macula_route_packet_ipv6 (macula v4.0.0)

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Minimal IPv6 header parser for macula-net routing.

We only ever care about source + destination addresses (the routing layer is dst-based; src is preserved for ICMPv6 error replies). Per RFC 8200 the IPv6 fixed header is 40 bytes:

     bytes 0..1   version (4) + traffic class (8) + flow label start
     bytes 2..3   flow label rest
     bytes 4..5   payload length
     byte 6       next header
     byte 7       hop limit
     bytes 8..23  source address (128 bits)
     bytes 24..39 destination address (128 bits)

Summary

Types

address/0
header/0

Functions

dst(_)

Quick extract of destination address (16 bytes).

parse_header(_)

Parse the 40-byte IPv6 fixed header. Returns the full header map. Raises badarg if the input is shorter than 40 bytes or version != 6.

src(_)

Quick extract of source address (16 bytes), without building the full header map. Useful on the hot path.

Types

address/0

-type address() :: <<_:128>>.

header/0

-type header() ::
          #{version := 6,
            traffic_class := non_neg_integer(),
            flow_label := non_neg_integer(),
            payload_len := non_neg_integer(),
            next_header := non_neg_integer(),
            hop_limit := non_neg_integer(),
            src := address(),
            dst := address()}.

Functions

dst(_)

-spec dst(binary()) -> address().

Quick extract of destination address (16 bytes).

parse_header(_)

-spec parse_header(binary()) -> header().

Parse the 40-byte IPv6 fixed header. Returns the full header map. Raises badarg if the input is shorter than 40 bytes or version != 6.

src(_)

-spec src(binary()) -> address().

Quick extract of source address (16 bytes), without building the full header map. Useful on the hot path.