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>
This commit is contained in:
David S. Miller 2011-08-07 22:48:07 -07:00
parent dd23198e58
commit 6602a4baf4
2 changed files with 5 additions and 3 deletions

View file

@ -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 */

View file

@ -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 @@ struct seq_file;
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.