Annotation of embedaddon/libnet/sample/dns.c, revision 1.1
1.1 ! misho 1: /*
! 2: *
! 3: * libnet 1.1
! 4: * Build a DNSv4 packet
! 5: * To view: /usr/sbin/tcpdump -vvvvven -s 0 port 53
! 6: *
! 7: * Copyright (c) 2003 Frédéric Raynal <pappy@security-labs.org>
! 8: * All rights reserved.
! 9: *
! 10: * Redistribution and use in source and binary forms, with or without
! 11: * modification, are permitted provided that the following conditions
! 12: * are met:
! 13: * 1. Redistributions of source code must retain the above copyright
! 14: * notice, this list of conditions and the following disclaimer.
! 15: * 2. Redistributions in binary form must reproduce the above copyright
! 16: * notice, this list of conditions and the following disclaimer in the
! 17: * documentation and/or other materials provided with the distribution.
! 18: *
! 19: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! 20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 22: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 29: * SUCH DAMAGE.
! 30: *
! 31: */
! 32:
! 33: #if (HAVE_CONFIG_H)
! 34: #include "../include/config.h"
! 35: #endif
! 36: #include "./libnet_test.h"
! 37: #ifdef __WIN32__
! 38: #include "../include/win32/getopt.h"
! 39: #endif
! 40:
! 41: void
! 42: usage(char *prog)
! 43: {
! 44: fprintf(stderr, "Usage: %s -d dst_ip -q query_host [-s src_ip] [-t]\n", prog);
! 45: exit(1);
! 46: }
! 47:
! 48:
! 49: int
! 50: main(int argc, char *argv[])
! 51: {
! 52: char c;
! 53: u_long src_ip = 0, dst_ip = 0;
! 54: u_short type = LIBNET_UDP_DNSV4_H;
! 55: libnet_t *l;
! 56:
! 57: libnet_ptag_t ip;
! 58: libnet_ptag_t ptag4; /* TCP or UDP ptag */
! 59: libnet_ptag_t dns;
! 60:
! 61: char errbuf[LIBNET_ERRBUF_SIZE];
! 62: char *query = NULL;
! 63: char payload[1024];
! 64: u_short payload_s;
! 65:
! 66: printf("libnet 1.1 packet shaping: DNSv4[raw]\n");
! 67:
! 68: /*
! 69: * Initialize the library. Root priviledges are required.
! 70: */
! 71: l = libnet_init(
! 72: LIBNET_RAW4, /* injection type */
! 73: NULL, /* network interface */
! 74: errbuf); /* error buffer */
! 75:
! 76: if (!l)
! 77: {
! 78: fprintf(stderr, "libnet_init: %s", errbuf);
! 79: exit(EXIT_FAILURE);
! 80: }
! 81:
! 82: /*
! 83: * parse options
! 84: */
! 85: while ((c = getopt(argc, argv, "d:s:q:t")) != EOF)
! 86: {
! 87: switch (c)
! 88: {
! 89:
! 90: case 'd':
! 91: if ((dst_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)
! 92: {
! 93: fprintf(stderr, "Bad destination IP address: %s\n", optarg);
! 94: exit(EXIT_FAILURE);
! 95: }
! 96: break;
! 97: case 's':
! 98: if ((src_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)
! 99: {
! 100: fprintf(stderr, "Bad source IP address: %s\n", optarg);
! 101: exit(EXIT_FAILURE);
! 102: }
! 103: break;
! 104: case 'q':
! 105: query = optarg;
! 106: break;
! 107: case 't':
! 108: type = LIBNET_TCP_DNSV4_H;
! 109: break;
! 110: default:
! 111: exit(EXIT_FAILURE);
! 112: }
! 113: }
! 114:
! 115: if (!src_ip)
! 116: {
! 117: src_ip = libnet_get_ipaddr4(l);
! 118: }
! 119:
! 120: if (!dst_ip || !query)
! 121: {
! 122: usage(argv[0]);
! 123: exit(EXIT_FAILURE);
! 124: }
! 125:
! 126: /*
! 127: * build dns payload
! 128: */
! 129: payload_s = snprintf(payload, sizeof payload, "%c%s%c%c%c%c%c",
! 130: (char)(strlen(query)&0xff), query, 0x00, 0x00, 0x01, 0x00, 0x01);
! 131:
