source3/smbd/conn.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Manage connections_struct structures
   4    Copyright (C) Andrew Tridgell 1998
   5    Copyright (C) Alexander Bokovoy 2002
   6    Copyright (C) Jeremy Allison 2010
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "smbd/smbd.h"
  24 #include "smbd/globals.h"
  25 #include "rpc_server/rpc_ncacn_np.h"
  26
  27 /* The connections bitmap is expanded in increments of BITMAP_BLOCK_SZ. The
  28  * maximum size of the bitmap is the largest positive integer, but you will hit
  29  * the "max connections" limit, looong before that.
  30  */
  31
  32 #define BITMAP_BLOCK_SZ 128
  33
  34 /****************************************************************************
  35  Init the conn structures.
  36 ****************************************************************************/
  37
  38 void conn_init(struct smbd_server_connection *sconn)
  39 {
  40         sconn->smb1.tcons.Connections = NULL;
  41         sconn->smb1.tcons.bmap = bitmap_talloc(sconn, BITMAP_BLOCK_SZ);
  42 }
  43
  44 /****************************************************************************
  45  Return the number of open connections.
  46 ****************************************************************************/
  47
  48 int conn_num_open(struct smbd_server_connection *sconn)
  49 {
  50         return sconn->num_tcons_open;
  51 }
  52
  53 /****************************************************************************
  54  Check if a snum is in use.
  55 ****************************************************************************/
  56
  57 bool conn_snum_used(int snum)
  58 {
  59         struct smbd_server_connection *sconn = smbd_server_conn;
  60
  61         if (sconn->using_smb2) {
  62                 /* SMB2 */
  63                 struct smbd_smb2_session *sess;
  64                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
  65                         struct smbd_smb2_tcon *ptcon;
  66
  67                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
  68                                 if (ptcon->compat_conn &&
  69                                                 ptcon->compat_conn->params &&
  70                                                 (ptcon->compat_conn->params->service == snum)) {
  71                                         return true;
  72                                 }
  73                         }
  74                 }
  75         } else {
  76                 /* SMB1 */
  77                 connection_struct *conn;
  78                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
  79                         if (conn->params->service == snum) {
  80                                 return true;
  81                         }
  82                 }
  83         }
  84         return false;
  85 }
  86
  87 /****************************************************************************
  88  Find a conn given a cnum.
  89 ****************************************************************************/
  90
  91 connection_struct *conn_find(struct smbd_server_connection *sconn,unsigned cnum)
  92 {
  93         if (sconn->using_smb2) {
  94                 /* SMB2 */
  95                 struct smbd_smb2_session *sess;
  96                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
  97                         struct smbd_smb2_tcon *ptcon;
  98
  99                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
 100                                 if (ptcon->compat_conn &&
 101                                                 ptcon->compat_conn->cnum == cnum) {
 102                                         return ptcon->compat_conn;
 103                                 }
 104                         }
 105                 }
 106         } else {
 107                 /* SMB1 */
 108                 int count=0;
 109                 connection_struct *conn;
 110                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next,count++) {
 111                         if (conn->cnum == cnum) {
 112                                 if (count > 10) {
 113                                         DLIST_PROMOTE(sconn->smb1.tcons.Connections,
 114                                                 conn);
 115                                 }
 116                                 return conn;
 117                         }
 118                 }
 119         }
 120
 121         return NULL;
 122 }
 123
 124 /****************************************************************************
 125  Find first available connection slot, starting from a random position.
 126  The randomisation stops problems with the server dieing and clients
 127  thinking the server is still available.
