Commit | Line | Data |
---|---|---|
17926a79 DH |
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 | ||
9b6d5398 JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
17926a79 DH |
14 | #include <linux/module.h> |
15 | #include <linux/net.h> | |
16 | #include <linux/skbuff.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
17926a79 DH |
18 | #include <net/sock.h> |
19 | #include <net/af_rxrpc.h> | |
20 | #include "ar-internal.h" | |
21 | ||
5873c083 DH |
22 | /* |
23 | * Time after last use at which transport record is cleaned up. | |
24 | */ | |
dad8aff7 | 25 | unsigned int rxrpc_transport_expiry = 3600 * 24; |
5873c083 | 26 | |
17926a79 DH |
27 | static void rxrpc_transport_reaper(struct work_struct *work); |
28 | ||
29 | static LIST_HEAD(rxrpc_transports); | |
30 | static DEFINE_RWLOCK(rxrpc_transport_lock); | |
17926a79 DH |
31 | static DECLARE_DELAYED_WORK(rxrpc_transport_reap, rxrpc_transport_reaper); |
32 | ||
33 | /* | |
34 | * allocate a new transport session manager | |
35 | */ | |
36 | static struct rxrpc_transport *rxrpc_alloc_transport(struct rxrpc_local *local, | |
37 | struct rxrpc_peer *peer, | |
38 | gfp_t gfp) | |
39 | { | |
40 | struct rxrpc_transport *trans; | |
41 | ||
42 | _enter(""); | |
43 | ||
44 | trans = kzalloc(sizeof(struct rxrpc_transport), gfp); | |
45 | if (trans) { | |
46 | trans->local = local; | |
47 | trans->peer = peer; | |
48 | INIT_LIST_HEAD(&trans->link); | |
49 | trans->bundles = RB_ROOT; | |
50 | trans->client_conns = RB_ROOT; | |
51 | trans->server_conns = RB_ROOT; | |
17926a79 DH |
52 | spin_lock_init(&trans->client_lock); |
53 | rwlock_init(&trans->conn_lock); | |
54 | atomic_set(&trans->usage, 1); | |
0d12f8a4 | 55 | trans->conn_idcounter = peer->srx.srx_service << 16; |
17926a79 | 56 | trans->debug_id = atomic_inc_return(&rxrpc_debug_id); |
17926a79 DH |
57 | } |
58 | ||
59 | _leave(" = %p", trans); | |
60 | return trans; | |
61 | } | |
62 | ||
63 | /* | |
64 | * obtain a transport session for the nominated endpoints | |
65 | */ | |
66 | struct rxrpc_transport *rxrpc_get_transport(struct rxrpc_local *local, | |
67 | struct rxrpc_peer *peer, | |
68 | gfp_t gfp) | |
69 | { | |
70 | struct rxrpc_transport *trans, *candidate; | |
71 | const char *new = "old"; | |
72 | int usage; | |
73 | ||
21454aaa HH |
74 | _enter("{%pI4+%hu},{%pI4+%hu},", |
75 | &local->srx.transport.sin.sin_addr, | |
17926a79 | 76 | ntohs(local->srx.transport.sin.sin_port), |
21454aaa | 77 | &peer->srx.transport.sin.sin_addr, |
17926a79 DH |
78 | ntohs(peer->srx.transport.sin.sin_port)); |
79 | ||
80 | /* search the transport list first */ | |
81 | read_lock_bh(&rxrpc_transport_lock); | |
82 | list_for_each_entry(trans, &rxrpc_transports, link) { | |
83 | if (trans->local == local && trans->peer == peer) | |
84 | goto found_extant_transport; | |
85 | } | |
86 | read_unlock_bh(&rxrpc_transport_lock); | |
87 | ||
88 | /* not yet present - create a candidate for a new record and then | |
89 | * redo the search */ | |
90 | candidate = rxrpc_alloc_transport(local, peer, gfp); | |
91 | if (!candidate) { | |
92 | _leave(" = -ENOMEM"); | |
93 | return ERR_PTR(-ENOMEM); | |
94 | } | |
95 | ||
96 | write_lock_bh(&rxrpc_transport_lock); | |
97 | ||
98 | list_for_each_entry(trans, &rxrpc_transports, link) { | |
99 | if (trans->local == local && trans->peer == peer) | |
100 | goto found_extant_second; | |
101 | } | |
102 | ||
103 | /* we can now add the new candidate to the list */ | |
104 | trans = candidate; | |
105 | candidate = NULL; | |
ed84cadb | 106 | usage = atomic_read(&trans->usage); |
17926a79 DH |
107 | |
108 | rxrpc_get_local(trans->local); | |
be6e6707 | 109 | rxrpc_get_peer(trans->peer); |
17926a79 DH |
110 | list_add_tail(&trans->link, &rxrpc_transports); |
111 | write_unlock_bh(&rxrpc_transport_lock); | |
112 | new = "new"; | |
113 | ||
114 | success: | |
115 | _net("TRANSPORT %s %d local %d -> peer %d", | |
116 | new, | |
117 | trans->debug_id, | |
118 | trans->local->debug_id, | |
119 | trans->peer->debug_id); | |
120 | ||
ed84cadb | 121 | _leave(" = %p {u=%d}", trans, usage); |
17926a79 DH |
122 | return trans; |
123 | ||
124 | /* we found the transport in the list immediately */ | |
125 | found_extant_transport: | |
126 | usage = atomic_inc_return(&trans->usage); | |
127 | read_unlock_bh(&rxrpc_transport_lock); | |
128 | goto success; | |
129 | ||
130 | /* we found the transport on the second time through the list */ | |
131 | found_extant_second: | |
132 | usage = atomic_inc_return(&trans->usage); | |
133 | write_unlock_bh(&rxrpc_transport_lock); | |
134 | kfree(candidate); | |
135 | goto success; | |
136 | } | |
137 | ||
138 | /* | |
139 | * find the transport connecting two endpoints | |
140 | */ | |
141 | struct rxrpc_transport *rxrpc_find_transport(struct rxrpc_local *local, | |
142 | struct rxrpc_peer *peer) | |
143 | { | |
144 | struct rxrpc_transport *trans; | |
145 | ||
21454aaa HH |
146 | _enter("{%pI4+%hu},{%pI4+%hu},", |
147 | &local->srx.transport.sin.sin_addr, | |
17926a79 | 148 | ntohs(local->srx.transport.sin.sin_port), |
21454aaa | 149 | &peer->srx.transport.sin.sin_addr, |
17926a79 DH |
150 | ntohs(peer->srx.transport.sin.sin_port)); |
151 | ||
152 | /* search the transport list */ | |
153 | read_lock_bh(&rxrpc_transport_lock); | |
154 | ||
155 | list_for_each_entry(trans, &rxrpc_transports, link) { | |
156 | if (trans->local == local && trans->peer == peer) | |
157 | goto found_extant_transport; | |
158 | } | |
159 | ||
160 | read_unlock_bh(&rxrpc_transport_lock); | |
161 | _leave(" = NULL"); | |
162 | return NULL; | |
163 | ||
164 | found_extant_transport: | |
165 | atomic_inc(&trans->usage); | |
166 | read_unlock_bh(&rxrpc_transport_lock); | |
167 | _leave(" = %p", trans); | |
168 | return trans; | |
169 | } | |
170 | ||
171 | /* | |
172 | * release a transport session | |
173 | */ | |
174 | void rxrpc_put_transport(struct rxrpc_transport *trans) | |
175 | { | |
176 | _enter("%p{u=%d}", trans, atomic_read(&trans->usage)); | |
177 | ||
178 | ASSERTCMP(atomic_read(&trans->usage), >, 0); | |
179 | ||
22a3f9a2 | 180 | trans->put_time = ktime_get_seconds(); |
50aab54f | 181 | if (unlikely(atomic_dec_and_test(&trans->usage))) { |
