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  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 first available connection slot, starting from a random position.
  89 The randomisation stops problems with the server dieing and clients
  90 thinking the server is still available.
  91 ****************************************************************************/
  92 connection_struct *conn_new(void)
  93 {
  94         TALLOC_CTX *mem_ctx;
  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 ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 143                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 144                 return NULL;
 145         }
 146
 147         if (!(conn=TALLOC_ZERO_P(mem_ctx, connection_struct)) ||
 148             !(conn->params = TALLOC_P(mem_ctx, struct share_params))) {
 149                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 150                 TALLOC_FREE(mem_ctx);
 151                 return NULL;
 152         }
 153         conn->mem_ctx = mem_ctx;
 154         conn->cnum = i;
 155
 156         bitmap_set(bmap, i);
 157
 158         num_open++;
 159
 160         string_set(&conn->user,"");
 161         string_set(&conn->dirpath,"");
 162         string_set(&conn->connectpath,"");
 163         string_set(&conn->origpath,"");
 164
 165         DLIST_ADD(Connections, conn);
 166
 167         return conn;
 168 }
 169
 170 /****************************************************************************
 171  Close all conn structures.
 172 ****************************************************************************/
 173
 174 void conn_close_all(void)
 175 {
 176         connection_struct *conn, *next;
 177         for (conn=Connections;conn;conn=next) {
 178                 next=conn->next;
 179                 set_current_service(conn, 0, True);
 180                 close_cnum(conn, conn->vuid);
 181         }
 182 }
 183
 184 /****************************************************************************
 185  Idle inactive connections.
 186 ****************************************************************************/
 187
 188 bool conn_idle_all(time_t t)
 189 {
 190         int deadtime = lp_deadtime()*60;
 191         pipes_struct *plist = NULL;
 192         connection_struct *conn;
 193
 194         if (deadtime <= 0)
 195                 deadtime = DEFAULT_SMBD_TIMEOUT;
 196
 197         for (conn=Connections;conn;conn=conn->next) {
 198
 199                 time_t age = t - conn->lastused;
 200
 201                 /* Update if connection wasn't idle. */
 202                 if (conn->lastused != conn->lastused_count) {
 203                         conn->lastused = t;
 204                         conn->lastused_count = t;
 205                 }
 206
 207                 /* close dirptrs on connections that are idle */
 208                 if (age > DPTR_IDLE_TIMEOUT) {
 209                         dptr_idlecnum(conn);
 210                 }
 211
 212                 if (conn->num_files_open > 0 || age < deadtime) {
 213                         return False;
 214                 }
 215         }
 216
 217         /*
 218          * Check all pipes for any open handles. We cannot
 219          * idle with a handle open.
 220          */
 221
 222         for (plist = get_first_internal_pipe(); plist;
 223              plist = get_next_internal_pipe(plist)) {
 224                 if (plist->pipe_handles && plist->pipe_handles->count) {
 225                         return False;
 226                 }
 227         }
 228
 229         return True;
 230 }
 231
 232 /****************************************************************************
 233  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 234 ****************************************************************************/
 235
 236 void conn_clear_vuid_cache(uint16 vuid)
 237 {
 238         connection_struct *conn;
 239         unsigned int i;
 240
 241         for (conn=Connections;conn;conn=conn->next) {
 242                 if (conn->vuid == vuid) {
 243                         conn->vuid = UID_FIELD_INVALID;
 244                 }
 245
 246                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 247                         if (conn->vuid_cache.array[i].vuid == vuid) {
 248                                 struct vuid_cache_entry *ent = &conn->vuid_cache.array[i];
 249                                 ent->vuid = UID_FIELD_INVALID;
 250                                 ent->read_only = False;
 251                                 ent->admin_user = False;
 252                         }
 253                 }
 254         }
 255 }
 256
 257 /****************************************************************************
 258  Free a conn structure - internal part.
 259 ****************************************************************************/
 260
 261 void conn_free_internal(connection_struct *conn)
 262 {
 263         vfs_handle_struct *handle = NULL, *thandle = NULL;
 264         TALLOC_CTX *mem_ctx = NULL;
 265         struct trans_state *state = NULL;
 266
 267         /* Free vfs_connection_struct */
 268         handle = conn->vfs_handles;
 269         while(handle) {
 270                 thandle = handle->next;
 271                 DLIST_REMOVE(conn->vfs_handles, handle);
 272                 if (handle->free_data)
 273                         handle->free_data(&handle->data);
 274                 handle = thandle;
 275         }
 276
 277         /* Free any pending transactions stored on this conn. */
 278         for (state = conn->pending_trans; state; state = state->next) {
 279                 /* state->setup is a talloc child of state. */
 280                 SAFE_FREE(state->param);
 281                 SAFE_FREE(state->data);
 282         }
 283
 284         free_namearray(conn->veto_list);
 285         free_namearray(conn->hide_list);
 286         free_namearray(conn->veto_oplock_list);
 287         free_namearray(conn->aio_write_behind_list);
 288
 289         string_free(&conn->user);
 290         string_free(&conn->dirpath);
 291         string_free(&conn->connectpath);
 292         string_free(&conn->origpath);
 293
 294         mem_ctx = conn->mem_ctx;
 295         ZERO_STRUCTP(conn);
 296         talloc_destroy(mem_ctx);
 297 }
 298
 299 /****************************************************************************
 300  Free a conn structure.
 301 ****************************************************************************/
 302
 303 void conn_free(connection_struct *conn)
 304 {
 305         DLIST_REMOVE(Connections, conn);
 306
 307         bitmap_clear(bmap, conn->cnum);
 308
 309         SMB_ASSERT(num_open > 0);
 310         num_open--;
 311
 312         conn_free_internal(conn);
 313 }
 314
 315 /****************************************************************************
 316 receive a smbcontrol message to forcibly unmount a share
 317 the message contains just a share name and all instances of that
 318 share are unmounted
 319 the special sharename '*' forces unmount of all shares
 320 ****************************************************************************/
 321 void msg_force_tdis(struct messaging_context *msg,
 322                     void *private_data,
 323                     uint32_t msg_type,
 324                     struct server_id server_id,
 325                     DATA_BLOB *data)
 326 {
 327         connection_struct *conn, *next;
 328         fstring sharename;
 329
 330         fstrcpy(sharename, (const char *)data->data);
 331
 332         if (strcmp(sharename, "*") == 0) {
 333                 DEBUG(1,("Forcing close of all shares\n"));
 334                 conn_close_all();
 335                 return;
 336         }
 337
 338         for (conn=Connections;conn;conn=next) {
 339                 next=conn->next;
 340                 if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 341                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 342                                  sharename, conn->cnum));
 343                         close_cnum(conn, (uint16)-1);
 344                 }
 345         }
 346 }