RxRPC: Use uX/sX rather than uintX_t/intX_t types
[linux-2.6.git] / net / rxrpc / ar-transport.c
1 /* RxRPC point-to-point transport session management
2  *
3  * Copyright (C) 2007 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 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <net/sock.h>
16 #include <net/af_rxrpc.h>
17 #include "ar-internal.h"
18
19 static void rxrpc_transport_reaper(struct work_struct *work);
20
21 static LIST_HEAD(rxrpc_transports);
22 static DEFINE_RWLOCK(rxrpc_transport_lock);
23 static unsigned long rxrpc_transport_timeout = 3600 * 24;
24 static DECLARE_DELAYED_WORK(rxrpc_transport_reap, rxrpc_transport_reaper);
25
26 /*
27  * allocate a new transport session manager
28  */
29 static struct rxrpc_transport *rxrpc_alloc_transport(struct rxrpc_local *local,
30                                                      struct rxrpc_peer *peer,
31                                                      gfp_t gfp)
32 {
33         struct rxrpc_transport *trans;
34
35         _enter("");
36
37         trans = kzalloc(sizeof(struct rxrpc_transport), gfp);
38         if (trans) {
39                 trans->local = local;
40                 trans->peer = peer;
41                 INIT_LIST_HEAD(&trans->link);
42                 trans->bundles = RB_ROOT;
43                 trans->client_conns = RB_ROOT;
44                 trans->server_conns = RB_ROOT;
45                 skb_queue_head_init(&trans->error_queue);
46                 spin_lock_init(&trans->client_lock);
47                 rwlock_init(&trans->conn_lock);
48                 atomic_set(&trans->usage, 1);
49                 trans->debug_id = atomic_inc_return(&rxrpc_debug_id);
50
51                 if (peer->srx.transport.family == AF_INET) {
52                         switch (peer->srx.transport_type) {
53                         case SOCK_DGRAM:
54                                 INIT_WORK(&trans->error_handler,
55                                           rxrpc_UDP_error_handler);
56                                 break;
57                         default:
58                                 BUG();
59                                 break;
60                         }
61                 } else {
62                         BUG();
63                 }
64         }
65
66         _leave(" = %p", trans);
67         return trans;
68 }
69
70 /*
71  * obtain a transport session for the nominated endpoints
72  */
73 struct rxrpc_transport *rxrpc_get_transport(struct rxrpc_local *local,
74                                             struct rxrpc_peer *peer,
75                                             gfp_t gfp)
76 {
77         struct rxrpc_transport *trans, *candidate;
78         const char *new = "old";
79         int usage;
80
81         _enter("{%pI4+%hu},{%pI4+%hu},",
82                &local->srx.transport.sin.sin_addr,
83                ntohs(local->srx.transport.sin.sin_port),
84                &peer->srx.transport.sin.sin_addr,
85                ntohs(peer->srx.transport.sin.sin_port));
86
87         /* search the transport list first */
88         read_lock_bh(&rxrpc_transport_lock);
89         list_for_each_entry(trans, &rxrpc_transports, link) {
90                 if (trans->local == local && trans->peer == peer)
91                         goto found_extant_transport;
92         }
93         read_unlock_bh(&rxrpc_transport_lock);
94
95         /* not yet present - create a candidate for a new record and then
96          * redo the search */
97         candidate = rxrpc_alloc_transport(local, peer, gfp);
98         if (!candidate) {
99                 _leave(" = -ENOMEM");
100                 return ERR_PTR(-ENOMEM);
101         }
102
103         write_lock_bh(&rxrpc_transport_lock);
104
105         list_for_each_entry(trans, &rxrpc_transports, link) {
106                 if (trans->local == local && trans->peer == peer)
107                         goto found_extant_second;
108         }
109
110         /* we can now add the new candidate to the list */
111         trans = candidate;
112         candidate = NULL;
113
114         rxrpc_get_local(trans->local);
115         atomic_inc(&trans->peer->usage);
116         list_add_tail(&trans->link, &rxrpc_transports);
117         write_unlock_bh(&rxrpc_transport_lock);
118         new = "new";
119
120 success:
121         _net("TRANSPORT %s %d local %d -> peer %d",
122              new,
123              trans->debug_id,
124              trans->local->debug_id,
125              trans->peer->debug_id);
126
127         _leave(" = %p {u=%d}", trans, atomic_read(&trans->usage));
128         return trans;
129
130         /* we found the transport in the list immediately */
131 found_extant_transport:
132         usage = atomic_inc_return(&trans->usage);
133         read_unlock_bh(&rxrpc_transport_lock);
134         goto success;
135
136         /* we found the transport on the second time through the list */
