source3/lib/serverid.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Implementation of a reliable server_exists()
   4    Copyright (C) Volker Lendecke 2010
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "system/filesys.h"
  22 #include "serverid.h"
  23 #include "util_tdb.h"
  24 #include "dbwrap/dbwrap.h"
  25 #include "dbwrap/dbwrap_open.h"
  26 #include "lib/tdb_wrap/tdb_wrap.h"
  27 #include "lib/param/param.h"
  28 #include "ctdbd_conn.h"
  29 #include "messages.h"
  30
  31 struct serverid_key {
  32         pid_t pid;
  33         uint32_t task_id;
  34         uint32_t vnn;
  35 };
  36
  37 struct serverid_data {
  38         uint64_t unique_id;
  39         uint32_t msg_flags;
  40 };
  41
  42 static struct db_context *serverid_db(void)
  43 {
  44         static struct db_context *db;
  45
  46         if (db != NULL) {
  47                 return db;
  48         }
  49         db = db_open(NULL, lock_path("serverid.tdb"), 0,
  50                      TDB_DEFAULT|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
  51                      O_RDWR|O_CREAT, 0644, DBWRAP_LOCK_ORDER_2,
  52                      DBWRAP_FLAG_NONE);
  53         return db;
  54 }
  55
  56 bool serverid_parent_init(TALLOC_CTX *mem_ctx)
  57 {
  58         struct tdb_wrap *db;
  59
  60         db = serverid_db();
  61         if (db == NULL) {
  62                 DEBUG(1, ("could not open serverid.tdb: %s\n",
  63                           strerror(errno)));
  64                 return false;
  65         }
  66
  67         return true;
  68 }
  69
  70 static void serverid_fill_key(const struct server_id *id,
  71                               struct serverid_key *key)
  72 {
  73         ZERO_STRUCTP(key);
  74         key->pid = id->pid;
  75         key->task_id = id->task_id;
  76         key->vnn = id->vnn;
  77 }
  78
  79 bool serverid_register(const struct server_id id, uint32_t msg_flags)
  80 {
  81         struct db_context *db;
  82         struct serverid_key key;
  83         struct serverid_data data;
  84         struct db_record *rec;
  85         TDB_DATA tdbkey, tdbdata;
  86         NTSTATUS status;
  87         bool ret = false;
  88
  89         db = serverid_db();
  90         if (db == NULL) {
  91                 return false;
  92         }
  93
  94         serverid_fill_key(&id, &key);
  95         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
  96
  97         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
  98         if (rec == NULL) {
  99                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 100                 return false;
 101         }
 102
 103         ZERO_STRUCT(data);
 104         data.unique_id = id.unique_id;
 105         data.msg_flags = msg_flags;
 106
 107         tdbdata = make_tdb_data((uint8_t *)&data, sizeof(data));
 108         status = dbwrap_record_store(rec, tdbdata, 0);
 109         if (!NT_STATUS_IS_OK(status)) {
 110                 DEBUG(1, ("Storing serverid.tdb record failed: %s\n",
 111                           nt_errstr(status)));
 112                 goto done;
 113         }
 114
 115         if (lp_clustering() &&
 116             ctdb_serverids_exist_supported(messaging_ctdbd_connection()))
 117         {
 118                 register_with_ctdbd(messaging_ctdbd_connection(), id.unique_id);
 119         }
 120
 121         ret = true;
 122 done:
 123         TALLOC_FREE(rec);
 124         return ret;
 125 }
 126
 127 bool serverid_register_msg_flags(const struct server_id id, bool do_reg,
 128                                  uint32_t msg_flags)
 129 {
 130         struct db_context *db;
 131         struct serverid_key key;
 132         struct serverid_data *data;
 133         struct db_record *rec;
 134         TDB_DATA tdbkey;
 135         TDB_DATA value;
 136         NTSTATUS status;
 137         bool ret = false;
 138
 139         db = serverid_db();
 140         if (db == NULL) {
 141                 return false;
 142         }
 143
 144         serverid_fill_key(&id, &key);
 145         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 146
 147         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
 148         if (rec == NULL) {
 149                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 150                 return false;
 151         }
 152
 153         value = dbwrap_record_get_value(rec);
 154
 155         if (value.dsize != sizeof(struct serverid_data)) {
 156                 DEBUG(1, ("serverid record has unexpected size %d "
 157                           "(wanted %d)\n", (int)value.dsize,
 158                           (int)sizeof(struct serverid_data)));
 159                 goto done;
 160         }
