From c9b95a13598750e2840d99322f844ec0ff9e6246 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sun, 5 Jul 2020 01:30:17 +0200 Subject: [PATCH] mptcp: support IPV6_V6ONLY setsockopt Without this, Opensshd fails to open an ipv6 socket listening socket: error: setsockopt IPV6_V6ONLY: Operation not supported error: Bind to port 22 on :: failed: Address already in use. Opensshd opens an ipv4 and and ipv6 listening socket, but because IPV6_V6ONLY setsockopt fails, the port number is already in use. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 612f6d49f1bb..3ab060e30038 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1632,6 +1632,33 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen); } +static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname, + char __user *optval, unsigned int optlen) +{ + struct sock *sk = (struct sock *)msk; + int ret = -EOPNOTSUPP; + struct socket *ssock; + + switch (optname) { + case IPV6_V6ONLY: + lock_sock(sk); + ssock = __mptcp_nmpc_socket(msk); + if (!ssock) { + release_sock(sk); + return -EINVAL; + } + + ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen); + if (ret == 0) + sk->sk_ipv6only = ssock->sk->sk_ipv6only; + + release_sock(sk); + break; + } + + return ret; +} + static int mptcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen) { @@ -1655,6 +1682,9 @@ static int mptcp_setsockopt(struct sock *sk, int level, int optname, if (ssk) return tcp_setsockopt(ssk, level, optname, optval, optlen); + if (level == SOL_IPV6) + return mptcp_setsockopt_v6(msk, optname, optval, optlen); + return -EOPNOTSUPP; }