bc: convert to "G trick" - this returns bc to zero bss increase

[oweals/busybox.git] / util-linux / rdate.c

diff --git a/util-linux/rdate.c b/util-linux/rdate.c
index e2824607eb35e68bd27f1bf33fabd0347635fea0..5ec795208050f4c251a546c65a468e2a3a1a1b8c 100644 (file)
--- a/util-linux/rdate.c
+++ b/util-linux/rdate.c
@@ -1,88 +1,107 @@
 /* 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.
+ * and optionally set the system time.
  *
  * by Sterling Huxley <sterling@europa.com>
  *
- * Licensed under GPL v2 or later, see file License for details.
-*/
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//config:config RDATE
+//config:      bool "rdate (6 kb)"
+//config:      default y
+//config:      help
+//config:      The rdate utility allows you to synchronize the date and time of your
+//config:      system clock with the date and time of a remote networked system using
+//config:      the RFC868 protocol, which is built into the inetd daemon on most
+//config:      systems.
 
-#include <sys/time.h>
-#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>
+//applet:IF_RDATE(APPLET(rdate, BB_DIR_USR_SBIN, BB_SUID_DROP))
 
-#include "busybox.h"
+//kbuild:lib-$(CONFIG_RDATE) += rdate.o
 
+//usage:#define rdate_trivial_usage
+//usage:       "[-s/-p] HOST"
+//usage:#define rdate_full_usage "\n\n"
+//usage:       "Set and print time from HOST using RFC 868\n"
+//usage:     "\n       -s      Only set system time"
+//usage:     "\n       -p      Only print time"
 
-static const int RFC_868_BIAS = 2208988800UL;
+#include "libbb.h"
 
-static void socket_timeout(int sig)
+enum { RFC_868_BIAS = 2208988800UL };
+
+static void socket_timeout(int sig UNUSED_PARAM)
 {
        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;
+       uint32_t nett;
        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 */
+       /* Timeout for dead or inaccessible servers */
        alarm(10);
        signal(SIGALRM, socket_timeout);
 
-       fd = xconnect(&s_in);
+       fd = create_and_connect_stream_or_die(host, bb_lookup_std_port("time", "tcp", 37));
 
-       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);
+       if (safe_read(fd, &nett, 4) != 4)    /* read time from server */
+               bb_error_msg_and_die("%s: %s", host, "short read");
+       if (ENABLE_FEATURE_CLEAN_UP)
+               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
+       /* Convert from network byte order to local byte order.
+        * RFC 868 time is seconds since 1900-01-01 00:00 GMT.
+        * RFC 868 time 2,208,988,800 corresponds to 1970-01-01 00:00 GMT.
+        * Subtract the RFC 868 time to get Linux epoch.
         */
-       
-       return(ntohl(nett) - RFC_868_BIAS);
+       nett = ntohl(nett) - RFC_868_BIAS;
+
+       if (sizeof(time_t) > 4) {
+               /* Now we have 32-bit lsb of a wider time_t
+                * Imagine that  nett =   0x00000001,
+                * current time  cur = 0x123ffffffff.
+                * Assuming our time is not some 40 years off,
+                * remote time must be 0x12400000001.
+                * Need to adjust our time by (int32_t)(nett - cur).
+                */
+               time_t cur = time(NULL);
+               int32_t adjust = (int32_t)(nett - (uint32_t)cur);
+               return cur + adjust;
+       }
+       /* This is not going to work, but what can we do */
+       return (time_t)nett;
 }
 
-int rdate_main(int argc, char **argv)
+int rdate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int rdate_main(int argc UNUSED_PARAM, char **argv)
 {
        time_t remote_time;
-       
-       unsigned long flags = bb_getopt_ulflags(argc, argv, "sp");
-       
-       if (!flags || argc == optind)
-               bb_show_usage();
-       
+       unsigned flags;
+
+       flags = getopt32(argv, "^" "sp" "\0" "-1");
+
        remote_time = askremotedate(argv[optind]);
 
-       if (flags & 1) {
-               time_t current_time;
+       /* Manpages of various Unixes are confusing. What happens is:
+        * (no opts) set and print time
+        * -s: set time ("do not print the time")
+        * -p: print time ("do not set, just print the remote time")
+        * -sp: print time (that's what we do, not sure this is right)
+        */
 
-               time(&current_time);
-               if (current_time == remote_time)
-                       bb_error_msg("Current time matches remote time.");
+       if (!(flags & 2)) { /* no -p (-s may be present) */
+               if (time(NULL) == remote_time)
+                       bb_error_msg("current time matches remote time");
                else
                        if (stime(&remote_time) < 0)
-                               bb_perror_msg_and_die("Could not set time of day");
-               
-       /* No need to check for the -p flag as it's the only option left */
-               
-       } else printf("%s", ctime(&remote_time));
+                               bb_perror_msg_and_die("can't set time of day");
+       }
+
+       if (flags != 1) /* not lone -s */
+               printf("%s", ctime(&remote_time));
 
        return EXIT_SUCCESS;
 }