/*
   * 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/rtnetlink.h>

  #include <linux/skbuff.h>

  #include <net/netlink.h>

  #include <net/act_api.h>
  #include <net/pkt_cls.h>

  struct tc_u_knode {

  	struct tc_u_knode	*next;
  	u32			handle;
  	struct tc_u_hnode	*ht_up;
  	struct tcf_exts		exts;
  #ifdef CONFIG_NET_CLS_IND
  	char                     indev[IFNAMSIZ];
  #endif
  	u8			fshift;
  	struct tcf_result	res;
  	struct tc_u_hnode	*ht_down;
  #ifdef CONFIG_CLS_U32_PERF
  	struct tc_u32_pcnt	*pf;
  #endif
  #ifdef CONFIG_CLS_U32_MARK
  	struct tc_u32_mark	mark;
  #endif
  	struct tc_u32_sel	sel;
  };

  struct tc_u_hnode {

  	struct tc_u_hnode	*next;
  	u32			handle;
  	u32			prio;
  	struct tc_u_common	*tp_c;
  	int			refcnt;

  	unsigned int		divisor;

  	struct tc_u_knode	*ht[1];
  };

  struct tc_u_common {

  	struct tc_u_hnode	*hlist;
  	struct Qdisc		*q;
  	int			refcnt;
  	u32			hgenerator;
  };

  static const struct tcf_ext_map u32_ext_map = {

  	.action = TCA_U32_ACT,
  	.police = TCA_U32_POLICE
  };

  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 = (struct tc_u_hnode *)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 = ht->ht[sel];
  
  next_knode:
  	if (n) {
  		struct tc_u32_key *key = n->sel.keys;
  
  #ifdef CONFIG_CLS_U32_PERF

  		n->pf->rcnt += 1;

  		j = 0;
  #endif
  
  #ifdef CONFIG_CLS_U32_MARK

  		if ((skb->mark & n->mark.mask) != n->mark.val) {

  			n = n->next;
  			goto next_knode;
  		} else {
  			n->mark.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 = n->next;
  				goto next_knode;
  			}
  #ifdef CONFIG_CLS_U32_PERF

  			n->pf->kcnts[j] += 1;

  			j++;
  #endif
  		}
  		if (n->ht_down == NULL) {
  check_terminal:

  			if (n->sel.flags & TC_U32_TERMINAL) {

  
  				*res = n->res;
  #ifdef CONFIG_NET_CLS_IND
  				if (!tcf_match_indev(skb, n->indev)) {
  					n = n->next;
  					goto next_knode;
  				}
  #endif
  #ifdef CONFIG_CLS_U32_PERF

  				n->pf->rhit += 1;

  #endif
  				r = tcf_exts_exec(skb, &n->exts, res);
  				if (r < 0) {
  					n = n->next;
  					goto next_knode;
  				}
  
  				return r;
  			}
  			n = n->next;
  			goto next_knode;
  		}
  
  		/* PUSH */
  		if (sdepth >= TC_U32_MAXDEPTH)
  			goto deadloop;
  		stack[sdepth].knode = n;

  		stack[sdepth].off = off;

  		sdepth++;
  
  		ht = 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 = n->ht_up;

  		off = stack[sdepth].off;

  		goto check_terminal;
  	}

  out:

  	return -1;
  
  deadloop:
  	if (net_ratelimit())

  		pr_warning("cls_u32: dead loop
  ");

  	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 = tp_c->hlist; ht; ht = 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 = ht->ht[sel]; n; n = 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 = 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;
  
  	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++;
  	root_ht->next = tp_c->hlist;
  	tp_c->hlist = root_ht;
  	root_ht->tp_c = tp_c;
  
  	tp->root = root_ht;
  	tp->data = tp_c;
  	return 0;
  }
  
  static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n)
  {
  	tcf_unbind_filter(tp, &n->res);
  	tcf_exts_destroy(tp, &n->exts);
  	if (n->ht_down)
  		n->ht_down->refcnt--;
  #ifdef CONFIG_CLS_U32_PERF

  	kfree(n->pf);

  #endif
  	kfree(n);
  	return 0;
  }
  
  static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode* key)
  {
  	struct tc_u_knode **kp;
  	struct tc_u_hnode *ht = key->ht_up;
  
  	if (ht) {
  		for (kp = &ht->ht[TC_U32_HASH(key->handle)]; *kp; kp = &(*kp)->next) {
  			if (*kp == key) {
  				tcf_tree_lock(tp);
  				*kp = key->next;
  				tcf_tree_unlock(tp);
  
  				u32_destroy_key(tp, key);
  				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 = ht->ht[h]) != NULL) {
  			ht->ht[h] = n->next;
  
  			u32_destroy_key(tp, n);
  		}
  	}
  }
  
  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 **hn;

  	WARN_ON(ht->refcnt);

  
  	u32_clear_hnode(tp, ht);
  
  	for (hn = &tp_c->hlist; *hn; hn = &(*hn)->next) {
  		if (*hn == ht) {
  			*hn = ht->next;
  			kfree(ht);
  			return 0;
  		}
  	}

  	WARN_ON(1);

  	return -ENOENT;
  }
  
  static void u32_destroy(struct tcf_proto *tp)
  {
  	struct tc_u_common *tp_c = tp->data;

  	struct tc_u_hnode *root_ht = 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 = tp_c->hlist; ht; ht = ht->next) {
  			ht->refcnt--;

  			u32_clear_hnode(tp, ht);

  		}

  
  		while ((ht = tp_c->hlist) != NULL) {
  			tp_c->hlist = ht->next;

  			WARN_ON(ht->refcnt != 0);

  
  			kfree(ht);

