[thirdparty/kernel/stable.git] / net / sched / cls_bpf.c

/*
 * Berkeley Packet Filter based traffic classifier
 *
 * Might be used to classify traffic through flexible, user-defined and
 * possibly JIT-ed BPF filters for traffic control as an alternative to
 * ematches.
 *
 * (C) 2013 Daniel Borkmann <dborkman@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
#include <net/sock.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
MODULE_DESCRIPTION("TC BPF based classifier");

struct cls_bpf_head {
	struct list_head plist;
	u32 hgen;
	struct rcu_head rcu;
};

struct cls_bpf_prog {
	struct bpf_prog *filter;
	struct sock_filter *bpf_ops;
	struct tcf_exts exts;
	struct tcf_result res;
	struct list_head link;
	u32 handle;
	u16 bpf_len;
	struct tcf_proto *tp;
	struct rcu_head rcu;
};

static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
	[TCA_BPF_CLASSID]	= { .type = NLA_U32 },
	[TCA_BPF_OPS_LEN]	= { .type = NLA_U16 },
	[TCA_BPF_OPS]		= { .type = NLA_BINARY,
				    .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
};

static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
			    struct tcf_result *res)
{
	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
	struct cls_bpf_prog *prog;
	int ret;

	list_for_each_entry_rcu(prog, &head->plist, link) {
		int filter_res = BPF_PROG_RUN(prog->filter, skb);

		if (filter_res == 0)
			continue;

		*res = prog->res;
		if (filter_res != -1)
			res->classid = filter_res;

		ret = tcf_exts_exec(skb, &prog->exts, res);
		if (ret < 0)
			continue;

		return ret;
	}

	return -1;
}

static int cls_bpf_init(struct tcf_proto *tp)
{
	struct cls_bpf_head *head;

	head = kzalloc(sizeof(*head), GFP_KERNEL);
	if (head == NULL)
		return -ENOBUFS;

	INIT_LIST_HEAD_RCU(&head->plist);
	rcu_assign_pointer(tp->root, head);

	return 0;
}

static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
{
	tcf_exts_destroy(&prog->exts);

	bpf_prog_destroy(prog->filter);

	kfree(prog->bpf_ops);
	kfree(prog);
}

static void __cls_bpf_delete_prog(struct rcu_head *rcu)
{
	struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);

	cls_bpf_delete_prog(prog->tp, prog);
}

static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
{
	struct cls_bpf_prog *prog = (struct cls_bpf_prog *) arg;

	list_del_rcu(&prog->link);
	tcf_unbind_filter(tp, &prog->res);
	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
	return 0;
}

static void cls_bpf_destroy(struct tcf_proto *tp)
{
	struct cls_bpf_head *head = rtnl_dereference(tp->root);
	struct cls_bpf_prog *prog, *tmp;

	list_for_each_entry_safe(prog, tmp, &head->plist, link) {
		list_del_rcu(&prog->link);
		tcf_unbind_filter(tp, &prog->res);
		call_rcu(&prog->rcu, __cls_bpf_delete_prog);
	}

	RCU_INIT_POINTER(tp->root, NULL);
	kfree_rcu(head, rcu);
}

static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
{
	struct cls_bpf_head *head = rtnl_dereference(tp->root);
	struct cls_bpf_prog *prog;
	unsigned long ret = 0UL;

	if (head == NULL)
		return 0UL;

	list_for_each_entry_rcu(prog, &head->plist, link) {
		if (prog->handle == handle) {
			ret = (unsigned long) prog;
			break;
		}
	}

	return ret;
}

static void cls_bpf_put(struct tcf_proto *tp, unsigned long f)
{
}

static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
				   struct cls_bpf_prog *prog,
				   unsigned long base, struct nlattr **tb,
				   struct nlattr *est, bool ovr)
{
	struct sock_filter *bpf_ops;
	struct tcf_exts exts;
	struct sock_fprog_kern tmp;
	struct bpf_prog *fp;
	u16 bpf_size, bpf_len;
	u32 classid;
	int ret;

	if (!tb[TCA_BPF_OPS_LEN] || !tb[TCA_BPF_OPS] || !tb[TCA_BPF_CLASSID])
		return -EINVAL;

	tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
	if (ret < 0)
		return ret;

	classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
	bpf_len = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
	if (bpf_len > BPF_MAXINSNS || bpf_len == 0) {
		ret = -EINVAL;
		goto errout;
	}

	bpf_size = bpf_len * sizeof(*bpf_ops);
	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
	if (bpf_ops == NULL) {
		ret = -ENOMEM;
		goto errout;
	}

