From: Pablo Neira Ayuso <pablo@netfilter•org>
To: netfilter-devel@vger•kernel.org
Cc: davem@davemloft•net, netdev@vger•kernel.org
Subject: [PATCH 07/29] netfilter: nf_tables: add hash expression
Date: Mon, 5 Sep 2016 12:58:22 +0200 [thread overview]
Message-ID: <1473073124-5015-8-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1473073124-5015-1-git-send-email-pablo@netfilter.org>
From: Laura Garcia Liebana <nevola@gmail•com>
This patch adds a new hash expression, this provides jhash support but
this can be extended to support for other hash functions. The modulus
and seed already comes embedded into this new expression.
Use case example:
... meta mark set hash ip saddr mod 10
Signed-off-by: Laura Garcia Liebana <nevola@gmail•com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter•org>
---
include/uapi/linux/netfilter/nf_tables.h | 20 +++++
net/netfilter/Kconfig | 6 ++
net/netfilter/Makefile | 1 +
net/netfilter/nft_hash.c | 136 +++++++++++++++++++++++++++++++
4 files changed, 163 insertions(+)
create mode 100644 net/netfilter/nft_hash.c
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 01751fa..6ce0a6d 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -724,6 +724,26 @@ enum nft_meta_keys {
};
/**
+ * enum nft_hash_attributes - nf_tables hash expression netlink attributes
+ *
+ * @NFTA_HASH_SREG: source register (NLA_U32)
+ * @NFTA_HASH_DREG: destination register (NLA_U32)
+ * @NFTA_HASH_LEN: source data length (NLA_U32)
+ * @NFTA_HASH_MODULUS: modulus value (NLA_U32)
+ * @NFTA_HASH_SEED: seed value (NLA_U32)
+ */
+enum nft_hash_attributes {
+ NFTA_HASH_UNSPEC,
+ NFTA_HASH_SREG,
+ NFTA_HASH_DREG,
+ NFTA_HASH_LEN,
+ NFTA_HASH_MODULUS,
+ NFTA_HASH_SEED,
+ __NFTA_HASH_MAX,
+};
+#define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1)
+
+/**
* enum nft_meta_attributes - nf_tables meta expression netlink attributes
*
* @NFTA_META_DREG: destination register (NLA_U32)
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index e5740e1..9cfaa00 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -563,6 +563,12 @@ config NFT_COMPAT
x_tables match/target extensions over the nf_tables
framework.
+config NFT_HASH
+ tristate "Netfilter nf_tables hash module"
+ help
+ This option adds the "hash" expression that you can use to perform
+ a hash operation on registers.
+
if NF_TABLES_NETDEV
config NF_DUP_NETDEV
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 101fb85..1106ccd 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -92,6 +92,7 @@ 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
+obj-$(CONFIG_NFT_HASH) += nft_hash.o
# nf_tables netdev
obj-$(CONFIG_NFT_DUP_NETDEV) += nft_dup_netdev.o
diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c
new file mode 100644
index 0000000..b82ff29
--- /dev/null
+++ b/net/netfilter/nft_hash.c
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2016 Laura Garcia <nevola@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_tables_core.h>
+#include <linux/jhash.h>
+
+struct nft_hash {
+ enum nft_registers sreg:8;
+ enum nft_registers dreg:8;
+ u8 len;
+ u32 modulus;
+ u32 seed;
+};
+
+static void nft_hash_eval(const struct nft_expr *expr,
+ struct nft_regs *regs,
+ const struct nft_pktinfo *pkt)
+{
+ struct nft_hash *priv = nft_expr_priv(expr);
+ const void *data = ®s->data[priv->sreg];
+
+ regs->data[priv->dreg] =
+ reciprocal_scale(jhash(data, priv->len, priv->seed),
+ priv->modulus);
+}
+
+const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = {
+ [NFTA_HASH_SREG] = { .type = NLA_U32 },
+ [NFTA_HASH_DREG] = { .type = NLA_U32 },
+ [NFTA_HASH_LEN] = { .type = NLA_U32 },
+ [NFTA_HASH_MODULUS] = { .type = NLA_U32 },
+ [NFTA_HASH_SEED] = { .type = NLA_U32 },
+};
+
+static int nft_hash_init(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nlattr * const tb[])
+{
+ struct nft_hash *priv = nft_expr_priv(expr);
+ u32 len;
+
+ if (!tb[NFTA_HASH_SREG] ||
+ !tb[NFTA_HASH_DREG] ||
+ !tb[NFTA_HASH_LEN] ||
+ !tb[NFTA_HASH_SEED] ||
+ !tb[NFTA_HASH_MODULUS])
+ return -EINVAL;
+
+ priv->sreg = nft_parse_register(tb[NFTA_HASH_SREG]);
+ priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
+
+ len = ntohl(nla_get_be32(tb[NFTA_HASH_LEN]));
+ if (len == 0 || len > U8_MAX)
+ return -ERANGE;
+
+ priv->len = len;
+
+ priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS]));
+ if (priv->modulus <= 1)
+ return -ERANGE;
+
+ priv->seed = ntohl(nla_get_be32(tb[NFTA_HASH_SEED]));
+
+ return nft_validate_register_load(priv->sreg, len) &&
+ nft_validate_register_store(ctx, priv->dreg, NULL,
+ NFT_DATA_VALUE, sizeof(u32));
+}
+
+static int nft_hash_dump(struct sk_buff *skb,
+ const struct nft_expr *expr)
+{
+ const struct nft_hash *priv = nft_expr_priv(expr);
+
+ if (nft_dump_register(skb, NFTA_HASH_SREG, priv->sreg))
+ goto nla_put_failure;
