summaryrefslogtreecommitdiffstats
path: root/kdm/backend/access.c
blob: 82736be57f93b4cbcc09faabc8907c580c0e3a3a (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
/*

Copyright 1990, 1998  The Open Group
Copyright 2001,2004 Oswald Buddenhagen <ossi@kde.org>
Copyright 2002 Sun Microsystems, Inc.  All rights reserved.

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of a copyright holder shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from the copyright holder.

*/

/*
 * xdm - display manager daemon
 * Author:  Keith Packard, MIT X Consortium
 *
 * Access control for XDMCP - keep a database of allowable display addresses
 * and (potentially) a list of hosts to send ForwardQuery packets to
 */

#include <config.h>

#ifdef XDMCP

#include "dm.h"
#include "dm_error.h"
#include "dm_socket.h"

#include <stdio.h>
#include <ctype.h>

#include <netdb.h>
#if defined(IPv6) && defined(AF_INET6)
# include <arpa/inet.h>
#endif

typedef struct {
	short int type;
	union {
		char *aliasPattern;
		char *hostPattern;
		struct _displayAddress {
			CARD16 connectionType;
			ARRAY8 hostAddress;
		} displayAddress;
	} entry;
} HostEntry;

typedef struct {
	short int iface;
	short int mcasts;
	short int nmcasts;
} ListenEntry;

typedef struct {
	char *name;
	short int hosts;
	short int nhosts;
} AliasEntry;

typedef struct {
	short int entries;
	short int nentries;
	short int hosts;
	short int nhosts;
	short int flags;
} AclEntry;

typedef struct {
	HostEntry *hostList;
	ListenEntry *listenList;
	AliasEntry *aliasList;
	AclEntry *acList;
	short int nHosts, nListens, nAliases, nAcls;
	CfgDep dep;
} AccArr;

static AccArr accData[1];


static ARRAY8 localAddress;

ARRAY8Ptr
getLocalAddress( void )
{
	static int haveLocalAddress;

	if (!haveLocalAddress) {
#if defined(IPv6) && defined(AF_INET6)
		struct addrinfo *ai;

		if (getaddrinfo( localHostname(), NULL, NULL, &ai )) {
			XdmcpAllocARRAY8( &localAddress, 4 );
			localAddress.data[0] = 127;
			localAddress.data[1] = 0;
			localAddress.data[2] = 0;
			localAddress.data[3] = 1;
		} else {
			if (ai->ai_family == AF_INET) {
				XdmcpAllocARRAY8( &localAddress, sizeof(struct in_addr) );
				memcpy( localAddress.data,
				        &((struct sockaddr_in *)ai->ai_addr)->sin_addr,
				        sizeof(struct in_addr) );
			} else /* if (ai->ai_family == AF_INET6) */ {
				XdmcpAllocARRAY8( &localAddress, sizeof(struct in6_addr) );
				memcpy( localAddress.data,
				        &((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr,
				        sizeof(struct in6_addr) );
			}
			freeaddrinfo( ai );
#else
		struct hostent *hostent;

		if ((hostent = gethostbyname( localHostname() ))) {
			XdmcpAllocARRAY8( &localAddress, hostent->h_length );
			memmove( localAddress.data, hostent->h_addr, hostent->h_length );
#endif
			haveLocalAddress = 1;
		}
	}
	return &localAddress;
}


void
ScanAccessDatabase( int force )
{
	struct _displayAddress *da;
	char *cptr;
	int nChars, i;

