From patchwork Wed Oct 14 18:02:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 302851 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 2D395C433E7 for ; Wed, 14 Oct 2020 18:04:00 +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 524AB2222A for ; Wed, 14 Oct 2020 18:03:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ygz+KcnS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 524AB2222A 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]:36498 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSl82-0008RX-5o for qemu-devel@archiver.kernel.org; Wed, 14 Oct 2020 14:03:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54842) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSl6c-00079q-Ll for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28266) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSl6a-0008F0-D6 for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602698547; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hwiVYfYhegRv5GmS5AHN3gcMT85782uB9GTZ9TRVxFA=; b=Ygz+KcnS89dcADmZRoaj6uOWJWi1xC23PT5MN8Wp0ytS5A3K0lt1++s3TLJbw/u1UNOvAU pCXqlnyMuK7hEAIm4ZZ6s6j5Hhe9i/TgOEE6xRu9zAMU3BC+Ner/4abgF63DfZYzNeKjva naPx6SJ3xVcWbg29JgWmwQoHLb5LccQ= 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-401-kHypdRg9PtCrP74JrJ97gw-1; Wed, 14 Oct 2020 14:02:25 -0400 X-MC-Unique: kHypdRg9PtCrP74JrJ97gw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0CFCA8030BA for ; Wed, 14 Oct 2020 18:02:24 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id A02E16EF67; Wed, 14 Oct 2020 18:02:22 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, dinechin@redhat.com, virtio-fs@redhat.com Subject: [PATCH v3 1/5] tools/virtiofsd: xattr name mappings: Add option Date: Wed, 14 Oct 2020 19:02:05 +0100 Message-Id: <20201014180209.49299-2-dgilbert@redhat.com> In-Reply-To: <20201014180209.49299-1-dgilbert@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/14 01:12:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H4=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Add an option to define mappings of xattr names so that the client and server filesystems see different views. This can be used to have different SELinux mappings as seen by the guest, to run the virtiofsd with less privileges (e.g. in a case where it can't set trusted/system/security xattrs but you want the guest to be able to), or to isolate multiple users of the same name; e.g. trusted attributes used by stacking overlayfs. A mapping engine is used wit 3 simple rules; the rules can be combined to allow most useful mapping scenarios. The ruleset is defined by -o xattrmap='rules...'. This patch doesn't use the rule maps yet. Signed-off-by: Dr. David Alan Gilbert --- docs/tools/virtiofsd.rst | 54 ++++++++++ tools/virtiofsd/passthrough_ll.c | 180 +++++++++++++++++++++++++++++++ 2 files changed, 234 insertions(+) diff --git a/docs/tools/virtiofsd.rst b/docs/tools/virtiofsd.rst index 7ecee49834..a3a120da2f 100644 --- a/docs/tools/virtiofsd.rst +++ b/docs/tools/virtiofsd.rst @@ -109,6 +109,60 @@ Options timeout. ``always`` sets a long cache lifetime at the expense of coherency. The default is ``auto``. +xattr-mapping +------------- + +By default the name of xattr's used by the client are passed through to the server +file system. This can be a problem where either those xattr names are used +by something on the server (e.g. selinux client/server confusion) or if the +virtiofsd is running in a container with restricted privileges where it cannot +access some attributes. + +A mapping of xattr names can be made using -o xattrmap=mapping where the ``mapping`` +string consists of a series of rules. + +The first matching rule terminates the mapping. + +Each rule consists of a number of fields separated with a separator that is the +first non-white space character in the rule. This separator must then be used +for the whole rule. +White space may be added before and after each rule. +Using ':' as the separator a rule is of the form: + +``:type:scope:key:prepend:`` + +**type** is one of: + +- 'prefix' - If 'key' matches the client then the 'prepend' + is added before the name