From 44f3625bc61653ea3bde9960298faf2f5518fda5 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 8 Oct 2020 12:45:17 +0200 Subject: netlink: export policy in extended ACK Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK to advertise the policy, e.g. if an attribute was out of range, you'll know the range that's permissible. Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL() macros to set this, since realistically it's only useful to do this when the bad attribute (offset) is also returned. Use it in lib/nlattr.c which practically does all the policy validation. v2: - add and use netlink_policy_dump_attr_size_estimate() v3: - remove redundant break v4: - really remove redundant break ... sorry Reviewed-by: Jakub Kicinski Signed-off-by: Johannes Berg Signed-off-by: Jakub Kicinski --- include/uapi/linux/netlink.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h index d02e472ba54c..c3816ff7bfc3 100644 --- a/include/uapi/linux/netlink.h +++ b/include/uapi/linux/netlink.h @@ -129,6 +129,7 @@ struct nlmsgerr { * @NLMSGERR_ATTR_COOKIE: arbitrary subsystem specific cookie to * be used - in the success case - to identify a created * object or operation or similar (binary) + * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute * @__NLMSGERR_ATTR_MAX: number of attributes * @NLMSGERR_ATTR_MAX: highest attribute number */ @@ -137,6 +138,7 @@ enum nlmsgerr_attrs { NLMSGERR_ATTR_MSG, NLMSGERR_ATTR_OFFS, NLMSGERR_ATTR_COOKIE, + NLMSGERR_ATTR_POLICY, __NLMSGERR_ATTR_MAX, NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1 -- cgit v1.2.3