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bug 247: tcp checksum crashes when enabled.

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This commit is contained in:
Mathieu Lacage
2008-07-10 15:58:24 -07:00
parent 7f07acc254
commit 731a76246f
8 changed files with 78 additions and 99 deletions
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6
src/common/buffer.cc
View File

@@ -1128,6 +1128,12 @@ Buffer::Iterator::CalculateIpChecksum(uint16_t size, uint32_t initialChecksum)
return ~sum;
}
uint32_t
Buffer::Iterator::GetSize (void) const
{
return m_dataEnd - m_dataStart;
}
} // namespace ns3

5
src/common/buffer.h
View File

@@ -358,6 +358,11 @@ public:
*/
uint16_t CalculateIpChecksum(uint16_t size, uint32_t initialChecksum);
/**
* \returns the size of the underlying buffer we are iterating
*/
uint32_t GetSize (void) const;
private:
friend class Buffer;
Iterator (Buffer const*buffer);

68
src/internet-stack/tcp-header.cc
View File

@@ -23,6 +23,7 @@
#include "tcp-socket-impl.h"
#include "tcp-header.h"
#include "ns3/buffer.h"
#include "ns3/address-utils.h"
namespace ns3 {
@@ -37,8 +38,6 @@ TcpHeader::TcpHeader ()
m_flags (0),
m_windowSize (0xffff),
m_urgentPointer (0),
m_initialChecksum(0),
m_checksum (0),
m_calcChecksum(false),
m_goodChecksum(true)
{}
@@ -52,11 +51,6 @@ TcpHeader::EnableChecksums (void)
m_calcChecksum = true;
}
void TcpHeader::SetPayloadSize(uint16_t payloadSize)
{
m_payloadSize = payloadSize;
}
void TcpHeader::SetSourcePort (uint16_t port)
{
m_sourcePort = port;
@@ -85,10 +79,6 @@ void TcpHeader::SetWindowSize (uint16_t windowSize)
{
m_windowSize = windowSize;
}
void TcpHeader::SetChecksum (uint16_t checksum)
{
m_checksum = checksum;
}
void TcpHeader::SetUrgentPointer (uint16_t urgentPointer)
{
m_urgentPointer = urgentPointer;
@@ -122,10 +112,6 @@ uint16_t TcpHeader::GetWindowSize () const
{
return m_windowSize;
}
uint16_t TcpHeader::GetChecksum () const
{
return m_checksum;
}
uint16_t TcpHeader::GetUrgentPointer () const
{
return m_urgentPointer;
@@ -133,29 +119,31 @@ uint16_t TcpHeader::GetUrgentPointer () const
void
TcpHeader::InitializeChecksum (Ipv4Address source,
Ipv4Address destination,
uint8_t protocol)
Ipv4Address destination,
uint8_t protocol)
{
Buffer buf = Buffer(12);
uint8_t tmp[4];
Buffer::Iterator it;
uint16_t tcpLength = m_payloadSize + GetSerializedSize();
m_source = source;
m_destination = destination;
m_protocol = protocol;
}
buf.AddAtStart(12);
it = buf.Begin();
uint16_t
TcpHeader::CalculateHeaderChecksum (uint16_t size) const
{
Buffer buf = Buffer (12);
buf.AddAtStart (12);
Buffer::Iterator it = buf.Begin ();
source.Serialize(tmp);
it.Write(tmp, 4); /* source IP address */
destination.Serialize(tmp);
it.Write(tmp, 4); /* destination IP address */
it.WriteU8(0); /* protocol */
it.WriteU8(protocol); /* protocol */
it.WriteU8(tcpLength >> 8); /* length */
it.WriteU8(tcpLength & 0xff); /* length */
WriteTo (it, m_source);
WriteTo (it, m_destination);
it.WriteU8 (0); /* protocol */
it.WriteU8 (m_protocol); /* protocol */
it.WriteU8 (size >> 8); /* length */
it.WriteU8 (size & 0xff); /* length */
it = buf.Begin();
it = buf.Begin ();
/* we don't CompleteChecksum ( ~ ) now */
m_initialChecksum = ~(it.CalculateIpChecksum(12));
return ~(it.CalculateIpChecksum (12));
}
bool
@@ -219,7 +207,6 @@ uint32_t TcpHeader::GetSerializedSize (void) const
void TcpHeader::Serialize (Buffer::Iterator start) const
{
Buffer::Iterator i = start;
uint16_t tcpLength = m_payloadSize + GetSerializedSize();
i.WriteHtonU16 (m_sourcePort);
i.WriteHtonU16 (m_destinationPort);
i.WriteHtonU32 (m_sequenceNumber);
@@ -231,8 +218,9 @@ void TcpHeader::Serialize (Buffer::Iterator start) const
if(m_calcChecksum)
{
uint16_t headerChecksum = CalculateHeaderChecksum (start.GetSize ());
i = start;
uint16_t checksum = i.CalculateIpChecksum(tcpLength, m_initialChecksum);
uint16_t checksum = i.CalculateIpChecksum(start.GetSize (), headerChecksum);
i = start;
i.Next(16);
@@ -250,16 +238,16 @@ uint32_t TcpHeader::Deserialize (Buffer::Iterator start)
m_flags = field & 0x3F;
m_length = field>>12;
m_windowSize = i.ReadNtohU16 ();
m_checksum = i.ReadU16 ();
i.Next (2);
m_urgentPointer = i.ReadNtohU16 ();
if(m_calcChecksum)
{
{
uint16_t headerChecksum = CalculateHeaderChecksum (start.GetSize ());
i = start;
uint16_t checksum = i.CalculateIpChecksum(m_payloadSize + GetSerializedSize(), m_initialChecksum);
uint16_t checksum = i.CalculateIpChecksum(start.GetSize (), headerChecksum);
m_goodChecksum = (checksum == 0);
}
}
return GetSerializedSize ();
}

