From 716ca530e1c4515d8683c9d5be3d56b301758b66 Mon Sep 17 00:00:00 2001
From: James <>
Date: Wed, 4 Nov 2015 11:49:21 +0000
Subject: trunk-47381

---
 .../643-bridge_remove_ipv6_dependency.patch        | 123 +++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 target/linux/generic/patches-4.3/643-bridge_remove_ipv6_dependency.patch

(limited to 'target/linux/generic/patches-4.3/643-bridge_remove_ipv6_dependency.patch')

diff --git a/target/linux/generic/patches-4.3/643-bridge_remove_ipv6_dependency.patch b/target/linux/generic/patches-4.3/643-bridge_remove_ipv6_dependency.patch
new file mode 100644
index 0000000..ee5c244
--- /dev/null
+++ b/target/linux/generic/patches-4.3/643-bridge_remove_ipv6_dependency.patch
@@ -0,0 +1,123 @@
+From: Jonas Gorski <jonas.gorski+openwrt@gmail.com>
+Subject: [PATCH] bridge: remove IPv6 depependency of bridge in 2.6.38+
+
+Since 2.6.38 the bridge module has a dependency to IPv6 if IPv6 is
+enabled. Since the IPv6 module isn't exactly lightweight and bridge also
+only needs a single function from IPv6, it's rather easy to create a
+common "lib" module with a RCU pointer to the actual implementation, if
+the IPv6 module is loaded (although slightly hackish).
+
+The codepath seems to be only taken when using IPv6, so there should be
+no negative side effects when IPv6 isn't loaded. I did not measure how
+big the performance impact is.
+---
+--- a/include/net/addrconf.h
++++ b/include/net/addrconf.h
+@@ -122,6 +122,12 @@ static inline int addrconf_ifid_eui48(u8
+ 	return 0;
+ }
+ 
++extern int			(*ipv6_dev_get_saddr_hook)(struct net *net,
++						const struct net_device *dev,
++						const struct in6_addr *daddr,
++						unsigned int prefs,
++						struct in6_addr *saddr);
++
+ static inline unsigned long addrconf_timeout_fixup(u32 timeout,
+ 						   unsigned int unit)
+ {
+--- a/net/bridge/Kconfig
++++ b/net/bridge/Kconfig
+@@ -6,7 +6,6 @@ config BRIDGE
+ 	tristate "802.1d Ethernet Bridging"
+ 	select LLC
+ 	select STP
+-	depends on IPV6 || IPV6=n
+ 	---help---
+ 	  If you say Y here, then your Linux box will be able to act as an
+ 	  Ethernet bridge, which means that the different Ethernet segments it
+--- a/net/ipv6/Makefile
++++ b/net/ipv6/Makefile
+@@ -46,6 +46,7 @@ obj-y += addrconf_core.o exthdrs_core.o
+ obj-$(CONFIG_INET) += output_core.o protocol.o $(ipv6-offload)
+ 
+ obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o
++obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_stubs.o
+ 
+ ifneq ($(CONFIG_IPV6),)
+ obj-$(CONFIG_NET_UDP_TUNNEL) += ip6_udp_tunnel.o
+--- a/net/ipv6/addrconf.c
++++ b/net/ipv6/addrconf.c
+@@ -1509,7 +1509,7 @@ out:
+ 	return hiscore_idx;
+ }
+ 
+-int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
++static int ___ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
+ 		       const struct in6_addr *daddr, unsigned int prefs,
+ 		       struct in6_addr *saddr)
+ {
+@@ -1579,7 +1579,6 @@ int ipv6_dev_get_saddr(struct net *net,
+ 	in6_ifa_put(hiscore->ifa);
+ 	return 0;
+ }
+-EXPORT_SYMBOL(ipv6_dev_get_saddr);
+ 
+ int __ipv6_get_lladdr(struct inet6_dev *idev, struct in6_addr *addr,
+ 		      u32 banned_flags)
+@@ -5941,6 +5940,9 @@ int __init addrconf_init(void)
+ 
+ 	ipv6_addr_label_rtnl_register();
+ 
++	BUG_ON(ipv6_dev_get_saddr_hook != NULL);
++	rcu_assign_pointer(ipv6_dev_get_saddr_hook, ___ipv6_dev_get_saddr);
++
+ 	return 0;
+ errout:
+ 	rtnl_af_unregister(&inet6_ops);
+@@ -5960,6 +5962,9 @@ void addrconf_cleanup(void)
+ 	struct net_device *dev;
+ 	int i;
+ 
++	rcu_assign_pointer(ipv6_dev_get_saddr_hook, NULL);
++	synchronize_rcu();
++
+ 	unregister_netdevice_notifier(&ipv6_dev_notf);
+ 	unregister_pernet_subsys(&addrconf_ops);
+ 	ipv6_addr_label_cleanup();
+--- /dev/null
++++ b/net/ipv6/inet6_stubs.c
+@@ -0,0 +1,33 @@
++/*
++ *      This program is free software; you can redistribute it and/or
++ *      modify it under the terms of the GNU General Public License
++ *      as published by the Free Software Foundation; either version
++ *      2 of the License, or (at your option) any later version.
++ */
++#include <linux/export.h>
++#include <net/ipv6.h>
++
++int (*ipv6_dev_get_saddr_hook)(struct net *net, const struct net_device *dev,
++			const struct in6_addr *daddr, unsigned int prefs,
++			struct in6_addr *saddr);
++
++EXPORT_SYMBOL(ipv6_dev_get_saddr_hook);
++
++int ipv6_dev_get_saddr(struct net *net, const struct net_device *dst_dev,
++			const struct in6_addr *daddr, unsigned int prefs,
++			struct in6_addr *saddr)
++{
++	int ret = -EADDRNOTAVAIL;
++	typeof(ipv6_dev_get_saddr_hook) dev_get_saddr;
++
++	rcu_read_lock();
++	dev_get_saddr = rcu_dereference(ipv6_dev_get_saddr_hook);
++
++	if (dev_get_saddr)
++		ret = dev_get_saddr(net, dst_dev, daddr, prefs, saddr);
++
++	rcu_read_unlock();
++	return ret;
++}
++EXPORT_SYMBOL(ipv6_dev_get_saddr);
++
-- 
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