1 files changed, 463 insertions, 0 deletions

diff --git a/ldb/modules/paged_searches.c b/ldb/modules/paged_searches.c
new file mode 100644
index 000000000..40e87f70d
--- /dev/null
+++ b/ldb/modules/paged_searches.c
@@ -0,0 +1,463 @@
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce  2005-2006
+
+     ** 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 "includes.h"
+#include "ldb_includes.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;
+	void *up_context;
+	int (*up_callback)(struct ldb_context *, void *, struct ldb_reply *);
+
+	struct ldb_request *orig_req;
+
+	struct ldb_request *new_req;
+
+	bool pending;
+
+	char **saved_referrals;
+	int num_referrals;
+};
+
+static struct ldb_handle *init_handle(void *mem_ctx, struct ldb_module *module,
+					    void *context,
+					    int (*callback)(struct ldb_context *, void *, struct ldb_reply *))
+{
+	struct ps_context *ac;
+	struct ldb_handle *h;
+
+	h = talloc_zero(mem_ctx, struct ldb_handle);
+	if (h == NULL) {
+		ldb_set_errstring(module->ldb, "Out of Memory");
+		return NULL;
+	}
+
+	h->module = module;
+
+	ac = talloc_zero(h, struct ps_context);
+	if (ac == NULL) {
+		ldb_set_errstring(module->ldb, "Out of Memory");
+		talloc_free(h);
+		return NULL;
+	}
+
+	h->private_data = (void *)ac;
+
+	h->state = LDB_ASYNC_INIT;
+	h->status = LDB_SUCCESS;
+
+	ac->module = module;
+	ac->up_context = context;
+	ac->up_callback = callback;
+
+	ac->pending = false;
+
+
+
+	ac->saved_referrals = NULL;
+	ac->num_referrals = 0;
+
+	return h;
+}
+
+static int check_ps_continuation(struct ldb_reply *ares, struct ps_context *ac)
+{
+	struct ldb_paged_control *rep_control, *req_control;
+
+	/* look up our paged control */
+	if (!ares->controls || strcmp(LDB_CONTROL_PAGED_RESULTS_OID, ares->controls[0]->oid) != 0) {
+		/* something wrong here */
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	rep_control = talloc_get_type(ares->controls[0]->data, struct ldb_paged_control);
+	if (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 (strcmp(LDB_CONTROL_PAGED_RESULTS_OID, ac->new_req->controls[0]->oid) != 0) {
+		/* something wrong here */
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	req_control = talloc_get_type(ac->new_req->controls[0]->data, struct ldb_paged_control);
+
+	if (req_control->cookie) {
+		talloc_free(req_control->cookie);
+	}
+
+	req_control->cookie = talloc_memdup(req_control,
+					    rep_control->cookie,
+					    rep_control->cookie_len);
+	req_control->cookie_len = rep_control->cookie_len;
+
+	ac->pending = true;
+	return LDB_SUCCESS;
+}
+
+static int store_referral(char *referral, struct ps_context *ac)
+{
+	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 ldb_context *ldb, struct ps_context *ac)
+{
+	struct ldb_reply *ares;
+	int i;
+
+	for (i = 0; i < ac->num_referrals; i++) {
+		ares = talloc_zero(ac, struct ldb_reply);
+		if (!ares) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		ares->type = LDB_REPLY_REFERRAL;
+		ares->referral = ac->saved_referrals[i];
+
+		ac->up_callback(ldb, ac->up_context, ares);
+	}
+
+	return LDB_SUCCESS;
+}
+
+static int ps_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares)
+{
+	struct ps_context *ac = NULL;
+	int ret = LDB_ERR_OPERATIONS_ERROR;
+
+	if (!context || !ares) {
+		ldb_set_errstring(ldb, "NULL Context or Result in callback");
+		goto error;
+	}
+
+	ac = talloc_get_type(context, struct ps_context);
+
