From: Maxim Galaganov max@internet.ru
Support for IP_BIND_ADDRESS_NO_PORT sockopt was introduced in [1]. Recently [2] allowed its value to be accessed without locking the socket.
Support for (newer) IP_LOCAL_PORT_RANGE sockopt was introduced in [3]. In the same series a selftest was added in [4]. This selftest also covers the IP_BIND_ADDRESS_NO_PORT sockopt.
This patch enables getsockopt()/setsockopt() on MPTCP sockets for these socket options, syncing set values to subflows in sync_socket_options(). Ephemeral port range is synced to subflows, enabling NAT usecase described in [3].
[1] commit 90c337da1524 ("inet: add IP_BIND_ADDRESS_NO_PORT to overcome bind(0) limitations") [2] commit ca571e2eb7eb ("inet: move inet->bind_address_no_port to inet->inet_flags") [3] commit 91d0b78c5177 ("inet: Add IP_LOCAL_PORT_RANGE socket option") [4] commit ae5439658cce ("selftests/net: Cover the IP_LOCAL_PORT_RANGE socket option")
Signed-off-by: Maxim Galaganov max@internet.ru Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts matttbe@kernel.org --- net/mptcp/sockopt.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index a4bf337e6f77..c40f1428e602 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -440,6 +440,8 @@ static bool mptcp_supported_sockopt(int level, int optname) /* should work fine */ case IP_FREEBIND: case IP_TRANSPARENT: + case IP_BIND_ADDRESS_NO_PORT: + case IP_LOCAL_PORT_RANGE:
/* the following are control cmsg related */ case IP_PKTINFO: @@ -455,7 +457,6 @@ static bool mptcp_supported_sockopt(int level, int optname) /* common stuff that need some love */ case IP_TOS: case IP_TTL: - case IP_BIND_ADDRESS_NO_PORT: case IP_MTU_DISCOVER: case IP_RECVERR:
@@ -710,6 +711,14 @@ static int mptcp_setsockopt_sol_ip_set(struct mptcp_sock *msk, int optname, inet_assign_bit(TRANSPARENT, ssk, inet_test_bit(TRANSPARENT, sk)); break; + case IP_BIND_ADDRESS_NO_PORT: + inet_assign_bit(BIND_ADDRESS_NO_PORT, ssk, + inet_test_bit(BIND_ADDRESS_NO_PORT, sk)); + break; + case IP_LOCAL_PORT_RANGE: + WRITE_ONCE(inet_sk(ssk)->local_port_range, + READ_ONCE(inet_sk(sk)->local_port_range)); + break; default: release_sock(sk); WARN_ON_ONCE(1); @@ -755,6 +764,8 @@ static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname, switch (optname) { case IP_FREEBIND: case IP_TRANSPARENT: + case IP_BIND_ADDRESS_NO_PORT: + case IP_LOCAL_PORT_RANGE: return mptcp_setsockopt_sol_ip_set(msk, optname, optval, optlen); case IP_TOS: return mptcp_setsockopt_v4_set_tos(msk, optname, optval, optlen); @@ -1350,6 +1361,12 @@ static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, switch (optname) { case IP_TOS: return mptcp_put_int_option(msk, optval, optlen, READ_ONCE(inet_sk(sk)->tos)); + case IP_BIND_ADDRESS_NO_PORT: + return mptcp_put_int_option(msk, optval, optlen, + inet_test_bit(BIND_ADDRESS_NO_PORT, sk)); + case IP_LOCAL_PORT_RANGE: + return mptcp_put_int_option(msk, optval, optlen, + READ_ONCE(inet_sk(sk)->local_port_range)); }
return -EOPNOTSUPP; @@ -1450,6 +1467,8 @@ static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk)
inet_assign_bit(TRANSPARENT, ssk, inet_test_bit(TRANSPARENT, sk)); inet_assign_bit(FREEBIND, ssk, inet_test_bit(FREEBIND, sk)); + inet_assign_bit(BIND_ADDRESS_NO_PORT, ssk, inet_test_bit(BIND_ADDRESS_NO_PORT, sk)); + WRITE_ONCE(inet_sk(ssk)->local_port_range, READ_ONCE(inet_sk(sk)->local_port_range)); }
void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk)