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Commit | Line | Data |
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87563616 | 1 | /* Local endpoint object management |
17926a79 DH |
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 | |
87563616 | 7 | * modify it under the terms of the GNU General Public Licence |
17926a79 | 8 | * as published by the Free Software Foundation; either version |
87563616 | 9 | * 2 of the Licence, or (at your option) any later version. |
17926a79 DH |
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> |
44ba0698 DH |
18 | #include <linux/udp.h> |
19 | #include <linux/ip.h> | |
17926a79 DH |
20 | #include <net/sock.h> |
21 | #include <net/af_rxrpc.h> | |
22 | #include "ar-internal.h" | |
23 | ||
24 | static LIST_HEAD(rxrpc_locals); | |
25 | DEFINE_RWLOCK(rxrpc_local_lock); | |
26 | static DECLARE_RWSEM(rxrpc_local_sem); | |
27 | static DECLARE_WAIT_QUEUE_HEAD(rxrpc_local_wq); | |
28 | ||
29 | static void rxrpc_destroy_local(struct work_struct *work); | |
30 | ||
31 | /* | |
32 | * allocate a new local | |
33 | */ | |
34 | static | |
35 | struct rxrpc_local *rxrpc_alloc_local(struct sockaddr_rxrpc *srx) | |
36 | { | |
37 | struct rxrpc_local *local; | |
38 | ||
39 | local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); | |
40 | if (local) { | |
41 | INIT_WORK(&local->destroyer, &rxrpc_destroy_local); | |
42 | INIT_WORK(&local->acceptor, &rxrpc_accept_incoming_calls); | |
43 | INIT_WORK(&local->rejecter, &rxrpc_reject_packets); | |
44ba0698 | 44 | INIT_WORK(&local->event_processor, &rxrpc_process_local_events); |
17926a79 DH |
45 | INIT_LIST_HEAD(&local->services); |
46 | INIT_LIST_HEAD(&local->link); | |
47 | init_rwsem(&local->defrag_sem); | |
48 | skb_queue_head_init(&local->accept_queue); | |
49 | skb_queue_head_init(&local->reject_queue); | |
44ba0698 | 50 | skb_queue_head_init(&local->event_queue); |
17926a79 DH |
51 | spin_lock_init(&local->lock); |
52 | rwlock_init(&local->services_lock); | |
53 | atomic_set(&local->usage, 1); | |
54 | local->debug_id = atomic_inc_return(&rxrpc_debug_id); | |
55 | memcpy(&local->srx, srx, sizeof(*srx)); | |
56 | } | |
57 | ||
58 | _leave(" = %p", local); | |
59 | return local; | |
60 | } | |
61 | ||
62 | /* | |
63 | * create the local socket | |
64 | * - must be called with rxrpc_local_sem writelocked | |
65 | */ | |
66 | static int rxrpc_create_local(struct rxrpc_local *local) | |
67 | { | |
68 | struct sock *sock; | |
69 | int ret, opt; | |
70 | ||
71 | _enter("%p{%d}", local, local->srx.transport_type); | |
72 | ||
73 | /* create a socket to represent the local endpoint */ | |
eeb1bd5c EB |
74 | ret = sock_create_kern(&init_net, PF_INET, local->srx.transport_type, |
75 | IPPROTO_UDP, &local->socket); | |
17926a79 DH |
76 | if (ret < 0) { |
77 | _leave(" = %d [socket]", ret); | |
78 | return ret; | |
79 | } | |
80 | ||
81 | /* if a local address was supplied then bind it */ | |
82 | if (local->srx.transport_len > sizeof(sa_family_t)) { | |
83 | _debug("bind"); | |
84 | ret = kernel_bind(local->socket, | |
85 | (struct sockaddr *) &local->srx.transport, | |
86 | local->srx.transport_len); | |
87 | if (ret < 0) { | |
88 | _debug("bind failed"); | |
89 | goto error; | |
90 | } | |
91 | } | |
92 | ||
93 | /* we want to receive ICMP errors */ | |
94 | opt = 1; | |
95 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, | |
96 | (char *) &opt, sizeof(opt)); | |
97 | if (ret < 0) { | |
98 | _debug("setsockopt failed"); | |
99 | goto error; | |
100 | } | |
101 | ||
102 | /* we want to set the don't fragment bit */ | |
