[SCM] Samba Shared Repository - branch master updated
David Disseldorp
ddiss at samba.org
Tue May 14 23:32:02 UTC 2019
The branch, master has been updated
via 9345d11c44e docs: add vfs_ceph_snapshots manpage
via 76f3b194c25 vfs: add ceph_snapshots module
via 76d7d05b1da vfs_ceph: drop fdopendir handler
from 43958af1d50 CVE-2018-16860 Heimdal KDC: Reject PA-S4U2Self with unkeyed checksum
https://git.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit 9345d11c44e55e9ad1eb6b55975d04561f5d2ba3
Author: David Disseldorp <ddiss at samba.org>
Date: Wed Mar 27 15:57:45 2019 +0100
docs: add vfs_ceph_snapshots manpage
Signed-off-by: David Disseldorp <ddiss at samba.org>
Reviewed-by: Jeremy Allison <jra at samba.org>
Autobuild-User(master): David Disseldorp <ddiss at samba.org>
Autobuild-Date(master): Tue May 14 23:31:27 UTC 2019 on sn-devel-184
commit 76f3b194c25e8d388cde2da971d116479ac63d9d
Author: David Disseldorp <ddiss at samba.org>
Date: Tue Mar 26 16:35:18 2019 +0100
vfs: add ceph_snapshots module
vfs_ceph_snapshots is a module for accessing CephFS snapshots as
Previous Versions. The module is separate from vfs_ceph, so that it can
also be used atop a CephFS kernel backed share with vfs_default.
Signed-off-by: David Disseldorp <ddiss at samba.org>
Reviewed-by: Jeremy Allison <jra at samba.org>
commit 76d7d05b1da6c0703b1c2bade0c4467c7cc1adec
Author: David Disseldorp <ddiss at samba.org>
Date: Wed Mar 27 13:10:04 2019 +0100
vfs_ceph: drop fdopendir handler
libcephfs doesn't currently offer an fdopendir equivalent, so the
existing implementation peeks at fsp->fsp_name->base_name, which can
break if vfs_ceph is used under a separate path-munging VFS module.
Return ENOSYS instead and rely on existing OpenDir_fsp() fallback.
Signed-off-by: David Disseldorp <ddiss at samba.org>
Reviewed-by: Jeremy Allison <jra at samba.org>
-----------------------------------------------------------------------
Summary of changes:
docs-xml/manpages/vfs_ceph_snapshots.8.xml | 130 ++
docs-xml/wscript_build | 1 +
source3/modules/vfs_ceph.c | 15 +-
source3/modules/vfs_ceph_snapshots.c | 1835 ++++++++++++++++++++++++++++
source3/modules/wscript_build | 8 +
source3/wscript | 5 +
6 files changed, 1982 insertions(+), 12 deletions(-)
create mode 100644 docs-xml/manpages/vfs_ceph_snapshots.8.xml
create mode 100644 source3/modules/vfs_ceph_snapshots.c
Changeset truncated at 500 lines:
diff --git a/docs-xml/manpages/vfs_ceph_snapshots.8.xml b/docs-xml/manpages/vfs_ceph_snapshots.8.xml
new file mode 100644
index 00000000000..7fa2806fd95
--- /dev/null
+++ b/docs-xml/manpages/vfs_ceph_snapshots.8.xml
@@ -0,0 +1,130 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
+<refentry id="vfs_ceph_snapshots.8">
+
+<refmeta>
+ <refentrytitle>vfs_ceph_snapshots</refentrytitle>
+ <manvolnum>8</manvolnum>
+ <refmiscinfo class="source">Samba</refmiscinfo>
+ <refmiscinfo class="manual">System Administration tools</refmiscinfo>
+ <refmiscinfo class="version">&doc.version;</refmiscinfo>
+</refmeta>
+
+
+<refnamediv>
+ <refname>vfs_ceph_snapshots</refname>
+ <refpurpose>
+ Expose CephFS snapshots as shadow-copies
+ </refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+ <cmdsynopsis>
+ <command>vfs objects = ceph_snapshots</command>
+ </cmdsynopsis>
+</refsynopsisdiv>
+
+<refsect1>
+ <title>DESCRIPTION</title>
+
+ <para>This VFS module is part of the
+ <citerefentry><refentrytitle>samba</refentrytitle>
+ <manvolnum>8</manvolnum></citerefentry> suite.</para>
+
+ <para>
+ The <command>vfs_ceph_snapshots</command> VFS module exposes
+ CephFS snapshots for use by Samba. When enabled, SMB clients
+ such as Windows Explorer's Previous Versions dialog, can
+ enumerate snaphots and access them via "timewarp" tokens.
