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Message-Id: <20220412202240.234207-2-axboe@kernel.dk>
Date: Tue, 12 Apr 2022 14:22:39 -0600
From: Jens Axboe <axboe@...nel.dk>
To: io-uring@...r.kernel.org, netdev@...r.kernel.org
Cc: Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 1/2] net: add __sys_socket_file()
This works like __sys_socket(), except instead of allocating and
returning a socket fd, it just returns the file associated with the
socket. No fd is installed into the process file table.
This is similar to do_accept(), and allows io_uring to use this without
instantiating a file descriptor in the process file table.
Signed-off-by: Jens Axboe <axboe@...nel.dk>
---
include/linux/socket.h | 1 +
net/socket.c | 52 ++++++++++++++++++++++++++++++++++--------
2 files changed, 43 insertions(+), 10 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 6f85f5d957ef..a1882e1e71d2 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -434,6 +434,7 @@ extern struct file *do_accept(struct file *file, unsigned file_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);
+extern struct file *__sys_socket_file(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_storage *addr,
int addrlen, int file_flags);
diff --git a/net/socket.c b/net/socket.c
index 6887840682bb..bb6a1a12fbde 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -504,7 +504,7 @@ static int sock_map_fd(struct socket *sock, int flags)
struct socket *sock_from_file(struct file *file)
{
if (file->f_op == &socket_file_ops)
- return file->private_data; /* set in sock_map_fd */
+ return file->private_data; /* set in sock_alloc_file */
return NULL;
}
@@ -1538,11 +1538,10 @@ int sock_create_kern(struct net *net, int family, int type, int protocol, struct
}
EXPORT_SYMBOL(sock_create_kern);
-int __sys_socket(int family, int type, int protocol)
+static struct socket *__sys_socket_create(int family, int type, int protocol)
{
- int retval;
struct socket *sock;
- int flags;
+ int retval;
/* Check the SOCK_* constants for consistency. */
BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
@@ -1550,17 +1549,50 @@ int __sys_socket(int family, int type, int protocol)
BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
- flags = type & ~SOCK_TYPE_MASK;
- if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
- return -EINVAL;
+ if ((type & ~SOCK_TYPE_MASK) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+ return ERR_PTR(-EINVAL);
type &= SOCK_TYPE_MASK;
+ retval = sock_create(family, type, protocol, &sock);
+ if (retval < 0)
+ return ERR_PTR(retval);
+
+ return sock;
+}
+
+struct file *__sys_socket_file(int family, int type, int protocol)
+{
+ struct socket *sock;
+ struct file *file;
+ int flags;
+
+ sock = __sys_socket_create(family, type, protocol);
+ if (IS_ERR(sock))
+ return ERR_CAST(sock);
+
+ flags = type & ~SOCK_TYPE_MASK;
if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
- retval = sock_create(family, type, protocol, &sock);
- if (retval < 0)
- return retval;
+ file = sock_alloc_file(sock, flags, NULL);
+ if (IS_ERR(file))
+ sock_release(sock);
+
+ return file;
+}
+
+int __sys_socket(int family, int type, int protocol)
+{
+ struct socket *sock;
+ int flags;
+
+ sock = __sys_socket_create(family, type, protocol);
+ if (IS_ERR(sock))
+ return PTR_ERR(sock);
+
+ flags = type & ~SOCK_TYPE_MASK;
+ if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
+ flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
return sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
}
--
2.35.1
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