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9fa0fd2682
{ip,udp,tcp} header and return a void * pointing to the payload (i.e. the
first byte past the end of the header and any required padding). Use them
consistently throughout libalias to a) reduce code duplication, b) improve
code legibility, c) get rid of a bunch of alignment warnings.
124 lines
3.6 KiB
C
124 lines
3.6 KiB
C
/*-
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* Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
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* with the aid of code written by
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* Junichi SATOH <junichi@astec.co.jp> 1996, 1997.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <stdio.h>
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#include <sys/types.h>
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#include <netinet/in_systm.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/udp.h>
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#include "alias_local.h"
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/* CU-SeeMe Data Header */
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struct cu_header {
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u_int16_t dest_family;
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u_int16_t dest_port;
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u_int32_t dest_addr;
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int16_t family;
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u_int16_t port;
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u_int32_t addr;
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u_int32_t seq;
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u_int16_t msg;
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u_int16_t data_type;
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u_int16_t packet_len;
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};
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/* Open Continue Header */
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struct oc_header {
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u_int16_t client_count; /* Number of client info structs */
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u_int32_t seq_no;
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char user_name [20];
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char reserved [4]; /* flags, version stuff, etc */
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};
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/* client info structures */
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struct client_info {
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u_int32_t address;/* Client address */
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char reserved [8]; /* Flags, pruning bitfield, packet
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* counts etc */
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};
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void
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AliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk)
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{
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struct udphdr *ud = ip_next(pip);
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if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) {
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struct cu_header *cu;
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struct alias_link *cu_lnk;
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cu = udp_next(ud);
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if (cu->addr)
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cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr;
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cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk),
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ud->uh_dport, 0, IPPROTO_UDP, 1);
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#ifndef NO_FW_PUNCH
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if (cu_lnk)
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PunchFWHole(cu_lnk);
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#endif
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}
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}
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void
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AliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr)
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{
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struct in_addr alias_addr;
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struct udphdr *ud;
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struct cu_header *cu;
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struct oc_header *oc;
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struct client_info *ci;
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char *end;
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int i;
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(void)la;
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alias_addr.s_addr = pip->ip_dst.s_addr;
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ud = ip_next(pip);
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cu = udp_next(ud);
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oc = (struct oc_header *)(cu + 1);
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ci = (struct client_info *)(oc + 1);
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end = (char *)ud + ntohs(ud->uh_ulen);
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if ((char *)oc <= end) {
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if (cu->dest_addr)
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cu->dest_addr = (u_int32_t) original_addr.s_addr;
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if (ntohs(cu->data_type) == 101)
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/* Find and change our address */
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for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
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if (ci->address == (u_int32_t) alias_addr.s_addr) {
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ci->address = (u_int32_t) original_addr.s_addr;
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break;
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}
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}
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}
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