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