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17926a79 DH |
1 | /* AF_RXRPC local endpoint 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> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
44ba0698 DH |
16 | #include <linux/udp.h> |
17 | #include <linux/ip.h> | |
17926a79 DH |
18 | #include <net/sock.h> |
19 | #include <net/af_rxrpc.h> | |
44ba0698 | 20 | #include <generated/utsrelease.h> |
17926a79 DH |
21 | #include "ar-internal.h" |
22 | ||
44ba0698 DH |
23 | static const char rxrpc_version_string[65] = "linux-" UTS_RELEASE " AF_RXRPC"; |
24 | ||
17926a79 DH |
25 | static LIST_HEAD(rxrpc_locals); |
26 | DEFINE_RWLOCK(rxrpc_local_lock); | |
27 | static DECLARE_RWSEM(rxrpc_local_sem); | |
28 | static DECLARE_WAIT_QUEUE_HEAD(rxrpc_local_wq); | |
29 | ||
30 | static void rxrpc_destroy_local(struct work_struct *work); | |
44ba0698 | 31 | static void rxrpc_process_local_events(struct work_struct *work); |
17926a79 DH |
32 | |
33 | /* | |
34 | * allocate a new local | |
35 | */ | |
36 | static | |
37 | struct rxrpc_local *rxrpc_alloc_local(struct sockaddr_rxrpc *srx) | |
38 | { | |
39 | struct rxrpc_local *local; | |
40 | ||
41 | local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); | |
42 | if (local) { | |
43 | INIT_WORK(&local->destroyer, &rxrpc_destroy_local); | |
44 | INIT_WORK(&local->acceptor, &rxrpc_accept_incoming_calls); | |
45 | INIT_WORK(&local->rejecter, &rxrpc_reject_packets); | |
44ba0698 | 46 | INIT_WORK(&local->event_processor, &rxrpc_process_local_events); |
17926a79 DH |
47 | INIT_LIST_HEAD(&local->services); |
48 | INIT_LIST_HEAD(&local->link); | |
49 | init_rwsem(&local->defrag_sem); | |
50 | skb_queue_head_init(&local->accept_queue); | |
51 | skb_queue_head_init(&local->reject_queue); | |
44ba0698 | 52 | skb_queue_head_init(&local->event_queue); |
17926a79 DH |
53 | spin_lock_init(&local->lock); |
54 | rwlock_init(&local->services_lock); | |
55 | atomic_set(&local->usage, 1); | |
56 | local->debug_id = atomic_inc_return(&rxrpc_debug_id); | |
57 | memcpy(&local->srx, srx, sizeof(*srx)); | |
58 | } | |
59 | ||
60 | _leave(" = %p", local); | |
61 | return local; | |
62 | } | |
63 | ||
64 | /* | |
65 | * create the local socket | |
66 | * - must be called with rxrpc_local_sem writelocked | |
67 | */ | |
68 | static int rxrpc_create_local(struct rxrpc_local *local) | |
69 | { | |
70 | struct sock *sock; | |
71 | int ret, opt; | |
72 | ||
73 | _enter("%p{%d}", local, local->srx.transport_type); | |
74 | ||
75 | /* create a socket to represent the local endpoint */ | |
eeb1bd5c EB |
76 | ret = sock_create_kern(&init_net, PF_INET, local->srx.transport_type, |
77 | IPPROTO_UDP, &local->socket); | |
17926a79 DH |
78 | if (ret < 0) { |
79 | _leave(" = %d [socket]", ret); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | /* if a local address was supplied then bind it */ | |
84 | if (local->srx.transport_len > sizeof(sa_family_t)) { | |
85 | _debug("bind"); | |
86 | ret = kernel_bind(local->socket, | |
87 | (struct sockaddr *) &local->srx.transport, | |
88 | local->srx.transport_len); | |
89 | if (ret < 0) { | |
90 | _debug("bind failed"); | |
91 | goto error; | |
92 | } | |
93 | } | |
94 | ||
95 | /* we want to receive ICMP errors */ | |
96 | opt = 1; | |
97 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, | |
