Add buffer size checks to Net::Ethernet

This commit is contained in:
Sijmen 2020-12-28 17:46:13 +01:00
parent 40ecbd51f6
commit 56cf8cf447
Signed by: vijfhoek
GPG Key ID: DAF7821E067D9C48
9 changed files with 177 additions and 110 deletions

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@ -369,32 +369,34 @@ void InitialiseLCD()
void updateNetwork()
{
unsigned int size = 0;
unsigned int frameSize = 0;
uint8_t ipBuffer[USPI_FRAME_BUFFER_SIZE];
if (!USPiEthernetAvailable() || !USPiReceiveFrame(ipBuffer, &size))
if (!USPiEthernetAvailable() || !USPiReceiveFrame(ipBuffer, &frameSize))
{
return;
}
auto ethernetHeader = Net::Ethernet::Header::Deserialize(ipBuffer);
const auto offset = ethernetHeader.SerializedLength();
Net::Ethernet::Header ethernetHeader;
auto headerSize = Net::Ethernet::Header::Deserialize(
ethernetHeader, ipBuffer, frameSize);
assert(headerSize != 0);
static bool announcementSent = false;
if (!announcementSent)
static bool arpAnnouncementSent = false;
if (!arpAnnouncementSent)
{
Net::Arp::SendAnnouncement(
Net::Utils::GetMacAddress(), Net::Utils::Ipv4Address);
announcementSent = true;
arpAnnouncementSent = true;
}
switch (ethernetHeader.type)
{
case Net::Ethernet::EtherType::Arp:
Net::Arp::HandlePacket(ethernetHeader, ipBuffer + offset);
Net::Arp::HandlePacket(ethernetHeader, ipBuffer + headerSize);
break;
case Net::Ethernet::EtherType::Ipv4:
Net::Ipv4::HandlePacket(
ethernetHeader, ipBuffer + offset, sizeof(ipBuffer) - offset);
ethernetHeader, ipBuffer + headerSize, frameSize - headerSize);
break;
}
}

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@ -1,3 +1,4 @@
#include <cassert>
#include <cstring>
#include "net-arp.h"
@ -87,8 +88,14 @@ namespace Net::Arp
uint8_t buffer[USPI_FRAME_BUFFER_SIZE];
size_t size = 0;
size += ethernetHeader.Serialize(buffer + size);
size += ethernetHeader.Serialize(buffer + size, sizeof(buffer) - size);
size += arpPacket.Serialize(buffer + size);
const auto expectedSize =
ethernetHeader.SerializedLength() + arpPacket.SerializedLength();
assert(size == expectedSize);
assert(size <= USPI_FRAME_BUFFER_SIZE);
USPiSendFrame(buffer, size);
}

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@ -149,22 +149,18 @@ namespace Net::Dhcp
uint8_t buffer[USPI_FRAME_BUFFER_SIZE];
size_t size = 0;
size += ethernetHeader.Serialize(buffer + size, sizeof(buffer) - size);
size += ipv4Header.Serialize(buffer + size);
size += udpHeader.Serialize(buffer + size);
size += dhcpHeader.Serialize(buffer + size, sizeof(buffer) - size);
const auto expectedSize =
ethernetHeader.SerializedLength() +
ipv4Header.SerializedLength() +
udpHeader.SerializedLength() +
dhcpHeader.SerializedLength();
size += ethernetHeader.Serialize(buffer + size);
size += ipv4Header.Serialize(buffer + size);
size += udpHeader.Serialize(buffer + size);
size += dhcpHeader.Serialize(buffer + size, USPI_FRAME_BUFFER_SIZE - size);
if (size != expectedSize)
{
// TODO Log
return;
}
assert(size == expectedSize);
assert(size <= sizeof(buffer));
USPiSendFrame(buffer, size);
}
@ -204,22 +200,19 @@ namespace Net::Dhcp
uint8_t buffer[USPI_FRAME_BUFFER_SIZE];
size_t size = 0;
size += ethernetHeader.Serialize(buffer + size, sizeof(buffer) - size);
size += ipv4Header.Serialize(buffer + size);
size += udpHeader.Serialize(buffer + size);
size += dhcpHeader.Serialize(buffer + size, sizeof(buffer) - size);
const auto expectedSize =
ethernetHeader.SerializedLength() +
ipv4Header.SerializedLength() +
udpHeader.SerializedLength() +
dhcpHeader.SerializedLength();
size += ethernetHeader.Serialize(buffer + size);
size += ipv4Header.Serialize(buffer + size);
size += udpHeader.Serialize(buffer + size);
size += dhcpHeader.Serialize(buffer + size, USPI_FRAME_BUFFER_SIZE - size);
if (size != expectedSize)
{
// TODO Log
return;
}
assert(size == expectedSize);
assert(size <= sizeof(buffer));
USPiSendFrame(buffer, size);

