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32 results

act_api.c

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  • act_api.c 39.63 KiB
    // SPDX-License-Identifier: GPL-2.0-or-later
    /*
     * net/sched/act_api.c	Packet action API.
     *
     * Author:	Jamal Hadi Salim
     */
    
    #include <linux/types.h>
    #include <linux/kernel.h>
    #include <linux/string.h>
    #include <linux/errno.h>
    #include <linux/slab.h>
    #include <linux/skbuff.h>
    #include <linux/init.h>
    #include <linux/kmod.h>
    #include <linux/err.h>
    #include <linux/module.h>
    #include <net/net_namespace.h>
    #include <net/sock.h>
    #include <net/sch_generic.h>
    #include <net/pkt_cls.h>
    #include <net/act_api.h>
    #include <net/netlink.h>
    
    #ifdef CONFIG_INET
    DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);
    EXPORT_SYMBOL_GPL(tcf_frag_xmit_count);
    #endif
    
    int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
    {
    #ifdef CONFIG_INET
    	if (static_branch_unlikely(&tcf_frag_xmit_count))
    		return sch_frag_xmit_hook(skb, xmit);
    #endif
    
    	return xmit(skb);
    }
    EXPORT_SYMBOL_GPL(tcf_dev_queue_xmit);
    
    static void tcf_action_goto_chain_exec(const struct tc_action *a,
    				       struct tcf_result *res)
    {
    	const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
    
    	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
    }
    
    static void tcf_free_cookie_rcu(struct rcu_head *p)
    {
    	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
    
    	kfree(cookie->data);
    	kfree(cookie);
    }
    
    static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
    				  struct tc_cookie *new_cookie)
    {
    	struct tc_cookie *old;
    
    	old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
    	if (old)
    		call_rcu(&old->rcu, tcf_free_cookie_rcu);
    }
    
    int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
    			     struct tcf_chain **newchain,
    			     struct netlink_ext_ack *extack)
    {
    	int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
    	u32 chain_index;
    
    	if (!opcode)
    		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
    	else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
    		ret = 0;
    	if (ret) {
    		NL_SET_ERR_MSG(extack, "invalid control action");
    		goto end;
    	}
    
    	if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
    		chain_index = action & TC_ACT_EXT_VAL_MASK;
    		if (!tp || !newchain) {
    			ret = -EINVAL;
    			NL_SET_ERR_MSG(extack,
    				       "can't goto NULL proto/chain");
    			goto end;
    		}
    		*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
    		if (!*newchain) {
    			ret = -ENOMEM;
    			NL_SET_ERR_MSG(extack,
    				       "can't allocate goto_chain");
    		}
    	}
    end:
    	return ret;
    }
    EXPORT_SYMBOL(tcf_action_check_ctrlact);
    
    struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
    					 struct tcf_chain *goto_chain)
    {
    	a->tcfa_action = action;
    	goto_chain = rcu_replace_pointer(a->goto_chain, goto_chain, 1);
    	return goto_chain;
    }
    EXPORT_SYMBOL(tcf_action_set_ctrlact);
    
    /* XXX: For standalone actions, we don't need a RCU grace period either, because
     * actions are always connected to filters and filters are already destroyed in
     * RCU callbacks, so after a RCU grace period actions are already disconnected
     * from filters. Readers later can not find us.
     */
    static void free_tcf(struct tc_action *p)
    {
    	struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
    
    	free_percpu(p->cpu_bstats);
    	free_percpu(p->cpu_bstats_hw);
    	free_percpu(p->cpu_qstats);
    
    	tcf_set_action_cookie(&p->act_cookie, NULL);
    	if (chain)
    		tcf_chain_put_by_act(chain);
    
    	kfree(p);
    }
    
    static void tcf_action_cleanup(struct tc_action *p)
    {
    	if (p->ops->cleanup)
    		p->ops->cleanup(p);
    
    	gen_kill_estimator(&p->tcfa_rate_est);
    	free_tcf(p);
    }
    
    static int __tcf_action_put(struct tc_action *p, bool bind)
    {
    	struct tcf_idrinfo *idrinfo = p->idrinfo;
    
    	if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
    		if (bind)
    			atomic_dec(&p->tcfa_bindcnt);
    		idr_remove(&idrinfo->action_idr, p->tcfa_index);
    		mutex_unlock(&idrinfo->lock);
    
    		tcf_action_cleanup(p);
    		return 1;
    	}
    
    	if (bind)
    		atomic_dec(&p->tcfa_bindcnt);
    
    	return 0;
    }
    
    int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
    {
    	int ret = 0;
    
    	/* Release with strict==1 and bind==0 is only called through act API
    	 * interface (classifiers always bind). Only case when action with
    	 * positive reference count and zero bind count can exist is when it was
    	 * also created with act API (unbinding last classifier will destroy the
    	 * action if it was created by classifier). So only case when bind count
    	 * can be changed after initial check is when unbound action is
    	 * destroyed by act API while classifier binds to action with same id
    	 * concurrently. This result either creation of new action(same behavior
    	 * as before), or reusing existing action if concurrent process
    	 * increments reference count before action is deleted. Both scenarios
    	 * are acceptable.
    	 */
    	if (p) {
    		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
    			return -EPERM;
    
    		if (__tcf_action_put(p, bind))
    			ret = ACT_P_DELETED;
    	}
    
    	return ret;
    }
    EXPORT_SYMBOL(__tcf_idr_release);
    
    static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
    {
    	struct tc_cookie *act_cookie;
    	u32 cookie_len = 0;
    
    	rcu_read_lock();
    	act_cookie = rcu_dereference(act->act_cookie);
    
    	if (act_cookie)
    		cookie_len = nla_total_size(act_cookie->len);
    	rcu_read_unlock();
    
