2 * $Id: libnet_insert_ipo.c,v 1.1.1.1 2000/05/25 00:28:49 route Exp $
5 * libnet_insert_ipo.c - inserts IP options into a prebuilt IP packet
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_insert_ipo(struct ipoption *opt, u_char opt_len, u_char *buf)
41 struct libnet_ip_hdr *ip_hdr;
51 ip_hdr = (struct libnet_ip_hdr *)(buf);
52 s = UNFIX(ip_hdr->ip_len);
54 if ((s + opt_len) > IP_MAXPACKET)
60 libnet_error(LIBNET_ERR_WARNING,
61 "insert_ipo: options list would result in too large of a packet\n");
67 * Do we have more then just an IP header?
72 * Move over whatever's in the way.
74 memmove((u_char *)ip_hdr + LIBNET_IP_H + opt_len, (u_char *)ip_hdr
75 + LIBNET_IP_H, opt_len);
79 * Copy over option list. We rely on the programmer having been
80 * smart enough to allocate enough heap memory here. Uh oh.
82 p = (u_char *)ip_hdr + LIBNET_IP_H;
83 memcpy(p, opt->ipopt_list, opt_len);
86 * Count up number of 32-bit words in options list, padding if
89 for (i = 0, j = 0; i < opt_len; i++) (i % 4) ? j : j++;
92 ip_hdr->ip_len = FIX(opt_len + s);