This patch adds a new nft module named "nft_queue" which is a
nftables target sending packet to nfnetlink_queue subsystem. It has
the same level of functionnality as is iptables ancestor and share
some code with it.
Signed-off-by: Eric Leblond <eric@xxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 20 ++++
net/netfilter/Kconfig | 9 ++
net/netfilter/Makefile | 1 +
net/netfilter/nft_queue.c | 192 +++++++++++++++++++++++++++++++
4 files changed, 222 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 c3398cd..cf0872d 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 nfnetlink queue
+ on more than the default queue 0 or with the other features
+
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..88cdf16
--- /dev/null
+++ b/net/netfilter/nft_queue.c
@@ -0,0 +1,192 @@
+/*
+ * Copyright (c) 2013 Eric Leblond <eric@xxxxxxxxx>
+ *
+ * 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/ip.h>
+#include <linux/ipv6.h>
+#include <linux/jhash.h>
+
+#include <linux/jhash.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables.h>
+
+struct nft_queue {
+ u16 queuenum;
+ u16 queues_total;
+ u16 flags;
+ int family;
+};
+
+static u32 jhash_initval __read_mostly;
+
+static u32 hash_v4(const struct sk_buff *skb)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+
+ /* packets in either direction go into same queue */
+ if ((__force u32)iph->saddr < (__force u32)iph->daddr)
+ return jhash_3words((__force u32)iph->saddr,
+ (__force u32)iph->daddr, iph->protocol, jhash_initval);
+
+ return jhash_3words((__force u32)iph->daddr,
+ (__force u32)iph->saddr, iph->protocol, jhash_initval);
+}
+
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+static u32 hash_v6(const struct sk_buff *skb)
+{
+ const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ u32 a, b, c;
+
+ if ((__force u32)ip6h->saddr.s6_addr32[3] <
+ (__force u32)ip6h->daddr.s6_addr32[3]) {
+ a = (__force u32) ip6h->saddr.s6_addr32[3];
+ b = (__force u32) ip6h->daddr.s6_addr32[3];
+ } else {
+ b = (__force u32) ip6h->saddr.s6_addr32[3];
+ a = (__force u32) ip6h->daddr.s6_addr32[3];
+ }
+
+ if ((__force u32)ip6h->saddr.s6_addr32[1] <
+ (__force u32)ip6h->daddr.s6_addr32[1])
+ c = (__force u32) ip6h->saddr.s6_addr32[1];
+ else
+ c = (__force u32) ip6h->daddr.s6_addr32[1];
+
+ return jhash_3words(a, b, c, jhash_initval);
+}
+#endif
+
+static u32
+nfqueue_hash(const struct nft_pktinfo *pkt, const struct nft_queue *priv)
+{
+ u32 queue = priv->queuenum;
+
+ if (priv->family == AF_INET)
+ queue += ((u64) hash_v4(pkt->skb) * priv->queues_total) >> 32;
+#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
+ else if (priv->family == AF_INET6)
+ queue += ((u64) hash_v6(pkt->skb) * priv->queues_total) >> 32;
+#endif
+
+ return queue;
+}
+
+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, priv);
+ }
+
+ 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);
+
+ while (jhash_initval == 0)
+ jhash_initval = prandom_u32();
+
+ priv->family = ctx->afi->family;
+
+ if (tb[NFTA_QUEUE_NUM] == NULL)
+ return -EINVAL;
+ 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)))
+ goto nla_put_failure;
+
+ if (nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)))
+ goto nla_put_failure;
+
+ if (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 <eric@xxxxxxxxx>");
+MODULE_ALIAS_NFT_EXPR("queue");
--
1.8.4.4
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