[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;
	bool exts_integrated;
	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_FLAGS]		= { .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;

	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;

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

		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 (prog->exts_integrated) {
			res->class = prog->res.class;
			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;

		*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)
{
	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(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;

	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;
	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;

	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;

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

		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
			tcf_exts_destroy(&exts);
			return -EINVAL;
		}

		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
	}

	prog->exts_integrated = have_exts;

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

	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;
}

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(&oldprog->link, &prog->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;
	u32 bpf_flags = 0;
	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 (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;

	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	40	struct tcf_result res;
045efa82	41	bool exts_integrated;
e2e9b654	42	struct tcf_exts exts;
7d1d65cb	43	u32 handle;
e2e9b654 DB	44	union {
	45	u32 bpf_fd;
	46	u16 bpf_num_ops;
	47	};
	48	struct sock_filter *bpf_ops;
	49	const char *bpf_name;
1f947bf1 JF	50	struct tcf_proto *tp;
1f947bf1 JF	51	struct rcu_head rcu;
7d1d65cb DB	52	};
	53
	54	static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
	55	[TCA_BPF_CLASSID] = { .type = NLA_U32 },
045efa82	56	[TCA_BPF_FLAGS] = { .type = NLA_U32 },
e2e9b654 DB	57	[TCA_BPF_FD] = { .type = NLA_U32 },
e2e9b654 DB	58	[TCA_BPF_NAME] = { .type = NLA_NUL_STRING, .len = CLS_BPF_NAME_LEN },
7d1d65cb DB	59	[TCA_BPF_OPS_LEN] = { .type = NLA_U16 },
	60	[TCA_BPF_OPS] = { .type = NLA_BINARY,
	61	.len = sizeof(struct sock_filter) * BPF_MAXINSNS },
	62	};
	63
045efa82 DB	64	static int cls_bpf_exec_opcode(int code)
	65	{
	66	switch (code) {
	67	case TC_ACT_OK:
045efa82	68	case TC_ACT_SHOT:
045efa82	69	case TC_ACT_STOLEN:
27b29f63	70	case TC_ACT_REDIRECT:
045efa82 DB	71	case TC_ACT_UNSPEC:
	72	return code;
	73	default:
	74	return TC_ACT_UNSPEC;
	75	}
	76	}
	77
7d1d65cb DB	78	static int cls_bpf_classify(struct sk_buff skb, const struct tcf_proto tp,
	79	struct tcf_result *res)
	80	{
80dcbd12	81	struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
fdc5432a	82	bool at_ingress = skb_at_tc_ingress(skb);
7d1d65cb	83	struct cls_bpf_prog *prog;
54720df1	84	int ret = -1;
7d1d65cb	85
a166151c AS	86	if (unlikely(!skb_mac_header_was_set(skb)))
	87	return -1;
	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
3431205e AS	96	if (at_ingress) {
	97	/* It is safe to push/pull even if skb_shared() */
	98	__skb_push(skb, skb->mac_len);
