From: Florian Westphal <fw@strlen.de>
Date: Sat, 4 Jul 2020 23:30:15 +0000 (+0200)
Subject: net: use mptcp setsockopt function for SOL_SOCKET on mptcp sockets
X-Git-Tag: v5.10.7~1943^2~341^2~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=83f0c10bc36f956102ce4a33c5fe596ae9891297;p=platform%2Fkernel%2Flinux-rpi.git

net: use mptcp setsockopt function for SOL_SOCKET on mptcp sockets

setsockopt(mptcp_fd, SOL_SOCKET, ...)...  appears to work (returns 0),
but it has no effect -- this is because the MPTCP layer never has a
chance to copy the settings to the subflow socket.

Skip the generic handling for the mptcp case and instead call the
mptcp specific handler instead for SOL_SOCKET too.

Next patch adds more specific handling for SOL_SOCKET to mptcp.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index fa137a9..320f306 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1609,6 +1609,9 @@ static int mptcp_setsockopt(struct sock *sk, int level, int optname,
 
 	pr_debug("msk=%p", msk);
 
+	if (level == SOL_SOCKET)
+		return sock_setsockopt(sk->sk_socket, level, optname, optval, optlen);
+
 	/* @@ the meaning of setsockopt() when the socket is connected and
 	 * there are multiple subflows is not yet defined. It is up to the
 	 * MPTCP-level socket to configure the subflows until the subflow
diff --git a/net/socket.c b/net/socket.c
index 976426d..d87812a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2080,6 +2080,17 @@ SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
 	return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL);
 }
 
+static bool sock_use_custom_sol_socket(const struct socket *sock)
+{
+	const struct sock *sk = sock->sk;
+
+	/* Use sock->ops->setsockopt() for MPTCP */
+	return IS_ENABLED(CONFIG_MPTCP) &&
+	       sk->sk_protocol == IPPROTO_MPTCP &&
+	       sk->sk_type == SOCK_STREAM &&
+	       (sk->sk_family == AF_INET || sk->sk_family == AF_INET6);
+}
+
 /*
  *	Set a socket option. Because we don't know the option lengths we have
  *	to pass the user mode parameter for the protocols to sort out.
@@ -2118,7 +2129,7 @@ static int __sys_setsockopt(int fd, int level, int optname,
 			optval = (char __user __force *)kernel_optval;
 		}
 
-		if (level == SOL_SOCKET)
+		if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
 			err =
 			    sock_setsockopt(sock, level, optname, optval,
 					    optlen);