root/source4/lib/ldb/modules/sort.c

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DEFINITIONS

This source file includes following definitions.
  1. build_response
  2. sort_compare
  3. server_sort_results
  4. server_sort_search_callback
  5. server_sort_search
  6. server_sort_init

   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_module.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)
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  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)
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 104 {
 105         struct sort_context *ac = talloc_get_type(opaque, struct sort_context);
 106         struct ldb_message_element *el1, *el2;
 107         struct ldb_context *ldb;
 108 
 109         ldb = ldb_module_get_ctx(ac->module);
 110 
 111         if (ac->sort_result != 0) {
 112                 /* an error occurred previously,
 113                  * let's exit the sorting by returning always 0 */
 114                 return 0;
 115         }
 116 
 117         el1 = ldb_msg_find_element(*msg1, ac->attributeName);
 118         el2 = ldb_msg_find_element(*msg2, ac->attributeName);
 119 
 120         if (!el1 || !el2) {
 121                 /* the attribute was not found return and
 122                  * set an error */
 123                 ac->sort_result = LDB_ERR_UNWILLING_TO_PERFORM;
 124                 return 0;
 125         }
 126 
 127         if (ac->reverse)
 128                 return ac->a->syntax->comparison_fn(ldb, ac, &el2->values[0], &el1->values[0]);
 129 
 130         return ac->a->syntax->comparison_fn(ldb, ac, &el1->values[0], &el2->values[0]);
 131 }
 132 
 133 static int server_sort_results(struct sort_context *ac)
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 134 {
 135         struct ldb_context *ldb;
 136         struct ldb_reply *ares;
 137         int i, ret;
 138 
 139         ldb = ldb_module_get_ctx(ac->module);
 140 
 141         ac->a = ldb_schema_attribute_by_name(ldb, ac->attributeName);
 142         ac->sort_result = 0;
 143 
 144         ldb_qsort(ac->msgs, ac->num_msgs,
 145                   sizeof(struct ldb_message *),
 146                   ac, (ldb_qsort_cmp_fn_t)sort_compare);
 147 
 148         if (ac->sort_result != LDB_SUCCESS) {
 149                 return ac->sort_result;
 150         }
 151 
 152         for (i = 0; i < ac->num_msgs; i++) {
 153                 ares = talloc_zero(ac, struct ldb_reply);
 154                 if (!ares) {
 155                         return LDB_ERR_OPERATIONS_ERROR;
 156                 }
 157 
 158                 ares->type = LDB_REPLY_ENTRY;
 159                 ares->message = talloc_move(ares, &ac->msgs[i]);
 160 
 161                 ret = ldb_module_send_entry(ac->req, ares->message, ares->controls);
 162                 if (ret != LDB_SUCCESS) {
 163                         return ret;
 164                 }
 165         }
 166 
 167         for (i = 0; i < ac->num_refs; i++) {
 168                 ares = talloc_zero(ac, struct ldb_reply);
 169                 if (!ares) {
 170                         return LDB_ERR_OPERATIONS_ERROR;
 171                 }
 172 
 173                 ares->type = LDB_REPLY_REFERRAL;
 174                 ares->referral = talloc_move(ares, &ac->referrals[i]);
 175 
 176                 ret = ldb_module_send_referral(ac->req, ares->referral);
 177                 if (ret != LDB_SUCCESS) {
 178                         return ret;
 179                 }
 180         }
 181 
 182         return LDB_SUCCESS;
 183 }
 184 
 185 static int server_sort_search_callback(struct ldb_request *req, struct ldb_reply *ares)
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 186 {
 187         struct sort_context *ac;
 188         struct ldb_context *ldb;
 189         int ret;
 190 
 191         ac = talloc_get_type(req->context, struct sort_context);
 192         ldb = ldb_module_get_ctx(ac->module);
 193 
 194         if (!ares) {
 195                 return ldb_module_done(ac->req, NULL, NULL,
 196                                         LDB_ERR_OPERATIONS_ERROR);
 197         }
 198         if (ares->error != LDB_SUCCESS) {
 199                 return ldb_module_done(ac->req, ares->controls,
 200                                         ares->response, ares->error);
 201         }
 202 
 203         switch (ares->type) {
 204         case LDB_REPLY_ENTRY:
 205                 ac->msgs = talloc_realloc(ac, ac->msgs, struct ldb_message *, ac->num_msgs + 2);
 206                 if (! ac->msgs) {
 207                         talloc_free(ares);
 208                         ldb_oom(ldb);
 209                         return ldb_module_done(ac->req, NULL, NULL,
 210                                                 LDB_ERR_OPERATIONS_ERROR);
 211                 }
 212 
 213                 ac->msgs[ac->num_msgs] = talloc_steal(ac->msgs, ares->message);
 214                 ac->num_msgs++;
 215                 ac->msgs[ac->num_msgs] = NULL;
 216 
 217                 break;
 218 
 219         case LDB_REPLY_REFERRAL:
 220                 ac->referrals = talloc_realloc(ac, ac->referrals, char *, ac->num_refs + 2);
 221                 if (! ac->referrals) {
 222                         talloc_free(ares);
 223                         ldb_oom(ldb);
