Add a "fork" of musl as //fusl.

fusl/src/misc/syslog.c

Index: fusl/src/misc/syslog.c
diff --git a/fusl/src/misc/syslog.c b/fusl/src/misc/syslog.c
new file mode 100644
index 0000000000000000000000000000000000000000..9dd1ddb5889322ed69099b008e384cee47b89d4d
--- /dev/null
+++ b/fusl/src/misc/syslog.c
@@ -0,0 +1,144 @@
+#include <stdarg.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <time.h>
+#include <signal.h>
+#include <string.h>
+#include <pthread.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "libc.h"
+
+static volatile int lock[2];
+static char log_ident[32];
+static int log_opt;
+static int log_facility = LOG_USER;
+static int log_mask = 0xff;
+static int log_fd = -1;
+
+int setlogmask(int maskpri)
+{
+	LOCK(lock);
+	int ret = log_mask;
+	if (maskpri) log_mask = maskpri;
+	UNLOCK(lock);
+	return ret;
+}
+
+static const struct {
+	short sun_family;
+	char sun_path[9];
+} log_addr = {
+	AF_UNIX,
+	"/dev/log"
+};
+
+void closelog(void)
+{
+	int cs;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	LOCK(lock);
+	close(log_fd);
+	log_fd = -1;
+	UNLOCK(lock);
+	pthread_setcancelstate(cs, 0);
+}
+
+static void __openlog()
+{
+	log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);
+	if (log_fd >= 0) connect(log_fd, (void *)&log_addr, sizeof log_addr);
+}
+
+void openlog(const char *ident, int opt, int facility)
+{
+	int cs;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	LOCK(lock);
+
+	if (ident) {
+		size_t n = strnlen(ident, sizeof log_ident - 1);
+		memcpy(log_ident, ident, n);
+		log_ident[n] = 0;
+	} else {
+		log_ident[0] = 0;
+	}
+	log_opt = opt;
+	log_facility = facility;
+
+	if ((opt & LOG_NDELAY) && log_fd<0) __openlog();
+
+	UNLOCK(lock);
+	pthread_setcancelstate(cs, 0);
+}
+
+static int is_lost_conn(int e)
+{
+	return e==ECONNREFUSED || e==ECONNRESET || e==ENOTCONN || e==EPIPE;
+}
+
+static void _vsyslog(int priority, const char *message, va_list ap)
+{
+	char timebuf[16];
+	time_t now;
+	struct tm tm;
+	char buf[1024];
+	int errno_save = errno;
+	int pid;
+	int l, l2;
+	int hlen;
+	int fd;
+
+	if (log_fd < 0) __openlog();
+
+	if (!(priority & LOG_FACMASK)) priority |= log_facility;
+
+	now = time(NULL);
+	gmtime_r(&now, &tm);
+	strftime(timebuf, sizeof timebuf, "%b %e %T", &tm);
+
+	pid = (log_opt & LOG_PID) ? getpid() : 0;
+	l = snprintf(buf, sizeof buf, "<%d>%s %n%s%s%.0d%s: ",
+		priority, timebuf, &hlen, log_ident, "["+!pid, pid, "]"+!pid);
+	errno = errno_save;
+	l2 = vsnprintf(buf+l, sizeof buf - l, message, ap);
+	if (l2 >= 0) {
+		if (l2 >= sizeof buf - l) l = sizeof buf - 1;
+		else l += l2;
+		if (buf[l-1] != '\n') buf[l++] = '\n';
+		if (send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno)
+		    || connect(log_fd, (void *)&log_addr, sizeof log_addr) < 0
+		    || send(log_fd, buf, l, 0) < 0)
+		    && (log_opt & LOG_CONS)) {
+			fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC);
+			if (fd >= 0) {
+				dprintf(fd, "%.*s", l-hlen, buf+hlen);
+				close(fd);
+			}
+		}
+		if (log_opt & LOG_PERROR) dprintf(2, "%.*s", l-hlen, buf+hlen);
+	}
+}
+
+void __vsyslog(int priority, const char *message, va_list ap)
+{
+	int cs;
+	if (!(log_mask & LOG_MASK(priority&7)) || (priority&~0x3ff)) return;
+	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
+	LOCK(lock);
+	_vsyslog(priority, message, ap);
+	UNLOCK(lock);
+	pthread_setcancelstate(cs, 0);
+}
+
+void syslog(int priority, const char *message, ...)
+{
+	va_list ap;
+	va_start(ap, message);
+	__vsyslog(priority, message, ap);
+	va_end(ap);
+}
+
+weak_alias(__vsyslog, vsyslog);