[PATCH] Create a 'binddns dir' for files used by the bind_dlz module and named

Andreas Schneider asn at samba.org
Tue Sep 12 14:25:06 UTC 2017


On Tuesday, 12 September 2017 14:48:23 CEST Andreas Schneider via samba-
technical wrote:
> On Wednesday, 6 September 2017 11:27:38 CEST Andreas Schneider via samba-
> 
> technical wrote:
> > On Tuesday, 5 September 2017 12:31:20 CEST Andreas Schneider via samba-
> > 
> > technical wrote:
> > > On Monday, 4 September 2017 21:22:39 CEST Andrew Bartlett wrote:
> > > > Andreas,
> > > 
> > > Andrew,
> > > 
> > > > I know this won't make you very happy, but I think this is a 4.8 patch
> > > > at this point.  You can of course patch Fedora packages, but I fear
> > > > further dragons, given the fight it has given so far, and while parts
> > > > of the DLZ mode are tested (thankfully!) the whole integration is not
> > > > verified in make test.
> > 
> > Hi,
> > 
> > > would you accept it if Marc and I would do manual testing and fix
> > > remaining
> > > issues.
> > > 
> > > This means upgrading from 4.6 to 4.7 with my patchset and check if it
> > > works
> > > seemlessly.
> > > Switching backends etc.
> > > 
> > > I do not feel very happy with the current code and giving named broad
> > > access to keytab and AD partitions.
> > > 
> > > Also when switching from bind_dlz to the internal DNS we should remove
> > > files which give the named group full access to AD.
> > 
> > Jeremy pushed the last patchset from this thread to master.
> > 
> > Yesterday I asked Marc for help. He tested the feature and we discussed
> > several aspects, especially security concerns, like file and directory
> > permission.
> > We fixed some issues we found during extensive testing and we improved the
> > messages samba-tool and samba_upgradedns print so that the user knows what
> > he has to do.
> > We also found some things we need to fix in the documentation in the wiki.
> > 
> > 
> > The attached patchset addresses the remaining issues. Marc will answer and
> > add the test plan we created and he followed.
> > 
> > I hope this gives you the confidence in the changes that we can include
> > them in 4.7.
> > 
> > Please review carefully.
> 
> Ping!

With another fix. We need to honor make DESTDIR=/home/abuild/rpmbuild install.
 
> > Thanks,
> > 
> > 	Andreas
> > 
> > P.S.: The internel DNS server doesn't work in 4.7 and master
> > 
> >       https://bugzilla.samba.org/show_bug.cgi?id=13019


-- 
Andreas Schneider                   GPG-ID: CC014E3D
Samba Team                             asn at samba.org
www.samba.org
-------------- next part --------------
>From 86051302a61987cf9a1619718caab3284ecf5877 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Tue, 5 Sep 2017 14:18:44 +0200
Subject: [PATCH 01/10] wafsamba: Do not chmod already existing dirs on install

This might break backward compatibility.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 buildtools/wafsamba/wafsamba.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/buildtools/wafsamba/wafsamba.py b/buildtools/wafsamba/wafsamba.py
index 57913af2bd7..f91adca1a0c 100644
--- a/buildtools/wafsamba/wafsamba.py
+++ b/buildtools/wafsamba/wafsamba.py
@@ -900,8 +900,6 @@ def INSTALL_DIR(bld, path, chmod=0o755):
             except OSError, e:
                 if not os.path.isdir(path):
                     raise Utils.WafError("Cannot create the folder '%s' (error: %s)" % (path, e))
-        else:
-            os.chmod(path, chmod)
 Build.BuildContext.INSTALL_DIR = INSTALL_DIR
 
 def INSTALL_DIRS(bld, destdir, dirs, chmod=0o755):
-- 
2.14.1


>From 05921ff542a602da33164ff1d9c5eb46386e44a7 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Tue, 5 Sep 2017 20:36:47 +0200
Subject: [PATCH 02/10] samba:provision: Give a hint to copy the krb5.conf and
 not symlink it

