rawping.html

SDK FAQ集

<font color="#2040a0">cleanup</font><font color="4444FF">:</font>
    <strong>delete</strong><font color="4444FF">[</font><font color="4444FF">]</font><font color="#2040a0">send_buf</font><font color="4444FF">;</font>
    <strong>delete</strong><font color="4444FF">[</font><font color="4444FF">]</font><font color="#2040a0">recv_buf</font><font color="4444FF">;</font>
    <font color="#2040a0">WSACleanup</font><font color="4444FF">(</font><font color="4444FF">)</font><font color="4444FF">;</font>
    <strong>return</strong> <font color="#FF0000">0</font><font color="4444FF">;</font>
<font color="4444FF"><strong>}</strong></font>


<font color="#444444">/////////////////////////// allocate_buffers ///////////////////////////</font>
<font color="#444444">// Allocates send and receive buffers.  Returns &lt; 0 for failure.</font>

<strong>int</strong> <font color="#2040a0">allocate_buffers</font><font color="4444FF">(</font><font color="#2040a0">ICMPHeader</font><font color="4444FF">*</font><font color="4444FF">&amp;</font> <font color="#2040a0">send_buf</font>, <font color="#2040a0">IPHeader</font><font color="4444FF">*</font><font color="4444FF">&amp;</font> <font color="#2040a0">recv_buf</font>,
        <strong>int</strong> <font color="#2040a0">packet_size</font><font color="4444FF">)</font>
<font color="4444FF"><strong>{</strong></font>
    <font color="#444444">// First the send buffer</font>
    <font color="#2040a0">send_buf</font> <font color="4444FF">=</font> <font color="4444FF">(</font><font color="#2040a0">ICMPHeader</font><font color="4444FF">*</font><font color="4444FF">)</font><strong>new</strong> <strong>char</strong><font color="4444FF">[</font><font color="#2040a0">packet_size</font><font color="4444FF">]</font><font color="4444FF">;</font>  
    <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">send_buf</font> <font color="4444FF">=</font><font color="4444FF">=</font> <font color="#FF0000">0</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
        <font color="#2040a0">cerr</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#008000">&quot;Failed to allocate output buffer.&quot;</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">endl</font><font color="4444FF">;</font>
        <strong>return</strong> <font color="4444FF">-</font><font color="#FF0000">1</font><font color="4444FF">;</font>
    <font color="4444FF"><strong>}</strong></font>

    <font color="#444444">// And then the receive buffer</font>
    <font color="#2040a0">recv_buf</font> <font color="4444FF">=</font> <font color="4444FF">(</font><font color="#2040a0">IPHeader</font><font color="4444FF">*</font><font color="4444FF">)</font><strong>new</strong> <strong>char</strong><font color="4444FF">[</font><font color="#2040a0">MAX_PING_PACKET_SIZE</font><font color="4444FF">]</font><font color="4444FF">;</font>
    <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">recv_buf</font> <font color="4444FF">=</font><font color="4444FF">=</font> <font color="#FF0000">0</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
        <font color="#2040a0">cerr</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#008000">&quot;Failed to allocate output buffer.&quot;</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">endl</font><font color="4444FF">;</font>
        <strong>return</strong> <font color="4444FF">-</font><font color="#FF0000">1</font><font color="4444FF">;</font>
    <font color="4444FF"><strong>}</strong></font>
    
    <strong>return</strong> <font color="#FF0000">0</font><font color="4444FF">;</font>
<font color="4444FF"><strong>}</strong></font>
</pre>


<hr noshade size=1 color=#404040>

<h4 class=lmargin><a href="../examples/src/rawping.cpp">rawping.cpp</a></h4>

<pre>
<font color="#444444">/***********************************************************************
 rawping.cpp - Contains all of the functions essential to sending &quot;ping&quot;
    packets using Winsock 2 raw sockets.  Depends on ip_checksum.cpp for 
    calculating IP-style checksums on blocks of data, however.
***********************************************************************/</font>

