home *** CD-ROM | disk | FTP | other *** search
- /*
- * $Id: build_ip.c,v 1.1.1.1 1999/05/18 15:33:42 dugsong Exp $
- *
- * libnet
- * build_ip.c - IP packet assembler
- *
- * Copyright (c) 1998, 1999 Mike D. Schiffman <mike@infonexus.com>
- * route|daemon9 <route@infonexus.com>
- * 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 "../include/libnet.h"
-
- void
- build_ip(u_short len, u_char tos, u_short id, u_short frag, u_char ttl,
- u_char prot, u_long src, u_long dst, const u_char *payload,
- int payload_s, u_char *buf)
- {
- struct ip ip_hdr;
-
- assert(buf);
-
- ip_hdr.ip_v = 4; /* version 4 */
- ip_hdr.ip_hl = 5; /* 20 byte header */
- ip_hdr.ip_tos = tos; /* IP tos */
- ip_hdr.ip_len = htons(IP_H + len); /* total length */
- ip_hdr.ip_id = htons(id); /* IP ID */
- ip_hdr.ip_off = htons(frag); /* fragmentation flags */
- ip_hdr.ip_ttl = ttl; /* time to live */
- ip_hdr.ip_p = prot; /* transport protocol */
- ip_hdr.ip_sum = 0; /* do this later */
- ip_hdr.ip_src.s_addr = src;
- ip_hdr.ip_dst.s_addr = dst;
- if (payload && payload_s)
- {
- /*
- * Unchecked runtime error for buf + IP_H + payload to be greater than
- * the allocated heap memory.
- */
- memcpy(buf + IP_H, payload, payload_s);
- }
- memcpy((u_char *)buf, (u_char *)&ip_hdr, sizeof(ip_hdr));
- }
-
-
- /* EOF */
-