This is a note to let you know that I've just added the patch titled
ipv6: ignore dst hint for multipath routes
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ipv6-ignore-dst-hint-for-multipath-routes.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 33d439c8bac978b68b474affba2854198e92b446
Author: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
Date: Thu Aug 31 10:03:31 2023 +0200
ipv6: ignore dst hint for multipath routes
[ Upstream commit 8423be8926aa82cd2e28bba5cc96ccb72c7ce6be ]
Route hints when the nexthop is part of a multipath group causes packets
in the same receive batch to be sent to the same nexthop irrespective of
the multipath hash of the packet. So, do not extract route hint for
packets whose destination is part of a multipath group.
A new SKB flag IP6SKB_MULTIPATH is introduced for this purpose, set the
flag when route is looked up in fib6_select_path() and use it in
ip6_can_use_hint() to check for the existence of the flag.
Fixes: 197dbf24e360 ("ipv6: introduce and uses route look hints for list input.")
Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
Reviewed-by: Ido Schimmel <idosch@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 37dfdcfcdd542..15d7529ac9534 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -146,6 +146,7 @@ struct inet6_skb_parm {
#define IP6SKB_JUMBOGRAM 128
#define IP6SKB_SEG6 256
#define IP6SKB_FAKEJUMBO 512
+#define IP6SKB_MULTIPATH 1024
};
#if defined(CONFIG_NET_L3_MASTER_DEV)
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index d94041bb42872..b8378814532ce 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -99,7 +99,8 @@ static bool ip6_can_use_hint(const struct sk_buff *skb,
static struct sk_buff *ip6_extract_route_hint(const struct net *net,
struct sk_buff *skb)
{
- if (fib6_routes_require_src(net) || fib6_has_custom_rules(net))
+ if (fib6_routes_require_src(net) || fib6_has_custom_rules(net) ||
+ IP6CB(skb)->flags & IP6SKB_MULTIPATH)
return NULL;
return skb;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 960ab43a49c46..93957b20fccce 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -425,6 +425,9 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
if (match->nh && have_oif_match && res->nh)
return;
+ if (skb)
+ IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
+
/* We might have already computed the hash for ICMPv6 errors. In such
* case it will always be non-zero. Otherwise now is the time to do it.
*/
