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
14 static volatile int lock[1];
15 static char log_ident[32];
16 static int log_opt;
17 static int log_facility = LOG_USER;
18 static int log_mask = 0xff;
19 static int log_fd = -1;
20
setlogmask(int maskpri)21 int 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
30 static const struct {
31 short sun_family;
32 char sun_path[9];
33 } log_addr = {
34 AF_UNIX,
35 "/dev/log"
36 };
37
closelog(void)38 void 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
__openlog()49 static 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
openlog(const char * ident,int opt,int facility)55 void 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
is_lost_conn(int e)77 static int is_lost_conn(int e)
78 {
79 return e==ECONNREFUSED || e==ECONNRESET || e==ENOTCONN || e==EPIPE;
80 }
81
_vsyslog(int priority,const char * message,va_list ap)82 static 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
__vsyslog(int priority,const char * message,va_list ap)125 static void __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
syslog(int priority,const char * message,...)136 void 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
144 weak_alias(__vsyslog, vsyslog);
145