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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)); | |
d1912747 | 61 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
62 | case AF_INET6: |
63 | /* If the choice of UDP6 port is left up to the transport, then | |
64 | * the endpoint record doesn't match. | |
65 | */ | |
66 | return ((u16 __force)local->srx.transport.sin6.sin6_port - | |
67 | (u16 __force)srx->transport.sin6.sin6_port) ?: | |
68 | memcmp(&local->srx.transport.sin6.sin6_addr, | |
69 | &srx->transport.sin6.sin6_addr, | |
70 | sizeof(struct in6_addr)); | |
d1912747 | 71 | #endif |
4f95dd78 DH |
72 | default: |
73 | BUG(); | |
74 | } | |
75 | } | |
76 | ||
77 | /* | |
78 | * Allocate a new local endpoint. | |
79 | */ | |
80 | static struct rxrpc_local *rxrpc_alloc_local(const struct sockaddr_rxrpc *srx) | |
17926a79 DH |
81 | { |
82 | struct rxrpc_local *local; | |
83 | ||
84 | local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); | |
85 | if (local) { | |
4f95dd78 | 86 | atomic_set(&local->usage, 1); |
17926a79 | 87 | INIT_LIST_HEAD(&local->link); |
4f95dd78 | 88 | INIT_WORK(&local->processor, rxrpc_local_processor); |
17926a79 | 89 | init_rwsem(&local->defrag_sem); |
17926a79 | 90 | skb_queue_head_init(&local->reject_queue); |
44ba0698 | 91 | skb_queue_head_init(&local->event_queue); |
999b69f8 DH |
92 | local->client_conns = RB_ROOT; |
93 | spin_lock_init(&local->client_conns_lock); | |
17926a79 DH |
94 | spin_lock_init(&local->lock); |
95 | rwlock_init(&local->services_lock); | |
17926a79 DH |
96 | local->debug_id = atomic_inc_return(&rxrpc_debug_id); |
97 | memcpy(&local->srx, srx, sizeof(*srx)); | |
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 | */ |
4f95dd78 | 108 | static int rxrpc_open_socket(struct rxrpc_local *local) |
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 */ | |
aaa31cbc DH |
117 | ret = sock_create_kern(&init_net, local->srx.transport.family, |
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 | ||
136 | /* we want to receive ICMP errors */ | |
137 | opt = 1; | |
138 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, | |
139 | (char *) &opt, sizeof(opt)); | |
140 | if (ret < 0) { | |
141 | _debug("setsockopt failed"); | |
142 | goto error; | |
143 | } | |
144 | ||
145 | /* we want to set the don't fragment bit */ | |
146 | opt = IP_PMTUDISC_DO; | |
147 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
148 | (char *) &opt, sizeof(opt)); | |
149 | if (ret < 0) { | |
150 | _debug("setsockopt failed"); | |
151 | goto error; | |
152 | } | |
153 | ||
17926a79 DH |
154 | /* set the socket up */ |
155 | sock = local->socket->sk; | |
156 | sock->sk_user_data = local; | |
157 | sock->sk_data_ready = rxrpc_data_ready; | |
abe89ef0 | 158 | sock->sk_error_report = rxrpc_error_report; |
17926a79 DH |
159 | _leave(" = 0"); |
160 | return 0; | |
161 | ||
162 | error: | |
91cf45f0 | 163 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
164 | local->socket->sk->sk_user_data = NULL; |
165 | sock_release(local->socket); | |
166 | local->socket = NULL; | |
167 | ||
168 | _leave(" = %d", ret); | |
169 | return ret; | |
170 | } | |
171 | ||
172 | /* | |
4f95dd78 | 173 | * Look up or create a new local endpoint using the specified local address. |
17926a79 | 174 | */ |
4f95dd78 | 175 | struct rxrpc_local *rxrpc_lookup_local(const struct sockaddr_rxrpc *srx) |
17926a79 DH |
176 | { |
177 | struct rxrpc_local *local; | |
4f95dd78 DH |
178 | struct list_head *cursor; |