    	return  nla_total_size(0) /* action number nested */
    		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
    		+ cookie_len /* TCA_ACT_COOKIE */
    		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
    		+ nla_total_size(0) /* TCA_ACT_STATS nested */
    		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
    		/* TCA_STATS_BASIC */
    		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
    		/* TCA_STATS_PKT64 */
    		+ nla_total_size_64bit(sizeof(u64))
    		/* TCA_STATS_QUEUE */
    		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
    		+ nla_total_size(0) /* TCA_OPTIONS nested */
    		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
    }
    
    static size_t tcf_action_full_attrs_size(size_t sz)
    {
    	return NLMSG_HDRLEN                     /* struct nlmsghdr */
    		+ sizeof(struct tcamsg)
    		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
    		+ sz;
    }
    
    static size_t tcf_action_fill_size(const struct tc_action *act)
    {
    	size_t sz = tcf_action_shared_attrs_size(act);
    
    	if (act->ops->get_fill_size)
    		return act->ops->get_fill_size(act) + sz;
    	return sz;
    }
    
    static int
    tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a, bool from_act)
    {
    	unsigned char *b = skb_tail_pointer(skb);
    	struct tc_cookie *cookie;
    
    	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
    		goto nla_put_failure;
    	if (tcf_action_copy_stats(skb, a, 0))
    		goto nla_put_failure;
    	if (from_act && nla_put_u32(skb, TCA_ACT_INDEX, a->tcfa_index))
    		goto nla_put_failure;
    
    	rcu_read_lock();
    	cookie = rcu_dereference(a->act_cookie);
    	if (cookie) {
    		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
    			rcu_read_unlock();
    			goto nla_put_failure;
    		}
    	}
    	rcu_read_unlock();
    
    	return 0;
    
    nla_put_failure:
    	nlmsg_trim(skb, b);
    	return -1;
    }
    
    static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
    			   struct netlink_callback *cb)
    {
    	int err = 0, index = -1, s_i = 0, n_i = 0;
    	u32 act_flags = cb->args[2];
    	unsigned long jiffy_since = cb->args[3];
    	struct nlattr *nest;
    	struct idr *idr = &idrinfo->action_idr;
    	struct tc_action *p;
    	unsigned long id = 1;
    	unsigned long tmp;
    
    	mutex_lock(&idrinfo->lock);
    
    	s_i = cb->args[0];
    
    	idr_for_each_entry_ul(idr, p, tmp, id) {
    		index++;
    		if (index < s_i)
    			continue;
    		if (IS_ERR(p))
    			continue;
    
    		if (jiffy_since &&
    		    time_after(jiffy_since,
    			       (unsigned long)p->tcfa_tm.lastuse))
    			continue;
    
    		nest = nla_nest_start_noflag(skb, n_i);
    		if (!nest) {
    			index--;
    			goto nla_put_failure;
    		}
    		err = (act_flags & TCA_ACT_FLAG_TERSE_DUMP) ?
    			tcf_action_dump_terse(skb, p, true) :
    			tcf_action_dump_1(skb, p, 0, 0);
    		if (err < 0) {
    			index--;
    			nlmsg_trim(skb, nest);
    			goto done;
    		}
    		nla_nest_end(skb, nest);
    		n_i++;
    		if (!(act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON) &&
    		    n_i >= TCA_ACT_MAX_PRIO)
    			goto done;
    	}
    done:
    	if (index >= 0)
    		cb->args[0] = index + 1;
    
    	mutex_unlock(&idrinfo->lock);
    	if (n_i) {
    		if (act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON)
    			cb->args[1] = n_i;
    	}
    	return n_i;
    
    nla_put_failure:
    	nla_nest_cancel(skb, nest);
    	goto done;
    }
    
    static int tcf_idr_release_unsafe(struct tc_action *p)
    {
    	if (atomic_read(&p->tcfa_bindcnt) > 0)
    		return -EPERM;
    
    	if (refcount_dec_and_test(&p->tcfa_refcnt)) {
    		idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
    		tcf_action_cleanup(p);
    		return ACT_P_DELETED;
    	}
    
    	return 0;
    }
    
    static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
    			  const struct tc_action_ops *ops)
    {
    	struct nlattr *nest;
    	int n_i = 0;
    	int ret = -EINVAL;
    	struct idr *idr = &idrinfo->action_idr;
    	struct tc_action *p;
    	unsigned long id = 1;
    	unsigned long tmp;
    
    	nest = nla_nest_start_noflag(skb, 0);
    	if (nest == NULL)
    		goto nla_put_failure;
    	if (nla_put_string(skb, TCA_KIND, ops->kind))
    		goto nla_put_failure;
    
    	mutex_lock(&idrinfo->lock);
    	idr_for_each_entry_ul(idr, p, tmp, id) {
    		if (IS_ERR(p))
    			continue;
    		ret = tcf_idr_release_unsafe(p);
    		if (ret == ACT_P_DELETED) {
    			module_put(ops->owner);
    			n_i++;
    		} else if (ret < 0) {
    			mutex_unlock(&idrinfo->lock);
    			goto nla_put_failure;
    		}
    	}
    	mutex_unlock(&idrinfo->lock);
    
    	if (nla_put_u32(skb, TCA_FCNT, n_i))
    		goto nla_put_failure;
    	nla_nest_end(skb, nest);
    
    	return n_i;
    nla_put_failure:
    	nla_nest_cancel(skb, nest);
    	return ret;
    }
    
    int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
    		       struct netlink_callback *cb, int type,
    		       const struct tc_action_ops *ops,
    		       struct netlink_ext_ack *extack)
    {
    	struct tcf_idrinfo *idrinfo = tn->idrinfo;
    
