From e9105f1bead4ec3f64904564c7c6268185d6b363 Mon Sep 17 00:00:00 2001 From: Arturo Borrero Date: Fri, 17 Oct 2014 12:39:09 +0200 Subject: [PATCH] netfilter: nf_tables: add new expression nft_redir This new expression provides NAT in the redirect flavour, which is to redirect packets to local machine. Signed-off-by: Arturo Borrero Gonzalez Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nft_redir.h | 21 +++++ include/uapi/linux/netfilter/nf_tables.h | 16 ++++ net/ipv4/netfilter/Kconfig | 9 +++ net/ipv4/netfilter/Makefile | 1 + net/ipv4/netfilter/nft_redir_ipv4.c | 77 +++++++++++++++++++ net/ipv6/netfilter/Kconfig | 9 +++ net/ipv6/netfilter/Makefile | 1 + net/ipv6/netfilter/nft_redir_ipv6.c | 77 +++++++++++++++++++ net/netfilter/Kconfig | 9 +++ net/netfilter/Makefile | 1 + net/netfilter/nft_redir.c | 98 ++++++++++++++++++++++++ 11 files changed, 319 insertions(+) create mode 100644 include/net/netfilter/nft_redir.h create mode 100644 net/ipv4/netfilter/nft_redir_ipv4.c create mode 100644 net/ipv6/netfilter/nft_redir_ipv6.c create mode 100644 net/netfilter/nft_redir.c diff --git a/include/net/netfilter/nft_redir.h b/include/net/netfilter/nft_redir.h new file mode 100644 index 000000000000..a2d67546afab --- /dev/null +++ b/include/net/netfilter/nft_redir.h @@ -0,0 +1,21 @@ +#ifndef _NFT_REDIR_H_ +#define _NFT_REDIR_H_ + +struct nft_redir { + enum nft_registers sreg_proto_min:8; + enum nft_registers sreg_proto_max:8; + u16 flags; +}; + +extern const struct nla_policy nft_redir_policy[]; + +int nft_redir_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]); + +int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr); + +int nft_redir_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, + const struct nft_data **data); + +#endif /* _NFT_REDIR_H_ */ diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index f31fe7b660a5..16f62a5cf04d 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -837,6 +837,22 @@ enum nft_masq_attributes { }; #define NFTA_MASQ_MAX (__NFTA_MASQ_MAX - 1) +/** + * enum nft_redir_attributes - nf_tables redirect expression netlink attributes + * + * @NFTA_REDIR_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers) + * @NFTA_REDIR_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers) + * @NFTA_REDIR_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32) + */ +enum nft_redir_attributes { + NFTA_REDIR_UNSPEC, + NFTA_REDIR_REG_PROTO_MIN, + NFTA_REDIR_REG_PROTO_MAX, + NFTA_REDIR_FLAGS, + __NFTA_REDIR_MAX +}; +#define NFTA_REDIR_MAX (__NFTA_REDIR_MAX - 1) + /** * enum nft_gen_attributes - nf_tables ruleset generation attributes * diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index a300e2c32b26..8358b2da1549 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -119,6 +119,15 @@ config NFT_MASQ_IPV4 This is the expression that provides IPv4 masquerading support for nf_tables. +config NFT_REDIR_IPV4 + tristate "IPv4 redirect support for nf_tables" + depends on NF_TABLES_IPV4 + depends on NFT_REDIR + select NF_NAT_REDIRECT_IPV4 + help + This is the expression that provides IPv4 redirect support for + nf_tables. + config NF_NAT_SNMP_BASIC tristate "Basic SNMP-ALG support" depends on NF_CONNTRACK_SNMP diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 34e436c92015..902bcd1597bb 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -41,6 +41,7 @@ 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-$(CONFIG_NFT_REDIR_IPV4) += nft_redir_ipv4.o obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o # generic IP tables diff --git a/net/ipv4/netfilter/nft_redir_ipv4.c