net/ipv4/ipmr_base.c - linux - Git at Google

 /* Linux multicast routing support
  * Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation
  */

 #include <linux/rhashtable.h>
 #include <linux/mroute_base.h>

 /* Sets everything common except 'dev', since that is done under locking */
 void vif_device_init(struct vif_device *v,
 		     struct net_device *dev,
 		     unsigned long rate_limit,
 		     unsigned char threshold,
 		     unsigned short flags,
 		     unsigned short get_iflink_mask)
 {
 	RCU_INIT_POINTER(v->dev, NULL);
 	v->bytes_in = 0;
 	v->bytes_out = 0;
 	v->pkt_in = 0;
 	v->pkt_out = 0;
 	v->rate_limit = rate_limit;
 	v->flags = flags;
 	v->threshold = threshold;
 	if (v->flags & get_iflink_mask)
 		v->link = dev_get_iflink(dev);
 	else
 		v->link = dev->ifindex;
 }
 EXPORT_SYMBOL(vif_device_init);

 struct mr_table *
 mr_table_alloc(struct net *net, u32 id,
 	       struct mr_table_ops *ops,
 	       void (*expire_func)(struct timer_list *t),
 	       void (*table_set)(struct mr_table *mrt,
 				 struct net *net))
 {
 	struct mr_table *mrt;
 	int err;

 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
 	if (!mrt)
 		return ERR_PTR(-ENOMEM);
 	mrt->id = id;
 	write_pnet(&mrt->net, net);

 	mrt->ops = *ops;
 	err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
 	if (err) {
 		kfree(mrt);
 		return ERR_PTR(err);
 	}
 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);

 	timer_setup(&mrt->ipmr_expire_timer, expire_func, 0);

 	mrt->mroute_reg_vif_num = -1;
 	table_set(mrt, net);
 	return mrt;
 }
 EXPORT_SYMBOL(mr_table_alloc);

 void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent)
 {
 	struct rhlist_head *tmp, *list;
 	struct mr_mfc *c;

 	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
 		if (parent == -1 || parent == c->mfc_parent)
 			return c;

 	return NULL;
 }
 EXPORT_SYMBOL(mr_mfc_find_parent);

 void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi)
 {
 	struct rhlist_head *tmp, *list;
 	struct mr_mfc *c;

 	list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
 			       *mrt->ops.rht_params);
 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
 		if (c->mfc_un.res.ttls[vifi] < 255)
 			return c;

 	return NULL;
 }
 EXPORT_SYMBOL(mr_mfc_find_any_parent);

 void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg)
 {
 	struct rhlist_head *tmp, *list;
 	struct mr_mfc *c, *proxy;

 	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
 	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
 		if (c->mfc_un.res.ttls[vifi] < 255)
 			return c;

 		/* It's ok if the vifi is part of the static tree */
 		proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
 		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
 			return c;
 	}

 	return mr_mfc_find_any_parent(mrt, vifi);
 }
 EXPORT_SYMBOL(mr_mfc_find_any);

 #ifdef CONFIG_PROC_FS
 void *mr_vif_seq_idx(struct net *net, struct mr_vif_iter *iter, loff_t pos)
 {
 	struct mr_table *mrt = iter->mrt;

 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
 		if (!VIF_EXISTS(mrt, iter->ct))
 			continue;
 		if (pos-- == 0)
 			return &mrt->vif_table[iter->ct];
 	}
 	return NULL;
 }
 EXPORT_SYMBOL(mr_vif_seq_idx);

 void *mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct mr_vif_iter *iter = seq->private;
 	struct net *net = seq_file_net(seq);
 	struct mr_table *mrt = iter->mrt;