98 | (char *) &opt, sizeof(opt)); | |
99 | if (ret < 0) { | |
100 | _debug("setsockopt failed"); | |
101 | goto error; | |
102 | } | |
103 | ||
104 | /* we want to set the don't fragment bit */ | |
105 | opt = IP_PMTUDISC_DO; | |
106 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
107 | (char *) &opt, sizeof(opt)); | |
108 | if (ret < 0) { | |
109 | _debug("setsockopt failed"); | |
110 | goto error; | |
111 | } | |
112 | ||
113 | write_lock_bh(&rxrpc_local_lock); | |
114 | list_add(&local->link, &rxrpc_locals); | |
115 | write_unlock_bh(&rxrpc_local_lock); | |
116 | ||
117 | /* set the socket up */ | |
118 | sock = local->socket->sk; | |
119 | sock->sk_user_data = local; | |
120 | sock->sk_data_ready = rxrpc_data_ready; | |
121 | sock->sk_error_report = rxrpc_UDP_error_report; | |
122 | _leave(" = 0"); | |
123 | return 0; | |
124 | ||
125 | error: | |
91cf45f0 | 126 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
127 | local->socket->sk->sk_user_data = NULL; |
128 | sock_release(local->socket); | |
129 | local->socket = NULL; | |
130 | ||
131 | _leave(" = %d", ret); | |
132 | return ret; | |
133 | } | |
134 | ||
135 | /* | |
136 | * create a new local endpoint using the specified UDP address | |
137 | */ | |
138 | struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *srx) | |
139 | { | |
140 | struct rxrpc_local *local; | |
141 | int ret; | |
142 | ||
21454aaa | 143 | _enter("{%d,%u,%pI4+%hu}", |
17926a79 DH |
144 | srx->transport_type, |
145 | srx->transport.family, | |
21454aaa | 146 | &srx->transport.sin.sin_addr, |
17926a79 DH |
147 | ntohs(srx->transport.sin.sin_port)); |
148 | ||
149 | down_write(&rxrpc_local_sem); | |
150 | ||
151 | /* see if we have a suitable local local endpoint already */ | |
152 | read_lock_bh(&rxrpc_local_lock); | |
153 | ||
154 | list_for_each_entry(local, &rxrpc_locals, link) { | |
21454aaa | 155 | _debug("CMP {%d,%u,%pI4+%hu}", |
17926a79 DH |
156 | local->srx.transport_type, |
157 | local->srx.transport.family, | |
21454aaa | 158 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
159 | ntohs(local->srx.transport.sin.sin_port)); |
160 | ||
161 | if (local->srx.transport_type != srx->transport_type || | |
162 | local->srx.transport.family != srx->transport.family) | |
163 | continue; | |
164 | ||
165 | switch (srx->transport.family) { | |
166 | case AF_INET: | |
167 | if (local->srx.transport.sin.sin_port != | |
168 | srx->transport.sin.sin_port) | |
169 | continue; | |
170 | if (memcmp(&local->srx.transport.sin.sin_addr, | |
171 | &srx->transport.sin.sin_addr, | |
172 | sizeof(struct in_addr)) != 0) | |
173 | continue; | |
174 | goto found_local; | |
175 | ||
176 | default: | |
177 | BUG(); | |
178 | } | |
179 | } | |
180 | ||
181 | read_unlock_bh(&rxrpc_local_lock); | |
182 | ||
183 | /* we didn't find one, so we need to create one */ | |
184 | local = rxrpc_alloc_local(srx); | |
185 | if (!local) { | |
186 | up_write(&rxrpc_local_sem); | |
187 | return ERR_PTR(-ENOMEM); | |
188 | } | |
189 | ||
190 | ret = rxrpc_create_local(local); | |
191 | if (ret < 0) { | |
192 | up_write(&rxrpc_local_sem); | |
193 | kfree(local); | |
194 | _leave(" = %d", ret); | |
195 | return ERR_PTR(ret); | |
196 | } | |
197 | ||
198 | up_write(&rxrpc_local_sem); | |
199 | ||
21454aaa | 200 | _net("LOCAL new %d {%d,%u,%pI4+%hu}", |