 128 ****************************************************************************/
 129
 130 connection_struct *conn_new(struct smbd_server_connection *sconn)
 131 {
 132         connection_struct *conn;
 133         int i;
 134         int find_offset = 1;
 135
 136         if (sconn->using_smb2) {
 137                 /* SMB2 */
 138                 if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
 139                     !(conn->params = TALLOC_P(conn, struct share_params))) {
 140                         DEBUG(0,("TALLOC_ZERO() failed!\n"));
 141                         TALLOC_FREE(conn);
 142                         return NULL;
 143                 }
 144                 conn->sconn = sconn;
 145                 return conn;
 146         }
 147
 148         /* SMB1 */
 149 find_again:
 150         i = bitmap_find(sconn->smb1.tcons.bmap, find_offset);
 151
 152         if (i == -1) {
 153                 /* Expand the connections bitmap. */
 154                 int             oldsz = sconn->smb1.tcons.bmap->n;
 155                 int             newsz = sconn->smb1.tcons.bmap->n +
 156                                         BITMAP_BLOCK_SZ;
 157                 struct bitmap * nbmap;
 158
 159                 if (newsz <= oldsz) {
 160                         /* Integer wrap. */
 161                         DEBUG(0,("ERROR! Out of connection structures\n"));
 162                         return NULL;
 163                 }
 164
 165                 DEBUG(4,("resizing connections bitmap from %d to %d\n",
 166                         oldsz, newsz));
 167
 168                 nbmap = bitmap_talloc(sconn, newsz);
 169                 if (!nbmap) {
 170                         DEBUG(0,("ERROR! malloc fail.\n"));
 171                         return NULL;
 172                 }
 173
 174                 bitmap_copy(nbmap, sconn->smb1.tcons.bmap);
 175                 TALLOC_FREE(sconn->smb1.tcons.bmap);
 176
 177                 sconn->smb1.tcons.bmap = nbmap;
 178                 find_offset = oldsz; /* Start next search in the new portion. */
 179
 180                 goto find_again;
 181         }
 182
 183         /* The bitmap position is used below as the connection number
 184          * conn->cnum). This ends up as the TID field in the SMB header,
 185          * which is limited to 16 bits (we skip 0xffff which is the
 186          * NULL TID).
 187          */
 188         if (i > 65534) {
 189                 DEBUG(0, ("Maximum connection limit reached\n"));
 190                 return NULL;
 191         }
 192
 193         if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
 194             !(conn->params = TALLOC_P(conn, struct share_params))) {
 195                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 196                 TALLOC_FREE(conn);
 197                 return NULL;
 198         }
 199         conn->sconn = sconn;
 200         conn->cnum = i;
 201         conn->force_group_gid = (gid_t)-1;
 202
 203         bitmap_set(sconn->smb1.tcons.bmap, i);
 204
 205         sconn->num_tcons_open++;
 206
 207         string_set(&conn->connectpath,"");
 208         string_set(&conn->origpath,"");
 209
 210         DLIST_ADD(sconn->smb1.tcons.Connections, conn);
 211
 212         return conn;
 213 }
 214
 215 /****************************************************************************
 216  Close all conn structures.
 217  Return true if any were closed.
 218 ****************************************************************************/
 219
 220 bool conn_close_all(struct smbd_server_connection *sconn)
 221 {
 222         bool ret = false;
 223         if (sconn->using_smb2) {
 224                 /* SMB2 */
 225                 struct smbd_smb2_session *sess;
 226                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 227                         struct smbd_smb2_tcon *tcon, *tc_next;
 228
 229                         for (tcon = sess->tcons.list; tcon; tcon = tc_next) {
 230                                 tc_next = tcon->next;
 231                                 TALLOC_FREE(tcon);
 232                                 ret = true;
 233                         }
 234                 }
 235         } else {
 236                 /* SMB1 */
 237                 connection_struct *conn, *next;
 238
 239                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
 240                         next=conn->next;
 241                         set_current_service(conn, 0, True);
 242                         close_cnum(conn, conn->vuid);
 243                         ret = true;
 244                 }
 245         }
 246         return ret;
 247 }
 248
 249 /****************************************************************************
