CVS commit: src/sys/net/npf

["Maxime Villard" <maxv%netbsd.org@localhost>]

Module Name:    src
Committed By:   maxv
Date:           Fri Aug 31 14:16:07 UTC 2018

Modified Files:
        src/sys/net/npf: npf_ext_normalize.c npf_impl.h npf_inet.c

Log Message:
Introduce npf_set_mss(). When the MSS is not 16bit-aligned, it sets:

        0      8           16          24    32
        +------+-----------+-----------+------+
        | data | MSS (low) | MSS (hig) | data |
        +------+-----------+-----------+------+
        ^                  ^
        old[0]             old[1]

And sets new[0,1] accordingly with the new value. The MSS-clamping code
then adjusts twice the checksum on a 16bit boundary:

        from old[0] to new[0]
        from old[1] to new[1]

Fixes PR/53479, opened by myself. Tested with wireshark and kASan.


To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/sys/net/npf/npf_ext_normalize.c
cvs rdiff -u -r1.70 -r1.71 src/sys/net/npf/npf_impl.h
cvs rdiff -u -r1.50 -r1.51 src/sys/net/npf/npf_inet.c

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