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		ac->up_callback(ldb, ac->up_context, ares);
+		break;
+
+	case LDB_REPLY_REFERRAL:
+		ret = store_referral(ares->referral, ac);
+		if (ret != LDB_SUCCESS) {
+			goto error;
+		}
+		break;
+
+	case LDB_REPLY_DONE:
+		ret = check_ps_continuation(ares, ac);
+		if (ret != LDB_SUCCESS) {
+			goto error;
+		}
+		if (!ac->pending) {
+			/* send referrals */
+			ret = send_referrals(ldb, ac);
+			if (ret != LDB_SUCCESS) {
+				goto error;
+			}
+
+			/* send REPLY_DONE */
+			ac->up_callback(ldb, ac->up_context, ares);
+		}
+		break;
+	default:
+		goto error;
+	}
+
+	return LDB_SUCCESS;
+
+error:
+	talloc_free(ares);
+	return ret;
+}
+
+static int ps_search(struct ldb_module *module, struct ldb_request *req)
+{
+	struct private_data *private_data;
+	struct ldb_paged_control *control;
+	struct ps_context *ac;
+	struct ldb_handle *h;
+
+	private_data = talloc_get_type(module->private_data, struct private_data);
+
+	/* check if paging is supported and if there is a any control */
+	if (!private_data || !private_data->paged_supported || req->controls) {
+		/* do not touch this request paged controls not
+		 * supported or explicit controls have been set or we
+		 * are just not setup yet */
+		return ldb_next_request(module, req);
+	}
+
+	if (!req->callback || !req->context) {
+		ldb_set_errstring(module->ldb,
+				  "Async interface called with NULL callback function or NULL context");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	
+	h = init_handle(req, module, req->context, req->callback);
+	if (!h) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ac = talloc_get_type(h->private_data, struct ps_context);
+
+	ac->new_req = talloc(ac, struct ldb_request);
+	if (!ac->new_req) return LDB_ERR_OPERATIONS_ERROR;
+
+	ac->new_req->controls = talloc_array(ac->new_req, struct ldb_control *, 2);
+	if (!ac->new_req->controls) return LDB_ERR_OPERATIONS_ERROR;
+
+	ac->new_req->controls[0] = talloc(ac->new_req->controls, struct ldb_control);
+	if (!ac->new_req->controls[0]) return LDB_ERR_OPERATIONS_ERROR;
+
+	control = talloc(ac->new_req->controls[0], struct ldb_paged_control);
+	if (!control) return LDB_ERR_OPERATIONS_ERROR;
+
+	control->size = PS_DEFAULT_PAGE_SIZE;
+	control->cookie = NULL;
+	control->cookie_len = 0;
+
+	ac->new_req->controls[0]->oid = LDB_CONTROL_PAGED_RESULTS_OID;
+	ac->new_req->controls[0]->critical = 1;
+	ac->new_req->controls[0]->data = control;
+
+	ac->new_req->controls[1] = NULL;
+
+	ac->new_req->operation = req->operation;
+	ac->new_req->op.search.base = req->op.search.base;
+	ac->new_req->op.search.scope = req->op.search.scope;
+	ac->new_req->op.search.tree = req->op.search.tree;
+	ac->new_req->op.search.attrs = req->op.search.attrs;
+	ac->new_req->context = ac;
+	ac->new_req->callback = ps_callback;
+	ldb_set_timeout_from_prev_req(module->ldb, req, ac->new_req);
+
+	req->handle = h;
+
+	return ldb_next_request(module, ac->new_req);
+}
+
+static int ps_continuation(struct ldb_handle *handle)
+{
+	struct ps_context *ac;
+
+	if (!handle || !handle->private_data) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac = talloc_get_type(handle->private_data, struct ps_context);
+
+	/* reset the requests handle */
+	ac->new_req->handle = NULL;
+
+	return ldb_next_request(handle->module, ac->new_req);
+}
+
+static int ps_wait_once(struct ldb_handle *handle)
+{
+	struct ps_context *ac;
+	int ret;
