summaryrefslogtreecommitdiffstats
path: root/plugins/imgssapi/imgssapi.c
blob: d87918802d62ed91c5c83d34e776ae268a2b32d6 (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
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
/* imgssapi.c
 * This is the implementation of the GSSAPI input module.
 *
 * Note: the root gssapi code was contributed by varmojfekoj and is most often
 * maintened by him. I am just doing the plumbing around it (I event don't have a
 * test lab for gssapi yet... ). I am very grateful for this useful code
 * contribution -- rgerhards, 2008-03-05
 *
 * NOTE: read comments in module-template.h to understand how this file
 *       works!
 *
 * Copyright 2007, 2009 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of rsyslog.
 *
 * Rsyslog 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 3 of the License, or
 * (at your option) any later version.
 *
 * Rsyslog 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 Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
 *
 * A copy of the GPL can be found in the file "COPYING" in this distribution.
 */
#include "config.h"
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdarg.h>
#include <ctype.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include <gssapi/gssapi.h>
#include "rsyslog.h"
#include "dirty.h"
#include "cfsysline.h"
#include "module-template.h"
#include "net.h"
#include "srUtils.h"
#include "gss-misc.h"
#include "tcpsrv.h"
#include "tcps_sess.h"
#include "errmsg.h"
#include "netstrm.h"
#include "glbl.h"


MODULE_TYPE_INPUT

/* defines */
#define ALLOWEDMETHOD_GSS 2
#define ALLOWEDMETHOD_TCP 1


/* some forward definitions - they may go away when we no longer include imtcp.c */
static rsRetVal addGSSListener(void __attribute__((unused)) *pVal, uchar *pNewVal);
static int TCPSessGSSInit(void);
static void TCPSessGSSClose(tcps_sess_t* pSess);
static rsRetVal TCPSessGSSRecv(tcps_sess_t *pSess, void *buf, size_t buf_len, ssize_t *);
static rsRetVal onSessAccept(tcpsrv_t *pThis, tcps_sess_t *ppSess);
static rsRetVal OnSessAcceptGSS(tcpsrv_t *pThis, tcps_sess_t *ppSess);

/* static data */
DEF_IMOD_STATIC_DATA
DEFobjCurrIf(tcpsrv)
DEFobjCurrIf(tcps_sess)
DEFobjCurrIf(gssutil)
DEFobjCurrIf(errmsg)
DEFobjCurrIf(netstrm)
DEFobjCurrIf(net)
DEFobjCurrIf(glbl)

static tcpsrv_t *pOurTcpsrv = NULL;  /* our TCP server(listener) TODO: change for multiple instances */
static gss_cred_id_t gss_server_creds = GSS_C_NO_CREDENTIAL;

/* our usr structure for the tcpsrv object */
typedef struct gsssrv_s {
	char allowedMethods;
} gsssrv_t;

/* our usr structure for the session object */
typedef struct gss_sess_s {
	OM_uint32 gss_flags;
	gss_ctx_id_t gss_context;
	char allowedMethods;
} gss_sess_t;


/* config variables */
static int iTCPSessMax = 200; /* max number of sessions */
static char *gss_listen_service_name = NULL;
static int bPermitPlainTcp = 0; /* plain tcp syslog allowed on GSSAPI port? */


/* methods */
/* callbacks */
static rsRetVal OnSessConstructFinalize(void *ppUsr)
{
	DEFiRet;
	gss_sess_t **ppGSess = (gss_sess_t**) ppUsr;
	gss_sess_t *pGSess;

	assert(ppGSess != NULL);

	if((pGSess = calloc(1, sizeof(gss_sess_t))) == NULL)
		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);

	pGSess->gss_flags = 0;
	pGSess->gss_context = GSS_C_NO_CONTEXT;
	pGSess->allowedMethods = 0;

