Make pdb_ads survive a restart of Samba4

The search function retries once, the modifying call that hits a dead smbd
returns an error. The next try will reconnect. This was simple to implement and
provides a good compromise against Samba4 idling our connection. Most of the
modifying calls are quickly after a search (like OpenUser) anyway.

diff --git a/source3/passdb/pdb_ads.c b/source3/passdb/pdb_ads.c
index f4ab29984460e1e49a70c990f12f808986a6ed4f..cdde30dcdcaa33e71f71e50b9133414da4efbc85 100644 (file)
--- a/source3/passdb/pdb_ads.c
+++ b/source3/passdb/pdb_ads.c
@@ -20,6 +20,7 @@
 #include "includes.h"
 
 struct pdb_ads_state {
+       struct sockaddr_un socket_address;
        struct tldap_context *ld;
        struct dom_sid domainsid;
        char *domaindn;
@@ -32,11 +33,17 @@ static NTSTATUS pdb_ads_getsampwsid(struct pdb_methods *m,
                                    const DOM_SID *sid);
 static bool pdb_ads_gid_to_sid(struct pdb_methods *m, gid_t gid,
                               DOM_SID *sid);
-static bool pdb_ads_dnblob2sid(struct tldap_context *ld, DATA_BLOB *dnblob,
+static bool pdb_ads_dnblob2sid(struct pdb_ads_state *state, DATA_BLOB *dnblob,
                               struct dom_sid *psid);
 static NTSTATUS pdb_ads_sid2dn(struct pdb_ads_state *state,
                               const struct dom_sid *sid,
                               TALLOC_CTX *mem_ctx, char **pdn);
+static struct tldap_context *pdb_ads_ld(struct pdb_ads_state *state);
+static int pdb_ads_search_fmt(struct pdb_ads_state *state, const char *base,
+                             int scope, const char *attrs[], int num_attrs,
+                             int attrsonly,
+                             TALLOC_CTX *mem_ctx, struct tldap_message ***res,
+                             const char *fmt, ...);
 
 static bool pdb_ads_pull_time(struct tldap_message *msg, const char *attr,
                              time_t *ptime)
@@ -317,9 +324,9 @@ static NTSTATUS pdb_ads_getsampwfilter(struct pdb_methods *m,
        struct tldap_message **users;
        int rc, count;
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
-                             &users, "%s", filter);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &users, "%s", filter);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -377,6 +384,7 @@ static NTSTATUS pdb_ads_create_user(struct pdb_methods *m,
 {
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        const char *attrs[1] = { "objectSid" };
        struct tldap_mod *mods = NULL;
        int num_mods = 0;
@@ -392,6 +400,11 @@ static NTSTATUS pdb_ads_create_user(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        /* TODO: Create machines etc */
 
        ok = true;
@@ -404,18 +417,20 @@ static NTSTATUS pdb_ads_create_user(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_add(state->ld, dn, num_mods, mods, NULL, 0, NULL, 0);
+
+       rc = tldap_add(ld, dn, num_mods, mods, NULL, 0, NULL, 0);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_add failed %s\n",
-                          tldap_errstr(debug_ctx(), state->ld, rc)));
+                          tldap_errstr(debug_ctx(), ld, rc)));
                TALLOC_FREE(dn);
                return NT_STATUS_LDAP(rc);
        }
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &user,
-                            "(&(objectclass=user)(samaccountname=%s))",
-                            name);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &user,
+                               "(&(objectclass=user)(samaccountname=%s))",
+                               name);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("Could not find just created user %s: %s\n",
                           name, tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -449,20 +464,26 @@ static NTSTATUS pdb_ads_delete_user(struct pdb_methods *m,
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
        NTSTATUS status;
+       struct tldap_context *ld;
        char *dn;
        int rc;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        status = pdb_ads_sid2dn(state, pdb_get_user_sid(sam), talloc_tos(),
                                &dn);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
 