	99	filter_res = BPF_PROG_RUN(prog->filter, skb);
	100	__skb_pull(skb, skb->mac_len);
	101	} else {
	102	filter_res = BPF_PROG_RUN(prog->filter, skb);
	103	}
7d1d65cb	104
045efa82 DB	105	if (prog->exts_integrated) {
	106	res->class = prog->res.class;
	107	res->classid = qdisc_skb_cb(skb)->tc_classid;
	108
	109	ret = cls_bpf_exec_opcode(filter_res);
	110	if (ret == TC_ACT_UNSPEC)
	111	continue;
	112	break;
	113	}
	114
7d1d65cb DB	115	if (filter_res == 0)
	116	continue;
	117
	118	*res = prog->res;
	119	if (filter_res != -1)
	120	res->classid = filter_res;
	121
	122	ret = tcf_exts_exec(skb, &prog->exts, res);
	123	if (ret < 0)
	124	continue;
	125
54720df1	126	break;
7d1d65cb	127	}
54720df1	128	rcu_read_unlock();
7d1d65cb	129
54720df1	130	return ret;
7d1d65cb DB	131	}
7d1d65cb DB	132
e2e9b654 DB	133	static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
	134	{
	135	return !prog->bpf_ops;
	136	}
	137
7d1d65cb DB	138	static int cls_bpf_init(struct tcf_proto *tp)
	139	{
	140	struct cls_bpf_head *head;
	141
	142	head = kzalloc(sizeof(*head), GFP_KERNEL);
	143	if (head == NULL)
	144	return -ENOBUFS;
	145
1f947bf1 JF	146	INIT_LIST_HEAD_RCU(&head->plist);
1f947bf1 JF	147	rcu_assign_pointer(tp->root, head);
7d1d65cb DB	148
	149	return 0;
	150	}
	151
	152	static void cls_bpf_delete_prog(struct tcf_proto tp, struct cls_bpf_prog prog)
	153	{
18d0264f	154	tcf_exts_destroy(&prog->exts);
7d1d65cb	155
e2e9b654 DB	156	if (cls_bpf_is_ebpf(prog))
	157	bpf_prog_put(prog->filter);
	158	else
	159	bpf_prog_destroy(prog->filter);
7d1d65cb	160
e2e9b654	161	kfree(prog->bpf_name);
7d1d65cb DB	162	kfree(prog->bpf_ops);
	163	kfree(prog);
	164	}
	165
1f947bf1 JF	166	static void __cls_bpf_delete_prog(struct rcu_head *rcu)
	167	{
	168	struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
	169
	170	cls_bpf_delete_prog(prog->tp, prog);
	171	}
	172
7d1d65cb DB	173	static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
7d1d65cb DB	174	{
472f5837	175	struct cls_bpf_prog prog = (struct cls_bpf_prog ) arg;
7d1d65cb	176
472f5837 JP	177	list_del_rcu(&prog->link);
	178	tcf_unbind_filter(tp, &prog->res);
	179	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
e2e9b654	180
472f5837	181	return 0;
7d1d65cb DB	182	}
7d1d65cb DB	183
1e052be6	184	static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
7d1d65cb	185	{
1f947bf1	186	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	187	struct cls_bpf_prog prog, tmp;
7d1d65cb DB	188
1e052be6 CW	189	if (!force && !list_empty(&head->plist))
	190	return false;
	191
7d1d65cb	192	list_for_each_entry_safe(prog, tmp, &head->plist, link) {
1f947bf1	193	list_del_rcu(&prog->link);
18cdb37e	194	tcf_unbind_filter(tp, &prog->res);
1f947bf1	195	call_rcu(&prog->rcu, __cls_bpf_delete_prog);
7d1d65cb DB	196	}
7d1d65cb DB	197
1f947bf1 JF	198	RCU_INIT_POINTER(tp->root, NULL);
1f947bf1 JF	199	kfree_rcu(head, rcu);
1e052be6	200	return true;
7d1d65cb DB	201	}
	202
	203	static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
	204	{
1f947bf1	205	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	206	struct cls_bpf_prog *prog;
	207	unsigned long ret = 0UL;
	208
	209	if (head == NULL)
	210	return 0UL;
	211
3fe6b49e	212	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	213	if (prog->handle == handle) {