    	if (type == RTM_DELACTION) {
    		return tcf_del_walker(idrinfo, skb, ops);
    	} else if (type == RTM_GETACTION) {
    		return tcf_dump_walker(idrinfo, skb, cb);
    	} else {
    		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
    		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
    		return -EINVAL;
    	}
    }
    EXPORT_SYMBOL(tcf_generic_walker);
    
    int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
    {
    	struct tcf_idrinfo *idrinfo = tn->idrinfo;
    	struct tc_action *p;
    
    	mutex_lock(&idrinfo->lock);
    	p = idr_find(&idrinfo->action_idr, index);
    	if (IS_ERR(p))
    		p = NULL;
    	else if (p)
    		refcount_inc(&p->tcfa_refcnt);
    	mutex_unlock(&idrinfo->lock);
    
    	if (p) {
    		*a = p;
    		return true;
    	}
    	return false;
    }
    EXPORT_SYMBOL(tcf_idr_search);
    
    static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
    {
    	struct tc_action *p;
    	int ret = 0;
    
    	mutex_lock(&idrinfo->lock);
    	p = idr_find(&idrinfo->action_idr, index);
    	if (!p) {
    		mutex_unlock(&idrinfo->lock);
    		return -ENOENT;
    	}
    
    	if (!atomic_read(&p->tcfa_bindcnt)) {
    		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
    			struct module *owner = p->ops->owner;
    
    			WARN_ON(p != idr_remove(&idrinfo->action_idr,
    						p->tcfa_index));
    			mutex_unlock(&idrinfo->lock);
    
    			tcf_action_cleanup(p);
    			module_put(owner);
    			return 0;
    		}
    		ret = 0;
    	} else {
    		ret = -EPERM;
    	}
    
    	mutex_unlock(&idrinfo->lock);
    	return ret;
    }
    
    int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
    		   struct tc_action **a, const struct tc_action_ops *ops,
    		   int bind, bool cpustats, u32 flags)
    {
    	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
    	struct tcf_idrinfo *idrinfo = tn->idrinfo;
    	int err = -ENOMEM;
    
    	if (unlikely(!p))
    		return -ENOMEM;
    	refcount_set(&p->tcfa_refcnt, 1);
    	if (bind)
    		atomic_set(&p->tcfa_bindcnt, 1);
    
    	if (cpustats) {
    		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
    		if (!p->cpu_bstats)
    			goto err1;
    		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
    		if (!p->cpu_bstats_hw)
    			goto err2;
    		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
    		if (!p->cpu_qstats)
    			goto err3;
    	}
    	spin_lock_init(&p->tcfa_lock);
    	p->tcfa_index = index;
    	p->tcfa_tm.install = jiffies;
    	p->tcfa_tm.lastuse = jiffies;
    	p->tcfa_tm.firstuse = 0;
    	p->tcfa_flags = flags;
    	if (est) {
    		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
    					&p->tcfa_rate_est,
    					&p->tcfa_lock, NULL, est);
    		if (err)
    			goto err4;
    	}
    
    	p->idrinfo = idrinfo;
    	p->ops = ops;
    	*a = p;
    	return 0;
    err4:
    	free_percpu(p->cpu_qstats);
    err3:
    	free_percpu(p->cpu_bstats_hw);
    err2:
    	free_percpu(p->cpu_bstats);
    err1:
    	kfree(p);
    	return err;
    }
    EXPORT_SYMBOL(tcf_idr_create);
    
    int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
    			      struct nlattr *est, struct tc_action **a,
    			      const struct tc_action_ops *ops, int bind,
    			      u32 flags)
    {
    	/* Set cpustats according to actions flags. */
    	return tcf_idr_create(tn, index, est, a, ops, bind,
    			      !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
    }
    EXPORT_SYMBOL(tcf_idr_create_from_flags);
    
    /* Cleanup idr index that was allocated but not initialized. */
    
    void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
    {
    	struct tcf_idrinfo *idrinfo = tn->idrinfo;
    
    	mutex_lock(&idrinfo->lock);
    	/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
    	WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
    	mutex_unlock(&idrinfo->lock);
    }
    EXPORT_SYMBOL(tcf_idr_cleanup);
    
    /* Check if action with specified index exists. If actions is found, increments
     * its reference and bind counters, and return 1. Otherwise insert temporary
     * error pointer (to prevent concurrent users from inserting actions with same
     * index) and return 0.
     */
    
    int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
    			struct tc_action **a, int bind)
    {
    	struct tcf_idrinfo *idrinfo = tn->idrinfo;
    	struct tc_action *p;
    	int ret;
    
    again:
    	mutex_lock(&idrinfo->lock);
    	if (*index) {
    		p = idr_find(&idrinfo->action_idr, *index);
    		if (IS_ERR(p)) {
    			/* This means that another process allocated
    			 * index but did not assign the pointer yet.
    			 */
    			mutex_unlock(&idrinfo->lock);
    			goto again;
    		}
    
    		if (p) {
    			refcount_inc(&p->tcfa_refcnt);
    			if (bind)
    				atomic_inc(&p->tcfa_bindcnt);
    			*a = p;
    			ret = 1;
    		} else {
    			*a = NULL;
    			ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
    					    *index, GFP_KERNEL);
    			if (!ret)
    				idr_replace(&idrinfo->action_idr,
    					    ERR_PTR(-EBUSY), *index);
    		}
    	} else {
    		*index = 1;
    		*a = NULL;
    		ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
    				    UINT_MAX, GFP_KERNEL);
    		if (!ret)
    			idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
    				    *index);
    	}
    	mutex_unlock(&idrinfo->lock);
    	return ret;
    }
    EXPORT_SYMBOL(tcf_idr_check_alloc);
    
