[mirror_ubuntu-bionic-kernel.git] / net / netfilter / xt_bpf.c

/* Xtables module to match packets using a BPF filter.
 * Copyright 2013 Google Inc.
 * Written by Willem de Bruijn <willemb@google.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/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;

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

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