path: root/source3/smbd/service.c

/* 
   Unix SMB/CIFS implementation.
   service (connection) opening and closing
   Copyright (C) Andrew Tridgell 1992-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

extern struct timeval smb_last_time;
extern int case_default;
extern BOOL case_preserve;
extern BOOL short_case_preserve;
extern BOOL case_mangle;
extern BOOL case_sensitive;
extern BOOL use_mangled_map;
extern userdom_struct current_user_info;


/****************************************************************************
 Load parameters specific to a connection/service.
****************************************************************************/

BOOL set_current_service(connection_struct *conn,BOOL do_chdir)
{
	extern char magic_char;
	static connection_struct *last_conn;
	int snum;

	if (!conn)  {
		last_conn = NULL;
		return(False);
	}

	conn->lastused = smb_last_time.tv_sec;

	snum = SNUM(conn);
  
	if (do_chdir &&
	    vfs_ChDir(conn,conn->connectpath) != 0 &&
	    vfs_ChDir(conn,conn->origpath) != 0) {
		DEBUG(0,("chdir (%s) failed\n",
			 conn->connectpath));
		return(False);
	}

	if (conn == last_conn)
		return(True);

	last_conn = conn;

	case_default = lp_defaultcase(snum);
	case_preserve = lp_preservecase(snum);
	short_case_preserve = lp_shortpreservecase(snum);
	case_mangle = lp_casemangle(snum);
	case_sensitive = lp_casesensitive(snum);
	magic_char = lp_magicchar(snum);
	use_mangled_map = (*lp_mangled_map(snum) ? True:False);
	return(True);
}

/****************************************************************************
 Add a home service. Returns the new service number or -1 if fail.
****************************************************************************/

int add_home_service(const char *service, const char *username, const char *homedir)
{
	int iHomeService;

	if (!service || !homedir)
		return -1;

	if ((iHomeService = lp_servicenumber(HOMES_NAME)) < 0)
		return -1;

	/*
	 * If this is a winbindd provided username, remove
	 * the domain component before adding the service.
	 * Log a warning if the "path=" parameter does not
	 * include any macros.
	 */

	{
		const char *p = strchr(service,*lp_winbind_separator());

		/* We only want the 'user' part of the string */
		if (p) {
			service = p + 1;
		}
	}

	if (!lp_add_home(service, iHomeService, username, homedir)) {
		return -1;
	}
	
	return lp_servicenumber(service);

}


/**
 * Find a service entry. service is always in dos codepage.
 *
 * @param service is modified (to canonical form??)
 **/
int find_service(fstring service)
{
   int iService;

   all_string_sub(service,"\\","/",0);

   iService = lp_servicenumber(service);

   /* now handle the special case of a home directory */
   if (iService < 0)
   {
      char *phome_dir = get_user_home_dir(service);

      if(!phome_dir)
      {
        /*
         * Try mapping the servicename, it may
         * be a Windows to unix mapped user name.
         */
        if(map_username(service))
          phome_dir = get_user_home_dir(service);
      }

      DEBUG(3,("checking for home directory %s gave %s\n",service,
            phome_dir?phome_dir:"(NULL)"));

      iService = add_home_service(service,service /* 'username' */, phome_dir);
   }

   /* If we still don't have a service, attempt to add it as a printer. */
   if (iService < 0)
   {
      int iPrinterService;

      if ((iPrinterService = lp_servicenumber(PRINTERS_NAME)) >= 0)
      {
         char *pszTemp;

         DEBUG(3,("checking whether %s is a valid printer name...\n", service));
         pszTemp = lp_printcapname();
         if ((pszTemp != NULL) && pcap_printername_ok(service, pszTemp))
         {
            DEBUG(3,("%s is a valid printer name\n", service));
            DEBUG(3,("adding %s as a printer service\n", service));
            lp_add_printer(service, iPrinterService);
            iService = lp_servicenumber(service);
            if (iService < 0)
               DEBUG(0,("failed to add %s as a printer service!\n", service));
         }
         else
            DEBUG(3,("%s is not a valid printer name\n", service));
      }
   }

   /* Check for default vfs service?  Unsure whether to implement this */
   if (iService < 0)
   {
   }