    void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
    			 struct tcf_idrinfo *idrinfo)
    {
    	struct idr *idr = &idrinfo->action_idr;
    	struct tc_action *p;
    	int ret;
    	unsigned long id = 1;
    	unsigned long tmp;
    
    	idr_for_each_entry_ul(idr, p, tmp, id) {
    		ret = __tcf_idr_release(p, false, true);
    		if (ret == ACT_P_DELETED)
    			module_put(ops->owner);
    		else if (ret < 0)
    			return;
    	}
    	idr_destroy(&idrinfo->action_idr);
    }
    EXPORT_SYMBOL(tcf_idrinfo_destroy);
    
    static LIST_HEAD(act_base);
    static DEFINE_RWLOCK(act_mod_lock);
    
    int tcf_register_action(struct tc_action_ops *act,
    			struct pernet_operations *ops)
    {
    	struct tc_action_ops *a;
    	int ret;
    
    	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
    		return -EINVAL;
    
    	/* We have to register pernet ops before making the action ops visible,
    	 * otherwise tcf_action_init_1() could get a partially initialized
    	 * netns.
    	 */
    	ret = register_pernet_subsys(ops);
    	if (ret)
    		return ret;
    
    	write_lock(&act_mod_lock);
    	list_for_each_entry(a, &act_base, head) {
    		if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
    			write_unlock(&act_mod_lock);
    			unregister_pernet_subsys(ops);
    			return -EEXIST;
    		}
    	}
    	list_add_tail(&act->head, &act_base);
    	write_unlock(&act_mod_lock);
    
    	return 0;
    }
    EXPORT_SYMBOL(tcf_register_action);
    
    int tcf_unregister_action(struct tc_action_ops *act,
    			  struct pernet_operations *ops)
    {
    	struct tc_action_ops *a;
    	int err = -ENOENT;
    
    	write_lock(&act_mod_lock);
    	list_for_each_entry(a, &act_base, head) {
    		if (a == act) {
    			list_del(&act->head);
    			err = 0;
    			break;
    		}
    	}
    	write_unlock(&act_mod_lock);
    	if (!err)
    		unregister_pernet_subsys(ops);
    	return err;
    }
    EXPORT_SYMBOL(tcf_unregister_action);
    
    /* lookup by name */
    static struct tc_action_ops *tc_lookup_action_n(char *kind)
    {
    	struct tc_action_ops *a, *res = NULL;
    
    	if (kind) {
    		read_lock(&act_mod_lock);
    		list_for_each_entry(a, &act_base, head) {
    			if (strcmp(kind, a->kind) == 0) {
    				if (try_module_get(a->owner))
    					res = a;
    				break;
    			}
    		}
    		read_unlock(&act_mod_lock);
    	}
    	return res;
    }
    
    /* lookup by nlattr */
    static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
    {
    	struct tc_action_ops *a, *res = NULL;
    
    	if (kind) {
    		read_lock(&act_mod_lock);
    		list_for_each_entry(a, &act_base, head) {
    			if (nla_strcmp(kind, a->kind) == 0) {
    				if (try_module_get(a->owner))
    					res = a;
    				break;
    			}
    		}
    		read_unlock(&act_mod_lock);
    	}
    	return res;
    }
    
    /*TCA_ACT_MAX_PRIO is 32, there count up to 32 */
    #define TCA_ACT_MAX_PRIO_MASK 0x1FF
    int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
    		    int nr_actions, struct tcf_result *res)
    {
    	u32 jmp_prgcnt = 0;
    	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
    	int i;
    	int ret = TC_ACT_OK;
    
    	if (skb_skip_tc_classify(skb))
    		return TC_ACT_OK;
    
    restart_act_graph:
    	for (i = 0; i < nr_actions; i++) {
    		const struct tc_action *a = actions[i];
    
    		if (jmp_prgcnt > 0) {
    			jmp_prgcnt -= 1;
    			continue;
    		}
    repeat:
    		ret = a->ops->act(skb, a, res);
    		if (ret == TC_ACT_REPEAT)
    			goto repeat;	/* we need a ttl - JHS */
    
    		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
    			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
    			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
    				/* faulty opcode, stop pipeline */
    				return TC_ACT_OK;
    			} else {
    				jmp_ttl -= 1;
    				if (jmp_ttl > 0)
    					goto restart_act_graph;
    				else /* faulty graph, stop pipeline */
    					return TC_ACT_OK;
    			}
    		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
    			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
    				net_warn_ratelimited("can't go to NULL chain!\n");
    				return TC_ACT_SHOT;
    			}
    			tcf_action_goto_chain_exec(a, res);
    		}
    
    		if (ret != TC_ACT_PIPE)
    			break;
    	}
    
    	return ret;
    }
    EXPORT_SYMBOL(tcf_action_exec);
    
    int tcf_action_destroy(struct tc_action *actions[], int bind)
    {
    	const struct tc_action_ops *ops;
    	struct tc_action *a;
    	int ret = 0, i;
    
    	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
    		a = actions[i];
    		actions[i] = NULL;
    		ops = a->ops;
    		ret = __tcf_idr_release(a, bind, true);
    		if (ret == ACT_P_DELETED)
    			module_put(ops->owner);
    		else if (ret < 0)
    			return ret;
    	}
    	return ret;
    }
    
    static int tcf_action_put(struct tc_action *p)
    {
    	return __tcf_action_put(p, false);
    }
    
    /* Put all actions in this array, skip those NULL's. */
    static void tcf_action_put_many(struct tc_action *actions[])
    {
    	int i;
    
