blob: 12d4da8e6c7728ed6bcc723f5b583fbfd0dc895c [file] [log] [blame]
/* 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/skbuff.h>
#include <linux/filter.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(const struct xt_mtchk_param *par)
{
struct xt_bpf_info *info = par->matchinfo;
struct sock_fprog program;
program.len = info->bpf_program_num_elem;
program.filter = (struct sock_filter __user *) info->bpf_program;
if (sk_unattached_filter_create(&info->filter, &program)) {
pr_info("bpf: check failed: parse error\n");
return -EINVAL;
}
return 0;
}
static bool bpf_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_bpf_info *info = par->matchinfo;
return SK_RUN_FILTER(info->filter, skb);
}
static void bpf_mt_destroy(const struct xt_mtdtor_param *par)
{
const struct xt_bpf_info *info = par->matchinfo;
sk_unattached_filter_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),
.me = THIS_MODULE,
};
static int __init bpf_mt_init(void)
{
return xt_register_match(&bpf_mt_reg);
}
static void __exit bpf_mt_exit(void)
{
xt_unregister_match(&bpf_mt_reg);
}
module_init(bpf_mt_init);
module_exit(bpf_mt_exit);