rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size

Commit 00e77ed ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
added those attributes to rtnl_fill_ifinfo, but forgot to extend
if_nlmsg_size.

Fixes: 00e77ed ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME")
Signed-off-by: Sabrina Dubroca <[email protected]>
Link: https://patch.msgid.link/0b849da95562af45487080528d60f578636aba5c.1773919462.git.sd@queasysnail.net
Signed-off-by: Jakub Kicinski <[email protected]>

Author: qsn

net/core/rtnetlink.c

@@ -1267,6 +1267,21 @@ static size_t rtnl_dpll_pin_size(const struct net_device *dev)
 	return size;
 }
 
+static size_t rtnl_dev_parent_size(const struct net_device *dev)
+{
+	size_t size = 0;
+
+	/* IFLA_PARENT_DEV_NAME */
+	if (dev->dev.parent)
+		size += nla_total_size(strlen(dev_name(dev->dev.parent)) + 1);
+
+	/* IFLA_PARENT_DEV_BUS_NAME */
+	if (dev->dev.parent && dev->dev.parent->bus)
+		size += nla_total_size(strlen(dev->dev.parent->bus->name) + 1);
+
+	return size;
+}
+
 static noinline size_t if_nlmsg_size(const struct net_device *dev,
 				     u32 ext_filter_mask)
 {
@@ -1328,6 +1343,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(8)  /* IFLA_MAX_PACING_OFFLOAD_HORIZON */
 	       + nla_total_size(2)  /* IFLA_HEADROOM */
 	       + nla_total_size(2)  /* IFLA_TAILROOM */
+	       + rtnl_dev_parent_size(dev)
 	       + 0;
 
 	if (!(ext_filter_mask & RTEXT_FILTER_SKIP_STATS))