aboutsummaryrefslogtreecommitdiff
path: root/syslogd.c
blob: 9a4af49269038816cf23c25fcd860650120692bb (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
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
/* vi: set sw=4 ts=4: */
/*
 * Mini syslogd implementation for busybox
 *
 * Copyright (C) 1999,2000 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 *
 * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "internal.h"
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/klog.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/param.h>
#include <time.h>
#include <unistd.h>

#define ksyslog klogctl
extern int ksyslog(int type, char *buf, int len);


/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
#define SYSLOG_NAMES
#include <sys/syslog.h>

/* Path for the file where all log messages are written */
#define __LOG_FILE "/var/log/messages"

/* Path to the unix socket */
char lfile[BUFSIZ] = "";

static char *logFilePath = __LOG_FILE;

/* interval between marks in seconds */
static int MarkInterval = 20 * 60;

/* localhost's name */
static char LocalHostName[32];

static const char syslogd_usage[] =
	"syslogd [OPTION]...\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
	"\nLinux system and kernel (provides klogd) logging utility.\n"
	"Note that this version of syslogd/klogd ignores /etc/syslog.conf.\n\n"
	"Options:\n"
	"\t-m\tChange the mark timestamp interval. default=20min. 0=off\n"
	"\t-n\tDo not fork into the background (for when run by init)\n"
#ifdef BB_KLOGD
	"\t-K\tDo not start up the klogd process (by default syslogd spawns klogd).\n"
#endif
	"\t-O\tSpecify an alternate log file.  default=/var/log/messages\n"
#endif
	;

/* Note: There is also a function called "message()" in init.c */
/* Print a message to the log file. */
static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
static void message (char *fmt, ...)
{
	int fd;
	struct flock fl;
	va_list arguments;

	fl.l_whence = SEEK_SET;
	fl.l_start  = 0;
	fl.l_len    = 1;

	if ((fd = device_open (logFilePath,
						   O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
						   O_NONBLOCK)) >= 0) {
		fl.l_type = F_WRLCK;
		fcntl (fd, F_SETLKW, &fl);
		va_start (arguments, fmt);
		vdprintf (fd, fmt, arguments);
		va_end (arguments);
		fl.l_type = F_UNLCK;
		fcntl (fd, F_SETLKW, &fl);
		close (fd);
	} else {
		/* Always send console messages to /dev/console so people will see them. */
		if ((fd = device_open (_PATH_CONSOLE,
							   O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) {
			va_start (arguments, fmt);
			vdprintf (fd, fmt, arguments);
			va_end (arguments);
			close (fd);
		} else {
			fprintf (stderr, "Bummer, can't print: ");
			va_start (arguments, fmt);
			vfprintf (stderr, fmt, arguments);
			fflush (stderr);
			va_end (arguments);
		}
	}
}

static void logMessage (int pri, char *msg)
{
	time_t now;
	char *timestamp;
	static char res[20] = "";
	CODE *c_pri, *c_fac;

	if (pri != 0) {
		for (c_fac = facilitynames;
			 c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++);
		for (c_pri = prioritynames;
			 c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++);
		if (*c_fac->c_name == '\0' || *c_pri->c_name == '\0')
			snprintf(res, sizeof(res), "<%d>", pri);
		else
			snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
	}

	if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
		msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') {
		time(&now);
		timestamp = ctime(&now) + 4;
		timestamp[15] = '\0';
	} else {
		timestamp = msg;
		timestamp[15] = '\0';
		msg += 16;
	}

	/* todo: supress duplicates */

	/* now spew out the message to wherever it is supposed to go */
	message("%s %s %s %s\n", timestamp, LocalHostName, res, msg);
}

static void quit_signal(int sig)
{
	logMessage(0, "System log daemon exiting.");
	unlink(lfile);
	exit(TRUE);
}

static void domark(int sig)
{
	if (MarkInterval > 0) {
		logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
		alarm(MarkInterval);
	}
}

static void doSyslogd (void) __attribute__ ((noreturn));
static void doSyslogd (void)
{
	struct sockaddr_un sunx;
	socklen_t addrLength;


	int sock_fd;
	fd_set fds;

	char lfile[BUFSIZ];

	/* Set up signal handlers. */
	signal (SIGINT,  quit_signal);
	signal (SIGTERM, quit_signal);
	signal (SIGQUIT, quit_signal);
	signal (SIGHUP,  SIG_IGN);
	signal (SIGCLD,  SIG_IGN);
	signal (SIGALRM, domark);
	alarm (MarkInterval);

	/* Create the syslog file so realpath() can work. */
	close (open (_PATH_LOG, O_RDWR | O_CREAT, 0644));
	if (realpath (_PATH_LOG, lfile) == NULL)
		fatalError ("Could not resolv path to " _PATH_LOG ": %s\n", strerror (errno));

	unlink (lfile);

	memset (&sunx, 0, sizeof (sunx));
	sunx.sun_family = AF_UNIX;
	strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path));
	if ((sock_fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
		fatalError ("Couldn't obtain descriptor for socket " _PATH_LOG ": %s\n", strerror (errno));

	addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
	if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
		fatalError ("Could not connect to socket " _PATH_LOG ": %s\n", strerror (errno));

	if (chmod (lfile, 0666) < 0)
		fatalError ("Could not set permission on " _PATH_LOG ": %s\n", strerror (errno));

	FD_ZERO (&fds);
	FD_SET (sock_fd, &fds);

	logMessage (0, "syslogd started: BusyBox v" BB_VER " (" BB_BT ")");

	for (;;) {

		fd_set readfds;
		int    n_ready;
		int    fd;

		memcpy (&readfds, &fds, sizeof (fds));

		if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
			if (errno == EINTR) continue; /* alarm may have happened. */
			fatalError ("select error: %s\n", strerror (errno));
		}

		for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
			if (FD_ISSET (fd, &readfds)) {

