10596608c4
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>
90 lines
2.4 KiB
C
90 lines
2.4 KiB
C
/*
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* Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nft_masq.h>
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#include <net/netfilter/ipv6/nf_nat_masquerade.h>
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static void nft_masq_ipv6_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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struct nft_masq *priv = nft_expr_priv(expr);
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struct nf_nat_range range;
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memset(&range, 0, sizeof(range));
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range.flags = priv->flags;
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if (priv->sreg_proto_min) {
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range.min_proto.all = (__force __be16)nft_reg_load16(
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®s->data[priv->sreg_proto_min]);
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range.max_proto.all = (__force __be16)nft_reg_load16(
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®s->data[priv->sreg_proto_max]);
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}
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regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range,
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nft_out(pkt));
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}
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static void
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nft_masq_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
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{
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nf_ct_netns_put(ctx->net, NFPROTO_IPV6);
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}
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static struct nft_expr_type nft_masq_ipv6_type;
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static const struct nft_expr_ops nft_masq_ipv6_ops = {
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.type = &nft_masq_ipv6_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
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.eval = nft_masq_ipv6_eval,
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.init = nft_masq_init,
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.destroy = nft_masq_ipv6_destroy,
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.dump = nft_masq_dump,
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.validate = nft_masq_validate,
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};
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static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
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.family = NFPROTO_IPV6,
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.name = "masq",
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.ops = &nft_masq_ipv6_ops,
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.policy = nft_masq_policy,
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.maxattr = NFTA_MASQ_MAX,
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.owner = THIS_MODULE,
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};
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static int __init nft_masq_ipv6_module_init(void)
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{
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int ret;
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ret = nft_register_expr(&nft_masq_ipv6_type);
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if (ret < 0)
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return ret;
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nf_nat_masquerade_ipv6_register_notifier();
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return ret;
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}
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static void __exit nft_masq_ipv6_module_exit(void)
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{
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nft_unregister_expr(&nft_masq_ipv6_type);
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nf_nat_masquerade_ipv6_unregister_notifier();
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}
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module_init(nft_masq_ipv6_module_init);
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module_exit(nft_masq_ipv6_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
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MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "masq");
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