From: Jakub Sitnicki <jakub@cloudflare.com>
Date: Fri, 17 Jul 2020 12:35:30 +0200
Subject: udp6: Extract helper for selecting socket from reuseport group
Patch-mainline: v5.9-rc1
Git-commit: 2a08748cd384cdfb8e1222bd3645a8d1d36e6a5d
References: bsc#1177028
Prepare for calling into reuseport from __udp6_lib_lookup as well.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200717103536.397595-10-jakub@cloudflare.com
Acked-by: Gary Lin <glin@suse.com>
NOTE from Gary:
The original commit conflicts with a 5.8-rc7 fix(*1). Follow the merge commit
to modify this patch.
(*1) efc6b6f6c3113 udp: Improve load balancing for SO_REUSEPORT.
(*2) a57066b1a0197 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
---
net/ipv6/udp.c | 44 ++++++++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 16 deletions(-)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -141,6 +141,27 @@ static int compute_score(struct sock *sk
return score;
}
+static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
+ struct sk_buff *skb,
+ const struct in6_addr *saddr,
+ __be16 sport,
+ const struct in6_addr *daddr,
+ unsigned int hnum)
+{
+ struct sock *reuse_sk = NULL;
+ u32 hash;
+
+ if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) {
+ hash = udp6_ehashfn(net, daddr, hnum, saddr, sport);
+ reuse_sk = reuseport_select_sock(sk, hash, skb,
+ sizeof(struct udphdr));
+ /* Fall back to scoring if group has connections */
+ if (reuseport_has_conns(sk, false))
+ return NULL;
+ }
+ return reuse_sk;
+}
+
/* called with rcu_read_lock() */
static struct sock *udp6_lib_lookup2(struct net *net,
const struct in6_addr *saddr, __be16 sport,
@@ -148,9 +169,8 @@ static struct sock *udp6_lib_lookup2(str
int dif, int sdif, struct udp_hslot *hslot2,
struct sk_buff *skb)
{
- struct sock *sk, *result, *reuseport_result;
+ struct sock *sk, *result;
int score, badness;
- u32 hash = 0;
result = NULL;
badness = -1;
@@ -158,20 +178,12 @@ static struct sock *udp6_lib_lookup2(str
score = compute_score(sk, net, saddr, sport,
daddr, hnum, dif, sdif);
if (score > badness) {
- reuseport_result = NULL;
-
- if (sk->sk_reuseport &&
- sk->sk_state != TCP_ESTABLISHED) {
- hash = udp6_ehashfn(net, daddr, hnum,
- saddr, sport);
-
- reuseport_result = reuseport_select_sock(sk, hash, skb,
- sizeof(struct udphdr));
- if (reuseport_result && !reuseport_has_conns(sk, false))
- return reuseport_result;
- }
-
- result = reuseport_result ? : sk;
+ result = lookup_reuseport(net, sk, skb,
+ saddr, sport, daddr, hnum);
+ /* Fall back to scoring if group has connections */
+ if (result && !reuseport_has_conns(sk, false))
+ return result;
+ result = result ? : sk;
badness = score;
}
}