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100a11b698
nf_tables relies on manual test of netlink attributes coming from userspace even in cases where this could be handled via netlink policy. Convert a bunch of 'flag' attributes to use NLA_POLICY_MASK checks. Signed-off-by: Florian Westphal <fw@strlen.de>
289 lines
7 KiB
C
289 lines
7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
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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/nf_nat_masquerade.h>
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struct nft_masq {
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u32 flags;
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u8 sreg_proto_min;
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u8 sreg_proto_max;
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};
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static const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
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[NFTA_MASQ_FLAGS] =
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NLA_POLICY_MASK(NLA_BE32, NF_NAT_RANGE_MASK),
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[NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 },
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[NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 },
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};
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static int nft_masq_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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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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return nft_chain_validate_hooks(ctx->chain,
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(1 << NF_INET_POST_ROUTING));
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}
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static int nft_masq_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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u32 plen = sizeof_field(struct nf_nat_range, min_proto.all);
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struct nft_masq *priv = nft_expr_priv(expr);
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int err;
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if (tb[NFTA_MASQ_FLAGS])
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priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
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if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
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err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MIN],
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&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_MASQ_REG_PROTO_MAX]) {
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err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MAX],
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&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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return nf_ct_netns_get(ctx->net, ctx->family);
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}
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static int nft_masq_dump(struct sk_buff *skb,
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const struct nft_expr *expr, bool reset)
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{
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const struct nft_masq *priv = nft_expr_priv(expr);
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if (priv->flags != 0 &&
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nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
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goto nla_put_failure;
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if (priv->sreg_proto_min) {
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if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
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priv->sreg_proto_min) ||
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nft_dump_register(skb, NFTA_MASQ_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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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 nft_masq_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_masq *priv = nft_expr_priv(expr);
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struct nf_nat_range2 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)
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nft_reg_load16(®s->data[priv->sreg_proto_min]);
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range.max_proto.all = (__force __be16)
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nft_reg_load16(®s->data[priv->sreg_proto_max]);
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}
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switch (nft_pf(pkt)) {
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case NFPROTO_IPV4:
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regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb,
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nft_hook(pkt),
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&range,
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nft_out(pkt));
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break;
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#ifdef CONFIG_NF_TABLES_IPV6
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case NFPROTO_IPV6:
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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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break;
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#endif
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default:
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WARN_ON_ONCE(1);
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break;
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}
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}
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static void
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nft_masq_ipv4_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_IPV4);
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}
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static struct nft_expr_type nft_masq_ipv4_type;
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static const struct nft_expr_ops nft_masq_ipv4_ops = {
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.type = &nft_masq_ipv4_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
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.eval = nft_masq_eval,
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.init = nft_masq_init,
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.destroy = nft_masq_ipv4_destroy,
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.dump = nft_masq_dump,
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.validate = nft_masq_validate,
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.reduce = NFT_REDUCE_READONLY,
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};
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static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
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.family = NFPROTO_IPV4,
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.name = "masq",
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.ops = &nft_masq_ipv4_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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#ifdef CONFIG_NF_TABLES_IPV6
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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_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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.reduce = NFT_REDUCE_READONLY,
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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_module_init_ipv6(void)
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{
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return nft_register_expr(&nft_masq_ipv6_type);
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}
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static void nft_masq_module_exit_ipv6(void)
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{
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nft_unregister_expr(&nft_masq_ipv6_type);
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}
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#else
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static inline int nft_masq_module_init_ipv6(void) { return 0; }
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static inline void nft_masq_module_exit_ipv6(void) {}
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#endif
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#ifdef CONFIG_NF_TABLES_INET
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static void
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nft_masq_inet_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_INET);
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}
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static struct nft_expr_type nft_masq_inet_type;
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static const struct nft_expr_ops nft_masq_inet_ops = {
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.type = &nft_masq_inet_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
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.eval = nft_masq_eval,
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.init = nft_masq_init,
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.destroy = nft_masq_inet_destroy,
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.dump = nft_masq_dump,
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.validate = nft_masq_validate,
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.reduce = NFT_REDUCE_READONLY,
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};
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static struct nft_expr_type nft_masq_inet_type __read_mostly = {
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.family = NFPROTO_INET,
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.name = "masq",
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.ops = &nft_masq_inet_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_module_init_inet(void)
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{
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return nft_register_expr(&nft_masq_inet_type);
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}
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static void nft_masq_module_exit_inet(void)
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{
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nft_unregister_expr(&nft_masq_inet_type);
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}
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#else
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static inline int nft_masq_module_init_inet(void) { return 0; }
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static inline void nft_masq_module_exit_inet(void) {}
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#endif
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static int __init nft_masq_module_init(void)
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{
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int ret;
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ret = nft_masq_module_init_ipv6();
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if (ret < 0)
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return ret;
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ret = nft_masq_module_init_inet();
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if (ret < 0) {
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nft_masq_module_exit_ipv6();
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return ret;
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}
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ret = nft_register_expr(&nft_masq_ipv4_type);
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if (ret < 0) {
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nft_masq_module_exit_inet();
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nft_masq_module_exit_ipv6();
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return ret;
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}
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ret = nf_nat_masquerade_inet_register_notifiers();
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if (ret < 0) {
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nft_masq_module_exit_ipv6();
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nft_masq_module_exit_inet();
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nft_unregister_expr(&nft_masq_ipv4_type);
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return ret;
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}
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return ret;
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}
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static void __exit nft_masq_module_exit(void)
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{
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nft_masq_module_exit_ipv6();
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nft_masq_module_exit_inet();
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nft_unregister_expr(&nft_masq_ipv4_type);
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nf_nat_masquerade_inet_unregister_notifiers();
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}
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module_init(nft_masq_module_init);
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module_exit(nft_masq_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_EXPR("masq");
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MODULE_DESCRIPTION("Netfilter nftables masquerade expression support");
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