From patchwork Thu Feb 23 11:10:45 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: nevola X-Patchwork-Id: 731504 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vTWv93sPKz9s7p for ; Thu, 23 Feb 2017 22:18:29 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="bzcqYfC1"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751049AbdBWLS2 (ORCPT ); Thu, 23 Feb 2017 06:18:28 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35773 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbdBWLS2 (ORCPT ); Thu, 23 Feb 2017 06:18:28 -0500 Received: by mail-wm0-f65.google.com with SMTP id u63so2161891wmu.2 for ; Thu, 23 Feb 2017 03:18:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:subject:message-id:mime-version:content-disposition :user-agent; bh=KQmJ3b7S6alt/2yYdEyz+AJyXAQHbQq0kVaiXjs8F4c=; b=bzcqYfC1biljfCQ4GOyxquc15mJWubb7b3JDiR6zWDNbdYCLIui44UkM1JiNlv6Gkb CUYLQ36OxPHaitEMICx/RAnjCOcqRVl4w+VgEwS9obpM4F+Fi0Y52K4ZVsgdpXmKMhQi jfBA8CJIl2gWd1mgnn6gRoo4tOYEYHfKCZgcs2kJ1SbGOKXEwsfCgRCFqTRuyrIJlGV5 ZjuZU53Dkqg7oAVpt3F6KuTOLoWyZdw6pamqJeyMlAkpqJ6xxJrHycilHkKsEgwLWB6Q bACYB+K++2XT8zYgWc0Lhx4fVUQwBv8x+2jS29BK9ErmcKlHVIgBzOwJm8Uud/z1zSVs ADUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:subject:message-id:mime-version :content-disposition:user-agent; bh=KQmJ3b7S6alt/2yYdEyz+AJyXAQHbQq0kVaiXjs8F4c=; b=kgOhPjTqcgQDw8PKf11pFAfzOqkupQFO2dqqOtKJUIzUO13VQMhRmr6q7Cjna0hqVA bREQsvX9XyoV8U7jEHT0yB7gS0tGaTi/Fr48WDHLIUZCyQSe7D9mly3wfAu2hdXTYHWP HWNGis8ziAJyCN+da+Pdek4KFFAgSUoWLgqq0MQaGen2ZiZTfErxRSs6E0MVnzDS3sbn 7ucHE1CVJ+l9TgCZVp2fqG4E3gpNVjfkHv1CJgDrq6kMP3uqiXOE1fxs3pQLKdGrI3Vx RqKnCL5a3ID8uIBmZ8AcGHL4PK0tTFOqyybHQ6x4QBHcxNaHPvE33B/PF2TkT13aLWxB vkzA== X-Gm-Message-State: AMke39n9JinTqtUdO4U6akSNkUI0GIIRPOBh65tf0tHyLQo4gJJTKZUaz6u3pggIXGLinw== X-Received: by 10.28.129.5 with SMTP id c5mr2192197wmd.19.1487848247919; Thu, 23 Feb 2017 03:10:47 -0800 (PST) Received: from nevthink ([91.126.73.162]) by smtp.gmail.com with ESMTPSA id i203sm5885243wmf.12.2017.02.23.03.10.47 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 23 Feb 2017 03:10:47 -0800 (PST) From: Laura Garcia Liebana X-Google-Original-From: Laura Garcia Liebana Date: Thu, 23 Feb 2017 12:10:45 +0100 To: netfilter-devel@vger.kernel.org Subject: [PATCH nf-next 2/2] netfilter: nft_hash: support of symmetric hash Message-ID: <20170223111045.hry4tifqq7f4rfzx@nevthink> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org This patch provides symmetric hash support according to source ip address and port, and destination ip address and port. For this purpose, the __skb_get_hash_symmetric() is used to identify the flow as it uses FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL flag by default. The new attribute NFTA_HASH_TYPE has been included to support different types of hashing functions. Currently supported NFT_HASH_JENKINS through jhash and NFT_HASH_SYM through symhash. The main difference between both types are: - jhash requires an expression with sreg, symhash doesn't. - symhash supports modulus and offset, but not seed. Examples: nft add rule ip nat prerouting ct mark set jhash ip saddr mod 2 nft add rule ip nat prerouting ct mark set symhash mod 2 Signed-off-by: Laura Garcia Liebana --- include/uapi/linux/netfilter/nf_tables.h | 13 +++++ net/netfilter/nft_hash.c | 98 +++++++++++++++++++++++++++++++- 2 files changed, 110 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 7b730cab99bd..a444a63a9eee 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -793,6 +793,17 @@ enum nft_rt_keys { }; /** + * enum nft_hash_types - nf_tables hash expression types + * + * @NFT_HASH_JENKINS: Jenkins Hash + * @NFT_HASH_SYM: Symmetric Hash + */ +enum nft_hash_types { + NFT_HASH_JENKINS, + NFT_HASH_SYM, +}; + +/** * enum nft_hash_attributes - nf_tables hash expression netlink attributes * * @NFTA_HASH_SREG: source register (NLA_U32) @@ -801,6 +812,7 @@ enum