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 python/samba/provision/__init__.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/python/samba/provision/__init__.py b/python/samba/provision/__init__.py
index f820f6ab675..8a8c033105f 100644
--- a/python/samba/provision/__init__.py
+++ b/python/samba/provision/__init__.py
@@ -2200,6 +2200,9 @@ def provision(logger, session_info, smbconf=None,
                          realm=names.realm)
         logger.info("A Kerberos configuration suitable for Samba AD has been "
                     "generated at %s", paths.krb5conf)
+        logger.info("Merge the contents of this file with your system "
+                    "krb5.conf or replace it with this one. Do not create a "
+                    "symlink!")
 
         if serverrole == "active directory domain controller":
             create_dns_update_list(lp, logger, paths)
-- 
2.14.1


>From 44100f933073a1d924541fa95eca857fe7dacfef Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Thu, 10 Aug 2017 15:04:08 +0200
Subject: [PATCH 03/10] dynconfig: Fix location of the default 'binddns dir'

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 dynconfig/wscript | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/dynconfig/wscript b/dynconfig/wscript
index fee37eaaf5f..54977e42bd4 100644
--- a/dynconfig/wscript
+++ b/dynconfig/wscript
@@ -174,6 +174,12 @@ dynconfig = {
          'OPTION':    '--with-privatedir',
          'HELPTEXT':  'Where to put sam.ldb and other private files',
     },
+    'BINDDNS_DIR' : {
+         'STD-PATH':  '${PREFIX}/bind-dns',
+         'FHS-PATH':  '${LOCALSTATEDIR}/lib/samba/bind-dns',
+         'OPTION':    '--with-bind-dns-dir',
+         'HELPTEXT':  'bind-dns config directory',
+    },
     'LOCKDIR' : {
          'STD-PATH':  '${LOCALSTATEDIR}/lock',
          'FHS-PATH':  '${LOCALSTATEDIR}/lock/samba',
@@ -192,12 +198,6 @@ dynconfig = {
          'OPTION':    '--with-statedir',
          'HELPTEXT':  'Where to put persistent state files',
     },
-    'BINDDNS_DIR' : {
-         'STD-PATH':  '${LOCALSTATEDIR}/lib',
-         'FHS-PATH':  '${LOCALSTATEDIR}/lib/samba/bind-dns',
-         'OPTION':    '--with-bind-dns-dir',
-         'HELPTEXT':  'bind-dns config directory',
-    },
     'CACHEDIR' : {
          'STD-PATH':  '${LOCALSTATEDIR}/cache',
          'FHS-PATH':  '${LOCALSTATEDIR}/cache/samba',
-- 
2.14.1


>From 789d3a701fbb960539334a920131b78eb613be47 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Tue, 22 Aug 2017 17:10:01 +0200
Subject: [PATCH 04/10] s4:bind_dlz: Try the 'binddns dir' first

The directory is normally empty if you did not provision or call
samba_upgradedns for the bind_dlz module.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 source4/dns_server/dlz_bind9.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/source4/dns_server/dlz_bind9.c b/source4/dns_server/dlz_bind9.c
index 75a9ce0f648..5079257c9fe 100644
--- a/source4/dns_server/dlz_bind9.c
+++ b/source4/dns_server/dlz_bind9.c
@@ -682,9 +682,9 @@ _PUBLIC_ isc_result_t dlz_create(const char *dlzname,
 	}
 
