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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 | |
17926a79 | 28 | /* |
4f95dd78 DH |
29 | * Compare a local to an address. Return -ve, 0 or +ve to indicate less than, |
30 | * same or greater than. | |
31 | * | |
32 | * We explicitly don't compare the RxRPC service ID as we want to reject | |
33 | * conflicting uses by differing services. Further, we don't want to share | |
34 | * addresses with different options (IPv6), so we don't compare those bits | |
35 | * either. | |
17926a79 | 36 | */ |
4f95dd78 DH |
37 | static long rxrpc_local_cmp_key(const struct rxrpc_local *local, |
38 | const struct sockaddr_rxrpc *srx) | |
39 | { | |
40 | long diff; | |
41 | ||
42 | diff = ((local->srx.transport_type - srx->transport_type) ?: | |
43 | (local->srx.transport_len - srx->transport_len) ?: | |
44 | (local->srx.transport.family - srx->transport.family)); | |
45 | if (diff != 0) | |
46 | return diff; | |
47 | ||
48 | switch (srx->transport.family) { | |
49 | case AF_INET: | |
50 | /* If the choice of UDP port is left up to the transport, then | |
51 | * the endpoint record doesn't match. | |
52 | */ | |
53 | return ((u16 __force)local->srx.transport.sin.sin_port - | |
54 | (u16 __force)srx->transport.sin.sin_port) ?: | |
55 | memcmp(&local->srx.transport.sin.sin_addr, | |
56 | &srx->transport.sin.sin_addr, | |
57 | sizeof(struct in_addr)); | |
d1912747 | 58 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
59 | case AF_INET6: |
60 | /* If the choice of UDP6 port is left up to the transport, then | |
61 | * the endpoint record doesn't match. | |
62 | */ | |
63 | return ((u16 __force)local->srx.transport.sin6.sin6_port - | |
64 | (u16 __force)srx->transport.sin6.sin6_port) ?: | |
65 | memcmp(&local->srx.transport.sin6.sin6_addr, | |
66 | &srx->transport.sin6.sin6_addr, | |
67 | sizeof(struct in6_addr)); | |
d1912747 | 68 | #endif |
4f95dd78 DH |
69 | default: |
70 | BUG(); | |
71 | } | |
72 | } | |
73 | ||
74 | /* | |
75 | * Allocate a new local endpoint. | |
76 | */ | |
2baec2c3 DH |
77 | static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, |
78 | const struct sockaddr_rxrpc *srx) | |
17926a79 DH |
79 | { |
80 | struct rxrpc_local *local; | |
81 | ||
82 | local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); | |
83 | if (local) { | |
4f95dd78 | 84 | atomic_set(&local->usage, 1); |
2baec2c3 | 85 | local->rxnet = rxnet; |
17926a79 | 86 | INIT_LIST_HEAD(&local->link); |
4f95dd78 | 87 | INIT_WORK(&local->processor, rxrpc_local_processor); |
17926a79 | 88 | init_rwsem(&local->defrag_sem); |
17926a79 | 89 | skb_queue_head_init(&local->reject_queue); |
44ba0698 | 90 | skb_queue_head_init(&local->event_queue); |
999b69f8 DH |
91 | local->client_conns = RB_ROOT; |
92 | spin_lock_init(&local->client_conns_lock); | |
17926a79 DH |
93 | spin_lock_init(&local->lock); |
94 | rwlock_init(&local->services_lock); | |
17926a79 DH |
95 | local->debug_id = atomic_inc_return(&rxrpc_debug_id); |
96 | memcpy(&local->srx, srx, sizeof(*srx)); | |
28036f44 | 97 | local->srx.srx_service = 0; |
17926a79 DH |
98 | } |
99 | ||
100 | _leave(" = %p", local); | |
101 | return local; | |
102 | } | |
103 | ||
104 | /* | |
105 | * create the local socket | |
4f95dd78 | 106 | * - must be called with rxrpc_local_mutex locked |
17926a79 | 107 | */ |
2baec2c3 | 108 | static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net) |
17926a79 DH |
109 | { |
110 | struct sock *sock; | |
111 | int ret, opt; | |
112 | ||
75b54cb5 DH |
113 | _enter("%p{%d,%d}", |
