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// TraceRoute1.cpp: implementation of the CTraceRoute class.
//
//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "TraceRoute1.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CTraceRoute::CTraceRoute()
{
m_nTTL = 1;
m_nMaxhops = MAX_HOPS;
m_sockRaw = INVALID_SOCKET;
m_RcvBuffer = NULL;
m_IcmpData = NULL;
m_nTimeout = 1000;
m_bDone = FALSE;
WSADATA wsaData;
if (WSAStartup(MAKEWORD(2,2),&wsaData) != 0)
{
printf("WSAStartup() failed: %d/n", WSAGetLastError());
}
}
CTraceRoute::~CTraceRoute()
{
}
void CTraceRoute::ConnectToHost(char* strHost)
{
m_sockRaw = WSASocket(AF_INET, SOCK_RAW, IPPROTO_ICMP,
NULL, 0,WSA_FLAG_OVERLAPPED);
if (m_sockRaw == INVALID_SOCKET)
{
printf("WSASocket() failed: %d\n", WSAGetLastError());
ExitProcess(-1);
}
int ret = setsockopt(m_sockRaw, SOL_SOCKET, SO_RCVTIMEO,
(char *)&m_nTimeout, sizeof(m_nTimeout));
if (ret == SOCKET_ERROR)
{
printf("setsockopt(SO_RCVTIMEO) failed: %d\n", WSAGetLastError());
return ;
}
ret = setsockopt(m_sockRaw, SOL_SOCKET, SO_SNDTIMEO,
(char *)&m_nTimeout, sizeof(m_nTimeout));
if (ret == SOCKET_ERROR)
{
printf("setsockopt(SO_SNDTIMEO) failed: %d\n", WSAGetLastError());
return ;
}
m_addrDest.sin_family = AF_INET;
if ((m_addrDest.sin_addr.s_addr = inet_addr(strHost)) == INADDR_NONE)
{
HOSTENT* hp;
hp = gethostbyname(strHost);
if (hp)
memcpy(&(m_addrDest.sin_addr), hp->h_addr, hp->h_length);
else
{
printf("gethostbyname failed: %d\n", WSAGetLastError());
return ;
}
}
int bOpt = TRUE;
if (setsockopt(m_sockRaw, SOL_SOCKET, SO_DONTROUTE, (char *)&bOpt,
sizeof(BOOL)) == SOCKET_ERROR)
{
printf("setsockopt failed: %d\n", WSAGetLastError());
return ;
}
m_nDatasize = DEF_PACKET_SIZE;
m_nDatasize += sizeof(IcmpHeader);
//
// Allocate the sending and receiving buffers for ICMP packets
//
m_IcmpData = (char*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET);
m_RcvBuffer = (char*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET);
if ((!m_IcmpData) || (!m_RcvBuffer))
{
printf("HeapAlloc() failed: %d\n", WSAGetLastError());
return ;
}
// Set the socket to bypass the standard routing mechanisms
// i.e. use the local protocol stack to the appropriate network
// interface
//
//
// Here we are creating and filling in an ICMP header that is the
// core of trace route.
//
memset(m_IcmpData, 0, MAX_PACKET);
printf("\nTracing route to %s over a maximum of %d hops:\n\n",
strHost, m_nMaxhops);
fill_icmp_data(m_IcmpData, m_nDatasize);
for(m_nTTL = 1; ((m_nTTL < m_nMaxhops) && (!m_bDone)); m_nTTL++)
{
int bwrote;
// Set the time to live option on the socket
//
set_ttl(m_sockRaw, m_nTTL);
//
// Fill in some more data in the ICMP header
//
((IcmpHeader*)m_IcmpData)->i_cksum = 0;
((IcmpHeader*)m_IcmpData)->timestamp = GetTickCount();
((IcmpHeader*)m_IcmpData)->i_seq = m_nSeqno++;
((IcmpHeader*)m_IcmpData)->i_cksum = checksum((USHORT*)m_IcmpData,
m_nDatasize);
//
// Send the ICMP packet to the destination
//
bwrote = sendto(m_sockRaw, m_IcmpData, m_nDatasize, 0,
(SOCKADDR *)&m_addrDest, sizeof(m_addrDest));
if (bwrote == SOCKET_ERROR)
{
if (WSAGetLastError() == WSAETIMEDOUT)
{
printf("%2d Send request timed out.\n", m_nTTL);
continue;
}
printf("sendto() failed: %d\n", WSAGetLastError());
return ;
}
// Read a packet back from the destination or a router along
// the way.