 	++*pos;
 	if (v == SEQ_START_TOKEN)
 		return mr_vif_seq_idx(net, iter, 0);

 	while (++iter->ct < mrt->maxvif) {
 		if (!VIF_EXISTS(mrt, iter->ct))
 			continue;
 		return &mrt->vif_table[iter->ct];
 	}
 	return NULL;
 }
 EXPORT_SYMBOL(mr_vif_seq_next);

 void *mr_mfc_seq_idx(struct net *net,
 		     struct mr_mfc_iter *it, loff_t pos)
 {
 	struct mr_table *mrt = it->mrt;
 	struct mr_mfc *mfc;

 	rcu_read_lock();
 	it->cache = &mrt->mfc_cache_list;
 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
 		if (pos-- == 0)
 			return mfc;
 	rcu_read_unlock();

 	spin_lock_bh(it->lock);
 	it->cache = &mrt->mfc_unres_queue;
 	list_for_each_entry(mfc, it->cache, list)
 		if (pos-- == 0)
 			return mfc;
 	spin_unlock_bh(it->lock);

 	it->cache = NULL;
 	return NULL;
 }
 EXPORT_SYMBOL(mr_mfc_seq_idx);

 void *mr_mfc_seq_next(struct seq_file *seq, void *v,
 		      loff_t *pos)
 {
 	struct mr_mfc_iter *it = seq->private;
 	struct net *net = seq_file_net(seq);
 	struct mr_table *mrt = it->mrt;
 	struct mr_mfc *c = v;

 	++*pos;

 	if (v == SEQ_START_TOKEN)
 		return mr_mfc_seq_idx(net, seq->private, 0);

 	if (c->list.next != it->cache)
 		return list_entry(c->list.next, struct mr_mfc, list);

 	if (it->cache == &mrt->mfc_unres_queue)
 		goto end_of_list;

 	/* exhausted cache_array, show unresolved */
 	rcu_read_unlock();
 	it->cache = &mrt->mfc_unres_queue;

 	spin_lock_bh(it->lock);
 	if (!list_empty(it->cache))
 		return list_first_entry(it->cache, struct mr_mfc, list);

 end_of_list:
 	spin_unlock_bh(it->lock);
 	it->cache = NULL;

 	return NULL;
 }
 EXPORT_SYMBOL(mr_mfc_seq_next);
 #endif

 int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 		   struct mr_mfc *c, struct rtmsg *rtm)
 {
 	struct net_device *vif_dev;
 	struct rta_mfc_stats mfcs;
 	struct nlattr *mp_attr;
 	struct rtnexthop *nhp;
 	unsigned long lastuse;
 	int ct;

 	/* If cache is unresolved, don't try to parse IIF and OIF */
 	if (c->mfc_parent >= MAXVIFS) {
 		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
 		return -ENOENT;
 	}

 	rcu_read_lock();
 	vif_dev = rcu_dereference(mrt->vif_table[c->mfc_parent].dev);
 	if (vif_dev && nla_put_u32(skb, RTA_IIF, vif_dev->ifindex) < 0) {
 		rcu_read_unlock();
 		return -EMSGSIZE;
 	}
 	rcu_read_unlock();

 	if (c->mfc_flags & MFC_OFFLOAD)
 		rtm->rtm_flags |= RTNH_F_OFFLOAD;

 	mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH);
 	if (!mp_attr)
 		return -EMSGSIZE;

 	rcu_read_lock();
 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
 		struct vif_device *vif = &mrt->vif_table[ct];

 		vif_dev = rcu_dereference(vif->dev);
 		if (vif_dev && c->mfc_un.res.ttls[ct] < 255) {

 			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
 			if (!nhp) {
 				rcu_read_unlock();
 				nla_nest_cancel(skb, mp_attr);
 				return -EMSGSIZE;
 			}

 			nhp->rtnh_flags = 0;
 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
 			nhp->rtnh_ifindex = vif_dev->ifindex;
 			nhp->rtnh_len = sizeof(*nhp);
 		}
 	}
 	rcu_read_unlock();

 	nla_nest_end(skb, mp_attr);

 	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
 	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;

 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
 	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
 	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
 			      RTA_PAD))
 		return -EMSGSIZE;

 	rtm->rtm_type = RTN_MULTICAST;
 	return 1;
 }
 EXPORT_SYMBOL(mr_fill_mroute);

 static bool mr_mfc_uses_dev(const struct mr_table *mrt,
 			    const struct mr_mfc *c,
 			    const struct net_device *dev)
 {
 	int ct;