is passed to the server. + For a server case, the prepend is tested and stripped + if matching. + +- 'ok' - The attribute name is OK and passed through to + the server unchanged. + +- 'bad' - If a client tries to use this name it's + denied using EPERM; when the server passes an attribute + name matching it's hidden. + +**scope** is: + +- 'client' - match 'key' against a xattr name from the client for + setxattr/getxattr/removexattr +- 'server' - match 'prepend' against a xattr name from the server + for listxattr +- 'all' - can be used to match both cases. + +**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. + +**prepend** is a string tested as a prefix on an attribute name originating +on the server, and used as a new prefix. It may be empty +in which case a 'server' rule will always match on all names from +the server. + + Examples -------- diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index ff53df4451..f5a33014f9 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -64,6 +64,7 @@ #include #include +#include "qemu/cutils.h" #include "passthrough_helpers.h" #include "passthrough_seccomp.h" @@ -137,6 +138,12 @@ enum { CACHE_ALWAYS, }; +typedef struct xattr_map_entry { + char *key; + char *prepend; + unsigned int flags; +} XattrMapEntry; + struct lo_data { pthread_mutex_t mutex; int debug; @@ -144,6 +151,7 @@ struct lo_data { int flock; int posix_lock; int xattr; + char *xattrmap; char *source; char *modcaps; double timeout; @@ -157,6 +165,7 @@ struct lo_data { struct lo_map ino_map; /* protected by lo->mutex */ struct lo_map dirp_map; /* protected by lo->mutex */ struct lo_map fd_map; /* protected by lo->mutex */ + XattrMapEntry *xattr_map_list; /* An O_PATH file descriptor to /proc/self/fd/ */ int proc_self_fd; @@ -172,6 +181,7 @@ static const struct fuse_opt lo_opts[] = { { "no_posix_lock", offsetof(struct lo_data, posix_lock), 0 }, { "xattr", offsetof(struct lo_data, xattr), 1 }, { "no_xattr", offsetof(struct lo_data, xattr), 0 }, + { "xattrmap=%s", offsetof(struct lo_data, xattrmap), 0 }, { "modcaps=%s", offsetof(struct lo_data, modcaps), 0 }, { "timeout=%lf", offsetof(struct lo_data, timeout), 0 }, { "timeout=", offsetof(struct lo_data, timeout_set), 1 }, @@ -2010,6 +2020,169 @@ static void lo_flock(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi, fuse_reply_err(req, res == -1 ? errno : 0); } +/* + * Exit; process attribute unmodified if matched. + * An empty key applies to all. + */ +#define XATTR_MAP_FLAG_END_OK (1 << 0) +/* + * The attribute is unwanted; + * EPERM on write hidden on read. + */ +#define XATTR_MAP_FLAG_END_BAD (1 << 1) +/* + * For attr that start with 'key' prepend 'prepend' + * 'key' maybe empty to prepend for all attrs + * key is defined from set/remove point of view. + * Automatically reversed on read + */ +#define XATTR_MAP_FLAG_PREFIX (1 << 2) +/* Apply rule to get/set/remove */ +#define XATTR_MAP_FLAG_CLIENT (1 << 16) +/* Apply rule to list */ +#define XATTR_MAP_FLAG_SERVER (1 << 17) +/* Apply rule to all */ +#define XATTR_MAP_FLAG_ALL (XATTR_MAP_FLAG_SERVER | XATTR_MAP_FLAG_CLIENT) + +/* Last rule in the XATTR_MAP */ +#define XATTR_MAP_FLAG_LAST (1 << 30) + +static XattrMapEntry *add_xattrmap_entry(XattrMapEntry *orig_map, + size_t *nentries, + const XattrMapEntry *new_entry) +{ + XattrMapEntry *res = g_realloc_n(orig_map, ++*nentries, + sizeof(XattrMapEntry)); + res[*nentries - 1] = *new_entry; + + return res; +} + +static void free_xattrmap(XattrMapEntry *map) +{ + XattrMapEntry *curr = map; + + if (!map) { + return; + }; + + do { + g_free(curr->key); + g_free(curr->prepend); + } while (!