Refactoring of the code to match dolphin style

Changed access for offsetof + some clean up
This commit is contained in:
schthack
2022-07-08 10:20:18 -04:00
parent 01ada3850f
commit 087020b23a
8 changed files with 733 additions and 383 deletions

View File

@ -17,6 +17,7 @@
#include <fmt/format.h>
#include "Common/BitUtils.h"
#include "Common/Random.h"
#include "Common/StringUtil.h"
@ -114,6 +115,11 @@ u16 IPv4Header::Size() const
return static_cast<u16>(SIZE);
}
u8 IPv4Header::DefinedSize() const
{
return (version_ihl & 0xf) * 4;
}
TCPHeader::TCPHeader() = default;
TCPHeader::TCPHeader(const sockaddr_in& from, const sockaddr_in& to, u32 seq, const u8* data,
@ -148,12 +154,17 @@ TCPHeader::TCPHeader(const sockaddr_in& from, const sockaddr_in& to, u32 seq, u3
destination_port = to.sin_port;
sequence_number = htonl(seq);
acknowledgement_number = htonl(ack);
properties = 0x50 | flags;
properties = htons(flags);
window_size = 0x7c;
checksum = 0;
}
u8 TCPHeader::GetHeaderSize() const
{
return (ntohs(properties) & 0xf000) >> 10;
}
u16 TCPHeader::Size() const
{
return static_cast<u16>(SIZE);
@ -185,7 +196,7 @@ u8 UDPHeader::IPProto() const
ARPHeader::ARPHeader() = default;
ARPHeader::ARPHeader(u32 from_ip, MACAddress from_mac, u32 to_ip, MACAddress to_mac)
ARPHeader::ARPHeader(u32 from_ip, const MACAddress& from_mac, u32 to_ip, const MACAddress& to_mac)
{
hardware_type = htons(BBA_HARDWARE_TYPE);
protocol_type = IPV4_HEADER_TYPE;
@ -205,7 +216,7 @@ u16 ARPHeader::Size() const
DHCPBody::DHCPBody() = default;
DHCPBody::DHCPBody(u32 transaction, MACAddress client_address, u32 new_ip, u32 serv_ip)
DHCPBody::DHCPBody(u32 transaction, const MACAddress& client_address, u32 new_ip, u32 serv_ip)
{
transaction_id = transaction;
message_type = DHCPConst::MESSAGE_REPLY;
@ -216,24 +227,57 @@ DHCPBody::DHCPBody(u32 transaction, MACAddress client_address, u32 new_ip, u32 s
server_ip = serv_ip;
}
// Add an option to the DHCP Body
bool DHCPBody::AddDHCPOption(u8 size, u8 fnc, const std::vector<u8>& params)
{
int i = 0;
while (options[i] != 0)
{
i += options[i + 1] + 2;
if (i >= std::size(options))
{
return false;
}
}
DHCPPacket::DHCPPacket() = default;
options[i++] = fnc;
options[i++] = size;
for (auto val : params)
options[i++] = val;
return true;
DHCPPacket::DHCPPacket(const std::vector<u8>& data)
{
if (data.size() < DHCPBody::SIZE)
return;
body = Common::BitCastPtr<DHCPBody>(data.data());
std::size_t offset = DHCPBody::SIZE;
while (offset < data.size() - 1)
{
const u8 fnc = data[offset];
if (fnc == 0)
{
++offset;
continue;
}
if (fnc == 255)
break;
const u8 len = data[offset + 1];
const auto opt_begin = data.begin() + offset;
offset += 2 + len;
if (offset > data.size())
break;
const auto opt_end = data.begin() + offset;
options.emplace_back(opt_begin, opt_end);
}
}
void DHCPPacket::AddOption(u8 fnc, const std::vector<u8>& params)
{
if (params.size() > 255)
return;
std::vector<u8> opt = {fnc, u8(params.size())};
opt.insert(opt.end(), params.begin(), params.end());
options.emplace_back(std::move(opt));
}
std::vector<u8> DHCPPacket::Build() const
