Windows/router/iphelp.cpp

/*
 *  iphelp.cpp - ip router
 *
 *  Basilisk II (C) 1997-2008 Christian Bauer
 *
 *  Windows platform specific code copyright (C) Lauri Pesonen
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"
#include "cpu_emulation.h"
#include "ether_windows.h"
#include "ether.h"
#include "router.h"
#include "router_types.h"
#include "tcp.h"
#include "icmp.h"
#include "udp.h"
#include "iphelp.h"
#include "dump.h"


#if DEBUG
#pragma optimize("",off)
#endif

#include "debug.h"


void make_icmp_checksum( icmp_t *icmp, int len )
{
        icmp->checksum = 0;

        uint16 sz = (len-sizeof(ip_t))/2;
        uint16 *p = (uint16 *)( (uint8 *)icmp + sizeof(ip_t) );

        uint32 sum32 = 0;
        for( int i=0; i<sz; i++ ) {
                sum32 += ntohs(p[i]);
        }

        while( HIWORD(sum32) ) {
                sum32 = HIWORD(sum32) + LOWORD(sum32);
        }
        sum32 = ~sum32;
        icmp->checksum = htons((uint16)sum32);
}

void make_tcp_checksum( tcp_t *tcp, int len )
{
        tcp->checksum = 0;

        int tcp_len = len - sizeof(ip_t);
        uint16 sz = tcp_len/2;
        uint16 *p = (uint16 *)( (uint8 *)tcp + sizeof(ip_t) );

        uint32 sum32 = 0;
        for( int i=0; i<sz; i++ ) {
                sum32 += ntohs(p[i]);
        }

        if(len & 1) {
                uint8 *p8 = (uint8 *)p;
                sum32 += p8[tcp_len-1] << 8;
        }

        pseudo_ip_t pseudo;
        pseudo.src_lo = LOWORD(ntohl(tcp->ip.src));
        pseudo.src_hi = HIWORD(ntohl(tcp->ip.src));
        pseudo.dest_lo = LOWORD(ntohl(tcp->ip.dest));
        pseudo.dest_hi = HIWORD(ntohl(tcp->ip.dest));
        pseudo.proto = (uint16)tcp->ip.proto;
        pseudo.msg_len = tcp->header_len >> 2;

        int datalen = len - sizeof(tcp_t);
        pseudo.msg_len += datalen;

        p = (uint16 *)&pseudo;

        for( int i=0; i<sizeof(pseudo_ip_t)/2; i++ ) {
                sum32 += p[i];
        }

        while( HIWORD(sum32) ) {
                sum32 = HIWORD(sum32) + LOWORD(sum32);
        }
        sum32 = ~sum32;
        tcp->checksum = htons((uint16)sum32);
}

void make_ip4_checksum( ip_t *ip )
{
        ip->checksum = 0;
        uint16 sz = ip->header_len * 2;
        uint16 *p = (uint16 *)( (uint8 *)ip + sizeof(mac_t) );

        uint32 sum32 = 0;
        for( int i=0; i<sz; i++ ) {
                sum32 += ntohs(p[i]);
        }

        while( HIWORD(sum32) ) {
                sum32 = HIWORD(sum32) + LOWORD(sum32);
        }

        sum32 = ~sum32;
        ip->checksum = htons((uint16)sum32);
}

void make_udp_checksum( udp_t *udp )
{
        udp->checksum = 0;
        return;

        // UDP checksums are optional.

        /*
        uint16 sz = ntohs(udp->msg_len) / 2;
        uint16 *p = (uint16 *)( (uint8 *)udp + sizeof(ip_t) );

        uint32 sum32 = 0;
        for( int i=0; i<sz; i++ ) {
                sum32 += ntohs(p[i]);
        }

        // last byte??

        pseudo_ip_t pseudo;
        pseudo.src_lo = LOWORD(ntohl(udp->ip.src));
        pseudo.src_hi = HIWORD(ntohl(udp->ip.src));
        pseudo.dest_lo = LOWORD(ntohl(udp->ip.dest));
        pseudo.dest_hi = HIWORD(ntohl(udp->ip.dest));
        pseudo.proto = (uint16)udp->ip.proto;
        pseudo.msg_len = ntohs(udp->msg_len); // ???

        p = (uint16 *)&pseudo;

        for( i=0; i<sizeof(pseudo_ip_t)/2; i++ ) {
                sum32 += p[i];
        }

        while( HIWORD(sum32) ) {
                sum32 = HIWORD(sum32) + LOWORD(sum32);
        }
        sum32 = ~sum32;
        udp->checksum = htons((uint16)sum32);
        */
}

void error_winsock_2_icmp( int err, ip_t *ip_err, int dlen_err )
{
        int type = -1, code = -1, msg_size = 0;

