s4-dsdb: move the RID allocation logic into ridalloc.c

This will end up having the RID Manager logic as well, so all the RID
pool allocation logic is in one spot

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

1 files changed, 140 insertions, 0 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/ridalloc.c b/source4/dsdb/samdb/ldb_modules/ridalloc.c
new file mode 100644
index 0000000000..12318314d8
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/ridalloc.c
@@ -0,0 +1,140 @@
+/*
+   RID allocation helper functions
+
+   Copyright (C) Andrew Bartlett 2010
+   Copyright (C) Andrew Tridgell 2010
+
+   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/>.
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: RID allocation logic
+ *
+ *  Description: manage RID Set and RID Manager objects
+ *
+ */
+
+#include "includes.h"
+#include "ldb_module.h"
+#include "dsdb/samdb/samdb.h"
+#include "dsdb/samdb/ldb_modules/util.h"
+
+/* allocate a RID using our RID Set
+   If we run out of RIDs then allocate a new pool
+   either locally or by contacting the RID Manager
+*/
+int ridalloc_allocate_rid(struct ldb_module *module, uint32_t *rid)
+{
+	struct ldb_context *ldb;
+	static const char * const attrs[] = { "rIDAllocationPool", "rIDNextRID" , NULL };
+	int ret;
+	struct ldb_dn *rid_set_dn;
+	struct ldb_result *res;
+	uint64_t alloc_pool;
+	uint32_t alloc_pool_lo, alloc_pool_hi;
+	int next_rid;
+	struct ldb_message *msg;
+	TALLOC_CTX *tmp_ctx = talloc_new(module);
+	struct ldb_message_element *el;
+	struct ldb_val v1, v2;
+	char *ridstring;
+
+	ldb = ldb_module_get_ctx(module);
+
+	ret = samdb_rid_set_dn(ldb, tmp_ctx, &rid_set_dn);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb, __location__ ": No RID Set DN");
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = dsdb_module_search_dn(module, tmp_ctx, &res, rid_set_dn, attrs, 0);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb, __location__ ": No RID Set %s",
+				       ldb_dn_get_linearized(rid_set_dn));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	alloc_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAllocationPool", 0);
+	next_rid = ldb_msg_find_attr_as_int(res->msgs[0], "rIDNextRID", -1);
+	if (next_rid == -1 || alloc_pool == 0) {
+		ldb_asprintf_errstring(ldb, __location__ ": Bad RID Set %s",
+				       ldb_dn_get_linearized(rid_set_dn));
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	alloc_pool_lo = alloc_pool & 0xFFFFFFFF;
+	alloc_pool_hi = alloc_pool >> 32;
+	if (next_rid > alloc_pool_hi) {
+		/* TODO: add call to RID Manager */
+		ldb_asprintf_errstring(ldb, __location__ ": Out of RIDs in RID Set %s",
+				       ldb_dn_get_linearized(rid_set_dn));
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* despite the name, rIDNextRID is the value of the last user
+	 * added by this DC, not the next available RID */
+
+	(*rid) = next_rid + 1;
+
+	/* now modify the RID Set to use up this RID using a
+	 * constrained delete/add */
+	msg = ldb_msg_new(tmp_ctx);
+	msg->dn = rid_set_dn;
+
+	ret = ldb_msg_add_empty(msg, "rIDNextRID", LDB_FLAG_MOD_DELETE, &el);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+	el->num_values = 1;
+	el->values = &v1;
+	ridstring = talloc_asprintf(msg, "%u", (unsigned)next_rid);
+	if (!ridstring) {
+		ldb_module_oom(module);
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	v1 = data_blob_string_const(ridstring);
+
+	ret = ldb_msg_add_empty(msg, "rIDNextRID", LDB_FLAG_MOD_ADD, &el);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+	el->num_values = 1;
+	el->values = &v2;
+	ridstring = talloc_asprintf(msg, "%u", (unsigned)next_rid+1);
+	if (!ridstring) {
+		ldb_module_oom(module);
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	v2 = data_blob_string_const(ridstring);
+
+	ret = dsdb_module_modify(module, msg, 0);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	talloc_free(tmp_ctx);
+
+	return LDB_SUCCESS;
+}