RxRPC: Use uX/sX rather than uintX_t/intX_t types
[linux-2.6.git] / net / rxrpc / ar-accept.c
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 (IS_ERR(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);
142                         rxrpc_queue_conn(call->conn);
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                         BUG_ON(ret < 0);
160                 }
161                 spin_unlock(&call->conn->state_lock);
162
163                 _debug("queued");
164         }
165         write_unlock(&rx->call_lock);
166
167         _debug("process");
168         rxrpc_fast_process_packet(call, skb);
169
170         _debug("done");
171         read_unlock_bh(&local->services_lock);
172         rxrpc_free_skb(notification);
173         rxrpc_put_call(call);
174         _leave(" = 0");
175         return 0;
176
177 invalid_service:
178         _debug("invalid");
179         read_unlock_bh(&local->services_lock);
180
181         read_lock_bh(&call->state_lock);
182         if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
183             !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
184                 rxrpc_get_call(call);
185                 rxrpc_queue_call(call);
186         }
187         read_unlock_bh(&call->state_lock);
188         rxrpc_put_call(call);
189         ret = -ECONNREFUSED;
190 error:
191         rxrpc_free_skb(notification);
192         _leave(" = %d", ret);
193         return ret;
194 }
195
196 /*
197  * accept incoming calls that need peer, transport and/or connection setting up
198  * - the packets we get are all incoming client DATA packets that have seq == 1
199  */
200 void rxrpc_accept_incoming_calls(struct work_struct *work)
201 {
202         struct rxrpc_local *local =
203                 container_of(work, struct rxrpc_local, acceptor);
204         struct rxrpc_skb_priv *sp;
205         struct sockaddr_rxrpc srx;
206         struct rxrpc_sock *rx;
207         struct sk_buff *skb;
208         __be16 service_id;
209         int ret;
210
211         _enter("%d", local->debug_id);
212
213         read_lock_bh(&rxrpc_local_lock);
214         if (atomic_read(&local->usage) > 0)
215                 rxrpc_get_local(local);
216         else
217                 local = NULL;
218         read_unlock_bh(&rxrpc_local_lock);
219         if (!local) {
220                 _leave(" [local dead]");
221                 return;
222         }
223
224 process_next_packet:
225         skb = skb_dequeue(&local->accept_queue);
226         if (!skb) {
227                 rxrpc_put_local(local);
228                 _leave("\n");
229                 return;
230         }
231
232         _net("incoming call skb %p", skb);
233
234         sp = rxrpc_skb(skb);
235
236         /* determine the remote address */
237         memset(&srx, 0, sizeof(srx));
238         srx.srx_family = AF_RXRPC;
239         srx.transport.family = local->srx.transport.family;
240         srx.transport_type = local->srx.transport_type;
241         switch (srx.transport.family) {
242         case AF_INET:
243                 srx.transport_len = sizeof(struct sockaddr_in);
244                 srx.transport.sin.sin_port = udp_hdr(skb)->source;
245                 srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
246                 break;
247         default:
248                 goto busy;
249         }
250
251         /* get the socket providing the service */
252         service_id = sp->hdr.serviceId;
253         read_lock_bh(&local->services_lock);
254         list_for_each_entry(rx, &local->services, listen_link) {
255                 if (rx->service_id == service_id &&
256                     rx->sk.sk_state != RXRPC_CLOSE)
257                         goto found_service;
258         }
259         read_unlock_bh(&local->services_lock);
260         goto invalid_service;
261
262 found_service:
263         _debug("found service %hd", ntohs(rx->service_id));
264         if (sk_acceptq_is_full(&rx->sk))
265                 goto backlog_full;
266         sk_acceptq_added(&rx->sk);
267         sock_hold(&rx->sk);
268         read_unlock_bh(&local->services_lock);
269
270         ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
271         if (ret < 0)
272                 sk_acceptq_removed(&rx->sk);
273         sock_put(&rx->sk);
274         switch (ret) {
275         case -ECONNRESET: /* old calls are ignored */
276         case -ECONNABORTED: /* aborted calls are reaborted or ignored */
277         case 0:
278                 goto process_next_packet;
279         case -ECONNREFUSED:
280                 goto invalid_service;
281         case -EBUSY:
282                 goto busy;
283         case -EKEYREJECTED:
284                 goto security_mismatch;
285         default:
286                 BUG();
287         }
288
289 backlog_full:
290         read_unlock_bh(&local->services_lock);
291 busy:
292         rxrpc_busy(local, &srx, &sp->hdr);
293         rxrpc_free_skb(skb);
294         goto process_next_packet;
295
296 invalid_service:
297         skb->priority = RX_INVALID_OPERATION;
298         rxrpc_reject_packet(local, skb);
299         goto process_next_packet;
300
301         /* can't change connection security type mid-flow */
302 security_mismatch:
303         skb->priority = RX_PROTOCOL_ERROR;
304         rxrpc_reject_packet(local, skb);
305         goto process_next_packet;
306 }
307
308 /*
309  * handle acceptance of a call by userspace
310  * - assign the user call ID to the call at the front of the queue
311  */
312 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
313                                      unsigned long user_call_ID)
314 {
315         struct rxrpc_call *call;
316         struct rb_node *parent, **pp;
317         int ret;
318
319         _enter(",%lx", user_call_ID);
320
321         ASSERT(!irqs_disabled());
322
323         write_lock(&rx->call_lock);
324
325         ret = -ENODATA;
326         if (list_empty(&rx->acceptq))
327                 goto out;
328
329         /* check the user ID isn't already in use */
330         ret = -EBADSLT;
331         pp = &rx->calls.rb_node;
332         parent = NULL;
