libpcap (sous windows xp)
bonjours,
je suis entrain d'utiliser winpcap pour envoyer des paquets UDP, voici mon programme :
Code:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
int main()
{
#define PACKET_SIZE (1450)
pcap_if_t *alldevs;
pcap_if_t *d;
int inum;
int i=0;
pcap_t *adhandle;
char errbuf[PCAP_ERRBUF_SIZE];
u_int netmask;
//char packet_filter[] = "ip and udp";
//struct bpf_program fcode;
u_char buf[PACKET_SIZE];
int cpt = 0;
/* Retrieve the device list */
if(pcap_findalldevs(&alldevs, errbuf) == -1)
{
fprintf(stderr,"Error in pcap_findalldevs: %s\n", errbuf);
exit(1);
}
/* Print the list */
for(d=alldevs; d; d=d->next)
{
printf("%d. %s", ++i, d->name);
if (d->description)
printf(" (%s)\n", d->description);
else
printf(" (No description available)\n");
}
if(i==0)
{
printf("\nNo interfaces found! Make sure WinPcap is installed.\n");
return -1;
}
printf("Enter the interface number (1-%d):",i);
scanf("%d", &inum);
/* Check if the user specified a valid adapter */
if(inum < 1 || inum > i)
{
printf("\nAdapter number out of range.\n");
/* Free the device list */
pcap_freealldevs(alldevs);
return -1;
}
/* Jump to the selected adapter */
for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++);
/* Open the adapter */
if ((adhandle= pcap_open_live(d->name, // name of the device
65536, // portion of the packet to capture.
// 65536 grants that the whole packet will be captured on all the MACs.
1, // promiscuous mode (nonzero means promiscuous)
1000, // read timeout
errbuf // error buffer
)) == NULL)
{
fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name);
/* Free the device list */
pcap_freealldevs(alldevs);
return -1;
}
/* Check the link layer. We support only Ethernet for simplicity. */
if(pcap_datalink(adhandle) != DLT_EN10MB)
{
fprintf(stderr,"\nThis program works only on Ethernet networks.\n");
/* Free the device list */
pcap_freealldevs(alldevs);
return -1;
}
if(d->addresses != NULL){
/* Retrieve the mask of the first address of the interface */
netmask=((struct sockaddr_in *)(d->addresses->netmask))->sin_addr.S_un.S_addr;
} else {
/* If the interface is without addresses we suppose to be in a C class network */
netmask=0xffffff;
}
// ***********************
// MAC destination : 01:00:5e:01:01:01
buf[0]=0x01;
buf[1]=0x00;
buf[2]=0x5e;
buf[3]=0x01;
buf[4]=0x01;
buf[5]=0x01;
// MAC source : 00:24:E8:00:3B:A0
buf[6]=0x00;
buf[7]=0x24;
buf[8]=0x00;
buf[9]=0xE8;
buf[10]=0x3B;
buf[11]=0xA0;
// ***********************
// trame type IP
buf[12]=0x08;
buf[13]=0x00;
buf[14]=0x45; // version IP V4 / len = 20 bytes
buf[15]=0x88; // ???
// total len => 1436
buf[16]=0x05;
buf[17]=0x9C;
// identification => incrémenté de 2 a chaque paquet envoyé
//buf[18]=0x00;
//buf[19]=0x00;
buf[18]=(cpt >> 8) & 0x1F;
buf[19]=cpt & 0xFF;
cpt+=2;
// flag = 0x02 / Fragment offset = 0;
buf[20]=0x40;
buf[21]=0x00;
buf[22]=0x0a; // TTL = 10
buf[23]=0x11; // PROTOCL = UDP
// IP Checksum
buf[24]=0xb7;
buf[25]=0x83;
// IP Source : 10.0.200.3
buf[26]=10;
buf[27]=0;
buf[28]=200;
buf[29]=3;
// IP Destination : 224.1.1.1
buf[30]=224;
buf[31]=1;
buf[32]=1;
buf[33]=1;
// ***********************
// source port = 6840
buf[34]=0x1a;
buf[35]=0xb8;
// destination port = 6780
buf[36]=0x1a;
buf[37]=0x7c;
// len = 1416
buf[38]=0x05;
buf[39]=0x88;
// UDP Checksum
buf[40]=0x5f;
buf[41]=0xc1;
// ***********************
// remplissage des data UDP
for(i=42;i<PACKET_SIZE;i++){
buf[i]= (u_char)i;
}
// ************************
// => mettre des byte de bourrage si le paquet est trop petit (la norme impose une taille min)
while(1){
//for(i=0; i<1000; i++){
// Send down the packet
if (pcap_sendpacket(adhandle, // Adapter
buf, // buffer with the packet
PACKET_SIZE // size
) != 0)
{
fprintf(stderr,"\nError sending the packet: %s\n", pcap_geterr(adhandle));
return 3;
}
}
pcap_close(adhandle);
return 0;
} |
=> comment faut-il faire pour calculer les checksums des entetes IP et UDP ?
Merci d'avance,