	*ppGSess = pGSess;

finalize_it:
	RETiRet;
}


/* Destruct the user session pointer for a GSSAPI session. Please note
 * that it *is* valid to receive a NULL user pointer. In this case, the
 * sessions is to be torn down before it was fully initialized. This 
 * happens in error cases, e.g. when the host ACL did not match.
 * rgerhards, 2008-03-03
 */
static rsRetVal
OnSessDestruct(void *ppUsr)
{
	DEFiRet;
	gss_sess_t **ppGSess = (gss_sess_t**) ppUsr;

	assert(ppGSess != NULL);
	if(*ppGSess == NULL)
		FINALIZE;

	if((*ppGSess)->allowedMethods & ALLOWEDMETHOD_GSS) {
		OM_uint32 maj_stat, min_stat;
		maj_stat = gss_delete_sec_context(&min_stat, &(*ppGSess)->gss_context, GSS_C_NO_BUFFER);
		if (maj_stat != GSS_S_COMPLETE)
			gssutil.display_status("deleting context", maj_stat, min_stat);
	}

	free(*ppGSess);
	*ppGSess = NULL;

finalize_it:
	RETiRet;
}


/* Check if the host is permitted to send us messages.
 * Note: the pUsrSess may be zero if the server is running in tcp-only mode!
 */
static int
isPermittedHost(struct sockaddr *addr, char *fromHostFQDN, void *pUsrSrv, void*pUsrSess)
{
	gsssrv_t *pGSrv;
	gss_sess_t *pGSess;
	char allowedMethods = 0;

	BEGINfunc
	assert(pUsrSrv != NULL);
	pGSrv = (gsssrv_t*) pUsrSrv;
	pGSess = (gss_sess_t*) pUsrSess;

	if((pGSrv->allowedMethods & ALLOWEDMETHOD_TCP) &&
	   net.isAllowedSender((uchar*)"TCP", addr, (char*)fromHostFQDN))
		allowedMethods |= ALLOWEDMETHOD_TCP;
	if((pGSrv->allowedMethods & ALLOWEDMETHOD_GSS) &&
	   net.isAllowedSender((uchar*)"GSS", addr, (char*)fromHostFQDN))
		allowedMethods |= ALLOWEDMETHOD_GSS;
	if(allowedMethods && pGSess != NULL)
		pGSess->allowedMethods = allowedMethods;
	ENDfunc
	return allowedMethods;
}


static rsRetVal
onSessAccept(tcpsrv_t *pThis, tcps_sess_t *pSess)
{
	DEFiRet;
	gsssrv_t *pGSrv;
	
	pGSrv = (gsssrv_t*) pThis->pUsr;

	if(pGSrv->allowedMethods & ALLOWEDMETHOD_GSS) {
		iRet = OnSessAcceptGSS(pThis, pSess);
	} 

	RETiRet;
}


static rsRetVal
onRegularClose(tcps_sess_t *pSess)
{
	DEFiRet;
	gss_sess_t *pGSess;

	assert(pSess != NULL);
	assert(pSess->pUsr != NULL);
	pGSess = (gss_sess_t*) pSess->pUsr;

	if(pGSess->allowedMethods & ALLOWEDMETHOD_GSS)
		TCPSessGSSClose(pSess);
	else {
		/* process any incomplete frames left over */
		tcps_sess.PrepareClose(pSess);
		/* Session closed */
		tcps_sess.Close(pSess);
	}
	RETiRet;
}


static rsRetVal
onErrClose(tcps_sess_t *pSess)
{
	DEFiRet;
	gss_sess_t *pGSess;

	assert(pSess != NULL);
	assert(pSess->pUsr != NULL);
	pGSess = (gss_sess_t*) pSess->pUsr;

	if(pGSess->allowedMethods & ALLOWEDMETHOD_GSS)
		TCPSessGSSClose(pSess);
	else
		tcps_sess.Close(pSess);

	RETiRet;
}


/* open the listen sockets */
static rsRetVal
doOpenLstnSocks(tcpsrv_t *pSrv)
{
	gsssrv_t *pGSrv;
	DEFiRet;

	ISOBJ_TYPE_assert(pSrv, tcpsrv);
	pGSrv = pSrv->pUsr;
	assert(pGSrv != NULL);

	/* first apply some config settings */
	if(pGSrv->allowedMethods) {
		if(pGSrv->allowedMethods & ALLOWEDMETHOD_GSS) {
			if(TCPSessGSSInit()) {
				errmsg.LogError(0, NO_ERRCODE, "GSS-API initialization failed\n");
				pGSrv->allowedMethods &= ~(ALLOWEDMETHOD_GSS);
			}
		}
		if(pGSrv->allowedMethods) {
			/* fallback to plain TCP */
			CHKiRet(tcpsrv.create_tcp_socket(pSrv));
		} else {
			ABORT_FINALIZE(RS_RET_GSS_ERR);
		}
	}

finalize_it:
	RETiRet;
}


static rsRetVal
doRcvData(tcps_sess_t *pSess, char *buf, size_t lenBuf, ssize_t *piLenRcvd)
{
	DEFiRet;
	int allowedMethods;
	gss_sess_t *pGSess;

