// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * net/sched/cls_matchll.c		Match-all classifier
   *
   * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>

   */
  
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/module.h>

  #include <linux/percpu.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;

  	unsigned int in_hw_count;

  	struct tc_matchall_pcnt __percpu *pf;

  	struct rcu_work rwork;

  	bool deleting;

  };
  
  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 (unlikely(!head))
  		return -1;

  	if (tc_skip_sw(head->flags))

  		return -1;

  	*res = head->res;

  	__this_cpu_inc(head->pf->rhit);

  	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);

  	free_percpu(head->pf);

  	kfree(head);
  }

  static void mall_destroy_work(struct work_struct *work)
  {

  	struct cls_mall_head *head = container_of(to_rcu_work(work),
  						  struct cls_mall_head,
  						  rwork);

  	rtnl_lock();

  	__mall_destroy(head);

  	rtnl_unlock();
  }

  static void mall_destroy_hw_filter(struct tcf_proto *tp,
  				   struct cls_mall_head *head,

  				   unsigned long cookie,
  				   struct netlink_ext_ack *extack)

  {

  	struct tc_cls_matchall_offload cls_mall = {};

  	struct tcf_block *block = tp->chain->block;

  	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);

  	cls_mall.command = TC_CLSMATCHALL_DESTROY;

  	cls_mall.cookie = cookie;

  	tc_setup_cb_destroy(block, tp, TC_SETUP_CLSMATCHALL, &cls_mall, false,
  			    &head->flags, &head->in_hw_count, true);

  }

  static int mall_replace_hw_filter(struct tcf_proto *tp,
  				  struct cls_mall_head *head,

  				  unsigned long cookie,
  				  struct netlink_ext_ack *extack)

  {

  	struct tc_cls_matchall_offload cls_mall = {};

  	struct tcf_block *block = tp->chain->block;
  	bool skip_sw = tc_skip_sw(head->flags);
  	int err;

  	cls_mall.rule =	flow_rule_alloc(tcf_exts_num_actions(&head->exts));
  	if (!cls_mall.rule)
  		return -ENOMEM;

  	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);

  	cls_mall.command = TC_CLSMATCHALL_REPLACE;

  	cls_mall.cookie = cookie;

  	err = tc_setup_flow_action(&cls_mall.rule->action, &head->exts);

  	if (err) {
  		kfree(cls_mall.rule);
  		mall_destroy_hw_filter(tp, head, cookie, NULL);
  		if (skip_sw)
  			NL_SET_ERR_MSG_MOD(extack, "Failed to setup flow action");
  		else
  			err = 0;
  
  		return err;
  	}

  	err = tc_setup_cb_add(block, tp, TC_SETUP_CLSMATCHALL, &cls_mall,
  			      skip_sw, &head->flags, &head->in_hw_count, true);

  	tc_cleanup_flow_action(&cls_mall.rule->action);

  	kfree(cls_mall.rule);

  	if (err) {

  		mall_destroy_hw_filter(tp, head, cookie, NULL);

  		return err;

  	}
  
  	if (skip_sw && !(head->flags & TCA_CLS_FLAGS_IN_HW))
  		return -EINVAL;
  
  	return 0;

  }

  static void mall_destroy(struct tcf_proto *tp, bool rtnl_held,
  			 struct netlink_ext_ack *extack)

  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);

  	if (!head)

  		return;

  	tcf_unbind_filter(tp, &head->res);

  	if (!tc_skip_hw(head->flags))

  		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);

  	if (tcf_exts_get_net(&head->exts))

  		tcf_queue_work(&head->rwork, mall_destroy_work);

  	else
  		__mall_destroy(head);

  }

  static void *mall_get(struct tcf_proto *tp, u32 handle)

  {

  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  
  	if (head && head->handle == handle)
  		return head;

  	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 },

  	[TCA_MATCHALL_FLAGS]		= { .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,
  			  struct netlink_ext_ack *extack)

  {

  	int err;

  	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, true,
  				extack);

  	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, bool rtnl_held,
  		       struct netlink_ext_ack *extack)

  {
  	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_deprecated(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, net, TCA_MATCHALL_ACT, 0);

  	if (err)
  		goto err_exts_init;

  
  	if (!handle)
  		handle = 1;

  	new->handle = handle;
  	new->flags = flags;

  	new->pf = alloc_percpu(struct tc_matchall_pcnt);
  	if (!new->pf) {
  		err = -ENOMEM;
  		goto err_alloc_percpu;
  	}

