connect

/*
 * call-seq:
 *      socket.connect(server_sockaddr) => 0
 * 
 * Requests a connection to be made on the given +server_sockaddr+. Returns 0 if
 * successful, otherwise an exception is raised.
 *  
 * === Parameter
 * * +server_sockaddr+ - the +struct+ sockaddr contained in a string
 * 
 * === Example:
 *      # Pull down Google's web page
 *      require 'socket'
 *      include Socket::Constants
 *      socket = Socket.new( AF_INET, SOCK_STREAM, 0 )
 *      sockaddr = Socket.pack_sockaddr_in( 80, 'www.google.com' )
 *      socket.connect( sockaddr )
 *      socket.write( "GET / HTTP/1.0\r\n\r\n" )
 *      results = socket.read 
 * 
 * === Unix-based Exceptions
 * On unix-based systems the following system exceptions may be raised if 
 * the call to _connect_ fails:
 * * Errno::EACCES - search permission is denied for a component of the prefix
 *   path or write access to the +socket+ is denided
 * * Errno::EADDRINUSE - the _sockaddr_ is already in use
 * * Errno::EADDRNOTAVAIL - the specified _sockaddr_ is not available from the
 *   local machine
 * * Errno::EAFNOSUPPORT - the specified _sockaddr_ is not a valid address for 
 *   the address family of the specified +socket+
 * * Errno::EALREADY - a connection is already in progress for the specified
 *   socket
 * * Errno::EBADF - the +socket+ is not a valid file descriptor
 * * Errno::ECONNREFUSED - the target _sockaddr_ was not listening for connections
 *   refused the connection request
 * * Errno::ECONNRESET - the remote host reset the connection request
 * * Errno::EFAULT - the _sockaddr_ cannot be accessed
 * * Errno::EHOSTUNREACH - the destination host cannot be reached (probably 
 *   because the host is down or a remote router cannot reach it)
 * * Errno::EINPROGRESS - the O_NONBLOCK is set for the +socket+ and the
 *   connection cnanot be immediately established; the connection will be
 *   established asynchronously
 * * Errno::EINTR - the attempt to establish the connection was interrupted by
 *   delivery of a signal that was caught; the connection will be established
 *   asynchronously
 * * Errno::EISCONN - the specified +socket+ is already connected
 * * Errno::EINVAL - the address length used for the _sockaddr_ is not a valid
 *   length for the address family or there is an invalid family in _sockaddr_ 
 * * Errno::ENAMETOOLONG - the pathname resolved had a length which exceeded
 *   PATH_MAX
 * * Errno::ENETDOWN - the local interface used to reach the destination is down
 * * Errno::ENETUNREACH - no route to the network is present
 * * Errno::ENOBUFS - no buffer space is available
 * * Errno::ENOSR - there were insufficient STREAMS resources available to 
 *   complete the operation
 * * Errno::ENOTSOCK - the +socket+ argument does not refer to a socket
 * * Errno::EOPNOTSUPP - the calling +socket+ is listening and cannot be connected
 * * Errno::EPROTOTYPE - the _sockaddr_ has a different type than the socket 
 *   bound to the specified peer address
 * * Errno::ETIMEDOUT - the attempt to connect time out before a connection
 *   was made.
 * 
 * On unix-based systems if the address family of the calling +socket+ is
 * AF_UNIX the follow exceptions may be raised if the call to _connect_
 * fails:
 * * Errno::EIO - an i/o error occured while reading from or writing to the 
 *   file system
 * * Errno::ELOOP - too many symbolic links were encountered in translating
 *   the pathname in _sockaddr_
 * * Errno::ENAMETOOLLONG - a component of a pathname exceeded NAME_MAX 
 *   characters, or an entired pathname exceeded PATH_MAX characters
 * * Errno::ENOENT - a component of the pathname does not name an existing file
 *   or the pathname is an empty string
 * * Errno::ENOTDIR - a component of the path prefix of the pathname in _sockaddr_
 *   is not a directory 
 * 
 * === Windows Exceptions
 * On Windows systems the following system exceptions may be raised if 
 * the call to _connect_ fails:
 * * Errno::ENETDOWN - the network is down
 * * Errno::EADDRINUSE - the socket's local address is already in use
 * * Errno::EINTR - the socket was cancelled
 * * Errno::EINPROGRESS - a blocking socket is in progress or the service provider
 *   is still processing a callback function. Or a nonblocking connect call is 
 *   in progress on the +socket+.
 * * Errno::EALREADY - see Errno::EINVAL
 * * Errno::EADDRNOTAVAIL - the remote address is not a valid address, such as 
 *   ADDR_ANY TODO check ADDRANY TO INADDR_ANY
 * * Errno::EAFNOSUPPORT - addresses in the specified family cannot be used with
 *   with this +socket+
 * * Errno::ECONNREFUSED - the target _sockaddr_ was not listening for connections
 *   refused the connection request
 * * Errno::EFAULT - the socket's internal address or address length parameter
 *   is too small or is not a valid part of the user space address
 * * Errno::EINVAL - the +socket+ is a listening socket
 * * Errno::EISCONN - the +socket+ is already connected
 * * Errno::ENETUNREACH - the network cannot be reached from this host at this time
 * * Errno::EHOSTUNREACH - no route to the network is present
 * * Errno::ENOBUFS - no buffer space is available
 * * Errno::ENOTSOCK - the +socket+ argument does not refer to a socket
 * * Errno::ETIMEDOUT - the attempt to connect time out before a connection
 *   was made.
 * * Errno::EWOULDBLOCK - the socket is marked as nonblocking and the 
 *   connection cannot be completed immediately
 * * Errno::EACCES - the attempt to connect the datagram socket to the 
 *   broadcast address failed
 * 
 * === See
 * * connect manual pages on unix-based systems
 * * connect function in Microsoft's Winsock functions reference
 */
static VALUE
sock_connect(sock, addr)
    VALUE sock, addr;
{
    rb_io_t *fptr;
    int fd;

    StringValue(addr);
    addr = rb_str_new4(addr);
    GetOpenFile(sock, fptr);
    fd = fileno(fptr->f);
    if (ruby_connect(fd, (struct sockaddr*)RSTRING(addr)->ptr, RSTRING(addr)->len, 0) < 0) {
        rb_sys_fail("connect(2)");
    }

    return INT2FIX(0);
}