From: Linus Lüssing <linus.luessing@c0d3.blue>
Date: Fri, 19 Aug 2022 20:23:11 +0200
Subject: batman-adv: compat: use backported bridge MRD support for 5.10

The per protocol family Multicast Router Discovery support was
backported from Linux 5.14 to Linux 5.10. As well as the bridge exports
added in 5.14 for batman-adv to retrieve the more accurate MRD based
multicast router state, compared to the previous "guessing" on ff02::2
approach to detect IPv6 multicast routers..

This enables the use of routable multicast addresses in bridged setups
in batman-adv's multicast optimizations.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>

diff --git a/batman-adv/src/compat-hacks.h b/batman-adv/src/compat-hacks.h
index 99a1bb39fedcbd2069a0f790a624fdeaed12b47c..dd9122cb44f3931b8d95c74d76856c6c690205f3 100644
--- a/batman-adv/src/compat-hacks.h
+++ b/batman-adv/src/compat-hacks.h
@@ -47,10 +47,6 @@ inline void __batadv_br_ip_list_check(void)
 #define br_ip batadv_br_ip
 #define br_ip_list batadv_br_ip_list
 
-#endif /* LINUX_VERSION_IS_LESS(5, 10, 0) */
-
-#if LINUX_VERSION_IS_LESS(5, 14, 0)
-
 #include <linux/if_bridge.h>
 #include <net/addrconf.h>
 
@@ -90,10 +86,12 @@ br_multicast_has_router_adjacent(struct net_device *dev, int proto)
 }
 #endif
 
-#endif /* LINUX_VERSION_IS_LESS(5, 14, 0) */
+#endif /* LINUX_VERSION_IS_LESS(5, 10, 0) */
 
 #if LINUX_VERSION_IS_LESS(5, 15, 0)
 
+#include <linux/etherdevice.h>
+
 static inline void batadv_eth_hw_addr_set(struct net_device *dev,
 					  const u8 *addr)
 {