mirror of
https://github.com/SerenityOS/serenity
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87 lines
2.6 KiB
C++
87 lines
2.6 KiB
C++
#pragma once
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#include <AK/AKString.h>
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#include <AK/Assertions.h>
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#include <AK/IPv4Address.h>
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#include <AK/NetworkOrdered.h>
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#include <AK/Types.h>
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enum class IPv4Protocol : word {
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ICMP = 1,
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TCP = 6,
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UDP = 17,
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};
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NetworkOrdered<word> internet_checksum(const void*, size_t);
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class [[gnu::packed]] IPv4Packet
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{
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public:
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byte version() const { return (m_version_and_ihl >> 4) & 0xf; }
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void set_version(byte version) { m_version_and_ihl = (m_version_and_ihl & 0x0f) | (version << 4); }
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byte internet_header_length() const { return m_version_and_ihl & 0xf; }
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void set_internet_header_length(byte ihl) { m_version_and_ihl = (m_version_and_ihl & 0xf0) | (ihl & 0x0f); }
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word length() const { return m_length; }
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void set_length(word length) { m_length = length; }
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word ident() const { return m_ident; }
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void set_ident(word ident) { m_ident = ident; }
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byte ttl() const { return m_ttl; }
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void set_ttl(byte ttl) { m_ttl = ttl; }
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byte protocol() const { return m_protocol; }
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void set_protocol(byte protocol) { m_protocol = protocol; }
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word checksum() const { return m_checksum; }
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void set_checksum(word checksum) { m_checksum = checksum; }
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const IPv4Address& source() const { return m_source; }
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void set_source(const IPv4Address& address) { m_source = address; }
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const IPv4Address& destination() const { return m_destination; }
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void set_destination(const IPv4Address& address) { m_destination = address; }
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void* payload() { return this + 1; }
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const void* payload() const { return this + 1; }
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word payload_size() const { return m_length - sizeof(IPv4Packet); }
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NetworkOrdered<word> compute_checksum() const
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{
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ASSERT(!m_checksum);
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return internet_checksum(this, sizeof(IPv4Packet));
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}
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private:
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byte m_version_and_ihl { 0 };
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byte m_dscp_and_ecn { 0 };
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NetworkOrdered<word> m_length;
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NetworkOrdered<word> m_ident;
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NetworkOrdered<word> m_flags_and_fragment;
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byte m_ttl { 0 };
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NetworkOrdered<byte> m_protocol;
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NetworkOrdered<word> m_checksum;
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IPv4Address m_source;
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IPv4Address m_destination;
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};
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static_assert(sizeof(IPv4Packet) == 20);
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inline NetworkOrdered<word> internet_checksum(const void* ptr, size_t count)
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{
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dword checksum = 0;
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auto* w = (const word*)ptr;
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while (count > 1) {
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checksum += convert_between_host_and_network(*w++);
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if (checksum & 0x80000000)
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checksum = (checksum & 0xffff) | (checksum >> 16);
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count -= 2;
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}
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while (checksum >> 16)
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checksum = (checksum & 0xffff) + (checksum >> 16);
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return ~checksum & 0xffff;
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}
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