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authorWillem de Bruijn <willemb@google.com>2019-09-12 21:16:39 -0400
committerDavid S. Miller <davem@davemloft.net>2019-09-16 09:02:18 +0200
commitacdcecc61285faed359f1a3568c32089cc3a8329 (patch)
treea399174289b4b976c7831f1eda392d0feb8bd51f /net
parent05a82481a3024b94db00b8c816bb3d526b5209e0 (diff)
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udp: correct reuseport selection with connected sockets
UDP reuseport groups can hold a mix unconnected and connected sockets. Ensure that connections only receive all traffic to their 4-tuple. Fast reuseport returns on the first reuseport match on the assumption that all matches are equal. Only if connections are present, return to the previous behavior of scoring all sockets. Record if connections are present and if so (1) treat such connected sockets as an independent match from the group, (2) only return 2-tuple matches from reuseport and (3) do not return on the first 2-tuple reuseport match to allow for a higher scoring match later. New field has_conns is set without locks. No other fields in the bitmap are modified at runtime and the field is only ever set unconditionally, so an RMW cannot miss a change. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Link: http://lkml.kernel.org/r/CA+FuTSfRP09aJNYRt04SS6qj22ViiOEWaWmLAwX0psk8-PGNxw@mail.gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Craig Gallek <kraig@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock_reuseport.c15
-rw-r--r--net/ipv4/datagram.c2
-rw-r--r--net/ipv4/udp.c5
-rw-r--r--net/ipv6/datagram.c2
-rw-r--r--net/ipv6/udp.c5
5 files changed, 23 insertions, 6 deletions
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index 9408f9264d05..f3ceec93f392 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -295,8 +295,19 @@ struct sock *reuseport_select_sock(struct sock *sk,
select_by_hash:
/* no bpf or invalid bpf result: fall back to hash usage */
- if (!sk2)
- sk2 = reuse->socks[reciprocal_scale(hash, socks)];
+ if (!sk2) {
+ int i, j;
+
+ i = j = reciprocal_scale(hash, socks);
+ while (reuse->socks[i]->sk_state == TCP_ESTABLISHED) {
+ i++;
+ if (i >= reuse->num_socks)
+ i = 0;
+ if (i == j)
+ goto out;
+ }
+ sk2 = reuse->socks[i];
+ }
}
out:
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index 7bd29e694603..9a0fe0c2fa02 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -15,6 +15,7 @@
#include <net/sock.h>
#include <net/route.h>
#include <net/tcp_states.h>
+#include <net/sock_reuseport.h>
int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
@@ -69,6 +70,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
}
inet->inet_daddr = fl4->daddr;
inet->inet_dport = usin->sin_port;
+ reuseport_has_conns(sk, true);
sk->sk_state = TCP_ESTABLISHED;
sk_set_txhash(sk);
inet->inet_id = jiffies;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d88821c794fb..16486c8b708b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -423,12 +423,13 @@ static struct sock *udp4_lib_lookup2(struct net *net,
score = compute_score(sk, net, saddr, sport,
daddr, hnum, dif, sdif);
if (score > badness) {
- if (sk->sk_reuseport) {
+ if (sk->sk_reuseport &&
+ sk->sk_state != TCP_ESTABLISHED) {
hash = udp_ehashfn(net, daddr, hnum,
saddr, sport);
result = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr));
- if (result)
+ if (result && !reuseport_has_conns(sk, false))
return result;
}
badness = score;
diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 9ab897ded4df..96f939248d2f 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -27,6 +27,7 @@
#include <net/ip6_route.h>
#include <net/tcp_states.h>
#include <net/dsfield.h>
+#include <net/sock_reuseport.h>
#include <linux/errqueue.h>
#include <linux/uaccess.h>
@@ -254,6 +255,7 @@ ipv4_connected:
goto out;
}
+ reuseport_has_conns(sk, true);
sk->sk_state = TCP_ESTABLISHED;
sk_set_txhash(sk);
out:
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 827fe7385078..5995fdc99d3f 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -158,13 +158,14 @@ static struct sock *udp6_lib_lookup2(struct net *net,
score = compute_score(sk, net, saddr, sport,
daddr, hnum, dif, sdif);
if (score > badness) {
- if (sk->sk_reuseport) {
+ if (sk->sk_reuseport &&
+ sk->sk_state != TCP_ESTABLISHED) {
hash = udp6_ehashfn(net, daddr, hnum,
saddr, sport);
result = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr));
- if (result)
+ if (result && !reuseport_has_conns(sk, false))
return result;
}
result = sk;