23
src/internet-stack/tcp-header.h
View File

@@ -77,10 +77,6 @@ public:
* \param windowSize the window size for this TcpHeader
*/
void SetWindowSize (uint16_t windowSize);
/**
* \param checksum the checksum for this TcpHeader
*/
void SetChecksum (uint16_t checksum);
/**
* \param urgentPointer the urgent pointer for this TcpHeader
*/
@@ -116,10 +112,6 @@ public:
* \return the window size for this TcpHeader
*/
uint16_t GetWindowSize () const;
/**
* \return the checksum for this TcpHeader
*/
uint16_t GetChecksum () const;
/**
* \return the urgent pointer for this TcpHeader
*/
@@ -150,11 +142,6 @@ public:
virtual void Serialize (Buffer::Iterator start) const;
virtual uint32_t Deserialize (Buffer::Iterator start);
/**
* \param size The payload size in bytes
*/
void SetPayloadSize (uint16_t size);
/**
* \brief Is the TCP checksum correct ?
* \returns true if the checksum is correct, false otherwise.
@@ -162,6 +149,7 @@ public:
bool IsChecksumOk (void) const;
private:
uint16_t CalculateHeaderChecksum (uint16_t size) const;
uint16_t m_sourcePort;
uint16_t m_destinationPort;
uint32_t m_sequenceNumber;
@@ -170,13 +158,14 @@ private:
uint8_t m_flags; // really a uint6_t
uint16_t m_windowSize;
uint16_t m_urgentPointer;
uint16_t m_payloadSize;
uint16_t m_initialChecksum;
uint16_t m_checksum;
Ipv4Address m_source;
Ipv4Address m_destination;
uint8_t m_protocol;
uint16_t m_initialChecksum;
bool m_calcChecksum;
bool m_goodChecksum;
};
}; // namespace ns3

3
src/internet-stack/tcp-l4-protocol.cc
View File

@@ -448,6 +448,7 @@ TcpL4Protocol::Receive (Ptr<Packet> packet,
if(m_calcChecksum)
{
tcpHeader.EnableChecksums();
tcpHeader.InitializeChecksum (source, destination, PROT_NUMBER);
}
packet->PeekHeader (tcpHeader);
@@ -495,7 +496,6 @@ TcpL4Protocol::Send (Ptr<Packet> packet,
TcpHeader tcpHeader;
tcpHeader.SetDestinationPort (dport);
tcpHeader.SetSourcePort (sport);
tcpHeader.SetPayloadSize(packet->GetSize());
if(m_calcChecksum)
{
tcpHeader.EnableChecksums();
@@ -529,7 +529,6 @@ TcpL4Protocol::SendPacket (Ptr<Packet> packet, TcpHeader outgoingHeader,
// XXX outgoingHeader cannot be logged
outgoingHeader.SetLength (5); //header length in units of 32bit words
outgoingHeader.SetPayloadSize(packet->GetSize());
/* outgoingHeader.SetUrgentPointer (0); //XXX */
if(m_calcChecksum)
{

