/* af_ax25.c: * * AX.25 Address Example : * */#include <stdio.h>#include <unistd.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <linux/ax25.h>const ax25_address null_ax25_address =    { { 0x40,0x40,0x40,0x40,0x40,0x40,0x00 } };intmain(int argc,char **argv,char **envp) {    int x;              /* Work index */    int z;              /* Status return code */    int sck_ax25;               /* Socket */    struct full_sockaddr_ax25 adr_ax25;    int len_ax25;               /* length */    const char ax25_call[]        = "VE3WWG" /*SSID*/ "3";    /*     * Create a AF_X25 socket (with no digis) :     */    sck_ax25 = socket(AF_AX25,SOCK_SEQPACKET,0);    if ( sck_ax25 == -1 ) {        /* No socket available : */        fprintf(stderr,            "%s: socket(AF_AX25,...)\n",            strerror(errno));        exit(1);    }    /*     * Form an AF_AX25 Address :     */    adr_ax25.fsa_ax25.sax25_family = AF_AX25;    strcpy(adr_ax25.fsa_ax25.sax25_call.ax25_call,        ax25_call);    adr_ax25.fsa_ax25.sax25_ndigis = 1;    adr_ax25.fsa_digipeater[0] = null_ax25_address;    /*     * Call sign + SSID must be shifted     * up one bit :     */    for ( x=0; x<strlen(ax25_call); ++x )        adr_ax25.fsa_ax25.sax25_call.ax25_call[x]            <<= 1;    len_ax25 = sizeof adr_ax25;    /*     * Now bind the address to the socket :     */    z = bind(sck_ax25,        (struct sockaddr *)&adr_ax25,        len_ax25);    if ( z == -1 ) {        /* bind failed : */        fprintf(stderr,            "%s: bind() for AF_AX25\n",            strerror(errno));        exit(1);    }    /*     * Display all of our bound sockets :     */    system("netstat -pa 2>/dev/null | "        "sed -n '/AX.25 sockets/,$p'");    return 0;}