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| // Module Name: Ping.c
//
// Code by Rise
//
// Command Line Options/Parameters:
// Ping [host] [packet-size]
//
// host String name of host to ping
// packet-size Integer size of packet to send (smaller than 1024 bytes)
//
//#pragma pack(1)
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
#define IP_RECORD_ROUTE 0x7
//
// IP header structure
//
typedef struct _iphdr
{
unsigned int h_len:4; // Length of the header
unsigned int version:4; // Version of IP
unsigned char tos; // Type of service
unsigned short total_len; // Total length of the packet
unsigned short ident; // Unique identifier
unsigned short frag_and_flags; // Flags
unsigned short ttl; // Time to live
unsigned short proto; // Protocol (TCP, UDP, etc.)
unsigned short checksum; // IP checksum
unsigned int sourceIP;
unsigned int destIP;
}IpHeader;
#define ICMP_ECHO 8
#define ICMP_ECHOREPLY 0
#define ICMP_MIN 8 // Minimun 8-byte ICMP packet (header)
//
// ICMP header structure
//
typedef struct _icmphdr
{
BYTE i_type;
BYTE i_code; // Type sub code
USHORT i_cksum;
USHORT i_id;
USHORT i_seq;
// This is not the standard header, but we reserve space for time
ULONG timestamp;
}IcmpHeader;
//
// IP option header – use with socket option IP_OPTIONS
//
typedef struct _ipoptionhdr
{
unsigned char code; // Option type
unsigned char len; // Length of option hdr
unsigned char prt; // Offset into options
unsigned long addr[9]; // List of IP addrs
}IpOptionHeader;
#define DEF_PACKET_SIZE 32 // Default packet size
#define MAX_PACKET 1024 // Max ICMP packet size
#define MAX_IP_HDR_SIZE 60 // Max IP header size w/options
BOOL bRecordRoute;
int datasize;
char* lpdest;
//
// Function: usage
//
// Description:
// Print usage information
//
void usage(char* progname)
{
printf(“usage: ping -r <host> [data size]\n”);
printf(“ -r record route\n”);
printf(“ host remote machine to Ping\n”);
printf(“ datasize can be up to 1 KB\n”);
ExitProcess(-1);
}
//
// Function: FillICMPData
//
// Description:
// Helper function to fill in various fields for our ICMP request
//
void FillICMPData(char* icmp_data, int datasize)
{
IcmpHeader* icmp_hdr = NULL;
char* datapart = NULL;
icmp_hdr = (IcmpHeader*)icmp_data;
icmp_hdr->i_type = ICMP_ECHO; // Request an 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
//
memset(datapart, ‘E’, datasize - sizeof(IcmpHeader));
}
//
// Function: checksum
//
// Description:
// This funcion calculates the 16-bit one’s complement sum
// of the supplied buffer (ICMP)header
//
USHORT 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);
}
//
// Function: DecodeIPOptions
//
// Description:
// If the IP option header is present. find the IP options
// within the IP header and print the record route option
// values
//
void DecodeIPOptions(charbuf,int bytes)
{
IpOptionHeader* ipopt = NULL;
IN_ADDR inaddr;
int i;
HOSTENT host = NULL;
ipopt = (IpOptionHeader)(buf + 20);
printf(“RR: ”);
for(i=0;i<(ipopt->prt/4)-1;i++)
{
inaddr.S_un.S_addr = ipopt->addr[i];
if(i != 0 )
printf(“ ”);
host = gethostbyaddr((char*)&inaddr.S_un.S_addr, sizeof(inaddr.S_un.S_addr), AF_INET);
if(host)
printf(“(%-15s) %s\n”, inet_ntoa(inaddr), host->h_name);
else
printf(“(%-15s)\n”, inet_ntoa(inaddr));
}
return;
}
//
// Function: DecodeICMPHeader
//
// Description:
// The response is an IP packet. We must decode the IP header to locate the ICMP data.
//
void DecodeICMPHeader(char* buf, int bytes, struct sockaddr_in from)
{
IpHeader iphdr = NULL;
IcmpHeader* icmphdr = NULL;
unsigned short iphdrlen;
DWORD tick;
static int icmpcount = 0;
iphdr = (IpHeader*)buf;
// Number of 32-bit words * 4 = bytes
iphdrlen = iphdr->h_len * 4;
tick = GetTickCount();
if((iphdrlen == MAX_IP_HDR_SIZE)&&(!icmpcount))
DecodeIPOptions(buf,bytes);
if(bytes < iphdrlen + ICMP_MIN)
{
printf(“Too Few bytes from %s\n”,inet_ntoa(from->sin_addr));
}
icmphdr = (IcmpHeader*)(buf + iphdrlen);
if(icmphdr->i_type != ICMP_ECHOREPLY)
{
printf(“nonecho type %d recvd\n”, icmphdr->i_type);
return;
}
// Make sure this is an ICMP reply to something we sent!
//
if(icmphdr->i_id != (USHORT)GetCurrentProcessId())
{
printf(“someone else’s packet!\n”);
return;
}
printf(“%d bytes from %s:”, bytes, inet_ntoa(from->sin_addr));
printf(“ icmp->seq = %d.”, icmphdr->i_seq);
printf(“ time: %d ms”, tick-icmphdr->timestamp);
printf(“\n”);
icmpcount++;
return;
}
void ValidateArgs(int argc, char argv)
{
int i;
bRecordRoute = FALSE;
lpdest = NULL;
datasize = DEF_PACKET_SIZE;
for(i = 1; i < argc; i++)
{
if((argv[i][0] == ‘-‘)||(argv[i][0] == ‘/‘))
{
switch(tolower(argv[i][1]))
{
case ‘r’: // Record route option
bRecordRoute = TRUE;
break;
default:
usage(argv[0]);
break;
}
}
else if(isdigit(argv[i][0]))
datasize = atoi(argv[i]);
else
lpdest = argv[i];
}
}
//
// Function: main
//
// Description
// Set up the ICMP raw socket, and create the ICMP header. Add
// the appropriate IP ooption header, and start sending ICMP
// echo requests to the endpoint. For each send and receive.