17926a79 DH |
201 | local->debug_id, |
202 | local->srx.transport_type, | |
203 | local->srx.transport.family, | |
21454aaa | 204 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
205 | ntohs(local->srx.transport.sin.sin_port)); |
206 | ||
207 | _leave(" = %p [new]", local); | |
208 | return local; | |
209 | ||
210 | found_local: | |
211 | rxrpc_get_local(local); | |
212 | read_unlock_bh(&rxrpc_local_lock); | |
213 | up_write(&rxrpc_local_sem); | |
214 | ||
21454aaa | 215 | _net("LOCAL old %d {%d,%u,%pI4+%hu}", |
17926a79 DH |
216 | local->debug_id, |
217 | local->srx.transport_type, | |
218 | local->srx.transport.family, | |
21454aaa | 219 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
220 | ntohs(local->srx.transport.sin.sin_port)); |
221 | ||
222 | _leave(" = %p [reuse]", local); | |
223 | return local; | |
224 | } | |
225 | ||
226 | /* | |
227 | * release a local endpoint | |
228 | */ | |
229 | void rxrpc_put_local(struct rxrpc_local *local) | |
230 | { | |
231 | _enter("%p{u=%d}", local, atomic_read(&local->usage)); | |
232 | ||
233 | ASSERTCMP(atomic_read(&local->usage), >, 0); | |
234 | ||
235 | /* to prevent a race, the decrement and the dequeue must be effectively | |
236 | * atomic */ | |
237 | write_lock_bh(&rxrpc_local_lock); | |
238 | if (unlikely(atomic_dec_and_test(&local->usage))) { | |
239 | _debug("destroy local"); | |
651350d1 | 240 | rxrpc_queue_work(&local->destroyer); |
17926a79 DH |
241 | } |
242 | write_unlock_bh(&rxrpc_local_lock); | |
243 | _leave(""); | |
244 | } | |
245 | ||
246 | /* | |
247 | * destroy a local endpoint | |
248 | */ | |
249 | static void rxrpc_destroy_local(struct work_struct *work) | |
250 | { | |
251 | struct rxrpc_local *local = | |
252 | container_of(work, struct rxrpc_local, destroyer); | |
253 | ||
254 | _enter("%p{%d}", local, atomic_read(&local->usage)); | |
255 | ||
256 | down_write(&rxrpc_local_sem); | |
257 | ||
258 | write_lock_bh(&rxrpc_local_lock); | |
259 | if (atomic_read(&local->usage) > 0) { | |
260 | write_unlock_bh(&rxrpc_local_lock); | |
261 | up_read(&rxrpc_local_sem); | |
262 | _leave(" [resurrected]"); | |
263 | return; | |
264 | } | |
265 | ||
266 | list_del(&local->link); | |
267 | local->socket->sk->sk_user_data = NULL; | |
268 | write_unlock_bh(&rxrpc_local_lock); | |
269 | ||
270 | downgrade_write(&rxrpc_local_sem); | |
271 | ||
272 | ASSERT(list_empty(&local->services)); | |
273 | ASSERT(!work_pending(&local->acceptor)); | |
274 | ASSERT(!work_pending(&local->rejecter)); | |
44ba0698 | 275 | ASSERT(!work_pending(&local->event_processor)); |
17926a79 DH |
276 | |
277 | /* finish cleaning up the local descriptor */ | |
278 | rxrpc_purge_queue(&local->accept_queue); | |
279 | rxrpc_purge_queue(&local->reject_queue); | |
44ba0698 | 280 | rxrpc_purge_queue(&local->event_queue); |
91cf45f0 | 281 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
282 | sock_release(local->socket); |
283 | ||
284 | up_read(&rxrpc_local_sem); | |
285 | ||
286 | _net("DESTROY LOCAL %d", local->debug_id); | |
287 | kfree(local); | |
288 | ||
289 | if (list_empty(&rxrpc_locals)) | |
290 | wake_up_all(&rxrpc_local_wq); | |
291 | ||
292 | _leave(""); | |
293 | } | |
294 | ||
295 | /* | |
296 | * preemptively destroy all local local endpoint rather than waiting for | |
297 | * them to be destroyed | |
