• Peter Dawson's avatar
    ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets · 0e9a7095
    Peter Dawson authored
    This fix addresses two problems in the way the DSCP field is formulated
     on the encapsulating header of IPv6 tunnels.
    Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195661
    
    1) The IPv6 tunneling code was manipulating the DSCP field of the
     encapsulating packet using the 32b flowlabel. Since the flowlabel is
     only the lower 20b it was incorrect to assume that the upper 12b
     containing the DSCP and ECN fields would remain intact when formulating
     the encapsulating header. This fix handles the 'inherit' and
     'fixed-value' DSCP cases explicitly using the extant dsfield u8 variable.
    
    2) The use of INET_ECN_encapsulate(0, dsfield) in ip6_tnl_xmit was
     incorrect and resulted in the DSCP value always being set to 0.
    
    Commit 90427ef5 ("ipv6: fix flow labels when the traffic class
     is non-0") caused the regression by masking out the flowlabel
     which exposed the incorrect handling of the DSCP portion of the
     flowlabel in ip6_tunnel and ip6_gre.
    
    Fixes: 90427ef5 ("ipv6: fix flow labels when the traffic class is non-0")
    Signed-off-by: default avatarPeter Dawson <peter.a.dawson@boeing.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    0e9a7095
ip6_gre.c 38.7 KB