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