[mirror_ubuntu-zesty-kernel.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 <linux/bpf.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");

#define CLS_BPF_NAME_LEN	256
#define CLS_BPF_SUPPORTED_GEN_FLAGS		\
	(TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW)

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

struct cls_bpf_prog {
	struct bpf_prog *filter;
	struct list_head link;
	struct tcf_result res;
	bool exts_integrated;
	bool offloaded;
	u32 gen_flags;
	struct tcf_exts exts;
	u32 handle;
	u16 bpf_num_ops;
	struct sock_filter *bpf_ops;
	const char *bpf_name;
	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_FLAGS]		= { .type = NLA_U32 },
	[TCA_BPF_FLAGS_GEN]	= { .type = NLA_U32 },
	[TCA_BPF_FD]		= { .type = NLA_U32 },
	[TCA_BPF_NAME]		= { .type = NLA_NUL_STRING,
				    .len = CLS_BPF_NAME_LEN },
	[TCA_BPF_OPS_LEN]	= { .type = NLA_U16 },
	[TCA_BPF_OPS]		= { .type = NLA_BINARY,
				    .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
};

static int cls_bpf_exec_opcode(int code)
{
	switch (code) {
	case TC_ACT_OK:
	case TC_ACT_SHOT:
	case TC_ACT_STOLEN:
	case TC_ACT_REDIRECT:
	case TC_ACT_UNSPEC:
		return code;
	default:
		return TC_ACT_UNSPEC;
	}
}

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);
	bool at_ingress = skb_at_tc_ingress(skb);
	struct cls_bpf_prog *prog;
	int ret = -1;

	/* Needed here for accessing maps. */
	rcu_read_lock();
	list_for_each_entry_rcu(prog, &head->plist, link) {
		int filter_res;

		qdisc_skb_cb(skb)->tc_classid = prog->res.classid;

		if (tc_skip_sw(prog->gen_flags)) {
			filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
		} else if (at_ingress) {
			/* It is safe to push/pull even if skb_shared() */
			__skb_push(skb, skb->mac_len);
			bpf_compute_data_end(skb);
			filter_res = BPF_PROG_RUN(prog->filter, skb);
			__skb_pull(skb, skb->mac_len);
		} else {
			bpf_compute_data_end(skb);
			filter_res = BPF_PROG_RUN(prog->filter, skb);
		}

		if (prog->exts_integrated) {
			res->class   = 0;
			res->classid = TC_H_MAJ(prog->res.classid) |
				       qdisc_skb_cb(skb)->tc_classid;

			ret = cls_bpf_exec_opcode(filter_res);
			if (ret == TC_ACT_UNSPEC)
				continue;
			break;
		}

		if (filter_res == 0)
			continue;
		if (filter_res != -1) {
			res->class   = 0;
			res->classid = filter_res;
		} else {
			*res = prog->res;
		}

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

		break;
	}
	rcu_read_unlock();

	return ret;
}

static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
{
	return !prog->bpf_ops;
}

static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
			       enum tc_clsbpf_command cmd)
{
	struct net_device *dev = tp->q->dev_queue->dev;
	struct tc_cls_bpf_offload bpf_offload = {};
	struct tc_to_netdev offload;

	offload.type = TC_SETUP_CLSBPF;
	offload.cls_bpf = &bpf_offload;

	bpf_offload.command = cmd;
	bpf_offload.exts = &prog->exts;
	bpf_offload.prog = prog->filter;
	bpf_offload.name = prog->bpf_name;
	bpf_offload.exts_integrated = prog->exts_integrated;
	bpf_offload.gen_flags = prog->gen_flags;

	return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
					     tp->protocol, &offload);
}

static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog,
			   struct cls_bpf_prog *oldprog)
{
	struct net_device *dev = tp->q->dev_queue->dev;
	struct cls_bpf_prog *obj = prog;
	enum tc_clsbpf_command cmd;
	bool skip_sw;
	int ret;

	skip_sw = tc_skip_sw(prog->gen_flags) ||
		(oldprog && tc_skip_sw(oldprog->gen_flags));

	if (oldprog && oldprog->offloaded) {
		if (tc_should_offload(dev, tp, prog->gen_flags)) {
			cmd = TC_CLSBPF_REPLACE;
		} else if (!tc_skip_sw(prog->gen_flags)) {
			obj = oldprog;
			cmd = TC_CLSBPF_DESTROY;
		} else {
			return -EINVAL;
		}
	} else {
		if (!tc_should_offload(dev, tp, prog->gen_flags))
			return skip_sw ? -EINVAL : 0;
		cmd = TC_CLSBPF_ADD;
	}

