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: src/sys/netinet/libalias/alias_cuseeme.c,v 1.13.6.1 2008/11/25 02:59:29 kensmith Exp $");
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/module.h>
38 #include <sys/types.h>
42 #include <netinet/in_systm.h>
43 #include <netinet/in.h>
44 #include <netinet/ip.h>
45 #include <netinet/udp.h>
48 #include <netinet/libalias/alias.h>
49 #include <netinet/libalias/alias_local.h>
50 #include <netinet/libalias/alias_mod.h>
52 #include "alias_local.h"
53 #include "alias_mod.h"
56 #define CUSEEME_PORT_NUMBER 7648
59 AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip,
60 struct alias_link *lnk);
63 AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip,
64 struct in_addr original_addr);
67 fingerprint(struct libalias *la, struct ip *pip, struct alias_data *ah)
70 if (ah->dport == NULL || ah->oaddr == NULL)
72 if (ntohs(*ah->dport) == CUSEEME_PORT_NUMBER)
78 protohandlerin(struct libalias *la, struct ip *pip, struct alias_data *ah)
81 AliasHandleCUSeeMeIn(la, pip, *ah->oaddr);
86 protohandlerout(struct libalias *la, struct ip *pip, struct alias_data *ah)
89 AliasHandleCUSeeMeOut(la, pip, ah->lnk);
93 /* Kernel module definition. */
94 struct proto_handler handlers[] = {
99 .fingerprint = &fingerprint,
100 .protohandler = &protohandlerout
106 .fingerprint = &fingerprint,
107 .protohandler = &protohandlerin
113 mod_handler(module_t mod, int type, void *data)
120 LibAliasAttachHandlers(handlers);
124 LibAliasDetachHandlers(handlers);
137 "alias_cuseeme", mod_handler, NULL
141 DECLARE_MODULE(alias_cuseeme, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
142 MODULE_VERSION(alias_cuseeme, 1);
143 MODULE_DEPEND(alias_cuseeme, libalias, 1, 1, 1);
146 /* CU-SeeMe Data Header */
148 u_int16_t dest_family;
157 u_int16_t packet_len;
160 /* Open Continue Header */
162 u_int16_t client_count; /* Number of client info structs */
165 char reserved [4]; /* flags, version stuff, etc */
168 /* client info structures */
170 u_int32_t address;/* Client address */
171 char reserved [8]; /* Flags, pruning bitfield, packet
176 AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk)
178 struct udphdr *ud = ip_next(pip);
180 if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
181 struct cu_header *cu;
182 struct alias_link *cu_lnk;
186 cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr;
188 cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk),
189 ud->uh_dport, 0, IPPROTO_UDP, 1);
199 AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr)
201 struct in_addr alias_addr;
203 struct cu_header *cu;
204 struct oc_header *oc;
205 struct client_info *ci;
210 alias_addr.s_addr = pip->ip_dst.s_addr;
213 oc = (struct oc_header *)(cu + 1);
214 ci = (struct client_info *)(oc + 1);
215 end = (char *)ud + ntohs(ud->uh_ulen);
217 if ((char *)oc <= end) {
219 cu->dest_addr = (u_int32_t) original_addr.s_addr;
220 if (ntohs(cu->data_type) == 101)
221 /* Find and change our address */
222 for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
223 if (ci->address == (u_int32_t) alias_addr.s_addr) {
224 ci->address = (u_int32_t) original_addr.s_addr;