+ </para>
+
+ <para>
+ This module can be combined with <command>vfs_ceph</command>,
+ but <command>vfs_ceph_snapshots</command> must be listed first
+ in the <command>vfs objects</command> parameter list.
+ </para>
+
+ <para>
+ CephFS support for ceph.snap.btime virtual extended attributes
+ is required for this module to work properly. This support was
+ added via https://tracker.ceph.com/issues/38838.
+ </para>
+</refsect1>
+
+<refsect1>
+ <title>CONFIGURATION</title>
+
+ <para>
+ When used atop <command>vfs_ceph</command>,
+ <command>path</command> refers to an absolute path within the
+ Ceph filesystem and should not be mounted locally:
+ </para>
+
+ <programlisting>
+ <smbconfsection name="[share]"/>
+ <smbconfoption name="vfs objects">ceph_snapshots ceph</smbconfoption>
+ <smbconfoption name="path">/non-mounted/cephfs/path</smbconfoption>
+ <smbconfoption name="kernel share modes">no</smbconfoption>
+ </programlisting>
+
+ <para>
+ <command>vfs_ceph_snapshots</command> can also be used atop a
+ kernel CephFS mounted share path, without
+ <command>vfs_ceph</command>. In this case Samba's default VFS
+ backend <command>vfs_default</command> is used:
+ </para>
+
+ <programlisting>
+ <smbconfsection name="[share]"/>
+ <smbconfoption name="vfs objects">ceph_snapshots</smbconfoption>
+ <smbconfoption name="path">/mnt/cephfs/</smbconfoption>
+ </programlisting>
+</refsect1>
+
+<refsect1>
+ <title>OPTIONS</title>
+
+ <variablelist>
+ <varlistentry>
+ <term>ceph:snapdir = subdirectory</term>
+ <listitem>
+ <para>
+ Allows for the configuration of the special CephFS
+ snapshot subdirectory name. This parameter should only
+ be changed from the ".snap" default if the ceph.conf
+ <command>client snapdir</command> or
+ <command>snapdirname</command> mount option settings
+ are changed from their matching ".snap" defaults.
+ </para>
+ <para>
+ Default:
+ <smbconfoption name="ceph:snapdir">.snap</smbconfoption>
+ </para>
+ <para>
+ Example:
+ <smbconfoption name="ceph:snapdir">.snapshots</smbconfoption>
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+</refsect1>
+
+<refsect1>
+ <title>VERSION</title>
+
+ <para>
+ This man page is part of version &doc.version; of the Samba suite.