b/net/ipv4/netfilter/nft_redir_ipv4.c new file mode 100644 index 000000000000..643c5967aa27 --- /dev/null +++ b/net/ipv4/netfilter/nft_redir_ipv4.c @@ -0,0 +1,77 @@ +/* + * Copyright (c) 2014 Arturo Borrero Gonzalez + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static void nft_redir_ipv4_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + struct nft_redir *priv = nft_expr_priv(expr); + struct nf_nat_ipv4_multi_range_compat mr; + unsigned int verdict; + + memset(&mr, 0, sizeof(mr)); + if (priv->sreg_proto_min) { + mr.range[0].min.all = (__force __be16) + data[priv->sreg_proto_min].data[0]; + mr.range[0].max.all = (__force __be16) + data[priv->sreg_proto_max].data[0]; + mr.range[0].flags |= NF_NAT_RANGE_PROTO_SPECIFIED; + } + + mr.range[0].flags |= priv->flags; + + verdict = nf_nat_redirect_ipv4(pkt->skb, &mr, pkt->ops->hooknum); + data[NFT_REG_VERDICT].verdict = verdict; +} + +static struct nft_expr_type nft_redir_ipv4_type; +static const struct nft_expr_ops nft_redir_ipv4_ops = { + .type = &nft_redir_ipv4_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_redir)), + .eval = nft_redir_ipv4_eval, + .init = nft_redir_init, + .dump = nft_redir_dump, + .validate = nft_redir_validate, +}; + +static struct nft_expr_type nft_redir_ipv4_type __read_mostly = { + .family = NFPROTO_IPV4, + .name = "redir", + .ops = &nft_redir_ipv4_ops, + .policy = nft_redir_policy, + .maxattr = NFTA_REDIR_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_redir_ipv4_module_init(void) +{ + return nft_register_expr(&nft_redir_ipv4_type); +} + +static void __exit nft_redir_ipv4_module_exit(void) +{ + nft_unregister_expr(&nft_redir_ipv4_type); +} + +module_init(nft_redir_ipv4_module_init); +module_exit(nft_redir_ipv4_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arturo Borrero Gonzalez "); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "redir"); diff --git a/net/ipv6/netfilter/Kconfig b/net/ipv6/netfilter/Kconfig index 462eebbf4377..0dbe5c7953e5 100644 --- a/net/ipv6/netfilter/Kconfig +++ b/net/ipv6/netfilter/Kconfig @@ -97,6 +97,15 @@ config NFT_MASQ_IPV6 This is the expression that provides IPv4 masquerading support for nf_tables. +config NFT_REDIR_IPV6 + tristate "IPv6 redirect support for nf_tables" + depends on NF_TABLES_IPV6 + depends on NFT_REDIR + select NF_NAT_REDIRECT_IPV6 + help + This is the expression that provides IPv4 redirect support for + nf_tables. + endif # NF_NAT_IPV6 config IP6_NF_IPTABLES diff --git a/net/ipv6/netfilter/Makefile b/net/ipv6/netfilter/Makefile index 6c2baab10f21..d2ac9f5f212c 100644 --- a/net/ipv6/netfilter/Makefile +++ b/net/ipv6/netfilter/Makefile @@ -37,6 +37,7 @@ 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 +obj-$(CONFIG_NFT_REDIR_IPV6) += nft_redir_ipv6.o # matches obj-$(CONFIG_IP6_NF_MATCH_AH) += ip6t_ah.o diff --git a/net/ipv6/netfilter/nft_redir_ipv6.c b/net/ipv6/netfilter/nft_redir_ipv6.c new file mode 100644 index 000000000000..83420eeaad1c --- /dev/null +++ b/net/ipv6/netfilter/nft_redir_ipv6.c @@ -0,0 +1,77 @@ +/* + * Copyright (c) 2014 Arturo Borrero Gonzalez + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static void nft_redir_ipv6_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + struct nft_redir *priv = nft_expr_priv(expr); + struct nf_nat_range range; + unsigned int verdict; + + memset(&range, 0, sizeof(range)); + if (priv->sreg_proto_min) { + range.min_proto.all = (__force __be16) + data[priv->sreg_proto_min].data[0]; + range.max_proto.all = (__force __be16) + data[priv->sreg_proto_max].data[0]; + range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; + } + + range.flags |= priv->flags; + + verdict = nf_nat_redirect_ipv6(pkt->skb, &range, pkt->ops->hooknum); + data[NFT_REG_VERDICT].verdict = verdict; +} + +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, + .