source/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         TALLOC_CTX *mem_ctx;
  96         connection_struct *conn;
  97         int i;
  98         int find_offset = 1;
  99
 100 find_again:
 101         i = bitmap_find(bmap, find_offset);
 102
 103         if (i == -1) {
 104                 /* Expand the connections bitmap. */
 105                 int             oldsz = bmap->n;
 106                 int             newsz = bmap->n + BITMAP_BLOCK_SZ;
 107                 struct bitmap * nbmap;
 108
 109                 if (newsz <= oldsz) {
 110                         /* Integer wrap. */
 111                         DEBUG(0,("ERROR! Out of connection structures\n"));
 112                         return NULL;
 113                 }
 114
 115                 DEBUG(4,("resizing connections bitmap from %d to %d\n",
 116                         oldsz, newsz));
 117
 118                 nbmap = bitmap_allocate(newsz);
 119                 if (!nbmap) {
 120                         DEBUG(0,("ERROR! malloc fail.\n"));
 121                         return NULL;
 122                 }
 123
 124                 bitmap_copy(nbmap, bmap);
 125                 bitmap_free(bmap);
 126
 127                 bmap = nbmap;
 128                 find_offset = oldsz; /* Start next search in the new portion. */
 129
 130                 goto find_again;
 131         }
 132
 133         /* The bitmap position is used below as the connection number
 134          * conn->cnum). This ends up as the TID field in the SMB header,
 135          * which is limited to 16 bits (we skip 0xffff which is the
 136          * NULL TID).
 137          */
 138         if (i > 65534) {
 139                 DEBUG(0, ("Maximum connection limit reached\n"));
 140                 return NULL;
 141         }
 142
 143         if ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 144                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 145                 return NULL;
 146         }
 147
 148         if (!(conn=TALLOC_ZERO_P(mem_ctx, connection_struct)) ||
 149             !(conn->params = TALLOC_P(mem_ctx, struct share_params))) {
 150                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 151                 TALLOC_FREE(mem_ctx);
 152                 return NULL;
 153         }
 154         conn->mem_ctx = mem_ctx;
 155         conn->cnum = i;
 156
 157         bitmap_set(bmap, i);
 158
 159         num_open++;
 160
 161         string_set(&conn->user,"");
 162         string_set(&conn->dirpath,"");
 163         string_set(&conn->connectpath,"");
 164         string_set(&conn->origpath,"");
 165
 166         DLIST_ADD(Connections, conn);
 167
 168         return conn;
 169 }
 170
 171 /****************************************************************************
 172  Close all conn structures.
 173 ****************************************************************************/
 174
 175 void conn_close_all(void)
 176 {
 177         connection_struct *conn, *next;
 178         for (conn=Connections;conn;conn=next) {
 179                 next=conn->next;
 180                 set_current_service(conn, 0, True);
 181                 close_cnum(conn, conn->vuid);
 182         }
 183 }
 184
 185 /****************************************************************************
 186  Idle inactive connections.
 187 ****************************************************************************/
 188
 189 bool conn_idle_all(time_t t)
 190 {
 191         int deadtime = lp_deadtime()*60;
 192         pipes_struct *plist = NULL;
 193         connection_struct *conn;
 194
 195         if (deadtime <= 0)
 196                 deadtime = DEFAULT_SMBD_TIMEOUT;
 197
 198         for (conn=Connections;conn;conn=conn->next) {
 199
 200                 time_t age = t - conn->lastused;
 201
 202                 /* Update if connection wasn't idle. */
 203                 if (conn->lastused != conn->lastused_count) {
 204                         conn->lastused = t;
 205                         conn->lastused_count = t;
 206                 }
 207
 208                 /* close dirptrs on connections that are idle */
 209                 if (age > DPTR_IDLE_TIMEOUT) {
 210                         dptr_idlecnum(conn);
 211                 }
 212
 213                 if (conn->num_files_open > 0 || age < deadtime) {
 214                         return False;
 215                 }
 216         }
 217
 218         /*
 219          * Check all pipes for any open handles. We cannot
 220          * idle with a handle open.