+ </para>
+</refsect1>
+
+<refsect1>
+ <title>AUTHOR</title>
+
+ <para>The original Samba software and related utilities
+ were created by Andrew Tridgell. Samba is now developed
+ by the Samba Team as an Open Source project similar
+ to the way the Linux kernel is developed.</para>
+
+</refsect1>
+
+</refentry>
diff --git a/docs-xml/wscript_build b/docs-xml/wscript_build
index 796b685c709..575fb702b46 100644
--- a/docs-xml/wscript_build
+++ b/docs-xml/wscript_build
@@ -72,6 +72,7 @@ vfs_module_manpages = ['vfs_acl_tdb',
'vfs_cap',
'vfs_catia',
'vfs_ceph',
+ 'vfs_ceph_snapshots',
'vfs_commit',
'vfs_crossrename',
'vfs_default_quota',
diff --git a/source3/modules/vfs_ceph.c b/source3/modules/vfs_ceph.c
index 6f29629566e..e1f3d757bf1 100644
--- a/source3/modules/vfs_ceph.c
+++ b/source3/modules/vfs_ceph.c
@@ -328,18 +328,9 @@ static DIR *cephwrap_fdopendir(struct vfs_handle_struct *handle,
const char *mask,
uint32_t attributes)
{
- int ret = 0;
- struct ceph_dir_result *result;
- DBG_DEBUG("[CEPH] fdopendir(%p, %p)\n", handle, fsp);
-
- ret = ceph_opendir(handle->data, fsp->fsp_name->base_name, &result);
- if (ret < 0) {
- result = NULL;
- errno = -ret; /* We return result which is NULL in this case */
- }
-
- DBG_DEBUG("[CEPH] fdopendir(...) = %d\n", ret);
- return (DIR *) result;
+ /* OpenDir_fsp() falls back to regular open */
+ errno = ENOSYS;
+ return NULL;
}
static struct dirent *cephwrap_readdir(struct vfs_handle_struct *handle,
diff --git a/source3/modules/vfs_ceph_snapshots.c b/source3/modules/vfs_ceph_snapshots.c
new file mode 100644
index 00000000000..4183069a5c2
--- /dev/null
+++ b/source3/modules/vfs_ceph_snapshots.c
@@ -0,0 +1,1835 @@
+/*
+ * Module for accessing CephFS snapshots as Previous Versions. This module is
+ * separate to vfs_ceph, so that it can also be used atop a CephFS kernel backed
+ * share with vfs_default.
+ *
+ * Copyright (C) David Disseldorp 2019
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <dirent.h>
+#include <libgen.h>
+#include "includes.h"
+#include "include/ntioctl.h"
+#include "include/smb.h"
+#include "system/filesys.h"
+#include "smbd/smbd.h"
+#include "lib/util/tevent_ntstatus.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_VFS
+
+/*
+ * CephFS has a magic snapshots subdirectory in all parts of the directory tree.
+ * This module automatically makes all snapshots in this subdir visible to SMB
+ * clients (if permitted by corresponding access control).
+ */
+#define CEPH_SNAP_SUBDIR_DEFAULT ".snap"
+/*
+ * The ceph.snap.btime (virtual) extended attribute carries the snapshot
+ * creation time in $secs.$nsecs format. It was added as part of
+ * https://tracker.ceph.com/issues/38838. Running Samba atop old Ceph versions
+ * which don't provide this xattr will not be able to enumerate or access
+ * snapshots using this module. As an alternative, vfs_shadow_copy2 could be
+ * used instead, alongside special shadow:format snapshot directory names.
+ */
+#define CEPH_SNAP_BTIME_XATTR "ceph.snap.btime"
+
+static int ceph_snap_get_btime(struct vfs_handle_struct *handle,
+ struct smb_filename *smb_fname,
+ time_t *_snap_secs)
+{
+ int ret;
+ char snap_btime[33];
+ char *s = NULL;
+ char *endptr = NULL;
+ struct timespec snap_timespec;
+ int err;
+
+ ret = SMB_VFS_NEXT_GETXATTR(handle, smb_fname, CEPH_SNAP_BTIME_XATTR,
+ snap_btime, sizeof(snap_btime));
+ if (ret < 0) {
+ DBG_ERR("failed to get %s xattr: %s\n",
+ CEPH_SNAP_BTIME_XATTR, strerror(errno));
+ return -errno;
+ }
+
+ if (ret == 0 || ret >= sizeof(snap_btime) - 1) {
+ return -EINVAL;
+ }
+
+ /* ensure zero termination */
+ snap_btime[ret] = '\0';
+
+ /* format is sec.nsec */
+ s = strchr(snap_btime, '.');
+ if (s == NULL) {
+ DBG_ERR("invalid %s xattr value: %s\n",
+ CEPH_SNAP_BTIME_XATTR, snap_btime);
+ return -EINVAL;
+ }
+
+ /* First component is seconds, extract it */
+ *s = '\0';
+ snap_timespec.tv_sec = strtoull_err(snap_btime, &endptr, 10, &err);
+ if (err != 0) {
+ return -err;
+ }
+ if ((endptr == snap_btime) || (*endptr != '\0')) {
+ DBG_ERR("couldn't process snap.tv_sec in %s\n", snap_btime);
+ return -EINVAL;
+ }
+
+ /* second component is nsecs */
+ s++;
+ snap_timespec.tv_nsec = strtoul_err(s, &endptr, 10, &err);
+ if (err != 0) {
+ return -err;
+ }
+ if ((endptr == s) || (*endptr != '\0')) {
+ DBG_ERR("couldn't process snap.tv_nsec in %s\n", s);
+ return -EINVAL;
+ }
+
+ /*
+ * >> 30 is a rough divide by ~10**9. No need to be exact, as @GMT
+ * tokens only offer 1-second resolution (while twrp is nsec).