114 | local, local->srx.transport_type, local->srx.transport.family); | |
17926a79 DH |
115 | |
116 | /* create a socket to represent the local endpoint */ | |
2baec2c3 | 117 | ret = sock_create_kern(net, local->srx.transport.family, |
aaa31cbc | 118 | local->srx.transport_type, 0, &local->socket); |
17926a79 DH |
119 | if (ret < 0) { |
120 | _leave(" = %d [socket]", ret); | |
121 | return ret; | |
122 | } | |
123 | ||
124 | /* if a local address was supplied then bind it */ | |
125 | if (local->srx.transport_len > sizeof(sa_family_t)) { | |
126 | _debug("bind"); | |
127 | ret = kernel_bind(local->socket, | |
4f95dd78 | 128 | (struct sockaddr *)&local->srx.transport, |
17926a79 DH |
129 | local->srx.transport_len); |
130 | if (ret < 0) { | |
4f95dd78 | 131 | _debug("bind failed %d", ret); |
17926a79 DH |
132 | goto error; |
133 | } | |
134 | } | |
135 | ||
c7dc828f | 136 | switch (local->srx.transport.family) { |
9fff0211 DH |
137 | case AF_INET6: |
138 | /* we want to receive ICMPv6 errors */ | |
c7dc828f | 139 | opt = 1; |
9fff0211 | 140 | ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR, |
c7dc828f DH |
141 | (char *) &opt, sizeof(opt)); |
142 | if (ret < 0) { | |
143 | _debug("setsockopt failed"); | |
144 | goto error; | |
145 | } | |
17926a79 | 146 | |
c7dc828f | 147 | /* we want to set the don't fragment bit */ |
9fff0211 DH |
148 | opt = IPV6_PMTUDISC_DO; |
149 | ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_MTU_DISCOVER, | |
c7dc828f DH |
150 | (char *) &opt, sizeof(opt)); |
151 | if (ret < 0) { | |
152 | _debug("setsockopt failed"); | |
153 | goto error; | |
154 | } | |
c7dc828f | 155 | |
9fff0211 DH |
156 | /* Fall through and set IPv4 options too otherwise we don't get |
157 | * errors from IPv4 packets sent through the IPv6 socket. | |
158 | */ | |
159 | ||
160 | case AF_INET: | |
c7dc828f DH |
161 | /* we want to receive ICMP errors */ |
162 | opt = 1; | |
9fff0211 | 163 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, |
c7dc828f DH |
164 | (char *) &opt, sizeof(opt)); |
165 | if (ret < 0) { | |
166 | _debug("setsockopt failed"); | |
167 | goto error; | |
168 | } | |
169 | ||
170 | /* we want to set the don't fragment bit */ | |
9fff0211 DH |
171 | opt = IP_PMTUDISC_DO; |
172 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
c7dc828f DH |
173 | (char *) &opt, sizeof(opt)); |
174 | if (ret < 0) { | |
175 | _debug("setsockopt failed"); | |
176 | goto error; | |
177 | } | |
178 | break; | |
179 | ||
180 | default: | |
181 | BUG(); | |
17926a79 DH |
182 | } |
183 | ||
17926a79 DH |
184 | /* set the socket up */ |
185 | sock = local->socket->sk; | |
186 | sock->sk_user_data = local; | |
187 | sock->sk_data_ready = rxrpc_data_ready; | |
abe89ef0 | 188 | sock->sk_error_report = rxrpc_error_report; |
17926a79 DH |
189 | _leave(" = 0"); |
190 | return 0; | |
191 | ||
192 | error: | |
91cf45f0 | 193 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
194 | local->socket->sk->sk_user_data = NULL; |
195 | sock_release(local->socket); | |
196 | local->socket = NULL; | |
197 | ||
198 | _leave(" = %d", ret); | |
199 | return ret; | |
200 | } | |
201 | ||
202 | /* | |
4f95dd78 | 203 | * Look up or create a new local endpoint using the specified local address. |
17926a79 | 204 | */ |
2baec2c3 DH |
205 | struct rxrpc_local *rxrpc_lookup_local(struct net *net, |
206 | const struct sockaddr_rxrpc *srx) | |
17926a79 DH |
207 | { |
208 | struct rxrpc_local *local; | |
2baec2c3 | 209 | struct rxrpc_net *rxnet = rxrpc_net(net); |
4f95dd78 DH |
210 | struct list_head *cursor; |
211 | const char *age; | |