333         while (*pp) {
334                 parent = *pp;
335                 call = rb_entry(parent, struct rxrpc_call, sock_node);
336
337                 if (user_call_ID < call->user_call_ID)
338                         pp = &(*pp)->rb_left;
339                 else if (user_call_ID > call->user_call_ID)
340                         pp = &(*pp)->rb_right;
341                 else
342                         goto out;
343         }
344
345         /* dequeue the first call and check it's still valid */
346         call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
347         list_del_init(&call->accept_link);
348         sk_acceptq_removed(&rx->sk);
349
350         write_lock_bh(&call->state_lock);
351         switch (call->state) {
352         case RXRPC_CALL_SERVER_ACCEPTING:
353                 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
354                 break;
355         case RXRPC_CALL_REMOTELY_ABORTED:
356         case RXRPC_CALL_LOCALLY_ABORTED:
357                 ret = -ECONNABORTED;
358                 goto out_release;
359         case RXRPC_CALL_NETWORK_ERROR:
360                 ret = call->conn->error;
361                 goto out_release;
362         case RXRPC_CALL_DEAD:
363                 ret = -ETIME;
364                 goto out_discard;
365         default:
366                 BUG();
367         }
368
369         /* formalise the acceptance */
370         call->user_call_ID = user_call_ID;
371         rb_link_node(&call->sock_node, parent, pp);
372         rb_insert_color(&call->sock_node, &rx->calls);
373         if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
374                 BUG();
375         if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
376                 BUG();
377         rxrpc_queue_call(call);
378
379         rxrpc_get_call(call);
380         write_unlock_bh(&call->state_lock);
381         write_unlock(&rx->call_lock);
382         _leave(" = %p{%d}", call, call->debug_id);
383         return call;
384
385         /* if the call is already dying or dead, then we leave the socket's ref
386          * on it to be released by rxrpc_dead_call_expired() as induced by
387          * rxrpc_release_call() */
388 out_release:
389         _debug("release %p", call);
390         if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
391             !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
392                 rxrpc_queue_call(call);
393 out_discard:
394         write_unlock_bh(&call->state_lock);
395         _debug("discard %p", call);
396 out:
397         write_unlock(&rx->call_lock);
398         _leave(" = %d", ret);
399         return ERR_PTR(ret);
400 }
401
402 /*
403  * handle rejectance of a call by userspace
404  * - reject the call at the front of the queue
405  */
406 int rxrpc_reject_call(struct rxrpc_sock *rx)
407 {
408         struct rxrpc_call *call;
409         int ret;
410
411         _enter("");
412
413         ASSERT(!irqs_disabled());
414
415         write_lock(&rx->call_lock);
416
417         ret = -ENODATA;
418         if (list_empty(&rx->acceptq))
419                 goto out;
420
421         /* dequeue the first call and check it's still valid */
422         call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
423         list_del_init(&call->accept_link);
424         sk_acceptq_removed(&rx->sk);
425
426         write_lock_bh(&call->state_lock);
427         switch (call->state) {
428         case RXRPC_CALL_SERVER_ACCEPTING:
429                 call->state = RXRPC_CALL_SERVER_BUSY;
430                 if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
431                         rxrpc_queue_call(call);
432                 ret = 0;
433                 goto out_release;
434         case RXRPC_CALL_REMOTELY_ABORTED:
435         case RXRPC_CALL_LOCALLY_ABORTED:
436                 ret = -ECONNABORTED;
437                 goto out_release;
438         case RXRPC_CALL_NETWORK_ERROR:
439                 ret = call->conn->error;
440                 goto out_release;
441         case RXRPC_CALL_DEAD:
442                 ret = -ETIME;
443                 goto out_discard;
444         default:
445                 BUG();
446         }
447
448         /* if the call is already dying or dead, then we leave the socket's ref
449          * on it to be released by rxrpc_dead_call_expired() as induced by
450          * rxrpc_release_call() */
451 out_release:
452         _debug("release %p", call);
453         if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
454             !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
455                 rxrpc_queue_call(call);
456 out_discard:
457         write_unlock_bh(&call->state_lock);
458         _debug("discard %p", call);
459 out:
460         write_unlock(&rx->call_lock);
461         _leave(" = %d", ret);
462         return ret;
463 }
464
465 /**
466  * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
467  * @sock: The socket on which the impending call is waiting
468  * @user_call_ID: The tag to attach to the call
469  *
470  * Allow a kernel service to accept an incoming call, assuming the incoming
471  * call is still valid.
472  */
473 struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock,
474                                             unsigned long user_call_ID)
475 {
476         struct rxrpc_call *call;
477
478         _enter(",%lx", user_call_ID);
479         call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
480         _leave(" = %p", call);
481         return call;
482 }
483
484 EXPORT_SYMBOL(rxrpc_kernel_accept_call);
485
486 /**
487  * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
488  * @sock: The socket on which the impending call is waiting
489  *
490  * Allow a kernel service to reject an incoming call with a BUSY message,
491  * assuming the incoming call is still valid.
492  */
493 int rxrpc_kernel_reject_call(struct socket *sock)
494 {
495         int ret;
496
497         _enter("");
498         ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
499         _leave(" = %d", ret);
500         return ret;
501 }
502
503 EXPORT_SYMBOL(rxrpc_kernel_reject_call);