From patchwork Sat Jun 8 19:54:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Lemon X-Patchwork-Id: 1112537 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45Lqq83FWzz9sNT for ; Sun, 9 Jun 2019 05:54:28 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727723AbfFHTy1 (ORCPT ); Sat, 8 Jun 2019 15:54:27 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:40718 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727684AbfFHTyX (ORCPT ); Sat, 8 Jun 2019 15:54:23 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x58JoANG027523 for ; Sat, 8 Jun 2019 12:54:22 -0700 Received: from mail.thefacebook.com (mailout.thefacebook.com [199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2t08b318v6-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Sat, 08 Jun 2019 12:54:22 -0700 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::127) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Sat, 8 Jun 2019 12:54:20 -0700 Received: by devvm34215.prn1.facebook.com (Postfix, from userid 172786) id 9658B23490D34; Sat, 8 Jun 2019 12:54:19 -0700 (PDT) Smtp-Origin-Hostprefix: devvm From: Jonathan Lemon Smtp-Origin-Hostname: devvm34215.prn1.facebook.com To: , , CC: , Smtp-Origin-Cluster: prn1c35 Subject: [PATCH v2 bpf] bpf: lpm_trie: check left child of last leftmost node for NULL Date: Sat, 8 Jun 2019 12:54:19 -0700 Message-ID: <20190608195419.1137313-1-jonathan.lemon@gmail.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-08_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1034 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=677 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906080152 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If the leftmost parent node of the tree has does not have a child on the left side, then trie_get_next_key (and bpftool map dump) will not look at the child on the right. This leads to the traversal missing elements. Lookup is not affected. Update selftest to handle this case. Reproducer: bpftool map create /sys/fs/bpf/lpm type lpm_trie key 6 \ value 1 entries 256 name test_lpm flags 1 bpftool map update pinned /sys/fs/bpf/lpm key 8 0 0 0 0 0 value 1 bpftool map update pinned /sys/fs/bpf/lpm key 16 0 0 0 0 128 value 2 bpftool map dump pinned /sys/fs/bpf/lpm Returns only 1 element. (2 expected) Fixes: b471f2f1de8 ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE") Signed-off-by: Jonathan Lemon Acked-by: Martin KaFai Lau --- kernel/bpf/lpm_trie.c | 9 +++-- tools/testing/selftests/bpf/test_lpm_map.c | 41 ++++++++++++++++++++-- 2 files changed, 45 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index 09334f13a8a0..ec047a3658b4 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -710,9 +710,14 @@ static int trie_get_next_key(struct bpf_map *map, void *_key, void *_next_key) * have exact two children, so this function will never return NULL. */ for (node = search_root; node;) { - if (!(node->flags & LPM_TREE_NODE_FLAG_IM)) + if (node->flags & LPM_TREE_NODE_FLAG_IM) { + node = rcu_dereference(node->child[0]); + } else { next_node = node; - node = rcu_dereference(node->child[0]); + node = rcu_dereference(node->child[0]); + if (!node) + node = rcu_dereference(next_node->child[1]); + } } do_copy: next_key->prefixlen = next_node->prefixlen; diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c index 02d7c871862a..006be3963977 100644 --- a/tools/testing/selftests/bpf/test_lpm_map.c +++ b/tools/testing/selftests/bpf/test_lpm_map.c @@ -573,13 +573,13 @@ static void test_lpm_get_next_key(void) /* add one more element (total two) */ key_p->prefixlen = 24; - inet_pton(AF_INET, "192.168.0.0", key_p->data); + inet_pton(AF_INET, "192.168.128.0", key_p->data); assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0); memset(key_p, 0, key_size); assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0); assert(key_p->prefixlen == 24 && key_p->data[0] == 192 && - key_p->data[1] == 168 && key_p->data[2] == 0); + key_p->data[1] == 168 && key_p->data[2] == 128); memset(next_key_p, 0, key_size); assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0); @@ -592,7 +592,7 @@ static void test_lpm_get_next_key(void) /* Add one more element (total three) */ key_p->prefixlen = 24; - inet_pton(AF_INET, "192.168.128.0", key_p->data); + inet_pton(AF_INET, "192.168.0.0", key_p->data); assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0); memset(key_p, 0, key_size); @@ -643,6 +643,41 @@ static void test_lpm_get_next_key(void) assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -1 && errno == ENOENT); + /* Add one more element (total five) */ + key_p->prefixlen = 28; + inet_pton(AF_INET, "192.168.1.128", key_p->data); + assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0); + + memset(key_p, 0, key_size); + assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0); + assert(key_p->prefixlen == 24 && key_p->data[0] == 192 && + key_p->data[1] == 168 && key_p->data[2] == 0); + + memset(next_key_p, 0, key_size); + assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0); + assert(next_key_p->prefixlen == 28 && next_key_p->data[0] == 192 && + next_key_p->data[1] == 168 && next_key_p->data[2] == 1 && + next_key_p->data[3] == 128); + + memcpy(key_p, next_key_p, key_size); + assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0); + assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 && + next_key_p->data[1] == 168 && next_key_p->data[2] == 1); + + memcpy(key_p, next_key_p, key_size); + assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0); + assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 && + next_key_p->data[1] == 168 && next_key_p->data[2] == 128); + + memcpy(key_p, next_key_p, key_size); + assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0); + assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 && + next_key_p->data[1] == 168); + + memcpy(key_p, next_key_p, key_size); + assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -1 && + errno == ENOENT); + /* no exact matching key should return the first one in post order */ key_p->prefixlen = 22; inet_pton(AF_INET, "192.168.1.0", key_p->data);