 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
 		const struct net_device *vif_dev;
 		const struct vif_device *vif;

 		vif = &mrt->vif_table[ct];
 		vif_dev = rcu_access_pointer(vif->dev);
 		if (vif_dev && c->mfc_un.res.ttls[ct] < 255 &&
 		    vif_dev == dev)
 			return true;
 	}
 	return false;
 }

 int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
 		  struct netlink_callback *cb,
 		  int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
 			      u32 portid, u32 seq, struct mr_mfc *c,
 			      int cmd, int flags),
 		  spinlock_t *lock, struct fib_dump_filter *filter)
 {
 	unsigned int e = 0, s_e = cb->args[1];
 	unsigned int flags = NLM_F_MULTI;
 	struct mr_mfc *mfc;
 	int err;

 	if (filter->filter_set)
 		flags |= NLM_F_DUMP_FILTERED;

 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list,
 				lockdep_rtnl_is_held()) {
 		if (e < s_e)
 			goto next_entry;
 		if (filter->dev &&
 		    !mr_mfc_uses_dev(mrt, mfc, filter->dev))
 			goto next_entry;

 		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
 			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
 		if (err < 0)
 			goto out;
 next_entry:
 		e++;
 	}

 	spin_lock_bh(lock);
 	list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
 		if (e < s_e)
 			goto next_entry2;
 		if (filter->dev &&
 		    !mr_mfc_uses_dev(mrt, mfc, filter->dev))
 			goto next_entry2;

 		err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
 			   cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
 		if (err < 0) {
 			spin_unlock_bh(lock);
 			goto out;
 		}
 next_entry2:
 		e++;
 	}
 	spin_unlock_bh(lock);
 	err = 0;
 out:
 	cb->args[1] = e;
 	return err;
 }
 EXPORT_SYMBOL(mr_table_dump);

 int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 		     struct mr_table *(*iter)(struct net *net,
 					      struct mr_table *mrt),
 		     int (*fill)(struct mr_table *mrt,
 				 struct sk_buff *skb,
 				 u32 portid, u32 seq, struct mr_mfc *c,
 				 int cmd, int flags),
 		     spinlock_t *lock, struct fib_dump_filter *filter)
 {
 	unsigned int t = 0, s_t = cb->args[0];
 	struct net *net = sock_net(skb->sk);
 	struct mr_table *mrt;
 	int err;

 	/* multicast does not track protocol or have route type other
 	 * than RTN_MULTICAST
 	 */
 	if (filter->filter_set) {
 		if (filter->protocol || filter->flags ||
 		    (filter->rt_type && filter->rt_type != RTN_MULTICAST))
 			return skb->len;
 	}

 	rcu_read_lock();
 	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
 		if (t < s_t)
 			goto next_table;

 		err = mr_table_dump(mrt, skb, cb, fill, lock, filter);
 		if (err < 0)
 			break;
 		cb->args[1] = 0;
 next_table:
 		t++;
 	}
 	rcu_read_unlock();

 	cb->args[0] = t;

 	return skb->len;
 }
 EXPORT_SYMBOL(mr_rtm_dumproute);

 int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 	    int (*rules_dump)(struct net *net,
 			      struct notifier_block *nb,
 			      struct netlink_ext_ack *extack),
 	    struct mr_table *(*mr_iter)(struct net *net,
 					struct mr_table *mrt),
 	    struct netlink_ext_ack *extack)
 {
 	struct mr_table *mrt;
 	int err;

 	err = rules_dump(net, nb, extack);
 	if (err)
 		return err;

 	for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) {
 		struct vif_device *v = &mrt->vif_table[0];
 		struct net_device *vif_dev;
 		struct mr_mfc *mfc;
 		int vifi;

 		/* Notifiy on table VIF entries */
 		rcu_read_lock();
 		for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
 			vif_dev = rcu_dereference(v->dev);
 			if (!vif_dev)
 				continue;

 			err = mr_call_vif_notifier(nb, family,
 						   FIB_EVENT_VIF_ADD, v,
 						   vif_dev, vifi,
 						   mrt->id, extack);
 			if (err)
 				break;
 		}
 		rcu_read_unlock();

 		if (err)
 			return err;

 		/* Notify on table MFC entries */
 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
 			err = mr_call_mfc_notifier(nb, family,
 						   FIB_EVENT_ENTRY_ADD,
 						   mfc, mrt->id, extack);
 			if (err)
 				return err;
 		}
 	}

 	return 0;
 }
 EXPORT_SYMBOL(mr_dump);
	/* Linux multicast routing support
	* Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation
	*/