   /* just possibly it's a default service? */
   if (iService < 0) 
   {
     char *pdefservice = lp_defaultservice();
     if (pdefservice && *pdefservice && 
	 !strequal(pdefservice,service) &&
	 !strstr(service,".."))
     {
       /*
        * We need to do a local copy here as lp_defaultservice() 
        * returns one of the rotating lp_string buffers that
        * could get overwritten by the recursive find_service() call
        * below. Fix from Josef Hinteregger <joehtg@joehtg.co.at>.
        */
       pstring defservice;
       pstrcpy(defservice, pdefservice);
       iService = find_service(defservice);
       if (iService >= 0)
       {
         all_string_sub(service, "_","/",0);
         iService = lp_add_service(service, iService);
       }
     }
   }

   if (iService >= 0)
     if (!VALID_SNUM(iService))
     {
       DEBUG(0,("Invalid snum %d for %s\n",iService, service));
       iService = -1;
     }

   if (iService < 0)
     DEBUG(3,("find_service() failed to find service %s\n", service));

   return (iService);
}


/****************************************************************************
 do some basic sainity checks on the share.  
 This function modifies dev, ecode.
****************************************************************************/
static NTSTATUS share_sanity_checks(int snum, fstring dev) 
{
	
	if (!lp_snum_ok(snum) || 
	    !check_access(smbd_server_fd(), 
			  lp_hostsallow(snum), lp_hostsdeny(snum))) {    
		return NT_STATUS_ACCESS_DENIED;
	}

	if (dev[0] == '?' || !dev[0]) {
		if (lp_print_ok(snum)) {
			fstrcpy(dev,"LPT1:");
		} else if (strequal(lp_fstype(snum), "IPC")) {
			fstrcpy(dev, "IPC");
		} else {
			fstrcpy(dev,"A:");
		}
	}

	strupper_m(dev);

	if (lp_print_ok(snum)) {
		if (!strequal(dev, "LPT1:")) {
			return NT_STATUS_BAD_DEVICE_TYPE;
		}
	} else if (strequal(lp_fstype(snum), "IPC")) {
		if (!strequal(dev, "IPC")) {
			return NT_STATUS_BAD_DEVICE_TYPE;
		}
	} else if (!strequal(dev, "A:")) {
		return NT_STATUS_BAD_DEVICE_TYPE;
	}

	/* Behave as a printer if we are supposed to */
	if (lp_print_ok(snum) && (strcmp(dev, "A:") == 0)) {
		fstrcpy(dev, "LPT1:");
	}

	return NT_STATUS_OK;
}

/****************************************************************************
 readonly share?
****************************************************************************/

static void set_read_only(connection_struct *conn, gid_t *groups, size_t n_groups)
{
	char **list;
	const char *service = lp_servicename(conn->service);
	conn->read_only = lp_readonly(conn->service);

	if (!service)
		return;

	str_list_copy(&list, lp_readlist(conn->service));
	if (list) {
		if (!str_list_sub_basic(list, current_user_info.smb_name) ) {
			DEBUG(0, ("ERROR: read list substitution failed\n"));
		}
		if (!str_list_substitute(list, "%S", service)) {
			DEBUG(0, ("ERROR: read list service substitution failed\n"));
		}
		if (user_in_list(conn->user, (const char **)list, groups, n_groups))
			conn->read_only = True;
		str_list_free(&list);
	}
	
	str_list_copy(&list, lp_writelist(conn->service));
	if (list) {
		if (!str_list_sub_basic(list, current_user_info.smb_name) ) {
			DEBUG(0, ("ERROR: write list substitution failed\n"));
		}
		if (!str_list_substitute(list, "%S", service)) {
			DEBUG(0, ("ERROR: write list service substitution failed\n"));
		}
		if (user_in_list(conn->user, (const char **)list, groups, n_groups))
			conn->read_only = False;
		str_list_free(&list);
	}
}

/****************************************************************************
  admin user check
****************************************************************************/

static void set_admin_user(connection_struct *conn, gid_t *groups, size_t n_groups)
{
	/* admin user check */
	
	/* JRA - original code denied admin user if the share was
	   marked read_only. Changed as I don't think this is needed,
	   but old code left in case there is a problem here.
	*/
	if (user_in_list(conn->user,lp_admin_users(conn->service), groups, n_groups) 
#if 0
	    && !conn->read_only
#endif
	    ) {
		conn->admin_user = True;
		conn->force_user = True;  /* Admin users are effectivly 'forced' */
		DEBUG(0,("%s logged in as admin user (root privileges)\n",conn->user));
	} else {
		conn->admin_user = False;
	}

