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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); | |
c3824d21 TH |
91 | if (!notification) { |
92 | _debug("no memory"); | |
93 | ret = -ENOMEM; | |
94 | goto error_nofree; | |
95 | } | |
17926a79 DH |
96 | rxrpc_new_skb(notification); |
97 | notification->mark = RXRPC_SKB_MARK_NEW_CALL; | |
98 | ||
99 | peer = rxrpc_get_peer(srx, GFP_NOIO); | |
100 | if (IS_ERR(peer)) { | |
101 | _debug("no peer"); | |
102 | ret = -EBUSY; | |
103 | goto error; | |
104 | } | |
105 | ||
106 | trans = rxrpc_get_transport(local, peer, GFP_NOIO); | |
107 | rxrpc_put_peer(peer); | |
34093d05 | 108 | if (IS_ERR(trans)) { |
17926a79 DH |
109 | _debug("no trans"); |
110 | ret = -EBUSY; | |
111 | goto error; | |
112 | } | |
113 | ||
114 | conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO); | |
115 | rxrpc_put_transport(trans); | |
116 | if (IS_ERR(conn)) { | |
117 | _debug("no conn"); | |
118 | ret = PTR_ERR(conn); | |
119 | goto error; | |
120 | } | |
121 | ||
122 | call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO); | |
123 | rxrpc_put_connection(conn); | |
124 | if (IS_ERR(call)) { | |
125 | _debug("no call"); | |
126 | ret = PTR_ERR(call); | |
127 | goto error; | |
128 | } | |
129 | ||
130 | /* attach the call to the socket */ | |
131 | read_lock_bh(&local->services_lock); | |
132 | if (rx->sk.sk_state == RXRPC_CLOSE) | |
133 | goto invalid_service; | |
134 | ||
135 | write_lock(&rx->call_lock); | |
136 | if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) { | |
137 | rxrpc_get_call(call); | |
138 | ||
139 | spin_lock(&call->conn->state_lock); | |
140 | if (sp->hdr.securityIndex > 0 && | |
141 | call->conn->state == RXRPC_CONN_SERVER_UNSECURED) { | |
142 | _debug("await conn sec"); | |
143 | list_add_tail(&call->accept_link, &rx->secureq); | |
144 | call->conn->state = RXRPC_CONN_SERVER_CHALLENGING; | |
145 | atomic_inc(&call->conn->usage); | |
146 | set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events); | |
651350d1 | 147 | rxrpc_queue_conn(call->conn); |
17926a79 DH |
148 | } else { |
149 | _debug("conn ready"); | |
150 | call->state = RXRPC_CALL_SERVER_ACCEPTING; | |
151 | list_add_tail(&call->accept_link, &rx->acceptq); | |
152 | rxrpc_get_call(call); | |
153 | nsp = rxrpc_skb(notification); | |
154 | nsp->call = call; | |
155 | ||
156 | ASSERTCMP(atomic_read(&call->usage), >=, 3); | |
157 | ||
158 | _debug("notify"); | |
159 | spin_lock(&call->lock); | |
160 | ret = rxrpc_queue_rcv_skb(call, notification, true, | |
161 | false); | |
162 | spin_unlock(&call->lock); | |
163 | notification = NULL; | |
163e3cb7 | 164 | BUG_ON(ret < 0); |
17926a79 DH |
165 | } |
166 | spin_unlock(&call->conn->state_lock); | |
167 | ||
168 | _debug("queued"); | |
169 | } | |
170 | write_unlock(&rx->call_lock); | |
171 | ||
172 | _debug("process"); | |
173 | rxrpc_fast_process_packet(call, skb); | |
174 | ||
175 | _debug("done"); | |
176 | read_unlock_bh(&local->services_lock); | |
177 | rxrpc_free_skb(notification); | |
178 | rxrpc_put_call(call); | |
179 | _leave(" = 0"); | |
180 | return 0; | |
181 | ||
182 | invalid_service: | |
183 | _debug("invalid"); | |
184 | read_unlock_bh(&local->services_lock); | |
185 | ||
186 | read_lock_bh(&call->state_lock); | |
187 | if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) && | |
188 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) { | |
189 | rxrpc_get_call(call); | |
651350d1 | 190 | rxrpc_queue_call(call); |
17926a79 DH |
191 | } |
192 | read_unlock_bh(&call->state_lock); | |
