The nft_masq expression is intended to perform NAT in the masquerade flavour.
We decided to have the masquerade functionality in a separated expression other
than nft_nat.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
--- /dev/null
+#ifndef _NFT_MASQ_H_
+#define _NFT_MASQ_H_
+
+struct nft_masq {
+ u32 flags;
+};
+
+extern const struct nla_policy nft_masq_policy[];
+
+int nft_masq_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[]);
+
+int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr);
+
+#endif /* _NFT_MASQ_H_ */
};
#define NFTA_NAT_MAX (__NFTA_NAT_MAX - 1)
+/**
+ * enum nft_masq_attributes - nf_tables masquerade expression attributes
+ *
+ * @NFTA_MASQ_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)
+ */
+enum nft_masq_attributes {
+ NFTA_MASQ_FLAGS,
+ __NFTA_MASQ_MAX
+};
+#define NFTA_MASQ_MAX (__NFTA_MASQ_MAX - 1)
+
#endif /* _LINUX_NF_TABLES_H */
This is the kernel functionality to provide NAT in the masquerade
flavour (automatic source address selection).
+config NFT_MASQ_IPV4
+ tristate "IPv4 masquerading support for nf_tables"
+ depends on NF_TABLES_IPV4
+ depends on NFT_MASQ
+ select NF_NAT_MASQUERADE_IPV4
+
config IP_NF_TARGET_MASQUERADE
tristate "MASQUERADE target support"
select NF_NAT_MASQUERADE_IPV4
obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o
obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o
obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o
+obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o
obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o
# generic IP tables
--- /dev/null
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.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/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/nft_masq.h>
+#include <net/netfilter/ipv4/nf_nat_masquerade.h>
+
+static void nft_masq_ipv4_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_masq *priv = nft_expr_priv(expr);
+ struct nf_nat_range range;
+ unsigned int verdict;
+
+ range.flags = priv->flags;
+
+ verdict = nf_nat_masquerade_ipv4(pkt->skb, pkt->ops->hooknum,
+ &range, pkt->out);
+
+ data[NFT_REG_VERDICT].verdict = verdict;
+}
+
+static int nft_masq_ipv4_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ int err;
+
+ err = nft_masq_init(ctx, expr, tb);
+ if (err < 0)
+ return err;
+
+ nf_nat_masquerade_ipv4_register_notifier();
+ return 0;
+}
+
+static void nft_masq_ipv4_destroy(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ nf_nat_masquerade_ipv4_unregister_notifier();
+}
+
+static struct nft_expr_type nft_masq_ipv4_type;
+static const struct nft_expr_ops nft_masq_ipv4_ops = {
+ .type = &nft_masq_ipv4_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
+ .eval = nft_masq_ipv4_eval,
+ .init = nft_masq_ipv4_init,
+ .destroy = nft_masq_ipv4_destroy,
+ .dump = nft_masq_dump,
+};
+
+static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
+ .family = NFPROTO_IPV4,
+ .name = "masq",
+ .ops = &nft_masq_ipv4_ops,
+ .policy = nft_masq_policy,
+ .maxattr = NFTA_MASQ_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_masq_ipv4_module_init(void)
+{
+ return nft_register_expr(&nft_masq_ipv4_type);
+}
+
+static void __exit nft_masq_ipv4_module_exit(void)
+{
+ nft_unregister_expr(&nft_masq_ipv4_type);
+}
+
+module_init(nft_masq_ipv4_module_init);
+module_exit(nft_masq_ipv4_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");
This is the kernel functionality to provide NAT in the masquerade
flavour (automatic source address selection) for IPv6.
