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 bool serverid_parent_init(TALLOC_CTX *mem_ctx)
  43 {
  44         struct tdb_wrap *db;
  45         struct loadparm_context *lp_ctx;
  46
  47         lp_ctx = loadparm_init_s3(mem_ctx, loadparm_s3_context());
  48         if (lp_ctx == NULL) {
  49                 DEBUG(0, ("loadparm_init_s3 failed\n"));
  50                 return false;
  51         }
  52
  53         /*
  54          * Open the tdb in the parent process (smbd) so that our
  55          * CLEAR_IF_FIRST optimization in tdb_reopen_all can properly
  56          * work.
  57          */
  58
  59         db = tdb_wrap_open(mem_ctx, lock_path("serverid.tdb"),
  60                            0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH, O_RDWR|O_CREAT,
  61                            0644, lp_ctx);
  62         talloc_unlink(mem_ctx, lp_ctx);
  63         if (db == NULL) {
  64                 DEBUG(1, ("could not open serverid.tdb: %s\n",
  65                           strerror(errno)));
  66                 return false;
  67         }
  68         return true;
  69 }
  70
  71 static struct db_context *serverid_db(void)
  72 {
  73         static struct db_context *db;
  74
  75         if (db != NULL) {
  76                 return db;
  77         }
  78         db = db_open(NULL, lock_path("serverid.tdb"), 0,
  79                      TDB_DEFAULT|TDB_CLEAR_IF_FIRST|TDB_INCOMPATIBLE_HASH,
  80                      O_RDWR|O_CREAT, 0644, DBWRAP_LOCK_ORDER_2);
  81         return db;
  82 }
  83
  84 static void serverid_fill_key(const struct server_id *id,
  85                               struct serverid_key *key)
  86 {
  87         ZERO_STRUCTP(key);
  88         key->pid = id->pid;
  89         key->task_id = id->task_id;
  90         key->vnn = id->vnn;
  91 }
  92
  93 bool serverid_register(const struct server_id id, uint32_t msg_flags)
  94 {
  95         struct db_context *db;
  96         struct serverid_key key;
  97         struct serverid_data data;
  98         struct db_record *rec;
  99         TDB_DATA tdbkey, tdbdata;
 100         NTSTATUS status;
 101         bool ret = false;
 102
 103         db = serverid_db();
 104         if (db == NULL) {
 105                 return false;
 106         }
 107
 108         serverid_fill_key(&id, &key);
 109         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 110
 111         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
 112         if (rec == NULL) {
 113                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 114                 return false;
 115         }
 116
 117         ZERO_STRUCT(data);
 118         data.unique_id = id.unique_id;
 119         data.msg_flags = msg_flags;
 120
 121         tdbdata = make_tdb_data((uint8_t *)&data, sizeof(data));
 122         status = dbwrap_record_store(rec, tdbdata, 0);
 123         if (!NT_STATUS_IS_OK(status)) {
 124                 DEBUG(1, ("Storing serverid.tdb record failed: %s\n",
 125                           nt_errstr(status)));
 126                 goto done;
 127         }
 128 #ifdef HAVE_CTDB_CONTROL_CHECK_SRVIDS_DECL
 129         if (lp_clustering()) {
 130                 register_with_ctdbd(messaging_ctdbd_connection(), id.unique_id);
 131         }
 132 #endif
 133         ret = true;
 134 done:
 135         TALLOC_FREE(rec);
 136         return ret;
 137 }
 138
 139 bool serverid_register_msg_flags(const struct server_id id, bool do_reg,
 140                                  uint32_t msg_flags)
 141 {
 142         struct db_context *db;
 143         struct serverid_key key;
 144         struct serverid_data *data;
 145         struct db_record *rec;
 146         TDB_DATA tdbkey;
 147         TDB_DATA value;
 148         NTSTATUS status;
 149         bool ret = false;
 150
 151         db = serverid_db();
 152         if (db == NULL) {
 153                 return false;
 154         }
 155
 156         serverid_fill_key(&id, &key);
 157         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 158
 159         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
 160         if (rec == NULL) {
 161                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 162                 return false;
 163         }
 164
 165         value = dbwrap_record_get_value(rec);
 166
 167         if (value.dsize != sizeof(struct serverid_data)) {
 168                 DEBUG(1, ("serverid record has unexpected size %d "
 169                           "(wanted %d)\n", (int)value.dsize,
 170                           (int)sizeof(struct serverid_data)));
 171                 goto done;
 172         }
 173
 174         data = (struct serverid_data *)value.dptr;
 175
