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Commit 2190d1d0 authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
Browse files

net: sched: introduce helpers to work with filter chains 



Introduce struct tcf_chain object and set of helpers around it. Wraps up
insertion, deletion and search in the filter chain.

Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Acked-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7961973a

include/net/sch_generic.h

+6 −1
Original line number Diff line number Diff line
@@ -248,10 +248,15 @@ struct qdisc_skb_cb { 
	unsigned char		data[QDISC_CB_PRIV_LEN];

};



struct tcf_block {

struct tcf_chain {

	struct tcf_proto __rcu *filter_chain;

	struct tcf_proto __rcu **p_filter_chain;

};



struct tcf_block {

	struct tcf_chain *chain;

};



static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)

{

	struct qdisc_skb_cb *qcb;

net/sched/cls_api.c

+107 −41
Original line number Diff line number Diff line
@@ -106,13 +106,12 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb, 


static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,

				 struct nlmsghdr *n,

				 struct tcf_proto __rcu **chain, int event)

				 struct tcf_chain *chain, int event)

{

	struct tcf_proto __rcu **it_chain;

	struct tcf_proto *tp;



	for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL;

	     it_chain = &tp->next)

	for (tp = rtnl_dereference(chain->filter_chain);

	     tp; tp = rtnl_dereference(tp->next))

		tfilter_notify(net, oskb, n, tp, 0, event, false);

}
@@ -187,26 +186,49 @@ static void tcf_proto_destroy(struct tcf_proto *tp) 
	kfree_rcu(tp, rcu);

}



static void tcf_chain_destroy(struct tcf_proto __rcu **fl)

static struct tcf_chain *tcf_chain_create(void)

{

	return kzalloc(sizeof(struct tcf_chain), GFP_KERNEL);

}



static void tcf_chain_destroy(struct tcf_chain *chain)

{

	struct tcf_proto *tp;



	while ((tp = rtnl_dereference(*fl)) != NULL) {

		RCU_INIT_POINTER(*fl, tp->next);

	while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {

		RCU_INIT_POINTER(chain->filter_chain, tp->next);

		tcf_proto_destroy(tp);

	}

	kfree(chain);

}



static void

tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain,

			       struct tcf_proto __rcu **p_filter_chain)

{

	chain->p_filter_chain = p_filter_chain;

}



int tcf_block_get(struct tcf_block **p_block,

		  struct tcf_proto __rcu **p_filter_chain)

{

	struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);

	int err;



	if (!block)

		return -ENOMEM;

	block->p_filter_chain = p_filter_chain;

	block->chain = tcf_chain_create();

	if (!block->chain) {

		err = -ENOMEM;

		goto err_chain_create;

	}

	tcf_chain_filter_chain_ptr_set(block->chain, p_filter_chain);

	*p_block = block;

	return 0;



err_chain_create:

	kfree(block);

	return err;

}

EXPORT_SYMBOL(tcf_block_get);
@@ -214,7 +236,7 @@ void tcf_block_put(struct tcf_block *block) 
{

	if (!block)

		return;

	tcf_chain_destroy(block->p_filter_chain);

	tcf_chain_destroy(block->chain);

	kfree(block);

}

EXPORT_SYMBOL(tcf_block_put);
@@ -267,6 +289,65 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 
}

EXPORT_SYMBOL(tcf_classify);



struct tcf_chain_info {

	struct tcf_proto __rcu **pprev;

	struct tcf_proto __rcu *next;

};



static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)

{

	return rtnl_dereference(*chain_info->pprev);

}



static void tcf_chain_tp_insert(struct tcf_chain *chain,

				struct tcf_chain_info *chain_info,

				struct tcf_proto *tp)

{

	if (chain->p_filter_chain &&

	    *chain_info->pprev == chain->filter_chain)

		*chain->p_filter_chain = tp;

	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));

	rcu_assign_pointer(*chain_info->pprev, tp);

}



static void tcf_chain_tp_remove(struct tcf_chain *chain,

				struct tcf_chain_info *chain_info,

				struct tcf_proto *tp)

{

	struct tcf_proto *next = rtnl_dereference(chain_info->next);



	if (chain->p_filter_chain && tp == chain->filter_chain)

		*chain->p_filter_chain = next;

	RCU_INIT_POINTER(*chain_info->pprev, next);

}



static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,

					   struct tcf_chain_info *chain_info,

					   u32 protocol, u32 prio,

					   bool prio_allocate)