nft_rt_keys { * @NFTA_HASH_MODULUS: modulus value (NLA_U32) * @NFTA_HASH_SEED: seed value (NLA_U32) * @NFTA_HASH_OFFSET: add this offset value to hash result (NLA_U32) + * @NFTA_HASH_TYPE: hash operation (NLA_U32: nft_hash_types) */ enum nft_hash_attributes { NFTA_HASH_UNSPEC, @@ -810,6 +822,7 @@ enum nft_hash_attributes { NFTA_HASH_MODULUS, NFTA_HASH_SEED, NFTA_HASH_OFFSET, + NFTA_HASH_TYPE, __NFTA_HASH_MAX, }; #define NFTA_HASH_MAX (__NFTA_HASH_MAX - 1) diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c index ccb834ef049b..da0171908f92 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -38,6 +38,25 @@ static void nft_jhash_eval(const struct nft_expr *expr, regs->data[priv->dreg] = h + priv->offset; } +struct nft_symhash { + enum nft_registers dreg:8; + u32 modulus; + u32 offset; +}; + +static void nft_symhash_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_symhash *priv = nft_expr_priv(expr); + const struct sk_buff *skb = pkt->skb; + u32 h; + + h = reciprocal_scale(__skb_get_hash_symmetric(skb), priv->modulus); + + regs->data[priv->dreg] = h + priv->offset; +} + static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { [NFTA_HASH_SREG] = { .type = NLA_U32 }, [NFTA_HASH_DREG] = { .type = NLA_U32 }, @@ -45,6 +64,7 @@ static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, [NFTA_HASH_SEED] = { .type = NLA_U32 }, [NFTA_HASH_OFFSET] = { .type = NLA_U32 }, + [NFTA_HASH_TYPE] = { .type = NLA_U32 }, }; static int nft_jhash_init(const struct nft_ctx *ctx, @@ -92,6 +112,32 @@ static int nft_jhash_init(const struct nft_ctx *ctx, NFT_DATA_VALUE, sizeof(u32)); } +static int nft_symhash_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_symhash *priv = nft_expr_priv(expr); + + if (!tb[NFTA_HASH_DREG] || + !tb[NFTA_HASH_MODULUS]) + return -EINVAL; + + if (tb[NFTA_HASH_OFFSET]) + priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET])); + + priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]); + + priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); + if (priv->modulus <= 1) + return -ERANGE; + + if (priv->offset + priv->modulus - 1 < priv->offset) + return -EOVERFLOW; + + return nft_validate_register_store(ctx, priv->dreg, NULL, + NFT_DATA_VALUE, sizeof(u32)); +} + static int nft_jhash_dump(struct sk_buff *skb, const struct nft_expr *expr) { @@ -110,6 +156,28 @@ static int nft_jhash_dump(struct sk_buff *skb, if (priv->offset != 0) if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset))) goto nla_put_failure; + if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_JENKINS))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static int nft_symhash_dump(struct sk_buff *skb, + const struct nft_expr *expr) +{ + const struct nft_symhash *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg)) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus))) + goto nla_put_failure; + if (priv->offset != 0) + if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_SYM))) + goto nla_put_failure; return 0; nla_put_failure: @@ -125,9 +193,37 @@ static const struct nft_expr_ops nft_jhash_ops = { .dump = nft_jhash_dump, }; +static const struct nft_expr_ops nft_symhash_ops = { + .type = &nft_hash_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_symhash)), + .eval = nft_symhash_eval, + .init = nft_symhash_init, + .dump = nft_symhash_dump, +}; + +static const struct nft_expr_ops * +nft_hash_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + u32 type; + + if (!tb[NFTA_HASH_TYPE]) + return ERR_PTR(-EINVAL); + + type = ntohl(nla_get_be32(tb[NFTA_HASH_TYPE])); + + switch (type) { + case NFT_HASH_SYM: + return &nft_symhash_ops; + case NFT_HASH_JENKINS: + default: + return &nft_jhash_ops; + } +} + static struct nft_expr_type nft_hash_type __read_mostly = { .name = "hash", - .ops = &nft_jhash_ops, + .select_ops = &nft_hash_select_ops, .policy = nft_hash_policy, .maxattr = NFTA_HASH_MAX, .owner = THIS_MODULE,