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From b08906169216fdec43008c38891145386017d12f Mon Sep 17 00:00:00 2001
From: Alexey Tikhonov <atikhono@redhat.com>
Date: Fri, 22 Mar 2019 16:06:49 +0100
Subject: [PATCH 12/15] responder/negcache: avoid calling nsswitch NSS API

Changed "negcache_files.c::is_*_local_by_*()" to use functions from
"libnss_files" directly to check users (instead of calling glibc
NSS API).
Changed affected tests to avoid using NSS-wrapper and to use real
local user&group (otherwise tests were broken).

Resolves: https://pagure.io/SSSD/sssd/issue/3964

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
(cherry picked from commit 2b564f849a20289a857cf19bbfaa5c6eb8670bad)

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
---
 Makefile.am                           |  20 +++
 src/responder/common/negcache.c       |  52 +++++-
 src/responder/common/negcache_files.c |  74 ++++-----
 src/responder/common/negcache_files.h |  12 +-
 src/tests/cwrap/Makefile.am           |   4 +
 src/tests/cwrap/test_negcache.c       | 227 +++++++++++++++++++-------
 src/tests/intg/test_ldap.py           | 114 ++++++-------
 7 files changed, 333 insertions(+), 170 deletions(-)

diff --git a/Makefile.am b/Makefile.am
index 05f5f4e26..6a67dc7b1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -569,6 +569,7 @@ SSSD_RESPONDER_IFACE_OBJ = \
 SSSD_RESPONDER_OBJ = \
     src/responder/common/negcache_files.c \
     src/responder/common/negcache.c \
+    src/util/nss_dl_load.c \
     src/responder/common/responder_cmd.c \
     src/responder/common/responder_common.c \
     src/responder/common/responder_dp.c \
@@ -1380,6 +1381,7 @@ sssd_nss_SOURCES = \
     src/responder/nss/nsssrv_mmap_cache.c \
     $(SSSD_RESPONDER_OBJ)
 sssd_nss_LDADD = \
+    $(LIBADD_DL) \
     $(TDB_LIBS) \
     $(SSSD_LIBS) \
     libsss_idmap.la \
@@ -1396,6 +1398,7 @@ sssd_pam_SOURCES = \
     src/responder/pam/pam_helpers.c \
     $(SSSD_RESPONDER_OBJ)
 sssd_pam_LDADD = \
+    $(LIBADD_DL) \
     $(TDB_LIBS) \
     $(SSSD_LIBS) \
     $(SELINUX_LIBS) \
@@ -1414,6 +1417,7 @@ sssd_sudo_SOURCES = \
     src/responder/sudo/sudosrv_dp.c \
     $(SSSD_RESPONDER_OBJ)
 sssd_sudo_LDADD = \
+    $(LIBADD_DL) \
     $(SSSD_LIBS) \
     $(SYSTEMD_DAEMON_LIBS) \
     $(SSSD_INTERNAL_LTLIBS)
@@ -1426,6 +1430,7 @@ sssd_autofs_SOURCES = \
     src/responder/autofs/autofssrv_dp.c \
     $(SSSD_RESPONDER_OBJ)
 sssd_autofs_LDADD = \
+    $(LIBADD_DL) \
     $(SSSD_LIBS) \
     $(SYSTEMD_DAEMON_LIBS) \
     $(SSSD_INTERNAL_LTLIBS)
@@ -1441,6 +1446,7 @@ sssd_ssh_SOURCES = \
     $(SSSD_RESPONDER_OBJ) \
     $(NULL)
 sssd_ssh_LDADD = \
+    $(LIBADD_DL) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
     $(SYSTEMD_DAEMON_LIBS) \
@@ -1457,6 +1463,7 @@ sssd_pac_CFLAGS = \
     $(AM_CFLAGS) \
     $(NDR_KRB5PAC_CFLAGS)
 sssd_pac_LDADD = \
+    $(LIBADD_DL) \
     $(NDR_KRB5PAC_LIBS) \
     $(TDB_LIBS) \
     $(SSSD_LIBS) \
@@ -1481,6 +1488,7 @@ sssd_ifp_SOURCES = \
 sssd_ifp_CFLAGS = \
     $(AM_CFLAGS)
 sssd_ifp_LDADD = \
+    $(LIBADD_DL) \
     $(SSSD_LIBS) \
     $(SYSTEMD_DAEMON_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -1525,6 +1533,7 @@ sssd_secrets_SOURCES = \
     $(SSSD_RESPONDER_OBJ) \
     $(NULL)
 sssd_secrets_LDADD = \
+    $(LIBADD_DL) \
     $(HTTP_PARSER_LIBS) \
     $(JANSSON_LIBS) \
     $(TDB_LIBS) \
@@ -1559,6 +1568,7 @@ sssd_kcm_CFLAGS = \
     $(JANSSON_CFLAGS) \
     $(NULL)
 sssd_kcm_LDADD = \
+    $(LIBADD_DL) \
     $(KRB5_LIBS) \
     $(CURL_LIBS) \
     $(JANSSON_LIBS) \
@@ -2254,6 +2264,7 @@ responder_socket_access_tests_SOURCES = \
     src/tests/responder_socket_access-tests.c \
     src/responder/common/negcache_files.c \
     src/responder/common/negcache.c \
+    src/util/nss_dl_load.c \
     src/responder/common/responder_common.c \
     src/responder/common/responder_packet.c \
     src/responder/common/responder_cmd.c \
@@ -2267,6 +2278,7 @@ responder_socket_access_tests_CFLAGS = \
     $(AM_CFLAGS) \
     $(CHECK_CFLAGS)
 responder_socket_access_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CHECK_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -2358,6 +2370,7 @@ TEST_MOCK_RESP_OBJ = \
      src/responder/common/responder_cmd.c \
      src/responder/common/negcache_files.c \
      src/responder/common/negcache.c \
+     src/util/nss_dl_load.c \
      src/responder/common/responder_common.c \
      src/responder/common/data_provider/rdp_message.c \
      src/responder/common/data_provider/rdp_client.c \
@@ -2409,6 +2422,7 @@ nss_srv_tests_LDFLAGS = \
     -Wl,-wrap,sss_cmd_send_empty \
     -Wl,-wrap,sss_cmd_done
 nss_srv_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -2444,6 +2458,7 @@ pam_srv_tests_LDFLAGS = \
     -Wl,-wrap,pam_dp_send_req \
     $(NULL)
 pam_srv_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(PAM_LIBS) \
     $(SSSD_LIBS) \
@@ -2480,6 +2495,7 @@ ssh_srv_tests_LDFLAGS = \
     -Wl,-wrap,ssh_dp_send_req \
     $(NULL)
 ssh_srv_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -2499,6 +2515,7 @@ responder_get_domains_tests_LDFLAGS = \
     -Wl,-wrap,sss_parse_name_for_domains \
     -Wl,-wrap,sss_ncache_reset_repopulate_permanent
 responder_get_domains_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -2578,6 +2595,7 @@ test_negcache_CFLAGS = \
     $(TALLOC_CFLAGS) \
     $(DHASH_CFLAGS)
 test_negcache_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SYSTEMD_DAEMON_LIBS) \
@@ -2922,6 +2940,7 @@ ifp_tests_SOURCES = \
 ifp_tests_CFLAGS = \
     $(AM_CFLAGS)
 ifp_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
@@ -3178,6 +3197,7 @@ responder_cache_req_tests_LDFLAGS = \
     -Wl,-wrap,sss_dp_get_account_send \
     $(NULL)
 responder_cache_req_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SSSD_INTERNAL_LTLIBS) \
diff --git a/src/responder/common/negcache.c b/src/responder/common/negcache.c
index f9034d164..d6f72d816 100644
--- a/src/responder/common/negcache.c
+++ b/src/responder/common/negcache.c
@@ -19,14 +19,16 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <fcntl.h>
+#include <time.h>
+#include "tdb.h"
 #include "util/util.h"
+#include "util/nss_dl_load.h"
 #include "confdb/confdb.h"
 #include "responder/common/negcache_files.h"
 #include "responder/common/responder.h"
 #include "responder/common/negcache.h"
-#include <fcntl.h>
-#include <time.h>
-#include "tdb.h"
+
 
