From 38bfd8f5bec496e8e0db8849e01c99a33479418a Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Thu, 29 Oct 2009 02:59:18 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/linux/net.h | 3 +++ include/linux/socket.h | 3 +++ net/ipv4/af_inet.c | 2 +- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/net.h b/include/linux/net.h index b42bb60fe92f..4da9d571b053 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -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); diff --git a/include/linux/socket.h b/include/linux/socket.h index 59966f12990c..7b3aae2052a6 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -24,6 +24,9 @@ struct __kernel_sockaddr_storage { #include /* pid_t */ #include /* __user */ +#define __sockaddr_check_size(size) \ + BUILD_BUG_ON(((size) > sizeof(struct __kernel_sockaddr_storage))) + #ifdef __KERNEL__ # ifdef CONFIG_PROC_FS struct seq_file; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 04a14b1600ac..538e84d0bcba 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -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) { -- 2.20.1