#if 0 /* This done later, for now */    
	/* admin users always run as uid=0 */
	if (conn->admin_user) {
		conn->uid = 0;
	}
#endif
}

/****************************************************************************
  Make a connection, given the snum to connect to, and the vuser of the
  connecting user if appropriate.
****************************************************************************/

static connection_struct *make_connection_snum(int snum, user_struct *vuser,
					       DATA_BLOB password, 
					       const char *pdev, NTSTATUS *status)
{
	struct passwd *pass = NULL;
	BOOL guest = False;
	connection_struct *conn;
	struct stat st;
	fstring user;
	fstring dev;

	*user = 0;
	fstrcpy(dev, pdev);

	if (NT_STATUS_IS_ERR(*status = share_sanity_checks(snum, dev))) {
		return NULL;
	}	

	conn = conn_new();
	if (!conn) {
		DEBUG(0,("Couldn't find free connection.\n"));
		*status = NT_STATUS_INSUFFICIENT_RESOURCES;
		return NULL;
	}

	if (lp_guest_only(snum)) {
		const char *guestname = lp_guestaccount();
		guest = True;
		pass = getpwnam_alloc(guestname);
		if (!pass) {
			DEBUG(0,("make_connection_snum: Invalid guest account %s??\n",guestname));
			conn_free(conn);
			*status = NT_STATUS_NO_SUCH_USER;
			return NULL;
		}
		fstrcpy(user,pass->pw_name);
		conn->force_user = True;
		conn->uid = pass->pw_uid;
		conn->gid = pass->pw_gid;
		string_set(&conn->user,pass->pw_name);
		passwd_free(&pass);
		DEBUG(3,("Guest only user %s\n",user));
	} else if (vuser) {
		if (vuser->guest) {
			if (!lp_guest_ok(snum)) {
				DEBUG(2, ("guest user (from session setup) not permitted to access this share (%s)\n", lp_servicename(snum)));
				      conn_free(conn);
				      *status = NT_STATUS_ACCESS_DENIED;
				      return NULL;
			}
		} else {
			if (!user_ok(vuser->user.unix_name, snum, vuser->groups, vuser->n_groups)) {
				DEBUG(2, ("user '%s' (from session setup) not permitted to access this share (%s)\n", vuser->user.unix_name, lp_servicename(snum)));
				conn_free(conn);
				*status = NT_STATUS_ACCESS_DENIED;
				return NULL;
			}
		}
		conn->vuid = vuser->vuid;
		conn->uid = vuser->uid;
		conn->gid = vuser->gid;
		string_set(&conn->user,vuser->user.unix_name);
		fstrcpy(user,vuser->user.unix_name);
		guest = vuser->guest; 
	} else if (lp_security() == SEC_SHARE) {
		/* add it as a possible user name if we 
		   are in share mode security */
		add_session_user(lp_servicename(snum));
		/* shall we let them in? */
		if (!authorise_login(snum,user,password,&guest)) {
			DEBUG( 2, ( "Invalid username/password for [%s]\n", 
				    lp_servicename(snum)) );
			conn_free(conn);
			*status = NT_STATUS_WRONG_PASSWORD;
			return NULL;
		}
		pass = Get_Pwnam(user);
		conn->force_user = True;
		conn->uid = pass->pw_uid;
		conn->gid = pass->pw_gid;
		string_set(&conn->user, pass->pw_name);
		fstrcpy(user, pass->pw_name);

	} else {
		DEBUG(0, ("invalid VUID (vuser) but not in security=share\n"));
		conn_free(conn);
		*status = NT_STATUS_ACCESS_DENIED;
		return NULL;
	}

	add_session_user(user);

	safe_strcpy(conn->client_address, client_addr(), 
		    sizeof(conn->client_address)-1);
	conn->num_files_open = 0;
	conn->lastused = time(NULL);
	conn->service = snum;
	conn->used = True;
	conn->printer = (strncmp(dev,"LPT",3) == 0);
	conn->ipc = ((strncmp(dev,"IPC",3) == 0) || strequal(dev,"ADMIN$"));
	conn->dirptr = NULL;
	conn->veto_list = NULL;
	conn->hide_list = NULL;
	conn->veto_oplock_list = NULL;
	string_set(&conn->dirpath,"");
	string_set(&conn->user,user);
	conn->nt_user_token = NULL;
	
	set_read_only(conn, vuser ? vuser->groups : NULL, vuser ? vuser->n_groups : 0);
	
	set_admin_user(conn, vuser ? vuser->groups : NULL, vuser ? vuser->n_groups : 0);