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@ -28,8 +28,13 @@ namespace Net::Ethernet
type(type)
{}
size_t Header::Serialize(uint8_t* buffer) const
size_t Header::Serialize(uint8_t* buffer, const size_t size) const
{
if (size < SerializedLength())
{
return 0;
}
size_t i = 0;
std::memcpy(buffer + i, macDestination.data(), macDestination.size());
@ -44,12 +49,16 @@ namespace Net::Ethernet
return i;
}
Header Header::Deserialize(const uint8_t* buffer)
size_t Header::Deserialize(Header& out, const uint8_t* buffer, const size_t size)
{
Header self;
std::memcpy(self.macDestination.data(), buffer + 0, self.macDestination.size());
std::memcpy(self.macSource.data(), buffer + 6, self.macSource.size());
self.type = static_cast<EtherType>(buffer[12] << 8 | buffer[13]);
return self;
if (size < SerializedLength())
{
return 0;
}
std::memcpy(out.macDestination.data(), buffer + 0, out.macDestination.size());
std::memcpy(out.macSource.data(), buffer + 6, out.macSource.size());
out.type = static_cast<EtherType>(buffer[12] << 8 | buffer[13]);
return 14;
}
} // namespace Net::Ethernet

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@ -28,7 +28,8 @@ namespace Net::Ethernet
return sizeof(macDestination) + sizeof(macSource) + sizeof(type);
}
size_t Serialize(uint8_t* buffer) const;
static Header Deserialize(const uint8_t* buffer);
size_t Serialize(uint8_t* buffer, const size_t size) const;
static size_t Deserialize(
Header& out, const uint8_t* buffer, const size_t size);
};
} // namespace Net::Ethernet

