[PATCH net 1/2] net: refactor bind_bucket fastreuse into helper

From: Tim Froidcoeur
Date: Thu Aug 06 2020 - 02:41:33 EST


Refactor the fastreuse update code in inet_csk_get_port into a small
helper function that can be called from other places.

Acked-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@xxxxxxxxxxxx>
---
include/net/inet_connection_sock.h | 4 ++
net/ipv4/inet_connection_sock.c | 99 ++++++++++++++++--------------
2 files changed, 58 insertions(+), 45 deletions(-)

diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index e5b388f5fa20..1d59bf55bb4d 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -316,6 +316,10 @@ int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, unsigned int optlen);

+/* update the fast reuse flag when adding a socket */
+void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
+ struct sock *sk);
+
struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);

#define TCP_PINGPONG_THRESH 3
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index afaf582a5aa9..3b46b1f6086e 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -266,7 +266,7 @@ inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *
static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
struct sock *sk)
{
- kuid_t uid = sock_i_uid(sk);
+ kuid_t uid = sock_i_uid((struct sock *)sk);

if (tb->fastreuseport <= 0)
return 0;
@@ -296,6 +296,57 @@ static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
ipv6_only_sock(sk), true, false);
}

+void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
+ struct sock *sk)
+{
+ kuid_t uid = sock_i_uid((struct sock *)sk);
+ bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
+
+ if (hlist_empty(&tb->owners)) {
+ tb->fastreuse = reuse;
+ if (sk->sk_reuseport) {
+ tb->fastreuseport = FASTREUSEPORT_ANY;
+ tb->fastuid = uid;
+ tb->fast_rcv_saddr = sk->sk_rcv_saddr;
+ tb->fast_ipv6_only = ipv6_only_sock(sk);
+ tb->fast_sk_family = sk->sk_family;
+#if IS_ENABLED(CONFIG_IPV6)
+ tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
+#endif
+ } else {
+ tb->fastreuseport = 0;
+ }
+ } else {
+ if (!reuse)
+ tb->fastreuse = 0;
+ if (sk->sk_reuseport) {
+ /* We didn't match or we don't have fastreuseport set on
+ * the tb, but we have sk_reuseport set on this socket
+ * and we know that there are no bind conflicts with
+ * this socket in this tb, so reset our tb's reuseport
+ * settings so that any subsequent sockets that match
+ * our current socket will be put on the fast path.
+ *
+ * If we reset we need to set FASTREUSEPORT_STRICT so we
+ * do extra checking for all subsequent sk_reuseport
+ * socks.
+ */
+ if (!sk_reuseport_match(tb, sk)) {
+ tb->fastreuseport = FASTREUSEPORT_STRICT;
+ tb->fastuid = uid;
+ tb->fast_rcv_saddr = sk->sk_rcv_saddr;
+ tb->fast_ipv6_only = ipv6_only_sock(sk);
+ tb->fast_sk_family = sk->sk_family;
+#if IS_ENABLED(CONFIG_IPV6)
+ tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
+#endif
+ }
+ } else {
+ tb->fastreuseport = 0;
+ }
+ }
+}
+
/* Obtain a reference to a local port for the given sock,
* if snum is zero it means select any available local port.
* We try to allocate an odd port (and leave even ports for connect())
@@ -308,7 +359,6 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
struct inet_bind_hashbucket *head;
struct net *net = sock_net(sk);
struct inet_bind_bucket *tb = NULL;
- kuid_t uid = sock_i_uid(sk);
int l3mdev;

l3mdev = inet_sk_bound_l3mdev(sk);
@@ -345,49 +395,8 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
goto fail_unlock;
}
success:
- if (hlist_empty(&tb->owners)) {
- tb->fastreuse = reuse;
- if (sk->sk_reuseport) {
- tb->fastreuseport = FASTREUSEPORT_ANY;
- tb->fastuid = uid;
- tb->fast_rcv_saddr = sk->sk_rcv_saddr;
- tb->fast_ipv6_only = ipv6_only_sock(sk);
- tb->fast_sk_family = sk->sk_family;
-#if IS_ENABLED(CONFIG_IPV6)
- tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
-#endif
- } else {
- tb->fastreuseport = 0;
- }
- } else {
- if (!reuse)
- tb->fastreuse = 0;
- if (sk->sk_reuseport) {
- /* We didn't match or we don't have fastreuseport set on
- * the tb, but we have sk_reuseport set on this socket
- * and we know that there are no bind conflicts with
- * this socket in this tb, so reset our tb's reuseport
- * settings so that any subsequent sockets that match
- * our current socket will be put on the fast path.
- *
- * If we reset we need to set FASTREUSEPORT_STRICT so we
- * do extra checking for all subsequent sk_reuseport
- * socks.
- */
- if (!sk_reuseport_match(tb, sk)) {
- tb->fastreuseport = FASTREUSEPORT_STRICT;
- tb->fastuid = uid;
- tb->fast_rcv_saddr = sk->sk_rcv_saddr;
- tb->fast_ipv6_only = ipv6_only_sock(sk);
- tb->fast_sk_family = sk->sk_family;
-#if IS_ENABLED(CONFIG_IPV6)
- tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
-#endif
- }
- } else {
- tb->fastreuseport = 0;
- }
- }
+ inet_csk_update_fastreuse(tb, sk);
+
if (!inet_csk(sk)->icsk_bind_hash)
inet_bind_hash(sk, tb, port);
WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
--
2.25.1


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