Module ipv6_shim 

IPv6 Header Compression for the FIPS IPv6 Shim (FSP Port 256)

Compresses and decompresses IPv6 headers for mesh-internal traffic. Source and destination addresses are stripped (derivable from session context), along with version and payload length. Residual fields (traffic class, flow label, next header, hop limit) are preserved.

Compressed Format (format 0x00)

[format:1][ver_tc_flow:4][next_header:1][hop_limit:1][upper_layer_payload...]

The ver_tc_flow field stores the original IPv6 bytes 0-3 verbatim (including the version nibble). On decompression, the version nibble is forced to 6, payload length is computed from the remaining data, and source/destination addresses are reconstructed from session context.

Constants

IPV6_SHIM_FORMAT_COMPRESSED

Compressed format byte for mesh-internal traffic.

Functions

compress_ipv6

Compress an IPv6 packet for the shim.

decompress_ipv6

Decompress a shim payload back to a full IPv6 packet.