+ */
+ *_snap_secs = snap_timespec.tv_sec + (snap_timespec.tv_nsec >> 30);
+
+ return 0;
+}
+
+/*
+ * XXX Ceph snapshots can be created with sub-second granularity, which means
+ * that multiple snapshots may be mapped to the same @GMT- label.
+ *
+ * @this_label is a pre-zeroed buffer to be filled with a @GMT label
+ * @return 0 if label successfully filled or -errno on error.
+ */
+static int ceph_snap_fill_label(struct vfs_handle_struct *handle,
+ TALLOC_CTX *tmp_ctx,
+ const char *parent_snapsdir,
+ const char *subdir,
+ SHADOW_COPY_LABEL this_label)
+{
+ struct smb_filename *smb_fname;
+ time_t snap_secs;
+ struct tm gmt_snap_time;
+ struct tm *tm_ret;
+ size_t str_sz;
+ char snap_path[PATH_MAX + 1];
+ int ret;
+
+ /*
+ * CephFS snapshot creation times are available via a special
+ * xattr - snapshot b/m/ctimes all match the snap source.
+ */
+ ret = snprintf(snap_path, sizeof(snap_path), "%s/%s",
+ parent_snapsdir, subdir);
+ if (ret >= sizeof(snap_path)) {
+ return -EINVAL;
+ }
+
+ smb_fname = synthetic_smb_fname(tmp_ctx, snap_path,
+ NULL, NULL, 0);
+ if (smb_fname == NULL) {
+ return -ENOMEM;
+ }
+
+ ret = ceph_snap_get_btime(handle, smb_fname, &snap_secs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ tm_ret = gmtime_r(&snap_secs, &gmt_snap_time);
+ if (tm_ret == NULL) {
+ return -EINVAL;
+ }
+ str_sz = strftime(this_label, sizeof(SHADOW_COPY_LABEL),
+ "@GMT-%Y.%m.%d-%H.%M.%S", &gmt_snap_time);
+ if (str_sz == 0) {
+ DBG_ERR("failed to convert tm to @GMT token\n");
+ return -EINVAL;
+ }
+
+ DBG_DEBUG("mapped snapshot at %s to enum snaps label %s\n",
+ snap_path, this_label);
+
+ return 0;
+}
+
+static int ceph_snap_enum_snapdir(struct vfs_handle_struct *handle,
+ struct smb_filename *snaps_dname,
+ bool labels,
+ struct shadow_copy_data *sc_data)
+{
+ NTSTATUS status;
+ int ret;
+ DIR *d = NULL;
+ struct dirent *e = NULL;
+ uint32_t slots;
+
+ status = smbd_check_access_rights(handle->conn,
+ snaps_dname,
+ false,
+ SEC_DIR_LIST);
+ if (!NT_STATUS_IS_OK(status)) {
+ DEBUG(0,("user does not have list permission "
+ "on snapdir %s\n",
+ snaps_dname->base_name));
+ ret = -map_errno_from_nt_status(status);
+ goto err_out;
+ }
+
+ DBG_DEBUG("enumerating shadow copy dir at %s\n",
+ snaps_dname->base_name);
+
+ /*
+ * CephFS stat(dir).size *normally* returns the number of child entries
+ * for a given dir, but it unfortunately that's not the case for the one
+ * place we need it (dir=.snap), so we need to dynamically determine it
+ * via readdir.
