![Florian Westphal](/assets/img/avatar_default.png)
We need minimal support from the nat core for this, as we do not want to register additional base hooks. When an inet hook is registered, interally register ipv4 and ipv6 hooks for them and unregister those when inet hooks are removed. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
351 lines
8.8 KiB
C
351 lines
8.8 KiB
C
/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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* Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
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* Copyright (c) 2012 Intel Corporation
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/string.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/ip.h>
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struct nft_nat {
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enum nft_registers sreg_addr_min:8;
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enum nft_registers sreg_addr_max:8;
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enum nft_registers sreg_proto_min:8;
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enum nft_registers sreg_proto_max:8;
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enum nf_nat_manip_type type:8;
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u8 family;
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u16 flags;
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};
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static void nft_nat_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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const struct nft_nat *priv = nft_expr_priv(expr);
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enum ip_conntrack_info ctinfo;
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struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
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struct nf_nat_range2 range;
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memset(&range, 0, sizeof(range));
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if (priv->sreg_addr_min) {
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if (priv->family == AF_INET) {
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range.min_addr.ip = (__force __be32)
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regs->data[priv->sreg_addr_min];
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range.max_addr.ip = (__force __be32)
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regs->data[priv->sreg_addr_max];
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} else {
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memcpy(range.min_addr.ip6,
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®s->data[priv->sreg_addr_min],
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sizeof(range.min_addr.ip6));
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memcpy(range.max_addr.ip6,
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®s->data[priv->sreg_addr_max],
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sizeof(range.max_addr.ip6));
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}
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range.flags |= NF_NAT_RANGE_MAP_IPS;
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}
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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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range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
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}
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range.flags |= priv->flags;
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regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
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}
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static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
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[NFTA_NAT_TYPE] = { .type = NLA_U32 },
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[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
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[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
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[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
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[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
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[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
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[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
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};
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static int nft_nat_validate(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nft_data **data)
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{
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struct nft_nat *priv = nft_expr_priv(expr);
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int err;
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err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
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if (err < 0)
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return err;
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switch (priv->type) {
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case NFT_NAT_SNAT:
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err = nft_chain_validate_hooks(ctx->chain,
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(1 << NF_INET_POST_ROUTING) |
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(1 << NF_INET_LOCAL_IN));
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break;
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case NFT_NAT_DNAT:
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err = nft_chain_validate_hooks(ctx->chain,
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(1 << NF_INET_PRE_ROUTING) |
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(1 << NF_INET_LOCAL_OUT));
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break;
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}
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return err;
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}
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static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_nat *priv = nft_expr_priv(expr);
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unsigned int alen, plen;
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u32 family;
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int err;
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if (tb[NFTA_NAT_TYPE] == NULL ||
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(tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
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tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
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return -EINVAL;
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switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
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case NFT_NAT_SNAT:
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priv->type = NF_NAT_MANIP_SRC;
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break;
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case NFT_NAT_DNAT:
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priv->type = NF_NAT_MANIP_DST;
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break;
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default:
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return -EINVAL;
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}
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if (tb[NFTA_NAT_FAMILY] == NULL)
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return -EINVAL;
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family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
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if (ctx->family != NFPROTO_INET && ctx->family != family)
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return -EOPNOTSUPP;
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switch (family) {
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case NFPROTO_IPV4:
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alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip);
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break;
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case NFPROTO_IPV6:
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alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6);
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break;
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default:
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return -EAFNOSUPPORT;
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}
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priv->family = family;
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if (tb[NFTA_NAT_REG_ADDR_MIN]) {
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priv->sreg_addr_min =
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nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
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err = nft_validate_register_load(priv->sreg_addr_min, alen);
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if (err < 0)
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return err;
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if (tb[NFTA_NAT_REG_ADDR_MAX]) {
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priv->sreg_addr_max =
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nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);
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err = nft_validate_register_load(priv->sreg_addr_max,
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alen);
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if (err < 0)
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return err;
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} else {
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priv->sreg_addr_max = priv->sreg_addr_min;
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}
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}
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plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
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if (tb[NFTA_NAT_REG_PROTO_MIN]) {