 #define NC_ENTRY_PREFIX "NCE/"
 #define NC_USER_PREFIX NC_ENTRY_PREFIX"USER"
@@ -44,6 +46,7 @@ struct sss_nc_ctx {
     struct tdb_context *tdb;
     uint32_t timeout;
     uint32_t local_timeout;
+    struct sss_nss_ops ops;
 };
 
 typedef int (*ncache_set_byname_fn_t)(struct sss_nc_ctx *, bool,
@@ -63,14 +66,49 @@ static int string_to_tdb_data(char *str, TDB_DATA *ret)
     return EOK;
 }
 
+static errno_t ncache_load_nss_symbols(struct sss_nss_ops *ops)
+{
+    errno_t ret;
+    size_t i;
+
+    ret = sss_load_nss_symbols(ops, "files");
+    if (ret != EOK) {
+        return ret;
+    }
+
+    void *mandatory_syms[] = {
+        (void*)ops->getpwnam_r,
+        (void*)ops->getpwuid_r,
+        (void*)ops->getgrnam_r,
+        (void*)ops->getgrgid_r
+    };
+    for (i = 0; i < sizeof(mandatory_syms)/sizeof(mandatory_syms[0]); ++i) {
+        if (!mandatory_syms[i]) {
+            DEBUG(SSSDBG_CRIT_FAILURE, "The 'files' library does not provide mandatory function");
+            return ELIBBAD;
+        }
+    }
+
+    return EOK;
+}
+
 int sss_ncache_init(TALLOC_CTX *memctx, uint32_t timeout,
                     uint32_t local_timeout, struct sss_nc_ctx **_ctx)
 {
+    errno_t ret;
     struct sss_nc_ctx *ctx;
 
     ctx = talloc_zero(memctx, struct sss_nc_ctx);
     if (!ctx) return ENOMEM;
 
+    ret = ncache_load_nss_symbols(&ctx->ops);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_FATAL_FAILURE, "Unable to load NSS symbols [%d]: %s\n",
+              ret, sss_strerror(ret));
+        talloc_free(ctx);
+        return ret;
+    }
+
     errno = 0;
     /* open a memory only tdb with default hash size */
     ctx->tdb = tdb_open("memcache", 0, TDB_INTERNAL, O_RDWR|O_CREAT, 0);
@@ -488,7 +526,7 @@ static int sss_ncache_set_user_int(struct sss_nc_ctx *ctx, bool permanent,
     if (!str) return ENOMEM;
 
     if ((!permanent) && (ctx->local_timeout > 0)) {
-        use_local_negative = is_user_local_by_name(name);
+        use_local_negative = is_user_local_by_name(&ctx->ops, name);
     }
     ret = sss_ncache_set_str(ctx, str, permanent, use_local_negative);
 
