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