 176         if (do_reg) {
 177                 data->msg_flags |= msg_flags;
 178         } else {
 179                 data->msg_flags &= ~msg_flags;
 180         }
 181
 182         status = dbwrap_record_store(rec, value, 0);
 183         if (!NT_STATUS_IS_OK(status)) {
 184                 DEBUG(1, ("Storing serverid.tdb record failed: %s\n",
 185                           nt_errstr(status)));
 186                 goto done;
 187         }
 188         ret = true;
 189 done:
 190         TALLOC_FREE(rec);
 191         return ret;
 192 }
 193
 194 bool serverid_deregister(struct server_id id)
 195 {
 196         struct db_context *db;
 197         struct serverid_key key;
 198         struct db_record *rec;
 199         TDB_DATA tdbkey;
 200         NTSTATUS status;
 201         bool ret = false;
 202
 203         db = serverid_db();
 204         if (db == NULL) {
 205                 return false;
 206         }
 207
 208         serverid_fill_key(&id, &key);
 209         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 210
 211         rec = dbwrap_fetch_locked(db, talloc_tos(), tdbkey);
 212         if (rec == NULL) {
 213                 DEBUG(1, ("Could not fetch_lock serverid.tdb record\n"));
 214                 return false;
 215         }
 216
 217         status = dbwrap_record_delete(rec);
 218         if (!NT_STATUS_IS_OK(status)) {
 219                 DEBUG(1, ("Deleting serverid.tdb record failed: %s\n",
 220                           nt_errstr(status)));
 221                 goto done;
 222         }
 223         ret = true;
 224 done:
 225         TALLOC_FREE(rec);
 226         return ret;
 227 }
 228
 229 struct serverid_exists_state {
 230         const struct server_id *id;
 231         bool exists;
 232 };
 233
 234 static void server_exists_parse(TDB_DATA key, TDB_DATA data, void *priv)
 235 {
 236         struct serverid_exists_state *state =
 237                 (struct serverid_exists_state *)priv;
 238
 239         if (data.dsize != sizeof(struct serverid_data)) {
 240                 state->exists = false;
 241                 return;
 242         }
 243
 244         /*
 245          * Use memcmp, not direct compare. data.dptr might not be
 246          * aligned.
 247          */
 248         state->exists = (memcmp(&state->id->unique_id, data.dptr,
 249                                 sizeof(state->id->unique_id)) == 0);
 250 }
 251
 252 bool serverid_exists(const struct server_id *id)
 253 {
 254         struct db_context *db;
 255         struct serverid_exists_state state;
 256         struct serverid_key key;
 257         TDB_DATA tdbkey;
 258         NTSTATUS status;
 259
 260         if (procid_is_me(id)) {
 261                 return true;
 262         }
 263
 264         if (!process_exists(*id)) {
 265                 return false;
 266         }
 267
 268         if (id->unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 269                 return true;
 270         }
 271
 272         db = serverid_db();
 273         if (db == NULL) {
 274                 return false;
 275         }
 276
 277         serverid_fill_key(id, &key);
 278         tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 279
 280         state.id = id;
 281         state.exists = false;
 282
 283         status = dbwrap_parse_record(db, tdbkey, server_exists_parse, &state);
 284         if (!NT_STATUS_IS_OK(status)) {
 285                 return false;
 286         }
 287         return state.exists;
 288 }
 289
 290 bool serverids_exist(const struct server_id *ids, int num_ids, bool *results)
 291 {
 292         struct db_context *db;
 293         int i;
 294
 295 #ifdef HAVE_CTDB_CONTROL_CHECK_SRVIDS_DECL
 296         if (lp_clustering()) {
 297                 return ctdb_serverids_exist(messaging_ctdbd_connection(),
 298                                             ids, num_ids, results);
 299         }
 300 #endif
 301         if (!processes_exist(ids, num_ids, results)) {
 302                 return false;
 303         }
 304
 305         db = serverid_db();
 306         if (db == NULL) {
 307                 return false;
 308         }
 309
 310         for (i=0; i<num_ids; i++) {
 311                 struct serverid_exists_state state;
 312                 struct serverid_key key;
 313                 TDB_DATA tdbkey;
 314
 315                 if (ids[i].unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 316                         results[i] = true;
 317                         continue;
 318                 }
 319                 if (!results[i]) {
 320                         continue;
 321                 }
 322
 323                 serverid_fill_key(&ids[i], &key);
 324                 tdbkey = make_tdb_data((uint8_t *)&key, sizeof(key));