212 | long diff; | |
17926a79 DH |
213 | int ret; |
214 | ||
75b54cb5 DH |
215 | _enter("{%d,%d,%pISp}", |
216 | srx->transport_type, srx->transport.family, &srx->transport); | |
17926a79 | 217 | |
2baec2c3 | 218 | mutex_lock(&rxnet->local_mutex); |
17926a79 | 219 | |
2baec2c3 DH |
220 | for (cursor = rxnet->local_endpoints.next; |
221 | cursor != &rxnet->local_endpoints; | |
4f95dd78 DH |
222 | cursor = cursor->next) { |
223 | local = list_entry(cursor, struct rxrpc_local, link); | |
17926a79 | 224 | |
4f95dd78 DH |
225 | diff = rxrpc_local_cmp_key(local, srx); |
226 | if (diff < 0) | |
17926a79 | 227 | continue; |
4f95dd78 DH |
228 | if (diff > 0) |
229 | break; | |
230 | ||
231 | /* Services aren't allowed to share transport sockets, so | |
232 | * reject that here. It is possible that the object is dying - | |
233 | * but it may also still have the local transport address that | |
234 | * we want bound. | |
235 | */ | |
236 | if (srx->srx_service) { | |
237 | local = NULL; | |
238 | goto addr_in_use; | |
239 | } | |
17926a79 | 240 | |
4f95dd78 DH |
241 | /* Found a match. We replace a dying object. Attempting to |
242 | * bind the transport socket may still fail if we're attempting | |
243 | * to use a local address that the dying object is still using. | |
244 | */ | |
5627cc8b | 245 | if (!rxrpc_get_local_maybe(local)) { |
4f95dd78 DH |
246 | cursor = cursor->next; |
247 | list_del_init(&local->link); | |
248 | break; | |
17926a79 | 249 | } |
17926a79 | 250 | |
4f95dd78 DH |
251 | age = "old"; |
252 | goto found; | |
253 | } | |
17926a79 | 254 | |
2baec2c3 | 255 | local = rxrpc_alloc_local(rxnet, srx); |
4f95dd78 DH |
256 | if (!local) |
257 | goto nomem; | |
17926a79 | 258 | |
2baec2c3 | 259 | ret = rxrpc_open_socket(local, net); |
4f95dd78 DH |
260 | if (ret < 0) |
261 | goto sock_error; | |
262 | ||
263 | list_add_tail(&local->link, cursor); | |
264 | age = "new"; | |
17926a79 | 265 | |
4f95dd78 | 266 | found: |
2baec2c3 | 267 | mutex_unlock(&rxnet->local_mutex); |
17926a79 | 268 | |
75b54cb5 DH |
269 | _net("LOCAL %s %d {%pISp}", |
270 | age, local->debug_id, &local->srx.transport); | |
17926a79 | 271 | |
4f95dd78 | 272 | _leave(" = %p", local); |
17926a79 DH |
273 | return local; |
274 | ||
4f95dd78 DH |
275 | nomem: |
276 | ret = -ENOMEM; | |
277 | sock_error: | |
2baec2c3 | 278 | mutex_unlock(&rxnet->local_mutex); |
4f95dd78 DH |
279 | kfree(local); |
280 | _leave(" = %d", ret); | |
281 | return ERR_PTR(ret); | |
17926a79 | 282 | |
4f95dd78 | 283 | addr_in_use: |
2baec2c3 | 284 | mutex_unlock(&rxnet->local_mutex); |
4f95dd78 DH |
285 | _leave(" = -EADDRINUSE"); |
286 | return ERR_PTR(-EADDRINUSE); | |
287 | } | |
17926a79 | 288 | |
4f95dd78 DH |
289 | /* |
290 | * A local endpoint reached its end of life. | |
291 | */ | |
292 | void __rxrpc_put_local(struct rxrpc_local *local) | |
293 | { | |
294 | _enter("%d", local->debug_id); | |
295 | rxrpc_queue_work(&local->processor); | |
17926a79 DH |
296 | } |
297 | ||
298 | /* | |
4f95dd78 DH |
299 | * Destroy a local endpoint's socket and then hand the record to RCU to dispose |
300 | * of. | |
301 | * | |
302 | * Closing the socket cannot be done from bottom half context or RCU callback | |
303 | * context because it might sleep. | |
17926a79 | 304 | */ |
4f95dd78 | 305 | static void rxrpc_local_destroyer(struct rxrpc_local *local) |
17926a79 | 306 | { |
4f95dd78 | 307 | struct socket *socket = local->socket; |
2baec2c3 | 308 | struct rxrpc_net *rxnet = local->rxnet; |
17926a79 | 309 | |
4f95dd78 | 310 | _enter("%d", local->debug_id); |
17926a79 | 311 | |
