1 /* connection-level event 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 * pass a connection-level abort onto all calls on that connection
27 */
rxrpc_abort_calls(struct rxrpc_connection * conn,int state,u32 abort_code)28 static void rxrpc_abort_calls(struct rxrpc_connection *conn, int state,
29 u32 abort_code)
30 {
31 struct rxrpc_call *call;
32 struct rb_node *p;
33
34 _enter("{%d},%x", conn->debug_id, abort_code);
35
36 read_lock_bh(&conn->lock);
37
38 for (p = rb_first(&conn->calls); p; p = rb_next(p)) {
39 call = rb_entry(p, struct rxrpc_call, conn_node);
40 write_lock(&call->state_lock);
41 if (call->state <= RXRPC_CALL_COMPLETE) {
42 call->state = state;
43 call->abort_code = abort_code;
44 if (state == RXRPC_CALL_LOCALLY_ABORTED)
45 set_bit(RXRPC_CALL_CONN_ABORT, &call->events);
46 else
47 set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
48 rxrpc_queue_call(call);
49 }
50 write_unlock(&call->state_lock);
51 }
52
53 read_unlock_bh(&conn->lock);
54 _leave("");
55 }
56
57 /*
58 * generate a connection-level abort
59 */
rxrpc_abort_connection(struct rxrpc_connection * conn,u32 error,u32 abort_code)60 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
61 u32 error, u32 abort_code)
62 {
63 struct rxrpc_header hdr;
64 struct msghdr msg;
65 struct kvec iov[2];
66 __be32 word;
67 size_t len;
68 int ret;
69
70 _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
71
72 /* generate a connection-level abort */
73 spin_lock_bh(&conn->state_lock);
74 if (conn->state < RXRPC_CONN_REMOTELY_ABORTED) {
75 conn->state = RXRPC_CONN_LOCALLY_ABORTED;
76 conn->error = error;
77 spin_unlock_bh(&conn->state_lock);
78 } else {
79 spin_unlock_bh(&conn->state_lock);
80 _leave(" = 0 [already dead]");
81 return 0;
82 }
83
84 rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code);
85
86 msg.msg_name = &conn->trans->peer->srx.transport.sin;
87 msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin);
88 msg.msg_control = NULL;
89 msg.msg_controllen = 0;
90 msg.msg_flags = 0;
91
92 hdr.epoch = conn->epoch;
93 hdr.cid = conn->cid;
94 hdr.callNumber = 0;
95 hdr.seq = 0;
96 hdr.type = RXRPC_PACKET_TYPE_ABORT;
97 hdr.flags = conn->out_clientflag;
98 hdr.userStatus = 0;
99 hdr.securityIndex = conn->security_ix;
100 hdr._rsvd = 0;
101 hdr.serviceId = conn->service_id;
102
103 word = htonl(abort_code);
104
105 iov[0].iov_base = &hdr;
106 iov[0].iov_len = sizeof(hdr);
107 iov[1].iov_base = &word;
108 iov[1].iov_len = sizeof(word);
109
110 len = iov[0].iov_len + iov[1].iov_len;
111
112 hdr.serial = htonl(atomic_inc_return(&conn->serial));
113 _proto("Tx CONN ABORT %%%u { %d }", ntohl(hdr.serial), abort_code);
114
115 ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
116 if (ret < 0) {
117 _debug("sendmsg failed: %d", ret);
118 return -EAGAIN;
119 }
120
121 _leave(" = 0");
122 return 0;
123 }
124
125 /*
126 * mark a call as being on a now-secured channel
127 * - must be called with softirqs disabled
128 */
rxrpc_call_is_secure(struct rxrpc_call * call)129 static void rxrpc_call_is_secure(struct rxrpc_call *call)
130 {
131 _enter("%p", call);
132 if (call) {
133 read_lock(&call->state_lock);
134 if (call->state < RXRPC_CALL_COMPLETE &&
135 !test_and_set_bit(RXRPC_CALL_SECURED, &call->events))
136 rxrpc_queue_call(call);
137 read_unlock(&call->state_lock);
138 }
139 }
140
141 /*