//
int fromlen;
fromlen = sizeof(SOCKADDR);
ret = recvfrom(m_sockRaw, m_RcvBuffer, MAX_PACKET, 0,
(struct sockaddr*)&m_addrFrom, &fromlen);
if (ret == SOCKET_ERROR)
{
if (WSAGetLastError() == WSAETIMEDOUT)
{
printf("%2d Receive Request timed out.\n", m_nTTL);
continue;
}
printf("recvfrom() failed: %d\n", WSAGetLastError());
return ;
}
//
// Decode the response to see if the ICMP response is from a
// router along the way or whether it has reached the destination.
//
m_bDone = decode_resp(m_RcvBuffer, ret, &m_addrFrom, m_nTTL);
Sleep(1000);
}
}
void CTraceRoute::fill_icmp_data(char * icmp_data, int datasize)
{
IcmpHeader *icmp_hdr;
char *datapart;
icmp_hdr = (IcmpHeader*)icmp_data;
icmp_hdr->i_type = ICMP_ECHO;
icmp_hdr->i_code = 0;
icmp_hdr->i_id = (USHORT)GetCurrentProcessId();
icmp_hdr->i_cksum = 0;
icmp_hdr->i_seq = 0;
datapart = icmp_data + sizeof(IcmpHeader);
//
// Place some junk in the buffer. Don't care about the data...
//
memset(datapart,'E', datasize - sizeof(IcmpHeader));
}
int CTraceRoute::set_ttl(SOCKET s, int nTimeToLive)
{
int nRet;
nRet = setsockopt(s, IPPROTO_IP, IP_TTL, (LPSTR)&nTimeToLive,
sizeof(int));
if (nRet == SOCKET_ERROR)
{
printf("setsockopt(IP_TTL) failed: %d\n",
WSAGetLastError());
return 0;
}
return 1;
}
USHORT CTraceRoute::checksum(USHORT *buffer, int size)
{
unsigned long cksum=0;
while(size > 1)
{
cksum += *buffer++;
size -= sizeof(USHORT);
}
if(size )
cksum += *(UCHAR*)buffer;
cksum = (cksum >> 16) + (cksum & 0xffff);
cksum += (cksum >> 16);
return (USHORT)(~cksum);
}
void CTraceRoute::Cleanup()
{
HeapFree(GetProcessHeap(), 0, m_RcvBuffer);
HeapFree(GetProcessHeap(), 0, m_IcmpData);
if (m_sockRaw != NULL)
closesocket(m_sockRaw);
WSACleanup();
}
int CTraceRoute::decode_resp(char *buf, int bytes, SOCKADDR_IN *from, int ttl)
{
IpHeader *iphdr = NULL;
IcmpHeader *icmphdr = NULL;
unsigned short iphdrlen;
struct hostent *lpHostent = NULL;
struct in_addr inaddr = from->sin_addr;
iphdr = (IpHeader *)buf;
// Number of 32-bit words * 4 = bytes
iphdrlen = iphdr->h_len * 4;
if (bytes < iphdrlen + ICMP_MIN)
printf("Too few bytes from %s\n",
inet_ntoa(from->sin_addr));
icmphdr = (IcmpHeader*)(buf + iphdrlen);
switch (icmphdr->i_type)
{
case ICMP_ECHOREPLY: // Response from destination
lpHostent = gethostbyaddr((const char *)&from->sin_addr,
AF_INET, sizeof(struct in_addr));
if (lpHostent != NULL)
printf("%2d %s (%s)\n", ttl, lpHostent->h_name,
inet_ntoa(inaddr));
return 1;
break;
case ICMP_TIMEOUT: // Response from router along the way
printf("%2d %s\n", ttl, inet_ntoa(inaddr));
return 0;
break;
case ICMP_DESTUNREACH: // Can't reach the destination at all
printf("%2d %s reports: Host is unreachable\n", ttl,
inet_ntoa(inaddr));
return 1;
break;
default:
printf("non-echo type %d recvd\n", icmphdr->i_type);
return 1;
break;
}
return 0;
}