        switch( err ) {
                case WSAEHOSTUNREACH:
                case WSAETIMEDOUT:
                        type = icmp_Destination_unreachable;
                        code = 1;       // Host unreachable
                        msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
                        break;
                case WSAENETDOWN:
                case WSAENETUNREACH:
                        type = icmp_Destination_unreachable;
                        code = 0;       // Network unreachable
                        msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
                        break;
                case WSAETTLEXCEEDED:
                        type = icmp_Time_exceeded;
                        code = 0;               // Transit TTL exceeded
                        msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
                        break;
        }

        if(type >= 0 && macos_ip_address != 0) {
          D(bug("sending icmp error reply. type=%d, code=%d, msg_size=%d\r\n", type, code, msg_size));

                int icmp_size = sizeof(icmp_t) + msg_size;

                icmp_t *icmp = (icmp_t *)malloc( icmp_size );
                if(icmp) {
                        mac_t *mac = (mac_t *)icmp;
                        ip_t *ip = (ip_t *)icmp;

                        memcpy( mac->dest, ether_addr, 6 );
                        memcpy( mac->src, router_mac_addr, 6 );
                        mac->type = htons(mac_type_ip4);

                        ip->version = 4;
                        ip->header_len = 5;
                        ip->tos = 0;
                        ip->total_len = htons(sizeof(icmp_t) - sizeof(mac_t) + msg_size);

                        ip->ident = htons(next_ip_ident_number++);
                        ip->flags_n_frag_offset = 0;
                        ip->ttl = 128;
                        ip->proto = ip_proto_icmp;
                        ip->src = htonl(router_ip_address);
                        ip->dest = htonl(macos_ip_address);
                        make_ip4_checksum( ip );

                        icmp->type = type;
                        icmp->code = code;

                        // zero out the unused field
                        memset( (char *)icmp + sizeof(icmp_t), 0, sizeof(uint32) );

                        // copy 64 bits of original message
                        memcpy( 
                                (char *)icmp + sizeof(icmp_t) + sizeof(uint32),
                                (char *)ip_err + sizeof(mac_t),
                                msg_size
                        );

                        make_icmp_checksum( icmp, icmp_size );

                        dump_bytes( (uint8 *)icmp, icmp_size );

