/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
 * See: http://wiki.inspircd.org/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#ifndef INSPIRCD_SOCKET_H
#define INSPIRCD_SOCKET_H

#ifndef WIN32

#include <arpa/inet.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>

#else

#include "inspircd_win32wrapper.h"

#endif

#include <cerrno>
#include "socketengine.h"

/* Contains irc-specific definitions */
namespace irc
{
	/** This namespace contains various protocol-independent helper classes.
	 * It also contains some types which are often used by the core and modules
	 * in place of inet_* functions and types.
	 */
	namespace sockets
	{
		union CoreExport sockaddrs {
			struct sockaddr sa;
			struct sockaddr_in in4;
			struct sockaddr_in6 in6;
			/** Return the size of the structure for syscall passing */
			int sa_size() const;
			/** Return port number or -1 if invalid */
			int port() const;
			/** Return IP only */
			std::string addr() const;
			/** Return human-readable IP/port pair */
			std::string str() const;
		};

		struct cidr_mask
		{
			/** Type, AF_INET or AF_INET6 */
			unsigned char type;
			/** Length of the mask in bits (0-128) */
			unsigned char length;
			/** Raw bits. Unused bits must be zero */
			unsigned char bits[16];

			cidr_mask() {}
			/** Construct a CIDR mask from the string. Will normalize (127.0.0.1/8 => 127.0.0.0/8). */
			cidr_mask(const std::string& mask);
			/** Construct a CIDR mask of a given length from the given address */
			cidr_mask(const irc::sockets::sockaddrs& addr, int len);
			/** Equality of bits, type, and length */
			bool operator==(const cidr_mask& other) const;
			/** Ordering defined for maps */
			bool operator<(const cidr_mask& other) const;
			/** Match within this CIDR? */
			bool match(const irc::sockets::sockaddrs& addr) const;
			/** Human-readable string */
			std::string str() const;
		};

		/** Match CIDR, including an optional username/nickname part.
		 *
		 * This function will compare a human-readable address (plus
		 * optional username and nickname) against a human-readable
		 * CIDR mask, for example joe!bloggs\@1.2.3.4 against
		 * *!bloggs\@1.2.0.0/16. This method supports both IPV4 and
		 * IPV6 addresses.
		 * @param address The human readable address, e.g. fred\@1.2.3.4
		 * @param cidr_mask The human readable mask, e.g. *\@1.2.0.0/16
		 * @return True if the mask matches the address
		 */
		CoreExport bool MatchCIDR(const std::string &address, const std::string &cidr_mask, bool match_with_username);

		/** Create a new valid file descriptor using socket()
		 * @return On return this function will return a value >= 0 for success,
		 * or a negative value upon failure (negative values are invalid file
		 * descriptors)
		 */
		CoreExport int OpenTCPSocket(const std::string& addr, int socktype = SOCK_STREAM);

		/** Return the size of the structure for syscall passing */
		inline int sa_size(const irc::sockets::sockaddrs& sa) { return sa.sa_size(); }

		/** Convert an address-port pair into a binary sockaddr
		 * @param addr The IP address, IPv4 or IPv6
		 * @param port The port, 0 for unspecified
		 * @param sa The structure to place the result in. Will be zeroed prior to conversion
		 * @return true if the conversion was successful, false if not.
		 */
		CoreExport bool aptosa(const std::string& addr, int port, irc::sockets::sockaddrs& sa);

		/** Convert a binary sockaddr to an address-port pair
		 * @param sa The structure to convert
		 * @param addr the IP address
		 * @param port the port
		 * @return true if the conversion was successful, false if unknown address family
		 */
		CoreExport bool satoap(const irc::sockets::sockaddrs& sa, std::string& addr, int &port);

		/** Convert a binary sockaddr to a user-readable string.
		 * This means IPv6 addresses are written as [::1]:6667, and *:6668 is used for 0.0.0.0:6668
		 * @param sa The structure to convert
		 * @return The string; "<unknown>" if not a valid address
		 */
		inline std::string satouser(const irc::sockets::sockaddrs& sa) { return sa.str(); }
	}
}

/** This class handles incoming connections on client ports.
 * It will create a new User for every valid connection
 * and assign it a file descriptor.
 */
class CoreExport ListenSocket : public EventHandler
{
 public:
	const reference<ConfigTag> bind_tag;
	std::string bind_addr;
	int bind_port;
	/** Human-readable bind description */
	std::string bind_desc;
	/** Create a new listening socket
	 */
	ListenSocket(ConfigTag* tag, const std::string& addr, int port);
	/** Handle an I/O event
	 */
	void HandleEvent(EventType et, int errornum = 0);
	/** Close the socket
	 */
	~ListenSocket();

	/** Handles sockets internals crap of a connection, convenience wrapper really
	 */
	void AcceptInternal();
};

#endif