/* napscan.c - quick portscanner written by napster. */

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>


char *ipaddy;
int portlow, porthigh;

unsigned int resolved_host;

/* prototypes... */

void reseed(void);
void usage(char *progname);
unsigned int resolve(char *host);

void usage(char *progname)
{
        system("clear");
        printf("napscan v1.0 by napster.\n");
        printf ("usage: %s <address> <portlow> <porthigh> \n",progname); exit(1); 
}

main(int argc, char *argv[])
{
    
        struct sockaddr_in sin;
        int sockdesc, x;

        if (argc<4) usage(argv[0]);
  
        ipaddy    = argv[1];
        portlow   = atoi(argv[2]);
        porthigh  = atoi(argv[3]);

        resolved_host = resolve(ipaddy);

        if (porthigh > 65535) 
        {
                printf("Uh, dood... highest possible high port is 65535.. \n");
                exit(0);
        }
        if (portlow < 0)
        {
                printf("Uh, dood... negative ports? get some help... \n");
                exit(0);
        }
        system("clear");
        printf("                       napscan.c by napster.\n");
        printf("                             [1.28.97]\n\n");
        printf("Portscanning: %s.\n", ipaddy);
        printf("Portlow: %d\n", portlow);
        printf("Porthigh: %d\n\n", porthigh);
        printf("Ports open:");
        
        reseed();

        for (x=portlow;x<=porthigh;x++)
        {
        
                fflush(stdout);

                sockdesc = socket(AF_INET, SOCK_STREAM, 0);

                if (sockdesc < 0) {
                        perror("socket");
                        exit(-1);
                }
  
                sin.sin_family = AF_INET;
                sin.sin_port = htons(x);
                sin.sin_addr.s_addr = resolved_host;
                if (connect(sockdesc, (struct sockaddr *)&sin, sizeof(sin)) == 0) printf(" %d", x); 
                fflush(stdout); 
                close(sockdesc);
        }
        printf("\n");
        exit(0);
}


void reseed(void) 
{
        srand(time(NULL));
}


unsigned int resolve(char *host)
{
  /* resolve routine written by Aut0psy. */

        struct hostent *he;
        struct sockaddr_in tmp;

        /* Lookup host. */
        he = gethostbyname(host);

        if (he)
        {
                /* Copy host into a temporary endpoint. */
                memcpy((caddr_t)&tmp.sin_addr.s_addr, he->h_addr, he->h_length);        
        } else {
                perror("resolving");
                exit(-1);
        }

        /* Return address in network byte order. */
        return(tmp.sin_addr.s_addr);
}