hurd/hurdauth.c

   1 /* Copyright (C) 1991-2021 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 <hurd.h>
  19 #include <hurd/msg_server.h>
  20 #include <hurd/id.h>
  21 #include <string.h>
  22
  23 int
  24 _hurd_refport_secure_p (mach_port_t ref)
  25 {
  26   if (ref == __mach_task_self ())
  27     return 1;
  28   if (__USEPORT (AUTH, ref == port))
  29     return 1;
  30   return 0;
  31 }
  32
  33 kern_return_t
  34 _S_msg_add_auth (mach_port_t me,
  35                  auth_t addauth)
  36 {
  37   error_t err;
  38   auth_t newauth;
  39   uid_t *genuids, *gengids, *auxuids, *auxgids;
  40   mach_msg_type_number_t ngenuids, ngengids, nauxuids, nauxgids;
  41   uid_t *newgenuids, *newgengids, *newauxuids, *newauxgids;
  42   mach_msg_type_number_t nnewgenuids, nnewgengids, nnewauxuids, nnewauxgids;
  43
  44   /* Create a list of ids and store it in NEWLISTP, length NEWLISTLEN.
  45      Keep all the ids in EXIST (len NEXIST), adding in those from NEW
  46      (len NNEW) which are not already there.  */
  47   error_t make_list (uid_t **newlistp, mach_msg_type_number_t *newlistlen,
  48                      uid_t *exist, mach_msg_type_number_t nexist,
  49                      uid_t *new, mach_msg_type_number_t nnew)
  50     {
  51       error_t urp;
  52       int i, j, k;
  53       vm_size_t offset;
  54
  55       urp = __vm_allocate (mach_task_self (), (vm_address_t *) newlistp,
  56                            nexist + nnew * sizeof (uid_t), 1);
  57       if (urp)
  58         return urp;
  59
  60       j = 0;
  61       for (i = 0; i < nexist; i++)
  62         (*newlistp)[j++] = exist[i];
  63
  64       for (i = 0; i < nnew; i++)
  65         {
  66           for (k = 0; k < nexist; k++)
  67             if (exist[k] == new[i])
  68               break;
  69           if (k < nexist)
  70             continue;
  71
  72           (*newlistp)[j++] = new[i];
  73         }
  74
  75       offset = (round_page (nexist + nnew * sizeof (uid_t))
  76                 - round_page (j * sizeof (uid_t)));
  77       if (offset)
  78         __vm_deallocate (mach_task_self (),
  79                          (vm_address_t) (*newlistp
  80                                          + (nexist + nnew * sizeof (uid_t))),
  81                          offset);
  82       *newlistlen = j;
  83       return 0;
  84     }
  85
  86   /* Find out what ids ADDAUTH refers to */
  87
  88   genuids = gengids = auxuids = auxgids = 0;
  89   ngenuids = ngengids = nauxuids = nauxgids = 0;
  90   err = __auth_getids (addauth,
  91                        &genuids, &ngenuids,
  92                        &auxuids, &nauxuids,
  93                        &gengids, &ngengids,
  94                        &auxgids, &nauxgids);
  95   if (err)
  96     return err;
  97
  98   /* OR in these ids to what we already have, creating a new list. */
  99
 100   HURD_CRITICAL_BEGIN;
 101   __mutex_lock (&_hurd_id.lock);
 102   _hurd_check_ids ();
 103
 104 #define MAKE(genaux,uidgid)                                                 \
 105   make_list (&new ## genaux ## uidgid ## s,                                 \
 106              &nnew ## genaux ## uidgid ## s,                                \
 107              _hurd_id.genaux.uidgid ## s,                                   \
 108              _hurd_id.genaux.n ## uidgid ## s,                              \
 109              genaux ## uidgid ## s,                                         \
 110              n ## genaux ## uidgid ## s)
 111
 112   err = MAKE (gen, uid);
 113   if (!err)
 114     MAKE (aux, uid);
 115   if (!err)
 116     MAKE (gen, gid);
 117   if (!err)
 118     MAKE (aux, gid);
 119 #undef MAKE
 120
 121   __mutex_unlock (&_hurd_id.lock);
 122   HURD_CRITICAL_END;
 123
