source/lib/ldb/modules/sort.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce  2005
   5
   6      ** NOTE! The following LGPL license applies to the ldb
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 /*
  25  *  Name: ldb
  26  *
  27  *  Component: ldb server side sort control module
  28  *
  29  *  Description: this module sorts the results of a search
  30  *
  31  *  Author: Simo Sorce
  32  */
  33
  34 #include "includes.h"
  35 #include "ldb/include/includes.h"
  36
  37 struct opaque {
  38         struct ldb_context *ldb;
  39         const struct ldb_attrib_handler *h;
  40         const char *attribute;
  41         int reverse;
  42         int result;
  43 };
  44
  45 struct sort_context {
  46         struct ldb_module *module;
  47         void *up_context;
  48         int (*up_callback)(struct ldb_context *, void *, struct ldb_reply *);
  49
  50         char *attributeName;
  51         char *orderingRule;
  52         int reverse;
  53
  54         struct ldb_request *req;
  55         struct ldb_message **msgs;
  56         char **referrals;
  57         struct ldb_control **controls;
  58         int num_msgs;
  59         int num_refs;
  60
  61         const struct ldb_attrib_handler *h;
  62         int sort_result;
  63 };
  64
  65 static struct ldb_handle *init_handle(void *mem_ctx, struct ldb_module *module,
  66                                             void *context,
  67                                             int (*callback)(struct ldb_context *, void *, struct ldb_reply *))
  68 {
  69         struct sort_context *ac;
  70         struct ldb_handle *h;
  71
  72         h = talloc_zero(mem_ctx, struct ldb_handle);
  73         if (h == NULL) {
  74                 ldb_set_errstring(module->ldb, "Out of Memory");
  75                 return NULL;
  76         }
  77
  78         h->module = module;
  79
  80         ac = talloc_zero(h, struct sort_context);
  81         if (ac == NULL) {
  82                 ldb_set_errstring(module->ldb, "Out of Memory");
  83                 talloc_free(h);
  84                 return NULL;
  85         }
  86
  87         h->private_data = (void *)ac;
  88
  89         h->state = LDB_ASYNC_INIT;
  90         h->status = LDB_SUCCESS;
  91
  92         ac->module = module;
  93         ac->up_context = context;
  94         ac->up_callback = callback;
  95
  96         return h;
  97 }
  98
  99 static int build_response(void *mem_ctx, struct ldb_control ***ctrls, int result, const char *desc)
 100 {
 101         struct ldb_control **controls;
 102         struct ldb_sort_resp_control *resp;
 103         int i;
 104
 105         if (*ctrls) {
 106                 controls = *ctrls;
 107                 for (i = 0; controls[i]; i++);
 108                 controls = talloc_realloc(mem_ctx, controls, struct ldb_control *, i + 2);
 109         } else {
 110                 i = 0;
 111                 controls = talloc_array(mem_ctx, struct ldb_control *, 2);
 112         }
 113         if (! controls )
 114                 return LDB_ERR_OPERATIONS_ERROR;
 115
 116         *ctrls = controls;
 117
 118         controls[i+1] = NULL;
 119         controls[i] = talloc(controls, struct ldb_control);
 120         if (! controls[i] )
 121                 return LDB_ERR_OPERATIONS_ERROR;
 122
 123         controls[i]->oid = LDB_CONTROL_SORT_RESP_OID;
 124         controls[i]->critical = 0;
 125
 126         resp = talloc(controls[i], struct ldb_sort_resp_control);
 127         if (! resp )
 128                 return LDB_ERR_OPERATIONS_ERROR;
 129
 130         resp->result = result;
 131         resp->attr_desc = talloc_strdup(resp, desc);
 132
 133         if (! resp->attr_desc )
 134                 return LDB_ERR_OPERATIONS_ERROR;
 135
 136         controls[i]->data = resp;
 137
 138         return LDB_SUCCESS;
 139 }
 140
 141 static int sort_compare(struct ldb_message **msg1, struct ldb_message **msg2, void *opaque)
 142 {
 143         struct sort_context *ac = talloc_get_type(opaque, struct sort_context);
 144         struct ldb_message_element *el1, *el2;
 145
 146         if (ac->sort_result != 0) {
 147                 /* an error occurred previously,
 148                  * let's exit the sorting by returning always 0 */
 149                 return 0;
 150         }
 151
 152         el1 = ldb_msg_find_element(*msg1, ac->attributeName);
 153         el2 = ldb_msg_find_element(*msg2, ac->attributeName);
 154
 155         if (!el1 || !el2) {
 156                 /* the attribute was not found return and
 157                  * set an error */
 158                 ac->sort_result = 53;
 159                 return 0;
 160         }
 161
 162         if (ac->reverse)
 163                 return ac->h->comparison_fn(ac->module->ldb, ac, &el2->values[0], &el1->values[0]);
 164
 165         return ac->h->comparison_fn(ac->module->ldb, ac, &el1->values[0], &el2->values[0]);
 166 }
 167
 168 static int server_sort_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares)
 169 {
 170         struct sort_context *ac = NULL;
 171
