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