/*
 * Copyright (c) 2012, Nasel
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * 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.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
 * OWNER 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.
 *
 */
 
#ifndef TINS_ICMPV6_H
#define TINS_ICMPV6_H

#include <list>
#include <vector>
#include "macros.h"
#include "pdu.h"
#include "ipv6_address.h"
#include "pdu_option.h"
#include "endianness.h"
#include "small_uint.h"
#include "hw_address.h"

namespace Tins {
/**
 * Represents an ICMPv6 PDU.
 */
class ICMPv6 : public PDU {
public:
    /**
     * \brief This PDU's flag.
     */
    static const PDU::PDUType pdu_flag = PDU::ICMPv6;
    
    /**
     * The types of ICMPv6 messages
     */
    enum Types {
        DEST_UNREACHABLE = 1,
        PACKET_TOOBIG = 2,
        TIME_EXCEEDED = 3,
        PARAM_PROBLEM = 4,
        ECHO_REQUEST = 128,
        ECHO_REPLY = 129,
        MGM_QUERY = 130,
        MGM_REPORT = 131,
        MGM_REDUCTION = 132,
        ROUTER_SOLICIT = 133,
        ROUTER_ADVERT = 134,
        NEIGHBOUR_SOLICIT = 135,
        NEIGHBOUR_ADVERT = 136,
        REDIRECT = 137,
        ROUTER_RENUMBER = 137,
        NI_QUERY = 139,
        NI_REPLY = 140,
        MLD2_REPORT = 143,
        DHAAD_REQUEST = 144,
        DHAAD_REPLY = 145,
        MOBILE_PREFIX_SOL = 146,
        MOBILE_PREFIX_ADV = 147
    };
    
    /**
     * The types of ICMPv6 options.
     */
    enum Options {
        SOURCE_ADDRESS = 1,
        TARGET_ADDRESS,
        PREFIX_INFO,
        REDIRECT_HEADER,
        MTU,
        NBMA_SHORT_LIMIT,
        ADVERT_INTERVAL,
        HOME_AGENT_INFO,
        S_ADDRESS_LIST,
        T_ADDRESS_LIST,
        CGA,
        RSA_SIGN,
        TIMESTAMP,
        NONCE,
        TRUST_ANCHOR,
        CERTIFICATE,
        IP_PREFIX,
        NEW_ROUTER_PREFIX,
        LINK_ADDRESS,
        NEIGHBOUR_ADVERT_ACK,
        MAP = 23,
        ROUTE_INFO,
        RECURSIVE_DNS_SERV,
        RA_FLAGS_EXT,
        HANDOVER_KEY_REQ,
        HANDOVER_KEY_REPLY,
        HANDOVER_ASSIST_INFO,
        MOBILE_NODE_ID,
        DNS_SEARCH_LIST,
        PROXY_SIGNATURE,
        ADDRESS_REG,
        SIXLOWPAN_CONTEXT,
        AUTHORITATIVE_BORDER_ROUTER,
        CARD_REQUEST = 138,
        CARD_REPLY
    };
    
    /**
     * The type used to store addresses.
     */
    typedef IPv6Address ipaddress_type;
    
    /**
     * The type used to store addresses.
     */
    typedef HWAddress<6> hwaddress_type;
    
    /**
     * The type used to represent ICMPv6 options.
     */
    typedef PDUOption<uint8_t> icmpv6_option;
    
    /**
     * The type used to store options.
     */
    typedef std::list<icmpv6_option> options_type;
    
    /**
     * \brief The type used to store the new home agent information 
     * option data.
     * 
     * The first member contains the home agent preference field, while
     * the second one contains the home agent lifetime.
     */
    typedef std::pair<uint16_t, uint16_t> new_ha_info_type;
    
    /**
     * The type used to store the source/target address list options.
     */
    typedef std::vector<ipaddress_type> addr_list_type;
    
    /**
     * The type used to store the nonce option data.
     */
    typedef std::vector<uint8_t> nonce_type;
    
    /**
     * \brief The type used to store the link layer address option data.
     */
    struct lladdr_type {
        typedef std::vector<uint8_t> address_type;
        
        uint8_t option_code;
        address_type address;
        
        /**
         * Constructor taking an option code and an address.
         * 
         * \param option_code The option code.
         * \param address The address to be stored.
         */
        lladdr_type(uint8_t option_code = 0, 
          const address_type &address = address_type())
        : option_code(option_code), address(address) 
        {
            
