From: Sven Eckelmann <sven@narfation.org>
Date: Mon, 10 May 2021 15:05:42 +0200
Subject: batman-adv: Always send iface index+name in genlmsg

The batman-adv netlink messages often contain the interface index and
interface name in the same message. This makes it easy for the receiver to
operate on the incoming data when it either needs to print something or
needs to operate on the interface index.

But one of the attributes was missing for:

* neighbor table dumps
* originator table dumps
* gateway list dumps
* query of hardif information
* query of vid information

The userspace therefore had to implement special workarounds using
SIOCGIFNAME or SIOCGIFINDEX depending on what was actually provided.
Providing both information simplifies the userspace code massively without
adding a lot of extra overhead in the kernel portion.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/77c7d62618259f22f36427eaa62668e6e1c43090

--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1849,6 +1849,8 @@ batadv_iv_ogm_orig_dump_subentry(struct
 		    orig_node->orig) ||
 	    nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
 		    neigh_node->addr) ||
+	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+			   neigh_node->if_incoming->net_dev->name) ||
 	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
 			neigh_node->if_incoming->net_dev->ifindex) ||
 	    nla_put_u8(msg, BATADV_ATTR_TQ, tq_avg) ||
@@ -2078,6 +2080,8 @@ batadv_iv_ogm_neigh_dump_neigh(struct sk
 
 	if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
 		    hardif_neigh->addr) ||
+	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+			   hardif_neigh->if_incoming->net_dev->name) ||
 	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
 			hardif_neigh->if_incoming->net_dev->ifindex) ||
 	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
@@ -2459,6 +2463,8 @@ static int batadv_iv_gw_dump_entry(struc
 		    router->addr) ||
 	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
 			   router->if_incoming->net_dev->name) ||
+	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+			router->if_incoming->net_dev->ifindex) ||
 	    nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
 			gw_node->bandwidth_down) ||
 	    nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP,
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -145,6 +145,8 @@ batadv_v_neigh_dump_neigh(struct sk_buff
 
 	if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
 		    hardif_neigh->addr) ||
+	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+			   hardif_neigh->if_incoming->net_dev->name) ||
 	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
 			hardif_neigh->if_incoming->net_dev->ifindex) ||
 	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
@@ -297,6 +299,8 @@ batadv_v_orig_dump_subentry(struct sk_bu
 	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN, orig_node->orig) ||
 	    nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
 		    neigh_node->addr) ||
+	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+			   neigh_node->if_incoming->net_dev->name) ||
 	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
 			neigh_node->if_incoming->net_dev->ifindex) ||
 	    nla_put_u32(msg, BATADV_ATTR_THROUGHPUT, throughput) ||
@@ -737,6 +741,12 @@ static int batadv_v_gw_dump_entry(struct
 		genlmsg_cancel(msg, hdr);
 		goto out;
 	}
+
+	if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+			router->if_incoming->net_dev->ifindex)) {
+		genlmsg_cancel(msg, hdr);
+		goto out;
+	}
 
 	if (nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
 			gw_node->bandwidth_down)) {
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -813,6 +813,10 @@ static int batadv_netlink_hardif_fill(st
 			bat_priv->soft_iface->ifindex))
 		goto nla_put_failure;
 
+	if (nla_put_string(msg, BATADV_ATTR_MESH_IFNAME,
+			   bat_priv->soft_iface->name))
+		goto nla_put_failure;
+
 	if (nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
 			net_dev->ifindex) ||
 	    nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
@@ -1044,6 +1048,10 @@ static int batadv_netlink_vlan_fill(stru
 			bat_priv->soft_iface->ifindex))
 		goto nla_put_failure;
 
+	if (nla_put_string(msg, BATADV_ATTR_MESH_IFNAME,
+			   bat_priv->soft_iface->name))
+		goto nla_put_failure;
+
 	if (nla_put_u32(msg, BATADV_ATTR_VLANID, vlan->vid & VLAN_VID_MASK))
 		goto nla_put_failure;