	ret = cls_bpf_offload_cmd(tp, obj, cmd);
	if (ret)
		return skip_sw ? ret : 0;

	obj->offloaded = true;
	if (oldprog)
		oldprog->offloaded = false;

	return 0;
}

static void cls_bpf_stop_offload(struct tcf_proto *tp,
				 struct cls_bpf_prog *prog)
{
	int err;

	if (!prog->offloaded)
		return;

	err = cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_DESTROY);
	if (err) {
		pr_err("Stopping hardware offload failed: %d\n", err);
		return;
	}

	prog->offloaded = false;
}

static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
					 struct cls_bpf_prog *prog)
{
	if (!prog->offloaded)
		return;

	cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_STATS);
}

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 cls_bpf_prog *prog)
{
	tcf_exts_destroy(&prog->exts);

	if (cls_bpf_is_ebpf(prog))
		bpf_prog_put(prog->filter);
	else
		bpf_prog_destroy(prog->filter);

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

static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
{
	__cls_bpf_delete_prog(container_of(rcu, struct cls_bpf_prog, rcu));
}

static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
{
	cls_bpf_stop_offload(tp, prog);
	list_del_rcu(&prog->link);
	tcf_unbind_filter(tp, &prog->res);
	call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
}

static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
{
	__cls_bpf_delete(tp, (struct cls_bpf_prog *) arg);
	return 0;
}

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

	if (!force && !list_empty(&head->plist))
		return false;

	list_for_each_entry_safe(prog, tmp, &head->plist, link)
		__cls_bpf_delete(tp, prog);

	kfree_rcu(head, rcu);
	return true;
}

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;

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

	return ret;
}

static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
{
	struct sock_filter *bpf_ops;
	struct sock_fprog_kern fprog_tmp;
	struct bpf_prog *fp;
	u16 bpf_size, bpf_num_ops;
	int ret;

	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
	if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
		return -EINVAL;

	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
		return -EINVAL;

	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
	if (bpf_ops == NULL)
		return -ENOMEM;

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

	fprog_tmp.len = bpf_num_ops;
	fprog_tmp.filter = bpf_ops;

	ret = bpf_prog_create(&fp, &fprog_tmp);
	if (ret < 0) {
		kfree(bpf_ops);
		return ret;
	}

	prog->bpf_ops = bpf_ops;
	prog->bpf_num_ops = bpf_num_ops;
	prog->bpf_name = NULL;
	prog->filter = fp;

	return 0;
}

static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
				 const struct tcf_proto *tp)
{
	struct bpf_prog *fp;
	char *name = NULL;
	u32 bpf_fd;

	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);

	fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_CLS);
	if (IS_ERR(fp))
		return PTR_ERR(fp);

	if (tb[TCA_BPF_NAME]) {
		name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
		if (!name) {
			bpf_prog_put(fp);
			return -ENOMEM;
		}
	}

	prog->bpf_ops = NULL;
	prog->bpf_name = name;
	prog->filter = fp;

	if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
		netif_keep_dst(qdisc_dev(tp->q));

	return 0;
}

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)
{
	bool is_bpf, is_ebpf, have_exts = false;
	struct tcf_exts exts;
	u32 gen_flags = 0;
	int ret;

	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
	is_ebpf = tb[TCA_BPF_FD];
	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
		return -EINVAL;

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

	if (tb[TCA_BPF_FLAGS]) {
		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);

		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
			ret = -EINVAL;
			goto errout;
		}

		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
	}
	if (tb[TCA_BPF_FLAGS_GEN]) {
		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
		    !tc_flags_valid(gen_flags)) {
			ret = -EINVAL;
			goto errout;
		}
	}

	prog->exts_integrated = have_exts;
	prog->gen_flags = gen_flags;

	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
		       cls_bpf_prog_from_efd(tb, prog, tp);
	if (ret < 0)
		goto errout;

	if (tb[TCA_BPF_CLASSID]) {
		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
		tcf_bind_filter(tp, &prog->res, base);
	}

	tcf_exts_change(tp, &prog->exts, &exts);
	return 0;

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;
	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,
			  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;

	ret = tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
	if (ret < 0)
		goto errout;

	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;

	ret = cls_bpf_offload(tp, prog, oldprog);
	if (ret) {
		__cls_bpf_delete_prog(prog);
		return ret;
	}

