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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.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 static connection_struct *Connections;
  31
  32 /* number of open connections */
  33 static struct bitmap *bmap;
  34 static int num_open;
  35
  36 /****************************************************************************
  37 init the conn structures
  38 ****************************************************************************/
  39 void conn_init(void)
  40 {
  41         bmap = bitmap_allocate(BITMAP_BLOCK_SZ);
  42 }
  43
  44 /****************************************************************************
  45 return the number of open connections
  46 ****************************************************************************/
  47 int conn_num_open(void)
  48 {
  49         return num_open;
  50 }
  51
  52
  53 /****************************************************************************
  54 check if a snum is in use
  55 ****************************************************************************/
  56 BOOL conn_snum_used(int snum)
  57 {
  58         connection_struct *conn;
  59         for (conn=Connections;conn;conn=conn->next) {
  60                 if (conn->params->service == snum) {
  61                         return(True);
  62                 }
  63         }
  64         return(False);
  65 }
  66
  67 /****************************************************************************
  68  Find a conn given a cnum.
  69 ****************************************************************************/
  70
  71 connection_struct *conn_find(unsigned cnum)
  72 {
  73         int count=0;
  74         connection_struct *conn;
  75
  76         for (conn=Connections;conn;conn=conn->next,count++) {
  77                 if (conn->cnum == cnum) {
  78                         if (count > 10) {
  79                                 DLIST_PROMOTE(Connections, conn);
  80                         }
  81                         return conn;
  82                 }
  83         }
  84
  85         return NULL;
  86 }
  87
  88 /****************************************************************************
  89  Find a conn given a service name.
  90 ****************************************************************************/
  91
  92 connection_struct *conn_find_byname(const char *service)
  93 {
  94         connection_struct *conn;
  95
  96         for (conn=Connections;conn;conn=conn->next) {
  97                 if (strequal(lp_servicename(SNUM(conn)),service)) {
  98                         if (conn != Connections) {
  99                                 /* Promote if not first. */
 100                                 DLIST_PROMOTE(Connections, conn);
 101                         }
 102                         return conn;
 103                 }
 104         }
 105
 106         return NULL;
 107 }
 108
 109
 110 /****************************************************************************
 111   find first available connection slot, starting from a random position.
 112 The randomisation stops problems with the server dieing and clients
 113 thinking the server is still available.
 114 ****************************************************************************/
 115 connection_struct *conn_new(void)
 116 {
 117         TALLOC_CTX *mem_ctx;
 118         connection_struct *conn;
 119         int i;
 120         int find_offset = 1;
 121
 122 find_again:
 123         i = bitmap_find(bmap, find_offset);
 124
 125         if (i == -1) {
 126                 /* Expand the connections bitmap. */
 127                 int             oldsz = bmap->n;
 128                 int             newsz = bmap->n + BITMAP_BLOCK_SZ;
 129                 struct bitmap * nbmap;
 130
 131                 if (newsz <= oldsz) {
 132                         /* Integer wrap. */
 133                         DEBUG(0,("ERROR! Out of connection structures\n"));
 134                         return NULL;
 135                 }
 136
 137                 DEBUG(4,("resizing connections bitmap from %d to %d\n",
 138                         oldsz, newsz));
 139
 140                 nbmap = bitmap_allocate(newsz);
 141                 if (!nbmap) {
 142                         DEBUG(0,("ERROR! malloc fail.\n"));
 143                         return NULL;
 144                 }
 145
 146                 bitmap_copy(nbmap, bmap);
 147                 bitmap_free(bmap);
 148
 149                 bmap = nbmap;
 150                 find_offset = oldsz; /* Start next search in the new portion. */
 151
 152                 goto find_again;
 153         }
 154
 155         /* The bitmap position is used below as the connection number
 156          * conn->cnum). This ends up as the TID field in the SMB header,
 157          * which is limited to 16 bits (we skip 0xffff which is the
 158          * NULL TID).
 159          */
 160         if (i > 65534) {
 161                 DEBUG(0, ("Maximum connection limit reached\n"));
 162                 return NULL;
 163         }
 164
 165         if ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 166                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 167                 return NULL;
 168         }
 169
 170         if (!(conn=TALLOC_ZERO_P(mem_ctx, connection_struct)) ||
 171             !(conn->params = TALLOC_P(mem_ctx, struct share_params))) {
 172                 DEBUG(0,("TALLOC_ZERO() failed!\n"));
 173                 TALLOC_FREE(mem_ctx);
 174                 return NULL;
 175         }
 176         conn->mem_ctx = mem_ctx;
 177         conn->cnum = i;
 178
 179         bitmap_set(bmap, i);
 180
 181         num_open++;
 182
 183         string_set(&conn->user,"");
 184         string_set(&conn->dirpath,"");
 185         string_set(&conn->connectpath,"");
 186         string_set(&conn->origpath,"");
 187
 188         DLIST_ADD(Connections, conn);
 189
 190         return conn;
 191 }
 192
 193 /****************************************************************************
 194  Close all conn structures.
 195 ****************************************************************************/
 196
 197 void conn_close_all(void)
 198 {
 199         connection_struct *conn, *next;
 200         for (conn=Connections;conn;conn=next) {
 201                 next=conn->next;
 202                 set_current_service(conn, 0, True);
 203                 close_cnum(conn, conn->vuid);
 204         }
 205 }
 206
 207 /****************************************************************************
