/Users/yzchen/ns/ns-allinone-2.33/ns-2.33/common/packet.h

/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Computer Systems
 *      Engineering Group at Lawrence Berkeley Laboratory.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#) $Header: /cvsroot/nsnam/ns-2/common/packet.h,v 1.102 2008/02/18 03:39:02 tom_henderson Exp $ (LBL)
 */

#ifndef ns_packet_h
#define ns_packet_h

#include <string.h>
#include <assert.h>

#include "config.h"
#include "scheduler.h"
#include "object.h"
#include "lib/bsd-list.h"
#include "packet-stamp.h"
#include "ns-process.h"

// Used by wireless routing code to attach routing agent
#define RT_PORT         255     /* port that all route msgs are sent to */

#define HDR_CMN(p)      (hdr_cmn::access(p))
#define HDR_ARP(p)      (hdr_arp::access(p))
#define HDR_MAC(p)      (hdr_mac::access(p))
#define HDR_MAC802_11(p) ((hdr_mac802_11 *)hdr_mac::access(p))
#define HDR_MAC_TDMA(p) ((hdr_mac_tdma *)hdr_mac::access(p))
#define HDR_SMAC(p)     ((hdr_smac *)hdr_mac::access(p))
#define HDR_LL(p)       (hdr_ll::access(p))
#define HDR_HDLC(p)     ((hdr_hdlc *)hdr_ll::access(p))
#define HDR_IP(p)       (hdr_ip::access(p))
#define HDR_RTP(p)      (hdr_rtp::access(p))
#define HDR_TCP(p)      (hdr_tcp::access(p))
#define HDR_SCTP(p)     (hdr_sctp::access(p))
#define HDR_SR(p)       (hdr_sr::access(p))
#define HDR_TFRC(p)     (hdr_tfrc::access(p))
#define HDR_TORA(p)     (hdr_tora::access(p))
#define HDR_IMEP(p)     (hdr_imep::access(p))
#define HDR_CDIFF(p)    (hdr_cdiff::access(p))  /* chalermak's diffusion*/
//#define HDR_DIFF(p)     (hdr_diff::access(p))  /* SCADD's diffusion ported into ns */
#define HDR_LMS(p)              (hdr_lms::access(p))

/* --------------------------------------------------------------------*/

/*
 * modified ns-2.33, adding support for dynamic libraries
 *
 * packet_t is changed from enum to unsigned int in order to allow
 * dynamic definition of  new packet types within dynamic libraries.
 * Pre-defined packet types are implemented as static const.
 *
 */

typedef unsigned int packet_t;

static const packet_t PT_TCP = 0;
static const packet_t PT_UDP = 1;
static const packet_t PT_CBR = 2;
static const packet_t PT_AUDIO = 3;
static const packet_t PT_VIDEO = 4;
static const packet_t PT_ACK = 5;
static const packet_t PT_START = 6;
static const packet_t PT_STOP = 7;
static const packet_t PT_PRUNE = 8;
static const packet_t PT_GRAFT = 9;
static const packet_t PT_GRAFTACK = 10;
static const packet_t PT_JOIN = 11;
static const packet_t PT_ASSERT = 12;
static const packet_t PT_MESSAGE = 13;
static const packet_t PT_RTCP = 14;
static const packet_t PT_RTP = 15;
static const packet_t PT_RTPROTO_DV = 16;
static const packet_t PT_CtrMcast_Encap = 17;
static const packet_t PT_CtrMcast_Decap = 18;
static const packet_t PT_SRM = 19;
        /* simple signalling messages */
static const packet_t PT_REQUEST = 20;
static const packet_t PT_ACCEPT = 21;
static const packet_t PT_CONFIRM = 22;
static const packet_t PT_TEARDOWN = 23;
static const packet_t PT_LIVE = 24;   // packet from live network
static const packet_t PT_REJECT = 25;

static const packet_t PT_TELNET = 26; // not needed: telnet use TCP
static const packet_t PT_FTP = 27;
static const packet_t PT_PARETO = 28;
static const packet_t PT_EXP = 29;
static const packet_t PT_INVAL = 30;
static const packet_t PT_HTTP = 31;