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

	*arg = (unsigned long) prog;
	return 0;

errout:
	tcf_exts_destroy(&prog->exts);
	kfree(prog);
	return ret;
}

static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
				 struct sk_buff *skb)
{
	struct nlattr *nla;

	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
		return -EMSGSIZE;

	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
			  sizeof(struct sock_filter));
	if (nla == NULL)
		return -EMSGSIZE;

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

	return 0;
}

static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
				  struct sk_buff *skb)
{
	struct nlattr *nla;

	if (prog->bpf_name &&
	    nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
		return -EMSGSIZE;

	nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
	if (nla == NULL)
		return -EMSGSIZE;

	memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));

	return 0;
}

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;
	u32 bpf_flags = 0;
	int ret;

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

	tm->tcm_handle = prog->handle;

	cls_bpf_offload_update_stats(tp, prog);

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

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

	if (cls_bpf_is_ebpf(prog))
		ret = cls_bpf_dump_ebpf_info(prog, skb);
	else
		ret = cls_bpf_dump_bpf_info(prog, skb);
	if (ret)
		goto nla_put_failure;

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

	if (prog->exts_integrated)
		bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
		goto nla_put_failure;
	if (prog->gen_flags &&
	    nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
		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(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,
	.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>
e2e9b654 DB	19	#include <linux/bpf.h>
e2e9b654 DB	20
7d1d65cb DB	21	#include <net/rtnetlink.h>
	22	#include <net/pkt_cls.h>
	23	#include <net/sock.h>
	24
	25	MODULE_LICENSE("GPL");
	26	MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
	27	MODULE_DESCRIPTION("TC BPF based classifier");
	28
e2e9b654	29	#define CLS_BPF_NAME_LEN 256
0d01d45f	30	#define CLS_BPF_SUPPORTED_GEN_FLAGS \
eadb4148	31	(TCA_CLS_FLAGS_SKIP_HW \| TCA_CLS_FLAGS_SKIP_SW)
e2e9b654	32
7d1d65cb DB	33	struct cls_bpf_head {
	34	struct list_head plist;
	35	u32 hgen;
1f947bf1	36	struct rcu_head rcu;
7d1d65cb DB	37	};
	38
	39	struct cls_bpf_prog {
7ae457c1	40	struct bpf_prog *filter;
7d1d65cb	41	struct list_head link;
e2e9b654	42	struct tcf_result res;
045efa82	43	bool exts_integrated;
332ae8e2	44	bool offloaded;
0d01d45f	45	u32 gen_flags;
e2e9b654	46	struct tcf_exts exts;
7d1d65cb	47	u32 handle;
55556dd5	48	u16 bpf_num_ops;
e2e9b654 DB	49	struct sock_filter *bpf_ops;
e2e9b654 DB	50	const char *bpf_name;
1f947bf1 JF	51	struct tcf_proto *tp;
1f947bf1 JF	52	struct rcu_head rcu;
7d1d65cb DB	53	};
	54
	55	static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
	56	[TCA_BPF_CLASSID] = { .type = NLA_U32 },
045efa82	57	[TCA_BPF_FLAGS] = { .type = NLA_U32 },
0d01d45f	58	[TCA_BPF_FLAGS_GEN] = { .type = NLA_U32 },
e2e9b654	59	[TCA_BPF_FD] = { .type = NLA_U32 },
5a7a5555 JHS	60	[TCA_BPF_NAME] = { .type = NLA_NUL_STRING,
5a7a5555 JHS	61	.len = CLS_BPF_NAME_LEN },
7d1d65cb DB	62	[TCA_BPF_OPS_LEN] = { .type = NLA_U16 },
	63	[TCA_BPF_OPS] = { .type = NLA_BINARY,
	64	.len = sizeof(struct sock_filter) * BPF_MAXINSNS },
	65	};
	66
045efa82 DB	67	static int cls_bpf_exec_opcode(int code)
	68	{
	69	switch (code) {
	70	case TC_ACT_OK:
045efa82	71	case TC_ACT_SHOT:
