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