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|
u_short calcul_du_checksum(u_char *data, u_short len)
{
unsigned long checksum = 0;
u_short *DataPtr;
u_short valData;
u_short valTmp, valTmp2;
DataPtr = (u_short*)&data[0];
while(len > 0)
{
valData = *DataPtr++;
if(len == 1){
valData &= 0x00FF;
len--;
} else {
len -= 2;
}
checksum += valData;
}
checksum = (checksum & 0xFFFF) + ((checksum >> 16) & 0xFFFF);
valTmp = ((checksum >> 16) & 0xFFFF);
valTmp2 = (checksum & 0xFFFF);
valTmp2 += valTmp;
checksum &= 0xFFFF0000;
checksum |= valTmp2;
valTmp2 = (checksum & 0xFFFF);
return ~valTmp2;
}
// */
// *************************************************************
int main()
{
#define PACKET_SIZE (1500)
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];
unsigned short crc;
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]=0x00;
buf[25]=0x00;
//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;
// affectation du checksum du Header IP
crc = calcul_du_checksum(&buf[14], 20);
buf[24]= crc & 0xFF;
buf[25]= (crc >> 8) & 0xFF;
// ***********************
// 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;
buf[40]=0x00;
buf[41]=0x00;
// affectation du checksum du Header UDP
crc = calcul_du_checksum(&buf[34], 8);
buf[40]= crc & 0xFF;
buf[41]= (crc >> 8) & 0xFF;
// ***********************
// remplissage des data UDP
for(i=42;i<PACKET_SIZE;i++){
buf[i]= (u_char)i;
}
// ************************
// => mettre des bytes 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;
} |
winpcap : problème de performance
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