text: /*
   * net/sched/cls_matchll.c		Match-all classifier
   *
   * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
   *
   * 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.
   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>
  
  #include <net/sch_generic.h>
  #include <net/pkt_cls.h>
  
  struct cls_mall_head {
  	struct tcf_exts exts;
  	struct tcf_result res;
  	u32 handle;
  	u32 flags;
  	union {
  		struct work_struct work;
  		struct rcu_head	rcu;
  	};
  };
  
  static int mall_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  			 struct tcf_result *res)
  {
  	struct cls_mall_head *head = rcu_dereference_bh(tp->root);
  
  	if (tc_skip_sw(head->flags))
  		return -1;
  
  	*res = head->res;
  	return tcf_exts_exec(skb, &head->exts, res);
  }
  
  static int mall_init(struct tcf_proto *tp)
  {
  	return 0;
  }
  
  static void __mall_destroy(struct cls_mall_head *head)
  {
  	tcf_exts_destroy(&head->exts);
  	tcf_exts_put_net(&head->exts);
  	kfree(head);
  }
  
  static void mall_destroy_work(struct work_struct *work)
  {
  	struct cls_mall_head *head = container_of(work, struct cls_mall_head,
  						  work);
  	rtnl_lock();
  	__mall_destroy(head);
  	rtnl_unlock();
  }
  
  static void mall_destroy_rcu(struct rcu_head *rcu)
  {
  	struct cls_mall_head *head = container_of(rcu, struct cls_mall_head,
  						  rcu);
  
  	INIT_WORK(&head->work, mall_destroy_work);
  	tcf_queue_work(&head->work);
  }
  
  static void mall_destroy_hw_filter(struct tcf_proto *tp,
  				   struct cls_mall_head *head,
  				   unsigned long cookie)
  {
  	struct tc_cls_matchall_offload cls_mall = {};
  	struct tcf_block *block = tp->chain->block;
  
  	tc_cls_common_offload_init(&cls_mall.common, tp);
  	cls_mall.command = TC_CLSMATCHALL_DESTROY;
  	cls_mall.cookie = cookie;
  
  	tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL, &cls_mall, false);
  }
  
  static int mall_replace_hw_filter(struct tcf_proto *tp,
  				  struct cls_mall_head *head,
  				  unsigned long cookie)
  {
  	struct tc_cls_matchall_offload cls_mall = {};
  	struct tcf_block *block = tp->chain->block;
  	bool skip_sw = tc_skip_sw(head->flags);
  	int err;
  
  	tc_cls_common_offload_init(&cls_mall.common, tp);
  	cls_mall.command = TC_CLSMATCHALL_REPLACE;
  	cls_mall.exts = &head->exts;
  	cls_mall.cookie = cookie;
  
  	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSMATCHALL,
  			       &cls_mall, skip_sw);
  	if (err < 0) {
  		mall_destroy_hw_filter(tp, head, cookie);
  		return err;
  	} else if (err > 0) {
  		head->flags |= TCA_CLS_FLAGS_IN_HW;
  	}
  
  	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
  		return -EINVAL;
  
  	return 0;
  }
  
  static void mall_destroy(struct tcf_proto *tp)
  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  
  	if (!head)
  		return;
  
  	if (!tc_skip_hw(head->flags))
  		mall_destroy_hw_filter(tp, head, (unsigned long) head);
  
  	if (tcf_exts_get_net(&head->exts))
  		call_rcu(&head->rcu, mall_destroy_rcu);
  	else
  		__mall_destroy(head);
  }
  
  static void *mall_get(struct tcf_proto *tp, u32 handle)
  {
  	return NULL;
  }
  
  static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
  	[TCA_MATCHALL_UNSPEC]		= { .type = NLA_UNSPEC },
  	[TCA_MATCHALL_CLASSID]		= { .type = NLA_U32 },
  };
  
  static int mall_set_parms(struct net *net, struct tcf_proto *tp,
  			  struct cls_mall_head *head,
  			  unsigned long base, struct nlattr **tb,
  			  struct nlattr *est, bool ovr)
  {
  	int err;
  