045efa82	72	case TC_ACT_STOLEN:
27b29f63	73	case TC_ACT_REDIRECT:
045efa82 DB	74	case TC_ACT_UNSPEC:
	75	return code;
	76	default:
	77	return TC_ACT_UNSPEC;
	78	}
	79	}
	80
7d1d65cb DB	81	static int cls_bpf_classify(struct sk_buff skb, const struct tcf_proto tp,
	82	struct tcf_result *res)
	83	{
80dcbd12	84	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
fdc5432a	85	bool at_ingress = skb_at_tc_ingress(skb);
7d1d65cb	86	struct cls_bpf_prog *prog;
54720df1	87	int ret = -1;
7d1d65cb	88
54720df1 DB	89	/* Needed here for accessing maps. */
54720df1 DB	90	rcu_read_lock();
1f947bf1	91	list_for_each_entry_rcu(prog, &head->plist, link) {
3431205e AS	92	int filter_res;
3431205e AS	93
045efa82 DB	94	qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
045efa82 DB	95
eadb4148 JK	96	if (tc_skip_sw(prog->gen_flags)) {
	97	filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0;
	98	} else if (at_ingress) {
3431205e AS	99	/* It is safe to push/pull even if skb_shared() */
3431205e AS	100	__skb_push(skb, skb->mac_len);
db58ba45	101	bpf_compute_data_end(skb);
3431205e AS	102	filter_res = BPF_PROG_RUN(prog->filter, skb);
	103	__skb_pull(skb, skb->mac_len);
	104	} else {
db58ba45	105	bpf_compute_data_end(skb);
3431205e AS	106	filter_res = BPF_PROG_RUN(prog->filter, skb);
3431205e AS	107	}
7d1d65cb	108
045efa82	109	if (prog->exts_integrated) {
3a461da1 DB	110	res->class = 0;
	111	res->classid = TC_H_MAJ(prog->res.classid) \|
	112	qdisc_skb_cb(skb)->tc_classid;
045efa82 DB	113
	114	ret = cls_bpf_exec_opcode(filter_res);
	115	if (ret == TC_ACT_UNSPEC)
	116	continue;
	117	break;
	118	}
	119
7d1d65cb DB	120	if (filter_res == 0)
7d1d65cb DB	121	continue;
3a461da1 DB	122	if (filter_res != -1) {
3a461da1 DB	123	res->class = 0;
7d1d65cb	124	res->classid = filter_res;
3a461da1 DB	125	} else {
	126	*res = prog->res;
	127	}
7d1d65cb DB	128
	129	ret = tcf_exts_exec(skb, &prog->exts, res);
	130	if (ret < 0)
	131	continue;
	132
54720df1	133	break;
7d1d65cb	134	}
54720df1	135	rcu_read_unlock();
7d1d65cb	136
54720df1	137	return ret;
7d1d65cb DB	138	}
7d1d65cb DB	139
e2e9b654 DB	140	static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
	141	{
	142	return !prog->bpf_ops;
	143	}
	144
332ae8e2 JK	145	static int cls_bpf_offload_cmd(struct tcf_proto tp, struct cls_bpf_prog prog,
	146	enum tc_clsbpf_command cmd)
	147	{
	148	struct net_device *dev = tp->q->dev_queue->dev;
	149	struct tc_cls_bpf_offload bpf_offload = {};
	150	struct tc_to_netdev offload;
	151
	152	offload.type = TC_SETUP_CLSBPF;
	153	offload.cls_bpf = &bpf_offload;
	154
	155	bpf_offload.command = cmd;
	156	bpf_offload.exts = &prog->exts;
	157	bpf_offload.prog = prog->filter;
	158	bpf_offload.name = prog->bpf_name;
	159	bpf_offload.exts_integrated = prog->exts_integrated;
0d01d45f	160	bpf_offload.gen_flags = prog->gen_flags;
332ae8e2 JK	161
	162	return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
	163	tp->protocol, &offload);
	164	}
	165
eadb4148 JK	166	static int cls_bpf_offload(struct tcf_proto tp, struct cls_bpf_prog prog,
eadb4148 JK	167	struct cls_bpf_prog *oldprog)
332ae8e2 JK	168	{
	169	struct net_device *dev = tp->q->dev_queue->dev;
	170	struct cls_bpf_prog *obj = prog;
	171	enum tc_clsbpf_command cmd;
eadb4148 JK	172	bool skip_sw;
	173	int ret;
	174
	175	skip_sw = tc_skip_sw(prog->gen_flags) \|\|
	176	(oldprog && tc_skip_sw(oldprog->gen_flags));
332ae8e2 JK	177
332ae8e2 JK	178	if (oldprog && oldprog->offloaded) {
0d01d45f	179	if (tc_should_offload(dev, tp, prog->gen_flags)) {
332ae8e2	180	cmd = TC_CLSBPF_REPLACE;
eadb4148	181	} else if (!tc_skip_sw(prog->gen_flags)) {
