Commit 4f6265d4 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

netlink: Allow ext_ack to carry non-error messages 



The NLMSGERR API already carries data (eg, a cookie) on the success path.
Allow a message string to be returned as well.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a7b216b1

net/netlink/af_netlink.c

+9 −9
Original line number Diff line number Diff line
@@ -2313,17 +2313,16 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, 
	 * requests to cap the error message, and get extra error data if

	 * requested.

	 */

	if (nlk_has_extack && extack && extack->_msg)

		tlvlen += nla_total_size(strlen(extack->_msg) + 1);



	if (err) {

		if (!(nlk->flags & NETLINK_F_CAP_ACK))

			payload += nlmsg_len(nlh);

		else

			flags |= NLM_F_CAPPED;

		if (nlk_has_extack && extack) {

			if (extack->_msg)

				tlvlen += nla_total_size(strlen(extack->_msg) + 1);

			if (extack->bad_attr)

		if (nlk_has_extack && extack && extack->bad_attr)

			tlvlen += nla_total_size(sizeof(u32));

		}

	} else {

		flags |= NLM_F_CAPPED;
@@ -2348,10 +2347,11 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, 
	memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));



	if (nlk_has_extack && extack) {

		if (err) {

			if (extack->_msg)

		if (extack->_msg) {

			WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,

					       extack->_msg));

		}

		if (err) {

			if (extack->bad_attr &&

			    !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||

				     (u8 *)extack->bad_attr >= in_skb->data +