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
 121                 bitmap_copy(nbmap, bmap);
 122                 bitmap_free(bmap);
 123
 124                 bmap = nbmap;
 125                 find_offset = oldsz; /* Start next search in the new portion. */
 126
 127                 goto find_again;
 128         }
 129
 130         if ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 131                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 132                 return NULL;
 133         }
 134
 135         if ((conn=TALLOC_ZERO_P(mem_ctx, connection_struct))==NULL) {
 136                 DEBUG(0,("talloc_zero() failed!\n"));
 137                 return NULL;
 138         }
 139         conn->mem_ctx = mem_ctx;
 140         conn->cnum = i;
 141
 142         bitmap_set(bmap, i);
 143
 144         num_open++;
 145
 146         string_set(&conn->user,"");
 147         string_set(&conn->dirpath,"");
 148         string_set(&conn->connectpath,"");
 149         string_set(&conn->origpath,"");
 150
 151         DLIST_ADD(Connections, conn);
 152
 153         return conn;
 154 }
 155
 156 /****************************************************************************
 157 close all conn structures
 158 ****************************************************************************/
 159 void conn_close_all(void)
 160 {
 161         connection_struct *conn, *next;
 162         for (conn=Connections;conn;conn=next) {
 163                 next=conn->next;
 164                 set_current_service(conn, 0, True);
 165                 close_cnum(conn, conn->vuid);
 166         }
 167 }
 168
 169 /****************************************************************************
 170  Idle inactive connections.
 171 ****************************************************************************/
 172
 173 BOOL conn_idle_all(time_t t, int deadtime)
 174 {
 175         pipes_struct *plist = NULL;
 176         BOOL allidle = True;
 177         connection_struct *conn, *next;
 178
 179         for (conn=Connections;conn;conn=next) {
 180                 next=conn->next;
 181                 /* close dirptrs on connections that are idle */
 182                 if ((t-conn->lastused) > DPTR_IDLE_TIMEOUT)
 183                         dptr_idlecnum(conn);
 184
 185                 if (conn->num_files_open > 0 ||
 186                     (t-conn->lastused)<deadtime)
 187                         allidle = False;
 188         }
 189
 190         /*
 191          * Check all pipes for any open handles. We cannot
 192          * idle with a handle open.
 193          */
 194
 195         for (plist = get_first_internal_pipe(); plist; plist = get_next_internal_pipe(plist))
 196                 if (plist->pipe_handles && plist->pipe_handles->count)
 197                         allidle = False;
 198
 199         return allidle;
 200 }
 201
 202 /****************************************************************************
 203  Clear a vuid out of the validity cache, and as the 'owner' of a connection.
 204 ****************************************************************************/
 205
 206 void conn_clear_vuid_cache(uint16 vuid)
 207 {
 208         connection_struct *conn;
 209         unsigned int i;
 210
 211         for (conn=Connections;conn;conn=conn->next) {
 212                 if (conn->vuid == vuid) {
 213                         conn->vuid = UID_FIELD_INVALID;
 214                 }
 215
 216                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 217                         if (conn->vuid_cache.array[i].vuid == vuid) {
 218                                 struct vuid_cache_entry *ent = &conn->vuid_cache.array[i];
 219                                 ent->vuid = UID_FIELD_INVALID;
 220                                 ent->read_only = False;
 221                                 ent->admin_user = False;
 222                         }
 223                 }
 224         }
 225 }
 226
 227 /****************************************************************************
 228  Free a conn structure.
 229 ****************************************************************************/
 230
 231 void conn_free(connection_struct *conn)
 232 {
 233         vfs_handle_struct *handle = NULL, *thandle = NULL;
 234         TALLOC_CTX *mem_ctx = NULL;
 235
 236         /* Free vfs_connection_struct */
 237         handle = conn->vfs_handles;
 238         while(handle) {
 239                 DLIST_REMOVE(conn->vfs_handles, handle);
 240                 thandle = handle->next;
 241                 if (handle->free_data)
 242                         handle->free_data(&handle->data);
 243                 handle = thandle;
 244         }
 245
 246         DLIST_REMOVE(Connections, conn);
 247
 248         if (conn->ngroups && conn->groups) {
 249                 SAFE_FREE(conn->groups);
 250                 conn->ngroups = 0;
 251         }
 252
 253         free_namearray(conn->veto_list);
 254         free_namearray(conn->hide_list);
 255         free_namearray(conn->veto_oplock_list);
 256
 257         string_free(&conn->user);
 258         string_free(&conn->dirpath);
 259         string_free(&conn->connectpath);
 260         string_free(&conn->origpath);
 261
 262         bitmap_clear(bmap, conn->cnum);
 263         num_open--;
 264
 265         mem_ctx = conn->mem_ctx;
 266         ZERO_STRUCTP(conn);
 267         talloc_destroy(mem_ctx);
 268 }
 269
 270
 271 /****************************************************************************
 272 receive a smbcontrol message to forcibly unmount a share
 273 the message contains just a share name and all instances of that
 274 share are unmounted
 275 the special sharename '*' forces unmount of all shares
 276 ****************************************************************************/
 277 void msg_force_tdis(int msg_type, pid_t pid, void *buf, size_t len)
 278 {
 279         connection_struct *conn, *next;
 280         fstring sharename;
 281
 282         fstrcpy(sharename, buf);
 283
 284         if (strcmp(sharename, "*") == 0) {
 285                 DEBUG(1,("Forcing close of all shares\n"));
 286                 conn_close_all();
 287                 return;
 288         }
 289
 290         for (conn=Connections;conn;conn=next) {
 291                 next=conn->next;
 292                 if (strequal(lp_servicename(conn->service), sharename)) {
 293                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 294                                  sharename, conn->cnum));
 295                         close_cnum(conn, (uint16)-1);
 296                 }
 297         }
 298 }