(curr++->flags & XATTR_MAP_FLAG_LAST)); + + g_free(map); +} + +static XattrMapEntry *parse_xattrmap(struct lo_data *lo) +{ + XattrMapEntry *res = NULL; + XattrMapEntry tmp_entry; + size_t nentries = 0; + const char *map = lo->xattrmap; + const char *tmp; + + while (*map) { + char sep; + + if (isspace(*map)) { + map++; + continue; + } + /* The separator is the first non-space of the rule */ + sep = *map++; + if (!sep) { + break; + } + + /* Start of 'type' */ + if (strstart(map, "prefix", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_PREFIX; + } else if (strstart(map, "ok", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_END_OK; + } else if (strstart(map, "bad", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_END_BAD; + } else { + fuse_log(FUSE_LOG_ERR, + "%s: Unexpected type;" + "Expecting 'prefix', 'ok', or 'bad' in rule %zu\n", + __func__, nentries); + exit(1); + } + + if (*map++ != sep) { + fuse_log(FUSE_LOG_ERR, + "%s: Missing '%c' at end of type field of rule %zu\n", + __func__, sep, nentries); + exit(1); + } + + /* Start of 'scope' */ + if (strstart(map, "client", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_CLIENT; + } else if (strstart(map, "server", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_SERVER; + } else if (strstart(map, "all", &map)) { + tmp_entry.flags |= XATTR_MAP_FLAG_ALL; + } else { + fuse_log(FUSE_LOG_ERR, + "%s: Unexpected scope;" + " Expecting 'client', 'server', or 'all', in rule %zu\n", + __func__, nentries); + exit(1); + } + + if (*map++ != sep) { + fuse_log(FUSE_LOG_ERR, + "%s: Expecting '%c' found '%c'" + " after scope in rule %zu\n", + __func__, sep, *map, nentries); + exit(1); + } + + /* At start of 'key' field */ + tmp = strchr(map, sep); + if (!tmp) { + fuse_log(FUSE_LOG_ERR, + "%s: Missing '%c' at end of key field of rule %zu", + __func__, sep, nentries); + exit(1); + } + tmp_entry.key = g_strndup(map, tmp - map); + map = tmp + 1; + + /* At start of 'prepend' field */ + tmp = strchr(map, sep); + if (!tmp) { + fuse_log(FUSE_LOG_ERR, + "%s: Missing '%c' at end of prepend field of rule %zu", + __func__, sep, nentries); + exit(1); + } + tmp_entry.prepend = g_strndup(map, tmp - map); + map = tmp + 1; + + lo->xattr_map_list = add_xattrmap_entry(lo->xattr_map_list, &nentries, + &tmp_entry); + /* End of rule - go around again for another rule */ + } + + if (!nentries) { + fuse_log(FUSE_LOG_ERR, "Empty xattr map\n"); + exit(1); + } + + /* Add a terminator to error in cases the user hasn't specified */ + tmp_entry.flags = XATTR_MAP_FLAG_ALL | XATTR_MAP_FLAG_END_BAD | + XATTR_MAP_FLAG_LAST; + tmp_entry.key = g_strdup(""); + tmp_entry.prepend = g_strdup(""); + lo->xattr_map_list = add_xattrmap_entry(lo->xattr_map_list, &nentries, + &tmp_entry); + + return res; +} + static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name, size_t size) { @@ -2806,6 +2979,8 @@ static void fuse_lo_data_cleanup(struct lo_data *lo) close(lo->root.fd); } + free(lo->xattrmap); + free_xattrmap(lo->xattr_map_list); free(lo->source); } @@ -2906,6 +3081,11 @@ int main(int argc, char *argv[]) } else { lo.source = strdup("/"); } + + if (lo.xattrmap) { + lo.xattr_map_list = parse_xattrmap(&lo); + } + if (!lo.timeout_set) { switch (lo.cache) { case CACHE_NONE: From patchwork Wed Oct 14 18:02:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 271254 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 A3D0BC43457 for ; Wed, 14 Oct 2020 18:04:01 +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 1C78421D81 for ; Wed, 14 Oct 2020 18:04:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AkCxoVBT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C78421D81 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]:36668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSl84-0008Vd-2L for qemu-devel@archiver.kernel.org; Wed, 14 Oct 2020 14:04:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54870) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSl6e-0007DI-So for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43001) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSl6d-0008FM-4L for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602698550; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TcFpzXSrk4RWtW0UvOW/XxU3RU348JJw5NrURzCJoKY=; b=AkCxoVBTcIbjpczOTedG9rC63aoWZtup+odQ2zZNGNtT0PEJUAwUnBvaRxMQe06xxAk8WY msDUFtcPEiDvkrSB3edcu2C9xBSTJ1NFY3JoF9t2RNWrc1x6yT85sPpLhpFQ7TmivTNiO+ XLyI0v0Wph3IRyZdm2laY47g1BEyZFU= 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-563-c6wZJt5_M0mUrbJBh0WBmA-1; Wed, 14 Oct 2020 14:02:27 -0400 X-MC-Unique: c6wZJt5_M0mUrbJBh0WBmA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F1DED18BE16B