332ae8e2 JK	182	obj = oldprog;
332ae8e2 JK	183	cmd = TC_CLSBPF_DESTROY;
eadb4148 JK	184	} else {
eadb4148 JK	185	return -EINVAL;
332ae8e2 JK	186	}
332ae8e2 JK	187	} else {
0d01d45f	188	if (!tc_should_offload(dev, tp, prog->gen_flags))
eadb4148	189	return skip_sw ? -EINVAL : 0;
332ae8e2 JK	190	cmd = TC_CLSBPF_ADD;
	191	}
	192
eadb4148 JK	193	ret = cls_bpf_offload_cmd(tp, obj, cmd);
	194	if (ret)
	195	return skip_sw ? ret : 0;
332ae8e2 JK	196
	197	obj->offloaded = true;
	198	if (oldprog)
	199	oldprog->offloaded = false;
eadb4148 JK	200
eadb4148 JK	201	return 0;
332ae8e2 JK	202	}
	203
	204	static void cls_bpf_stop_offload(struct tcf_proto *tp,
	205	struct cls_bpf_prog *prog)
	206	{
	207	int err;
	208
	209	if (!prog->offloaded)
	210	return;
	211
	212	err = cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_DESTROY);
	213	if (err) {
	214	pr_err("Stopping hardware offload failed: %d\n", err);
	215	return;
	216	}
	217
	218	prog->offloaded = false;
	219	}
	220
68d64063 JK	221	static void cls_bpf_offload_update_stats(struct tcf_proto *tp,
	222	struct cls_bpf_prog *prog)
	223	{
	224	if (!prog->offloaded)
	225	return;
	226
	227	cls_bpf_offload_cmd(tp, prog, TC_CLSBPF_STATS);
	228	}
	229
7d1d65cb DB	230	static int cls_bpf_init(struct tcf_proto *tp)
	231	{
	232	struct cls_bpf_head *head;
	233
	234	head = kzalloc(sizeof(*head), GFP_KERNEL);
	235	if (head == NULL)
	236	return -ENOBUFS;
	237
1f947bf1 JF	238	INIT_LIST_HEAD_RCU(&head->plist);
1f947bf1 JF	239	rcu_assign_pointer(tp->root, head);
7d1d65cb DB	240
	241	return 0;
	242	}
	243
8d829bdb	244	static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
7d1d65cb	245	{
18d0264f	246	tcf_exts_destroy(&prog->exts);
7d1d65cb	247
e2e9b654 DB	248	if (cls_bpf_is_ebpf(prog))
	249	bpf_prog_put(prog->filter);
	250	else
	251	bpf_prog_destroy(prog->filter);
7d1d65cb	252
e2e9b654	253	kfree(prog->bpf_name);
7d1d65cb DB	254	kfree(prog->bpf_ops);
	255	kfree(prog);
	256	}
	257
8d829bdb	258	static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
1f947bf1	259	{
8d829bdb	260	__cls_bpf_delete_prog(container_of(rcu, struct cls_bpf_prog, rcu));
1f947bf1 JF	261	}
1f947bf1 JF	262
8d829bdb	263	static void __cls_bpf_delete(struct tcf_proto tp, struct cls_bpf_prog prog)
7d1d65cb	264	{
332ae8e2	265	cls_bpf_stop_offload(tp, prog);
472f5837 JP	266	list_del_rcu(&prog->link);
472f5837 JP	267	tcf_unbind_filter(tp, &prog->res);
8d829bdb DB	268	call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
8d829bdb DB	269	}
e2e9b654	270
8d829bdb DB	271	static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
	272	{
	273	__cls_bpf_delete(tp, (struct cls_bpf_prog *) arg);
472f5837	274	return 0;
7d1d65cb DB	275	}
7d1d65cb DB	276
1e052be6	277	static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
7d1d65cb	278	{
1f947bf1	279	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	280	struct cls_bpf_prog prog, tmp;
7d1d65cb DB	281
1e052be6 CW	282	if (!force && !list_empty(&head->plist))
	283	return false;
	284
8d829bdb DB	285	list_for_each_entry_safe(prog, tmp, &head->plist, link)
8d829bdb DB	286	__cls_bpf_delete(tp, prog);
7d1d65cb	287
1f947bf1	288	kfree_rcu(head, rcu);
1e052be6	289	return true;
7d1d65cb DB	290	}
	291
	292	static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
	293	{
1f947bf1	294	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	295	struct cls_bpf_prog *prog;
	296	unsigned long ret = 0UL;
	297
3fe6b49e	298	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	299	if (prog->handle == handle) {
	300	ret = (unsigned long) prog;
	301	break;
	302	}
	303	}
	304
	305	return ret;
