[PATCH v2 2/3] socket: Split out a getsockname helper for io_uring

[Gabriel Krisman Bertazi <krisman@suse.de>]

Similar to getsockopt, split out a helper to check security and issue
the operation from the main handler that can be used by io_uring.

Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 include/linux/socket.h |  2 ++
 net/socket.c           | 34 +++++++++++++++++++---------------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 937fe331ff1e..5afb5ef2990c 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -453,6 +453,8 @@ extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
 			 int addrlen);
 extern int __sys_listen(int fd, int backlog);
 extern int __sys_listen_socket(struct socket *sock, int backlog);
+extern int do_getsockname(struct socket *sock, struct sockaddr_storage *address,
+			  int peer, struct sockaddr __user *usockaddr, int __user *usockaddr_len);
 extern int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 			     int __user *usockaddr_len, int peer);
 extern int __sys_socketpair(int family, int type, int protocol,
diff --git a/net/socket.c b/net/socket.c
index ee438b9425da..9c110b529cdd 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2127,6 +2127,24 @@ SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
 	return __sys_connect(fd, uservaddr, addrlen);
 }
 
+int do_getsockname(struct socket *sock, struct sockaddr_storage *address, int peer,
+		   struct sockaddr __user *usockaddr, int __user *usockaddr_len)
+{
+	int err;
+
+	if (peer)
+		err = security_socket_getpeername(sock);
+	else
+		err = security_socket_getsockname(sock);
+	if (err)
+		return err;
+	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)address, peer);
+	if (err < 0)
+		return err;
+	/* "err" is actually length in this case */
+	return move_addr_to_user(address, err, usockaddr, usockaddr_len);
+}
+
 /*
  *	Get the address (remote or local ('name')) of a socket object. Move the
  *	obtained name to user space.
@@ -2137,27 +2155,13 @@ int __sys_getsockname(int fd, struct sockaddr __user *usockaddr,
 	struct socket *sock;
 	struct sockaddr_storage address;
 	CLASS(fd, f)(fd);
-	int err;
 
 	if (fd_empty(f))
 		return -EBADF;
 	sock = sock_from_file(fd_file(f));
 	if (unlikely(!sock))
 		return -ENOTSOCK;
-
-	if (peer)
-		err = security_socket_getpeername(sock);
-	else
-		err = security_socket_getsockname(sock);
-	if (err)
-		return err;
-
-	err = READ_ONCE(sock->ops)->getname(sock, (struct sockaddr *)&address, peer);
-	if (err < 0)
-		return err;
-
-	/* "err" is actually length in this case */
-	return move_addr_to_user(&address, err, usockaddr, usockaddr_len);
+	return do_getsockname(sock, &address, peer, usockaddr, usockaddr_len);
 }
 
 SYSCALL_DEFINE3(getsockname, int, fd, struct sockaddr __user *, usockaddr,
-- 
2.51.0