ladybird/Kernel/Net/IPv4.h
Andreas Kling 73fdbba59c AK: Rename <AK/AKString.h> to <AK/String.h>
This was a workaround to be able to build on case-insensitive file
systems where it might get confused about <string.h> vs <String.h>.

Let's just not support building that way, so String.h can have an
objectively nicer name. :^)
2019-09-06 15:36:54 +02:00

86 lines
2.6 KiB
C++

#pragma once
#include <AK/String.h>
#include <AK/Assertions.h>
#include <AK/IPv4Address.h>
#include <AK/NetworkOrdered.h>
#include <AK/Types.h>
enum class IPv4Protocol : u16 {
ICMP = 1,
TCP = 6,
UDP = 17,
};
NetworkOrdered<u16> internet_checksum(const void*, size_t);
class [[gnu::packed]] IPv4Packet
{
public:
u8 version() const { return (m_version_and_ihl >> 4) & 0xf; }
void set_version(u8 version) { m_version_and_ihl = (m_version_and_ihl & 0x0f) | (version << 4); }
u8 internet_header_length() const { return m_version_and_ihl & 0xf; }
void set_internet_header_length(u8 ihl) { m_version_and_ihl = (m_version_and_ihl & 0xf0) | (ihl & 0x0f); }
u16 length() const { return m_length; }
void set_length(u16 length) { m_length = length; }
u16 ident() const { return m_ident; }
void set_ident(u16 ident) { m_ident = ident; }
u8 ttl() const { return m_ttl; }
void set_ttl(u8 ttl) { m_ttl = ttl; }
u8 protocol() const { return m_protocol; }
void set_protocol(u8 protocol) { m_protocol = protocol; }
u16 checksum() const { return m_checksum; }
void set_checksum(u16 checksum) { m_checksum = checksum; }
const IPv4Address& source() const { return m_source; }
void set_source(const IPv4Address& address) { m_source = address; }
const IPv4Address& destination() const { return m_destination; }
void set_destination(const IPv4Address& address) { m_destination = address; }
void* payload() { return this + 1; }
const void* payload() const { return this + 1; }
u16 payload_size() const { return m_length - sizeof(IPv4Packet); }
NetworkOrdered<u16> compute_checksum() const
{
ASSERT(!m_checksum);
return internet_checksum(this, sizeof(IPv4Packet));
}
private:
u8 m_version_and_ihl { 0 };
u8 m_dscp_and_ecn { 0 };
NetworkOrdered<u16> m_length;
NetworkOrdered<u16> m_ident;
NetworkOrdered<u16> m_flags_and_fragment;
u8 m_ttl { 0 };
NetworkOrdered<u8> m_protocol;
NetworkOrdered<u16> m_checksum;
IPv4Address m_source;
IPv4Address m_destination;
};
static_assert(sizeof(IPv4Packet) == 20);
inline NetworkOrdered<u16> internet_checksum(const void* ptr, size_t count)
{
u32 checksum = 0;
auto* w = (const u16*)ptr;
while (count > 1) {
checksum += convert_between_host_and_network(*w++);
if (checksum & 0x80000000)
checksum = (checksum & 0xffff) | (checksum >> 16);
count -= 2;
}
while (checksum >> 16)
checksum = (checksum & 0xffff) + (checksum >> 16);
return ~checksum & 0xffff;
}