/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2007-2009 Strasbourg University
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Sebastien Vincent <vincent@clarinet.u-strasbg.fr>
 */

#ifndef IPV6_L3_PROTOCOL_H
#define IPV6_L3_PROTOCOL_H

#include <list>

#include "ns3/traced-callback.h"
#include "ns3/net-device.h"
#include "ns3/ipv6.h"
#include "ns3/ipv6-address.h"
#include "ns3/ipv6-header.h"

namespace ns3
{

class Node;
class Ipv6Interface;
class Ipv6L4Protocol;
class Ipv6Route;
class Ipv6MulticastRoute;
class Ipv6RawSocketImpl;
class Icmpv6L4Protocol;
class Ipv6AutoconfiguredPrefix;

/**
 * \class Ipv6L3Protocol
 * \brief IPv6 layer implementation.
 *
 * This class contains two distinct groups of trace sources.  The
 * trace sources 'Rx' and 'Tx' are called, respectively, immediately
 * after receiving from the NetDevice and immediately before sending
 * to a NetDevice for transmitting a packet.  These are low level
 * trace sources that include the Ipv6Header already serialized into
 * the packet.  In contrast, the Drop, SendOutgoing, UnicastForward,
 * and LocalDeliver trace sources are slightly higher-level and pass
 * around the Ipv6Header as an explicit parameter and not as part of
 * the packet.
 */
class Ipv6L3Protocol : public Ipv6
{
  public:
    /** 
     * \brief Get the type ID of this class.
     * \return type ID
     */
    static TypeId GetTypeId ();

    /**
     * \brief The protocol number for IPv6 (0x86DD).
     */
    static const uint16_t PROT_NUMBER;

    /**
     * \enum DropReason
     * \brief Reason why a packet has been dropped.
     */
    enum DropReason 
      {
        DROP_TTL_EXPIRED = 1, /**< Packet TTL has expired */
        DROP_NO_ROUTE, /**< No route to host */
        DROP_INTERFACE_DOWN, /**< Interface is down so can not send packet */
        DROP_ROUTE_ERROR, /**< Route error */
        DROP_UNKNOWN_PROTOCOL, /**< Unkown L4 protocol */
      };
    
    /**
     * \brief Constructor.
     */
    Ipv6L3Protocol ();

    /**
     * \brief Destructor.
     */
    virtual ~Ipv6L3Protocol ();
    
    /**
     * \brief Set node for this stack.
     * \param node node to set
     */
    void SetNode (Ptr<Node> node);

    /**
     * \brief Add an L4 protocol.
     * \param protocol L4 protocol
     */
    void Insert (Ptr<Ipv6L4Protocol> protocol);

    /**
     * \brief Remove an L4 protocol.
     * \param protocol L4 protocol to remove
     */
    void Remove (Ptr<Ipv6L4Protocol> protocol);

    /**
     * \brief Get L4 protocol by protocol number.
     * \param protocolNumber protocol number
     * \return corresponding Ipv6L4Protocol or 0 if not found
     */
    Ptr<Ipv6L4Protocol> GetProtocol (int protocolNumber) const;

    /**
     * \brief Create raw IPv6 socket.
     * \return newly raw socket
     */
    Ptr<Socket> CreateRawSocket ();

    /**
     * \brief Remove raw IPv6 socket.
     * \param socket socket to remove
     */
    void DeleteRawSocket (Ptr<Socket> socket);

    /**
     * \brief Set the default TTL.
     * \param ttl TTL to set
     */
    void SetDefaultTtl (uint8_t ttl);

    /**
     * \brief Receive method when a packet arrive in the stack.
     * This method removes IPv6 header and forward up to L4 protocol.
     *
     * \param device network device
     * \param p the packet
     * \param protocol next header value
     * \param from address of the correspondant
     * \param to address of the destination
     * \param packetType type of the packet
     */
    void Receive (Ptr<NetDevice> device, Ptr<const Packet> p, uint16_t protocol, const Address &from, const Address &to, NetDevice::PacketType packetType);

    /**
     * \brief Higher-level layers call this method to send a packet
     * down the stack to the MAC and PHY layers.
     *
     * \param packet packet to send
     * \param source source address of packet
     * \param destination address of packet
     * \param protocol number of packet
     * \param route route to take
     */
    void Send (Ptr<Packet> packet, Ipv6Address source, Ipv6Address destination, uint8_t protocol, Ptr<Ipv6Route> route);
   
    /**
     * \brief Set routing protocol for this stack.
     * \param routingProtocol IPv6 routing protocol to set
     */
    void SetRoutingProtocol (Ptr<Ipv6RoutingProtocol> routingProtocol);

    /**
     * \brief Get current routing protocol used.
     * \return routing protocol
     */
    Ptr<Ipv6RoutingProtocol> GetRoutingProtocol () const;

    /**
     * \brief Add IPv6 interface for a device.
     * \param device net device
     * \return interface index
     */
    uint32_t AddInterface (Ptr<NetDevice> device);

