text: // 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;
  }
  
  static 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;
  }
  
  int tcf_idr_release(struct tc_action *a, bool bind)
  {
  	const struct tc_action_ops *ops = a->ops;
  	int ret;
  
  	ret = __tcf_idr_release(a, bind, false);
  	if (ret == ACT_P_DELETED)
  		module_put(ops->owner);
  	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);
  
  	ret = nla_put_u32(skb, TCA_FCNT, n_i);
  	if (ret)
  		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;
  	__module_get(ops->owner);
  	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),
  };
  
  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_ops *tc_action_load_ops(char *name, struct nlattr *nla,
  					 bool rtnl_held,
  					 struct netlink_ext_ack *extack)
  {
  	struct nlattr *tb[TCA_ACT_MAX + 1];
  	struct tc_action_ops *a_o;
  	char act_name[IFNAMSIZ];
  	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)
  			return ERR_PTR(err);
  		err = -EINVAL;
  		kind = tb[TCA_ACT_KIND];
  		if (!kind) {
  			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
  			return ERR_PTR(err);
  		}
  		if (nla_strscpy(act_name, kind, IFNAMSIZ) < 0) {
  			NL_SET_ERR_MSG(extack, "TC action name too long");
  			return ERR_PTR(err);
  		}
  	} else {
  		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
  			NL_SET_ERR_MSG(extack, "TC action name too long");
  			return ERR_PTR(-EINVAL);
  		}
  	}
  
  	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) {
  			module_put(a_o->owner);
  			return ERR_PTR(-EAGAIN);
  		}
  #endif
  		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
  		return ERR_PTR(-ENOENT);
  	}
  
  	return a_o;
  }
  
  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,
  				    struct tc_action_ops *a_o, int *init_res,
  				    bool rtnl_held,
  				    struct netlink_ext_ack *extack)
  {
  	struct nla_bitfield32 flags = { 0, 0 };
  	u8 hw_stats = TCA_ACT_HW_STATS_ANY;
  	struct nlattr *tb[TCA_ACT_MAX + 1];
  	struct tc_cookie *cookie = NULL;
  	struct tc_action *a;
  	int err;
  
  	/* backward compatibility for policer */
  	if (name == NULL) {
  		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
  						  tcf_action_policy, extack);
  		if (err < 0)
  			return ERR_PTR(err);
  		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]);
  
  		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_out;
  	*init_res = err;
  
  	if (!name && tb[TCA_ACT_COOKIE])
  		tcf_set_action_cookie(&a->act_cookie, cookie);
  
  	if (!name)
  		a->hw_stats = hw_stats;
  
  	return a;
  
  err_out:
  	if (cookie) {
  		kfree(cookie->data);
  		kfree(cookie);
  	}
  	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[], int init_res[], size_t *attr_size,
  		    bool rtnl_held, struct netlink_ext_ack *extack)
  {
  	struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
  	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++) {
  		struct tc_action_ops *a_o;
  
  		a_o = tc_action_load_ops(name, tb[i], rtnl_held, extack);
  		if (IS_ERR(a_o)) {
  			err = PTR_ERR(a_o);
  			goto err_mod;
  		}
  		ops[i - 1] = a_o;
  	}
  
  	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
  		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
  					ops[i - 1], &init_res[i - 1], 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);
  	err = i - 1;
  	goto err_mod;
  
  err:
  	tcf_action_destroy(actions, bind);
  err_mod:
  	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
  		if (ops[i])
  			module_put(ops[i]->owner);
  	}
  	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, i;
  	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
  	int init_res[TCA_ACT_MAX_PRIO] = {};
  
  	for (loop = 0; loop < 10; loop++) {
  		ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0,
  				      actions, init_res, &attr_size, true, extack);
  		if (ret != -EAGAIN)
  			break;
  	}
  
  	if (ret < 0)
  		return ret;
  	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
  
  	/* only put existing actions */
  	for (i = 0; i < TCA_ACT_MAX_PRIO; i++)
  		if (init_res[i] == ACT_P_CREATED)
  			actions[i] = NULL;
  	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);
  