summaryrefslogtreecommitdiff
path: root/auth/auth.c
blob: 3c5fa861fb943efc5b5130733427801a4244772d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
/* Authentication server.
   Copyright (C) 1996,97,98,99,2002 Free Software Foundation, Inc.
   Written by Roland McGrath.

   This file is part of the GNU Hurd.

   The GNU Hurd 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, or (at
   your option) any later version.

   The GNU Hurd 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 <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <mach.h>
#include <cthreads.h>
#include <hurd.h>
#include <hurd/startup.h>
#include <hurd/ports.h>
#include <hurd/ihash.h>
#include <idvec.h>
#include <assert.h>
#include <argp.h>
#include <error.h>
#include <version.h>
#include "auth_S.h"
#include "auth_reply_U.h"

const char *argp_program_version = STANDARD_HURD_VERSION(auth);


/* Auth handles are server ports with sets of ids.  */
struct authhandle
  {
    struct port_info pi;
    struct idvec euids, egids, auids, agids;
  };

struct port_bucket *auth_bucket;
struct port_class *authhandle_portclass;


/* Create a new auth port.  */

static error_t
create_authhandle (struct authhandle **new)
{
  error_t err = ports_create_port (authhandle_portclass, auth_bucket,
				   sizeof **new, new);
  if (! err)
    bzero (&(*new)->euids, (void *) &(*new)[1] - (void *) &(*new)->euids);
  return err;
}

/* Clean up a dead auth port.  */

static void
destroy_authhandle (void *p)
{
  struct authhandle *h = p;
  idvec_free_contents (&h->euids);
  idvec_free_contents (&h->egids);
  idvec_free_contents (&h->auids);
  idvec_free_contents (&h->agids);
}

/* Called by server stub functions.  */

authhandle_t
auth_port_to_handle (auth_t auth)
{
  return ports_lookup_port (auth_bucket, auth, authhandle_portclass);
}

/* id management.  */

static inline void
idvec_copyout (struct idvec *idvec, uid_t **ids, size_t *nids)
{
  if (idvec->num > *nids)
    *ids = idvec->ids;
  else
    memcpy (*ids, idvec->ids, idvec->num * sizeof *ids);
  *nids = idvec->num;
}

#define C(auth, ids)	idvec_copyout (&auth->ids, ids, n##ids)
#define OUTIDS(auth)	(C (auth, euids), C (auth, egids), \
			 C (auth, auids), C (auth, agids))

/* Implement auth_getids as described in <hurd/auth.defs>. */
kern_return_t
S_auth_getids (struct authhandle *auth,
	       uid_t **euids,
	       size_t *neuids,
	       uid_t **auids,
	       size_t *nauids,
	       uid_t **egids,
	       size_t *negids,
	       uid_t **agids,
	       size_t *nagids)
{
  if (! auth)
    return EOPNOTSUPP;

  OUTIDS (auth);

  return 0;
}

/* Implement auth_makeauth as described in <hurd/auth.defs>. */
kern_return_t
S_auth_makeauth (struct authhandle *auth,
		 mach_port_t *authpts, size_t nauths,
		 uid_t *euids, size_t neuids,
		 uid_t *auids, size_t nauids,
		 uid_t *egids, size_t negids,
		 uid_t *agids, size_t nagids,
		 mach_port_t *newhandle)
{
  struct authhandle *newauth, *auths[1 + nauths];
  int hasroot = 0;
  error_t err;
  size_t i, j;

  if (!auth)
    return EOPNOTSUPP;

  auths[0] = auth;

  /* Fetch the auth structures for all the ports passed in. */
  for (i = 0; i < nauths; i++)
    auths[i + 1] = auth_port_to_handle (authpts[i]);

  ++nauths;

  /* Verify that the union of the handles passed in either contains euid 0
     (root), or contains all the requested ids.  */

#define isuid(uid, auth) \
  (idvec_contains (&(auth)->euids, uid) \
   || idvec_contains (&(auth)->auids, uid))
#define groupmember(gid, auth) \
  (idvec_contains (&(auth)->egids, gid) \
   || idvec_contains (&(auth)->agids, gid))
#define isroot(auth)		isuid (0, auth)

  for (i = 0; i < nauths; i++)
    if (auths[i] && isroot (auths[i]))
      {
	hasroot = 1;
	break;
      }

  if (!hasroot)
    {
      int has_it;

      for (i = 0; i < neuids; i++)
	{
	  has_it = 0;
	  for (j = 0; j < nauths; j++)
	    if (auths[j] && isuid (euids[i], auths[j]))
	      {
		has_it = 1;
		break;
	      }
	  if (!has_it)
	    goto eperm;
	}

      for (i = 0; i < nauids; i++)
	{
	  has_it = 0;
	  for (j = 0; j < nauths; j++)
	    if (auths[j] && isuid (auids[i], auths[j]))
	      {
		has_it = 1;
		break;
	      }
	  if (!has_it)
	    goto eperm;
	}

      for (i = 0; i < negids; i++)
	{
	  has_it = 0;
	  for (j = 0; j < nauths; j++)
	    if (auths[j] && groupmember (egids[i], auths[j]))
	      {
		has_it = 1;
		break;
	      }
	  if (!has_it)
	    goto eperm;
	}

      for (i = 0; i < nagids; i++)
	{
	  has_it = 0;
	  for (j = 0; j < nauths; j++)
	    if (auths[j] && groupmember (agids[i], auths[j]))
	      {
		has_it = 1;
		break;
	      }
	  if (!has_it)
	    goto eperm;
	}
    }

  err = create_authhandle (&newauth);

