Jiri mentioned that flowi6_tos of struct flowi6 is never used/read anywhere. In fact, rest of the kernel uses the flowi6's flowlabel, where the traffic class _and_ the flowlabel (aka flowinfo) is encoded.
For example, for policy routing, fib6_rule_match() uses ip6_tclass() that is applied on the flowlabel member for matching on tclass. Similar fix is needed for geneve, where flowi6_tos is set as well. Installing a v6 blackhole rule that f.e. matches on tos is now working with vxlan. Fixes: 1400615d64cf ("vxlan: allow setting ipv6 traffic class") Reported-by: Jiri Benc <jb...@redhat.com> Signed-off-by: Daniel Borkmann <dan...@iogearbox.net> --- drivers/net/vxlan.c | 3 +-- include/net/ipv6.h | 6 ++++++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 800106a7..7bfcb9a62a 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1810,10 +1810,9 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan, memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_oif = oif; - fl6.flowi6_tos = RT_TOS(tos); fl6.daddr = *daddr; fl6.saddr = vxlan->cfg.saddr.sin6.sin6_addr; - fl6.flowlabel = label; + fl6.flowlabel = ip6_make_flowinfo(RT_TOS(tos), label); fl6.flowi6_mark = skb->mark; fl6.flowi6_proto = IPPROTO_UDP; diff --git a/include/net/ipv6.h b/include/net/ipv6.h index f3c9857..d0aeb97 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -835,6 +835,12 @@ static inline u8 ip6_tclass(__be32 flowinfo) { return ntohl(flowinfo & IPV6_TCLASS_MASK) >> IPV6_TCLASS_SHIFT; } + +static inline __be32 ip6_make_flowinfo(unsigned int tclass, __be32 flowlabel) +{ + return htonl(tclass << IPV6_TCLASS_SHIFT) | flowlabel; +} + /* * Prototypes exported by ipv6 */ -- 1.9.3