@@ -509,7 +547,7 @@ static int sss_ncache_set_group_int(struct sss_nc_ctx *ctx, bool permanent,
     if (!str) return ENOMEM;
 
     if ((!permanent) && (ctx->local_timeout > 0)) {
-        use_local_negative = is_group_local_by_name(name);
+        use_local_negative = is_group_local_by_name(&ctx->ops, name);
     }
     ret = sss_ncache_set_str(ctx, str, permanent, use_local_negative);
 
@@ -606,7 +644,7 @@ int sss_ncache_set_uid(struct sss_nc_ctx *ctx, bool permanent,
     if (!str) return ENOMEM;
 
     if ((!permanent) && (ctx->local_timeout > 0)) {
-        use_local_negative = is_user_local_by_uid(uid);
+        use_local_negative = is_user_local_by_uid(&ctx->ops, uid);
     }
     ret = sss_ncache_set_str(ctx, str, permanent, use_local_negative);
 
@@ -630,7 +668,7 @@ int sss_ncache_set_gid(struct sss_nc_ctx *ctx, bool permanent,
     if (!str) return ENOMEM;
 
     if ((!permanent) && (ctx->local_timeout > 0)) {
-        use_local_negative = is_group_local_by_gid(gid);
+        use_local_negative = is_group_local_by_gid(&ctx->ops, gid);
     }
     ret = sss_ncache_set_str(ctx, str, permanent, use_local_negative);
 
diff --git a/src/responder/common/negcache_files.c b/src/responder/common/negcache_files.c
index 4256186d9..85a7065a4 100644
--- a/src/responder/common/negcache_files.c
+++ b/src/responder/common/negcache_files.c
@@ -19,94 +19,90 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <sys/types.h>
-#include <pwd.h>
-#include <grp.h>
 #include "util/util.h"
+#include "util/nss_dl_load.h"
 #include "responder/common/negcache_files.h"
 
 #define BUFFER_SIZE 16384
 
-bool is_user_local_by_name(const char *name)
+bool is_user_local_by_name(const struct sss_nss_ops *ops, const char *name)
 {
     struct passwd pwd = { 0 };
-    struct passwd *pwd_result;
+    int errnop;
     char buffer[BUFFER_SIZE];
-    bool is_local = false;
-    int ret;
+    enum nss_status ret;
     char *shortname = NULL;
+    int parse_ret;
 
-    ret = sss_parse_internal_fqname(NULL, name, &shortname, NULL);
-    if (ret != EOK) {
+    parse_ret = sss_parse_internal_fqname(NULL, name, &shortname, NULL);
+    if (parse_ret != EOK) {
         return false;
     }
 
-    ret = getpwnam_r(shortname, &pwd, buffer, BUFFER_SIZE, &pwd_result);
+    ret = ops->getpwnam_r(shortname, &pwd, buffer, BUFFER_SIZE, &errnop);
     talloc_free(shortname);
-    if (ret == EOK && pwd_result != NULL) {
+    if (ret == NSS_STATUS_SUCCESS) {
         DEBUG(SSSDBG_TRACE_FUNC, "User %s is a local user\n", name);
-        is_local = true;
+        return true;
     }
 
-    return is_local;
+    return false;
 }
 
-bool is_user_local_by_uid(uid_t uid)
+bool is_user_local_by_uid(const struct sss_nss_ops *ops, uid_t uid)
 {
     struct passwd pwd = { 0 };
-    struct passwd *pwd_result;
+    int errnop;
     char buffer[BUFFER_SIZE];
-    bool is_local = false;
-    int ret;
+    enum nss_status ret;
 
-    ret = getpwuid_r(uid, &pwd, buffer, BUFFER_SIZE, &pwd_result);
-    if (ret == EOK && pwd_result != NULL) {
+    ret = ops->getpwuid_r(uid, &pwd, buffer, BUFFER_SIZE, &errnop);
+    if (ret == NSS_STATUS_SUCCESS) {
         DEBUG(SSSDBG_TRACE_FUNC,
               "User with UID %"SPRIuid" is a local user\n", uid);
-        is_local = true;
+        return true;
     }
 
-    return is_local;
+    return false;
 }
 
-bool is_group_local_by_name(const char *name)
+bool is_group_local_by_name(const struct sss_nss_ops *ops, const char *name)
 {
     struct group grp = { 0 };
-    struct group *grp_result;
+    int errnop;
     char buffer[BUFFER_SIZE];
-    bool is_local = false;
-    int ret;
+    enum nss_status ret;
     char *shortname = NULL;
+    int parse_ret;
 
-    ret = sss_parse_internal_fqname(NULL, name, &shortname, NULL);
-    if (ret != EOK) {
+    parse_ret = sss_parse_internal_fqname(NULL, name, &shortname, NULL);
+    if (parse_ret != EOK) {
         return false;
     }
 
-    ret = getgrnam_r(shortname, &grp, buffer, BUFFER_SIZE, &grp_result);
+    ret = ops->getgrnam_r(shortname, &grp, buffer, BUFFER_SIZE, &errnop);
     talloc_free(shortname);
-    if (ret == EOK && grp_result != NULL) {
+    if (ret == NSS_STATUS_SUCCESS) {
         DEBUG(SSSDBG_TRACE_FUNC, "Group %s is a local group\n", name);
-        is_local = true;
+        return true;
     }
 
