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author | Lorenz Bauer <lmb@isovalent.com> | 2023-07-20 17:30:05 +0200 |
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committer | Martin KaFai Lau <martin.lau@kernel.org> | 2023-07-25 13:51:43 -0700 |
commit | f0ea27e7bfe1c34e1f451a63eb68faa1d4c3a86d (patch) | |
tree | d50c7e7bcfcda04a65cadc9616b4ba027bb7a853 /net | |
parent | 7b2b20125f1e9ec49e3d13c41264afef70e70463 (diff) | |
download | linux-stable-f0ea27e7bfe1c34e1f451a63eb68faa1d4c3a86d.tar.gz linux-stable-f0ea27e7bfe1c34e1f451a63eb68faa1d4c3a86d.tar.bz2 linux-stable-f0ea27e7bfe1c34e1f451a63eb68faa1d4c3a86d.zip |
udp: re-score reuseport groups when connected sockets are present
Contrary to TCP, UDP reuseport groups can contain TCP_ESTABLISHED
sockets. To support these properly we remember whether a group has
a connected socket and skip the fast reuseport early-return. In
effect we continue scoring all reuseport sockets and then choose the
one with the highest score.
The current code fails to re-calculate the score for the result of
lookup_reuseport. According to Kuniyuki Iwashima:
1) SO_INCOMING_CPU is set
-> selected sk might have +1 score
2) BPF prog returns ESTABLISHED and/or SO_INCOMING_CPU sk
-> selected sk will have more than 8
Using the old score could trigger more lookups depending on the
order that sockets are created.
sk -> sk (SO_INCOMING_CPU) -> sk (ESTABLISHED)
| |
`-> select the next SO_INCOMING_CPU sk
|
`-> select itself (We should save this lookup)
Fixes: efc6b6f6c311 ("udp: Improve load balancing for SO_REUSEPORT.")
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-1-7021b683cdae@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'net')
-rw-r--r-- | net/ipv4/udp.c | 20 | ||||
-rw-r--r-- | net/ipv6/udp.c | 19 |
2 files changed, 29 insertions, 10 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 8c3ebd95f5b9..0d81339bda2f 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -451,14 +451,24 @@ static struct sock *udp4_lib_lookup2(struct net *net, score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif); if (score > badness) { - result = lookup_reuseport(net, sk, skb, - saddr, sport, daddr, hnum); + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + /* Fall back to scoring if group has connections */ - if (result && !reuseport_has_conns(sk)) + if (!reuseport_has_conns(sk)) return result; - result = result ? : sk; - badness = score; + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(result, net, saddr, sport, + daddr, hnum, dif, sdif); + } } return result; diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 95c75d8f73d5..556d74a7d7ab 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -194,14 +194,23 @@ static struct sock *udp6_lib_lookup2(struct net *net, score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif); if (score > badness) { - result = lookup_reuseport(net, sk, skb, - saddr, sport, daddr, hnum); + badness = score; + result = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); + if (!result) { + result = sk; + continue; + } + /* Fall back to scoring if group has connections */ - if (result && !reuseport_has_conns(sk)) + if (!reuseport_has_conns(sk)) return result; - result = result ? : sk; - badness = score; + /* Reuseport logic returned an error, keep original score. */ + if (IS_ERR(result)) + continue; + + badness = compute_score(sk, net, saddr, sport, + daddr, hnum, dif, sdif); } } return result; |