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, write to the Free Software
  22    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 */
  24
  25 /*
  26  *  Name: ldb
  27  *
  28  *  Component: ldb server side sort control module
  29  *
  30  *  Description: this module sorts the results of a search
  31  *
  32  *  Author: Simo Sorce
  33  */
  34
  35 #include "includes.h"
  36 #include "ldb/include/includes.h"
  37
  38 struct opaque {
  39         struct ldb_context *ldb;
  40         const struct ldb_attrib_handler *h;
  41         const char *attribute;
  42         int reverse;
  43         int result;
  44 };
  45
  46 struct sort_context {
  47         struct ldb_module *module;
  48         void *up_context;
  49         int (*up_callback)(struct ldb_context *, void *, struct ldb_reply *);
  50
  51         char *attributeName;
  52         char *orderingRule;
  53         int reverse;
  54
  55         struct ldb_request *req;
  56         struct ldb_message **msgs;
  57         char **referrals;
  58         struct ldb_control **controls;
  59         int num_msgs;
  60         int num_refs;
  61
  62         const struct ldb_attrib_handler *h;
  63         int sort_result;
  64 };
  65
  66 static struct ldb_handle *init_handle(void *mem_ctx, struct ldb_module *module,
  67                                             void *context,
  68                                             int (*callback)(struct ldb_context *, void *, struct ldb_reply *))
  69 {
  70         struct sort_context *ac;
  71         struct ldb_handle *h;
  72
  73         h = talloc_zero(mem_ctx, struct ldb_handle);
  74         if (h == NULL) {
  75                 ldb_set_errstring(module->ldb, "Out of Memory");
  76                 return NULL;
  77         }
  78
  79         h->module = module;
  80
  81         ac = talloc_zero(h, struct sort_context);
  82         if (ac == NULL) {
  83                 ldb_set_errstring(module->ldb, "Out of Memory");
  84                 talloc_free(h);
  85                 return NULL;
  86         }
  87
  88         h->private_data = (void *)ac;
  89
  90         h->state = LDB_ASYNC_INIT;
  91         h->status = LDB_SUCCESS;
  92
  93         ac->module = module;
  94         ac->up_context = context;
  95         ac->up_callback = callback;
  96
  97         return h;
  98 }
  99
 100 static int build_response(void *mem_ctx, struct ldb_control ***ctrls, int result, const char *desc)
 101 {
 102         struct ldb_control **controls;
 103         struct ldb_sort_resp_control *resp;
 104         int i;
 105
 106         if (*ctrls) {
 107                 controls = *ctrls;
 108                 for (i = 0; controls[i]; i++);
 109                 controls = talloc_realloc(mem_ctx, controls, struct ldb_control *, i + 2);
 110         } else {
 111                 i = 0;
 112                 controls = talloc_array(mem_ctx, struct ldb_control *, 2);
 113         }
 114         if (! controls )
 115                 return LDB_ERR_OPERATIONS_ERROR;
 116
 117         *ctrls = controls;
 118
 119         controls[i+1] = NULL;
 120         controls[i] = talloc(controls, struct ldb_control);
 121         if (! controls[i] )
 122                 return LDB_ERR_OPERATIONS_ERROR;
 123
 124         controls[i]->oid = LDB_CONTROL_SORT_RESP_OID;
 125         controls[i]->critical = 0;
 126
 127         resp = talloc(controls[i], struct ldb_sort_resp_control);
 128         if (! resp )
 129                 return LDB_ERR_OPERATIONS_ERROR;
 130
 131         resp->result = result;
 132         resp->attr_desc = talloc_strdup(resp, desc);
 133
 134         if (! resp->attr_desc )
 135                 return LDB_ERR_OPERATIONS_ERROR;
 136
 137         controls[i]->data = resp;
 138
 139         return LDB_SUCCESS;
 140 }
 141
 142 static int sort_compare(struct ldb_message **msg1, struct ldb_message **msg2, void *opaque)
 143 {
 144         struct sort_context *ac = talloc_get_type(opaque, struct sort_context);
 145         struct ldb_message_element *el1, *el2;
 146
 147         if (ac->sort_result != 0) {
 148                 /* an error occurred previously,
 149                  * let's exit the sorting by returning always 0 */
 150                 return 0;
 151         }
 152
 153         el1 = ldb_msg_find_element(*msg1, ac->attributeName);
 154         el2 = ldb_msg_find_element(*msg2, ac->attributeName);
 155
 156         if (!el1 || !el2) {
 157                 /* the attribute was not found return and
 158                  * set an error */
 159                 ac->sort_result = 53;
 160                 return 0;
 161         }
 162
 163         if (ac->reverse)
 164                 return ac->h->comparison_fn(ac->module->ldb, ac, &el2->values[0], &el1->values[0]);
 165
 166         return ac->h->comparison_fn(ac->module->ldb, ac, &el1->values[0], &el2->values[0]);
 167 }
 168
 169 static int server_sort_search_callback(struct ldb_context *ldb, void *context, struct ldb_reply *ares)
 170 {
 171         struct sort_context *ac = NULL;
 172
 173         if (!context || !ares) {