// we set a timeout value so that we don’t wait forever for a
// response in case the endpoint is not responding. When we
// receive a packet. decode it.
//
int main(int argc, char argv)
{
WSADATA wsaData;
SOCKET sockRaw = INVALID_SOCKET;
struct sockaddr_in dest, from;
int bread, fromlen = sizeof(from), timeout = 1000, ret;
char icmp_data = NULL, recvbuf = NULL;
unsigned int addr = 0;
USHORT seq_no = 0;
struct hostent hp = NULL;
IpOptionHeader ipopt;
if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
{
printf(“WSAStartup() failed: %d\n”, GetLastError());
return -1;
}
ValidateArgs(argc,argv);
sockRaw = WSASocket(AF_INET, SOCK_RAW, IPPROTO_ICMP, NULL, 0, WSA_FLAG_OVERLAPPED);
if(sockRaw == INVALID_SOCKET)
{
printf(“WSASocket() failed: %d\n”, WSAGetLastError());
return -1;
}
if(bRecordRoute)
{
// Setup the IP option header to go out on every ICMP packet
//
ZeroMemory(&ipopt, sizeof(ipopt));
ipopt.code = IP_RECORD_ROUTE; // Record route option
ipopt.prt = 4; // Point to the first addr offset
ipopt.len = 39; // Length of option header
ret = setsockopt(sockRaw, IPPROTO_IP, IP_OPTIONS, (char)&ipopt, sizeof(ipopt));
if(ret == SOCKET_ERROR)
{
printf(“setsockopt(IP_OPTIONs) failed: %d\n”,WSAGetLastError());
}
}
// Set the send/recv timeout values
//
bread = setsockopt(sockRaw, SOL_SOCKET, SO_RCVTIMEO, (char)&timeout, sizeof(timeout));
if(bread == SOCKET_ERROR)
{
printf(“setsockopt(SO_RCVTIME0)failed: %d\n”, WSAGetLastError());
return -1;
}
timeout = 1000;
bread = setsockopt(sockRaw, SOL_SOCKET, SO_SNDTIMEO, (char)&timeout, sizeof(timeout));
if(bread == SOCKET_ERROR)
{
printf(“setsockopt(SO_SNDTIME0) failed: %d\n”, WSAGetLastError());
return -1;
}
memset(&dest, 0, sizeof(dest));
//
// Resolve the endpoint`s name if necessary
//
dest.sin_family = AF_INET;
if((dest.sin_addr.s_addr = inet_addr(lpdest)) == INADDR_NONE)
{
if((hp = gethostbyname(lpdest)) != NULL)
{
memcpy(&(dest.sin_addr), hp->h_addr, hp->h_length);
dest.sin_family = hp->h_addrtype;
printf(“dest.sin_addr = %s\n”, inet_ntoa(dest.sin_addr));
}
else
{
printf(“gethostbyname() failed: %d\n”,WSAGetLastError());
return -1;
}
}
//
// Create the ICMP packet
//
datasize += sizeof(IcmpHeader);
icmp_data = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET);
recvbuf = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_PACKET);
if(!icmp_data)
{
printf(“HeapAlloc() failed: %d\n”,GetLastError());
return -1;
}
memset(icmp_data, 0, MAX_PACKET);
FillICMPData(icmp_data, datasize);
//
// Start sending/receiving ICMP packets
//
while(1)
{
static int nCount = 0;
int bwrote;
if(nCount++ ==4)
break;
((IcmpHeader*)icmp_data)->i_cksum = 0;
((IcmpHeader*)icmp_data)->timestamp = GetTickCount();
((IcmpHeader*)icmp_data)->i_seq = seq_no++;
((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data, datasize, 0, (struct sockaddr*)&dest, sizeof(dest));
bwrote = sendto(sockRaw, icmp_data, datasize, 0, (struct sockaddr*)&dest, sizeof(dest));
if(bwrote == SOCKET_ERROR)
{
if(WSAGetLastError() == WSAETIMEDOUT)
{
printf(“timed out\n”);
continue;
}
printf(“recvfrom() failed: %d\n”, WSAGetLastError());
return -1;
}
if(bwrote < datasize)
{
printf(“Wrote %d bytes\n”, bwrote);
}
bread = recvfrom(sockRaw, recvbuf, MAX_PACKET, 0, (struct sockaddr*)&from, &fromlen);
if(bread == SOCKET_ERROR)
{
if(WSAGetLastError() == WSAETIMEDOUT)
{
printf(“timed out\n”);
continue;
}
printf(“recvfrom() failed: %d\n”, WSAGetLastError());
}
DecodeICMPHeader(recvbuf, bread, &from);
Sleep(1000);
}
//Cleanup
//
if(sockRaw != INVALID_SOCKET)
closesocket(sockRaw);
HeapFree(GetProcessHeap(), 0, recvbuf);
HeapFree(GetProcessHeap(), 0, icmp_data);
WSACleanup();
return 0;
}
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