	306	}
	307
045efa82	308	static int cls_bpf_prog_from_ops(struct nlattr *tb, struct cls_bpf_prog prog)
7d1d65cb	309	{
1f947bf1	310	struct sock_filter *bpf_ops;
e2e9b654	311	struct sock_fprog_kern fprog_tmp;
1f947bf1	312	struct bpf_prog *fp;
33e9fcc6	313	u16 bpf_size, bpf_num_ops;
7d1d65cb DB	314	int ret;
7d1d65cb DB	315
33e9fcc6	316	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
e2e9b654 DB	317	if (bpf_num_ops > BPF_MAXINSNS \|\| bpf_num_ops == 0)
e2e9b654 DB	318	return -EINVAL;
7d1d65cb	319
33e9fcc6	320	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
e2e9b654 DB	321	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
e2e9b654 DB	322	return -EINVAL;
7913ecf6	323
7d1d65cb	324	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
e2e9b654 DB	325	if (bpf_ops == NULL)
e2e9b654 DB	326	return -ENOMEM;
7d1d65cb DB	327
	328	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
	329
e2e9b654 DB	330	fprog_tmp.len = bpf_num_ops;
e2e9b654 DB	331	fprog_tmp.filter = bpf_ops;
7d1d65cb	332
e2e9b654 DB	333	ret = bpf_prog_create(&fp, &fprog_tmp);
	334	if (ret < 0) {
	335	kfree(bpf_ops);
	336	return ret;
	337	}
7d1d65cb	338
7d1d65cb	339	prog->bpf_ops = bpf_ops;
e2e9b654 DB	340	prog->bpf_num_ops = bpf_num_ops;
e2e9b654 DB	341	prog->bpf_name = NULL;
7d1d65cb	342	prog->filter = fp;
7d1d65cb	343
e2e9b654 DB	344	return 0;
	345	}
	346
c46646d0 DB	347	static int cls_bpf_prog_from_efd(struct nlattr *tb, struct cls_bpf_prog prog,
c46646d0 DB	348	const struct tcf_proto *tp)
e2e9b654 DB	349	{
	350	struct bpf_prog *fp;
	351	char *name = NULL;
	352	u32 bpf_fd;
	353
	354	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
	355
113214be	356	fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_CLS);
e2e9b654 DB	357	if (IS_ERR(fp))
	358	return PTR_ERR(fp);
	359
e2e9b654	360	if (tb[TCA_BPF_NAME]) {
b15ca182	361	name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL);
e2e9b654 DB	362	if (!name) {
	363	bpf_prog_put(fp);
	364	return -ENOMEM;
	365	}
	366	}
	367
	368	prog->bpf_ops = NULL;
e2e9b654	369	prog->bpf_name = name;
e2e9b654	370	prog->filter = fp;
e2e9b654	371
1f211a1b	372	if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
c46646d0 DB	373	netif_keep_dst(qdisc_dev(tp->q));
c46646d0 DB	374
e2e9b654 DB	375	return 0;
	376	}
	377
	378	static int cls_bpf_modify_existing(struct net net, struct tcf_proto tp,
	379	struct cls_bpf_prog *prog,
	380	unsigned long base, struct nlattr **tb,
	381	struct nlattr *est, bool ovr)
	382	{
045efa82	383	bool is_bpf, is_ebpf, have_exts = false;
e2e9b654	384	struct tcf_exts exts;
0d01d45f	385	u32 gen_flags = 0;
e2e9b654 DB	386	int ret;
	387
	388	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
	389	is_ebpf = tb[TCA_BPF_FD];
ef146fa4	390	if ((!is_bpf && !is_ebpf) \|\| (is_bpf && is_ebpf))
e2e9b654 DB	391	return -EINVAL;
e2e9b654 DB	392
b9a24bb7	393	ret = tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
e2e9b654 DB	394	if (ret < 0)
e2e9b654 DB	395	return ret;
b9a24bb7 WC	396	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
	397	if (ret < 0)
	398	goto errout;
e2e9b654	399
045efa82 DB	400	if (tb[TCA_BPF_FLAGS]) {
	401	u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
	402
	403	if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
b9a24bb7 WC	404	ret = -EINVAL;
b9a24bb7 WC	405	goto errout;
045efa82 DB	406	}
	407
	408	have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
	409	}
0d01d45f JK	410	if (tb[TCA_BPF_FLAGS_GEN]) {
	411	gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
	412	if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS \|\|
