unix remote reboot client for nos

[kd4nc!km4ba!alan@gatech.edu (Alan Barrow)]

Hello all,

Here is a quick UDB client that I hacked out that will reboot or reset
a KA9Q machine remotely. It is modeled after the remote command in NOS, and
the syntax is similar.

I run it from cron to reboot my ether <=> 56k gateway machine nightly.
(It replaces an X-10 BSR module that rebooted it the old fashioned way)

I have found over the last 2-3 yrs of running nos/net that it will usually
lock up after 3-4 days of being up. I have tried every release (including 12/29)
and they all seem to die. (12/29 did last a week.)

I have tried compiling my own, as well as using the distributed .exe's with
the same results.

I can only assume it is either my HW (2 different PC's) or the busy 56K AX.25
lan we have.

Anyway, this is my solution to the problem. This keeps things nice and fresh as
well as makes remote admin easier.

I have only tested this on an HP 9k/360, but it should work on any system
with Berkely sockets & hostname resolution, as well as getopts.

If anyone comes up with any ifdef's for a specific machine, please let me know
and I will add it to the code.

have fun!


 Alan Barrow  km4ba | I've seen things you people wouldn't believe. Attack
 jab@hpuerca.hp.com | ships on fire off the shoulder of Orion. I watched
                    | C-beams glitter in the dark near the Tannhauser gate.
 ..!gatech!kd4nc!   | All those moments will be lost in time -
         km4ba!alan | like tears in rain. Time to die.          Roy Batty

---- cut here ------------------------------------------------------------

/* This program emulates the KA9Q NOS remote function
   The syntax was kept as close as possible to the one in
   NOS.

   The command argument selection code fragments were modeled after
   KA9Q NOS to keep them similar. (Thanks Phil! How many ways
   can you use getopt & switch's :-) )

   You need to add a line to /etc/services as follows:
      remote      1234/udp                # ka9q reboot socket

   Or you can just specify the port via the -p option.

   Tested on my HP9000/360 HP-UX 7.0   Should work on any sys
   with Berkely sockets & getopts.

   Written by Alan Barrow KM4BA 1/8/92

   Use however you wish!

 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <netinet/in.h>
#include <stdio.h>
#include <signal.h>
#include <netdb.h>

extern int errno;

int s;                          /* socket descriptor */
int port;                       /* port number */
char *datagram;                 /* datagram */
char *key = "mymindisgoing";    /* password key */
int len,c ;
extern char *optarg;
extern int optind;
char *cmd, *host;

struct hostent *hp;             /* pointer to host info for nameserver host */
struct servent *sp;             /* pointer to service information */

struct sockaddr_in myaddr_in;   /* for local socket address */
struct sockaddr_in servaddr_in; /* for server socket address */

#define ADDRNOTFOUND    0xffffffff      /* value returned for unknown host */
#define RETRIES 5               /* number of times to retry before givin up */


main(argc, argv)
int argc;
char *argv[];
{

        port = 0;
        while((c = getopt(argc, argv, "p:k:" )) != EOF ){
                switch(c){
                case 'p':
                        port = atoi( optarg );
                        break;
                case 'k':
                        key = (char *) optarg;
                        break;
                }
        }
        if (optind > argc - 2) {
                fprintf(stderr, "Usage:  %s [-p port#] [-k key] hostname reset|e
xit\n", argv[0]);
                exit(1);
        }

        host = argv[ optind++ ];
        cmd = argv[ optind ];

                /* clear out address structures */
        memset ((char *)&myaddr_in, 0, sizeof(struct sockaddr_in));
        memset ((char *)&servaddr_in, 0, sizeof(struct sockaddr_in));

                /* Set up the server address. */
        servaddr_in.sin_family = AF_INET;

                /* Get the host information for the server's hostname that the
                 * user passed in.
                 */
        hp = gethostbyname (host);
        if (hp == NULL) {
                fprintf(stderr, "%s: Unable to resolve %s \n",
                                argv[0], host);
                exit(1);
        }
        servaddr_in.sin_addr.s_addr = ((struct in_addr *)(hp->h_addr))->s_addr;

        /* If we did not specify a port */
        if (port == 0) {

                /* Find the information for the "remote" server
                 * in order to get the needed port number.
                 */
                sp = getservbyname ("remote", "udp");
                if (sp == NULL) {
                        fprintf(stderr,"%s: remote not found in /etc/services\n"
,
                                        argv[0]);
                        exit(1);
                }
                servaddr_in.sin_port = sp->s_port;
        }else{
                /* use the port from the cmd line */
                servaddr_in.sin_port = port;
        }

                /* Create the socket. */
        s = socket (AF_INET, SOCK_DGRAM, 0);
        if (s == -1) {
                perror(argv[0]);
                fprintf(stderr, "%s: unable to create socket\n", argv[0]);
                exit(1);
        }

#define NOS_RESET 1
#define NOS_EXIT 2

#define      NULLCHAR        (char *)0

        /* create a buffer to hold the cmd flag & the key string */
        len = strlen(key) + 1;
        datagram = (char *) malloc(len);

        /* stuff the cmd flag into the buffer */
        switch(cmd[0]){
        case 'r':
                datagram[0] = NOS_RESET;
                break;

        case 'e':
                datagram[0] = NOS_EXIT;
                break;
        default:
                fprintf(stderr,"%s: Unknown command %s\n",argv[0],cmd);
                exit(1);
        }



        /* stuff the string into the buffer */
        if(key != NULLCHAR){
                        strcpy(&datagram[1],key);
        }
        else{
                fprintf(stderr,"%s: key must not be null string\n",cmd);
                exit(1);
        }

                /* Send the request to the target. */

        if (sendto (s, datagram, strlen(datagram), 0, &servaddr_in,
                                sizeof(struct sockaddr_in)) == -1) {
                perror(argv[0]);
                fprintf(stderr, "%s: unable to send request\n", argv[0]);
                exit(1);
        }

}

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