diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp')
| -rw-r--r-- | pkg/tcpip/transport/tcp/segment.go | 29 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/tcp_test.go | 4 |
2 files changed, 12 insertions, 21 deletions
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go index 7712ce652..40461fd31 100644 --- a/pkg/tcpip/transport/tcp/segment.go +++ b/pkg/tcpip/transport/tcp/segment.go @@ -144,11 +144,7 @@ func (s *segment) logicalLen() seqnum.Size { // TCP checksum and stores the checksum and result of checksum verification in // the csum and csumValid fields of the segment. func (s *segment) parse() bool { - h, ok := s.data.PullUp(header.TCPMinimumSize) - if !ok { - return false - } - hdr := header.TCP(h) + h := header.TCP(s.data.First()) // h is the header followed by the payload. We check that the offset to // the data respects the following constraints: @@ -160,16 +156,12 @@ func (s *segment) parse() bool { // N.B. The segment has already been validated as having at least the // minimum TCP size before reaching here, so it's safe to read the // fields. - offset := int(hdr.DataOffset()) - if offset < header.TCPMinimumSize { - return false - } - hdrWithOpts, ok := s.data.PullUp(offset) - if !ok { + offset := int(h.DataOffset()) + if offset < header.TCPMinimumSize || offset > len(h) { return false } - s.options = []byte(hdrWithOpts[header.TCPMinimumSize:]) + s.options = []byte(h[header.TCPMinimumSize:offset]) s.parsedOptions = header.ParseTCPOptions(s.options) // Query the link capabilities to decide if checksum validation is @@ -181,19 +173,18 @@ func (s *segment) parse() bool { s.data.TrimFront(offset) } if verifyChecksum { - hdr = header.TCP(hdrWithOpts) - s.csum = hdr.Checksum() + s.csum = h.Checksum() xsum := s.route.PseudoHeaderChecksum(ProtocolNumber, uint16(s.data.Size())) - xsum = hdr.CalculateChecksum(xsum) + xsum = h.CalculateChecksum(xsum) s.data.TrimFront(offset) xsum = header.ChecksumVV(s.data, xsum) s.csumValid = xsum == 0xffff } - s.sequenceNumber = seqnum.Value(hdr.SequenceNumber()) - s.ackNumber = seqnum.Value(hdr.AckNumber()) - s.flags = hdr.Flags() - s.window = seqnum.Size(hdr.WindowSize()) + s.sequenceNumber = seqnum.Value(h.SequenceNumber()) + s.ackNumber = seqnum.Value(h.AckNumber()) + s.flags = h.Flags() + s.window = seqnum.Size(h.WindowSize()) return true } diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go index 286c66cf5..ab1014c7f 100644 --- a/pkg/tcpip/transport/tcp/tcp_test.go +++ b/pkg/tcpip/transport/tcp/tcp_test.go @@ -3548,7 +3548,7 @@ func TestReceivedInvalidSegmentCountIncrement(t *testing.T) { AckNum: c.IRS.Add(1), RcvWnd: 30000, }) - tcpbuf := vv.ToView()[header.IPv4MinimumSize:] + tcpbuf := vv.First()[header.IPv4MinimumSize:] tcpbuf[header.TCPDataOffset] = ((header.TCPMinimumSize - 1) / 4) << 4 c.SendSegment(vv) @@ -3575,7 +3575,7 @@ func TestReceivedIncorrectChecksumIncrement(t *testing.T) { AckNum: c.IRS.Add(1), RcvWnd: 30000, }) - tcpbuf := vv.ToView()[header.IPv4MinimumSize:] + tcpbuf := vv.First()[header.IPv4MinimumSize:] // Overwrite a byte in the payload which should cause checksum // verification to fail. tcpbuf[(tcpbuf[header.TCPDataOffset]>>4)*4] = 0x4 |