	/*
	 * If force user is true, then store the
	 * given userid and also the groups
	 * of the user we're forcing.
	 */
	
	if (*lp_force_user(snum)) {
		struct passwd *pass2;
		pstring fuser;
		pstrcpy(fuser,lp_force_user(snum));

		/* Allow %S to be used by force user. */
		pstring_sub(fuser,"%S",lp_servicename(snum));

		pass2 = (struct passwd *)Get_Pwnam(fuser);
		if (pass2) {
			conn->uid = pass2->pw_uid;
			conn->gid = pass2->pw_gid;
			string_set(&conn->user,pass2->pw_name);
			fstrcpy(user,pass2->pw_name);
			conn->force_user = True;
			DEBUG(3,("Forced user %s\n",user));	  
		} else {
			DEBUG(1,("Couldn't find user %s\n",fuser));
			conn_free(conn);
			*status = NT_STATUS_NO_SUCH_USER;
			return NULL;
		}
	}

	/* admin users always run as uid=0 */
	if (conn->admin_user) {
		conn->uid = 0;
	}

#ifdef HAVE_GETGRNAM 
	/*
	 * If force group is true, then override
	 * any groupid stored for the connecting user.
	 */
	
	if (*lp_force_group(snum)) {
		gid_t gid;
		pstring gname;
		pstring tmp_gname;
		BOOL user_must_be_member = False;
		
		pstrcpy(tmp_gname,lp_force_group(snum));
		
		if (tmp_gname[0] == '+') {
			user_must_be_member = True;
			/* even now, tmp_gname is null terminated */
			pstrcpy(gname,&tmp_gname[1]);
		} else {
			pstrcpy(gname,tmp_gname);
		}
		/* default service may be a group name 		*/
		pstring_sub(gname,"%S",lp_servicename(snum));
		gid = nametogid(gname);
		
		if (gid != (gid_t)-1) {

			/*
			 * If the user has been forced and the forced group starts
			 * with a '+', then we only set the group to be the forced
			 * group if the forced user is a member of that group.
			 * Otherwise, the meaning of the '+' would be ignored.
			 */
			if (conn->force_user && user_must_be_member) {
				if (user_in_group_list( user, gname, NULL, 0)) {
						conn->gid = gid;
						DEBUG(3,("Forced group %s for member %s\n",gname,user));
				}
			} else {
				conn->gid = gid;
				DEBUG(3,("Forced group %s\n",gname));
			}
			conn->force_group = True;
		} else {
			DEBUG(1,("Couldn't find group %s\n",gname));
			conn_free(conn);
			*status = NT_STATUS_NO_SUCH_GROUP;
			return NULL;
		}
	}
#endif /* HAVE_GETGRNAM */

	{
		pstring s;
		pstrcpy(s,lp_pathname(snum));
		standard_sub_conn(conn,s,sizeof(s));
		string_set(&conn->connectpath,s);
		DEBUG(3,("Connect path is '%s' for service [%s]\n",s, lp_servicename(snum)));
	}

	if (conn->force_user || conn->force_group) {

		/* groups stuff added by ih */
		conn->ngroups = 0;
		conn->groups = NULL;
		
		/* Find all the groups this uid is in and
		   store them. Used by change_to_user() */
		initialise_groups(conn->user, conn->uid, conn->gid); 
		get_current_groups(conn->gid, &conn->ngroups,&conn->groups);
		
		conn->nt_user_token = create_nt_token(conn->uid, conn->gid, 
						      conn->ngroups, conn->groups,
						      guest);
	}

	/*
	 * New code to check if there's a share security descripter
	 * added from NT server manager. This is done after the
	 * smb.conf checks are done as we need a uid and token. JRA.
	 *
	 */