142 * connection-level Rx packet processor
143 */
rxrpc_process_event(struct rxrpc_connection * conn,struct sk_buff * skb,u32 * _abort_code)144 static int rxrpc_process_event(struct rxrpc_connection *conn,
145 struct sk_buff *skb,
146 u32 *_abort_code)
147 {
148 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
149 __be32 tmp;
150 u32 serial;
151 int loop, ret;
152
153 if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
154 kleave(" = -ECONNABORTED [%u]", conn->state);
155 return -ECONNABORTED;
156 }
157
158 serial = ntohl(sp->hdr.serial);
159
160 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, serial);
161
162 switch (sp->hdr.type) {
163 case RXRPC_PACKET_TYPE_ABORT:
164 if (skb_copy_bits(skb, 0, &tmp, sizeof(tmp)) < 0)
165 return -EPROTO;
166 _proto("Rx ABORT %%%u { ac=%d }", serial, ntohl(tmp));
167
168 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
169 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
170 ntohl(tmp));
171 return -ECONNABORTED;
172
173 case RXRPC_PACKET_TYPE_CHALLENGE:
174 if (conn->security)
175 return conn->security->respond_to_challenge(
176 conn, skb, _abort_code);
177 return -EPROTO;
178
179 case RXRPC_PACKET_TYPE_RESPONSE:
180 if (!conn->security)
181 return -EPROTO;
182
183 ret = conn->security->verify_response(conn, skb, _abort_code);
184 if (ret < 0)
185 return ret;
186
187 ret = conn->security->init_connection_security(conn);
188 if (ret < 0)
189 return ret;
190
191 conn->security->prime_packet_security(conn);
192 read_lock_bh(&conn->lock);
193 spin_lock(&conn->state_lock);
194
195 if (conn->state == RXRPC_CONN_SERVER_CHALLENGING) {
196 conn->state = RXRPC_CONN_SERVER;
197 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
198 rxrpc_call_is_secure(conn->channels[loop]);
199 }
200
201 spin_unlock(&conn->state_lock);
202 read_unlock_bh(&conn->lock);
203 return 0;
204
205 default:
206 _leave(" = -EPROTO [%u]", sp->hdr.type);
207 return -EPROTO;
208 }
209 }
210
211 /*
212 * set up security and issue a challenge
213 */
rxrpc_secure_connection(struct rxrpc_connection * conn)214 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
215 {
216 u32 abort_code;
217 int ret;
218
219 _enter("{%d}", conn->debug_id);
220
221 ASSERT(conn->security_ix != 0);
222
223 if (!conn->key) {
224 _debug("set up security");
225 ret = rxrpc_init_server_conn_security(conn);
226 switch (ret) {
227 case 0:
228 break;
229 case -ENOENT:
230 abort_code = RX_CALL_DEAD;
231 goto abort;
232 default:
233 abort_code = RXKADNOAUTH;
234 goto abort;
235 }
236 }
237
238 ASSERT(conn->security != NULL);
239
240 if (conn->security->issue_challenge(conn) < 0) {
241 abort_code = RX_CALL_DEAD;
242 ret = -ENOMEM;
243 goto abort;
244 }
245
246 _leave("");
247 return;
248
249 abort:
250 _debug("abort %d, %d", ret, abort_code);
251 rxrpc_abort_connection(conn, -ret, abort_code);
252 _leave(" [aborted]");
253 }
254
255 /*
256 * connection-level event processor
257 */
rxrpc_process_connection(struct work_struct * work)258 void rxrpc_process_connection(struct work_struct *work)
259 {
260 struct rxrpc_connection *conn =
261 container_of(work, struct rxrpc_connection, processor);
262 struct sk_buff *skb;
263 u32 abort_code = RX_PROTOCOL_ERROR;
264 int ret;
265
266 _enter("{%d}", conn->debug_id);
267
268 atomic_inc(&conn->usage);
269
270 if (test_and_clear_bit(RXRPC_CONN_CHALLENGE, &conn->events)) {