-       rc = tldap_delete(state->ld, dn, NULL, 0, NULL, 0);
+       rc = tldap_delete(ld, dn, NULL, 0, NULL, 0);
        TALLOC_FREE(dn);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_delete for %s failed: %s\n", dn,
-                          tldap_errstr(debug_ctx(), state->ld, rc)));
+                          tldap_errstr(debug_ctx(), ld, rc)));
                return NT_STATUS_LDAP(rc);
        }
        return NT_STATUS_OK;
@@ -480,9 +501,15 @@ static NTSTATUS pdb_ads_update_sam_account(struct pdb_methods *m,
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
        struct pdb_ads_samu_private *priv = pdb_ads_get_samu_private(m, sam);
+       struct tldap_context *ld;
        struct tldap_mod *mods = NULL;
        int rc, num_mods = 0;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        if (!pdb_ads_init_ads_from_sam(state, priv->ldapmsg, talloc_tos(),
                                       &num_mods, &mods, sam)) {
                return NT_STATUS_NO_MEMORY;
@@ -493,16 +520,15 @@ static NTSTATUS pdb_ads_update_sam_account(struct pdb_methods *m,
                return NT_STATUS_OK;
        }
 
-       rc = tldap_modify(state->ld, priv->dn, num_mods, mods, NULL, 0,
+       rc = tldap_modify(ld, priv->dn, num_mods, mods, NULL, 0,
                          NULL, 0);
+       TALLOC_FREE(mods);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_modify for %s failed: %s\n", priv->dn,
-                          tldap_errstr(debug_ctx(), state->ld, rc)));
+                          tldap_errstr(debug_ctx(), ld, rc)));
                return NT_STATUS_LDAP(rc);
        }
 
-       TALLOC_FREE(mods);
-
        return NT_STATUS_OK;
 }
 
@@ -538,9 +564,9 @@ static NTSTATUS pdb_ads_getgrfilter(struct pdb_methods *m, GROUP_MAP *map,
        uint32_t grouptype;
        int rc;
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
-                             &group, "%s", filter);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &group, "%s", filter);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -644,6 +670,7 @@ static NTSTATUS pdb_ads_create_dom_group(struct pdb_methods *m,
        TALLOC_CTX *frame = talloc_stackframe();
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        const char *attrs[1] = { "objectSid" };
        int num_mods = 0;
        struct tldap_mod *mods = NULL;
@@ -653,6 +680,11 @@ static NTSTATUS pdb_ads_create_dom_group(struct pdb_methods *m,
        int rc;
        bool ok = true;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        dn = talloc_asprintf(talloc_tos(), "cn=%s,cn=users,%s", name,
                             state->domaindn);
        if (dn == NULL) {
@@ -674,7 +706,7 @@ static NTSTATUS pdb_ads_create_dom_group(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_add(state->ld, dn, num_mods, mods, NULL, 0, NULL, 0);
+       rc = tldap_add(ld, dn, num_mods, mods, NULL, 0, NULL, 0);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_add failed %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -682,8 +714,8 @@ static NTSTATUS pdb_ads_create_dom_group(struct pdb_methods *m,
                return NT_STATUS_LDAP(rc);
        }
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &alias,
                "(&(objectclass=group)(samaccountname=%s))", name);
        if (rc != TLDAP_SUCCESS) {
@@ -717,6 +749,7 @@ static NTSTATUS pdb_ads_delete_dom_group(struct pdb_methods *m,
 {
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        struct dom_sid sid;
        char *sidstr;
        struct tldap_message **msg;
@@ -728,10 +761,10 @@ static NTSTATUS pdb_ads_delete_dom_group(struct pdb_methods *m,
        sidstr = sid_binstring(talloc_tos(), &sid);
        NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             NULL, 0, 0, talloc_tos(), &msg,
-                             ("(&(objectSid=%s)(objectClass=group))"),
-                             sidstr);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               NULL, 0, 0, talloc_tos(), &msg,
+                               ("(&(objectSid=%s)(objectClass=group))"),
+                               sidstr);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
@@ -749,18 +782,24 @@ static NTSTATUS pdb_ads_delete_dom_group(struct pdb_methods *m,
        }
 
        if (!tldap_entry_dn(msg[0], &dn)) {
+               TALLOC_FREE(msg);
                return NT_STATUS_INTERNAL_DB_CORRUPTION;
        }
 
