// SPDX-License-Identifier: GPL-2.0/* 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;} static void __mr_free_table(struct work_struct *work){	struct mr_table *mrt = container_of(to_rcu_work(work),					    struct mr_table, work); 	rhltable_destroy(&mrt->mfc_hash);	kfree(mrt);} void mr_table_free(struct mr_table *mrt){	queue_rcu_work(system_dfl_wq, &mrt->work);} 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_obj(*mrt, GFP_KERNEL_ACCOUNT);	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_RCU_WORK(&mrt->work, __mr_free_table);	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;} 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;} 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;} 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);} #ifdef CONFIG_PROC_FSvoid *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;} 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;} 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;} 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;}#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, READ_ONCE(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 = READ_ONCE(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 = atomic_long_read(&c->mfc_un.res.pkt);	mfcs.mfcs_bytes = atomic_long_read(&c->mfc_un.res.bytes);	mfcs.mfcs_wrong_if = atomic_long_read(&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;} 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; 		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;} 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;} 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;}