103 | opt = IP_PMTUDISC_DO; | |
104 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
105 | (char *) &opt, sizeof(opt)); | |
106 | if (ret < 0) { | |
107 | _debug("setsockopt failed"); | |
108 | goto error; | |
109 | } | |
110 | ||
111 | write_lock_bh(&rxrpc_local_lock); | |
112 | list_add(&local->link, &rxrpc_locals); | |
113 | write_unlock_bh(&rxrpc_local_lock); | |
114 | ||
115 | /* set the socket up */ | |
116 | sock = local->socket->sk; | |
117 | sock->sk_user_data = local; | |
118 | sock->sk_data_ready = rxrpc_data_ready; | |
abe89ef0 | 119 | sock->sk_error_report = rxrpc_error_report; |
17926a79 DH |
120 | _leave(" = 0"); |
121 | return 0; | |
122 | ||
123 | error: | |
91cf45f0 | 124 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
125 | local->socket->sk->sk_user_data = NULL; |
126 | sock_release(local->socket); | |
127 | local->socket = NULL; | |
128 | ||
129 | _leave(" = %d", ret); | |
130 | return ret; | |
131 | } | |
132 | ||
133 | /* | |
134 | * create a new local endpoint using the specified UDP address | |
135 | */ | |
136 | struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *srx) | |
137 | { | |
138 | struct rxrpc_local *local; | |
139 | int ret; | |
140 | ||
21454aaa | 141 | _enter("{%d,%u,%pI4+%hu}", |
17926a79 DH |
142 | srx->transport_type, |
143 | srx->transport.family, | |
21454aaa | 144 | &srx->transport.sin.sin_addr, |
17926a79 DH |
145 | ntohs(srx->transport.sin.sin_port)); |
146 | ||
147 | down_write(&rxrpc_local_sem); | |
148 | ||
149 | /* see if we have a suitable local local endpoint already */ | |
150 | read_lock_bh(&rxrpc_local_lock); | |
151 | ||
152 | list_for_each_entry(local, &rxrpc_locals, link) { | |
21454aaa | 153 | _debug("CMP {%d,%u,%pI4+%hu}", |
17926a79 DH |
154 | local->srx.transport_type, |
155 | local->srx.transport.family, | |
21454aaa | 156 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
157 | ntohs(local->srx.transport.sin.sin_port)); |
158 | ||
159 | if (local->srx.transport_type != srx->transport_type || | |
160 | local->srx.transport.family != srx->transport.family) | |
161 | continue; | |
162 | ||
163 | switch (srx->transport.family) { | |
164 | case AF_INET: | |
165 | if (local->srx.transport.sin.sin_port != | |
166 | srx->transport.sin.sin_port) | |
167 | continue; | |
168 | if (memcmp(&local->srx.transport.sin.sin_addr, | |
169 | &srx->transport.sin.sin_addr, | |
170 | sizeof(struct in_addr)) != 0) | |
171 | continue; | |
172 | goto found_local; | |
173 | ||
174 | default: | |
175 | BUG(); | |
176 | } | |
177 | } | |
178 | ||
179 | read_unlock_bh(&rxrpc_local_lock); | |
180 | ||
181 | /* we didn't find one, so we need to create one */ | |
182 | local = rxrpc_alloc_local(srx); | |
183 | if (!local) { | |
184 | up_write(&rxrpc_local_sem); | |
185 | return ERR_PTR(-ENOMEM); | |
186 | } | |
187 | ||
188 | ret = rxrpc_create_local(local); | |
189 | if (ret < 0) { | |
190 | up_write(&rxrpc_local_sem); | |
191 | kfree(local); | |
192 | _leave(" = %d", ret); | |
193 | return ERR_PTR(ret); | |
194 | } | |
195 | ||
196 | up_write(&rxrpc_local_sem); | |
197 | ||
21454aaa | 198 | _net("LOCAL new %d {%d,%u,%pI4+%hu}", |
17926a79 DH |
199 | local->debug_id, |
200 | local->srx.transport_type, | |
201 | local->srx.transport.family, | |
21454aaa | 202 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
203 | ntohs(local->srx.transport.sin.sin_port)); |
204 | ||
205 | _leave(" = %p [new]", local); | |
206 | return local; | |
207 | ||
208 | found_local: | |
209 | rxrpc_get_local(local); | |
210 | read_unlock_bh(&rxrpc_local_lock); | |
