net/ipv4: Move loop over addresses on a device into in_dev_dump_addr

Similar to IPv6 move the logic that walks over the ipv4 address list
for a device into a helper.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/devinet.c

@@ -1713,6 +1713,32 @@ static int inet_valid_dump_ifaddr_req(const struct nlmsghdr *nlh,
 	return 0;
 }
 
+static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb,
+			    struct netlink_callback *cb, int s_ip_idx,
+			    struct inet_fill_args *fillargs)
+{
+	struct in_ifaddr *ifa;
+	int ip_idx = 0;
+	int err;
+
+	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next, ip_idx++) {
+		if (ip_idx < s_ip_idx)
+			continue;
+
+		err = inet_fill_ifaddr(skb, ifa, fillargs);
+		if (err < 0)
+			goto done;
+
+		nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+	}
+	err = 0;
+
+done:
+	cb->args[2] = ip_idx;
+
+	return err;
+}
+
 static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	const struct nlmsghdr *nlh = cb->nlh;
@@ -1727,19 +1753,17 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 	struct net *tgt_net = net;
 	int h, s_h;
 	int idx, s_idx;
-	int ip_idx, s_ip_idx;
+	int s_ip_idx;
 	struct net_device *dev;
 	struct in_device *in_dev;
-	struct in_ifaddr *ifa;
 	struct hlist_head *head;
+	int err;
 
 	s_h = cb->args[0];
 	s_idx = idx = cb->args[1];
-	s_ip_idx = ip_idx = cb->args[2];
+	s_ip_idx = cb->args[2];
 
 	if (cb->strict_check) {
-		int err;
-
 		err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
 						 skb->sk, cb->extack);
 		if (err < 0)
@@ -1761,16 +1785,12 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 			if (!in_dev)
 				goto cont;
 
-			for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
-			     ifa = ifa->ifa_next, ip_idx++) {
-				if (ip_idx < s_ip_idx)
-					continue;
-				if (inet_fill_ifaddr(skb, ifa, &fillargs) < 0) {
+			err = in_dev_dump_addr(in_dev, skb, cb, s_ip_idx,
+					       &fillargs);
+			if (err < 0) {
 				rcu_read_unlock();
 				goto done;
 			}
-				nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-			}
 cont:
 			idx++;
 		}
@@ -1780,7 +1800,6 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 done:
 	cb->args[0] = h;
 	cb->args[1] = idx;
-	cb->args[2] = ip_idx;
 	if (fillargs.netnsid >= 0)
 		put_net(tgt_net);