        /* new encapsulator */
static const packet_t PT_ENCAPSULATED = 32;
static const packet_t PT_MFTP = 33;

        /* CMU/Monarch's extnsions */
static const packet_t PT_ARP = 34;
static const packet_t PT_MAC = 35;
static const packet_t PT_TORA = 36;
static const packet_t PT_DSR = 37;
static const packet_t PT_AODV = 38;
static const packet_t PT_IMEP = 39;

        // RAP packets
static const packet_t PT_RAP_DATA = 40;
static const packet_t PT_RAP_ACK = 41;

static const packet_t PT_TFRC = 42;
static const packet_t PT_TFRC_ACK = 43;
static const packet_t PT_PING = 44;

static const packet_t PT_PBC = 45;
        // Diffusion packets - Chalermek
static const packet_t PT_DIFF = 46;

        // LinkState routing update packets
static const packet_t PT_RTPROTO_LS = 47;

        // MPLS LDP header
static const packet_t PT_LDP = 48;

        // GAF packet
static const packet_t PT_GAF = 49;

        // ReadAudio traffic
static const packet_t PT_REALAUDIO = 50;

        // Pushback Messages
static const packet_t PT_PUSHBACK = 51;

#ifdef HAVE_STL
        // Pragmatic General Multicast
static const packet_t PT_PGM = 52;
#endif //STL
        // LMS packets
static const packet_t PT_LMS = 53;
static const packet_t PT_LMS_SETUP = 54;

static const packet_t PT_SCTP = 55;
static const packet_t PT_SCTP_APP1 = 56;

        // SMAC packet
static const packet_t PT_SMAC = 57;
        // XCP packet
static const packet_t PT_XCP = 58;

        // HDLC packet
static const packet_t PT_HDLC = 59;

        // Bell Labs Traffic Trace Type (PackMime OL)
static const packet_t PT_BLTRACE = 60;

        // UM-OLSR packet type
                // added manually - YPC 20090228
static const packet_t PT_OLSR = 61;

                // CDSWL packet
                // added by YPC 20090719
static const packet_t PT_CDSWL = 62;

                // MM app from "NS by Example
static const packet_t PT_Multimedia = 63;

        // insert new packet types here
static packet_t       PT_NTYPE = 64; // This MUST be the LAST one

enum packetClass
{
        UNCLASSIFIED,
        ROUTING,
        DATApkt
};


/*
 * ns-2.33 adding support for dynamic libraries
 *
 * The PacketClassifier class is needed to make
 * p_info::data_packet(packet_t) work also with dynamically defined
 * packet types.
 *
 */
class PacketClassifier
{
        public:
                PacketClassifier(): next_(0){}
                virtual ~PacketClassifier() {}
                void setNext(PacketClassifier *next){next_ = next;}
                PacketClassifier *getNext(){return next_;}
                packetClass classify(packet_t type)
                {
                        packetClass c = getClass(type);
                        if(c == UNCLASSIFIED && next_)
                                c = next_->classify(type);
                        return c;
                }

        protected:
                //return 0 if the packet is unknown
                virtual packetClass getClass(packet_t type) = 0;
                PacketClassifier *next_;
};


class p_info {
public:
        p_info()
        {
                initName();
        }

        const char* name(packet_t p) const {
                if ( p <= p_info::nPkt_ ) return name_[p];
                return 0;
        }

        static bool data_packet(packet_t type) {
                return ( (type) == PT_TCP || \
                         (type) == PT_TELNET || \
                         (type) == PT_CBR || \
                         (type) == PT_AUDIO || \
                         (type) == PT_VIDEO || \
                         (type) == PT_ACK || \
                         (type) == PT_SCTP || \
                         (type) == PT_SCTP_APP1 || \
                         (type) == PT_HDLC \
                        );
        }

        static packetClass classify(packet_t type) {
                if (type == PT_DSR ||
                    type == PT_MESSAGE ||
                    type == PT_TORA ||
                    type == PT_OLSR ||
                    type == PT_CDSWL ||
                    type == PT_AODV)
                        return ROUTING;
                if (type == PT_TCP ||
                    type == PT_TELNET ||
                    type == PT_CBR ||
                    type == PT_AUDIO ||
                    type == PT_VIDEO ||
                    type == PT_ACK ||
                    type == PT_SCTP ||
                    type == PT_SCTP_APP1 ||
                    type == PT_HDLC)
                        return DATApkt;
                if (pc_)
                        return pc_->classify(type);
                return UNCLASSIFIED;
        }

        static void addPacketClassifier(PacketClassifier *pc)
        {
                if(!pc)
                        return;
                pc->setNext(pc_);
                pc_ = pc;
        }

        static void initName()
        {
                if (nPkt_ >= PT_NTYPE+1)
                        return;
                char **nameNew = new char*[PT_NTYPE+1];
                for(unsigned int i = (unsigned int)PT_SMAC+1; i < nPkt_; i++)
                {
                        nameNew[i] = name_[i];
                }
                if (!nPkt_)
                        delete [] name_;

                name_ = nameNew;
                nPkt_ = PT_NTYPE+1;

                name_[PT_TCP]= "tcp";
                name_[PT_UDP]= "udp";
                name_[PT_CBR]= "cbr";
                name_[PT_AUDIO]= "audio";
                name_[PT_VIDEO]= "video";
                name_[PT_ACK]= "ack";
                name_[PT_START]= "start";
                name_[PT_STOP]= "stop";
                name_[PT_PRUNE]= "prune";
                name_[PT_GRAFT]= "graft";
                name_[PT_GRAFTACK]= "graftAck";
                name_[PT_JOIN]= "join";
                name_[PT_ASSERT]= "assert";
                name_[PT_MESSAGE]= "message";
                name_[PT_RTCP]= "rtcp";
                name_[PT_RTP]= "rtp";
                name_[PT_RTPROTO_DV]= "rtProtoDV";
                name_[PT_CtrMcast_Encap]= "CtrMcast_Encap";
                name_[PT_CtrMcast_Decap]= "CtrMcast_Decap";
                name_[PT_SRM]= "SRM";
                name_[PT_REQUEST]= "sa_req";
                name_[PT_ACCEPT]= "sa_accept";
                name_[PT_CONFIRM]= "sa_conf";
                name_[PT_TEARDOWN]= "sa_teardown";
                name_[PT_LIVE]= "live";
                name_[PT_REJECT]= "sa_reject";
                name_[PT_TELNET]= "telnet";
                name_[PT_FTP]= "ftp";
                name_[PT_PARETO]= "pareto";
                name_[PT_EXP]= "exp";
                name_[PT_INVAL]= "httpInval";
                name_[PT_HTTP]= "http";
                name_[PT_ENCAPSULATED]= "encap";
                name_[PT_MFTP]= "mftp";
                name_[PT_ARP]= "ARP";
                name_[PT_MAC]= "MAC";
                name_[PT_TORA]= "TORA";
                name_[PT_DSR]= "DSR";
                name_[PT_AODV]= "AODV";
                name_[PT_IMEP]= "IMEP";
                name_[PT_RAP_DATA] = "rap_data";
                name_[PT_RAP_ACK] = "rap_ack";
                name_[PT_TFRC]= "tcpFriend";
                name_[PT_TFRC_ACK]= "tcpFriendCtl";
                name_[PT_PING]="ping";
                name_[PT_PBC] = "PBC";
                /* For diffusion : Chalermek */
                name_[PT_DIFF] = "diffusion";
                // Link state routing updates
                name_[PT_RTPROTO_LS] = "rtProtoLS";
                // MPLS LDP packets
                name_[PT_LDP] = "LDP";
                // for GAF
                name_[PT_GAF] = "gaf";
                // RealAudio packets
                name_[PT_REALAUDIO] = "ra";
                //pushback
                name_[PT_PUSHBACK] = "pushback";
#ifdef HAVE_STL
                // for PGM
                name_[PT_PGM] = "PGM";
#endif //STL
                // LMS entries
                name_[PT_LMS]="LMS";
                name_[PT_LMS_SETUP]="LMS_SETUP";
                name_[PT_SCTP]= "sctp";
                name_[PT_SCTP_APP1] = "sctp_app1";
                // smac
                name_[PT_SMAC]="smac";
                // HDLC
                name_[PT_HDLC]="HDLC";
                // XCP
                name_[PT_XCP]="xcp";
                // Bell Labs (PackMime OL)
                name_[PT_BLTRACE]="BellLabsTrace";
                // UM-OLSR
                name_[PT_OLSR]= "OLSR";
                // MUN-CDSWL
                name_[PT_CDSWL] = "CDSWL";
                name_[PT_Multimedia] = "Multimedia";
                name_[PT_NTYPE]= "undefined";
        }