+    
+	if (!handle || !handle->private_data) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	if (handle->state == LDB_ASYNC_DONE) {
+		return handle->status;
+	}
+
+	handle->state = LDB_ASYNC_PENDING;
+	handle->status = LDB_SUCCESS;
+
+	ac = talloc_get_type(handle->private_data, struct ps_context);
+
+	ret = ldb_wait(ac->new_req->handle, LDB_WAIT_NONE);
+
+	if (ret != LDB_SUCCESS) {
+		handle->status = ret;
+		goto done;
+	}
+
+	if (ac->new_req->handle->status != LDB_SUCCESS) {
+		handle->status = ac->new_req->handle->status;
+		goto done;
+	}
+
+	if (ac->new_req->handle->state != LDB_ASYNC_DONE) {
+		return LDB_SUCCESS;
+	} 
+
+	/* see if we need to send another request for the next batch */
+	if (ac->pending) {
+		ret = ps_continuation(handle);
+		if (ret != LDB_SUCCESS) {
+			handle->status = ret;
+			goto done;
+		}
+
+		/* continue the search with the next request */
+		return LDB_SUCCESS;
+	}
+
+	ret = LDB_SUCCESS;
+
+done:
+	handle->state = LDB_ASYNC_DONE;
+	return ret;
+}
+
+static int ps_wait(struct ldb_handle *handle, enum ldb_wait_type type)
+{
+	int ret;
+
+	if (!handle || !handle->private_data) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	if (type == LDB_WAIT_ALL) {
+		while (handle->state != LDB_ASYNC_DONE) {
+			ret = ps_wait_once(handle);
+			if (ret != LDB_SUCCESS) {
+				return ret;
+			}
+		}
+
+		return handle->status;
+	}
+	return ps_wait_once(handle);
+}
+
+static int check_supported_paged(struct ldb_context *ldb, void *context, 
+				 struct ldb_reply *ares) 
+{
+	struct private_data *data;
+	data = talloc_get_type(context,
+			       struct private_data);
+	if (ares->type == LDB_REPLY_ENTRY) {
+		if (ldb_msg_check_string_attribute(ares->message,
+						   "supportedControl",
+						   LDB_CONTROL_PAGED_RESULTS_OID)) {
+			data->paged_supported = true;
+		}
+	}
+	return LDB_SUCCESS;
+}
+
+
+static int ps_init(struct ldb_module *module)
+{
+	static const char *attrs[] = { "supportedControl", NULL };
+	struct private_data *data;
+	int ret;
+	struct ldb_request *req;
+
+	data = talloc(module, struct private_data);
+	if (data == NULL) {
+		ldb_set_errstring(module->ldb, "Out of Memory");
+		return LDB_ERR_OTHER;
+	}
+	module->private_data = data;
+	data->paged_supported = false;
+
+	req = talloc(module, struct ldb_request);
+	if (req == NULL) {
+		ldb_set_errstring(module->ldb, "Out of Memory");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	req->operation = LDB_SEARCH;
+	req->op.search.base = ldb_dn_new(req, module->ldb, "");
+	req->op.search.scope = LDB_SCOPE_BASE;
+
+	req->op.search.tree = ldb_parse_tree(req, "objectClass=*");
+	if (req->op.search.tree == NULL) {
+		ldb_set_errstring(module->ldb, "Unable to parse search expression");
+		talloc_free(req);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	req->op.search.attrs = attrs;
+	req->controls = NULL;
+	req->context = data;
+	req->callback = check_supported_paged;
+	ldb_set_timeout(module->ldb, req, 0); /* use default timeout */
+
+	ret = ldb_next_request(module, req);
+	
+	if (ret == LDB_SUCCESS) {
+		ret = ldb_wait(req->handle, LDB_WAIT_ALL);
+	}
+	
+	talloc_free(req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	return ldb_next_init(module);
+}
+
+_PUBLIC_ const struct ldb_module_ops ldb_paged_searches_module_ops = {
+	.name           = "paged_searches",
+	.search         = ps_search,
+	.wait           = ps_wait,
+	.init_context 	= ps_init
+};