1 files changed, 386 insertions, 0 deletions

diff --git a/lib/ldb/modules/paged_searches.c b/lib/ldb/modules/paged_searches.c
new file mode 100644
index 0000000000..68eeb4c76e
--- /dev/null
+++ b/lib/ldb/modules/paged_searches.c
@@ -0,0 +1,386 @@
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce  2005-2008
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2009
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ *  Name: paged_searches
+ *
+ *  Component: ldb paged searches module
+ *
+ *  Description: this module detects if the remote ldap server supports
+ *               paged results and use them to transparently access all objects
+ *
+ *  Author: Simo Sorce
+ */
+
+#include "replace.h"
+#include "system/filesys.h"
+#include "system/time.h"
+#include "ldb_module.h"
+
+#define PS_DEFAULT_PAGE_SIZE 500
+/* 500 objects per query seem to be a decent compromise
+ * the default AD limit per request is 1000 entries */
+
+struct private_data {
+
+	bool paged_supported;
+};
+
+struct ps_context {
+	struct ldb_module *module;
+	struct ldb_request *req;
+
+	bool pending;
+
+	char **saved_referrals;
+	unsigned int num_referrals;
+
+	struct ldb_request *down_req;
+};
+
+static int check_ps_continuation(struct ps_context *ac, struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct ldb_context *ldb;
+	struct ldb_control *rep_control, *req_control;
+	struct ldb_paged_control *paged_rep_control = NULL, *paged_req_control = NULL;
+	ldb = ldb_module_get_ctx(ac->module);
+
+	rep_control = ldb_reply_get_control(ares, LDB_CONTROL_PAGED_RESULTS_OID);
+	if (rep_control) {
+		paged_rep_control = talloc_get_type(rep_control->data, struct ldb_paged_control);
+	}
+
+	req_control = ldb_request_get_control(req, LDB_CONTROL_PAGED_RESULTS_OID);
+	paged_req_control = talloc_get_type(req_control->data, struct ldb_paged_control);
+
+	if (!rep_control || !paged_rep_control) {
+		if (paged_req_control->cookie) {
+			/* something wrong here - why give us a control back befre, but not one now? */
+			ldb_set_errstring(ldb, "paged_searches:  ERROR: We got back a control from a previous page, but this time no control was returned!");
+			return LDB_ERR_OPERATIONS_ERROR;
+		} else {
+			/* No cookie received yet, valid to just return the full data set */
+
+			/* we are done */
+			ac->pending = false;
+			return LDB_SUCCESS;
+		}
+	}
+
+	if (paged_rep_control->cookie_len == 0) {
+		/* we are done */
+		ac->pending = false;
+		return LDB_SUCCESS;
+	}
+
+	/* more processing required */
+	/* let's fill in the request control with the new cookie */
+	/* if there's a reply control we must find a request
+	 * control matching it */
+
+	if (paged_req_control->cookie) {
+		talloc_free(paged_req_control->cookie);
+	}
+
+	paged_req_control->cookie = talloc_memdup(req_control,
+						  paged_rep_control->cookie,
+						  paged_rep_control->cookie_len);
+	paged_req_control->cookie_len = paged_rep_control->cookie_len;
+
+	ac->pending = true;
+	return LDB_SUCCESS;
+}
+
+static int store_referral(struct ps_context *ac, char *referral)
+{
+	ac->saved_referrals = talloc_realloc(ac, ac->saved_referrals, char *, ac->num_referrals + 2);
+	if (!ac->saved_referrals) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->saved_referrals[ac->num_referrals] = talloc_strdup(ac->saved_referrals, referral);
+	if (!ac->saved_referrals[ac->num_referrals]) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->num_referrals++;
+	ac->saved_referrals[ac->num_referrals] = NULL;
+
+	return LDB_SUCCESS;
+}
+
+static int send_referrals(struct ps_context *ac)
+{
+	struct ldb_reply *ares;
+	int ret;
+	unsigned int i;
+
+	for (i = 0; i < ac->num_referrals; i++) {
+		ares = talloc_zero(ac->req, struct ldb_reply);
+		if (!ares) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		ares->type = LDB_REPLY_REFERRAL;
+		ares->referral = ac->saved_referrals[i];
+
+		ret = ldb_module_send_referral(ac->req, ares->referral);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
+
+	return LDB_SUCCESS;
+}
+
+static int ps_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct ps_context *ac;
+	int ret;
+
+	ac = talloc_get_type(req->context, struct ps_context);
+
+	if (!ares) {
+		return ldb_module_done(ac->req, NULL, NULL,
+					LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_module_done(ac->req, ares->controls,
+					ares->response, ares->error);
+	}
+
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+		break;
+
+	case LDB_REPLY_REFERRAL:
+		ret = store_referral(ac, ares->referral);
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+		break;
