[deliverable/linux.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

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;
	struct tcf_exts exts;
	u32 handle;
	union {
		u32 bpf_fd;
		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_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_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;
#ifdef CONFIG_NET_CLS_ACT
	bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS;
#else
	bool at_ingress = false;
#endif
	int ret = -1;

	if (unlikely(!skb_mac_header_was_set(skb)))
		return -1;

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

		if (at_ingress) {
			/* It is safe to push/pull even if skb_shared() */
			__skb_push(skb, skb->mac_len);
			filter_res = BPF_PROG_RUN(prog->filter, skb);
			__skb_pull(skb, skb->mac_len);
		} else {
			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;

		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_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);

	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(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 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) {
		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);
	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;

	if (head == NULL)
		return 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, u32 classid)
{
	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;
	prog->res.classid = classid;

	return 0;
}

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

	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);

	fp = bpf_prog_get(bpf_fd);
	if (IS_ERR(fp))
		return PTR_ERR(fp);

	if (fp->type != BPF_PROG_TYPE_SCHED_CLS) {
		bpf_prog_put(fp);
		return -EINVAL;
	}

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

	prog->bpf_ops = NULL;
	prog->bpf_fd = bpf_fd;
	prog->bpf_name = name;

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

	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)
{
	struct tcf_exts exts;
	bool is_bpf, is_ebpf;
	u32 classid;
	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) ||
	    !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]);

	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog, classid) :
		       cls_bpf_prog_from_efd(tb, prog, classid);
	if (ret < 0) {
		tcf_exts_destroy(&exts);
		return ret;
	}

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

	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,
			  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_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)
{
	if (nla_put_u32(skb, TCA_BPF_FD, prog->bpf_fd))
		return -EMSGSIZE;

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

	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;
	int ret;

	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 (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;

