/*
 * Copyright (c) 2016, Matias Fontanini
 * 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.
 *
 */

#include "internals.h"
#include <pcap.h>
#include "ip.h"
#include "ethernetII.h"
#include "ieee802_3.h"
#include "radiotap.h"
#include "dot11/dot11_base.h"
#include "ipv6.h"
#include "tcp.h"
#include "udp.h"
#include "ipsec.h"
#include "icmp.h"
#include "loopback.h"
#include "sll.h"
#include "ppi.h"
#include "icmpv6.h"
#include "mpls.h"
#include "arp.h"
#include "eapol.h"
#include "rawpdu.h"
#include "dot1q.h"
#include "pppoe.h"
#include "exceptions.h"
#include "ip_address.h"
#include "ipv6_address.h"
#include "pdu_allocator.h"
#include "memory_helpers.h"

using std::string;

using Tins::Memory::InputMemoryStream;

namespace Tins {
namespace Internals {

bool from_hex(const string& str, uint32_t& result) {
    unsigned i(0);
    result = 0;
    while (i < str.size()) {
        uint8_t tmp;
        if (str[i] >= 'A' && str[i] <= 'F') {
            tmp = (str[i] - 'A' + 10);
        }
        else if (str[i] >= '0' && str[i] <= '9') {
            tmp = (str[i] - '0');
        }
        else {
            return false;
        }
        result = (result << 4) | tmp;
        i++;
    }
    return true;
}

void skip_line(std::istream& input) {
    int c = 0;
    while (c != '\n' && input) {
        c = input.get();
    }
}

Tins::PDU* pdu_from_flag(Constants::Ethernet::e flag,
                         const uint8_t* buffer,
                         uint32_t size,
                         bool rawpdu_on_no_match) {
    switch (flag) {
        case Tins::Constants::Ethernet::IP:
            return new IP(buffer, size);
        case Constants::Ethernet::IPV6:
            return new IPv6(buffer, size);
        case Tins::Constants::Ethernet::ARP:
            return new ARP(buffer, size);
        case Tins::Constants::Ethernet::PPPOED:
        case Tins::Constants::Ethernet::PPPOES:
            return new PPPoE(buffer, size);
        case Tins::Constants::Ethernet::EAPOL:
            return EAPOL::from_bytes(buffer, size);
        case Tins::Constants::Ethernet::VLAN:
        case Tins::Constants::Ethernet::QINQ:
        case Tins::Constants::Ethernet::OLD_QINQ:
            return new Dot1Q(buffer, size);
        case Tins::Constants::Ethernet::MPLS:
            return new MPLS(buffer, size);
        default:
            {
                PDU* pdu = Internals::allocate<EthernetII>(
                    static_cast<uint16_t>(flag),
                    buffer, 
                    size
                );
                if (pdu) {
                    return pdu;
                }
            }
            return rawpdu_on_no_match ? new RawPDU(buffer, size) : 0;
    };
}

Tins::PDU* pdu_from_flag(Constants::IP::e flag, 
                         const uint8_t* buffer, 
                         uint32_t size,
                         bool rawpdu_on_no_match) {
    switch (flag) {
        case Constants::IP::PROTO_IPIP:
            return new Tins::IP(buffer, size);
        case Constants::IP::PROTO_TCP:
            return new Tins::TCP(buffer, size);
        case Constants::IP::PROTO_UDP:
            return new Tins::UDP(buffer, size);
        case Constants::IP::PROTO_ICMP:
            return new Tins::ICMP(buffer, size);
        case Constants::IP::PROTO_ICMPV6:
            return new Tins::ICMPv6(buffer, size);
        case Constants::IP::PROTO_IPV6:
            return new Tins::IPv6(buffer, size);
        case Constants::IP::PROTO_AH:
            return new Tins::IPSecAH(buffer, size);
        case Constants::IP::PROTO_ESP:
            return new Tins::IPSecESP(buffer, size);
        default:
            break;
    }
    if (rawpdu_on_no_match) {
        return new Tins::RawPDU(buffer, size);
    }
    return 0;
}

PDU* pdu_from_dlt_flag(int flag, 
                       const uint8_t* buffer, 
                       uint32_t size,
                       bool rawpdu_on_no_match) {
    switch (flag) {
        case DLT_EN10MB:
            return new EthernetII(buffer, size);

        #ifdef TINS_HAVE_DOT11
        case DLT_IEEE802_11_RADIO:
            return new RadioTap(buffer, size);
        case DLT_IEEE802_11:
            return Dot11::from_bytes(buffer, size);
        #else // TINS_HAVE_DOT11
        case DLT_IEEE802_11_RADIO:
        case DLT_IEEE802_11:
            throw protocol_disabled();
        #endif // TINS_HAVE_DOT11

        case DLT_NULL:
            return new Loopback(buffer, size);
        case DLT_LINUX_SLL:
            return new SLL(buffer, size);
        case DLT_PPI:
            return new PPI(buffer, size);
        default:
            return rawpdu_on_no_match ? new RawPDU(buffer, size) : 0;
    };
}