179 | const char *age; | |
180 | long diff; | |
17926a79 DH |
181 | int ret; |
182 | ||
75b54cb5 DH |
183 | _enter("{%d,%d,%pISp}", |
184 | srx->transport_type, srx->transport.family, &srx->transport); | |
17926a79 | 185 | |
4f95dd78 | 186 | mutex_lock(&rxrpc_local_mutex); |
17926a79 | 187 | |
4f95dd78 DH |
188 | for (cursor = rxrpc_local_endpoints.next; |
189 | cursor != &rxrpc_local_endpoints; | |
190 | cursor = cursor->next) { | |
191 | local = list_entry(cursor, struct rxrpc_local, link); | |
17926a79 | 192 | |
4f95dd78 DH |
193 | diff = rxrpc_local_cmp_key(local, srx); |
194 | if (diff < 0) | |
17926a79 | 195 | continue; |
4f95dd78 DH |
196 | if (diff > 0) |
197 | break; | |
198 | ||
199 | /* Services aren't allowed to share transport sockets, so | |
200 | * reject that here. It is possible that the object is dying - | |
201 | * but it may also still have the local transport address that | |
202 | * we want bound. | |
203 | */ | |
204 | if (srx->srx_service) { | |
205 | local = NULL; | |
206 | goto addr_in_use; | |
207 | } | |
17926a79 | 208 | |
4f95dd78 DH |
209 | /* Found a match. We replace a dying object. Attempting to |
210 | * bind the transport socket may still fail if we're attempting | |
211 | * to use a local address that the dying object is still using. | |
212 | */ | |
5627cc8b | 213 | if (!rxrpc_get_local_maybe(local)) { |
4f95dd78 DH |
214 | cursor = cursor->next; |
215 | list_del_init(&local->link); | |
216 | break; | |
17926a79 | 217 | } |
17926a79 | 218 | |
4f95dd78 DH |
219 | age = "old"; |
220 | goto found; | |
221 | } | |
17926a79 | 222 | |
17926a79 | 223 | local = rxrpc_alloc_local(srx); |
4f95dd78 DH |
224 | if (!local) |
225 | goto nomem; | |
17926a79 | 226 | |
4f95dd78 DH |
227 | ret = rxrpc_open_socket(local); |
228 | if (ret < 0) | |
229 | goto sock_error; | |
230 | ||
231 | list_add_tail(&local->link, cursor); | |
232 | age = "new"; | |
17926a79 | 233 | |
4f95dd78 DH |
234 | found: |
235 | mutex_unlock(&rxrpc_local_mutex); | |
17926a79 | 236 | |
75b54cb5 DH |
237 | _net("LOCAL %s %d {%pISp}", |
238 | age, local->debug_id, &local->srx.transport); | |
17926a79 | 239 | |
4f95dd78 | 240 | _leave(" = %p", local); |
17926a79 DH |
241 | return local; |
242 | ||
4f95dd78 DH |
243 | nomem: |
244 | ret = -ENOMEM; | |
245 | sock_error: | |
246 | mutex_unlock(&rxrpc_local_mutex); | |
247 | kfree(local); | |
248 | _leave(" = %d", ret); | |
249 | return ERR_PTR(ret); | |
17926a79 | 250 | |
4f95dd78 DH |
251 | addr_in_use: |
252 | mutex_unlock(&rxrpc_local_mutex); | |
253 | _leave(" = -EADDRINUSE"); | |
254 | return ERR_PTR(-EADDRINUSE); | |
255 | } | |
17926a79 | 256 | |
4f95dd78 DH |
257 | /* |
258 | * A local endpoint reached its end of life. | |
259 | */ | |
260 | void __rxrpc_put_local(struct rxrpc_local *local) | |
261 | { | |
262 | _enter("%d", local->debug_id); | |
263 | rxrpc_queue_work(&local->processor); | |
17926a79 DH |
264 | } |
265 | ||
266 | /* | |
4f95dd78 DH |
267 | * Destroy a local endpoint's socket and then hand the record to RCU to dispose |
268 | * of. | |
269 | * | |
270 | * Closing the socket cannot be done from bottom half context or RCU callback | |
271 | * context because it might sleep. | |
17926a79 | 272 | */ |
4f95dd78 | 273 | static void rxrpc_local_destroyer(struct rxrpc_local *local) |
17926a79 | 274 | { |
4f95dd78 | 275 | struct socket *socket = local->socket; |
17926a79 | 276 | |
4f95dd78 | 277 | _enter("%d", local->debug_id); |
17926a79 | 278 | |
4f95dd78 DH |