 224                         return ldb_module_done(ac->req, NULL, NULL,
 225                                                 LDB_ERR_OPERATIONS_ERROR);
 226                 }
 227 
 228                 ac->referrals[ac->num_refs] = talloc_steal(ac->referrals, ares->referral);
 229                 ac->num_refs++;
 230                 ac->referrals[ac->num_refs] = NULL;
 231 
 232                 break;
 233 
 234         case LDB_REPLY_DONE:
 235 
 236                 ret = server_sort_results(ac);
 237                 return ldb_module_done(ac->req, ares->controls,
 238                                         ares->response, ret);
 239         }
 240 
 241         talloc_free(ares);
 242         return LDB_SUCCESS;
 243 }
 244 
 245 static int server_sort_search(struct ldb_module *module, struct ldb_request *req)
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 246 {
 247         struct ldb_control *control;
 248         struct ldb_server_sort_control **sort_ctrls;
 249         struct ldb_control **saved_controls;
 250         struct ldb_control **controls;
 251         struct ldb_request *down_req;
 252         struct sort_context *ac;
 253         struct ldb_context *ldb;
 254         int ret;
 255 
 256         ldb = ldb_module_get_ctx(module);
 257 
 258         /* check if there's a paged request control */
 259         control = ldb_request_get_control(req, LDB_CONTROL_SERVER_SORT_OID);
 260         if (control == NULL) {
 261                 /* not found go on */
 262                 return ldb_next_request(module, req);
 263         }
 264 
 265         ac = talloc_zero(req, struct sort_context);
 266         if (ac == NULL) {
 267                 ldb_oom(ldb);
 268                 return LDB_ERR_OPERATIONS_ERROR;
 269         }
 270 
 271         ac->module = module;
 272         ac->req = req;
 273 
 274         sort_ctrls = talloc_get_type(control->data, struct ldb_server_sort_control *);
 275         if (!sort_ctrls) {
 276                 return LDB_ERR_PROTOCOL_ERROR;
 277         }
 278 
 279         /* FIXME: we do not support more than one attribute for sorting right now */
 280         /* FIXME: we need to check if the attribute type exist or return an error */
 281                 
 282         if (sort_ctrls[1] != NULL) {
 283                 if (control->critical) {
 284 
 285                         /* callback immediately */
 286                         ret = build_response(req, &controls,
 287                                              LDB_ERR_UNWILLING_TO_PERFORM,
 288                                              "sort control is not complete yet");
 289                         if (ret != LDB_SUCCESS) {
 290                                 return ldb_module_done(req, NULL, NULL,
 291                                                     LDB_ERR_OPERATIONS_ERROR);
 292                         }
 293 
 294                         return ldb_module_done(req, controls, NULL, ret);
 295                 } else {
 296                         /* just pass the call down and don't do any sorting */
 297                         return ldb_next_request(module, req);
 298                 }
 299         }
 300 
 301         ac->attributeName = sort_ctrls[0]->attributeName;
 302         ac->orderingRule = sort_ctrls[0]->orderingRule;
 303         ac->reverse = sort_ctrls[0]->reverse;
 304 
 305         ret = ldb_build_search_req_ex(&down_req, ldb, ac,
 306                                         req->op.search.base,
 307                                         req->op.search.scope,
 308                                         req->op.search.tree,
 309                                         req->op.search.attrs,
 310                                         req->controls,
 311                                         ac,
 312                                         server_sort_search_callback,
 313                                         req);
 314         if (ret != LDB_SUCCESS) {
 315                 return LDB_ERR_OPERATIONS_ERROR;
 316         }
 317 
 318         /* save it locally and remove it from the list */
 319         /* we do not need to replace them later as we
 320          * are keeping the original req intact */
 321         if (!save_controls(control, down_req, &saved_controls)) {
 322                 return LDB_ERR_OPERATIONS_ERROR;
 323         }
 324 
 325         return ldb_next_request(module, down_req);
 326 }
 327 
 328 static int server_sort_init(struct ldb_module *module)
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 329 {
 330         struct ldb_context *ldb;
 331         int ret;
 332 
 333         ldb = ldb_module_get_ctx(module);
 334 
 335         ret = ldb_mod_register_control(module, LDB_CONTROL_SERVER_SORT_OID);
 336         if (ret != LDB_SUCCESS) {
 337                 ldb_debug(ldb, LDB_DEBUG_WARNING,
 338                         "server_sort:"
 339                         "Unable to register control with rootdse!\n");
 340         }
 341 
 342         return ldb_next_init(module);
 343 }
 344 
 345 const struct ldb_module_ops ldb_server_sort_module_ops = {
 346         .name              = "server_sort",
 347         .search            = server_sort_search,
 348         .init_context      = server_sort_init
 349 };

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