 174                 ldb_set_errstring(ldb, "NULL Context or Result in callback");
 175                 goto error;
 176         }
 177
 178         ac = talloc_get_type(context, struct sort_context);
 179
 180         if (ares->type == LDB_REPLY_ENTRY) {
 181                 ac->msgs = talloc_realloc(ac, ac->msgs, struct ldb_message *, ac->num_msgs + 2);
 182                 if (! ac->msgs) {
 183                         goto error;
 184                 }
 185
 186                 ac->msgs[ac->num_msgs + 1] = NULL;
 187
 188                 ac->msgs[ac->num_msgs] = talloc_move(ac->msgs, &ares->message);
 189                 ac->num_msgs++;
 190         }
 191
 192         if (ares->type == LDB_REPLY_REFERRAL) {
 193                 ac->referrals = talloc_realloc(ac, ac->referrals, char *, ac->num_refs + 2);
 194                 if (! ac->referrals) {
 195                         goto error;
 196                 }
 197
 198                 ac->referrals[ac->num_refs + 1] = NULL;
 199                 ac->referrals[ac->num_refs] = talloc_move(ac->referrals, &ares->referral);
 200
 201                 ac->num_refs++;
 202         }
 203
 204         if (ares->type == LDB_REPLY_DONE) {
 205                 ac->controls = talloc_move(ac, &ares->controls);
 206         }
 207
 208         talloc_free(ares);
 209         return LDB_SUCCESS;
 210
 211 error:
 212         talloc_free(ares);
 213         return LDB_ERR_OPERATIONS_ERROR;
 214 }
 215
 216 static int server_sort_search(struct ldb_module *module, struct ldb_request *req)
 217 {
 218         struct ldb_control *control;
 219         struct ldb_server_sort_control **sort_ctrls;
 220         struct ldb_control **saved_controls;
 221         struct sort_context *ac;
 222         struct ldb_handle *h;
 223         int ret;
 224
 225         /* check if there's a paged request control */
 226         control = get_control_from_list(req->controls, LDB_CONTROL_SERVER_SORT_OID);
 227         if (control == NULL) {
 228                 /* not found go on */
 229                 return ldb_next_request(module, req);
 230         }
 231
 232         req->handle = NULL;
 233
 234         if (!req->callback || !req->context) {
 235                 ldb_set_errstring(module->ldb,
 236                                   "Async interface called with NULL callback function or NULL context");
 237                 return LDB_ERR_OPERATIONS_ERROR;
 238         }
 239
 240         h = init_handle(req, module, req->context, req->callback);
 241         if (!h) {
 242                 return LDB_ERR_OPERATIONS_ERROR;
 243         }
 244         ac = talloc_get_type(h->private_data, struct sort_context);
 245
 246         sort_ctrls = talloc_get_type(control->data, struct ldb_server_sort_control *);
 247         if (!sort_ctrls) {
 248                 return LDB_ERR_PROTOCOL_ERROR;
 249         }
 250
 251         /* FIXME: we do not support more than one attribute for sorting right now */
 252         /* FIXME: we need to check if the attribute type exist or return an error */
 253
 254         if (sort_ctrls[1] != NULL) {
 255                 if (control->critical) {
 256                         struct ldb_reply *ares;
 257
 258                         ares = talloc_zero(req, struct ldb_reply);
 259                         if (!ares)
 260                                 return LDB_ERR_OPERATIONS_ERROR;
 261
 262                         /* 53 = unwilling to perform */
 263                         ares->type = LDB_REPLY_DONE;
 264                         if ((ret = build_response(ares, &ares->controls, 53, "sort control is not complete yet")) != LDB_SUCCESS) {
 265                                 return ret;
 266                         }
 267
 268                         h->status = LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
 269                         h->state = LDB_ASYNC_DONE;
 270                         ret = ac->up_callback(module->ldb, ac->up_context, ares);
 271
 272                         return ret;
 273                 } else {
 274                         /* just pass the call down and don't do any sorting */
 275                         ldb_next_request(module, req);
 276                 }
 277         }
 278
 279         ac->attributeName = sort_ctrls[0]->attributeName;
 280         ac->orderingRule = sort_ctrls[0]->orderingRule;
 281         ac->reverse = sort_ctrls[0]->reverse;
 282
 283         ac->req = talloc(req, struct ldb_request);
 284         if (!ac->req)
 285                 return LDB_ERR_OPERATIONS_ERROR;
 286
 287         ac->req->operation = req->operation;
 288         ac->req->op.search.base = req->op.search.base;
 289         ac->req->op.search.scope = req->op.search.scope;
 290         ac->req->op.search.tree = req->op.search.tree;
 291         ac->req->op.search.attrs = req->op.search.attrs;
 292         ac->req->controls = req->controls;
 293
 294         /* save it locally and remove it from the list */
 295         /* we do not need to replace them later as we
 296          * are keeping the original req intact */
