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#pragma once
#include <algorithm>
#include <array>
#include <cstdint>
#include <optional>
#include <span>
#include "wireframe/byteio.hpp"
namespace wireframe::net {
inline constexpr std::size_t kEthernetHeaderLen = 14;
inline constexpr std::uint16_t kEthertypeIPv4 = 0x0800;
inline constexpr std::uint16_t kEthertypeIPv6 = 0x86DD;
inline constexpr std::uint16_t kEthertypeArp = 0x0806;
struct MacAddress {
std::array<unsigned char, 6> bytes;
};
struct EthernetHeader {
MacAddress dst;
MacAddress src;
std::uint16_t ethertype;
};
struct EthernetFrame {
EthernetHeader header;
std::span<const unsigned char> payload;
};
inline std::optional<EthernetFrame> parse_ethernet(std::span<const unsigned char> bytes) {
if (bytes.size() < kEthernetHeaderLen) return std::nullopt;
EthernetHeader header{};
std::copy_n(bytes.begin(), 6, header.dst.bytes.begin());
std::copy_n(bytes.begin() + 6, 6, header.src.bytes.begin());
header.ethertype = read_be16(bytes, 12);
return EthernetFrame{header, bytes.subspan(kEthernetHeaderLen)};
}
} // namespace wireframe::net
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