-    return is_local;
+    return false;
 }
 
-bool is_group_local_by_gid(uid_t gid)
+bool is_group_local_by_gid(const struct sss_nss_ops *ops, uid_t gid)
 {
     struct group grp = { 0 };
-    struct group *grp_result;
+    int errnop;
     char buffer[BUFFER_SIZE];
-    bool is_local = false;
-    int ret;
+    enum nss_status ret;
 
-    ret = getgrgid_r(gid, &grp, buffer, BUFFER_SIZE, &grp_result);
-    if (ret == EOK && grp_result != NULL) {
+    ret = ops->getgrgid_r(gid, &grp, buffer, BUFFER_SIZE, &errnop);
+    if (ret == NSS_STATUS_SUCCESS) {
         DEBUG(SSSDBG_TRACE_FUNC,
               "Group with GID %"SPRIgid" is a local group\n", gid);
-        is_local = true;
+        return true;
     }
 
-    return is_local;
+    return false;
 }
diff --git a/src/responder/common/negcache_files.h b/src/responder/common/negcache_files.h
index 01d9f0828..a3e18deb0 100644
--- a/src/responder/common/negcache_files.h
+++ b/src/responder/common/negcache_files.h
@@ -22,10 +22,14 @@
 #ifndef _NEGCACHE_FILES_H_
 #define _NEGCACHE_FILES_H_
 
-bool is_user_local_by_name(const char *name);
-bool is_user_local_by_uid(uid_t uid);
+#include <stdbool.h>
 
-bool is_group_local_by_name(const char *name);
-bool is_group_local_by_gid(uid_t gid);
+struct sss_nss_ops;
+
+bool is_user_local_by_name(const struct sss_nss_ops *ops, const char *name);
+bool is_user_local_by_uid(const struct sss_nss_ops *ops, uid_t uid);
+
+bool is_group_local_by_name(const struct sss_nss_ops *ops, const char *name);
+bool is_group_local_by_gid(const struct sss_nss_ops *ops, uid_t gid);
 
 #endif /* _NEGCACHE_FILES_H_ */
diff --git a/src/tests/cwrap/Makefile.am b/src/tests/cwrap/Makefile.am
index a559abe9e..bfc493395 100644
--- a/src/tests/cwrap/Makefile.am
+++ b/src/tests/cwrap/Makefile.am
@@ -75,6 +75,7 @@ SSSD_RESPONDER_IFACE_OBJ = \
 
 SSSD_RESPONDER_OBJ = \
     ../../../src/responder/common/negcache_files.c \
+    ../../../src/util/nss_dl_load.c \
     ../../../src/responder/common/negcache.c \
     ../../../src/responder/common/responder_cmd.c \
     ../../../src/responder/common/responder_common.c \
@@ -175,6 +176,7 @@ responder_common_tests_SOURCES =\
     ../../../src/responder/common/iface/responder_ncache.c \
     ../../../src/responder/common/iface/responder_iface_generated.c \
     ../../../src/responder/common/negcache_files.c \
+    ../../../src/util/nss_dl_load.c \
     ../../../src/responder/common/negcache.c \
     ../../../src/responder/common/data_provider/rdp_message.c \
     ../../../src/responder/common/data_provider/rdp_client.c \
@@ -189,6 +191,7 @@ responder_common_tests_CFLAGS = \
     $(AM_CFLAGS) \
     $(NULL)
 responder_common_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SELINUX_LIBS) \
@@ -207,6 +210,7 @@ negcache_tests_CFLAGS = \
     -DBASE_FILE_STEM=\"$(*F)\" \
     $(NULL)
 negcache_tests_LDADD = \
+    $(LIBADD_DL) \
     $(CMOCKA_LIBS) \
     $(SSSD_LIBS) \
     $(SELINUX_LIBS) \
diff --git a/src/tests/cwrap/test_negcache.c b/src/tests/cwrap/test_negcache.c
index c4f601b34..690e797e2 100644
--- a/src/tests/cwrap/test_negcache.c
+++ b/src/tests/cwrap/test_negcache.c
@@ -18,6 +18,10 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <stdio.h>
+#include <sys/types.h>
+#include <pwd.h>
+
 #include <stdarg.h>
 #include <stddef.h>
 #include <setjmp.h>
@@ -35,38 +39,40 @@
 #define TEST_CONF_DB "test_negcache_confdb.ldb"
 #define TEST_DOM_NAME "test_domain.test"
 
-#define TEST_LOCAL_USER_NAME_1 "foobar"
-#define TEST_LOCAL_USER_NAME_2 "sssd"
-
-#define TEST_LOCAL_USER_UID_1 10001
-#define TEST_LOCAL_USER_UID_2 123
-
-#define TEST_LOCAL_GROUP_NAME_1 "foogroup"
-#define TEST_LOCAL_GROUP_NAME_2 "sssd"
-
-#define TEST_LOCAL_GID_1 10001
-#define TEST_LOCAL_GID_2 123
-
-struct test_user {
+struct user_descriptor_t {
     const char *name;
     uid_t uid;
+};
+
+struct group_descriptor_t {
+    const char *name;
     gid_t gid;
-} users[] = { { "test_user1", 1001, 50001 },
-              { "test_user2", 1002, 50002 } };
+};
 
