Commit | Line | Data |
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87563616 | 1 | /* Local endpoint object management |
17926a79 | 2 | * |
4f95dd78 | 3 | * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. |
17926a79 DH |
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> | |
4f95dd78 | 20 | #include <linux/hashtable.h> |
17926a79 DH |
21 | #include <net/sock.h> |
22 | #include <net/af_rxrpc.h> | |
23 | #include "ar-internal.h" | |
24 | ||
4f95dd78 DH |
25 | static void rxrpc_local_processor(struct work_struct *); |
26 | static void rxrpc_local_rcu(struct rcu_head *); | |
17926a79 | 27 | |
4f95dd78 DH |
28 | static DEFINE_MUTEX(rxrpc_local_mutex); |
29 | static LIST_HEAD(rxrpc_local_endpoints); | |
17926a79 DH |
30 | |
31 | /* | |
4f95dd78 DH |
32 | * Compare a local to an address. Return -ve, 0 or +ve to indicate less than, |
33 | * same or greater than. | |
34 | * | |
35 | * We explicitly don't compare the RxRPC service ID as we want to reject | |
36 | * conflicting uses by differing services. Further, we don't want to share | |
37 | * addresses with different options (IPv6), so we don't compare those bits | |
38 | * either. | |
17926a79 | 39 | */ |
4f95dd78 DH |
40 | static long rxrpc_local_cmp_key(const struct rxrpc_local *local, |
41 | const struct sockaddr_rxrpc *srx) | |
42 | { | |
43 | long diff; | |
44 | ||
45 | diff = ((local->srx.transport_type - srx->transport_type) ?: | |
46 | (local->srx.transport_len - srx->transport_len) ?: | |
47 | (local->srx.transport.family - srx->transport.family)); | |
48 | if (diff != 0) | |
49 | return diff; | |
50 | ||
51 | switch (srx->transport.family) { | |
52 | case AF_INET: | |
53 | /* If the choice of UDP port is left up to the transport, then | |
54 | * the endpoint record doesn't match. | |
55 | */ | |
56 | return ((u16 __force)local->srx.transport.sin.sin_port - | |
57 | (u16 __force)srx->transport.sin.sin_port) ?: | |
58 | memcmp(&local->srx.transport.sin.sin_addr, | |
59 | &srx->transport.sin.sin_addr, | |
60 | sizeof(struct in_addr)); | |
61 | default: | |
62 | BUG(); | |
63 | } | |
64 | } | |
65 | ||
66 | /* | |
67 | * Allocate a new local endpoint. | |
68 | */ | |
69 | static struct rxrpc_local *rxrpc_alloc_local(const struct sockaddr_rxrpc *srx) | |
17926a79 DH |
70 | { |
71 | struct rxrpc_local *local; | |
72 | ||
73 | local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); | |
74 | if (local) { | |
4f95dd78 | 75 | atomic_set(&local->usage, 1); |
17926a79 | 76 | INIT_LIST_HEAD(&local->link); |
4f95dd78 | 77 | INIT_WORK(&local->processor, rxrpc_local_processor); |
de8d6c74 | 78 | INIT_HLIST_HEAD(&local->services); |
17926a79 | 79 | init_rwsem(&local->defrag_sem); |
17926a79 | 80 | skb_queue_head_init(&local->reject_queue); |
44ba0698 | 81 | skb_queue_head_init(&local->event_queue); |
999b69f8 DH |
82 | local->client_conns = RB_ROOT; |
83 | spin_lock_init(&local->client_conns_lock); | |
17926a79 DH |
84 | spin_lock_init(&local->lock); |
85 | rwlock_init(&local->services_lock); | |
17926a79 DH |
86 | local->debug_id = atomic_inc_return(&rxrpc_debug_id); |
87 | memcpy(&local->srx, srx, sizeof(*srx)); | |
88 | } | |
89 | ||
90 | _leave(" = %p", local); | |
91 | return local; | |
92 | } | |
93 | ||
94 | /* | |
95 | * create the local socket | |
4f95dd78 | 96 | * - must be called with rxrpc_local_mutex locked |