-       rc = tldap_delete(state->ld, dn, NULL, 0, NULL, 0);
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               TALLOC_FREE(msg);
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
+       rc = tldap_delete(ld, dn, NULL, 0, NULL, 0);
+       TALLOC_FREE(msg);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_delete failed: %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
-               TALLOC_FREE(dn);
                return NT_STATUS_LDAP(rc);
        }
 
-       TALLOC_FREE(msg);
        return NT_STATUS_OK;
 }
 
@@ -810,9 +849,9 @@ static NTSTATUS pdb_ads_enum_group_members(struct pdb_methods *m,
        sidstr = sid_binstring(talloc_tos(), group);
        NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &msg,
-                             "(objectsid=%s)", sidstr);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &msg, "(objectsid=%s)", sidstr);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
@@ -841,7 +880,7 @@ static NTSTATUS pdb_ads_enum_group_members(struct pdb_methods *m,
 
        for (i=0; i<num_members; i++) {
                struct dom_sid sid;
-               if (!pdb_ads_dnblob2sid(state->ld, &blobs[i], &sid)
+               if (!pdb_ads_dnblob2sid(state, &blobs[i], &sid)
                    || !sid_peek_rid(&sid, &members[i])) {
                        TALLOC_FREE(members);
                        return NT_STATUS_INTERNAL_DB_CORRUPTION;
@@ -871,8 +910,8 @@ static NTSTATUS pdb_ads_enum_group_memberships(struct pdb_methods *m,
        struct dom_sid *group_sids;
        gid_t *gids;
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &groups,
                "(&(member=%s)(grouptype=%d)(objectclass=group))",
                priv->dn, GTYPE_SECURITY_GLOBAL_GROUP);
@@ -929,12 +968,18 @@ static NTSTATUS pdb_ads_mod_groupmem(struct pdb_methods *m,
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
        TALLOC_CTX *frame = talloc_stackframe();
+       struct tldap_context *ld;
        struct dom_sid groupsid, membersid;
        char *groupdn, *memberdn;
        struct tldap_mod *mods;
        int rc;
        NTSTATUS status;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        sid_compose(&groupsid, &state->domainsid, grouprid);
        sid_compose(&membersid, &state->domainsid, memberrid);
 
