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
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/globals.h"
  23
  24 /* The connections bitmap is expanded in increments of BITMAP_BLOCK_SZ. The
  25  * maximum size of the bitmap is the largest positive integer, but you will hit
  26  * the "max connections" limit, looong before that.
  27  */
  28 #define BITMAP_BLOCK_SZ 128
  29
  30 /****************************************************************************
  31 init the conn structures
  32 ****************************************************************************/
  33 void conn_init(struct smbd_server_connection *sconn)
  34 {
  35         sconn->smb1.tcons.Connections = NULL;
  36         sconn->smb1.tcons.num_open = 0;
  37         sconn->smb1.tcons.bmap = bitmap_talloc(sconn, BITMAP_BLOCK_SZ);
  38 }
  39
  40 /****************************************************************************
  41 return the number of open connections
  42 ****************************************************************************/
  43 int conn_num_open(struct smbd_server_connection *sconn)
  44 {
  45         return sconn->smb1.tcons.num_open;
  46 }
  47
  48
  49 /****************************************************************************
  50 check if a snum is in use
  51 ****************************************************************************/
  52 bool conn_snum_used(int snum)
  53 {
  54         struct smbd_server_connection *sconn = smbd_server_conn;
  55         connection_struct *conn;
  56         for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
  57                 if (conn->params->service == snum) {
  58                         return(True);
  59                 }
  60         }
  61         return(False);
  62 }
  63
  64 /****************************************************************************
  65  Find a conn given a cnum.
  66 ****************************************************************************/
  67
  68 connection_struct *conn_find(struct smbd_server_connection *sconn,unsigned cnum)
  69 {
  70         int count=0;
  71         connection_struct *conn;
  72
  73         for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next,count++) {
  74                 if (conn->cnum == cnum) {
  75                         if (count > 10) {
  76                                 DLIST_PROMOTE(sconn->smb1.tcons.Connections,
  77                                               conn);
  78                         }
  79                         return conn;
  80                 }
  81         }
  82
  83         return NULL;
  84 }
  85
  86 /****************************************************************************
  87   find first available connection slot, starting from a random position.
  88 The randomisation stops problems with the server dieing and clients
  89 thinking the server is still available.
  90 ****************************************************************************/
  91 connection_struct *conn_new(struct smbd_server_connection *sconn)
  92 {
  93         connection_struct *conn;
  94         int i;
  95         int find_offset = 1;
  96
  97         if (sconn->using_smb2) {
  98                 if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
  99                     !(conn->params = TALLOC_P(conn, struct share_params))) {
 100                         DEBUG(0,("TALLOC_ZERO() failed!\n"));
 101                         TALLOC_FREE(conn);
 102                         return NULL;
 103                 }
 104                 conn->sconn = sconn;
 105                 return conn;
 106         }
 107
 108 find_again:
 109         i = bitmap_find(sconn->smb1.tcons.bmap, find_offset);
 110
 111         if (i == -1) {
 112                 /* Expand the connections bitmap. */
 113                 int             oldsz = sconn->smb1.tcons.bmap->n;
 114                 int             newsz = sconn->smb1.tcons.bmap->n +
 115                                         BITMAP_BLOCK_SZ;
 116                 struct bitmap * nbmap;
 117
 118                 if (newsz <= oldsz) {
 119                         /* Integer wrap. */
 120                         DEBUG(0,("ERROR! Out of connection structures\n"));
 121                         return NULL;
 122                 }
 123
 124                 DEBUG(4,("resizing connections bitmap from %d to %d\n",
 125                         oldsz, newsz));
 126
 127                 nbmap = bitmap_talloc(sconn, newsz);
 128                 if (!nbmap) {
 129                         DEBUG(0,("ERROR! malloc fail.\n"));
 130                         return NULL;
 131                 }
 132
 133                 bitmap_copy(nbmap, sconn->smb1.tcons.bmap);
 134                 TALLOC_FREE(sconn->smb1.tcons.bmap);
 135
 136                 sconn->smb1.tcons.bmap = nbmap;
 137                 find_offset = oldsz; /* Start next search in the new portion. */
 138
 139                 goto find_again;
 140         }
 141
 142         /* The bitmap position is used below as the connection number
 143          * conn->cnum). This ends up as the TID field in the SMB header,
 144          * which is limited to 16 bits (we skip 0xffff which is the
 145          * NULL TID).