4f95dd78 DH |
312 | /* We can get a race between an incoming call packet queueing the |
313 | * processor again and the work processor starting the destruction | |
314 | * process which will shut down the UDP socket. | |
315 | */ | |
316 | if (local->dead) { | |
317 | _leave(" [already dead]"); | |
318 | return; | |
17926a79 | 319 | } |
4f95dd78 DH |
320 | local->dead = true; |
321 | ||
2baec2c3 | 322 | mutex_lock(&rxnet->local_mutex); |
4f95dd78 | 323 | list_del_init(&local->link); |
2baec2c3 | 324 | mutex_unlock(&rxnet->local_mutex); |
4f95dd78 | 325 | |
999b69f8 | 326 | ASSERT(RB_EMPTY_ROOT(&local->client_conns)); |
1e9e5c95 | 327 | ASSERT(!local->service); |
4f95dd78 DH |
328 | |
329 | if (socket) { | |
330 | local->socket = NULL; | |
331 | kernel_sock_shutdown(socket, SHUT_RDWR); | |
332 | socket->sk->sk_user_data = NULL; | |
333 | sock_release(socket); | |
334 | } | |
335 | ||
336 | /* At this point, there should be no more packets coming in to the | |
337 | * local endpoint. | |
338 | */ | |
4f95dd78 DH |
339 | rxrpc_purge_queue(&local->reject_queue); |
340 | rxrpc_purge_queue(&local->event_queue); | |
341 | ||
342 | _debug("rcu local %d", local->debug_id); | |
343 | call_rcu(&local->rcu, rxrpc_local_rcu); | |
17926a79 DH |
344 | } |
345 | ||
346 | /* | |
4f95dd78 | 347 | * Process events on an endpoint |
17926a79 | 348 | */ |
4f95dd78 | 349 | static void rxrpc_local_processor(struct work_struct *work) |
17926a79 DH |
350 | { |
351 | struct rxrpc_local *local = | |
4f95dd78 DH |
352 | container_of(work, struct rxrpc_local, processor); |
353 | bool again; | |
17926a79 | 354 | |
4f95dd78 | 355 | _enter("%d", local->debug_id); |
17926a79 | 356 | |
4f95dd78 DH |
357 | do { |
358 | again = false; | |
359 | if (atomic_read(&local->usage) == 0) | |
360 | return rxrpc_local_destroyer(local); | |
17926a79 | 361 | |
4f95dd78 DH |
362 | if (!skb_queue_empty(&local->reject_queue)) { |
363 | rxrpc_reject_packets(local); | |
364 | again = true; | |
365 | } | |
17926a79 | 366 | |
4f95dd78 DH |
367 | if (!skb_queue_empty(&local->event_queue)) { |
368 | rxrpc_process_local_events(local); | |
369 | again = true; | |
370 | } | |
371 | } while (again); | |
372 | } | |
17926a79 | 373 | |
4f95dd78 DH |
374 | /* |
375 | * Destroy a local endpoint after the RCU grace period expires. | |
376 | */ | |
377 | static void rxrpc_local_rcu(struct rcu_head *rcu) | |
378 | { | |
379 | struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); | |
17926a79 | 380 | |
4f95dd78 | 381 | _enter("%d", local->debug_id); |
17926a79 | 382 | |
4f95dd78 | 383 | ASSERT(!work_pending(&local->processor)); |
17926a79 DH |
384 | |
385 | _net("DESTROY LOCAL %d", local->debug_id); | |
386 | kfree(local); | |
17926a79 DH |
387 | _leave(""); |
388 | } | |
389 | ||
390 | /* | |
4f95dd78 | 391 | * Verify the local endpoint list is empty by this point. |
17926a79 | 392 | */ |
2baec2c3 | 393 | void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet) |
17926a79 | 394 | { |
4f95dd78 | 395 | struct rxrpc_local *local; |
17926a79 DH |
396 | |
397 | _enter(""); | |
398 | ||
dee46364 | 399 | flush_workqueue(rxrpc_workqueue); |
17926a79 | 400 | |
2baec2c3 DH |
401 | if (!list_empty(&rxnet->local_endpoints)) { |
402 | mutex_lock(&rxnet->local_mutex); | |
403 | list_for_each_entry(local, &rxnet->local_endpoints, link) { | |
dee46364 DH |
404 | pr_err("AF_RXRPC: Leaked local %p {%d}\n", |
405 | local, atomic_read(&local->usage)); | |
406 | } | |
2baec2c3 | 407 | mutex_unlock(&rxnet->local_mutex); |
dee46364 | 408 | BUG(); |
17926a79 | 409 | } |
17926a79 | 410 | } |