From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54AAA214E5 for ; Wed, 12 Jul 2023 15:45:11 +0000 (UTC) Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E29B810C4 for ; Wed, 12 Jul 2023 08:45:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1689176710; x=1720712710; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=LVkqknivcPirB5ohT5MQZsWKw6GBJux2RVxcITSCNjQ=; b=BCDgyHJMCM1qRnJiY+jy9s6Zxy4CfFjBRDQqUyIPTedzdpfRefNzqF44 maUs1nhQ7RZ2GzKv0vMem5SRBwVYdKhsF7tGUMTlO2TrypVXrlksUtniK AN8M0gzD92DGL0In/n7GdnwW+WmOuWaRfyVcv8dEueo5S2d/Ge0M2zGdB I=; X-IronPort-AV: E=Sophos;i="6.01,200,1684800000"; d="scan'208";a="346406182" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-iad-1d-m6i4x-25ac6bd5.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2023 15:45:07 +0000 Received: from EX19MTAUWB002.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1d-m6i4x-25ac6bd5.us-east-1.amazon.com (Postfix) with ESMTPS id 7A1F84660E; Wed, 12 Jul 2023 15:45:04 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWB002.ant.amazon.com (10.250.64.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.30; Wed, 12 Jul 2023 15:45:03 +0000 Received: from 88665a182662.ant.amazon.com.com (10.119.181.74) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.30; Wed, 12 Jul 2023 15:45:00 +0000 From: Kuniyuki Iwashima To: Roopa Prabhu , Nikolay Aleksandrov , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: "Eric W. Biederman" , Kuniyuki Iwashima , Kuniyuki Iwashima , , , Harry Coin , Ido Schimmel Subject: [PATCH v2 net] bridge: Add extack warning when enabling STP in netns. Date: Wed, 12 Jul 2023 08:44:49 -0700 Message-ID: <20230712154449.6093-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.119.181.74] X-ClientProxiedBy: EX19D044UWB003.ant.amazon.com (10.13.139.168) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: Bulk X-Spam-Status: No, score=-4.0 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE, T_SCC_BODY_TEXT_LINE,T_SPF_PERMERROR autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net When we create an L2 loop on a bridge in netns, we will see packets storm even if STP is enabled. # unshare -n # ip link add br0 type bridge # ip link add veth0 type veth peer name veth1 # ip link set veth0 master br0 up # ip link set veth1 master br0 up # ip link set br0 type bridge stp_state 1 # ip link set br0 up # sleep 30 # ip -s link show br0 2: br0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped missed mcast 956553768 12861249 0 0 0 12861249 <-. Keep TX: bytes packets errors dropped carrier collsns | increasing 1027834 11951 0 0 0 0 <-' rapidly This is because llc_rcv() drops all packets in non-root netns and BPDU is dropped. Let's add extack warning when enabling STP in netns. # unshare -n # ip link add br0 type bridge # ip link set br0 type bridge stp_state 1 Warning: bridge: STP does not work in non-root netns. Note this commit will be reverted later when we namespacify the whole LLC infra. Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace safe") Suggested-by: Harry Coin Link: https://lore.kernel.org/netdev/0f531295-e289-022d-5add-5ceffa0df9bc@quietfountain.com/ Suggested-by: Ido Schimmel Signed-off-by: Kuniyuki Iwashima --- v2: - Just add extack instead of returning error (Ido Schimmel) v1: https://lore.kernel.org/netdev/20230711235415.92166-1-kuniyu@amazon.com/ --- net/bridge/br_stp_if.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index 75204d36d7f9..b65962682771 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -201,6 +201,9 @@ int br_stp_set_enabled(struct net_bridge *br, unsigned long val, { ASSERT_RTNL(); + if (!net_eq(dev_net(br->dev), &init_net)) + NL_SET_ERR_MSG_MOD(extack, "STP does not work in non-root netns"); + if (br_mrp_enabled(br)) { NL_SET_ERR_MSG_MOD(extack, "STP can't be enabled if MRP is already enabled"); -- 2.30.2