From patchwork Thu Jun 23 10:24:08 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arturo Borrero X-Patchwork-Id: 639570 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 3rZyHf2SNlz9t0J for ; Thu, 23 Jun 2016 20:24:14 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751549AbcFWKYN (ORCPT ); Thu, 23 Jun 2016 06:24:13 -0400 Received: from smtp3.cica.es ([150.214.5.190]:54753 "EHLO smtp.cica.es" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751480AbcFWKYN (ORCPT ); Thu, 23 Jun 2016 06:24:13 -0400 Received: from localhost (unknown [127.0.0.1]) by smtp.cica.es (Postfix) with ESMTP id 4F5E051F24B for ; Thu, 23 Jun 2016 10:24:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at cica.es Received: from smtp.cica.es ([127.0.0.1]) by localhost (mail.cica.es [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id B6HbokSBD7ql for ; Thu, 23 Jun 2016 12:24:05 +0200 (CEST) Received: from nfdev2.cica.es (nfdev2.cica.es [IPv6:2a00:9ac0:c1ca:31::221]) (Authenticated sender: servers@cica.es) by smtp.cica.es (Postfix) with ESMTP id 23AF751F242 for ; Thu, 23 Jun 2016 12:24:04 +0200 (CEST) Subject: [nf-next PATCH v5] netfilter: nf_tables: add support for inverted logic in nft_lookup From: Arturo Borrero Gonzalez To: netfilter-devel@vger.kernel.org Date: Thu, 23 Jun 2016 12:24:08 +0200 Message-ID: <146667735220.10551.13573034041353542334.stgit@nfdev2.cica.es> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Introduce a new configuration option for this expression, which allows users to invert the logic of set lookups. In _init() we will now return EINVAL if NFT_LOOKUP_F_INV is in anyway related to a map lookup. The code in the _eval() function has been untangled and updated to sopport the XOR of options, as we should consider 4 cases: * lookup false, invert false -> NFT_BREAK * lookup false, invert true -> return w/o NFT_BREAK * lookup true, invert false -> return w/o NFT_BREAK * lookup true, invert true -> NFT_BREAK Signed-off-by: Arturo Borrero Gonzalez --- v2: better aling memory of struct nft_lookup, put 'bool invert' before bindings v3: include flags coherence validation v4: stronger validation in _init(), stronger validation in _eval(), also untangle code, and update patch description v5: simplify _eval() with guidelines by Pablo, update patch description include/uapi/linux/netfilter/nf_tables.h | 6 +++++ net/netfilter/nft_lookup.c | 37 ++++++++++++++++++++++++++---- 2 files changed, 38 insertions(+), 5 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 6a4dbe0..01751fa 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -546,6 +546,10 @@ enum nft_cmp_attributes { }; #define NFTA_CMP_MAX (__NFTA_CMP_MAX - 1) +enum nft_lookup_flags { + NFT_LOOKUP_F_INV = (1 << 0), +}; + /** * enum nft_lookup_attributes - nf_tables set lookup expression netlink attributes * @@ -553,6 +557,7 @@ enum nft_cmp_attributes { * @NFTA_LOOKUP_SREG: source register of the data to look for (NLA_U32: nft_registers) * @NFTA_LOOKUP_DREG: destination register (NLA_U32: nft_registers) * @NFTA_LOOKUP_SET_ID: uniquely identifies a set in a transaction (NLA_U32) + * @NFTA_LOOKUP_FLAGS: flags (NLA_U32: enum nft_lookup_flags) */ enum nft_lookup_attributes { NFTA_LOOKUP_UNSPEC, @@ -560,6 +565,7 @@ enum nft_lookup_attributes { NFTA_LOOKUP_SREG, NFTA_LOOKUP_DREG, NFTA_LOOKUP_SET_ID, + NFTA_LOOKUP_FLAGS, __NFTA_LOOKUP_MAX }; #define NFTA_LOOKUP_MAX (__NFTA_LOOKUP_MAX - 1) diff --git a/net/netfilter/nft_lookup.c b/net/netfilter/nft_lookup.c index b3c31ef..423da12 100644 --- a/net/netfilter/nft_lookup.c +++ b/net/netfilter/nft_lookup.c @@ -22,6 +22,7 @@ struct nft_lookup { struct nft_set *set; enum nft_registers sreg:8; enum nft_registers dreg:8; + bool invert; struct nft_set_binding binding; }; @@ -32,14 +33,20 @@ static void nft_lookup_eval(const struct nft_expr *expr, const struct nft_lookup *priv = nft_expr_priv(expr); const struct nft_set *set = priv->set; const struct nft_set_ext *ext; + bool found; - if (set->ops->lookup(set, ®s->data[priv->sreg], &ext)) { - if (set->flags & NFT_SET_MAP) - nft_data_copy(®s->data[priv->dreg], - nft_set_ext_data(ext), set->dlen); + found = set->ops->lookup(set, ®s->data[priv->sreg], &ext) ^ + priv->invert; + + if (!found) { + regs->verdict.code = NFT_BREAK; return; } - regs->verdict.code = NFT_BREAK; + + if (found && set->flags & NFT_SET_MAP) + nft_data_copy(®s->data[priv->dreg], + nft_set_ext_data(ext), set->dlen); + } static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = { @@ -47,6 +54,7 @@ static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = { [NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 }, [NFTA_LOOKUP_SREG] = { .type = NLA_U32 }, [NFTA_LOOKUP_DREG] = { .type = NLA_U32 }, + [NFTA_LOOKUP_FLAGS] = { .type = NLA_U32 }, }; static int nft_lookup_init(const struct nft_ctx *ctx, @@ -55,6 +63,7 @@ static int nft_lookup_init(const struct nft_ctx *ctx, { struct nft_lookup *priv = nft_expr_priv(expr); struct nft_set *set; + u32 flags; int err; if (tb[NFTA_LOOKUP_SET] == NULL || @@ -79,7 +88,22 @@ static int nft_lookup_init(const struct nft_ctx *ctx, if (err < 0) return err; + if (tb[NFTA_LOOKUP_FLAGS]) { + flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS])); + + if (flags & ~NFT_LOOKUP_F_INV) + return -EINVAL; + + if (flags & NFT_LOOKUP_F_INV) { + if (set->flags & NFT_SET_MAP) + return -EINVAL; + priv->invert = true; + } + } + if (tb[NFTA_LOOKUP_DREG] != NULL) { + if (priv->invert) + return -EINVAL; if (!(set->flags & NFT_SET_MAP)) return -EINVAL; @@ -112,6 +136,7 @@ static void nft_lookup_destroy(const struct nft_ctx *ctx, static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_lookup *priv = nft_expr_priv(expr); + u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0; if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name)) goto nla_put_failure; @@ -120,6 +145,8 @@ static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr) if (priv->set->flags & NFT_SET_MAP) if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg)) goto nla_put_failure; + if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags))) + goto nla_put_failure; return 0; nla_put_failure: