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->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 <= 0) {
 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         if ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 135                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 136                 return NULL;
 137         }
 138
 139         if ((conn=TALLOC_ZERO_P(mem_ctx, connection_struct))==NULL) {
 140                 DEBUG(0,("talloc_zero() failed!\n"));
 141                 return NULL;
 142         }
 143         conn->mem_ctx = mem_ctx;
 144         conn->cnum = i;
 145
 146         bitmap_set(bmap, i);
 147
 148         num_open++;
 149
 150         string_set(&conn->user,"");
 151         string_set(&conn->dirpath,"");
 152         string_set(&conn->connectpath,"");
 153         string_set(&conn->origpath,"");
 154
 155         DLIST_ADD(Connections, conn);
 156
 157         return conn;
 158 }
 159
 160 /****************************************************************************
 161  Close all conn structures.
 162 ****************************************************************************/
 163
 164 void conn_close_all(void)
 165 {
 166         connection_struct *conn, *next;
 167         for (conn=Connections;conn;conn=next) {
 168                 next=conn->next;
 169                 set_current_service(conn, 0, True);
 170                 close_cnum(conn, conn->vuid);
 171         }
 172 }
 173
 174 /****************************************************************************
 175  Idle inactive connections.
 176 ****************************************************************************/
 177
 178 BOOL conn_idle_all(time_t t, int deadtime)
 179 {
 180         pipes_struct *plist = NULL;
 181         BOOL allidle = True;
 182         connection_struct *conn, *next;
 183
 184         for (conn=Connections;conn;conn=next) {
 185                 next=conn->next;
 186
 187                 /* Update if connection wasn't idle. */
 188                 if (conn->lastused != conn->lastused_count) {
 189                         conn->lastused = t;
 190                 }
 191
 192                 /* close dirptrs on connections that are idle */
 193                 if ((t-conn->lastused) > DPTR_IDLE_TIMEOUT) {
 194                         dptr_idlecnum(conn);
 195                 }
 196
 197                 if (conn->num_files_open > 0 || (t-conn->lastused)<deadtime) {
 198                         allidle = False;
 199                 }
 200         }
 201
 202         /*
 203          * Check all pipes for any open handles. We cannot
 204          * idle with a handle open.
 205          */
 206
 207         for (plist = get_first_internal_pipe(); plist; plist = get_next_internal_pipe(plist))
 208                 if (plist->pipe_handles && plist->pipe_handles->count)
 209                         allidle = False;
 210
 211         return allidle;
 212 }
 213
 214 /****************************************************************************
 215  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 216 ****************************************************************************/
 217
 218 void conn_clear_vuid_cache(uint16 vuid)
 219 {
 220         connection_struct *conn;
 221         unsigned int i;
 222
 223         for (conn=Connections;conn;conn=conn->next) {
 224                 if (conn->vuid == vuid) {
 225                         conn->vuid = UID_FIELD_INVALID;
 226                 }
 227
 228                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 229                         if (conn->vuid_cache.array[i].vuid == vuid) {
 230                                 struct vuid_cache_entry *ent = &conn->vuid_cache.array[i];
 231                                 ent->vuid = UID_FIELD_INVALID;
 232                                 ent->read_only = False;
 233                                 ent->admin_user = False;
 234                         }
 235                 }
 236         }
 237 }
 238
 239 /****************************************************************************
 240  Free a conn structure - internal part.
 241 ****************************************************************************/
 242
 243 void conn_free_internal(connection_struct *conn)
 244 {
 245         vfs_handle_struct *handle = NULL, *thandle = NULL;
 246         TALLOC_CTX *mem_ctx = NULL;
 247
 248         /* Free vfs_connection_struct */
 249         handle = conn->vfs_handles;
 250         while(handle) {
 251                 DLIST_REMOVE(conn->vfs_handles, handle);
 252                 thandle = handle->next;
 253                 if (handle->free_data)
 254                         handle->free_data(&handle->data);
 255                 handle = thandle;
 256         }
 257
 258         if (conn->ngroups && conn->groups) {
 259                 SAFE_FREE(conn->groups);
 260                 conn->ngroups = 0;
 261         }
 262
 263         if (conn->nt_user_token) {
 264                 TALLOC_FREE(conn->nt_user_token);
 265         }
 266
 267         free_namearray(conn->veto_list);
 268         free_namearray(conn->hide_list);
 269         free_namearray(conn->veto_oplock_list);
 270         free_namearray(conn->aio_write_behind_list);
 271
 272         string_free(&conn->user);
 273         string_free(&conn->dirpath);
 274         string_free(&conn->connectpath);
 275         string_free(&conn->origpath);
 276
 277         mem_ctx = conn->mem_ctx;
 278         ZERO_STRUCTP(conn);
 279         talloc_destroy(mem_ctx);
 280 }
 281
 282 /****************************************************************************
 283  Free a conn structure.
 284 ****************************************************************************/
 285
 286 void conn_free(connection_struct *conn)
 287 {
 288         DLIST_REMOVE(Connections, conn);
 289
 290         bitmap_clear(bmap, conn->cnum);
 291         num_open--;
 292
 293         conn_free_internal(conn);
 294 }
 295
 296 /****************************************************************************
 297 receive a smbcontrol message to forcibly unmount a share
 298 the message contains just a share name and all instances of that
 299 share are unmounted
 300 the special sharename '*' forces unmount of all shares
 301 ****************************************************************************/
 302 void msg_force_tdis(int msg_type, struct process_id pid, void *buf, size_t len)
 303 {
 304         connection_struct *conn, *next;
 305         fstring sharename;
 306
 307         fstrcpy(sharename, (const char *)buf);
 308
 309         if (strcmp(sharename, "*") == 0) {
 310                 DEBUG(1,("Forcing close of all shares\n"));
 311                 conn_close_all();
 312                 return;
 313         }
 314
 315         for (conn=Connections;conn;conn=next) {
 316                 next=conn->next;
 317                 if (strequal(lp_servicename(conn->service), sharename)) {
 318                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 319                                  sharename, conn->cnum));
 320                         close_cnum(conn, (uint16)-1);
 321                 }
 322         }
 323 }