for ; Wed, 14 Oct 2020 18:02:26 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 625226EF53; Wed, 14 Oct 2020 18:02:24 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, dinechin@redhat.com, virtio-fs@redhat.com Subject: [PATCH v3 2/5] tools/virtiofsd: xattr name mappings: Map client xattr names Date: Wed, 14 Oct 2020 19:02:06 +0100 Message-Id: <20201014180209.49299-3-dgilbert@redhat.com> In-Reply-To: <20201014180209.49299-1-dgilbert@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/14 01:12:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H4=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Map xattr names originating at the client; from get/set/remove xattr. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Stefan Hajnoczi --- tools/virtiofsd/passthrough_ll.c | 101 ++++++++++++++++++++++++++++++- 1 file changed, 98 insertions(+), 3 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index f5a33014f9..57ebe17ed6 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2183,20 +2183,80 @@ static XattrMapEntry *parse_xattrmap(struct lo_data *lo) return res; } -static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name, +/* + * For use with getxattr/setxattr/removexattr, where the client + * gives us a name and we may need to choose a different one. + * Allocates a buffer for the result placing it in *out_name. + * If there's no change then *out_name is not set. + * Returns 0 on success + * Can return -EPERM to indicate we block a given attribute + * (in which case out_name is not allocated) + * Can return -ENOMEM to indicate out_name couldn't be allocated. + */ +static int xattr_map_client(const struct lo_data *lo, const char *client_name, + char **out_name) +{ + const XattrMapEntry *cur_entry; + + for (cur_entry = lo->xattr_map_list; ; cur_entry++) { + if ((cur_entry->flags & XATTR_MAP_FLAG_CLIENT) && + (strstart(client_name, cur_entry->key, NULL))) { + if (cur_entry->flags & XATTR_MAP_FLAG_END_BAD) { + return -EPERM; + } + if (cur_entry->flags & XATTR_MAP_FLAG_END_OK) { + /* Unmodified name */ + return 0; + } + if (cur_entry->flags & XATTR_MAP_FLAG_PREFIX) { + *out_name = g_try_malloc(strlen(client_name) + + strlen(cur_entry->prepend) + 1); + if (!*out_name) { + return -ENOMEM; + } + sprintf(*out_name, "%s%s", cur_entry->prepend, client_name); + return 0; + } + } + } + + /* Shouldn't get here - rules should have an END_* */ + abort(); +} + +static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, size_t size) { struct lo_data *lo = lo_data(req); char *value = NULL; char procname[64]; + const char *name; + char *mapped_name; struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + if (ret == -EPERM) { + ret = -ENODATA; + } + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2261,6 +2321,7 @@ out_err: saverr = errno; out: fuse_reply_err(req, saverr); + g_free(mapped_name); goto out_free; } @@ -2338,19 +2399,35 @@ out: goto out_free; } -static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name, +static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, const char *value, size_t size, int flags) { char procname[64]; + const char *name; + char *mapped_name; struct lo_data *lo = lo_data(req); struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2385,21 +2462,38 @@ out: } lo_inode_put(lo, &inode); + g_free(mapped_name); fuse_reply_err(req, saverr); } -static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *name) +static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) { char procname[64]; + const char *name; + char *mapped_name; struct lo_data *lo = lo_data(req); struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2434,6 +2528,7 @@ out: } lo_inode_put(lo, &inode); + g_free(mapped_name); fuse_reply_err(req, saverr); } From patchwork Wed Oct 14 18:02:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 271253 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 900CAC43457 for ; Wed, 14 Oct 2020 18:06:07 +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 D22C621D81 for ; Wed, 14 Oct 2020 18:06:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Bs3bMZOo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D22C621D81 