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17926a79 DH |
1 | /* incoming call handling |
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> | |
15 | #include <linux/errqueue.h> | |
16 | #include <linux/udp.h> | |
17 | #include <linux/in.h> | |
18 | #include <linux/in6.h> | |
19 | #include <linux/icmp.h> | |
20 | #include <net/sock.h> | |
21 | #include <net/af_rxrpc.h> | |
22 | #include <net/ip.h> | |
23 | #include "ar-internal.h" | |
24 | ||
25 | /* | |
26 | * generate a connection-level abort | |
27 | */ | |
28 | static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx, | |
29 | struct rxrpc_header *hdr) | |
30 | { | |
31 | struct msghdr msg; | |
32 | struct kvec iov[1]; | |
33 | size_t len; | |
34 | int ret; | |
35 | ||
36 | _enter("%d,,", local->debug_id); | |
37 | ||
38 | msg.msg_name = &srx->transport.sin; | |
39 | msg.msg_namelen = sizeof(srx->transport.sin); | |
40 | msg.msg_control = NULL; | |
41 | msg.msg_controllen = 0; | |
42 | msg.msg_flags = 0; | |
43 | ||
44 | hdr->seq = 0; | |
45 | hdr->type = RXRPC_PACKET_TYPE_BUSY; | |
46 | hdr->flags = 0; | |
47 | hdr->userStatus = 0; | |
48 | hdr->_rsvd = 0; | |
49 | ||
50 | iov[0].iov_base = hdr; | |
51 | iov[0].iov_len = sizeof(*hdr); | |
52 | ||
53 | len = iov[0].iov_len; | |
54 | ||
55 | hdr->serial = htonl(1); | |
56 | _proto("Tx BUSY %%%u", ntohl(hdr->serial)); | |
57 | ||
58 | ret = kernel_sendmsg(local->socket, &msg, iov, 1, len); | |
59 | if (ret < 0) { | |
60 | _leave(" = -EAGAIN [sendmsg failed: %d]", ret); | |
61 | return -EAGAIN; | |
62 | } | |
63 | ||
64 | _leave(" = 0"); | |
65 | return 0; | |
66 | } | |
67 | ||
68 | /* | |
69 | * accept an incoming call that needs peer, transport and/or connection setting | |
70 | * up | |
71 | */ | |
72 | static int rxrpc_accept_incoming_call(struct rxrpc_local *local, | |
73 | struct rxrpc_sock *rx, | |
74 | struct sk_buff *skb, | |
75 | struct sockaddr_rxrpc *srx) | |
76 | { | |
77 | struct rxrpc_connection *conn; | |
78 | struct rxrpc_transport *trans; | |
79 | struct rxrpc_skb_priv *sp, *nsp; | |
80 | struct rxrpc_peer *peer; | |
81 | struct rxrpc_call *call; | |
82 | struct sk_buff *notification; | |
83 | int ret; | |
84 | ||
85 | _enter(""); | |
86 | ||
87 | sp = rxrpc_skb(skb); | |
88 | ||
89 | /* get a notification message to send to the server app */ | |
90 | notification = alloc_skb(0, GFP_NOFS); | |
91 | rxrpc_new_skb(notification); | |
92 | notification->mark = RXRPC_SKB_MARK_NEW_CALL; | |
93 | ||
94 | peer = rxrpc_get_peer(srx, GFP_NOIO); | |
95 | if (IS_ERR(peer)) { | |
96 | _debug("no peer"); | |
97 | ret = -EBUSY; | |
98 | goto error; | |
99 | } | |
100 | ||
101 | trans = rxrpc_get_transport(local, peer, GFP_NOIO); | |
102 | rxrpc_put_peer(peer); | |
103 | if (!trans) { | |
104 | _debug("no trans"); | |
105 | ret = -EBUSY; | |
106 | goto error; | |
107 | } | |
108 | ||
109 | conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO); | |
110 | rxrpc_put_transport(trans); | |
111 | if (IS_ERR(conn)) { | |
112 | _debug("no conn"); | |
113 | ret = PTR_ERR(conn); | |
114 | goto error; | |
115 | } | |
116 | ||
117 | call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO); | |
118 | rxrpc_put_connection(conn); | |
119 | if (IS_ERR(call)) { | |
120 | _debug("no call"); | |