    	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
    		struct tc_action *a = actions[i];
    		const struct tc_action_ops *ops;
    
    		if (!a)
    			continue;
    		ops = a->ops;
    		if (tcf_action_put(a))
    			module_put(ops->owner);
    	}
    }
    
    int
    tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
    {
    	return a->ops->dump(skb, a, bind, ref);
    }
    
    int
    tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
    {
    	int err = -EINVAL;
    	unsigned char *b = skb_tail_pointer(skb);
    	struct nlattr *nest;
    
    	if (tcf_action_dump_terse(skb, a, false))
    		goto nla_put_failure;
    
    	if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
    	    nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
    			       a->hw_stats, TCA_ACT_HW_STATS_ANY))
    		goto nla_put_failure;
    
    	if (a->used_hw_stats_valid &&
    	    nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
    			       a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
    		goto nla_put_failure;
    
    	if (a->tcfa_flags &&
    	    nla_put_bitfield32(skb, TCA_ACT_FLAGS,
    			       a->tcfa_flags, a->tcfa_flags))
    		goto nla_put_failure;
    
    	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
    	if (nest == NULL)
    		goto nla_put_failure;
    	err = tcf_action_dump_old(skb, a, bind, ref);
    	if (err > 0) {
    		nla_nest_end(skb, nest);
    		return err;
    	}
    
    nla_put_failure:
    	nlmsg_trim(skb, b);
    	return -1;
    }
    EXPORT_SYMBOL(tcf_action_dump_1);
    
    int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
    		    int bind, int ref, bool terse)
    {
    	struct tc_action *a;
    	int err = -EINVAL, i;
    	struct nlattr *nest;
    
    	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
    		a = actions[i];
    		nest = nla_nest_start_noflag(skb, i + 1);
    		if (nest == NULL)
    			goto nla_put_failure;
    		err = terse ? tcf_action_dump_terse(skb, a, false) :
    			tcf_action_dump_1(skb, a, bind, ref);
    		if (err < 0)
    			goto errout;
    		nla_nest_end(skb, nest);
    	}
    
    	return 0;
    
    nla_put_failure:
    	err = -EINVAL;
    errout:
    	nla_nest_cancel(skb, nest);
    	return err;
    }
    
    static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
    {
    	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
    	if (!c)
    		return NULL;
    
    	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
    	if (!c->data) {
    		kfree(c);
    		return NULL;
    	}
    	c->len = nla_len(tb[TCA_ACT_COOKIE]);
    
    	return c;
    }
    
    static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
    {
    	struct nla_bitfield32 hw_stats_bf;
    
    	/* If the user did not pass the attr, that means he does
    	 * not care about the type. Return "any" in that case
    	 * which is setting on all supported types.
    	 */
    	if (!hw_stats_attr)
    		return TCA_ACT_HW_STATS_ANY;
    	hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
    	return hw_stats_bf.value;
    }
    
    static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
    	[TCA_ACT_KIND]		= { .type = NLA_STRING },
    	[TCA_ACT_INDEX]		= { .type = NLA_U32 },
    	[TCA_ACT_COOKIE]	= { .type = NLA_BINARY,
    				    .len = TC_COOKIE_MAX_SIZE },
    	[TCA_ACT_OPTIONS]	= { .type = NLA_NESTED },
    	[TCA_ACT_FLAGS]		= NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS),
    	[TCA_ACT_HW_STATS]	= NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
    };
    
    static void tcf_idr_insert_many(struct tc_action *actions[])
    {
    	int i;
    
    	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
    		struct tc_action *a = actions[i];
    		struct tcf_idrinfo *idrinfo;
    
    		if (!a)
    			continue;
    		idrinfo = a->idrinfo;
    		mutex_lock(&idrinfo->lock);
    		/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
    		 * it is just created, otherwise this is just a nop.
    		 */
    		idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
    		mutex_unlock(&idrinfo->lock);
    	}
    }
    
    struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
    				    struct nlattr *nla, struct nlattr *est,
    				    char *name, int ovr, int bind,
    				    bool rtnl_held,
    				    struct netlink_ext_ack *extack)
    {
    	struct nla_bitfield32 flags = { 0, 0 };
    	u8 hw_stats = TCA_ACT_HW_STATS_ANY;
    	struct tc_action *a;
    	struct tc_action_ops *a_o;
    	struct tc_cookie *cookie = NULL;
    	char act_name[IFNAMSIZ];
    	struct nlattr *tb[TCA_ACT_MAX + 1];
    	struct nlattr *kind;
    	int err;
    
    	if (name == NULL) {
    		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
    						  tcf_action_policy, extack);
    		if (err < 0)
    			goto err_out;
    		err = -EINVAL;
    		kind = tb[TCA_ACT_KIND];
    		if (!kind) {
    			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
    			goto err_out;
    		}
    		if (nla_strscpy(act_name, kind, IFNAMSIZ) < 0) {
    			NL_SET_ERR_MSG(extack, "TC action name too long");
    			goto err_out;
    		}
    		if (tb[TCA_ACT_COOKIE]) {
    			cookie = nla_memdup_cookie(tb);
    			if (!cookie) {
    				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
    				err = -ENOMEM;
    				goto err_out;
    			}
    		}
    		hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
    		if (tb[TCA_ACT_FLAGS])
    			flags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
    	} else {
    		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
    			NL_SET_ERR_MSG(extack, "TC action name too long");
    			err = -EINVAL;
    			goto err_out;
    		}
    	}
    
    	a_o = tc_lookup_action_n(act_name);
    	if (a_o == NULL) {
    #ifdef CONFIG_MODULES
    		if (rtnl_held)
    			rtnl_unlock();
    		request_module("act_%s", act_name);
    		if (rtnl_held)
    			rtnl_lock();
    
    		a_o = tc_lookup_action_n(act_name);
    
