124 lines
3.7 KiB
C
124 lines
3.7 KiB
C
/*-
|
|
* 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("$FreeBSD$");
|
|
|
|
#include <stdio.h>
|
|
#include <sys/types.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/udp.h>
|
|
|
|
#include "alias_local.h"
|
|
|
|
/* 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 */
|
|
};
|
|
|
|
void
|
|
AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *link)
|
|
{
|
|
struct udphdr *ud;
|
|
|
|
ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
|
|
if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
|
|
struct cu_header *cu;
|
|
struct alias_link *cu_link;
|
|
|
|
cu = (struct cu_header *)(ud + 1);
|
|
if (cu->addr)
|
|
cu->addr = (u_int32_t) GetAliasAddress(link).s_addr;
|
|
|
|
cu_link = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(link),
|
|
ud->uh_dport, 0, IPPROTO_UDP, 1);
|
|
|
|
#ifndef NO_FW_PUNCH
|
|
if (cu_link)
|
|
PunchFWHole(cu_link);
|
|
#endif
|
|
}
|
|
}
|
|
|
|
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;
|
|
|
|
alias_addr.s_addr = pip->ip_dst.s_addr;
|
|
ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
|
|
cu = (struct cu_header *)(ud + 1);
|
|
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;
|
|
}
|
|
}
|
|
}
|