Subject: [PATCH RFC net-next 3/5] netlink: introduce NLM_F_DUMP_PROPER_HDR flag

From: [email-masked]
Date: Fri, 28 Sep 2018 08:45:00 -0700

From: David Ahern <[email-masked]>

Add a new flag, NLM_F_DUMP_PROPER_HDR, for userspace to indicate to the
kernel that it believes it is sending the right header struct for the
dump message type (ifinfomsg, ifaddrmsg, rtmsg, fib_rule_hdr, ...).

Setting the flag in the netlink message header indicates to the kernel
it should do rigid checking on all data passed in the dump request and
filter the data returned based on data passed in.

Signed-off-by: David Ahern <[email-masked]>
---
 include/uapi/linux/netlink.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h
index 776bc92e9118..e722bed88dee 100644
--- a/include/uapi/linux/netlink.h
+++ b/include/uapi/linux/netlink.h
@@ -57,6 +57,7 @@ struct nlmsghdr {
 #define NLM_F_ECHO		0x08	/* Echo this request 		*/
 #define NLM_F_DUMP_INTR		0x10	/* Dump was inconsistent due to sequence change */
 #define NLM_F_DUMP_FILTERED	0x20	/* Dump was filtered as requested */
+#define NLM_F_DUMP_PROPER_HDR	0x40	/* Dump request has the proper header for type */
 
 /* Modifiers to GET request */
 #define NLM_F_ROOT	0x100	/* specify tree	root	*/
-- 
2.11.0