	214	ret = (unsigned long) prog;
	215	break;
	216	}
	217	}
	218
	219	return ret;
	220	}
	221
045efa82	222	static int cls_bpf_prog_from_ops(struct nlattr *tb, struct cls_bpf_prog prog)
7d1d65cb	223	{
1f947bf1	224	struct sock_filter *bpf_ops;
e2e9b654	225	struct sock_fprog_kern fprog_tmp;
1f947bf1	226	struct bpf_prog *fp;
33e9fcc6	227	u16 bpf_size, bpf_num_ops;
7d1d65cb DB	228	int ret;
7d1d65cb DB	229
33e9fcc6	230	bpf_num_ops = nla_get_u16(tb[TCA_BPF_OPS_LEN]);
e2e9b654 DB	231	if (bpf_num_ops > BPF_MAXINSNS \|\| bpf_num_ops == 0)
e2e9b654 DB	232	return -EINVAL;
7d1d65cb	233
33e9fcc6	234	bpf_size = bpf_num_ops * sizeof(*bpf_ops);
e2e9b654 DB	235	if (bpf_size != nla_len(tb[TCA_BPF_OPS]))
e2e9b654 DB	236	return -EINVAL;
7913ecf6	237
7d1d65cb	238	bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
e2e9b654 DB	239	if (bpf_ops == NULL)
e2e9b654 DB	240	return -ENOMEM;
7d1d65cb DB	241
	242	memcpy(bpf_ops, nla_data(tb[TCA_BPF_OPS]), bpf_size);
	243
e2e9b654 DB	244	fprog_tmp.len = bpf_num_ops;
e2e9b654 DB	245	fprog_tmp.filter = bpf_ops;
7d1d65cb	246
e2e9b654 DB	247	ret = bpf_prog_create(&fp, &fprog_tmp);
	248	if (ret < 0) {
	249	kfree(bpf_ops);
	250	return ret;
	251	}
7d1d65cb	252
7d1d65cb	253	prog->bpf_ops = bpf_ops;
e2e9b654 DB	254	prog->bpf_num_ops = bpf_num_ops;
e2e9b654 DB	255	prog->bpf_name = NULL;
7d1d65cb	256	prog->filter = fp;
7d1d65cb	257
e2e9b654 DB	258	return 0;
	259	}
	260
c46646d0 DB	261	static int cls_bpf_prog_from_efd(struct nlattr *tb, struct cls_bpf_prog prog,
c46646d0 DB	262	const struct tcf_proto *tp)
e2e9b654 DB	263	{
	264	struct bpf_prog *fp;
	265	char *name = NULL;
	266	u32 bpf_fd;
	267
	268	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
	269
	270	fp = bpf_prog_get(bpf_fd);
	271	if (IS_ERR(fp))
	272	return PTR_ERR(fp);
	273
	274	if (fp->type != BPF_PROG_TYPE_SCHED_CLS) {
	275	bpf_prog_put(fp);
	276	return -EINVAL;
	277	}
	278
	279	if (tb[TCA_BPF_NAME]) {
	280	name = kmemdup(nla_data(tb[TCA_BPF_NAME]),
	281	nla_len(tb[TCA_BPF_NAME]),
	282	GFP_KERNEL);
	283	if (!name) {
	284	bpf_prog_put(fp);
	285	return -ENOMEM;
	286	}
	287	}
	288
	289	prog->bpf_ops = NULL;
	290	prog->bpf_fd = bpf_fd;
	291	prog->bpf_name = name;
e2e9b654	292	prog->filter = fp;
e2e9b654	293
1f211a1b	294	if (fp->dst_needed && !(tp->q->flags & TCQ_F_INGRESS))
c46646d0 DB	295	netif_keep_dst(qdisc_dev(tp->q));
c46646d0 DB	296
e2e9b654 DB	297	return 0;
	298	}
	299
	300	static int cls_bpf_modify_existing(struct net net, struct tcf_proto tp,
	301	struct cls_bpf_prog *prog,
	302	unsigned long base, struct nlattr **tb,
	303	struct nlattr *est, bool ovr)
	304	{
045efa82	305	bool is_bpf, is_ebpf, have_exts = false;
e2e9b654	306	struct tcf_exts exts;
e2e9b654 DB	307	int ret;
	308
	309	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
	310	is_ebpf = tb[TCA_BPF_FD];
ef146fa4	311	if ((!is_bpf && !is_ebpf) \|\| (is_bpf && is_ebpf))
e2e9b654 DB	312	return -EINVAL;
	313
	314	tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
	315	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
	316	if (ret < 0)
	317	return ret;
	318
045efa82 DB	319	if (tb[TCA_BPF_FLAGS]) {
	320	u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
	321