  	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
  			     extack);

  	if (err)

  		goto err_set_parms;

  	if (!tc_skip_hw(new->flags)) {

  		err = mall_replace_hw_filter(tp, new, (unsigned long)new,
  					     extack);

  		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:

  	free_percpu(new->pf);
  err_alloc_percpu:

  	tcf_exts_destroy(&new->exts);

  err_exts_init:

  	kfree(new);

  	return err;
  }

  static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,

  		       bool rtnl_held, struct netlink_ext_ack *extack)

  {

  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  
  	head->deleting = true;
  	*last = true;
  	return 0;

  }

  static void mall_walk(struct tcf_proto *tp, struct tcf_walker *arg,
  		      bool rtnl_held)

  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);

  
  	if (arg->count < arg->skip)
  		goto skip;

  	if (!head || head->deleting)

  		return;

  	if (arg->fn(tp, head, arg) < 0)

  		arg->stop = 1;
  skip:
  	arg->count++;
  }

  static int mall_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,

  			  void *cb_priv, struct netlink_ext_ack *extack)
  {
  	struct cls_mall_head *head = rtnl_dereference(tp->root);
  	struct tc_cls_matchall_offload cls_mall = {};
  	struct tcf_block *block = tp->chain->block;
  	int err;
  
  	if (tc_skip_hw(head->flags))
  		return 0;

  	cls_mall.rule =	flow_rule_alloc(tcf_exts_num_actions(&head->exts));
  	if (!cls_mall.rule)
  		return -ENOMEM;

  	tc_cls_common_offload_init(&cls_mall.common, tp, head->flags, extack);

  	cls_mall.command = add ?
  		TC_CLSMATCHALL_REPLACE : TC_CLSMATCHALL_DESTROY;

  	cls_mall.cookie = (unsigned long)head;

  	err = tc_setup_flow_action(&cls_mall.rule->action, &head->exts);

  	if (err) {
  		kfree(cls_mall.rule);
  		if (add && tc_skip_sw(head->flags)) {
  			NL_SET_ERR_MSG_MOD(extack, "Failed to setup flow action");
  			return err;
  		}

  		return 0;

  	}

  	err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSMATCHALL,
  				    &cls_mall, cb_priv, &head->flags,
  				    &head->in_hw_count);

  	tc_cleanup_flow_action(&cls_mall.rule->action);

  	kfree(cls_mall.rule);

  	if (err)
  		return err;

  
  	return 0;
  }

  static void mall_stats_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, head->flags, NULL);

  	cls_mall.command = TC_CLSMATCHALL_STATS;
  	cls_mall.cookie = cookie;

  	tc_setup_cb_call(block, TC_SETUP_CLSMATCHALL, &cls_mall, false, true);

  
  	tcf_exts_stats_update(&head->exts, cls_mall.stats.bytes,

  			      cls_mall.stats.pkts, cls_mall.stats.drops,
  			      cls_mall.stats.lastused,

  			      cls_mall.stats.used_hw_stats,
  			      cls_mall.stats.used_hw_stats_valid);

  }

  static int mall_dump(struct net *net, struct tcf_proto *tp, void *fh,

  		     struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)

  {

  	struct tc_matchall_pcnt gpf = {};

  	struct cls_mall_head *head = fh;

  	struct nlattr *nest;

  	int cpu;

  	if (!head)

  		return skb->len;

  	if (!tc_skip_hw(head->flags))
  		mall_stats_hw_filter(tp, head, (unsigned long)head);

  	t->tcm_handle = head->handle;

  	nest = nla_nest_start_noflag(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;

  	for_each_possible_cpu(cpu) {
  		struct tc_matchall_pcnt *pf = per_cpu_ptr(head->pf, cpu);
  
  		gpf.rhit += pf->rhit;
  	}
  
  	if (nla_put_64bit(skb, TCA_MATCHALL_PCNT,
  			  sizeof(struct tc_matchall_pcnt),
  			  &gpf, TCA_MATCHALL_PAD))
  		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, void *q,
  			    unsigned long base)

  {
  	struct cls_mall_head *head = fh;

  	if (head && head->res.classid == classid) {
  		if (cl)
  			__tcf_bind_filter(q, &head->res, base);
  		else
  			__tcf_unbind_filter(q, &head->res);
  	}

  }

  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,

  	.reoffload	= mall_reoffload,

  	.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");