	Debug( "ScanAccessDatabase\n" );
	if (Setjmp( cnftalk.errjmp ))
		return; /* may memleak */
	if (startConfig( GC_gXaccess, &accData->dep, force ) <= 0)
		return;
	if (accData->hostList)
		free( accData->hostList );
	accData->nHosts = GRecvInt();
	accData->nListens = GRecvInt();
	accData->nAliases = GRecvInt();
	accData->nAcls = GRecvInt();
	nChars = GRecvInt();
	if (!(accData->hostList = (HostEntry *)
	      Malloc( accData->nHosts * sizeof(HostEntry) +
	              accData->nListens * sizeof(ListenEntry) +
	              accData->nAliases * sizeof(AliasEntry) +
	              accData->nAcls * sizeof(AclEntry) +
	              nChars )))
	{
		CloseGetter();
		return;
	}
	accData->listenList = (ListenEntry *)(accData->hostList + accData->nHosts);
	accData->aliasList = (AliasEntry *)(accData->listenList + accData->nListens);
	accData->acList = (AclEntry *)(accData->aliasList + accData->nAliases);
	cptr = (char *)(accData->acList + accData->nAcls);
	for (i = 0; i < accData->nHosts; i++) {
		switch ((accData->hostList[i].type = GRecvInt())) {
		case HOST_ALIAS:
			accData->hostList[i].entry.aliasPattern = cptr;
			cptr += GRecvStrBuf( cptr );
			break;
		case HOST_PATTERN:
			accData->hostList[i].entry.hostPattern = cptr;
			cptr += GRecvStrBuf( cptr );
			break;
		case HOST_ADDRESS:
			da = &accData->hostList[i].entry.displayAddress;
			da->hostAddress.data = (unsigned char *)cptr;
			cptr += (da->hostAddress.length = GRecvArrBuf( cptr ));
			switch (GRecvInt())
			{
#ifdef AF_INET
			case AF_INET:
				da->connectionType = FamilyInternet;
				break;
#endif
#if defined(IPv6) && defined(AF_INET6)
			case AF_INET6:
				da->connectionType = FamilyInternet6;
				break;
#endif
#ifdef AF_DECnet
			case AF_DECnet:
				da->connectionType = FamilyDECnet;
				break;
#endif
/*#ifdef AF_UNIX
			case AF_UNIX:
#endif*/
			default:
				da->connectionType = FamilyLocal;
				break;
			}
			break;
		case HOST_BROADCAST:
			break;
		default:
			LogError( "Received unknown host type %d from config reader\n", accData->hostList[i].type );
			return;
		}
	}
	for (i = 0; i < accData->nListens; i++) {
		accData->listenList[i].iface = GRecvInt();
		accData->listenList[i].mcasts = GRecvInt();
		accData->listenList[i].nmcasts = GRecvInt();
	}
	for (i = 0; i < accData->nAliases; i++) {
		accData->aliasList[i].name = cptr;
		cptr += GRecvStrBuf( cptr );
		accData->aliasList[i].hosts = GRecvInt();
		accData->aliasList[i].nhosts = GRecvInt();
	}
	for (i = 0; i < accData->nAcls; i++) {
		accData->acList[i].entries = GRecvInt();
		accData->acList[i].nentries = GRecvInt();
		accData->acList[i].hosts = GRecvInt();
		accData->acList[i].nhosts = GRecvInt();
		accData->acList[i].flags = GRecvInt();
	}
}


/* Returns non-0 if string is matched by pattern.  Does case folding.
 */
static int
patternMatch( const char *string, const char *pattern )
{
	int p, s;

	if (!string)
		string = "";

	for (;;) {
		s = *string++;
		switch (p = *pattern++) {
		case '*':
			if (!*pattern)
				return 1;
			for (string--; *string; string++)
				if (patternMatch( string, pattern ))
					return 1;
			return 0;
		case '?':
			if (s == '\0')
				return 0;
			break;
		case '\0':
			return s == '\0';
		case '\\':
			p = *pattern++;
			/* fall through */
		default:
			if (tolower( p ) != tolower( s ))
				return 0;
		}
	}
}


#define MAX_DEPTH 32

static void
scanHostlist( int fh, int nh,
              ARRAY8Ptr clientAddress, CARD16 connectionType,
              ChooserFunc function, char *closure,
              int broadcast, int *haveLocalhost )
{
	HostEntry *h;
	AliasEntry *a;
	int na;

	for (h = accData->hostList + fh; nh; nh--, h++) {
		switch (h->type) {
		case HOST_ALIAS:
			for (a = accData->aliasList, na = accData->nAliases; na; na--, a++)
				if (patternMatch( a->name, h->entry.aliasPattern )) /* XXX originally swapped, no wildcards in alias name matching */
					scanHostlist( a->hosts, a->nhosts,
					              clientAddress, connectionType,
					              function, closure, broadcast,
					              haveLocalhost );
			break;
		case HOST_ADDRESS:
			if (XdmcpARRAY8Equal( getLocalAddress(), &h->entry.displayAddress.hostAddress ))
				*haveLocalhost = 1;
			else if (function)
				(*function)( connectionType, &h->entry.displayAddress.hostAddress, closure );
			break;
		case HOST_BROADCAST:
			if (broadcast && function)
				(*function)( FamilyBroadcast, 0, closure );
			break;
		default:
			break;
		}
	}
}

static int
scanEntrylist( int fh, int nh,
               ARRAY8Ptr clientAddress, CARD16 connectionType,
               char **clientName )
{
	HostEntry *h;
	AliasEntry *a;
	int na;