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priv->sreg_proto_min =
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nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);
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err = nft_validate_register_load(priv->sreg_proto_min, plen);
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if (err < 0)
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return err;
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if (tb[NFTA_NAT_REG_PROTO_MAX]) {
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priv->sreg_proto_max =
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nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);
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err = nft_validate_register_load(priv->sreg_proto_max,
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plen);
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if (err < 0)
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return err;
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} else {
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priv->sreg_proto_max = priv->sreg_proto_min;
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}
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}
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if (tb[NFTA_NAT_FLAGS]) {
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priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
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if (priv->flags & ~NF_NAT_RANGE_MASK)
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return -EINVAL;
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}
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return nf_ct_netns_get(ctx->net, family);
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}
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static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_nat *priv = nft_expr_priv(expr);
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switch (priv->type) {
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case NF_NAT_MANIP_SRC:
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if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
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goto nla_put_failure;
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break;
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case NF_NAT_MANIP_DST:
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if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
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goto nla_put_failure;
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break;
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}
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if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
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goto nla_put_failure;
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if (priv->sreg_addr_min) {
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if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
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priv->sreg_addr_min) ||
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nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
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priv->sreg_addr_max))
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goto nla_put_failure;
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}
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if (priv->sreg_proto_min) {
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if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
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priv->sreg_proto_min) ||
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nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
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priv->sreg_proto_max))
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goto nla_put_failure;
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}
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if (priv->flags != 0) {
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if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
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goto nla_put_failure;
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}
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return 0;
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nla_put_failure:
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return -1;
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}
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static void
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nft_nat_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
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{
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const struct nft_nat *priv = nft_expr_priv(expr);
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nf_ct_netns_put(ctx->net, priv->family);
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}
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static struct nft_expr_type nft_nat_type;
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static const struct nft_expr_ops nft_nat_ops = {
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.type = &nft_nat_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
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.eval = nft_nat_eval,
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.init = nft_nat_init,
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.destroy = nft_nat_destroy,
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.dump = nft_nat_dump,
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.validate = nft_nat_validate,
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};
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static struct nft_expr_type nft_nat_type __read_mostly = {
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.name = "nat",
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.ops = &nft_nat_ops,
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.policy = nft_nat_policy,
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.maxattr = NFTA_NAT_MAX,
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.owner = THIS_MODULE,
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};
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#ifdef CONFIG_NF_TABLES_INET
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static void nft_nat_inet_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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const struct nft_nat *priv = nft_expr_priv(expr);
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if (priv->family == nft_pf(pkt))
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nft_nat_eval(expr, regs, pkt);
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}
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static const struct nft_expr_ops nft_nat_inet_ops = {
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.type = &nft_nat_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
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.eval = nft_nat_inet_eval,
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.init = nft_nat_init,
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.destroy = nft_nat_destroy,
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.dump = nft_nat_dump,
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.validate = nft_nat_validate,
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};
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static struct nft_expr_type nft_inet_nat_type __read_mostly = {
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.name = "nat",
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.family = NFPROTO_INET,
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.ops = &nft_nat_inet_ops,
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.policy = nft_nat_policy,
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.maxattr = NFTA_NAT_MAX,
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.owner = THIS_MODULE,
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};
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static int nft_nat_inet_module_init(void)
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{
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return nft_register_expr(&nft_inet_nat_type);
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}
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static void nft_nat_inet_module_exit(void)
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{
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nft_unregister_expr(&nft_inet_nat_type);
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}
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#else
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static int nft_nat_inet_module_init(void) { return 0; }
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static void nft_nat_inet_module_exit(void) { }
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#endif
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static int __init nft_nat_module_init(void)
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{
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int ret = nft_nat_inet_module_init();
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if (ret)
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return ret;
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ret = nft_register_expr(&nft_nat_type);
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if (ret)
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nft_nat_inet_module_exit();
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return ret;
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}
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static void __exit nft_nat_module_exit(void)
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{
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nft_nat_inet_module_exit();
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nft_unregister_expr(&nft_nat_type);
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}
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module_init(nft_nat_module_init);
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module_exit(nft_nat_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
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MODULE_ALIAS_NFT_EXPR("nat");
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