1 files changed, 89 insertions, 0 deletions
diff --git a/usr/klibc/syslog.c b/usr/klibc/syslog.c
new file mode 100644
index 0000000..4052eaa
--- /dev/null
+++ b/usr/klibc/syslog.c
@@ -0,0 +1,89 @@
+/*
+ * syslog.c
+ *
+ * Issue syslog messages via the kernel printk queue.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+/* Maximum size for a kernel message */
+#define BUFLEN 1024
+
+/* Logging node */
+#define LOGDEV "/dev/kmsg"
+
+/* Max length of ID string */
+#define MAXID 31		/* MAXID+5 must be < BUFLEN */
+
+int __syslog_fd = -1;
+static char id[MAXID + 1];
+static int syslog_flags = 0;
+
+void openlog(const char *ident, int option, int facility)
+{
+	int fd;
+
+	(void)option;
+	(void)facility;		/* Unused */
+
+	if (__syslog_fd == -1) {
+		__syslog_fd = fd = open(LOGDEV, O_WRONLY);
+		if (fd == -1)
+			return;
+		fcntl(fd, F_SETFD, (long)FD_CLOEXEC);
+	}
+
+	syslog_flags = option;
+
+	strncpy(id, ident ? ident : "", MAXID);
+}
+
+void vsyslog(int prio, const char *format, va_list ap)
+{
+	char buf[BUFLEN];
+	int len;
+	int fd;
+
+	if (__syslog_fd == -1)
+		openlog(NULL, 0, 0);
+
+	buf[0] = '<';
+	buf[1] = LOG_PRI(prio) + '0';
+	buf[2] = '>';
+	len = 3;
+
+	if (syslog_flags & LOG_PID)
+		len += sprintf(buf + 3, "%s[%u]: ", id, getpid());
+	else if (*id)
+		len += sprintf(buf + 3, "%s: ", id);
+
+	len += vsnprintf(buf + len, BUFLEN - len, format, ap);
+
+	if (len > BUFLEN - 1)
+		len = BUFLEN - 1;
+	if (buf[len - 1] != '\n')
+		buf[len++] = '\n';
+
+	fd = __syslog_fd;
+	if (fd == -1)
+		fd = 2;		/* Failed to open log, write to stderr */
+
+	write(fd, buf, len);
+
+	if (syslog_flags & LOG_PERROR)
+		_fwrite(buf + 3, len - 3, stderr);
+}
+
+void syslog(int prio, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	vsyslog(prio, format, ap);
+	va_end(ap);
+}