	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);

	tmp.len = bpf_len;
	tmp.filter = bpf_ops;

	ret = bpf_prog_create(&fp, &tmp);
	if (ret)
		goto errout_free;

	prog->bpf_len = bpf_len;
	prog->bpf_ops = bpf_ops;
	prog->filter = fp;
	prog->res.classid = classid;

	tcf_bind_filter(tp, &prog->res, base);
	tcf_exts_change(tp, &prog->exts, &exts);

	return 0;
errout_free:
	kfree(bpf_ops);
errout:
	tcf_exts_destroy(&exts);
	return ret;
}

static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
				   struct cls_bpf_head *head)
{
	unsigned int i = 0x80000000;

	do {
		if (++head->hgen == 0x7FFFFFFF)
			head->hgen = 1;
	} while (--i > 0 && cls_bpf_get(tp, head->hgen));
	if (i == 0)
		pr_err("Insufficient number of handles\n");

	return i;
}

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,
			  unsigned long *arg, bool ovr)
{
	struct cls_bpf_head *head = rtnl_dereference(tp->root);
	struct cls_bpf_prog *oldprog = (struct cls_bpf_prog *) *arg;
	struct nlattr *tb[TCA_BPF_MAX + 1];
	struct cls_bpf_prog *prog;
	int ret;

	if (tca[TCA_OPTIONS] == NULL)
		return -EINVAL;

	ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
	if (ret < 0)
		return ret;

	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
	if (!prog)
		return -ENOBUFS;

	tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);

	if (oldprog) {
		if (handle && oldprog->handle != handle) {
			ret = -EINVAL;
			goto errout;
		}
	}

	if (handle == 0)
		prog->handle = cls_bpf_grab_new_handle(tp, head);
	else
		prog->handle = handle;
	if (prog->handle == 0) {
		ret = -EINVAL;
		goto errout;
	}

	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
	if (ret < 0)
		goto errout;

	if (oldprog) {
		list_replace_rcu(&prog->link, &oldprog->link);
		tcf_unbind_filter(tp, &oldprog->res);
		call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
	} else {
		list_add_rcu(&prog->link, &head->plist);
	}

	*arg = (unsigned long) prog;
	return 0;
errout:
	kfree(prog);

	return ret;
}

static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
			struct sk_buff *skb, struct tcmsg *tm)
{
	struct cls_bpf_prog *prog = (struct cls_bpf_prog *) fh;
	struct nlattr *nest, *nla;

	if (prog == NULL)
		return skb->len;

	tm->tcm_handle = prog->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	if (nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
		goto nla_put_failure;
	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_len))
		goto nla_put_failure;

	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_len *
			  sizeof(struct sock_filter));
	if (nla == NULL)
		goto nla_put_failure;

	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));

	if (tcf_exts_dump(skb, &prog->exts) < 0)
		goto nla_put_failure;

	nla_nest_end(skb, nest);

	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
	struct cls_bpf_head *head = rtnl_dereference(tp->root);
	struct cls_bpf_prog *prog;

	list_for_each_entry_rcu(prog, &head->plist, link) {
		if (arg->count < arg->skip)
			goto skip;
		if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
			arg->stop = 1;
			break;
		}
skip:
		arg->count++;
	}
}

static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
	.kind		=	"bpf",
	.owner		=	THIS_MODULE,
	.classify	=	cls_bpf_classify,
	.init		=	cls_bpf_init,
	.destroy	=	cls_bpf_destroy,
	.get		=	cls_bpf_get,
	.put		=	cls_bpf_put,
	.change		=	cls_bpf_change,
	.delete		=	cls_bpf_delete,
	.walk		=	cls_bpf_walk,
	.dump		=	cls_bpf_dump,
};

static int __init cls_bpf_init_mod(void)
{
	return register_tcf_proto_ops(&cls_bpf_ops);
}

static void __exit cls_bpf_exit_mod(void)
{
	unregister_tcf_proto_ops(&cls_bpf_ops);
}