@@ -957,7 +1002,7 @@ static NTSTATUS pdb_ads_mod_groupmem(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_modify(state->ld, groupdn, 1, mods, NULL, 0, NULL, 0);
+       rc = tldap_modify(ld, groupdn, 1, mods, NULL, 0, NULL, 0);
        TALLOC_FREE(frame);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_modify failed: %s\n",
@@ -996,6 +1041,7 @@ static NTSTATUS pdb_ads_create_alias(struct pdb_methods *m,
        TALLOC_CTX *frame = talloc_stackframe();
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        const char *attrs[1] = { "objectSid" };
        int num_mods = 0;
        struct tldap_mod *mods = NULL;
@@ -1005,6 +1051,11 @@ static NTSTATUS pdb_ads_create_alias(struct pdb_methods *m,
        int rc;
        bool ok = true;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        dn = talloc_asprintf(talloc_tos(), "cn=%s,cn=users,%s", name,
                             state->domaindn);
        if (dn == NULL) {
@@ -1026,7 +1077,7 @@ static NTSTATUS pdb_ads_create_alias(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_add(state->ld, dn, num_mods, mods, NULL, 0, NULL, 0);
+       rc = tldap_add(ld, dn, num_mods, mods, NULL, 0, NULL, 0);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_add failed %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -1034,8 +1085,8 @@ static NTSTATUS pdb_ads_create_alias(struct pdb_methods *m,
                return NT_STATUS_LDAP(rc);
        }
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &alias,
                "(&(objectclass=group)(samaccountname=%s))", name);
        if (rc != TLDAP_SUCCESS) {
@@ -1069,21 +1120,27 @@ static NTSTATUS pdb_ads_delete_alias(struct pdb_methods *m,
 {
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        struct tldap_message **alias;
        char *sidstr, *dn;
        int rc;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        sidstr = sid_binstring(talloc_tos(), sid);
        if (sidstr == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             NULL, 0, 0, talloc_tos(), &alias,
-                             "(&(objectSid=%s)(objectclass=group)"
-                             "(|(grouptype=%d)(grouptype=%d)))",
-                             sidstr, GTYPE_SECURITY_BUILTIN_LOCAL_GROUP,
-                             GTYPE_SECURITY_DOMAIN_LOCAL_GROUP);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               NULL, 0, 0, talloc_tos(), &alias,
+                               "(&(objectSid=%s)(objectclass=group)"
+                               "(|(grouptype=%d)(grouptype=%d)))",
+                               sidstr, GTYPE_SECURITY_BUILTIN_LOCAL_GROUP,
+                               GTYPE_SECURITY_DOMAIN_LOCAL_GROUP);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed: %s\n",
@@ -1102,7 +1159,7 @@ static NTSTATUS pdb_ads_delete_alias(struct pdb_methods *m,
                return NT_STATUS_INTERNAL_ERROR;
        }
 
-       rc = tldap_delete(state->ld, dn, NULL, 0, NULL, 0);
+       rc = tldap_delete(ld, dn, NULL, 0, NULL, 0);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_delete failed: %s\n",
                           tldap_errstr(debug_ctx(), state->ld, rc)));
@@ -1119,6 +1176,7 @@ static NTSTATUS pdb_ads_set_aliasinfo(struct pdb_methods *m,
 {
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        const char *attrs[3] = { "objectSid", "description",
                                 "samAccountName" };
        struct tldap_message **msg;
@@ -1128,15 +1186,20 @@ static NTSTATUS pdb_ads_set_aliasinfo(struct pdb_methods *m,
        int num_mods;
        bool ok;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        sidstr = sid_binstring(talloc_tos(), sid);
        NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
-                             &msg, "(&(objectSid=%s)(objectclass=group)"
-                             "(|(grouptype=%d)(grouptype=%d)))",
-                             sidstr, GTYPE_SECURITY_BUILTIN_LOCAL_GROUP,
-                             GTYPE_SECURITY_DOMAIN_LOCAL_GROUP);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &msg, "(&(objectSid=%s)(objectclass=group)"
+                               "(|(grouptype=%d)(grouptype=%d)))",
+                               sidstr, GTYPE_SECURITY_BUILTIN_LOCAL_GROUP,
+                               GTYPE_SECURITY_DOMAIN_LOCAL_GROUP);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
@@ -1177,7 +1240,7 @@ static NTSTATUS pdb_ads_set_aliasinfo(struct pdb_methods *m,
                return NT_STATUS_OK;
        }
 
-       rc = tldap_modify(state->ld, dn, num_mods, mods, NULL, 0, NULL, 0);
+       rc = tldap_modify(ld, dn, num_mods, mods, NULL, 0, NULL, 0);
        TALLOC_FREE(msg);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_modify failed: %s\n",
@@ -1198,9 +1261,9 @@ static NTSTATUS pdb_ads_sid2dn(struct pdb_ads_state *state,
        sidstr = sid_binstring(talloc_tos(), sid);
        NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             NULL, 0, 0, talloc_tos(), &msg,
-                             "(objectsid=%s)", sidstr);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               NULL, 0, 0, talloc_tos(), &msg,
+                               "(objectsid=%s)", sidstr);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
@@ -1238,12 +1301,18 @@ static NTSTATUS pdb_ads_mod_aliasmem(struct pdb_methods *m,
 {
        struct pdb_ads_state *state = talloc_get_type_abort(
                m->private_data, struct pdb_ads_state);
+       struct tldap_context *ld;
        TALLOC_CTX *frame = talloc_stackframe();
        struct tldap_mod *mods;
        int rc;
        char *aliasdn, *memberdn;
        NTSTATUS status;
 
