From patchwork Wed Sep 22 19:02:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 12511315 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B783AC433F5 for ; Wed, 22 Sep 2021 19:28:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4C44660FE8 for ; Wed, 22 Sep 2021 19:28:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4C44660FE8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:38422 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mT7up-0007Aj-2X for qemu-devel@archiver.kernel.org; Wed, 22 Sep 2021 15:28:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54528) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mT7VX-0005wh-P3 for qemu-devel@nongnu.org; Wed, 22 Sep 2021 15:02:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27658) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mT7VT-0008GR-KO for qemu-devel@nongnu.org; Wed, 22 Sep 2021 15:02:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632337329; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type; bh=9UpxaD7aFIe/K6LlYP5Rf37+eRiivxr+F6I4MeUAdtk=; b=ClNIE1UXPw6qTIK2N3/BdCLTMCLI/WC/MhOvjl3Fh8ItE7WQjxOVjhJCgvw9cUwpRjQF/q V0KrJAiMbkhu1AQgD+8VNJCnT2QJvDbgLwa/caqZufwMhaBSoVdoE+tFzCZG0ucA3WXw9b OMMXcVLNTk4IRRd4Q3b1ei1pA+/EWAY= 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-146-GJq9ZAXTOZSMiJH2S5sqkA-1; Wed, 22 Sep 2021 15:02:02 -0400 X-MC-Unique: GJq9ZAXTOZSMiJH2S5sqkA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1EE91835DE0 for ; Wed, 22 Sep 2021 19:02:02 +0000 (UTC) Received: from horse.redhat.com (unknown [10.22.9.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5C5A5D9CA; Wed, 22 Sep 2021 19:02:01 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 7FAC5222E4F; Wed, 22 Sep 2021 15:02:01 -0400 (EDT) Date: Wed, 22 Sep 2021 15:02:01 -0400 From: Vivek Goyal To: qemu-devel@nongnu.org, virtio-fs@redhat.com, dgilbert@redhat.com Subject: [PATCH] virtiofsd: xattr mapping add a new type "unsupported" Message-ID: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.472, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Right now for xattr remapping, we support types of "prefix", "ok" or "bad". Type "bad" returns -EPERM on setxattr and hides xattr in listxattr. For getxattr, mapping code returns -EPERM but getxattr code converts it to -ENODATA. I need a new semantics where if an xattr is unsupported, then getxattr()/setxattr() return -ENOTSUP and listxattr() should hide the xattr. This is needed to simulate that security.selinux is not supported by virtiofs filesystem and in that case client falls back to some default label specified by policy. So add a new type "unsupported" which returns -ENOTSUP on getxattr() and setxattr() and hides xattrs in listxattr(). For example, one can use following mapping rule to not support security.selinux xattr and allow others. "-o xattrmap=/unsupported/all/security.selinux/security.selinux//ok/all///" Suggested-by: "Dr. David Alan Gilbert" Signed-off-by: Vivek Goyal Reviewed-by: Dr. David Alan Gilbert --- docs/tools/virtiofsd.rst | 6 ++++++ tools/virtiofsd/passthrough_ll.c | 17 ++++++++++++++--- 2 files changed, 20 insertions(+), 3 deletions(-) Index: rhvgoyal-qemu/tools/virtiofsd/passthrough_ll.c =================================================================== --- rhvgoyal-qemu.orig/tools/virtiofsd/passthrough_ll.c 2021-09-22 08:37:16.070377732 -0400 +++ rhvgoyal-qemu/tools/virtiofsd/passthrough_ll.c 2021-09-22 14:17:09.543016250 -0400 @@ -2465,6 +2465,11 @@ static void lo_flock(fuse_req_t req, fus * Automatically reversed on read */ #define XATTR_MAP_FLAG_PREFIX (1 << 2) +/* + * The attribute is unsupported; + * ENOTSUP on write, hidden on read. + */ +#define XATTR_MAP_FLAG_UNSUPPORTED (1 << 3) /* scopes */ /* Apply rule to get/set/remove */ @@ -2636,6 +2641,8 @@ static void parse_xattrmap(struct lo_dat tmp_entry.flags |= XATTR_MAP_FLAG_OK; } else if (strstart(map, "bad", &map)) { tmp_entry.flags |= XATTR_MAP_FLAG_BAD; + } else if (strstart(map, "unsupported", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_UNSUPPORTED; } else if (strstart(map, "map", &map)) { /* * map is sugar that adds a number of rules, and must be @@ -2646,8 +2653,8 @@ static void parse_xattrmap(struct lo_dat } else { fuse_log(FUSE_LOG_ERR, "%s: Unexpected type;" - "Expecting 'prefix', 'ok', 'bad' or 'map' in rule %zu\n", - __func__, lo->xattr_map_nentries); + "Expecting 'prefix', 'ok', 'bad', 'unsupported' or 'map'" + " in rule %zu\n", __func__, lo->xattr_map_nentries); exit(1); } @@ -2749,6 +2756,9 @@ static int xattr_map_client(const struct if (cur_entry->flags & XATTR_MAP_FLAG_BAD) { return -EPERM; } + if (cur_entry->flags & XATTR_MAP_FLAG_UNSUPPORTED) { + return -ENOTSUP; + } if (cur_entry->flags & XATTR_MAP_FLAG_OK) { /* Unmodified name */ return 0; @@ -2788,7 +2798,8 @@ static int xattr_map_server(const struct if ((cur_entry->flags & XATTR_MAP_FLAG_SERVER) && (strstart(server_name, cur_entry->prepend, &end))) { - if (cur_entry->flags & XATTR_MAP_FLAG_BAD) { + if (cur_entry->flags & XATTR_MAP_FLAG_BAD || + cur_entry->flags & XATTR_MAP_FLAG_UNSUPPORTED) { return -ENODATA; } if (cur_entry->flags & XATTR_MAP_FLAG_OK) { Index: rhvgoyal-qemu/docs/tools/virtiofsd.rst =================================================================== --- rhvgoyal-qemu.orig/docs/tools/virtiofsd.rst 2021-09-22 08:37:15.938372097 -0400 +++ rhvgoyal-qemu/docs/tools/virtiofsd.rst 2021-09-22 14:44:09.814188712 -0400 @@ -183,6 +183,12 @@ Using ':' as the separator a rule is of 'ok' as either an explicit terminator or for special handling of certain patterns. +- 'unsupported' - If a client tries to use a name matching 'key' it's + denied using ENOTSUP; when the server passes an attribute + name matching 'prepend' it's hidden. In many ways it's use is very like + 'ok' as either an explicit terminator or for special handling of certain + patterns. + **key** is a string tested as a prefix on an attribute name originating on the client. It maybe empty in which case a 'client' rule will always match on client names.