 146          */
 147         if (i > 65534) {
 148                 DEBUG(0, ("Maximum connection limit reached\n"));
 149                 return NULL;
 150         }
 151
 152         if (!(conn=TALLOC_ZERO_P(NULL, connection_struct)) ||
 153             !(conn->params = TALLOC_P(conn, struct share_params))) {
 154                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 155                 TALLOC_FREE(conn);
 156                 return NULL;
 157         }
 158         conn->sconn = sconn;
 159         conn->cnum = i;
 160         conn->force_group_gid = (gid_t)-1;
 161
 162         bitmap_set(sconn->smb1.tcons.bmap, i);
 163
 164         sconn->smb1.tcons.num_open++;
 165
 166         string_set(&conn->connectpath,"");
 167         string_set(&conn->origpath,"");
 168
 169         DLIST_ADD(sconn->smb1.tcons.Connections, conn);
 170
 171         return conn;
 172 }
 173
 174 /****************************************************************************
 175  Close all conn structures.
 176 return true if any were closed
 177 ****************************************************************************/
 178 bool conn_close_all(struct smbd_server_connection *sconn)
 179 {
 180         if (sconn->using_smb2) {
 181                 /* SMB2 */
 182                 if (sconn->smb2.sessions.list &&
 183                                 sconn->smb2.sessions.list->tcons.list) {
 184                         struct smbd_smb2_tcon *tcon, *tc_next;
 185
 186                         for (tcon = sconn->smb2.sessions.list->tcons.list;
 187                                         tcon; tcon = tc_next) {
 188                                 tc_next = tcon->next;
 189                                 TALLOC_FREE(tcon);
 190                         }
 191                         return true;
 192                 }
 193                 return false;
 194         } else {
 195                 /* SMB1 */
 196                 connection_struct *conn, *next;
 197                 bool ret = false;
 198
 199                 for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
 200                         next=conn->next;
 201                         set_current_service(conn, 0, True);
 202                         close_cnum(conn, conn->vuid);
 203                         ret = true;
 204                 }
 205                 return ret;
 206         }
 207 }
 208
 209 /****************************************************************************
 210  Idle inactive connections.
 211 ****************************************************************************/
 212
 213 bool conn_idle_all(struct smbd_server_connection *sconn,time_t t)
 214 {
 215         int deadtime = lp_deadtime()*60;
 216         connection_struct *conn;
 217
 218         if (deadtime <= 0)
 219                 deadtime = DEFAULT_SMBD_TIMEOUT;
 220
 221         for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 222
 223                 time_t age = t - conn->lastused;
 224
 225                 /* Update if connection wasn't idle. */
 226                 if (conn->lastused != conn->lastused_count) {
 227                         conn->lastused = t;
 228                         conn->lastused_count = t;
 229                 }
 230
 231                 /* close dirptrs on connections that are idle */
 232                 if (age > DPTR_IDLE_TIMEOUT) {
 233                         dptr_idlecnum(conn);
 234                 }
 235
 236                 if (conn->num_files_open > 0 || age < deadtime) {
 237                         return False;
 238                 }
 239         }
 240
 241         /*
 242          * Check all pipes for any open handles. We cannot
 243          * idle with a handle open.