137 found_extant_second:
138         usage = atomic_inc_return(&trans->usage);
139         write_unlock_bh(&rxrpc_transport_lock);
140         kfree(candidate);
141         goto success;
142 }
143
144 /*
145  * find the transport connecting two endpoints
146  */
147 struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *local,
148                                              struct rxrpc_peer *peer)
149 {
150         struct rxrpc_transport *trans;
151
152         _enter("{%pI4+%hu},{%pI4+%hu},",
153                &local->srx.transport.sin.sin_addr,
154                ntohs(local->srx.transport.sin.sin_port),
155                &peer->srx.transport.sin.sin_addr,
156                ntohs(peer->srx.transport.sin.sin_port));
157
158         /* search the transport list */
159         read_lock_bh(&rxrpc_transport_lock);
160
161         list_for_each_entry(trans, &rxrpc_transports, link) {
162                 if (trans->local == local && trans->peer == peer)
163                         goto found_extant_transport;
164         }
165
166         read_unlock_bh(&rxrpc_transport_lock);
167         _leave(" = NULL");
168         return NULL;
169
170 found_extant_transport:
171         atomic_inc(&trans->usage);
172         read_unlock_bh(&rxrpc_transport_lock);
173         _leave(" = %p", trans);
174         return trans;
175 }
176
177 /*
178  * release a transport session
179  */
180 void rxrpc_put_transport(struct rxrpc_transport *trans)
181 {
182         _enter("%p{u=%d}", trans, atomic_read(&trans->usage));
183
184         ASSERTCMP(atomic_read(&trans->usage), >, 0);
185
186         trans->put_time = get_seconds();
187         if (unlikely(atomic_dec_and_test(&trans->usage))) {
188                 _debug("zombie");
189                 /* let the reaper determine the timeout to avoid a race with
190                  * overextending the timeout if the reaper is running at the
191                  * same time */
192                 rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0);
193         }
194         _leave("");
195 }
196
197 /*
198  * clean up a transport session
199  */
200 static void rxrpc_cleanup_transport(struct rxrpc_transport *trans)
201 {
202         _net("DESTROY TRANS %d", trans->debug_id);
203
204         rxrpc_purge_queue(&trans->error_queue);
205
206         rxrpc_put_local(trans->local);
207         rxrpc_put_peer(trans->peer);
208         kfree(trans);
209 }
210
211 /*
212  * reap dead transports that have passed their expiry date
213  */
214 static void rxrpc_transport_reaper(struct work_struct *work)
215 {
216         struct rxrpc_transport *trans, *_p;
217         unsigned long now, earliest, reap_time;
218
219         LIST_HEAD(graveyard);
220
221         _enter("");
222
223         now = get_seconds();
224         earliest = ULONG_MAX;
225
226         /* extract all the transports that have been dead too long */
227         write_lock_bh(&rxrpc_transport_lock);
228         list_for_each_entry_safe(trans, _p, &rxrpc_transports, link) {
229                 _debug("reap TRANS %d { u=%d t=%ld }",
230                        trans->debug_id, atomic_read(&trans->usage),
231                        (long) now - (long) trans->put_time);
232
233                 if (likely(atomic_read(&trans->usage) > 0))
234                         continue;
235
236                 reap_time = trans->put_time + rxrpc_transport_timeout;
237                 if (reap_time <= now)
238                         list_move_tail(&trans->link, &graveyard);
239                 else if (reap_time < earliest)
240                         earliest = reap_time;
241         }
242         write_unlock_bh(&rxrpc_transport_lock);
243
244         if (earliest != ULONG_MAX) {
245                 _debug("reschedule reaper %ld", (long) earliest - now);
246                 ASSERTCMP(earliest, >, now);
247                 rxrpc_queue_delayed_work(&rxrpc_transport_reap,
248                                          (earliest - now) * HZ);
249         }
250
251         /* then destroy all those pulled out */
252         while (!list_empty(&graveyard)) {
253                 trans = list_entry(graveyard.next, struct rxrpc_transport,
254                                    link);
255                 list_del_init(&trans->link);
256
257                 ASSERTCMP(atomic_read(&trans->usage), ==, 0);
258                 rxrpc_cleanup_transport(trans);
259         }
260
261         _leave("");
262 }
263
264 /*
265  * preemptively destroy all the transport session records rather than waiting
266  * for them to time out
267  */
268 void __exit rxrpc_destroy_all_transports(void)
269 {
270         _enter("");
271
272         rxrpc_transport_timeout = 0;
273         cancel_delayed_work(&rxrpc_transport_reap);
274         rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0);
275
276         _leave("");
277 }