[linux-2.6-block.git] / net / netfilter / xt_bpf.c

// SPDX-License-Identifier: GPL-2.0-only
/* Xtables module to match packets using a BPF filter.
 * Copyright 2013 Google Inc.
 * Written by Willem de Bruijn <willemb@google.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/bpf.h>

#include <linux/netfilter/xt_bpf.h>
#include <linux/netfilter/x_tables.h>

MODULE_AUTHOR("Willem de Bruijn <willemb@google.com>");
MODULE_DESCRIPTION("Xtables: BPF filter match");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_bpf");
MODULE_ALIAS("ip6t_bpf");

static int __bpf_mt_check_bytecode(struct sock_filter *insns, __u16 len,
				   struct bpf_prog **ret)
{
	struct sock_fprog_kern program;

	if (len > XT_BPF_MAX_NUM_INSTR)
		return -EINVAL;

	program.len = len;
	program.filter = insns;

	if (bpf_prog_create(ret, &program)) {
		pr_info_ratelimited("check failed: parse error\n");
		return -EINVAL;
	}

	return 0;
}

static int __bpf_mt_check_fd(int fd, struct bpf_prog **ret)
{
	struct bpf_prog *prog;

	prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
	if (IS_ERR(prog))
		return PTR_ERR(prog);

	*ret = prog;
	return 0;
}

static int __bpf_mt_check_path(const char *path, struct bpf_prog **ret)
{
	if (strnlen(path, XT_BPF_PATH_MAX) == XT_BPF_PATH_MAX)
		return -EINVAL;

	*ret = bpf_prog_get_type_path(path, BPF_PROG_TYPE_SOCKET_FILTER);
	return PTR_ERR_OR_ZERO(*ret);
}

static int bpf_mt_check(const struct xt_mtchk_param *par)
{
	struct xt_bpf_info *info = par->matchinfo;

	return __bpf_mt_check_bytecode(info->bpf_program,
				       info->bpf_program_num_elem,
				       &info->filter);
}

static int bpf_mt_check_v1(const struct xt_mtchk_param *par)
{
	struct xt_bpf_info_v1 *info = par->matchinfo;

	if (info->mode == XT_BPF_MODE_BYTECODE)
		return __bpf_mt_check_bytecode(info->bpf_program,
					       info->bpf_program_num_elem,
					       &info->filter);
	else if (info->mode == XT_BPF_MODE_FD_ELF)
		return __bpf_mt_check_fd(info->fd, &info->filter);
	else if (info->mode == XT_BPF_MODE_PATH_PINNED)
		return __bpf_mt_check_path(info->path, &info->filter);
	else
		return -EINVAL;
}

static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_bpf_info *info = par->matchinfo;

	return bpf_prog_run(info->filter, skb);
}

static bool bpf_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_bpf_info_v1 *info = par->matchinfo;

	return !!bpf_prog_run_save_cb(info->filter, (struct sk_buff *) skb);
}

static void bpf_mt_destroy(const struct xt_mtdtor_param *par)
{
	const struct xt_bpf_info *info = par->matchinfo;

	bpf_prog_destroy(info->filter);
}

static void bpf_mt_destroy_v1(const struct xt_mtdtor_param *par)
{
	const struct xt_bpf_info_v1 *info = par->matchinfo;

	bpf_prog_destroy(info->filter);
}

static struct xt_match bpf_mt_reg[] __read_mostly = {
	{
		.name		= "bpf",
		.revision	= 0,
		.family		= NFPROTO_UNSPEC,
		.checkentry	= bpf_mt_check,
		.match		= bpf_mt,
		.destroy	= bpf_mt_destroy,
		.matchsize	= sizeof(struct xt_bpf_info),
		.usersize	= offsetof(struct xt_bpf_info, filter),
		.me		= THIS_MODULE,
	},
	{
		.name		= "bpf",
		.revision	= 1,
		.family		= NFPROTO_UNSPEC,
		.checkentry	= bpf_mt_check_v1,
		.match		= bpf_mt_v1,
		.destroy	= bpf_mt_destroy_v1,
		.matchsize	= sizeof(struct xt_bpf_info_v1),
		.usersize	= offsetof(struct xt_bpf_info_v1, filter),
		.me		= THIS_MODULE,
	},
};

static int __init bpf_mt_init(void)
{
	return xt_register_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
}

static void __exit bpf_mt_exit(void)
{
	xt_unregister_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
}