{
const u8* body_ptr = reinterpret_cast<const u8*>(&body);
std::vector<u8> result(body_ptr, body_ptr + DHCPBody::SIZE);
for (auto& opt : options)
{
result.insert(result.end(), opt.begin(), opt.end());
}
const std::vector<u8> no_option = {255, 0, 0, 0};
result.insert(result.end(), no_option.begin(), no_option.end());
return result;
}
// Compute the network checksum with a 32-bit accumulator using the
@ -253,13 +297,12 @@ u16 ComputeNetworkChecksum(const void* data, u16 length, u32 initial_value)
return ~static_cast<u16>(checksum);
}
// Compute the TCP network checksum with a fake header
u16 ComputeTCPNetworkChecksum(const sockaddr_in& from, const sockaddr_in& to, const void* data,
// Compute the TCP checksum with its pseudo header
u16 ComputeTCPNetworkChecksum(const IPAddress& from, const IPAddress& to, const void* data,
u16 length, u8 protocol)
{
// Compute the TCP checksum with its pseudo header
const u32 source_addr = ntohl(from.sin_addr.s_addr);
const u32 destination_addr = ntohl(to.sin_addr.s_addr);
const u32 source_addr = ntohl(Common::BitCast<u32>(from));
const u32 destination_addr = ntohl(Common::BitCast<u32>(to));
const u32 initial_value = (source_addr >> 16) + (source_addr & 0xFFFF) +
(destination_addr >> 16) + (destination_addr & 0xFFFF) + protocol +
length;
@ -267,6 +310,244 @@ u16 ComputeTCPNetworkChecksum(const sockaddr_in& from, const sockaddr_in& to, co
return htons(static_cast<u16>(tcp_checksum));
}
ARPPacket::ARPPacket() = default;
u16 ARPPacket::Size() const
{
return static_cast<u16>(SIZE);
}
ARPPacket::ARPPacket(const MACAddress& destination, const MACAddress& source)
{
eth_header.destination = destination;
eth_header.source = source;
eth_header.ethertype = htons(ARP_ETHERTYPE);
}
std::vector<u8> ARPPacket::Build() const
{
std::vector<u8> result;
result.reserve(EthernetHeader::SIZE + ARPHeader::SIZE);
const u8* eth_ptr = reinterpret_cast<const u8*>(&eth_header);
result.insert(result.end(), eth_ptr, eth_ptr + EthernetHeader::SIZE);
const u8* arp_ptr = reinterpret_cast<const u8*>(&arp_header);
result.insert(result.end(), arp_ptr, arp_ptr + ARPHeader::SIZE);
return result;
}
TCPPacket::TCPPacket() = default;
TCPPacket::TCPPacket(const MACAddress& destination, const MACAddress& source)
{
eth_header.destination = destination;
eth_header.source = source;
eth_header.ethertype = htons(IPV4_ETHERTYPE);
}
TCPPacket::TCPPacket(const MACAddress& destination, const MACAddress& source,
const sockaddr_in& from, const sockaddr_in& to, u32 seq, u32 ack, u16 flags)
{
eth_header.destination = destination;
eth_header.source = source;
eth_header.ethertype = htons(IPV4_ETHERTYPE);
ip_header = Common::IPv4Header(Common::TCPHeader::SIZE, IPPROTO_TCP, from, to);
tcp_header = Common::TCPHeader(from, to, seq, ack, flags);
}
std::vector<u8> TCPPacket::Build()
{
std::vector<u8> result;
result.reserve(Size());
// recalc size
ip_header.total_len = htons(static_cast<u16>(IPv4Header::SIZE + ipv4_options.size() +
TCPHeader::SIZE + tcp_options.size() + data.size()));
// copy data
const u8* eth_ptr = reinterpret_cast<const u8*>(&eth_header);
