Merge branch 'mlxsw-Add-support-for-offloading-IPv4-multicast-routes'

Jiri Pirko says:

====================
mlxsw: Add support for offloading IPv4 multicast routes

Yotam says:

This patch-set introduces offloading of the kernel IPv4 multicast router
logic in the Spectrum driver.

The first patch makes the Spectrum driver ignore FIB notifications that are
not of address family IPv4 or IPv6. This is needed in order to prevent
crashes while the next patches introduce the RTNL_FAMILY_IPMR FIB
notifications.

Patches 2-5 update ipmr to use the FIB notification chain for both MFC and
VIF notifications, and patches 8-12 update the Spectrum driver to register
to these notifications and offload the routes.

Similarly to IPv4 and IPv6, any failure will trigger the abort mechanism
which is updated in this patch-set to eject multicast route tables too.

At this stage, the following limitations apply:
 - A multicast MFC route will be offloaded by the driver if all the output
   interfaces are Spectrum router interfaces (RIFs). In any other case
   (which includes pimreg device, tunnel devices and management ports) the
   route will be trapped to the CPU and the packets will be forwarded by
   software.
 - ipmr proxy routes are not supported and will trigger the abort
   mechanism.
 - The MFC TTL values are currently treated as boolean: if the value is
   different than 255, the traffic is forwarded to the interface and if the
   value is 255 it is not forwarded. Dropping packets based on their TTL isn't
   currently supported.

To allow users to have visibility on which of the routes are offloaded and
which are not, patch 6 introduces a per-route offload indication similar to
IPv4 and IPv6 routes which is sent to the user via the RTNetlink interface.

The Spectrum driver multicast router offloading support, which is
introduced in patches 8 and 9, is divided into two parts:
 - The hardware logic which abstracts the Spectrum hardware and provides a
   simple API for the upper levels.
 - The offloading logic which gets the MFC and VIF notifications from the
   kernel and updates the hardware using the hardware logic part.

Finally, the last patch makes the Spectrum router logic not ignore the
multicast FIB notifications and call the corresponding functions in the
multicast router offloading logic.

---
v2->v3:
 - Move the ipmr_rule_default function definition to be inside the already
   existing CONFIG_IP_MROUTE_MULTIPLE_TABLES ifdef block (patch 6)
 - Remove double =0 initialization in spectrum_mr.c (patch 7)
 - Fix route4 allocation size (patch 7)
v1->v2:
 - Add comments for struct fields in mroute.h
 - Take the mrt_lock while dumping VIFs in the fib_notifier dump callback
 - Update the MFC lastuse field too
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -17,7 +17,8 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_kvdl.o spectrum_acl_tcam.o \
 				   spectrum_acl.o spectrum_flower.o \
 				   spectrum_cnt.o spectrum_fid.o \
-				   spectrum_ipip.o spectrum_acl_flex_actions.o
+				   spectrum_ipip.o spectrum_acl_flex_actions.o \
+				   spectrum_mr.o spectrum_mr_tcam.o
 mlxsw_spectrum-$(CONFIG_MLXSW_SPECTRUM_DCB)	+= spectrum_dcb.o
 mlxsw_spectrum-$(CONFIG_NET_DEVLINK) += spectrum_dpipe.o
 obj-$(CONFIG_MLXSW_MINIMAL)	+= mlxsw_minimal.o

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -139,6 +139,7 @@ struct mlxsw_sp_port_mall_tc_entry {
 struct mlxsw_sp_sb;
 struct mlxsw_sp_bridge;
 struct mlxsw_sp_router;
+struct mlxsw_sp_mr;
 struct mlxsw_sp_acl;
 struct mlxsw_sp_counter_pool;
 struct mlxsw_sp_fid_core;
@@ -153,6 +154,7 @@ struct mlxsw_sp {
 	struct mlxsw_sp_sb *sb;
 	struct mlxsw_sp_bridge *bridge;
 	struct mlxsw_sp_router *router;
+	struct mlxsw_sp_mr *mr;
 	struct mlxsw_afa *afa;
 	struct mlxsw_sp_acl *acl;
 	struct mlxsw_sp_fid_core *fid_core;

drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.h

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.h
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MLXSW_SPECTRUM_MCROUTER_H
+#define _MLXSW_SPECTRUM_MCROUTER_H
+
+#include <linux/mroute.h>
+#include "spectrum_router.h"
+#include "spectrum.h"
+
+enum mlxsw_sp_mr_route_action {
+	MLXSW_SP_MR_ROUTE_ACTION_FORWARD,
+	MLXSW_SP_MR_ROUTE_ACTION_TRAP,
+};
+
+enum mlxsw_sp_mr_route_prio {
+	MLXSW_SP_MR_ROUTE_PRIO_SG,
+	MLXSW_SP_MR_ROUTE_PRIO_STARG,
+	MLXSW_SP_MR_ROUTE_PRIO_CATCHALL,
+	__MLXSW_SP_MR_ROUTE_PRIO_MAX
+};
+
+#define MLXSW_SP_MR_ROUTE_PRIO_MAX (__MLXSW_SP_MR_ROUTE_PRIO_MAX - 1)
+
+struct mlxsw_sp_mr_route_key {
+	int vrid;
+	enum mlxsw_sp_l3proto proto;
+	union mlxsw_sp_l3addr group;
+	union mlxsw_sp_l3addr group_mask;
+	union mlxsw_sp_l3addr source;
+	union mlxsw_sp_l3addr source_mask;
+};
+
+struct mlxsw_sp_mr_route_info {
+	enum mlxsw_sp_mr_route_action route_action;
+	u16 irif_index;
+	u16 *erif_indices;
+	size_t erif_num;
+	u16 min_mtu;
+};
+
+struct mlxsw_sp_mr_route_params {
+	struct mlxsw_sp_mr_route_key key;
+	struct mlxsw_sp_mr_route_info value;
+	enum mlxsw_sp_mr_route_prio prio;
+};
+
+struct mlxsw_sp_mr_ops {
+	int priv_size;
+	int route_priv_size;
+	int (*init)(struct mlxsw_sp *mlxsw_sp, void *priv);
+	int (*route_create)(struct mlxsw_sp *mlxsw_sp, void *priv,
+			    void *route_priv,
+			    struct mlxsw_sp_mr_route_params *route_params);
+	int (*route_update)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+			    struct mlxsw_sp_mr_route_info *route_info);
+	int (*route_stats)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+			   u64 *packets, u64 *bytes);
+	int (*route_action_update)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+				   enum mlxsw_sp_mr_route_action route_action);
+	int (*route_min_mtu_update)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+				    u16 min_mtu);
+	int (*route_irif_update)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+				 u16 irif_index);
+	int (*route_erif_add)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+			      u16 erif_index);
+	int (*route_erif_del)(struct mlxsw_sp *mlxsw_sp, void *route_priv,
+			      u16 erif_index);
+	void (*route_destroy)(struct mlxsw_sp *mlxsw_sp, void *priv,
+			      void *route_priv);
+	void (*fini)(void *priv);
+};
+
+struct mlxsw_sp_mr;
+struct mlxsw_sp_mr_table;
+
+int mlxsw_sp_mr_init(struct mlxsw_sp *mlxsw_sp,
+		     const struct mlxsw_sp_mr_ops *mr_ops);
+void mlxsw_sp_mr_fini(struct mlxsw_sp *mlxsw_sp);
+int mlxsw_sp_mr_route4_add(struct mlxsw_sp_mr_table *mr_table,
+			   struct mfc_cache *mfc, bool replace);
+void mlxsw_sp_mr_route4_del(struct mlxsw_sp_mr_table *mr_table,
+			    struct mfc_cache *mfc);
+int mlxsw_sp_mr_vif_add(struct mlxsw_sp_mr_table *mr_table,
+			struct net_device *dev, vifi_t vif_index,
+			unsigned long vif_flags,
+			const struct mlxsw_sp_rif *rif);
+void mlxsw_sp_mr_vif_del(struct mlxsw_sp_mr_table *mr_table, vifi_t vif_index);
+int mlxsw_sp_mr_rif_add(struct mlxsw_sp_mr_table *mr_table,
+			const struct mlxsw_sp_rif *rif);
+void mlxsw_sp_mr_rif_del(struct mlxsw_sp_mr_table *mr_table,
+			 const struct mlxsw_sp_rif *rif);
+void mlxsw_sp_mr_rif_mtu_update(struct mlxsw_sp_mr_table *mr_table,
+				const struct mlxsw_sp_rif *rif, int mtu);
+struct mlxsw_sp_mr_table *mlxsw_sp_mr_table_create(struct mlxsw_sp *mlxsw_sp,
+						   u32 tb_id,
+						   enum mlxsw_sp_l3proto proto);
+void mlxsw_sp_mr_table_destroy(struct mlxsw_sp_mr_table *mr_table);
+void mlxsw_sp_mr_table_flush(struct mlxsw_sp_mr_table *mr_table);
+bool mlxsw_sp_mr_table_empty(const struct mlxsw_sp_mr_table *mr_table);
+
+#endif

