source3/smbd/smb1_service.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    service (connection) opening and closing
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "system/filesys.h"
  22 #include "system/passwd.h" /* uid_wrapper */
  23 #include "../lib/tsocket/tsocket.h"
  24 #include "smbd/smbd.h"
  25 #include "smbd/globals.h"
  26 #include "../librpc/gen_ndr/netlogon.h"
  27 #include "../libcli/security/security.h"
  28 #include "printing/pcap.h"
  29 #include "passdb/lookup_sid.h"
  30 #include "auth.h"
  31 #include "../auth/auth_util.h"
  32 #include "lib/param/loadparm.h"
  33 #include "messages.h"
  34 #include "lib/afs/afs_funcs.h"
  35 #include "lib/util_path.h"
  36 #include "lib/util/string_wrappers.h"
  37 #include "source3/lib/substitute.h"
  38
  39 /****************************************************************************
  40  Make a connection to a service from SMB1. Internal interface.
  41 ****************************************************************************/
  42
  43 static connection_struct *make_connection_smb1(struct smb_request *req,
  44                                         NTTIME now,
  45                                         int snum,
  46                                         const char *pdev,
  47                                         NTSTATUS *pstatus)
  48 {
  49         const struct loadparm_substitution *lp_sub =
  50                 loadparm_s3_global_substitution();
  51         uint32_t session_global_id;
  52         char *share_name = NULL;
  53         struct smbXsrv_tcon *tcon;
  54         NTSTATUS status;
  55         struct connection_struct *conn;
  56
  57         session_global_id = req->session->global->session_global_id;
  58         share_name = lp_servicename(talloc_tos(), lp_sub, snum);
  59         if (share_name == NULL) {
  60                 *pstatus = NT_STATUS_NO_MEMORY;
  61                 return NULL;
  62         }
  63
  64         if ((lp_max_connections(snum) > 0)
  65             && (count_current_connections(lp_const_servicename(snum), true) >=
  66                 lp_max_connections(snum))) {
  67
  68                 DBG_WARNING("Max connections (%d) exceeded for [%s][%s]\n",
  69                           lp_max_connections(snum),
  70                           lp_const_servicename(snum), share_name);
  71                 TALLOC_FREE(share_name);
  72                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
  73                 return NULL;
  74         }
  75
  76         status = smb1srv_tcon_create(req->xconn,
  77                                      session_global_id,
  78                                      share_name,
  79                                      now, &tcon);
  80         if (!NT_STATUS_IS_OK(status)) {
  81                 DEBUG(0,("make_connection_smb1: Couldn't find free tcon for [%s] - %s\n",
  82                          share_name, nt_errstr(status)));
  83                 TALLOC_FREE(share_name);
  84                 *pstatus = status;
  85                 return NULL;
  86         }
  87         TALLOC_FREE(share_name);
  88
  89         conn = conn_new(req->sconn);
  90         if (!conn) {
  91                 TALLOC_FREE(tcon);
  92
  93                 DEBUG(0,("make_connection_smb1: Couldn't find free connection.\n"));
  94                 *pstatus = NT_STATUS_INSUFFICIENT_RESOURCES;
  95                 return NULL;
  96         }
  97
  98         conn->cnum = tcon->global->tcon_wire_id;
  99         conn->tcon = tcon;
 100
 101         *pstatus = make_connection_snum(req->xconn,
 102                                         conn,
 103                                         snum,
 104                                         req->session,
 105                                         pdev);
 106         if (!NT_STATUS_IS_OK(*pstatus)) {
 107                 conn_free(conn);
 108                 TALLOC_FREE(tcon);
 109                 return NULL;
 110         }
 111
 112         tcon->compat = talloc_move(tcon, &conn);
 113         tcon->status = NT_STATUS_OK;
 114
 115         *pstatus = NT_STATUS_OK;
 116
 117         return tcon->compat;
 118 }
 119
 120 /****************************************************************************
