text: /*
   * net/sched/cls_u32.c	Ugly (or Universal) 32bit key Packet Classifier.
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   *
   * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   *
   *	The filters are packed to hash tables of key nodes
   *	with a set of 32bit key/mask pairs at every node.
   *	Nodes reference next level hash tables etc.
   *
   *	This scheme is the best universal classifier I managed to
   *	invent; it is not super-fast, but it is not slow (provided you
   *	program it correctly), and general enough.  And its relative
   *	speed grows as the number of rules becomes larger.
   *
   *	It seems that it represents the best middle point between
   *	speed and manageability both by human and by machine.
   *
   *	It is especially useful for link sharing combined with QoS;
   *	pure RSVP doesn't need such a general approach and can use
   *	much simpler (and faster) schemes, sort of cls_rsvp.c.
   *
   *	JHS: We should remove the CONFIG_NET_CLS_IND from here
   *	eventually when the meta match extension is made available
   *
   *	nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
   */
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/string.h>
  #include <linux/errno.h>
  #include <linux/percpu.h>
  #include <linux/rtnetlink.h>
  #include <linux/skbuff.h>
  #include <linux/bitmap.h>
  #include <net/netlink.h>
  #include <net/act_api.h>
  #include <net/pkt_cls.h>
  
  struct tc_u_knode {
  	struct tc_u_knode __rcu	*next;
  	u32			handle;
  	struct tc_u_hnode __rcu	*ht_up;
  	struct tcf_exts		exts;
  #ifdef CONFIG_NET_CLS_IND
  	int			ifindex;
  #endif
  	u8			fshift;
  	struct tcf_result	res;
  	struct tc_u_hnode __rcu	*ht_down;
  #ifdef CONFIG_CLS_U32_PERF
  	struct tc_u32_pcnt __percpu *pf;
  #endif
  #ifdef CONFIG_CLS_U32_MARK
  	u32			val;
  	u32			mask;
  	u32 __percpu		*pcpu_success;
  #endif
  	struct tcf_proto	*tp;
  	struct rcu_head		rcu;
  	/* The 'sel' field MUST be the last field in structure to allow for
  	 * tc_u32_keys allocated at end of structure.
  	 */
  	struct tc_u32_sel	sel;
  };
  
  struct tc_u_hnode {
  	struct tc_u_hnode __rcu	*next;
  	u32			handle;
  	u32			prio;
  	struct tc_u_common	*tp_c;
  	int			refcnt;
  	unsigned int		divisor;
  	struct rcu_head		rcu;
  	/* The 'ht' field MUST be the last field in structure to allow for
  	 * more entries allocated at end of structure.
  	 */
  	struct tc_u_knode __rcu	*ht[1];
  };
  
  struct tc_u_common {
  	struct tc_u_hnode __rcu	*hlist;
  	struct Qdisc		*q;
  	int			refcnt;
  	u32			hgenerator;
  	struct rcu_head		rcu;
  };
  
  static inline unsigned int u32_hash_fold(__be32 key,
  					 const struct tc_u32_sel *sel,
  					 u8 fshift)
  {
  	unsigned int h = ntohl(key & sel->hmask) >> fshift;
  
  	return h;
  }
  
  static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res)
  {
  	struct {
  		struct tc_u_knode *knode;
  		unsigned int	  off;
  	} stack[TC_U32_MAXDEPTH];
  
  	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
  	unsigned int off = skb_network_offset(skb);
  	struct tc_u_knode *n;
  	int sdepth = 0;
  	int off2 = 0;
  	int sel = 0;
  #ifdef CONFIG_CLS_U32_PERF
  	int j;
  #endif
  	int i, r;
  
  next_ht:
  	n = rcu_dereference_bh(ht->ht[sel]);
  
  next_knode:
  	if (n) {
  		struct tc_u32_key *key = n->sel.keys;
  