                        enqueue_packet( (uint8 *)icmp, icmp_size );
                        free(icmp);
                }
        }
}
Revision:	1.2
Committed:	2008-01-01T09:40:34Z (16 years, 11 months ago) by gbeauche
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.1:	+1 -1 lines
Log Message:	Happy New Year!
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* iphelp.cpp - ip router
3			*
4	gbeauche	1.2	* Basilisk II (C) 1997-2008 Christian Bauer
5	gbeauche	1.1	*
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 "ether_windows.h"
26			#include "ether.h"
27			#include "router.h"
28			#include "router_types.h"
29			#include "tcp.h"
30			#include "icmp.h"
31			#include "udp.h"
32			#include "iphelp.h"
33			#include "dump.h"
34
35
36			#if DEBUG
37			#pragma optimize("",off)
38			#endif
39
40			#include "debug.h"
41
42
43			void make_icmp_checksum( icmp_t *icmp, int len )
44			{
45			icmp->checksum = 0;
46
47			uint16 sz = (len-sizeof(ip_t))/2;
48			uint16 p = (uint16 )( (uint8 *)icmp + sizeof(ip_t) );
49
50			uint32 sum32 = 0;
51			for( int i=0; i<sz; i++ ) {
52			sum32 += ntohs(p[i]);
53			}
54
55			while( HIWORD(sum32) ) {
56			sum32 = HIWORD(sum32) + LOWORD(sum32);
57			}
58			sum32 = ~sum32;
59			icmp->checksum = htons((uint16)sum32);
60			}
61
62			void make_tcp_checksum( tcp_t *tcp, int len )
63			{
64			tcp->checksum = 0;
65
66			int tcp_len = len - sizeof(ip_t);
67			uint16 sz = tcp_len/2;
68			uint16 p = (uint16 )( (uint8 *)tcp + sizeof(ip_t) );
69
70			uint32 sum32 = 0;
71			for( int i=0; i<sz; i++ ) {
72			sum32 += ntohs(p[i]);
73			}
74
75			if(len & 1) {
76			uint8 p8 = (uint8 )p;
77			sum32 += p8[tcp_len-1] << 8;
78			}
79
80			pseudo_ip_t pseudo;
81			pseudo.src_lo = LOWORD(ntohl(tcp->ip.src));
82			pseudo.src_hi = HIWORD(ntohl(tcp->ip.src));
83			pseudo.dest_lo = LOWORD(ntohl(tcp->ip.dest));
84			pseudo.dest_hi = HIWORD(ntohl(tcp->ip.dest));
85			pseudo.proto = (uint16)tcp->ip.proto;
86			pseudo.msg_len = tcp->header_len >> 2;
87
88			int datalen = len - sizeof(tcp_t);
89			pseudo.msg_len += datalen;
90
91			p = (uint16 *)&pseudo;
92
93			for( int i=0; i<sizeof(pseudo_ip_t)/2; i++ ) {
94			sum32 += p[i];
95			}
96
97			while( HIWORD(sum32) ) {
98			sum32 = HIWORD(sum32) + LOWORD(sum32);
99			}
100			sum32 = ~sum32;
101			tcp->checksum = htons((uint16)sum32);
102			}
103
104			void make_ip4_checksum( ip_t *ip )
105			{
106			ip->checksum = 0;
107			uint16 sz = ip->header_len * 2;
108			uint16 p = (uint16 )( (uint8 *)ip + sizeof(mac_t) );
109
110			uint32 sum32 = 0;
111			for( int i=0; i<sz; i++ ) {
112			sum32 += ntohs(p[i]);
113			}
114
115			while( HIWORD(sum32) ) {
116			sum32 = HIWORD(sum32) + LOWORD(sum32);
117			}
118
119			sum32 = ~sum32;
120			ip->checksum = htons((uint16)sum32);
121			}
122
123			void make_udp_checksum( udp_t *udp )
124			{
125			udp->checksum = 0;
126			return;
127
128			// UDP checksums are optional.
129
130			/*
131			uint16 sz = ntohs(udp->msg_len) / 2;
132			uint16 p = (uint16 )( (uint8 *)udp + sizeof(ip_t) );
133
134			uint32 sum32 = 0;
135			for( int i=0; i<sz; i++ ) {
136			sum32 += ntohs(p[i]);
137			}
138
139			// last byte??
140
141			pseudo_ip_t pseudo;
142			pseudo.src_lo = LOWORD(ntohl(udp->ip.src));
143			pseudo.src_hi = HIWORD(ntohl(udp->ip.src));
144			pseudo.dest_lo = LOWORD(ntohl(udp->ip.dest));
145			pseudo.dest_hi = HIWORD(ntohl(udp->ip.dest));
146			pseudo.proto = (uint16)udp->ip.proto;
147			pseudo.msg_len = ntohs(udp->msg_len); // ???
148
149			p = (uint16 *)&pseudo;
150
151			for( i=0; i<sizeof(pseudo_ip_t)/2; i++ ) {
152			sum32 += p[i];
153			}
154
155			while( HIWORD(sum32) ) {
156			sum32 = HIWORD(sum32) + LOWORD(sum32);
157			}
158			sum32 = ~sum32;
159			udp->checksum = htons((uint16)sum32);
160			*/
161			}
162
163			void error_winsock_2_icmp( int err, ip_t *ip_err, int dlen_err )
164			{
165			int type = -1, code = -1, msg_size = 0;
166
167			switch( err ) {
168			case WSAEHOSTUNREACH:
169			case WSAETIMEDOUT:
170			type = icmp_Destination_unreachable;
171			code = 1; // Host unreachable
172			msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
173			break;
174			case WSAENETDOWN:
175			case WSAENETUNREACH:
176			type = icmp_Destination_unreachable;
177			code = 0; // Network unreachable
178			msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
179			break;
180			case WSAETTLEXCEEDED:
181			type = icmp_Time_exceeded;
182			code = 0; // Transit TTL exceeded
183			msg_size = (ip_err->header_len << 2) + 4 + 8; // ip header + unused + 64 msg bits
184			break;
185			}
186
187			if(type >= 0 && macos_ip_address != 0) {
188			D(bug("sending icmp error reply. type=%d, code=%d, msg_size=%d\r\n", type, code, msg_size));
189
190			int icmp_size = sizeof(icmp_t) + msg_size;
191
192			icmp_t icmp = (icmp_t )malloc( icmp_size );
193			if(icmp) {
194			mac_t mac = (mac_t )icmp;
195			ip_t ip = (ip_t )icmp;
196
197			memcpy( mac->dest, ether_addr, 6 );
198			memcpy( mac->src, router_mac_addr, 6 );
199			mac->type = htons(mac_type_ip4);
200
201			ip->version = 4;
202			ip->header_len = 5;
203			ip->tos = 0;
204			ip->total_len = htons(sizeof(icmp_t) - sizeof(mac_t) + msg_size);
205
206			ip->ident = htons(next_ip_ident_number++);
207			ip->flags_n_frag_offset = 0;
208			ip->ttl = 128;
209			ip->proto = ip_proto_icmp;
210			ip->src = htonl(router_ip_address);
211			ip->dest = htonl(macos_ip_address);
212			make_ip4_checksum( ip );
213
214			icmp->type = type;
215			icmp->code = code;
216
217			// zero out the unused field
218			memset( (char *)icmp + sizeof(icmp_t), 0, sizeof(uint32) );
219
220			// copy 64 bits of original message
221			memcpy(
222			(char *)icmp + sizeof(icmp_t) + sizeof(uint32),
223			(char *)ip_err + sizeof(mac_t),
224			msg_size
225			);
226
227			make_icmp_checksum( icmp, icmp_size );
228
229			dump_bytes( (uint8 *)icmp, icmp_size );
230
231			enqueue_packet( (uint8 *)icmp, icmp_size );
232			free(icmp);
233			}
234			}
235			}