	322	if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
	323	tcf_exts_destroy(&exts);
	324	return -EINVAL;
	325	}
	326
	327	have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
	328	}
	329
045efa82	330	prog->exts_integrated = have_exts;
e2e9b654	331
045efa82	332	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
c46646d0	333	cls_bpf_prog_from_efd(tb, prog, tp);
e2e9b654 DB	334	if (ret < 0) {
	335	tcf_exts_destroy(&exts);
	336	return ret;
	337	}
	338
ef146fa4 DB	339	if (tb[TCA_BPF_CLASSID]) {
	340	prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
	341	tcf_bind_filter(tp, &prog->res, base);
	342	}
7d1d65cb	343
ef146fa4	344	tcf_exts_change(tp, &prog->exts, &exts);
7d1d65cb	345	return 0;
7d1d65cb DB	346	}
	347
	348	static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
	349	struct cls_bpf_head *head)
	350	{
	351	unsigned int i = 0x80000000;
3f2ab135	352	u32 handle;
7d1d65cb DB	353
	354	do {
	355	if (++head->hgen == 0x7FFFFFFF)
	356	head->hgen = 1;
	357	} while (--i > 0 && cls_bpf_get(tp, head->hgen));
3f2ab135 DB	358
3f2ab135 DB	359	if (unlikely(i == 0)) {
7d1d65cb	360	pr_err("Insufficient number of handles\n");
3f2ab135 DB	361	handle = 0;
	362	} else {
	363	handle = head->hgen;
	364	}
7d1d65cb	365
3f2ab135	366	return handle;
7d1d65cb DB	367	}
	368
	369	static int cls_bpf_change(struct net net, struct sk_buff in_skb,
	370	struct tcf_proto *tp, unsigned long base,
	371	u32 handle, struct nlattr **tca,
2f7ef2f8	372	unsigned long *arg, bool ovr)
7d1d65cb	373	{
1f947bf1 JF	374	struct cls_bpf_head *head = rtnl_dereference(tp->root);
1f947bf1 JF	375	struct cls_bpf_prog oldprog = (struct cls_bpf_prog ) *arg;
7d1d65cb	376	struct nlattr *tb[TCA_BPF_MAX + 1];
1f947bf1	377	struct cls_bpf_prog *prog;
7d1d65cb DB	378	int ret;
	379
	380	if (tca[TCA_OPTIONS] == NULL)
	381	return -EINVAL;
	382
	383	ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
	384	if (ret < 0)
	385	return ret;
	386
7d1d65cb	387	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
1f947bf1	388	if (!prog)
7d1d65cb DB	389	return -ENOBUFS;
7d1d65cb DB	390
5da57f42	391	tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
1f947bf1 JF	392
	393	if (oldprog) {
	394	if (handle && oldprog->handle != handle) {
	395	ret = -EINVAL;
	396	goto errout;
	397	}
	398	}
	399
7d1d65cb DB	400	if (handle == 0)
	401	prog->handle = cls_bpf_grab_new_handle(tp, head);
	402	else
	403	prog->handle = handle;
	404	if (prog->handle == 0) {
	405	ret = -EINVAL;
	406	goto errout;
	407	}
	408
2f7ef2f8	409	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
7d1d65cb DB	410	if (ret < 0)
	411	goto errout;
	412
1f947bf1	413	if (oldprog) {
f6bfc46d	414	list_replace_rcu(&oldprog->link, &prog->link);
18cdb37e	415	tcf_unbind_filter(tp, &oldprog->res);
1f947bf1 JF	416	call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
	417	} else {
	418	list_add_rcu(&prog->link, &head->plist);
	419	}
7d1d65cb DB	420
7d1d65cb DB	421	*arg = (unsigned long) prog;
7d1d65cb DB	422	return 0;
7d1d65cb DB	423	errout:
1f947bf1	424	kfree(prog);
7d1d65cb DB	425
	426	return ret;
	427	}
	428
e2e9b654 DB	429	static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
	430	struct sk_buff *skb)
	431	{
	432	struct nlattr *nla;
	433
	434	if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
