2 * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
3 * with the aid of code written by
4 * Junichi SATOH <junichi@astec.co.jp> 1996, 1997.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/types.h>
33 #include <netinet/in_systm.h>
34 #include <netinet/in.h>
35 #include <netinet/ip.h>
36 #include <netinet/udp.h>
38 #include "alias_local.h"
40 /* CU-SeeMe Data Header */
42 u_int16_t dest_family;
54 /* Open Continue Header */
56 u_int16_t client_count; /* Number of client info structs */
59 char reserved[4]; /* flags, version stuff, etc */
62 /* client info structures */
64 u_int32_t address; /* Client address */
65 char reserved[8]; /* Flags, pruning bitfield, packet counts etc */
69 AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link)
73 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
74 if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
76 struct alias_link *cu_link;
78 cu = (struct cu_header *)(ud + 1);
80 cu->addr = (u_int32_t)GetAliasAddress(link).s_addr;
82 cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link),
83 ud->uh_dport, 0, IPPROTO_UDP, 1);
93 AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr)
95 struct in_addr alias_addr;
99 struct client_info *ci;
103 alias_addr.s_addr = pip->ip_dst.s_addr;
104 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
105 cu = (struct cu_header *)(ud + 1);
106 oc = (struct oc_header *)(cu + 1);
107 ci = (struct client_info *)(oc + 1);
108 end = (char *)ud + ntohs(ud->uh_ulen);
110 if ((char *)oc <= end) {
112 cu->dest_addr = (u_int32_t)original_addr.s_addr;
113 if(ntohs(cu->data_type) == 101)
114 /* Find and change our address */
115 for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
116 if(ci->address == (u_int32_t)alias_addr.s_addr) {
117 ci->address = (u_int32_t)original_addr.s_addr;