 325
 326                 state.id = &ids[i];
 327                 state.exists = false;
 328                 dbwrap_parse_record(db, tdbkey, server_exists_parse, &state);
 329                 results[i] = state.exists;
 330         }
 331         return true;
 332 }
 333
 334 static bool serverid_rec_parse(const struct db_record *rec,
 335                                struct server_id *id, uint32_t *msg_flags)
 336 {
 337         struct serverid_key key;
 338         struct serverid_data data;
 339         TDB_DATA tdbkey;
 340         TDB_DATA tdbdata;
 341
 342         tdbkey = dbwrap_record_get_key(rec);
 343         tdbdata = dbwrap_record_get_value(rec);
 344
 345         if (tdbkey.dsize != sizeof(key)) {
 346                 DEBUG(1, ("Found invalid key length %d in serverid.tdb\n",
 347                           (int)tdbkey.dsize));
 348                 return false;
 349         }
 350         if (tdbdata.dsize != sizeof(data)) {
 351                 DEBUG(1, ("Found invalid value length %d in serverid.tdb\n",
 352                           (int)tdbdata.dsize));
 353                 return false;
 354         }
 355
 356         memcpy(&key, tdbkey.dptr, sizeof(key));
 357         memcpy(&data, tdbdata.dptr, sizeof(data));
 358
 359         id->pid = key.pid;
 360         id->task_id = key.task_id;
 361         id->vnn = key.vnn;
 362         id->unique_id = data.unique_id;
 363         *msg_flags = data.msg_flags;
 364         return true;
 365 }
 366
 367 struct serverid_traverse_read_state {
 368         int (*fn)(const struct server_id *id, uint32_t msg_flags,
 369                   void *private_data);
 370         void *private_data;
 371 };
 372
 373 static int serverid_traverse_read_fn(struct db_record *rec, void *private_data)
 374 {
 375         struct serverid_traverse_read_state *state =
 376                 (struct serverid_traverse_read_state *)private_data;
 377         struct server_id id;
 378         uint32_t msg_flags;
 379
 380         if (!serverid_rec_parse(rec, &id, &msg_flags)) {
 381                 return 0;
 382         }
 383         return state->fn(&id, msg_flags,state->private_data);
 384 }
 385
 386 bool serverid_traverse_read(int (*fn)(const struct server_id *id,
 387                                       uint32_t msg_flags, void *private_data),
 388                             void *private_data)
 389 {
 390         struct db_context *db;
 391         struct serverid_traverse_read_state state;
 392         NTSTATUS status;
 393
 394         db = serverid_db();
 395         if (db == NULL) {
 396                 return false;
 397         }
 398         state.fn = fn;
 399         state.private_data = private_data;
 400
 401         status = dbwrap_traverse_read(db, serverid_traverse_read_fn, &state,
 402                                       NULL);
 403         return NT_STATUS_IS_OK(status);
 404 }
 405
 406 struct serverid_traverse_state {
 407         int (*fn)(struct db_record *rec, const struct server_id *id,
 408                   uint32_t msg_flags, void *private_data);
 409         void *private_data;
 410 };
 411
 412 static int serverid_traverse_fn(struct db_record *rec, void *private_data)
 413 {
 414         struct serverid_traverse_state *state =
 415                 (struct serverid_traverse_state *)private_data;
 416         struct server_id id;
 417         uint32_t msg_flags;
 418
 419         if (!serverid_rec_parse(rec, &id, &msg_flags)) {
 420                 return 0;
 421         }
 422         return state->fn(rec, &id, msg_flags, state->private_data);
 423 }
 424
 425 bool serverid_traverse(int (*fn)(struct db_record *rec,
 426                                  const struct server_id *id,
 427                                  uint32_t msg_flags, void *private_data),
 428                             void *private_data)
 429 {
 430         struct db_context *db;
 431         struct serverid_traverse_state state;
 432         NTSTATUS status;
 433
 434         db = serverid_db();
 435         if (db == NULL) {
 436                 return false;
 437         }
 438         state.fn = fn;
 439         state.private_data = private_data;
 440
 441         status = dbwrap_traverse(db, serverid_traverse_fn, &state, NULL);
 442         return NT_STATUS_IS_OK(status);
 443 }
 444
 445 uint64_t serverid_get_random_unique_id(void)
 446 {
 447         uint64_t unique_id = SERVERID_UNIQUE_ID_NOT_TO_VERIFY;
 448
 449         while (unique_id == SERVERID_UNIQUE_ID_NOT_TO_VERIFY) {
 450                 generate_random_buffer((uint8_t *)&unique_id,
 451                                        sizeof(unique_id));
 452         }
 453
 454         return unique_id;
 455 }