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authorJohannes Berg <johannes.berg@intel.com>2017-04-12 14:34:06 +0200
committerDavid S. Miller <davem@davemloft.net>2017-04-13 13:58:21 -0400
commitba0dc5f6e0ba5a5d2f575bcdb35e5d1960cf7c04 (patch)
tree67f74587529492b36ee1566352d961f245efa45c /net
parent7ab606d1609dd6dfeae9c8ad0a8a4e051d831e46 (diff)
downloadlinux-ba0dc5f6e0ba5a5d2f575bcdb35e5d1960cf7c04.tar.bz2
netlink: allow sending extended ACK with cookie on success
Now that we have extended error reporting and a new message format for netlink ACK messages, also extend this to be able to return arbitrary cookie data on success. This will allow, for example, nl80211 to not send an extra message for cookies identifying newly created objects, but return those directly in the ACK message. The cookie data size is currently limited to 20 bytes (since Jamal talked about using SHA1 for identifiers.) Thanks to Jamal Hadi Salim for bringing up this idea during the discussions. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/netlink/af_netlink.c33
1 files changed, 22 insertions, 11 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c1564768000e..ee841f00a6ec 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -2311,6 +2311,10 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
}
} else {
flags |= NLM_F_CAPPED;
+
+ if (nlk->flags & NETLINK_F_EXT_ACK &&
+ extack && extack->cookie_len)
+ tlvlen += nla_total_size(extack->cookie_len);
}
if (tlvlen)
@@ -2337,17 +2341,24 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
errmsg->error = err;
memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
- if (err && nlk->flags & NETLINK_F_EXT_ACK && extack) {
- if (extack->_msg)
- WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
- extack->_msg));
- if (extack->bad_attr &&
- !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
- (u8 *)extack->bad_attr >= in_skb->data +
- in_skb->len))
- WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
- (u8 *)extack->bad_attr -
- in_skb->data));
+ if (nlk->flags & NETLINK_F_EXT_ACK && extack) {
+ if (err) {
+ if (extack->_msg)
+ WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
+ extack->_msg));
+ if (extack->bad_attr &&
+ !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
+ (u8 *)extack->bad_attr >= in_skb->data +
+ in_skb->len))
+ WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+ (u8 *)extack->bad_attr -
+ in_skb->data));
+ } else {
+ if (extack->cookie_len)
+ WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
+ extack->cookie_len,
+ extack->cookie));
+ }
}
nlmsg_end(skb, rep);