+config NFT_MASQ_IPV6
+ tristate "IPv6 masquerade support for nf_tables"
+ depends on NF_TABLES_IPV6
+ depends on NFT_MASQ
+ select NF_NAT_MASQUERADE_IPV6
+
config IP6_NF_TARGET_MASQUERADE
tristate "MASQUERADE target support"
select NF_NAT_MASQUERADE_IPV6
obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV6) += nft_chain_route_ipv6.o
obj-$(CONFIG_NFT_CHAIN_NAT_IPV6) += nft_chain_nat_ipv6.o
obj-$(CONFIG_NFT_REJECT_IPV6) += nft_reject_ipv6.o
+obj-$(CONFIG_NFT_MASQ_IPV6) += nft_masq_ipv6.o
# matches
obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o
--- /dev/null
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.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/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_masq.h>
+#include <net/netfilter/ipv6/nf_nat_masquerade.h>
+
+static void nft_masq_ipv6_eval(const struct nft_expr *expr,
+ struct nft_data data[NFT_REG_MAX + 1],
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_masq *priv = nft_expr_priv(expr);
+ struct nf_nat_range range;
+ unsigned int verdict;
+
+ range.flags = priv->flags;
+
+ verdict = nf_nat_masquerade_ipv6(pkt->skb, &range, pkt->out);
+
+ data[NFT_REG_VERDICT].verdict = verdict;
+}
+
+static int nft_masq_ipv6_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ int err;
+
+ err = nft_masq_init(ctx, expr, tb);
+ if (err < 0)
+ return err;
+
+ nf_nat_masquerade_ipv6_register_notifier();
+ return 0;
+}
+
+static void nft_masq_ipv6_destroy(const struct nft_ctx *ctx,
+ const struct nft_expr *expr)
+{
+ nf_nat_masquerade_ipv6_unregister_notifier();
+}
+
+static struct nft_expr_type nft_masq_ipv6_type;
+static const struct nft_expr_ops nft_masq_ipv6_ops = {
+ .type = &nft_masq_ipv6_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
+ .eval = nft_masq_ipv6_eval,
+ .init = nft_masq_ipv6_init,
+ .destroy = nft_masq_ipv6_destroy,
+ .dump = nft_masq_dump,
+};
+
+static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
+ .family = NFPROTO_IPV6,
+ .name = "masq",
+ .ops = &nft_masq_ipv6_ops,
+ .policy = nft_masq_policy,
+ .maxattr = NFTA_MASQ_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_masq_ipv6_module_init(void)
+{
+ return nft_register_expr(&nft_masq_ipv6_type);
+}
+
+static void __exit nft_masq_ipv6_module_exit(void)
+{
+ nft_unregister_expr(&nft_masq_ipv6_type);
+}
+
+module_init(nft_masq_ipv6_module_init);
+module_exit(nft_masq_ipv6_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
+MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "masq");
This option adds the "limit" expression that you can use to
ratelimit rule matchings.
+config NFT_MASQ
+ depends on NF_TABLES
+ depends on NF_CONNTRACK
+ depends on NF_NAT
+ tristate "Netfilter nf_tables masquerade support"
+ help
+ This option adds the "masquerade" expression that you can use
+ to perform NAT in the masquerade flavour.
+
config NFT_NAT
depends on NF_TABLES
depends on NF_CONNTRACK
obj-$(CONFIG_NFT_HASH) += nft_hash.o
obj-$(CONFIG_NFT_COUNTER) += nft_counter.o
obj-$(CONFIG_NFT_LOG) += nft_log.o
+obj-$(CONFIG_NFT_MASQ) += nft_masq.o
# generic X tables
obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o
--- /dev/null
+/*
+ * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.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/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_masq.h>
+
+const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
+ [NFTA_MASQ_FLAGS] = { .type = NLA_U32 },
+};
+EXPORT_SYMBOL_GPL(nft_masq_policy);
+
+int nft_masq_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_masq *priv = nft_expr_priv(expr);
+
+ if (tb[NFTA_MASQ_FLAGS] == NULL)
+ return 0;
+
+ priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
+ if (priv->flags & ~NF_NAT_RANGE_MASK)
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nft_masq_init);
+
+int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
+{
+ const struct nft_masq *priv = nft_expr_priv(expr);
+
+ if (priv->flags == 0)
+ return 0;
+
+ if (nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+EXPORT_SYMBOL_GPL(nft_masq_dump);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");