Tins::PDU* pdu_from_flag(PDU::PDUType type, const uint8_t* buffer, uint32_t size) {
    switch(type) {
        case Tins::PDU::ETHERNET_II:
            return new Tins::EthernetII(buffer, size);
        case Tins::PDU::IP:
            return new Tins::IP(buffer, size);
        case Tins::PDU::IPv6:
            return new Tins::IPv6(buffer, size);
        case Tins::PDU::ARP:
            return new Tins::ARP(buffer, size);
        case Tins::PDU::IEEE802_3:
            return new Tins::IEEE802_3(buffer, size);
        case Tins::PDU::PPPOE:
            return new Tins::PPPoE(buffer, size);
        #ifdef TINS_HAVE_DOT11
            case Tins::PDU::RADIOTAP:
                return new Tins::RadioTap(buffer, size);
            case Tins::PDU::DOT11:
            case Tins::PDU::DOT11_ACK:
            case Tins::PDU::DOT11_ASSOC_REQ:
            case Tins::PDU::DOT11_ASSOC_RESP:
            case Tins::PDU::DOT11_AUTH:
            case Tins::PDU::DOT11_BEACON:
            case Tins::PDU::DOT11_BLOCK_ACK:
            case Tins::PDU::DOT11_BLOCK_ACK_REQ:
            case Tins::PDU::DOT11_CF_END:
            case Tins::PDU::DOT11_DATA:
            case Tins::PDU::DOT11_CONTROL:
            case Tins::PDU::DOT11_DEAUTH:
            case Tins::PDU::DOT11_DIASSOC:
            case Tins::PDU::DOT11_END_CF_ACK:
            case Tins::PDU::DOT11_MANAGEMENT:
            case Tins::PDU::DOT11_PROBE_REQ:
            case Tins::PDU::DOT11_PROBE_RESP:
            case Tins::PDU::DOT11_PS_POLL:
            case Tins::PDU::DOT11_REASSOC_REQ:
            case Tins::PDU::DOT11_REASSOC_RESP:
            case Tins::PDU::DOT11_RTS:
            case Tins::PDU::DOT11_QOS_DATA:
                return Tins::Dot11::from_bytes(buffer, size);
        #endif // TINS_HAVE_DOT11
        default:
            return 0;
    };
}

Constants::Ethernet::e pdu_flag_to_ether_type(PDU::PDUType flag) {
    switch (flag) {
        case PDU::IP:
            return Constants::Ethernet::IP;
        case PDU::IPv6:
            return Constants::Ethernet::IPV6;
        case PDU::ARP:
            return Constants::Ethernet::ARP;
        case PDU::DOT1Q:
            return Constants::Ethernet::VLAN;
        case PDU::PPPOE:
            return Constants::Ethernet::PPPOED;
        case PDU::MPLS:
            return Constants::Ethernet::MPLS;
        case PDU::RSNEAPOL:
        case PDU::RC4EAPOL:
            return Constants::Ethernet::EAPOL;
        default:
            if (Internals::pdu_type_registered<EthernetII>(flag)) {
                return static_cast<Constants::Ethernet::e>(
                    Internals::pdu_type_to_id<EthernetII>(flag)
                );
            }
            return Constants::Ethernet::UNKNOWN;
    }
}

PDU::PDUType ether_type_to_pdu_flag(Constants::Ethernet::e flag) {
    switch (flag) {
        case Constants::Ethernet::IP:
            return PDU::IP;
        case Constants::Ethernet::IPV6:
            return PDU::IPv6;
        case Constants::Ethernet::ARP:
            return PDU::ARP;
        case Constants::Ethernet::VLAN:
            return PDU::DOT1Q;
        case Constants::Ethernet::PPPOED:
            return PDU::PPPOE;
        //case PDU::RSNEAPOL
        //case PDU::RC4EAPOL:
        //    return Constants::Ethernet::EAPOL;
        default:
            return PDU::UNKNOWN;
    }
}

