blob: 92a87fde8bfeb2b86f20a914275494e656636e1c [file] [log] [blame]
David Howells17926a72007-04-26 15:48:28 -07001/* 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 */
28static 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 */
72static 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);
David Howells651350d2007-04-26 15:50:17 -0700142 rxrpc_queue_conn(call->conn);
David Howells17926a72007-04-26 15:48:28 -0700143 } 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
178invalid_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);
David Howells651350d2007-04-26 15:50:17 -0700186 rxrpc_queue_call(call);
David Howells17926a72007-04-26 15:48:28 -0700187 }
188 read_unlock_bh(&call->state_lock);
189 rxrpc_put_call(call);
190 ret = -ECONNREFUSED;
191error:
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 */
201void 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
225process_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
263found_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
290backlog_full:
291 read_unlock_bh(&local->services_lock);
292busy:
293 rxrpc_busy(local, &srx, &sp->hdr);
294 rxrpc_free_skb(skb);
295 goto process_next_packet;
296
297invalid_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 */
303security_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 */
David Howells651350d2007-04-26 15:50:17 -0700313struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
314 unsigned long user_call_ID)
David Howells17926a72007-04-26 15:48:28 -0700315{
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();
David Howells651350d2007-04-26 15:50:17 -0700378 rxrpc_queue_call(call);
David Howells17926a72007-04-26 15:48:28 -0700379
David Howells651350d2007-04-26 15:50:17 -0700380 rxrpc_get_call(call);
David Howells17926a72007-04-26 15:48:28 -0700381 write_unlock_bh(&call->state_lock);
382 write_unlock(&rx->call_lock);
David Howells651350d2007-04-26 15:50:17 -0700383 _leave(" = %p{%d}", call, call->debug_id);
384 return call;
David Howells17926a72007-04-26 15:48:28 -0700385
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() */
389out_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))
David Howells651350d2007-04-26 15:50:17 -0700393 rxrpc_queue_call(call);
394out_discard:
395 write_unlock_bh(&call->state_lock);
396 _debug("discard %p", call);
397out:
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 */
407int 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 }
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() */
452out_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))
456 rxrpc_queue_call(call);
David Howells17926a72007-04-26 15:48:28 -0700457out_discard:
458 write_unlock_bh(&call->state_lock);
459 _debug("discard %p", call);
460out:
461 write_unlock(&rx->call_lock);
462 _leave(" = %d", ret);
463 return ret;
464}
David Howells651350d2007-04-26 15:50:17 -0700465
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 */
474struct 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
485EXPORT_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 */
494int 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
504EXPORT_SYMBOL(rxrpc_kernel_reject_call);