diff mbox series

[2/3] ipv6: ignore dst hint for multipath routes

Message ID 20230819114825.30867-3-sriram.yagnaraman@est.tech
State Superseded
Headers show
Series Avoid TCP resets when using ECMP for load-balancing between multiple servers. | expand

Commit Message

Sriram Yagnaraman Aug. 19, 2023, 11:48 a.m. UTC 
Route hints when the next hop is part of a multipath group causes
packets in the same receive batch to the same next hop irrespective of
multipath hash of the packet. So, do not extract route hint for packets
whose destination is part of multipath group.

Fixes: 197dbf24e360 ("ipv6: introduce and uses route look hints for list input.")

Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@est.tech>
---
 include/linux/ipv6.h | 1 +
 net/ipv6/ip6_input.c | 3 ++-
 net/ipv6/route.c     | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 839247a4f48e..fe3492a67b35 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 d94041bb4287..b8378814532c 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 56a55585eb79..4631e03c84b4 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -424,6 +424,8 @@  void fib6_select_path(const struct net *net, struct fib6_result *res,
 	if (match->nh && have_oif_match && res->nh)
 		return;
 
+	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.
 	 */