17926a79 | 97 | */ |
4f95dd78 | 98 | static int rxrpc_open_socket(struct rxrpc_local *local) |
17926a79 DH |
99 | { |
100 | struct sock *sock; | |
101 | int ret, opt; | |
102 | ||
103 | _enter("%p{%d}", local, local->srx.transport_type); | |
104 | ||
105 | /* create a socket to represent the local endpoint */ | |
eeb1bd5c EB |
106 | ret = sock_create_kern(&init_net, PF_INET, local->srx.transport_type, |
107 | IPPROTO_UDP, &local->socket); | |
17926a79 DH |
108 | if (ret < 0) { |
109 | _leave(" = %d [socket]", ret); | |
110 | return ret; | |
111 | } | |
112 | ||
113 | /* if a local address was supplied then bind it */ | |
114 | if (local->srx.transport_len > sizeof(sa_family_t)) { | |
115 | _debug("bind"); | |
116 | ret = kernel_bind(local->socket, | |
4f95dd78 | 117 | (struct sockaddr *)&local->srx.transport, |
17926a79 DH |
118 | local->srx.transport_len); |
119 | if (ret < 0) { | |
4f95dd78 | 120 | _debug("bind failed %d", ret); |
17926a79 DH |
121 | goto error; |
122 | } | |
123 | } | |
124 | ||
125 | /* we want to receive ICMP errors */ | |
126 | opt = 1; | |
127 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, | |
128 | (char *) &opt, sizeof(opt)); | |
129 | if (ret < 0) { | |
130 | _debug("setsockopt failed"); | |
131 | goto error; | |
132 | } | |
133 | ||
134 | /* we want to set the don't fragment bit */ | |
135 | opt = IP_PMTUDISC_DO; | |
136 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
137 | (char *) &opt, sizeof(opt)); | |
138 | if (ret < 0) { | |
139 | _debug("setsockopt failed"); | |
140 | goto error; | |
141 | } | |
142 | ||
17926a79 DH |
143 | /* set the socket up */ |
144 | sock = local->socket->sk; | |
145 | sock->sk_user_data = local; | |
146 | sock->sk_data_ready = rxrpc_data_ready; | |
abe89ef0 | 147 | sock->sk_error_report = rxrpc_error_report; |
17926a79 DH |
148 | _leave(" = 0"); |
149 | return 0; | |
150 | ||
151 | error: | |
91cf45f0 | 152 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
153 | local->socket->sk->sk_user_data = NULL; |
154 | sock_release(local->socket); | |
155 | local->socket = NULL; | |
156 | ||
157 | _leave(" = %d", ret); | |
158 | return ret; | |
159 | } | |
160 | ||
161 | /* | |
4f95dd78 | 162 | * Look up or create a new local endpoint using the specified local address. |
17926a79 | 163 | */ |
4f95dd78 | 164 | struct rxrpc_local *rxrpc_lookup_local(const struct sockaddr_rxrpc *srx) |
17926a79 DH |
165 | { |
166 | struct rxrpc_local *local; | |
4f95dd78 DH |
167 | struct list_head *cursor; |
168 | const char *age; | |
169 | long diff; | |
17926a79 DH |
170 | int ret; |
171 | ||
4f95dd78 DH |
172 | if (srx->transport.family == AF_INET) { |
173 | _enter("{%d,%u,%pI4+%hu}", | |
174 | srx->transport_type, | |
175 | srx->transport.family, | |
176 | &srx->transport.sin.sin_addr, | |
177 | ntohs(srx->transport.sin.sin_port)); | |
178 | } else { | |
179 | _enter("{%d,%u}", | |
180 | srx->transport_type, | |
181 | srx->transport.family); | |
182 | return ERR_PTR(-EAFNOSUPPORT); | |
183 | } | |
17926a79 | 184 | |
4f95dd78 | 185 | mutex_lock(&rxrpc_local_mutex); |
17926a79 | 186 | |
4f95dd78 DH |
187 | for (cursor = rxrpc_local_endpoints.next; |
188 | cursor != &rxrpc_local_endpoints; | |
189 | cursor = cursor->next) { | |
190 | local = list_entry(cursor, struct rxrpc_local, link); | |
17926a79 | 191 | |
