ping.cpp

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//
// Description:
//    This routine posts an overlapped WSARecvFrom on the raw socket.
//
int PostRecvfrom(SOCKET s, char *buf, int buflen, SOCKADDR *from, int *fromlen, WSAOVERLAPPED *ol)
{
    WSABUF  wbuf;
    DWORD   flags,
            bytes;
    int     rc;

    wbuf.buf = buf;
    wbuf.len = buflen;

    flags = 0;

    rc = WSARecvFrom(
            s,
           &wbuf,
            1,
           &bytes,
           &flags,
            from,
            fromlen,
            ol,
            NULL
            );
    if (rc == SOCKET_ERROR)
    {
        if (WSAGetLastError() != WSA_IO_PENDING)
        {
            fprintf(stderr, "WSARecvFrom failed: %d\n", WSAGetLastError());
            return SOCKET_ERROR;
        }
    }
    return NO_ERROR;
}

//
// Function: PrintPayload
// 
// Description:
//    This routine is for IPv4 only. It determines if there are any IP options
//    present (by seeing if the IP header length is greater than 20 bytes) and
//    if so it prints the IP record route options.
//
void PrintPayload(char *buf, int bytes)
{
    int     hdrlen=0,
            routes=0,
            i;

    if (gAddressFamily == AF_INET)
    {
        SOCKADDR_IN      hop;
        IPV4_OPTION_HDR *v4opt=NULL;
        IPV4_HDR        *v4hdr=NULL;

        hop.sin_family = (USHORT)gAddressFamily;
        hop.sin_port   = 0;

        v4hdr = (IPV4_HDR *)buf;
        hdrlen = (v4hdr->ip_verlen & 0x0F) * 4;

        // If the header length is greater than the size of the basic IPv4
        //    header then there are options present. Find them and print them.
        if (hdrlen > sizeof(IPV4_HDR))
        {
            v4opt = (IPV4_OPTION_HDR *)(buf + sizeof(IPV4_HDR));
            routes = (v4opt->opt_ptr / sizeof(ULONG)) - 1;
            for(i=0; i < routes ;i++)
            {
                hop.sin_addr.s_addr = v4opt->opt_addr[i];

                // Print the route
                if (i == 0)
                    printf("    Route: ");
                else
                    printf("           ");
                PrintAddress((SOCKADDR *)&hop, sizeof(hop));

                if (i < routes-1)
                    printf(" ->\n");
                else
                    printf("\n");
            }
        }
    }
    return;
}

//
// Function: SetTtl
//
// Description:
//    Sets the TTL on the socket.
//
int SetTtl(SOCKET s, int ttl)
{
    int     optlevel,
            option,
            rc;

    rc = NO_ERROR;
    if (gAddressFamily == AF_INET)
    {
        optlevel = IPPROTO_IP;
        option   = IP_TTL;
    }
    else if (gAddressFamily == AF_INET6)
    {
        optlevel = IPPROTO_IPV6;
        option   = IPV6_UNICAST_HOPS;
    }
    else
    {
        rc = SOCKET_ERROR;
    }
    if (rc == NO_ERROR)
    {
        rc = setsockopt(
                s,
                optlevel,
                option,
                (char *)&ttl,
                sizeof(ttl)
                );
    }
    if (rc == SOCKET_ERROR)
    {
        fprintf(stderr, "SetTtl: setsockopt failed: %d\n", WSAGetLastError());
    }
    return rc;
}
        
//
// Function: main
//
// Description:
//    Setup the ICMP raw socket and create the ICMP header. Add
//    the appropriate IP option 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 __cdecl main(int argc, char **argv)
{

    WSADATA            wsd;
    WSAOVERLAPPED      recvol;
    SOCKET             s=INVALID_SOCKET;
    char              *icmpbuf=NULL,
                       recvbuf[0xFFFF];
    struct addrinfo   *dest=NULL,
                      *local=NULL;
    IPV4_OPTION_HDR    ipopt;
    SOCKADDR_STORAGE   from;
    DWORD              bytes,
                       flags;
    int                packetlen=0,
                       recvbuflen=0xFFFF,
                       fromlen,
                       time=0,
                       rc,
                       i;


    // Load Winsock
    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        printf("WSAStartup() failed: %d\n", GetLastError());
        return -1;
    }

    // Parse the command line
    ValidateArgs(argc, argv);

    // Resolve the destination address
    dest = ResolveAddress(
            gDestination,
            "0",
            gAddressFamily,
            0,
            0
            );
    if (dest == NULL)
    {
        printf("bad name %s\n", gDestination);
        return -1;
    }
    gAddressFamily = dest->ai_family;

    if (gAddressFamily == AF_INET)
        gProtocol = IPPROTO_ICMP;
    else if (gAddressFamily == AF_INET6)
        gProtocol = IPPROTO_ICMP6;

    // Get the bind address
    local = ResolveAddress(
            NULL,
            "0",
            gAddressFamily,
            0,
            0
            );
    if (local == NULL)
    {
        printf("Unable to obtain the bind address!\n");
        return -1;
    }