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]:42974 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSlA5-0002oA-Pd for qemu-devel@archiver.kernel.org; Wed, 14 Oct 2020 14:06:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54874) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSl6f-0007Ej-R1 for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:57898) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSl6d-0008FT-W6 for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602698551; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hQzfpBQyIOAMSS4gTbXq1Y2zMQV4ZJZ5H5JizCSV80Y=; b=Bs3bMZOoHFyF/SgMiRDiGwtzPb+ebNO4eWnNKfm/9r9pQKztgzKIo2nZDRL3YOsDDv8krz gWJFwN3nE78ZDWiL50gOG0EZMRPIUKciPGO3nCsOcmGabJmyL/KcQX6oxxynyMm2Vq3wLj vAx9S0ABFpxpMciVUWXVTzx0lYYGKJ0= 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-19-TCXEAuQaM5OthuWRe0_qUQ-1; Wed, 14 Oct 2020 14:02:29 -0400 X-MC-Unique: TCXEAuQaM5OthuWRe0_qUQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9B8FB10866AD for ; Wed, 14 Oct 2020 18:02:28 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E8E46EF67; Wed, 14 Oct 2020 18:02:27 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, dinechin@redhat.com, virtio-fs@redhat.com Subject: [PATCH v3 3/5] tools/virtiofsd: xattr name mappings: Map server xattr names Date: Wed, 14 Oct 2020 19:02:07 +0100 Message-Id: <20201014180209.49299-4-dgilbert@redhat.com> In-Reply-To: <20201014180209.49299-1-dgilbert@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/14 01:12:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H4=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Map xattr names coming from the server, i.e. the host filesystem; currently this is only from listxattr. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Stefan Hajnoczi --- tools/virtiofsd/passthrough_ll.c | 89 ++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 57ebe17ed6..8406a2ae86 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2220,6 +2220,43 @@ static int xattr_map_client(const struct lo_data *lo, const char *client_name, } } + /* Shouldn't get here - rules should have an END_* - check parse_xattrmap */ + abort(); +} + +/* + * For use with listxattr where the server fs gives us a name and we may need + * to sanitize this for the client. + * Returns a pointer to the result in *out_name + * This is always the original string or the current string with some prefix + * removed; no reallocation is done. + * Returns 0 on success + * Can return -ENODATA to indicate the name should be dropped from the list. + */ +static int xattr_map_server(const struct lo_data *lo, const char *server_name, + const char **out_name) +{ + const XattrMapEntry *cur_entry; + const char *end; + + for (cur_entry = lo->xattr_map_list; ; cur_entry++) { + if ((cur_entry->flags & XATTR_MAP_FLAG_SERVER) && + (strstart(server_name, cur_entry->prepend, &end))) { + if (cur_entry->flags & XATTR_MAP_FLAG_END_BAD) { + return -ENODATA; + } + if (cur_entry->flags & XATTR_MAP_FLAG_END_OK) { + *out_name = server_name; + return 0; + } + if (cur_entry->flags & XATTR_MAP_FLAG_PREFIX) { + /* Remove prefix */ + *out_name = end; + return 0; + } + } + } + /* Shouldn't get here - rules should have an END_* */ abort(); } @@ -2378,8 +2415,60 @@ 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, + * some shortened, but not increased, so we shouldn't + * run out of room. + */ + size_t out_index, in_index; + out_index = 0; + in_index = 0; + while (in_index < ret) { + const char *map_out; + char *in_ptr = value + in_index; + /* Length of current attribute name */ + size_t in_len = strlen(value + in_index) + 1; + + int mapret = xattr_map_server(lo, in_ptr, &map_out); + if (mapret != -ENODATA && mapret != 0) { + /* Shouldn't happen */ + saverr = -mapret; + goto out; + } + if (mapret == 0) { + /* Either unchanged, or truncated */ + size_t out_len; + if (map_out != in_ptr) { + /* +1 copies the NIL */ + out_len = strlen(map_out) + 1; + } else { + /* No change */ + out_len = in_len; + } + /* + * Move result along, may still be needed for an unchanged + * entry if a