    /**
     * \brief Get an interface.
     * \param i interface index
     * \return IPv6 interface pointer
     */
    Ptr<Ipv6Interface> GetInterface (uint32_t i) const;
    
    /**
     * \brief Get current number of interface on this stack.
     * \return number of interface registered
     */
    uint32_t GetNInterfaces () const;

    /**
     * \brief Get interface index which has specified IPv6 address
     * \param addr IPv6 address
     * \return interface index or -1 if not found
     */
    int32_t GetInterfaceForAddress (Ipv6Address addr) const;

    /**
     * \brief Get interface index which match specified address/prefix.
     * \param addr IPv6 address
     * \param mask IPv6 prefix (mask)
     * \return interface index or -1 if not found
     */
    int32_t GetInterfaceForPrefix (Ipv6Address addr, Ipv6Prefix mask) const;

    /**
     * \brief Get interface index which is on a specified net device.
     * \param device net device
     */
    int32_t GetInterfaceForDevice (Ptr<const NetDevice> device) const;

    /**
     * \brief Add an address on interface.
     * \param i interface index
     * \param address to add
     */
    bool AddAddress (uint32_t i, Ipv6InterfaceAddress address);

    /**
     * \brief Get an address.
     * \param interfaceIndex interface index
     * \param addressIndex address index on the interface
     * \return Ipv6InterfaceAddress or assert if not found
     */
    Ipv6InterfaceAddress GetAddress (uint32_t interfaceIndex, uint32_t addressIndex) const;

    /**
     * \brief Get number of address for an interface.
     * \param interface interface index
     * \return number of address
     */
    uint32_t GetNAddresses (uint32_t interface) const;

    /**
     * \brief Remove an address from an interface.
     * \param interfaceIndex interface index
     * \param addressIndex address index on the interface
     */
    bool RemoveAddress (uint32_t interfaceIndex, uint32_t addressIndex);
    
    /**
     * \brief Set metric for an interface.
     * \param i index
     * \param metric
     */
    void SetMetric (uint32_t i, uint16_t metric);

    /**
     * \brief Get metric for an interface.
     * \param i index
     * \return metric
     */
    uint16_t GetMetric (uint32_t i) const;

    /**
     * \brief Get MTU for an interface.
     * \param i index
     * \return MTU
     */
    uint16_t GetMtu (uint32_t i) const;

    /**
     * \brief Is specified interface up ?
     * \param i interface index
     */
    bool IsUp (uint32_t i) const;

    /**
     * \brief Set an interface up.
     * \param i interface index
     */
    void SetUp (uint32_t i);

    /**
     * \brief set an interface down.
     * \param i interface index
     */
    void SetDown (uint32_t i);

    /**
     * \brief Is interface allows forwarding ?
     * \param i interface index
     */
    bool IsForwarding (uint32_t i) const;

    /**
     * \brief Enable or disable forwarding on interface
     * \param i interface index
     * \param val true = enable forwarding, false = disable
     */
    void SetForwarding (uint32_t i, bool val);

    /**
     * \brief Get device by index.
     * \param i device index on this stack
     * \return NetDevice pointer
     */
    Ptr<NetDevice> GetNetDevice (uint32_t i);
    
    /**
     * \brief Get ICMPv6 protocol.
     * \return Icmpv6L4Protocol pointer
     */
    Ptr<Icmpv6L4Protocol> GetIcmpv6 () const;

    /**
     * \brief Add an autoconfigured address with RA information.
     * \param interface interface index
     * \param network network prefix
     * \param mask network mask
     * \param flags flags of the prefix information option (home agent, ...)
     * \param validTime valid time of the prefix
     * \param preferredTime preferred time of the prefix
     * \param defaultRouter default router address
     */
    void AddAutoconfiguredAddress (uint32_t interface, Ipv6Address network, Ipv6Prefix mask, uint8_t flags, uint32_t validTime, uint32_t preferredTime, Ipv6Address defaultRouter = Ipv6Address::GetZero ());

    /**
     * \brief Remove an autoconfigured address.
     *
     * Typically it is used when an autoconfigured address expires.
     * \param interface interface index
     * \param network network prefix
     * \param mask network mask
     * \param defaultRouter gateway
     */
    void RemoveAutoconfiguredAddress (uint32_t interface, Ipv6Address network, Ipv6Prefix mask, Ipv6Address defaultRouter);

    /**
     * \brief Register the IPv6 Extensions.
     */
    virtual void RegisterExtensions ();

    /**
     * \brief Register the IPv6 Options.
     */
    virtual void RegisterOptions ();

  protected:
    /**
     * \brief Dispose object.
     */
    virtual void DoDispose ();

