net: Make userland include of netlink.h more sane. (6602a4ba) · Commits · 戴 / test

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>

include/linux/netlink.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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 */

include/linux/socket.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -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.

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