+
+	case LDB_REPLY_DONE:
+
+		ret = check_ps_continuation(ac, req, ares);
+		if (ret != LDB_SUCCESS) {
+			return ldb_module_done(ac->req, NULL, NULL, ret);
+		}
+
+		if (ac->pending) {
+
+			ret = ldb_next_request(ac->module, ac->down_req);
+
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req,
+							NULL, NULL, ret);
+			}
+
+		} else {
+
+			/* send referrals */
+			ret = send_referrals(ac);
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req,
+							NULL, NULL, ret);
+			}
+
+			/* send REPLY_DONE */
+			return ldb_module_done(ac->req, ares->controls,
+						ares->response, LDB_SUCCESS);
+		}
+		break;
+	}
+
+	talloc_free(ares);
+	return LDB_SUCCESS;
+}
+
+static int ps_search(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_context *ldb;
+	struct private_data *private_data;
+	struct ps_context *ac;
+	struct ldb_paged_control *control;
+	int ret;
+
+	private_data = talloc_get_type(ldb_module_get_private(module), struct private_data);
+	ldb = ldb_module_get_ctx(module);
+
+	/* check if paging is supported */
+	if (!private_data || !private_data->paged_supported) {
+		/* do not touch this request paged controls not
+		 * supported or we
+		 * are just not setup yet */
+		return ldb_next_request(module, req);
+	}
+
+	ac = talloc_zero(req, struct ps_context);
+	if (ac == NULL) {
+		ldb_oom(ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->module = module;
+	ac->req = req;
+	ac->pending = false;
+	ac->saved_referrals = NULL;
+	ac->num_referrals = 0;
+
+	ldb = ldb_module_get_ctx(ac->module);
+
+	control = talloc(ac, struct ldb_paged_control);
+	if (!control) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	control->size = PS_DEFAULT_PAGE_SIZE;
+	control->cookie = NULL;
+	control->cookie_len = 0;
+
+	ret = ldb_build_search_req_ex(&ac->down_req, ldb, ac,
+					ac->req->op.search.base,
+					ac->req->op.search.scope,
+					ac->req->op.search.tree,
+					ac->req->op.search.attrs,
+					ac->req->controls,
+					ac,
+					ps_callback,
+					ac->req);
+	LDB_REQ_SET_LOCATION(ac->down_req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	ret = ldb_request_add_control(ac->down_req, LDB_CONTROL_PAGED_RESULTS_OID,
+				      true, control);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	talloc_steal(ac->down_req, control);
+
+	return ldb_next_request(ac->module, ac->down_req);
+}
+
+static int check_supported_paged(struct ldb_request *req,
+				 struct ldb_reply *ares)
+{
+	struct private_data *data;
+
+	data = talloc_get_type(req->context, struct private_data);
+
+	if (!ares) {
+		return ldb_request_done(req, LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_request_done(req, LDB_ERR_OPERATIONS_ERROR);
+	}
+
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		if (ldb_msg_check_string_attribute(ares->message,
+						   "supportedControl",
+						   LDB_CONTROL_PAGED_RESULTS_OID)) {
+			data->paged_supported = true;
+		}
+		break;
+
+	case LDB_REPLY_REFERRAL:
+		/* ignore */
+		break;
+
+	case LDB_REPLY_DONE:
+		return ldb_request_done(req, LDB_SUCCESS);
+	}
+
+	talloc_free(ares);
+	return LDB_SUCCESS;
+}
+
+static int ps_init(struct ldb_module *module)
+{
+	struct ldb_context *ldb;
+	static const char *attrs[] = { "supportedControl", NULL };
+	struct private_data *data;
+	struct ldb_dn *base;
+	int ret;
+	struct ldb_request *req;
+
+	ldb = ldb_module_get_ctx(module);
+
+	data = talloc(module, struct private_data);
+	if (data == NULL) {
+		ldb_oom(ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	data->paged_supported = false;
+
+	ldb_module_set_private(module, data);
+
+	base = ldb_dn_new(module, ldb, "");
+	if (base == NULL) {
+		ldb_oom(ldb);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ret = ldb_build_search_req(&req, ldb, module,
+				   base, LDB_SCOPE_BASE,
+				   "(objectClass=*)",
+				   attrs, NULL,
+				   data, check_supported_paged,
+				   NULL);
+	LDB_REQ_SET_LOCATION(req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	ret = ldb_next_request(module, req);
+	if (ret == LDB_SUCCESS) {
+		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
+	}
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	talloc_free(base);
+	talloc_free(req);
+
+	return ldb_next_init(module);
+}
+
+static const struct ldb_module_ops ldb_paged_searches_module_ops = {
+	.name           = "paged_searches",
+	.search         = ps_search,
+	.init_context 	= ps_init
+};
+
+int ldb_paged_searches_init(const char *version)
+{
+	LDB_MODULE_CHECK_VERSION(version);
+	return ldb_register_module(&ldb_paged_searches_module_ops);
+}