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source: src/router/busybox/sysklogd/syslogd.c @ 17628

Last change on this file since 17628 was 17628, checked in by BrainSlayer, 20 months ago
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File size: 25.7 KB

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1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini syslogd implementation for busybox
4	*
5	* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6	*
7	* Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
8	*
9	* "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
10	*
11	* Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
12	*
13	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
14	*/
15
16	//usage:#define syslogd_trivial_usage
17	//usage: "[OPTIONS]"
18	//usage:#define syslogd_full_usage "\n\n"
19	//usage: "System logging utility\n"
20	//usage: IF_NOT_FEATURE_SYSLOGD_CFG(
21	//usage: "(this version of syslogd ignores /etc/syslog.conf)\n"
22	//usage: )
23	//usage: "\n -n Run in foreground"
24	//usage: "\n -O FILE Log to FILE (default:/var/log/messages)"
25	//usage: "\n -l N Log only messages more urgent than prio N (1-8)"
26	//usage: "\n -S Smaller output"
27	//usage: IF_FEATURE_ROTATE_LOGFILE(
28	//usage: "\n -s SIZE Max size (KB) before rotation (default:200KB, 0=off)"
29	//usage: "\n -b N N rotated logs to keep (default:1, max=99, 0=purge)"
30	//usage: )
31	//usage: IF_FEATURE_REMOTE_LOG(
32	//usage: "\n -R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP)"
33	//usage: "\n -L Log locally and via network (default is network only if -R)"
34	//usage: )
35	//usage: IF_FEATURE_SYSLOGD_DUP(
36	//usage: "\n -D Drop duplicates"
37	//usage: )
38	//usage: IF_FEATURE_IPC_SYSLOG(
39	/* NB: -Csize shouldn't have space (because size is optional) */
40	//usage: "\n -C[size_kb] Log to shared mem buffer (use logread to read it)"
41	//usage: )
42	//usage: IF_FEATURE_SYSLOGD_CFG(
43	//usage: "\n -f FILE Use FILE as config (default:/etc/syslog.conf)"
44	//usage: )
45	/* //usage: "\n -m MIN Minutes between MARK lines (default:20, 0=off)" */
46	//usage:
47	//usage:#define syslogd_example_usage
48	//usage: "$ syslogd -R masterlog:514\n"
49	//usage: "$ syslogd -R 192.168.1.1:601\n"
50
51	/*
52	* Done in syslogd_and_logger.c:
53	#include "libbb.h"
54	#define SYSLOG_NAMES
55	#define SYSLOG_NAMES_CONST
56	#include <syslog.h>
57	*/
58
59	#include <sys/un.h>
60	#include <sys/uio.h>
61
62	#if ENABLE_FEATURE_REMOTE_LOG
63	#include <netinet/in.h>
64	#endif
65
66	#if ENABLE_FEATURE_IPC_SYSLOG
67	#include <sys/ipc.h>
68	#include <sys/sem.h>
69	#include <sys/shm.h>
70	#endif
71
72
73	#define DEBUG 0
74
75	/* MARK code is not very useful, is bloat, and broken:
76	* can deadlock if alarmed to make MARK while writing to IPC buffer
77	* (semaphores are down but do_mark routine tries to down them again) */
78	#undef SYSLOGD_MARK
79
80	/* Write locking does not seem to be useful either */
81	#undef SYSLOGD_WRLOCK
82
83	enum {
84	MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
85	DNS_WAIT_SEC = 2 * 60,
86	};
87
88	/* Semaphore operation structures */
89	struct shbuf_ds {
90	int32_t size; /* size of data - 1 */
91	int32_t tail; /* end of message list */
92	char data[1]; /* data/messages */
93	};
94
95	#if ENABLE_FEATURE_REMOTE_LOG
96	typedef struct {
97	int remoteFD;
98	unsigned last_dns_resolve;
99	len_and_sockaddr *remoteAddr;
100	const char *remoteHostname;
101	} remoteHost_t;
102	#endif
103
104	typedef struct logFile_t {
105	const char *path;
106	int fd;
107	#if ENABLE_FEATURE_ROTATE_LOGFILE
108	unsigned size;
109	uint8_t isRegular;
110	#endif
111	} logFile_t;
112
113	#if ENABLE_FEATURE_SYSLOGD_CFG
114	typedef struct logRule_t {
115	uint8_t enabled_facility_priomap[LOG_NFACILITIES];
116	struct logFile_t *file;
117	struct logRule_t *next;
118	} logRule_t;
119	#endif
120
121	/* Allows us to have smaller initializer. Ugly. */
122	#define GLOBALS \
123	logFile_t logFile; \