 250  Update last used timestamps.
 251 ****************************************************************************/
 252
 253 static void conn_lastused_update(struct smbd_server_connection *sconn,time_t t)
 254 {
 255         if (sconn->using_smb2) {
 256                 /* SMB2 */
 257                 struct smbd_smb2_session *sess;
 258                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 259                         struct smbd_smb2_tcon *ptcon;
 260
 261                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
 262                                 connection_struct *conn = ptcon->compat_conn;
 263                                 /* Update if connection wasn't idle. */
 264                                 if (conn && conn->lastused != conn->lastused_count) {
 265                                         conn->lastused = t;
 266                                         conn->lastused_count = t;
 267                                 }
 268                         }
 269                 }
 270         } else {
 271                 /* SMB1 */
 272                 connection_struct *conn;
 273                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 274                         /* Update if connection wasn't idle. */
 275                         if (conn->lastused != conn->lastused_count) {
 276                                 conn->lastused = t;
 277                                 conn->lastused_count = t;
 278                         }
 279                 }
 280         }
 281 }
 282
 283 /****************************************************************************
 284  Idle inactive connections.
 285 ****************************************************************************/
 286
 287 bool conn_idle_all(struct smbd_server_connection *sconn, time_t t)
 288 {
 289         int deadtime = lp_deadtime()*60;
 290
 291         conn_lastused_update(sconn, t);
 292
 293         if (deadtime <= 0) {
 294                 deadtime = DEFAULT_SMBD_TIMEOUT;
 295         }
 296
 297         if (sconn->using_smb2) {
 298                 /* SMB2 */
 299                 struct smbd_smb2_session *sess;
 300                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 301                         struct smbd_smb2_tcon *ptcon;
 302
 303                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
 304                                 time_t age;
 305                                 connection_struct *conn = ptcon->compat_conn;
 306
 307                                 if (conn == NULL) {
 308                                         continue;
 309                                 }
 310
 311                                 age = t - conn->lastused;
 312                                 /* close dirptrs on connections that are idle */
 313                                 if (age > DPTR_IDLE_TIMEOUT) {
 314                                         dptr_idlecnum(conn);
 315                                 }
 316
 317                                 if (conn->num_files_open > 0 || age < deadtime) {
 318                                         return false;
 319                                 }
 320                         }
 321                 }
 322         } else {
 323                 /* SMB1 */
 324                 connection_struct *conn;
 325                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 326                         time_t age = t - conn->lastused;
 327
 328                         /* close dirptrs on connections that are idle */
 329                         if (age > DPTR_IDLE_TIMEOUT) {
 330                                 dptr_idlecnum(conn);
 331                         }
 332
 333                         if (conn->num_files_open > 0 || age < deadtime) {
 334                                 return false;
 335                         }
 336                 }
 337         }
 338
 339         /*
 340          * Check all pipes for any open handles. We cannot
 341          * idle with a handle open.
 342          */
 343         if (check_open_pipes()) {
 344                 return false;
 345         }
 346
 347         return true;
 348 }
 349
 350 /****************************************************************************
 351  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 352 ****************************************************************************/
 353
 354 void conn_clear_vuid_caches(struct smbd_server_connection *sconn,uint16_t vuid)
 355 {
 356         connection_struct *conn;
 357
 358         if (sconn->using_smb2) {
 359                 /* SMB2 */
 360                 struct smbd_smb2_session *sess;
 361                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 362                         struct smbd_smb2_tcon *ptcon;
 363
 364                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
 365                                 if (ptcon->compat_conn) {
 366                                         if (ptcon->compat_conn->vuid == vuid) {
 367                                                 ptcon->compat_conn->vuid = UID_FIELD_INVALID;
 368                                         }
 369                                         conn_clear_vuid_cache(ptcon->compat_conn, vuid);
 370                                 }
 371                         }
 372                 }
 373         } else {
 374                 /* SMB1 */
 375                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 376                         if (conn->vuid == vuid) {
 377                                 conn->vuid = UID_FIELD_INVALID;
 378                         }
 379                         conn_clear_vuid_cache(conn, vuid);
 380                 }
 381         }
 382 }
 383
 384 /****************************************************************************
