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("$FreeBSD$");
33 #include <sys/types.h>
34 #include <netinet/in_systm.h>
35 #include <netinet/in.h>
36 #include <netinet/ip.h>
37 #include <netinet/udp.h>
39 #include "alias_local.h"
41 /* CU-SeeMe Data Header */
43 u_int16_t dest_family;
55 /* Open Continue Header */
57 u_int16_t client_count; /* Number of client info structs */
60 char reserved [4]; /* flags, version stuff, etc */
63 /* client info structures */
65 u_int32_t address;/* Client address */
66 char reserved [8]; /* Flags, pruning bitfield, packet
71 AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk)
73 struct udphdr *ud = ip_next(pip);
75 if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
77 struct alias_link *cu_lnk;
81 cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr;
83 cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk),
84 ud->uh_dport, 0, IPPROTO_UDP, 1);
94 AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr)
96 struct in_addr alias_addr;
100 struct client_info *ci;
105 alias_addr.s_addr = pip->ip_dst.s_addr;
108 oc = (struct oc_header *)(cu + 1);
109 ci = (struct client_info *)(oc + 1);
110 end = (char *)ud + ntohs(ud->uh_ulen);
112 if ((char *)oc <= end) {
114 cu->dest_addr = (u_int32_t) original_addr.s_addr;
115 if (ntohs(cu->data_type) == 101)
116 /* Find and change our address */
117 for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
118 if (ci->address == (u_int32_t) alias_addr.s_addr) {
119 ci->address = (u_int32_t) original_addr.s_addr;