    		/* We dropped the RTNL semaphore in order to
    		 * perform the module load.  So, even if we
    		 * succeeded in loading the module we have to
    		 * tell the caller to replay the request.  We
    		 * indicate this using -EAGAIN.
    		 */
    		if (a_o != NULL) {
    			err = -EAGAIN;
    			goto err_mod;
    		}
    #endif
    		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
    		err = -ENOENT;
    		goto err_free;
    	}
    
    	/* backward compatibility for policer */
    	if (name == NULL)
    		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
    				rtnl_held, tp, flags.value, extack);
    	else
    		err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
    				tp, flags.value, extack);
    	if (err < 0)
    		goto err_mod;
    
    	if (!name && tb[TCA_ACT_COOKIE])
    		tcf_set_action_cookie(&a->act_cookie, cookie);
    
    	if (!name)
    		a->hw_stats = hw_stats;
    
    	/* module count goes up only when brand new policy is created
    	 * if it exists and is only bound to in a_o->init() then
    	 * ACT_P_CREATED is not returned (a zero is).
    	 */
    	if (err != ACT_P_CREATED)
    		module_put(a_o->owner);
    
    	return a;
    
    err_mod:
    	module_put(a_o->owner);
    err_free:
    	if (cookie) {
    		kfree(cookie->data);
    		kfree(cookie);
    	}
    err_out:
    	return ERR_PTR(err);
    }
    
    /* Returns numbers of initialized actions or negative error. */
    
    int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
    		    struct nlattr *est, char *name, int ovr, int bind,
    		    struct tc_action *actions[], size_t *attr_size,
    		    bool rtnl_held, struct netlink_ext_ack *extack)
    {
    	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
    	struct tc_action *act;
    	size_t sz = 0;
    	int err;
    	int i;
    
    	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
    					  extack);
    	if (err < 0)
    		return err;
    
    	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
    		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
    					rtnl_held, extack);
    		if (IS_ERR(act)) {
    			err = PTR_ERR(act);
    			goto err;
    		}
    		sz += tcf_action_fill_size(act);
    		/* Start from index 0 */
    		actions[i - 1] = act;
    	}
    
    	/* We have to commit them all together, because if any error happened in
    	 * between, we could not handle the failure gracefully.
    	 */
    	tcf_idr_insert_many(actions);
    
    	*attr_size = tcf_action_full_attrs_size(sz);
    	return i - 1;
    
    err:
    	tcf_action_destroy(actions, bind);
    	return err;
    }
    
    void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
    			     u64 drops, bool hw)
    {
    	if (a->cpu_bstats) {
    		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
    
    		this_cpu_ptr(a->cpu_qstats)->drops += drops;
    
    		if (hw)
    			_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
    					   bytes, packets);
    		return;
    	}
    
    	_bstats_update(&a->tcfa_bstats, bytes, packets);
    	a->tcfa_qstats.drops += drops;
    	if (hw)
    		_bstats_update(&a->tcfa_bstats_hw, bytes, packets);
    }
    EXPORT_SYMBOL(tcf_action_update_stats);
    
    int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
    			  int compat_mode)
    {
    	int err = 0;
    	struct gnet_dump d;
    
    	if (p == NULL)
    		goto errout;
    
    	/* compat_mode being true specifies a call that is supposed
    	 * to add additional backward compatibility statistic TLVs.
    	 */
    	if (compat_mode) {
    		if (p->type == TCA_OLD_COMPAT)
    			err = gnet_stats_start_copy_compat(skb, 0,
    							   TCA_STATS,
    							   TCA_XSTATS,
    							   &p->tcfa_lock, &d,
    							   TCA_PAD);
    		else
    			return 0;
    	} else
    		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
    					    &p->tcfa_lock, &d, TCA_ACT_PAD);
    
    	if (err < 0)
    		goto errout;
    
    	if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
    	    gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
    				     &p->tcfa_bstats_hw) < 0 ||
    	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
    	    gnet_stats_copy_queue(&d, p->cpu_qstats,
    				  &p->tcfa_qstats,
    				  p->tcfa_qstats.qlen) < 0)
    		goto errout;
    
    	if (gnet_stats_finish_copy(&d) < 0)
    		goto errout;
    
    	return 0;
    
    errout:
    	return -1;
    }
    
    static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
    			u32 portid, u32 seq, u16 flags, int event, int bind,
    			int ref)
    {
    	struct tcamsg *t;
    	struct nlmsghdr *nlh;
    	unsigned char *b = skb_tail_pointer(skb);
    	struct nlattr *nest;
    
    	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
    	if (!nlh)
    		goto out_nlmsg_trim;
    	t = nlmsg_data(nlh);
    	t->tca_family = AF_UNSPEC;
    	t->tca__pad1 = 0;
    	t->tca__pad2 = 0;
    
    	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
    	if (!nest)
    		goto out_nlmsg_trim;
    
    	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
    		goto out_nlmsg_trim;
    
    	nla_nest_end(skb, nest);
    
    	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
    	return skb->len;
    
    out_nlmsg_trim:
    	nlmsg_trim(skb, b);
    	return -1;
    }
    
    static int
    tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
    	       struct tc_action *actions[], int event,
    	       struct netlink_ext_ack *extack)
    {
    	struct sk_buff *skb;
    
    	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
    	if (!skb)
    		return -ENOBUFS;
    	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
    			 0, 1) <= 0) {
    		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
    		kfree_skb(skb);
    		return -EINVAL;
    	}
    
    	return rtnl_unicast(skb, net, portid);
    }
    
    static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
    					  struct nlmsghdr *n, u32 portid,
    					  struct netlink_ext_ack *extack)
    {
    	struct nlattr *tb[TCA_ACT_MAX + 1];
    	const struct tc_action_ops *ops;
    	struct tc_action *a;
    	int index;
    	int err;
    