121 | ret = PTR_ERR(call); | |
122 | goto error; | |
123 | } | |
124 | ||
125 | /* attach the call to the socket */ | |
126 | read_lock_bh(&local->services_lock); | |
127 | if (rx->sk.sk_state == RXRPC_CLOSE) | |
128 | goto invalid_service; | |
129 | ||
130 | write_lock(&rx->call_lock); | |
131 | if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) { | |
132 | rxrpc_get_call(call); | |
133 | ||
134 | spin_lock(&call->conn->state_lock); | |
135 | if (sp->hdr.securityIndex > 0 && | |
136 | call->conn->state == RXRPC_CONN_SERVER_UNSECURED) { | |
137 | _debug("await conn sec"); | |
138 | list_add_tail(&call->accept_link, &rx->secureq); | |
139 | call->conn->state = RXRPC_CONN_SERVER_CHALLENGING; | |
140 | atomic_inc(&call->conn->usage); | |
141 | set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events); | |
651350d1 | 142 | rxrpc_queue_conn(call->conn); |
17926a79 DH |
143 | } else { |
144 | _debug("conn ready"); | |
145 | call->state = RXRPC_CALL_SERVER_ACCEPTING; | |
146 | list_add_tail(&call->accept_link, &rx->acceptq); | |
147 | rxrpc_get_call(call); | |
148 | nsp = rxrpc_skb(notification); | |
149 | nsp->call = call; | |
150 | ||
151 | ASSERTCMP(atomic_read(&call->usage), >=, 3); | |
152 | ||
153 | _debug("notify"); | |
154 | spin_lock(&call->lock); | |
155 | ret = rxrpc_queue_rcv_skb(call, notification, true, | |
156 | false); | |
157 | spin_unlock(&call->lock); | |
158 | notification = NULL; | |
159 | if (ret < 0) | |
160 | BUG(); | |
161 | } | |
162 | spin_unlock(&call->conn->state_lock); | |
163 | ||
164 | _debug("queued"); | |
165 | } | |
166 | write_unlock(&rx->call_lock); | |
167 | ||
168 | _debug("process"); | |
169 | rxrpc_fast_process_packet(call, skb); | |
170 | ||
171 | _debug("done"); | |
172 | read_unlock_bh(&local->services_lock); | |
173 | rxrpc_free_skb(notification); | |
174 | rxrpc_put_call(call); | |
175 | _leave(" = 0"); | |
176 | return 0; | |
177 | ||
178 | invalid_service: | |
179 | _debug("invalid"); | |
180 | read_unlock_bh(&local->services_lock); | |
181 | ||
182 | read_lock_bh(&call->state_lock); | |
183 | if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) && | |
184 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) { | |
185 | rxrpc_get_call(call); | |
651350d1 | 186 | rxrpc_queue_call(call); |
17926a79 DH |
187 | } |
188 | read_unlock_bh(&call->state_lock); | |
189 | rxrpc_put_call(call); | |
190 | ret = -ECONNREFUSED; | |
191 | error: | |
192 | rxrpc_free_skb(notification); | |
193 | _leave(" = %d", ret); | |
194 | return ret; | |
195 | } | |
196 | ||
197 | /* | |
198 | * accept incoming calls that need peer, transport and/or connection setting up | |
199 | * - the packets we get are all incoming client DATA packets that have seq == 1 | |
200 | */ | |
201 | void rxrpc_accept_incoming_calls(struct work_struct *work) | |
202 | { | |
203 | struct rxrpc_local *local = | |
204 | container_of(work, struct rxrpc_local, acceptor); | |
205 | struct rxrpc_skb_priv *sp; | |
206 | struct sockaddr_rxrpc srx; | |
207 | struct rxrpc_sock *rx; | |
208 | struct sk_buff *skb; | |
209 | __be16 service_id; | |
210 | int ret; | |
211 | ||
212 | _enter("%d", local->debug_id); | |
213 | ||
214 | read_lock_bh(&rxrpc_local_lock); | |
