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 */
28static 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 */
60static 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 */
129static 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 */
144static 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 */
214static 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
249abort:
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 */
258void 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
294out:
295	rxrpc_put_connection(conn);
296	_leave("");
297	return;
298
299requeue_and_leave:
300	skb_queue_head(&conn->rx_queue, skb);
301	goto out;
302
303protocol_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 */
315void 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 */
331void 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