	assert(pSess != NULL);
	assert(pSess->pUsr != NULL);
	pGSess = (gss_sess_t*) pSess->pUsr;
	assert(piLenRcvd != NULL);

	allowedMethods = pGSess->allowedMethods;
	if(allowedMethods & ALLOWEDMETHOD_GSS) {
		CHKiRet(TCPSessGSSRecv(pSess, buf, lenBuf, piLenRcvd));
	} else {
		*piLenRcvd = lenBuf;
		CHKiRet(netstrm.Rcv(pSess->pStrm, (uchar*) buf, piLenRcvd) != RS_RET_OK);
	}

finalize_it:
	RETiRet;
}


/* end callbacks */

static rsRetVal
addGSSListener(void __attribute__((unused)) *pVal, uchar *pNewVal)
{
	DEFiRet;
	gsssrv_t *pGSrv;

	if(pOurTcpsrv == NULL) {
		/* first create/init the gsssrv "object" */
		if((pGSrv = calloc(1, sizeof(gsssrv_t))) == NULL)
			ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);

		pGSrv->allowedMethods = ALLOWEDMETHOD_GSS;
		if(bPermitPlainTcp)
			pGSrv->allowedMethods |= ALLOWEDMETHOD_TCP;
		/* gsssrv initialized */

		CHKiRet(tcpsrv.Construct(&pOurTcpsrv));
		CHKiRet(tcpsrv.SetUsrP(pOurTcpsrv, pGSrv));
		CHKiRet(tcpsrv.SetCBOnSessConstructFinalize(pOurTcpsrv, OnSessConstructFinalize));
		CHKiRet(tcpsrv.SetCBOnSessDestruct(pOurTcpsrv, OnSessDestruct));
		CHKiRet(tcpsrv.SetCBIsPermittedHost(pOurTcpsrv, isPermittedHost));
		CHKiRet(tcpsrv.SetCBRcvData(pOurTcpsrv, doRcvData));
		CHKiRet(tcpsrv.SetCBOpenLstnSocks(pOurTcpsrv, doOpenLstnSocks));
		CHKiRet(tcpsrv.SetCBOnSessAccept(pOurTcpsrv, onSessAccept));
		CHKiRet(tcpsrv.SetCBOnRegularClose(pOurTcpsrv, onRegularClose));
		CHKiRet(tcpsrv.SetCBOnErrClose(pOurTcpsrv, onErrClose));
		tcpsrv.configureTCPListen(pOurTcpsrv, pNewVal);
		CHKiRet(tcpsrv.ConstructFinalize(pOurTcpsrv));
	}

finalize_it:
	if(iRet != RS_RET_OK) {
		errmsg.LogError(0, NO_ERRCODE, "error %d trying to add listener", iRet);
		if(pOurTcpsrv != NULL)
			tcpsrv.Destruct(&pOurTcpsrv);
	}
	RETiRet;
}


/* returns 0 if all went OK, -1 if it failed */
static int TCPSessGSSInit(void)
{
	gss_buffer_desc name_buf;
	gss_name_t server_name;
	OM_uint32 maj_stat, min_stat;

	if (gss_server_creds != GSS_C_NO_CREDENTIAL)
		return 0;

	name_buf.value = (gss_listen_service_name == NULL) ? "host" : gss_listen_service_name;
	name_buf.length = strlen(name_buf.value) + 1;
	maj_stat = gss_import_name(&min_stat, &name_buf, GSS_C_NT_HOSTBASED_SERVICE, &server_name);
	if (maj_stat != GSS_S_COMPLETE) {
		gssutil.display_status("importing name", maj_stat, min_stat);
		return -1;
	}

	maj_stat = gss_acquire_cred(&min_stat, server_name, 0,
				    GSS_C_NULL_OID_SET, GSS_C_ACCEPT,
				    &gss_server_creds, NULL, NULL);
	if (maj_stat != GSS_S_COMPLETE) {
		gssutil.display_status("acquiring credentials", maj_stat, min_stat);
		return -1;
	}

	gss_release_name(&min_stat, &server_name);
	dbgprintf("GSS-API initialized\n");
	return 0;
}