 121  Make a connection to a service. External SMB1 interface.
 122  *
 123  * @param service
 124 ****************************************************************************/
 125
 126 connection_struct *make_connection(struct smb_request *req,
 127                                    NTTIME now,
 128                                    const char *service_in,
 129                                    const char *pdev, uint64_t vuid,
 130                                    NTSTATUS *status)
 131 {
 132         struct smbd_server_connection *sconn = req->sconn;
 133         struct smbXsrv_session *session = req->session;
 134         const struct loadparm_substitution *lp_sub =
 135                 loadparm_s3_global_substitution();
 136         uid_t euid;
 137         char *service = NULL;
 138         fstring dev;
 139         int snum = -1;
 140
 141         fstrcpy(dev, pdev);
 142
 143         /* This must ONLY BE CALLED AS ROOT. As it exits this function as
 144          * root. */
 145         if (!non_root_mode() && (euid = geteuid()) != 0) {
 146                 DEBUG(0,("make_connection: PANIC ERROR. Called as nonroot "
 147                          "(%u)\n", (unsigned int)euid ));
 148                 smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");
 149         }
 150
 151         if (conn_num_open(sconn) > 2047) {
 152                 *status = NT_STATUS_INSUFF_SERVER_RESOURCES;
 153                 return NULL;
 154         }
 155
 156         if (session == NULL) {
 157                 DEBUG(1,("make_connection: refusing to connect with "
 158                          "no session setup\n"));
 159                 *status = NT_STATUS_ACCESS_DENIED;
 160                 return NULL;
 161         }
 162
 163         /* Logic to try and connect to the correct [homes] share, preferably
 164            without too many getpwnam() lookups.  This is particularly nasty for
 165            winbind usernames, where the share name isn't the same as unix
 166            username.
 167         */
 168
 169         if (strequal(service_in,HOMES_NAME)) {
 170                 if (session->homes_snum == -1) {
 171                         DEBUG(2, ("[homes] share not available for "
 172                                   "this user because it was not found "
 173                                   "or created at session setup "
 174                                   "time\n"));
 175                         *status = NT_STATUS_BAD_NETWORK_NAME;
 176                         return NULL;
 177                 }
 178                 DEBUG(5, ("making a connection to [homes] service "
 179                           "created at session setup time\n"));
 180                 return make_connection_smb1(req, now,
 181                                             session->homes_snum,
 182                                             dev, status);
 183         } else if ((session->homes_snum != -1)
 184                    && strequal(service_in,
 185                                lp_const_servicename(session->homes_snum))) {
 186                 DEBUG(5, ("making a connection to 'homes' service [%s] "
 187                           "created at session setup time\n", service_in));
 188                 return make_connection_smb1(req, now,
 189                                             session->homes_snum,
 190                                             dev, status);
 191         }
 192
 193         service = talloc_strdup(talloc_tos(), service_in);
 194         if (!service) {
 195                 *status = NT_STATUS_NO_MEMORY;
 196                 return NULL;
 197         }
 198
 199         if (!strlower_m(service)) {
 200                 DEBUG(2, ("strlower_m %s failed\n", service));
 201                 *status = NT_STATUS_INVALID_PARAMETER;
 202                 return NULL;
 203         }
 204
 205         snum = find_service(talloc_tos(), service, &service);
 206         if (!service) {
 207                 *status = NT_STATUS_NO_MEMORY;
 208                 return NULL;
 209         }
 210
 211         if (snum < 0) {
 212                 if (strequal(service,"IPC$") ||
 213                     (lp_enable_asu_support() && strequal(service,"ADMIN$"))) {
 214                         DEBUG(3,("refusing IPC connection to %s\n", service));
 215                         *status = NT_STATUS_ACCESS_DENIED;
 216                         return NULL;
 217                 }
 218
 219                 DEBUG(3,("%s (%s) couldn't find service %s\n",
 220                         get_remote_machine_name(),
 221                         tsocket_address_string(
 222                                 sconn->remote_address, talloc_tos()),
 223                         service));
 224                 *status = NT_STATUS_BAD_NETWORK_NAME;
 225                 return NULL;
 226         }
 227
 228         /* Handle non-Dfs clients attempting connections to msdfs proxy */
 229         if (lp_host_msdfs() && (*lp_msdfs_proxy(talloc_tos(), lp_sub, snum) != '\0'))  {
 230                 DEBUG(3, ("refusing connection to dfs proxy share '%s' "
 231                           "(pointing to %s)\n",
 232                         service, lp_msdfs_proxy(talloc_tos(), lp_sub, snum)));
 233                 *status = NT_STATUS_BAD_NETWORK_NAME;
 234                 return NULL;
 235         }
 236
 237         DEBUG(5, ("making a connection to 'normal' service %s\n", service));
 238
 239         return make_connection_smb1(req, now, snum,
 240                                     dev, status);
 241 }