271 rxrpc_secure_connection(conn);
272 rxrpc_put_connection(conn);
273 }
274
275 /* go through the conn-level event packets, releasing the ref on this
276 * connection that each one has when we've finished with it */
277 while ((skb = skb_dequeue(&conn->rx_queue))) {
278 ret = rxrpc_process_event(conn, skb, &abort_code);
279 switch (ret) {
280 case -EPROTO:
281 case -EKEYEXPIRED:
282 case -EKEYREJECTED:
283 goto protocol_error;
284 case -EAGAIN:
285 goto requeue_and_leave;
286 case -ECONNABORTED:
287 default:
288 rxrpc_put_connection(conn);
289 rxrpc_free_skb(skb);
290 break;
291 }
292 }
293
294 out:
295 rxrpc_put_connection(conn);
296 _leave("");
297 return;
298
299 requeue_and_leave:
300 skb_queue_head(&conn->rx_queue, skb);
301 goto out;
302
303 protocol_error:
304 if (rxrpc_abort_connection(conn, -ret, abort_code) < 0)
305 goto requeue_and_leave;
306 rxrpc_put_connection(conn);
307 rxrpc_free_skb(skb);
308 _leave(" [EPROTO]");
309 goto out;
310 }
311
312 /*
313 * put a packet up for transport-level abort
314 */
rxrpc_reject_packet(struct rxrpc_local * local,struct sk_buff * skb)315 void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
316 {
317 CHECK_SLAB_OKAY(&local->usage);
318
319 if (!atomic_inc_not_zero(&local->usage)) {
320 printk("resurrected on reject\n");
321 BUG();
322 }
323
324 skb_queue_tail(&local->reject_queue, skb);
325 rxrpc_queue_work(&local->rejecter);
326 }
327
328 /*
329 * reject packets through the local endpoint
330 */
rxrpc_reject_packets(struct work_struct * work)331 void rxrpc_reject_packets(struct work_struct *work)
332 {
333 union {
334 struct sockaddr sa;
335 struct sockaddr_in sin;
336 } sa;
337 struct rxrpc_skb_priv *sp;
338 struct rxrpc_header hdr;
339 struct rxrpc_local *local;
340 struct sk_buff *skb;
341 struct msghdr msg;
342 struct kvec iov[2];
343 size_t size;
344 __be32 code;
345
346 local = container_of(work, struct rxrpc_local, rejecter);
347 rxrpc_get_local(local);
348
349 _enter("%d", local->debug_id);
350
351 iov[0].iov_base = &hdr;
352 iov[0].iov_len = sizeof(hdr);
353 iov[1].iov_base = &code;
354 iov[1].iov_len = sizeof(code);
355 size = sizeof(hdr) + sizeof(code);
356
357 msg.msg_name = &sa;
358 msg.msg_control = NULL;
359 msg.msg_controllen = 0;
360 msg.msg_flags = 0;
361
362 memset(&sa, 0, sizeof(sa));
363 sa.sa.sa_family = local->srx.transport.family;
364 switch (sa.sa.sa_family) {
365 case AF_INET:
366 msg.msg_namelen = sizeof(sa.sin);
367 break;
368 default:
369 msg.msg_namelen = 0;
370 break;
371 }
372
373 memset(&hdr, 0, sizeof(hdr));
374 hdr.type = RXRPC_PACKET_TYPE_ABORT;
375
376 while ((skb = skb_dequeue(&local->reject_queue))) {
377 sp = rxrpc_skb(skb);
378 switch (sa.sa.sa_family) {
379 case AF_INET:
380 sa.sin.sin_port = udp_hdr(skb)->source;
381 sa.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
382 code = htonl(skb->priority);
383
384 hdr.epoch = sp->hdr.epoch;
385 hdr.cid = sp->hdr.cid;
386 hdr.callNumber = sp->hdr.callNumber;
387 hdr.serviceId = sp->hdr.serviceId;
388 hdr.flags = sp->hdr.flags;
389 hdr.flags ^= RXRPC_CLIENT_INITIATED;
390 hdr.flags &= RXRPC_CLIENT_INITIATED;
391
392 kernel_sendmsg(local->socket, &msg, iov, 2, size);
393 break;
394
395 default:
396 break;
397 }
398
399 rxrpc_free_skb(skb);
400 rxrpc_put_local(local);
401 }
402
403 rxrpc_put_local(local);
404 _leave("");
405 }
406