minix/commands/simple/rdate.c
2005-04-21 14:53:53 +00:00

109 lines
2.4 KiB
C
Executable file

/* rdate 1.0 - Set time&date from remote host Author: Kees J. Bot
* 12 Oct 1995
*/
#define nil 0
#include <sys/types.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <net/hton.h>
#include <net/netlib.h>
#include <net/gen/in.h>
#include <net/gen/netdb.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>
void report(const char *label)
{
fprintf(stderr, "rdate: %s: %s\n", label, strerror(errno));
}
void fatal(const char *label)
{
report(label);
exit(1);
}
int main(int argc, char **argv)
{
char *tcp_device;
int fd;
int i;
struct servent *servent;
struct hostent *hostent;
u16_t time_port;
nwio_tcpconf_t tcpconf;
nwio_tcpcl_t tcpcl;
u32_t net_time;
time_t unix_time;
if (argc <= 1) {
fprintf(stderr, "Usage: rdate host ...\n");
exit(1);
}
/* Look up the port number of the TCP service "time". */
if ((servent= getservbyname("time", "tcp")) == nil) {
fprintf(stderr, "rdate: \"time\": unknown service\n");
exit(1);
}
time_port= servent->s_port;
if ((tcp_device= getenv("TCP_DEVICE")) == nil) tcp_device= TCP_DEVICE;
if ((fd= open(tcp_device, O_RDWR)) < 0) fatal(tcp_device);
/* Try each host on the command line. */
for (i= 1; i < argc; i++) {
if ((hostent= gethostbyname(argv[i])) == nil) {
fprintf(stderr, "rdate: %s: unknown host\n", argv[i]);
continue;
}
/* Configure a TCP channel and connect to the remote host. */
tcpconf.nwtc_flags= NWTC_LP_SEL | NWTC_SET_RA | NWTC_SET_RP;
memcpy(&tcpconf.nwtc_remaddr, hostent->h_addr, 4);
tcpconf.nwtc_remport= time_port;
if (ioctl(fd, NWIOSTCPCONF, &tcpconf) == -1) fatal(tcp_device);
tcpcl.nwtcl_flags= 0;
if (ioctl(fd, NWIOTCPCONN, &tcpcl) < 0) {
report(argv[i]);
continue;
}
/* Read four bytes to obtain the time. */
switch (read(fd, &net_time, sizeof(net_time))) {
case -1:
report(argv[i]);
continue;
default:
fprintf(stderr, "rdate: %s: short read\n", argv[i]);
continue;
case sizeof(net_time):
break;
}
break;
}
if (i == argc) exit(1);
/* Internet time is in seconds since 1900, UNIX time is in seconds
* since 1970.
*/
unix_time= ntohl(net_time) - 2208988800;
/* Try to set the time and tell us about it. */
if (stime(&unix_time) < 0) {
printf("time on ");
} else {
printf("time set to ");
}
printf("%s: %s", argv[i], ctime(&unix_time));
exit(0);
}