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