[PATCH bpf-next 01/14] net: Change sock_setsockopt from taking sock ptr to sk ptr

[Martin KaFai Lau <kafai@fb.com>]

A latter patch refactors bpf_setsockopt(SOL_SOCKET) with the
sock_setsockopt() to avoid code duplication and code
drift between the two duplicates.

The current sock_setsockopt() takes sock ptr as the argument.
The very first thing of this function is to get back the sk ptr
by 'sk = sock->sk'.

bpf_setsockopt() could be called when the sk does not have
a userspace owner.  Meaning sk->sk_socket is NULL.  For example,
when a passive tcp connection has just been established.  Thus,
it cannot use the sock_setsockopt(sk->sk_socket) or else it will
pass a NULL sock ptr.

All existing callers have both sock->sk and sk->sk_socket pointer.
Thus, this patch changes the sock_setsockopt() to take a sk ptr
instead of the sock ptr.  The bpf_setsockopt() only allows
optnames that do not require a sock ptr.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 drivers/nvme/host/tcp.c  |  2 +-
 fs/ksmbd/transport_tcp.c |  2 +-
 include/net/sock.h       |  2 +-
 net/core/sock.c          |  4 ++--
 net/mptcp/sockopt.c      | 12 ++++++------
 net/socket.c             |  2 +-
 6 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 7a9e6ffa2342..60e14cc39e49 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -1555,7 +1555,7 @@ static int nvme_tcp_alloc_queue(struct nvme_ctrl *nctrl,
 		char *iface = nctrl->opts->host_iface;
 		sockptr_t optval = KERNEL_SOCKPTR(iface);
 
-		ret = sock_setsockopt(queue->sock, SOL_SOCKET, SO_BINDTODEVICE,
+		ret = sock_setsockopt(queue->sock->sk, SOL_SOCKET, SO_BINDTODEVICE,
 				      optval, strlen(iface));
 		if (ret) {
 			dev_err(nctrl->device,
diff --git a/fs/ksmbd/transport_tcp.c b/fs/ksmbd/transport_tcp.c
index 143bba4e4db8..982eed2dd575 100644
--- a/fs/ksmbd/transport_tcp.c
+++ b/fs/ksmbd/transport_tcp.c
@@ -420,7 +420,7 @@ static int create_socket(struct interface *iface)
 	ksmbd_tcp_nodelay(ksmbd_socket);
 	ksmbd_tcp_reuseaddr(ksmbd_socket);
 
-	ret = sock_setsockopt(ksmbd_socket,
+	ret = sock_setsockopt(ksmbd_socket->sk,
 			      SOL_SOCKET,
 			      SO_BINDTODEVICE,
 			      KERNEL_SOCKPTR(iface->name),
diff --git a/include/net/sock.h b/include/net/sock.h
index f7ad1a7705e9..9e2539dcc293 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1795,7 +1795,7 @@ void sock_pfree(struct sk_buff *skb);
 #define sock_edemux sock_efree
 #endif
 
-int sock_setsockopt(struct socket *sock, int level, int op,
+int sock_setsockopt(struct sock *sk, int level, int op,
 		    sockptr_t optval, unsigned int optlen);
 
 int sock_getsockopt(struct socket *sock, int level, int op,
diff --git a/net/core/sock.c b/net/core/sock.c
index 4cb957d934a2..18bb4f269cf1 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1041,12 +1041,12 @@ static int sock_reserve_memory(struct sock *sk, int bytes)
  *	at the socket level. Everything here is generic.
  */
 
-int sock_setsockopt(struct socket *sock, int level, int optname,
+int sock_setsockopt(struct sock *sk, int level, int optname,
 		    sockptr_t optval, unsigned int optlen)
 {
 	struct so_timestamping timestamping;
+	struct socket *sock = sk->sk_socket;
 	struct sock_txtime sk_txtime;
-	struct sock *sk = sock->sk;
 	int val;
 	int valbool;
 	struct linger ling;
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index 423d3826ca1e..5684499b4d39 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -124,7 +124,7 @@ static int mptcp_sol_socket_intval(struct mptcp_sock *msk, int optname, int val)
 	struct sock *sk = (struct sock *)msk;
 	int ret;
 
-	ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
+	ret = sock_setsockopt(sk, SOL_SOCKET, optname,
 			      optval, sizeof(val));
 	if (ret)
 		return ret;
@@ -149,7 +149,7 @@ static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optnam
 	struct sock *sk = (struct sock *)msk;
 	int ret;
 
-	ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
+	ret = sock_setsockopt(sk, SOL_SOCKET, optname,
 			      optval, sizeof(val));
 	if (ret)
 		return ret;
@@ -225,7 +225,7 @@ static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk,
 		return -EINVAL;
 	}
 
-	ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
+	ret = sock_setsockopt(sk, SOL_SOCKET, optname,
 			      KERNEL_SOCKPTR(&timestamping),
 			      sizeof(timestamping));
 	if (ret)
@@ -262,7 +262,7 @@ static int mptcp_setsockopt_sol_socket_linger(struct mptcp_sock *msk, sockptr_t
 		return -EFAULT;
 
 	kopt = KERNEL_SOCKPTR(&ling);
-	ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling));
+	ret = sock_setsockopt(sk, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling));
 	if (ret)
 		return ret;
 
@@ -306,7 +306,7 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname,
 			return -EINVAL;
 		}
 
-		ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen);
+		ret = sock_setsockopt(ssock->sk, SOL_SOCKET, optname, optval, optlen);
 		if (ret == 0) {
 			if (optname == SO_REUSEPORT)
 				sk->sk_reuseport = ssock->sk->sk_reuseport;
@@ -349,7 +349,7 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname,
 	case SO_PREFER_BUSY_POLL:
 	case SO_BUSY_POLL_BUDGET:
 		/* No need to copy: only relevant for msk */
-		return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen);
+		return sock_setsockopt(sk, SOL_SOCKET, optname, optval, optlen);
 	case SO_NO_CHECK:
 	case SO_DONTROUTE:
 	case SO_BROADCAST:
diff --git a/net/socket.c b/net/socket.c
index b6bd4cf44d3f..c6911d613ae2 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2245,7 +2245,7 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 	if (kernel_optval)
 		optval = KERNEL_SOCKPTR(kernel_optval);
 	if (level == SOL_SOCKET && !sock_use_custom_sol_socket(sock))
-		err = sock_setsockopt(sock, level, optname, optval, optlen);
+		err = sock_setsockopt(sock->sk, level, optname, optval, optlen);
 	else if (unlikely(!sock->ops->setsockopt))
 		err = -EOPNOTSUPP;
 	else
-- 
2.30.2