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root/cebix/BasiliskII/src/Windows/router/icmp.cpp
Revision: 1.1
Committed: 2004-12-05T16:48:36Z (19 years, 11 months ago) by gbeauche
Branch: MAIN
Log Message:
import NAT-Router code from original Basilisk II for Windows

File Contents

# Content
1 /*
2 * icmp.cpp - ip router
3 *
4 * Basilisk II (C) 1997-2004 Christian Bauer
5 *
6 * Windows platform specific code copyright (C) Lauri Pesonen
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include "sysdeps.h"
24 #include "cpu_emulation.h"
25 #include "ws2tcpip.h"
26 #include "prefs.h"
27 #include "ether_windows.h"
28 #include "ether.h"
29 #include "router.h"
30 #include "router_types.h"
31 #include "dynsockets.h"
32 #include "ipsocket.h"
33 #include "iphelp.h"
34 #include "icmp.h"
35 #include "dump.h"
36
37
38 #if DEBUG
39 #pragma optimize("",off)
40 #endif
41
42 #include "debug.h"
43
44
45 // Saved for cleanup.
46 static socket_t *icmp_incoming_s = 0;
47
48
49 void stop_icmp_listen()
50 {
51 if(icmp_incoming_s) {
52 delete icmp_incoming_s;
53 icmp_incoming_s = 0;
54 }
55 }
56
57 void start_icmp_listen()
58 {
59 if(!icmp_incoming_s) {
60 icmp_incoming_s = new socket_t(IPPROTO_ICMP);
61
62 icmp_incoming_s->permanent = TRUE;
63 icmp_incoming_s->s = _socket( AF_INET, SOCK_RAW, IPPROTO_ICMP );
64
65 memset( &icmp_incoming_s->from, 0, icmp_incoming_s->from_len );
66 icmp_incoming_s->from.sin_family = AF_INET;
67
68 if(icmp_incoming_s->s == INVALID_SOCKET) {
69 D(bug("Failed to create icmp listening socket (NT/no admin?)\r\n" ));
70 delete icmp_incoming_s;
71 icmp_incoming_s = 0;
72 } else {
73 D(bug("icmp listening socket created\r\n" ));
74 raw_sockets_available = true;
75 struct sockaddr_in to;
76 memset( &to, 0, sizeof(to) );
77 to.sin_family = AF_INET;
78 if( _bind ( icmp_incoming_s->s, (const struct sockaddr *)&to, sizeof(to) ) == SOCKET_ERROR ) {
79 D(bug("Listening to inbound icmp failed, error code = %d\r\n", _WSAGetLastError() ));
80 _closesocket( icmp_incoming_s->s );
81 delete icmp_incoming_s;
82 icmp_incoming_s = 0;
83 } else {
84 D(bug("icmp listening socket bound\r\n" ));
85 if(!icmp_incoming_s->b_recfrom()) {
86 D(bug("b_recfrom() from inbound icmp failed, error code = %d\r\n", _WSAGetLastError() ));
87 // _closesocket( icmp_incoming_s->s );
88 // delete icmp_incoming_s;
89 // icmp_incoming_s = 0;
90 }
91 }
92 }
93 }
94 }
95
96 void CALLBACK icmp_read_completion(
97 DWORD error,
98 DWORD bytes_read,
99 LPWSAOVERLAPPED lpOverlapped,
100 DWORD flags
101 )
102 {
103 D(bug("icmp_read_completion(error=0x%x, bytes_read=%d, flags=0x%x)\r\n", error, bytes_read, flags));
104
105 socket_t *cmpl = (socket_t *)lpOverlapped->hEvent;
106
107 if(error == 0 && macos_ip_address != 0) {
108 if(bytes_read > 1460) {
109 D(bug("discarding oversized icmp packet, size = \r\n", bytes_read));
110 } else {
111 int icmp_size = sizeof(mac_t) + bytes_read;
112 icmp_t *icmp = (icmp_t *)malloc( icmp_size );
113 if(icmp) {
114 mac_t *mac = (mac_t *)icmp;
115 ip_t *ip = (ip_t *)icmp;
116
117 memcpy( mac->dest, ether_addr, 6 );
118 memcpy( mac->src, router_mac_addr, 6 );
119 mac->type = htons(mac_type_ip4);
120
121 // Copy payload (used by ICMP checksum)
122 memcpy( (char *)icmp + sizeof(mac_t), cmpl->buffers[0].buf, bytes_read );
123
124 switch( icmp->type ) {
125 // May need to patch the returned ip header.