  #ifdef CONFIG_CLS_U32_PERF
  		__this_cpu_inc(n->pf->rcnt);
  		j = 0;
  #endif
  
  #ifdef CONFIG_CLS_U32_MARK
  		if ((skb->mark & n->mask) != n->val) {
  			n = rcu_dereference_bh(n->next);
  			goto next_knode;
  		} else {
  			__this_cpu_inc(*n->pcpu_success);
  		}
  #endif
  
  		for (i = n->sel.nkeys; i > 0; i--, key++) {
  			int toff = off + key->off + (off2 & key->offmask);
  			__be32 *data, hdata;
  
  			if (skb_headroom(skb) + toff > INT_MAX)
  				goto out;
  
  			data = skb_header_pointer(skb, toff, 4, &hdata);
  			if (!data)
  				goto out;
  			if ((*data ^ key->val) & key->mask) {
  				n = rcu_dereference_bh(n->next);
  				goto next_knode;
  			}
  #ifdef CONFIG_CLS_U32_PERF
  			__this_cpu_inc(n->pf->kcnts[j]);
  			j++;
  #endif
  		}
  
  		ht = rcu_dereference_bh(n->ht_down);
  		if (!ht) {
  check_terminal:
  			if (n->sel.flags & TC_U32_TERMINAL) {
  
  				*res = n->res;
  #ifdef CONFIG_NET_CLS_IND
  				if (!tcf_match_indev(skb, n->ifindex)) {
  					n = rcu_dereference_bh(n->next);
  					goto next_knode;
  				}
  #endif
  #ifdef CONFIG_CLS_U32_PERF
  				__this_cpu_inc(n->pf->rhit);
  #endif
  				r = tcf_exts_exec(skb, &n->exts, res);
  				if (r < 0) {
  					n = rcu_dereference_bh(n->next);
  					goto next_knode;
  				}
  
  				return r;
  			}
  			n = rcu_dereference_bh(n->next);
  			goto next_knode;
  		}
  
  		/* PUSH */
  		if (sdepth >= TC_U32_MAXDEPTH)
  			goto deadloop;
  		stack[sdepth].knode = n;
  		stack[sdepth].off = off;
  		sdepth++;
  
  		ht = rcu_dereference_bh(n->ht_down);
  		sel = 0;
  		if (ht->divisor) {
  			__be32 *data, hdata;
  
  			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
  						  &hdata);
  			if (!data)
  				goto out;
  			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
  							  n->fshift);
  		}
  		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
  			goto next_ht;
  
  		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
  			off2 = n->sel.off + 3;
  			if (n->sel.flags & TC_U32_VAROFFSET) {
  				__be16 *data, hdata;
  
  				data = skb_header_pointer(skb,
  							  off + n->sel.offoff,
  							  2, &hdata);
  				if (!data)
  					goto out;
  				off2 += ntohs(n->sel.offmask & *data) >>
  					n->sel.offshift;
  			}
  			off2 &= ~3;
  		}
  		if (n->sel.flags & TC_U32_EAT) {
  			off += off2;
  			off2 = 0;
  		}
  
  		if (off < skb->len)
  			goto next_ht;
  	}
  
  	/* POP */
  	if (sdepth--) {
  		n = stack[sdepth].knode;
  		ht = rcu_dereference_bh(n->ht_up);
  		off = stack[sdepth].off;
  		goto check_terminal;
  	}
  out:
  	return -1;
  
  deadloop:
  	net_warn_ratelimited("cls_u32: dead loop\n");
  	return -1;
  }
  
  static struct tc_u_hnode *
  u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
  {
  	struct tc_u_hnode *ht;
  
  	for (ht = rtnl_dereference(tp_c->hlist);
  	     ht;
  	     ht = rtnl_dereference(ht->next))
  		if (ht->handle == handle)
  			break;
  
  	return ht;
  }
  
  static struct tc_u_knode *
  u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
  {
  	unsigned int sel;
  	struct tc_u_knode *n = NULL;
  
  	sel = TC_U32_HASH(handle);
  	if (sel > ht->divisor)
  		goto out;
  
  	for (n = rtnl_dereference(ht->ht[sel]);
  	     n;
  	     n = rtnl_dereference(n->next))
  		if (n->handle == handle)
  			break;
  out:
  	return n;
  }
  
  
  static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
  {
  	struct tc_u_hnode *ht;
  	struct tc_u_common *tp_c = tp->data;
  
  	if (TC_U32_HTID(handle) == TC_U32_ROOT)
  		ht = rtnl_dereference(tp->root);
  	else
  		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
  
  	if (!ht)
  		return 0;
  
  	if (TC_U32_KEY(handle) == 0)
  		return (unsigned long)ht;
  
  	return (unsigned long)u32_lookup_key(ht, handle);
  }
  
  static void u32_put(struct tcf_proto *tp, unsigned long f)
  {
  }
  
  static u32 gen_new_htid(struct tc_u_common *tp_c)
  {
  	int i = 0x800;
  
