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/rtnetlink.c b/net/core/rtnetlink.c
index 0ee5479..088f9c8 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2213,7 +2213,8 @@
 	return err;
 }
 
-static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ifinfomsg *ifm;
@@ -2222,7 +2223,8 @@
 	struct nlattr *tb[IFLA_MAX+1];
 	char ifname[IFNAMSIZ];
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
+			  extack);
 	if (err < 0)
 		goto errout;
 
@@ -2306,7 +2308,8 @@
 }
 EXPORT_SYMBOL_GPL(rtnl_delete_link);
 
-static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct net_device *dev;
@@ -2315,7 +2318,7 @@
 	struct nlattr *tb[IFLA_MAX+1];
 	int err;
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
 	if (err < 0)
 		return err;
 
@@ -2426,7 +2429,8 @@
 	return 0;
 }
 
-static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	const struct rtnl_link_ops *ops;
@@ -2444,7 +2448,7 @@
 #ifdef CONFIG_MODULES
 replay:
 #endif
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
 	if (err < 0)
 		return err;
 
@@ -2678,7 +2682,8 @@
 	}
 }
 
-static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh)
+static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ifinfomsg *ifm;
@@ -2689,7 +2694,7 @@
 	int err;
 	u32 ext_filter_mask = 0;
 
-	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, NULL);
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
 	if (err < 0)
 		return err;
 
@@ -2960,7 +2965,8 @@
 	return 0;
 }
 
-static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ndmsg *ndm;
@@ -2970,7 +2976,7 @@
 	u16 vid;
 	int err;
 
-	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)
 		return err;
 
@@ -3060,7 +3066,8 @@
 }
 EXPORT_SYMBOL(ndo_dflt_fdb_del);
 
-static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ndmsg *ndm;
@@ -3073,7 +3080,7 @@
 	if (!netlink_capable(skb, CAP_NET_ADMIN))
 		return -EPERM;
 
-	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)
 		return err;
 
@@ -3503,7 +3510,8 @@
 	return err;
 }
 
-static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ifinfomsg *ifm;
@@ -3577,7 +3585,8 @@
 	return err;
 }
 
-static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
+			       struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct ifinfomsg *ifm;
@@ -3945,7 +3954,8 @@
 	return size;
 }
 
-static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
 	struct net_device *dev = NULL;
@@ -4107,7 +4117,7 @@
 	if (doit == NULL)
 		return -EOPNOTSUPP;
 
-	return doit(skb, nlh);
+	return doit(skb, nlh, extack);
 }
 
 static void rtnetlink_rcv(struct sk_buff *skb)