215 | if (atomic_read(&local->usage) > 0) | |
216 | rxrpc_get_local(local); | |
217 | else | |
218 | local = NULL; | |
219 | read_unlock_bh(&rxrpc_local_lock); | |
220 | if (!local) { | |
221 | _leave(" [local dead]"); | |
222 | return; | |
223 | } | |
224 | ||
225 | process_next_packet: | |
226 | skb = skb_dequeue(&local->accept_queue); | |
227 | if (!skb) { | |
228 | rxrpc_put_local(local); | |
229 | _leave("\n"); | |
230 | return; | |
231 | } | |
232 | ||
233 | _net("incoming call skb %p", skb); | |
234 | ||
235 | sp = rxrpc_skb(skb); | |
236 | ||
237 | /* determine the remote address */ | |
238 | memset(&srx, 0, sizeof(srx)); | |
239 | srx.srx_family = AF_RXRPC; | |
240 | srx.transport.family = local->srx.transport.family; | |
241 | srx.transport_type = local->srx.transport_type; | |
242 | switch (srx.transport.family) { | |
243 | case AF_INET: | |
244 | srx.transport_len = sizeof(struct sockaddr_in); | |
245 | srx.transport.sin.sin_port = udp_hdr(skb)->source; | |
246 | srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr; | |
247 | break; | |
248 | default: | |
249 | goto busy; | |
250 | } | |
251 | ||
252 | /* get the socket providing the service */ | |
253 | service_id = sp->hdr.serviceId; | |
254 | read_lock_bh(&local->services_lock); | |
255 | list_for_each_entry(rx, &local->services, listen_link) { | |
256 | if (rx->service_id == service_id && | |
257 | rx->sk.sk_state != RXRPC_CLOSE) | |
258 | goto found_service; | |
259 | } | |
260 | read_unlock_bh(&local->services_lock); | |
261 | goto invalid_service; | |
262 | ||
263 | found_service: | |
264 | _debug("found service %hd", ntohs(rx->service_id)); | |
265 | if (sk_acceptq_is_full(&rx->sk)) | |
266 | goto backlog_full; | |
267 | sk_acceptq_added(&rx->sk); | |
268 | sock_hold(&rx->sk); | |
269 | read_unlock_bh(&local->services_lock); | |
270 | ||
271 | ret = rxrpc_accept_incoming_call(local, rx, skb, &srx); | |
272 | if (ret < 0) | |
273 | sk_acceptq_removed(&rx->sk); | |
274 | sock_put(&rx->sk); | |
275 | switch (ret) { | |
276 | case -ECONNRESET: /* old calls are ignored */ | |
277 | case -ECONNABORTED: /* aborted calls are reaborted or ignored */ | |
278 | case 0: | |
279 | goto process_next_packet; | |
280 | case -ECONNREFUSED: | |
281 | goto invalid_service; | |
282 | case -EBUSY: | |
283 | goto busy; | |
284 | case -EKEYREJECTED: | |
285 | goto security_mismatch; | |
286 | default: | |
287 | BUG(); | |
288 | } | |
289 | ||
290 | backlog_full: | |
291 | read_unlock_bh(&local->services_lock); | |
292 | busy: | |
293 | rxrpc_busy(local, &srx, &sp->hdr); | |
294 | rxrpc_free_skb(skb); | |
295 | goto process_next_packet; | |
296 | ||
297 | invalid_service: | |
298 | skb->priority = RX_INVALID_OPERATION; | |
299 | rxrpc_reject_packet(local, skb); | |
300 | goto process_next_packet; | |
301 | ||
302 | /* can't change connection security type mid-flow */ | |
303 | security_mismatch: | |
304 | skb->priority = RX_PROTOCOL_ERROR; | |
305 | rxrpc_reject_packet(local, skb); | |
306 | goto process_next_packet; | |
307 | } | |
308 | ||
309 | /* | |
310 | * handle acceptance of a call by userspace | |
311 | * - assign the user call ID to the call at the front of the queue | |
312 | */ | |
651350d1 DH |
313 | struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, |