4f95dd78 DH |
192 | diff = rxrpc_local_cmp_key(local, srx); |
193 | if (diff < 0) | |
17926a79 | 194 | continue; |
4f95dd78 DH |
195 | if (diff > 0) |
196 | break; | |
197 | ||
198 | /* Services aren't allowed to share transport sockets, so | |
199 | * reject that here. It is possible that the object is dying - | |
200 | * but it may also still have the local transport address that | |
201 | * we want bound. | |
202 | */ | |
203 | if (srx->srx_service) { | |
204 | local = NULL; | |
205 | goto addr_in_use; | |
206 | } | |
17926a79 | 207 | |
4f95dd78 DH |
208 | /* Found a match. We replace a dying object. Attempting to |
209 | * bind the transport socket may still fail if we're attempting | |
210 | * to use a local address that the dying object is still using. | |
211 | */ | |
5627cc8b | 212 | if (!rxrpc_get_local_maybe(local)) { |
4f95dd78 DH |
213 | cursor = cursor->next; |
214 | list_del_init(&local->link); | |
215 | break; | |
17926a79 | 216 | } |
17926a79 | 217 | |
4f95dd78 DH |
218 | age = "old"; |
219 | goto found; | |
220 | } | |
17926a79 | 221 | |
17926a79 | 222 | local = rxrpc_alloc_local(srx); |
4f95dd78 DH |
223 | if (!local) |
224 | goto nomem; | |
17926a79 | 225 | |
4f95dd78 DH |
226 | ret = rxrpc_open_socket(local); |
227 | if (ret < 0) | |
228 | goto sock_error; | |
229 | ||
230 | list_add_tail(&local->link, cursor); | |
231 | age = "new"; | |
17926a79 | 232 | |
4f95dd78 DH |
233 | found: |
234 | mutex_unlock(&rxrpc_local_mutex); | |
17926a79 | 235 | |
4f95dd78 DH |
236 | _net("LOCAL %s %d {%d,%u,%pI4+%hu}", |
237 | age, | |
17926a79 DH |
238 | local->debug_id, |
239 | local->srx.transport_type, | |
240 | local->srx.transport.family, | |
21454aaa | 241 | &local->srx.transport.sin.sin_addr, |
17926a79 DH |
242 | ntohs(local->srx.transport.sin.sin_port)); |
243 | ||
4f95dd78 | 244 | _leave(" = %p", local); |
17926a79 DH |
245 | return local; |
246 | ||
4f95dd78 DH |
247 | nomem: |
248 | ret = -ENOMEM; | |
249 | sock_error: | |
250 | mutex_unlock(&rxrpc_local_mutex); | |
251 | kfree(local); | |
252 | _leave(" = %d", ret); | |
253 | return ERR_PTR(ret); | |
17926a79 | 254 | |
4f95dd78 DH |
255 | addr_in_use: |
256 | mutex_unlock(&rxrpc_local_mutex); | |
257 | _leave(" = -EADDRINUSE"); | |
258 | return ERR_PTR(-EADDRINUSE); | |
259 | } | |
17926a79 | 260 | |
4f95dd78 DH |
261 | /* |
262 | * A local endpoint reached its end of life. | |
263 | */ | |
264 | void __rxrpc_put_local(struct rxrpc_local *local) | |
265 | { | |
266 | _enter("%d", local->debug_id); | |
267 | rxrpc_queue_work(&local->processor); | |
17926a79 DH |
268 | } |
269 | ||
270 | /* | |
4f95dd78 DH |
271 | * Destroy a local endpoint's socket and then hand the record to RCU to dispose |
272 | * of. | |
273 | * | |
274 | * Closing the socket cannot be done from bottom half context or RCU callback | |
275 | * context because it might sleep. | |
17926a79 | 276 | */ |
4f95dd78 | 277 | static void rxrpc_local_destroyer(struct rxrpc_local *local) |
17926a79 | 278 | { |
4f95dd78 | 279 | struct socket *socket = local->socket; |
17926a79 | 280 | |
4f95dd78 | 281 | _enter("%d", local->debug_id); |
17926a79 | 282 | |
4f95dd78 DH |
283 | /* We can get a race between an incoming call packet queueing the |
284 | * processor again and the work processor starting the destruction | |
285 | * process which will shut down the UDP socket. | |
