xref: /third_party/musl/src/misc/syslog.c (revision 570af302)
1#include <stdarg.h>
2#include <sys/socket.h>
3#include <stdio.h>
4#include <unistd.h>
5#include <time.h>
6#include <signal.h>
7#include <string.h>
8#include <pthread.h>
9#include <errno.h>
10#include <fcntl.h>
11#include "lock.h"
12#include "fork_impl.h"
13#include <unsupported_api.h>
14#include "locale_impl.h"
15#include <syslog.h>
16
17static volatile int lock[1];
18static char log_ident[32];
19static int log_opt;
20static int log_facility = LOG_USER;
21static int log_mask = 0xff;
22static int log_fd = -1;
23volatile int *const __syslog_lockptr = lock;
24
25int setlogmask(int maskpri)
26{
27	UNSUPPORTED_API_VOID(LITEOS_A);
28	LOCK(lock);
29	int ret = log_mask;
30	if (maskpri) log_mask = maskpri;
31	UNLOCK(lock);
32	return ret;
33}
34
35static const struct {
36	short sun_family;
37	char sun_path[9];
38} log_addr = {
39	AF_UNIX,
40	"/dev/log"
41};
42
43void closelog(void)
44{
45	int cs;
46	UNSUPPORTED_API_VOID(LITEOS_A);
47	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
48	LOCK(lock);
49	close(log_fd);
50	log_fd = -1;
51	UNLOCK(lock);
52	pthread_setcancelstate(cs, 0);
53}
54
55static void __openlog()
56{
57	UNSUPPORTED_API_VOID(LITEOS_A);
58	log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
59	if (log_fd >= 0) connect(log_fd, (void *)&log_addr, sizeof log_addr);
60}
61
62void openlog(const char *ident, int opt, int facility)
63{
64	int cs;
65	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
66	LOCK(lock);
67
68	if (ident) {
69		size_t n = strnlen(ident, sizeof log_ident - 1);
70		memcpy(log_ident, ident, n);
71		log_ident[n] = 0;
72	} else {
73		log_ident[0] = 0;
74	}
75	log_opt = opt;
76	log_facility = facility;
77
78	if ((opt & LOG_NDELAY) && log_fd<0) __openlog();
79
80	UNLOCK(lock);
81	pthread_setcancelstate(cs, 0);
82}
83
84static int is_lost_conn(int e)
85{
86	return e==ECONNREFUSED || e==ECONNRESET || e==ENOTCONN || e==EPIPE;
87}
88
89static void _vsyslog(int priority, const char *message, va_list ap)
90{
91	char timebuf[16];
92	time_t now;
93	struct tm tm;
94	char buf[1024];
95	int errno_save = errno;
96	int pid;
97	int l, l2;
98	int hlen;
99	int fd;
100
101	if (log_fd < 0) __openlog();
102
103	if (!(priority & LOG_FACMASK)) priority |= log_facility;
104
105	now = time(NULL);
106	gmtime_r(&now, &tm);
107	strftime_l(timebuf, sizeof timebuf, "%b %e %T", &tm, C_LOCALE);
108
109	pid = (log_opt & LOG_PID) ? getpid() : 0;
110	l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ",
111		priority, timebuf, &hlen, log_ident, "["+!pid, pid, "]"+!pid);
112	errno = errno_save;
113	l2 = vsnprintf(buf+l, sizeof buf - l, message, ap);
114	if (l2 >= 0) {
115		if (l2 >= sizeof buf - l) l = sizeof buf - 1;
116		else l += l2;
117		if (buf[l-1] != '\n') buf[l++] = '\n';
118		if (send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno)
119		    || connect(log_fd, (void *)&log_addr, sizeof log_addr) < 0
120		    || send(log_fd, buf, l, 0) < 0)
121		    && (log_opt & LOG_CONS)) {
122			fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
123			if (fd >= 0) {
124				dprintf(fd, "%.*s", l-hlen, buf+hlen);
125				close(fd);
126			}
127		}
128		if (log_opt & LOG_PERROR) dprintf(2, "%.*s", l-hlen, buf+hlen);
129	}
130}
131
132static void __vsyslog(int priority, const char *message, va_list ap)
133{
134	int cs;
135	if (!(log_mask & LOG_MASK(priority&7)) || (priority&~0x3ff)) return;
136	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
137	LOCK(lock);
138	_vsyslog(priority, message, ap);
139	UNLOCK(lock);
140	pthread_setcancelstate(cs, 0);
141}
142
143void syslog(int priority, const char *message, ...)
144{
145	UNSUPPORTED_API_VOID(LITEOS_A);
146	va_list ap;
147	va_start(ap, message);
148	__vsyslog(priority, message, ap);
149	va_end(ap);
150}
151
152weak_alias(__vsyslog, vsyslog);
153