aboutsummaryrefslogtreecommitdiffstats
path: root/net/rxrpc/krxsecd.c
blob: 3ab0f77409f49c79de6c65dc361962bf14be1c94 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
/* krxsecd.c: Rx security daemon
 *
 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * This daemon deals with:
 * - consulting the application as to whether inbound peers and calls should be authorised
 * - generating security challenges for inbound connections
 * - responding to security challenges on outbound connections
 */

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <rxrpc/krxsecd.h>
#include <rxrpc/transport.h>
#include <rxrpc/connection.h>
#include <rxrpc/message.h>
#include <rxrpc/peer.h>
#include <rxrpc/call.h>
#include <linux/udp.h>
#include <linux/ip.h>
#include <linux/freezer.h>
#include <net/sock.h>
#include "internal.h"

static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxsecd_sleepq);
static DECLARE_COMPLETION(rxrpc_krxsecd_dead);
static volatile int rxrpc_krxsecd_die;

static atomic_t rxrpc_krxsecd_qcount;

/* queue of unprocessed inbound messages with seqno #1 and
 * RXRPC_CLIENT_INITIATED flag set */
static LIST_HEAD(rxrpc_krxsecd_initmsgq);
static DEFINE_SPINLOCK(rxrpc_krxsecd_initmsgq_lock);

static void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg);

/*****************************************************************************/
/*
 * Rx security daemon
 */
static int rxrpc_krxsecd(void *arg)
{
	DECLARE_WAITQUEUE(krxsecd, current);

	int die;

	printk("Started krxsecd %d\n", current->pid);

	daemonize("krxsecd");

	/* loop around waiting for work to do */
	do {
		/* wait for work or to be told to exit */
		_debug("### Begin Wait");
		if (!atomic_read(&rxrpc_krxsecd_qcount)) {
			set_current_state(TASK_INTERRUPTIBLE);

			add_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);

			for (;;) {
				set_current_state(TASK_INTERRUPTIBLE);
				if (atomic_read(&rxrpc_krxsecd_qcount) ||
				    rxrpc_krxsecd_die ||
				    signal_pending(current))
					break;

				schedule();
			}

			remove_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);
			set_current_state(TASK_RUNNING);
		}
		die = rxrpc_krxsecd_die;
		_debug("### End Wait");

		/* see if there're incoming calls in need of authenticating */
		_debug("### Begin Inbound Calls");

		if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
			struct rxrpc_message *msg = NULL;

			spin_lock(&rxrpc_krxsecd_initmsgq_lock);

			if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
				msg = list_entry(rxrpc_krxsecd_initmsgq.next,
						 struct rxrpc_message, link);
				list_del_init(&msg->link);
				atomic_dec(&rxrpc_krxsecd_qcount);
			}

			spin_unlock(&rxrpc_krxsecd_initmsgq_lock);

			if (msg) {
				rxrpc_krxsecd_process_incoming_call(msg);
				rxrpc_put_message(msg);
			}
		}

		_debug("### End Inbound Calls");

		try_to_freeze();

                /* discard pending signals */
		rxrpc_discard_my_signals();

	} while (!die);

	/* and that's all */
	complete_and_exit(&rxrpc_krxsecd_dead, 0);

} /* end rxrpc_krxsecd() */

/*****************************************************************************/
/*
 * start up a krxsecd daemon
 */
int __init rxrpc_krxsecd_init(void)
{
	return kernel_thread(rxrpc_krxsecd, NULL, 0);

} /* end rxrpc_krxsecd_init() */

/*****************************************************************************/
/*
 * kill the krxsecd daemon and wait for it to complete
 */
void rxrpc_krxsecd_kill(void)
{
	rxrpc_krxsecd_die = 1;
	wake_up_all(&rxrpc_krxsecd_sleepq);
	wait_for_completion(&rxrpc_krxsecd_dead);

} /* end rxrpc_krxsecd_kill() */

/*****************************************************************************/
/*
 * clear all pending incoming calls for the specified transport
 */
void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans)
{
	LIST_HEAD(tmp);

	struct rxrpc_message *msg;
	struct list_head *_p, *_n;

	_enter("%p",trans);

	/* move all the messages for this transport onto a temp list */
	spin_lock(&rxrpc_krxsecd_initmsgq_lock);

	list_for_each_safe(_p, _n, &rxrpc_krxsecd_initmsgq) {
		msg = list_entry(_p, struct rxrpc_message, link);
		if (msg->trans == trans) {
			list_move_tail(&msg->link, &tmp);
			atomic_dec(&rxrpc_krxsecd_qcount);
		}
	}

	spin_unlock(&rxrpc_krxsecd_initmsgq_lock);

	/* zap all messages on the temp list */
	while (!list_empty(&tmp)) {
		msg = list_entry(tmp.next, struct rxrpc_message, link);
		list_del_init(&msg->link);
		rxrpc_put_message(msg);
	}

	_leave("");
} /* end rxrpc_krxsecd_clear_transport() */

/*****************************************************************************/
/*
 * queue a message on the incoming calls list
 */
void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg)
{
	_enter("%p", msg);

	/* queue for processing by krxsecd */
	spin_lock(&rxrpc_krxsecd_initmsgq_lock);

	if (!rxrpc_krxsecd_die) {
		rxrpc_get_message(msg);
		list_add_tail(&msg->link, &rxrpc_krxsecd_initmsgq);
		atomic_inc(&rxrpc_krxsecd_qcount);
	}

	spin_unlock(&rxrpc_krxsecd_initmsgq_lock);

	wake_up(&rxrpc_krxsecd_sleepq);

	_leave("");
} /* end rxrpc_krxsecd_queue_incoming_call() */

/*****************************************************************************/
/*
 * process the initial message of an incoming call
 */
void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg)
{
	struct rxrpc_transport *trans = msg->trans;
	struct rxrpc_service *srv;
	struct rxrpc_call *call;
	struct list_head *_p;
	unsigned short sid;
	int ret;

	_enter("%p{tr=%p}", msg, trans);

	ret = rxrpc_incoming_call(msg->conn, msg, &call);
	if (ret < 0)
		goto out;

	/* find the matching service on the transport */
	sid = ntohs(msg->hdr.serviceId);
	srv = NULL;

	spin_lock(&trans->lock);
	list_for_each(_p, &trans->services) {
		srv = list_entry(_p, struct rxrpc_service, link);
		if (srv->service_id == sid && try_module_get(srv->owner)) {
			/* found a match (made sure it won't vanish) */
			_debug("found service '%s'", srv->name);
			call->owner = srv->owner;
			break;
		}
	}
	spin_unlock(&trans->lock);

	/* report the new connection
	 * - the func must inc the call's usage count to keep it
	 */
	ret = -ENOENT;
	if (_p != &trans->services) {
		/* attempt to accept the call */
		call->conn->service = srv;
		call->app_attn_func = srv->attn_func;
		call->app_error_func = srv->error_func;
		call->app_aemap_func = srv->aemap_func;

		ret = srv->new_call(call);

		/* send an abort if an error occurred */
		if (ret < 0) {
			rxrpc_call_abort(call, ret);
		}
		else {
			/* formally receive and ACK the new packet */
			ret = rxrpc_conn_receive_call_packet(call->conn,
							     call, msg);
		}
	}

	rxrpc_put_call(call);
 out:
	if (ret < 0)
		rxrpc_trans_immediate_abort(trans, msg, ret);

	_leave(" (%d)", ret);
} /* end rxrpc_krxsecd_process_incoming_call() */