/*
   * Copyright (c) 2008, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
   * Place - Suite 330, Boston, MA 02111-1307 USA.
   *
   * Author: Alexander Duyck <alexander.h.duyck@intel.com>
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/skbuff.h>
  #include <linux/rtnetlink.h>
  #include <net/netlink.h>
  #include <net/pkt_sched.h>
  
  #include <linux/tc_act/tc_skbedit.h>
  #include <net/tc_act/tc_skbedit.h>
  
  #define SKBEDIT_TAB_MASK     15
  static struct tcf_common *tcf_skbedit_ht[SKBEDIT_TAB_MASK + 1];
  static u32 skbedit_idx_gen;
  static DEFINE_RWLOCK(skbedit_lock);
  
  static struct tcf_hashinfo skbedit_hash_info = {
  	.htab	=	tcf_skbedit_ht,
  	.hmask	=	SKBEDIT_TAB_MASK,
  	.lock	=	&skbedit_lock,
  };

  static int tcf_skbedit(struct sk_buff *skb, const struct tc_action *a,

  		       struct tcf_result *res)
  {
  	struct tcf_skbedit *d = a->priv;
  
  	spin_lock(&d->tcf_lock);
  	d->tcf_tm.lastuse = jiffies;

  	bstats_update(&d->tcf_bstats, skb);

  
  	if (d->flags & SKBEDIT_F_PRIORITY)
  		skb->priority = d->priority;
  	if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
  	    skb->dev->real_num_tx_queues > d->queue_mapping)
  		skb_set_queue_mapping(skb, d->queue_mapping);

  	if (d->flags & SKBEDIT_F_MARK)
  		skb->mark = d->mark;

  
  	spin_unlock(&d->tcf_lock);
  	return d->tcf_action;
  }
  
  static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
  	[TCA_SKBEDIT_PARMS]		= { .len = sizeof(struct tc_skbedit) },
  	[TCA_SKBEDIT_PRIORITY]		= { .len = sizeof(u32) },
  	[TCA_SKBEDIT_QUEUE_MAPPING]	= { .len = sizeof(u16) },

  	[TCA_SKBEDIT_MARK]		= { .len = sizeof(u32) },

  };
  
  static int tcf_skbedit_init(struct nlattr *nla, struct nlattr *est,
  			 struct tc_action *a, int ovr, int bind)
  {
  	struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
  	struct tc_skbedit *parm;
  	struct tcf_skbedit *d;
  	struct tcf_common *pc;

  	u32 flags = 0, *priority = NULL, *mark = NULL;

  	u16 *queue_mapping = NULL;
  	int ret = 0, err;
  
  	if (nla == NULL)
  		return -EINVAL;
  
  	err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy);
  	if (err < 0)
  		return err;
  
  	if (tb[TCA_SKBEDIT_PARMS] == NULL)
  		return -EINVAL;
  
  	if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
  		flags |= SKBEDIT_F_PRIORITY;
  		priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
  	}
  
  	if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
  		flags |= SKBEDIT_F_QUEUE_MAPPING;
  		queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
  	}

  
  	if (tb[TCA_SKBEDIT_MARK] != NULL) {
  		flags |= SKBEDIT_F_MARK;
  		mark = nla_data(tb[TCA_SKBEDIT_MARK]);
  	}

  	if (!flags)
  		return -EINVAL;
  
  	parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
  
  	pc = tcf_hash_check(parm->index, a, bind, &skbedit_hash_info);
  	if (!pc) {
  		pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
  				     &skbedit_idx_gen, &skbedit_hash_info);

  		if (IS_ERR(pc))

  			return PTR_ERR(pc);

  
  		d = to_skbedit(pc);
  		ret = ACT_P_CREATED;
  	} else {
  		d = to_skbedit(pc);
  		if (!ovr) {
  			tcf_hash_release(pc, bind, &skbedit_hash_info);
  			return -EEXIST;
  		}
  	}
  
  	spin_lock_bh(&d->tcf_lock);
  
  	d->flags = flags;
  	if (flags & SKBEDIT_F_PRIORITY)
  		d->priority = *priority;
  	if (flags & SKBEDIT_F_QUEUE_MAPPING)
  		d->queue_mapping = *queue_mapping;

  	if (flags & SKBEDIT_F_MARK)
  		d->mark = *mark;

  	d->tcf_action = parm->action;
  
  	spin_unlock_bh(&d->tcf_lock);
  
  	if (ret == ACT_P_CREATED)
  		tcf_hash_insert(pc, &skbedit_hash_info);
  	return ret;
  }

  static int tcf_skbedit_cleanup(struct tc_action *a, int bind)

  {
  	struct tcf_skbedit *d = a->priv;
  
  	if (d)
  		return tcf_hash_release(&d->common, bind, &skbedit_hash_info);
  	return 0;
  }

  static int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
  			    int bind, int ref)

  {
  	unsigned char *b = skb_tail_pointer(skb);
  	struct tcf_skbedit *d = a->priv;

  	struct tc_skbedit opt = {
  		.index   = d->tcf_index,
  		.refcnt  = d->tcf_refcnt - ref,
  		.bindcnt = d->tcf_bindcnt - bind,
  		.action  = d->tcf_action,
  	};

  	struct tcf_t t;

  	NLA_PUT(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt);
  	if (d->flags & SKBEDIT_F_PRIORITY)
  		NLA_PUT(skb, TCA_SKBEDIT_PRIORITY, sizeof(d->priority),
  			&d->priority);
  	if (d->flags & SKBEDIT_F_QUEUE_MAPPING)
  		NLA_PUT(skb, TCA_SKBEDIT_QUEUE_MAPPING,
  			sizeof(d->queue_mapping), &d->queue_mapping);

  	if (d->flags & SKBEDIT_F_MARK)
  		NLA_PUT(skb, TCA_SKBEDIT_MARK, sizeof(d->mark),
  			&d->mark);

  	t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
  	t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
  	t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
  	NLA_PUT(skb, TCA_SKBEDIT_TM, sizeof(t), &t);
  	return skb->len;
  
  nla_put_failure:
  	nlmsg_trim(skb, b);
  	return -1;
  }
  
  static struct tc_action_ops act_skbedit_ops = {
  	.kind		=	"skbedit",
  	.hinfo		=	&skbedit_hash_info,
  	.type		=	TCA_ACT_SKBEDIT,
  	.capab		=	TCA_CAP_NONE,
  	.owner		=	THIS_MODULE,
  	.act		=	tcf_skbedit,
  	.dump		=	tcf_skbedit_dump,
  	.cleanup	=	tcf_skbedit_cleanup,
  	.init		=	tcf_skbedit_init,
  	.walk		=	tcf_generic_walker,
  };
  
  MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
  MODULE_DESCRIPTION("SKB Editing");
  MODULE_LICENSE("GPL");
  
  static int __init skbedit_init_module(void)
  {
  	return tcf_register_action(&act_skbedit_ops);
  }
  
  static void __exit skbedit_cleanup_module(void)
  {
  	tcf_unregister_action(&act_skbedit_ops);
  }
  
  module_init(skbedit_init_module);
  module_exit(skbedit_cleanup_module);