diff options
Diffstat (limited to 'pkg/tcpip/header/tcp.go')
| -rw-r--r-- | pkg/tcpip/header/tcp.go | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/pkg/tcpip/header/tcp.go b/pkg/tcpip/header/tcp.go index 8dabe3354..a75e51a28 100644 --- a/pkg/tcpip/header/tcp.go +++ b/pkg/tcpip/header/tcp.go @@ -390,6 +390,35 @@ func (b TCP) EncodePartial(partialChecksum, length uint16, seqnum, acknum uint32 b.SetChecksum(^checksum) } +// SetSourcePortWithChecksumUpdate implements ChecksummableTransport. +func (b TCP) SetSourcePortWithChecksumUpdate(new uint16) { + old := b.SourcePort() + b.SetSourcePort(new) + b.SetChecksum(^checksumUpdate2ByteAlignedUint16(^b.Checksum(), old, new)) +} + +// SetDestinationPortWithChecksumUpdate implements ChecksummableTransport. +func (b TCP) SetDestinationPortWithChecksumUpdate(new uint16) { + old := b.DestinationPort() + b.SetDestinationPort(new) + b.SetChecksum(^checksumUpdate2ByteAlignedUint16(^b.Checksum(), old, new)) +} + +// UpdateChecksumPseudoHeaderAddress implements ChecksummableTransport. +func (b TCP) UpdateChecksumPseudoHeaderAddress(old, new tcpip.Address, fullChecksum bool) { + xsum := b.Checksum() + if fullChecksum { + xsum = ^xsum + } + + xsum = checksumUpdate2ByteAlignedAddress(xsum, old, new) + if fullChecksum { + xsum = ^xsum + } + + b.SetChecksum(xsum) +} + // ParseSynOptions parses the options received in a SYN segment and returns the // relevant ones. opts should point to the option part of the TCP header. func ParseSynOptions(opts []byte, isAck bool) TCPSynOptions { |