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)); | |
75b54cb5 DH |
61 | case AF_INET6: |
62 | /* If the choice of UDP6 port is left up to the transport, then | |
63 | * the endpoint record doesn't match. | |
64 | */ | |
65 | return ((u16 __force)local->srx.transport.sin6.sin6_port - | |
66 | (u16 __force)srx->transport.sin6.sin6_port) ?: | |
67 | memcmp(&local->srx.transport.sin6.sin6_addr, | |
68 | &srx->transport.sin6.sin6_addr, | |
69 | sizeof(struct in6_addr)); | |
4f95dd78 DH |
70 | default: |
71 | BUG(); | |
72 | } | |
73 | } | |
74 | ||
75 | /* | |
76 | * Allocate a new local endpoint. | |
77 | */ | |
78 | static struct rxrpc_local *rxrpc_alloc_local(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); |
17926a79 | 85 | INIT_LIST_HEAD(&local->link); |
4f95dd78 | 86 | INIT_WORK(&local->processor, rxrpc_local_processor); |
de8d6c74 | 87 | INIT_HLIST_HEAD(&local->services); |
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)); | |
97 | } | |
98 | ||
99 | _leave(" = %p", local); | |
100 | return local; | |
101 | } | |
102 | ||
103 | /* | |
104 | * create the local socket | |
4f95dd78 | 105 | * - must be called with rxrpc_local_mutex locked |
17926a79 | 106 | */ |
4f95dd78 | 107 | static int rxrpc_open_socket(struct rxrpc_local *local) |
17926a79 DH |
108 | { |
109 | struct sock *sock; | |
110 | int ret, opt; | |
111 | ||
75b54cb5 DH |
112 | _enter("%p{%d,%d}", |
113 | local, local->srx.transport_type, local->srx.transport.family); | |
17926a79 DH |
114 | |
115 | /* create a socket to represent the local endpoint */ | |
aaa31cbc DH |
116 | ret = sock_create_kern(&init_net, local->srx.transport.family, |
117 | local->srx.transport_type, 0, &local->socket); | |
17926a79 DH |
118 | if (ret < 0) { |
119 | _leave(" = %d [socket]", ret); | |
120 | return ret; | |
121 | } | |
122 | ||
123 | /* if a local address was supplied then bind it */ | |
124 | if (local->srx.transport_len > sizeof(sa_family_t)) { | |
125 | _debug("bind"); | |
126 | ret = kernel_bind(local->socket, | |
4f95dd78 | 127 | (struct sockaddr *)&local->srx.transport, |
17926a79 DH |
128 | local->srx.transport_len); |
129 | if (ret < 0) { | |
4f95dd78 | 130 | _debug("bind failed %d", ret); |
17926a79 DH |
131 | goto error; |
132 | } | |
133 | } | |
134 | ||
135 | /* we want to receive ICMP errors */ | |
136 | opt = 1; | |
137 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, | |
138 | (char *) &opt, sizeof(opt)); | |
139 | if (ret < 0) { | |
140 | _debug("setsockopt failed"); | |
141 | goto error; | |
142 | } | |
143 | ||
144 | /* we want to set the don't fragment bit */ | |
145 | opt = IP_PMTUDISC_DO; | |
146 | ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, | |
147 | (char *) &opt, sizeof(opt)); | |
148 | if (ret < 0) { | |
149 | _debug("setsockopt failed"); | |
150 | goto error; | |
151 | } | |
152 | ||
17926a79 DH |
153 | /* set the socket up */ |
154 | sock = local->socket->sk; | |
155 | sock->sk_user_data = local; | |
156 | sock->sk_data_ready = rxrpc_data_ready; | |
abe89ef0 | 157 | sock->sk_error_report = rxrpc_error_report; |
17926a79 DH |
158 | _leave(" = 0"); |
159 | return 0; | |
160 | ||
161 | error: | |
91cf45f0 | 162 | kernel_sock_shutdown(local->socket, SHUT_RDWR); |
17926a79 DH |
163 | local->socket->sk->sk_user_data = NULL; |
164 | sock_release(local->socket); | |
165 | local->socket = NULL; | |
166 | ||
167 | _leave(" = %d", ret); | |
168 | return ret; | |
169 | } | |
170 | ||
171 | /* | |
4f95dd78 | 172 | * Look up or create a new local endpoint using the specified local address. |
17926a79 | 173 | */ |
4f95dd78 | 174 | struct rxrpc_local *rxrpc_lookup_local(const struct sockaddr_rxrpc *srx) |
17926a79 DH |
175 | { |
176 | struct rxrpc_local *local; | |
4f95dd78 DH |
177 | struct list_head *cursor; |
178 | const char *age; | |
179 | long diff; | |
17926a79 DH |
180 | int ret; |
181 | ||
75b54cb5 DH |
182 | _enter("{%d,%d,%pISp}", |
183 | srx->transport_type, srx->transport.family, &srx->transport); | |
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 | |
75b54cb5 DH |
236 | _net("LOCAL %s %d {%pISp}", |
237 | age, local->debug_id, &local->srx.transport); | |
17926a79 | 238 | |
4f95dd78 | 239 | _leave(" = %p", local); |
17926a79 DH |
240 | return local; |
241 | ||
4f95dd78 DH |
242 | nomem: |
243 | ret = -ENOMEM; | |
244 | sock_error: | |
245 | mutex_unlock(&rxrpc_local_mutex); | |
246 | kfree(local); | |
247 | _leave(" = %d", ret); | |
248 | return ERR_PTR(ret); | |
17926a79 | 249 | |
4f95dd78 DH |
250 | addr_in_use: |