				--n_ready;

				if (fd == sock_fd) {

					int   conn;
					pid_t pid;

					if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
						fatalError ("accept error: %s\n", strerror (errno));
					}

					pid = fork();

					if (pid < 0) {
						perror ("syslogd: fork");
						close (conn);
						continue;
					}

					if (pid > 0) {

#						define BUFSIZE 1023
						char   buf[ BUFSIZE + 1 ];
						int    n_read;

						while ((n_read = read (conn, buf, BUFSIZE )) > 0) {

							int           pri = (LOG_USER | LOG_NOTICE);
							char          line[ BUFSIZE + 1 ];
							unsigned char c;

							char *p = buf, *q = line;

							buf[ n_read - 1 ] = '\0';

							while (p && (c = *p) && q < &line[ sizeof (line) - 1 ]) {
								if (c == '<') {
								/* Parse the magic priority number. */
									pri = 0;
									while (isdigit (*(++p))) {
										pri = 10 * pri + (*p - '0');
									}
									if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
										pri = (LOG_USER | LOG_NOTICE);
								} else if (c == '\n') {
									*q++ = ' ';
								} else if (iscntrl (c) && (c < 0177)) {
									*q++ = '^';
									*q++ = c ^ 0100;
								} else {
									*q++ = c;
								}
								p++;
							}
							*q = '\0';
							/* Now log it */
							logMessage (pri, line);
						}
						exit (0);
					}
					close (conn);
				}
			}
		}
	}
}

#ifdef BB_KLOGD

static void klogd_signal(int sig)
{
	ksyslog(7, NULL, 0);
	ksyslog(0, 0, 0);
	logMessage(0, "Kernel log daemon exiting.");
	exit(TRUE);
}

static void doKlogd (void) __attribute__ ((noreturn));
static void doKlogd (void)
{
	int priority = LOG_INFO;
	char log_buffer[4096];
	char *logp;

	/* Set up sig handlers */
	signal(SIGINT, klogd_signal);
	signal(SIGKILL, klogd_signal);
	signal(SIGTERM, klogd_signal);
	signal(SIGHUP, SIG_IGN);
	logMessage(0, "klogd started: "
			   "BusyBox v" BB_VER " (" BB_BT ")");

	ksyslog(1, NULL, 0);

	while (1) {
		/* Use kernel syscalls */
		memset(log_buffer, '\0', sizeof(log_buffer));
		if (ksyslog(2, log_buffer, sizeof(log_buffer)) < 0) {
			char message[80];

			if (errno == EINTR)
				continue;
			snprintf(message, 79, "klogd: Error return from sys_sycall: " \
					 "%d - %s.\n", errno, strerror(errno));
			logMessage(LOG_SYSLOG | LOG_ERR, message);
			exit(1);
		}
		logp = log_buffer;
		if (*log_buffer == '<') {
			switch (*(log_buffer + 1)) {
			case '0':
				priority = LOG_EMERG;
				break;
			case '1':
				priority = LOG_ALERT;
				break;
			case '2':
				priority = LOG_CRIT;
				break;
			case '3':
				priority = LOG_ERR;
				break;
			case '4':
				priority = LOG_WARNING;
				break;
			case '5':
				priority = LOG_NOTICE;
				break;
			case '6':
				priority = LOG_INFO;
				break;
			case '7':
			default:
				priority = LOG_DEBUG;
			}
			logp += 3;
		}
		logMessage(LOG_KERN | priority, logp);
	}

}

#endif

static void daemon_init (char **argv, char *dz, void fn (void))
{
	setsid();
	chdir ("/");
	strncpy(argv[0], dz, strlen(argv[0]));
	fn();
	exit(0);
}

extern int syslogd_main(int argc, char **argv)
{
	int pid, klogd_pid;
	int doFork = TRUE;

#ifdef BB_KLOGD
	int startKlogd = TRUE;
#endif
	int stopDoingThat = FALSE;
	char *p;
	char **argv1 = argv;

	while (--argc > 0 && **(++argv1) == '-') {
		stopDoingThat = FALSE;
		while (stopDoingThat == FALSE && *(++(*argv1))) {
			switch (**argv1) {
			case 'm':
				if (--argc == 0) {
					usage(syslogd_usage);
				}
				MarkInterval = atoi(*(++argv1)) * 60;
				break;
			case 'n':
				doFork = FALSE;
				break;
#ifdef BB_KLOGD
			case 'K':
				startKlogd = FALSE;
				break;
#endif
			case 'O':
				if (--argc == 0) {
					usage(syslogd_usage);
				}
				logFilePath = *(++argv1);
				stopDoingThat = TRUE;
				break;
			default:
				usage(syslogd_usage);
			}
		}
	}

	/* Store away localhost's name before the fork */
	gethostname(LocalHostName, sizeof(LocalHostName));
	if ((p = strchr(LocalHostName, '.'))) {
		*p++ = '\0';
	}

	umask(0);

#ifdef BB_KLOGD
	/* Start up the klogd process */
	if (startKlogd == TRUE) {
		klogd_pid = fork();
		if (klogd_pid == 0) {
			daemon_init (argv, "klogd", doKlogd);
		}
	}
#endif

	if (doFork == TRUE) {
		pid = fork();
		if (pid < 0)
			exit(pid);
		else if (pid == 0) {
			daemon_init (argv, "syslogd", doSyslogd);
		}
	} else {
		doSyslogd();
	}

	exit(TRUE);
}

/*
Local Variables
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/