Здравствуйте!
При попытке пинга роутера, ответ приходит, но с внешнего узла ответа нет.
В чём может быть причина?
Структуры:
| Код |
#pragma pack(push,1)
//Ethernet Header
typedef struct ethernet_header
{
UCHAR dest[6]; //Total 48 bits
UCHAR source[6]; //Total 48 bits
USHORT type; //16 bits
}ETH_HDR;
#pragma pack(pop)
#pragma pack(push,1)
typedef struct IP_header
{
unsigned char ver;
unsigned char ServicesField;
unsigned short TotalLength;
unsigned short Identification;
unsigned short FragmentFlags;
unsigned char TimeToLive;
unsigned char NextProtocol;
unsigned short Checksum;
unsigned int ip_srcaddr; // Source address
unsigned int ip_destaddr; // Destination address
}IP_HDR;
#pragma pack(pop)
#pragma pack(push,1)
typedef struct ICMP_HEADER
{
unsigned char type;
unsigned char code;
unsigned short checksum;
unsigned short id;
unsigned short seqno;
}ICMP_HDR;
#pragma pack(pop)
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........................
| Код |
unsigned char Data_ICMP[32] = {0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69};
//
char ip[16];
unsigned char s_mac[6], d_mac[6], packet[0x4A];
char *temp_packet;
ETH_HDR eth_header;
IP_HDR ip_header;
ICMP_HEADER ping_header;
//
FILE *in, *out, *last;
char ip_source[] = "192.168.0.13";//адрес сетевой карты
//char ip_dest[16];
char ip_dest[] = "192.168.0.1";//адрес роутера
DWORD pcap;
////////////////////////
HANDLE hThread;//Поток
DWORD dwThreadId;// Id потока
//
USHORT Checksum(PUCHAR Data, USHORT Length )
{
ULONG Sum = 0;
USHORT ShortSum = 0;
PUSHORT WordData = (PUSHORT) Data;
USHORT WordCount = Length >> 1;
while( WordCount-- )
Sum += *WordData++;
if( Length & 1 )
Sum += *(PUCHAR)WordData;
Sum = (USHORT) Sum + (Sum >> 16) & 0xFFFF;
ShortSum = (USHORT) Sum + (USHORT)(Sum >> 16);
return (ShortSum != 0xFFFF) ? ~ShortSum : ShortSum;
}
/////////////////
DWORD WINAPI scan(LPVOID param)
{
//Заполнение пакета Ethernet
memcpy(ð_header.dest, d_mac, 6);
memcpy(ð_header.source, s_mac, 6);
eth_header.type = htons(0x0800);
//Заполнение структуры IP header
ip_header.ver = 0x45;
ip_header.ServicesField = 0;
ip_header.TotalLength = htons(sizeof(ip_header)+sizeof(ping_header)+sizeof(Data_ICMP));
ip_header.Identification = htons(27601);
ip_header.FragmentFlags = htons(0);
ip_header.TimeToLive = 0x80;
ip_header.NextProtocol = 0x01;//0x06
ip_header.Checksum = 0;
ip_header.ip_srcaddr = inet_addr(ip_source);
ip_header.ip_destaddr = inet_addr(ip_dest);
//ICMP
ping_header.type = 0x8;
ping_header.code = htons(0x00);
ping_header.checksum = 0;
ping_header.id = htons(0x200);
ping_header.seqno = htons(0x1E00);
ping_header.checksum = Checksum((char*)&ping_header, sizeof(ping_header));
//расчёт контрольной суммы ip header
ip_header.Checksum = Checksum((char*)&ip_header, sizeof(ip_header));
////////
printf("Build packet\n");
memcpy(packet, ð_header, sizeof(eth_header));
memcpy(packet+sizeof(eth_header), &ip_header, sizeof(ip_header));
memcpy(packet+sizeof(eth_header)+sizeof(ip_header),&ping_header, sizeof(ping_header));
memcpy(packet+sizeof(eth_header)+sizeof(ip_header)+sizeof(ping_header), Data_ICMP, 32);
//Отправка пакета
pcap_sendpacket(adhandle , packet, sizeof(eth_header)+sizeof(ip_header)+sizeof(ping_header)+sizeof(Data_ICMP));
//printf(".");
ExitThread(0);
return 0;
}
void main()
{
FILE *in, *out;
in = fopen("ip.txt", "rb");
memset(packet, '.', sizeof(packet));
//mac роутера
d_mac[0] = 0x*;
d_mac[1] = 0x*;
d_mac[2] = 0x*;
d_mac[3] = 0x*;
d_mac[4] = 0x*;
d_mac[5] = 0x*;
//mac моей сетевой карты
s_mac[0] = 0x*;
s_mac[1] = 0x*;
s_mac[2] = 0x*;
s_mac[3] = 0x*;
s_mac[4] = 0x*;
s_mac[5] = 0x*;
Init_Pcap();//Инициализация интерфейса WinPcap
Sleep(500);
while (!feof(in))
{
fscanf(in,"%s\n",&ip_dest);
printf("\nNext %s\n", ip_dest);
hThread = CreateThread(NULL, 0, scan,
(LPVOID)scan, 0, &dwThreadId);
Sleep(10);
WaitForSingleObject(hThread, 0);
CloseHandle(hThread);
Sleep(1);
}
fclose(in);
free(packet);
system("pause");
}
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