314 | unsigned long user_call_ID) | |
17926a79 DH |
315 | { |
316 | struct rxrpc_call *call; | |
317 | struct rb_node *parent, **pp; | |
318 | int ret; | |
319 | ||
320 | _enter(",%lx", user_call_ID); | |
321 | ||
322 | ASSERT(!irqs_disabled()); | |
323 | ||
324 | write_lock(&rx->call_lock); | |
325 | ||
326 | ret = -ENODATA; | |
327 | if (list_empty(&rx->acceptq)) | |
328 | goto out; | |
329 | ||
330 | /* check the user ID isn't already in use */ | |
331 | ret = -EBADSLT; | |
332 | pp = &rx->calls.rb_node; | |
333 | parent = NULL; | |
334 | while (*pp) { | |
335 | parent = *pp; | |
336 | call = rb_entry(parent, struct rxrpc_call, sock_node); | |
337 | ||
338 | if (user_call_ID < call->user_call_ID) | |
339 | pp = &(*pp)->rb_left; | |
340 | else if (user_call_ID > call->user_call_ID) | |
341 | pp = &(*pp)->rb_right; | |
342 | else | |
343 | goto out; | |
344 | } | |
345 | ||
346 | /* dequeue the first call and check it's still valid */ | |
347 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); | |
348 | list_del_init(&call->accept_link); | |
349 | sk_acceptq_removed(&rx->sk); | |
350 | ||
351 | write_lock_bh(&call->state_lock); | |
352 | switch (call->state) { | |
353 | case RXRPC_CALL_SERVER_ACCEPTING: | |
354 | call->state = RXRPC_CALL_SERVER_RECV_REQUEST; | |
355 | break; | |
356 | case RXRPC_CALL_REMOTELY_ABORTED: | |
357 | case RXRPC_CALL_LOCALLY_ABORTED: | |
358 | ret = -ECONNABORTED; | |
359 | goto out_release; | |
360 | case RXRPC_CALL_NETWORK_ERROR: | |
361 | ret = call->conn->error; | |
362 | goto out_release; | |
363 | case RXRPC_CALL_DEAD: | |
364 | ret = -ETIME; | |
365 | goto out_discard; | |
366 | default: | |
367 | BUG(); | |
368 | } | |
369 | ||
370 | /* formalise the acceptance */ | |
371 | call->user_call_ID = user_call_ID; | |
372 | rb_link_node(&call->sock_node, parent, pp); | |
373 | rb_insert_color(&call->sock_node, &rx->calls); | |
374 | if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) | |
375 | BUG(); | |
376 | if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events)) | |
377 | BUG(); | |
651350d1 | 378 | rxrpc_queue_call(call); |
17926a79 | 379 | |
651350d1 | 380 | rxrpc_get_call(call); |
17926a79 DH |
381 | write_unlock_bh(&call->state_lock); |
382 | write_unlock(&rx->call_lock); | |
651350d1 DH |
383 | _leave(" = %p{%d}", call, call->debug_id); |
384 | return call; | |
385 | ||
386 | /* if the call is already dying or dead, then we leave the socket's ref | |
387 | * on it to be released by rxrpc_dead_call_expired() as induced by | |
388 | * rxrpc_release_call() */ | |
389 | out_release: | |
390 | _debug("release %p", call); | |
391 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
392 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
393 | rxrpc_queue_call(call); | |
394 | out_discard: | |
395 | write_unlock_bh(&call->state_lock); | |
396 | _debug("discard %p", call); | |
397 | out: | |
398 | write_unlock(&rx->call_lock); | |
399 | _leave(" = %d", ret); | |
400 | return ERR_PTR(ret); | |
401 | } | |
402 | ||
403 | /* | |
404 | * handle rejectance of a call by userspace | |
405 | * - reject the call at the front of the queue | |
406 | */ | |
407 | int rxrpc_reject_call(struct rxrpc_sock *rx) | |
408 | { | |
409 | struct rxrpc_call *call; | |
