1 files changed, 86 insertions, 0 deletions
diff --git a/util-linux/rdate.c b/util-linux/rdate.c
new file mode 100644
index 000000000..12105953d
--- /dev/null
+++ b/util-linux/rdate.c
@@ -0,0 +1,86 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * The Rdate command will ask a time server for the RFC 868 time
+ *  and optionally set the system time.
+ *
+ * by Sterling Huxley <sterling@europa.com>
+ *
+ * Licensed under GPL v2 or later, see file License for details.
+*/
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include "busybox.h"
+
+
+static const int RFC_868_BIAS = 2208988800UL;
+
+static void socket_timeout(int sig)
+{
+	bb_error_msg_and_die("timeout connecting to time server");
+}
+
+static time_t askremotedate(const char *host)
+{
+	unsigned long nett;
+	struct sockaddr_in s_in;
+	int fd;
+
+	bb_lookup_host(&s_in, host);
+	s_in.sin_port = bb_lookup_port("time", "tcp", 37);
+
+	/* Add a timeout for dead or inaccessible servers */
+	alarm(10);
+	signal(SIGALRM, socket_timeout);
+
+	fd = xconnect_tcp_v4(&s_in);
+
+	if (safe_read(fd, (void *)&nett, 4) != 4)    /* read time from server */
+		bb_error_msg_and_die("%s did not send the complete time", host);
+	close(fd);
+
+	/* convert from network byte order to local byte order.
+	 * RFC 868 time is the number of seconds
+	 *  since 00:00 (midnight) 1 January 1900 GMT
+	 *  the RFC 868 time 2,208,988,800 corresponds to 00:00  1 Jan 1970 GMT
+	 * Subtract the RFC 868 time  to get Linux epoch
+	 */
+
+	return ntohl(nett) - RFC_868_BIAS;
+}
+
+int rdate_main(int argc, char **argv)
+{
+	time_t remote_time;
+	unsigned long flags;
+
+	opt_complementary = "-1";
+	flags = getopt32(argc, argv, "sp");
+
+	remote_time = askremotedate(argv[optind]);
+
+	if ((flags & 2) == 0) {
+		time_t current_time;
+
+		time(&current_time);
+		if (current_time == remote_time)
+			bb_error_msg("current time matches remote time");
+		else
+			if (stime(&remote_time) < 0)
+				bb_perror_msg_and_die("cannot set time of day");
+	}
+
+	if ((flags & 1) == 0)
+		printf("%s", ctime(&remote_time));
+
+	return EXIT_SUCCESS;
+}