124	/* interval between marks in seconds */ \
125	/int markInterval;/ \
126	/* level of messages to be logged */ \
127	int logLevel; \
128	IF_FEATURE_ROTATE_LOGFILE( \
129	/* max size of file before rotation */ \
130	unsigned logFileSize; \
131	/* number of rotated message files */ \
132	unsigned logFileRotate; \
133	) \
134	IF_FEATURE_IPC_SYSLOG( \
135	int shmid; /* ipc shared memory id */ \
136	int s_semid; /* ipc semaphore id */ \
137	int shm_size; \
138	struct sembuf SMwup[1]; \
139	struct sembuf SMwdn[3]; \
140	) \
141	IF_FEATURE_SYSLOGD_CFG( \
142	logRule_t *log_rules; \
143	)
144
145	struct init_globals {
146	GLOBALS
147	};
148
149	struct globals {
150	GLOBALS
151
152	#if ENABLE_FEATURE_REMOTE_LOG
153	llist_t *remoteHosts;
154	#endif
155	#if ENABLE_FEATURE_IPC_SYSLOG
156	struct shbuf_ds *shbuf;
157	#endif
158	time_t last_log_time;
159	/* localhost's name. We print only first 64 chars */
160	char *hostname;
161
162	/* We recv into recvbuf... */
163	char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
164	/* ...then copy to parsebuf, escaping control chars */
165	/* (can grow x2 max) */
166	char parsebuf[MAX_READ*2];
167	/* ...then sprintf into printbuf, adding timestamp (15 chars),
168	* host (64), fac.prio (20) to the message */
169	/* (growth by: 15 + 64 + 20 + delims = ~110) */
170	char printbuf[MAX_READ*2 + 128];
171	};
172
173	static const struct init_globals init_data = {
174	.logFile = {
175	.path = "/var/log/messages",
176	.fd = -1,
177	},
178	#ifdef SYSLOGD_MARK
179	.markInterval = 20 * 60,
180	#endif
181	.logLevel = 8,
182	#if ENABLE_FEATURE_ROTATE_LOGFILE
183	.logFileSize = 200 * 1024,
184	.logFileRotate = 1,
185	#endif
186	#if ENABLE_FEATURE_IPC_SYSLOG
187	.shmid = -1,
188	.s_semid = -1,
189	.shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)1024), / default shm size */
190	.SMwup = { {1, -1, IPC_NOWAIT} },
191	.SMwdn = { {0, 0}, {1, 0}, {1, +1} },
192	#endif
193	};
194
195	#define G (*ptr_to_globals)
196	#define INIT_G() do { \
197	SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
198	} while (0)
199
200
201	/* Options */
202	enum {
203	OPTBIT_mark = 0, // -m
204	OPTBIT_nofork, // -n
205	OPTBIT_outfile, // -O
206	OPTBIT_loglevel, // -l
207	OPTBIT_small, // -S
208	IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
209	IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
210	IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,) // -R
211	IF_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L
212	IF_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
213	IF_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,) // -D
214	IF_FEATURE_SYSLOGD_CFG( OPTBIT_cfg ,) // -f
215
216	OPT_mark = 1 << OPTBIT_mark ,
217	OPT_nofork = 1 << OPTBIT_nofork ,
218	OPT_outfile = 1 << OPTBIT_outfile ,
219	OPT_loglevel = 1 << OPTBIT_loglevel,
220	OPT_small = 1 << OPTBIT_small ,
221	OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
222	OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
223	OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
224	OPT_locallog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
225	OPT_circularlog = IF_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
226	OPT_dup = IF_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
227	OPT_cfg = IF_FEATURE_SYSLOGD_CFG( (1 << OPTBIT_cfg )) + 0,
228	};
229	#define OPTION_STR "m:nO:l:S" \
230	IF_FEATURE_ROTATE_LOGFILE("s:" ) \
231	IF_FEATURE_ROTATE_LOGFILE("b:" ) \
232	IF_FEATURE_REMOTE_LOG( "R:" ) \
233	IF_FEATURE_REMOTE_LOG( "L" ) \
234	IF_FEATURE_IPC_SYSLOG( "C::") \
235	IF_FEATURE_SYSLOGD_DUP( "D" ) \
236	IF_FEATURE_SYSLOGD_CFG( "f:" )
237	#define OPTION_DECL opt_m, opt_l \
238	IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
239	IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
240	IF_FEATURE_IPC_SYSLOG( ,*opt_C = NULL) \
241	IF_FEATURE_SYSLOGD_CFG( ,*opt_f = NULL)
242	#define OPTION_PARAM &opt_m, &(G.logFile.path), &opt_l \
243	IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