126 case icmp_Destination_unreachable:
127 case icmp_Source_quench:
128 case icmp_Redirect:
129 case icmp_Time_exceeded:
130 case icmp_Parameter_problem:
131 ip_t *ip_if = (ip_t *)( (char *)icmp + sizeof(icmp_t) + sizeof(uint32) - sizeof(mac_t) );
132
133 // This would be needed (traceroute)
134 // ip_if->ident = ??;
135
136 // Cannot fix some fields, this should be enough:
137 ip_if->src = htonl(macos_ip_address);
138
139 if(ip_if->proto == ip_proto_udp) {
140 udp_t *udp_if = (udp_t *)ip_if;
141 // udp_if->src_port = ... don't know!;
142 } else if(ip_if->proto == ip_proto_tcp) {
143 tcp_t *tcp_if = (tcp_t *)ip_if;
144 // tcp_if->src_port = ... don't know!;
145 }
146 break;
147 }
148
149 make_icmp_checksum( icmp, icmp_size );
150
151 // Replace the target ip address
152 ip->dest = htonl(macos_ip_address);
153 ip->ttl--;
154 make_ip4_checksum( ip );
155
156 dump_bytes( (uint8 *)icmp, icmp_size );
157
158 if( ip->ttl == 0 ) {
159 D(bug("icmp packet ttl expired\r\n"));
160 } else {
161 enqueue_packet( (uint8 *)icmp, icmp_size );
162 }
163 free(icmp);
164 }
165 }
166 }
167
168 memset( &cmpl->from, 0, cmpl->from_len );
169
170 if(is_router_shutting_down) {
171 delete cmpl;
172 } else if(cmpl->s == INVALID_SOCKET || !cmpl->b_recfrom()) {
173 // delete cmpl;
174 }
175 }
176
177 void write_icmp( icmp_t *icmp, int len )
178 {
179 struct in_addr ia;
180 ia.s_addr = icmp->ip.dest;
181 D(bug("write_icmp(%s)\r\n", _inet_ntoa(ia) ));
182
183 if(!raw_sockets_available) {
184 D(bug("write_icmp() cannot proceed, raw sockets not available\r\n" ));
185 return;
186 }
187
188 if(len < sizeof(icmp_t)) {
189 D(bug("Too small icmp packet(%d), dropped\r\n", len));
190 return;
191 }
192
193 // must be updated, ttl changed
194 make_icmp_checksum( icmp, len );
195
196 SOCKET s = _socket( AF_INET, SOCK_RAW, IPPROTO_ICMP );
197 if(s != INVALID_SOCKET) {
198 struct sockaddr_in to;
199 memset( &to, 0, sizeof(to) );
200 to.sin_family = AF_INET;
201 to.sin_addr.s_addr = icmp->ip.dest;
202
203 char *data = (char *)icmp + sizeof(ip_t);
204 int dlen = len - sizeof(ip_t);
205
206 int ttl = icmp->ip.ttl;
207 if(_setsockopt( s, IPPROTO_IP, IP_TTL, (const char *)&ttl, sizeof(int) ) == SOCKET_ERROR ) {
208 D(bug("could not set ttl to %d.\r\n", ttl));
209 } else {
210 D(bug("ttl set to %d.\r\n", ttl));
211 }
212
213 if(SOCKET_ERROR == _sendto( s, data, dlen, 0, (struct sockaddr *)&to, sizeof(to) )) {
214 D(bug("Failed to send icmp via raw socket\r\n" ));
215 }
216 _closesocket(s);
217 } else {
218 D(bug("Could not create raw socket for icmp\r\n" ));
219 }
220 }