        }
        
        /**
         * \brief Constructor taking an option code and hwaddress_type.
         * 
         * This is a helper constructor, since it'll be common to use
         * hwaddress_type as the link layer address.
         * 
         * \param option_code The option code.
         * \param address The address to be stored.
         */
        lladdr_type(uint8_t option_code, 
          const hwaddress_type &address)
        : option_code(option_code), address(address.begin(), address.end()) 
        {
            
        }
    };
    
    /**
     * Type type used to store the prefix information option data.
     */
    TINS_BEGIN_PACK
    struct prefix_info_type {
        uint8_t prefix_len;
        #if TINS_IS_LITTLE_ENDIAN
            uint8_t reserved1:6,
                    A:1,
                    L:1;
        #else
            uint8_t L:1,
                    A:1,
                    reserved1:6;
        #endif
        uint32_t valid_lifetime,
                preferred_lifetime,
                reserved2;
        uint8_t prefix[ipaddress_type::address_size];
        
        prefix_info_type(uint8_t prefix_len=0, small_uint<1> A=0, small_uint<1> L=0,
            uint32_t valid_lifetime=0, uint32_t preferred_lifetime=0,
            const ipaddress_type &addr = ipaddress_type())
        : prefix_len(prefix_len), reserved1(0), 
        #if TINS_IS_LITTLE_ENDIAN
        A(A), L(L), 
        #else
        L(L), A(A), 
        #endif
        valid_lifetime(valid_lifetime), preferred_lifetime(preferred_lifetime)
        {
            addr.copy(prefix);
        }
    } TINS_END_PACK;
    
    /**
     * The type used to store the RSA signature option.
     */
    struct rsa_sign_type {
        typedef std::vector<uint8_t> signature_type;
        
        uint8_t key_hash[16];
        signature_type signature;
        
        /**
         * \brief Constructs a rsa_sign_type object.
         * 
         * The first parameter must be a random access iterator
         * which will be used to initialize the key_hash member. 
         * It is assumed that std::distance(hash, end_of_hash) >= 16.
         * 
         * The second and third arguments indicate the start and end of 
         * the sequence which will be used to initialize the signature
         * member.
         * 
         * \param hash A random access iterator used to initialize the
         * key_hash member.
         * \param start A forward iterator pointing to the start of the 
         * sequence which will be used to initialize the signature member.
         * \param end A forward iterator pointing to the end of the 
         * sequence used to initialize signature.
         */
        template<typename RAIterator, typename ForwardIterator>
        rsa_sign_type(RAIterator hash, ForwardIterator start, ForwardIterator end)
        : signature(start, end)
        {
            std::copy(hash, hash + sizeof(key_hash), key_hash);
        }
        
        /**
         * \brief Constructs a rsa_sign_type object.
         * 
         * The first parameter must be a random access iterator
         * which will be used to initialize the key_hash member. 
         * It is assumed that std::distance(hash, end_of_hash) >= 16.
         * 
         * 
         * \param hash A random access iterator used to initialize the
         * key_hash member.
         * \param sign The signature to be set.
         */
        template<typename RAIterator>
        rsa_sign_type(RAIterator hash, const signature_type &sign)
        : signature(sign)
        {
            std::copy(hash, hash + sizeof(key_hash), key_hash);
        }
        
        /**
         * \brief Default constructs a rsa_sign_type.
         * 
         * The key_hash member will be 0-initialized.
         */
        rsa_sign_type()
        {
            std::fill(key_hash, key_hash + sizeof(key_hash), 0);
        }
    };
    
    /**
     * The type used to store IP address/preffix option.
     */
    struct ip_prefix_type {
        uint8_t option_code, prefix_len;
        ipaddress_type address;
        
        ip_prefix_type(uint8_t option_code = 0, uint8_t prefix_len = 0,
          const ipaddress_type &address = ipaddress_type())
        : option_code(option_code), prefix_len(prefix_len), address(address)
        {}
    };
    
    /**
     * \brief Constructs an ICMPv6 object.
     * 
     * The type of the constructed object will be an echo request, unless
     * you provide another one in the tp parameter.
     * 
     * \param tp The message type of this ICMPv6 object.
     */
    ICMPv6(Types tp = ECHO_REQUEST);
    
    /**
     * \brief Constructor which creates an ICMP object from a buffer and 
     * adds all identifiable PDUs found in the buffer as children of this one.
     * 
     * \param buffer The buffer from which this PDU will be constructed.
     * \param total_sz The total size of the buffer.
     */
    ICMPv6(const uint8_t *buffer, uint32_t total_sz);
    
