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 <unsupported_api.h>
13 #include "lock.h"
14 #include "fork_impl.h"
15
16 static volatile int lock[1];
17 static char log_ident[32];
18 static int log_opt;
19 static int log_facility = LOG_USER;
20 static int log_mask = 0xff;
21 static int log_fd = -1;
22 volatile int *const __syslog_lockptr = lock;
23
setlogmask(int maskpri)24 int setlogmask(int maskpri)
25 {
26 unsupported_api(__FUNCTION__);
27 LOCK(lock);
28 int ret = log_mask;
29 if (maskpri) log_mask = maskpri;
30 UNLOCK(lock);
31 return ret;
32 }
33
34 static const struct {
35 short sun_family;
36 char sun_path[9];
37 } log_addr = {
38 AF_UNIX,
39 "/dev/log"
40 };
41
closelog(void)42 void closelog(void)
43 {
44 int cs;
45 unsupported_api(__FUNCTION__);
46 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
47 LOCK(lock);
48 close(log_fd);
49 log_fd = -1;
50 UNLOCK(lock);
51 pthread_setcancelstate(cs, 0);
52 }
53
__openlognull54 static void __openlog()
55 {
56 log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
57 if (log_fd >= 0) connect(log_fd, (void *)&log_addr, sizeof log_addr);
58 }
59
openlog(const char *ident, int opt, int facility)60 void openlog(const char *ident, int opt, int facility)
61 {
62 int cs;
63 unsupported_api(__FUNCTION__);
64 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
65 LOCK(lock);
66
67 if (ident) {
68 size_t n = strnlen(ident, sizeof log_ident - 1);
69 memcpy(log_ident, ident, n);
70 log_ident[n] = 0;
71 } else {
72 log_ident[0] = 0;
73 }
74 log_opt = opt;
75 log_facility = facility;
76
77 if ((opt & LOG_NDELAY) && log_fd<0) __openlog();
78
79 UNLOCK(lock);
80 pthread_setcancelstate(cs, 0);
81 }
82
is_lost_conn(int e)83 static int is_lost_conn(int e)
84 {
85 return e==ECONNREFUSED || e==ECONNRESET || e==ENOTCONN || e==EPIPE;
86 }
87
_vsyslog(int priority, const char *message, va_list ap)88 static void _vsyslog(int priority, const char *message, va_list ap)
89 {
90 char timebuf[16];
91 time_t now;
92 struct tm tm;
93 char buf[1024];
94 int errno_save = errno;
95 int pid;
96 int l, l2;
97 int hlen;
98 int fd;
99
100 if (log_fd < 0) __openlog();
101
102 if (!(priority & LOG_FACMASK)) priority |= log_facility;
103
104 now = time(NULL);
105 gmtime_r(&now, &tm);
106 strftime(timebuf, sizeof timebuf, "%b %e %T", &tm);
107
108 pid = (log_opt & LOG_PID) ? getpid() : 0;
109 l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ",
110 priority, timebuf, &hlen, log_ident, "["+!pid, pid, "]"+!pid);
111 errno = errno_save;
112 l2 = vsnprintf(buf+l, sizeof buf - l, message, ap);
113 if (l2 >= 0) {
114 if (l2 >= sizeof buf - l) l = sizeof buf - 1;
115 else l += l2;
116 if (buf[l-1] != '\n') buf[l++] = '\n';
117 if (send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno)
118 || connect(log_fd, (void *)&log_addr, sizeof log_addr) < 0
119 || send(log_fd, buf, l, 0) < 0)
120 && (log_opt & LOG_CONS)) {
121 fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
122 if (fd >= 0) {
123 dprintf(fd, "%.*s", l-hlen, buf+hlen);
124 close(fd);
125 }
126 }
127 if (log_opt & LOG_PERROR) dprintf(2, "%.*s", l-hlen, buf+hlen);
128 }
129 }
130
__vsyslog(int priority, const char *message, va_list ap)131 static void __vsyslog(int priority, const char *message, va_list ap)
132 {
133 int cs;
134 if (!(log_mask & LOG_MASK(priority&7)) || (priority&~0x3ff)) return;
135 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
136 LOCK(lock);
137 _vsyslog(priority, message, ap);
138 UNLOCK(lock);
139 pthread_setcancelstate(cs, 0);
140 }
141
syslog(int priority, const char *message, ...)142 void syslog(int priority, const char *message, ...)
143 {
144 unsupported_api(__FUNCTION__);
145 va_list ap;
146 va_start(ap, message);
147 __vsyslog(priority, message, ap);
148 va_end(ap);
149 }
150
151 weak_alias(__vsyslog, vsyslog);
152