251 | mutex_unlock(&rxrpc_local_mutex); | |
252 | _leave(" = -EADDRINUSE"); | |
253 | return ERR_PTR(-EADDRINUSE); | |
254 | } | |
17926a79 | 255 | |
4f95dd78 DH |
256 | /* |
257 | * A local endpoint reached its end of life. | |
258 | */ | |
259 | void __rxrpc_put_local(struct rxrpc_local *local) | |
260 | { | |
261 | _enter("%d", local->debug_id); | |
262 | rxrpc_queue_work(&local->processor); | |
17926a79 DH |
263 | } |
264 | ||
265 | /* | |
4f95dd78 DH |
266 | * Destroy a local endpoint's socket and then hand the record to RCU to dispose |
267 | * of. | |
268 | * | |
269 | * Closing the socket cannot be done from bottom half context or RCU callback | |
270 | * context because it might sleep. | |
17926a79 | 271 | */ |
4f95dd78 | 272 | static void rxrpc_local_destroyer(struct rxrpc_local *local) |
17926a79 | 273 | { |
4f95dd78 | 274 | struct socket *socket = local->socket; |
17926a79 | 275 | |
4f95dd78 | 276 | _enter("%d", local->debug_id); |
17926a79 | 277 | |
4f95dd78 DH |
278 | /* We can get a race between an incoming call packet queueing the |
279 | * processor again and the work processor starting the destruction | |
280 | * process which will shut down the UDP socket. | |
281 | */ | |
282 | if (local->dead) { | |
283 | _leave(" [already dead]"); | |
284 | return; | |
17926a79 | 285 | } |
4f95dd78 DH |
286 | local->dead = true; |
287 | ||
288 | mutex_lock(&rxrpc_local_mutex); | |
289 | list_del_init(&local->link); | |
290 | mutex_unlock(&rxrpc_local_mutex); | |
291 | ||
999b69f8 | 292 | ASSERT(RB_EMPTY_ROOT(&local->client_conns)); |
de8d6c74 | 293 | ASSERT(hlist_empty(&local->services)); |
4f95dd78 DH |
294 | |
295 | if (socket) { | |
296 | local->socket = NULL; | |
297 | kernel_sock_shutdown(socket, SHUT_RDWR); | |
298 | socket->sk->sk_user_data = NULL; | |
299 | sock_release(socket); | |
300 | } | |
301 | ||
302 | /* At this point, there should be no more packets coming in to the | |
303 | * local endpoint. | |
304 | */ | |
4f95dd78 DH |
305 | rxrpc_purge_queue(&local->reject_queue); |
306 | rxrpc_purge_queue(&local->event_queue); | |
307 | ||
308 | _debug("rcu local %d", local->debug_id); | |
309 | call_rcu(&local->rcu, rxrpc_local_rcu); | |
17926a79 DH |
310 | } |
311 | ||
312 | /* | |
4f95dd78 | 313 | * Process events on an endpoint |
17926a79 | 314 | */ |
4f95dd78 | 315 | static void rxrpc_local_processor(struct work_struct *work) |
17926a79 DH |
316 | { |
317 | struct rxrpc_local *local = | |
4f95dd78 DH |
318 | container_of(work, struct rxrpc_local, processor); |
319 | bool again; | |
17926a79 | 320 | |
4f95dd78 | 321 | _enter("%d", local->debug_id); |
17926a79 | 322 | |
4f95dd78 DH |
323 | do { |
324 | again = false; | |
325 | if (atomic_read(&local->usage) == 0) | |
326 | return rxrpc_local_destroyer(local); | |
17926a79 | 327 | |
4f95dd78 DH |
328 | if (!skb_queue_empty(&local->reject_queue)) { |
329 | rxrpc_reject_packets(local); | |
330 | again = true; | |
331 | } | |
17926a79 | 332 | |
4f95dd78 DH |
333 | if (!skb_queue_empty(&local->event_queue)) { |
334 | rxrpc_process_local_events(local); | |
335 | again = true; | |
336 | } | |
337 | } while (again); | |
338 | } | |
17926a79 | 339 | |
4f95dd78 DH |
340 | /* |
341 | * Destroy a local endpoint after the RCU grace period expires. | |
342 | */ | |
343 | static void rxrpc_local_rcu(struct rcu_head *rcu) | |
344 | { | |
345 | struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); | |
17926a79 | 346 | |
4f95dd78 | 347 | _enter("%d", local->debug_id); |
17926a79 | 348 | |
4f95dd78 | 349 | ASSERT(!work_pending(&local->processor)); |
17926a79 DH |
350 | |
351 | _net("DESTROY LOCAL %d", local->debug_id); | |
352 | kfree(local); | |
17926a79 DH |
353 | _leave(""); |
354 | } | |
355 | ||
356 | /* | |
4f95dd78 | 357 | * Verify the local endpoint list is empty by this point. |
17926a79 DH |
358 | */ |
359 | void __exit rxrpc_destroy_all_locals(void) | |
360 | { | |
4f95dd78 | 361 | struct rxrpc_local *local; |
17926a79 DH |
362 | |
363 | _enter(""); | |
364 | ||
dee46364 | 365 | flush_workqueue(rxrpc_workqueue); |
17926a79 | 366 | |
dee46364 DH |
367 | if (!list_empty(&rxrpc_local_endpoints)) { |
368 | mutex_lock(&rxrpc_local_mutex); | |
369 | list_for_each_entry(local, &rxrpc_local_endpoints, link) { | |
370 | pr_err("AF_RXRPC: Leaked local %p {%d}\n", | |
371 | local, atomic_read(&local->usage)); | |
372 | } | |
373 | mutex_unlock(&rxrpc_local_mutex); | |
374 | BUG(); | |
17926a79 | 375 | } |
dee46364 DH |
376 | |
377 | rcu_barrier(); | |
17926a79 | 378 | } |