From patchwork Thu Mar 5 20:33:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Brivio X-Patchwork-Id: 1249878 X-Patchwork-Delegate: pablo@netfilter.org Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netfilter-devel-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=Ci/MsYNj; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48YMs93jG7z9sPK for ; Fri, 6 Mar 2020 07:33:33 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726282AbgCEUdd (ORCPT ); Thu, 5 Mar 2020 15:33:33 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:43070 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726049AbgCEUdd (ORCPT ); Thu, 5 Mar 2020 15:33:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583440412; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=FNftTzZxI1b3cESst7sMGN9YhZe1vN+5jFr1kxCiOHw=; b=Ci/MsYNjwXfXAHMNktPhjyih8f2A8IFCHdPe0a/rdJuFMw0EnuI9xpdPNi3s0lah9dwvAP XhYZ6yqglUN/2USVC686EydftR2cbfqEQxmJUoUQDwKt5tGBQeUiEIJAssRb1Y/BdMVOu5 fA9R0u1J28PthHpyhrmiUfEXV7AJSyo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-328-bRoXTGYfOBGVq20avs5IcQ-1; Thu, 05 Mar 2020 15:33:28 -0500 X-MC-Unique: bRoXTGYfOBGVq20avs5IcQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 48A8B107ACC7; Thu, 5 Mar 2020 20:33:27 +0000 (UTC) Received: from epycfail.redhat.com (ovpn-200-16.brq.redhat.com [10.40.200.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1127810016EB; Thu, 5 Mar 2020 20:33:25 +0000 (UTC) From: Stefano Brivio To: Pablo Neira Ayuso Cc: Phil Sutter , netfilter-devel@vger.kernel.org Subject: [PATCH nf 4/4] nft_set_rbtree: Detect partial overlaps on insertion Date: Thu, 5 Mar 2020 21:33:05 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org ...and return -ENOTEMPTY to the front-end in this case, instead of proceeding. Currently, nft takes care of checking for these cases and not sending them to the kernel, but if we drop the set_overlap() call in nft we can end up in situations like: # nft add table t # nft add set t s '{ type inet_service ; flags interval ; }' # nft add element t s '{ 1 - 5 }' # nft add element t s '{ 6 - 10 }' # nft add element t s '{ 4 - 7 }' # nft list set t s table ip t { set s { type inet_service flags interval elements = { 1-3, 4-5, 6-7 } } } This change has the primary purpose of making the behaviour consistent with nft_set_pipapo, but is also functional to avoid inconsistent behaviour if userspace sends overlapping elements for any reason. Signed-off-by: Stefano Brivio --- net/netfilter/nft_set_rbtree.c | 68 ++++++++++++++++++++++++++++++++-- 1 file changed, 65 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 85572b2a6051..c97c493cd867 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -213,8 +213,43 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set, u8 genmask = nft_genmask_next(net); struct nft_rbtree_elem *rbe; struct rb_node *parent, **p; + bool overlap = false; int d; + /* Detect overlaps as we descend the tree. Set the flag in these cases: + * + * a1. |__ _ _? >|__ _ _ (insert start after existing start) + * a2. _ _ __>| ?_ _ __| (insert end before existing end) + * a3. _ _ ___| ?_ _ _>| (insert end after existing end) + * a4. >|__ _ _ _ _ __| (insert start before existing end) + * + * and clear it later on, as we eventually reach the points indicated by + * '?' above, in the cases described below. We'll always meet these + * later, locally, due to tree ordering, and overlaps for the intervals + * that are the closest together are always evaluated last. + * + * b1. |__ _ _! >|__ _ _ (insert start after existing end) + * b2. _ _ __>| !_ _ __| (insert end before existing start) + * b3. !_____>| (insert end after existing start) + * + * Case a4. resolves to b1.: + * - if the inserted start element is the leftmost, because the '0' + * element in the tree serves as end element + * - otherwise, if an existing end is found. Note that end elements are + * always inserted after corresponding start elements. + * + * For a new, rightmost pair of elements, we'll hit cases b1. and b3., + * in that order. + * + * The flag is also cleared in two special cases: + * + * b4. |__ _ _!|<_ _ _ (insert start right before existing end) + * b5. |__ _ >|!__ _ _ (insert end right after existing start) + * + * which always happen as last step and imply that no further + * overlapping is possible. + */ + parent = NULL; p = &priv->root.rb_node; while (*p != NULL) { @@ -223,17 +258,40 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set, d = memcmp(nft_set_ext_key(&rbe->ext), nft_set_ext_key(&new->ext), set->klen); - if (d < 0) + if (d < 0) { p = &parent->rb_left; - else if (d > 0) + + if (nft_rbtree_interval_start(new)) { + overlap = nft_rbtree_interval_start(rbe) && + nft_set_elem_active(&rbe->ext, + genmask); + } else { + overlap = nft_rbtree_interval_end(rbe) && + nft_set_elem_active(&rbe->ext, + genmask); + } + } else if (d > 0) { p = &parent->rb_right; - else { + + if (nft_rbtree_interval_end(new)) { + overlap = nft_rbtree_interval_end(rbe) && + nft_set_elem_active(&rbe->ext, + genmask); + } else if (nft_rbtree_interval_end(rbe) && + nft_set_elem_active(&rbe->ext, genmask)) { + overlap = true; + } + } else { if (nft_rbtree_interval_end(rbe) && nft_rbtree_interval_start(new)) { p = &parent->rb_left; + + overlap = false; } else if (nft_rbtree_interval_start(rbe) && nft_rbtree_interval_end(new)) { p = &parent->rb_right; + + overlap = false; } else if (nft_set_elem_active(&rbe->ext, genmask)) { *ext = &rbe->ext; return -EEXIST; @@ -242,6 +300,10 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set, } } } + + if (overlap) + return -ENOTEMPTY; + rb_link_node_rcu(&new->node, parent, p); rb_insert_color(&new->node, &priv->root); return 0;