        static int addPacket(char *name);

        static packet_t getType(const char *name)
        {
                for(unsigned int i = 0; i < nPkt_; i++)
                {
                        if(strcmp(name, name_[i]) == 0)
                                return i;
                }
                return PT_NTYPE;
        }

private:
        static char** name_;
        static unsigned int nPkt_;
        static PacketClassifier *pc_;
};

extern p_info packet_info; /* map PT_* to string name */
//extern char* p_info::name_[];

#define DATA_PACKET(type) ( (type) == PT_TCP || \
                            (type) == PT_TELNET || \
                            (type) == PT_CBR || \
                            (type) == PT_AUDIO || \
                            (type) == PT_VIDEO || \
                            (type) == PT_ACK || \
                            (type) == PT_SCTP || \
                            (type) == PT_SCTP_APP1 \
                            )

//#define OFFSET(type, field)   ((long) &((type *)0)->field)
#define OFFSET(type, field) ( (char *)&( ((type *)256)->field )  - (char *)256)

class PacketData : public AppData {
public:
        PacketData(int sz) : AppData(PACKET_DATA) {
                datalen_ = sz;
                if (datalen_ > 0)
                        data_ = new unsigned char[datalen_];
                else
                        data_ = NULL;
        }
        PacketData(PacketData& d) : AppData(d) {
                datalen_ = d.datalen_;
                if (datalen_ > 0) {
                        data_ = new unsigned char[datalen_];
                        memcpy(data_, d.data_, datalen_);
                } else
                        data_ = NULL;
        }
        virtual ~PacketData() {
                if (data_ != NULL)
                        delete []data_;
        }
        unsigned char* data() { return data_; }

        virtual int size() const { return datalen_; }
        virtual AppData* copy() { return new PacketData(*this); }
private:
        unsigned char* data_;
        int datalen_;
};

//Monarch ext
typedef void (*FailureCallback)(Packet *,void *);

class Packet : public Event {
private:
        unsigned char* bits_;   // header bits
//      unsigned char* data_;   // variable size buffer for 'data'
//      unsigned int datalen_;  // length of variable size buffer
        AppData* data_;         // variable size buffer for 'data'
        static void init(Packet*);     // initialize pkt hdr
        bool fflag_;
protected:
        static Packet* free_;   // packet free list
        int     ref_count_;     // free the pkt until count to 0
public:
        Packet* next_;          // for queues and the free list
        static int hdrlen_;

        Packet() : bits_(0), data_(0), ref_count_(0), next_(0) { }
        inline unsigned char* const bits() { return (bits_); }
        inline Packet* copy() const;
        inline Packet* refcopy() { ++ref_count_; return this; }
        inline int& ref_count() { return (ref_count_); }
        static inline Packet* alloc();
        static inline Packet* alloc(int);
        inline void allocdata(int);
        // dirty hack for diffusion data
        inline void initdata() { data_  = 0;}
        static inline void free(Packet*);
        inline unsigned char* access(int off) const {
                if (off < 0)
                        abort();
                return (&bits_[off]);
        }
        // This is used for backward compatibility, i.e., assuming user data
        // is PacketData and return its pointer.
        inline unsigned char* accessdata() const {
                if (data_ == 0)
                        return 0;
                assert(data_->type() == PACKET_DATA);
                return (((PacketData*)data_)->data());
        }
        // This is used to access application-specific data, not limited
        // to PacketData.
        inline AppData* userdata() const {
                return data_;
        }
        inline void setdata(AppData* d) {
                if (data_ != NULL)
                        delete data_;
                data_ = d;
        }
        inline int datalen() const { return data_ ? data_->size() : 0; }