 161
 162         data = (struct serverid_data *)value.dptr;
 163
 164         if (do_reg) {
 165                 data->msg_flags |= msg_flags;
 166         } else {
 167                 data->msg_flags &= ~msg_flags;
 168         }
 169
 170         status = dbwrap_record_store(rec, value, 0);
 171         if (!NT_STATUS_IS_OK(status)) {
 172                 DEBUG(1, ("Storing serverid.tdb record failed: %s\n",
 173                           nt_errstr(status)));
 174                 goto done;
 175         }
 176         ret = true;
 177 done:
 178         TALLOC_FREE(rec);
 179         return ret;
 180 }
 181
 182 bool serverid_deregister(struct server_id id)
 183 {
 184         struct db_context *db;
 185         struct serverid_key key;
 186         struct db_record *rec;
 187         TDB_DATA tdbkey;
 188         NTSTATUS status;
 189         bool ret = false;
 190
 191         db = serverid_db();
 192         if (db == NULL) {
 193                 return false;
 194         }
 195
 196         serverid_fill_key(&id, &key);
 197         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 198
 199         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
 200         if (rec == NULL) {
 201                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 202                 return false;
 203         }
 204
 205         status = dbwrap_record_delete(rec);
 206         if (!NT_STATUS_IS_OK(status)) {
 207                 DEBUG(1, ("Deleting serverid.tdb record failed: %s\n",
 208                           nt_errstr(status)));
 209                 goto done;
 210         }
 211         ret = true;
 212 done:
 213         TALLOC_FREE(rec);
 214         return ret;
 215 }
 216
 217 struct serverid_exists_state {
 218         const struct server_id *id;
 219         bool exists;
 220 };
 221
 222 static void server_exists_parse(TDB_DATA key, TDB_DATA data, void *priv)
 223 {
 224         struct serverid_exists_state *state =
 225                 (struct serverid_exists_state *)priv;
 226
 227         if (data.dsize != sizeof(struct serverid_data)) {
 228                 state->exists = false;
 229                 return;
 230         }
 231
 232         /*
 233          * Use memcmp, not direct compare. data.dptr might not be
 234          * aligned.
 235          */
 236         state->exists = (memcmp(&state->id->unique_id, data.dptr,
 237                                 sizeof(state->id->unique_id)) == 0);
 238 }
 239
 240 bool serverid_exists(const struct server_id *id)
 241 {
 242         bool result = false;
 243         bool ok = false;
 244
 245         ok = serverids_exist(id, 1, &result);
 246         if (!ok) {
 247                 return false;
 248         }
 249
 250         return result;
 251 }
 252
 253 bool serverids_exist(const struct server_id *ids, int num_ids, bool *results)
 254 {
 255         int *todo_idx = NULL;
 256         struct server_id *todo_ids = NULL;
 257         bool *todo_results = NULL;
 258         int todo_num = 0;
 259         int *remote_idx = NULL;
 260         int remote_num = 0;
 261         int *verify_idx = NULL;
 262         int verify_num = 0;
 263         int t, idx;
 264         bool result = false;
 265         struct db_context *db;
 266
 267         db = serverid_db();
 268         if (db == NULL) {
 269                 return false;
 270         }
 271
 272         todo_idx = talloc_array(talloc_tos(), int, num_ids);
 273         if (todo_idx == NULL) {
 274                 goto fail;
 275         }
 276         todo_ids = talloc_array(talloc_tos(), struct server_id, num_ids);
 277         if (todo_ids == NULL) {
 278                 goto fail;
 279         }
 280         todo_results = talloc_array(talloc_tos(), bool, num_ids);
 281         if (todo_results == NULL) {
 282                 goto fail;
 283         }
 284
 285         remote_idx = talloc_array(talloc_tos(), int, num_ids);
 286         if (remote_idx == NULL) {
 287                 goto fail;
 288         }
 289         verify_idx = talloc_array(talloc_tos(), int, num_ids);
 290         if (verify_idx == NULL) {
 291                 goto fail;
 292         }
 293
 294         for (idx=0; idx<num_ids; idx++) {
 295                 results[idx] = false;
 296
 297                 if (server_id_is_disconnected(&ids[idx])) {
 298                         continue;
 299                 }
 300
 301                 if (procid_is_me(&ids[idx])) {
 302                         results[idx] = true;
 303                         continue;
 304                 }
 305
 306                 if (procid_is_local(&ids[idx])) {
 307                         bool exists = process_exists_by_pid(ids[idx].pid);
 308