244	IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
245	IF_FEATURE_REMOTE_LOG( ,&remoteAddrList) \
246	IF_FEATURE_IPC_SYSLOG( ,&opt_C) \
247	IF_FEATURE_SYSLOGD_CFG( ,&opt_f)
248
249
250	#if ENABLE_FEATURE_SYSLOGD_CFG
251	static const CODE* find_by_name(char name, const CODE c_set)
252	{
253	for (; c_set->c_name; c_set++) {
254	if (strcmp(name, c_set->c_name) == 0)
255	return c_set;
256	}
257	return NULL;
258	}
259	#endif
260	static const CODE* find_by_val(int val, const CODE* c_set)
261	{
262	for (; c_set->c_name; c_set++) {
263	if (c_set->c_val == val)
264	return c_set;
265	}
266	return NULL;
267	}
268
269	#if ENABLE_FEATURE_SYSLOGD_CFG
270	static void parse_syslogdcfg(const char *file)
271	{
272	char *t;
273	logRule_t **pp_rule;
274	/* tok[0] set of selectors */
275	/* tok[1] file name */
276	/* tok[2] has to be NULL */
277	char *tok[3];
278	parser_t *parser;
279
280	parser = config_open2(file ? file : "/etc/syslog.conf",
281	file ? xfopen_for_read : fopen_or_warn_stdin);
282	if (!parser)
283	/* didn't find default /etc/syslog.conf */
284	/* proceed as if we built busybox without config support */
285	return;
286
287	/* use ptr to ptr to avoid checking whether head was initialized */
288	pp_rule = &G.log_rules;
289	/* iterate through lines of config, skipping comments */
290	while (config_read(parser, tok, 3, 2, "# \t", PARSE_NORMAL \| PARSE_MIN_DIE)) {
291	char *cur_selector;
292	logRule_t *cur_rule;
293
294	/* unexpected trailing token? */
295	if (tok[2])
296	goto cfgerr;
297
298	cur_rule = pp_rule = xzalloc(sizeof(cur_rule));
299
300	cur_selector = tok[0];
301	/* iterate through selectors: "kern.info;kern.!err;..." */
302	do {
303	const CODE *code;
304	char *next_selector;
305	uint8_t negated_prio; /* "kern.!err" */
306	uint8_t single_prio; /* "kern.=err" */
307	uint32_t facmap; /* bitmap of enabled facilities */
308	uint8_t primap; /* bitmap of enabled priorities */
309	unsigned i;
310
311	next_selector = strchr(cur_selector, ';');
312	if (next_selector)
313	*next_selector++ = '\0';
314
315	t = strchr(cur_selector, '.');
316	if (!t)
317	goto cfgerr;
318	t++ = '\0'; / separate facility from priority */
319
320	negated_prio = 0;
321	single_prio = 0;
322	if (*t == '!') {
323	negated_prio = 1;
324	++t;
325	}
326	if (*t == '=') {
327	single_prio = 1;
328	++t;
329	}
330
331	/* parse priority */
332	if (t == '')
333	primap = 0xff; /* all 8 log levels enabled */
334	else {
335	uint8_t priority;
336	code = find_by_name(t, prioritynames);
337	if (!code)
338	goto cfgerr;
339	primap = 0;
340	priority = code->c_val;
341	if (priority == INTERNAL_NOPRI) {
342	/* ensure we take "enabled_facility_priomap[fac] &= 0" branch below */
343	negated_prio = 1;
344	} else {
345	priority = 1 << priority;
346	do {
347	primap \|= priority;
348	if (single_prio)
349	break;
350	priority >>= 1;
351	} while (priority);
352	if (negated_prio)
353	primap = ~primap;
354	}
355	}
356
357	/* parse facility */
358	if (cur_selector == '')
359	facmap = (1<<LOG_NFACILITIES) - 1;
360	else {
361	char *next_facility;
362	facmap = 0;
363	t = cur_selector;
364	/* iterate through facilities: "kern,daemon.<priospec>" */
365	do {
366	next_facility = strchr(t, ',');
367	if (next_facility)
368	*next_facility++ = '\0';
369	code = find_by_name(t, facilitynames);
370	if (!code)
371	goto cfgerr;
372	/* "mark" is not a real facility, skip it */
373	if (code->c_val != INTERNAL_MARK)
374	facmap \|= 1<<(LOG_FAC(code->c_val));
375	t = next_facility;
376	} while (t);
377	}
378
379	/* merge result with previous selectors */
380	for (i = 0; i < LOG_NFACILITIES; ++i) {
381	if (!(facmap & (1<<i)))
382	continue;
383	if (negated_prio)
384	cur_rule->enabled_facility_priomap[i] &= primap;
385	else
386	cur_rule->enabled_facility_priomap[i] \|= primap;
387	}
388
389	cur_selector = next_selector;
390	} while (cur_selector);
391
392	/* check whether current file name was mentioned in previous rules or
393	* as global logfile (G.logFile).