        // Monarch extn

        static void dump_header(Packet *p, int offset, int length);

        // the pkt stamp carries all info about how/where the pkt
        // was sent needed for a receiver to determine if it correctly
        // receives the pkt
        PacketStamp     txinfo_;

        /*
         * According to cmu code:
         * This flag is set by the MAC layer on an incoming packet
         * and is cleared by the link layer.  It is an ugly hack, but
         * there's really no other way because NS always calls
         * the recv() function of an object.
         *
         */
        u_int8_t        incoming;

        //monarch extns end;
};

/*
 * static constant associations between interface special (negative)
 * values and their c-string representations that are used from tcl
 */
class iface_literal {
public:
        enum iface_constant {
                UNKN_IFACE= -1, /*
                                 * iface value for locally originated packets
                                 */
                ANY_IFACE= -2   /*
                                 * hashnode with iif == ANY_IFACE_
                                 * matches any pkt iface (imported from TCL);
                                 * this value should be different from
                                 * hdr_cmn::UNKN_IFACE (packet.h)
                                 */
        };
        iface_literal(const iface_constant i, const char * const n) :
                value_(i), name_(n) {}
        inline int value() const { return value_; }
        inline const char * const name() const { return name_; }
private:
        const iface_constant value_;
        /* strings used in TCL to access those special values */
        const char * const name_;
};

static const iface_literal UNKN_IFACE(iface_literal::UNKN_IFACE, "?");
static const iface_literal ANY_IFACE(iface_literal::ANY_IFACE, "*");

/*
 * Note that NS_AF_* doesn't necessarily correspond with
 * the constants used in your system (because many
 * systems don't have NONE or ILINK).
 */
enum ns_af_enum { NS_AF_NONE, NS_AF_ILINK, NS_AF_INET };

enum ModulationScheme {BPSK = 0, QPSK = 1, QAM16 = 2, QAM64 = 3};

struct hdr_cmn {
        enum dir_t { DOWN= -1, NONE= 0, UP= 1 };
        packet_t ptype_;        // packet type (see above)
        int             size_;          // simulated packet size
        int             uid_;           // unique id
        int             error_;         // error flag
        int     errbitcnt_;     // # of corrupted bits jahn
        int     fecsize_;
        double  ts_;            // timestamp: for q-delay measurement
        int             iface_;         // receiving interface (label)
        dir_t   direction_;     // direction: 0=none, 1=up, -1=down
        // source routing
        char    src_rt_valid;
        double  ts_arr_; // Required by Marker of JOBS

        //Monarch extn begins
        nsaddr_t prev_hop_;     // IP addr of forwarding hop
        nsaddr_t next_hop_;             // next hop for this packet
        int      addr_type_;    // type of next_hop_ addr
        nsaddr_t last_hop_;     // for tracing on multi-user channels

        // called if pkt can't obtain media or isn't ack'd. not called if
        // dropped by a queue
        FailureCallback xmit_failure_;
        void *xmit_failure_data_;

        /*
         * MONARCH wants to know if the MAC layer is passing this back because
         * it could not get the RTS through or because it did not receive
         * an ACK.
         */
        int     xmit_reason_;
        #define XMIT_REASON_RTS 0x01
        #define XMIT_REASON_ACK 0x02

        // filled in by GOD on first transmission, used for trace analysis
        int num_forwards_;              // how many times this pkt was forwarded
        int opt_num_forwards_;  // optimal #forwards
        // Monarch extn ends;

        // tx time for this packet in sec
        double txtime_;
        inline double& txtime() { return(txtime_); }

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

        /* per-field member functions */
        inline packet_t& ptype() { return (ptype_); }
        inline int& size() { return (size_); }
        inline int& uid() { return (uid_); }
        inline int& error() { return error_; }
        inline int& errbitcnt() {return errbitcnt_; }
        inline int& fecsize() {return fecsize_; }
        inline double& timestamp() { return (ts_); }
        inline int& iface() { return (iface_); }
        inline dir_t& direction() { return (direction_); }
        // monarch_begin
        inline nsaddr_t& next_hop() { return (next_hop_); }
        inline int& addr_type() { return (addr_type_); }
        inline int& num_forwards() { return (num_forwards_); }
        inline int& opt_num_forwards() { return (opt_num_forwards_); }
        //monarch_end