211 | up_write(&rxrpc_local_sem); | |
212 | ||
21454aaa | 213 | _net("LOCAL old %d {%d,%u,%pI4+%hu}", |
17926a79 DH |
214 | local->debug_id, |
215 | local->srx.transport_type, | |
216 | local->srx.transport.family, | |
21454aaa | 217 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
218 | ntohs(local->srx.transport.sin.sin_port)); |
219 | ||
220 | _leave(" = %p [reuse]", local); | |
221 | return local; | |
222 | } | |
223 | ||
224 | /* | |
225 | * release a local endpoint | |
226 | */ | |
227 | void rxrpc_put_local(struct rxrpc_local *local) | |
228 | { | |
229 | _enter("%p{u=%d}", local, atomic_read(&local->usage)); | |
230 | ||
231 | ASSERTCMP(atomic_read(&local->usage), >, 0); | |
232 | ||
233 | /* to prevent a race, the decrement and the dequeue must be effectively | |
234 | * atomic */ | |
235 | write_lock_bh(&rxrpc_local_lock); | |
236 | if (unlikely(atomic_dec_and_test(&local->usage))) { | |
237 | _debug("destroy local"); | |
651350d1 | 238 | rxrpc_queue_work(&local->destroyer); |
17926a79 DH |
239 | } |
240 | write_unlock_bh(&rxrpc_local_lock); | |
241 | _leave(""); | |
242 | } | |
243 | ||
244 | /* | |
245 | * destroy a local endpoint | |
246 | */ | |
247 | static void rxrpc_destroy_local(struct work_struct *work) | |
248 | { | |
249 | struct rxrpc_local *local = | |
250 | container_of(work, struct rxrpc_local, destroyer); | |
251 | ||
252 | _enter("%p{%d}", local, atomic_read(&local->usage)); | |
253 | ||
254 | down_write(&rxrpc_local_sem); | |
255 | ||
256 | write_lock_bh(&rxrpc_local_lock); | |
257 | if (atomic_read(&local->usage) > 0) { | |
258 | write_unlock_bh(&rxrpc_local_lock); | |
259 | up_read(&rxrpc_local_sem); | |
260 | _leave(" [resurrected]"); | |
261 | return; | |
262 | } | |
263 | ||
264 | list_del(&local->link); | |
265 | local->socket->sk->sk_user_data = NULL; | |
266 | write_unlock_bh(&rxrpc_local_lock); | |
267 | ||
268 | downgrade_write(&rxrpc_local_sem); | |
269 | ||
270 | ASSERT(list_empty(&local->services)); | |
271 | ASSERT(!work_pending(&local->acceptor)); | |
272 | ASSERT(!work_pending(&local->rejecter)); | |
44ba0698 | 273 | ASSERT(!work_pending(&local->event_processor)); |
17926a79 DH |
274 | |
275 | /* finish cleaning up the local descriptor */ | |
276 | rxrpc_purge_queue(&local->accept_queue); | |
277 | rxrpc_purge_queue(&local->reject_queue); | |
44ba0698 | 278 | rxrpc_purge_queue(&local->event_queue); |
91cf45f0 | 279 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
280 | sock_release(local->socket); |
281 | ||
282 | up_read(&rxrpc_local_sem); | |
283 | ||
284 | _net("DESTROY LOCAL %d", local->debug_id); | |
285 | kfree(local); | |
286 | ||
287 | if (list_empty(&rxrpc_locals)) | |
288 | wake_up_all(&rxrpc_local_wq); | |
289 | ||
290 | _leave(""); | |
291 | } | |
292 | ||
293 | /* | |
294 | * preemptively destroy all local local endpoint rather than waiting for | |
295 | * them to be destroyed | |
296 | */ | |
297 | void __exit rxrpc_destroy_all_locals(void) | |
298 | { | |
299 | DECLARE_WAITQUEUE(myself,current); | |
300 | ||
301 | _enter(""); | |
302 | ||
303 | /* we simply have to wait for them to go away */ | |
304 | if (!list_empty(&rxrpc_locals)) { | |
305 | set_current_state(TASK_UNINTERRUPTIBLE); | |
306 | add_wait_queue(&rxrpc_local_wq, &myself); | |
307 | ||
308 | while (!list_empty(&rxrpc_locals)) { | |
309 | schedule(); | |
310 | set_current_state(TASK_UNINTERRUPTIBLE); | |
311 | } | |
312 | ||
313 | remove_wait_queue(&rxrpc_local_wq, &myself); | |
314 | set_current_state(TASK_RUNNING); | |
315 | } | |
316 | ||
317 | _leave(""); | |
318 | } |