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POListening socket connecting without accept being called on Linux
 

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  1. POListening socket connecting without accept being called on Linux
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    <p>I am running code on Ubuntu Linux it is supposed to use a Set and select to check when a listening socket has activity (ie someone trying to connect) and let them connect, the trouble is select ALLWAYS returns 0, and when I try to connect it just connects straight away. but on the server Accept is never called as select always returns 0, so I am wondering what could cause this?</p> <pre><code>namespace SocketLib { const int MAX = FD_SETSIZE; class SocketSet { public: SocketSet(); void AddSocket( const Socket&amp; p_sock ); void RemoveSocket( const Socket&amp; p_sock ); inline int Poll( long p_time = 0 ) { // this is the time value structure. It will determine how long // the select function will wait. struct timeval t = { 0, p_time * 1000 }; // copy the set over into the activity set. m_activityset = m_set; // now run select() on the sockets. #ifdef WIN32 return select( 0, &amp;m_activityset, 0, 0, &amp;t ); #else if( m_socketdescs.size() == 0 ) return 0; return select( *(m_socketdescs.rbegin()), &amp;m_activityset, 0, 0, &amp;t ); #endif } inline bool HasActivity( const Socket&amp; p_sock ) { return FD_ISSET( p_sock.GetSock(), &amp;m_activityset ) != 0; } protected: // a set representing the socket descriptors. fd_set m_set; // this set will represent all the sockets that have activity on them. fd_set m_activityset; // this is only used for linux, since select() requires the largest // descriptor +1 passed into it. BLAH! #ifndef WIN32 std::set&lt;sock&gt; m_socketdescs; #endif }; </code></pre> <p>is the code running the poll in case it helps</p> <p>Additional code is: </p> <pre><code>#include &lt;algorithm&gt; #include "SocketSet.h" namespace SocketLib { SocketSet::SocketSet() { FD_ZERO( &amp;m_set ); FD_ZERO( &amp;m_activityset ); } void SocketSet::AddSocket( const Socket&amp; p_sock ) { // add the socket desc to the set FD_SET( p_sock.GetSock(), &amp;m_set ); // if linux, then record the descriptor into the vector, // and check if it's the largest descriptor. #ifndef WIN32 m_socketdescs.insert( p_sock.GetSock() ); #endif } void SocketSet::RemoveSocket( const Socket&amp; p_sock ) { FD_CLR( p_sock.GetSock(), &amp;m_set ); #ifndef WIN32 // remove the descriptor from the vector m_socketdescs.erase( p_sock.GetSock() ); #endif } } // end namespace SocketSet </code></pre> <p>also it is being used here { // define a data socket that will receive connections from the listening // sockets DataSocket datasock;</p> <pre><code> // detect if any sockets have action on them int i=m_set.Poll(); if( i &gt; 0 ) { // loop through every listening socket for( size_t s = 0; s &lt; m_sockets.size(); s++ ) { // check to see if the current socket has a connection waiting if( m_set.HasActivity( m_sockets[s] ) ) { try { // accept the connection datasock = m_sockets[s].Accept(); // run the action function on the new data socket m_manager-&gt;NewConnection( datasock ); } </code></pre> <p>as you can see, it wont do a .Accept until AFTER it has got activity from the select, but it never gets that far Bind and listen call is here template void ListeningManager::AddPort( port p_port ) { if( m_sockets.size() == MAX ) { Exception e( ESocketLimitReached ); throw( e ); }</p> <pre><code> // create a new socket ListeningSocket lsock; // listen on the requested port lsock.Listen( p_port ); // make the socket non-blocking, so that it won't block if a // connection exploit is used when accepting (see Chapter 4) lsock.SetBlocking( false ); // add the socket to the socket vector m_sockets.push_back( lsock ); // add the socket descriptor to the set m_set.AddSocket( lsock ); } </code></pre>
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