]> git.saurik.com Git - apple/network_cmds.git/blob - alias/alias_cuseeme.c
network_cmds-85.tar.gz
[apple/network_cmds.git] / alias / alias_cuseeme.c
1 /*-
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.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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.
15 *
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
26 * SUCH DAMAGE.
27 *
28 * $Id: alias_cuseeme.c,v 1.1.1.1 2000/01/11 01:48:42 wsanchez Exp $
29 */
30
31 #include <sys/types.h>
32 #include <netinet/in_systm.h>
33 #include <netinet/in.h>
34 #include <netinet/ip.h>
35 #include <netinet/udp.h>
36
37 #include "alias_local.h"
38
39 /* CU-SeeMe Data Header */
40 struct cu_header {
41 u_int16_t dest_family;
42 u_int16_t dest_port;
43 u_int32_t dest_addr;
44 int16_t family;
45 u_int16_t port;
46 u_int32_t addr;
47 u_int32_t seq;
48 u_int16_t msg;
49 u_int16_t data_type;
50 u_int16_t packet_len;
51 };
52
53 /* Open Continue Header */
54 struct oc_header {
55 u_int16_t client_count; /* Number of client info structs */
56 u_int32_t seq_no;
57 char user_name[20];
58 char reserved[4]; /* flags, version stuff, etc */
59 };
60
61 /* client info structures */
62 struct client_info {
63 u_int32_t address; /* Client address */
64 char reserved[8]; /* Flags, pruning bitfield, packet counts etc */
65 };
66
67 void
68 AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link)
69 {
70 struct udphdr *ud;
71
72 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
73 if(ud->uh_ulen >= sizeof(struct cu_header)) {
74 struct cu_header *cu;
75 struct alias_link *cu_link;
76
77 cu = (struct cu_header *)(ud + 1);
78 if (cu->addr)
79 cu->addr = (u_int32_t)GetAliasAddress(link).s_addr;
80
81 cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link),
82 ud->uh_dport, 0, IPPROTO_UDP);
83
84 #ifndef NO_FW_PUNCH
85 if (cu_link)
86 PunchFWHole(cu_link);
87 #endif
88 }
89 }
90
91 void
92 AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr)
93 {
94 struct in_addr alias_addr;
95 struct udphdr *ud;
96 struct cu_header *cu;
97 struct oc_header *oc;
98 struct client_info *ci;
99 char *end;
100 int i;
101
102 alias_addr.s_addr = pip->ip_dst.s_addr;
103 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
104 cu = (struct cu_header *)(ud + 1);
105 oc = (struct oc_header *)(cu + 1);
106 ci = (struct client_info *)(oc + 1);
107 end = (char *)cu + ud->uh_ulen;
108
109 if ((char *)oc <= end) {
110 if(cu->dest_addr)
111 cu->dest_addr = (u_int32_t)original_addr.s_addr;
112 if(ntohs(cu->data_type) == 101)
113 /* Find and change our address */
114 for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
115 if(ci->address == (u_int32_t)alias_addr.s_addr) {
116 ci->address = (u_int32_t)original_addr.s_addr;
117 break;
118 }
119 }
120 }