Commit 944fd1ae authored by Mike Manning's avatar Mike Manning Committed by David S. Miller
Browse files

net: allow unbound socket for packets in VRF when tcp_l3mdev_accept set 



The commit 3c82a21f ("net: allow binding socket in a VRF when
there's an unbound socket") changed the inet socket lookup to avoid
packets in a VRF from matching an unbound socket. This is to ensure the
necessary isolation between the default and other VRFs for routing and
forwarding. VRF-unaware processes running in the default VRF cannot
access another VRF and have to be run with 'ip vrf exec <vrf>'. This is
to be expected with tcp_l3mdev_accept disabled, but could be reallowed
when this sysctl option is enabled. So instead of directly checking dif
and sdif in inet[6]_match, here call inet_sk_bound_dev_eq(). This
allows a match on unbound socket for non-zero sdif i.e. for packets in
a VRF, if tcp_l3mdev_accept is enabled.

Fixes: 3c82a21f ("net: allow binding socket in a VRF when there's an unbound socket")
Signed-off-by: default avatarMike Manning <mvrmanning@gmail.com>
Link: https://lore.kernel.org/netdev/a54c149aed38fded2d3b5fdb1a6c89e36a083b74.camel@lasnet.de/


Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d7c4c9e0

include/net/inet6_hashtables.h

+3 −4
Original line number Diff line number Diff line
@@ -110,8 +110,6 @@ static inline bool inet6_match(struct net *net, const struct sock *sk, 
			       const __portpair ports,

			       const int dif, const int sdif)

{

	int bound_dev_if;



	if (!net_eq(sock_net(sk), net) ||

	    sk->sk_family != AF_INET6 ||

	    sk->sk_portpair != ports ||
@@ -119,8 +117,9 @@ static inline bool inet6_match(struct net *net, const struct sock *sk, 
	    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))

		return false;



	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);

	return bound_dev_if == dif || bound_dev_if == sdif;

	/* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */

	return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,

				    sdif);

}

#endif /* IS_ENABLED(CONFIG_IPV6) */

include/net/inet_hashtables.h

+3 −16
Original line number Diff line number Diff line
@@ -175,17 +175,6 @@ static inline void inet_ehash_locks_free(struct inet_hashinfo *hashinfo) 
	hashinfo->ehash_locks = NULL;

}



static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,

					int dif, int sdif)

{

#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)

	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),

				 bound_dev_if, dif, sdif);

#else

	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);

#endif

}



struct inet_bind_bucket *

inet_bind_bucket_create(struct kmem_cache *cachep, struct net *net,

			struct inet_bind_hashbucket *head,
@@ -271,16 +260,14 @@ static inline bool inet_match(struct net *net, const struct sock *sk, 
			      const __addrpair cookie, const __portpair ports,

			      int dif, int sdif)

{

	int bound_dev_if;



	if (!net_eq(sock_net(sk), net) ||

	    sk->sk_portpair != ports ||

	    sk->sk_addrpair != cookie)

	        return false;



	/* Paired with WRITE_ONCE() from sock_bindtoindex_locked() */

	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);

	return bound_dev_if == dif || bound_dev_if == sdif;

	/* READ_ONCE() paired with WRITE_ONCE() in sock_bindtoindex_locked() */

	return inet_sk_bound_dev_eq(net, READ_ONCE(sk->sk_bound_dev_if), dif,

				    sdif);

}



/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so we need

include/net/inet_sock.h

+11 −0
Original line number Diff line number Diff line
@@ -149,6 +149,17 @@ static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if, 
	return bound_dev_if == dif || bound_dev_if == sdif;

}



static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,

					int dif, int sdif)

{

#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)

	return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),

				 bound_dev_if, dif, sdif);

#else

	return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);

#endif

}



struct inet_cork {

	unsigned int		flags;

	__be32			addr;