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authorJohannes Berg <johannes.berg@intel.com>2020-10-08 12:45:17 +0200
committerJakub Kicinski <kuba@kernel.org>2020-10-09 20:22:32 -0700
commit44f3625bc61653ea3bde9960298faf2f5518fda5 (patch)
treee36d5d8e5795a8992618cc2f756c5bc38d977434 /net/netlink/af_netlink.c
parentd2681e93b0ab7afe01d07f8c96f14afaccdcea4c (diff)
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 <kuba@kernel.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/netlink/af_netlink.c')
-rw-r--r--net/netlink/af_netlink.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index df675a8e1918..daca50d6bb12 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2420,6 +2420,8 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
tlvlen += nla_total_size(sizeof(u32));
if (nlk_has_extack && extack && extack->cookie_len)
tlvlen += nla_total_size(extack->cookie_len);
+ if (err && nlk_has_extack && extack && extack->policy)
+ tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy);
if (tlvlen)
flags |= NLM_F_ACK_TLVS;
@@ -2452,6 +2454,9 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
if (extack->cookie_len)
WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
extack->cookie_len, extack->cookie));
+ if (extack->policy)
+ netlink_policy_dump_write_attr(skb, extack->policy,
+ NLMSGERR_ATTR_POLICY);
}
nlmsg_end(skb, rep);