/* returns 0 if all went OK, -1 if it failed 
 * tries to guess if the connection uses gssapi.
 */
static rsRetVal
OnSessAcceptGSS(tcpsrv_t *pThis, tcps_sess_t *pSess)
{
	DEFiRet;
	gss_buffer_desc send_tok, recv_tok;
	gss_name_t client;
	OM_uint32 maj_stat, min_stat, acc_sec_min_stat;
	gss_ctx_id_t *context;
	OM_uint32 *sess_flags;
	int fdSess;
	char allowedMethods;
	gsssrv_t *pGSrv;
	gss_sess_t *pGSess;

	assert(pSess != NULL);

	pGSrv = (gsssrv_t*) pThis->pUsr;
	pGSess = (gss_sess_t*) pSess->pUsr;
	allowedMethods = pGSrv->allowedMethods;
	if(allowedMethods & ALLOWEDMETHOD_GSS) {
		/* Buffer to store raw message in case that
		 * gss authentication fails halfway through. This buffer
		 * is currently dynamically allocated, for performance
		 * reasons we should look for a better way to do it.
		 * rgerhars, 2008-09-02
		 */
		char *buf;
		int ret = 0;
		CHKmalloc(buf = (char*) malloc(sizeof(char) * (glbl.GetMaxLine() + 1)));

		dbgprintf("GSS-API Trying to accept TCP session %p\n", pSess);

		CHKiRet(netstrm.GetSock(pSess->pStrm, &fdSess)); // TODO: method access!
		if (allowedMethods & ALLOWEDMETHOD_TCP) {
			int len;
			fd_set  fds;
			struct timeval tv;
		
			do {
				FD_ZERO(&fds);
				FD_SET(fdSess, &fds);
				tv.tv_sec = 1;
				tv.tv_usec = 0;
				ret = select(fdSess + 1, &fds, NULL, NULL, &tv);
			} while (ret < 0 && errno == EINTR);
			if (ret < 0) {
				errmsg.LogError(0, RS_RET_ERR, "TCP session %p will be closed, error ignored\n", pSess);
				ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
			} else if (ret == 0) {
				dbgprintf("GSS-API Reverting to plain TCP\n");
				pGSess->allowedMethods = ALLOWEDMETHOD_TCP;
				ABORT_FINALIZE(RS_RET_OK); // TODO: define good error codes
			}

			do {
				ret = recv(fdSess, buf, sizeof (buf), MSG_PEEK);
			} while (ret < 0 && errno == EINTR);
			if (ret <= 0) {
				if (ret == 0)
					dbgprintf("GSS-API Connection closed by peer\n");
				else
					errmsg.LogError(0, RS_RET_ERR, "TCP(GSS) session %p will be closed, error ignored\n", pSess);
				ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
			}

			if (ret < 4) {
				dbgprintf("GSS-API Reverting to plain TCP\n");
				pGSess->allowedMethods = ALLOWEDMETHOD_TCP;
				ABORT_FINALIZE(RS_RET_OK); // TODO: define good error codes
			} else if (ret == 4) {
				/* The client might has been interupted after sending
				 * the data length (4B), give him another chance.
				 */
				srSleep(1, 0);
				do {
					ret = recv(fdSess, buf, sizeof (buf), MSG_PEEK);
				} while (ret < 0 && errno == EINTR);
				if (ret <= 0) {
					if (ret == 0)
						dbgprintf("GSS-API Connection closed by peer\n");
					else
						errmsg.LogError(0, NO_ERRCODE, "TCP session %p will be closed, error ignored\n", pSess);
					ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
				}
			}

			/* TODO: how does this work together with IPv6? Does it? */
			len = ntohl((buf[0] << 24)
				    | (buf[1] << 16)
				    | (buf[2] << 8)
				    | buf[3]);
			if ((ret - 4) < len || len == 0) {
				dbgprintf("GSS-API Reverting to plain TCP\n");
				pGSess->allowedMethods = ALLOWEDMETHOD_TCP;
				ABORT_FINALIZE(RS_RET_OK); // TODO: define good error codes
			}
		}