    	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
    					  tcf_action_policy, extack);
    	if (err < 0)
    		goto err_out;
    
    	err = -EINVAL;
    	if (tb[TCA_ACT_INDEX] == NULL ||
    	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
    		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
    		goto err_out;
    	}
    	index = nla_get_u32(tb[TCA_ACT_INDEX]);
    
    	err = -EINVAL;
    	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
    	if (!ops) { /* could happen in batch of actions */
    		NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
    		goto err_out;
    	}
    	err = -ENOENT;
    	if (ops->lookup(net, &a, index) == 0) {
    		NL_SET_ERR_MSG(extack, "TC action with specified index not found");
    		goto err_mod;
    	}
    
    	module_put(ops->owner);
    	return a;
    
    err_mod:
    	module_put(ops->owner);
    err_out:
    	return ERR_PTR(err);
    }
    
    static int tca_action_flush(struct net *net, struct nlattr *nla,
    			    struct nlmsghdr *n, u32 portid,
    			    struct netlink_ext_ack *extack)
    {
    	struct sk_buff *skb;
    	unsigned char *b;
    	struct nlmsghdr *nlh;
    	struct tcamsg *t;
    	struct netlink_callback dcb;
    	struct nlattr *nest;
    	struct nlattr *tb[TCA_ACT_MAX + 1];
    	const struct tc_action_ops *ops;
    	struct nlattr *kind;
    	int err = -ENOMEM;
    
    	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
    	if (!skb)
    		return err;
    
    	b = skb_tail_pointer(skb);
    
    	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
    					  tcf_action_policy, extack);
    	if (err < 0)
    		goto err_out;
    
    	err = -EINVAL;
    	kind = tb[TCA_ACT_KIND];
    	ops = tc_lookup_action(kind);
    	if (!ops) { /*some idjot trying to flush unknown action */
    		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
    		goto err_out;
    	}
    
    	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
    			sizeof(*t), 0);
    	if (!nlh) {
    		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
    		goto out_module_put;
    	}
    	t = nlmsg_data(nlh);
    	t->tca_family = AF_UNSPEC;
    	t->tca__pad1 = 0;
    	t->tca__pad2 = 0;
    
    	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
    	if (!nest) {
    		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
    		goto out_module_put;
    	}
    
    	err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
    	if (err <= 0) {
    		nla_nest_cancel(skb, nest);
    		goto out_module_put;
    	}
    
    	nla_nest_end(skb, nest);
    
    	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
    	nlh->nlmsg_flags |= NLM_F_ROOT;
    	module_put(ops->owner);
    	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
    			     n->nlmsg_flags & NLM_F_ECHO);
    	if (err > 0)
    		return 0;
    	if (err < 0)
    		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
    
    	return err;
    
    out_module_put:
    	module_put(ops->owner);
    err_out:
    	kfree_skb(skb);
    	return err;
    }
    
    static int tcf_action_delete(struct net *net, struct tc_action *actions[])
    {
    	int i;
    
    	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
    		struct tc_action *a = actions[i];
    		const struct tc_action_ops *ops = a->ops;
    		/* Actions can be deleted concurrently so we must save their
    		 * type and id to search again after reference is released.
    		 */
    		struct tcf_idrinfo *idrinfo = a->idrinfo;
    		u32 act_index = a->tcfa_index;
    
    		actions[i] = NULL;
    		if (tcf_action_put(a)) {
    			/* last reference, action was deleted concurrently */
    			module_put(ops->owner);
    		} else  {
    			int ret;
    
    			/* now do the delete */
    			ret = tcf_idr_delete_index(idrinfo, act_index);
    			if (ret < 0)
    				return ret;
    		}
    	}
    	return 0;
    }
    
    static int
    tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
    	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
    {
    	int ret;
    	struct sk_buff *skb;
    
    	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
    			GFP_KERNEL);
    	if (!skb)
    		return -ENOBUFS;
    
    	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
    			 0, 2) <= 0) {
    		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
    		kfree_skb(skb);
    		return -EINVAL;
    	}
    
    	/* now do the delete */
    	ret = tcf_action_delete(net, actions);
    	if (ret < 0) {
    		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
    		kfree_skb(skb);
    		return ret;
    	}
    
    	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
    			     n->nlmsg_flags & NLM_F_ECHO);
    	if (ret > 0)
    		return 0;
    	return ret;
    }
    
    static int
    tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
    	      u32 portid, int event, struct netlink_ext_ack *extack)
    {
    	int i, ret;
    	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
    	struct tc_action *act;
    	size_t attr_size = 0;
    	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
    
    	ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
    					  extack);
    	if (ret < 0)
    		return ret;
    
    	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
    		if (tb[1])
    			return tca_action_flush(net, tb[1], n, portid, extack);
    
    		NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
    		return -EINVAL;
    	}
    
    	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
    		act = tcf_action_get_1(net, tb[i], n, portid, extack);
    		if (IS_ERR(act)) {
    			ret = PTR_ERR(act);
    			goto err;
    		}
    		attr_size += tcf_action_fill_size(act);
    		actions[i - 1] = act;
    	}
    
    	attr_size = tcf_action_full_attrs_size(attr_size);
    
    	if (event == RTM_GETACTION)
    		ret = tcf_get_notify(net, portid, n, actions, event, extack);
    	else { /* delete */
    		ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
    		if (ret)
    			goto err;
    		return 0;
    	}
    err:
    	tcf_action_put_many(actions);
    	return ret;
    }
    
    static int
    tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
    	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
    {
    	struct sk_buff *skb;
    	int err = 0;
    
    	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
    			GFP_KERNEL);
    	if (!skb)
    		return -ENOBUFS;
    
