58 lines
1.5 KiB
C++
58 lines
1.5 KiB
C++
#pragma once
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#include <array>
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#include <cstdint>
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#include <cstdio>
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#include <functional>
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#include <span>
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#include <string>
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#include "eth.h"
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#include "span_writer.h"
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namespace ipv4 {
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using ip4_addr = std::array<uint8_t, 4>;
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inline std::string to_string(const ip4_addr& ip) {
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char buf[16];
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snprintf(buf, sizeof(buf), "%u.%u.%u.%u", ip[0], ip[1], ip[2], ip[3]);
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return buf;
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}
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struct __attribute__((packed)) header {
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eth::header eth;
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uint8_t ver_ihl;
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uint8_t dscp_ecn;
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uint16_t total_len;
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uint16_t identification;
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uint16_t flags_frag;
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uint8_t ttl;
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uint8_t protocol;
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uint16_t checksum;
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ip4_addr src;
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ip4_addr dst;
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size_t ip_header_len() const { return (ver_ihl & 0x0F) * 4; }
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size_t ip_total_len() const { return __builtin_bswap16(total_len); }
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const uint8_t* ip_start() const { return reinterpret_cast<const uint8_t*>(&ver_ihl); }
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uint8_t* ip_start() { return reinterpret_cast<uint8_t*>(&ver_ihl); }
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};
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static_assert(sizeof(header) == 34);
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struct __attribute__((packed)) udp_header {
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header ip;
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uint16_t src_port;
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uint16_t dst_port;
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uint16_t length;
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uint16_t checksum;
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};
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static_assert(sizeof(udp_header) == 42);
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uint16_t checksum(const void* data, size_t len);
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void handle(std::span<const uint8_t> frame, span_writer& tx,
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eth::mac_addr our_mac, ip4_addr our_ip, ip4_addr subnet_broadcast,
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std::function<void(std::span<const uint8_t>)> send_raw,
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std::function<void(std::span<const uint8_t>, span_writer&)> handle_udp);
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} // namespace ipv4
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