net: rtnetlink: plumb extended ack to doit function

Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
for doit functions that call it directly.

This is the first step to using extended error reporting in rtnetlink.
>From here individual subsystems can be updated to set netlink_ext_ack as
needed.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 31f37b2..58b0bcc 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1590,7 +1590,8 @@ static struct neigh_table *neigh_find_table(int family)
 	return tbl;
 }
 
-static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ndmsg *ndm;
@@ -1648,7 +1649,8 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh)
 	return err;
 }
 
-static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh,
+		     struct netlink_ext_ack *extack)
 {
 	int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE;
 	struct net *net = sock_net(skb->sk);
@@ -1661,7 +1663,7 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int err;
 
 	ASSERT_RTNL();
-	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, extack);
 	if (err < 0)
 		goto out;
 
@@ -1936,7 +1938,8 @@ static const struct nla_policy nl_ntbl_parm_policy[NDTPA_MAX+1] = {
 	[NDTPA_LOCKTIME]		= { .type = NLA_U64 },
 };
 
-static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct neigh_table *tbl;
@@ -1946,7 +1949,7 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
 	int err, tidx;
 
 	err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX,
-			  nl_neightbl_policy, NULL);
+			  nl_neightbl_policy, extack);
 	if (err < 0)
 		goto errout;
 
@@ -1984,7 +1987,7 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh)
 		int i, ifindex = 0;
 
 		err = nla_parse_nested(tbp, NDTPA_MAX, tb[NDTA_PARMS],
-				       nl_ntbl_parm_policy, NULL);
+				       nl_ntbl_parm_policy, extack);
 		if (err < 0)
 			goto errout_tbl_lock;