    	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
    			 RTM_NEWACTION, 0, 0) <= 0) {
    		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
    		kfree_skb(skb);
    		return -EINVAL;
    	}
    
    	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
    			     n->nlmsg_flags & NLM_F_ECHO);
    	if (err > 0)
    		err = 0;
    	return err;
    }
    
    static int tcf_action_add(struct net *net, struct nlattr *nla,
    			  struct nlmsghdr *n, u32 portid, int ovr,
    			  struct netlink_ext_ack *extack)
    {
    	size_t attr_size = 0;
    	int loop, ret;
    	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
    
    	for (loop = 0; loop < 10; loop++) {
    		ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
    				      actions, &attr_size, true, extack);
    		if (ret != -EAGAIN)
    			break;
    	}
    
    	if (ret < 0)
    		return ret;
    	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
    	if (ovr)
    		tcf_action_put_many(actions);
    
    	return ret;
    }
    
    static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
    	[TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_ACT_FLAG_LARGE_DUMP_ON |
    						 TCA_ACT_FLAG_TERSE_DUMP),
    	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
    };
    
    static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
    			 struct netlink_ext_ack *extack)
    {
    	struct net *net = sock_net(skb->sk);
    	struct nlattr *tca[TCA_ROOT_MAX + 1];
    	u32 portid = NETLINK_CB(skb).portid;
    	int ret = 0, ovr = 0;
    
    	if ((n->nlmsg_type != RTM_GETACTION) &&
    	    !netlink_capable(skb, CAP_NET_ADMIN))
    		return -EPERM;
    
    	ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
    				     TCA_ROOT_MAX, NULL, extack);
    	if (ret < 0)
    		return ret;
    
    	if (tca[TCA_ACT_TAB] == NULL) {
    		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
    		return -EINVAL;
    	}
    
    	/* n->nlmsg_flags & NLM_F_CREATE */
    	switch (n->nlmsg_type) {
    	case RTM_NEWACTION:
    		/* we are going to assume all other flags
    		 * imply create only if it doesn't exist
    		 * Note that CREATE | EXCL implies that
    		 * but since we want avoid ambiguity (eg when flags
    		 * is zero) then just set this
    		 */
    		if (n->nlmsg_flags & NLM_F_REPLACE)
    			ovr = 1;
    		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
    				     extack);
    		break;
    	case RTM_DELACTION:
    		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
    				    portid, RTM_DELACTION, extack);
    		break;
    	case RTM_GETACTION:
    		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
    				    portid, RTM_GETACTION, extack);
    		break;
    	default:
    		BUG();
    	}
    
    	return ret;
    }
    
    static struct nlattr *find_dump_kind(struct nlattr **nla)
    {
    	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
    	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
    	struct nlattr *kind;
    
    	tb1 = nla[TCA_ACT_TAB];
    	if (tb1 == NULL)
    		return NULL;
    
    	if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
    		return NULL;
    
    	if (tb[1] == NULL)
    		return NULL;
    	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
    		return NULL;
    	kind = tb2[TCA_ACT_KIND];
    
    	return kind;
    }
    
    static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
    {
    	struct net *net = sock_net(skb->sk);
    	struct nlmsghdr *nlh;
    	unsigned char *b = skb_tail_pointer(skb);
    	struct nlattr *nest;
    	struct tc_action_ops *a_o;
    	int ret = 0;
    	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
    	struct nlattr *tb[TCA_ROOT_MAX + 1];
    	struct nlattr *count_attr = NULL;
    	unsigned long jiffy_since = 0;
    	struct nlattr *kind = NULL;
    	struct nla_bitfield32 bf;
    	u32 msecs_since = 0;
    	u32 act_count = 0;
    
    	ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
    				     TCA_ROOT_MAX, tcaa_policy, cb->extack);
    	if (ret < 0)
    		return ret;
    
    	kind = find_dump_kind(tb);
    	if (kind == NULL) {
    		pr_info("tc_dump_action: action bad kind\n");
    		return 0;
    	}
    
    	a_o = tc_lookup_action(kind);
    	if (a_o == NULL)
    		return 0;
    
    	cb->args[2] = 0;
    	if (tb[TCA_ROOT_FLAGS]) {
    		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
    		cb->args[2] = bf.value;
    	}
    
    	if (tb[TCA_ROOT_TIME_DELTA]) {
    		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
    	}
    
    	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
    			cb->nlh->nlmsg_type, sizeof(*t), 0);
    	if (!nlh)
    		goto out_module_put;
    
    	if (msecs_since)
    		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
    
    	t = nlmsg_data(nlh);
    	t->tca_family = AF_UNSPEC;
    	t->tca__pad1 = 0;
    	t->tca__pad2 = 0;
    	cb->args[3] = jiffy_since;
    	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
    	if (!count_attr)
    		goto out_module_put;
    
    	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
    	if (nest == NULL)
    		goto out_module_put;
    
    	ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
    	if (ret < 0)
    		goto out_module_put;
    
    	if (ret > 0) {
    		nla_nest_end(skb, nest);
    		ret = skb->len;
    		act_count = cb->args[1];
    		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
    		cb->args[1] = 0;
    	} else
    		nlmsg_trim(skb, b);
    
    	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
    	if (NETLINK_CB(cb->skb).portid && ret)
    		nlh->nlmsg_flags |= NLM_F_MULTI;
    	module_put(a_o->owner);
    	return skb->len;
    
    out_module_put:
    	module_put(a_o->owner);
    	nlmsg_trim(skb, b);
    	return skb->len;
    }
    
    static int __init tc_action_init(void)
    {
    	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
    	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
    	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
    		      0);
    
    	return 0;
    }
    
    subsys_initcall(tc_action_init);