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=-9.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 68C83C388F2 for ; Thu, 22 Oct 2020 13:56:13 +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 AB0B422249 for ; Thu, 22 Oct 2020 13:56:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LE/qoDok" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB0B422249 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]:59244 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kVb4d-00055O-HS for qemu-devel@archiver.kernel.org; Thu, 22 Oct 2020 09:56:11 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38056) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVarP-0002po-Dj for qemu-devel@nongnu.org; Thu, 22 Oct 2020 09:42:31 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24867) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kVarL-00060u-Qj for qemu-devel@nongnu.org; Thu, 22 Oct 2020 09:42:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603374145; 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=b57Q9CDu/hck4fF2HnLLkpPl8SKO/AI0JINVAJqQR60=; b=LE/qoDokR3Zjb1IHZnpgvnUpe4SaP7x6NmV+jQQt1p7m5ybZajJFzyNKwS2QKQqeEz0Wc2 EzBq5M9YpI5ZVuFO5mK+2xNdFFRKDUI+S3bPfcpoACaNH+eYXU9Vblf+9CGHOh5yiX9hww pnznQpFDWIjK0Mjko8hY21mJB4t2LTw= 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-420-woPzYvanPpOqQZN6622DzQ-1; Thu, 22 Oct 2020 09:42:22 -0400 X-MC-Unique: woPzYvanPpOqQZN6622DzQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CB1401054FAE for ; Thu, 22 Oct 2020 13:42:21 +0000 (UTC) Received: from horse.redhat.com (ovpn-116-67.rdu2.redhat.com [10.10.116.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 71BF56266E; Thu, 22 Oct 2020 13:42:07 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id F4085222F9C; Thu, 22 Oct 2020 09:42:06 -0400 (EDT) Date: Thu, 22 Oct 2020 09:42:06 -0400 From: Vivek Goyal To: "Dr. David Alan Gilbert (git)" Subject: Re: [PATCH v3 5/5] tools/virtiofsd: xattr name mappings: Simple 'map' Message-ID: <20201022134206.GA512900@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> <20201014180209.49299-6-dgilbert@redhat.com> MIME-Version: 1.0 In-Reply-To: <20201014180209.49299-6-dgilbert@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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=63.128.21.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/22 08:09:01 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: , Cc: dinechin@redhat.com, virtio-fs@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Oct 14, 2020 at 07:02:09PM +0100, Dr. David Alan Gilbert (git) wrote: > 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. Will it block "user.virtiofs.trusted." from client? As we discussed that either we need to block it or we need to prefix it with another user.virtiofs. I mean this rule alone is problematic and needs to be coupled with more rules. I am assuming one can specify multiple xattrmap on single line. So one can also say. -o xattrmap=":map:trusted.:user.virtiofs.:" -o xattrmap=":map:user.virtiofs.:user.virtiofs." Thanks Vivek > > 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); > } > -- > 2.28.0 > From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 22 Oct 2020 09:42:06 -0400 From: Vivek Goyal Message-ID: <20201022134206.GA512900@redhat.com> References: <20201014180209.49299-1-dgilbert@redhat.com> <20201014180209.49299-6-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201014180209.49299-6-dgilbert@redhat.com> Subject: Re: [Virtio-fs] [PATCH v3 5/5] tools/virtiofsd: xattr name mappings: Simple 'map' List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: dinechin@redhat.com, virtio-fs@redhat.com, qemu-devel@nongnu.org On Wed, Oct 14, 2020 at 07:02:09PM +0100, Dr. David Alan Gilbert (git) wrote: > 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. Will it block "user.virtiofs.trusted." from client? As we discussed that either we need to block it or we need to prefix it with another user.virtiofs. I mean this rule alone is problematic and needs to be coupled with more rules. I am assuming one can specify multiple xattrmap on single line. So one can also say. -o xattrmap=":map:trusted.:user.virtiofs.:" -o xattrmap=":map:user.virtiofs.:user.virtiofs." Thanks Vivek > > 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); > } > -- > 2.28.0 >