	{
		BOOL can_write = share_access_check(conn, snum, vuser, FILE_WRITE_DATA);

		if (!can_write) {
			if (!share_access_check(conn, snum, vuser, FILE_READ_DATA)) {
				/* No access, read or write. */
				DEBUG(0,( "make_connection: connection to %s denied due to security descriptor.\n",
					  lp_servicename(snum)));
				conn_free(conn);
				*status = NT_STATUS_ACCESS_DENIED;
				return NULL;
			} else {
				conn->read_only = True;
			}
		}
	}
	/* Initialise VFS function pointers */

	if (!smbd_vfs_init(conn)) {
		DEBUG(0, ("vfs_init failed for service %s\n", lp_servicename(SNUM(conn))));
		conn_free(conn);
		*status = NT_STATUS_BAD_NETWORK_NAME;
		return NULL;
	}

/* ROOT Activities: */	
	/* check number of connections */
	if (!claim_connection(conn,
			      lp_servicename(SNUM(conn)),
			      lp_max_connections(SNUM(conn)),
			      False,0)) {
		DEBUG(1,("too many connections - rejected\n"));
		conn_free(conn);
		*status = NT_STATUS_INSUFFICIENT_RESOURCES;
		return NULL;
	}  

	/* Preexecs are done here as they might make the dir we are to ChDir to below */
	/* execute any "root preexec = " line */
	if (*lp_rootpreexec(SNUM(conn))) {
		int ret;
		pstring cmd;
		pstrcpy(cmd,lp_rootpreexec(SNUM(conn)));
		standard_sub_conn(conn,cmd,sizeof(cmd));
		DEBUG(5,("cmd=%s\n",cmd));
		ret = smbrun(cmd,NULL);
		if (ret != 0 && lp_rootpreexec_close(SNUM(conn))) {
			DEBUG(1,("root preexec gave %d - failing connection\n", ret));
			yield_connection(conn, lp_servicename(SNUM(conn)));
			conn_free(conn);
			*status = NT_STATUS_ACCESS_DENIED;
			return NULL;
		}
	}

/* USER Activites: */
	if (!change_to_user(conn, conn->vuid)) {
		/* No point continuing if they fail the basic checks */
		DEBUG(0,("Can't become connected user!\n"));
		conn_free(conn);
		*status = NT_STATUS_LOGON_FAILURE;
		return NULL;
	}

	/* Remember that a different vuid can connect later without these checks... */
	
	/* Preexecs are done here as they might make the dir we are to ChDir to below */
	/* execute any "preexec = " line */
	if (*lp_preexec(SNUM(conn))) {
		int ret;
		pstring cmd;
		pstrcpy(cmd,lp_preexec(SNUM(conn)));
		standard_sub_conn(conn,cmd,sizeof(cmd));
		ret = smbrun(cmd,NULL);
		if (ret != 0 && lp_preexec_close(SNUM(conn))) {
			DEBUG(1,("preexec gave %d - failing connection\n", ret));
			change_to_root_user();
			yield_connection(conn, lp_servicename(SNUM(conn)));
			conn_free(conn);
			*status = NT_STATUS_ACCESS_DENIED;
			return NULL;
		}
	}

#ifdef WITH_FAKE_KASERVER
	if (lp_afs_share(SNUM(conn))) {
		afs_login(conn);
	}
#endif
	
#if CHECK_PATH_ON_TCONX
	/* win2000 does not check the permissions on the directory
	   during the tree connect, instead relying on permission
	   check during individual operations. To match this behaviour
	   I have disabled this chdir check (tridge) */
	if (vfs_ChDir(conn,conn->connectpath) != 0) {
		DEBUG(0,("%s (%s) Can't change directory to %s (%s)\n",
			 get_remote_machine_name(), conn->client_address,
			 conn->connectpath,strerror(errno)));
		change_to_root_user();
		yield_connection(conn, lp_servicename(SNUM(conn)));
		conn_free(conn);
		*status = NT_STATUS_BAD_NETWORK_NAME;
		return NULL;
	}
#else
	/* the alternative is just to check the directory exists */
	if (stat(conn->connectpath, &st) != 0 || !S_ISDIR(st.st_mode)) {
		DEBUG(0,("'%s' does not exist or is not a directory, when connecting to [%s]\n", conn->connectpath, lp_servicename(SNUM(conn))));
		change_to_root_user();
		yield_connection(conn, lp_servicename(SNUM(conn)));
		conn_free(conn);
		*status = NT_STATUS_BAD_NETWORK_NAME;
		return NULL;
	}
#endif
	
	string_set(&conn->origpath,conn->connectpath);
	
