Squid internals

The comm interface (src/comm.c)
Functions to manipulate socket FDs
Bind to a given port
commBind(s, in_addr, port)
Create a socket
sock = comm_open(sock_type, proto, addr, port, flags, desc)
Listen on a socket
comm_listen(sock)
Set socket timeout handler
commSetTimeout(fd, timeout, callback, callbackdata)
Accept an incoming connection
sock = comm_accept(fd, &peeraddr, &myaddr)
Close a socket
comm_close(fd)
Set defer handler
commSetDefer(fd, callback, callbackdata)
Register for IO callback
commSetSelect(fd, type, callback, callbackdata, timeout)