  /* Create a new handle with the specified ids.  */

#define MERGE S (euids); S (egids); S (auids); S (agids);
#define S(uids) if (!err) err = idvec_merge_ids (&newauth->uids, uids, n##uids)

  MERGE;

#undef S

  if (! err)
    {
      for (j = 1; j < nauths; ++j)
	mach_port_deallocate (mach_task_self (), authpts[j - 1]);
      *newhandle = ports_get_right (newauth);
      ports_port_deref (newauth);
    }

  for (j = 1; j < nauths; j++)
    if (auths[j])
      ports_port_deref (auths[j]);
  return err;

 eperm:
  for (j = 1; j < nauths; j++)
    if (auths[j])
      ports_port_deref (auths[j]);
  return EPERM;
}

/* Transaction handling.  */

/* A pending transaction.  */
struct pending
  {
    hurd_ihash_locp_t locp;	/* Position in one of the ihash tables.  */
    struct condition wakeup;    /* The waiter is blocked on this condition.  */

    /* The user's auth handle.  */
    struct authhandle *user;

    /* The port to pass back to the user.  */
    mach_port_t passthrough;
  };

/* Table of pending transactions keyed on RENDEZVOUS.  */
struct hurd_ihash pending_users
  = HURD_IHASH_INITIALIZER (offsetof (struct pending, locp));
struct hurd_ihash pending_servers
  = HURD_IHASH_INITIALIZER (offsetof (struct pending, locp));
struct mutex pending_lock = MUTEX_INITIALIZER;

/* Implement auth_user_authenticate as described in <hurd/auth.defs>. */
kern_return_t
S_auth_user_authenticate (struct authhandle *userauth,
			  mach_port_t reply,
			  mach_msg_type_name_t reply_type,
			  mach_port_t rendezvous,
			  mach_port_t *newport,
			  mach_msg_type_name_t *newporttype)
{
  struct pending *s;

  if (! userauth)
    return EOPNOTSUPP;

  if (rendezvous == MACH_PORT_DEAD) /* Port died in transit.  */
    return EINVAL;

  mutex_lock (&pending_lock);

  /* Look for this port in the server list.  */
  s = hurd_ihash_find (&pending_servers, rendezvous);
  if (s)
    {
      /* Found it!  Extract the port.  */
      *newport = s->passthrough;
      *newporttype = MACH_MSG_TYPE_MOVE_SEND;

      /* Remove it from the pending list.  */
      hurd_ihash_locp_remove (&pending_servers, s->locp);

      /* Give the server the auth port and wake the RPC up.
	 We need to add a ref in case the port dies.  */
      s->user = userauth;
      ports_port_ref (userauth);

      condition_signal (&s->wakeup);
      mutex_unlock (&pending_lock);

      mach_port_deallocate (mach_task_self (), rendezvous);
      return 0;
    }
  else
    {
      /* No pending server RPC for this port.
	 Create a pending user RPC record.  */
      struct pending u;
      error_t err;

      err = hurd_ihash_add (&pending_users, rendezvous, &u);
      if (! err)
	{
	  /* Store the user auth port and wait for the server RPC to wake
             us up.  */
	  u.user = userauth;
	  condition_init (&u.wakeup);
	  ports_interrupt_self_on_port_death (userauth, rendezvous);
	  if (hurd_condition_wait (&u.wakeup, &pending_lock))
	    /* We were interrupted; remove our record.  */
	    {
	      hurd_ihash_locp_remove (&pending_users, u.locp);
	      err = EINTR;
	    }
	}
      /* The server side has already removed U from the ihash table.  */
      mutex_unlock (&pending_lock);

      if (! err)
	{
	  /* The server RPC has set the port and signalled U.wakeup.  */
	  *newport = u.passthrough;
	  *newporttype = MACH_MSG_TYPE_MOVE_SEND;
	  mach_port_deallocate (mach_task_self (), rendezvous);
	}
      return err;
    }
}

