From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 49104C433E0 for ; Thu, 18 Feb 2021 15:07:39 +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 E412C64E6F for ; Thu, 18 Feb 2021 15:07:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E412C64E6F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35650 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lCku1-0001wS-TG for qemu-devel@archiver.kernel.org; Thu, 18 Feb 2021 10:07:37 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:36888) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lCkrO-0008SN-9l for qemu-devel@nongnu.org; Thu, 18 Feb 2021 10:04:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32924) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lCkrL-0002xG-Hq for qemu-devel@nongnu.org; Thu, 18 Feb 2021 10:04:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613660690; 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: in-reply-to:in-reply-to:references:references; bh=+3Xc6Ry9oRCOEQMxmcKPUDDkxSOgcK8HVTjgb8rEUWI=; b=aOz8NpTFLZcAJ2V4nPeNrEGrcIb1Aj7a2/Swzjy6vJEujaqcpSi3irAKN4RdFcwLYwFYNB ugdLBCN0JMnPlD3K9nBK7sH+FQySZcGowsA0YzNJIe6BilYaBUiBcdTdIDr/Vkj9ebShPd 0BhqnHPx30ZUD2WEFeTSSfvakWKt7RM= 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-165-Ta5t4GKqMAyj5QqWHtMVPQ-1; Thu, 18 Feb 2021 10:04:48 -0500 X-MC-Unique: Ta5t4GKqMAyj5QqWHtMVPQ-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 8A81C100CCCB; Thu, 18 Feb 2021 15:04:46 +0000 (UTC) Received: from horse.redhat.com (ovpn-117-5.rdu2.redhat.com [10.10.117.5]) by smtp.corp.redhat.com (Postfix) with ESMTP id C40985D9C2; Thu, 18 Feb 2021 15:04:36 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 5C54C22054F; Thu, 18 Feb 2021 10:04:36 -0500 (EST) Date: Thu, 18 Feb 2021 10:04:36 -0500 From: Vivek Goyal To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: Re: [PATCH v2 1/3] virtiofsd: Add an option to enable/disable posix acls Message-ID: <20210218150436.GA92815@redhat.com> References: <20210217233046.81418-1-vgoyal@redhat.com> <20210217233046.81418-2-vgoyal@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210217233046.81418-2-vgoyal@redhat.com> 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-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H3=0.001, RCVD_IN_MSPIKE_WL=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: , Cc: lhenriques@suse.de, dgilbert@redhat.com, stefanha@redhat.com, miklos@szeredi.hu Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Feb 17, 2021 at 06:30:44PM -0500, Vivek Goyal wrote: > fuse has an option FUSE_POSIX_ACL which needs to be opted in by fuse > server to enable posix acls. > > Add virtiofsd option "-o posix_acl/no_posix_acl" to let users enable/disable > posix acl support. By default it is disabled as of now. > > Currently even if file server has not opted in for FUSE_POSIX_ACL, user can > still query acl and set acl, and system.posix_acl_access and > system.posix_acl_default xattrs show up listxattr response. > > Miklos said this is confusing. So he said lets block and filter > system.posix_acl_access and system.posix_acl_default xattrs in > getxattr/setxattr/listxattr if user has explicitly disabled > posix acls using -o no_posix_acl. I forgot to block acl xattrs in lo_removexattr(). Will respin this patch. Vivek > > As of now continuing to keeping the existing behavior if user did not > specify any option to disable acl support due to concerns about backward > compatibility. > > v2: block system.posix_acl_access and system.posix_acl_default xattrs > if user explicitly disabled acls. (Miklos) > > Signed-off-by: Vivek Goyal > --- > tools/virtiofsd/passthrough_ll.c | 95 +++++++++++++++++++++++++++++++- > 1 file changed, 94 insertions(+), 1 deletion(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 58d24c0010..26cdfbd1f0 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -169,6 +169,7 @@ struct lo_data { > /* An O_PATH file descriptor to /proc/self/fd/ */ > int proc_self_fd; > int user_killpriv_v2, killpriv_v2; > + int user_posix_acl; > }; > > static const struct fuse_opt lo_opts[] = { > @@ -201,6 +202,8 @@ static const struct fuse_opt lo_opts[] = { > { "announce_submounts", offsetof(struct lo_data, announce_submounts), 1 }, > { "killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 1 }, > { "no_killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 0 }, > + { "posix_acl", offsetof(struct lo_data, user_posix_acl), 1 }, > + { "no_posix_acl", offsetof(struct lo_data, user_posix_acl), 0 }, > FUSE_OPT_END > }; > static bool use_syslog = false; > @@ -661,6 +664,23 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn) > conn->want &= ~FUSE_CAP_HANDLE_KILLPRIV_V2; > lo->killpriv_v2 = 0; > } > + > + if (lo->user_posix_acl == 1) { > + /* > + * User explicitly asked for this option. Enable it unconditionally. > + * If connection does not have this capability, it should fail > + * in fuse_lowlevel.c > + */ > + fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling posix acl\n"); > + conn->want |= FUSE_CAP_POSIX_ACL; > + } else { > + /* > + * Either user specified to disable posix_acl, or did not specify > + * anything. In both the cases do not enable posix acl. > + */ > + fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling posix_acl\n"); > + conn->want &= ~FUSE_CAP_POSIX_ACL; > + } > } > > static void lo_getattr(fuse_req_t req, fuse_ino_t ino, > @@ -2612,6 +2632,63 @@ static int xattr_map_server(const struct lo_data *lo, const char *server_name, > return -ENODATA; > } > > +static bool block_xattr(struct lo_data *lo, const char *name) > +{ > + /* > + * If user explicitly enabled posix_acl or did not provide any option, > + * do not block acl. Otherwise block system.posix_acl_access and > + * system.posix_acl_default xattrs. > + */ > + if (lo->user_posix_acl) { > + return false; > + } > + if (!strcmp(name, "system.posix_acl_access") || > + !strcmp(name, "system.posix_acl_default")) > + return true; > + > + return false; > +} > + > +/* > + * Returns number of bytes in xattr_list after filtering on success. This > + * could be zero as well if nothing is left after filtering. > + * > + * Returns negative error code on failure. > + * xattr_list is modified in place. > + */ > +static int remove_blocked_xattrs(struct lo_data *lo, char *xattr_list, > + unsigned in_size) > +{ > + size_t out_index, in_index; > + > + /* > + * As of now we only filter out acl xattrs. If acls are enabled or > + * they have not been explicitly disabled, there is nothing to > + * filter. > + */ > + if (lo->user_posix_acl) { > + return in_size; > + } > + > + out_index = 0; > + in_index = 0; > + while (in_index < in_size) { > + char *in_ptr = xattr_list + in_index; > + > + /* Length of current attribute name */ > + size_t in_len = strlen(xattr_list + in_index) + 1; > + > + if (!block_xattr(lo, in_ptr)) { > + if (in_index != out_index) { > + memmove(xattr_list + out_index, xattr_list + in_index, in_len); > + } > + out_index += in_len; > + } > + in_index += in_len; > + } > + return out_index; > +} > + > static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > size_t size) > { > @@ -2625,6 +2702,11 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > int saverr; > int fd = -1; > > + if (block_xattr(lo, in_name)) { > + fuse_reply_err(req, EOPNOTSUPP); > + return; > + } > + > mapped_name = NULL; > name = in_name; > if (lo->xattrmap) { > @@ -2766,7 +2848,6 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > if (ret == 0) { > goto out; > } > - > if (lo->xattr_map_list) { > /* > * Map the names back, some attributes might be dropped, > @@ -2813,6 +2894,12 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > goto out; > } > } > + > + ret = remove_blocked_xattrs(lo, value, ret); > + if (ret <= 0) { > + saverr = -ret; > + goto out; > + } > fuse_reply_buf(req, value, ret); > } else { > /* > @@ -2851,6 +2938,11 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > int saverr; > int fd = -1; > > + if (block_xattr(lo, in_name)) { > + fuse_reply_err(req, EOPNOTSUPP); > + return; > + } > + > mapped_name = NULL; > name = in_name; > if (lo->xattrmap) { > @@ -3604,6 +3696,7 @@ int main(int argc, char *argv[]) > .allow_direct_io = 0, > .proc_self_fd = -1, > .user_killpriv_v2 = -1, > + .user_posix_acl = -1, > }; > struct lo_map_elem *root_elem; > struct lo_map_elem *reserve_elem; > -- > 2.25.4 > From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 18 Feb 2021 10:04:36 -0500 From: Vivek Goyal Message-ID: <20210218150436.GA92815@redhat.com> References: <20210217233046.81418-1-vgoyal@redhat.com> <20210217233046.81418-2-vgoyal@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217233046.81418-2-vgoyal@redhat.com> Subject: Re: [Virtio-fs] [PATCH v2 1/3] virtiofsd: Add an option to enable/disable posix acls List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, virtio-fs@redhat.com Cc: miklos@szeredi.hu On Wed, Feb 17, 2021 at 06:30:44PM -0500, Vivek Goyal wrote: > fuse has an option FUSE_POSIX_ACL which needs to be opted in by fuse > server to enable posix acls. > > Add virtiofsd option "-o posix_acl/no_posix_acl" to let users enable/disable > posix acl support. By default it is disabled as of now. > > Currently even if file server has not opted in for FUSE_POSIX_ACL, user can > still query acl and set acl, and system.posix_acl_access and > system.posix_acl_default xattrs show up listxattr response. > > Miklos said this is confusing. So he said lets block and filter > system.posix_acl_access and system.posix_acl_default xattrs in > getxattr/setxattr/listxattr if user has explicitly disabled > posix acls using -o no_posix_acl. I forgot to block acl xattrs in lo_removexattr(). Will respin this patch. Vivek > > As of now continuing to keeping the existing behavior if user did not > specify any option to disable acl support due to concerns about