#if SOFTLINK_OPTIMISATION
	/* resolve any soft links early if possible */
	if (vfs_ChDir(conn,conn->connectpath) == 0) {
		pstring s;
		pstrcpy(s,conn->connectpath);
		vfs_GetWd(conn,s);
		string_set(&conn->connectpath,s);
		vfs_ChDir(conn,conn->connectpath);
	}
#endif
	
	/*
	 * Print out the 'connected as' stuff here as we need
	 * to know the effective uid and gid we will be using
	 * (at least initially).
	 */

	if( DEBUGLVL( IS_IPC(conn) ? 3 : 1 ) ) {
		dbgtext( "%s (%s) ", get_remote_machine_name(), conn->client_address );
		dbgtext( "%s", srv_is_signing_active() ? "signed " : "");
		dbgtext( "connect to service %s ", lp_servicename(SNUM(conn)) );
		dbgtext( "initially as user %s ", user );
		dbgtext( "(uid=%d, gid=%d) ", (int)geteuid(), (int)getegid() );
		dbgtext( "(pid %d)\n", (int)sys_getpid() );
	}
	
	/* Add veto/hide lists */
	if (!IS_IPC(conn) && !IS_PRINT(conn)) {
		set_namearray( &conn->veto_list, lp_veto_files(SNUM(conn)));
		set_namearray( &conn->hide_list, lp_hide_files(SNUM(conn)));
		set_namearray( &conn->veto_oplock_list, lp_veto_oplocks(SNUM(conn)));
	}
	
	/* Invoke VFS make connection hook */

	if (SMB_VFS_CONNECT(conn, lp_servicename(snum), user) < 0) {
		DEBUG(0,("make_connection: VFS make connection failed!\n"));
		change_to_root_user();
		conn_free(conn);
		*status = NT_STATUS_UNSUCCESSFUL;
		return NULL;
	}

	/* we've finished with the user stuff - go back to root */
	change_to_root_user();
            
	return(conn);
}

/***************************************************************************************
 Simple wrapper function for make_connection() to include a call to 
 vfs_chdir()
 **************************************************************************************/
 
connection_struct *make_connection_with_chdir(const char *service_in, DATA_BLOB password, 
				   const char *dev, uint16 vuid, NTSTATUS *status)
{
	connection_struct *conn = NULL;
	
	conn = make_connection(service_in, password, dev, vuid, status);
	
	/*
	 * make_connection() does not change the directory for us any more
	 * so we have to do it as a separate step  --jerry
	 */
	 
	if ( conn && vfs_ChDir(conn,conn->connectpath) != 0 ) {
		DEBUG(0,("move_driver_to_download_area: Can't change directory to %s for [print$] (%s)\n",
			 conn->connectpath,strerror(errno)));
		yield_connection(conn, lp_servicename(SNUM(conn)));
		conn_free(conn);
		*status = NT_STATUS_UNSUCCESSFUL;
		return NULL;
	}
	
	return conn;
}

/****************************************************************************
 Make a connection to a service.
 *
 * @param service 
****************************************************************************/

connection_struct *make_connection(const char *service_in, DATA_BLOB password, 
				   const char *pdev, uint16 vuid, NTSTATUS *status)
{
	uid_t euid;
	user_struct *vuser = NULL;
	fstring service;
	fstring dev;
	int snum = -1;

	fstrcpy(dev, pdev);

	/* This must ONLY BE CALLED AS ROOT. As it exits this function as root. */
	if (!non_root_mode() && (euid = geteuid()) != 0) {
		DEBUG(0,("make_connection: PANIC ERROR. Called as nonroot (%u)\n", (unsigned int)euid ));
		smb_panic("make_connection: PANIC ERROR. Called as nonroot\n");
	}

	if(lp_security() != SEC_SHARE) {
		vuser = get_valid_user_struct(vuid);
		if (!vuser) {
			DEBUG(1,("make_connection: refusing to connect with no session setup\n"));
			*status = NT_STATUS_ACCESS_DENIED;
			return NULL;
		}
	}

	/* Logic to try and connect to the correct [homes] share, preferably without too many
	   getpwnam() lookups.  This is particulary nasty for winbind usernames, where the
	   share name isn't the same as unix username.