	435	return -EMSGSIZE;
	436
	437	nla = nla_reserve(skb, TCA_BPF_OPS, prog->bpf_num_ops *
	438	sizeof(struct sock_filter));
	439	if (nla == NULL)
	440	return -EMSGSIZE;
	441
	442	memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
	443
	444	return 0;
	445	}
	446
	447	static int cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
	448	struct sk_buff *skb)
	449	{
	450	if (nla_put_u32(skb, TCA_BPF_FD, prog->bpf_fd))
	451	return -EMSGSIZE;
	452
	453	if (prog->bpf_name &&
	454	nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
	455	return -EMSGSIZE;
	456
	457	return 0;
	458	}
	459
832d1d5b	460	static int cls_bpf_dump(struct net net, struct tcf_proto tp, unsigned long fh,
7d1d65cb DB	461	struct sk_buff skb, struct tcmsg tm)
	462	{
	463	struct cls_bpf_prog prog = (struct cls_bpf_prog ) fh;
e2e9b654	464	struct nlattr *nest;
bf007d1c	465	u32 bpf_flags = 0;
e2e9b654	466	int ret;
7d1d65cb DB	467
	468	if (prog == NULL)
	469	return skb->len;
	470
	471	tm->tcm_handle = prog->handle;
	472
	473	nest = nla_nest_start(skb, TCA_OPTIONS);
	474	if (nest == NULL)
	475	goto nla_put_failure;
	476
ef146fa4 DB	477	if (prog->res.classid &&
ef146fa4 DB	478	nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
7d1d65cb	479	goto nla_put_failure;
7d1d65cb	480
e2e9b654 DB	481	if (cls_bpf_is_ebpf(prog))
	482	ret = cls_bpf_dump_ebpf_info(prog, skb);
	483	else
	484	ret = cls_bpf_dump_bpf_info(prog, skb);
	485	if (ret)
7d1d65cb DB	486	goto nla_put_failure;
7d1d65cb DB	487
5da57f42	488	if (tcf_exts_dump(skb, &prog->exts) < 0)
7d1d65cb DB	489	goto nla_put_failure;
7d1d65cb DB	490
bf007d1c DB	491	if (prog->exts_integrated)
	492	bpf_flags \|= TCA_BPF_FLAG_ACT_DIRECT;
	493	if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
	494	goto nla_put_failure;
	495
7d1d65cb DB	496	nla_nest_end(skb, nest);
7d1d65cb DB	497
5da57f42	498	if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
7d1d65cb DB	499	goto nla_put_failure;
	500
	501	return skb->len;
	502
	503	nla_put_failure:
	504	nla_nest_cancel(skb, nest);
	505	return -1;
	506	}
	507
	508	static void cls_bpf_walk(struct tcf_proto tp, struct tcf_walker arg)
	509	{
1f947bf1	510	struct cls_bpf_head *head = rtnl_dereference(tp->root);
7d1d65cb DB	511	struct cls_bpf_prog *prog;
7d1d65cb DB	512
3fe6b49e	513	list_for_each_entry(prog, &head->plist, link) {
7d1d65cb DB	514	if (arg->count < arg->skip)
	515	goto skip;
	516	if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
	517	arg->stop = 1;
	518	break;
	519	}
	520	skip:
	521	arg->count++;
	522	}
	523	}
	524
	525	static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
	526	.kind = "bpf",
	527	.owner = THIS_MODULE,
	528	.classify = cls_bpf_classify,
	529	.init = cls_bpf_init,
	530	.destroy = cls_bpf_destroy,
	531	.get = cls_bpf_get,
7d1d65cb DB	532	.change = cls_bpf_change,
	533	.delete = cls_bpf_delete,
	534	.walk = cls_bpf_walk,
	535	.dump = cls_bpf_dump,
	536	};
	537
	538	static int __init cls_bpf_init_mod(void)
	539	{
	540	return register_tcf_proto_ops(&cls_bpf_ops);
	541	}
	542
	543	static void __exit cls_bpf_exit_mod(void)
	544	{
	545	unregister_tcf_proto_ops(&cls_bpf_ops);
	546	}
	547
	548	module_init(cls_bpf_init_mod);
	549	module_exit(cls_bpf_exit_mod);