Module ethernet 

Ethernet → VLAN → IP → UDP/TCP frame dissection.

This module walks a raw captured Ethernet frame down through optional VLAN tags, the IPv4 header, and finally UDP or TCP, handing back the transport-layer payload for protocol-specific parsers to consume.

Structs

IpHeader

TcpSegment

A dissected TCP segment: ports plus payload past the header/options.

Constants

ETHERTYPE_8021AD

802.1ad “Q-in-Q” outer service tag. Frames carrying this ethertype have a second, inner 802.1Q tag before the real payload ethertype.

ETHERTYPE_8021Q

802.1Q VLAN tag (single tag).

ETHERTYPE_IP

PROTO_TCP

PROTO_UDP

Functions

extract_ip

Extracts the IPv4 header and payload from a raw Ethernet frame, transparently handling untagged, 802.1Q, and 802.1ad Q-in-Q framing.

extract_tcp

Extracts ports and payload from an IP payload whose protocol is PROTO_TCP, accounting for the variable-length TCP header (data offset field) so that TCP options don’t leak into payload.

extract_udp

Extracts (src_port, dst_port, udp_payload) from an IP payload whose protocol is PROTO_UDP.

strip_ethernet

Strips the Ethernet header (and any VLAN tags) from a raw frame, returning the IPv4 payload.