net: Make userland include of netlink.h more sane.
Currently userland will barf when including linux/netlink.h unless it
precisely includes sys/socket.h first. The issue is where the
definition of "sa_family_t" comes from.
We've been back and forth on how to fix this issue in the past, see:
http://thread.gmane.org/gmane.linux.debian.devel.bugs.general/622621
http://thread.gmane.org/gmane.linux.network/143380
Ben Hutchings suggested we take a hint from how we handle the
sockaddr_storage type. First we define a "__kernel_sa_family_t"
to linux/socket.h that is always defined.
Then if __KERNEL__ is defined, we also define "sa_family_t" as
equal to "__kernel_sa_family_t".
Then in places like linux/netlink.h we use __kernel_sa_family_t
in user visible datastructures.
Reported-by: Michel Machado <michel@digirati.com.br>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 2e17c5d..180540a 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -29,7 +29,7 @@
#define MAX_LINKS 32
struct sockaddr_nl {
- sa_family_t nl_family; /* AF_NETLINK */
+ __kernel_sa_family_t nl_family; /* AF_NETLINK */
unsigned short nl_pad; /* zero */
__u32 nl_pid; /* port ID */
__u32 nl_groups; /* multicast groups mask */
diff --git a/include/linux/socket.h b/include/linux/socket.h
index e17f822..d0e77f6 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -8,8 +8,10 @@
#define _K_SS_ALIGNSIZE (__alignof__ (struct sockaddr *))
/* Implementation specific desired alignment */
+typedef unsigned short __kernel_sa_family_t;
+
struct __kernel_sockaddr_storage {
- unsigned short ss_family; /* address family */
+ __kernel_sa_family_t ss_family; /* address family */
/* Following field(s) are implementation specific */
char __data[_K_SS_MAXSIZE - sizeof(unsigned short)];
/* space to achieve desired size, */
@@ -35,7 +37,7 @@
extern void socket_seq_show(struct seq_file *seq);
#endif
-typedef unsigned short sa_family_t;
+typedef __kernel_sa_family_t sa_family_t;
/*
* 1003.1g requires sa_family_t and that sa_data is char.