  	/* hgenerator only used inside rtnl lock it is safe to increment
  	 * without read _copy_ update semantics
  	 */
  	do {
  		if (++tp_c->hgenerator == 0x7FF)
  			tp_c->hgenerator = 1;
  	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
  
  	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
  }
  
  static int u32_init(struct tcf_proto *tp)
  {
  	struct tc_u_hnode *root_ht;
  	struct tc_u_common *tp_c;
  
  	tp_c = tp->q->u32_node;
  
  	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
  	if (root_ht == NULL)
  		return -ENOBUFS;
  
  	root_ht->divisor = 0;
  	root_ht->refcnt++;
  	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
  	root_ht->prio = tp->prio;
  
  	if (tp_c == NULL) {
  		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
  		if (tp_c == NULL) {
  			kfree(root_ht);
  			return -ENOBUFS;
  		}
  		tp_c->q = tp->q;
  		tp->q->u32_node = tp_c;
  	}
  
  	tp_c->refcnt++;
  	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
  	rcu_assign_pointer(tp_c->hlist, root_ht);
  	root_ht->tp_c = tp_c;
  
  	rcu_assign_pointer(tp->root, root_ht);
  	tp->data = tp_c;
  	return 0;
  }
  
  static int u32_destroy_key(struct tcf_proto *tp,
  			   struct tc_u_knode *n,
  			   bool free_pf)
  {
  	tcf_exts_destroy(&n->exts);
  	if (n->ht_down)
  		n->ht_down->refcnt--;
  #ifdef CONFIG_CLS_U32_PERF
  	if (free_pf)
  		free_percpu(n->pf);
  #endif
  #ifdef CONFIG_CLS_U32_MARK
  	if (free_pf)
  		free_percpu(n->pcpu_success);
  #endif
  	kfree(n);
  	return 0;
  }
  
  /* u32_delete_key_rcu should be called when free'ing a copied
   * version of a tc_u_knode obtained from u32_init_knode(). When
   * copies are obtained from u32_init_knode() the statistics are
   * shared between the old and new copies to allow readers to
   * continue to update the statistics during the copy. To support
   * this the u32_delete_key_rcu variant does not free the percpu
   * statistics.
   */
  static void u32_delete_key_rcu(struct rcu_head *rcu)
  {
  	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
  
  	u32_destroy_key(key->tp, key, false);
  }
  
  /* u32_delete_key_freepf_rcu is the rcu callback variant
   * that free's the entire structure including the statistics
   * percpu variables. Only use this if the key is not a copy
   * returned by u32_init_knode(). See u32_delete_key_rcu()
   * for the variant that should be used with keys return from
   * u32_init_knode()
   */
  static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
  {
  	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
  
  	u32_destroy_key(key->tp, key, true);
  }
  
  static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
  {
  	struct tc_u_knode __rcu **kp;
  	struct tc_u_knode *pkp;
  	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
  
  	if (ht) {
  		kp = &ht->ht[TC_U32_HASH(key->handle)];
  		for (pkp = rtnl_dereference(*kp); pkp;
  		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
  			if (pkp == key) {
  				RCU_INIT_POINTER(*kp, key->next);
  
  				tcf_unbind_filter(tp, &key->res);
  				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
  				return 0;
  			}
  		}
  	}
  	WARN_ON(1);
  	return 0;
  }
  
  static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
  {
  	struct tc_u_knode *n;
  	unsigned int h;
  
  	for (h = 0; h <= ht->divisor; h++) {
  		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
  			RCU_INIT_POINTER(ht->ht[h],
  					 rtnl_dereference(n->next));
  			tcf_unbind_filter(tp, &n->res);
  			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
  		}
  	}
  }
  
  static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
  {
  	struct tc_u_common *tp_c = tp->data;
  	struct tc_u_hnode __rcu **hn;
  	struct tc_u_hnode *phn;
  