 	if (state->options.url == NULL) {
-		state->options.url = lpcfg_private_path(state,
-							state->lp,
-							"dns/sam.ldb");
+		state->options.url = talloc_asprintf(state,
+						     "%s/dns/sam.ldb",
+						     lpcfg_binddns_dir(state->lp));
 		if (state->options.url == NULL) {
 			result = ISC_R_NOMEMORY;
 			goto failed;
@@ -693,7 +693,7 @@ _PUBLIC_ isc_result_t dlz_create(const char *dlzname,
 		if (!file_exist(state->options.url)) {
 			state->options.url = talloc_asprintf(state,
 							     "%s/dns/sam.ldb",
-							     lpcfg_binddns_dir(state->lp));
+							     lpcfg_private_dir(state->lp));
 			if (state->options.url == NULL) {
 				result = ISC_R_NOMEMORY;
 				goto failed;
@@ -1324,7 +1324,7 @@ _PUBLIC_ isc_boolean_t dlz_ssumatch(const char *signer, const char *name, const
 
 	keytab_file = talloc_asprintf(tmp_ctx,
 				      "%s/dns.keytab",
-				      lpcfg_private_dir(state->lp));
+				      lpcfg_binddns_dir(state->lp));
 	if (keytab_file == NULL) {
 		state->log(ISC_LOG_ERROR, "samba_dlz: Out of memory!");
 		talloc_free(tmp_ctx);
@@ -1334,7 +1334,7 @@ _PUBLIC_ isc_boolean_t dlz_ssumatch(const char *signer, const char *name, const
 	if (!file_exist(keytab_file)) {
 		keytab_file = talloc_asprintf(tmp_ctx,
 					      "%s/dns.keytab",
-					      lpcfg_binddns_dir(state->lp));
+					      lpcfg_private_dir(state->lp));
 		if (keytab_file == NULL) {
 			state->log(ISC_LOG_ERROR, "samba_dlz: Out of memory!");
 			talloc_free(tmp_ctx);
-- 
2.14.1


>From 35232209be8f9fa8219d9af33bb0ea755fa189cd Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Wed, 6 Sep 2017 07:23:57 +0200
Subject: [PATCH 05/10] python:provision: Change the group of the 'binddns dir'
 too

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 python/samba/provision/__init__.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/python/samba/provision/__init__.py b/python/samba/provision/__init__.py
index 8a8c033105f..07c24795477 100644
--- a/python/samba/provision/__init__.py
+++ b/python/samba/provision/__init__.py
@@ -2238,6 +2238,14 @@ def provision(logger, session_info, smbconf=None,
 
         # chown the dns.keytab in the bind-dns directory
         if paths.bind_gid is not None:
+            try:
+                os.chmod(paths.binddns_dir, 0770)
+                os.chown(paths.binddns_dir, -1, paths.bind_gid)
+            except OSError:
+                if not os.environ.has_key('SAMBA_SELFTEST'):
+                    logger.info("Failed to chown %s to bind gid %u",
+                                paths.binddns_dir, paths.bind_gid)
+
             try:
                 os.chmod(bind_dns_keytab_path, 0640)
                 os.chown(bind_dns_keytab_path, -1, paths.bind_gid)
-- 
2.14.1


>From 798d7bc6959699ab1f62dc0cfb63e20dcbca39b1 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Wed, 6 Sep 2017 07:25:04 +0200
Subject: [PATCH 06/10] python:provision: Do not change the owner of the
 sam.ldb.d dir

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 python/samba/provision/sambadns.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/python/samba/provision/sambadns.py b/python/samba/provision/sambadns.py
index d4cb93a89ea..c95583162e7 100644
--- a/python/samba/provision/sambadns.py
+++ b/python/samba/provision/sambadns.py
@@ -864,9 +864,6 @@ def create_samdb_copy(samdb, logger, paths, names, domainsid, domainguid):
     # Give bind read/write permissions dns partitions
     if paths.bind_gid is not None:
         try:
-            os.chown(samldb_dir, -1, paths.bind_gid)
-            os.chmod(samldb_dir, 0750)
-
             for dirname, dirs, files in os.walk(dns_dir):
                 for d in dirs:
                     dpath = os.path.join(dirname, d)
-- 
2.14.1


