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