193 | rxrpc_put_call(call); | |
194 | ret = -ECONNREFUSED; | |
195 | error: | |
196 | rxrpc_free_skb(notification); | |
c3824d21 | 197 | error_nofree: |
17926a79 DH |
198 | _leave(" = %d", ret); |
199 | return ret; | |
200 | } | |
201 | ||
202 | /* | |
203 | * accept incoming calls that need peer, transport and/or connection setting up | |
204 | * - the packets we get are all incoming client DATA packets that have seq == 1 | |
205 | */ | |
206 | void rxrpc_accept_incoming_calls(struct work_struct *work) | |
207 | { | |
208 | struct rxrpc_local *local = | |
209 | container_of(work, struct rxrpc_local, acceptor); | |
210 | struct rxrpc_skb_priv *sp; | |
211 | struct sockaddr_rxrpc srx; | |
212 | struct rxrpc_sock *rx; | |
213 | struct sk_buff *skb; | |
214 | __be16 service_id; | |
215 | int ret; | |
216 | ||
217 | _enter("%d", local->debug_id); | |
218 | ||
219 | read_lock_bh(&rxrpc_local_lock); | |
220 | if (atomic_read(&local->usage) > 0) | |
221 | rxrpc_get_local(local); | |
222 | else | |
223 | local = NULL; | |
224 | read_unlock_bh(&rxrpc_local_lock); | |
225 | if (!local) { | |
226 | _leave(" [local dead]"); | |
227 | return; | |
228 | } | |
229 | ||
230 | process_next_packet: | |
231 | skb = skb_dequeue(&local->accept_queue); | |
232 | if (!skb) { | |
233 | rxrpc_put_local(local); | |
234 | _leave("\n"); | |
235 | return; | |
236 | } | |
237 | ||
238 | _net("incoming call skb %p", skb); | |
239 | ||
240 | sp = rxrpc_skb(skb); | |
241 | ||
242 | /* determine the remote address */ | |
243 | memset(&srx, 0, sizeof(srx)); | |
244 | srx.srx_family = AF_RXRPC; | |
245 | srx.transport.family = local->srx.transport.family; | |
246 | srx.transport_type = local->srx.transport_type; | |
247 | switch (srx.transport.family) { | |
248 | case AF_INET: | |
249 | srx.transport_len = sizeof(struct sockaddr_in); | |
250 | srx.transport.sin.sin_port = udp_hdr(skb)->source; | |
251 | srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr; | |
252 | break; | |
253 | default: | |
254 | goto busy; | |
255 | } | |
256 | ||
257 | /* get the socket providing the service */ | |
258 | service_id = sp->hdr.serviceId; | |
259 | read_lock_bh(&local->services_lock); | |
260 | list_for_each_entry(rx, &local->services, listen_link) { | |
261 | if (rx->service_id == service_id && | |
262 | rx->sk.sk_state != RXRPC_CLOSE) | |
263 | goto found_service; | |
264 | } | |
265 | read_unlock_bh(&local->services_lock); | |
266 | goto invalid_service; | |
267 | ||
268 | found_service: | |
269 | _debug("found service %hd", ntohs(rx->service_id)); | |
270 | if (sk_acceptq_is_full(&rx->sk)) | |
271 | goto backlog_full; | |
272 | sk_acceptq_added(&rx->sk); | |
273 | sock_hold(&rx->sk); | |
274 | read_unlock_bh(&local->services_lock); | |
275 | ||
276 | ret = rxrpc_accept_incoming_call(local, rx, skb, &srx); | |
277 | if (ret < 0) | |
278 | sk_acceptq_removed(&rx->sk); | |
279 | sock_put(&rx->sk); | |
280 | switch (ret) { | |
281 | case -ECONNRESET: /* old calls are ignored */ | |
282 | case -ECONNABORTED: /* aborted calls are reaborted or ignored */ | |
283 | case 0: | |
284 | goto process_next_packet; | |
285 | case -ECONNREFUSED: | |
286 | goto invalid_service; | |
287 | case -EBUSY: | |
288 | goto busy; | |
289 | case -EKEYREJECTED: | |
290 | goto security_mismatch; | |
291 | default: | |
292 | BUG(); | |
293 | } | |
294 | ||
295 | backlog_full: | |
296 | read_unlock_bh(&local->services_lock); | |
297 | busy: | |
298 | rxrpc_busy(local, &srx, &sp->hdr); | |
299 | rxrpc_free_skb(skb); | |
300 | goto process_next_packet; | |
301 | ||
302 | invalid_service: | |
