tree 72253181555e3c9a74b87e074da9b54c645c4c5b
parent 16b79f2e4e95ea23b2bf9903c9809ff7b013ce85
author Mikio Hara <mikioh.public.networking@gmail.com> 1542357465 +0900
committer Mikio Hara <mikioh.public.networking@gmail.com> 1552182029 +0000

ipv4: fix error values on header manipulation

This change makes header manipulation methods and functions return a nil
header error if the receiver or wire header is nil, a header too short
error if the header length field value of receiver or wire header is
short, and a extension header error if the wire extnsion header is
short.

Also replaces syscall.EWINDOWS or syscall.EPLAN9 with more descriptive,
platform independent error values.

Change-Id: I923fb60b1d68857cffc9df20f3f6cb2babbcdb1f
Reviewed-on: https://go-review.googlesource.com/c/net/+/129136
Reviewed-by: Matt Layher <mdlayher@gmail.com>