#ifndef ETHERLIB_IPV4_PACKET_H
#define ETHERLIB_IPV4_PACKET_H

#include <stdint.h>
#include "../../packet_registry.h"
#include "../../packet_sieve.h"
#include "ipv4_types.h"

#define ETH_IPv4_PACKET_CLASS (0x0800)
#define ETH_IPv4_HEADER_SIZE (20)

typedef enum {
    IP_FLAG_DNF = 0x02,
    IP_FLAG_MF = 0x01
} IPv4Flags;

/**
 * IPv4 header structure
 */
typedef struct {
    PcktPropsHeader

    // 1. 32-bit
    uint8_t IHL; ///< header size
    uint8_t Version; ///< version (always 4)
    uint8_t DSF; ///< service type
    uint16_t TotalLength; ///< total packet length

    // 2. 32-bit
    uint16_t Identification; ///< identification
    uint8_t Flags; ///< packet flags
    uint16_t FragmentOffset; ///< packet fragmentation offset

    // 3. 32-bit
    uint8_t TTL; ///< Time-To-Live
    uint8_t Protocol; ///< Protocol
    uint16_t HeaderChecksum; ///< header IP-checksum

    // 4. 32-bit
    uint32_t SourceIPAddr; ///< source IP-address
    uint32_t DestIPAddr; ///< destination IP-address
} IPv4Props;

struct EthInterface_;

/**
 * Parse raw IPv4 packets.
 * @param hdr pointer to the IPv4 packet header
 * @param size total packet size
 * @param pcktHdrLe pointer to property storage
 * @return Protocol on success or -1 on failure
 */
int parse_ipv4(const uint8_t *hdr, uint32_t size, PcktHeaderElement *pcktHdrLe, struct EthInterface_ *intf, PcktProcFnPassbackData * pb);

/**
 * Insert IPv4 header.
 * @param hdr space where the header is to be inserted
 * @param headers linked list of header, top is always relevant
 */
void insert_ipv4_header(uint8_t *hdr, const PcktHeaderElement *headers, struct EthInterface_ *intf);

/**
 * Calculate Ethernet IPv4 multicast address from multicast
 * @param hwa
 * @param ipa
 */
void ethmc_from_ipmc(uint8_t * hwa, ip4_addr ipa);

/**
 * Fill IPv4 properties structure based on passed fields. Fields not listed among parameters is set to a default value.
 * @param ipProps IPv4 properties structure to fill
 * @param payloadSize payload size in bytes (contained header AND its payload size)
 * @param protocol contained packet protocol
 * @param srcIpA source IP address
 * @param dstIpA destination IP address
 */
void ipv4_fill_props(IPv4Props *ipProps, uint32_t payloadSize, uint16_t protocol, ip4_addr srcIpA, ip4_addr dstIpA);

#endif //ETHERLIB_IPV4_PACKET_H