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@ -1,3 +1,4 @@
#include <cassert>
#include <cstring>
#include "net-icmp.h"
@ -75,64 +76,108 @@ namespace Net::Icmp
mac, Utils::GetMacAddress(), Ethernet::EtherType::Ipv4);
uint8_t buffer[USPI_FRAME_BUFFER_SIZE];
size_t i = 0;
size_t size = 0;
i += ethernetHeader.Serialize(buffer + i);
i += ipv4Header.Serialize(buffer + i);
i += pingHeader.Serialize(buffer + i);
i += icmpHeader.Serialize(buffer + 1);
size += ethernetHeader.Serialize(buffer + size, sizeof(buffer) - size);
size += ipv4Header.Serialize(buffer + size);
size += pingHeader.Serialize(buffer + size);
size += icmpHeader.Serialize(buffer + 1);
USPiSendFrame(buffer, i);
const auto expectedSize =
ethernetHeader.SerializedLength() +
ipv4Header.SerializedLength() +
pingHeader.SerializedLength() +
icmpHeader.SerializedLength();
assert(size == expectedSize);
assert(size <= sizeof(buffer));
USPiSendFrame(buffer, size);
}
void HandlePacket(const uint8_t* buffer)
static void handleEchoRequest(
const Ethernet::Header& reqEthernetHeader,
const Ipv4::Header& reqIpv4Header,
const Icmp::PacketHeader& reqIcmpHeader,
const uint8_t* reqBuffer,
const size_t reqBufferSize
) {
const auto reqEchoHeader = Icmp::EchoHeader::Deserialize(reqBuffer);
const auto reqHeaderSize = reqEchoHeader.SerializedLength();
const Icmp::PacketHeader respIcmpHeader(Icmp::Type::EchoReply, 0);
const Ipv4::Header respIpv4Header(
Ipv4::Protocol::Icmp,
Utils::Ipv4Address,
reqIpv4Header.sourceIp,
reqIpv4Header.totalLength
);
const Ethernet::Header respEthernetHeader(
reqEthernetHeader.macSource,
Utils::GetMacAddress(),
Ethernet::EtherType::Ipv4
);
const auto payloadLength =
reqIpv4Header.totalLength -
reqIpv4Header.SerializedLength() -
reqIcmpHeader.SerializedLength() -
reqEchoHeader.SerializedLength();
std::array<uint8_t, USPI_FRAME_BUFFER_SIZE> respBuffer;
size_t respSize = 0;
respSize += respEthernetHeader.Serialize(
respBuffer.data() + respSize, respBuffer.size() - respSize);
respSize += respIpv4Header.Serialize(respBuffer.data() + respSize);
respSize += respIcmpHeader.Serialize(respBuffer.data() + respSize);
std::memcpy(
respBuffer.data() + respSize,
reqBuffer + reqHeaderSize,
payloadLength
);
respSize += payloadLength;
const auto expectedRespSize =
respEthernetHeader.SerializedLength() +
respIpv4Header.SerializedLength() +
respIcmpHeader.SerializedLength() +
payloadLength;
assert(respSize == expectedRespSize);
assert(respSize <= respBuffer.size());
USPiSendFrame(respBuffer.data(), respSize);
}
void HandlePacket(const uint8_t* buffer, const size_t bufferSize)
{
// TODO Don't re-parse the upper layers
size_t requestSize = 0;
const auto requestEthernetHeader =
Ethernet::Header::Deserialize(buffer + requestSize);
requestSize += requestEthernetHeader.SerializedLength();
const auto requestIpv4Header = Ipv4::Header::Deserialize(buffer + requestSize);
requestSize += requestIpv4Header.SerializedLength();
const auto requestIcmpHeader =
Icmp::PacketHeader::Deserialize(buffer + requestSize);
requestSize += requestIcmpHeader.SerializedLength();
size_t headerSize = 0;
if (requestIcmpHeader.type == Icmp::Type::EchoRequest)
Ethernet::Header ethernetHeader;
headerSize += Ethernet::Header::Deserialize(
ethernetHeader, buffer + headerSize, bufferSize - headerSize);
const auto ipv4Header = Ipv4::Header::Deserialize(buffer + headerSize);
headerSize += ipv4Header.SerializedLength();
const auto icmpHeader = Icmp::PacketHeader::Deserialize(buffer + headerSize);
headerSize += icmpHeader.SerializedLength();
const auto expectedHeaderSize =
ethernetHeader.SerializedLength() +
ipv4Header.SerializedLength() +
icmpHeader.SerializedLength();
assert(headerSize == expectedHeaderSize);
if (icmpHeader.type == Icmp::Type::EchoRequest)
{
const auto requestEchoHeader =
Icmp::EchoHeader::Deserialize(buffer + requestSize);
requestSize += requestEchoHeader.SerializedLength();
const Icmp::PacketHeader responseIcmpHeader(
Icmp::Type::EchoReply, 0);
const Ipv4::Header responseIpv4Header(
Ipv4::Protocol::Icmp,
Utils::Ipv4Address,
requestIpv4Header.sourceIp,
requestIpv4Header.totalLength
handleEchoRequest(
ethernetHeader,
ipv4Header,
icmpHeader,
buffer + headerSize,
bufferSize - headerSize
);
const Ethernet::Header responseEthernetHeader(
requestEthernetHeader.macSource,
Utils::GetMacAddress(),
Ethernet::EtherType::Ipv4
);
const auto payloadLength =
requestIpv4Header.totalLength -
requestIpv4Header.SerializedLength() -
requestIcmpHeader.SerializedLength() -
requestEchoHeader.SerializedLength();
std::array<uint8_t, USPI_FRAME_BUFFER_SIZE> bufferResp;
size_t respSize = 0;
respSize += responseEthernetHeader.Serialize(bufferResp.data() + respSize);
respSize += responseIpv4Header.Serialize(bufferResp.data() + respSize);
respSize += responseIcmpHeader.Serialize(bufferResp.data() + respSize);
std::memcpy(
bufferResp.data() + respSize, buffer + requestSize, payloadLength);
respSize += payloadLength;
USPiSendFrame(bufferResp.data(), respSize);
}
}
} // namespace Net::Icmp