        ModulationScheme mod_scheme_;
        inline ModulationScheme& mod_scheme() { return (mod_scheme_); }
};


class PacketHeaderClass : public TclClass {
protected:
        PacketHeaderClass(const char* classname, int hdrsize);
        virtual int method(int argc, const char*const* argv);
        void field_offset(const char* fieldname, int offset);
        inline void bind_offset(int* off) { offset_ = off; }
        inline void offset(int* off) {offset_= off;}
        int hdrlen_;            // # of bytes for this header
        int* offset_;           // offset for this header
public:
        virtual void bind();
        virtual void export_offsets();
        TclObject* create(int argc, const char*const* argv);
};


inline void Packet::init(Packet* p)
{
        bzero(p->bits_, hdrlen_);
}

inline Packet* Packet::alloc()
{
        Packet* p = free_;
        if (p != 0) {
                assert(p->fflag_ == FALSE);
                free_ = p->next_;
                assert(p->data_ == 0);
                p->uid_ = 0;
                p->time_ = 0;
        } else {
                p = new Packet;
                p->bits_ = new unsigned char[hdrlen_];
                if (p == 0 || p->bits_ == 0)
                        abort();
        }
        init(p); // Initialize bits_[]
        (HDR_CMN(p))->next_hop_ = -2; // -1 reserved for IP_BROADCAST
        (HDR_CMN(p))->last_hop_ = -2; // -1 reserved for IP_BROADCAST
        p->fflag_ = TRUE;
        (HDR_CMN(p))->direction() = hdr_cmn::DOWN;
        /* setting all direction of pkts to be downward as default;
           until channel changes it to +1 (upward) */
        p->next_ = 0;
        return (p);
}

/*
 * Allocate an n byte data buffer to an existing packet
 *
 * To set application-specific AppData, use Packet::setdata()
 */
inline void Packet::allocdata(int n)
{
        assert(data_ == 0);
        data_ = new PacketData(n);
        if (data_ == 0)
                abort();
}

/* allocate a packet with an n byte data buffer */
inline Packet* Packet::alloc(int n)
{
        Packet* p = alloc();
        if (n > 0)
                p->allocdata(n);
        return (p);
}


inline void Packet::free(Packet* p)
{
        if (p->fflag_) {
                if (p->ref_count_ == 0) {
                        /*
                         * A packet's uid may be < 0 (out of a event queue), or
                         * == 0 (newed but never gets into the event queue.
                         */
                        assert(p->uid_ <= 0);
                        // Delete user data because we won't need it any more.
                        if (p->data_ != 0) {
                                delete p->data_;
                                p->data_ = 0;
                        }
                        init(p);
                        p->next_ = free_;
                        free_ = p;
                        p->fflag_ = FALSE;
                } else {
                        --p->ref_count_;
                }
        }
}

inline Packet* Packet::copy() const
{

        Packet* p = alloc();
        memcpy(p->bits(), bits_, hdrlen_);
        if (data_)
                p->data_ = data_->copy();
        p->txinfo_.init(&txinfo_);

        return (p);
}

inline void
Packet::dump_header(Packet *p, int offset, int length)
{
        assert(offset + length <= p->hdrlen_);
        struct hdr_cmn *ch = HDR_CMN(p);

        fprintf(stderr, "\nPacket ID: %d\n", ch->uid());

        for(int i = 0; i < length ; i+=16) {
                fprintf(stderr, "%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
                        p->bits_[offset + i],     p->bits_[offset + i + 1],
                        p->bits_[offset + i + 2], p->bits_[offset + i + 3],
                        p->bits_[offset + i + 4], p->bits_[offset + i + 5],
                        p->bits_[offset + i + 6], p->bits_[offset + i + 7],
                        p->bits_[offset + i + 8], p->bits_[offset + i + 9],
                        p->bits_[offset + i + 10], p->bits_[offset + i + 11],
                        p->bits_[offset + i + 12], p->bits_[offset + i + 13],
                        p->bits_[offset + i + 14], p->bits_[offset + i + 15]);
        }
}

#endif