-static void create_users(TALLOC_CTX *mem_ctx,
-                         struct sss_domain_info *domain)
+struct ncache_test_ctx {
+    struct sss_test_ctx *tctx;
+    struct sss_nc_ctx *ncache;
+    struct user_descriptor_t local_users[2];
+    struct user_descriptor_t non_local_users[2];
+    struct group_descriptor_t local_groups[2];
+    struct group_descriptor_t non_local_groups[2];
+};
+
+static void create_users(struct ncache_test_ctx *test_ctx)
 {
     errno_t ret;
     char *fqname;
+    struct sss_domain_info *domain = test_ctx->tctx->dom;
+    const struct user_descriptor_t *users = test_ctx->non_local_users;
+    const struct group_descriptor_t *groups = test_ctx->non_local_groups;
 
     for (int i = 0; i < 2; i++) {
-        fqname = sss_create_internal_fqname(mem_ctx,
+        fqname = sss_create_internal_fqname(test_ctx,
                                             users[i].name,
                                             domain->name);
         assert_non_null(fqname);
 
-        ret = sysdb_add_user(domain, users[i].name, users[i].uid, users[i].gid,
+        ret = sysdb_add_user(domain, users[i].name, users[i].uid, groups[i].gid,
                              fqname, NULL, "/bin/bash", domain->name,
                              NULL, 30, time(NULL));
         talloc_free(fqname);
@@ -74,25 +80,15 @@ static void create_users(TALLOC_CTX *mem_ctx,
     }
 }
 
-struct test_group {
-    const char *name;
-    gid_t gid;
-} groups[] = { { "test_group1", 50001 },
-               { "test_group2", 50002 } };
-
-struct ncache_test_ctx {
-    struct sss_test_ctx *tctx;
-    struct sss_nc_ctx *ncache;
-};
-
-static void create_groups(TALLOC_CTX *mem_ctx,
-                          struct sss_domain_info *domain)
+static void create_groups(struct ncache_test_ctx *test_ctx)
 {
     errno_t ret;
     char *fqname;
+    struct sss_domain_info *domain = test_ctx->tctx->dom;
+    const struct group_descriptor_t *groups = test_ctx->non_local_groups;
 
     for (int i = 0; i < 2; i++) {
-        fqname = sss_create_internal_fqname(mem_ctx,
+        fqname = sss_create_internal_fqname(test_ctx,
                                             groups[i].name,
                                             domain->name);
         assert_non_null(fqname);
@@ -116,6 +112,114 @@ struct cli_protocol_version *register_cli_protocol_version(void)
     return responder_test_cli_protocol_version;
 }
 
+static void find_local_users(struct ncache_test_ctx *test_ctx)
+{
+    int i;
+    FILE *passwd_file;
+    const struct passwd *pwd;
+
+    passwd_file = fopen("/etc/passwd", "r");
+    assert_non_null(passwd_file);
+
+    for (i = 0; i < 2; /*no-op*/) {
+        pwd = fgetpwent(passwd_file);
+        assert_non_null(pwd);
+        if (pwd->pw_uid == 0) {
+            /* skip root */
+            continue;
+        }
+        test_ctx->local_users[i].uid = pwd->pw_uid;
+        test_ctx->local_users[i].name = talloc_strdup(test_ctx, pwd->pw_name);
+        assert_non_null(test_ctx->local_users[i].name);
+        ++i;
+    }
+
+    fclose(passwd_file);
+}
+
+static void find_local_groups(struct ncache_test_ctx *test_ctx)
+{
+    int i;
+    FILE *group_file;
+    const struct group *grp;
+
+    group_file = fopen("/etc/group", "r");
+    assert_non_null(group_file);
+
+    for (i = 0; i < 2; /* no-op */) {
+        grp = fgetgrent(group_file);
+        assert_non_null(grp);
+        if (grp->gr_gid == 0) {
+            /* skip root */
+            continue;
+        }
+        test_ctx->local_groups[i].gid = grp->gr_gid;
+        test_ctx->local_groups[i].name = talloc_strdup(test_ctx, grp->gr_name);
+        assert_non_null(test_ctx->local_groups[i].name);
+        ++i;
+    }
+
+    fclose(group_file);
+}
+
+static void find_non_local_users(struct ncache_test_ctx *test_ctx)
+{
+    int i;
+    int k;
+    uid_t uid;
+    char *name;
+
+    for (i = 0, k = 1; (k < 100) && (i < 2); ++k) {
+        uid = 65534-k;
+        if (getpwuid(uid)) {
+            continue;
+        }
+        test_ctx->non_local_users[i].uid = uid;
+        ++i;
+    }
+    assert_int_equal(i, 2);
+
+    for (i = 0, k = 0; (k < 100) && (i < 2); ++k) {
+        name = talloc_asprintf(test_ctx, "nctestuser%d", k);
+        if (getpwnam(name)) {
+            talloc_free(name);
+            continue;
+        }
+        test_ctx->non_local_users[i].name = name;
+        ++i;
+    }
+    assert_int_equal(i, 2);
+}
+
+static void find_non_local_groups(struct ncache_test_ctx *test_ctx)
+{
+    int i = 0;
+    int k;
+    gid_t gid;
+    char *name;
+
+    for (i = 0, k = 1; (k < 100) && (i < 2); ++k) {
+        gid = 65534-k;
+        if (getgrgid(gid)) {
+            continue;
+        }
+        test_ctx->non_local_groups[i].gid = gid;
+        ++i;
+    }
+    assert_int_equal(i, 2);
+
+    for (i = 0, k = 0; (k < 100) && (i < 2); ++k) {
+        name = talloc_asprintf(test_ctx, "nctestgroup%d", k);
+        if (getgrnam(name)) {
+            talloc_free(name);
+            continue;
+        }
+        test_ctx->non_local_groups[i].name = name;
+        ++i;
+    }
+    assert_int_equal(i, 2);
+}
+
 static int test_ncache_setup(void **state)
 {
     struct ncache_test_ctx *test_ctx;
@@ -125,14 +229,19 @@ static int test_ncache_setup(void **state)
     test_ctx = talloc_zero(global_talloc_context, struct ncache_test_ctx);
     assert_non_null(test_ctx);
 
