Commit d32f89da authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

net: add accept helper not installing fd 



Introduce and reuse a helper that acts similarly to __sys_accept4_file()
but returns struct file instead of installing file descriptor. Will be
used by io_uring.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Acked-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Link: https://lore.kernel.org/r/c57b9e8e818d93683a3d24f8ca50ca038d1da8c4.1629888991.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dadebc35

include/linux/socket.h

+3 −0
Original line number Diff line number Diff line
@@ -421,6 +421,9 @@ extern int __sys_accept4_file(struct file *file, unsigned file_flags, 
			struct sockaddr __user *upeer_sockaddr,

			 int __user *upeer_addrlen, int flags,

			 unsigned long nofile);

extern struct file *do_accept(struct file *file, unsigned file_flags,

			      struct sockaddr __user *upeer_sockaddr,

			      int __user *upeer_addrlen, int flags);

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);

net/socket.c

+37 −34
Original line number Diff line number Diff line
@@ -1722,32 +1722,22 @@ SYSCALL_DEFINE2(listen, int, fd, int, backlog) 
	return __sys_listen(fd, backlog);

}



int __sys_accept4_file(struct file *file, unsigned file_flags,

struct file *do_accept(struct file *file, unsigned file_flags,

		       struct sockaddr __user *upeer_sockaddr,

		       int __user *upeer_addrlen, int flags,

		       unsigned long nofile)

		       int __user *upeer_addrlen, int flags)

{

	struct socket *sock, *newsock;

	struct file *newfile;

	int err, len, newfd;

	int err, len;

	struct sockaddr_storage address;



	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))

		return -EINVAL;



	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))

		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;



	sock = sock_from_file(file);

	if (!sock) {

		err = -ENOTSOCK;

		goto out;

	}

	if (!sock)

		return ERR_PTR(-ENOTSOCK);



	err = -ENFILE;

	newsock = sock_alloc();

	if (!newsock)

		goto out;

		return ERR_PTR(-ENFILE);



	newsock->type = sock->type;

	newsock->ops = sock->ops;
@@ -1758,18 +1748,9 @@ int __sys_accept4_file(struct file *file, unsigned file_flags, 
	 */

	__module_get(newsock->ops->owner);



	newfd = __get_unused_fd_flags(flags, nofile);

	if (unlikely(newfd < 0)) {

		err = newfd;

		sock_release(newsock);

		goto out;

	}

	newfile = sock_alloc_file(newsock, flags, sock->sk->sk_prot_creator->name);

	if (IS_ERR(newfile)) {

		err = PTR_ERR(newfile);

		put_unused_fd(newfd);

		goto out;

	}

	if (IS_ERR(newfile))

		return newfile;



	err = security_socket_accept(sock, newsock);

	if (err)
@@ -1794,16 +1775,38 @@ int __sys_accept4_file(struct file *file, unsigned file_flags, 
	}



	/* File flags are not inherited via accept() unlike another OSes. */



	fd_install(newfd, newfile);

	err = newfd;

out:

	return err;

	return newfile;

out_fd:

	fput(newfile);

	put_unused_fd(newfd);

	goto out;

	return ERR_PTR(err);

}



int __sys_accept4_file(struct file *file, unsigned file_flags,

		       struct sockaddr __user *upeer_sockaddr,

		       int __user *upeer_addrlen, int flags,

		       unsigned long nofile)

{

	struct file *newfile;

	int newfd;



	if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))

		return -EINVAL;



	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))

		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;



	newfd = __get_unused_fd_flags(flags, nofile);

	if (unlikely(newfd < 0))

		return newfd;



	newfile = do_accept(file, file_flags, upeer_sockaddr, upeer_addrlen,

			    flags);

	if (IS_ERR(newfile)) {

		put_unused_fd(newfd);

		return PTR_ERR(newfile);

	}

	fd_install(newfd, newfile);

	return newfd;

}



/*