  	WARN_ON(ht->refcnt);
  
  	u32_clear_hnode(tp, ht);
  
  	hn = &tp_c->hlist;
  	for (phn = rtnl_dereference(*hn);
  	     phn;
  	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
  		if (phn == ht) {
  			RCU_INIT_POINTER(*hn, ht->next);
  			kfree_rcu(ht, rcu);
  			return 0;
  		}
  	}
  
  	return -ENOENT;
  }
  
  static void u32_destroy(struct tcf_proto *tp)
  {
  	struct tc_u_common *tp_c = tp->data;
  	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
  
  	WARN_ON(root_ht == NULL);
  
  	if (root_ht && --root_ht->refcnt == 0)
  		u32_destroy_hnode(tp, root_ht);
  
  	if (--tp_c->refcnt == 0) {
  		struct tc_u_hnode *ht;
  
  		tp->q->u32_node = NULL;
  
  		for (ht = rtnl_dereference(tp_c->hlist);
  		     ht;
  		     ht = rtnl_dereference(ht->next)) {
  			ht->refcnt--;
  			u32_clear_hnode(tp, ht);
  		}
  
  		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
  			RCU_INIT_POINTER(tp_c->hlist, ht->next);
  			kfree_rcu(ht, rcu);
  		}
  
  		kfree(tp_c);
  	}
  
  	tp->data = NULL;
  }
  
  static int u32_delete(struct tcf_proto *tp, unsigned long arg)
  {
  	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
  	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
  
  	if (ht == NULL)
  		return 0;
  
  	if (TC_U32_KEY(ht->handle))
  		return u32_delete_key(tp, (struct tc_u_knode *)ht);
  
  	if (root_ht == ht)
  		return -EINVAL;
  
  	if (ht->refcnt == 1) {
  		ht->refcnt--;
  		u32_destroy_hnode(tp, ht);
  	} else {
  		return -EBUSY;
  	}
  
  	return 0;
  }
  
  #define NR_U32_NODE (1<<12)
  static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
  {
  	struct tc_u_knode *n;
  	unsigned long i;
  	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
  					GFP_KERNEL);
  	if (!bitmap)
  		return handle | 0xFFF;
  
  	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
  	     n;
  	     n = rtnl_dereference(n->next))
  		set_bit(TC_U32_NODE(n->handle), bitmap);
  
  	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
  	if (i >= NR_U32_NODE)
  		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
  
  	kfree(bitmap);
  	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
  }
  
  static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
  	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
  	[TCA_U32_HASH]		= { .type = NLA_U32 },
  	[TCA_U32_LINK]		= { .type = NLA_U32 },
  	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
  	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
  	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
  	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
  };
  
  static int u32_set_parms(struct net *net, struct tcf_proto *tp,
  			 unsigned long base, struct tc_u_hnode *ht,
  			 struct tc_u_knode *n, struct nlattr **tb,
  			 struct nlattr *est, bool ovr)
  {
  	int err;
  	struct tcf_exts e;
  
  	tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
  	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
  	if (err < 0)
  		return err;
  
  	err = -EINVAL;
  	if (tb[TCA_U32_LINK]) {
  		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
  		struct tc_u_hnode *ht_down = NULL, *ht_old;
  
  		if (TC_U32_KEY(handle))
  			goto errout;
  
  		if (handle) {
  			ht_down = u32_lookup_ht(ht->tp_c, handle);
  
  			if (ht_down == NULL)
  				goto errout;
  			ht_down->refcnt++;
  		}
  
  		ht_old = rtnl_dereference(n->ht_down);
  		rcu_assign_pointer(n->ht_down, ht_down);
  
  		if (ht_old)
  			ht_old->refcnt--;
  	}
  	if (tb[TCA_U32_CLASSID]) {
  		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
  		tcf_bind_filter(tp, &n->res, base);
  	}
  
  #ifdef CONFIG_NET_CLS_IND
  	if (tb[TCA_U32_INDEV]) {
  		int ret;
  		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
  		if (ret < 0)
  			goto errout;
  		n->ifindex = ret;
  	}
  #endif
  	tcf_exts_change(tp, &n->exts, &e);
  
  	return 0;
  errout:
  	tcf_exts_destroy(&e);
  	return err;
  }
  
  static void u32_replace_knode(struct tcf_proto *tp,
  			      struct tc_u_common *tp_c,
  			      struct tc_u_knode *n)
  {
  	struct tc_u_knode __rcu **ins;
  	struct tc_u_knode *pins;
  	struct tc_u_hnode *ht;
  