		context = &pGSess->gss_context;
		*context = GSS_C_NO_CONTEXT;
		sess_flags = &pGSess->gss_flags;
		do {
			if (gssutil.recv_token(fdSess, &recv_tok) <= 0) {
				errmsg.LogError(0, NO_ERRCODE, "TCP session %p will be closed, error ignored\n", pSess);
				ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
			}
			maj_stat = gss_accept_sec_context(&acc_sec_min_stat, context, gss_server_creds,
							  &recv_tok, GSS_C_NO_CHANNEL_BINDINGS, &client,
							  NULL, &send_tok, sess_flags, NULL, NULL);
			if (recv_tok.value) {
				free(recv_tok.value);
				recv_tok.value = NULL;
			}
			if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED) {
				gss_release_buffer(&min_stat, &send_tok);
				if (*context != GSS_C_NO_CONTEXT)
					gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER);
				if ((allowedMethods & ALLOWEDMETHOD_TCP) && 
				    (GSS_ROUTINE_ERROR(maj_stat) == GSS_S_DEFECTIVE_TOKEN)) {
					dbgprintf("GSS-API Reverting to plain TCP\n");
					dbgprintf("tcp session socket with new data: #%d\n", fdSess);
					if(tcps_sess.DataRcvd(pSess, buf, ret) != RS_RET_OK) {
						errmsg.LogError(0, NO_ERRCODE, "Tearing down TCP Session %p - see "
							    "previous messages for reason(s)\n", pSess);
						ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
					}
					pGSess->allowedMethods = ALLOWEDMETHOD_TCP;
					ABORT_FINALIZE(RS_RET_OK); // TODO: define good error codes
				}
				gssutil.display_status("accepting context", maj_stat, acc_sec_min_stat);
				ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
			}
			if (send_tok.length != 0) {
				if(gssutil.send_token(fdSess, &send_tok) < 0) {
					gss_release_buffer(&min_stat, &send_tok);
					errmsg.LogError(0, NO_ERRCODE, "TCP session %p will be closed, error ignored\n", pSess);
					if (*context != GSS_C_NO_CONTEXT)
						gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER);
					ABORT_FINALIZE(RS_RET_ERR); // TODO: define good error codes
				}
				gss_release_buffer(&min_stat, &send_tok);
			}
		} while (maj_stat == GSS_S_CONTINUE_NEEDED);

		maj_stat = gss_display_name(&min_stat, client, &recv_tok, NULL);
		if (maj_stat != GSS_S_COMPLETE)
			gssutil.display_status("displaying name", maj_stat, min_stat);
		else
			dbgprintf("GSS-API Accepted connection from: %s\n", (char*) recv_tok.value);
		gss_release_name(&min_stat, &client);
		gss_release_buffer(&min_stat, &recv_tok);

		dbgprintf("GSS-API Provided context flags:\n");
		gssutil.display_ctx_flags(*sess_flags);
		pGSess->allowedMethods = ALLOWEDMETHOD_GSS;
	}
	
finalize_it:
	RETiRet;
}


/* Replaces recv() for gssapi connections.
 */
int TCPSessGSSRecv(tcps_sess_t *pSess, void *buf, size_t buf_len, ssize_t *piLenRcvd)
{
	DEFiRet;
	gss_buffer_desc xmit_buf, msg_buf;
	gss_ctx_id_t *context;
	OM_uint32 maj_stat, min_stat;
	int fdSess;
	int     conf_state;
	int state;
	gss_sess_t *pGSess;

	assert(pSess->pUsr != NULL);
	assert(piLenRcvd != NULL);
	pGSess = (gss_sess_t*) pSess->pUsr;

	netstrm.GetSock(pSess->pStrm, &fdSess); // TODO: method access, CHKiRet!
	if ((state = gssutil.recv_token(fdSess, &xmit_buf)) <= 0)
		ABORT_FINALIZE(RS_RET_GSS_ERR);

	context = &pGSess->gss_context;
	maj_stat = gss_unwrap(&min_stat, *context, &xmit_buf, &msg_buf,
			      &conf_state, (gss_qop_t *) NULL);
	if(maj_stat != GSS_S_COMPLETE) {
		gssutil.display_status("unsealing message", maj_stat, min_stat);
		if(xmit_buf.value) {
			free(xmit_buf.value);
			xmit_buf.value = 0;
		}
		ABORT_FINALIZE(RS_RET_GSS_ERR);
	}
	if (xmit_buf.value) {
		free(xmit_buf.value);
		xmit_buf.value = 0;
	}

