Deadwood's sockets are a mixture of *NIX and Windows sockets in the code,
with macros in DwSocket.h changing the code to look like the appropriate
*NIX or Win32 code.  Here is the general coding style:

* Sockets are declared as a SOCKET, not as an int.  Instead of
  "int some_socket;", use "SOCKET some_socket;".  The macros make
  SOCKET an int in the *NIX compile of the code.

* An invalid socket has the value INVALID_SOCKET, not -1.  Instead
  of "foo = socket(AF_INET,SOCK_STREAM,0); if(foo == -1)...", do
  "foo = socket(yadda yadda yadda); if(foo == INVALID_SOCKET)..."
  The macros make INVALID_SOCKET -1 for the *NIX code.

* Don't use errno to find out what a given error is; use the macro
  SCKT_ERR instead.  The only error macro you can count on working
  is EINPROGRESS.

* Winsock doesn't have fcntl.  I have a macro that does either the
  *NIX or Windows version of "fcntl(foo,F_SETFL,O_NONBLOCK)" that
  looks like "make_socket_nonblock(foo)", and needs, in the Windows
  code, a u_long variable called dont_block (this is declared in
  DwSocket.c, and as an external in DwTcpSocket.c and DwUdpSocket.c)

* Don't do "close(socket)"; do "closesocket(socket)" instead.  I 
  have a macro for the *NIX code that simply makes this close().

* Don't read() or write() on a socket; *always* recv() or send() on
  a socket, otherwise the code won't work in Windows.  

* inet_pton() doesn't exist in Winsock, so I have written a wrapper 
  function that uses inet_addr() and looks like inet_pton().  Make
  sure any usage of inet_pton() is compatible with this wrapper 
  function.

* The build environment I am using in Windows, MinGW, doesn't have IPv6 
  support.  Make sure any IPv6 code is inside "#ifdef IPV6" conditionals.