  	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
  		ht = rtnl_dereference(tp->root);
  	else
  		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
  
  	ins = &ht->ht[TC_U32_HASH(n->handle)];
  
  	/* The node must always exist for it to be replaced if this is not the
  	 * case then something went very wrong elsewhere.
  	 */
  	for (pins = rtnl_dereference(*ins); ;
  	     ins = &pins->next, pins = rtnl_dereference(*ins))
  		if (pins->handle == n->handle)
  			break;
  
  	RCU_INIT_POINTER(n->next, pins->next);
  	rcu_assign_pointer(*ins, n);
  }
  
  static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
  					 struct tc_u_knode *n)
  {
  	struct tc_u_knode *new;
  	struct tc_u32_sel *s = &n->sel;
  
  	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
  		      GFP_KERNEL);
  
  	if (!new)
  		return NULL;
  
  	RCU_INIT_POINTER(new->next, n->next);
  	new->handle = n->handle;
  	RCU_INIT_POINTER(new->ht_up, n->ht_up);
  
  #ifdef CONFIG_NET_CLS_IND
  	new->ifindex = n->ifindex;
  #endif
  	new->fshift = n->fshift;
  	new->res = n->res;
  	RCU_INIT_POINTER(new->ht_down, n->ht_down);
  
  	/* bump reference count as long as we hold pointer to structure */
  	if (new->ht_down)
  		new->ht_down->refcnt++;
  
  #ifdef CONFIG_CLS_U32_PERF
  	/* Statistics may be incremented by readers during update
  	 * so we must keep them in tact. When the node is later destroyed
  	 * a special destroy call must be made to not free the pf memory.
  	 */
  	new->pf = n->pf;
  #endif
  
  #ifdef CONFIG_CLS_U32_MARK
  	new->val = n->val;
  	new->mask = n->mask;
  	/* Similarly success statistics must be moved as pointers */
  	new->pcpu_success = n->pcpu_success;
  #endif
  	new->tp = tp;
  	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
  
  	tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE);
  
  	return new;
  }
  
  static int u32_change(struct net *net, struct sk_buff *in_skb,
  		      struct tcf_proto *tp, unsigned long base, u32 handle,
  		      struct nlattr **tca,
  		      unsigned long *arg, bool ovr)
  {
  	struct tc_u_common *tp_c = tp->data;
  	struct tc_u_hnode *ht;
  	struct tc_u_knode *n;
  	struct tc_u32_sel *s;
  	struct nlattr *opt = tca[TCA_OPTIONS];
  	struct nlattr *tb[TCA_U32_MAX + 1];
  	u32 htid;
  	int err;
  #ifdef CONFIG_CLS_U32_PERF
  	size_t size;
  #endif
  
  	if (opt == NULL)
  		return handle ? -EINVAL : 0;
  
  	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
  	if (err < 0)
  		return err;
  
  	n = (struct tc_u_knode *)*arg;
  	if (n) {
  		struct tc_u_knode *new;
  
  		if (TC_U32_KEY(n->handle) == 0)
  			return -EINVAL;
  
  		new = u32_init_knode(tp, n);
  		if (!new)
  			return -ENOMEM;
  
  		err = u32_set_parms(net, tp, base,
  				    rtnl_dereference(n->ht_up), new, tb,
  				    tca[TCA_RATE], ovr);
  
  		if (err) {
  			u32_destroy_key(tp, new, false);
  			return err;
  		}
  
  		u32_replace_knode(tp, tp_c, new);
  		tcf_unbind_filter(tp, &n->res);
  		call_rcu(&n->rcu, u32_delete_key_rcu);
  		return 0;
  	}
  
  	if (tb[TCA_U32_DIVISOR]) {
  		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
  