    // Getters

    /**
     *  \brief Getter for the type field.
     *  \return The stored type field value.
     */
    Types type() const {
        return static_cast<Types>(_header.type);
    }

    /**
     *  \brief Getter for the code field.
     *  \return The stored code field value.
     */
    uint8_t code() const {
        return _header.code;
    }

    /**
     *  \brief Getter for the cksum field.
     *  \return The stored cksum field value.
     */
    uint16_t checksum() const {
        return Endian::be_to_host(_header.cksum);
    }

    /**
     *  \brief Getter for the identifier field.
     *  \return The stored identifier field value.
     */
    uint16_t identifier() const {
        return Endian::be_to_host(_header.u_echo.identifier);
    }

    /**
     *  \brief Getter for the sequence field.
     *  \return The stored sequence field value.
     */
    uint16_t sequence() const {
        return Endian::be_to_host(_header.u_echo.sequence);
    }

    /**
     *  \brief Getter for the override field.
     *  \return The stored override field value.
     */
    small_uint<1> override() const {
        return _header.u_nd_advt.override;
    }

    /**
     *  \brief Getter for the solicited field.
     *  \return The stored solicited field value.
     */
    small_uint<1> solicited() const {
        return _header.u_nd_advt.solicited;
    }

    /**
     *  \brief Getter for the router field.
     *  \return The stored router field value.
     */
    small_uint<1> router() const {
        return _header.u_nd_advt.router;
    }

    /**
     *  \brief Getter for the hop_limit field.
     *  \return The stored hop_limit field value.
     */
    uint8_t hop_limit() const {
        return _header.u_nd_ra.hop_limit;
    }

    /**
     *  \brief Getter for the router_pref field.
     *  \return The stored router_pref field value.
     */
    small_uint<2> router_pref() const {
        return _header.u_nd_ra.router_pref;
    }

    /**
     *  \brief Getter for the home_agent field.
     *  \return The stored home_agent field value.
     */
    small_uint<1> home_agent() const {
        return _header.u_nd_ra.home_agent;
    }

    /**
     *  \brief Getter for the other field.
     *  \return The stored other field value.
     */
    small_uint<1> other() const {
        return _header.u_nd_ra.other;
    }

    /**
     *  \brief Getter for the managed field.
     *  \return The stored managed field value.
     */
    small_uint<1> managed() const {
        return _header.u_nd_ra.managed;
    }

    /**
     *  \brief Getter for the router_lifetime field.
     *  \return The stored router_lifetime field value.
     */
    uint16_t router_lifetime() const {
        return Endian::be_to_host(_header.u_nd_ra.router_lifetime);
    }
    
    /**
     *  \brief Getter for the reachable_time field.
     *  \return The stored reachable_time field value.
     */
    uint32_t reachable_time() const {
        return Endian::be_to_host(reach_time);
    }
    
    /**
     *  \brief Getter for the retransmit_timer field.
     *  \return The stored retransmit_timer field value.
     */
    uint32_t retransmit_timer() const {
        return Endian::be_to_host(retrans_timer);
    }
    
    /**
     *  \brief Getter for the target address field.
     *  \return The stored target address field value.
     */
    const ipaddress_type &target_addr() const {
        return _target_address;
    }
    
    /**
     *  \brief Getter for the destination address field.
     *  \return The stored destination address field value.
     */
    const ipaddress_type &dest_addr() const {
        return _dest_address;
    }

    // Setters

    /**
     *  \brief Setter for the type field.
     *  \param new_type The new type field value.
     */
    void type(Types new_type);

    /**
     *  \brief Setter for the code field.
     *  \param new_code The new code field value.
     */
    void code(uint8_t new_code);

    /**
     *  \brief Setter for the cksum field.
     *  \param new_cksum The new cksum field value.
     */
    void checksum(uint16_t new_cksum);

    /**
     *  \brief Setter for the identifier field.
     *  \param new_identifier The new identifier field value.
     */
    void identifier(uint16_t new_identifier);

    /**
     *  \brief Setter for the sequence field.
     *  \param new_sequence The new sequence field value.
     */
    void sequence(uint16_t new_sequence);

    /**
     *  \brief Setter for the override field.
     *  \param new_override The new override field value.
     */
    void override(small_uint<1> new_override);

    /**
     *  \brief Setter for the solicited field.
     *  \param new_solicited The new solicited field value.
     */
    void solicited(small_uint<1> new_solicited);

    /**
     *  \brief Setter for the router field.
     *  \param new_router The new router field value.
     */
    void router(small_uint<1> new_router);