  	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
  	if (err < 0)
  		return err;
  
  	if (tb[TCA_MATCHALL_CLASSID]) {
  		head->res.classid = nla_get_u32(tb[TCA_MATCHALL_CLASSID]);
  		tcf_bind_filter(tp, &head->res, base);
  	}
  	return 0;
  }
  
  static int mall_change(struct net *net, struct sk_buff *in_skb,
  		       struct tcf_proto *tp, unsigned long base,
  		       u32 handle, struct nlattr **tca,
  		       void **arg, bool ovr)
  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
  	struct cls_mall_head *new;
  	u32 flags = 0;
  	int err;
  
  	if (!tca[TCA_OPTIONS])
  		return -EINVAL;
  
  	if (head)
  		return -EEXIST;
  
  	err = nla_parse_nested(tb, TCA_MATCHALL_MAX, tca[TCA_OPTIONS],
  			       mall_policy, NULL);
  	if (err < 0)
  		return err;
  
  	if (tb[TCA_MATCHALL_FLAGS]) {
  		flags = nla_get_u32(tb[TCA_MATCHALL_FLAGS]);
  		if (!tc_flags_valid(flags))
  			return -EINVAL;
  	}
  
  	new = kzalloc(sizeof(*new), GFP_KERNEL);
  	if (!new)
  		return -ENOBUFS;
  
  	err = tcf_exts_init(&new->exts, TCA_MATCHALL_ACT, 0);
  	if (err)
  		goto err_exts_init;
  
  	if (!handle)
  		handle = 1;
  	new->handle = handle;
  	new->flags = flags;
  
  	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
  	if (err)
  		goto err_set_parms;
  
  	if (!tc_skip_hw(new->flags)) {
  		err = mall_replace_hw_filter(tp, new, (unsigned long) new);
  		if (err)
  			goto err_replace_hw_filter;
  	}
  
  	if (!tc_in_hw(new->flags))
  		new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
  
  	*arg = head;
  	rcu_assign_pointer(tp->root, new);
  	return 0;
  
  err_replace_hw_filter:
  err_set_parms:
  	tcf_exts_destroy(&new->exts);
  err_exts_init:
  	kfree(new);
  	return err;
  }
  
  static int mall_delete(struct tcf_proto *tp, void *arg, bool *last)
  {
  	return -EOPNOTSUPP;
  }
  
  static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg)
  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  
  	if (arg->count < arg->skip)
  		goto skip;
  	if (arg->fn(tp, head, arg) < 0)
  		arg->stop = 1;
  skip:
  	arg->count++;
  }
  
  static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,
  		     struct sk_buff *skb, struct tcmsg *t)
  {
  	struct cls_mall_head *head = fh;
  	struct nlattr *nest;
  
  	if (!head)
  		return skb->len;
  
  	t->tcm_handle = head->handle;
  
  	nest = nla_nest_start(skb, TCA_OPTIONS);
  	if (!nest)
  		goto nla_put_failure;
  
  	if (head->res.classid &&
  	    nla_put_u32(skb, TCA_MATCHALL_CLASSID, head->res.classid))
  		goto nla_put_failure;
  
  	if (head->flags && nla_put_u32(skb, TCA_MATCHALL_FLAGS, head->flags))
  		goto nla_put_failure;
  
  	if (tcf_exts_dump(skb, &head->exts))
  		goto nla_put_failure;
  
  	nla_nest_end(skb, nest);
  
  	if (tcf_exts_dump_stats(skb, &head->exts) < 0)
  		goto nla_put_failure;
  
  	return skb->len;
  
  nla_put_failure:
  	nla_nest_cancel(skb, nest);
  	return -1;
  }
  
  static void mall_bind_class(void *fh, u32 classid, unsigned long cl)
  {
  	struct cls_mall_head *head = fh;
  
  	if (head && head->res.classid == classid)
  		head->res.class = cl;
  }
  
  static struct tcf_proto_ops cls_mall_ops __read_mostly = {
  	.kind		= "matchall",
  	.classify	= mall_classify,
  	.init		= mall_init,
  	.destroy	= mall_destroy,
  	.get		= mall_get,
  	.change		= mall_change,
  	.delete		= mall_delete,
  	.walk		= mall_walk,
  	.dump		= mall_dump,
  	.bind_class	= mall_bind_class,
  	.owner		= THIS_MODULE,
  };
  
  static int __init cls_mall_init(void)
  {
  	return register_tcf_proto_ops(&cls_mall_ops);
  }
  
  static void __exit cls_mall_exit(void)
  {
  	unregister_tcf_proto_ops(&cls_mall_ops);
  }
  
  module_init(cls_mall_init);
  module_exit(cls_mall_exit);
  
  MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
  MODULE_DESCRIPTION("Match-all classifier");
  MODULE_LICENSE("GPL v2");
  