 309                         if (!exists) {
 310                                 continue;
 311                         }
 312
 313                         if (ids[idx].unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 314                                 results[idx] = true;
 315                                 continue;
 316                         }
 317
 318                         verify_idx[verify_num] = idx;
 319                         verify_num += 1;
 320                         continue;
 321                 }
 322
 323                 if (!lp_clustering()) {
 324                         continue;
 325                 }
 326
 327                 remote_idx[remote_num] = idx;
 328                 remote_num += 1;
 329         }
 330
 331         if (remote_num != 0 &&
 332             ctdb_serverids_exist_supported(messaging_ctdbd_connection()))
 333         {
 334                 int old_remote_num = remote_num;
 335
 336                 remote_num = 0;
 337                 todo_num = 0;
 338
 339                 for (t=0; t<old_remote_num; t++) {
 340                         idx = remote_idx[t];
 341
 342                         if (ids[idx].unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 343                                 remote_idx[remote_num] = idx;
 344                                 remote_num += 1;
 345                                 continue;
 346                         }
 347
 348                         todo_idx[todo_num] = idx;
 349                         todo_ids[todo_num] = ids[idx];
 350                         todo_results[todo_num] = false;
 351                         todo_num += 1;
 352                 }
 353
 354                 /*
 355                  * Note: this only uses CTDB_CONTROL_CHECK_SRVIDS
 356                  * to verify that the server_id still exists,
 357                  * which means only the server_id.unique_id and
 358                  * server_id.vnn are verified, while server_id.pid
 359                  * is not verified at all.
 360                  *
 361                  * TODO: do we want to verify server_id.pid somehow?
 362                  */
 363                 if (!ctdb_serverids_exist(messaging_ctdbd_connection(),
 364                                           todo_ids, todo_num, todo_results))
 365                 {
 366                         goto fail;
 367                 }
 368
 369                 for (t=0; t<todo_num; t++) {
 370                         idx = todo_idx[t];
 371
 372                         results[idx] = todo_results[t];
 373                 }
 374         }
 375
 376         if (remote_num != 0) {
 377                 todo_num = 0;
 378
 379                 for (t=0; t<remote_num; t++) {
 380                         idx = remote_idx[t];
 381                         todo_idx[todo_num] = idx;
 382                         todo_ids[todo_num] = ids[idx];
 383                         todo_results[todo_num] = false;
 384                         todo_num += 1;
 385                 }
 386
 387                 if (!ctdb_processes_exist(messaging_ctdbd_connection(),
 388                                           todo_ids, todo_num,
 389                                           todo_results)) {
 390                         goto fail;
 391                 }
 392
 393                 for (t=0; t<todo_num; t++) {
 394                         idx = todo_idx[t];
 395
 396                         if (!todo_results[t]) {
 397                                 continue;
 398                         }
 399
 400                         if (ids[idx].unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 401                                 results[idx] = true;
 402                                 continue;
 403                         }
 404
 405                         verify_idx[verify_num] = idx;
 406                         verify_num += 1;
 407                 }
 408         }
 409
 410         for (t=0; t<verify_num; t++) {
 411                 struct serverid_exists_state state;
 412                 struct serverid_key key;
 413                 TDB_DATA tdbkey;
 414                 NTSTATUS status;
 415
 416                 idx = verify_idx[t];
 417
 418                 serverid_fill_key(&ids[idx], &key);
 419                 tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 420
 421                 state.id = &ids[idx];
 422                 state.exists = false;
 423                 status = dbwrap_parse_record(db, tdbkey, server_exists_parse, &state);
 424                 if (!NT_STATUS_IS_OK(status)) {
 425                         results[idx] = false;
 426                         continue;
 427                 }
 428                 results[idx] = state.exists;