  		if (--divisor > 0x100)
  			return -EINVAL;
  		if (TC_U32_KEY(handle))
  			return -EINVAL;
  		if (handle == 0) {
  			handle = gen_new_htid(tp->data);
  			if (handle == 0)
  				return -ENOMEM;
  		}
  		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
  		if (ht == NULL)
  			return -ENOBUFS;
  		ht->tp_c = tp_c;
  		ht->refcnt = 1;
  		ht->divisor = divisor;
  		ht->handle = handle;
  		ht->prio = tp->prio;
  		RCU_INIT_POINTER(ht->next, tp_c->hlist);
  		rcu_assign_pointer(tp_c->hlist, ht);
  		*arg = (unsigned long)ht;
  		return 0;
  	}
  
  	if (tb[TCA_U32_HASH]) {
  		htid = nla_get_u32(tb[TCA_U32_HASH]);
  		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
  			ht = rtnl_dereference(tp->root);
  			htid = ht->handle;
  		} else {
  			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
  			if (ht == NULL)
  				return -EINVAL;
  		}
  	} else {
  		ht = rtnl_dereference(tp->root);
  		htid = ht->handle;
  	}
  
  	if (ht->divisor < TC_U32_HASH(htid))
  		return -EINVAL;
  
  	if (handle) {
  		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
  			return -EINVAL;
  		handle = htid | TC_U32_NODE(handle);
  	} else
  		handle = gen_new_kid(ht, htid);
  
  	if (tb[TCA_U32_SEL] == NULL)
  		return -EINVAL;
  
  	s = nla_data(tb[TCA_U32_SEL]);
  
  	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
  	if (n == NULL)
  		return -ENOBUFS;
  
  #ifdef CONFIG_CLS_U32_PERF
  	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
  	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
  	if (!n->pf) {
  		kfree(n);
  		return -ENOBUFS;
  	}
  #endif
  
  	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
  	RCU_INIT_POINTER(n->ht_up, ht);
  	n->handle = handle;
  	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
  	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
  	n->tp = tp;
  
  #ifdef CONFIG_CLS_U32_MARK
  	n->pcpu_success = alloc_percpu(u32);
  	if (!n->pcpu_success) {
  		err = -ENOMEM;
  		goto errout;
  	}
  
  	if (tb[TCA_U32_MARK]) {
  		struct tc_u32_mark *mark;
  
  		mark = nla_data(tb[TCA_U32_MARK]);
  		n->val = mark->val;
  		n->mask = mark->mask;
  	}
  #endif
  
  	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
  	if (err == 0) {
  		struct tc_u_knode __rcu **ins;
  		struct tc_u_knode *pins;
  
  		ins = &ht->ht[TC_U32_HASH(handle)];
  		for (pins = rtnl_dereference(*ins); pins;
  		     ins = &pins->next, pins = rtnl_dereference(*ins))
  			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
  				break;
  
  		RCU_INIT_POINTER(n->next, pins);
  		rcu_assign_pointer(*ins, n);
  
  		*arg = (unsigned long)n;
  		return 0;
  	}
  
  #ifdef CONFIG_CLS_U32_MARK
  	free_percpu(n->pcpu_success);
  errout:
  #endif
  
  #ifdef CONFIG_CLS_U32_PERF
  	free_percpu(n->pf);
  #endif
  	kfree(n);
  	return err;
  }
  
  static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
  {
  	struct tc_u_common *tp_c = tp->data;
  	struct tc_u_hnode *ht;
  	struct tc_u_knode *n;
  	unsigned int h;
  
  	if (arg->stop)
  		return;
  
  	for (ht = rtnl_dereference(tp_c->hlist);
  	     ht;
  	     ht = rtnl_dereference(ht->next)) {
  		if (ht->prio != tp->prio)
  			continue;
  		if (arg->count >= arg->skip) {
  			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
  				arg->stop = 1;
  				return;
  			}
  		}
  		arg->count++;
  		for (h = 0; h <= ht->divisor; h++) {
  			for (n = rtnl_dereference(ht->ht[h]);
  			     n;
  			     n = rtnl_dereference(n->next)) {
  				if (arg->count < arg->skip) {
  					arg->count++;
  					continue;
  				}
  				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
  					arg->stop = 1;
  					return;
  				}
  				arg->count++;
  			}
  		}
  	}
  }
  
  static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
  		     struct sk_buff *skb, struct tcmsg *t)
  {
  	struct tc_u_knode *n = (struct tc_u_knode *)fh;
  	struct tc_u_hnode *ht_up, *ht_down;
  	struct nlattr *nest;
  
  	if (n == NULL)
  		return skb->len;
  
  	t->tcm_handle = n->handle;
  
  	nest = nla_nest_start(skb, TCA_OPTIONS);
  	if (nest == NULL)
  		goto nla_put_failure;
  
  	if (TC_U32_KEY(n->handle) == 0) {
  		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
  		u32 divisor = ht->divisor + 1;
  