	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 DB	29	#define CLS_BPF_NAME_LEN 256
e2e9b654 DB	30
7d1d65cb DB	31	struct cls_bpf_head {
	32	struct list_head plist;
	33	u32 hgen;
1f947bf1	34	struct rcu_head rcu;
7d1d65cb DB	35	};
	36
	37	struct cls_bpf_prog {
7ae457c1	38	struct bpf_prog *filter;
7d1d65cb	39	struct list_head link;
e2e9b654 DB	40	struct tcf_result res;
e2e9b654 DB	41	struct tcf_exts exts;
7d1d65cb	42	u32 handle;
e2e9b654 DB	43	union {
	44	u32 bpf_fd;
	45	u16 bpf_num_ops;
	46	};
	47	struct sock_filter *bpf_ops;
	48	const char *bpf_name;
1f947bf1 JF	49	struct tcf_proto *tp;
1f947bf1 JF	50	struct rcu_head rcu;
7d1d65cb DB	51	};
	52
	53	static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
	54	[TCA_BPF_CLASSID] = { .type = NLA_U32 },
e2e9b654 DB	55	[TCA_BPF_FD] = { .type = NLA_U32 },
e2e9b654 DB	56	[TCA_BPF_NAME] = { .type = NLA_NUL_STRING, .len = CLS_BPF_NAME_LEN },
7d1d65cb DB	57	[TCA_BPF_OPS_LEN] = { .type = NLA_U16 },
	58	[TCA_BPF_OPS] = { .type = NLA_BINARY,
	59	.len = sizeof(struct sock_filter) * BPF_MAXINSNS },
	60	};
	61
7d1d65cb DB	62	static int cls_bpf_classify(struct sk_buff skb, const struct tcf_proto tp,
	63	struct tcf_result *res)
	64	{
80dcbd12	65	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
7d1d65cb	66	struct cls_bpf_prog *prog;
3431205e AS	67	#ifdef CONFIG_NET_CLS_ACT
	68	bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS;
	69	#else
	70	bool at_ingress = false;
	71	#endif
54720df1	72	int ret = -1;
7d1d65cb	73
a166151c AS	74	if (unlikely(!skb_mac_header_was_set(skb)))
	75	return -1;
	76
54720df1 DB	77	/* Needed here for accessing maps. */
54720df1 DB	78	rcu_read_lock();
1f947bf1	79	list_for_each_entry_rcu(prog, &head->plist, link) {
3431205e AS	80	int filter_res;
	81
	82	if (at_ingress) {
	83	/* It is safe to push/pull even if skb_shared() */
	84	__skb_push(skb, skb->mac_len);
	85	filter_res = BPF_PROG_RUN(prog->filter, skb);
	86	__skb_pull(skb, skb->mac_len);
	87	} else {
	88	filter_res = BPF_PROG_RUN(prog->filter, skb);
	89	}
7d1d65cb DB	90
	91	if (filter_res == 0)
	92	continue;
	93
	94	*res = prog->res;
	95	if (filter_res != -1)
	96	res->classid = filter_res;
	97
	98	ret = tcf_exts_exec(skb, &prog->exts, res);
	99	if (ret < 0)
	100	continue;
	101
54720df1	102	break;
7d1d65cb	103	}
54720df1	104	rcu_read_unlock();
7d1d65cb	105
54720df1	106	return ret;
7d1d65cb DB	107	}
7d1d65cb DB	108
e2e9b654 DB	109	static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
	110	{
	111	return !prog->bpf_ops;
	112	}
	113
7d1d65cb DB	114	static int cls_bpf_init(struct tcf_proto *tp)
	115	{
	116	struct cls_bpf_head *head;
	117
	118	head = kzalloc(sizeof(*head), GFP_KERNEL);
	119	if (head == NULL)
	120	return -ENOBUFS;
	121
1f947bf1 JF	122	INIT_LIST_HEAD_RCU(&head->plist);
1f947bf1 JF	123	rcu_assign_pointer(tp->root, head);
7d1d65cb DB	124
	125	return 0;
	126	}
	127
	128	static void cls_bpf_delete_prog(struct tcf_proto tp, struct cls_bpf_prog prog)
	129	{
18d0264f	130	tcf_exts_destroy(&prog->exts);
7d1d65cb	131
e2e9b654 DB	132	if (cls_bpf_is_ebpf(prog))
	133	bpf_prog_put(prog->filter);
	134	else
	135	bpf_prog_destroy(prog->filter);
7d1d65cb	136
e2e9b654	137	kfree(prog->bpf_name);
7d1d65cb DB	138	kfree(prog->bpf_ops);
	139	kfree(prog);
	140	}
	141
1f947bf1 JF	142	static void __cls_bpf_delete_prog(struct rcu_head *rcu)
	143	{
	144	struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
	145
	146	cls_bpf_delete_prog(prog->tp, prog);
