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