summaryrefslogtreecommitdiff
path: root/src/run.c
blob: 34d20b0b5c483f2b5f8da0e60e9a5e1d84876f1a (plain)
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
271
272
273
274
275
276
277
278
279
280
281
282
/*
 * (C) 2006-2007 by Pablo Neira Ayuso <pablo@netfilter.org>
 * 
 * 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Description: run and init functions
 */

#include "conntrackd.h"
#include "netlink.h"
#include "filter.h"
#include "log.h"
#include "alarm.h"
#include "fds.h"

#include <errno.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <string.h>

void killer(int foo)
{
	/* no signals while handling signals */
	sigprocmask(SIG_BLOCK, &STATE(block), NULL);

	nfct_close(STATE(event));
	nfct_close(STATE(request));

	if (STATE(us_filter))
		ct_filter_destroy(STATE(us_filter));
	local_server_destroy(&STATE(local));
	STATE(mode)->kill();

	nfct_close(STATE(dump));	/* cache_wt needs this here */

	unlink(CONFIG(lockfile));
	dlog(LOG_NOTICE, "---- shutdown received ----");
	close_log();

	sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);

	exit(0);
}

static void child(int foo)
{
	while(wait(NULL) > 0);
}

void local_handler(int fd, void *data)
{
	int ret;
	int type;

	ret = read(fd, &type, sizeof(type));
	if (ret == -1) {
		dlog(LOG_ERR, "can't read from unix socket");
		return;
	}
	if (ret == 0)
		return;

	switch(type) {
	case FLUSH_MASTER:
		dlog(LOG_WARNING, "`conntrackd -F' is deprecated. "
				  "Use conntrack -F instead.");
		if (fork() == 0) {
			execlp("conntrack", "conntrack", "-F", NULL);
			exit(EXIT_SUCCESS);
		}
		return;
	case RESYNC_MASTER:
		dlog(LOG_NOTICE, "resync with master table");
		nl_dump_conntrack_table();
		return;
	}

	if (!STATE(mode)->local(fd, type, data))
		dlog(LOG_WARNING, "unknown local request %d", type);
}

static void do_overrun_alarm(struct alarm_block *a, void *data)
{
	nl_overrun_request_resync();
	add_alarm(&STATE(overrun_alarm), 2, 0);
}

int
init(void)
{
	if (CONFIG(flags) & CTD_STATS_MODE)
		STATE(mode) = &stats_mode;
	else if (CONFIG(flags) & CTD_SYNC_MODE)
		STATE(mode) = &sync_mode;
	else {
		fprintf(stderr, "WARNING: No running mode specified. "
				"Defaulting to statistics mode.\n");
		CONFIG(flags) |= CTD_STATS_MODE;
		STATE(mode) = &stats_mode;
	}

	/* Initialization */
	if (STATE(mode)->init() == -1) {
		dlog(LOG_ERR, "initialization failed");
		return -1;
	}

	/* local UNIX socket */
	if (local_server_create(&STATE(local), &CONFIG(local)) == -1) {
		dlog(LOG_ERR, "can't open unix socket!");
		return -1;
	}

	if (nl_init_event_handler() == -1) {
		dlog(LOG_ERR, "can't open netlink handler: %s",
		     strerror(errno));
		dlog(LOG_ERR, "no ctnetlink kernel support?");
		return -1;
	}

	if (nl_init_dump_handler() == -1) {
		dlog(LOG_ERR, "can't open netlink handler: %s",
		     strerror(errno));
		dlog(LOG_ERR, "no ctnetlink kernel support?");
		return -1;
	}

	if (nl_init_overrun_handler() == -1) {
		dlog(LOG_ERR, "can't open netlink handler: %s",
		     strerror(errno));
		dlog(LOG_ERR, "no ctnetlink kernel support?");
		return -1;
	}

	if (nl_init_request_handler() == -1) {
		dlog(LOG_ERR, "can't open netlink handler: %s",
		     strerror(errno));
		dlog(LOG_ERR, "no ctnetlink kernel support?");
		return -1;
	}

	init_alarm(&STATE(overrun_alarm), NULL, do_overrun_alarm);

	STATE(fds) = create_fds();
	if (STATE(fds) == NULL) {
		dlog(LOG_ERR, "can't create file descriptor pool");
		return -1;
	}

	register_fd(STATE(local).fd, STATE(fds));
	register_fd(nfct_fd(STATE(event)), STATE(fds));
	register_fd(nfct_fd(STATE(overrun)), STATE(fds));

	if (STATE(mode)->register_fds &&
	    STATE(mode)->register_fds(STATE(fds)) == -1) {
		dlog(LOG_ERR, "fds registration failed");
		return -1;
	}

	/* Signals handling */
	sigemptyset(&STATE(block));
	sigaddset(&STATE(block), SIGTERM);
	sigaddset(&STATE(block), SIGINT);
	sigaddset(&STATE(block), SIGCHLD);

	if (signal(SIGINT, killer) == SIG_ERR)
		return -1;

	if (signal(SIGTERM, killer) == SIG_ERR)
		return -1;

	/* ignore connection reset by peer */
	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
		return -1;

	if (signal(SIGCHLD, child) == SIG_ERR)
		return -1;

	dlog(LOG_NOTICE, "initialization completed");

	return 0;
}

static void __run(struct timeval *next_alarm)
{
	int ret;
	fd_set readfds = STATE(fds)->readfds;

	ret = select(STATE(fds)->maxfd + 1, &readfds, NULL, NULL, next_alarm);
	if (ret == -1) {
		/* interrupted syscall, retry */
		if (errno == EINTR)
			return;

		dlog(LOG_WARNING, "select failed: %s", strerror(errno));
		return;
	}

	/* signals are racy */
	sigprocmask(SIG_BLOCK, &STATE(block), NULL);

	/* order received via UNIX socket */
	if (FD_ISSET(STATE(local).fd, &readfds))
		do_local_server_step(&STATE(local), NULL, local_handler);

	/* conntrack event has happened */
	if (FD_ISSET(nfct_fd(STATE(event)), &readfds)) {
		while ((ret = nfct_catch(STATE(event))) != -1);
		if (ret == -1) {
			switch(errno) {
			case ENOBUFS:
				/*
				 * It seems that ctnetlink can't back off,
				 * it's likely that we're losing events.
				 * Solution: duplicate the socket buffer
				 * size and resync with master conntrack table.
				 */
				nl_resize_socket_buffer(STATE(event));
				nl_overrun_request_resync();
				add_alarm(&STATE(overrun_alarm), 2, 0);
				break;
			case ENOENT:
				/*
				 * We received a message from another
				 * netfilter subsystem that we are not
				 * interested in. Just ignore it.
				 */
				break;
			case EAGAIN:
				break;
			default:
				dlog(LOG_WARNING,
				     "event catch says: %s", strerror(errno));
				break;
			}
		}
	}

	if (FD_ISSET(nfct_fd(STATE(overrun)), &readfds)) {
		del_alarm(&STATE(overrun_alarm));
		nfct_catch(STATE(overrun));
		if (STATE(mode)->purge)
			STATE(mode)->purge();
	}

	if (STATE(mode)->run)
		STATE(mode)->run(&readfds);

	sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
}

void __attribute__((noreturn))
run(void)
{
	struct timeval next_alarm; 
	struct timeval *next = NULL;

	while(1) {
		sigprocmask(SIG_BLOCK, &STATE(block), NULL);
		if (next != NULL && !timerisset(next))
			next = do_alarm_run(&next_alarm);
		else
			next = get_next_alarm_run(&next_alarm);
		sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);

		__run(next);
	}
}