! 132: /*
! 133: * build packet
! 134: */
! 135: dns = libnet_build_dnsv4(
! 136: type, /* TCP or UDP */
! 137: 0x7777, /* id */
! 138: 0x0100, /* request */
! 139: 1, /* num_q */
! 140: 0, /* num_anws_rr */
! 141: 0, /* num_auth_rr */
! 142: 0, /* num_addi_rr */
! 143: payload,
! 144: payload_s,
! 145: l,
! 146: 0
! 147: );
! 148:
! 149: if (dns == -1)
! 150: {
! 151: fprintf(stderr, "Can't build DNS packet: %s\n", libnet_geterror(l));
! 152: goto bad;
! 153: }
! 154:
! 155: if (type == LIBNET_TCP_DNSV4_H) /* TCP DNS */
! 156: {
! 157: ptag4 = libnet_build_tcp(
! 158: 0x6666, /* source port */
! 159: 53, /* destination port */
! 160: 0x01010101, /* sequence number */
! 161: 0x02020202, /* acknowledgement num */
! 162: TH_PUSH|TH_ACK, /* control flags */
! 163: 32767, /* window size */
! 164: 0, /* checksum */
! 165: 0, /* urgent pointer */
! 166: LIBNET_TCP_H + LIBNET_TCP_DNSV4_H + payload_s, /* TCP packet size */
! 167: NULL, /* payload */
! 168: 0, /* payload size */
! 169: l, /* libnet handle */
! 170: 0); /* libnet id */
! 171:
! 172: if (ptag4 == -1)
! 173: {
! 174: fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l));
! 175: goto bad;
! 176: }
! 177:
! 178:
! 179: ip = libnet_build_ipv4(
! 180: LIBNET_IPV4_H + LIBNET_TCP_H + type + payload_s,/* length */
! 181: 0, /* TOS */
! 182: 242, /* IP ID */
! 183: 0, /* IP Frag */
! 184: 64, /* TTL */
! 185: IPPROTO_TCP, /* protocol */
! 186: 0, /* checksum */
! 187: src_ip, /* source IP */
! 188: dst_ip, /* destination IP */
! 189: NULL, /* payload */
! 190: 0, /* payload size */
! 191: l, /* libnet handle */
! 192: 0); /* libnet id */
! 193:
! 194: if (ip == -1)
! 195: {
! 196: fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l));
! 197: exit(EXIT_FAILURE);
! 198: }
! 199:
! 200: }
! 201: else /* UDP DNS */
! 202: {
! 203: ptag4 = libnet_build_udp(
! 204: 0x6666, /* source port */
! 205: 53, /* destination port */
! 206: LIBNET_UDP_H + LIBNET_UDP_DNSV4_H + payload_s, /* packet length */
! 207: 0, /* checksum */
! 208: NULL, /* payload */
! 209: 0, /* payload size */
! 210: l, /* libnet handle */
! 211: 0); /* libnet id */
! 212:
! 213: if (ptag4 == -1)
! 214: {
! 215: fprintf(stderr, "Can't build UDP header: %s\n", libnet_geterror(l));
! 216: goto bad;
! 217: }
! 218:
! 219:
! 220: ip = libnet_build_ipv4(
! 221: LIBNET_IPV4_H + LIBNET_UDP_H + type + payload_s,/* length */
! 222: 0, /* TOS */
! 223: 242, /* IP ID */
! 224: 0, /* IP Frag */
! 225: 64, /* TTL */
! 226: IPPROTO_UDP, /* protocol */
! 227: 0, /* checksum */
! 228: src_ip, /* source IP */
! 229: dst_ip, /* destination IP */
! 230: NULL, /* payload */
! 231: 0, /* payload size */
! 232: l, /* libnet handle */
! 233: 0); /* libnet id */
! 234:
! 235: if (ip == -1)
! 236: {
! 237: fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l));
! 238: exit(EXIT_FAILURE);
! 239: }
! 240: }
! 241:
! 242: /*
! 243: * write to the wire
! 244: */
! 245: c = libnet_write(l);
! 246: if (c == -1)
! 247: {
! 248: fprintf(stderr, "Write error: %s\n", libnet_geterror(l));
! 249: goto bad;
! 250: }
! 251: else
! 252: {
! 253: fprintf(stderr, "Wrote %d byte DNS packet; check the wire.\n", c);
! 254: }
! 255: libnet_destroy(l);
! 256: return (EXIT_SUCCESS);
! 257: bad:
! 258: libnet_destroy(l);
! 259: return (EXIT_FAILURE);
! 260: }
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