From da214a475f8bd1d3e9e7a19ddfeb4d1617551bab Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 12 Apr 2022 14:22:39 -0600 Subject: [PATCH] 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 Acked-by: David S. Miller Link: https://lore.kernel.org/r/20220412202240.234207-2-axboe@kernel.dk --- include/linux/socket.h | 1 + net/socket.c | 54 +++++++++++++++++++++++++++++++++--------- 2 files changed, 44 insertions(+), 11 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; - 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; + 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; + + 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)); }