previous entry was changed. + */ + memmove(value + out_index, map_out, out_len); + + out_index += out_len; + } + in_index += in_len; + } + ret = out_index; + if (ret == 0) { + goto out; + } + } fuse_reply_buf(req, value, ret); } else { + /* + * xattrmap only ever shortens the result, + * so we don't need to do anything clever with the + * allocation length here. + */ fuse_reply_xattr(req, ret); } out_free: From patchwork Wed Oct 14 18:02:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 302849 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 C1626C433E7 for ; Wed, 14 Oct 2020 18:06:10 +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 0F55021D81 for ; Wed, 14 Oct 2020 18:06:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="bzlAfdXQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F55021D81 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]:43204 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSlA8-0002uA-UV for qemu-devel@archiver.kernel.org; Wed, 14 Oct 2020 14:06:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54914) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSl6n-0007LZ-55 for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:36773) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSl6k-0008HD-R2 for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602698557; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z8enSobz6KFfIEiRA4KGb/6ffO3C7NW/uljYZU8UUeA=; b=bzlAfdXQoFOaB2h7wAjVQMNYeiwDFnDb3uO2cqwQFVSw35YPGwOqz0T4wu8QrB1Xawdjda M3iyJKoVtn+xDepsQiVCYGbBh8XoRQIqO9eyySqXLJpjvAA+K1LPIfEEgq42mvw7/y0vuG nWAQnCHS7zSLmGmT7njmRn2SHrxhh4c= 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-98-EOL9rcOsOOSfv_G93R-wNg-1; Wed, 14 Oct 2020 14:02:31 -0400 X-MC-Unique: EOL9rcOsOOSfv_G93R-wNg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 362CF18BE161 for ; Wed, 14 Oct 2020 18:02:30 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF8E46EF68; Wed, 14 Oct 2020 18:02:28 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, dinechin@redhat.com, virtio-fs@redhat.com Subject: [PATCH v3 4/5] tools/virtiofsd: xattr name mapping examples Date: Wed, 14 Oct 2020 19:02:08 +0100 Message-Id: <20201014180209.49299-5-dgilbert@redhat.com> In-Reply-To: <20201014180209.49299-1-dgilbert@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/14 03:37:33 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H5=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" Add a few examples of xattrmaps to the documentation. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Stefan Hajnoczi --- docs/tools/virtiofsd.rst | 50 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/docs/tools/virtiofsd.rst b/docs/tools/virtiofsd.rst index a3a120da2f..5cb64612ed 100644 --- a/docs/tools/virtiofsd.rst +++ b/docs/tools/virtiofsd.rst @@ -163,6 +163,56 @@ in which case a 'server' rule will always match on all names from the server. +xattr-mapping Examples +---------------------- + +1) Prefix all attributes with 'user.virtiofs.' + +:: + +-o xattrmap=":prefix:all::user.virtiofs.::bad:all:::" + + +This uses two rules, using : as the field separator; +the first rule prefixes and strips 'user.virtiofs.', +the second rule hides any non-prefixed attributes that +the host set. + +2) Prefix 'trusted.' attributes, allow others through + +:: + + "/prefix/all/trusted./user.virtiofs./ + /bad/server//trusted./ + /bad/client/user.virtiofs.// + /ok/all///" + + +Here there are four rules, using / as the field +separator, and also demonstrating that new lines can +be included between rules. +The first rule is the prefixing of 'trusted.' and +stripping of 'user.virtiofs.'