>From 377ce500daa83c2d20bd9bc7edb4a39e460e3aa5 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Wed, 6 Sep 2017 10:06:40 +0200
Subject: [PATCH 07/10] samba_upgradedns: Change the group of the 'binddns dir'
 too

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 source4/scripting/bin/samba_upgradedns | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/source4/scripting/bin/samba_upgradedns b/source4/scripting/bin/samba_upgradedns
index 2582da0f6bc..db3ef5c6d65 100755
--- a/source4/scripting/bin/samba_upgradedns
+++ b/source4/scripting/bin/samba_upgradedns
@@ -505,6 +505,13 @@ if __name__ == '__main__':
 
             # chown the dns.keytab in the bind-dns directory
             if paths.bind_gid is not None:
+                try:
+                    os.chmod(paths.binddns_dir, 0o770)
+                    os.chown(paths.binddns_dir, -1, paths.bind_gid)
+                except OSError:
+                    if not os.environ.has_key('SAMBA_SELFTEST'):
+                        logger.info("Failed to chown %s to bind gid %u",
+                                    paths.binddns_dir, paths.bind_gid)
                 try:
                     os.chmod(bind_dns_keytab_path, 0640)
                     os.chown(bind_dns_keytab_path, -1, paths.bind_gid)
-- 
2.14.1


>From cdf9e1dfb0c94f5d8015ec4b9b23201068a7b955 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Wed, 6 Sep 2017 07:25:40 +0200
Subject: [PATCH 08/10] samba_upgradedns: Print better hints after we migrated
 the config

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 source4/scripting/bin/samba_upgradedns | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/source4/scripting/bin/samba_upgradedns b/source4/scripting/bin/samba_upgradedns
index db3ef5c6d65..3369bcfed93 100755
--- a/source4/scripting/bin/samba_upgradedns
+++ b/source4/scripting/bin/samba_upgradedns
@@ -442,6 +442,12 @@ if __name__ == '__main__':
 
     # Special stuff for DLZ backend
     if opts.dns_backend == "BIND9_DLZ":
+        config_migration = False
+
+        if (paths.private_dir != paths.binddns_dir and
+            os.path.isfile(os.path.join(paths.private_dir, "named.conf"))):
+            config_migration = True
+
         # Check if dns-HOSTNAME account exists and create it if required
         secrets_msgs = ldbs.secrets.search(expression='(samAccountName=dns-%s)' % hostname, attrs=['secret'])
         msg = ldbs.sam.search(base=domaindn, scope=ldb.SCOPE_DEFAULT,
@@ -537,9 +543,15 @@ if __name__ == '__main__':
 
         cleanup_obsolete_dns_files(paths)
 
-        logger.info("See %s for an example configuration include file for BIND", paths.namedconf)
-        logger.info("and %s for further documentation required for secure DNS "
-                    "updates", paths.namedtxt)
+        if config_migration:
+            logger.info("ATTENTION: The BIND configuration and keytab has been moved to: %s",
+                        paths.binddns_dir)
+            logger.info("           Please update your BIND configuration accordingly.")
+        else:
+            logger.info("See %s for an example configuration include file for BIND", paths.namedconf)
+            logger.info("and %s for further documentation required for secure DNS "
+                        "updates", paths.namedtxt)
+
     elif opts.dns_backend == "SAMBA_INTERNAL":
         # Check if dns-HOSTNAME account exists and delete it if required
         try:
-- 
2.14.1


>From a459b0c6875a2cd6fac4c89a23073a92d78b60b4 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Tue, 5 Sep 2017 11:47:27 +0200
Subject: [PATCH 09/10] samba_upgradedns: When we setup the internal dns
 cleanup bind-dns dir

Make sure to remove everything from the bind-dns directory to avoid
possible security issues with the named group having write access to all
AD partions