	147	}
	148
7d1d65cb DB	149	static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
7d1d65cb DB	150	{
472f5837	151	struct cls_bpf_prog prog = (struct cls_bpf_prog ) arg;
7d1d65cb	152
472f5837 JP	153	list_del_rcu(&prog->link);
	154	tcf_unbind_filter(tp, &prog->res);
	155	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
e2e9b654	156
472f5837	157	return 0;
7d1d65cb DB	158	}
7d1d65cb DB	159
1e052be6	160	static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
7d1d65cb	161	{
1f947bf1	162	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	163	struct cls_bpf_prog prog, tmp;
7d1d65cb DB	164
1e052be6 CW	165	if (!force && !list_empty(&head->plist))
	166	return false;
	167
7d1d65cb	168	list_for_each_entry_safe(prog, tmp, &head->plist, link) {
1f947bf1	169	list_del_rcu(&prog->link);
18cdb37e	170	tcf_unbind_filter(tp, &prog->res);
1f947bf1	171	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
7d1d65cb DB	172	}
7d1d65cb DB	173
1f947bf1 JF	174	RCU_INIT_POINTER(tp->root, NULL);
1f947bf1 JF	175	kfree_rcu(head, rcu);
1e052be6	176	return true;
7d1d65cb DB	177	}
	178
	179	static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
	180	{
1f947bf1	181	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	182	struct cls_bpf_prog *prog;
	183	unsigned long ret = 0UL;
	184
	185	if (head == NULL)
	186	return 0UL;
	187
3fe6b49e	188	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	189	if (prog->handle == handle) {
	190	ret = (unsigned long) prog;
	191	break;
	192	}
	193	}
	194
	195	return ret;
	196	}
	197
e2e9b654 DB	198	static int cls_bpf_prog_from_ops(struct nlattr **tb,
e2e9b654 DB	199	struct cls_bpf_prog *prog, u32 classid)
7d1d65cb	200	{
1f947bf1	201	struct sock_filter *bpf_ops;
e2e9b654	202	struct sock_fprog_kern fprog_tmp;
1f947bf1	203	struct bpf_prog *fp;
33e9fcc6	204	u16 bpf_size, bpf_num_ops;
7d1d65cb DB	205	int ret;
7d1d65cb DB	206
33e9fcc6	207	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
e2e9b654 DB	208	if (bpf_num_ops > BPF_MAXINSNS \|\| bpf_num_ops == 0)
e2e9b654 DB	209	return -EINVAL;
7d1d65cb	210
33e9fcc6	211	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
e2e9b654 DB	212	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
e2e9b654 DB	213	return -EINVAL;
7913ecf6	214
7d1d65cb	215	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
e2e9b654 DB	216	if (bpf_ops == NULL)
e2e9b654 DB	217	return -ENOMEM;
7d1d65cb DB	218
	219	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
	220
e2e9b654 DB	221	fprog_tmp.len = bpf_num_ops;
e2e9b654 DB	222	fprog_tmp.filter = bpf_ops;
7d1d65cb	223
e2e9b654 DB	224	ret = bpf_prog_create(&fp, &fprog_tmp);
	225	if (ret < 0) {
	226	kfree(bpf_ops);
	227	return ret;
	228	}
7d1d65cb	229
7d1d65cb	230	prog->bpf_ops = bpf_ops;
e2e9b654 DB	231	prog->bpf_num_ops = bpf_num_ops;
	232	prog->bpf_name = NULL;
	233
7d1d65cb DB	234	prog->filter = fp;
7d1d65cb DB	235	prog->res.classid = classid;
7d1d65cb	236
e2e9b654 DB	237	return 0;
	238	}
	239
	240	static int cls_bpf_prog_from_efd(struct nlattr **tb,
	241	struct cls_bpf_prog *prog, u32 classid)
	242	{
	243	struct bpf_prog *fp;
	244	char *name = NULL;
	245	u32 bpf_fd;
	246
	247	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
	248
	249	fp = bpf_prog_get(bpf_fd);
	250	if (IS_ERR(fp))
	251	return PTR_ERR(fp);
	252
	253	if (fp->type != BPF_PROG_TYPE_SCHED_CLS) {
	254	bpf_prog_put(fp);
	255	return -EINVAL;
	256	}
	257
	258	if (tb[TCA_BPF_NAME]) {