303 | skb->priority = RX_INVALID_OPERATION; | |
304 | rxrpc_reject_packet(local, skb); | |
305 | goto process_next_packet; | |
306 | ||
307 | /* can't change connection security type mid-flow */ | |
308 | security_mismatch: | |
309 | skb->priority = RX_PROTOCOL_ERROR; | |
310 | rxrpc_reject_packet(local, skb); | |
311 | goto process_next_packet; | |
312 | } | |
313 | ||
314 | /* | |
315 | * handle acceptance of a call by userspace | |
316 | * - assign the user call ID to the call at the front of the queue | |
317 | */ | |
651350d1 DH |
318 | struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, |
319 | unsigned long user_call_ID) | |
17926a79 DH |
320 | { |
321 | struct rxrpc_call *call; | |
322 | struct rb_node *parent, **pp; | |
323 | int ret; | |
324 | ||
325 | _enter(",%lx", user_call_ID); | |
326 | ||
327 | ASSERT(!irqs_disabled()); | |
328 | ||
329 | write_lock(&rx->call_lock); | |
330 | ||
331 | ret = -ENODATA; | |
332 | if (list_empty(&rx->acceptq)) | |
333 | goto out; | |
334 | ||
335 | /* check the user ID isn't already in use */ | |
336 | ret = -EBADSLT; | |
337 | pp = &rx->calls.rb_node; | |
338 | parent = NULL; | |
339 | while (*pp) { | |
340 | parent = *pp; | |
341 | call = rb_entry(parent, struct rxrpc_call, sock_node); | |
342 | ||
343 | if (user_call_ID < call->user_call_ID) | |
344 | pp = &(*pp)->rb_left; | |
345 | else if (user_call_ID > call->user_call_ID) | |
346 | pp = &(*pp)->rb_right; | |
347 | else | |
348 | goto out; | |
349 | } | |
350 | ||
351 | /* dequeue the first call and check it's still valid */ | |
352 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); | |
353 | list_del_init(&call->accept_link); | |
354 | sk_acceptq_removed(&rx->sk); | |
355 | ||
356 | write_lock_bh(&call->state_lock); | |
357 | switch (call->state) { | |
358 | case RXRPC_CALL_SERVER_ACCEPTING: | |
359 | call->state = RXRPC_CALL_SERVER_RECV_REQUEST; | |
360 | break; | |
361 | case RXRPC_CALL_REMOTELY_ABORTED: | |
362 | case RXRPC_CALL_LOCALLY_ABORTED: | |
363 | ret = -ECONNABORTED; | |
364 | goto out_release; | |
365 | case RXRPC_CALL_NETWORK_ERROR: | |
366 | ret = call->conn->error; | |
367 | goto out_release; | |
368 | case RXRPC_CALL_DEAD: | |
369 | ret = -ETIME; | |
370 | goto out_discard; | |
371 | default: | |
372 | BUG(); | |
373 | } | |
374 | ||
375 | /* formalise the acceptance */ | |
376 | call->user_call_ID = user_call_ID; | |
377 | rb_link_node(&call->sock_node, parent, pp); | |
378 | rb_insert_color(&call->sock_node, &rx->calls); | |
379 | if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) | |
380 | BUG(); | |
381 | if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events)) | |
382 | BUG(); | |
651350d1 | 383 | rxrpc_queue_call(call); |
17926a79 | 384 | |
651350d1 | 385 | rxrpc_get_call(call); |
17926a79 DH |
386 | write_unlock_bh(&call->state_lock); |
387 | write_unlock(&rx->call_lock); | |
651350d1 DH |
388 | _leave(" = %p{%d}", call, call->debug_id); |
389 | return call; | |
390 | ||
391 | /* if the call is already dying or dead, then we leave the socket's ref | |
392 | * on it to be released by rxrpc_dead_call_expired() as induced by | |
393 | * rxrpc_release_call() */ | |
394 | out_release: | |
395 | _debug("release %p", call); | |
396 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
397 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
398 | rxrpc_queue_call(call); | |
399 | out_discard: | |
400 | write_unlock_bh(&call->state_lock); | |
401 | _debug("discard %p", call); | |
402 | out: | |
403 | write_unlock(&rx->call_lock); | |