    /**
     *  \brief Setter for the hop_limit field.
     *  \param new_hop_limit The new hop_limit field value.
     */
    void hop_limit(uint8_t new_hop_limit);

    /**
     *  \brief Setter for the router_pref field.
     *  \param new_router_pref The new router_pref field value.
     */
    void router_pref(small_uint<2> new_router_pref);

    /**
     *  \brief Setter for the home_agent field.
     *  \param new_home_agent The new home_agent field value.
     */
    void home_agent(small_uint<1> new_home_agent);

    /**
     *  \brief Setter for the other field.
     *  \param new_other The new other field value.
     */
    void other(small_uint<1> new_other);

    /**
     *  \brief Setter for the managed field.
     *  \param new_managed The new managed field value.
     */
    void managed(small_uint<1> new_managed);

    /**
     *  \brief Setter for the router_lifetime field.
     *  \param new_router_lifetime The new router_lifetime field value.
     */
    void router_lifetime(uint16_t new_router_lifetime);
    
    /**
     *  \brief Setter for the target address field.
     *  \param new_target_addr The new target address field value.
     */
    void target_addr(const ipaddress_type &new_target_addr);
    
    /**
     *  \brief Setter for the destination address field.
     *  \param new_dest_addr The new destination address field value.
     */
    void dest_addr(const ipaddress_type &new_dest_addr);

    /**
     *  \brief Setter for the reachable_time field.
     *  \param new_reachable_time The new reachable_time field value.
     */
    void reachable_time(uint32_t new_reachable_time);
    
    /**
     *  \brief Setter for the retransmit_timer field.
     *  \param new_retrans_timer The new retrans_timer field value.
     */
    void retransmit_timer(uint32_t new_retrans_timer);

    /**
     * \brief Getter for the PDU's type.
     *
     * \sa PDU::pdu_type
     */
    PDUType pdu_type() const { return pdu_flag; }

    /**
     * \brief Checks whether this ICMPv6 object has a target_addr field.
     * 
     * This depends on the type field.
     */
    bool has_target_addr() const {
        return type() == NEIGHBOUR_SOLICIT || 
                type() == NEIGHBOUR_ADVERT || 
                type() == REDIRECT;
    }
    
    /**
     * \brief Checks whether this ICMPv6 object has a target_addr field.
     * 
     * This depends on the type field.
     */
    bool has_dest_addr() const {
        return type() == REDIRECT;
    }
    
    /**
     * \brief Adds an ICMPv6 option.
     * 
     * The option is added after the last option in the option 
     * fields.
     * 
     * \param option The option to be added
     */
    void add_option(const icmpv6_option &option);

    /**
     * \brief Returns the header size.
     *
     * This metod overrides PDU::header_size. This size includes the
     * payload and options size. \sa PDU::header_size
     */
    uint32_t header_size() const;

    /**
     * \brief Searchs for an option that matchs the given flag.
     * 
     * If the header is not found, a null pointer is returned. 
     * Deleting the returned pointer will result in <b>undefined 
     * behaviour</b>.
     * 
     * \param id The option identifier to be searched.
     */
    const icmpv6_option *search_option(Options id) const;

    /**
     * \sa PDU::clone
     */
    ICMPv6 *clone() const {
        return new ICMPv6(*this);
    }
    
    // Option setters
    
    /**
     * \brief Setter for the source link layer address option.
     * 
     * \param addr The source link layer address.
     */
    void source_link_layer_addr(const hwaddress_type &addr);
    
    /**
     * \brief Setter for the target link layer address option.
     * 
     * \param addr The target link layer address.
     */
    void target_link_layer_addr(const hwaddress_type &addr);
    
    /**
     * \brief Setter for the prefix information option.
     * 
     * \param info The prefix information.
     */
    void prefix_info(prefix_info_type info);
    
    /**
     * \brief Setter for the redirect header option.
     * 
     * This method appends the 6 reserved bytes and inserts the 
     * necessary padding at the end.
     * 
     * \param data The redirect header option data.
     */
    void redirect_header(PDU::serialization_type data);
    
    /**
     * \brief Setter for the MTU option.
     * 
     * \param value The MTU option data.
     */
    void mtu(uint32_t value);
    
    /**
     * \brief Setter for the shortcut limit option.
     * 
     * \param value The shortcut limit option data.
     */
    void shortcut_limit(uint8_t value);
    
    /**
     * \brief Setter for the new advertisement interval option.
     * 
     * \param value The new advertisement interval option data.
     */
    void new_advert_interval(uint32_t value);
    