410 | int ret; | |
411 | ||
412 | _enter(""); | |
413 | ||
414 | ASSERT(!irqs_disabled()); | |
415 | ||
416 | write_lock(&rx->call_lock); | |
417 | ||
418 | ret = -ENODATA; | |
419 | if (list_empty(&rx->acceptq)) | |
420 | goto out; | |
421 | ||
422 | /* dequeue the first call and check it's still valid */ | |
423 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); | |
424 | list_del_init(&call->accept_link); | |
425 | sk_acceptq_removed(&rx->sk); | |
426 | ||
427 | write_lock_bh(&call->state_lock); | |
428 | switch (call->state) { | |
429 | case RXRPC_CALL_SERVER_ACCEPTING: | |
430 | call->state = RXRPC_CALL_SERVER_BUSY; | |
431 | if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) | |
432 | rxrpc_queue_call(call); | |
433 | ret = 0; | |
434 | goto out_release; | |
435 | case RXRPC_CALL_REMOTELY_ABORTED: | |
436 | case RXRPC_CALL_LOCALLY_ABORTED: | |
437 | ret = -ECONNABORTED; | |
438 | goto out_release; | |
439 | case RXRPC_CALL_NETWORK_ERROR: | |
440 | ret = call->conn->error; | |
441 | goto out_release; | |
442 | case RXRPC_CALL_DEAD: | |
443 | ret = -ETIME; | |
444 | goto out_discard; | |
445 | default: | |
446 | BUG(); | |
447 | } | |
17926a79 DH |
448 | |
449 | /* if the call is already dying or dead, then we leave the socket's ref | |
450 | * on it to be released by rxrpc_dead_call_expired() as induced by | |
451 | * rxrpc_release_call() */ | |
452 | out_release: | |
453 | _debug("release %p", call); | |
454 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
455 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
651350d1 | 456 | rxrpc_queue_call(call); |
17926a79 DH |
457 | out_discard: |
458 | write_unlock_bh(&call->state_lock); | |
459 | _debug("discard %p", call); | |
460 | out: | |
461 | write_unlock(&rx->call_lock); | |
462 | _leave(" = %d", ret); | |
463 | return ret; | |
464 | } | |
651350d1 DH |
465 | |
466 | /** | |
467 | * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call | |
468 | * @sock: The socket on which the impending call is waiting | |
469 | * @user_call_ID: The tag to attach to the call | |
470 | * | |
471 | * Allow a kernel service to accept an incoming call, assuming the incoming | |
472 | * call is still valid. | |
473 | */ | |
474 | struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock, | |
475 | unsigned long user_call_ID) | |
476 | { | |
477 | struct rxrpc_call *call; | |
478 | ||
479 | _enter(",%lx", user_call_ID); | |
480 | call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID); | |
481 | _leave(" = %p", call); | |
482 | return call; | |
483 | } | |
484 | ||
485 | EXPORT_SYMBOL(rxrpc_kernel_accept_call); | |
486 | ||
487 | /** | |
488 | * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call | |
489 | * @sock: The socket on which the impending call is waiting | |
490 | * | |
491 | * Allow a kernel service to reject an incoming call with a BUSY message, | |
492 | * assuming the incoming call is still valid. | |
493 | */ | |
494 | int rxrpc_kernel_reject_call(struct socket *sock) | |
495 | { | |
496 | int ret; | |
497 | ||
498 | _enter(""); | |
499 | ret = rxrpc_reject_call(rxrpc_sk(sock->sk)); | |
500 | _leave(" = %d", ret); | |
501 | return ret; | |
502 | } | |
503 | ||
504 | EXPORT_SYMBOL(rxrpc_kernel_reject_call); |