    /**
     * \brief Notify other components connected to the node that a new stack member is now connected.
     *
     * This will be used to notify Layer 3 protocol of layer 4 protocol stack to connect them together.
     */
    virtual void NotifyNewAggregate ();

  private:
    /* for unit-tests */
    friend class Ipv6L3ProtocolTestCase;

    typedef std::list<Ptr<Ipv6Interface> > Ipv6InterfaceList;
    typedef std::list<Ptr<Ipv6RawSocketImpl> > SocketList;
    typedef std::list<Ptr<Ipv6L4Protocol> > L4List_t;

    typedef std::list< Ptr<Ipv6AutoconfiguredPrefix> > Ipv6AutoconfiguredPrefixList;
    typedef std::list< Ptr<Ipv6AutoconfiguredPrefix> >::iterator Ipv6AutoconfiguredPrefixListI;

    /**
     * \brief Callback to trace TX (transmission) packets.
     */ 
    TracedCallback<Ptr<const Packet>, uint32_t> m_txTrace;
    
    /**
     * \brief Callback to trace RX (reception) packets.
     */ 
    TracedCallback<Ptr<const Packet>, uint32_t> m_rxTrace;
    
    /**
     * \brief Callback to trace drop packets.
     */ 
    TracedCallback<const Ipv6Header &, Ptr<const Packet>, DropReason, uint32_t> m_dropTrace;

    /**
     * \brief Copy constructor.
     * \param o object to copy
     */
    Ipv6L3Protocol (const Ipv6L3Protocol& o);
    
    /**
     * \brief Copy constructor.
     * \param o object to copy
     */
    Ipv6L3Protocol &operator = (const Ipv6L3Protocol& o);

    /**
     * \brief Construct an IPv6 header.
     * \param src source IPv6 address
     * \param dst destination IPv6 address
     * \param protocol L4 protocol
     * \param payloadSize payload size
     * \param ttl TTL
     * \return newly created IPv6 header
     */
    Ipv6Header BuildHeader (Ipv6Address src, Ipv6Address dst, uint8_t protocol,
                            uint16_t payloadSize, uint8_t ttl);

    /**
     * \brief Send packet with route.
     * \param route route 
     * \param packet packet to send
     * \param ipHeader IPv6 header to add to the packet
     */
    void SendRealOut (Ptr<Ipv6Route> route, Ptr<Packet> packet, Ipv6Header const& ipHeader);

    /**
     * \brief Forward a packet.
     * \param rtentry route 
     * \param p packet to forward
     * \param header IPv6 header to add to the packet
     */
    void IpForward (Ptr<Ipv6Route> rtentry, Ptr<const Packet> p, const Ipv6Header& header);

    /**
     * \brief Forward a packet in multicast.
     * \param mrtentry route 
     * \param p packet to forward
     * \param header IPv6 header to add to the packet
     */
    void IpMulticastForward (Ptr<Ipv6MulticastRoute> mrtentry, Ptr<const Packet> p, const Ipv6Header& header);

    /**
     * \brief Deliver a packet.
     * \param p packet delivered
     * \param ip IPv6 header
     * \param iif input interface packet was received
     */
    void LocalDeliver (Ptr<const Packet> p, Ipv6Header const& ip, uint32_t iif);
    
    /**
     * \brief Fallback when no route is found.
     * \param p packet
     * \param ipHeader IPv6 header
     * \param sockErrno error number
     */
    void RouteInputError (Ptr<const Packet> p, const Ipv6Header& ipHeader, Socket::SocketErrno sockErrno);

    /**
     * \brief Add an IPv6 interface to the stack.
     * \param interface interface to add
     * \return index of newly added interface
     */
    uint32_t AddIpv6Interface (Ptr<Ipv6Interface> interface);

    /**
     * \brief Setup loopback interface.
     */
    void SetupLoopback ();

    /**
     * \brief Set IPv6 forwarding state.
     * \param forward IPv6 forwarding enabled or not
     */
    virtual void SetIpForward (bool forward);

    /**
     * \brief Get IPv6 forwarding state.
     * \return forwarding state (enabled or not)
     */
    virtual bool GetIpForward () const;

    /**
     * \brief Node attached to stack.
     */
    Ptr<Node> m_node;

    /**
     * \brief Forwarding packets (i.e. router mode) state.
     */
    bool m_ipForward;

    /**
     * \brief List of transport protocol.
     */
    L4List_t m_protocols;

    /**
     * \brief List of IPv6 interfaces.
     */
    Ipv6InterfaceList m_interfaces;

    /**
     * \brief Number of IPv6 interfaces managed by the stack.
     */
    uint32_t m_nInterfaces;

    /**
     * \brief Default TTL for outgoing packets.
     */
    uint8_t m_defaultTtl;

    /**
     * \brief Routing protocol.
     */
    Ptr<Ipv6RoutingProtocol> m_routingProtocol;

    /**
     * \brief List of IPv6 raw sockets.
     */
    SocketList m_sockets;

    /**
     * \brief List of IPv6 prefix received from RA.
     */
    Ipv6AutoconfiguredPrefixList m_prefixes;
};

} /* namespace ns3 */

#endif /* IPV6_L3_PROTOCOL_H */