	for (h = accData->hostList + fh; nh; nh--, h++) {
		switch (h->type) {
		case HOST_ALIAS:
			for (a = accData->aliasList, na = accData->nAliases; na; na--, a++)
				if (patternMatch( a->name, h->entry.aliasPattern ))
					if (scanEntrylist( a->hosts, a->nhosts,
					                   clientAddress, connectionType,
					                   clientName ))
						return 1;
			break;
		case HOST_PATTERN:
			if (!*clientName)
				*clientName = NetworkAddressToHostname( connectionType,
				                                        clientAddress );
			if (patternMatch( *clientName, h->entry.hostPattern ))
				return 1;
			break;
		case HOST_ADDRESS:
			if (h->entry.displayAddress.connectionType == connectionType &&
			    XdmcpARRAY8Equal( &h->entry.displayAddress.hostAddress,
			                      clientAddress ))
				return 1;
			break;
		default:
			break;
		}
	}
	return 0;
}

static AclEntry *
matchAclEntry( ARRAY8Ptr clientAddress, CARD16 connectionType, int direct )
{
	AclEntry *e, *re;
	char *clientName = 0;
	int ne;

	for (e = accData->acList, ne = accData->nAcls, re = 0; ne; ne--, e++)
		if (!e->nhosts == direct)
			if (scanEntrylist( e->entries, e->nentries,
			                   clientAddress, connectionType,
			                   &clientName ))
			{
				re = e;
				break;
			}
	if (clientName)
		free( clientName );
	return re;
}

/*
 * calls the given function for each valid indirect entry.  Returns TRUE if
 * the local host exists on any of the lists, else FALSE
 */
int
ForEachMatchingIndirectHost( ARRAY8Ptr clientAddress,
                             CARD16 connectionType,
                             ChooserFunc function, char *closure )
{
	AclEntry *e;
	int haveLocalhost = 0;

	e = matchAclEntry( clientAddress, connectionType, 0 );
	if (e && !(e->flags & a_notAllowed)) {
		if (e->flags & a_useChooser) {
			ARRAY8Ptr choice;

			choice = IndirectChoice( clientAddress, connectionType );
			if (!choice || XdmcpARRAY8Equal( getLocalAddress(), choice ))
				haveLocalhost = 1;
			else
				(*function)( connectionType, choice, closure );
		} else
			scanHostlist( e->hosts, e->nhosts, clientAddress, connectionType,
			              function, closure, FALSE, &haveLocalhost );
	}
	return haveLocalhost;
}

int
UseChooser( ARRAY8Ptr clientAddress, CARD16 connectionType )
{
	AclEntry *e;

	e = matchAclEntry( clientAddress, connectionType, 0 );
	return e && !(e->flags & a_notAllowed) && (e->flags & a_useChooser) &&
		!IndirectChoice( clientAddress, connectionType );
}

void
ForEachChooserHost( ARRAY8Ptr clientAddress, CARD16 connectionType,
                    ChooserFunc function, char *closure )
{
	AclEntry *e;
	int haveLocalhost = 0;

	e = matchAclEntry( clientAddress, connectionType, 0 );
	if (e && !(e->flags & a_notAllowed) && (e->flags & a_useChooser))
		scanHostlist( e->hosts, e->nhosts, clientAddress, connectionType,
		              function, closure, TRUE, &haveLocalhost );
	if (haveLocalhost)
		(*function)( connectionType, getLocalAddress(), closure );
}

/*
 * returns TRUE if the given client is acceptable to the local host.  The
 * given display client is acceptable if it occurs without a host list.
 */
int
AcceptableDisplayAddress( ARRAY8Ptr clientAddress, CARD16 connectionType,
                          xdmOpCode type )
{
	AclEntry *e;

	if (type == INDIRECT_QUERY)
		return 1;

	e = matchAclEntry( clientAddress, connectionType, 1 );
	return e && !(e->flags & a_notAllowed) &&
		(type != BROADCAST_QUERY || !(e->flags & a_notBroadcast));
}

void
ForEachListenAddr( ListenFunc listenfunction, ListenFunc mcastfunction,
                   void **closure )
{
	int i, j, ifc, mc, nmc;

	for (i = 0; i < accData->nListens; i++) {
		ifc = accData->listenList[i].iface;
		(*listenfunction)( ifc < 0 ? 0 :
		                   &accData->hostList[ifc].entry.displayAddress.hostAddress,
		                   closure );
		mc = accData->listenList[i].mcasts;
		nmc = accData->listenList[i].nmcasts;
		for (j = 0; j < nmc; j++, mc++)
			(*mcastfunction)( &accData->hostList[mc].entry.displayAddress.hostAddress,
			                  closure );
	}
}
#endif /* XDMCP */