1  /* Copyright (C) 1993-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <sys/types.h>
      20  #include <grp.h>
      21  #include <hurd.h>
      22  #include <hurd/id.h>
      23  
      24  /* Set the group set for the current user to GROUPS (N of them).  */
      25  int
      26  setgroups (size_t n, const gid_t *groups)
      27  {
      28    error_t err;
      29    auth_t newauth;
      30    size_t i;
      31    gid_t new[n];
      32  
      33    /* Fault before taking locks.  */
      34    for (i = 0; i < n; ++i)
      35      new[i] = groups[i];
      36  
      37  retry:
      38    HURD_CRITICAL_BEGIN;
      39    __mutex_lock (&_hurd_id.lock);
      40    err = _hurd_check_ids ();
      41    if (! err)
      42      {
      43        /* Get a new auth port using those IDs.  */
      44        err = __USEPORT (AUTH,
      45  		       __auth_makeauth (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
      46  					_hurd_id.gen.uids, _hurd_id.gen.nuids,
      47  					_hurd_id.aux.uids, _hurd_id.aux.nuids,
      48  					new, n,
      49  					_hurd_id.aux.gids, _hurd_id.aux.ngids,
      50  					&newauth));
      51      }
      52    __mutex_unlock (&_hurd_id.lock);
      53    HURD_CRITICAL_END;
      54    if (err == EINTR)
      55      /* Got a signal while inside an RPC of the critical section, retry again */
      56      goto retry;
      57  
      58    if (err)
      59      return __hurd_fail (err);
      60  
      61    /* Install the new auth port and reauthenticate everything.  */
      62    err = __setauth (newauth);
      63    __mach_port_deallocate (__mach_task_self (), newauth);
      64    return err;
      65  }
      66  libc_hidden_def (setgroups)