394	*/
395	if (strcmp(G.logFile.path, tok[1]) == 0) {
396	cur_rule->file = &G.logFile;
397	goto found;
398	}
399	/* temporarily use cur_rule as iterator, but *pp_rule still points
400	* to currently processing rule entry.
401	* NOTE: *pp_rule points to the current (and last in the list) rule.
402	*/
403	for (cur_rule = G.log_rules; cur_rule != *pp_rule; cur_rule = cur_rule->next) {
404	if (strcmp(cur_rule->file->path, tok[1]) == 0) {
405	/* found - reuse the same file structure */
406	(*pp_rule)->file = cur_rule->file;
407	cur_rule = *pp_rule;
408	goto found;
409	}
410	}
411	cur_rule->file = xzalloc(sizeof(*cur_rule->file));
412	cur_rule->file->fd = -1;
413	cur_rule->file->path = xstrdup(tok[1]);
414	found:
415	pp_rule = &cur_rule->next;
416	}
417	config_close(parser);
418	return;
419
420	cfgerr:
421	bb_error_msg_and_die("error in '%s' at line %d", file, parser->lineno);
422	}
423	#endif
424
425	/* circular buffer variables/structures */
426	#if ENABLE_FEATURE_IPC_SYSLOG
427
428	#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
429	#error Sorry, you must set the syslogd buffer size to at least 4KB.
430	#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
431	#endif
432
433	/* our shared key (syslogd.c and logread.c must be in sync) */
434	enum { KEY_ID = 0x414e4547 }; /* "GENA" */
435
436	static void ipcsyslog_cleanup(void)
437	{
438	if (G.shmid != -1) {
439	shmdt(G.shbuf);
440	}
441	if (G.shmid != -1) {
442	shmctl(G.shmid, IPC_RMID, NULL);
443	}
444	if (G.s_semid != -1) {
445	semctl(G.s_semid, 0, IPC_RMID, 0);
446	}
447	}
448
449	static void ipcsyslog_init(void)
450	{
451	if (DEBUG)
452	printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
453
454	G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT \| 0644);
455	if (G.shmid == -1) {
456	bb_perror_msg_and_die("shmget");
457	}
458
459	G.shbuf = shmat(G.shmid, NULL, 0);
460	if (G.shbuf == (void) -1L) { / shmat has bizarre error return */
461	bb_perror_msg_and_die("shmat");
462	}
463
464	memset(G.shbuf, 0, G.shm_size);
465	G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
466	/G.shbuf->tail = 0;/
467
468	/* we'll trust the OS to set initial semval to 0 (let's hope) */
469	G.s_semid = semget(KEY_ID, 2, IPC_CREAT \| IPC_EXCL \| 1023);
470	if (G.s_semid == -1) {
471	if (errno == EEXIST) {
472	G.s_semid = semget(KEY_ID, 2, 0);
473	if (G.s_semid != -1)
474	return;
475	}
476	bb_perror_msg_and_die("semget");
477	}
478	}
479
480	/* Write message to shared mem buffer */
481	static void log_to_shmem(const char *msg)
482	{
483	int old_tail, new_tail;
484	int len;
485
486	if (semop(G.s_semid, G.SMwdn, 3) == -1) {
487	bb_perror_msg_and_die("SMwdn");
488	}
489
490	/* Circular Buffer Algorithm:
491	* --------------------------
492	* tail == position where to store next syslog message.
