[PATCH 1/2] net: add __sys_connect_file() helper

[Jens Axboe <axboe@xxxxxxxxx>]

This is identical to __sys_connect(), except it takes a struct file
instead of an fd, and it also allows passing in extra file->f_flags
flags. The latter is done to support masking in O_NONBLOCK without
manipulating the original file flags.

No functional changes in this patch.

Cc: netdev@xxxxxxxxxxxxxxx
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 include/linux/socket.h |  3 +++
 net/socket.c           | 30 ++++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index dd061f741bc1..868b906f1840 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -399,6 +399,9 @@ extern int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
 			 int __user *upeer_addrlen, int flags);
 extern int __sys_socket(int family, int type, int protocol);
 extern int __sys_bind(int fd, struct sockaddr __user *umyaddr, int addrlen);
+extern int __sys_connect_file(struct file *file,
+			struct sockaddr __user *uservaddr, int addrlen,
+			int file_flags);
 extern int __sys_connect(int fd, struct sockaddr __user *uservaddr,
 			 int addrlen);
 extern int __sys_listen(int fd, int backlog);
diff --git a/net/socket.c b/net/socket.c
index 40ab39f6c5d8..96e44b55d3d3 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1824,32 +1824,46 @@ SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr,
  *	include the -EINPROGRESS status for such sockets.
  */
 
-int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
+int __sys_connect_file(struct file *file, struct sockaddr __user *uservaddr,
+		       int addrlen, int file_flags)
 {
 	struct socket *sock;
 	struct sockaddr_storage address;
-	int err, fput_needed;
+	int err;
 
-	sock = sockfd_lookup_light(fd, &err, &fput_needed);
+	sock = sock_from_file(file, &err);
 	if (!sock)
 		goto out;
 	err = move_addr_to_kernel(uservaddr, addrlen, &address);
 	if (err < 0)
-		goto out_put;
+		goto out;
 
 	err =
 	    security_socket_connect(sock, (struct sockaddr *)&address, addrlen);
 	if (err)
-		goto out_put;
+		goto out;
 
 	err = sock->ops->connect(sock, (struct sockaddr *)&address, addrlen,
-				 sock->file->f_flags);
-out_put:
-	fput_light(sock->file, fput_needed);
+				 sock->file->f_flags | file_flags);
 out:
 	return err;
 }
 
+int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
+{
+	int ret = -EBADF;
+	struct fd f;
+
+	f = fdget(fd);
+	if (f.file) {
+		ret = __sys_connect_file(f.file, uservaddr, addrlen, 0);
+		if (f.flags)
+			fput(f.file);
+	}
+
+	return ret;
+}
+
 SYSCALL_DEFINE3(connect, int, fd, struct sockaddr __user *, uservaddr,
 		int, addrlen)
 {
-- 
2.24.0