1: /*
2: * $Id: tcp1.c,v 1.1.1.3 2023/09/27 11:11:38 misho Exp $
3: *
4: * libnet 1.1
5: * Build a TCP packet
6: *
7: * Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
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: #include "libnet_test.h"
34:
35: int
36: main(int argc, char *argv[])
37: {
38: int c;
39: char *cp;
40: libnet_t *l;
41: libnet_ptag_t t;
42: char *payload;
43: u_short payload_s;
44: u_long src_ip, dst_ip;
45: u_short src_prt, dst_prt;
46: char errbuf[LIBNET_ERRBUF_SIZE];
47:
48: printf("libnet 1.1 packet shaping: TCP + options[link]\n");
49:
50: /*
51: * Initialize the library. Root priviledges are required.
52: */
53: l = libnet_init(
54: LIBNET_LINK, /* injection type */
55: NULL, /* network interface */
56: errbuf); /* error buffer */
57:
58: if (l == NULL)
59: {
60: fprintf(stderr, "libnet_init() failed: %s", errbuf);
61: exit(EXIT_FAILURE);
62: }
63:
64: src_ip = 0;
65: dst_ip = 0;
66: src_prt = 0;
67: dst_prt = 0;
68: payload = NULL;
69: payload_s = 0;
70: while ((c = getopt(argc, argv, "d:s:p:")) != EOF)
71: {
72: switch (c)
73: {
74: /*
75: * We expect the input to be of the form `ip.ip.ip.ip.port`. We
76: * point cp to the last dot of the IP address/port string and
77: * then seperate them with a NULL byte. The optarg now points to
78: * just the IP address, and cp points to the port.
79: */
80: case 'd':
81: if (!(cp = strrchr(optarg, '.')))
82: {
83: usage(argv[0]);
84: }
85: *cp++ = 0;
86: dst_prt = (u_short)atoi(cp);
87: if ((dst_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)
88: {
89: fprintf(stderr, "Bad destination IP address: %s\n", optarg);
90: exit(EXIT_FAILURE);
91: }
92: break;
93: case 's':
94: if (!(cp = strrchr(optarg, '.')))
95: {
96: usage(argv[0]);
97: }
98: *cp++ = 0;
99: src_prt = (u_short)atoi(cp);
100: if ((src_ip = libnet_name2addr4(l, optarg, LIBNET_RESOLVE)) == -1)
101: {
102: fprintf(stderr, "Bad source IP address: %s\n", optarg);
103: exit(EXIT_FAILURE);
104: }
105: break;
106: case 'p':
107: payload = optarg;
108: payload_s = strlen(payload);
109: break;
110: default:
111: exit(EXIT_FAILURE);
112: }
113: }
114:
115: if (!src_ip || !src_prt || !dst_ip || !dst_prt)
116: {
117: usage(argv[0]);
118: exit(EXIT_FAILURE);
119: }
120:
121: t = libnet_build_tcp_options(
122: (uint8_t*)"\003\003\012\001\002\004\001\011\010\012\077\077\077\077\000\000\000\000\000\000",
123: 20,
124: l,
125: 0);
126: if (t == -1)
127: {
128: fprintf(stderr, "Can't build TCP options: %s\n", libnet_geterror(l));
129: goto bad;
130: }
131:
132: t = libnet_build_tcp(
133: src_prt, /* source port */
134: dst_prt, /* destination port */
135: 0x01010101, /* sequence number */
136: 0x02020202, /* acknowledgement num */
137: TH_SYN, /* control flags */
138: 32767, /* window size */
139: 0, /* checksum */
140: 10, /* urgent pointer */
141: LIBNET_TCP_H + 20 + payload_s, /* TCP packet size */
142: (uint8_t*)payload, /* payload */
143: payload_s, /* payload size */
144: l, /* libnet handle */
145: 0); /* libnet id */
146: if (t == -1)
147: {
148: fprintf(stderr, "Can't build TCP header: %s\n", libnet_geterror(l));
149: goto bad;
150: }
151:
152: t = libnet_build_ipv4(
153: LIBNET_IPV4_H + LIBNET_TCP_H + 20 + payload_s,/* length */
154: 0, /* TOS */
155: 242, /* IP ID */
156: 0, /* IP Frag */
157: 64, /* TTL */
158: IPPROTO_TCP, /* protocol */
159: 0, /* checksum */
160: src_ip, /* source IP */
161: dst_ip, /* destination IP */
162: NULL, /* payload */
163: 0, /* payload size */
164: l, /* libnet handle */
165: 0); /* libnet id */
166: if (t == -1)
167: {
168: fprintf(stderr, "Can't build IP header: %s\n", libnet_geterror(l));
169: goto bad;
170: }
171:
172: t = libnet_build_ethernet(
173: enet_dst, /* ethernet destination */
174: enet_src, /* ethernet source */
175: ETHERTYPE_IP, /* protocol type */
176: NULL, /* payload */
177: 0, /* payload size */
178: l, /* libnet handle */
179: 0); /* libnet id */
180: if (t == -1)
181: {
182: fprintf(stderr, "Can't build ethernet header: %s\n", libnet_geterror(l));
183: goto bad;
184: }
185:
186: /*
187: * Write it to the wire.
188: */
189: c = libnet_write(l);
190: if (c == -1)
191: {
192: fprintf(stderr, "Write error: %s\n", libnet_geterror(l));
193: goto bad;
194: }
195: else
196: {
197: fprintf(stderr, "Wrote %d byte TCP packet; check the wire.\n", c);
198: }
199:
200: libnet_destroy(l);
201: return (EXIT_SUCCESS);
202: bad:
203: libnet_destroy(l);
204: return (EXIT_FAILURE);
205: }
206:
207: void
208: usage(char *name)
209: {
210: fprintf(stderr,
211: "usage: %s -s source_ip.source_port -d destination_ip.destination_port"
212: " [-p payload]\n",
213: name);
214: }
215:
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