. +The second rule hides unprefixed 'trusted.' attributes +on the host. +The third rule stops a guest from explicitly setting +the 'user.viritofs.' path directly. +Finally, the fourth rule lets all remaining attributes +through. + +3) Hide 'security.' attributes, and allow everything else + +:: + + "/bad/all/security./security./ + /ok/all///' + +The first rule combines what could be separate client and server +rules into a single 'all' rule, matching 'security.' in either +client arguments or lists returned from the host. This stops +the client seeing any 'security.' attributes on the server and +stops it setting any. + Examples -------- From patchwork Wed Oct 14 18:02:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 302850 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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 43734C433DF for ; Wed, 14 Oct 2020 18:05:59 +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 9ED3A21D81 for ; Wed, 14 Oct 2020 18:05:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="d4T05Kk1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9ED3A21D81 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]:42286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSl9x-0002UY-Hp for qemu-devel@archiver.kernel.org; Wed, 14 Oct 2020 14:05:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54894) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSl6j-0007JV-UH for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:36948) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSl6h-0008Gs-ST for qemu-devel@nongnu.org; Wed, 14 Oct 2020 14:02:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602698555; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SijZu7DXL8pr3SqLNEV/Mnvf+aeAxCZg1WnVYAKhCWs=; b=d4T05Kk1LseQMeKr5rlAqP5Tu0x2LnIjyi0bDgtESOSwH9yMds9VAXnQ8ZiU46ypVP2TBv sQcCRTOfodRezcjKhPF2O5YtB4LEGZ4oqgVQyu0oxNG9f4+IrX0IsEBWelrs4iO6OrLdJw pzXV3YiQFrkA5a4gcXZiTM/X9NMAubY= 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-331-ivKh9la4NWeYlDjou7DiLw-1; Wed, 14 Oct 2020 14:02:33 -0400 X-MC-Unique: ivKh9la4NWeYlDjou7DiLw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B654418BE167 for ; Wed, 14 Oct 2020 18:02:31 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-95.ams2.redhat.com [10.36.113.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 860766EF68; Wed, 14 Oct 2020 18:02:30 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com, dinechin@redhat.com, virtio-fs@redhat.com Subject: [PATCH v3 5/5] tools/virtiofsd: xattr name mappings: Simple 'map' Date: Wed, 14 Oct 2020 19:02:09 +0100 Message-Id: <20201014180209.49299-6-dgilbert@redhat.com> In-Reply-To: <20201014180209.49299-1-dgilbert@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/14 01:12:43 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, RCVD_IN_MSPIKE_H4=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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: "Dr. David Alan Gilbert" The mapping rule system implemented in the last few patches is extremely flexible, but not easy to use. Add a simple 'map' type as a sprinkling of sugar to make it easy. e.g. -o xattrmap=":map::user.virtiofs.:" would be sufficient to prefix all xattr's or -o xattrmap=":map:trusted.:user.virtiofs.:" would just prefix 'trusted.' xattr's and leave everything else alone. Signed-off-by: Dr. David Alan Gilbert --- docs/tools/virtiofsd.rst | 18 ++++++ tools/virtiofsd/passthrough_ll.c | 108 ++++++++++++++++++++++++++++++- 2 files changed, 125 insertions(+), 1 deletion(-) diff --git a/docs/tools/virtiofsd.rst b/docs/tools/virtiofsd.rst index 5cb64612ed..e388ef253e 100644 --- a/docs/tools/virtiofsd.rst +++ b/docs/tools/virtiofsd.rst @@ -127,6 +127,7 @@ Each rule consists of a number of fields separated with a separator that is the first non-white space character in the rule. This separator must then be used for the whole rule. White space may be added before and after each rule. + Using ':' as the separator a rule is of the form: ``:type:scope:key:prepend:`` @@ -162,6 +163,13 @@ on the server, and used as a new prefix. It may be empty in which case a 'server' rule will always match on all names from the server. +A simpler 'map' type provides a shorter syntax for the common case: + +``:map:key:prepend:`` + +The 'map' type adds a number of separate rules to add **prepend** as a prefix +to the matched **key** (or all attributes if **key** is empty). +There may be at most one 'map' rule and it must be the last rule in the set. xattr-mapping Examples ---------------------- @@ -178,6 +186,11 @@ the first rule prefixes and strips 'user.virtiofs.', the