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 source4/scripting/bin/samba_upgradedns | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/source4/scripting/bin/samba_upgradedns b/source4/scripting/bin/samba_upgradedns
index 3369bcfed93..261d8a1922d 100755
--- a/source4/scripting/bin/samba_upgradedns
+++ b/source4/scripting/bin/samba_upgradedns
@@ -553,6 +553,23 @@ if __name__ == '__main__':
                         "updates", paths.namedtxt)
 
     elif opts.dns_backend == "SAMBA_INTERNAL":
+        # Make sure to remove everything from the bind-dns directory to avoid
+        # possible security issues with the named group having write access
+        # to all AD partions
+        cleanup_remove_file(os.path.join(paths.binddns_dir, "dns.keytab"))
+        cleanup_remove_file(os.path.join(paths.binddns_dir, "named.conf"))
+        cleanup_remove_file(os.path.join(paths.binddns_dir, "named.conf.update"))
+        cleanup_remove_file(os.path.join(paths.binddns_dir, "named.txt"))
+
+        cleanup_remove_dir(os.path.dirname(paths.dns))
+
+        try:
+            os.chmod(paths.private_dir, 0o700)
+            os.chown(paths.private_dir, -1, 0)
+        except:
+            logger.warn("Failed to restore owner and permissions for %s",
+                        (paths.private_dir))
+
         # Check if dns-HOSTNAME account exists and delete it if required
         try:
             dn_str = 'samAccountName=dns-%s,CN=Principals' % hostname
-- 
2.14.1


>From f9cdbd5946161b79b08a0d5043d00708e7ebda06 Mon Sep 17 00:00:00 2001
From: Andreas Schneider <asn at samba.org>
Date: Tue, 12 Sep 2017 15:56:44 +0200
Subject: [PATCH 10/10] wafsamba: We need to honor DESTDIR in INSTALL_DIR

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12957

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 buildtools/wafsamba/wafsamba.py | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/buildtools/wafsamba/wafsamba.py b/buildtools/wafsamba/wafsamba.py
index f91adca1a0c..23fd3c48342 100644
--- a/buildtools/wafsamba/wafsamba.py
+++ b/buildtools/wafsamba/wafsamba.py
@@ -885,29 +885,30 @@ def INSTALL_WILDCARD(bld, destdir, pattern, chmod=MODE_644, flat=False,
                   python_fixup=python_fixup, base_name=trim_path)
 Build.BuildContext.INSTALL_WILDCARD = INSTALL_WILDCARD
 
-def INSTALL_DIR(bld, path, chmod=0o755):
+def INSTALL_DIR(bld, path, chmod=0o755, env=None):
     """Install a directory if it doesn't exist, always set permissions."""
 
     if not path:
         return []
 
+    destpath = bld.get_install_path(path, env)
+
     if bld.is_install > 0:
-        path = bld.EXPAND_VARIABLES(path)
-        if not os.path.isdir(path):
+        if not os.path.isdir(destpath):
             try:
-                os.makedirs(path)
-                os.chmod(path, chmod)
+                os.makedirs(destpath)
+                os.chmod(destpath, chmod)
             except OSError, e:
-                if not os.path.isdir(path):
+                if not os.path.isdir(destpath):
                     raise Utils.WafError("Cannot create the folder '%s' (error: %s)" % (path, e))
 Build.BuildContext.INSTALL_DIR = INSTALL_DIR
 
-def INSTALL_DIRS(bld, destdir, dirs, chmod=0o755):
+def INSTALL_DIRS(bld, destdir, dirs, chmod=0o755, env=None):
     '''install a set of directories'''
     destdir = bld.EXPAND_VARIABLES(destdir)
     dirs = bld.EXPAND_VARIABLES(dirs)
     for d in TO_LIST(dirs):
-        INSTALL_DIR(bld, os.path.join(destdir, d), chmod)
+        INSTALL_DIR(bld, os.path.join(destdir, d), chmod, env)
 Build.BuildContext.INSTALL_DIRS = INSTALL_DIRS
 
 
-- 
2.14.1



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