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 /* set these to define the limits of the server. NOTE These are on a
  25    per-client basis. Thus any one machine can't connect to more than
  26    MAX_CONNECTIONS services, but any number of machines may connect at
  27    one time. */
  28 #define MAX_CONNECTIONS 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(MAX_CONNECTIONS);
  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
 100         i = bitmap_find(bmap, 1);
 101
 102         if (i == -1) {
 103                 DEBUG(1,("ERROR! Out of connection structures\n"));
 104                 return NULL;
 105         }
 106
 107         if ((mem_ctx=talloc_init("connection_struct"))==NULL) {
 108                 DEBUG(0,("talloc_init(connection_struct) failed!\n"));
 109                 return NULL;
 110         }
 111
 112         if ((conn=(connection_struct *)talloc_zero(mem_ctx, sizeof(*conn)))==NULL) {
 113                 DEBUG(0,("talloc_zero() failed!\n"));
 114                 return NULL;
 115         }
 116         conn->mem_ctx = mem_ctx;
 117         conn->cnum = i;
 118
 119         bitmap_set(bmap, i);
 120
 121         num_open++;
 122
 123         string_set(&conn->user,"");
 124         string_set(&conn->dirpath,"");
 125         string_set(&conn->connectpath,"");
 126         string_set(&conn->origpath,"");
 127
 128         DLIST_ADD(Connections, conn);
 129
 130         return conn;
 131 }
 132
 133 /****************************************************************************
 134 close all conn structures
 135 ****************************************************************************/
 136 void conn_close_all(void)
 137 {
 138         connection_struct *conn, *next;
 139         for (conn=Connections;conn;conn=next) {
 140                 next=conn->next;
 141                 close_cnum(conn, conn->vuid);
 142         }
 143 }
 144
 145 /****************************************************************************
 146  Idle inactive connections.
 147 ****************************************************************************/
 148
 149 BOOL conn_idle_all(time_t t, int deadtime)
 150 {
 151         pipes_struct *plist = NULL;
 152         BOOL allidle = True;
 153         connection_struct *conn, *next;
 154
 155         for (conn=Connections;conn;conn=next) {
 156                 next=conn->next;
 157                 /* close dirptrs on connections that are idle */
 158                 if ((t-conn->lastused) > DPTR_IDLE_TIMEOUT)
 159                         dptr_idlecnum(conn);
 160
 161                 if (conn->num_files_open > 0 ||
 162                     (t-conn->lastused)<deadtime)
 163                         allidle = False;
 164         }
 165
 166         /*
 167          * Check all pipes for any open handles. We cannot
 168          * idle with a handle open.
 169          */
 170
 171         for (plist = get_first_internal_pipe(); plist; plist = get_next_internal_pipe(plist))
 172                 if (plist->pipe_handles && plist->pipe_handles->count)
 173                         allidle = False;
 174
 175         return allidle;
 176 }
 177
 178 /****************************************************************************
 179 clear a vuid out of the validity cache, and as the 'owner' of a connection.
 180 ****************************************************************************/
 181 void conn_clear_vuid_cache(uint16 vuid)
 182 {
 183         connection_struct *conn;
 184         unsigned int i;
 185
 186         for (conn=Connections;conn;conn=conn->next) {
 187                 if (conn->vuid == vuid) {
 188                         conn->vuid = UID_FIELD_INVALID;
 189                 }
 190
 191                 for (i=0;i<conn->vuid_cache.entries && i< VUID_CACHE_SIZE;i++) {
 192                         if (conn->vuid_cache.list[i] == vuid) {
 193                                 conn->vuid_cache.list[i] = UID_FIELD_INVALID;
 194                         }
 195                 }
 196         }
 197 }
 198
 199 /****************************************************************************
 200  Free a conn structure.
 201 ****************************************************************************/
 202
 203 void conn_free(connection_struct *conn)
 204 {
 205         vfs_handle_struct *handle = NULL, *thandle = NULL;
 206         TALLOC_CTX *mem_ctx = NULL;
 207
 208         /* Free vfs_connection_struct */
 209         handle = conn->vfs_handles;
 210         while(handle) {
 211                 DLIST_REMOVE(conn->vfs_handles, handle);
 212                 thandle = handle->next;
 213                 if (handle->free_data)
 214                         handle->free_data(&handle->data);
 215                 handle = thandle;
 216         }
 217
 218         DLIST_REMOVE(Connections, conn);
 219
 220         if (conn->ngroups && conn->groups) {
 221                 SAFE_FREE(conn->groups);
 222                 conn->ngroups = 0;
 223         }
 224
 225         free_namearray(conn->veto_list);
 226         free_namearray(conn->hide_list);
 227         free_namearray(conn->veto_oplock_list);
 228
 229         string_free(&conn->user);
 230         string_free(&conn->dirpath);
 231         string_free(&conn->connectpath);
 232         string_free(&conn->origpath);
 233
 234         bitmap_clear(bmap, conn->cnum);
 235         num_open--;
 236
 237         mem_ctx = conn->mem_ctx;
 238         ZERO_STRUCTP(conn);
 239         talloc_destroy(mem_ctx);
 240 }
 241
 242
 243 /****************************************************************************
 244 receive a smbcontrol message to forcibly unmount a share
 245 the message contains just a share name and all instances of that
 246 share are unmounted
 247 the special sharename '*' forces unmount of all shares
 248 ****************************************************************************/
 249 void msg_force_tdis(int msg_type, pid_t pid, void *buf, size_t len)
 250 {
 251         connection_struct *conn, *next;
 252         fstring sharename;
 253
 254         fstrcpy(sharename, buf);
 255
 256         if (strcmp(sharename, "*") == 0) {
 257                 DEBUG(1,("Forcing close of all shares\n"));
 258                 conn_close_all();
 259                 return;
 260         }
 261
 262         for (conn=Connections;conn;conn=next) {
 263                 next=conn->next;
 264                 if (strequal(lp_servicename(conn->service), sharename)) {
 265                         DEBUG(1,("Forcing close of share %s cnum=%d\n",
 266                                  sharename, conn->cnum));
 267                         close_cnum(conn, (uint16)-1);
 268                 }
 269         }
 270 }