 208  Idle inactive connections.
 209 ****************************************************************************/
 210
 211 BOOL conn_idle_all(time_t t, int deadtime)
 212 {
 213         pipes_struct *plist = NULL;
 214         BOOL allidle = True;
 215         connection_struct *conn, *next;
 216
 217         for (conn=Connections;conn;conn=next) {
 218                 next=conn->next;
 219
 220                 /* Update if connection wasn't idle. */
 221                 if (conn->lastused != conn->lastused_count) {
 222                         conn->lastused = t;
 223                         conn->lastused_count = t;
 224                 }
 225
 226                 /* close dirptrs on connections that are idle */
 227                 if ((t-conn->lastused) > DPTR_IDLE_TIMEOUT) {
 228                         dptr_idlecnum(conn);
 229                 }
 230
 231                 if (conn->num_files_open > 0 || (t-conn->lastused)<deadtime) {
 232                         allidle = False;
 233                 }
 234         }
 235
 236         /*
 237          * Check all pipes for any open handles. We cannot
 238          * idle with a handle open.
 239          */
 240
 241         for (plist = get_first_internal_pipe(); plist; plist = get_next_internal_pipe(plist))
 242                 if (plist->pipe_handles && plist->pipe_handles->count)
 243                         allidle = False;
 244
 245         return allidle;
 246 }
 247
 248 /****************************************************************************
 249  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 250 ****************************************************************************/
 251
 252 void conn_clear_vuid_cache(uint16 vuid)
 253 {
 254         connection_struct *conn;
 255         unsigned int i;
 256
 257         for (conn=Connections;conn;conn=conn->next) {
 258                 if (conn->vuid == vuid) {
 259                         conn->vuid = UID_FIELD_INVALID;
 260                 }
 261
 262                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 263                         if (conn->vuid_cache.array[i].vuid == vuid) {
 264                                 struct vuid_cache_entry *ent = &conn->vuid_cache.array[i];
 265                                 ent->vuid = UID_FIELD_INVALID;
 266                                 ent->read_only = False;
 267                                 ent->admin_user = False;
 268                         }
 269                 }
 270         }
 271 }
 272
 273 /****************************************************************************
 274  Free a conn structure - internal part.
 275 ****************************************************************************/
 276
 277 void conn_free_internal(connection_struct *conn)
 278 {
 279         vfs_handle_struct *handle = NULL, *thandle = NULL;
 280         TALLOC_CTX *mem_ctx = NULL;
 281         struct trans_state *state = NULL;
 282
 283         /* Free vfs_connection_struct */
 284         handle = conn->vfs_handles;
 285         while(handle) {
 286                 DLIST_REMOVE(conn->vfs_handles, handle);
 287                 thandle = handle->next;
 288                 if (handle->free_data)
 289                         handle->free_data(&handle->data);
 290                 handle = thandle;
 291         }
 292
 293         /* Free any pending transactions stored on this conn. */
 294         for (state = conn->pending_trans; state; state = state->next) {
 295                 /* state->setup is a talloc child of state. */
 296                 SAFE_FREE(state->param);
 297                 SAFE_FREE(state->data);
 298         }
 299
 300         free_namearray(conn->veto_list);
 301         free_namearray(conn->hide_list);
 302         free_namearray(conn->veto_oplock_list);
 303         free_namearray(conn->aio_write_behind_list);
 304
 305         string_free(&conn->user);
 306         string_free(&conn->dirpath);
 307         string_free(&conn->connectpath);
 308         string_free(&conn->origpath);
 309
 310         mem_ctx = conn->mem_ctx;
 311         ZERO_STRUCTP(conn);
 312         talloc_destroy(mem_ctx);
 313 }
 314
 315 /****************************************************************************
 316  Free a conn structure.
 317 ****************************************************************************/
 318
 319 void conn_free(connection_struct *conn)
 320 {
 321         DLIST_REMOVE(Connections, conn);
 322
 323         bitmap_clear(bmap, conn->cnum);
 324         num_open--;
 325
 326         conn_free_internal(conn);
 327 }
 328
 329 /****************************************************************************
 330 receive a smbcontrol message to forcibly unmount a share
 331 the message contains just a share name and all instances of that
 332 share are unmounted
 333 the special sharename '*' forces unmount of all shares
 334 ****************************************************************************/
 335 void msg_force_tdis(int msg_type, struct process_id pid, void *buf, size_t len,
 336                     void *private_data)
 337 {
 338         connection_struct *conn, *next;
 339         fstring sharename;
 340
 341         fstrcpy(sharename, (const char *)buf);
 342
 343         if (strcmp(sharename, "*") == 0) {
 344                 DEBUG(1,("Forcing close of all shares\n"));
 345                 conn_close_all();
 346                 return;
 347         }
 348
 349         for (conn=Connections;conn;conn=next) {
 350                 next=conn->next;
 351                 if (strequal(lp_servicename(SNUM(conn)), sharename)) {
 352                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 353                                  sharename, conn->cnum));
 354                         close_cnum(conn, (uint16)-1);
 355                 }
 356         }
 357 }