Header file for network access points.

git-svn-id: file:///svn/unbound/trunk@24 be551aaa-1e26-0410-a405-d3ace91eadb9

doc/Changelog

@@ -1,3 +1,6 @@
+22  January 2007: Wouter
+	- Designed header file for network communication.
+
 16  January 2007: Wouter
 	- added readme.svn and readme.tests.
 

util/netevent.h

@@ -0,0 +1,95 @@
+/*
+ * util/netevent.h - event notification
+ *
+ * Copyright (c) 2007, NLnet Labs. All rights reserved.
+ *
+ * See LICENSE for the license.
+ *
+ */
+
+/**
+ * \file
+ *
+ * This file contains event notification functions.
+ *
+ * There are three types of communication points
+ *    o UDP socket - perthread buffer.
+ *    o TCP-accept socket - array of TCP-sockets, socketcount.
+ *    o TCP socket - own buffer, parent-TCPaccept, read/write state,
+ *                   number of bytes read/written, timeout.
+ *
+ * There are sockets aimed towards our clients and towards the internet.
+ *    o frontside - aimed towards our clients, queries come in, answers back.
+ *    o behind - aimed towards internet, to the authoritative DNS servers.
+ *
+ */
+
+#ifndef NET_EVENT_H
+#define NET_EVENT_H
+
+#include "config.h"
+struct buffer;
+
+/** internal event notification data storage structure. */
+struct internal_event;
+
+/** Communication point to the network */
+struct comm_point {
+	/** behind the scenes structure, with say libevent info. alloced. */
+	struct internal_event* ev;
+
+	/** file descriptor for communication point */
+	int fd;
+
+	/** timeout (NULL if it does not). Malloced. */
+	struct timeval *timeout;
+
+	/** buffer pointer. Either to perthread, or own buffer or NULL */
+	struct buffer *buffer;
+
+	/* -------- TCP Handler -------- */
+	/** Read/Write state for TCP */
+	int tcp_is_reading;
+	/** The current read/write count for TCP */
+	size_t tcp_byte_count;
+	/** parent communication point (for TCP sockets) */
+	struct comm_point tcp_parent;
+
+	/* -------- TCP Accept -------- */
+	/** current and max number of TCP connections on this socket */
+	int cur_tcp_count, max_tcp_count;
+	/** malloced array of tcp handlers for a tcp-accept, 
+	    of size max_tcp_count. */
+	struct comm_point *tcp_handlers;
+	/** linked list of free tcp_handlers to use for new queries.
+	    For tcp_accept the first entry, for tcp_handlers the next one. */
+	struct comm_point *tcp_free;
+
+	/** is this a UDP, TCP-accept or TCP socket. */
+	enum comm_point_type {comm_udp, comm_tcp_accept, comm_tcp} type;
+
+	/** what to do when read/write is done.
+
+	    For a query this means it is read in and ready to be processed.
+	    After that the buffer will be sent back to client.
+	    tcp_accept does not get called back, is NULL then.
+
+	    udp frontside: called after readdone. sendafter.
+	    tcp frontside: called readdone, sendafter. close.
+	    udp behind: called after readdone. No send after.
+	    tcp behind: write done, read done, then called. No send after.
+
+	    declare as: 
+	    int my_callback(struct comm_point*, void* cb_arg, int timeout);
+
+	    if the routine returns 0, no answer is sent back.
+	    For TCP handlers after the answer is sent back the fd is closed.
+	    If a timeout happens, TCP handler is closed, and callback with
+	    timeout=1 is called.
+	*/
+	int (*)(struct comm_point*, void*) callback;
+	/** argument to pass to callback. */
+	void *cb_arg;
+};
+
+#endif /* NET_EVENT_H */