 172         if (!context || !ares) {
 173                 ldb_set_errstring(ldb, "NULL Context or Result in callback");
 174                 goto error;
 175         }
 176
 177         ac = talloc_get_type(context, struct sort_context);
 178
 179         if (ares->type == LDB_REPLY_ENTRY) {
 180                 ac->msgs = talloc_realloc(ac, ac->msgs, struct ldb_message *, ac->num_msgs + 2);
 181                 if (! ac->msgs) {
 182                         goto error;
 183                 }
 184
 185                 ac->msgs[ac->num_msgs + 1] = NULL;
 186
 187                 ac->msgs[ac->num_msgs] = talloc_move(ac->msgs, &ares->message);
 188                 ac->num_msgs++;
 189         }
 190
 191         if (ares->type == LDB_REPLY_REFERRAL) {
 192                 ac->referrals = talloc_realloc(ac, ac->referrals, char *, ac->num_refs + 2);
 193                 if (! ac->referrals) {
 194                         goto error;
 195                 }
 196
 197                 ac->referrals[ac->num_refs + 1] = NULL;
 198                 ac->referrals[ac->num_refs] = talloc_move(ac->referrals, &ares->referral);
 199
 200                 ac->num_refs++;
 201         }
 202
 203         if (ares->type == LDB_REPLY_DONE) {
 204                 ac->controls = talloc_move(ac, &ares->controls);
 205         }
 206
 207         talloc_free(ares);
 208         return LDB_SUCCESS;
 209
 210 error:
 211         talloc_free(ares);
 212         return LDB_ERR_OPERATIONS_ERROR;
 213 }
 214
 215 static int server_sort_search(struct ldb_module *module, struct ldb_request *req)
 216 {
 217         struct ldb_control *control;
 218         struct ldb_server_sort_control **sort_ctrls;
 219         struct ldb_control **saved_controls;
 220         struct sort_context *ac;
 221         struct ldb_handle *h;
 222         int ret;
 223
 224         /* check if there's a paged request control */
 225         control = get_control_from_list(req->controls, LDB_CONTROL_SERVER_SORT_OID);
 226         if (control == NULL) {
 227                 /* not found go on */
 228                 return ldb_next_request(module, req);
 229         }
 230
 231         req->handle = NULL;
 232
 233         if (!req->callback || !req->context) {
 234                 ldb_set_errstring(module->ldb,
 235                                   "Async interface called with NULL callback function or NULL context");
 236                 return LDB_ERR_OPERATIONS_ERROR;
 237         }
 238
 239         h = init_handle(req, module, req->context, req->callback);
 240         if (!h) {
 241                 return LDB_ERR_OPERATIONS_ERROR;
 242         }
 243         ac = talloc_get_type(h->private_data, struct sort_context);
 244
 245         sort_ctrls = talloc_get_type(control->data, struct ldb_server_sort_control *);
 246         if (!sort_ctrls) {
 247                 return LDB_ERR_PROTOCOL_ERROR;
 248         }
 249
 250         /* FIXME: we do not support more than one attribute for sorting right now */
 251         /* FIXME: we need to check if the attribute type exist or return an error */
 252
 253         if (sort_ctrls[1] != NULL) {
 254                 if (control->critical) {
 255                         struct ldb_reply *ares;
 256
 257                         ares = talloc_zero(req, struct ldb_reply);
 258                         if (!ares)
 259                                 return LDB_ERR_OPERATIONS_ERROR;
 260
 261                         /* 53 = unwilling to perform */
 262                         ares->type = LDB_REPLY_DONE;
 263                         if ((ret = build_response(ares, &ares->controls, 53, "sort control is not complete yet")) != LDB_SUCCESS) {
 264                                 return ret;
 265                         }
 266
 267                         h->status = LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
 268                         h->state = LDB_ASYNC_DONE;
 269                         ret = ac->up_callback(module->ldb, ac->up_context, ares);
 270
 271                         return ret;
 272                 } else {
 273                         /* just pass the call down and don't do any sorting */
 274                         ldb_next_request(module, req);
 275                 }
 276         }
 277
 278         ac->attributeName = sort_ctrls[0]->attributeName;
 279         ac->orderingRule = sort_ctrls[0]->orderingRule;
 280         ac->reverse = sort_ctrls[0]->reverse;
 281
 282         ac->req = talloc(req, struct ldb_request);
 283         if (!ac->req)
 284                 return LDB_ERR_OPERATIONS_ERROR;
 285
 286         ac->req->operation = req->operation;
 287         ac->req->op.search.base = req->op.search.base;
 288         ac->req->op.search.scope = req->op.search.scope;
 289         ac->req->op.search.tree = req->op.search.tree;
 290         ac->req->op.search.attrs = req->op.search.attrs;
 291         ac->req->controls = req->controls;
 292
 293         /* save it locally and remove it from the list */
 294         /* we do not need to replace them later as we
 295          * are keeping the original req intact */