493	* tail's max value is (shbuf->size - 1)
494	* Last byte of buffer is never used and remains NUL.
495	*/
496	len = strlen(msg) + 1; /* length with NUL included */
497	again:
498	old_tail = G.shbuf->tail;
499	new_tail = old_tail + len;
500	if (new_tail < G.shbuf->size) {
501	/* store message, set new tail */
502	memcpy(G.shbuf->data + old_tail, msg, len);
503	G.shbuf->tail = new_tail;
504	} else {
505	/* k == available buffer space ahead of old tail */
506	int k = G.shbuf->size - old_tail;
507	/* copy what fits to the end of buffer, and repeat */
508	memcpy(G.shbuf->data + old_tail, msg, k);
509	msg += k;
510	len -= k;
511	G.shbuf->tail = 0;
512	goto again;
513	}
514	if (semop(G.s_semid, G.SMwup, 1) == -1) {
515	bb_perror_msg_and_die("SMwup");
516	}
517	if (DEBUG)
518	printf("tail:%d\n", G.shbuf->tail);
519	}
520	#else
521	void ipcsyslog_cleanup(void);
522	void ipcsyslog_init(void);
523	void log_to_shmem(const char *msg);
524	#endif /* FEATURE_IPC_SYSLOG */
525
526	/* Print a message to the log file. */
527	static void log_locally(time_t now, char msg, logFile_t log_file)
528	{
529	#ifdef SYSLOGD_WRLOCK
530	struct flock fl;
531	#endif
532	int len = strlen(msg);
533
534	if (log_file->fd >= 0) {
535	/* Reopen log file every second. This allows admin
536	* to delete the file and not worry about restarting us.
537	* This costs almost nothing since it happens
538	* _at most_ once a second.
539	*/
540	if (!now)
541	now = time(NULL);
542	if (G.last_log_time != now) {
543	G.last_log_time = now;
544	close(log_file->fd);
545	goto reopen;
546	}
547	} else {
548	reopen:
549	log_file->fd = open(log_file->path, O_WRONLY \| O_CREAT
550	\| O_NOCTTY \| O_APPEND \| O_NONBLOCK,
551	0666);
552	if (log_file->fd < 0) {
553	/* cannot open logfile? - print to /dev/console then */
554	int fd = device_open(DEV_CONSOLE, O_WRONLY \| O_NOCTTY \| O_NONBLOCK);
555	if (fd < 0)
556	fd = 2; /* then stderr, dammit */
557	full_write(fd, msg, len);
558	if (fd != 2)
559	close(fd);
560	return;
561	}
562	#if ENABLE_FEATURE_ROTATE_LOGFILE
563	{
564	struct stat statf;
565	log_file->isRegular = (fstat(log_file->fd, &statf) == 0 && S_ISREG(statf.st_mode));
566	/* bug (mostly harmless): can wrap around if file > 4gb */
567	log_file->size = statf.st_size;
568	}
569	#endif
570	}
571
572	#ifdef SYSLOGD_WRLOCK
573	fl.l_whence = SEEK_SET;
574	fl.l_start = 0;
575	fl.l_len = 1;
576	fl.l_type = F_WRLCK;
577	fcntl(log_file->fd, F_SETLKW, &fl);
578	#endif
579
580	#if ENABLE_FEATURE_ROTATE_LOGFILE
581	if (G.logFileSize && log_file->isRegular && log_file->size > G.logFileSize) {
582	if (G.logFileRotate) { /* always 0..99 */
583	int i = strlen(log_file->path) + 3 + 1;
584	char oldFile[i];
585	char newFile[i];
586	i = G.logFileRotate - 1;
587	/* rename: f.8 -> f.9; f.7 -> f.8; ... */
588	while (1) {
589	sprintf(newFile, "%s.%d", log_file->path, i);
590	if (i == 0) break;
591	sprintf(oldFile, "%s.%d", log_file->path, --i);
592	/* ignore errors - file might be missing */
593	rename(oldFile, newFile);
594	}
595	/* newFile == "f.0" now */
596	rename(log_file->path, newFile);
597	#ifdef SYSLOGD_WRLOCK
598	fl.l_type = F_UNLCK;
599	fcntl(log_file->fd, F_SETLKW, &fl);
600	#endif
601	close(log_file->fd);
602	goto reopen;
603	}
604	ftruncate(log_file->fd, 0);
605	}
606	log_file->size +=
607	#endif
608	full_write(log_file->fd, msg, len);
609	#ifdef SYSLOGD_WRLOCK
610	fl.l_type = F_UNLCK;
611	fcntl(log_file->fd, F_SETLKW, &fl);
612	#endif
613	}
614
615	static void parse_fac_prio_20(int pri, char *res20)
616	{
617	const CODE c_pri, c_fac;
618
619	c_fac = find_by_val(LOG_FAC(pri) << 3, facilitynames);
620	if (c_fac) {
621	c_pri = find_by_val(LOG_PRI(pri), prioritynames);
622	if (c_pri) {
623	snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
624	return;
625	}
626	}
627	snprintf(res20, 20, "<%d>", pri);
628	}
629
630	/* len parameter is used only for "is there a timestamp?" check.
