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#include <machine/rtems-bsd-config.h>
/*-
* Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
* with the aid of code written by
* Junichi SATOH <junichi@astec.co.jp> 1996, 1997.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#ifdef _KERNEL
#include <rtems/bsd/sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#else
#include <errno.h>
#include <rtems/bsd/sys/types.h>
#include <stdio.h>
#endif
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#ifdef _KERNEL
#include <netinet/libalias/alias.h>
#include <netinet/libalias/alias_local.h>
#include <netinet/libalias/alias_mod.h>
#else
#include <rtems/bsd/local/alias_local.h>
#include <rtems/bsd/local/alias_mod.h>
#endif
#define CUSEEME_PORT_NUMBER 7648
static void
AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip,
struct alias_link *lnk);
static void
AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip,
struct in_addr original_addr);
static int
fingerprint(struct libalias *la, struct alias_data *ah)
{
if (ah->dport == NULL || ah->oaddr == NULL)
return (-1);
if (ntohs(*ah->dport) == CUSEEME_PORT_NUMBER)
return (0);
return (-1);
}
static int
protohandlerin(struct libalias *la, struct ip *pip, struct alias_data *ah)
{
AliasHandleCUSeeMeIn(la, pip, *ah->oaddr);
return (0);
}
static int
protohandlerout(struct libalias *la, struct ip *pip, struct alias_data *ah)
{
AliasHandleCUSeeMeOut(la, pip, ah->lnk);
return (0);
}
/* Kernel module definition. */
struct proto_handler handlers[] = {
{
.pri = 120,
.dir = OUT,
.proto = UDP,
.fingerprint = &fingerprint,
.protohandler = &protohandlerout
},
{
.pri = 120,
.dir = IN,
.proto = UDP,
.fingerprint = &fingerprint,
.protohandler = &protohandlerin
},
{ EOH }
};
static int
mod_handler(module_t mod, int type, void *data)
{
int error;
switch (type) {
case MOD_LOAD:
error = 0;
LibAliasAttachHandlers(handlers);
break;
case MOD_UNLOAD:
error = 0;
LibAliasDetachHandlers(handlers);
break;
default:
error = EINVAL;
}
return (error);
}
#ifdef _KERNEL
static
#endif
moduledata_t
alias_mod = {
"alias_cuseeme", mod_handler, NULL
};
#ifdef _KERNEL
DECLARE_MODULE(alias_cuseeme, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
MODULE_VERSION(alias_cuseeme, 1);
MODULE_DEPEND(alias_cuseeme, libalias, 1, 1, 1);
#endif
/* CU-SeeMe Data Header */
struct cu_header {
u_int16_t dest_family;
u_int16_t dest_port;
u_int32_t dest_addr;
int16_t family;
u_int16_t port;
u_int32_t addr;
u_int32_t seq;
u_int16_t msg;
u_int16_t data_type;
u_int16_t packet_len;
};
/* Open Continue Header */
struct oc_header {
u_int16_t client_count; /* Number of client info structs */
u_int32_t seq_no;
char user_name [20];
char reserved [4]; /* flags, version stuff, etc */
};
/* client info structures */
struct client_info {
u_int32_t address;/* Client address */
char reserved [8]; /* Flags, pruning bitfield, packet
* counts etc */
};
static void
AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk)
{
struct udphdr *ud = ip_next(pip);
if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
struct cu_header *cu;
struct alias_link *cu_lnk;
cu = udp_next(ud);
if (cu->addr)
cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr;
cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk),
ud->uh_dport, 0, IPPROTO_UDP, 1);
#ifndef NO_FW_PUNCH
if (cu_lnk)
PunchFWHole(cu_lnk);
#endif
}
}
static void
AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr)
{
struct in_addr alias_addr;
struct udphdr *ud;
struct cu_header *cu;
struct oc_header *oc;
struct client_info *ci;
char *end;
int i;
(void)la;
alias_addr.s_addr = pip->ip_dst.s_addr;
ud = ip_next(pip);
cu = udp_next(ud);
oc = (struct oc_header *)(cu + 1);
ci = (struct client_info *)(oc + 1);
end = (char *)ud + ntohs(ud->uh_ulen);
if ((char *)oc <= end) {
if (cu->dest_addr)
cu->dest_addr = (u_int32_t) original_addr.s_addr;
if (ntohs(cu->data_type) == 101)
/* Find and change our address */
for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
if (ci->address == (u_int32_t) alias_addr.s_addr) {
ci->address = (u_int32_t) original_addr.s_addr;
break;
}
}
}
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