 244          */
 245         if (check_open_pipes()) {
 246                 return False;
 247         }
 248
 249         return True;
 250 }
 251
 252 /****************************************************************************
 253  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 254 ****************************************************************************/
 255
 256 void conn_clear_vuid_caches(struct smbd_server_connection *sconn,uint16_t vuid)
 257 {
 258         connection_struct *conn;
 259
 260         for (conn=sconn->smb1.tcons.Connections;conn;conn=conn->next) {
 261                 if (conn->vuid == vuid) {
 262                         conn->vuid = UID_FIELD_INVALID;
 263                 }
 264                 conn_clear_vuid_cache(conn, vuid);
 265         }
 266 }
 267
 268 /****************************************************************************
 269  Free a conn structure - internal part.
 270 ****************************************************************************/
 271
 272 static void conn_free_internal(connection_struct *conn)
 273 {
 274         vfs_handle_struct *handle = NULL, *thandle = NULL;
 275         struct trans_state *state = NULL;
 276
 277         /* Free vfs_connection_struct */
 278         handle = conn->vfs_handles;
 279         while(handle) {
 280                 thandle = handle->next;
 281                 DLIST_REMOVE(conn->vfs_handles, handle);
 282                 if (handle->free_data)
 283                         handle->free_data(&handle->data);
 284                 handle = thandle;
 285         }
 286
 287         /* Free any pending transactions stored on this conn. */
 288         for (state = conn->pending_trans; state; state = state->next) {
 289                 /* state->setup is a talloc child of state. */
 290                 SAFE_FREE(state->param);
 291                 SAFE_FREE(state->data);
 292         }
 293
 294         free_namearray(conn->veto_list);
 295         free_namearray(conn->hide_list);
 296         free_namearray(conn->veto_oplock_list);
 297         free_namearray(conn->aio_write_behind_list);
 298
 299         string_free(&conn->connectpath);
 300         string_free(&conn->origpath);
 301
 302         ZERO_STRUCTP(conn);
 303         talloc_destroy(conn);
 304 }
 305
 306 /****************************************************************************
 307  Free a conn structure.
 308 ****************************************************************************/
 309
 310 void conn_free(connection_struct *conn)
 311 {
 312         if (conn->sconn == NULL) {
 313                 conn_free_internal(conn);
 314                 return;
 315         }
 316
 317         if (conn->sconn->using_smb2) {
 318                 conn_free_internal(conn);
 319                 return;
 320         }
 321
 322         DLIST_REMOVE(conn->sconn->smb1.tcons.Connections, conn);
 323
 324         if (conn->sconn->smb1.tcons.bmap != NULL) {
 325                 /*
 326                  * Can be NULL for fake connections created by
 327                  * create_conn_struct()
 328                  */
 329                 bitmap_clear(conn->sconn->smb1.tcons.bmap, conn->cnum);
 330         }
 331
 332         SMB_ASSERT(conn->sconn->smb1.tcons.num_open > 0);
 333         conn->sconn->smb1.tcons.num_open--;
 334
 335         conn_free_internal(conn);
 336 }
 337
 338 /****************************************************************************
 339 receive a smbcontrol message to forcibly unmount a share
 340 the message contains just a share name and all instances of that
 341 share are unmounted
 342 the special sharename '*' forces unmount of all shares
 343 ****************************************************************************/
 344 void msg_force_tdis(struct messaging_context *msg,
 345                     void *private_data,
 346                     uint32_t msg_type,
 347                     struct server_id server_id,
 348                     DATA_BLOB *data)
 349 {
 350         struct smbd_server_connection *sconn = smbd_server_conn;
 351         connection_struct *conn, *next;
 352         fstring sharename;
 353
 354         fstrcpy(sharename, (const char *)data->data);
 355
 356         if (strcmp(sharename, "*") == 0) {
 357                 DEBUG(1,("Forcing close of all shares\n"));
 358                 conn_close_all(sconn);
 359                 return;
 360         }
 361
 362         for (conn=sconn->smb1.tcons.Connections;conn;conn=next) {
 363                 next=conn->next;
 364                 if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 365                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 366                                  sharename, conn->cnum));
 367                         close_cnum(conn, (uint16)-1);
 368                 }
 369         }
 370 }