	#include <linux/rhashtable.h>
	#include <linux/mroute_base.h>

	/* Sets everything common except 'dev', since that is done under locking */
	void vif_device_init(struct vif_device *v,
	struct net_device *dev,
	unsigned long rate_limit,
	unsigned char threshold,
	unsigned short flags,
	unsigned short get_iflink_mask)
	{
	RCU_INIT_POINTER(v->dev, NULL);
	v->bytes_in = 0;
	v->bytes_out = 0;
	v->pkt_in = 0;
	v->pkt_out = 0;
	v->rate_limit = rate_limit;
	v->flags = flags;
	v->threshold = threshold;
	if (v->flags & get_iflink_mask)
	v->link = dev_get_iflink(dev);
	else
	v->link = dev->ifindex;
	}
	EXPORT_SYMBOL(vif_device_init);

	struct mr_table *
	mr_table_alloc(struct net *net, u32 id,
	struct mr_table_ops *ops,
	void (expire_func)(struct timer_list t),
	void (table_set)(struct mr_table mrt,
	struct net *net))
	{
	struct mr_table *mrt;
	int err;

	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
	if (!mrt)
	return ERR_PTR(-ENOMEM);
	mrt->id = id;
	write_pnet(&mrt->net, net);

	mrt->ops = *ops;
	err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
	if (err) {
	kfree(mrt);
	return ERR_PTR(err);
	}
	INIT_LIST_HEAD(&mrt->mfc_cache_list);
	INIT_LIST_HEAD(&mrt->mfc_unres_queue);

	timer_setup(&mrt->ipmr_expire_timer, expire_func, 0);

	mrt->mroute_reg_vif_num = -1;
	table_set(mrt, net);
	return mrt;
	}
	EXPORT_SYMBOL(mr_table_alloc);

	void mr_mfc_find_parent(struct mr_table mrt, void *hasharg, int parent)
	{
	struct rhlist_head tmp, list;
	struct mr_mfc *c;

	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
	rhl_for_each_entry_rcu(c, tmp, list, mnode)
	if (parent == -1 \|\| parent == c->mfc_parent)
	return c;

	return NULL;
	}
	EXPORT_SYMBOL(mr_mfc_find_parent);

	void mr_mfc_find_any_parent(struct mr_table mrt, int vifi)
	{
	struct rhlist_head tmp, list;
	struct mr_mfc *c;

	list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
	*mrt->ops.rht_params);
	rhl_for_each_entry_rcu(c, tmp, list, mnode)
	if (c->mfc_un.res.ttls[vifi] < 255)
	return c;

	return NULL;
	}
	EXPORT_SYMBOL(mr_mfc_find_any_parent);

	void mr_mfc_find_any(struct mr_table mrt, int vifi, void *hasharg)
	{
	struct rhlist_head tmp, list;
	struct mr_mfc c, proxy;

	list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
	if (c->mfc_un.res.ttls[vifi] < 255)
	return c;

	/* It's ok if the vifi is part of the static tree */
	proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
	if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
	return c;
	}

	return mr_mfc_find_any_parent(mrt, vifi);
	}
	EXPORT_SYMBOL(mr_mfc_find_any);

	#ifdef CONFIG_PROC_FS
	void mr_vif_seq_idx(struct net net, struct mr_vif_iter *iter, loff_t pos)
	{
	struct mr_table *mrt = iter->mrt;

	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
	if (!VIF_EXISTS(mrt, iter->ct))
	continue;
	if (pos-- == 0)
	return &mrt->vif_table[iter->ct];
	}
	return NULL;
	}
	EXPORT_SYMBOL(mr_vif_seq_idx);

	void mr_vif_seq_next(struct seq_file seq, void v, loff_t pos)
	{
	struct mr_vif_iter *iter = seq->private;
	struct net *net = seq_file_net(seq);
	struct mr_table *mrt = iter->mrt;