  		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
  			goto nla_put_failure;
  	} else {
  #ifdef CONFIG_CLS_U32_PERF
  		struct tc_u32_pcnt *gpf;
  		int cpu;
  #endif
  
  		if (nla_put(skb, TCA_U32_SEL,
  			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
  			    &n->sel))
  			goto nla_put_failure;
  
  		ht_up = rtnl_dereference(n->ht_up);
  		if (ht_up) {
  			u32 htid = n->handle & 0xFFFFF000;
  			if (nla_put_u32(skb, TCA_U32_HASH, htid))
  				goto nla_put_failure;
  		}
  		if (n->res.classid &&
  		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
  			goto nla_put_failure;
  
  		ht_down = rtnl_dereference(n->ht_down);
  		if (ht_down &&
  		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
  			goto nla_put_failure;
  
  #ifdef CONFIG_CLS_U32_MARK
  		if ((n->val || n->mask)) {
  			struct tc_u32_mark mark = {.val = n->val,
  						   .mask = n->mask,
  						   .success = 0};
  			int cpum;
  
  			for_each_possible_cpu(cpum) {
  				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
  
  				mark.success += cnt;
  			}
  
  			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
  				goto nla_put_failure;
  		}
  #endif
  
  		if (tcf_exts_dump(skb, &n->exts) < 0)
  			goto nla_put_failure;
  
  #ifdef CONFIG_NET_CLS_IND
  		if (n->ifindex) {
  			struct net_device *dev;
  			dev = __dev_get_by_index(net, n->ifindex);
  			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
  				goto nla_put_failure;
  		}
  #endif
  #ifdef CONFIG_CLS_U32_PERF
  		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
  			      n->sel.nkeys * sizeof(u64),
  			      GFP_KERNEL);
  		if (!gpf)
  			goto nla_put_failure;
  
  		for_each_possible_cpu(cpu) {
  			int i;
  			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
  
  			gpf->rcnt += pf->rcnt;
  			gpf->rhit += pf->rhit;
  			for (i = 0; i < n->sel.nkeys; i++)
  				gpf->kcnts[i] += pf->kcnts[i];
  		}
  
  		if (nla_put(skb, TCA_U32_PCNT,
  			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
  			    gpf)) {
  			kfree(gpf);
  			goto nla_put_failure;
  		}
  		kfree(gpf);
  #endif
  	}
  
  	nla_nest_end(skb, nest);
  
  	if (TC_U32_KEY(n->handle))
  		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
  			goto nla_put_failure;
  	return skb->len;
  
  nla_put_failure:
  	nla_nest_cancel(skb, nest);
  	return -1;
  }
  
  static struct tcf_proto_ops cls_u32_ops __read_mostly = {
  	.kind		=	"u32",
  	.classify	=	u32_classify,
  	.init		=	u32_init,
  	.destroy	=	u32_destroy,
  	.get		=	u32_get,
  	.put		=	u32_put,
  	.change		=	u32_change,
  	.delete		=	u32_delete,
  	.walk		=	u32_walk,
  	.dump		=	u32_dump,
  	.owner		=	THIS_MODULE,
  };
  
  static int __init init_u32(void)
  {
  	pr_info("u32 classifier\n");
  #ifdef CONFIG_CLS_U32_PERF
  	pr_info("    Performance counters on\n");
  #endif
  #ifdef CONFIG_NET_CLS_IND
  	pr_info("    input device check on\n");
  #endif
  #ifdef CONFIG_NET_CLS_ACT
  	pr_info("    Actions configured\n");
  #endif
  	return register_tcf_proto_ops(&cls_u32_ops);
  }
  
  static void __exit exit_u32(void)
  {
  	unregister_tcf_proto_ops(&cls_u32_ops);
  }
  
  module_init(init_u32)
  module_exit(exit_u32)
  MODULE_LICENSE("GPL");
  