 297         if (!save_controls(control, ac->req, &saved_controls)) {
 298                 return LDB_ERR_OPERATIONS_ERROR;
 299         }
 300
 301         ac->req->context = ac;
 302         ac->req->callback = server_sort_search_callback;
 303         ldb_set_timeout_from_prev_req(module->ldb, req, ac->req);
 304
 305         req->handle = h;
 306
 307         return ldb_next_request(module, ac->req);
 308 }
 309
 310 static int server_sort_results(struct ldb_handle *handle)
 311 {
 312         struct sort_context *ac;
 313         struct ldb_reply *ares;
 314         int i, ret;
 315
 316         ac = talloc_get_type(handle->private_data, struct sort_context);
 317
 318         ac->h = ldb_attrib_handler(ac->module->ldb, ac->attributeName);
 319         ac->sort_result = 0;
 320
 321         ldb_qsort(ac->msgs, ac->num_msgs,
 322                   sizeof(struct ldb_message *),
 323                   ac, (ldb_qsort_cmp_fn_t)sort_compare);
 324
 325         for (i = 0; i < ac->num_msgs; i++) {
 326                 ares = talloc_zero(ac, struct ldb_reply);
 327                 if (!ares) {
 328                         handle->status = LDB_ERR_OPERATIONS_ERROR;
 329                         return handle->status;
 330                 }
 331
 332                 ares->type = LDB_REPLY_ENTRY;
 333                 ares->message = talloc_move(ares, &ac->msgs[i]);
 334
 335                 handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 336                 if (handle->status != LDB_SUCCESS) {
 337                         return handle->status;
 338                 }
 339         }
 340
 341         for (i = 0; i < ac->num_refs; i++) {
 342                 ares = talloc_zero(ac, struct ldb_reply);
 343                 if (!ares) {
 344                         handle->status = LDB_ERR_OPERATIONS_ERROR;
 345                         return handle->status;
 346                 }
 347
 348                 ares->type = LDB_REPLY_REFERRAL;
 349                 ares->referral = talloc_move(ares, &ac->referrals[i]);
 350
 351                 handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 352                 if (handle->status != LDB_SUCCESS) {
 353                         return handle->status;
 354                 }
 355         }
 356
 357         ares = talloc_zero(ac, struct ldb_reply);
 358         if (!ares) {
 359                 handle->status = LDB_ERR_OPERATIONS_ERROR;
 360                 return handle->status;
 361         }
 362
 363         ares->type = LDB_REPLY_DONE;
 364         ares->controls = talloc_move(ares, &ac->controls);
 365
 366         handle->status = ac->up_callback(ac->module->ldb, ac->up_context, ares);
 367         if (handle->status != LDB_SUCCESS) {
 368                 return handle->status;
 369         }
 370
 371         if ((ret = build_response(ac, &ac->controls, ac->sort_result, "sort control is not complete yet")) != LDB_SUCCESS) {
 372                 return ret;
 373         }
 374
 375         return LDB_SUCCESS;
 376 }
 377
 378 static int server_sort_wait(struct ldb_handle *handle, enum ldb_wait_type type)
 379 {
 380         struct sort_context *ac;
 381         int ret;
 382
 383         if (!handle || !handle->private_data) {
 384                 return LDB_ERR_OPERATIONS_ERROR;
 385         }
 386
 387         ac = talloc_get_type(handle->private_data, struct sort_context);
 388
 389         ret = ldb_wait(ac->req->handle, type);
 390
 391         if (ret != LDB_SUCCESS) {
 392                 handle->status = ret;
 393                 return ret;
 394         }
 395
 396         handle->state = ac->req->handle->state;
 397         handle->status = ac->req->handle->status;
 398
 399         if (handle->status != LDB_SUCCESS) {
 400                 return handle->status;
 401         }
 402
 403         if (handle->state == LDB_ASYNC_DONE) {
 404                 ret = server_sort_results(handle);
 405         }
 406
 407         return ret;
 408 }
 409
 410 static int server_sort_init(struct ldb_module *module)
 411 {
 412         struct ldb_request *req;
 413         int ret;
 414
 415         req = talloc(module, struct ldb_request);
 416         if (req == NULL) {
 417                 return LDB_ERR_OPERATIONS_ERROR;
 418         }
 419
 420         req->operation = LDB_REQ_REGISTER_CONTROL;
 421         req->op.reg_control.oid = LDB_CONTROL_SERVER_SORT_OID;
 422         req->controls = NULL;
 423
 424         ret = ldb_request(module->ldb, req);
 425         if (ret != LDB_SUCCESS) {
 426                 ldb_debug(module->ldb, LDB_DEBUG_WARNING, "server_sort: Unable to register control with rootdse!\n");
 427         }
 428
 429         talloc_free(req);
 430         return ldb_next_init(module);
 431 }
 432
 433 static const struct ldb_module_ops server_sort_ops = {
 434         .name              = "server_sort",
 435         .search            = server_sort_search,
 436         .wait              = server_sort_wait,
 437         .init_context      = server_sort_init
 438 };
 439
 440 int ldb_sort_init(void)
 441 {
 442         return ldb_register_module(&server_sort_ops);
 443 }