	++*pos;
	if (v == SEQ_START_TOKEN)
	return mr_vif_seq_idx(net, iter, 0);

	while (++iter->ct < mrt->maxvif) {
	if (!VIF_EXISTS(mrt, iter->ct))
	continue;
	return &mrt->vif_table[iter->ct];
	}
	return NULL;
	}
	EXPORT_SYMBOL(mr_vif_seq_next);

	void mr_mfc_seq_idx(struct net net,
	struct mr_mfc_iter *it, loff_t pos)
	{
	struct mr_table *mrt = it->mrt;
	struct mr_mfc *mfc;

	rcu_read_lock();
	it->cache = &mrt->mfc_cache_list;
	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
	if (pos-- == 0)
	return mfc;
	rcu_read_unlock();

	spin_lock_bh(it->lock);
	it->cache = &mrt->mfc_unres_queue;
	list_for_each_entry(mfc, it->cache, list)
	if (pos-- == 0)
	return mfc;
	spin_unlock_bh(it->lock);

	it->cache = NULL;
	return NULL;
	}
	EXPORT_SYMBOL(mr_mfc_seq_idx);

	void mr_mfc_seq_next(struct seq_file seq, void *v,
	loff_t *pos)
	{
	struct mr_mfc_iter *it = seq->private;
	struct net *net = seq_file_net(seq);
	struct mr_table *mrt = it->mrt;
	struct mr_mfc *c = v;

	++*pos;

	if (v == SEQ_START_TOKEN)
	return mr_mfc_seq_idx(net, seq->private, 0);

	if (c->list.next != it->cache)
	return list_entry(c->list.next, struct mr_mfc, list);

	if (it->cache == &mrt->mfc_unres_queue)
	goto end_of_list;

	/* exhausted cache_array, show unresolved */
	rcu_read_unlock();
	it->cache = &mrt->mfc_unres_queue;

	spin_lock_bh(it->lock);
	if (!list_empty(it->cache))
	return list_first_entry(it->cache, struct mr_mfc, list);

	end_of_list:
	spin_unlock_bh(it->lock);
	it->cache = NULL;

	return NULL;
	}
	EXPORT_SYMBOL(mr_mfc_seq_next);
	#endif

	int mr_fill_mroute(struct mr_table mrt, struct sk_buff skb,
	struct mr_mfc c, struct rtmsg rtm)
	{
	struct net_device *vif_dev;
	struct rta_mfc_stats mfcs;
	struct nlattr *mp_attr;
	struct rtnexthop *nhp;
	unsigned long lastuse;
	int ct;

	/* If cache is unresolved, don't try to parse IIF and OIF */
	if (c->mfc_parent >= MAXVIFS) {
	rtm->rtm_flags \|= RTNH_F_UNRESOLVED;
	return -ENOENT;
	}

	rcu_read_lock();
	vif_dev = rcu_dereference(mrt->vif_table[c->mfc_parent].dev);
	if (vif_dev && nla_put_u32(skb, RTA_IIF, vif_dev->ifindex) < 0) {
	rcu_read_unlock();
	return -EMSGSIZE;
	}
	rcu_read_unlock();

	if (c->mfc_flags & MFC_OFFLOAD)
	rtm->rtm_flags \|= RTNH_F_OFFLOAD;

	mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH);
	if (!mp_attr)
	return -EMSGSIZE;

	rcu_read_lock();
	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
	struct vif_device *vif = &mrt->vif_table[ct];

	vif_dev = rcu_dereference(vif->dev);
	if (vif_dev && c->mfc_un.res.ttls[ct] < 255) {

	nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
	if (!nhp) {
	rcu_read_unlock();
	nla_nest_cancel(skb, mp_attr);
	return -EMSGSIZE;
	}

	nhp->rtnh_flags = 0;
	nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
	nhp->rtnh_ifindex = vif_dev->ifindex;
	nhp->rtnh_len = sizeof(*nhp);
	}
	}
	rcu_read_unlock();

	nla_nest_end(skb, mp_attr);

	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;

	mfcs.mfcs_packets = c->mfc_un.res.pkt;
	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) \|\|
	nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
	RTA_PAD))
	return -EMSGSIZE;

	rtm->rtm_type = RTN_MULTICAST;
	return 1;
	}
	EXPORT_SYMBOL(mr_fill_mroute);

	static bool mr_mfc_uses_dev(const struct mr_table *mrt,
	const struct mr_mfc *c,
	const struct net_device *dev)
	{
	int ct;