286 | */ | |
287 | if (local->dead) { | |
288 | _leave(" [already dead]"); | |
289 | return; | |
17926a79 | 290 | } |
4f95dd78 DH |
291 | local->dead = true; |
292 | ||
293 | mutex_lock(&rxrpc_local_mutex); | |
294 | list_del_init(&local->link); | |
295 | mutex_unlock(&rxrpc_local_mutex); | |
296 | ||
999b69f8 | 297 | ASSERT(RB_EMPTY_ROOT(&local->client_conns)); |
de8d6c74 | 298 | ASSERT(hlist_empty(&local->services)); |
4f95dd78 DH |
299 | |
300 | if (socket) { | |
301 | local->socket = NULL; | |
302 | kernel_sock_shutdown(socket, SHUT_RDWR); | |
303 | socket->sk->sk_user_data = NULL; | |
304 | sock_release(socket); | |
305 | } | |
306 | ||
307 | /* At this point, there should be no more packets coming in to the | |
308 | * local endpoint. | |
309 | */ | |
4f95dd78 DH |
310 | rxrpc_purge_queue(&local->reject_queue); |
311 | rxrpc_purge_queue(&local->event_queue); | |
312 | ||
313 | _debug("rcu local %d", local->debug_id); | |
314 | call_rcu(&local->rcu, rxrpc_local_rcu); | |
17926a79 DH |
315 | } |
316 | ||
317 | /* | |
4f95dd78 | 318 | * Process events on an endpoint |
17926a79 | 319 | */ |
4f95dd78 | 320 | static void rxrpc_local_processor(struct work_struct *work) |
17926a79 DH |
321 | { |
322 | struct rxrpc_local *local = | |
4f95dd78 DH |
323 | container_of(work, struct rxrpc_local, processor); |
324 | bool again; | |
17926a79 | 325 | |
4f95dd78 | 326 | _enter("%d", local->debug_id); |
17926a79 | 327 | |
4f95dd78 DH |
328 | do { |
329 | again = false; | |
330 | if (atomic_read(&local->usage) == 0) | |
331 | return rxrpc_local_destroyer(local); | |
17926a79 | 332 | |
4f95dd78 DH |
333 | if (!skb_queue_empty(&local->reject_queue)) { |
334 | rxrpc_reject_packets(local); | |
335 | again = true; | |
336 | } | |
17926a79 | 337 | |
4f95dd78 DH |
338 | if (!skb_queue_empty(&local->event_queue)) { |
339 | rxrpc_process_local_events(local); | |
340 | again = true; | |
341 | } | |
342 | } while (again); | |
343 | } | |
17926a79 | 344 | |
4f95dd78 DH |
345 | /* |
346 | * Destroy a local endpoint after the RCU grace period expires. | |
347 | */ | |
348 | static void rxrpc_local_rcu(struct rcu_head *rcu) | |
349 | { | |
350 | struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); | |
17926a79 | 351 | |
4f95dd78 | 352 | _enter("%d", local->debug_id); |
17926a79 | 353 | |
4f95dd78 | 354 | ASSERT(!work_pending(&local->processor)); |
17926a79 DH |
355 | |
356 | _net("DESTROY LOCAL %d", local->debug_id); | |
357 | kfree(local); | |
17926a79 DH |
358 | _leave(""); |
359 | } | |
360 | ||
361 | /* | |
4f95dd78 | 362 | * Verify the local endpoint list is empty by this point. |
17926a79 DH |
363 | */ |
364 | void __exit rxrpc_destroy_all_locals(void) | |
365 | { | |
4f95dd78 | 366 | struct rxrpc_local *local; |
17926a79 DH |
367 | |
368 | _enter(""); | |
369 | ||
dee46364 | 370 | flush_workqueue(rxrpc_workqueue); |
17926a79 | 371 | |
dee46364 DH |
372 | if (!list_empty(&rxrpc_local_endpoints)) { |
373 | mutex_lock(&rxrpc_local_mutex); | |
374 | list_for_each_entry(local, &rxrpc_local_endpoints, link) { | |
375 | pr_err("AF_RXRPC: Leaked local %p {%d}\n", | |
376 | local, atomic_read(&local->usage)); | |
377 | } | |
378 | mutex_unlock(&rxrpc_local_mutex); | |
379 | BUG(); | |
17926a79 | 380 | } |
dee46364 DH |
381 | |
382 | rcu_barrier(); | |
17926a79 | 383 | } |