From 0aff078d58e1c69139189e45ba5e929c030e8056 Mon Sep 17 00:00:00 2001 From: Eric Leblond Date: Fri, 6 Dec 2013 00:24:13 +0100 Subject: [PATCH] netfilter: nft: add queue module This patch adds a new nft module named "nft_queue" which provides a new nftables expression that allows you to enqueue packets to userspace via the nfnetlink_queue subsystem. It provides the same level of functionality as NFQUEUE and it shares some code with it. Signed-off-by: Eric Leblond Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 20 +++++ net/netfilter/Kconfig | 9 +++ net/netfilter/Makefile | 1 + net/netfilter/nft_queue.c | 134 +++++++++++++++++++++++++++++++ 4 files changed, 164 insertions(+) create mode 100644 net/netfilter/nft_queue.c diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index fbfd229..256d36b 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -658,6 +658,26 @@ enum nft_log_attributes { #define NFTA_LOG_MAX (__NFTA_LOG_MAX - 1) /** + * enum nft_queue_attributes - nf_tables queue expression netlink attributes + * + * @NFTA_QUEUE_NUM: netlink queue to send messages to (NLA_U16) + * @NFTA_QUEUE_TOTAL: number of queues to load balance packets on (NLA_U16) + * @NFTA_QUEUE_FLAGS: various flags (NLA_U16) + */ +enum nft_queue_attributes { + NFTA_QUEUE_UNSPEC, + NFTA_QUEUE_NUM, + NFTA_QUEUE_TOTAL, + NFTA_QUEUE_FLAGS, + __NFTA_QUEUE_MAX +}; +#define NFTA_QUEUE_MAX (__NFTA_QUEUE_MAX - 1) + +#define NFT_QUEUE_FLAG_BYPASS 0x01 /* for compatibility with v2 */ +#define NFT_QUEUE_FLAG_CPU_FANOUT 0x02 /* use current CPU (no hashing) */ +#define NFT_QUEUE_FLAG_MASK 0x03 + +/** * enum nft_reject_types - nf_tables reject expression reject types * * @NFT_REJECT_ICMP_UNREACH: reject using ICMP unreachable diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 48acec1..4371c98 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -456,6 +456,15 @@ config NFT_NAT depends on NF_NAT tristate "Netfilter nf_tables nat module" +config NFT_QUEUE + depends on NF_TABLES + depends on NETFILTER_XTABLES + depends on NETFILTER_NETLINK_QUEUE + tristate "Netfilter nf_tables queue module" + help + This is required if you intend to use the userspace queueing + infrastructure (also known as NFQUEUE) from nftables. + config NFT_COMPAT depends on NF_TABLES depends on NETFILTER_XTABLES diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 394483b..e763746 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -76,6 +76,7 @@ obj-$(CONFIG_NFT_META) += nft_meta.o obj-$(CONFIG_NFT_CT) += nft_ct.o obj-$(CONFIG_NFT_LIMIT) += nft_limit.o obj-$(CONFIG_NFT_NAT) += nft_nat.o +obj-$(CONFIG_NFT_QUEUE) += nft_queue.o #nf_tables-objs += nft_meta_target.o obj-$(CONFIG_NFT_RBTREE) += nft_rbtree.o obj-$(CONFIG_NFT_HASH) += nft_hash.o diff --git a/net/netfilter/nft_queue.c b/net/netfilter/nft_queue.c new file mode 100644 index 0000000..cbea473 --- /dev/null +++ b/net/netfilter/nft_queue.c @@ -0,0 +1,134 @@ +/* + * Copyright (c) 2013 Eric Leblond + * + * 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. + * + * Development of this code partly funded by OISF + * (http://www.openinfosecfoundation.org/) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static u32 jhash_initval __read_mostly; + +struct nft_queue { + u16 queuenum; + u16 queues_total; + u16 flags; + u8 family; +}; + +static void nft_queue_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + struct nft_queue *priv = nft_expr_priv(expr); + u32 queue = priv->queuenum; + u32 ret; + + if (priv->queues_total > 1) { + if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) { + int cpu = smp_processor_id(); + + queue = priv->queuenum + cpu % priv->queues_total; + } else { + queue = nfqueue_hash(pkt->skb, queue, + priv->queues_total, priv->family, + jhash_initval); + } + } + + ret = NF_QUEUE_NR(queue); + if (priv->flags & NFT_QUEUE_FLAG_BYPASS) + ret |= NF_VERDICT_FLAG_QUEUE_BYPASS; + + data[NFT_REG_VERDICT].verdict = ret; +} + +static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = { + [NFTA_QUEUE_NUM] = { .type = NLA_U16 }, + [NFTA_QUEUE_TOTAL] = { .type = NLA_U16 }, + [NFTA_QUEUE_FLAGS] = { .type = NLA_U16 }, +}; + +static int nft_queue_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_queue *priv = nft_expr_priv(expr); + + if (tb[NFTA_QUEUE_NUM] == NULL) + return -EINVAL; + + init_hashrandom(&jhash_initval); + priv->family = ctx->afi->family; + priv->queuenum = ntohs(nla_get_be16(tb[NFTA_QUEUE_NUM])); + + if (tb[NFTA_QUEUE_TOTAL] != NULL) + priv->queues_total = ntohs(nla_get_be16(tb[NFTA_QUEUE_TOTAL])); + if (tb[NFTA_QUEUE_FLAGS] != NULL) { + priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS])); + if (priv->flags & ~NFT_QUEUE_FLAG_MASK) + return -EINVAL; + } + return 0; +} + +static int nft_queue_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_queue *priv = nft_expr_priv(expr); + + if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) || + nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) || + nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags))) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_queue_type; +static const struct nft_expr_ops nft_queue_ops = { + .type = &nft_queue_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_queue)), + .eval = nft_queue_eval, + .init = nft_queue_init, + .dump = nft_queue_dump, +}; + +static struct nft_expr_type nft_queue_type __read_mostly = { + .name = "queue", + .ops = &nft_queue_ops, + .policy = nft_queue_policy, + .maxattr = NFTA_QUEUE_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_queue_module_init(void) +{ + return nft_register_expr(&nft_queue_type); +} + +static void __exit nft_queue_module_exit(void) +{ + nft_unregister_expr(&nft_queue_type); +} + +module_init(nft_queue_module_init); +module_exit(nft_queue_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Eric Leblond "); +MODULE_ALIAS_NFT_EXPR("queue"); -- 2.7.4