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return NT_STATUS_LDAP(TLDAP_SERVER_DOWN);
+       }
+
        status = pdb_ads_sid2dn(state, alias, talloc_tos(), &aliasdn);
        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("pdb_ads_sid2dn (%s) failed: %s\n",
@@ -1267,7 +1336,7 @@ static NTSTATUS pdb_ads_mod_aliasmem(struct pdb_methods *m,
                return NT_STATUS_NO_MEMORY;
        }
 
-       rc = tldap_modify(state->ld, aliasdn, 1, mods, NULL, 0, NULL, 0);
+       rc = tldap_modify(ld, aliasdn, 1, mods, NULL, 0, NULL, 0);
        TALLOC_FREE(frame);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_modify failed: %s\n",
@@ -1298,7 +1367,7 @@ static NTSTATUS pdb_ads_del_aliasmem(struct pdb_methods *m,
        return pdb_ads_mod_aliasmem(m, alias, member, TLDAP_MOD_DELETE);
 }
 
-static bool pdb_ads_dnblob2sid(struct tldap_context *ld, DATA_BLOB *dnblob,
+static bool pdb_ads_dnblob2sid(struct pdb_ads_state *state, DATA_BLOB *dnblob,
                               struct dom_sid *psid)
 {
        const char *attrs[1] = { "objectSid" };
@@ -1313,9 +1382,9 @@ static bool pdb_ads_dnblob2sid(struct tldap_context *ld, DATA_BLOB *dnblob,
                                   false)) {
                return false;
        }
-       rc = tldap_search_fmt(ld, dn, TLDAP_SCOPE_BASE,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
-                             &msg, "(objectclass=*)");
+       rc = pdb_ads_search_fmt(state, dn, TLDAP_SCOPE_BASE,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &msg, "(objectclass=*)");
        TALLOC_FREE(dn);
        if (talloc_array_length(msg) != 1) {
                DEBUG(10, ("Got %d objects, expected one\n",
@@ -1347,9 +1416,9 @@ static NTSTATUS pdb_ads_enum_aliasmem(struct pdb_methods *m,
        sidstr = sid_binstring(talloc_tos(), alias);
        NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &msg,
-                             "(objectsid=%s)", sidstr);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &msg, "(objectsid=%s)", sidstr);
        TALLOC_FREE(sidstr);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("ldap_search failed %s\n",
@@ -1377,7 +1446,7 @@ static NTSTATUS pdb_ads_enum_aliasmem(struct pdb_methods *m,
        }
 
        for (i=0; i<num_members; i++) {
-               if (!pdb_ads_dnblob2sid(state->ld, &blobs[i], &members[i])) {
+               if (!pdb_ads_dnblob2sid(state, &blobs[i], &members[i])) {
                        TALLOC_FREE(members);
                        return NT_STATUS_INTERNAL_DB_CORRUPTION;
                }
@@ -1444,9 +1513,9 @@ static NTSTATUS pdb_ads_enum_alias_memberships(struct pdb_methods *m,
                goto done;
        }
 
-       rc = tldap_search_fmt(state->ld, state->domaindn, TLDAP_SCOPE_SUB,
-                             attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
-                             &msg, "%s))", filter);
+       rc = pdb_ads_search_fmt(state, state->domaindn, TLDAP_SCOPE_SUB,
+                               attrs, ARRAY_SIZE(attrs), 0, talloc_tos(),
+                               &msg, "%s))", filter);
        TALLOC_FREE(filter);
        if (rc != TLDAP_SUCCESS) {
                DEBUG(10, ("tldap_search failed %s\n",
@@ -1516,10 +1585,10 @@ static NTSTATUS pdb_ads_lookup_rids(struct pdb_methods *m,
                sidstr = sid_binstring(talloc_tos(), &sid);
                NT_STATUS_HAVE_NO_MEMORY(sidstr);
 
