scan.c

/*
 *   Totally eleetin class B, C, and single IP address scanner/lookup
 * program.  Make sure you don't goof up with the switches and the
 * address you provide it.  The switches are as follows:
 *      b - scan this class B network (xxx.xxx)
 *      c - scan this class C network (xxx.xxx.xxx)
 *      s - give the the hostname of this specific address (xxx.xxx.xxx.xxx)
 *      x - address provided is in hexadecimal
 *
 *                                      maxEpoo :)
 *                                      max-q@escape.com
 */
#include 
#include 
#include 
#include "netdb.h"
struct hostent *gethostbyaddr();
void bad_addr();
main(argc, argv)
        int     argc;
        char    *argv[];
{
        char            addr[4];
        int             i, j,
                        a0, a1, a2, a3,
                        c,
                        classB, classC, single, hex;
        char            *fmt = "%d.%d.%d";
        char            **ptr;
        struct hostent  *host;
        extern char     *optarg;
        classB = classC = single = hex = 0;
        while((c = getopt(argc,argv,"bcsx")) != EOF) {
                switch(c) {
                case 'b':
                        classB++;
                        break;
                case 'c':
                        classC++;
                        break;
                case 's':
                        single++;
                        break;
                case 'x':
                        hex++;
                        break;
                }
        }
        if(classB == 0 && classC == 0 && single == 0) {
                fprintf(stderr, "usage: %s [-b||-c||-s] [-x] xxx.xxx[.xxx[.xxx]]\n", argv[0]);
                exit(1);
        }
        if(classB)
                if(hex) {
                        fmt = "%x.%x";
                        sscanf(argv[3], fmt, &a0, &a1);
                } else {
                        fmt = "%d.%d";
                        sscanf(argv[2], fmt, &a0, &a1);
                }
        else if(classC)
                if(hex) {
                        fmt = "%x.%x.%x";
                        sscanf(argv[3], fmt, &a0, &a1, &a2);
                } else {
                        fmt = "%d.%d.%d";
                        sscanf(argv[2], fmt, &a0, &a1, &a2);
                }
        else if(single)
                if(hex) {
                        fmt = "%x.%x.%x.%x";
                        sscanf(argv[3], fmt, &a0, &a1, &a2, &a3);
                } else {
                        fmt = "%d.%d.%d.%d";
                        sscanf(argv[2], fmt, &a0, &a1, &a2, &a3);
                }
        sscanf(argv[1], fmt, &a0, &a1, &a2);
        addr[0] = (unsigned char)a0;
        addr[1] = (unsigned char)a1;
        if(a0>255||a0<0)
                bad_addr(a0);
        if(a1>255||a1<0)
                bad_addr(a1);
        if(classB) {
                if(hex)
                        printf("Converting address from hex. (%x.%x)\n", a0, a1);
                printf("Scanning Class B network %d.%d...\n", a0, a1);
                while(j!=256) {
                        a2=j;
                        addr[2] = (unsigned char)a2;
jmpC:
                if(classC)
                        if(hex)
                                printf("Converting address from hex. (%x.%x.%x)\n", a0, a1, a2);
                        printf("Scanning Class C network %d.%d.%d...\n", a0, a1, a2);
                while(i!=256) {
                        a3=i;
                        addr[3] = (unsigned char)a3;
jmpS:
                        if ((host = gethostbyaddr(addr, 4, AF_INET)) != NULL) {
                                printf("%d.%d.%d.%d => %s\n", a0, a1, a2, a3, host->h_name);
                                ptr = host->h_aliases;
                                while (*ptr != NULL) {
                                        printf("%d.%d.%d.%d => %s (alias)\n", a0, a1, a2, a3, *ptr);
                                        ptr++;
                                }
                        }
                        if(single)
                                exit(0);
                        i++;
                }
                if(classC)
                        exit(0);
                j++;
                }
        } else if(classC) {
                addr[2] = (unsigned char)a2;
                if(a2>255||a2<0)
                        bad_addr(a2);
                goto jmpC;
        } else if(single) {
                addr[2] = (unsigned char)a2;
                addr[3] = (unsigned char)a3;
                if(a2>255||a2<0)
                        bad_addr(a2);
                if(a3>255||a3<0)
                        bad_addr(a3);
                goto jmpS;
        }
        exit(0);
}
void
bad_addr(addr)
        int *addr;
{
        printf("Value %d is not valid.\n", addr);
        exit(0);
}