298 | */ | |
299 | void __exit rxrpc_destroy_all_locals(void) | |
300 | { | |
301 | DECLARE_WAITQUEUE(myself,current); | |
302 | ||
303 | _enter(""); | |
304 | ||
305 | /* we simply have to wait for them to go away */ | |
306 | if (!list_empty(&rxrpc_locals)) { | |
307 | set_current_state(TASK_UNINTERRUPTIBLE); | |
308 | add_wait_queue(&rxrpc_local_wq, &myself); | |
309 | ||
310 | while (!list_empty(&rxrpc_locals)) { | |
311 | schedule(); | |
312 | set_current_state(TASK_UNINTERRUPTIBLE); | |
313 | } | |
314 | ||
315 | remove_wait_queue(&rxrpc_local_wq, &myself); | |
316 | set_current_state(TASK_RUNNING); | |
317 | } | |
318 | ||
319 | _leave(""); | |
320 | } | |
44ba0698 DH |
321 | |
322 | /* | |
323 | * Reply to a version request | |
324 | */ | |
325 | static void rxrpc_send_version_request(struct rxrpc_local *local, | |
326 | struct rxrpc_header *hdr, | |
327 | struct sk_buff *skb) | |
328 | { | |
329 | struct sockaddr_in sin; | |
330 | struct msghdr msg; | |
331 | struct kvec iov[2]; | |
332 | size_t len; | |
333 | int ret; | |
334 | ||
335 | _enter(""); | |
336 | ||
337 | sin.sin_family = AF_INET; | |
338 | sin.sin_port = udp_hdr(skb)->source; | |
339 | sin.sin_addr.s_addr = ip_hdr(skb)->saddr; | |
340 | ||
341 | msg.msg_name = &sin; | |
342 | msg.msg_namelen = sizeof(sin); | |
343 | msg.msg_control = NULL; | |
344 | msg.msg_controllen = 0; | |
345 | msg.msg_flags = 0; | |
346 | ||
347 | hdr->seq = 0; | |
348 | hdr->serial = 0; | |
349 | hdr->type = RXRPC_PACKET_TYPE_VERSION; | |
350 | hdr->flags = RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED); | |
351 | hdr->userStatus = 0; | |
352 | hdr->_rsvd = 0; | |
353 | ||
354 | iov[0].iov_base = hdr; | |
355 | iov[0].iov_len = sizeof(*hdr); | |
356 | iov[1].iov_base = (char *)rxrpc_version_string; | |
357 | iov[1].iov_len = sizeof(rxrpc_version_string); | |
358 | ||
359 | len = iov[0].iov_len + iov[1].iov_len; | |
360 | ||
361 | _proto("Tx VERSION (reply)"); | |
362 | ||
363 | ret = kernel_sendmsg(local->socket, &msg, iov, 2, len); | |
364 | if (ret < 0) | |
365 | _debug("sendmsg failed: %d", ret); | |
366 | ||
367 | _leave(""); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Process event packets targetted at a local endpoint. | |
372 | */ | |
373 | static void rxrpc_process_local_events(struct work_struct *work) | |
374 | { | |
375 | struct rxrpc_local *local = container_of(work, struct rxrpc_local, event_processor); | |
376 | struct sk_buff *skb; | |
377 | char v; | |
378 | ||
379 | _enter(""); | |
380 | ||
381 | atomic_inc(&local->usage); | |
382 | ||
383 | while ((skb = skb_dequeue(&local->event_queue))) { | |
384 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
385 | ||
386 | kdebug("{%d},{%u}", local->debug_id, sp->hdr.type); | |
387 | ||
388 | switch (sp->hdr.type) { | |
389 | case RXRPC_PACKET_TYPE_VERSION: | |
390 | if (skb_copy_bits(skb, 0, &v, 1) < 0) | |
391 | return; | |
392 | _proto("Rx VERSION { %02x }", v); | |
393 | if (v == 0) | |
394 | rxrpc_send_version_request(local, &sp->hdr, skb); | |
395 | break; | |
396 | ||
397 | default: | |
398 | /* Just ignore anything we don't understand */ | |
399 | break; | |
400 | } | |
401 | ||
402 | rxrpc_put_local(local); | |
403 | rxrpc_free_skb(skb); | |
404 | } | |
405 | ||
406 | rxrpc_put_local(local); | |
407 | _leave(""); | |
408 | } |