/* * * libnet 1.1 * Build a DNSv4 packet * To view: /usr/sbin/tcpdump -vvvvven -s 0 port 53 * * Copyright (c) 2003 Frédéric Raynal * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ #if (HAVE_CONFIG_H) #include "../include/config.h" #endif #include "./libnet_test.h" #ifdef __WIN32__ #include "../include/win32/getopt.h" #endif void usage(char *prog) { fprintf(stderr, "Usage: %s -d dst_ip -q query_host [-s src_ip] [-t]\n", prog); exit(1); } int main(int argc, char *argv[]) { char c; u_long src_ip = 0, dst_ip = 0; u_short type = LIBNET_UDP_DNSV4_H; libnet_t *l; libnet_ptag_t ip; libnet_ptag_t ptag4; /* TCP or UDP ptag */ libnet_ptag_t dns; char errbuf[LIBNET_ERRBUF_SIZE]; char *query = NULL; char payload[1024]; u_short payload_s; printf("libnet 1.1 packet shaping: DNSv4[raw]\n"); /* * Initialize the library. Root priviledges are required. */ l = libnet_init( LIBNET_RAW4, /* injection type */ NULL, /* network interface */ errbuf); /* error buffer */ if (!l) { fprintf(stderr, "libnet_init: %s", errbuf); exit(EXIT_FAILURE); } /* * parse options */ while ((c = getopt(argc, argv, "d:s:q:t")) != EOF) { switch (c) { case 'd': if ((dst_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1) { fprintf(stderr, "Bad destination IP address: %s\n", optarg); exit(EXIT_FAILURE); } break; case 's': if ((src_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1) { fprintf(stderr, "Bad source IP address: %s\n", optarg); exit(EXIT_FAILURE); } break; case 'q': query = optarg; break; case 't': type = LIBNET_TCP_DNSV4_H; break; default: exit(EXIT_FAILURE); } } if (!src_ip) { src_ip = libnet_get_ipaddr4(l); } if (!dst_ip || !query) { usage(argv[0]); exit(EXIT_FAILURE); } /* * build dns payload */ payload_s = snprintf(payload, sizeof payload, "%c%s%c%c%c%c%c", (char)(strlen(query)&0xff), query, 0x00, 0x00, 0x01, 0x00, 0x01); /* * build packet */ dns = libnet_build_dnsv4( type, /* TCP or UDP */ 0x7777, /* id */ 0x0100, /* request */ 1, /* num_q */ 0, /* num_anws_rr */ 0, /* num_auth_rr */ 0, /* num_addi_rr */ payload, payload_s, l, 0 ); if (dns == -1) { fprintf(stderr, "Can't build DNS packet: %s\n", libnet_geterror(l)); goto bad; } if (type == LIBNET_TCP_DNSV4_H) /* TCP DNS */ { ptag4 = libnet_build_tcp( 0x6666, /* source port */ 53, /* destination port */ 0x01010101, /* sequence number */ 0x02020202, /* acknowledgement num */ TH_PUSH|TH_ACK, /* control flags */ 32767, /* window size */ 0, /* checksum */ 0, /* urgent pointer */ LIBNET_TCP_H + LIBNET_TCP_DNSV4_H + payload_s, /* TCP packet size */ NULL, /* payload */ 0, /* payload size */ l, /* libnet handle */ 0); /* libnet id */ if (ptag4 == -1) { fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l)); goto bad; } ip = libnet_build_ipv4( LIBNET_IPV4_H + LIBNET_TCP_H + type + payload_s,/* length */ 0, /* TOS */ 242, /* IP ID */ 0, /* IP Frag */ 64, /* TTL */ IPPROTO_TCP, /* protocol */ 0, /* checksum */ src_ip, /* source IP */ dst_ip, /* destination IP */ NULL, /* payload */ 0, /* payload size */ l, /* libnet handle */ 0); /* libnet id */ if (ip == -1) { fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l)); exit(EXIT_FAILURE); } } else /* UDP DNS */ { ptag4 = libnet_build_udp( 0x6666, /* source port */ 53, /* destination port */ LIBNET_UDP_H + LIBNET_UDP_DNSV4_H + payload_s, /* packet length */ 0, /* checksum */ NULL, /* payload */ 0, /* payload size */ l, /* libnet handle */ 0); /* libnet id */ if (ptag4 == -1) { fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l)); goto bad; } ip = libnet_build_ipv4( LIBNET_IPV4_H + LIBNET_UDP_H + type + payload_s,/* length */ 0, /* TOS */ 242, /* IP ID */ 0, /* IP Frag */ 64, /* TTL */ IPPROTO_UDP, /* protocol */ 0, /* checksum */ src_ip, /* source IP */ dst_ip, /* destination IP */ NULL, /* payload */ 0, /* payload size */ l, /* libnet handle */ 0); /* libnet id */ if (ip == -1) { fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l)); exit(EXIT_FAILURE); } } /* * write to the wire */ c = libnet_write(l); if (c == -1) { fprintf(stderr, "Write error: %s\n", libnet_geterror(l)); goto bad; } else { fprintf(stderr, "Wrote %d byte DNS packet; check the wire.\n", c); } libnet_destroy(l); return (EXIT_SUCCESS); bad: libnet_destroy(l); return (EXIT_FAILURE); }