backward > compatibility. > > v2: block system.posix_acl_access and system.posix_acl_default xattrs > if user explicitly disabled acls. (Miklos) > > Signed-off-by: Vivek Goyal > --- > tools/virtiofsd/passthrough_ll.c | 95 +++++++++++++++++++++++++++++++- > 1 file changed, 94 insertions(+), 1 deletion(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 58d24c0010..26cdfbd1f0 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -169,6 +169,7 @@ struct lo_data { > /* An O_PATH file descriptor to /proc/self/fd/ */ > int proc_self_fd; > int user_killpriv_v2, killpriv_v2; > + int user_posix_acl; > }; > > static const struct fuse_opt lo_opts[] = { > @@ -201,6 +202,8 @@ static const struct fuse_opt lo_opts[] = { > { "announce_submounts", offsetof(struct lo_data, announce_submounts), 1 }, > { "killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 1 }, > { "no_killpriv_v2", offsetof(struct lo_data, user_killpriv_v2), 0 }, > + { "posix_acl", offsetof(struct lo_data, user_posix_acl), 1 }, > + { "no_posix_acl", offsetof(struct lo_data, user_posix_acl), 0 }, > FUSE_OPT_END > }; > static bool use_syslog = false; > @@ -661,6 +664,23 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn) > conn->want &= ~FUSE_CAP_HANDLE_KILLPRIV_V2; > lo->killpriv_v2 = 0; > } > + > + if (lo->user_posix_acl == 1) { > + /* > + * User explicitly asked for this option. Enable it unconditionally. > + * If connection does not have this capability, it should fail > + * in fuse_lowlevel.c > + */ > + fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling posix acl\n"); > + conn->want |= FUSE_CAP_POSIX_ACL; > + } else { > + /* > + * Either user specified to disable posix_acl, or did not specify > + * anything. In both the cases do not enable posix acl. > + */ > + fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling posix_acl\n"); > + conn->want &= ~FUSE_CAP_POSIX_ACL; > + } > } > > static void lo_getattr(fuse_req_t req, fuse_ino_t ino, > @@ -2612,6 +2632,63 @@ static int xattr_map_server(const struct lo_data *lo, const char *server_name, > return -ENODATA; > } > > +static bool block_xattr(struct lo_data *lo, const char *name) > +{ > + /* > + * If user explicitly enabled posix_acl or did not provide any option, > + * do not block acl. Otherwise block system.posix_acl_access and > + * system.posix_acl_default xattrs. > + */ > + if (lo->user_posix_acl) { > + return false; > + } > + if (!strcmp(name, "system.posix_acl_access") || > + !strcmp(name, "system.posix_acl_default")) > + return true; > + > + return false; > +} > + > +/* > + * Returns number of bytes in xattr_list after filtering on success. This > + * could be zero as well if nothing is left after filtering. > + * > + * Returns negative error code on failure. > + * xattr_list is modified in place. > + */ > +static int remove_blocked_xattrs(struct lo_data *lo, char *xattr_list, > + unsigned in_size) > +{ > + size_t out_index, in_index; > + > + /* > + * As of now we only filter out acl xattrs. If acls are enabled or > + * they have not been explicitly disabled, there is nothing to > + * filter. > + */ > + if (lo->user_posix_acl) { > + return in_size; > + } > + > + out_index = 0; > + in_index = 0; > + while (in_index < in_size) { > + char *in_ptr = xattr_list + in_index; > + > + /* Length of current attribute name */ > + size_t in_len = strlen(xattr_list + in_index) + 1; > + > + if (!block_xattr(lo, in_ptr)) { > + if (in_index != out_index) { > + memmove(xattr_list + out_index, xattr_list + in_index, in_len); > + } > + out_index += in_len; > + } > + in_index += in_len; > + } > + return out_index; > +} > + > static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > size_t size) > { > @@ -2625,6 +2702,11 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > int saverr; > int fd = -1; > > + if (block_xattr(lo, in_name)) { > + fuse_reply_err(req, EOPNOTSUPP); > + return; > + } > + > mapped_name = NULL; > name = in_name; > if (lo->xattrmap) { > @@ -2766,7 +2848,6 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > if (ret == 0) { > goto out; > } > - > if (lo->xattr_map_list) { > /* > * Map the names back, some attributes might be dropped, > @@ -2813,6 +2894,12 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > goto out; > } > } > + > + ret = remove_blocked_xattrs(lo, value, ret); > + if (ret <= 0) { > + saverr = -ret; > + goto out; > + } > fuse_reply_buf(req, value, ret); > } else { > /* > @@ -2851,6 +2938,11 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > int saverr; > int fd = -1; > > + if (block_xattr(lo, in_name)) { > + fuse_reply_err(req, EOPNOTSUPP); > + return; > + } > + > mapped_name = NULL; > name = in_name; > if (lo->xattrmap) { > @@ -3604,6 +3696,7 @@ int main(int argc, char *argv[]) > .allow_direct_io = 0, > .proc_self_fd = -1, > .user_killpriv_v2 = -1, > + .user_posix_acl = -1, > }; > struct lo_map_elem *root_elem; > struct lo_map_elem *reserve_elem; > -- > 2.25.4 >