631	* NB: some callers cheat and supply len==0 when they know
632	* that there is no timestamp, short-circuiting the test. */
633	static void timestamp_and_log(int pri, char *msg, int len)
634	{
635	char *timestamp;
636	time_t now;
637
638	/* Jan 18 00:11:22 msg... */
639	/* 01234567890123456 */
640	if (len < 16 \|\| msg[3] != ' ' \|\| msg[6] != ' '
641	\|\| msg[9] != ':' \|\| msg[12] != ':' \|\| msg[15] != ' '
642	) {
643	time(&now);
644	timestamp = ctime(&now) + 4; /* skip day of week */
645	} else {
646	now = 0;
647	timestamp = msg;
648	msg += 16;
649	}
650	timestamp[15] = '\0';
651
652	if (option_mask32 & OPT_small)
653	sprintf(G.printbuf, "%s %s\n", timestamp, msg);
654	else {
655	char res[20];
656	parse_fac_prio_20(pri, res);
657	sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
658	}
659
660	/* Log message locally (to file or shared mem) */
661	#if ENABLE_FEATURE_SYSLOGD_CFG
662	{
663	bool match = 0;
664	logRule_t *rule;
665	uint8_t facility = LOG_FAC(pri);
666	uint8_t prio_bit = 1 << LOG_PRI(pri);
667
668	for (rule = G.log_rules; rule; rule = rule->next) {
669	if (rule->enabled_facility_priomap[facility] & prio_bit) {
670	log_locally(now, G.printbuf, rule->file);
671	match = 1;
672	}
673	}
674	if (match)
675	return;
676	}
677	#endif
678	if (LOG_PRI(pri) < G.logLevel) {
679	#if ENABLE_FEATURE_IPC_SYSLOG
680	if ((option_mask32 & OPT_circularlog) && G.shbuf) {
681	log_to_shmem(msg);
682	return;
683	}
684	#endif
685	log_locally(now, G.printbuf, &G.logFile);
686	}
687	}
688
689	static void timestamp_and_log_internal(const char *msg)
690	{
691	/* -L, or no -R */
692	if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
693	return;
694	timestamp_and_log(LOG_SYSLOG \| LOG_INFO, (char*)msg, 0);
695	}
696
697	/* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
698	* embedded NULs. Split messages on each of these NULs, parse prio,
699	* escape control chars and log each locally. */
700	static void split_escape_and_log(char *tmpbuf, int len)
701	{
702	char *p = tmpbuf;
703
704	tmpbuf += len;
705	while (p < tmpbuf) {
706	char c;
707	char *q = G.parsebuf;
708	int pri = (LOG_USER \| LOG_NOTICE);
709
710	if (*p == '<') {
711	/* Parse the magic priority number */
712	pri = bb_strtou(p + 1, &p, 10);
713	if (*p == '>')
714	p++;
715	if (pri & ~(LOG_FACMASK \| LOG_PRIMASK))
716	pri = (LOG_USER \| LOG_NOTICE);
717	}
718
719	while ((c = *p++)) {
720	if (c == '\n')
721	c = ' ';
722	if (!(c & ~0x1f) && c != '\t') {
723	*q++ = '^';
724	c += '@'; /* ^@, ^A, ^B... */
725	}
726	*q++ = c;
727	}
728	*q = '\0';
729
730	/* Now log it */
731	timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
732	}
733	}
734
735	#ifdef SYSLOGD_MARK
736	static void do_mark(int sig)
737	{
738	if (G.markInterval) {
739	timestamp_and_log_internal("-- MARK --");
740	alarm(G.markInterval);
741	}
742	}
743	#endif
744
745	/* Don't inline: prevent struct sockaddr_un to take up space on stack
746	* permanently */
747	static NOINLINE int create_socket(void)
748	{
749	struct sockaddr_un sunx;
750	int sock_fd;
751	char *dev_log_name;
752
753	#if ENABLE_FEATURE_SYSTEMD
754	if (sd_listen_fds() == 1)
755	return SD_LISTEN_FDS_START;
756	#endif
757
758	memset(&sunx, 0, sizeof(sunx));
759	sunx.sun_family = AF_UNIX;
760
761	/* Unlink old /dev/log or object it points to. */
762	/* (if it exists, bind will fail) */
763	strcpy(sunx.sun_path, "/dev/log");
764	dev_log_name = xmalloc_follow_symlinks("/dev/log");
765	if (dev_log_name) {