{

	struct tcf_proto **pprev;

	struct tcf_proto *tp;



	/* Check the chain for existence of proto-tcf with this priority */

	for (pprev = &chain->filter_chain;

	     (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {

		if (tp->prio >= prio) {

			if (tp->prio == prio) {

				if (prio_allocate ||

				    (tp->protocol != protocol && protocol))

					return ERR_PTR(-EINVAL);

			} else {

				tp = NULL;

			}

			break;

		}

	}

	chain_info->pprev = pprev;

	chain_info->next = tp ? tp->next : NULL;

	return tp;

}



/* Add/change/delete/get a filter node */



static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
@@ -281,10 +362,9 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
	u32 parent;

	struct net_device *dev;

	struct Qdisc  *q;

	struct tcf_proto __rcu **back;

	struct tcf_proto __rcu **chain;

	struct tcf_chain_info chain_info;

	struct tcf_chain *chain;

	struct tcf_block *block;

	struct tcf_proto *next;

	struct tcf_proto *tp;

	const struct Qdisc_class_ops *cops;

	unsigned long cl;
@@ -369,7 +449,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
		err = -EINVAL;

		goto errout;

	}

	chain = block->p_filter_chain;

	chain = block->chain;



	if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {

		tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
@@ -378,23 +458,12 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
		goto errout;

	}



	/* Check the chain for existence of proto-tcf with this priority */

	for (back = chain;

	     (tp = rtnl_dereference(*back)) != NULL;

	     back = &tp->next) {

		if (tp->prio >= prio) {

			if (tp->prio == prio) {

				if (prio_allocate ||

				    (tp->protocol != protocol && protocol)) {

					err = -EINVAL;

	tp = tcf_chain_tp_find(chain, &chain_info, protocol,

			       prio, prio_allocate);

	if (IS_ERR(tp)) {

		err = PTR_ERR(tp);

		goto errout;

	}

			} else {

				tp = NULL;

			}

			break;

		}

	}



	if (tp == NULL) {

		/* Proto-tcf does not exist, create new one */
@@ -411,7 +480,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
		}



		if (prio_allocate)

			prio = tcf_auto_prio(rtnl_dereference(*back));

			prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));



		tp = tcf_proto_create(nla_data(tca[TCA_KIND]),

				      protocol, prio, parent, q, block);
@@ -429,8 +498,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 


	if (fh == 0) {

		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {

			next = rtnl_dereference(tp->next);

			RCU_INIT_POINTER(*back, next);

			tcf_chain_tp_remove(chain, &chain_info, tp);

			tfilter_notify(net, skb, n, tp, fh,

				       RTM_DELTFILTER, false);

			tcf_proto_destroy(tp);
@@ -459,11 +527,10 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
			err = tp->ops->delete(tp, fh, &last);

			if (err)

				goto errout;

			next = rtnl_dereference(tp->next);

			tfilter_notify(net, skb, n, tp, t->tcm_handle,

				       RTM_DELTFILTER, false);

			if (last) {

				RCU_INIT_POINTER(*back, next);

				tcf_chain_tp_remove(chain, &chain_info, tp);

				tcf_proto_destroy(tp);

			}

			goto errout;
@@ -480,10 +547,8 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, 
	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,

			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);

	if (err == 0) {

		if (tp_created) {

			RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));

			rcu_assign_pointer(*back, tp);

		}

		if (tp_created)

			tcf_chain_tp_insert(chain, &chain_info, tp);

		tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);

	} else {

		if (tp_created)
@@ -584,7 +649,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 
	struct net_device *dev;

	struct Qdisc *q;

	struct tcf_block *block;

	struct tcf_proto *tp, __rcu **chain;

	struct tcf_proto *tp;

	struct tcf_chain *chain;

	struct tcmsg *tcm = nlmsg_data(cb->nlh);

	unsigned long cl = 0;

	const struct Qdisc_class_ops *cops;
@@ -615,11 +681,11 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 
	block = cops->tcf_block(q, cl);

	if (!block)

		goto errout;

	chain = block->p_filter_chain;

	chain = block->chain;



	s_t = cb->args[0];



	for (tp = rtnl_dereference(*chain), t = 0;

	for (tp = rtnl_dereference(chain->filter_chain), t = 0;

	     tp; tp = rtnl_dereference(tp->next), t++) {

		if (t < s_t)

			continue;