[PATCH v2 net-next 1/3] net: Make locking in sock_bindtoindex optional

Ferenc Fejes
2020-05-30T21:10:04Z

The sock_bindtoindex intended for kernel wide usage however
it will lock the socket regardless of the context. This modification
relax this behavior optionally: locking the socket will be optional
by calling the sock_bindtoindex with lock_sk = true.

The modification applied to all users of the sock_bindtoindex.

Signed-off-by: Ferenc Fejes <fejes@inf.elte.hu>
---
include/net/sock.h | 2 +-
net/core/sock.c | 10 ++++++----
net/ipv4/udp_tunnel.c | 2 +-
net/ipv6/ip6_udp_tunnel.c | 2 +-
4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index d994daa418ec..098d97d9fe72 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2688,7 +2688,7 @@ static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)

void sock_def_readable(struct sock *sk);

-int sock_bindtoindex(struct sock *sk, int ifindex);
+int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
void sock_enable_timestamps(struct sock *sk);
void sock_no_linger(struct sock *sk);
void sock_set_keepalive(struct sock *sk);
diff --git a/net/core/sock.c b/net/core/sock.c
index 2ca3425b519c..c7ee722cfbe9 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -594,13 +594,15 @@ static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
return ret;
}

-int sock_bindtoindex(struct sock *sk, int ifindex)
+int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
{
int ret;

- lock_sock(sk);
+ if (lock_sk)
+ lock_sock(sk);
ret = sock_bindtoindex_locked(sk, ifindex);
- release_sock(sk);
+ if (lock_sk)
+ release_sock(sk);

return ret;
}
@@ -646,7 +648,7 @@ static int sock_setbindtodevice(struct sock *sk, char __user *optval,
goto out;
}

- return sock_bindtoindex(sk, index);
+ return sock_bindtoindex(sk, index, true);
out:
#endif

diff --git a/net/ipv4/udp_tunnel.c b/net/ipv4/udp_tunnel.c
index 2158e8bddf41..3eecba0874aa 100644
--- a/net/ipv4/udp_tunnel.c
+++ b/net/ipv4/udp_tunnel.c
@@ -22,7 +22,7 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
goto error;

if (cfg->bind_ifindex) {
- err = sock_bindtoindex(sock->sk, cfg->bind_ifindex);
+ err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
if (err < 0)
goto error;
}
diff --git a/net/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c
index 2e0ad1bc84a8..cdc4d4ee2420 100644
--- a/net/ipv6/ip6_udp_tunnel.c
+++ b/net/ipv6/ip6_udp_tunnel.c
@@ -30,7 +30,7 @@ int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
goto error;
}
if (cfg->bind_ifindex) {
- err = sock_bindtoindex(sock->sk, cfg->bind_ifindex);
+ err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
if (err < 0)
goto error;
}
--
2.17.1