source4/lib/ldb/modules/sort.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce  2005-2008
   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 "ldb_includes.h"
  35
  36 struct opaque {
  37         struct ldb_context *ldb;
  38         const struct ldb_attrib_handler *h;
  39         const char *attribute;
  40         int reverse;
  41         int result;
  42 };
  43
  44 struct sort_context {
  45         struct ldb_module *module;
  46
  47         char *attributeName;
  48         char *orderingRule;
  49         int reverse;
  50
  51         struct ldb_request *req;
  52         struct ldb_message **msgs;
  53         char **referrals;
  54         int num_msgs;
  55         int num_refs;
  56
  57         const struct ldb_schema_attribute *a;
  58         int sort_result;
  59 };
  60
  61 static int build_response(void *mem_ctx, struct ldb_control ***ctrls, int result, const char *desc)
  62 {
  63         struct ldb_control **controls;
  64         struct ldb_sort_resp_control *resp;
  65         int i;
  66
  67         if (*ctrls) {
  68                 controls = *ctrls;
  69                 for (i = 0; controls[i]; i++);
  70                 controls = talloc_realloc(mem_ctx, controls, struct ldb_control *, i + 2);
  71         } else {
  72                 i = 0;
  73                 controls = talloc_array(mem_ctx, struct ldb_control *, 2);
  74         }
  75         if (! controls )
  76                 return LDB_ERR_OPERATIONS_ERROR;
  77
  78         *ctrls = controls;
  79
  80         controls[i+1] = NULL;
  81         controls[i] = talloc(controls, struct ldb_control);
  82         if (! controls[i] )
  83                 return LDB_ERR_OPERATIONS_ERROR;
  84
  85         controls[i]->oid = LDB_CONTROL_SORT_RESP_OID;
  86         controls[i]->critical = 0;
  87
  88         resp = talloc(controls[i], struct ldb_sort_resp_control);
  89         if (! resp )
  90                 return LDB_ERR_OPERATIONS_ERROR;
  91
  92         resp->result = result;
  93         resp->attr_desc = talloc_strdup(resp, desc);
  94
  95         if (! resp->attr_desc )
  96                 return LDB_ERR_OPERATIONS_ERROR;
  97
  98         controls[i]->data = resp;
  99
 100         return LDB_SUCCESS;
 101 }
 102
 103 static int sort_compare(struct ldb_message **msg1, struct ldb_message **msg2, void *opaque)
 104 {
 105         struct sort_context *ac = talloc_get_type(opaque, struct sort_context);
 106         struct ldb_message_element *el1, *el2;
 107
 108         if (!ac || ac->sort_result != 0) {
 109                 /* an error occurred previously,
 110                  * let's exit the sorting by returning always 0 */
 111                 return 0;
 112         }
 113
 114         el1 = ldb_msg_find_element(*msg1, ac->attributeName);
 115         el2 = ldb_msg_find_element(*msg2, ac->attributeName);
 116
 117         if (!el1 || !el2) {
 118                 /* the attribute was not found return and
 119                  * set an error */
 120                 ac->sort_result = LDB_ERR_UNWILLING_TO_PERFORM;
 121                 return 0;
 122         }
 123
 124         if (ac->reverse)
 125                 return ac->a->syntax->comparison_fn(ac->module->ldb, ac, &el2->values[0], &el1->values[0]);
 126
 127         return ac->a->syntax->comparison_fn(ac->module->ldb, ac, &el1->values[0], &el2->values[0]);
 128 }
 129
 130 static int server_sort_results(struct sort_context *ac)
 131 {
 132         struct ldb_reply *ares;
 133         int i, ret;
 134
 135         ac->a = ldb_schema_attribute_by_name(ac->module->ldb, ac->attributeName);
 136         ac->sort_result = 0;
 137
 138         ldb_qsort(ac->msgs, ac->num_msgs,
 139                   sizeof(struct ldb_message *),
 140                   ac, (ldb_qsort_cmp_fn_t)sort_compare);
 141
 142         if (ac->sort_result != LDB_SUCCESS) {
 143                 return ac->sort_result;
 144         }
 145
 146         for (i = 0; i < ac->num_msgs; i++) {
 147                 ares = talloc_zero(ac, struct ldb_reply);
 148                 if (!ares) {
 149                         return LDB_ERR_OPERATIONS_ERROR;
 150                 }
 151
 152                 ares->type = LDB_REPLY_ENTRY;
 153                 ares->message = talloc_move(ares, &ac->msgs[i]);
 154
 155                 ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
 156                 if (ret != LDB_SUCCESS) {
 157                         return ret;
 158                 }
 159         }
 160
 161         for (i = 0; i < ac->num_refs; i++) {
 162                 ares = talloc_zero(ac, struct ldb_reply);
 163                 if (!ares) {
 164                         return LDB_ERR_OPERATIONS_ERROR;
 165                 }
 166
 167                 ares->type = LDB_REPLY_REFERRAL;
 168                 ares->referral = talloc_move(ares, &ac->referrals[i]);
 169
 170                 ret = ldb_module_send_referral(ac->req, ares->referral);
 171                 if (ret != LDB_SUCCESS) {
 172                         return ret;
 173                 }
 174         }
 175
 176         return LDB_SUCCESS;
 177 }
 178
 179 static int server_sort_search_callback(struct ldb_request *req, struct ldb_reply *ares)
 180 {
 181         struct sort_context *ac;
 182         int ret;
 183
 184         ac = talloc_get_type(req->context, struct sort_context);
 185
 186         if (!ares) {
 187                 return ldb_module_done(ac->req, NULL, NULL,
 188                                         LDB_ERR_OPERATIONS_ERROR);
 189         }
 190         if (ares->error != LDB_SUCCESS) {
 191                 return ldb_module_done(ac->req, ares->controls,
 192                                         ares->response, ares->error);
 193         }
 194
 195         switch (ares->type) {
 196         case LDB_REPLY_ENTRY:
 197                 ac->msgs = talloc_realloc(ac, ac->msgs, struct ldb_message *, ac->num_msgs + 2);
 198                 if (! ac->msgs) {
 199                         talloc_free(ares);
 200                         ldb_oom(ac->module->ldb);
 201                         return ldb_module_done(ac->req, NULL, NULL,
 202                                                 LDB_ERR_OPERATIONS_ERROR);
 203                 }
 204
 205                 ac->msgs[ac->num_msgs] = talloc_steal(ac->msgs, ares->message);
 206                 ac->num_msgs++;
 207                 ac->msgs[ac->num_msgs] = NULL;
 208
 209                 break;
 210
 211         case LDB_REPLY_REFERRAL:
 212                 ac->referrals = talloc_realloc(ac, ac->referrals, char *, ac->num_refs + 2);
 213                 if (! ac->referrals) {
 214                         talloc_free(ares);
 215                         ldb_oom(ac->module->ldb);
 216                         return ldb_module_done(ac->req, NULL, NULL,
 217                                                 LDB_ERR_OPERATIONS_ERROR);
 218                 }
 219
 220                 ac->referrals[ac->num_refs] = talloc_steal(ac->referrals, ares->referral);
 221                 ac->num_refs++;
 222                 ac->referrals[ac->num_refs] = NULL;
 223
 224                 break;
 225
 226         case LDB_REPLY_DONE:
 227
 228                 ret = server_sort_results(ac);
 229                 return ldb_module_done(ac->req, ares->controls,
 230                                         ares->response, ret);
 231         }
 232
 233         talloc_free(ares);
 234         return LDB_SUCCESS;
 235 }
 236
 237 static int server_sort_search(struct ldb_module *module, struct ldb_request *req)
 238 {
 239         struct ldb_control *control;
 240         struct ldb_server_sort_control **sort_ctrls;
 241         struct ldb_control **saved_controls;
 242         struct ldb_control **controls;
 243         struct ldb_request *down_req;
 244         struct sort_context *ac;
 245         int ret;
 246
 247         /* check if there's a paged request control */
 248         control = ldb_request_get_control(req, LDB_CONTROL_SERVER_SORT_OID);
 249         if (control == NULL) {
 250                 /* not found go on */
 251                 return ldb_next_request(module, req);
 252         }
 253
 254         ac = talloc_zero(req, struct sort_context);
 255         if (ac == NULL) {
 256                 ldb_oom(module->ldb);
 257                 return LDB_ERR_OPERATIONS_ERROR;
 258         }
 259
 260         ac->module = module;
 261         ac->req = req;
 262
 263         sort_ctrls = talloc_get_type(control->data, struct ldb_server_sort_control *);
 264         if (!sort_ctrls) {
 265                 return LDB_ERR_PROTOCOL_ERROR;
 266         }
 267
 268         /* FIXME: we do not support more than one attribute for sorting right now */
 269         /* FIXME: we need to check if the attribute type exist or return an error */
 270
 271         if (sort_ctrls[1] != NULL) {
 272                 if (control->critical) {
 273
 274                         /* callback immediately */
 275                         ret = build_response(req, &controls,
 276                                              LDB_ERR_UNWILLING_TO_PERFORM,
 277                                              "sort control is not complete yet");
 278                         if (ret != LDB_SUCCESS) {
 279                                 return ldb_module_done(req, NULL, NULL,
 280                                                     LDB_ERR_OPERATIONS_ERROR);
 281                         }
 282
 283                         return ldb_module_done(req, controls, NULL, ret);
 284                 } else {
 285                         /* just pass the call down and don't do any sorting */
 286                         return ldb_next_request(module, req);
 287                 }
 288         }
 289
 290         ac->attributeName = sort_ctrls[0]->attributeName;
 291         ac->orderingRule = sort_ctrls[0]->orderingRule;
 292         ac->reverse = sort_ctrls[0]->reverse;
 293
 294         ret = ldb_build_search_req_ex(&down_req, module->ldb, ac,
 295                                         req->op.search.base,
 296                                         req->op.search.scope,
 297                                         req->op.search.tree,
 298                                         req->op.search.attrs,
 299                                         req->controls,
 300                                         ac,
 301                                         server_sort_search_callback,
 302                                         req);
 303         if (ret != LDB_SUCCESS) {
 304                 return LDB_ERR_OPERATIONS_ERROR;
 305         }
 306
 307         /* save it locally and remove it from the list */
 308         /* we do not need to replace them later as we
 309          * are keeping the original req intact */
 310         if (!save_controls(control, down_req, &saved_controls)) {
 311                 return LDB_ERR_OPERATIONS_ERROR;
 312         }
 313
 314         return ldb_next_request(module, down_req);
 315 }
 316
 317 static int server_sort_init(struct ldb_module *module)
 318 {
 319         int ret;
 320
 321         ret = ldb_mod_register_control(module, LDB_CONTROL_SERVER_SORT_OID);
 322         if (ret != LDB_SUCCESS) {
 323                 ldb_debug(module->ldb, LDB_DEBUG_WARNING,
 324                         "server_sort:"
 325                         "Unable to register control with rootdse!\n");
 326         }
 327
 328         return ldb_next_init(module);
 329 }
 330
 331 const struct ldb_module_ops ldb_server_sort_module_ops = {
 332         .name              = "server_sort",
 333         .search            = server_sort_search,
 334         .init_context      = server_sort_init
 335 };