-               rc = tldap_search_fmt(state->ld, state->domaindn,
-                                     TLDAP_SCOPE_SUB, attrs,
-                                     ARRAY_SIZE(attrs), 0, talloc_tos(),
-                                     &msg, "(objectsid=%s)", sidstr);
+               rc = pdb_ads_search_fmt(state, state->domaindn,
+                                       TLDAP_SCOPE_SUB, attrs,
+                                       ARRAY_SIZE(attrs), 0, talloc_tos(),
+                                       &msg, "(objectsid=%s)", sidstr);
                TALLOC_FREE(sidstr);
                if (rc != TLDAP_SUCCESS) {
                        DEBUG(10, ("ldap_search failed %s\n",
@@ -1654,8 +1723,8 @@ static bool pdb_ads_search_filter(struct pdb_methods *m,
                return false;
        }
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                attrs, ARRAY_SIZE(attrs), 0, talloc_tos(), &users,
                "%s", filter);
        if (rc != TLDAP_SUCCESS) {
@@ -1825,8 +1894,8 @@ static bool pdb_ads_sid_to_id(struct pdb_methods *m, const DOM_SID *sid,
                return false;
        }
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                NULL, 0, 0, talloc_tos(), &msg,
                "(&(objectsid=%s)(objectclass=user))", sidstr);
        if ((rc == TLDAP_SUCCESS) && (talloc_array_length(msg) > 0)) {
@@ -1836,8 +1905,8 @@ static bool pdb_ads_sid_to_id(struct pdb_methods *m, const DOM_SID *sid,
                return true;
        }
 
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_SUB,
                NULL, 0, 0, talloc_tos(), &msg,
                "(&(objectsid=%s)(objectclass=group))", sidstr);
        if ((rc == TLDAP_SUCCESS) && (talloc_array_length(msg) > 0)) {
@@ -1986,42 +2055,92 @@ static void s3_tldap_debug(void *context, enum tldap_debug_level level,
        free(s);
 }
 
-static NTSTATUS pdb_ads_connect(struct pdb_ads_state *state,
-                               const char *location)
+static struct tldap_context *pdb_ads_ld(struct pdb_ads_state *state)
 {
-       const char *rootdse_attrs[2] = {
-               "defaultNamingContext", "configurationNamingContext" };
-       const char *domain_attrs[1] = { "objectSid" };
-       const char *ncname_attrs[1] = { "netbiosname" };
-       struct tldap_message **rootdse, **domain, **ncname;
-       TALLOC_CTX *frame = talloc_stackframe();
-       struct sockaddr_un sunaddr;
        NTSTATUS status;
-       int num_domains;
-       int fd, rc;
+       int fd;
 
-       ZERO_STRUCT(sunaddr);
-       sunaddr.sun_family = AF_UNIX;
-       strncpy(sunaddr.sun_path, location, sizeof(sunaddr.sun_path) - 1);
+       if (tldap_connection_ok(state->ld)) {
+               return state->ld;
+       }
+       TALLOC_FREE(state->ld);
 
-       status = open_socket_out((struct sockaddr_storage *)(void *)&sunaddr,
-                                0, 0, &fd);
+       status = open_socket_out(
+               (struct sockaddr_storage *)(void *)&state->socket_address,
+               0, 0, &fd);
        if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(10, ("Could not connect to %s: %s\n", location,
-                          nt_errstr(status)));
-               goto done;
+               DEBUG(10, ("Could not connect to %s: %s\n",
+                          state->socket_address.sun_path, nt_errstr(status)));
+               return NULL;
        }
 
        state->ld = tldap_context_create(state, fd);
        if (state->ld == NULL) {
                close(fd);
-               status = NT_STATUS_NO_MEMORY;
-               goto done;
+               return NULL;
        }
        tldap_set_debug(state->ld, s3_tldap_debug, NULL);
 