 429         }
 430
 431         result = true;
 432 fail:
 433         TALLOC_FREE(verify_idx);
 434         TALLOC_FREE(remote_idx);
 435         TALLOC_FREE(todo_results);
 436         TALLOC_FREE(todo_ids);
 437         TALLOC_FREE(todo_idx);
 438         return result;
 439 }
 440
 441 static bool serverid_rec_parse(const struct db_record *rec,
 442                                struct server_id *id, uint32_t *msg_flags)
 443 {
 444         struct serverid_key key;
 445         struct serverid_data data;
 446         TDB_DATA tdbkey;
 447         TDB_DATA tdbdata;
 448
 449         tdbkey = dbwrap_record_get_key(rec);
 450         tdbdata = dbwrap_record_get_value(rec);
 451
 452         if (tdbkey.dsize != sizeof(key)) {
 453                 DEBUG(1, ("Found invalid key length %d in serverid.tdb\n",
 454                           (int)tdbkey.dsize));
 455                 return false;
 456         }
 457         if (tdbdata.dsize != sizeof(data)) {
 458                 DEBUG(1, ("Found invalid value length %d in serverid.tdb\n",
 459                           (int)tdbdata.dsize));
 460                 return false;
 461         }
 462
 463         memcpy(&key, tdbkey.dptr, sizeof(key));
 464         memcpy(&data, tdbdata.dptr, sizeof(data));
 465
 466         id->pid = key.pid;
 467         id->task_id = key.task_id;
 468         id->vnn = key.vnn;
 469         id->unique_id = data.unique_id;
 470         *msg_flags = data.msg_flags;
 471         return true;
 472 }
 473
 474 struct serverid_traverse_read_state {
 475         int (*fn)(const struct server_id *id, uint32_t msg_flags,
 476                   void *private_data);
 477         void *private_data;
 478 };
 479
 480 static int serverid_traverse_read_fn(struct db_record *rec, void *private_data)
 481 {
 482         struct serverid_traverse_read_state *state =
 483                 (struct serverid_traverse_read_state *)private_data;
 484         struct server_id id;
 485         uint32_t msg_flags;
 486
 487         if (!serverid_rec_parse(rec, &id, &msg_flags)) {
 488                 return 0;
 489         }
 490         return state->fn(&id, msg_flags,state->private_data);
 491 }
 492
 493 bool serverid_traverse_read(int (*fn)(const struct server_id *id,
 494                                       uint32_t msg_flags, void *private_data),
 495                             void *private_data)
 496 {
 497         struct db_context *db;
 498         struct serverid_traverse_read_state state;
 499         NTSTATUS status;
 500
 501         db = serverid_db();
 502         if (db == NULL) {
 503                 return false;
 504         }
 505         state.fn = fn;
 506         state.private_data = private_data;
 507
 508         status = dbwrap_traverse_read(db, serverid_traverse_read_fn, &state,
 509                                       NULL);
 510         return NT_STATUS_IS_OK(status);
 511 }
 512
 513 struct serverid_traverse_state {
 514         int (*fn)(struct db_record *rec, const struct server_id *id,
 515                   uint32_t msg_flags, void *private_data);
 516         void *private_data;
 517 };
 518
 519 static int serverid_traverse_fn(struct db_record *rec, void *private_data)
 520 {
 521         struct serverid_traverse_state *state =
 522                 (struct serverid_traverse_state *)private_data;
 523         struct server_id id;
 524         uint32_t msg_flags;
 525
 526         if (!serverid_rec_parse(rec, &id, &msg_flags)) {
 527                 return 0;
 528         }
 529         return state->fn(rec, &id, msg_flags, state->private_data);
 530 }
 531
 532 bool serverid_traverse(int (*fn)(struct db_record *rec,
 533                                  const struct server_id *id,
 534                                  uint32_t msg_flags, void *private_data),
 535                             void *private_data)
 536 {
 537         struct db_context *db;
 538         struct serverid_traverse_state state;
 539         NTSTATUS status;
 540
 541         db = serverid_db();
 542         if (db == NULL) {
 543                 return false;
 544         }
 545         state.fn = fn;
 546         state.private_data = private_data;
 547
 548         status = dbwrap_traverse(db, serverid_traverse_fn, &state, NULL);
 549         return NT_STATUS_IS_OK(status);
 550 }
 551
 552 uint64_t serverid_get_random_unique_id(void)
 553 {
 554         uint64_t unique_id = SERVERID_UNIQUE_ID_NOT_TO_VERIFY;
 555
 556         while (unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 557                 generate_random_buffer((uint8_t *)&unique_id,
 558                                        sizeof(unique_id));
 559         }
 560
 561         return unique_id;
 562 }