drivers/net/ethernet/mellanox/mlxsw/spectrum_mr_tcam.h

+/*
+ * drivers/net/ethernet/mellanox/mlxsw/spectrum_mr_tcam.h
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _MLXSW_SPECTRUM_MCROUTER_TCAM_H
+#define _MLXSW_SPECTRUM_MCROUTER_TCAM_H
+
+#include "spectrum.h"
+#include "spectrum_mr.h"
+
+extern const struct mlxsw_sp_mr_ops mlxsw_sp_mr_tcam_ops;
+
+#endif

include/linux/mroute.h

@@ -5,6 +5,8 @@
 #include <linux/pim.h>
 #include <linux/rhashtable.h>
 #include <net/sock.h>
+#include <net/fib_rules.h>
+#include <net/fib_notifier.h>
 #include <uapi/linux/mroute.h>
 
 #ifdef CONFIG_IP_MROUTE
@@ -18,6 +20,7 @@ int ip_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg);
 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
 int ip_mr_init(void);
+bool ipmr_rule_default(const struct fib_rule *rule);
 #else
 static inline int ip_mroute_setsockopt(struct sock *sock, int optname,
 				       char __user *optval, unsigned int optlen)
@@ -45,6 +48,11 @@ static inline int ip_mroute_opt(int opt)
 {
 	return 0;
 }
+
+static inline bool ipmr_rule_default(const struct fib_rule *rule)
+{
+	return true;
+}
 #endif
 
 struct vif_device {
@@ -58,6 +66,14 @@ struct vif_device {
 	int		link;			/* Physical interface index	*/
 };
 
+struct vif_entry_notifier_info {
+	struct fib_notifier_info info;
+	struct net_device *dev;
+	vifi_t vif_index;
+	unsigned short vif_flags;
+	u32 tb_id;
+};
+
 #define VIFF_STATIC 0x8000
 
 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
@@ -81,9 +97,11 @@ struct mr_table {
 
 /* mfc_flags:
  * MFC_STATIC - the entry was added statically (not by a routing daemon)
+ * MFC_OFFLOAD - the entry was offloaded to the hardware
  */
 enum {
 	MFC_STATIC = BIT(0),
+	MFC_OFFLOAD = BIT(1),
 };
 
 struct mfc_cache_cmp_arg {
@@ -109,6 +127,7 @@ struct mfc_cache_cmp_arg {
  * @wrong_if: number of wrong source interface hits
  * @lastuse: time of last use of the group (traffic or update)
  * @ttls: OIF TTL threshold array
+ * @refcount: reference count for this entry
  * @list: global entry list
  * @rcu: used for entry destruction
  */
@@ -138,14 +157,40 @@ struct mfc_cache {
 			unsigned long wrong_if;
 			unsigned long lastuse;
 			unsigned char ttls[MAXVIFS];
+			refcount_t refcount;
 		} res;
 	} mfc_un;
 	struct list_head list;
 	struct rcu_head	rcu;
 };
 
