We need to wait for the connections to be destroyed by RCU as they
485 * pin things that we still need to get rid of.
487 wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));