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