mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Liping Zhang](/assets/img/avatar_default.png)
Currently, there are two different methods to store an u16 integer to the u32 data register. For example: u32 *dest = ®s->data[priv->dreg]; 1. *dest = 0; *(u16 *) dest = val_u16; 2. *dest = val_u16; For method 1, the u16 value will be stored like this, either in big-endian or little-endian system: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | Value | 0 | +-+-+-+-+-+-+-+-+-+-+-+-+ For method 2, in little-endian system, the u16 value will be the same as listed above. But in big-endian system, the u16 value will be stored like this: 0 15 31 +-+-+-+-+-+-+-+-+-+-+-+-+ | 0 | Value | +-+-+-+-+-+-+-+-+-+-+-+-+ So later we use "memcmp(®s->data[priv->sreg], data, 2);" to do compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong result in big-endian system, as 0~15 bits will always be zero. For the similar reason, when loading an u16 value from the u32 data register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;", the 2nd method will get the wrong value in the big-endian system. So introduce some wrapper functions to store/load an u8 or u16 integer to/from the u32 data register, and use them in the right place. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
83 lines
2.3 KiB
C
83 lines
2.3 KiB
C
/*
|
|
* Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
|
|
*
|
|
* 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/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/netlink.h>
|
|
#include <linux/netfilter.h>
|
|
#include <linux/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_tables.h>
|
|
#include <net/netfilter/nf_nat.h>
|
|
#include <net/netfilter/nft_redir.h>
|
|
#include <net/netfilter/nf_nat_redirect.h>
|
|
|
|
static void nft_redir_ipv6_eval(const struct nft_expr *expr,
|
|
struct nft_regs *regs,
|
|
const struct nft_pktinfo *pkt)
|
|
{
|
|
struct nft_redir *priv = nft_expr_priv(expr);
|
|
struct nf_nat_range range;
|
|
|
|
memset(&range, 0, sizeof(range));
|
|
if (priv->sreg_proto_min) {
|
|
range.min_proto.all = (__force __be16)nft_reg_load16(
|
|
®s->data[priv->sreg_proto_min]);
|
|
range.max_proto.all = (__force __be16)nft_reg_load16(
|
|
®s->data[priv->sreg_proto_max]);
|
|
range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
|
|
}
|
|
|
|
range.flags |= priv->flags;
|
|
|
|
regs->verdict.code =
|
|
nf_nat_redirect_ipv6(pkt->skb, &range, nft_hook(pkt));
|
|
}
|
|
|
|
static void
|
|
nft_redir_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
|
|
{
|
|
nf_ct_netns_put(ctx->net, NFPROTO_IPV6);
|
|
}
|
|
|
|
static struct nft_expr_type nft_redir_ipv6_type;
|
|
static const struct nft_expr_ops nft_redir_ipv6_ops = {
|
|
.type = &nft_redir_ipv6_type,
|
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_redir)),
|
|
.eval = nft_redir_ipv6_eval,
|
|
.init = nft_redir_init,
|
|
.destroy = nft_redir_ipv6_destroy,
|
|
.dump = nft_redir_dump,
|
|
.validate = nft_redir_validate,
|
|
};
|
|
|
|
static struct nft_expr_type nft_redir_ipv6_type __read_mostly = {
|
|
.family = NFPROTO_IPV6,
|
|
.name = "redir",
|
|
.ops = &nft_redir_ipv6_ops,
|
|
.policy = nft_redir_policy,
|
|
.maxattr = NFTA_REDIR_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init nft_redir_ipv6_module_init(void)
|
|
{
|
|
return nft_register_expr(&nft_redir_ipv6_type);
|
|
}
|
|
|
|
static void __exit nft_redir_ipv6_module_exit(void)
|
|
{
|
|
nft_unregister_expr(&nft_redir_ipv6_type);
|
|
}
|
|
|
|
module_init(nft_redir_ipv6_module_init);
|
|
module_exit(nft_redir_ipv6_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
|
|
MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "redir");
|