<font color="0000ff"><strong>#include <font color="#008000">&lt;winsock2.h&gt;</font></strong></font>
<font color="0000ff"><strong>#include <font color="#008000">&lt;ws2tcpip.h&gt;</font></strong></font>
<font color="0000ff"><strong>#include <font color="#008000">&lt;iostream.h&gt;</font></strong></font>

<font color="0000ff"><strong>#include <font color="#008000">&quot;rawping.h&quot;</font></strong></font>
<font color="0000ff"><strong>#include <font color="#008000">&quot;ip_checksum.h&quot;</font></strong></font>


<font color="#444444">//////////////////////////// setup_for_ping ////////////////////////////</font>
<font color="#444444">// Creates the Winsock structures necessary for sending and recieving</font>
<font color="#444444">// ping packets.  host can be either a dotted-quad IP address, or a</font>
<font color="#444444">// host name.  ttl is the time to live (a.k.a. number of hops) for the</font>
<font color="#444444">// packet.  The other two parameters are outputs from the function.</font>
<font color="#444444">// Returns &lt; 0 for failure.</font>

<strong>int</strong> <font color="#2040a0">setup_for_ping</font><font color="4444FF">(</font><strong>char</strong><font color="4444FF">*</font> <font color="#2040a0">host</font>, <strong>int</strong> <font color="#2040a0">ttl</font>, <font color="#2040a0">SOCKET</font><font color="4444FF">&amp;</font> <font color="#2040a0">sd</font>, <font color="#2040a0">sockaddr_in</font><font color="4444FF">&amp;</font> <font color="#2040a0">dest</font><font color="4444FF">)</font>
<font color="4444FF"><strong>{</strong></font>
    <font color="#444444">// Create the socket</font>
    <font color="#2040a0">sd</font> <font color="4444FF">=</font> <font color="#2040a0">WSASocket</font><font color="4444FF">(</font><font color="#2040a0">AF_INET</font>, <font color="#2040a0">SOCK_RAW</font>, <font color="#2040a0">IPPROTO_ICMP</font>, <font color="#FF0000">0</font>, <font color="#FF0000">0</font>, <font color="#FF0000">0</font><font color="4444FF">)</font><font color="4444FF">;</font>
    <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">sd</font> <font color="4444FF">=</font><font color="4444FF">=</font> <font color="#2040a0">INVALID_SOCKET</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
        <font color="#2040a0">cerr</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#008000">&quot;Failed to create raw socket: &quot;</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">WSAGetLastError</font><font color="4444FF">(</font><font color="4444FF">)</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font>
                <font color="#2040a0">endl</font><font color="4444FF">;</font>
        <strong>return</strong> <font color="4444FF">-</font><font color="#FF0000">1</font><font color="4444FF">;</font>
    <font color="4444FF"><strong>}</strong></font>

    <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">setsockopt</font><font color="4444FF">(</font><font color="#2040a0">sd</font>, <font color="#2040a0">IPPROTO_IP</font>, <font color="#2040a0">IP_TTL</font>, <font color="4444FF">(</font><strong>const</strong> <strong>char</strong><font color="4444FF">*</font><font color="4444FF">)</font><font color="4444FF">&amp;</font><font color="#2040a0">ttl</font>, 
            <strong>sizeof</strong><font color="4444FF">(</font><font color="#2040a0">ttl</font><font color="4444FF">)</font><font color="4444FF">)</font> <font color="4444FF">=</font><font color="4444FF">=</font> <font color="#2040a0">SOCKET_ERROR</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
        <font color="#2040a0">cerr</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#008000">&quot;TTL setsockopt failed: &quot;</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">WSAGetLastError</font><font color="4444FF">(</font><font color="4444FF">)</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">endl</font><font color="4444FF">;</font>
        <strong>return</strong> <font color="4444FF">-</font><font color="#FF0000">1</font><font color="4444FF">;</font>
    <font color="4444FF"><strong>}</strong></font>

    <font color="#444444">// Initialize the destination host info block</font>
    <font color="#2040a0">memset</font><font color="4444FF">(</font><font color="4444FF">&amp;</font><font color="#2040a0">dest</font>, <font color="#FF0000">0</font>, <strong>sizeof</strong><font color="4444FF">(</font><font color="#2040a0">dest</font><font color="4444FF">)</font><font color="4444FF">)</font><font color="4444FF">;</font>

