diff options
Diffstat (limited to 'test/packetimpact/testbench/layers.go')
| -rw-r--r-- | test/packetimpact/testbench/layers.go | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go index fc45d2085..2fb7ca9ba 100644 --- a/test/packetimpact/testbench/layers.go +++ b/test/packetimpact/testbench/layers.go @@ -286,6 +286,7 @@ type IPv4 struct { Checksum *uint16 SrcAddr *tcpip.Address DstAddr *tcpip.Address + Options *header.IPv4Options } func (l *IPv4) String() string { @@ -294,10 +295,22 @@ func (l *IPv4) String() string { // ToBytes implements Layer.ToBytes. func (l *IPv4) ToBytes() ([]byte, error) { - b := make([]byte, header.IPv4MinimumSize) + // An IPv4 header is variable length depending on the size of the Options. + hdrLen := header.IPv4MinimumSize + if l.Options != nil { + hdrLen += l.Options.AllocationSize() + if hdrLen > header.IPv4MaximumHeaderSize { + // While ToBytes can be called on packets that were received as well + // as packets locally generated, it is physically impossible for a + // received packet to overflow this value so any such failure must + // be the result of a local programming error and not remotely + // triggered. A panic is therefore appropriate. + panic(fmt.Sprintf("IPv4 Options %d bytes, Max %d", len(*l.Options), header.IPv4MaximumOptionsSize)) + } + } + b := make([]byte, hdrLen) h := header.IPv4(b) fields := &header.IPv4Fields{ - IHL: 20, TOS: 0, TotalLength: 0, ID: 0, @@ -308,6 +321,11 @@ func (l *IPv4) ToBytes() ([]byte, error) { Checksum: 0, SrcAddr: tcpip.Address(""), DstAddr: tcpip.Address(""), + Options: nil, + } + // Leave an empty options slice as nil. + if hdrLen > header.IPv4MinimumSize { + fields.Options = *l.Options } if l.TOS != nil { fields.TOS = *l.TOS @@ -362,6 +380,11 @@ func (l *IPv4) ToBytes() ([]byte, error) { if l.Checksum == nil { h.SetChecksum(^h.CalculateChecksum()) } + // Encode cannot set this incorrectly so we need to overwrite what it wrote + // in order to test handling of a bad IHL value. + if l.IHL != nil { + h.SetHeaderLength(*l.IHL) + } return h, nil } @@ -377,8 +400,8 @@ func Uint8(v uint8) *uint8 { return &v } -// Address is a helper routine that allocates a new tcpip.Address value to store -// v and returns a pointer to it. +// Address is a helper routine that allocates a new tcpip.Address value to +// store v and returns a pointer to it. func Address(v tcpip.Address) *tcpip.Address { return &v } @@ -387,6 +410,13 @@ func Address(v tcpip.Address) *tcpip.Address { // continues parsing further encapsulations. func parseIPv4(b []byte) (Layer, layerParser) { h := header.IPv4(b) + hdrLen := h.HeaderLength() + // Even if there are no options, we set an empty options field instead of nil + // so that the decision to compare is up to the caller of that comparison. + var options header.IPv4Options + if hdrLen > header.IPv4MinimumSize { + options = append(options, h.Options()...) + } tos, _ := h.TOS() ipv4 := IPv4{ IHL: Uint8(h.HeaderLength()), @@ -400,6 +430,7 @@ func parseIPv4(b []byte) (Layer, layerParser) { Checksum: Uint16(h.Checksum()), SrcAddr: Address(h.SourceAddress()), DstAddr: Address(h.DestinationAddress()), + Options: &options, } var nextParser layerParser // If it is a fragment, don't treat it as having a transport protocol. |