279 | /* We can get a race between an incoming call packet queueing the |
280 | * processor again and the work processor starting the destruction | |
281 | * process which will shut down the UDP socket. | |
282 | */ | |
283 | if (local->dead) { | |
284 | _leave(" [already dead]"); | |
285 | return; | |
17926a79 | 286 | } |
4f95dd78 DH |
287 | local->dead = true; |
288 | ||
289 | mutex_lock(&rxrpc_local_mutex); | |
290 | list_del_init(&local->link); | |
291 | mutex_unlock(&rxrpc_local_mutex); | |
292 | ||
999b69f8 | 293 | ASSERT(RB_EMPTY_ROOT(&local->client_conns)); |
1e9e5c95 | 294 | ASSERT(!local->service); |
4f95dd78 DH |
295 | |
296 | if (socket) { | |
297 | local->socket = NULL; | |
298 | kernel_sock_shutdown(socket, SHUT_RDWR); | |
299 | socket->sk->sk_user_data = NULL; | |
300 | sock_release(socket); | |
301 | } | |
302 | ||
303 | /* At this point, there should be no more packets coming in to the | |
304 | * local endpoint. | |
305 | */ | |
4f95dd78 DH |
306 | rxrpc_purge_queue(&local->reject_queue); |
307 | rxrpc_purge_queue(&local->event_queue); | |
308 | ||
309 | _debug("rcu local %d", local->debug_id); | |
310 | call_rcu(&local->rcu, rxrpc_local_rcu); | |
17926a79 DH |
311 | } |
312 | ||
313 | /* | |
4f95dd78 | 314 | * Process events on an endpoint |
17926a79 | 315 | */ |
4f95dd78 | 316 | static void rxrpc_local_processor(struct work_struct *work) |
17926a79 DH |
317 | { |
318 | struct rxrpc_local *local = | |
4f95dd78 DH |
319 | container_of(work, struct rxrpc_local, processor); |
320 | bool again; | |
17926a79 | 321 | |
4f95dd78 | 322 | _enter("%d", local->debug_id); |
17926a79 | 323 | |
4f95dd78 DH |
324 | do { |
325 | again = false; | |
326 | if (atomic_read(&local->usage) == 0) | |
327 | return rxrpc_local_destroyer(local); | |
17926a79 | 328 | |
4f95dd78 DH |
329 | if (!skb_queue_empty(&local->reject_queue)) { |
330 | rxrpc_reject_packets(local); | |
331 | again = true; | |
332 | } | |
17926a79 | 333 | |
4f95dd78 DH |
334 | if (!skb_queue_empty(&local->event_queue)) { |
335 | rxrpc_process_local_events(local); | |
336 | again = true; | |
337 | } | |
338 | } while (again); | |
339 | } | |
17926a79 | 340 | |
4f95dd78 DH |
341 | /* |
342 | * Destroy a local endpoint after the RCU grace period expires. | |
343 | */ | |
344 | static void rxrpc_local_rcu(struct rcu_head *rcu) | |
345 | { | |
346 | struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); | |
17926a79 | 347 | |
4f95dd78 | 348 | _enter("%d", local->debug_id); |
17926a79 | 349 | |
4f95dd78 | 350 | ASSERT(!work_pending(&local->processor)); |
17926a79 DH |
351 | |
352 | _net("DESTROY LOCAL %d", local->debug_id); | |
353 | kfree(local); | |
17926a79 DH |
354 | _leave(""); |
355 | } | |
356 | ||
357 | /* | |
4f95dd78 | 358 | * Verify the local endpoint list is empty by this point. |
17926a79 DH |
359 | */ |
360 | void __exit rxrpc_destroy_all_locals(void) | |
361 | { | |
4f95dd78 | 362 | struct rxrpc_local *local; |
17926a79 DH |
363 | |
364 | _enter(""); | |
365 | ||
dee46364 | 366 | flush_workqueue(rxrpc_workqueue); |
17926a79 | 367 | |
dee46364 DH |
368 | if (!list_empty(&rxrpc_local_endpoints)) { |
369 | mutex_lock(&rxrpc_local_mutex); | |
370 | list_for_each_entry(local, &rxrpc_local_endpoints, link) { | |
371 | pr_err("AF_RXRPC: Leaked local %p {%d}\n", | |
372 | local, atomic_read(&local->usage)); | |
373 | } | |
374 | mutex_unlock(&rxrpc_local_mutex); | |
375 | BUG(); | |
17926a79 | 376 | } |
dee46364 DH |
377 | |
378 | rcu_barrier(); | |
17926a79 | 379 | } |