+struct mfc_entry_notifier_info {
+	struct fib_notifier_info info;
+	struct mfc_cache *mfc;
+	u32 tb_id;
+};
+
 struct rtmsg;
 int ipmr_get_route(struct net *net, struct sk_buff *skb,
 		   __be32 saddr, __be32 daddr,
 		   struct rtmsg *rtm, u32 portid);
+
+#ifdef CONFIG_IP_MROUTE
+void ipmr_cache_free(struct mfc_cache *mfc_cache);
+#else
+static inline void ipmr_cache_free(struct mfc_cache *mfc_cache)
+{
+}
+#endif
+
+static inline void ipmr_cache_put(struct mfc_cache *c)
+{
+	if (refcount_dec_and_test(&c->mfc_un.res.refcount))
+		ipmr_cache_free(c);
+}
+static inline void ipmr_cache_hold(struct mfc_cache *c)
+{
+	refcount_inc(&c->mfc_un.res.refcount);
+}
+
 #endif

include/net/fib_notifier.h

@@ -20,6 +20,8 @@ enum fib_event_type {
 	FIB_EVENT_RULE_DEL,
 	FIB_EVENT_NH_ADD,
 	FIB_EVENT_NH_DEL,
+	FIB_EVENT_VIF_ADD,
+	FIB_EVENT_VIF_DEL,
 };
 
 struct fib_notifier_ops {

include/net/netns/ipv4.h

@@ -163,6 +163,9 @@ struct netns_ipv4 {
 	struct fib_notifier_ops	*notifier_ops;
 	unsigned int	fib_seq;	/* protected by rtnl_mutex */
 
+	struct fib_notifier_ops	*ipmr_notifier_ops;
+	unsigned int	ipmr_seq;	/* protected by rtnl_mutex */
+
 	atomic_t	rt_genid;
 };
 #endif

net/ipv4/ipmr.c

@@ -264,6 +264,22 @@ static void __net_exit ipmr_rules_exit(struct net *net)
 	fib_rules_unregister(net->ipv4.mr_rules_ops);
 	rtnl_unlock();
 }
+
+static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
+{
+	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR);
+}
+
+static unsigned int ipmr_rules_seq_read(struct net *net)
+{
+	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
+}
+
+bool ipmr_rule_default(const struct fib_rule *rule)
+{
+	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
+}
+EXPORT_SYMBOL(ipmr_rule_default);
 #else
 #define ipmr_for_each_table(mrt, net) \
 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
@@ -298,6 +314,22 @@ static void __net_exit ipmr_rules_exit(struct net *net)
 	net->ipv4.mrt = NULL;
 	rtnl_unlock();
 }
+
+static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
+{
+	return 0;
+}
+
+static unsigned int ipmr_rules_seq_read(struct net *net)
+{
+	return 0;
+}
+
+bool ipmr_rule_default(const struct fib_rule *rule)
+{
+	return true;
+}
+EXPORT_SYMBOL(ipmr_rule_default);
 #endif
 
 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
@@ -587,6 +619,82 @@ static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 }
 #endif
 
