From patchwork Thu Dec 15 14:46:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eelco Chaudron X-Patchwork-Id: 13074270 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11305C2D0CC for ; Thu, 15 Dec 2022 14:47:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229524AbiLOOre (ORCPT ); Thu, 15 Dec 2022 09:47:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbiLOOrd (ORCPT ); Thu, 15 Dec 2022 09:47:33 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0284F2F679 for ; Thu, 15 Dec 2022 06:46:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671115606; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=T80T2RTbkC5KRh7Jw76cY3uGGh+y1qPRcu4aLturcGU=; b=Im5xHjOrDqgBuC67uwQUxd+aLGiNsw7iV5WAtNXhJeIwxKpfVKxoe/IRvd7Ia6Ji7vnSSf UC7lDrQrDk8XIiOvst+ll3VNCt6Qtw2U8Yvpak2wVB6hHvx/eZ/145JO1M3nrPYdhRO0tk kyUAi0tDo9Be6NXVczp3dvUi1Ph7C00= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-407-Wl_bl4jrOveTmaKBQbqVDg-1; Thu, 15 Dec 2022 09:46:42 -0500 X-MC-Unique: Wl_bl4jrOveTmaKBQbqVDg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 302EF1C09B67; Thu, 15 Dec 2022 14:46:42 +0000 (UTC) Received: from ebuild.redhat.com (unknown [10.39.195.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9A67D40C2064; Thu, 15 Dec 2022 14:46:40 +0000 (UTC) From: Eelco Chaudron To: netdev@vger.kernel.org Cc: pshelar@ovn.org, davem@davemloft.net, dev@openvswitch.org, i.maximets@ovn.org, aconole@redhat.com, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, stable@vger.kernel.org Subject: [PATCH net v3] openvswitch: Fix flow lookup to use unmasked key Date: Thu, 15 Dec 2022 15:46:33 +0100 Message-Id: <167111551443.359845.7122827280135116424.stgit@ebuild> User-Agent: StGit/1.1 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The commit mentioned below causes the ovs_flow_tbl_lookup() function to be called with the masked key. However, it's supposed to be called with the unmasked key. This due to the fact that the datapath supports installing wider flows, and OVS relies on this behavior. For example if ipv4(src=1.1.1.1/192.0.0.0, dst=1.1.1.2/192.0.0.0) exists, a wider flow (smaller mask) of ipv4(src=192.1.1.1/128.0.0.0,dst=192.1.1.2/ 128.0.0.0) is allowed to be added. However, if we try to add a wildcard rule, the installation fails: $ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \ ipv4(src=1.1.1.1/192.0.0.0,dst=1.1.1.2/192.0.0.0,frag=no)" 2 $ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \ ipv4(src=192.1.1.1/0.0.0.0,dst=49.1.1.2/0.0.0.0,frag=no)" 2 ovs-vswitchd: updating flow table (File exists) The reason is that the key used to determine if the flow is already present in the system uses the original key ANDed with the mask. This results in the IP address not being part of the (miniflow) key, i.e., being substituted with an all-zero value. When doing the actual lookup, this results in the key wrongfully matching the first flow, and therefore the flow does not get installed. This change reverses the commit below, but rather than having the key on the stack, it's allocated. Fixes: 190aa3e77880 ("openvswitch: Fix Frame-size larger than 1024 bytes warning.") Signed-off-by: Eelco Chaudron --- Version history: v3: Updated commit message to explain the problem in more details. v2: Fixed ENOMEN error :( Forgot to do a stg refresh. net/openvswitch/datapath.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 861dfb8daf4a..55b697c4d576 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -948,6 +948,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) struct sw_flow_mask mask; struct sk_buff *reply; struct datapath *dp; + struct sw_flow_key *key; struct sw_flow_actions *acts; struct sw_flow_match match; u32 ufid_flags = ovs_nla_get_ufid_flags(a[OVS_FLOW_ATTR_UFID_FLAGS]); @@ -975,24 +976,26 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) } /* Extract key. */ - ovs_match_init(&match, &new_flow->key, false, &mask); + key = kzalloc(sizeof(*key), GFP_KERNEL); + if (!key) { + error = -ENOMEM; + goto err_kfree_key; + } + + ovs_match_init(&match, key, false, &mask); error = ovs_nla_get_match(net, &match, a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK], log); if (error) goto err_kfree_flow; + ovs_flow_mask_key(&new_flow->key, key, true, &mask); + /* Extract flow identifier. */ error = ovs_nla_get_identifier(&new_flow->id, a[OVS_FLOW_ATTR_UFID], - &new_flow->key, log); + key, log); if (error) goto err_kfree_flow; - /* unmasked key is needed to match when ufid is not used. */ - if (ovs_identifier_is_key(&new_flow->id)) - match.key = new_flow->id.unmasked_key; - - ovs_flow_mask_key(&new_flow->key, &new_flow->key, true, &mask); - /* Validate actions. */ error = ovs_nla_copy_actions(net, a[OVS_FLOW_ATTR_ACTIONS], &new_flow->key, &acts, log); @@ -1019,7 +1022,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) if (ovs_identifier_is_ufid(&new_flow->id)) flow = ovs_flow_tbl_lookup_ufid(&dp->table, &new_flow->id); if (!flow) - flow = ovs_flow_tbl_lookup(&dp->table, &new_flow->key); + flow = ovs_flow_tbl_lookup(&dp->table, key); if (likely(!flow)) { rcu_assign_pointer(new_flow->sf_acts, acts); @@ -1089,6 +1092,8 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) if (reply) ovs_notify(&dp_flow_genl_family, reply, info); + + kfree(key); return 0; err_unlock_ovs: @@ -1098,6 +1103,8 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info) ovs_nla_free_flow_actions(acts); err_kfree_flow: ovs_flow_free(new_flow, false); +err_kfree_key: + kfree(key); error: return error; }