766	safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
767	free(dev_log_name);
768	}
769	unlink(sunx.sun_path);
770
771	sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
772	xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
773	chmod("/dev/log", 0666);
774
775	return sock_fd;
776	}
777
778	#if ENABLE_FEATURE_REMOTE_LOG
779	static int try_to_resolve_remote(remoteHost_t *rh)
780	{
781	if (!rh->remoteAddr) {
782	unsigned now = monotonic_sec();
783
784	/* Don't resolve name too often - DNS timeouts can be big */
785	if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
786	return -1;
787	rh->last_dns_resolve = now;
788	rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
789	if (!rh->remoteAddr)
790	return -1;
791	}
792	return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
793	}
794	#endif
795
796	static void do_syslogd(void) NORETURN;
797	static void do_syslogd(void)
798	{
799	int sock_fd;
800	#if ENABLE_FEATURE_REMOTE_LOG
801	llist_t *item;
802	#endif
803	#if ENABLE_FEATURE_SYSLOGD_DUP
804	int last_sz = -1;
805	char *last_buf;
806	char *recvbuf = G.recvbuf;
807	#else
808	#define recvbuf (G.recvbuf)
809	#endif
810
811	/* Set up signal handlers (so that they interrupt read()) */
812	signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
813	signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
814	//signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
815	signal(SIGHUP, SIG_IGN);
816	#ifdef SYSLOGD_MARK
817	signal(SIGALRM, do_mark);
818	alarm(G.markInterval);
819	#endif
820	sock_fd = create_socket();
821
822	if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
823	ipcsyslog_init();
824	}
825
826	timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
827
828	while (!bb_got_signal) {
829	ssize_t sz;
830
831	#if ENABLE_FEATURE_SYSLOGD_DUP
832	last_buf = recvbuf;
833	if (recvbuf == G.recvbuf)
834	recvbuf = G.recvbuf + MAX_READ;
835	else
836	recvbuf = G.recvbuf;
837	#endif
838	read_again:
839	sz = read(sock_fd, recvbuf, MAX_READ - 1);
840	if (sz < 0) {
841	if (!bb_got_signal)
842	bb_perror_msg("read from /dev/log");
843	break;
844	}
845
846	/* Drop trailing '\n' and NULs (typically there is one NUL) */
847	while (1) {
848	if (sz == 0)
849	goto read_again;
850	/* man 3 syslog says: "A trailing newline is added when needed".
851	* However, neither glibc nor uclibc do this:
852	* syslog(prio, "test") sends "test\0" to /dev/log,
853	* syslog(prio, "test\n") sends "test\n\0".
854	* IOW: newline is passed verbatim!
855	* I take it to mean that it's syslogd's job
856	* to make those look identical in the log files. */
857	if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
858	break;
859	sz--;
860	}
861	#if ENABLE_FEATURE_SYSLOGD_DUP
862	if ((option_mask32 & OPT_dup) && (sz == last_sz))
863	if (memcmp(last_buf, recvbuf, sz) == 0)
864	continue;
865	last_sz = sz;
866	#endif
867	#if ENABLE_FEATURE_REMOTE_LOG
868	/* Stock syslogd sends it '\n'-terminated
869	* over network, mimic that */
870	recvbuf[sz] = '\n';
871
872	/* We are not modifying log messages in any way before send */
873	/* Remote site cannot trust _us_ anyway and need to do validation again */
874	for (item = G.remoteHosts; item != NULL; item = item->link) {
875	remoteHost_t rh = (remoteHost_t )item->data;
876
877	if (rh->remoteFD == -1) {
878	rh->remoteFD = try_to_resolve_remote(rh);
879	if (rh->remoteFD == -1)
880	continue;
881	}
882
883	/* Send message to remote logger.
