This is a note to let you know that I've just added the patch titled
ipv4: ignore dst hint for multipath routes
to the 5.15-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:
ipv4-ignore-dst-hint-for-multipath-routes.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 617babff54c42d85e512672f4b901313d99919cf
Author: Sriram Yagnaraman <sriram.yagnaraman@xxxxxxxx>
Date: Thu Aug 31 10:03:30 2023 +0200
ipv4: ignore dst hint for multipath routes
[ Upstream commit 6ac66cb03ae306c2e288a9be18226310529f5b25 ]
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 IPSKB_MULTIPATH is introduced for this purpose, set the
flag when route is looked up in ip_mkroute_input() and use it in
ip_extract_route_hint() to check for the existence of the flag.
Fixes: 02b24941619f ("ipv4: use dst hint for ipv4 list receive")
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/net/ip.h b/include/net/ip.h
index fc05e016be060..e1a93c3391090 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -56,6 +56,7 @@ struct inet_skb_parm {
#define IPSKB_FRAG_PMTU BIT(6)
#define IPSKB_L3SLAVE BIT(7)
#define IPSKB_NOPOLICY BIT(8)
+#define IPSKB_MULTIPATH BIT(9)
u16 frag_max_size;
};
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 124bf8fdf924a..5d0bc0dbdb4d9 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -581,7 +581,8 @@ static void ip_sublist_rcv_finish(struct list_head *head)
static struct sk_buff *ip_extract_route_hint(const struct net *net,
struct sk_buff *skb, int rt_type)
{
- if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST)
+ if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST ||
+ IPCB(skb)->flags & IPSKB_MULTIPATH)
return NULL;
return skb;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ca59b61fd3a31..bc6240d327a8f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2151,6 +2151,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
int h = fib_multipath_hash(res->fi->fib_net, NULL, skb, hkeys);
fib_select_multipath(res, h);
+ IPCB(skb)->flags |= IPSKB_MULTIPATH;
}
#endif
