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Commit 76cf546c authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

net_sched: use idr to allocate bpf filter handles 



Instead of calling cls_bpf_get() in a loop to find
a unused handle, just switch to idr API to allocate
new handles.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Chris Mi <chrism@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f1975e3

net/sched/cls_bpf.c

+28 −29
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/skbuff.h>

#include <linux/filter.h>

#include <linux/bpf.h>

#include <linux/idr.h>



#include <net/rtnetlink.h>

#include <net/pkt_cls.h>
@@ -32,7 +33,7 @@ MODULE_DESCRIPTION("TC BPF based classifier"); 


struct cls_bpf_head {

	struct list_head plist;

	u32 hgen;

	struct idr handle_idr;

	struct rcu_head rcu;

};
@@ -238,6 +239,7 @@ static int cls_bpf_init(struct tcf_proto *tp) 
		return -ENOBUFS;



	INIT_LIST_HEAD_RCU(&head->plist);

	idr_init(&head->handle_idr);

	rcu_assign_pointer(tp->root, head);



	return 0;
@@ -264,6 +266,9 @@ static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu) 


static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)

{

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



	idr_remove_ext(&head->handle_idr, prog->handle);

	cls_bpf_stop_offload(tp, prog);

	list_del_rcu(&prog->link);

	tcf_unbind_filter(tp, &prog->res);
@@ -287,6 +292,7 @@ static void cls_bpf_destroy(struct tcf_proto *tp) 
	list_for_each_entry_safe(prog, tmp, &head->plist, link)

		__cls_bpf_delete(tp, prog);



	idr_destroy(&head->handle_idr);

	kfree_rcu(head, rcu);

}
@@ -421,27 +427,6 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp, 
	return 0;

}



static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,

				   struct cls_bpf_head *head)

{

	unsigned int i = 0x80000000;

	u32 handle;



	do {

		if (++head->hgen == 0x7FFFFFFF)

			head->hgen = 1;

	} while (--i > 0 && cls_bpf_get(tp, head->hgen));



	if (unlikely(i == 0)) {

		pr_err("Insufficient number of handles\n");

		handle = 0;

	} else {

		handle = head->hgen;

	}



	return handle;

}



static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,

			  struct tcf_proto *tp, unsigned long base,

			  u32 handle, struct nlattr **tca,
@@ -451,6 +436,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
	struct cls_bpf_prog *oldprog = *arg;

	struct nlattr *tb[TCA_BPF_MAX + 1];

	struct cls_bpf_prog *prog;

	unsigned long idr_index;

	int ret;



	if (tca[TCA_OPTIONS] == NULL)
@@ -476,21 +462,30 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
		}

	}



	if (handle == 0)

		prog->handle = cls_bpf_grab_new_handle(tp, head);

	else

		prog->handle = handle;

	if (prog->handle == 0) {

		ret = -EINVAL;

	if (handle == 0) {

		ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,

				    1, 0x7FFFFFFF, GFP_KERNEL);

		if (ret)

			goto errout;

		prog->handle = idr_index;

	} else {

		if (!oldprog) {

			ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,

					    handle, handle + 1, GFP_KERNEL);

			if (ret)

				goto errout;

		}

		prog->handle = handle;

	}



	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr);

	if (ret < 0)

		goto errout;

		goto errout_idr;



	ret = cls_bpf_offload(tp, prog, oldprog);

	if (ret) {

		if (!oldprog)

			idr_remove_ext(&head->handle_idr, prog->handle);

		__cls_bpf_delete_prog(prog);

		return ret;

	}
@@ -499,6 +494,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
		prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;



	if (oldprog) {

		idr_replace_ext(&head->handle_idr, prog, handle);

		list_replace_rcu(&oldprog->link, &prog->link);

		tcf_unbind_filter(tp, &oldprog->res);

		call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
@@ -509,6 +505,9 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
	*arg = prog;

	return 0;



errout_idr:

	if (!oldprog)

		idr_remove_ext(&head->handle_idr, prog->handle);

errout:

	tcf_exts_destroy(&prog->exts);

	kfree(prog);