884	* On some errors, close and set remoteFD to -1
885	* so that DNS resolution is retried.
886	*/
887	if (sendto(rh->remoteFD, recvbuf, sz+1,
888	MSG_DONTWAIT \| MSG_NOSIGNAL,
889	&(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
890	) {
891	switch (errno) {
892	case ECONNRESET:
893	case ENOTCONN: /* paranoia */
894	case EPIPE:
895	close(rh->remoteFD);
896	rh->remoteFD = -1;
897	free(rh->remoteAddr);
898	rh->remoteAddr = NULL;
899	}
900	}
901	}
902	#endif
903	if (!ENABLE_FEATURE_REMOTE_LOG \|\| (option_mask32 & OPT_locallog)) {
904	recvbuf[sz] = '\0'; /* ensure it is NUL terminated */
905	split_escape_and_log(recvbuf, sz);
906	}
907	} /* while (!bb_got_signal) */
908
909	timestamp_and_log_internal("syslogd exiting");
910	puts("syslogd exiting");
911	if (ENABLE_FEATURE_IPC_SYSLOG)
912	ipcsyslog_cleanup();
913	kill_myself_with_sig(bb_got_signal);
914	#undef recvbuf
915	}
916
917	int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
918	int syslogd_main(int argc UNUSED_PARAM, char **argv)
919	{
920	int opts;
921	char OPTION_DECL;
922	#if ENABLE_FEATURE_REMOTE_LOG
923	llist_t *remoteAddrList = NULL;
924	#endif
925
926	INIT_G();
927
928	/* No non-option params, -R can occur multiple times */
929	opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
930	opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
931	#if ENABLE_FEATURE_REMOTE_LOG
932	while (remoteAddrList) {
933	remoteHost_t rh = xzalloc(sizeof(rh));
934	rh->remoteHostname = llist_pop(&remoteAddrList);
935	rh->remoteFD = -1;
936	rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
937	llist_add_to(&G.remoteHosts, rh);
938	}
939	#endif
940
941	#ifdef SYSLOGD_MARK
942	if (opts & OPT_mark) // -m
943	G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
944	#endif
945	//if (opts & OPT_nofork) // -n
946	//if (opts & OPT_outfile) // -O
947	if (opts & OPT_loglevel) // -l
948	G.logLevel = xatou_range(opt_l, 1, 8);
949	//if (opts & OPT_small) // -S
950	#if ENABLE_FEATURE_ROTATE_LOGFILE
951	if (opts & OPT_filesize) // -s
952	G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
953	if (opts & OPT_rotatecnt) // -b
954	G.logFileRotate = xatou_range(opt_b, 0, 99);
955	#endif
956	#if ENABLE_FEATURE_IPC_SYSLOG
957	if (opt_C) // -Cn
958	G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
959	#endif
960	/* If they have not specified remote logging, then log locally */
961	if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
962	option_mask32 \|= OPT_locallog;
963	#if ENABLE_FEATURE_SYSLOGD_CFG
964	parse_syslogdcfg(opt_f);
965	#endif
966
967	/* Store away localhost's name before the fork */
968	G.hostname = safe_gethostname();
969	*strchrnul(G.hostname, '.') = '\0';
970
971	if (!(opts & OPT_nofork)) {
972	bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
973	}
974	//umask(0); - why??
975	write_pidfile("/var/run/syslogd.pid");
976	do_syslogd();
977	/* return EXIT_SUCCESS; */
978	}
979
980	/* Clean up. Needed because we are included from syslogd_and_logger.c */
981	#undef DEBUG
982	#undef SYSLOGD_MARK
983	#undef SYSLOGD_WRLOCK
984	#undef G
985	#undef GLOBALS
986	#undef INIT_G
987	#undef OPTION_STR
988	#undef OPTION_DECL
989	#undef OPTION_PARAM

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