/* Implement auth_server_authenticate as described in <hurd/auth.defs>. */
kern_return_t
S_auth_server_authenticate (struct authhandle *serverauth,
			    mach_port_t reply,
			    mach_msg_type_name_t reply_type,
			    mach_port_t rendezvous,
			    mach_port_t newport,
			    mach_msg_type_name_t newport_type,
			    uid_t **euids,
			    size_t *neuids,
			    uid_t **auids,
			    size_t *nauids,
			    uid_t **egids,
			    size_t *negids,
			    uid_t **agids,
			    size_t *nagids)
{
  struct pending *u;
  struct authhandle *user;

  if (! serverauth)
    return EOPNOTSUPP;

  if (rendezvous == MACH_PORT_DEAD) /* Port died in transit.  */
    return EINVAL;

  mutex_lock (&pending_lock);

  /* Look for this port in the user list.  */
  u = hurd_ihash_find (&pending_users, rendezvous);
  if (u)
    {
      /* Remove it from the pending list.  */
      hurd_ihash_locp_remove (&pending_users, u->locp);

      /* Found it!  We must add a ref because the one held by the
	 user RPC might die as soon as we unlock pending_lock.  */
      user = u->user;
      ports_port_ref (user);

      /* Give the user the new port and wake the RPC up.  */
      u->passthrough = newport;

      condition_signal (&u->wakeup);
      mutex_unlock (&pending_lock);
    }
  else
    {
      /* No pending user RPC for this port.
	 Create a pending server RPC record.  */
      struct pending s;
      error_t err;

      err = hurd_ihash_add (&pending_servers, rendezvous, &s);
      if (! err)
	{
	  /* Store the new port and wait for the user RPC to wake us up.  */
	  s.passthrough = newport;
	  condition_init (&s.wakeup);
	  ports_interrupt_self_on_port_death (serverauth, rendezvous);
	  if (hurd_condition_wait (&s.wakeup, &pending_lock))
	    /* We were interrupted; remove our record.  */
	    {
	      hurd_ihash_locp_remove (&pending_servers, s.locp);
	      err = EINTR;
	    }
	}
      /* The user side has already removed S from the ihash table.  */
      mutex_unlock (&pending_lock);

      if (err)
	return err;

      /* The user RPC has set the port (with a ref) and signalled S.wakeup.  */
      user = s.user;
    }

  /* Extract the ids.  We must use a separate reply stub so
     we can deref the user auth handle after the reply uses its
     contents.  */
  auth_server_authenticate_reply (reply, reply_type, 0,
				  user->euids.ids, user->euids.num,
				  user->auids.ids, user->auids.num,
				  user->egids.ids, user->egids.num,
				  user->agids.ids, user->agids.num);
  ports_port_deref (user);
  mach_port_deallocate (mach_task_self (), rendezvous);
  return MIG_NO_REPLY;
}



static int
auth_demuxer (mach_msg_header_t *inp, mach_msg_header_t *outp)
{
  extern int auth_server (mach_msg_header_t *inp, mach_msg_header_t *outp);
  return (auth_server (inp, outp) ||
	  ports_interrupt_server (inp, outp) ||
	  ports_notify_server (inp, outp));
}


int
main (int argc, char **argv)
{
  error_t err;
  mach_port_t boot;
  process_t proc;
  mach_port_t hostpriv, masterdev;
  struct authhandle *firstauth;
  struct argp argp = { 0, 0, 0, "Hurd standard authentication server." };

  argp_parse (&argp, argc, argv, 0, 0, 0);

  auth_bucket = ports_create_bucket ();
  authhandle_portclass = ports_create_class (&destroy_authhandle, 0);

  /* Create the initial root auth handle.  */
  err = create_authhandle (&firstauth);
  assert_perror (err);
  idvec_add (&firstauth->euids, 0);
  idvec_add (&firstauth->auids, 0);
  idvec_add (&firstauth->auids, 0);
  idvec_merge (&firstauth->egids, &firstauth->euids);
  idvec_merge (&firstauth->agids, &firstauth->auids);

  /* Fetch our bootstrap port and contact the bootstrap filesystem.  */
  err = task_get_bootstrap_port (mach_task_self (), &boot);
  assert_perror (err);
  if (boot == MACH_PORT_NULL)
    error (2, 0, "auth server can only be run by init during boot");
  err = startup_authinit (boot, ports_get_right (firstauth),
			  MACH_MSG_TYPE_MAKE_SEND, &proc);
  if (err)
    error (2, err, "cannot contact init for bootstrap");

  /* Register ourselves with the proc server and then start signals.  */
  proc_getprivports (proc, &hostpriv, &masterdev);
  proc_register_version (proc, hostpriv, "auth", "", HURD_VERSION);
  mach_port_deallocate (mach_task_self (), masterdev);
  _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], proc);
  _hurd_proc_init (argv, NULL, 0);

  /* Init knows intimately that we will be ready for messages
     as soon as this returns. */
  startup_essential_task (boot, mach_task_self (), MACH_PORT_NULL, "auth",
			  hostpriv);
  mach_port_deallocate (mach_task_self (), boot);
  mach_port_deallocate (mach_task_self (), hostpriv);

  /* Be a server.  */
  while (1)
    ports_manage_port_operations_multithread (auth_bucket,
					      auth_demuxer,
					      30 * 1000, 0, 0);
}