+    find_local_users(test_ctx);
+    find_local_groups(test_ctx);
+    find_non_local_users(test_ctx);
+    find_non_local_groups(test_ctx);
+
     test_dom_suite_setup(TESTS_PATH);
 
     test_ctx->tctx = create_dom_test_ctx(test_ctx, TESTS_PATH, TEST_CONF_DB,
                                          TEST_DOM_NAME, "ipa", NULL);
     assert_non_null(test_ctx->tctx);
 
-    create_groups(test_ctx, test_ctx->tctx->dom);
-    create_users(test_ctx, test_ctx->tctx->dom);
+    create_groups(test_ctx);
+    create_users(test_ctx);
 
     check_leaks_push(test_ctx);
 
@@ -213,11 +322,11 @@ static void set_users(struct ncache_test_ctx *test_ctx)
     int ret;
 
     ret = set_user_in_ncache(test_ctx->ncache, false, test_ctx->tctx->dom,
-                              users[0].name);
+                             test_ctx->non_local_users[0].name);
     assert_int_equal(ret, EOK);
 
     ret = set_user_in_ncache(test_ctx->ncache, false, test_ctx->tctx->dom,
-                             TEST_LOCAL_USER_NAME_1);
+                             test_ctx->local_users[0].name);
     assert_int_equal(ret, EOK);
 }
 
@@ -227,19 +336,19 @@ static void check_users(struct ncache_test_ctx *test_ctx,
     int ret;
 
     ret = check_user_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                users[0].name);
+                                test_ctx->non_local_users[0].name);
     assert_int_equal(ret, case_a);
 
     ret = check_user_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                users[1].name);
+                                test_ctx->non_local_users[1].name);
     assert_int_equal(ret, case_b);
 
     ret = check_user_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                TEST_LOCAL_USER_NAME_1);
+                                test_ctx->local_users[0].name);
     assert_int_equal(ret, case_c);
 
     ret = check_user_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                TEST_LOCAL_USER_NAME_2);
+                                test_ctx->local_users[1].name);
     assert_int_equal(ret, case_d);
 }
 
@@ -324,11 +433,11 @@ static void set_uids(struct ncache_test_ctx *test_ctx)
     int ret;
 
     ret = sss_ncache_set_uid(test_ctx->ncache, false, test_ctx->tctx->dom,
-                             users[0].uid);
+                             test_ctx->non_local_users[0].uid);
     assert_int_equal(ret, EOK);
 
     ret = sss_ncache_set_uid(test_ctx->ncache, false, test_ctx->tctx->dom,
-                             TEST_LOCAL_USER_UID_1);
+                             test_ctx->local_users[0].uid);
     assert_int_equal(ret, EOK);
 }
 
@@ -338,19 +447,19 @@ static void check_uids(struct ncache_test_ctx *test_ctx,
     int ret;
 
     ret = sss_ncache_check_uid(test_ctx->ncache, test_ctx->tctx->dom,
-                               users[0].uid);
+                               test_ctx->non_local_users[0].uid);
     assert_int_equal(ret, case_a);
 
     ret = sss_ncache_check_uid(test_ctx->ncache, test_ctx->tctx->dom,
-                               users[1].uid);
+                               test_ctx->non_local_users[1].uid);
     assert_int_equal(ret, case_b);
 
     ret = sss_ncache_check_uid(test_ctx->ncache, test_ctx->tctx->dom,
-                               TEST_LOCAL_USER_UID_1);
+                               test_ctx->local_users[0].uid);
     assert_int_equal(ret, case_c);
 
     ret = sss_ncache_check_uid(test_ctx->ncache, test_ctx->tctx->dom,
-                               TEST_LOCAL_USER_UID_2);
+                               test_ctx->local_users[1].uid);
     assert_int_equal(ret, case_d);
 }
 
@@ -435,11 +544,11 @@ static void set_groups(struct ncache_test_ctx *test_ctx)
     int ret;
 
     ret = set_group_in_ncache(test_ctx->ncache, false, test_ctx->tctx->dom,
-                              groups[0].name);
+                              test_ctx->non_local_groups[0].name);
     assert_int_equal(ret, EOK);
 
     ret = set_group_in_ncache(test_ctx->ncache, false, test_ctx->tctx->dom,
-                              TEST_LOCAL_GROUP_NAME_1);
+                              test_ctx->local_groups[0].name);
     assert_int_equal(ret, EOK);
 }
 
@@ -449,19 +558,19 @@ static void check_groups(struct ncache_test_ctx *test_ctx,
     int ret;
 
     ret = check_group_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                groups[0].name);
+                                test_ctx->non_local_groups[0].name);
     assert_int_equal(ret, case_a);
 
     ret = check_group_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                groups[1].name);
+                                test_ctx->non_local_groups[1].name);
     assert_int_equal(ret, case_b);
 
     ret = check_group_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                TEST_LOCAL_GROUP_NAME_1);
+                                test_ctx->local_groups[0].name);
     assert_int_equal(ret, case_c);
 
     ret = check_group_in_ncache(test_ctx->ncache, test_ctx->tctx->dom,
-                                TEST_LOCAL_GROUP_NAME_2);
+                                test_ctx->local_groups[1].name);
     assert_int_equal(ret, case_d);
 }
 
