diff options
| -rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 27 | ||||
| -rw-r--r-- | net/netfilter/Kconfig | 6 | ||||
| -rw-r--r-- | net/netfilter/Makefile | 1 | ||||
| -rw-r--r-- | net/netfilter/nft_rt.c | 153 |
4 files changed, 187 insertions, 0 deletions
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index a054ad2c8853..14e5f619167e 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -759,6 +759,19 @@ enum nft_meta_keys { }; /** + * enum nft_rt_keys - nf_tables routing expression keys + * + * @NFT_RT_CLASSID: realm value of packet's route (skb->dst->tclassid) + * @NFT_RT_NEXTHOP4: routing nexthop for IPv4 + * @NFT_RT_NEXTHOP6: routing nexthop for IPv6 + */ +enum nft_rt_keys { + NFT_RT_CLASSID, + NFT_RT_NEXTHOP4, + NFT_RT_NEXTHOP6, +}; + +/** * enum nft_hash_attributes - nf_tables hash expression netlink attributes * * @NFTA_HASH_SREG: source register (NLA_U32) @@ -797,6 +810,20 @@ enum nft_meta_attributes { #define NFTA_META_MAX (__NFTA_META_MAX - 1) /** + * enum nft_rt_attributes - nf_tables routing expression netlink attributes + * + * @NFTA_RT_DREG: destination register (NLA_U32) + * @NFTA_RT_KEY: routing data item to load (NLA_U32: nft_rt_keys) + */ +enum nft_rt_attributes { + NFTA_RT_UNSPEC, + NFTA_RT_DREG, + NFTA_RT_KEY, + __NFTA_RT_MAX +}; +#define NFTA_RT_MAX (__NFTA_RT_MAX - 1) + +/** * enum nft_ct_keys - nf_tables ct expression keys * * @NFT_CT_STATE: conntrack state (bitmask of enum ip_conntrack_info) diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index ed00ec114ea2..44410d30d461 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -478,6 +478,12 @@ config NFT_META This option adds the "meta" expression that you can use to match and to set packet metainformation such as the packet mark. +config NFT_RT + tristate "Netfilter nf_tables routing module" + help + This option adds the "rt" expression that you can use to match + packet routing information such as the packet nexthop. + config NFT_NUMGEN tristate "Netfilter nf_tables number generator module" help diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 8edd791743fe..5bbf767672ec 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_NF_TABLES_NETDEV) += nf_tables_netdev.o obj-$(CONFIG_NFT_COMPAT) += nft_compat.o obj-$(CONFIG_NFT_EXTHDR) += nft_exthdr.o obj-$(CONFIG_NFT_META) += nft_meta.o +obj-$(CONFIG_NFT_RT) += nft_rt.o obj-$(CONFIG_NFT_NUMGEN) += nft_numgen.o obj-$(CONFIG_NFT_CT) += nft_ct.o obj-$(CONFIG_NFT_LIMIT) += nft_limit.o diff --git a/net/netfilter/nft_rt.c b/net/netfilter/nft_rt.c new file mode 100644 index 000000000000..9e5ec1f67020 --- /dev/null +++ b/net/netfilter/nft_rt.c @@ -0,0 +1,153 @@ +/* + * Copyright (c) 2016 Anders K. Pedersen <akp@cohaesio.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/dst.h> +#include <net/ip6_route.h> +#include <net/route.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables_core.h> + +struct nft_rt { + enum nft_rt_keys key:8; + enum nft_registers dreg:8; +}; + +void nft_rt_get_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_rt *priv = nft_expr_priv(expr); + const struct sk_buff *skb = pkt->skb; + u32 *dest = ®s->data[priv->dreg]; + const struct dst_entry *dst; + + dst = skb_dst(skb); + if (!dst) + goto err; + + switch (priv->key) { +#ifdef CONFIG_IP_ROUTE_CLASSID + case NFT_RT_CLASSID: + *dest = dst->tclassid; + break; +#endif + case NFT_RT_NEXTHOP4: + if (pkt->pf != NFPROTO_IPV4) + goto err; + + *dest = rt_nexthop((const struct rtable *)dst, + ip_hdr(skb)->daddr); + break; + case NFT_RT_NEXTHOP6: + if (pkt->pf != NFPROTO_IPV6) + goto err; + + memcpy(dest, rt6_nexthop((struct rt6_info *)dst, + &ipv6_hdr(skb)->daddr), + sizeof(struct in6_addr)); + break; + default: + WARN_ON(1); + goto err; + } + return; + +err: + regs->verdict.code = NFT_BREAK; +} + +const struct nla_policy nft_rt_policy[NFTA_RT_MAX + 1] = { + [NFTA_RT_DREG] = { .type = NLA_U32 }, + [NFTA_RT_KEY] = { .type = NLA_U32 }, +}; + +int nft_rt_get_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_rt *priv = nft_expr_priv(expr); + unsigned int len; + + if (tb[NFTA_RT_KEY] == NULL || + tb[NFTA_RT_DREG] == NULL) + return -EINVAL; + + priv->key = ntohl(nla_get_be32(tb[NFTA_RT_KEY])); + switch (priv->key) { +#ifdef CONFIG_IP_ROUTE_CLASSID + case NFT_RT_CLASSID: +#endif + case NFT_RT_NEXTHOP4: + len = sizeof(u32); + break; + case NFT_RT_NEXTHOP6: + len = sizeof(struct in6_addr); + break; + default: + return -EOPNOTSUPP; + } + + priv->dreg = nft_parse_register(tb[NFTA_RT_DREG]); + return nft_validate_register_store(ctx, priv->dreg, NULL, + NFT_DATA_VALUE, len); +} + +int nft_rt_get_dump(struct sk_buff *skb, + const struct nft_expr *expr) +{ + const struct nft_rt *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_RT_KEY, htonl(priv->key))) + goto nla_put_failure; + if (nft_dump_register(skb, NFTA_RT_DREG, priv->dreg)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_rt_type; +static const struct nft_expr_ops nft_rt_get_ops = { + .type = &nft_rt_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_rt)), + .eval = nft_rt_get_eval, + .init = nft_rt_get_init, + .dump = nft_rt_get_dump, +}; + +static struct nft_expr_type nft_rt_type __read_mostly = { + .name = "rt", + .ops = &nft_rt_get_ops, + .policy = nft_rt_policy, + .maxattr = NFTA_RT_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_rt_module_init(void) +{ + return nft_register_expr(&nft_rt_type); +} + +static void __exit nft_rt_module_exit(void) +{ + nft_unregister_expr(&nft_rt_type); +} + +module_init(nft_rt_module_init); +module_exit(nft_rt_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Anders K. Pedersen <akp@cohaesio.com>"); +MODULE_ALIAS_NFT_EXPR("rt"); |