	259	name = kmemdup(nla_data(tb[TCA_BPF_NAME]),
	260	nla_len(tb[TCA_BPF_NAME]),
	261	GFP_KERNEL);
	262	if (!name) {
	263	bpf_prog_put(fp);
	264	return -ENOMEM;
	265	}
	266	}
	267
	268	prog->bpf_ops = NULL;
	269	prog->bpf_fd = bpf_fd;
	270	prog->bpf_name = name;
	271
	272	prog->filter = fp;
	273	prog->res.classid = classid;
	274
	275	return 0;
	276	}
	277
	278	static int cls_bpf_modify_existing(struct net net, struct tcf_proto tp,
	279	struct cls_bpf_prog *prog,
	280	unsigned long base, struct nlattr **tb,
	281	struct nlattr *est, bool ovr)
	282	{
	283	struct tcf_exts exts;
	284	bool is_bpf, is_ebpf;
	285	u32 classid;
	286	int ret;
	287
	288	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
	289	is_ebpf = tb[TCA_BPF_FD];
	290
	291	if ((!is_bpf && !is_ebpf) \|\| (is_bpf && is_ebpf) \|\|
	292	!tb[TCA_BPF_CLASSID])
	293	return -EINVAL;
	294
	295	tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
	296	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
	297	if (ret < 0)
	298	return ret;
	299
	300	classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
301
302	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog, classid) :
303	cls_bpf_prog_from_efd(tb, prog, classid);
304	if (ret < 0) {
305	tcf_exts_destroy(&exts);
306	return ret;
307	}
308
7d1d65cb DB	309	tcf_bind_filter(tp, &prog->res, base);
	310	tcf_exts_change(tp, &prog->exts, &exts);
	311
7d1d65cb	312	return 0;
7d1d65cb DB	313	}
	314
	315	static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
	316	struct cls_bpf_head *head)
	317	{
	318	unsigned int i = 0x80000000;
3f2ab135	319	u32 handle;
7d1d65cb DB	320
	321	do {
	322	if (++head->hgen == 0x7FFFFFFF)
	323	head->hgen = 1;
	324	} while (--i > 0 && cls_bpf_get(tp, head->hgen));
3f2ab135 DB	325
3f2ab135 DB	326	if (unlikely(i == 0)) {
7d1d65cb	327	pr_err("Insufficient number of handles\n");
3f2ab135 DB	328	handle = 0;
	329	} else {
	330	handle = head->hgen;
	331	}
7d1d65cb	332
3f2ab135	333	return handle;
7d1d65cb DB	334	}
	335
	336	static int cls_bpf_change(struct net net, struct sk_buff in_skb,
	337	struct tcf_proto *tp, unsigned long base,
	338	u32 handle, struct nlattr **tca,
2f7ef2f8	339	unsigned long *arg, bool ovr)
7d1d65cb	340	{
1f947bf1 JF	341	struct cls_bpf_head *head = rtnl_dereference(tp->root);
1f947bf1 JF	342	struct cls_bpf_prog oldprog = (struct cls_bpf_prog ) *arg;
7d1d65cb	343	struct nlattr *tb[TCA_BPF_MAX + 1];
1f947bf1	344	struct cls_bpf_prog *prog;
7d1d65cb DB	345	int ret;
	346
	347	if (tca[TCA_OPTIONS] == NULL)
	348	return -EINVAL;
	349
	350	ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
	351	if (ret < 0)
	352	return ret;
	353
7d1d65cb	354	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
1f947bf1	355	if (!prog)
7d1d65cb DB	356	return -ENOBUFS;
7d1d65cb DB	357
5da57f42	358	tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
1f947bf1 JF	359
	360	if (oldprog) {
	361	if (handle && oldprog->handle != handle) {
	362	ret = -EINVAL;
	363	goto errout;
	364	}
	365	}
	366
7d1d65cb DB	367	if (handle == 0)
	368	prog->handle = cls_bpf_grab_new_handle(tp, head);
	369	else
	370	prog->handle = handle;
	371	if (prog->handle == 0) {
	372	ret = -EINVAL;
	373	goto errout;
	374	}
	375
2f7ef2f8	376	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
7d1d65cb DB	377	if (ret < 0)
	378	goto errout;
	379
1f947bf1 JF	380	if (oldprog) {
1f947bf1 JF	381	list_replace_rcu(&prog->link, &oldprog->link);