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 "); +MODULE_ALIAS_NFT_AF_EXPR(AF_INET6, "redir"); diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 49deb4edbac6..373486ae4159 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -505,6 +505,15 @@ config NFT_MASQ This option adds the "masquerade" expression that you can use to perform NAT in the masquerade flavour. +config NFT_REDIR + depends on NF_TABLES + depends on NF_CONNTRACK + depends on NF_NAT + tristate "Netfilter nf_tables redirect support" + help + This options adds the "redirect" expression that you can use + to perform NAT in the redirect flavour. + config NFT_NAT depends on NF_TABLES depends on NF_CONNTRACK diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index a9571be3f791..f3eb4680f2ec 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -88,6 +88,7 @@ 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 +obj-$(CONFIG_NFT_REDIR) += nft_redir.o # generic X tables obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o diff --git a/net/netfilter/nft_redir.c b/net/netfilter/nft_redir.c new file mode 100644 index 000000000000..e27b4e35718a --- /dev/null +++ b/net/netfilter/nft_redir.c @@ -0,0 +1,98 @@ +/* + * Copyright (c) 2014 Arturo Borrero Gonzalez + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +const struct nla_policy nft_redir_policy[NFTA_REDIR_MAX + 1] = { + [NFTA_REDIR_REG_PROTO_MIN] = { .type = NLA_U32 }, + [NFTA_REDIR_REG_PROTO_MAX] = { .type = NLA_U32 }, + [NFTA_REDIR_FLAGS] = { .type = NLA_U32 }, +}; +EXPORT_SYMBOL_GPL(nft_redir_policy); + +int nft_redir_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_redir *priv = nft_expr_priv(expr); + u32 nla_be32; + int err; + + err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); + if (err < 0) + return err; + + if (tb[NFTA_REDIR_REG_PROTO_MIN]) { + nla_be32 = nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MIN]); + priv->sreg_proto_min = ntohl(nla_be32); + err = nft_validate_input_register(priv->sreg_proto_min); + if (err < 0) + return err; + + if (tb[NFTA_REDIR_REG_PROTO_MAX]) { + nla_be32 = nla_get_be32(tb[NFTA_REDIR_REG_PROTO_MAX]); + priv->sreg_proto_max = ntohl(nla_be32); + err = nft_validate_input_register(priv->sreg_proto_max); + if (err < 0) + return err; + } else { + priv->sreg_proto_max = priv->sreg_proto_min; + } + } + + if (tb[NFTA_REDIR_FLAGS]) { + priv->flags = ntohl(nla_get_be32(tb[NFTA_REDIR_FLAGS])); + if (priv->flags & ~NF_NAT_RANGE_MASK) + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(nft_redir_init); + +int nft_redir_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_redir *priv = nft_expr_priv(expr); + + if (priv->sreg_proto_min) { + if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MIN, + htonl(priv->sreg_proto_min))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_REDIR_REG_PROTO_MAX, + htonl(priv->sreg_proto_max))) + goto nla_put_failure; + } + + if (priv->flags != 0 && + nla_put_be32(skb, NFTA_REDIR_FLAGS, htonl(priv->flags))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} +EXPORT_SYMBOL_GPL(nft_redir_dump); + +int nft_redir_validate(const struct nft_ctx *ctx, const struct nft_expr *expr, + const struct nft_data **data) +{ + return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT); +} +EXPORT_SYMBOL_GPL(nft_redir_validate); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arturo Borrero Gonzalez "); -- 2.39.5