text: /* net/sched/sch_ingress.c - Ingress and clsact qdisc
   *
   *              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:     Jamal Hadi Salim 1999
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/list.h>
  #include <linux/skbuff.h>
  #include <linux/rtnetlink.h>
  
  #include <net/netlink.h>
  #include <net/pkt_sched.h>
  #include <net/pkt_cls.h>
  
  struct ingress_sched_data {
  	struct tcf_block *block;
  };
  
  static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
  {
  	return NULL;
  }
  
  static unsigned long ingress_find(struct Qdisc *sch, u32 classid)
  {
  	return TC_H_MIN(classid) + 1;
  }
  
  static unsigned long ingress_bind_filter(struct Qdisc *sch,
  					 unsigned long parent, u32 classid)
  {
  	return ingress_find(sch, classid);
  }
  
  static void ingress_unbind_filter(struct Qdisc *sch, unsigned long cl)
  {
  }
  
  static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
  {
  }
  
  static struct tcf_block *ingress_tcf_block(struct Qdisc *sch, unsigned long cl)
  {
  	struct ingress_sched_data *q = qdisc_priv(sch);
  
  	return q->block;
  }
  
  static int ingress_init(struct Qdisc *sch, struct nlattr *opt)
  {
  	struct ingress_sched_data *q = qdisc_priv(sch);
  	struct net_device *dev = qdisc_dev(sch);
  	int err;
  
  	err = tcf_block_get(&q->block, &dev->ingress_cl_list);
  	if (err)
  		return err;
  
  	net_inc_ingress_queue();
  	sch->flags |= TCQ_F_CPUSTATS;
  
  	return 0;
  }
  
  static void ingress_destroy(struct Qdisc *sch)
  {
  	struct ingress_sched_data *q = qdisc_priv(sch);
  
  	tcf_block_put(q->block);
  	net_dec_ingress_queue();
  }
  
  static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
  {
  	struct nlattr *nest;
  
  	nest = nla_nest_start(skb, TCA_OPTIONS);
  	if (nest == NULL)
  		goto nla_put_failure;
  
  	return nla_nest_end(skb, nest);
  
  nla_put_failure:
  	nla_nest_cancel(skb, nest);
  	return -1;
  }
  
  static const struct Qdisc_class_ops ingress_class_ops = {
  	.leaf		=	ingress_leaf,
  	.find		=	ingress_find,
  	.walk		=	ingress_walk,
  	.tcf_block	=	ingress_tcf_block,
  	.bind_tcf	=	ingress_bind_filter,
  	.unbind_tcf	=	ingress_unbind_filter,
  };
  
  static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
  	.cl_ops		=	&ingress_class_ops,
  	.id		=	"ingress",
  	.priv_size	=	sizeof(struct ingress_sched_data),
  	.init		=	ingress_init,
  	.destroy	=	ingress_destroy,
  	.dump		=	ingress_dump,
  	.owner		=	THIS_MODULE,
  };
  
  struct clsact_sched_data {
  	struct tcf_block *ingress_block;
  	struct tcf_block *egress_block;
  };
  
  static unsigned long clsact_find(struct Qdisc *sch, u32 classid)
  {
  	switch (TC_H_MIN(classid)) {
  	case TC_H_MIN(TC_H_MIN_INGRESS):
  	case TC_H_MIN(TC_H_MIN_EGRESS):
  		return TC_H_MIN(classid);
  	default:
  		return 0;
  	}
  }
  
  static unsigned long clsact_bind_filter(struct Qdisc *sch,
  					unsigned long parent, u32 classid)
  {
  	return clsact_find(sch, classid);
  }
  
  static struct tcf_block *clsact_tcf_block(struct Qdisc *sch, unsigned long cl)
  {
  	struct clsact_sched_data *q = qdisc_priv(sch);
  
  	switch (cl) {
  	case TC_H_MIN(TC_H_MIN_INGRESS):
  		return q->ingress_block;
  	case TC_H_MIN(TC_H_MIN_EGRESS):
  		return q->egress_block;
  	default:
  		return NULL;
  	}
  }
  
  static int clsact_init(struct Qdisc *sch, struct nlattr *opt)
  {
  	struct clsact_sched_data *q = qdisc_priv(sch);
  	struct net_device *dev = qdisc_dev(sch);
  	int err;
  
  	err = tcf_block_get(&q->ingress_block, &dev->ingress_cl_list);
  	if (err)
  		return err;
  
  	err = tcf_block_get(&q->egress_block, &dev->egress_cl_list);
  	if (err)
  		return err;
  
  	net_inc_ingress_queue();
  	net_inc_egress_queue();
  
  	sch->flags |= TCQ_F_CPUSTATS;
  
  	return 0;
  }
  
  static void clsact_destroy(struct Qdisc *sch)
  {
  	struct clsact_sched_data *q = qdisc_priv(sch);
  
  	tcf_block_put(q->egress_block);
  	tcf_block_put(q->ingress_block);
  
  	net_dec_ingress_queue();
  	net_dec_egress_queue();
  }
  
  static const struct Qdisc_class_ops clsact_class_ops = {
  	.leaf		=	ingress_leaf,
  	.find		=	clsact_find,
  	.walk		=	ingress_walk,
  	.tcf_block	=	clsact_tcf_block,
  	.bind_tcf	=	clsact_bind_filter,
  	.unbind_tcf	=	ingress_unbind_filter,
  };
  
  static struct Qdisc_ops clsact_qdisc_ops __read_mostly = {
  	.cl_ops		=	&clsact_class_ops,
  	.id		=	"clsact",
  	.priv_size	=	sizeof(struct clsact_sched_data),
  	.init		=	clsact_init,
  	.destroy	=	clsact_destroy,
  	.dump		=	ingress_dump,
  	.owner		=	THIS_MODULE,
  };
  
  static int __init ingress_module_init(void)
  {
  	int ret;
  
  	ret = register_qdisc(&ingress_qdisc_ops);
  	if (!ret) {
  		ret = register_qdisc(&clsact_qdisc_ops);
  		if (ret)
  			unregister_qdisc(&ingress_qdisc_ops);
  	}
  
  	return ret;
  }
  
  static void __exit ingress_module_exit(void)
  {
  	unregister_qdisc(&ingress_qdisc_ops);
  	unregister_qdisc(&clsact_qdisc_ops);
  }
  
  module_init(ingress_module_init);
  module_exit(ingress_module_exit);
  
  MODULE_ALIAS("sch_clsact");
  MODULE_LICENSE("GPL");
  