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  Idle inactive connections.
 249 ****************************************************************************/
 250
 251 bool conn_idle_all(struct smbd_server_connection *sconn,time_t t)
 252 {
 253         int deadtime = lp_deadtime()*60;
 254         connection_struct *conn;
 255
 256         if (deadtime <= 0)
 257                 deadtime = DEFAULT_SMBD_TIMEOUT;
 258
 259         for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 260
 261                 time_t age = t - conn->lastused;
 262
 263                 /* Update if connection wasn't idle. */
 264                 if (conn->lastused != conn->lastused_count) {
 265                         conn->lastused = t;
 266                         conn->lastused_count = t;
 267                 }
 268
 269                 /* close dirptrs on connections that are idle */
 270                 if (age > DPTR_IDLE_TIMEOUT) {
 271                         dptr_idlecnum(conn);
 272                 }
 273
 274                 if (conn->num_files_open > 0 || age < deadtime) {
 275                         return False;
 276                 }
 277         }
 278
 279         /*
 280          * Check all pipes for any open handles. We cannot
 281          * idle with a handle open.
 282          */
 283         if (check_open_pipes()) {
 284                 return False;
 285         }
 286
 287         return True;
 288 }
 289
 290 /****************************************************************************
 291  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 292 ****************************************************************************/
 293
 294 void conn_clear_vuid_caches(struct smbd_server_connection *sconn,uint16_t vuid)
 295 {
 296         connection_struct *conn;
 297
 298         if (sconn->using_smb2) {
 299                 /* SMB2 */
 300                 struct smbd_smb2_session *sess;
 301                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 302                         struct smbd_smb2_tcon *ptcon;
 303
 304                         for (ptcon = sess->tcons.list; ptcon; ptcon = ptcon->next) {
 305                                 if (ptcon->compat_conn) {
 306                                         if (ptcon->compat_conn->vuid == vuid) {
 307                                                 ptcon->compat_conn->vuid = UID_FIELD_INVALID;
 308                                         }
 309                                         conn_clear_vuid_cache(ptcon->compat_conn, vuid);
 310                                 }
 311                         }
 312                 }
 313         } else {
 314                 /* SMB1 */
 315                 for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 316                         if (conn->vuid == vuid) {
 317                                 conn->vuid = UID_FIELD_INVALID;
 318                         }
 319                         conn_clear_vuid_cache(conn, vuid);
 320                 }
 321         }
 322 }
 323
 324 /****************************************************************************
 325  Free a conn structure - internal part.
 326 ****************************************************************************/
 327
 328 static void conn_free_internal(connection_struct *conn)
 329 {
 330         vfs_handle_struct *handle = NULL, *thandle = NULL;
 331         struct trans_state *state = NULL;
 332
 333         /* Free vfs_connection_struct */
 334         handle = conn->vfs_handles;
 335         while(handle) {
 336                 thandle = handle->next;
 337                 DLIST_REMOVE(conn->vfs_handles, handle);
 338                 if (handle->free_data)
 339                         handle->free_data(&handle->data);
 340                 handle = thandle;
 341         }
 342
 343         /* Free any pending transactions stored on this conn. */
 344         for (state = conn->pending_trans; state; state = state->next) {
 345                 /* state->setup is a talloc child of state. */
 346                 SAFE_FREE(state->param);
 347                 SAFE_FREE(state->data);
 348         }
 349
 350         free_namearray(conn->veto_list);
 351         free_namearray(conn->hide_list);
 352         free_namearray(conn->veto_oplock_list);
 353         free_namearray(conn->aio_write_behind_list);
 354
 355         string_free(&conn->connectpath);
 356         string_free(&conn->origpath);
 357
 358         ZERO_STRUCTP(conn);
 359         talloc_destroy(conn);
 360 }
 361
 362 /****************************************************************************
 363  Free a conn structure.
 364 ****************************************************************************/
 365
 366 void conn_free(connection_struct *conn)
 367 {
 368         if (conn->sconn == NULL) {
 369                 conn_free_internal(conn);
 370                 return;
 371         }
 372
 373         if (conn->sconn->using_smb2) {
 374                 /* SMB2 */
 375                 conn_free_internal(conn);
 376                 return;
 377         }
 378
 379         /* SMB1 */
 380         DLIST_REMOVE(conn->sconn->smb1.tcons.Connections, conn);
 381
 382         if (conn->sconn->smb1.tcons.bmap != NULL) {
 383                 /*
 384                  * Can be NULL for fake connections created by
 385                  * create_conn_struct()
 386                  */
 387                 bitmap_clear(conn->sconn->smb1.tcons.bmap, conn->cnum);
 388         }
 389
 390         SMB_ASSERT(conn->sconn->num_tcons_open > 0);
 391         conn->sconn->num_tcons_open--;
 392
 393         conn_free_internal(conn);
 394 }
 395
 396 /****************************************************************************
 397  Receive a smbcontrol message to forcibly unmount a share.
 398  The message contains just a share name and all instances of that
 399  share are unmounted.
 400  The special sharename '*' forces unmount of all shares.
 401 ****************************************************************************/
 402
 403 void msg_force_tdis(struct messaging_context *msg,
 404                     void *private_data,
 405                     uint32_t msg_type,
 406                     struct server_id server_id,
 407                     DATA_BLOB *data)
 408 {
 409         struct smbd_server_connection *sconn;
 410         connection_struct *conn, *next;
 411         fstring sharename;
 412
 413         sconn = msg_ctx_to_sconn(msg);
 414         if (sconn == NULL) {
 415                 DEBUG(1, ("could not find sconn\n"));
 416                 return;
 417         }
 418
 419         fstrcpy(sharename, (const char *)data->data);
 420
 421         if (strcmp(sharename, "*") == 0) {
 422                 DEBUG(1,("Forcing close of all shares\n"));
 423                 conn_close_all(sconn);
 424                 return;
 425         }
 426
 427         if (sconn->using_smb2) {
 428                 /* SMB2 */
 429                 struct smbd_smb2_session *sess;
 430                 for (sess = sconn->smb2.sessions.list; sess; sess = sess->next) {
 431                         struct smbd_smb2_tcon *tcon, *tc_next;
 432
 433                         for (tcon = sess->tcons.list; tcon; tcon = tc_next) {
 434                                 tc_next = tcon->next;
 435                                 if (tcon->compat_conn &&
 436                                                 strequal(lp_servicename(SNUM(tcon->compat_conn)),
 437                                                                 sharename)) {
 438                                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 439                                                 sharename, tcon->compat_conn->cnum));
 440                                         TALLOC_FREE(tcon);
 441                                 }
 442                         }
 443                 }
 444         } else {
 445                 /* SMB1 */
 446                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
 447                         next=conn->next;
 448                         if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 449                                 DEBUG(1,("Forcing close of share %s cnum=%d\n",
 450                                         sharename, conn->cnum));
 451                                 close_cnum(conn, (uint16)-1);
 452                         }
 453                 }
 454         }
 455 }