	   The snum of the homes share is stored on the vuser at session setup time.
	*/

	if (strequal(service_in,HOMES_NAME)) {
		if(lp_security() != SEC_SHARE) {
			DATA_BLOB no_pw = data_blob(NULL, 0);
			if (vuser->homes_snum == -1) {
				DEBUG(2, ("[homes] share not available for this user because it was not found or created at session setup time\n"));
				*status = NT_STATUS_BAD_NETWORK_NAME;
				return NULL;
			}
			DEBUG(5, ("making a connection to [homes] service created at session setup time\n"));
			return make_connection_snum(vuser->homes_snum,
						    vuser, no_pw, 
						    dev, status);
		} else {
			/* Security = share. Try with current_user_info.smb_name
			 * as the username.  */
			if (*current_user_info.smb_name) {
				fstring unix_username;
				fstrcpy(unix_username,
					current_user_info.smb_name);
				map_username(unix_username);
				snum = find_service(unix_username);
			} 
			if (snum != -1) {
				DEBUG(5, ("making a connection to 'homes' service %s based on security=share\n", service_in));
				return make_connection_snum(snum, NULL,
							    password,
							    dev, status);
			}
		}
	} else if ((lp_security() != SEC_SHARE) && (vuser->homes_snum != -1)
		   && strequal(service_in, lp_servicename(vuser->homes_snum))) {
		DATA_BLOB no_pw = data_blob(NULL, 0);
		DEBUG(5, ("making a connection to 'homes' service [%s] created at session setup time\n", service_in));
		return make_connection_snum(vuser->homes_snum,
					    vuser, no_pw, 
					    dev, status);
	}
	
	fstrcpy(service, service_in);

	strlower_m(service);

	snum = find_service(service);

	if (snum < 0) {
		if (strequal(service,"IPC$") || strequal(service,"ADMIN$")) {
			DEBUG(3,("refusing IPC connection to %s\n", service));
			*status = NT_STATUS_ACCESS_DENIED;
			return NULL;
		}

		DEBUG(0,("%s (%s) couldn't find service %s\n",
			 get_remote_machine_name(), client_addr(), service));
		*status = NT_STATUS_BAD_NETWORK_NAME;
		return NULL;
	}

	/* Handle non-Dfs clients attempting connections to msdfs proxy */
	if (lp_host_msdfs() && (*lp_msdfs_proxy(snum) != '\0'))  {
		DEBUG(3, ("refusing connection to dfs proxy '%s'\n", service));
		*status = NT_STATUS_BAD_NETWORK_NAME;
		return NULL;
	}

	DEBUG(5, ("making a connection to 'normal' service %s\n", service));

	return make_connection_snum(snum, vuser,
				    password,
				    dev, status);
}

/****************************************************************************
close a cnum
****************************************************************************/
void close_cnum(connection_struct *conn, uint16 vuid)
{
	DirCacheFlush(SNUM(conn));

	change_to_root_user();

	DEBUG(IS_IPC(conn)?3:1, ("%s (%s) closed connection to service %s\n",
				 get_remote_machine_name(),conn->client_address,
				 lp_servicename(SNUM(conn))));

	/* Call VFS disconnect hook */    
	SMB_VFS_DISCONNECT(conn);

	yield_connection(conn, lp_servicename(SNUM(conn)));

	file_close_conn(conn);
	dptr_closecnum(conn);

	/* make sure we leave the directory available for unmount */
	vfs_ChDir(conn, "/");

	/* execute any "postexec = " line */
	if (*lp_postexec(SNUM(conn)) && 
	    change_to_user(conn, vuid))  {
		pstring cmd;
		pstrcpy(cmd,lp_postexec(SNUM(conn)));
		standard_sub_conn(conn,cmd,sizeof(cmd));
		smbrun(cmd,NULL);
		change_to_root_user();
	}

	change_to_root_user();
	/* execute any "root postexec = " line */
	if (*lp_rootpostexec(SNUM(conn)))  {
		pstring cmd;
		pstrcpy(cmd,lp_rootpostexec(SNUM(conn)));
		standard_sub_conn(conn,cmd,sizeof(cmd));
		smbrun(cmd,NULL);
	}

	conn_free(conn);
}