@@ -546,11 +655,11 @@ static void set_gids(struct ncache_test_ctx *test_ctx)
     int ret;
 
     ret = sss_ncache_set_gid(test_ctx->ncache, false, test_ctx->tctx->dom,
-                             users[0].gid);
+                             test_ctx->non_local_groups[0].gid);
     assert_int_equal(ret, EOK);
 
     ret = sss_ncache_set_gid(test_ctx->ncache, false, test_ctx->tctx->dom,
-                             TEST_LOCAL_GID_1);
+                             test_ctx->local_groups[0].gid);
     assert_int_equal(ret, EOK);
 }
 
@@ -560,19 +669,19 @@ static void check_gids(struct ncache_test_ctx *test_ctx,
     int ret;
 
     ret = sss_ncache_check_gid(test_ctx->ncache, test_ctx->tctx->dom,
-                               users[0].gid);
+                               test_ctx->non_local_groups[0].gid);
     assert_int_equal(ret, case_a);
 
     ret = sss_ncache_check_gid(test_ctx->ncache, test_ctx->tctx->dom,
-                               users[1].gid);
+                               test_ctx->non_local_groups[1].gid);
     assert_int_equal(ret, case_b);
 
     ret = sss_ncache_check_gid(test_ctx->ncache, test_ctx->tctx->dom,
-                               TEST_LOCAL_GID_1);
+                               test_ctx->local_groups[0].gid);
     assert_int_equal(ret, case_c);
 
     ret = sss_ncache_check_gid(test_ctx->ncache, test_ctx->tctx->dom,
-                               TEST_LOCAL_GID_2);
+                               test_ctx->local_groups[1].gid);
     assert_int_equal(ret, case_d);
 }
 
diff --git a/src/tests/intg/test_ldap.py b/src/tests/intg/test_ldap.py
index 63f6ea4ed..787255f92 100644
--- a/src/tests/intg/test_ldap.py
+++ b/src/tests/intg/test_ldap.py
@@ -43,15 +43,6 @@ from files_ops import passwd_ops_setup, group_ops_setup
 LDAP_BASE_DN = "dc=example,dc=com"
 INTERACTIVE_TIMEOUT = 4
 
-PASSWD_USER = dict(name='passwduser', passwd='x', uid=100000, gid=2000,
-                   gecos='User for tests',
-                   dir='/home/passwduser',
-                   shell='/bin/bash')
-
-PASSWD_GROUP = dict(name='passwdgroup',
-                    gid=200000,
-                    mem=['passwduser'])
-
 
 @pytest.fixture(scope="module")
 def ds_inst(request):
@@ -1860,14 +1851,32 @@ def test_rename_incomplete_group_rdn_changed(ldap_conn, rename_setup_cleanup):
 
 
 @pytest.fixture
-def user_and_group_rfc2307_lcl(passwd_ops_setup, group_ops_setup,
-                               user_and_group_rfc2307):
-    pwd_ops = passwd_ops_setup
-    pwd_ops.useradd(**PASSWD_USER)
-    grp_ops = group_ops_setup
-    grp_ops.groupadd(**PASSWD_GROUP)
+def find_local_user_and_group():
+    f = open("/etc/passwd")
+    for line in f:
+        passwd_user = line.split(':')
+        passwd_user[2] = int(passwd_user[2])
+        if passwd_user[2] != 0:
+            break
+    f.close()
+    assert passwd_user[2] != 0
+
+    f = open("/etc/group")
+    for line in f:
+        passwd_group = line.split(':')
+        passwd_group[2] = int(passwd_group[2])
+        if passwd_group[2] != 0:
+            break
+    f.close()
+    assert passwd_group[2] != 0
+
+    return (passwd_user, passwd_group)
 
-    return user_and_group_rfc2307
+
+@pytest.fixture
+def user_and_group_rfc2307_lcl(find_local_user_and_group,
+                               user_and_group_rfc2307):
+    return find_local_user_and_group
 
 
 def test_local_negative_timeout_enabled_by_default(ldap_conn,
@@ -1879,64 +1888,53 @@ def test_local_negative_timeout_enabled_by_default(ldap_conn,
     # sanity check - try resolving an LDAP user
     ent.assert_passwd_by_name("user", dict(name="user", uid=1001, gid=2000))
 
+    passwd_user, passwd_group = user_and_group_rfc2307_lcl
+
     # resolve a user who is not in LDAP, but exists locally
-    res, _ = call_sssd_getpwnam("passwduser")
+    res, _ = call_sssd_getpwnam(passwd_user[0])
     assert res == NssReturnCode.NOTFOUND
-    res = pwd.getpwnam("passwduser")
-    assert res is not None
     # Do the same by UID
-    res, _ = call_sssd_getpwuid(100000)
+    res, _ = call_sssd_getpwuid(passwd_user[2])
     assert res == NssReturnCode.NOTFOUND
-    res = pwd.getpwuid(100000)
-    assert res is not None
 
     # Do the same for a group both by name and by ID
-    res, _ = call_sssd_getgrnam("passwdgroup")
+    res, _ = call_sssd_getgrnam(passwd_group[0])
     assert res == NssReturnCode.NOTFOUND
-    res = grp.getgrnam("passwdgroup")
-    assert res is not None
-    res, _ = call_sssd_getgrgid(200000)
+    res, _ = call_sssd_getgrgid(passwd_group[2])
     assert res == NssReturnCode.NOTFOUND
-    res = grp.getgrgid(200000)
-    assert res is not None
 