54
src/internet-stack/udp-header.cc
View File

@@ -19,6 +19,7 @@
*/
#include "udp-header.h"
#include "ns3/address-utils.h"
namespace ns3 {
@@ -32,8 +33,6 @@ UdpHeader::UdpHeader ()
: m_sourcePort (0xfffd),
m_destinationPort (0xfffd),
m_payloadSize (0xfffd),
m_initialChecksum (0),
m_checksum(0),
m_calcChecksum(false),
m_goodChecksum(true)
{}
@@ -71,35 +70,31 @@ UdpHeader::GetDestinationPort (void) const
return m_destinationPort;
}
void
UdpHeader::SetPayloadSize (uint16_t size)
{
m_payloadSize = size;
}
void
UdpHeader::InitializeChecksum (Ipv4Address source,
Ipv4Address destination,
uint8_t protocol)
{
Buffer buf = Buffer(12);
uint8_t tmp[4];
Buffer::Iterator it;
uint16_t udpLength = m_payloadSize + GetSerializedSize();
m_source = source;
m_destination = destination;
m_protocol = protocol;
}
uint16_t
UdpHeader::CalculateHeaderChecksum (uint16_t size) const
{
Buffer buf = Buffer (12);
buf.AddAtStart (12);
Buffer::Iterator it = buf.Begin ();
buf.AddAtStart(12);
it = buf.Begin();
WriteTo (it, m_source);
WriteTo (it, m_destination);
it.WriteU8 (0); /* protocol */
it.WriteU8 (m_protocol); /* protocol */
it.WriteU8 (size >> 8); /* length */
it.WriteU8 (size & 0xff); /* length */
source.Serialize(tmp);
it.Write(tmp, 4); /* source IP address */
destination.Serialize(tmp);
it.Write(tmp, 4); /* destination IP address */
it.WriteU8(0); /* protocol */
it.WriteU8(protocol); /* protocol */
it.WriteU8(udpLength >> 8); /* length */
it.WriteU8(udpLength & 0xff); /* length */
it = buf.Begin();
it = buf.Begin ();
/* we don't CompleteChecksum ( ~ ) now */
m_initialChecksum = ~(it.CalculateIpChecksum(12));
return ~(it.CalculateIpChecksum (12));
}
bool
@@ -142,17 +137,17 @@ void
UdpHeader::Serialize (Buffer::Iterator start) const
{
Buffer::Iterator i = start;
uint16_t udpLength = m_payloadSize + GetSerializedSize();
i.WriteHtonU16 (m_sourcePort);
i.WriteHtonU16 (m_destinationPort);
i.WriteHtonU16 (udpLength);
i.WriteHtonU16 (start.GetSize ());
i.WriteU16 (0);
if (m_calcChecksum)
{
uint16_t headerChecksum = CalculateHeaderChecksum (start.GetSize ());
i = start;
uint16_t checksum = i.CalculateIpChecksum(udpLength, m_initialChecksum);
uint16_t checksum = i.CalculateIpChecksum (start.GetSize (), headerChecksum);
i = start;
i.Next(6);
@@ -166,12 +161,13 @@ UdpHeader::Deserialize (Buffer::Iterator start)
m_sourcePort = i.ReadNtohU16 ();
m_destinationPort = i.ReadNtohU16 ();
m_payloadSize = i.ReadNtohU16 () - GetSerializedSize ();
m_checksum = i.ReadU16();
i.Next (2);
if(m_calcChecksum)
{
uint16_t headerChecksum = CalculateHeaderChecksum (start.GetSize ());
i = start;
uint16_t checksum = i.CalculateIpChecksum(m_payloadSize + GetSerializedSize(), m_initialChecksum);
uint16_t checksum = i.CalculateIpChecksum (start.GetSize (), headerChecksum);
m_goodChecksum = (checksum == 0);
}

10
src/internet-stack/udp-header.h
View File

@@ -66,10 +66,6 @@ public:
* \return the destination port for this UdpHeader
*/
uint16_t GetDestinationPort (void) const;
/**
* \param size The payload size in bytes
*/
void SetPayloadSize (uint16_t size);
/**
* \param source the ip source to use in the underlying
@@ -100,12 +96,14 @@ public:
bool IsChecksumOk (void) const;
private:
uint16_t CalculateHeaderChecksum (uint16_t size) const;
uint16_t m_sourcePort;
uint16_t m_destinationPort;
uint16_t m_payloadSize;
uint16_t m_initialChecksum;
uint16_t m_checksum;
Ipv4Address m_source;
Ipv4Address m_destination;
uint8_t m_protocol;
bool m_calcChecksum;
bool m_goodChecksum;
};

8
src/internet-stack/udp-l4-protocol.cc
View File

@@ -163,7 +163,6 @@ UdpL4Protocol::Receive(Ptr<Packet> packet,
udpHeader.EnableChecksums();
}
udpHeader.SetPayloadSize (packet->GetSize () - udpHeader.GetSerializedSize ());
udpHeader.InitializeChecksum (source, destination, PROT_NUMBER);
packet->RemoveHeader (udpHeader);
@@ -195,13 +194,12 @@ UdpL4Protocol::Send (Ptr<Packet> packet,
if(m_calcChecksum)
{
udpHeader.EnableChecksums();
udpHeader.InitializeChecksum (saddr,
daddr,
PROT_NUMBER);
}
udpHeader.SetDestinationPort (dport);
udpHeader.SetSourcePort (sport);
udpHeader.SetPayloadSize (packet->GetSize ());
udpHeader.InitializeChecksum (saddr,
daddr,
PROT_NUMBER);
packet->AddHeader (udpHeader);