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