    <font color="#444444">// Turn first passed parameter into an IP address to ping</font>
    <strong>unsigned</strong> <strong>int</strong> <font color="#2040a0">addr</font> <font color="4444FF">=</font> <font color="#2040a0">inet_addr</font><font color="4444FF">(</font><font color="#2040a0">host</font><font color="4444FF">)</font><font color="4444FF">;</font>
    <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">addr</font> <font color="4444FF">!</font><font color="4444FF">=</font> <font color="#2040a0">INADDR_NONE</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
        <font color="#444444">// It was a dotted quad number, so save result</font>
        <font color="#2040a0">dest</font>.<font color="#2040a0">sin_addr</font>.<font color="#2040a0">s_addr</font> <font color="4444FF">=</font> <font color="#2040a0">addr</font><font color="4444FF">;</font>
        <font color="#2040a0">dest</font>.<font color="#2040a0">sin_family</font> <font color="4444FF">=</font> <font color="#2040a0">AF_INET</font><font color="4444FF">;</font>
    <font color="4444FF"><strong>}</strong></font>
    <strong>else</strong> <font color="4444FF"><strong>{</strong></font>
        <font color="#444444">// Not in dotted quad form, so try and look it up</font>
        <font color="#2040a0">hostent</font><font color="4444FF">*</font> <font color="#2040a0">hp</font> <font color="4444FF">=</font> <font color="#2040a0">gethostbyname</font><font color="4444FF">(</font><font color="#2040a0">host</font><font color="4444FF">)</font><font color="4444FF">;</font>
        <strong>if</strong> <font color="4444FF">(</font><font color="#2040a0">hp</font> <font color="4444FF">!</font><font color="4444FF">=</font> <font color="#FF0000">0</font><font color="4444FF">)</font> <font color="4444FF"><strong>{</strong></font>
            <font color="#444444">// Found an address for that host, so save it</font>
            <font color="#2040a0">memcpy</font><font color="4444FF">(</font><font color="4444FF">&amp;</font><font color="4444FF">(</font><font color="#2040a0">dest</font>.<font color="#2040a0">sin_addr</font><font color="4444FF">)</font>, <font color="#2040a0">hp</font><font color="4444FF">-</font><font color="4444FF">&gt;</font><font color="#2040a0">h_addr</font>, <font color="#2040a0">hp</font><font color="4444FF">-</font><font color="4444FF">&gt;</font><font color="#2040a0">h_length</font><font color="4444FF">)</font><font color="4444FF">;</font>
            <font color="#2040a0">dest</font>.<font color="#2040a0">sin_family</font> <font color="4444FF">=</font> <font color="#2040a0">hp</font><font color="4444FF">-</font><font color="4444FF">&gt;</font><font color="#2040a0">h_addrtype</font><font color="4444FF">;</font>
        <font color="4444FF"><strong>}</strong></font>
        <strong>else</strong> <font color="4444FF"><strong>{</strong></font>
            <font color="#444444">// Not a recognized hostname either!</font>
            <font color="#2040a0">cerr</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#008000">&quot;Failed to resolve &quot;</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">host</font> <font color="4444FF">&lt;</font><font color="4444FF">&lt;</font> <font color="#2040a0">endl</font><font color="4444FF">;</font>
            <strong>return</strong> <font color="4444FF">-</font><font color="#FF0000">1</font><font color="4444FF">;</font>
        <font color="4444FF"><strong>}</strong></font>
    <font color="4444FF"><strong>}</strong></font>

    <strong>return</strong> <font color="#FF0000">0</font><font color="4444FF">;</font>
<font color="4444FF"><strong>}</strong></font>



<font color="#444444">/////////////////////////// init_ping_packet ///////////////////////////</font>
<font color="#444444">// Fill in the fields and data area of an ICMP packet, making it </font>
<font color="#444444">// packet_size bytes by padding it with a byte pattern, and giving it</font>
<font color="#444444">// the given sequence number.  That completes the packet, so we also</font>
<font color="#444444">// calculate the checksum for the packet and place it in the appropriate</font>