    // Create the raw socket
    s = socket(gAddressFamily, SOCK_RAW, gProtocol);
    if (s == INVALID_SOCKET) 
    {
        printf("socket failed: %d\n", WSAGetLastError());
        return -1;
    }

    SetTtl(s, gTtl);

    // Figure out the size of the ICMP header and payload
    if (gAddressFamily == AF_INET)
        packetlen += sizeof(ICMP_HDR);
    else if (gAddressFamily == AF_INET6)
        packetlen += sizeof(ICMPV6_HDR) + sizeof(ICMPV6_ECHO_REQUEST);

    // Add in the data size
    packetlen += gDataSize;

    // Allocate the buffer that will contain the ICMP request
    icmpbuf = (char *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, packetlen);
    if (icmpbuf == NULL)
    {
        fprintf(stderr, "HeapAlloc failed: %d\n", GetLastError());
        return -1;
    }

    // Initialize the ICMP headers
    if (gAddressFamily == AF_INET)
    {
        if (bRecordRoute)
        {
            // Setup the IP option header to go out on every ICMP packet
            ZeroMemory(&ipopt, sizeof(ipopt));
            ipopt.opt_code = IP_RECORD_ROUTE; // record route option
            ipopt.opt_ptr  = 4;               // point to the first addr offset
            ipopt.opt_len  = 39;              // length of option header

            rc = setsockopt(s, IPPROTO_IP, IP_OPTIONS, 
                    (char *)&ipopt, sizeof(ipopt));
            if (rc == SOCKET_ERROR)
            {
                fprintf(stderr, "setsockopt(IP_OPTIONS) failed: %d\n", WSAGetLastError());
                return -1;
            }
        }

        InitIcmpHeader(icmpbuf, gDataSize);
    }
    else if (gAddressFamily == AF_INET6)
    {
        InitIcmp6Header(icmpbuf, gDataSize);
    }

    // Bind the socket -- need to do this since we post a receive first
    rc = bind(s, local->ai_addr, local->ai_addrlen);
    if (rc == SOCKET_ERROR)
    {
        fprintf(stderr, "bind failed: %d\n", WSAGetLastError());
        return -1;
    }

    // Setup the receive operation
    memset(&recvol, 0, sizeof(recvol));
    recvol.hEvent = WSACreateEvent();

    // Post the first overlapped receive
    fromlen = sizeof(from);
    PostRecvfrom(s, recvbuf, recvbuflen, (SOCKADDR *)&from, &fromlen, &recvol);

    printf("\nPinging ");
    PrintAddress(dest->ai_addr, dest->ai_addrlen);
    printf(" with %d bytes of data\n\n", gDataSize);

    // Start sending the ICMP requests
    for(i=0; i < DEFAULT_SEND_COUNT ;i++)
    {
        // Set the sequence number and compute the checksum
        SetIcmpSequence(icmpbuf);
        ComputeIcmpChecksum(s, icmpbuf, packetlen, dest);

        time = GetTickCount();
        rc = sendto(
                s,
                icmpbuf,
                packetlen,
                0,
                dest->ai_addr,
                dest->ai_addrlen
                );
        if (rc == SOCKET_ERROR)
        {
            fprintf(stderr, "sendto failed: %d\n", WSAGetLastError());
            return -1;
        }

        // Waite for a response
        rc = WaitForSingleObject((HANDLE)recvol.hEvent, DEFAULT_RECV_TIMEOUT);
        if (rc == WAIT_FAILED)
        {
            fprintf(stderr, "WaitForSingleObject failed: %d\n", GetLastError());
            return -1;
        }
        else if (rc == WAIT_TIMEOUT)
        {
            printf("Request timed out.\n");
        }
        else
        {
            rc = WSAGetOverlappedResult(
                    s,
                   &recvol,
                   &bytes,
                    FALSE,
                   &flags
                    );
            if (rc == FALSE)
            {
                fprintf(stderr, "WSAGetOverlappedResult failed: %d\n", WSAGetLastError());
            }
            time = time - GetTickCount();

            WSAResetEvent(recvol.hEvent);

            printf("Reply from ");
            PrintAddress((SOCKADDR *)&from, fromlen);
            if (time == 0)
                printf(": bytes=%d time<1ms TTL=%d\n", gDataSize, gTtl);
            else
                printf(": bytes=%d time=%dms TTL=%d\n", gDataSize, time, gTtl);

            PrintPayload(recvbuf, bytes);

            if (i < DEFAULT_SEND_COUNT)
            {
                fromlen = sizeof(from);
                PostRecvfrom(s, recvbuf, recvbuflen, (SOCKADDR *)&from, &fromlen, &recvol);
            }
        }
        Sleep(1000);
    }

    //
    // Cleanup
    //
    freeaddrinfo(dest);
    freeaddrinfo(local);
    if (s != INVALID_SOCKET) 
        closesocket(s);
    HeapFree(GetProcessHeap(), 0, icmpbuf);

    WSACleanup();
    return 0;
}