module_init(bpf_mt_init);
module_exit(bpf_mt_exit);
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
e6f30c73 WB	2	/* Xtables module to match packets using a BPF filter.
	3	* Copyright 2013 Google Inc.
	4	* Written by Willem de Bruijn <willemb@google.com>
e6f30c73 WB	5	*/
e6f30c73 WB	6
b2606644 FW	7	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
b2606644 FW	8
e6f30c73	9	#include <linux/module.h>
98589a09	10	#include <linux/syscalls.h>
e6f30c73 WB	11	#include <linux/skbuff.h>
e6f30c73 WB	12	#include <linux/filter.h>
2c16d603	13	#include <linux/bpf.h>
e6f30c73 WB	14
	15	#include <linux/netfilter/xt_bpf.h>
	16	#include <linux/netfilter/x_tables.h>
	17
	18	MODULE_AUTHOR("Willem de Bruijn <willemb@google.com>");
	19	MODULE_DESCRIPTION("Xtables: BPF filter match");
	20	MODULE_LICENSE("GPL");
	21	MODULE_ALIAS("ipt_bpf");
	22	MODULE_ALIAS("ip6t_bpf");
	23
2c16d603 WB	24	static int __bpf_mt_check_bytecode(struct sock_filter *insns, __u16 len,
2c16d603 WB	25	struct bpf_prog **ret)
e6f30c73	26	{
b1fcd35c	27	struct sock_fprog_kern program;
e6f30c73	28
6ab40511 JH	29	if (len > XT_BPF_MAX_NUM_INSTR)
	30	return -EINVAL;
	31
2c16d603 WB	32	program.len = len;
2c16d603 WB	33	program.filter = insns;
b1fcd35c	34
2c16d603	35	if (bpf_prog_create(ret, &program)) {
b2606644	36	pr_info_ratelimited("check failed: parse error\n");
e6f30c73 WB	37	return -EINVAL;
	38	}
	39
	40	return 0;
	41	}
	42
2c16d603 WB	43	static int __bpf_mt_check_fd(int fd, struct bpf_prog **ret)
	44	{
	45	struct bpf_prog *prog;
	46
	47	prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
	48	if (IS_ERR(prog))
	49	return PTR_ERR(prog);
	50
	51	*ret = prog;
	52	return 0;
	53	}
	54
98589a09 SL	55	static int __bpf_mt_check_path(const char path, struct bpf_prog *ret)
98589a09 SL	56	{
6ab40511 JH	57	if (strnlen(path, XT_BPF_PATH_MAX) == XT_BPF_PATH_MAX)
	58	return -EINVAL;
	59
040ee692 AV	60	*ret = bpf_prog_get_type_path(path, BPF_PROG_TYPE_SOCKET_FILTER);
040ee692 AV	61	return PTR_ERR_OR_ZERO(*ret);
98589a09 SL	62	}
98589a09 SL	63
2c16d603 WB	64	static int bpf_mt_check(const struct xt_mtchk_param *par)
	65	{
	66	struct xt_bpf_info *info = par->matchinfo;
	67
	68	return __bpf_mt_check_bytecode(info->bpf_program,
	69	info->bpf_program_num_elem,
	70	&info->filter);
	71	}
	72
	73	static int bpf_mt_check_v1(const struct xt_mtchk_param *par)
	74	{
	75	struct xt_bpf_info_v1 *info = par->matchinfo;
	76
	77	if (info->mode == XT_BPF_MODE_BYTECODE)
	78	return __bpf_mt_check_bytecode(info->bpf_program,
	79	info->bpf_program_num_elem,
	80	&info->filter);
98589a09	81	else if (info->mode == XT_BPF_MODE_FD_ELF)
2c16d603	82	return __bpf_mt_check_fd(info->fd, &info->filter);
98589a09 SL	83	else if (info->mode == XT_BPF_MODE_PATH_PINNED)
98589a09 SL	84	return __bpf_mt_check_path(info->path, &info->filter);
2c16d603 WB	85	else
	86	return -EINVAL;
	87	}
	88
e6f30c73 WB	89	static bool bpf_mt(const struct sk_buff skb, struct xt_action_param par)
	90	{
	91	const struct xt_bpf_info *info = par->matchinfo;
	92
fb7dd8bc	93	return bpf_prog_run(info->filter, skb);
e6f30c73 WB	94	}
e6f30c73 WB	95
2c16d603 WB	96	static bool bpf_mt_v1(const struct sk_buff skb, struct xt_action_param par)
	97	{
	98	const struct xt_bpf_info_v1 *info = par->matchinfo;
	99
	100	return !!bpf_prog_run_save_cb(info->filter, (struct sk_buff *) skb);
	101	}
	102
e6f30c73 WB	103	static void bpf_mt_destroy(const struct xt_mtdtor_param *par)
	104	{
	105	const struct xt_bpf_info *info = par->matchinfo;
2c16d603 WB	106
	107	bpf_prog_destroy(info->filter);
	108	}
	109
	110	static void bpf_mt_destroy_v1(const struct xt_mtdtor_param *par)
	111	{
	112	const struct xt_bpf_info_v1 *info = par->matchinfo;
	113
7ae457c1	114	bpf_prog_destroy(info->filter);
e6f30c73 WB	115	}
e6f30c73 WB	116
2c16d603 WB	117	static struct xt_match bpf_mt_reg[] __read_mostly = {
	118	{
	119	.name = "bpf",
	120	.revision = 0,
	121	.family = NFPROTO_UNSPEC,
	122	.checkentry = bpf_mt_check,
	123	.match = bpf_mt,
	124	.destroy = bpf_mt_destroy,
	125	.matchsize = sizeof(struct xt_bpf_info),
ec231890	126	.usersize = offsetof(struct xt_bpf_info, filter),
2c16d603 WB	127	.me = THIS_MODULE,
	128	},
	129	{
	130	.name = "bpf",
	131	.revision = 1,
	132	.family = NFPROTO_UNSPEC,
	133	.checkentry = bpf_mt_check_v1,
	134	.match = bpf_mt_v1,
	135	.destroy = bpf_mt_destroy_v1,
	136	.matchsize = sizeof(struct xt_bpf_info_v1),
ec231890	137	.usersize = offsetof(struct xt_bpf_info_v1, filter),
2c16d603 WB	138	.me = THIS_MODULE,
2c16d603 WB	139	},
e6f30c73 WB	140	};
	141
	142	static int __init bpf_mt_init(void)
	143	{
2c16d603	144	return xt_register_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
e6f30c73 WB	145	}
	146
	147	static void __exit bpf_mt_exit(void)
	148	{
2c16d603	149	xt_unregister_matches(bpf_mt_reg, ARRAY_SIZE(bpf_mt_reg));
e6f30c73 WB	150	}
	151
	152	module_init(bpf_mt_init);
	153	module_exit(bpf_mt_exit);