1 files changed, 265 insertions, 0 deletions
diff --git a/source4/dsdb/repl/drepl_ridalloc.c b/source4/dsdb/repl/drepl_ridalloc.c
new file mode 100644
index 0000000..6794d4b
--- /dev/null
+++ b/source4/dsdb/repl/drepl_ridalloc.c
@@ -0,0 +1,265 @@
+/*
+   Unix SMB/CIFS Implementation.
+
+   DSDB replication service - RID allocation code
+
+   Copyright (C) Andrew Tridgell 2010
+   Copyright (C) Andrew Bartlett 2010
+
+   based on drepl_notify.c
+
+   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 "includes.h"
+#include "ldb_module.h"
+#include "dsdb/samdb/samdb.h"
+#include "samba/service.h"
+#include "dsdb/repl/drepl_service.h"
+#include "param/param.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS            DBGC_DRS_REPL
+
+/*
+  called when a rid allocation request has completed
+ */
+static void drepl_new_rid_pool_callback(struct dreplsrv_service *service,
+					WERROR werr,
+					enum drsuapi_DsExtendedError ext_err,
+					void *cb_data)
+{
+	if (!W_ERROR_IS_OK(werr)) {
+		DEBUG(0,(__location__ ": RID Manager failed RID allocation - %s - extended_ret[0x%X]\n",
+			 win_errstr(werr), ext_err));
+	} else {
+		DEBUG(3,(__location__ ": RID Manager completed RID allocation OK\n"));
+	}
+
+	service->rid_alloc_in_progress = false;
+}
+
+/*
+  schedule a getncchanges request to the RID Manager to ask for a new
+  set of RIDs using DRSUAPI_EXOP_FSMO_RID_ALLOC
+ */
+static WERROR drepl_request_new_rid_pool(struct dreplsrv_service *service,
+					 struct ldb_dn *rid_manager_dn, struct ldb_dn *fsmo_role_dn,
+					 uint64_t alloc_pool)
+{
+	WERROR werr = drepl_request_extended_op(service,
+						rid_manager_dn,
+						fsmo_role_dn,
+						DRSUAPI_EXOP_FSMO_RID_ALLOC,
+						alloc_pool,
+						0,
+						drepl_new_rid_pool_callback, NULL);
+	if (W_ERROR_IS_OK(werr)) {
+		service->rid_alloc_in_progress = true;
+	}
+	return werr;
+}
+
+
+/*
+  see if we are on the last pool we have
+ */
+static int drepl_ridalloc_pool_exhausted(struct ldb_context *ldb,
+					 bool *exhausted,
+					 uint64_t *_alloc_pool)
+{
+	struct ldb_dn *server_dn, *machine_dn, *rid_set_dn;
+	TALLOC_CTX *tmp_ctx = talloc_new(ldb);
+	uint64_t alloc_pool;
+	uint64_t prev_pool;
+	uint32_t prev_pool_lo, prev_pool_hi;
+	uint32_t next_rid;
+	static const char * const attrs[] = {
+		"rIDAllocationPool",
+		"rIDPreviousAllocationPool",
+		"rIDNextRid",
+		NULL
+	};
+	int ret;
+	struct ldb_result *res;
+
+	*exhausted = false;
+	*_alloc_pool = UINT64_MAX;
+
+	server_dn = ldb_dn_get_parent(tmp_ctx, samdb_ntds_settings_dn(ldb, tmp_ctx));
+	if (!server_dn) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	ret = samdb_reference_dn(ldb, tmp_ctx, server_dn, "serverReference", &machine_dn);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed to find serverReference in %s - %s\n",
+			 ldb_dn_get_linearized(server_dn), ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = samdb_reference_dn(ldb, tmp_ctx, machine_dn, "rIDSetReferences", &rid_set_dn);
+	if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
+		*exhausted = true;
+		*_alloc_pool = 0;
+		talloc_free(tmp_ctx);
+		return LDB_SUCCESS;
+	}
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed to find rIDSetReferences in %s - %s\n",
+			 ldb_dn_get_linearized(machine_dn), ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = ldb_search(ldb, tmp_ctx, &res, rid_set_dn, LDB_SCOPE_BASE, attrs, NULL);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed to load RID Set attrs from %s - %s\n",