result.insert(result.end(), eth_ptr, eth_ptr + EthernetHeader::SIZE);
const u8* ip_ptr = reinterpret_cast<const u8*>(&ip_header);
result.insert(result.end(), ip_ptr, ip_ptr + IPv4Header::SIZE);
std::size_t offset = EthernetHeader::SIZE + IPv4Header::SIZE;
if (ipv4_options.size() > 0)
{
result.insert(result.end(), ipv4_options.begin(), ipv4_options.end());
offset += ipv4_options.size();
}
tcp_header.checksum = 0;
const u16 props = (ntohs(tcp_header.properties) & 0xfff) |
(static_cast<u16>((tcp_options.size() + TCPHeader::SIZE) & 0x3c) << 10);
tcp_header.properties = htons(props);
const u8* tcp_ptr = reinterpret_cast<const u8*>(&tcp_header);
result.insert(result.end(), tcp_ptr, tcp_ptr + TCPHeader::SIZE);
const std::size_t tcp_offset = offset;
offset += TCPHeader::SIZE;
if (tcp_options.size() > 0)
{
result.insert(result.end(), tcp_options.begin(), tcp_options.end());
offset += tcp_options.size();
}
if (data.size() > 0)
{
result.insert(result.end(), data.begin(), data.end());
}
tcp_header.checksum = ComputeTCPNetworkChecksum(
ip_header.source_addr, ip_header.destination_addr, &result[tcp_offset],
static_cast<u16>(result.size() - tcp_offset), IPPROTO_TCP);
std::copy(tcp_ptr, tcp_ptr + TCPHeader::SIZE, result.begin() + tcp_offset);
return result;
}
u16 TCPPacket::Size() const
{
return static_cast<u16>(MIN_SIZE + data.size() + ipv4_options.size() + tcp_options.size());
}
UDPPacket::UDPPacket() = default;
UDPPacket::UDPPacket(const MACAddress& destination, const MACAddress& source)
{
eth_header.destination = destination;
eth_header.source = source;
eth_header.ethertype = htons(IPV4_ETHERTYPE);
}
UDPPacket::UDPPacket(const MACAddress& destination, const MACAddress& source,
const sockaddr_in& from, const sockaddr_in& to, const std::vector<u8>& payload)
{
eth_header.destination = destination;
eth_header.source = source;
eth_header.ethertype = htons(IPV4_ETHERTYPE);
ip_header = Common::IPv4Header(static_cast<u16>(payload.size() + Common::UDPHeader::SIZE),
IPPROTO_UDP, from, to);
udp_header = Common::UDPHeader(from, to, static_cast<u16>(payload.size()));
data = payload;
}
std::vector<u8> UDPPacket::Build()
{
std::vector<u8> result;
result.reserve(Size());
// recalc size
ip_header.total_len = htons(
static_cast<u16>(IPv4Header::SIZE + ipv4_options.size() + UDPHeader::SIZE + data.size()));
udp_header.length = htons(static_cast<u16>(UDPHeader::SIZE + data.size()));
// copy data
const u8* eth_ptr = reinterpret_cast<const u8*>(&eth_header);
result.insert(result.end(), eth_ptr, eth_ptr + EthernetHeader::SIZE);
const u8* ip_ptr = reinterpret_cast<const u8*>(&ip_header);
result.insert(result.end(), ip_ptr, ip_ptr + IPv4Header::SIZE);
std::size_t offset = EthernetHeader::SIZE + IPv4Header::SIZE;
if (ipv4_options.size() > 0)
{
result.insert(result.end(), ipv4_options.begin(), ipv4_options.end());
offset += ipv4_options.size();
}
udp_header.checksum = 0;
const u8* udp_ptr = reinterpret_cast<const u8*>(&udp_header);
result.insert(result.end(), udp_ptr, udp_ptr + UDPHeader::SIZE);
const std::size_t udp_offset = offset;
