Sockets.h

/*
* Copyright 2008, 2010 Free Software Foundation, Inc.
* Copyright 2014 Range Networks, Inc.
*
* This software is distributed under the terms of the GNU Affero Public License.
* See the COPYING file in the main directory for details.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/


#ifndef SOCKETS_H
#define SOCKETS_H

#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <errno.h>
#include <list>
#include <stdint.h>
#include <stdio.h>





#define MAX_UDP_LENGTH 1500

/** A function to resolve IP host names. */
bool resolveAddress(struct sockaddr_in *address, const char *host, unsigned short port);

/** Resolve an address of the form "<host>:<port>". */
bool resolveAddress(struct sockaddr_in *address, const char *hostAndPort);

/** An exception to throw when a critical socket operation fails. */
struct SocketError {
	SocketError();
};
#define SOCKET_ERROR {throw SocketError(); }

/** Abstract class for connectionless sockets. */
class DatagramSocket {

protected:

	int mSocketFD;				///< underlying file descriptor
	char mDestination[256];		///< address to which packets are sent
	char mSource[256];		///< return address of most recent received packet

public:

	/** An almost-does-nothing constructor. */
	DatagramSocket();

	virtual ~DatagramSocket();

	/** Return the address structure size for this socket type. */
	virtual size_t addressSize() const = 0;

	/**
		Send a binary packet.
		@param buffer The data bytes to send to mDestination.
		@param length Number of bytes to send, or strlen(buffer) if defaulted to -1.
		@return number of bytes written, or -1 on error.
	*/
	int write( const char * buffer, size_t length);

	/**
		Send a C-style string packet.
		@param buffer The data bytes to send to mDestination.
		@return number of bytes written, or -1 on error.
	*/
	int write( const char * buffer);

	/**
		Send a binary packet.
		@param buffer The data bytes to send to mSource.
		@param length Number of bytes to send, or strlen(buffer) if defaulted to -1.
		@return number of bytes written, or -1 on error.
	*/
	int writeBack(const char * buffer, size_t length);

	/**
		Send a C-style string packet.
		@param buffer The data bytes to send to mSource.
		@return number of bytes written, or -1 on error.
	*/
	int writeBack(const char * buffer);


	/**
		Receive a packet.
		@param buffer A char[MAX_UDP_LENGTH] procured by the caller.
		@return The number of bytes received or -1 on non-blocking pass.
	*/
	int read(char* buffer);

	/**
		Receive a packet with a timeout.
		@param buffer A char[MAX_UDP_LENGTH] procured by the caller.
		@param maximum wait time in milliseconds
		@return The number of bytes received or -1 on timeout.
	*/
	int read(char* buffer, unsigned timeout);


	/** Send a packet to a given destination, other than the default. */
	int send(const struct sockaddr *dest, const char * buffer, size_t length);

	/** Send a C-style string to a given destination, other than the default. */
	int send(const struct sockaddr *dest, const char * buffer);

	/** Make the socket non-blocking. */
	void nonblocking();

	/** Make the socket blocking (the default). */
	void blocking();

	/** Close the socket. */
	void close();

};



/** UDP/IP User Datagram Socket */
class UDPSocket : public DatagramSocket {

public:
	// (pat) If you want to set the local port using some sql option, you MUST NOT do it in a constructor
	// unless that constructor is called from OpenBTS.cpp, because there is a constructor race between
	// class ConfigurationTable (needed by the call to gConfig) and the class containing the UDPSocket and calling gConfig.
	// Alternatively, since we cannot add an empty constructor (because it is ambiguous with the following)
	// you must use a UDPSocket* and allocate it with 'new'.

	/** Open a USP socket with an OS-assigned port and no default destination. */
	UDPSocket( unsigned short localPort=0);

	/** Given a full specification, open the socket and set the dest address. */
	UDPSocket( 	unsigned short localPort, 
			const char * remoteIP, unsigned short remotePort);

	/** Set the destination port. */
	void destination( unsigned short wDestPort, const char * wDestIP );

	/** Return the actual port number in use. */
	unsigned short port() const;

	/** Open and bind the UDP socket to a local port. */
	void open(unsigned short localPort=0);

	/** Give the return address of the most recently received packet. */
	const struct sockaddr_in* source() const { return (const struct sockaddr_in*)mSource; }

	size_t addressSize() const { return sizeof(struct sockaddr_in); }

};


/** Unix Domain Datagram Socket */
class UDDSocket : public DatagramSocket {

public:

	UDDSocket(const char* localPath=NULL, const char* remotePath=NULL);

	void destination(const char* remotePath);

	void open(const char* localPath);

	/** Give the return address of the most recently received packet. */
	const struct sockaddr_un* source() const { return (const struct sockaddr_un*)mSource; }

	size_t addressSize() const { return sizeof(struct sockaddr_un); }

};


#endif



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