     # add the user and the group to LDAP
     ent_list = ldap_ent.List(ldap_conn.ds_inst.base_dn)
-    ent_list.add_user("passwduser", 100000, 2000)
-    ent_list.add_group("passwdgroup", 200000)
+    ent_list.add_user(passwd_user[0], passwd_user[2], 2000)
+    ent_list.add_group(passwd_group[0], passwd_group[2])
     create_ldap_entries(ldap_conn, ent_list)
 
-    # Make sure the negative cache expired
+    # Make sure the negative cache would expire if global timeout was used
     time.sleep(2)
 
     # The user is now negatively cached and can't be resolved by either
     # name or UID
-    res, _ = call_sssd_getpwnam("passwduser")
+    res, _ = call_sssd_getpwnam(passwd_group[0])
     assert res == NssReturnCode.NOTFOUND
-    res, _ = call_sssd_getpwuid(100000)
+    res, _ = call_sssd_getpwuid(passwd_group[2])
     assert res == NssReturnCode.NOTFOUND
 
-    res, _ = call_sssd_getgrnam("passwdgroup")
+    res, _ = call_sssd_getgrnam(passwd_group[0])
     assert res == NssReturnCode.NOTFOUND
-    res, _ = call_sssd_getgrgid(200000)
+    res, _ = call_sssd_getgrgid(passwd_group[2])
     assert res == NssReturnCode.NOTFOUND
 
     cleanup_ldap_entries(ldap_conn, ent_list)
 
 
 @pytest.fixture
-def usr_and_grp_rfc2307_no_local_ncache(request, passwd_ops_setup,
-                                        group_ops_setup, ldap_conn):
+def usr_and_grp_rfc2307_no_local_ncache(request, find_local_user_and_group,
+                                        ldap_conn):
     """
     Create an RFC2307 directory fixture with interactive SSSD conf,
     one user and one group but with the local negative timeout
     disabled
     """
-    pwd_ops = passwd_ops_setup
-    pwd_ops.useradd(**PASSWD_USER)
-    grp_ops = group_ops_setup
-    grp_ops.groupadd(**PASSWD_GROUP)
-
     ent_list = ldap_ent.List(ldap_conn.ds_inst.base_dn)
     ent_list.add_user("user", 1001, 2000)
     ent_list.add_group("group", 2001)
@@ -1948,7 +1946,7 @@ def usr_and_grp_rfc2307_no_local_ncache(request, passwd_ops_setup,
         """)
     create_conf_fixture(request, conf)
     create_sssd_fixture(request)
-    return None
+    return find_local_user_and_group
 
 
 def test_local_negative_timeout_disabled(ldap_conn,
@@ -1960,46 +1958,40 @@ def test_local_negative_timeout_disabled(ldap_conn,
     # sanity check - try resolving an LDAP user
     ent.assert_passwd_by_name("user", dict(name="user", uid=1001, gid=2000))
 
+    passwd_user, passwd_group = usr_and_grp_rfc2307_no_local_ncache
+
     # resolve a user who is not in LDAP, but exists locally
-    res, _ = call_sssd_getpwnam("passwduser")
+    res, _ = call_sssd_getpwnam(passwd_user[0])
     assert res == NssReturnCode.NOTFOUND
-    res = pwd.getpwnam("passwduser")
-    assert res is not None
     # Do the same by UID
-    res, _ = call_sssd_getpwuid(100000)
+    res, _ = call_sssd_getpwuid(passwd_user[2])
     assert res == NssReturnCode.NOTFOUND
-    res = pwd.getpwuid(100000)
-    assert res is not None
 
     # Do the same for a group both by name and by ID
-    res, _ = call_sssd_getgrnam("passwdgroup")
+    res, _ = call_sssd_getgrnam(passwd_group[0])
     assert res == NssReturnCode.NOTFOUND
-    res = grp.getgrnam("passwdgroup")
-    assert res is not None
-    res, _ = call_sssd_getgrgid(200000)
+    res, _ = call_sssd_getgrgid(passwd_group[2])
     assert res == NssReturnCode.NOTFOUND
-    res = grp.getgrgid(200000)
-    assert res is not None
 
     # add the user and the group to LDAP
     ent_list = ldap_ent.List(ldap_conn.ds_inst.base_dn)
-    ent_list.add_user("passwduser", 100000, 2000)
-    ent_list.add_group("passwdgroup", 200000)
+    ent_list.add_user(passwd_user[0], passwd_user[2], 2000)
+    ent_list.add_group(passwd_group[0], passwd_group[2])
     create_ldap_entries(ldap_conn, ent_list)
 
     # Make sure the negative cache expired
     time.sleep(2)
 
     # The user can now be resolved
-    res, _ = call_sssd_getpwnam("passwduser")
+    res, _ = call_sssd_getpwnam(passwd_user[0])
     assert res == NssReturnCode.SUCCESS
     # Do the same by UID
-    res, _ = call_sssd_getpwuid(100000)
+    res, _ = call_sssd_getpwuid(passwd_user[2])
     assert res == NssReturnCode.SUCCESS
 
-    res, _ = call_sssd_getgrnam("passwdgroup")
+    res, _ = call_sssd_getgrnam(passwd_group[0])
     assert res == NssReturnCode.SUCCESS
-    res, _ = call_sssd_getgrgid(200000)
+    res, _ = call_sssd_getgrgid(passwd_group[2])
     assert res == NssReturnCode.SUCCESS
 
     cleanup_ldap_entries(ldap_conn, ent_list)
-- 
2.19.1