From 0e9a709560dbcfbace8bf4019dc5298619235891 Mon Sep 17 00:00:00 2001 From: Peter Dawson Date: Fri, 26 May 2017 06:35:18 +1000 Subject: ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets 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 90427ef5d2a4 ("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: 90427ef5d2a4 ("ipv6: fix flow labels when the traffic class is non-0") Signed-off-by: Peter Dawson Signed-off-by: David S. Miller --- net/ipv6/ip6_gre.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'net/ipv6/ip6_gre.c') diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 8d128ba79b66..0c5b4caa1949 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -537,11 +537,10 @@ static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev) memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); - dsfield = ipv4_get_dsfield(iph); - if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) - fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) - & IPV6_TCLASS_MASK; + dsfield = ipv4_get_dsfield(iph); + else + dsfield = ip6_tclass(t->parms.flowinfo); if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) fl6.flowi6_mark = skb->mark; else @@ -598,9 +597,11 @@ static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev) memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); - dsfield = ipv6_get_dsfield(ipv6h); if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) - fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); + dsfield = ipv6_get_dsfield(ipv6h); + else + dsfield = ip6_tclass(t->parms.flowinfo); + if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) fl6.flowlabel |= ip6_flowlabel(ipv6h); if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) -- cgit v1.2.3