	413	!tc_flags_valid(gen_flags)) {
	414	ret = -EINVAL;
	415	goto errout;
	416	}
	417	}
045efa82	418
045efa82	419	prog->exts_integrated = have_exts;
0d01d45f	420	prog->gen_flags = gen_flags;
e2e9b654	421
045efa82	422	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
c46646d0	423	cls_bpf_prog_from_efd(tb, prog, tp);
b9a24bb7 WC	424	if (ret < 0)
b9a24bb7 WC	425	goto errout;
e2e9b654	426
ef146fa4 DB	427	if (tb[TCA_BPF_CLASSID]) {
	428	prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
	429	tcf_bind_filter(tp, &prog->res, base);
	430	}
7d1d65cb	431
ef146fa4	432	tcf_exts_change(tp, &prog->exts, &exts);
7d1d65cb	433	return 0;
b9a24bb7 WC	434
	435	errout:
	436	tcf_exts_destroy(&exts);
	437	return ret;
7d1d65cb DB	438	}
	439
	440	static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
	441	struct cls_bpf_head *head)
	442	{
	443	unsigned int i = 0x80000000;
3f2ab135	444	u32 handle;
7d1d65cb DB	445
	446	do {
	447	if (++head->hgen == 0x7FFFFFFF)
	448	head->hgen = 1;
	449	} while (--i > 0 && cls_bpf_get(tp, head->hgen));
3f2ab135 DB	450
3f2ab135 DB	451	if (unlikely(i == 0)) {
7d1d65cb	452	pr_err("Insufficient number of handles\n");
3f2ab135 DB	453	handle = 0;
	454	} else {
	455	handle = head->hgen;
	456	}
7d1d65cb	457
3f2ab135	458	return handle;
7d1d65cb DB	459	}
	460
	461	static int cls_bpf_change(struct net net, struct sk_buff in_skb,
	462	struct tcf_proto *tp, unsigned long base,
	463	u32 handle, struct nlattr **tca,
2f7ef2f8	464	unsigned long *arg, bool ovr)
7d1d65cb	465	{
1f947bf1 JF	466	struct cls_bpf_head *head = rtnl_dereference(tp->root);
1f947bf1 JF	467	struct cls_bpf_prog oldprog = (struct cls_bpf_prog ) *arg;
7d1d65cb	468	struct nlattr *tb[TCA_BPF_MAX + 1];
1f947bf1	469	struct cls_bpf_prog *prog;
7d1d65cb DB	470	int ret;
	471
	472	if (tca[TCA_OPTIONS] == NULL)
	473	return -EINVAL;
	474
	475	ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
	476	if (ret < 0)
	477	return ret;
	478
7d1d65cb	479	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
1f947bf1	480	if (!prog)
7d1d65cb DB	481	return -ENOBUFS;
7d1d65cb DB	482
b9a24bb7 WC	483	ret = tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
	484	if (ret < 0)
	485	goto errout;
1f947bf1 JF	486
	487	if (oldprog) {
	488	if (handle && oldprog->handle != handle) {
	489	ret = -EINVAL;
	490	goto errout;
	491	}
	492	}
	493
7d1d65cb DB	494	if (handle == 0)
	495	prog->handle = cls_bpf_grab_new_handle(tp, head);
	496	else
	497	prog->handle = handle;
	498	if (prog->handle == 0) {
	499	ret = -EINVAL;
	500	goto errout;
	501	}
	502
5a7a5555 JHS	503	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE],
5a7a5555 JHS	504	ovr);
7d1d65cb DB	505	if (ret < 0)
	506	goto errout;
	507
eadb4148 JK	508	ret = cls_bpf_offload(tp, prog, oldprog);
eadb4148 JK	509	if (ret) {
8d829bdb	510	__cls_bpf_delete_prog(prog);
eadb4148 JK	511	return ret;
eadb4148 JK	512	}
332ae8e2	513
1f947bf1	514	if (oldprog) {
f6bfc46d	515	list_replace_rcu(&oldprog->link, &prog->link);
18cdb37e	516	tcf_unbind_filter(tp, &oldprog->res);
8d829bdb	517	call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
1f947bf1 JF	518	} else {
	519	list_add_rcu(&prog->link, &head->plist);
	520	}
7d1d65cb DB	521
7d1d65cb DB	522	*arg = (unsigned long) prog;
7d1d65cb	523	return 0;
b9a24bb7	524
7d1d65cb	525	errout:
b9a24bb7	526	tcf_exts_destroy(&prog->exts);
1f947bf1	527	kfree(prog);
7d1d65cb DB	528	return ret;
	529	}
	530
e2e9b654 DB	531	static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
	532	struct sk_buff *skb)
	533	{
	534	struct nlattr *nla;
	535
	536	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
	537	return -EMSGSIZE;