+ */
+ d = SMB_VFS_NEXT_OPENDIR(handle, snaps_dname, NULL, 0);
+ if (d == NULL) {
+ ret = -errno;
+ goto err_out;
+ }
+
+ slots = 0;
+ sc_data->num_volumes = 0;
+ sc_data->labels = NULL;
+
+ for (e = SMB_VFS_NEXT_READDIR(handle, d, NULL);
+ e != NULL;
+ e = SMB_VFS_NEXT_READDIR(handle, d, NULL)) {
+ if (ISDOT(e->d_name) || ISDOTDOT(e->d_name)) {
+ continue;
+ }
+ sc_data->num_volumes++;
+ if (!labels) {
+ continue;
+ }
+ if (sc_data->num_volumes > slots) {
+ uint32_t new_slot_count = slots + 10;
+ SMB_ASSERT(new_slot_count > slots);
+ sc_data->labels = talloc_realloc(sc_data,
+ sc_data->labels,
+ SHADOW_COPY_LABEL,
+ new_slot_count);
+ if (sc_data->labels == NULL) {
+ ret = -ENOMEM;
+ goto err_closedir;
+ }
+ memset(sc_data->labels[slots], 0,
+ sizeof(SHADOW_COPY_LABEL) * 10);
+
+ DBG_DEBUG("%d->%d slots for enum_snaps response\n",
+ slots, new_slot_count);
+ slots = new_slot_count;
+ }
+ DBG_DEBUG("filling shadow copy label for %s/%s\n",
+ snaps_dname->base_name, e->d_name);
+ ret = ceph_snap_fill_label(handle, snaps_dname,
+ snaps_dname->base_name, e->d_name,
+ sc_data->labels[sc_data->num_volumes - 1]);
+ if (ret < 0) {
+ goto err_closedir;
+ }
+ }
+
+ ret = SMB_VFS_NEXT_CLOSEDIR(handle, d);
+ if (ret != 0) {
+ ret = -errno;
+ goto err_out;
+ }
+
+ DBG_DEBUG("%s shadow copy enumeration found %d labels \n",
+ snaps_dname->base_name, sc_data->num_volumes);
+
+ return 0;
+
+err_closedir:
+ SMB_VFS_NEXT_CLOSEDIR(handle, d);
+err_out:
+ TALLOC_FREE(sc_data->labels);
+ return ret;
+}
+
+/*
+ * Prior reading: The Meaning of Path Names
+ * https://wiki.samba.org/index.php/Writing_a_Samba_VFS_Module
+ *
+ * translate paths so that we can use the parent dir for .snap access:
+ * myfile -> parent= trimmed=myfile
+ * /a -> parent=/ trimmed=a
+ * dir/sub/file -> parent=dir/sub trimmed=file
+ * /dir/sub -> parent=/dir/ trimmed=sub
+ */
+static int ceph_snap_get_parent_path(const char *connectpath,
+ const char *path,
+ char *_parent_buf,
+ size_t buflen,
+ const char **_trimmed)
+{
+ const char *p;
+ size_t len;
+ int ret;
+
+ if (!strcmp(path, "/")) {
+ DBG_ERR("can't go past root for %s .snap dir\n", path);
+ return -EINVAL;
+ }
+
+ p = strrchr_m(path, '/'); /* Find final '/', if any */
+ if (p == NULL) {
+ DBG_DEBUG("parent .snap dir for %s is cwd\n", path);
+ ret = strlcpy(_parent_buf, "", buflen);
+ if (ret >= buflen) {
+ return -EINVAL;
+ }
+ if (_trimmed != NULL) {
+ *_trimmed = path;
+ }
+ return 0;
+ }
+
+ SMB_ASSERT(p >= path);
+ len = p - path;
+
+ ret = snprintf(_parent_buf, buflen, "%.*s", (int)len, path);
+ if (ret >= buflen) {
+ return -EINVAL;
+ }
+
+ /* for absolute paths, check that we're not going outside the share */
+ if ((len > 0) && (_parent_buf[0] == '/')) {
+ bool connectpath_match = false;
--
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