net,socket: introduce DECLARE_SOCKADDR helper to catch overflow at build time

proto_ops->getname implies copying protocol specific data
into storage unit (particulary to __kernel_sockaddr_storage).
So when we implement new protocol support we should keep such
a detail in mind (which is easy to forget about).

Lets introduce DECLARE_SOCKADDR helper which check if
storage unit is not overfowed at build time.

Eventually inet_getname is switched to use DECLARE_SOCKADDR
(to show example of usage).

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cyrill Gorcunov 2009-10-29 02:59:18 -07:00 committed by David S. Miller
parent ed3f2e40f3
commit 38bfd8f5be
3 changed files with 7 additions and 1 deletions

View file

@ -199,6 +199,9 @@ struct proto_ops {
struct pipe_inode_info *pipe, size_t len, unsigned int flags);
};
#define DECLARE_SOCKADDR(type, dst, src) \
type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })
struct net_proto_family {
int family;
int (*create)(struct net *net, struct socket *sock, int protocol);

View file

@ -24,6 +24,9 @@ struct __kernel_sockaddr_storage {
#include <linux/types.h> /* pid_t */
#include <linux/compiler.h> /* __user */
#define __sockaddr_check_size(size) \
BUILD_BUG_ON(((size) > sizeof(struct __kernel_sockaddr_storage)))
#ifdef __KERNEL__
# ifdef CONFIG_PROC_FS
struct seq_file;

View file

@ -685,7 +685,7 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr,
{
struct sock *sk = sock->sk;
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
sin->sin_family = AF_INET;
if (peer) {