	538
	539	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
	540	sizeof(struct sock_filter));
	541	if (nla == NULL)
	542	return -EMSGSIZE;
	543
	544	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
	545
	546	return 0;
	547	}
	548
	549	static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
	550	struct sk_buff *skb)
	551	{
7bd509e3 DB	552	struct nlattr *nla;
7bd509e3 DB	553
e2e9b654 DB	554	if (prog->bpf_name &&
	555	nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
	556	return -EMSGSIZE;
	557
f1f7714e	558	nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag));
7bd509e3 DB	559	if (nla == NULL)
	560	return -EMSGSIZE;
	561
f1f7714e	562	memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
7bd509e3	563
e2e9b654 DB	564	return 0;
	565	}
	566
832d1d5b	567	static int cls_bpf_dump(struct net net, struct tcf_proto tp, unsigned long fh,
7d1d65cb DB	568	struct sk_buff skb, struct tcmsg tm)
	569	{
	570	struct cls_bpf_prog prog = (struct cls_bpf_prog ) fh;
e2e9b654	571	struct nlattr *nest;
bf007d1c	572	u32 bpf_flags = 0;
e2e9b654	573	int ret;
7d1d65cb DB	574
	575	if (prog == NULL)
	576	return skb->len;
	577
	578	tm->tcm_handle = prog->handle;
	579
68d64063 JK	580	cls_bpf_offload_update_stats(tp, prog);
68d64063 JK	581
7d1d65cb DB	582	nest = nla_nest_start(skb, TCA_OPTIONS);
	583	if (nest == NULL)
	584	goto nla_put_failure;
	585
ef146fa4 DB	586	if (prog->res.classid &&
ef146fa4 DB	587	nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
7d1d65cb	588	goto nla_put_failure;
7d1d65cb	589
e2e9b654 DB	590	if (cls_bpf_is_ebpf(prog))
	591	ret = cls_bpf_dump_ebpf_info(prog, skb);
	592	else
	593	ret = cls_bpf_dump_bpf_info(prog, skb);
	594	if (ret)
7d1d65cb DB	595	goto nla_put_failure;
7d1d65cb DB	596
5da57f42	597	if (tcf_exts_dump(skb, &prog->exts) < 0)
7d1d65cb DB	598	goto nla_put_failure;
7d1d65cb DB	599
bf007d1c DB	600	if (prog->exts_integrated)
	601	bpf_flags \|= TCA_BPF_FLAG_ACT_DIRECT;
	602	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
	603	goto nla_put_failure;
0d01d45f JK	604	if (prog->gen_flags &&
	605	nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_flags))
	606	goto nla_put_failure;
bf007d1c	607
7d1d65cb DB	608	nla_nest_end(skb, nest);
7d1d65cb DB	609
5da57f42	610	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
7d1d65cb DB	611	goto nla_put_failure;
	612
	613	return skb->len;
	614
	615	nla_put_failure:
	616	nla_nest_cancel(skb, nest);
	617	return -1;
	618	}
	619
	620	static void cls_bpf_walk(struct tcf_proto tp, struct tcf_walker arg)
	621	{
1f947bf1	622	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	623	struct cls_bpf_prog *prog;
7d1d65cb DB	624
3fe6b49e	625	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	626	if (arg->count < arg->skip)
	627	goto skip;
	628	if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
	629	arg->stop = 1;
	630	break;
	631	}
	632	skip:
	633	arg->count++;
	634	}
	635	}
	636
	637	static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
	638	.kind = "bpf",
	639	.owner = THIS_MODULE,
	640	.classify = cls_bpf_classify,
	641	.init = cls_bpf_init,
	642	.destroy = cls_bpf_destroy,
	643	.get = cls_bpf_get,
7d1d65cb DB	644	.change = cls_bpf_change,
	645	.delete = cls_bpf_delete,
	646	.walk = cls_bpf_walk,
	647	.dump = cls_bpf_dump,
	648	};
	649
	650	static int __init cls_bpf_init_mod(void)
	651	{
	652	return register_tcf_proto_ops(&cls_bpf_ops);
	653	}
	654
	655	static void __exit cls_bpf_exit_mod(void)
	656	{
	657	unregister_tcf_proto_ops(&cls_bpf_ops);
	658	}
	659
	660	module_init(cls_bpf_init_mod);
	661	module_exit(cls_bpf_exit_mod);