offset += UDPHeader::SIZE;
if (data.size() > 0)
{
result.insert(result.end(), data.begin(), data.end());
}
udp_header.checksum = ComputeTCPNetworkChecksum(
ip_header.source_addr, ip_header.destination_addr, &result[udp_offset],
static_cast<u16>(result.size() - udp_offset), IPPROTO_UDP);
std::copy(udp_ptr, udp_ptr + UDPHeader::SIZE, result.begin() + udp_offset);
return result;
}
u16 UDPPacket::Size() const
{
return static_cast<u16>(MIN_SIZE + data.size() + ipv4_options.size());
}
PacketView::PacketView(const u8* ptr, std::size_t size) : m_ptr(ptr), m_size(size)
{
}
std::optional<u16> PacketView::GetEtherType() const
{
if (m_size < EthernetHeader::SIZE)
return std::nullopt;
const std::size_t offset = offsetof(EthernetHeader, ethertype);
return ntohs(Common::BitCastPtr<u16>(m_ptr + offset));
}
std::optional<ARPPacket> PacketView::GetARPPacket() const
{
if (m_size < ARPPacket::SIZE)
return std::nullopt;
return Common::BitCastPtr<ARPPacket>(m_ptr);
}
std::optional<u8> PacketView::GetIPProto() const
{
if (m_size < EthernetHeader::SIZE + IPv4Header::SIZE)
return std::nullopt;
return m_ptr[EthernetHeader::SIZE + offsetof(IPv4Header, protocol)];
}
std::optional<TCPPacket> PacketView::GetTCPPacket() const
{
if (m_size < TCPPacket::MIN_SIZE)
return std::nullopt;
TCPPacket result;
result.eth_header = Common::BitCastPtr<EthernetHeader>(m_ptr);
result.ip_header = Common::BitCastPtr<IPv4Header>(m_ptr + EthernetHeader::SIZE);
const u16 offset = result.ip_header.DefinedSize() + EthernetHeader::SIZE;
if (m_size < offset + TCPHeader::SIZE)
return std::nullopt;
result.ipv4_options =
std::vector<u8>(m_ptr + EthernetHeader::SIZE + IPv4Header::SIZE, m_ptr + offset);
result.tcp_header = Common::BitCastPtr<TCPHeader>(m_ptr + offset);
const u16 data_offset = result.tcp_header.GetHeaderSize() + offset;
const u16 total_len = ntohs(result.ip_header.total_len);
const std::size_t end = EthernetHeader::SIZE + total_len;
if (m_size < end || end < data_offset)
return std::nullopt;
result.tcp_options = std::vector<u8>(m_ptr + offset + TCPHeader::SIZE, m_ptr + data_offset);
result.data = std::vector<u8>(m_ptr + data_offset, m_ptr + end);
return result;
}
std::optional<UDPPacket> PacketView::GetUDPPacket() const
{
if (m_size < UDPPacket::MIN_SIZE)
return std::nullopt;
UDPPacket result;
result.eth_header = Common::BitCastPtr<EthernetHeader>(m_ptr);
result.ip_header = Common::BitCastPtr<IPv4Header>(m_ptr + EthernetHeader::SIZE);
const u16 offset = result.ip_header.DefinedSize() + EthernetHeader::SIZE;
if (m_size < offset + UDPHeader::SIZE)
return std::nullopt;
result.ipv4_options =
std::vector<u8>(m_ptr + EthernetHeader::SIZE + IPv4Header::SIZE, m_ptr + offset);
result.udp_header = Common::BitCastPtr<UDPHeader>(m_ptr + offset);
const u16 data_offset = UDPHeader::SIZE + offset;
const u16 total_len = ntohs(result.udp_header.length);
const std::size_t end = offset + total_len;
if (m_size < end || end < data_offset)
return std::nullopt;
result.data = std::vector<u8>(m_ptr + data_offset, m_ptr + end);
return result;
}
NetworkErrorState SaveNetworkErrorState()
{
return {