module_init(cls_bpf_init_mod);
module_exit(cls_bpf_exit_mod);
Commit	Line	Data
7d1d65cb DB	1	/*
	2	* Berkeley Packet Filter based traffic classifier
	3	*
	4	* Might be used to classify traffic through flexible, user-defined and
	5	* possibly JIT-ed BPF filters for traffic control as an alternative to
	6	* ematches.
	7	*
	8	* (C) 2013 Daniel Borkmann <dborkman@redhat.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/types.h>
	17	#include <linux/skbuff.h>
	18	#include <linux/filter.h>
	19	#include <net/rtnetlink.h>
	20	#include <net/pkt_cls.h>
	21	#include <net/sock.h>
	22
	23	MODULE_LICENSE("GPL");
	24	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	25	MODULE_DESCRIPTION("TC BPF based classifier");
	26
	27	struct cls_bpf_head {
	28	struct list_head plist;
	29	u32 hgen;
1f947bf1	30	struct rcu_head rcu;
7d1d65cb DB	31	};
	32
	33	struct cls_bpf_prog {
7ae457c1	34	struct bpf_prog *filter;
7d1d65cb DB	35	struct sock_filter *bpf_ops;
	36	struct tcf_exts exts;
	37	struct tcf_result res;
	38	struct list_head link;
	39	u32 handle;
	40	u16 bpf_len;
1f947bf1 JF	41	struct tcf_proto *tp;
1f947bf1 JF	42	struct rcu_head rcu;
7d1d65cb DB	43	};
	44
	45	static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
	46	[TCA_BPF_CLASSID] = { .type = NLA_U32 },
	47	[TCA_BPF_OPS_LEN] = { .type = NLA_U16 },
	48	[TCA_BPF_OPS] = { .type = NLA_BINARY,
	49	.len = sizeof(struct sock_filter) * BPF_MAXINSNS },
	50	};
	51
7d1d65cb DB	52	static int cls_bpf_classify(struct sk_buff skb, const struct tcf_proto tp,
	53	struct tcf_result *res)
	54	{
80dcbd12	55	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
7d1d65cb DB	56	struct cls_bpf_prog *prog;
	57	int ret;
	58
1f947bf1	59	list_for_each_entry_rcu(prog, &head->plist, link) {
7ae457c1	60	int filter_res = BPF_PROG_RUN(prog->filter, skb);
7d1d65cb DB	61
	62	if (filter_res == 0)
	63	continue;
	64
	65	*res = prog->res;
	66	if (filter_res != -1)
	67	res->classid = filter_res;
	68
	69	ret = tcf_exts_exec(skb, &prog->exts, res);
	70	if (ret < 0)
	71	continue;
	72
	73	return ret;
	74	}
	75
	76	return -1;
	77	}
	78
	79	static int cls_bpf_init(struct tcf_proto *tp)
	80	{
	81	struct cls_bpf_head *head;
	82
	83	head = kzalloc(sizeof(*head), GFP_KERNEL);
	84	if (head == NULL)
	85	return -ENOBUFS;
	86
1f947bf1 JF	87	INIT_LIST_HEAD_RCU(&head->plist);
1f947bf1 JF	88	rcu_assign_pointer(tp->root, head);
7d1d65cb DB	89
	90	return 0;
	91	}
	92
	93	static void cls_bpf_delete_prog(struct tcf_proto tp, struct cls_bpf_prog prog)
	94	{
18d0264f	95	tcf_exts_destroy(&prog->exts);
7d1d65cb	96
7ae457c1	97	bpf_prog_destroy(prog->filter);
7d1d65cb DB	98
	99	kfree(prog->bpf_ops);
	100	kfree(prog);
	101	}
	102
1f947bf1 JF	103	static void __cls_bpf_delete_prog(struct rcu_head *rcu)
	104	{
	105	struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
	106
	107	cls_bpf_delete_prog(prog->tp, prog);
	108	}
	109
7d1d65cb DB	110	static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
7d1d65cb DB	111	{
472f5837	112	struct cls_bpf_prog prog = (struct cls_bpf_prog ) arg;
7d1d65cb	113
472f5837 JP	114	list_del_rcu(&prog->link);
	115	tcf_unbind_filter(tp, &prog->res);
	116	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
	117	return 0;
7d1d65cb DB	118	}
	119
	120	static void cls_bpf_destroy(struct tcf_proto *tp)
	121	{
1f947bf1	122	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	123	struct cls_bpf_prog prog, tmp;
	124
	125	list_for_each_entry_safe(prog, tmp, &head->plist, link) {
1f947bf1	126	list_del_rcu(&prog->link);
18cdb37e	127	tcf_unbind_filter(tp, &prog->res);
