net: dsa: Rename IFLA_DSA_MASTER to IFLA_DSA_CONDUIT

This preserves the existing IFLA_DSA_MASTER which is part of the uAPI
and creates an alias named IFLA_DSA_CONDUIT.

Reviewed-by: Andrew Lunn <[e-mail]>
Reviewed-by: Vladimir Oltean <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/networking/dsa/configuration.rst

···
 configure the system for the switch to use other conduits.
 
 DSA uses the ``rtnl_link_ops`` mechanism (with a "dsa" ``kind``) to allow
-changing the DSA conduit of a user port. The ``IFLA_DSA_MASTER`` u32 netlink
+changing the DSA conduit of a user port. The ``IFLA_DSA_CONDUIT`` u32 netlink
 attribute contains the ifindex of the conduit device that handles each user
 device. The DSA conduit must be a valid candidate based on firmware node
 information, or a LAG interface which contains only slaves which are valid
···
         dsa master bond0
 
 Notice that in the case of CPU ports under a LAG, the use of the
-``IFLA_DSA_MASTER`` netlink attribute is not strictly needed, but rather, DSA
+``IFLA_DSA_CONDUIT`` netlink attribute is not strictly needed, but rather, DSA
 reacts to the ``IFLA_MASTER`` attribute change of its present conduit (``eth0``)
 and migrates all user ports to the new upper of ``eth0``, ``bond0``. Similarly,
 when ``bond0`` is destroyed using ``RTM_DELLINK``, DSA migrates the user ports

include/uapi/linux/if_link.h

···
 
 enum {
 	IFLA_DSA_UNSPEC,
-	IFLA_DSA_MASTER,
+	IFLA_DSA_CONDUIT,
+	/* Deprecated, use IFLA_DSA_CONDUIT instead */
+	IFLA_DSA_MASTER = IFLA_DSA_CONDUIT,
 	__IFLA_DSA_MAX,
 };
 

net/dsa/netlink.c

···
 #include "user.h"
 
 static const struct nla_policy dsa_policy[IFLA_DSA_MAX + 1] = {
-	[IFLA_DSA_MASTER]	= { .type = NLA_U32 },
+	[IFLA_DSA_CONDUIT]	= { .type = NLA_U32 },
 };
 
 static int dsa_changelink(struct net_device *dev, struct nlattr *tb[],
···
 	if (!data)
 		return 0;
 
-	if (data[IFLA_DSA_MASTER]) {
-		u32 ifindex = nla_get_u32(data[IFLA_DSA_MASTER]);
+	if (data[IFLA_DSA_CONDUIT]) {
+		u32 ifindex = nla_get_u32(data[IFLA_DSA_CONDUIT]);
 		struct net_device *conduit;
 
 		conduit = __dev_get_by_index(dev_net(dev), ifindex);
···
 
 static size_t dsa_get_size(const struct net_device *dev)
 {
-	return nla_total_size(sizeof(u32)) +	/* IFLA_DSA_MASTER  */
+	return nla_total_size(sizeof(u32)) +	/* IFLA_DSA_CONDUIT  */
 	       0;
 }
 
···
 {
 	struct net_device *conduit = dsa_user_to_conduit(dev);
 
-	if (nla_put_u32(skb, IFLA_DSA_MASTER, conduit->ifindex))
+	if (nla_put_u32(skb, IFLA_DSA_CONDUIT, conduit->ifindex))
 		return -EMSGSIZE;
 
 	return 0;