From 4f6265d485ea0a2507692ded8ed47b323f49587c Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 27 Oct 2017 17:37:12 -0700 Subject: [PATCH] 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: David Ahern Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 767c84e10e20..26ded4239611 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -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) - tlvlen += nla_total_size(sizeof(u32)); - } + 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 (extack->_msg) { + WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, + extack->_msg)); + } 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 +