 124
 125   /* Create the new auth port */
 126
 127   if (!err)
 128     err = __USEPORT (AUTH,
 129                      __auth_makeauth (port,
 130                                       &addauth, MACH_MSG_TYPE_MOVE_SEND, 1,
 131                                       newgenuids, nnewgenuids,
 132                                       newauxuids, nnewauxuids,
 133                                       newgengids, nnewgengids,
 134                                       newauxgids, nnewauxgids,
 135                                       &newauth));
 136
 137 #define freeup(array, len) \
 138   if (array) \
 139     __vm_deallocate (mach_task_self (), (vm_address_t) array, \
 140                      len * sizeof (uid_t));
 141
 142   freeup (genuids, ngenuids);
 143   freeup (auxuids, nauxuids);
 144   freeup (gengids, ngengids);
 145   freeup (auxgids, nauxgids);
 146   freeup (newgenuids, nnewgenuids);
 147   freeup (newauxuids, nnewauxuids);
 148   freeup (newgengids, nnewgengids);
 149   freeup (newauxgids, nnewauxgids);
 150 #undef freeup
 151
 152   if (err)
 153     return err;
 154
 155   /* And install it. */
 156
 157   err = __setauth (newauth);
 158   __mach_port_deallocate (__mach_task_self (), newauth);
 159   if (err)
 160     return errno;
 161
 162   return 0;
 163 }
 164
 165 kern_return_t
 166 _S_msg_del_auth (mach_port_t me,
 167                  task_t task,
 168                  intarray_t uids, mach_msg_type_number_t nuids,
 169                  intarray_t gids, mach_msg_type_number_t ngids)
 170 {
 171   error_t err;
 172   auth_t newauth;
 173
 174   if (!_hurd_refport_secure_p (task))
 175     return EPERM;
 176
 177   HURD_CRITICAL_BEGIN;
 178   __mutex_lock (&_hurd_id.lock);
 179   err = _hurd_check_ids ();
 180
 181   if (!err)
 182     {
 183       size_t i, j;
 184       size_t nu = _hurd_id.gen.nuids, ng = _hurd_id.gen.ngids;
 185       uid_t newu[nu];
 186       gid_t newg[ng];
 187
 188       memcpy (newu, _hurd_id.gen.uids, nu * sizeof (uid_t));
 189       memcpy (newg, _hurd_id.gen.gids, ng * sizeof (gid_t));
 190
 191       for (j = 0; j < nuids; ++j)
 192         {
 193           const uid_t uid = uids[j];
 194           for (i = 0; i < nu; ++i)
 195             if (newu[i] == uid)
 196               /* Move the last uid into this slot, and decrease the
 197                  number of uids so the last slot is no longer used.  */
 198               newu[i] = newu[--nu];
 199         }
 200       __vm_deallocate (__mach_task_self (),
 201                        (vm_address_t) uids, nuids * sizeof (uid_t));
 202
 203       for (j = 0; j < ngids; ++j)
 204         {
 205           const gid_t gid = gids[j];
 206           for (i = 0; i < nu; ++i)
 207             if (newu[i] == gid)
 208               /* Move the last gid into this slot, and decrease the
 209                  number of gids so the last slot is no longer used.  */
 210               newu[i] = newu[--nu];
 211         }
 212       __vm_deallocate (__mach_task_self (),
 213                        (vm_address_t) gids, ngids * sizeof (gid_t));
 214
 215       err = __USEPORT (AUTH, __auth_makeauth
 216                        (port,
 217                         NULL, MACH_MSG_TYPE_COPY_SEND, 0,
 218                         newu, nu,
 219                         _hurd_id.aux.uids, _hurd_id.aux.nuids,
 220                         newg, ng,
 221                         _hurd_id.aux.uids, _hurd_id.aux.ngids,
 222                         &newauth));
 223     }
 224   __mutex_unlock (&_hurd_id.lock);
 225   HURD_CRITICAL_END;
 226
 227   if (err)
 228     return err;
 229
 230   err = __setauth (newauth);
 231   __mach_port_deallocate (__mach_task_self (), newauth);
 232   if (err)
 233     return errno;
 234
 235   return 0;
 236 }