1f947bf1	128	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
7d1d65cb DB	129	}
7d1d65cb DB	130
1f947bf1 JF	131	RCU_INIT_POINTER(tp->root, NULL);
1f947bf1 JF	132	kfree_rcu(head, rcu);
7d1d65cb DB	133	}
	134
	135	static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
	136	{
1f947bf1	137	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	138	struct cls_bpf_prog *prog;
	139	unsigned long ret = 0UL;
	140
	141	if (head == NULL)
	142	return 0UL;
	143
1f947bf1	144	list_for_each_entry_rcu(prog, &head->plist, link) {
7d1d65cb DB	145	if (prog->handle == handle) {
	146	ret = (unsigned long) prog;
	147	break;
	148	}
	149	}
	150
	151	return ret;
	152	}
	153
	154	static void cls_bpf_put(struct tcf_proto *tp, unsigned long f)
	155	{
	156	}
	157
	158	static int cls_bpf_modify_existing(struct net net, struct tcf_proto tp,
	159	struct cls_bpf_prog *prog,
	160	unsigned long base, struct nlattr **tb,
2f7ef2f8	161	struct nlattr *est, bool ovr)
7d1d65cb	162	{
1f947bf1	163	struct sock_filter *bpf_ops;
7d1d65cb	164	struct tcf_exts exts;
b1fcd35c	165	struct sock_fprog_kern tmp;
1f947bf1	166	struct bpf_prog *fp;
7d1d65cb DB	167	u16 bpf_size, bpf_len;
	168	u32 classid;
	169	int ret;
	170
	171	if (!tb[TCA_BPF_OPS_LEN] \|\| !tb[TCA_BPF_OPS] \|\| !tb[TCA_BPF_CLASSID])
	172	return -EINVAL;
	173
5da57f42	174	tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
2f7ef2f8	175	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
7d1d65cb DB	176	if (ret < 0)
	177	return ret;
	178
	179	classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
	180	bpf_len = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
	181	if (bpf_len > BPF_MAXINSNS \|\| bpf_len == 0) {
	182	ret = -EINVAL;
	183	goto errout;
	184	}
	185
	186	bpf_size = bpf_len * sizeof(*bpf_ops);
	187	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
	188	if (bpf_ops == NULL) {
	189	ret = -ENOMEM;
	190	goto errout;
	191	}
	192
	193	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
	194
	195	tmp.len = bpf_len;
b1fcd35c	196	tmp.filter = bpf_ops;
7d1d65cb	197
7ae457c1	198	ret = bpf_prog_create(&fp, &tmp);
7d1d65cb DB	199	if (ret)
	200	goto errout_free;
	201
7d1d65cb DB	202	prog->bpf_len = bpf_len;
	203	prog->bpf_ops = bpf_ops;
	204	prog->filter = fp;
	205	prog->res.classid = classid;
7d1d65cb DB	206
	207	tcf_bind_filter(tp, &prog->res, base);
	208	tcf_exts_change(tp, &prog->exts, &exts);
	209
7d1d65cb	210	return 0;
7d1d65cb DB	211	errout_free:
	212	kfree(bpf_ops);
	213	errout:
18d0264f	214	tcf_exts_destroy(&exts);
7d1d65cb DB	215	return ret;
	216	}
	217
	218	static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
	219	struct cls_bpf_head *head)
	220	{
	221	unsigned int i = 0x80000000;
	222
	223	do {
	224	if (++head->hgen == 0x7FFFFFFF)
	225	head->hgen = 1;
	226	} while (--i > 0 && cls_bpf_get(tp, head->hgen));
	227	if (i == 0)
	228	pr_err("Insufficient number of handles\n");
	229
	230	return i;
	231	}
	232
	233	static int cls_bpf_change(struct net net, struct sk_buff in_skb,
	234	struct tcf_proto *tp, unsigned long base,
	235	u32 handle, struct nlattr **tca,
2f7ef2f8	236	unsigned long *arg, bool ovr)
7d1d65cb	237	{
1f947bf1 JF	238	struct cls_bpf_head *head = rtnl_dereference(tp->root);
1f947bf1 JF	239	struct cls_bpf_prog oldprog = (struct cls_bpf_prog ) *arg;
7d1d65cb	240	struct nlattr *tb[TCA_BPF_MAX + 1];
1f947bf1	241	struct cls_bpf_prog *prog;
7d1d65cb DB	242	int ret;
	243
	244	if (tca[TCA_OPTIONS] == NULL)
	245	return -EINVAL;
	246
	247	ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
	248	if (ret < 0)