  		}

  
  		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;

  
  	if (ht == NULL)
  		return 0;
  
  	if (TC_U32_KEY(ht->handle))

  		return u32_delete_key(tp, (struct tc_u_knode *)ht);

  
  	if (tp->root == ht)
  		return -EINVAL;

  	if (ht->refcnt == 1) {
  		ht->refcnt--;

  		u32_destroy_hnode(tp, ht);

  	} else {
  		return -EBUSY;
  	}

  
  	return 0;
  }
  
  static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
  {
  	struct tc_u_knode *n;

  	unsigned int i = 0x7FF;

  	for (n = ht->ht[TC_U32_HASH(handle)]; n; n = n->next)

  		if (i < TC_U32_NODE(n->handle))
  			i = TC_U32_NODE(n->handle);
  	i++;

  	return handle | (i > 0xFFF ? 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 tcf_proto *tp, unsigned long base,
  			 struct tc_u_hnode *ht,

  			 struct tc_u_knode *n, struct nlattr **tb,
  			 struct nlattr *est)

  {
  	int err;
  	struct tcf_exts e;
  
  	err = tcf_exts_validate(tp, tb, est, &e, &u32_ext_map);
  	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++;
  		}
  
  		tcf_tree_lock(tp);

  		ht_old = n->ht_down;
  		n->ht_down = ht_down;

  		tcf_tree_unlock(tp);

  		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]) {
  		err = tcf_change_indev(tp, n->indev, tb[TCA_U32_INDEV]);

  		if (err < 0)
  			goto errout;
  	}
  #endif
  	tcf_exts_change(tp, &n->exts, &e);
  
  	return 0;
  errout:
  	tcf_exts_destroy(tp, &e);
  	return err;
  }
  
  static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,

  		      struct nlattr **tca,

  		      unsigned long *arg)
  {
  	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;
  
  	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) {

  		if (TC_U32_KEY(n->handle) == 0)
  			return -EINVAL;

  		return u32_set_parms(tp, base, n->ht_up, n, tb, tca[TCA_RATE]);

  	}

  	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;
  		ht->next = tp_c->hlist;
  		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 = tp->root;
  			htid = ht->handle;
  		} else {
  			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
  			if (ht == NULL)
  				return -EINVAL;
  		}
  	} else {
  		ht = 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

  	n->pf = kzalloc(sizeof(struct tc_u32_pcnt) + s->nkeys*sizeof(u64), GFP_KERNEL);

  	if (n->pf == NULL) {
  		kfree(n);
  		return -ENOBUFS;
  	}

  #endif
  
  	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
  	n->ht_up = ht;
  	n->handle = handle;

  	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;

  
  #ifdef CONFIG_CLS_U32_MARK

  	if (tb[TCA_U32_MARK]) {

  		struct tc_u32_mark *mark;

  		mark = nla_data(tb[TCA_U32_MARK]);

  		memcpy(&n->mark, mark, sizeof(struct tc_u32_mark));
  		n->mark.success = 0;
  	}
  #endif

  	err = u32_set_parms(tp, base, ht, n, tb, tca[TCA_RATE]);

  	if (err == 0) {
  		struct tc_u_knode **ins;
  		for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)
  			if (TC_U32_NODE(handle) < TC_U32_NODE((*ins)->handle))
  				break;
  
  		n->next = *ins;

  		tcf_tree_lock(tp);

  		*ins = n;

  		tcf_tree_unlock(tp);

  
  		*arg = (unsigned long)n;
  		return 0;
  	}
  #ifdef CONFIG_CLS_U32_PERF

  	kfree(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 = tp_c->hlist; ht; ht = 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 = ht->ht[h]; n; n = 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 tcf_proto *tp, unsigned long fh,
  		     struct sk_buff *skb, struct tcmsg *t)
  {

  	struct tc_u_knode *n = (struct tc_u_knode *)fh;

  	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;

  		NLA_PUT_U32(skb, TCA_U32_DIVISOR, divisor);

  	} else {

  		NLA_PUT(skb, TCA_U32_SEL,

  			sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
  			&n->sel);
  		if (n->ht_up) {
  			u32 htid = n->handle & 0xFFFFF000;

  			NLA_PUT_U32(skb, TCA_U32_HASH, htid);

  		}
  		if (n->res.classid)

  			NLA_PUT_U32(skb, TCA_U32_CLASSID, n->res.classid);

  		if (n->ht_down)

  			NLA_PUT_U32(skb, TCA_U32_LINK, n->ht_down->handle);

  
  #ifdef CONFIG_CLS_U32_MARK
  		if (n->mark.val || n->mark.mask)

  			NLA_PUT(skb, TCA_U32_MARK, sizeof(n->mark), &n->mark);

  #endif
  
  		if (tcf_exts_dump(skb, &n->exts, &u32_ext_map) < 0)

  			goto nla_put_failure;

  
  #ifdef CONFIG_NET_CLS_IND

  		if (strlen(n->indev))

  			NLA_PUT_STRING(skb, TCA_U32_INDEV, n->indev);

  #endif
  #ifdef CONFIG_CLS_U32_PERF

  		NLA_PUT(skb, TCA_U32_PCNT,

  		sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
  			n->pf);
  #endif
  	}

  	nla_nest_end(skb, nest);

  	if (TC_U32_KEY(n->handle))
  		if (tcf_exts_dump_stats(skb, &n->exts, &u32_ext_map) < 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
  ");

  #ifdef CONFIG_CLS_U32_PERF

  	pr_info("    Performance counters on
  ");

  #endif

  #ifdef CONFIG_NET_CLS_IND

  	pr_info("    input device check on
  ");

  #endif
  #ifdef CONFIG_NET_CLS_ACT

  	pr_info("    Actions configured
  ");

  #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");