 385  Free a conn structure - internal part.
 386 ****************************************************************************/
 387
 388 static void conn_free_internal(connection_struct *conn)
 389 {
 390         vfs_handle_struct *handle = NULL, *thandle = NULL;
 391         struct trans_state *state = NULL;
 392
 393         /* Free vfs_connection_struct */
 394         handle = conn->vfs_handles;
 395         while(handle) {
 396                 thandle = handle->next;
 397                 DLIST_REMOVE(conn->vfs_handles, handle);
 398                 if (handle->free_data)
 399                         handle->free_data(&handle->data);
 400                 handle = thandle;
 401         }
 402
 403         /* Free any pending transactions stored on this conn. */
 404         for (state = conn->pending_trans; state; state = state->next) {
 405                 /* state->setup is a talloc child of state. */
 406                 SAFE_FREE(state->param);
 407                 SAFE_FREE(state->data);
 408         }
 409
 410         free_namearray(conn->veto_list);
 411         free_namearray(conn->hide_list);
 412         free_namearray(conn->veto_oplock_list);
 413         free_namearray(conn->aio_write_behind_list);
 414
 415         string_free(&conn->connectpath);
 416         string_free(&conn->origpath);
 417
 418         ZERO_STRUCTP(conn);
 419         talloc_destroy(conn);
 420 }
 421
 422 /****************************************************************************
 423  Free a conn structure.
 424 ****************************************************************************/
 425
 426 void conn_free(connection_struct *conn)
 427 {
 428         if (conn->sconn == NULL) {
 429                 conn_free_internal(conn);
 430                 return;
 431         }
 432
 433         if (conn->sconn->using_smb2) {
 434                 /* SMB2 */
 435                 conn_free_internal(conn);
 436                 return;
 437         }
 438
 439         /* SMB1 */
 440         DLIST_REMOVE(conn->sconn->smb1.tcons.Connections, conn);
 441
 442         if (conn->sconn->smb1.tcons.bmap != NULL) {
 443                 /*
 444                  * Can be NULL for fake connections created by
 445                  * create_conn_struct()
 446                  */
 447                 bitmap_clear(conn->sconn->smb1.tcons.bmap, conn->cnum);
 448         }
 449
 450         SMB_ASSERT(conn->sconn->num_tcons_open > 0);
 451         conn->sconn->num_tcons_open--;
 452
 453         conn_free_internal(conn);
 454 }
 455
 456 /****************************************************************************
 457  Receive a smbcontrol message to forcibly unmount a share.
 458  The message contains just a share name and all instances of that
 459  share are unmounted.
 460  The special sharename '*' forces unmount of all shares.
 461 ****************************************************************************/
 462
 463 void msg_force_tdis(struct messaging_context *msg,
 464                     void *private_data,
 465                     uint32_t msg_type,
 466                     struct server_id server_id,
 467                     DATA_BLOB *data)
 468 {
 469         struct smbd_server_connection *sconn;
 470         connection_struct *conn, *next;
 471         fstring sharename;
 472
 473         sconn = msg_ctx_to_sconn(msg);
 474         if (sconn == NULL) {
 475                 DEBUG(1, ("could not find sconn\n"));
 476                 return;
 477         }
 478
 479         fstrcpy(sharename, (const char *)data->data);
 480
 481         if (strcmp(sharename, "*") == 0) {
 482                 DEBUG(1,("Forcing close of all shares\n"));
 483                 conn_close_all(sconn);
 484                 goto done;
 485         }
 486
 487         if (sconn->using_smb2) {
 488                 /* SMB2 */
 489                 struct smbd_smb2_session *sess;
 490                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 491                         struct smbd_smb2_tcon *tcon, *tc_next;
 492
 493                         for (tcon = sess->tcons.list; tcon; tcon = tc_next) {
 494                                 tc_next = tcon->next;
 495                                 if (tcon->compat_conn &&
 496                                                 strequal(lp_servicename(SNUM(tcon->compat_conn)),
 497                                                                 sharename)) {
 498                                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 499                                                 sharename, tcon->compat_conn->cnum));
 500                                         TALLOC_FREE(tcon);
 501                                 }
 502                         }
 503                 }
 504         } else {
 505                 /* SMB1 */
 506                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
 507                         next=conn->next;
 508                         if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 509                                 DEBUG(1,("Forcing close of share %s cnum=%d\n",
 510                                         sharename, conn->cnum));
 511                                 close_cnum(conn, (uint16)-1);
 512                         }
 513                 }
 514         }
 515
 516  done:
 517
 518         change_to_root_user();
 519         reload_services(msg, -1, true);
 520 }