	*piLenRcvd = msg_buf.length < buf_len ? msg_buf.length : buf_len;
	memcpy(buf, msg_buf.value, *piLenRcvd);
	gss_release_buffer(&min_stat, &msg_buf);

finalize_it:
	RETiRet;
}


/* Takes care of cleaning up gssapi stuff and then calls
 * TCPSessClose().
 */
void TCPSessGSSClose(tcps_sess_t* pSess)
{
	OM_uint32 maj_stat, min_stat;
	gss_ctx_id_t *context;
	gss_sess_t *pGSess;

	assert(pSess->pUsr != NULL);
	pGSess = (gss_sess_t*) pSess->pUsr;

	context = &pGSess->gss_context;
	maj_stat = gss_delete_sec_context(&min_stat, context, GSS_C_NO_BUFFER);
	if (maj_stat != GSS_S_COMPLETE)
		gssutil.display_status("deleting context", maj_stat, min_stat);
	*context = GSS_C_NO_CONTEXT;
	pGSess->gss_flags = 0;
	pGSess->allowedMethods = 0;

	tcps_sess.Close(pSess);
}


/* Counterpart of TCPSessGSSInit(). This is called to exit the GSS system
 * at all. It is a server-based session exit. 
 */
static rsRetVal
TCPSessGSSDeinit(void)
{
	DEFiRet;
	OM_uint32 maj_stat, min_stat;

	if (gss_server_creds != GSS_C_NO_CREDENTIAL) {
		maj_stat = gss_release_cred(&min_stat, &gss_server_creds);
		if (maj_stat != GSS_S_COMPLETE)
			gssutil.display_status("releasing credentials", maj_stat, min_stat);
	}
	RETiRet;
}

/* This function is called to gather input.
 */
BEGINrunInput
CODESTARTrunInput
	iRet = tcpsrv.Run(pOurTcpsrv);
ENDrunInput


/* initialize and return if will run or not */
BEGINwillRun
CODESTARTwillRun
	if(pOurTcpsrv == NULL)
		ABORT_FINALIZE(RS_RET_NO_RUN);

	net.PrintAllowedSenders(2); /* TCP */
	net.PrintAllowedSenders(3); /* GSS */
finalize_it:
ENDwillRun



BEGINmodExit
CODESTARTmodExit
	if(pOurTcpsrv != NULL)
		iRet = tcpsrv.Destruct(&pOurTcpsrv);
	TCPSessGSSDeinit();

	/* release objects we used */
	objRelease(tcps_sess, LM_TCPSRV_FILENAME);
	objRelease(tcpsrv, LM_TCPSRV_FILENAME);
	objRelease(gssutil, LM_GSSUTIL_FILENAME);
	objRelease(errmsg, CORE_COMPONENT);
	objRelease(glbl, CORE_COMPONENT);
	objRelease(netstrm, LM_NETSTRM_FILENAME);
	objRelease(net, LM_NET_FILENAME);
ENDmodExit


BEGINafterRun
CODESTARTafterRun
	/* do cleanup here */
	net.clearAllowedSenders((uchar*)"TCP");
	net.clearAllowedSenders((uchar*)"GSS");
ENDafterRun


BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_IMOD_QUERIES
ENDqueryEtryPt


static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __attribute__((unused)) *pVal)
{
	if (gss_listen_service_name != NULL) {
		free(gss_listen_service_name);
		gss_listen_service_name = NULL;
	}
	bPermitPlainTcp = 0;
	iTCPSessMax = 200;
	return RS_RET_OK;
}


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current definition */
CODEmodInit_QueryRegCFSLineHdlr
	pOurTcpsrv = NULL;
	/* request objects we use */
	CHKiRet(objUse(tcps_sess, LM_TCPSRV_FILENAME));
	CHKiRet(objUse(tcpsrv, LM_TCPSRV_FILENAME));
	CHKiRet(objUse(gssutil, LM_GSSUTIL_FILENAME));
	CHKiRet(objUse(errmsg, CORE_COMPONENT));
	CHKiRet(objUse(glbl, CORE_COMPONENT));
	CHKiRet(objUse(netstrm, LM_NETSTRM_FILENAME));
	CHKiRet(objUse(net, LM_NET_FILENAME));

	/* register config file handlers */
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputgssserverpermitplaintcp", 0, eCmdHdlrBinary,
				   NULL, &bPermitPlainTcp, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputgssserverrun", 0, eCmdHdlrGetWord,
				   addGSSListener, NULL, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputgssserverservicename", 0, eCmdHdlrGetWord,
				   NULL, &gss_listen_service_name, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"inputgssservermaxsessions", 0, eCmdHdlrInt,
				   NULL, &iTCPSessMax, STD_LOADABLE_MODULE_ID));
	CHKiRet(omsdRegCFSLineHdlr((uchar *)"resetconfigvariables", 1, eCmdHdlrCustomHandler,
		resetConfigVariables, NULL, STD_LOADABLE_MODULE_ID));
ENDmodInit

/* vim:set ai:
 */