 296         if (!save_controls(control, ac->req, &saved_controls)) {
 297                 return LDB_ERR_OPERATIONS_ERROR;
 298         }
 299
 300         ac->req->context = ac;
 301         ac->req->callback = server_sort_search_callback;
 302         ldb_set_timeout_from_prev_req(module->ldb, req, ac->req);
 303
 304         req->handle = h;
 305
 306         return ldb_next_request(module, ac->req);
 307 }
 308
 309 static int server_sort_results(struct ldb_handle *handle)
 310 {
 311         struct sort_context *ac;
 312         struct ldb_reply *ares;
 313         int i, ret;
 314
 315         ac = talloc_get_type(handle->private_data, struct sort_context);
 316
 317         ac->h = ldb_attrib_handler(ac->module->ldb, ac->attributeName);
 318         ac->sort_result = 0;
 319
 320         ldb_qsort(ac->msgs, ac->num_msgs,
 321                   sizeof(struct ldb_message *),
 322                   ac, (ldb_qsort_cmp_fn_t)sort_compare);
 323
 324         for (i = 0; i < ac->num_msgs; i++) {
 325                 ares = talloc_zero(ac, struct ldb_reply);
 326                 if (!ares) {
 327                         handle->status = LDB_ERR_OPERATIONS_ERROR;
 328                         return handle->status;
 329                 }
 330
 331                 ares->type = LDB_REPLY_ENTRY;
 332                 ares->message = talloc_move(ares, &ac->msgs[i]);
 333
 334                 handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 335                 if (handle->status != LDB_SUCCESS) {
 336                         return handle->status;
 337                 }
 338         }
 339
 340         for (i = 0; i < ac->num_refs; i++) {
 341                 ares = talloc_zero(ac, struct ldb_reply);
 342                 if (!ares) {
 343                         handle->status = LDB_ERR_OPERATIONS_ERROR;
 344                         return handle->status;
 345                 }
 346
 347                 ares->type = LDB_REPLY_REFERRAL;
 348                 ares->referral = talloc_move(ares, &ac->referrals[i]);
 349
 350                 handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 351                 if (handle->status != LDB_SUCCESS) {
 352                         return handle->status;
 353                 }
 354         }
 355
 356         ares = talloc_zero(ac, struct ldb_reply);
 357         if (!ares) {
 358                 handle->status = LDB_ERR_OPERATIONS_ERROR;
 359                 return handle->status;
 360         }
 361
 362         ares->type = LDB_REPLY_DONE;
 363         ares->controls = talloc_move(ares, &ac->controls);
 364
 365         handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 366         if (handle->status != LDB_SUCCESS) {
 367                 return handle->status;
 368         }
 369
 370         if ((ret = build_response(ac, &ac->controls, ac->sort_result, "sort control is not complete yet")) != LDB_SUCCESS) {
 371                 return ret;
 372         }
 373
 374         return LDB_SUCCESS;
 375 }
 376
 377 static int server_sort_wait(struct ldb_handle *handle, enum ldb_wait_type type)
 378 {
 379         struct sort_context *ac;
 380         int ret;
 381
 382         if (!handle || !handle->private_data) {
 383                 return LDB_ERR_OPERATIONS_ERROR;
 384         }
 385
 386         ac = talloc_get_type(handle->private_data, struct sort_context);
 387
 388         ret = ldb_wait(ac->req->handle, type);
 389
 390         if (ret != LDB_SUCCESS) {
 391                 handle->status = ret;
 392                 return ret;
 393         }
 394
 395         handle->state = ac->req->handle->state;
 396         handle->status = ac->req->handle->status;
 397
 398         if (handle->status != LDB_SUCCESS) {
 399                 return handle->status;
 400         }
 401
 402         if (handle->state == LDB_ASYNC_DONE) {
 403                 ret = server_sort_results(handle);
 404         }
 405
 406         return ret;
 407 }
 408
 409 static int server_sort_init(struct ldb_module *module)
 410 {
 411         struct ldb_request *req;
 412         int ret;
 413
 414         req = talloc(module, struct ldb_request);
 415         if (req == NULL) {
 416                 return LDB_ERR_OPERATIONS_ERROR;
 417         }
 418
 419         req->operation = LDB_REQ_REGISTER_CONTROL;
 420         req->op.reg_control.oid = LDB_CONTROL_SERVER_SORT_OID;
 421         req->controls = NULL;
 422
 423         ret = ldb_request(module->ldb, req);
 424         if (ret != LDB_SUCCESS) {
 425                 ldb_debug(module->ldb, LDB_DEBUG_WARNING, "server_sort: Unable to register control with rootdse!\n");
 426         }
 427
 428         talloc_free(req);
 429         return ldb_next_init(module);
 430 }
 431
 432 static const struct ldb_module_ops server_sort_ops = {
 433         .name              = "server_sort",
 434         .search            = server_sort_search,
 435         .wait              = server_sort_wait,
 436         .init_context      = server_sort_init
 437 };
 438
 439 int ldb_sort_init(void)
 440 {
 441         return ldb_register_module(&server_sort_ops);
 442 }