Constants::IP::e pdu_flag_to_ip_type(PDU::PDUType flag) {
    switch(flag) {
        case PDU::IP:
            return Constants::IP::PROTO_IPIP;
        case PDU::IPv6:
            return Constants::IP::PROTO_IPV6;
        case PDU::TCP:
            return Constants::IP::PROTO_TCP;
        case PDU::UDP:
            return Constants::IP::PROTO_UDP;
        case PDU::ICMP:
            return Constants::IP::PROTO_ICMP;
        case PDU::ICMPv6:
            return Constants::IP::PROTO_ICMPV6;
        case PDU::IPSEC_AH:
            return Constants::IP::PROTO_AH;
        case PDU::IPSEC_ESP:
            return Constants::IP::PROTO_ESP;
        default:
            return static_cast<Constants::IP::e>(0xff);
    };
}

uint32_t get_padded_icmp_inner_pdu_size(const PDU* inner_pdu, uint32_t pad_alignment) {
        // This gets the size of the next pdu, padded to the next 32 bit word boundary
    if (inner_pdu) {
        uint32_t inner_pdu_size = inner_pdu->size();
        uint32_t padding = inner_pdu_size % pad_alignment;
        inner_pdu_size = padding ? (inner_pdu_size - padding + pad_alignment) : inner_pdu_size;
        return inner_pdu_size;
    }
    else {
        return 0;
    }
}

void try_parse_icmp_extensions(InputMemoryStream& stream, 
                               uint32_t payload_length, 
                               ICMPExtensionsStructure& extensions) {
    if (!stream) {
        return;
    }
    // Check if this is one of the types defined in RFC 4884
    const uint32_t minimum_payload = ICMPExtensionsStructure::MINIMUM_ICMP_PAYLOAD;
    // Check if we actually have this amount of data and whether it's more than
    // the minimum encapsulated packet size
    const uint8_t* extensions_ptr;
    uint32_t extensions_size;
    if (stream.can_read(payload_length) && payload_length >= minimum_payload) {
        extensions_ptr = stream.pointer() + payload_length;
        extensions_size = stream.size() - payload_length;
    }
    else if (stream.can_read(minimum_payload)) {
        // This packet might be non-rfc compliant. In that case the length 
        // field can contain garbage.
        extensions_ptr = stream.pointer() + minimum_payload;
        extensions_size = stream.size() - minimum_payload;
    }
    else {
        // No more special cases, this doesn't have extensions
        return;
    }
    if (ICMPExtensionsStructure::validate_extensions(extensions_ptr, extensions_size)) {
        extensions = ICMPExtensionsStructure(extensions_ptr, extensions_size);
        stream.size(stream.size() - extensions_size);
    }
}

PDU::PDUType ip_type_to_pdu_flag(Constants::IP::e flag) {
    switch(flag) {
        case Constants::IP::PROTO_IPIP:
            return PDU::IP;
        case Constants::IP::PROTO_IPV6:
            return PDU::IPv6;
        case Constants::IP::PROTO_TCP:
            return PDU::TCP;
        case Constants::IP::PROTO_UDP:
            return PDU::UDP;
        case Constants::IP::PROTO_ICMP:
            return PDU::ICMP;
        case Constants::IP::PROTO_ICMPV6:
            return PDU::ICMPv6;
        case Constants::IP::PROTO_AH:
            return PDU::IPSEC_AH;
        case Constants::IP::PROTO_ESP:
            return PDU::IPSEC_ESP;
        default:
            return PDU::UNKNOWN;
    };
}

bool increment(IPv4Address &addr) {
    uint32_t addr_int = Endian::be_to_host<uint32_t>(addr);
    bool reached_end = ++addr_int == 0xffffffff;
    addr = IPv4Address(Endian::be_to_host<uint32_t>(addr_int));
    return reached_end;
}

bool increment(IPv6Address& addr) {
    return increment_buffer(addr);
}

bool decrement(IPv4Address& addr) {
    uint32_t addr_int = Endian::be_to_host<uint32_t>(addr);
    bool reached_end = --addr_int == 0;
    addr = IPv4Address(Endian::be_to_host<uint32_t>(addr_int));
    return reached_end;
}

bool decrement(IPv6Address& addr) {
    return decrement_buffer(addr);
}

int seq_compare(uint32_t seq1, uint32_t seq2) {
    // As defined by RFC 1982 - 2 ^ (SERIAL_BITS - 1)
    static const uint32_t seq_number_diff = 2147483648U;
    if (seq1 == seq2) {
        return 0;
    }
    if (seq1 < seq2) {
        return (seq2 - seq1 < seq_number_diff) ? -1 : 1;
    }
    else {
        return (seq1 - seq2 > seq_number_diff) ? -1 : 1;
    }
}

IPv4Address last_address_from_mask(IPv4Address addr, IPv4Address mask) {
    uint32_t addr_int = Endian::be_to_host<uint32_t>(addr),
             mask_int = Endian::be_to_host<uint32_t>(mask);
    return IPv4Address(Endian::host_to_be(addr_int | ~mask_int));
}

IPv6Address last_address_from_mask(IPv6Address addr, const IPv6Address& mask) {
    IPv6Address::iterator addr_iter = addr.begin();
    for (IPv6Address::const_iterator it = mask.begin(); it != mask.end(); ++it, ++addr_iter) {
        *addr_iter = *addr_iter | ~*it;
    }
    return addr;
}

} // namespace Internals
} // namespace Tins