17926a79 DH |
182 | _debug("zombie"); |
183 | /* let the reaper determine the timeout to avoid a race with | |
184 | * overextending the timeout if the reaper is running at the | |
185 | * same time */ | |
651350d1 | 186 | rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0); |
50aab54f | 187 | } |
17926a79 DH |
188 | _leave(""); |
189 | } | |
190 | ||
191 | /* | |
192 | * clean up a transport session | |
193 | */ | |
194 | static void rxrpc_cleanup_transport(struct rxrpc_transport *trans) | |
195 | { | |
196 | _net("DESTROY TRANS %d", trans->debug_id); | |
197 | ||
17926a79 DH |
198 | rxrpc_put_local(trans->local); |
199 | rxrpc_put_peer(trans->peer); | |
200 | kfree(trans); | |
201 | } | |
202 | ||
203 | /* | |
204 | * reap dead transports that have passed their expiry date | |
205 | */ | |
206 | static void rxrpc_transport_reaper(struct work_struct *work) | |
207 | { | |
208 | struct rxrpc_transport *trans, *_p; | |
209 | unsigned long now, earliest, reap_time; | |
210 | ||
211 | LIST_HEAD(graveyard); | |
212 | ||
213 | _enter(""); | |
214 | ||
22a3f9a2 | 215 | now = ktime_get_seconds(); |
17926a79 DH |
216 | earliest = ULONG_MAX; |
217 | ||
218 | /* extract all the transports that have been dead too long */ | |
219 | write_lock_bh(&rxrpc_transport_lock); | |
220 | list_for_each_entry_safe(trans, _p, &rxrpc_transports, link) { | |
221 | _debug("reap TRANS %d { u=%d t=%ld }", | |
222 | trans->debug_id, atomic_read(&trans->usage), | |
223 | (long) now - (long) trans->put_time); | |
224 | ||
225 | if (likely(atomic_read(&trans->usage) > 0)) | |
226 | continue; | |
227 | ||
5873c083 | 228 | reap_time = trans->put_time + rxrpc_transport_expiry; |
17926a79 DH |
229 | if (reap_time <= now) |
230 | list_move_tail(&trans->link, &graveyard); | |
231 | else if (reap_time < earliest) | |
232 | earliest = reap_time; | |
233 | } | |
234 | write_unlock_bh(&rxrpc_transport_lock); | |
235 | ||
236 | if (earliest != ULONG_MAX) { | |
237 | _debug("reschedule reaper %ld", (long) earliest - now); | |
238 | ASSERTCMP(earliest, >, now); | |
651350d1 DH |
239 | rxrpc_queue_delayed_work(&rxrpc_transport_reap, |
240 | (earliest - now) * HZ); | |
17926a79 DH |
241 | } |
242 | ||
243 | /* then destroy all those pulled out */ | |
244 | while (!list_empty(&graveyard)) { | |
245 | trans = list_entry(graveyard.next, struct rxrpc_transport, | |
246 | link); | |
247 | list_del_init(&trans->link); | |
248 | ||
249 | ASSERTCMP(atomic_read(&trans->usage), ==, 0); | |
250 | rxrpc_cleanup_transport(trans); | |
251 | } | |
252 | ||
253 | _leave(""); | |
254 | } | |
255 | ||
256 | /* | |
257 | * preemptively destroy all the transport session records rather than waiting | |
258 | * for them to time out | |
259 | */ | |
260 | void __exit rxrpc_destroy_all_transports(void) | |
261 | { | |
262 | _enter(""); | |
263 | ||
5873c083 | 264 | rxrpc_transport_expiry = 0; |
17926a79 | 265 | cancel_delayed_work(&rxrpc_transport_reap); |
651350d1 | 266 | rxrpc_queue_delayed_work(&rxrpc_transport_reap, 0); |
17926a79 DH |
267 | |
268 | _leave(""); | |
269 | } |