soypat/lneto
1
0
Fork 0
mirror of https://github.com/soypat/lneto.git synced 2026-09-07 23:39:04 +00:00
Code Issues Packages Projects Releases 1 Wiki Activity

Tcp rst handling (#40)

Browse Source 
* claude suggests a way forward

* add timing to capture printer

* add pcap.Flags

* fix ICMP CRC calculation and add test

* bugfix: still send data on half-close state(close-wait)

* fix pcap test
This commit is contained in:
Pat Whittingslow
2026-02-23 13:50:13 +01:00
committed by GitHub
parent 08423d0dba
commit 7d323aae19
10 changed files with 386 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files
internet/pcap/capture.go
+21 -14
View File
@@ -603,10 +603,21 @@ type FrameField struct {
FrameBitOffset int
BitLength int
SubFields []FrameField
RightAligned bool
Legacy bool
Flags Flags
}
// Flags stores frame field interpretation bits.
type Flags uint32
const (
FlagRightAligned Flags = 1 << iota
FlagLegacy
)
func (ff Flags) IsLegacy() bool { return ff&FlagLegacy != 0 }
func (ff Flags) IsRightAligned() bool { return ff&FlagRightAligned != 0 }
type Frame struct {
Protocol any
Fields []FrameField
@@ -653,7 +664,7 @@ func (frm Frame) FieldAsUint(fieldIdx int, pkt []byte) (uint64, error) {
return badUint64, errors.New("invalid field index")
}
field := frm.Fields[fieldIdx]
return fieldAsUint(pkt, frm.PacketBitOffset+field.FrameBitOffset, field.BitLength, field.RightAligned)
return fieldAsUint(pkt, frm.PacketBitOffset+field.FrameBitOffset, field.BitLength, field.Flags.IsRightAligned())
}
// AppendField appends the binary on-the-wire representation of the field and aligns the field so it starts at the first bit of appended data.
@@ -662,7 +673,7 @@ func (frm Frame) AppendField(dst []byte, fieldIdx int, pkt []byte) ([]byte, erro
return dst, errors.New("invalid field index")
}
field := frm.Fields[fieldIdx]
return appendField(dst, pkt, frm.PacketBitOffset+field.FrameBitOffset, field.BitLength, field.RightAligned)
return appendField(dst, pkt, frm.PacketBitOffset+field.FrameBitOffset, field.BitLength, field.Flags.IsRightAligned())
}
func fieldAsUint(pkt []byte, fieldBitStart, bitlen int, rightAligned bool) (uint64, error) {
@@ -860,14 +871,14 @@ var baseIPv6Fields = [...]FrameField{
Class: FieldClassFlags,
FrameBitOffset: 4,
BitLength: 1 * octet,
RightAligned: true,
Flags: FlagRightAligned,
},
{
Name: "Flow Label",
Class: FieldClassID,
FrameBitOffset: 12,
BitLength: 20,
RightAligned: true,
Flags: FlagRightAligned,
},
{
Name: "Total Length",
@@ -928,11 +939,6 @@ var baseIPv4Fields = [...]FrameField{
FrameBitOffset: 4 * octet,
BitLength: 2 * octet,
},
{
Class: FieldClassID,
FrameBitOffset: 4 * octet,
BitLength: 2 * octet,
},
{
Class: FieldClassFlags,
FrameBitOffset: 6 * octet,
@@ -1000,7 +1006,7 @@ var baseTCPFields = [...]FrameField{
Class: FieldClassFlags,
FrameBitOffset: 12*octet + 4,
BitLength: 12,
RightAligned: true,
Flags: FlagRightAligned,
},
{
Name: "Window",
@@ -1018,6 +1024,7 @@ var baseTCPFields = [...]FrameField{
Class: 0,
FrameBitOffset: 18 * octet,
BitLength: 2 * octet,
Flags: FlagLegacy,
},
}
@@ -1199,14 +1206,14 @@ var baseDHCPv4Fields = [...]FrameField{
Class: FieldClassBinaryText,
FrameBitOffset: (28 + 6) * octet, // Part of Client Hardware Address(16 bytes) but unused.
BitLength: 10 * octet,
Legacy: true,
Flags: FlagLegacy,
},
{
Name: "BOOTP",
Class: FieldClassBinaryText,
FrameBitOffset: (28 + 16) * octet,
BitLength: (dhcpv4.OptionsOffset - (28 + 16)) * octet,
Legacy: true,
Flags: FlagLegacy,
},
}