	249	return ret;
	250
7d1d65cb	251	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
1f947bf1	252	if (!prog)
7d1d65cb DB	253	return -ENOBUFS;
7d1d65cb DB	254
5da57f42	255	tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
1f947bf1 JF	256
	257	if (oldprog) {
	258	if (handle && oldprog->handle != handle) {
	259	ret = -EINVAL;
	260	goto errout;
	261	}
	262	}
	263
7d1d65cb DB	264	if (handle == 0)
	265	prog->handle = cls_bpf_grab_new_handle(tp, head);
	266	else
	267	prog->handle = handle;
	268	if (prog->handle == 0) {
	269	ret = -EINVAL;
	270	goto errout;
	271	}
	272
2f7ef2f8	273	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
7d1d65cb DB	274	if (ret < 0)
	275	goto errout;
	276
1f947bf1 JF	277	if (oldprog) {
1f947bf1 JF	278	list_replace_rcu(&prog->link, &oldprog->link);
18cdb37e	279	tcf_unbind_filter(tp, &oldprog->res);
1f947bf1 JF	280	call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
	281	} else {
	282	list_add_rcu(&prog->link, &head->plist);
	283	}
7d1d65cb DB	284
7d1d65cb DB	285	*arg = (unsigned long) prog;
7d1d65cb DB	286	return 0;
7d1d65cb DB	287	errout:
1f947bf1	288	kfree(prog);
7d1d65cb DB	289
	290	return ret;
	291	}
	292
832d1d5b	293	static int cls_bpf_dump(struct net net, struct tcf_proto tp, unsigned long fh,
7d1d65cb DB	294	struct sk_buff skb, struct tcmsg tm)
	295	{
	296	struct cls_bpf_prog prog = (struct cls_bpf_prog ) fh;
	297	struct nlattr nest, nla;
	298
	299	if (prog == NULL)
	300	return skb->len;
	301
	302	tm->tcm_handle = prog->handle;
	303
	304	nest = nla_nest_start(skb, TCA_OPTIONS);
	305	if (nest == NULL)
	306	goto nla_put_failure;
	307
	308	if (nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
	309	goto nla_put_failure;
	310	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_len))
	311	goto nla_put_failure;
	312
	313	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_len *
	314	sizeof(struct sock_filter));
	315	if (nla == NULL)
	316	goto nla_put_failure;
	317
1fab9abc	318	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
7d1d65cb	319
5da57f42	320	if (tcf_exts_dump(skb, &prog->exts) < 0)
7d1d65cb DB	321	goto nla_put_failure;
	322
	323	nla_nest_end(skb, nest);
	324
5da57f42	325	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
7d1d65cb DB	326	goto nla_put_failure;
	327
	328	return skb->len;
	329
	330	nla_put_failure:
	331	nla_nest_cancel(skb, nest);
	332	return -1;
	333	}
	334
	335	static void cls_bpf_walk(struct tcf_proto tp, struct tcf_walker arg)
	336	{
1f947bf1	337	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	338	struct cls_bpf_prog *prog;
7d1d65cb DB	339
1f947bf1	340	list_for_each_entry_rcu(prog, &head->plist, link) {
7d1d65cb DB	341	if (arg->count < arg->skip)
	342	goto skip;
	343	if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
	344	arg->stop = 1;
	345	break;
	346	}
	347	skip:
	348	arg->count++;
	349	}
	350	}
	351
	352	static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
	353	.kind = "bpf",
	354	.owner = THIS_MODULE,
	355	.classify = cls_bpf_classify,
	356	.init = cls_bpf_init,
	357	.destroy = cls_bpf_destroy,
	358	.get = cls_bpf_get,
	359	.put = cls_bpf_put,
	360	.change = cls_bpf_change,
	361	.delete = cls_bpf_delete,
	362	.walk = cls_bpf_walk,
	363	.dump = cls_bpf_dump,
	364	};
	365
	366	static int __init cls_bpf_init_mod(void)
	367	{
	368	return register_tcf_proto_ops(&cls_bpf_ops);
	369	}
	370
	371	static void __exit cls_bpf_exit_mod(void)
	372	{
	373	unregister_tcf_proto_ops(&cls_bpf_ops);
	374	}
	375
	376	module_init(cls_bpf_init_mod);
	377	module_exit(cls_bpf_exit_mod);