    /**
     * \brief Setter for the new home agent information option.
     * 
     * \param value The new home agent information option data.
     */
    void new_home_agent_info(const new_ha_info_type &value);
    
    /**
     * \brief Setter for the new source address list option.
     * 
     * \param value The new source address list option data.
     */
    void source_addr_list(const addr_list_type &value);
    
    /**
     * \brief Setter for the new target address list option.
     * 
     * \param value The new target address list option data.
     */
    void target_addr_list(const addr_list_type &value);
    
    /**
     * \brief Setter for the new RSA signature option.
     * 
     * \param value The new RSA signature option data.
     */
    void rsa_signature(const rsa_sign_type &value);
    
    /**
     * \brief Setter for the new timestamp option.
     * 
     * \param value The new timestamp option data.
     */
    void timestamp(uint64_t value);
    
    /**
     * \brief Setter for the new nonce option.
     * 
     * \param value The new nonce option data.
     */
    void nonce(const nonce_type &value);
    
    /**
     * \brief Setter for the new IP address/prefix option.
     * 
     * \param value The new IP address/prefix option data.
     */
    void ip_prefix(const ip_prefix_type &value);

    /**
     * \brief Setter for the new link layer address option.
     * 
     * \param value The new link layer address option data.
     */
    void link_layer_addr(lladdr_type value);

    // Option getters
    
    /**
     * \brief Getter for the source link layer address option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    hwaddress_type source_link_layer_addr() const;
    
    /**
     * \brief Getter for the target link layer address option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    hwaddress_type target_link_layer_addr() const;
        
    /**
     * \brief Getter for the prefix information option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    prefix_info_type prefix_info() const;
    
    /**
     * \brief Getter for the redirect header option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    PDU::serialization_type redirect_header() const;
    
    /**
     * \brief Getter for the MTU option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    uint32_t mtu() const;
    
    /**
     * \brief Getter for the shortcut limit option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    uint8_t shortcut_limit() const;
    
    /**
     * \brief Getter for the new advertisement interval option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    uint32_t new_advert_interval() const;
    
    /**
     * \brief Getter for the new home agent information option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    new_ha_info_type new_home_agent_info() const;
    
    /**
     * \brief Getter for the new source address list option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    addr_list_type source_addr_list() const;
    
    /**
     * \brief Getter for the new target address list option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    addr_list_type target_addr_list() const;
    
    /**
     * \brief Getter for the new RSA signature option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    rsa_sign_type rsa_signature() const;
    
    /**
     * \brief Getter for the new timestamp option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    uint64_t timestamp() const;
    
    /**
     * \brief Getter for the new nonce option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    nonce_type nonce() const;
    
    /**
     * \brief Getter for the new IP address/prefix option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    ip_prefix_type ip_prefix() const;
    
    /**
     * \brief Getter for the new link layer address option.
     * 
     * This method will throw an option_not_found exception if the
     * option is not found.
     */
    lladdr_type link_layer_addr() const;
private:
    TINS_BEGIN_PACK
    struct icmp6hdr {
        uint8_t	type;
        uint8_t code;
        uint16_t cksum;
        union {
            struct {
                uint16_t identifier;
                uint16_t sequence;
            } u_echo;
            
            struct {
        #if TINS_IS_LITTLE_ENDIAN
            uint32_t reserved:5,
                        override:1,
                        solicited:1,
                        router:1,
                        reserved2:24;
        #else
            uint32_t router:1,
                        solicited:1,
                        override:1,
                        reserved:29;
        #endif						
            } u_nd_advt;
            struct {
                uint8_t	hop_limit;
        #if TINS_IS_LITTLE_ENDIAN
                uint8_t reserved:3,
                        router_pref:2,
                        home_agent:1,
                        other:1,
                        managed:1;
        #else
                uint8_t managed:1,
                        other:1,
                        home_agent:1,
                        router_pref:2,
                        reserved:3;
        #endif
                uint16_t router_lifetime;
            } u_nd_ra;
        };
    } TINS_END_PACK;
    
    void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
    bool has_options() const;
    uint8_t *write_option(const icmpv6_option &opt, uint8_t *buffer);
    void parse_options(const uint8_t *&buffer, uint32_t &total_sz);
    void add_addr_list(uint8_t type, const addr_list_type &value);
    addr_list_type search_addr_list(Options type) const;


    icmp6hdr _header;
    ipaddress_type _target_address, _dest_address;
    options_type _options;
    uint32_t _options_size;
    uint32_t reach_time, retrans_timer;
};
}


#endif // TINS_ICMPV6_H