+			 ldb_dn_get_linearized(rid_set_dn), ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	alloc_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAllocationPool", 0);
+	prev_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDPreviousAllocationPool", 0);
+	prev_pool_lo = prev_pool & 0xFFFFFFFF;
+	prev_pool_hi = prev_pool >> 32;
+	next_rid = ldb_msg_find_attr_as_uint(res->msgs[0], "rIDNextRid", 0);
+
+	if (alloc_pool != prev_pool) {
+		talloc_free(tmp_ctx);
+		return LDB_SUCCESS;
+	}
+
+	if (next_rid < (prev_pool_hi + prev_pool_lo)/2) {
+		talloc_free(tmp_ctx);
+		return LDB_SUCCESS;
+	}
+
+	*exhausted = true;
+	*_alloc_pool = alloc_pool;
+	talloc_free(tmp_ctx);
+	return LDB_SUCCESS;
+}
+
+
+/*
+  see if we are low on RIDs in the RID Set rIDAllocationPool. If we
+  are, then schedule a replication call with DRSUAPI_EXOP_FSMO_RID_ALLOC
+  to the RID Manager
+ */
+WERROR dreplsrv_ridalloc_check_rid_pool(struct dreplsrv_service *service)
+{
+	struct ldb_dn *rid_manager_dn, *fsmo_role_dn;
+	TALLOC_CTX *tmp_ctx = talloc_new(service);
+	struct ldb_context *ldb = service->samdb;
+	bool exhausted;
+	WERROR werr;
+	int ret;
+	uint64_t alloc_pool;
+	bool is_us;
+
+	if (service->am_rodc) {
+		talloc_free(tmp_ctx);
+		return WERR_OK;
+	}
+
+	if (service->rid_alloc_in_progress) {
+		talloc_free(tmp_ctx);
+		return WERR_OK;
+	}
+
+	/*
+	  steps:
+	    - find who the RID Manager is
+	    - if we are the RID Manager then nothing to do
+	    - find our RID Set object
+	    - load rIDAllocationPool and rIDPreviousAllocationPool
+	    - if rIDAllocationPool != rIDPreviousAllocationPool then
+	      nothing to do
+	    - schedule a getncchanges with DRSUAPI_EXOP_FSMO_RID_ALLOC
+	      to the RID Manager
+	 */
+
+	/* work out who is the RID Manager */
+	ret = samdb_rid_manager_dn(ldb, tmp_ctx, &rid_manager_dn);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0, (__location__ ": Failed to find RID Manager object - %s\n", ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	/* find the DN of the RID Manager */
+	ret = samdb_reference_dn(ldb, tmp_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed to find fSMORoleOwner in RID Manager object - %s\n",
+			 ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	ret = samdb_dn_is_our_ntdsa(ldb, fsmo_role_dn, &is_us);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed to find detrmine if %s is our ntdsDsa object - %s\n",
+			 ldb_dn_get_linearized(fsmo_role_dn), ldb_errstring(ldb)));
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	if (is_us) {
+		/* we are the RID Manager - no need to do a
+		   DRSUAPI_EXOP_FSMO_RID_ALLOC */
+		talloc_free(tmp_ctx);
+		return WERR_OK;
+	}
+
+	ret = drepl_ridalloc_pool_exhausted(ldb, &exhausted, &alloc_pool);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	if (!exhausted) {
+		/* don't need a new pool */
+		talloc_free(tmp_ctx);
+		return WERR_OK;
+	}
+
+	DEBUG(2,(__location__ ": Requesting more RIDs from RID Manager\n"));
+
+	werr = drepl_request_new_rid_pool(service, rid_manager_dn, fsmo_role_dn, alloc_pool);
+	talloc_free(tmp_ctx);
+	return werr;
+}
+
+/* called by the samldb ldb module to tell us to ask for a new RID
+   pool */
+void dreplsrv_allocate_rid(struct imessaging_context *msg,
+			   void *private_data,
+			   uint32_t msg_type,
+			   struct server_id server_id,
+			   size_t num_fds,
+			   int *fds,
+			   DATA_BLOB *data)
+{
+	struct dreplsrv_service *service = talloc_get_type(private_data, struct dreplsrv_service);
+	if (num_fds != 0) {
+		DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
+		return;
+	}
+	dreplsrv_ridalloc_check_rid_pool(service);
+}