-       rc = tldap_search_fmt(
-               state->ld, "", TLDAP_SCOPE_BASE,
+       return state->ld;
+}
+
+int pdb_ads_search_fmt(struct pdb_ads_state *state, const char *base,
+                      int scope, const char *attrs[], int num_attrs,
+                      int attrsonly,
+                      TALLOC_CTX *mem_ctx, struct tldap_message ***res,
+                      const char *fmt, ...)
+{
+       struct tldap_context *ld;
+       va_list ap;
+       int ret;
+
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return TLDAP_SERVER_DOWN;
+       }
+
+       va_start(ap, fmt);
+       ret = tldap_search_va(ld, base, scope, attrs, num_attrs, attrsonly,
+                             mem_ctx, res, fmt, ap);
+       va_end(ap);
+
+       if (ret != TLDAP_SERVER_DOWN) {
+               return ret;
+       }
+
+       /* retry once */
+       ld = pdb_ads_ld(state);
+       if (ld == NULL) {
+               return TLDAP_SERVER_DOWN;
+       }
+
+       va_start(ap, fmt);
+       ret = tldap_search_va(ld, base, scope, attrs, num_attrs, attrsonly,
+                             mem_ctx, res, fmt, ap);
+       va_end(ap);
+       return ret;
+}
+
+static NTSTATUS pdb_ads_connect(struct pdb_ads_state *state,
+                               const char *location)
+{
+       const char *rootdse_attrs[2] = {
+               "defaultNamingContext", "configurationNamingContext" };
+       const char *domain_attrs[1] = { "objectSid" };
+       const char *ncname_attrs[1] = { "netbiosname" };
+       struct tldap_message **rootdse, **domain, **ncname;
+       TALLOC_CTX *frame = talloc_stackframe();
+       NTSTATUS status;
+       int num_domains;
+       int rc;
+
+       ZERO_STRUCT(state->socket_address);
+       state->socket_address.sun_family = AF_UNIX;
+       strncpy(state->socket_address.sun_path, location,
+               sizeof(state->socket_address.sun_path) - 1);
+
+       rc = pdb_ads_search_fmt(
+               state, "", TLDAP_SCOPE_BASE,
                rootdse_attrs, ARRAY_SIZE(rootdse_attrs), 0,
                talloc_tos(), &rootdse, "(objectclass=*)");
        if (rc != TLDAP_SUCCESS) {
@@ -2056,8 +2175,8 @@ static NTSTATUS pdb_ads_connect(struct pdb_ads_state *state,
        /*
         * Figure out our domain's SID
         */
-       rc = tldap_search_fmt(
-               state->ld, state->domaindn, TLDAP_SCOPE_BASE,
+       rc = pdb_ads_search_fmt(
+               state, state->domaindn, TLDAP_SCOPE_BASE,
                domain_attrs, ARRAY_SIZE(domain_attrs), 0,
                talloc_tos(), &domain, "(objectclass=*)");
        if (rc != TLDAP_SUCCESS) {
@@ -2083,8 +2202,8 @@ static NTSTATUS pdb_ads_connect(struct pdb_ads_state *state,
        /*
         * Figure out our domain's short name
         */
-       rc = tldap_search_fmt(
-               state->ld, state->configdn, TLDAP_SCOPE_SUB,
+       rc = pdb_ads_search_fmt(
+               state, state->configdn, TLDAP_SCOPE_SUB,
                ncname_attrs, ARRAY_SIZE(ncname_attrs), 0,
                talloc_tos(), &ncname, "(ncname=%s)", state->domaindn);
        if (rc != TLDAP_SUCCESS) {
@@ -2134,7 +2253,7 @@ static NTSTATUS pdb_init_ads(struct pdb_methods **pdb_method,
        if (m == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
-       state = talloc(m, struct pdb_ads_state);
+       state = talloc_zero(m, struct pdb_ads_state);
        if (state == NULL) {
                goto nomem;
        }