+ if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg))
+ goto nla_put_failure;
+ if (nft_dump_register(skb, NFTA_HASH_LEN, priv->len))
+ goto nla_put_failure;
+ if (nft_dump_register(skb, NFTA_HASH_MODULUS, priv->modulus))
+ goto nla_put_failure;
+ if (nft_dump_register(skb, NFTA_HASH_SEED, priv->seed))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -1;
+}
+
+static struct nft_expr_type nft_hash_type;
+static const struct nft_expr_ops nft_hash_ops = {
+ .type = &nft_hash_type,
+ .size = NFT_EXPR_SIZE(sizeof(struct nft_hash)),
+ .eval = nft_hash_eval,
+ .init = nft_hash_init,
+ .dump = nft_hash_dump,
+};
+
+static struct nft_expr_type nft_hash_type __read_mostly = {
+ .name = "hash",
+ .ops = &nft_hash_ops,
+ .policy = nft_hash_policy,
+ .maxattr = NFTA_HASH_MAX,
+ .owner = THIS_MODULE,
+};
+
+static int __init nft_hash_module_init(void)
+{
+ return nft_register_expr(&nft_hash_type);
+}
+
+static void __exit nft_hash_module_exit(void)
+{
+ nft_unregister_expr(&nft_hash_type);
+}
+
+module_init(nft_hash_module_init);
+module_exit(nft_hash_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Laura Garcia <nevola@gmail•com>");
+MODULE_ALIAS_NFT_EXPR("hash");
--
2.1.4
next prev parent reply other threads:[~2016-09-05 10:59 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-05 10:58 [PATCH 00/29] Netfilter updates for net-next Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 01/29] netfilter: conntrack: Only need first 4 bytes to get l4proto ports Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 02/29] netfilter: physdev: add missed blank Pablo Neira Ayuso
2016-09-05 17:43 ` Joe Perches
2016-09-05 10:58 ` [PATCH 03/29] netfilter: nf_dup4: remove redundant checksum recalculation Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 04/29] netfilter: use_nf_conn_expires helper in more places Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 05/29] ipvs: use nf_ct_kill helper Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 06/29] netfilter: nf_tables: rename set implementations Pablo Neira Ayuso
2016-09-05 10:58 ` Pablo Neira Ayuso [this message]
2016-09-05 10:58 ` [PATCH 08/29] netfilter: remove ip_conntrack* sysctl compat code Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 09/29] netfilter: conntrack: simplify the code by using nf_conntrack_get_ht Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 10/29] netfilter: nf_conntrack: restore nf_conntrack_htable_size as exported symbol Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 11/29] netfilter: nf_tables: add quota expression Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 12/29] netfilter: nf_tables: add number generator expression Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 13/29] netfilter: fix spelling mistake: "delimitter" -> "delimiter" Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 14/29] netfilter: nft_hash: fix non static symbol warning Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 15/29] netfilter: nf_tables: typo in trace attribute definition Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 16/29] netfilter: nf_tables: introduce nft_chain_parse_hook() Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 17/29] netfilter: nf_tables: reject hook configuration updates on existing chains Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 18/29] rhashtable: add rhashtable_lookup_get_insert_key() Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 19/29] netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 20/29] netfilter: nf_tables: Use nla_put_be32() to dump immediate parameters Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 21/29] netfilter: restart search if moved to other chain Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 22/29] netfilter: don't rely on DYING bit to detect when destroy event was sent Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 23/29] netfilter: conntrack: get rid of conntrack timer Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 24/29] netfilter: evict stale entries on netlink dumps Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 25/29] netfilter: conntrack: add gc worker to remove timed-out entries Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 26/29] netfilter: conntrack: resched gc again if eviction rate is high Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 27/29] netfilter: remove __nf_ct_kill_acct helper Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 28/29] netfilter: log_arp: Use ARPHRD_ETHER instead of literal '1' Pablo Neira Ayuso
2016-09-05 10:58 ` [PATCH 29/29] netfilter: log: Check param to avoid overflow in nf_log_set Pablo Neira Ayuso
2016-09-06 19:47 ` [PATCH 00/29] Netfilter updates for net-next David Miller
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