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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

# User Rev Content
1 gbeauche 1.1 /*
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     }