18cdb37e	382	tcf_unbind_filter(tp, &oldprog->res);
1f947bf1 JF	383	call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
	384	} else {
	385	list_add_rcu(&prog->link, &head->plist);
	386	}
7d1d65cb DB	387
7d1d65cb DB	388	*arg = (unsigned long) prog;
7d1d65cb DB	389	return 0;
7d1d65cb DB	390	errout:
1f947bf1	391	kfree(prog);
7d1d65cb DB	392
	393	return ret;
	394	}
	395
e2e9b654 DB	396	static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
	397	struct sk_buff *skb)
	398	{
	399	struct nlattr *nla;
	400
	401	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
	402	return -EMSGSIZE;
	403
	404	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
	405	sizeof(struct sock_filter));
	406	if (nla == NULL)
	407	return -EMSGSIZE;
	408
	409	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
	410
	411	return 0;
	412	}
	413
	414	static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
	415	struct sk_buff *skb)
	416	{
	417	if (nla_put_u32(skb, TCA_BPF_FD, prog->bpf_fd))
	418	return -EMSGSIZE;
	419
	420	if (prog->bpf_name &&
	421	nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
	422	return -EMSGSIZE;
	423
	424	return 0;
	425	}
	426
832d1d5b	427	static int cls_bpf_dump(struct net net, struct tcf_proto tp, unsigned long fh,
7d1d65cb DB	428	struct sk_buff skb, struct tcmsg tm)
	429	{
	430	struct cls_bpf_prog prog = (struct cls_bpf_prog ) fh;
e2e9b654 DB	431	struct nlattr *nest;
e2e9b654 DB	432	int ret;
7d1d65cb DB	433
	434	if (prog == NULL)
	435	return skb->len;
	436
	437	tm->tcm_handle = prog->handle;
	438
	439	nest = nla_nest_start(skb, TCA_OPTIONS);
	440	if (nest == NULL)
	441	goto nla_put_failure;
	442
	443	if (nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
	444	goto nla_put_failure;
7d1d65cb	445
e2e9b654 DB	446	if (cls_bpf_is_ebpf(prog))
	447	ret = cls_bpf_dump_ebpf_info(prog, skb);
	448	else
	449	ret = cls_bpf_dump_bpf_info(prog, skb);
	450	if (ret)
7d1d65cb DB	451	goto nla_put_failure;
7d1d65cb DB	452
5da57f42	453	if (tcf_exts_dump(skb, &prog->exts) < 0)
7d1d65cb DB	454	goto nla_put_failure;
	455
	456	nla_nest_end(skb, nest);
	457
5da57f42	458	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
7d1d65cb DB	459	goto nla_put_failure;
	460
	461	return skb->len;
	462
	463	nla_put_failure:
	464	nla_nest_cancel(skb, nest);
	465	return -1;
	466	}
	467
	468	static void cls_bpf_walk(struct tcf_proto tp, struct tcf_walker arg)
	469	{
1f947bf1	470	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	471	struct cls_bpf_prog *prog;
7d1d65cb DB	472
3fe6b49e	473	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	474	if (arg->count < arg->skip)
	475	goto skip;
	476	if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
	477	arg->stop = 1;
	478	break;
	479	}
	480	skip:
	481	arg->count++;
	482	}
	483	}
	484
	485	static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
	486	.kind = "bpf",
	487	.owner = THIS_MODULE,
	488	.classify = cls_bpf_classify,
	489	.init = cls_bpf_init,
	490	.destroy = cls_bpf_destroy,
	491	.get = cls_bpf_get,
7d1d65cb DB	492	.change = cls_bpf_change,
	493	.delete = cls_bpf_delete,
	494	.walk = cls_bpf_walk,
	495	.dump = cls_bpf_dump,
	496	};
	497
	498	static int __init cls_bpf_init_mod(void)
	499	{
	500	return register_tcf_proto_ops(&cls_bpf_ops);
	501	}
	502
	503	static void __exit cls_bpf_exit_mod(void)
	504	{
	505	unregister_tcf_proto_ops(&cls_bpf_ops);
	506	}
	507
	508	module_init(cls_bpf_init_mod);
	509	module_exit(cls_bpf_exit_mod);