+static int call_ipmr_vif_entry_notifier(struct notifier_block *nb,
+					struct net *net,
+					enum fib_event_type event_type,
+					struct vif_device *vif,
+					vifi_t vif_index, u32 tb_id)
+{
+	struct vif_entry_notifier_info info = {
+		.info = {
+			.family = RTNL_FAMILY_IPMR,
+			.net = net,
+		},
+		.dev = vif->dev,
+		.vif_index = vif_index,
+		.vif_flags = vif->flags,
+		.tb_id = tb_id,
+	};
+
+	return call_fib_notifier(nb, net, event_type, &info.info);
+}
+
+static int call_ipmr_vif_entry_notifiers(struct net *net,
+					 enum fib_event_type event_type,
+					 struct vif_device *vif,
+					 vifi_t vif_index, u32 tb_id)
+{
+	struct vif_entry_notifier_info info = {
+		.info = {
+			.family = RTNL_FAMILY_IPMR,
+			.net = net,
+		},
+		.dev = vif->dev,
+		.vif_index = vif_index,
+		.vif_flags = vif->flags,
+		.tb_id = tb_id,
+	};
+
+	ASSERT_RTNL();
+	net->ipv4.ipmr_seq++;
+	return call_fib_notifiers(net, event_type, &info.info);
+}
+
+static int call_ipmr_mfc_entry_notifier(struct notifier_block *nb,
+					struct net *net,
+					enum fib_event_type event_type,
+					struct mfc_cache *mfc, u32 tb_id)
+{
+	struct mfc_entry_notifier_info info = {
+		.info = {
+			.family = RTNL_FAMILY_IPMR,
+			.net = net,
+		},
+		.mfc = mfc,
+		.tb_id = tb_id
+	};
+
+	return call_fib_notifier(nb, net, event_type, &info.info);
+}
+
+static int call_ipmr_mfc_entry_notifiers(struct net *net,
+					 enum fib_event_type event_type,
+					 struct mfc_cache *mfc, u32 tb_id)
+{
+	struct mfc_entry_notifier_info info = {
+		.info = {
+			.family = RTNL_FAMILY_IPMR,
+			.net = net,
+		},
+		.mfc = mfc,
+		.tb_id = tb_id
+	};
+
+	ASSERT_RTNL();
+	net->ipv4.ipmr_seq++;
+	return call_fib_notifiers(net, event_type, &info.info);
+}
+
 /**
  *	vif_delete - Delete a VIF entry
  *	@notify: Set to 1, if the caller is a notifier_call
@@ -594,6 +702,7 @@ static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 		      struct list_head *head)
 {
+	struct net *net = read_pnet(&mrt->net);
 	struct vif_device *v;
 	struct net_device *dev;
 	struct in_device *in_dev;
@@ -603,6 +712,10 @@ static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 
 	v = &mrt->vif_table[vifi];
 
+	if (VIF_EXISTS(mrt, vifi))
+		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
+					      mrt->id);
+
 	write_lock_bh(&mrt_lock);
 	dev = v->dev;
 	v->dev = NULL;
@@ -652,10 +765,11 @@ static void ipmr_cache_free_rcu(struct rcu_head *head)
 	kmem_cache_free(mrt_cachep, c);
 }
 
-static inline void ipmr_cache_free(struct mfc_cache *c)
+void ipmr_cache_free(struct mfc_cache *c)
 {
 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
 }
+EXPORT_SYMBOL(ipmr_cache_free);
 
 /* Destroy an unresolved cache entry, killing queued skbs
  * and reporting error to netlink readers.
@@ -851,6 +965,7 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 	if (vifi+1 > mrt->maxvif)
 		mrt->maxvif = vifi+1;
 	write_unlock_bh(&mrt_lock);
+	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
 	return 0;
 }
 
@@ -949,6 +1064,7 @@ static struct mfc_cache *ipmr_cache_alloc(void)
 	if (c) {
 		c->mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
 		c->mfc_un.res.minvif = MAXVIFS;
+		refcount_set(&c->mfc_un.res.refcount, 1);
 	}
 	return c;
 }
@@ -1150,6 +1266,7 @@ static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
 
 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
 {
+	struct net *net = read_pnet(&mrt->net);
 	struct mfc_cache *c;
 
 	/* The entries are added/deleted only under RTNL */
@@ -1161,8 +1278,9 @@ static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
 		return -ENOENT;
 	rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
 	list_del_rcu(&c->list);
+	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
-	ipmr_cache_free(c);
+	ipmr_cache_put(c);
 
 	return 0;
 }
@@ -1189,6 +1307,8 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
 		if (!mrtsock)
 			c->mfc_flags |= MFC_STATIC;
 		write_unlock_bh(&mrt_lock);
+		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
+					      mrt->id);
 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
 		return 0;
 	}
@@ -1238,6 +1358,7 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
 		ipmr_cache_resolve(net, mrt, uc, c);
 		ipmr_cache_free(uc);
 	}
+	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
 	return 0;
 }
@@ -1245,6 +1366,7 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
 /* Close the multicast socket, and clear the vif tables etc */
 static void mroute_clean_tables(struct mr_table *mrt, bool all)
 {
+	struct net *net = read_pnet(&mrt->net);
 	struct mfc_cache *c, *tmp;
 	LIST_HEAD(list);
 	int i;
@@ -1263,8 +1385,10 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
 			continue;
 		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
 		list_del_rcu(&c->list);
+		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c,
+					      mrt->id);
 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
-		ipmr_cache_free(c);
+		ipmr_cache_put(c);
 	}
 
