//  Author: Leslie S. Liu (shihuali@usc.edu)
//  Written on April 22, 2003
//  IMSC , University of Southern California
//  File:   udp-pp.h 
//  Written for : ns-2.26
//  Last updated: April 24,2003
//

#ifndef ns_udp_pp_h
#define ns_udp_pp_h

#include "udp.h"
#include "ip.h"

#define MAX_STR_LEN 32 

// Multimedia Header Structure
struct hdr_pp {
	int join;    	//a join packet if == 1
	int ack_join; 	//an response packet to join request

	int leave; 	//a graceful leave message
	int ack_leave;  //a response packet for leave request

	int v_data;   	//a video stream packet
	
	int check;	//a check packet for connection
	int ack_check;	//ack packet to check request
	
	nsaddr_t ref_addr; // a address holder for different purposes
	
	char msg_data[MAX_STR_LEN]; //data that carried with the packet

	nsaddr_t src_addr; 	//address where the packet from
				//this address information is used in application
				//layer,so we must include it here in hdr	
	
	int seq;     	// pp sequence number
	int nbytes;  	// bytes for pp pkt
	double time; 	// current time
	int scale;   	// scale (0-4) associated with data rates


	// Packet header access functions
        static int offset_;
        inline static int& offset() { return offset_; }
        inline static hdr_pp* access(const Packet* p) {
                return (hdr_pp*) p->access(offset_);
        }
};


// Used for Re-assemble segmented (by UDP) PP packet
struct asm_pp { 
	int seq;     // pp sequence number
	int rbytes;  // currently received bytes
	int tbytes;  // total bytes to receive for PP packet
};


// UdpPPAgent Class definition
class UdpPPAgent : public UdpAgent {
public:
	UdpPPAgent();
	UdpPPAgent(packet_t);
	virtual int supportPP() { return 1; }
	virtual void enablePP() { support_pp_ = 1; }
	virtual void sendmsg(int nbytes, const char *flags = 0);
	void recv(Packet*, Handler*);
protected:
	int support_pp_; // set to 1 if above is PPApp
private:
	asm_pp asm_info; // packet re-assembly information
};

#endif