 221          */
 222
 223         for (plist = get_first_internal_pipe(); plist;
 224              plist = get_next_internal_pipe(plist)) {
 225                 if (plist->pipe_handles && plist->pipe_handles->count) {
 226                         return False;
 227                 }
 228         }
 229
 230         return True;
 231 }
 232
 233 /****************************************************************************
 234  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 235 ****************************************************************************/
 236
 237 void conn_clear_vuid_cache(uint16 vuid)
 238 {
 239         connection_struct *conn;
 240         unsigned int i;
 241
 242         for (conn=Connections;conn;conn=conn->next) {
 243                 if (conn->vuid == vuid) {
 244                         conn->vuid = UID_FIELD_INVALID;
 245                 }
 246
 247                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 248                         if (conn->vuid_cache.array[i].vuid == vuid) {
 249                                 struct vuid_cache_entry *ent = &conn->vuid_cache.array[i];
 250                                 ent->vuid = UID_FIELD_INVALID;
 251                                 ent->read_only = False;
 252                                 ent->admin_user = False;
 253                         }
 254                 }
 255         }
 256 }
 257
 258 /****************************************************************************
 259  Free a conn structure - internal part.
 260 ****************************************************************************/
 261
 262 void conn_free_internal(connection_struct *conn)
 263 {
 264         vfs_handle_struct *handle = NULL, *thandle = NULL;
 265         TALLOC_CTX *mem_ctx = NULL;
 266         struct trans_state *state = NULL;
 267
 268         /* Free vfs_connection_struct */
 269         handle = conn->vfs_handles;
 270         while(handle) {
 271                 DLIST_REMOVE(conn->vfs_handles, handle);
 272                 thandle = handle->next;
 273                 if (handle->free_data)
 274                         handle->free_data(&handle->data);
 275                 handle = thandle;
 276         }
 277
 278         /* Free any pending transactions stored on this conn. */
 279         for (state = conn->pending_trans; state; state = state->next) {
 280                 /* state->setup is a talloc child of state. */
 281                 SAFE_FREE(state->param);
 282                 SAFE_FREE(state->data);
 283         }
 284
 285         free_namearray(conn->veto_list);
 286         free_namearray(conn->hide_list);
 287         free_namearray(conn->veto_oplock_list);
 288         free_namearray(conn->aio_write_behind_list);
 289
 290         string_free(&conn->user);
 291         string_free(&conn->dirpath);
 292         string_free(&conn->connectpath);
 293         string_free(&conn->origpath);
 294
 295         mem_ctx = conn->mem_ctx;
 296         ZERO_STRUCTP(conn);
 297         talloc_destroy(mem_ctx);
 298 }
 299
 300 /****************************************************************************
 301  Free a conn structure.
 302 ****************************************************************************/
 303
 304 void conn_free(connection_struct *conn)
 305 {
 306         DLIST_REMOVE(Connections, conn);
 307
 308         bitmap_clear(bmap, conn->cnum);
 309
 310         SMB_ASSERT(num_open > 0);
 311         num_open--;
 312
 313         conn_free_internal(conn);
 314 }
 315
 316 /****************************************************************************
 317 receive a smbcontrol message to forcibly unmount a share
 318 the message contains just a share name and all instances of that
 319 share are unmounted
 320 the special sharename '*' forces unmount of all shares
 321 ****************************************************************************/
 322 void msg_force_tdis(struct messaging_context *msg,
 323                     void *private_data,
 324                     uint32_t msg_type,
 325                     struct server_id server_id,
 326                     DATA_BLOB *data)
 327 {
 328         connection_struct *conn, *next;
 329         fstring sharename;
 330
 331         fstrcpy(sharename, (const char *)data->data);
 332
 333         if (strcmp(sharename, "*") == 0) {
 334                 DEBUG(1,("Forcing close of all shares\n"));
 335                 conn_close_all();
 336                 return;
 337         }
 338
 339         for (conn=Connections;conn;conn=next) {
 340                 next=conn->next;
 341                 if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 342                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 343                                  sharename, conn->cnum));
 344                         close_cnum(conn, (uint16)-1);
 345                 }
 346         }
 347 }