second rule hides any non-prefixed attributes that the host set. +This is equivalent to the 'map' rule: + +:: +-o xattrmap=":map::user.virtiofs.:" + 2) Prefix 'trusted.' attributes, allow others through :: @@ -200,6 +213,11 @@ the 'user.viritofs.' path directly. Finally, the fourth rule lets all remaining attributes through. +This is equivalent to the 'map' rule: + +:: +-o xattrmap="/map/trusted./user.virtiofs./" + 3) Hide 'security.' attributes, and allow everything else :: diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 8406a2ae86..a1b3364ba3 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2074,6 +2074,106 @@ static void free_xattrmap(XattrMapEntry *map) g_free(map); } +/* + * Handle the 'map' type, which is sugar for a set of commands + * for the common case of prefixing a subset or everything, + * and allowing anything not prefixed through. + * It must be the last entry in the stream, although there + * can be other entries before it. + * The form is: + * :map:key:prefix: + * + * key maybe empty in which case all entries are prefixed. + */ +static XattrMapEntry *parse_xattrmap_map(const char *rule, + XattrMapEntry *map, + size_t *nentries) +{ + char sep = *rule++; + const char *tmp; + char *key; + char *prefix; + XattrMapEntry tmp_entry; + + /* At start of 'key' field */ + tmp = strchr(rule, sep); + if (!tmp) { + fuse_log(FUSE_LOG_ERR, + "%s: Missing '%c' at end of key field in map rule\n", + __func__, sep); + exit(1); + } + + key = g_strndup(rule, tmp - rule); + rule = tmp + 1; + + /* At start of prefix field */ + tmp = strchr(rule, sep); + if (!tmp) { + fuse_log(FUSE_LOG_ERR, + "%s: Missing '%c' at end of prefix field in map rule\n", + __func__, sep); + exit(1); + } + + prefix = g_strndup(rule, tmp - rule); + rule = tmp + 1; + + /* + * This should be the end of the string, we don't allow + * any more commands after 'map'. + */ + if (*rule) { + fuse_log(FUSE_LOG_ERR, + "%s: Expecting end of command after map, found '%c'\n", + __func__, *rule); + exit(1); + } + + /* 1st: Prefix matches/everything */ + tmp_entry.flags = XATTR_MAP_FLAG_PREFIX | XATTR_MAP_FLAG_ALL; + tmp_entry.key = g_strdup(key); + tmp_entry.prepend = g_strdup(prefix); + map = add_xattrmap_entry(map, nentries, &tmp_entry); + + if (!*key) { + /* Prefix all case */ + + /* 2nd: Hide any non-prefixed entries on the host */ + tmp_entry.flags = XATTR_MAP_FLAG_END_BAD | XATTR_MAP_FLAG_ALL | + XATTR_MAP_FLAG_LAST; + tmp_entry.key = g_strdup(""); + tmp_entry.prepend = g_strdup(""); + map = add_xattrmap_entry(map, nentries, &tmp_entry); + } else { + /* Prefix matching case */ + + /* 2nd: Hide non-prefixed but matching entries on the host */ + tmp_entry.flags = XATTR_MAP_FLAG_END_BAD | XATTR_MAP_FLAG_SERVER; + tmp_entry.key = g_strdup(""); /* Not used */ + tmp_entry.prepend = g_strdup(key); + map = add_xattrmap_entry(map, nentries, &tmp_entry); + + /* 3rd: Stop the client accessing prefixed attributes directly */ + tmp_entry.flags = XATTR_MAP_FLAG_END_BAD | XATTR_MAP_FLAG_CLIENT; + tmp_entry.key = g_strdup(prefix); + tmp_entry.prepend = g_strdup(""); /* Not used */ + map = add_xattrmap_entry(map, nentries, &tmp_entry); + + /* 4th: Everything else is OK */ + tmp_entry.flags = XATTR_MAP_FLAG_END_OK | XATTR_MAP_FLAG_ALL | + XATTR_MAP_FLAG_LAST; + tmp_entry.key = g_strdup(""); + tmp_entry.prepend = g_strdup(""); + map = add_xattrmap_entry(map, nentries, &tmp_entry); + } + + g_free(key); + g_free(prefix); + + return map; +} + static XattrMapEntry *parse_xattrmap(struct lo_data *lo) { XattrMapEntry *res = NULL; @@ -2102,10 +2202,16 @@ static XattrMapEntry *parse_xattrmap(struct lo_data *lo) tmp_entry.flags |= XATTR_MAP_FLAG_END_OK; } else if (strstart(map, "bad", &map)) { tmp_entry.flags |= XATTR_MAP_FLAG_END_BAD; + } else if (strstart(map, "map", &map)) { + /* + * map is sugar that adds a number of rules, and must be + * the last entry. + */ + return parse_xattrmap_map(map, res, &nentries); } else { fuse_log(FUSE_LOG_ERR, "%s: Unexpected type;" - "Expecting 'prefix', 'ok', or 'bad' in rule %zu\n", + "Expecting 'prefix', 'ok', 'bad' or 'map' in rule %zu\n", __func__, nentries); exit(1); }