2 * $Id: libnet_build_tcp.c,v 1.1.1.1 2000/05/25 00:28:49 route Exp $
5 * libnet_build_tcp.c - TCP packet assembler
7 * Copyright (c) 1998 - 2001 Mike D. Schiffman <mike@infonexus.com>
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
34 #include "../include/config.h"
36 #include "../include/libnet.h"
39 libnet_build_tcp(u_short sp, u_short dp, u_long seq, u_long ack, u_char control,
40 u_short win, u_short urg, const u_char *payload, int payload_s,
43 struct libnet_tcp_hdr tcp_hdr;
50 tcp_hdr.th_sport = htons(sp); /* source port */
51 tcp_hdr.th_dport = htons(dp); /* destination port */
52 tcp_hdr.th_seq = htonl(seq); /* sequence number */
53 tcp_hdr.th_ack = htonl(ack); /* acknowledgement number */
54 tcp_hdr.th_flags = control; /* control flags */
55 tcp_hdr.th_x2 = 0; /* UNUSED */
56 tcp_hdr.th_off = 5; /* 20 byte header */
57 tcp_hdr.th_win = htons(win); /* window size */
58 tcp_hdr.th_sum = 0; /* checksum done in userland */
59 tcp_hdr.th_urp = urg; /* urgent pointer */
61 if (payload && payload_s)
64 * Unchecked runtime error for buf + TCP_H + payload to be greater
65 * than the allocated heap memory.
67 memcpy(buf + LIBNET_TCP_H, payload, payload_s);
69 memcpy((u_char *)buf, (u_char *)&tcp_hdr, sizeof(tcp_hdr));