CVS commit: src/sys/net

["Ryota Ozaki" <ozaki-r%netbsd.org@localhost>]

Module Name:    src
Committed By:   ozaki-r
Date:           Wed Nov 30 06:02:37 UTC 2022

Modified Files:
        src/sys/net: bpf.c

Log Message:
bpf: support sending packets on loopback interfaces

Previously sending packets on a loopback interface via bpf failed
because the packets are treated as AF_UNSPEC by bpf and the loopback
interface couldn't handle such packets.

This fix enables user programs to prepend a protocol family (AF_INET or
AF_INET6) to a payload.  bpf interprets it and treats a packet as so,
not just AF_UNSPEC.  The protocol family is encoded as 4 bytes, host byte
order as per DLT_NULL in the specification(*).

(*) https://www.tcpdump.org/linktypes.html

Proposed on tech-net and tech-kern


To generate a diff of this commit:
cvs rdiff -u -r1.248 -r1.249 src/sys/net/bpf.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.