404 | _leave(" = %d", ret); | |
405 | return ERR_PTR(ret); | |
406 | } | |
407 | ||
408 | /* | |
409 | * handle rejectance of a call by userspace | |
410 | * - reject the call at the front of the queue | |
411 | */ | |
412 | int rxrpc_reject_call(struct rxrpc_sock *rx) | |
413 | { | |
414 | struct rxrpc_call *call; | |
415 | int ret; | |
416 | ||
417 | _enter(""); | |
418 | ||
419 | ASSERT(!irqs_disabled()); | |
420 | ||
421 | write_lock(&rx->call_lock); | |
422 | ||
423 | ret = -ENODATA; | |
424 | if (list_empty(&rx->acceptq)) | |
425 | goto out; | |
426 | ||
427 | /* dequeue the first call and check it's still valid */ | |
428 | call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); | |
429 | list_del_init(&call->accept_link); | |
430 | sk_acceptq_removed(&rx->sk); | |
431 | ||
432 | write_lock_bh(&call->state_lock); | |
433 | switch (call->state) { | |
434 | case RXRPC_CALL_SERVER_ACCEPTING: | |
435 | call->state = RXRPC_CALL_SERVER_BUSY; | |
436 | if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) | |
437 | rxrpc_queue_call(call); | |
438 | ret = 0; | |
439 | goto out_release; | |
440 | case RXRPC_CALL_REMOTELY_ABORTED: | |
441 | case RXRPC_CALL_LOCALLY_ABORTED: | |
442 | ret = -ECONNABORTED; | |
443 | goto out_release; | |
444 | case RXRPC_CALL_NETWORK_ERROR: | |
445 | ret = call->conn->error; | |
446 | goto out_release; | |
447 | case RXRPC_CALL_DEAD: | |
448 | ret = -ETIME; | |
449 | goto out_discard; | |
450 | default: | |
451 | BUG(); | |
452 | } | |
17926a79 DH |
453 | |
454 | /* if the call is already dying or dead, then we leave the socket's ref | |
455 | * on it to be released by rxrpc_dead_call_expired() as induced by | |
456 | * rxrpc_release_call() */ | |
457 | out_release: | |
458 | _debug("release %p", call); | |
459 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
460 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
651350d1 | 461 | rxrpc_queue_call(call); |
17926a79 DH |
462 | out_discard: |
463 | write_unlock_bh(&call->state_lock); | |
464 | _debug("discard %p", call); | |
465 | out: | |
466 | write_unlock(&rx->call_lock); | |
467 | _leave(" = %d", ret); | |
468 | return ret; | |
469 | } | |
651350d1 DH |
470 | |
471 | /** | |
472 | * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call | |
473 | * @sock: The socket on which the impending call is waiting | |
474 | * @user_call_ID: The tag to attach to the call | |
475 | * | |
476 | * Allow a kernel service to accept an incoming call, assuming the incoming | |
477 | * call is still valid. | |
478 | */ | |
479 | struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock, | |
480 | unsigned long user_call_ID) | |
481 | { | |
482 | struct rxrpc_call *call; | |
483 | ||
484 | _enter(",%lx", user_call_ID); | |
485 | call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID); | |
486 | _leave(" = %p", call); | |
487 | return call; | |
488 | } | |
489 | ||
490 | EXPORT_SYMBOL(rxrpc_kernel_accept_call); | |
491 | ||
492 | /** | |
493 | * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call | |
494 | * @sock: The socket on which the impending call is waiting | |
495 | * | |
496 | * Allow a kernel service to reject an incoming call with a BUSY message, | |
497 | * assuming the incoming call is still valid. | |
498 | */ | |
499 | int rxrpc_kernel_reject_call(struct socket *sock) | |
500 | { | |
501 | int ret; | |
502 | ||
503 | _enter(""); | |
504 | ret = rxrpc_reject_call(rxrpc_sk(sock->sk)); | |
505 | _leave(" = %d", ret); | |
506 | return ret; | |
507 | } | |
508 | ||
509 | EXPORT_SYMBOL(rxrpc_kernel_reject_call); |