	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
	const struct net_device *vif_dev;
	const struct vif_device *vif;

	vif = &mrt->vif_table[ct];
	vif_dev = rcu_access_pointer(vif->dev);
	if (vif_dev && c->mfc_un.res.ttls[ct] < 255 &&
	vif_dev == dev)
	return true;
	}
	return false;
	}

	int mr_table_dump(struct mr_table mrt, struct sk_buff skb,
	struct netlink_callback *cb,
	int (fill)(struct mr_table mrt, struct sk_buff *skb,
	u32 portid, u32 seq, struct mr_mfc *c,
	int cmd, int flags),
	spinlock_t lock, struct fib_dump_filter filter)
	{
	unsigned int e = 0, s_e = cb->args[1];
	unsigned int flags = NLM_F_MULTI;
	struct mr_mfc *mfc;
	int err;

	if (filter->filter_set)
	flags \|= NLM_F_DUMP_FILTERED;

	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list,
	lockdep_rtnl_is_held()) {
	if (e < s_e)
	goto next_entry;
	if (filter->dev &&
	!mr_mfc_uses_dev(mrt, mfc, filter->dev))
	goto next_entry;

	err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
	if (err < 0)
	goto out;
	next_entry:
	e++;
	}

	spin_lock_bh(lock);
	list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
	if (e < s_e)
	goto next_entry2;
	if (filter->dev &&
	!mr_mfc_uses_dev(mrt, mfc, filter->dev))
	goto next_entry2;

	err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
	if (err < 0) {
	spin_unlock_bh(lock);
	goto out;
	}
	next_entry2:
	e++;
	}
	spin_unlock_bh(lock);
	err = 0;
	out:
	cb->args[1] = e;
	return err;
	}
	EXPORT_SYMBOL(mr_table_dump);

	int mr_rtm_dumproute(struct sk_buff skb, struct netlink_callback cb,
	struct mr_table (iter)(struct net *net,
	struct mr_table *mrt),
	int (fill)(struct mr_table mrt,
	struct sk_buff *skb,
	u32 portid, u32 seq, struct mr_mfc *c,
	int cmd, int flags),
	spinlock_t lock, struct fib_dump_filter filter)
	{
	unsigned int t = 0, s_t = cb->args[0];
	struct net *net = sock_net(skb->sk);
	struct mr_table *mrt;
	int err;

	/* multicast does not track protocol or have route type other
	* than RTN_MULTICAST
	*/
	if (filter->filter_set) {
	if (filter->protocol \|\| filter->flags \|\|
	(filter->rt_type && filter->rt_type != RTN_MULTICAST))
	return skb->len;
	}

	rcu_read_lock();
	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
	if (t < s_t)
	goto next_table;

	err = mr_table_dump(mrt, skb, cb, fill, lock, filter);
	if (err < 0)
	break;
	cb->args[1] = 0;
	next_table:
	t++;
	}
	rcu_read_unlock();

	cb->args[0] = t;

	return skb->len;
	}
	EXPORT_SYMBOL(mr_rtm_dumproute);

	int mr_dump(struct net net, struct notifier_block nb, unsigned short family,
	int (rules_dump)(struct net net,
	struct notifier_block *nb,
	struct netlink_ext_ack *extack),
	struct mr_table (mr_iter)(struct net *net,
	struct mr_table *mrt),
	struct netlink_ext_ack *extack)
	{
	struct mr_table *mrt;
	int err;

	err = rules_dump(net, nb, extack);
	if (err)
	return err;

	for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) {
	struct vif_device *v = &mrt->vif_table[0];
	struct net_device *vif_dev;
	struct mr_mfc *mfc;
	int vifi;

	/* Notifiy on table VIF entries */
	rcu_read_lock();
	for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
	vif_dev = rcu_dereference(v->dev);
	if (!vif_dev)
	continue;

	err = mr_call_vif_notifier(nb, family,
	FIB_EVENT_VIF_ADD, v,
	vif_dev, vifi,
	mrt->id, extack);
	if (err)
	break;
	}
	rcu_read_unlock();

	if (err)
	return err;

	/* Notify on table MFC entries */
	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
	err = mr_call_mfc_notifier(nb, family,
	FIB_EVENT_ENTRY_ADD,
	mfc, mrt->id, extack);
	if (err)
	return err;
	}
	}

	return 0;
	}
	EXPORT_SYMBOL(mr_dump);