 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
@@ -2156,6 +2280,9 @@ static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
 		return -EMSGSIZE;
 
+	if (c->mfc_flags & MFC_OFFLOAD)
+		rtm->rtm_flags |= RTNH_F_OFFLOAD;
+
 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
 		return -EMSGSIZE;
 
@@ -3048,14 +3175,87 @@ static const struct net_protocol pim_protocol = {
 };
 #endif
 
+static unsigned int ipmr_seq_read(struct net *net)
+{
+	ASSERT_RTNL();
+
+	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
+}
+
+static int ipmr_dump(struct net *net, struct notifier_block *nb)
+{
+	struct mr_table *mrt;
+	int err;
+
+	err = ipmr_rules_dump(net, nb);
+	if (err)
+		return err;
+
+	ipmr_for_each_table(mrt, net) {
+		struct vif_device *v = &mrt->vif_table[0];
+		struct mfc_cache *mfc;
+		int vifi;
+
+		/* Notifiy on table VIF entries */
+		read_lock(&mrt_lock);
+		for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
+			if (!v->dev)
+				continue;
+
+			call_ipmr_vif_entry_notifier(nb, net, FIB_EVENT_VIF_ADD,
+						     v, vifi, mrt->id);
+		}
+		read_unlock(&mrt_lock);
+
+		/* Notify on table MFC entries */
+		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
+			call_ipmr_mfc_entry_notifier(nb, net,
+						     FIB_EVENT_ENTRY_ADD, mfc,
+						     mrt->id);
+	}
+
+	return 0;
+}
+
+static const struct fib_notifier_ops ipmr_notifier_ops_template = {
+	.family		= RTNL_FAMILY_IPMR,
+	.fib_seq_read	= ipmr_seq_read,
+	.fib_dump	= ipmr_dump,
+	.owner		= THIS_MODULE,
+};
+
+int __net_init ipmr_notifier_init(struct net *net)
+{
+	struct fib_notifier_ops *ops;
+
+	net->ipv4.ipmr_seq = 0;
+
+	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
+	if (IS_ERR(ops))
+		return PTR_ERR(ops);
+	net->ipv4.ipmr_notifier_ops = ops;
+
+	return 0;
+}
+
+static void __net_exit ipmr_notifier_exit(struct net *net)
+{
+	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
+	net->ipv4.ipmr_notifier_ops = NULL;
+}
+
 /* Setup for IP multicast routing */
 static int __net_init ipmr_net_init(struct net *net)
 {
 	int err;
 
+	err = ipmr_notifier_init(net);
+	if (err)
+		goto ipmr_notifier_fail;
+
 	err = ipmr_rules_init(net);
 	if (err < 0)
-		goto fail;
+		goto ipmr_rules_fail;
 
 #ifdef CONFIG_PROC_FS
 	err = -ENOMEM;
@@ -3072,7 +3272,9 @@ static int __net_init ipmr_net_init(struct net *net)
 proc_vif_fail:
 	ipmr_rules_exit(net);
 #endif
-fail:
+ipmr_rules_fail:
+	ipmr_notifier_exit(net);
+ipmr_notifier_fail:
 	return err;
 }
 
@@ -3082,6 +3284,7 @@ static void __net_exit ipmr_net_exit(struct net *net)
 	remove_proc_entry("ip_mr_cache", net->proc_net);
 	remove_proc_entry("ip_mr_vif", net->proc_net);
 #endif
+	ipmr_notifier_exit(net);
 	ipmr_rules_exit(net);
 }