/*
   * 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, see <http://www.gnu.org/licenses/>.

   *
   * 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>

  static unsigned int skbedit_net_id;

  static struct tc_action_ops act_skbedit_ops;

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

  		       struct tcf_result *res)
  {

  	struct tcf_skbedit *d = to_skbedit(a);

  
  	spin_lock(&d->tcf_lock);

  	tcf_lastuse_update(&d->tcf_tm);

  	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->mask;
  		skb->mark |= d->mark & d->mask;
  	}

  	if (d->flags & SKBEDIT_F_PTYPE)
  		skb->pkt_type = d->ptype;

  
  	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) },

  	[TCA_SKBEDIT_PTYPE]		= { .len = sizeof(u16) },

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

  };

  static int tcf_skbedit_init(struct net *net, struct nlattr *nla,

  			    struct nlattr *est, struct tc_action **a,

  			    int ovr, int bind)

  {

  	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

  	struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
  	struct tc_skbedit *parm;
  	struct tcf_skbedit *d;

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

  	u16 *queue_mapping = NULL, *ptype = NULL;

  	bool exists = false;
  	int ret = 0, err;

  
  	if (nla == NULL)
  		return -EINVAL;

  	err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy, NULL);

  	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_PTYPE] != NULL) {
  		ptype = nla_data(tb[TCA_SKBEDIT_PTYPE]);
  		if (!skb_pkt_type_ok(*ptype))
  			return -EINVAL;
  		flags |= SKBEDIT_F_PTYPE;
  	}

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

  	if (tb[TCA_SKBEDIT_MASK] != NULL) {
  		flags |= SKBEDIT_F_MASK;
  		mask = nla_data(tb[TCA_SKBEDIT_MASK]);
  	}

  	parm = nla_data(tb[TCA_SKBEDIT_PARMS]);

  	exists = tcf_idr_check(tn, parm->index, a, bind);

  	if (exists && bind)
  		return 0;
  
  	if (!flags) {

  		if (exists)
  			tcf_idr_release(*a, bind);

  		return -EINVAL;
  	}
  
  	if (!exists) {

  		ret = tcf_idr_create(tn, parm->index, est, a,
  				     &act_skbedit_ops, bind, false);

  		if (ret)
  			return ret;

  		d = to_skbedit(*a);

  		ret = ACT_P_CREATED;
  	} else {

  		d = to_skbedit(*a);

  		tcf_idr_release(*a, bind);

  		if (!ovr)

  			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;

  	if (flags & SKBEDIT_F_PTYPE)
  		d->ptype = *ptype;

  	/* default behaviour is to use all the bits */
  	d->mask = 0xffffffff;
  	if (flags & SKBEDIT_F_MASK)
  		d->mask = *mask;

  	d->tcf_action = parm->action;
  
  	spin_unlock_bh(&d->tcf_lock);
  
  	if (ret == ACT_P_CREATED)

  		tcf_idr_insert(tn, *a);

  	return ret;
  }

  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 = to_skbedit(a);

  	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;

  	if (nla_put(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt))
  		goto nla_put_failure;
  	if ((d->flags & SKBEDIT_F_PRIORITY) &&

  	    nla_put_u32(skb, TCA_SKBEDIT_PRIORITY, d->priority))

  		goto nla_put_failure;
  	if ((d->flags & SKBEDIT_F_QUEUE_MAPPING) &&

  	    nla_put_u16(skb, TCA_SKBEDIT_QUEUE_MAPPING, d->queue_mapping))

  		goto nla_put_failure;
  	if ((d->flags & SKBEDIT_F_MARK) &&

  	    nla_put_u32(skb, TCA_SKBEDIT_MARK, d->mark))

  		goto nla_put_failure;

  	if ((d->flags & SKBEDIT_F_PTYPE) &&

  	    nla_put_u16(skb, TCA_SKBEDIT_PTYPE, d->ptype))

  		goto nla_put_failure;

  	if ((d->flags & SKBEDIT_F_MASK) &&
  	    nla_put_u32(skb, TCA_SKBEDIT_MASK, d->mask))
  		goto nla_put_failure;

  
  	tcf_tm_dump(&t, &d->tcf_tm);

  	if (nla_put_64bit(skb, TCA_SKBEDIT_TM, sizeof(t), &t, TCA_SKBEDIT_PAD))

  		goto nla_put_failure;

  	return skb->len;
  
  nla_put_failure:
  	nlmsg_trim(skb, b);
  	return -1;
  }

  static int tcf_skbedit_walker(struct net *net, struct sk_buff *skb,
  			      struct netlink_callback *cb, int type,

  			      const struct tc_action_ops *ops)

  {
  	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

  	return tcf_generic_walker(tn, skb, cb, type, ops);

  }

  static int tcf_skbedit_search(struct net *net, struct tc_action **a, u32 index)

  {
  	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

  	return tcf_idr_search(tn, a, index);

  }

  static struct tc_action_ops act_skbedit_ops = {
  	.kind		=	"skbedit",

  	.type		=	TCA_ACT_SKBEDIT,

  	.owner		=	THIS_MODULE,
  	.act		=	tcf_skbedit,
  	.dump		=	tcf_skbedit_dump,

  	.init		=	tcf_skbedit_init,

  	.walk		=	tcf_skbedit_walker,
  	.lookup		=	tcf_skbedit_search,

  	.size		=	sizeof(struct tcf_skbedit),

  };
  
  static __net_init int skbedit_init_net(struct net *net)
  {
  	struct tc_action_net *tn = net_generic(net, skbedit_net_id);

  	return tc_action_net_init(tn, &act_skbedit_ops);

  }
  
  static void __net_exit skbedit_exit_net(struct net *net)
  {
  	struct tc_action_net *tn = net_generic(net, skbedit_net_id);
  
  	tc_action_net_exit(tn);
  }
  
  static struct pernet_operations skbedit_net_ops = {
  	.init = skbedit_init_net,
  	.exit = skbedit_exit_net,
  	.id   = &skbedit_net_id,
  	.size = sizeof(struct tc_action_net),

  };
  
  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, &skbedit_net_ops);

  }
  
  static void __exit skbedit_cleanup_module(void)
  {

  	tcf_unregister_action(&act_skbedit_ops, &skbedit_net_ops);

  }
  
  module_init(skbedit_init_module);
  module_exit(skbedit_cleanup_module);