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@ -45,5 +45,5 @@ namespace Net::Icmp
};
void SendEchoRequest(Utils::MacAddress mac, uint32_t ip);
void HandlePacket(const uint8_t* buffer);
void HandlePacket(const uint8_t* buffer, const size_t bufferSize);
} // namespace Net::Icmp

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@ -91,28 +91,28 @@ namespace Net::Ipv4
void HandlePacket(
const Ethernet::Header& ethernetHeader,
const uint8_t* buffer,
const size_t size
const size_t bufferSize
) {
const auto ipv4Header = Header::Deserialize(buffer);
const auto offset = Header::SerializedLength();
const auto header = Header::Deserialize(buffer);
const auto headerSize = Header::SerializedLength();
// Update ARP table
Arp::ArpTable.insert(
std::make_pair(ipv4Header.sourceIp, ethernetHeader.macSource));
std::make_pair(header.sourceIp, ethernetHeader.macSource));
if (ipv4Header.version != 4) return;
if (ipv4Header.ihl != 5) return; // Not supported
if (ipv4Header.destinationIp != Utils::Ipv4Address) return;
if (ipv4Header.fragmentOffset != 0) return; // TODO Support this
if (header.version != 4) return;
if (header.ihl != 5) return; // Not supported
if (header.destinationIp != Utils::Ipv4Address) return;
if (header.fragmentOffset != 0) return; // TODO Support this
if (ipv4Header.protocol == Ipv4::Protocol::Icmp)
if (header.protocol == Ipv4::Protocol::Icmp)
{
Icmp::HandlePacket(buffer);
Icmp::HandlePacket(buffer, bufferSize - headerSize);
}
else if (ipv4Header.protocol == Ipv4::Protocol::Udp)
else if (header.protocol == Ipv4::Protocol::Udp)
{
Udp::HandlePacket(
ethernetHeader, ipv4Header, buffer + offset, size - offset);
ethernetHeader, header, buffer + headerSize, bufferSize - headerSize);
}
}
} // namespace Net::Ipv4

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@ -1,7 +1,7 @@
#include <memory>
#include <cassert>
#include <cstring>
#include "ff.h"
#include "net-arp.h"
#include "net-ethernet.h"
#include "net-ipv4.h"
@ -9,6 +9,7 @@
#include "net-udp.h"
#include "net.h"
#include "ff.h"
#include "types.h"
#include <uspi.h>
@ -160,13 +161,22 @@ namespace Net::Tftp
Ethernet::EtherType::Ipv4
);
size_t i = 0;
size_t size = 0;
uint8_t buffer[USPI_FRAME_BUFFER_SIZE];
i += ethernetRespHeader.Serialize(buffer + i);
i += ipv4RespHeader.Serialize(buffer + i);
i += udpRespHeader.Serialize(buffer + i);
i += response->Serialize(buffer + i);
USPiSendFrame(buffer, i);
size += ethernetRespHeader.Serialize(buffer + size, sizeof(buffer) - size);
size += ipv4RespHeader.Serialize(buffer + size);
size += udpRespHeader.Serialize(buffer + size);
size += response->Serialize(buffer + size);
const auto expectedSize =
ethernetRespHeader.SerializedLength() +
ipv4RespHeader.SerializedLength() +
udpRespHeader.SerializedLength() +
response->SerializedLength();
assert(size == expectedSize);
assert(size <= sizeof(buffer));
USPiSendFrame(buffer, size);
}
if (last && shouldReboot)