alias_nbt.c@ 64808

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1	/*-
2	* Written by Atsushi Murai <[email protected]>
3	* Copyright (c) 1998, System Planning and Engineering Co.
4	* All rights reserved.
5	*
6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions
8	* are met:
9	* 1. Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.
11	* 2. Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.
14	*
15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25	* SUCH DAMAGE.
26	* TODO:
27	* oClean up.
28	* oConsidering for word alignment for other platform.
29	*/
30
31	#ifndef VBOX
32	#include <sys/cdefs.h>
33	__FBSDID("$FreeBSD: src/sys/netinet/libalias/alias_nbt.c,v 1.20.8.1 2009/04/15 03:14:26 kensmith Exp $");
34
35	/*
36	alias_nbt.c performs special processing for NetBios over TCP/IP
37	sessions by UDP.
38
39	Initial version: May, 1998 (Atsushi Murai <[email protected]>)
40
41	See HISTORY file for record of revisions.
42	*/
43
44	/* Includes */
45	#ifdef _KERNEL
46	#include <sys/param.h>
47	#include <sys/systm.h>
48	#include <sys/kernel.h>
49	#include <sys/module.h>
50	#else
51	#include <errno.h>
52	#include <sys/types.h>
53	#include <stdio.h>
54	#endif
55
56	#include <netinet/in_systm.h>
57	#include <netinet/in.h>
58	#include <netinet/ip.h>
59	#include <netinet/udp.h>
60
61	#ifdef _KERNEL
62	#include <netinet/libalias/alias_local.h>
63	#include <netinet/libalias/alias_mod.h>
64	#else
65	#include "alias_local.h"
66	#include "alias_mod.h"
67	#endif
68	#else /* VBOX */
69	# include <iprt/ctype.h>
70	# include <slirp.h>
71	# include "alias_local.h"
72	# include "alias_mod.h"
73	# define isprint RT_C_IS_PRINT
74	#endif /* VBOX */
75
76	#define NETBIOS_NS_PORT_NUMBER 137
77	#define NETBIOS_DGM_PORT_NUMBER 138
78
79	static int
80	AliasHandleUdpNbt(struct libalias , struct ip , struct alias_link *,
81	struct in_addr *, u_short);
82
83	static int
84	AliasHandleUdpNbtNS(struct libalias , struct ip , struct alias_link *,
85	struct in_addr , u_short , struct in_addr , u_short );
86	static int
87	fingerprint1(struct libalias la, struct ip pip, struct alias_data *ah)
88	{
89
90	#ifdef VBOX
91	NOREF(la);
92	NOREF(pip);
93	#endif
94	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
95	ah->aaddr == NULL \|\| ah->aport == NULL)
96	return (-1);
97	if (ntohs(*ah->dport) == NETBIOS_DGM_PORT_NUMBER
98	\|\| ntohs(*ah->sport) == NETBIOS_DGM_PORT_NUMBER)
99	return (0);
100	return (-1);
101	}
102
103	static int
104	protohandler1(struct libalias la, struct ip pip, struct alias_data *ah)
105	{
106
107	AliasHandleUdpNbt(la, pip, ah->lnk, ah->aaddr, *ah->aport);
108	return (0);
109	}
110
111	static int
112	fingerprint2(struct libalias la, struct ip pip, struct alias_data *ah)
113	{
114
115	#ifdef VBOX
116	NOREF(la);
117	NOREF(pip);
118	#endif
119	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
120	ah->aaddr == NULL \|\| ah->aport == NULL)
121	return (-1);
122	if (ntohs(*ah->dport) == NETBIOS_NS_PORT_NUMBER
123	\|\| ntohs(*ah->sport) == NETBIOS_NS_PORT_NUMBER)
124	return (0);
125	return (-1);
126	}
127
128	static int
129	protohandler2in(struct libalias la, struct ip pip, struct alias_data *ah)
130	{
131
132	AliasHandleUdpNbtNS(la, pip, ah->lnk, ah->aaddr, ah->aport,
133	ah->oaddr, ah->dport);
134	return (0);
135	}
136
137	static int
138	protohandler2out(struct libalias la, struct ip pip, struct alias_data *ah)
139	{
140
141	AliasHandleUdpNbtNS(la, pip, ah->lnk, &pip->ip_src, ah->sport,
142	ah->aaddr, ah->aport);
143	return (0);
144	}
145
146	/* Kernel module definition. */
147	#ifndef VBOX
148	struct proto_handler handlers[] = {
149	{
150	.pri = 130,
151	.dir = IN\|OUT,
152	.proto = UDP,
153	.fingerprint = &fingerprint1,
154	.protohandler = &protohandler1
155	},
156	{
157	.pri = 140,
158	.dir = IN,
159	.proto = UDP,
160	.fingerprint = &fingerprint2,
161	.protohandler = &protohandler2in
162	},
163	{
164	.pri = 140,
165	.dir = OUT,
166	.proto = UDP,
167	.fingerprint = &fingerprint2,
168	.protohandler = &protohandler2out
169	},
170	{ EOH }
171	};
172	#else /* VBOX */
173	#define handlers pData->nbt_module
174	#endif /* VBOX */
175
176	#ifndef VBOX
177	static int
178	mod_handler(module_t mod, int type, void *data)
179	#else /* VBOX */
180	static int nbt_alias_handler(PNATState pData, int type);
181
182	int
183	nbt_alias_load(PNATState pData)
184	{
185	return nbt_alias_handler(pData, MOD_LOAD);
186	}
187
188	int
189	nbt_alias_unload(PNATState pData)
190	{
191	return nbt_alias_handler(pData, MOD_UNLOAD);
192	}
193	static int
194	nbt_alias_handler(PNATState pData, int type)
195	#endif /* VBOX */
196	{
197	int error;
198	#ifdef VBOX
199	if (handlers == NULL)
200	handlers = RTMemAllocZ(4 * sizeof(struct proto_handler));
201	handlers[0].pri = 130;
202	handlers[0].dir = IN\|OUT;
203	handlers[0].proto = UDP;
204	handlers[0].fingerprint = &fingerprint1;
205	handlers[0].protohandler = &protohandler1;
206
207
208	handlers[1].pri = 140;
209	handlers[1].dir = IN;
210	handlers[1].proto = UDP;
211	handlers[1].fingerprint = &fingerprint2;
212	handlers[1].protohandler = &protohandler2in;
213
214
215	handlers[2].pri = 140;
216	handlers[2].dir = OUT;
217	handlers[2].proto = UDP;
218	handlers[2].fingerprint = &fingerprint2;
219	handlers[2].protohandler = &protohandler2out;
220
221	handlers[3].pri = (u_int)EOH;
222	#endif /* VBOX */
223
224	switch (type) {
225	case MOD_LOAD:
226	error = 0;
227	#ifdef VBOX
228	LibAliasAttachHandlers(pData, handlers);
229	#else
230	LibAliasAttachHandlers(handlers);
231	#endif
232	break;
233	case MOD_UNLOAD:
234	error = 0;
235	#ifdef VBOX
236	LibAliasDetachHandlers(pData, handlers);
237	RTMemFree(handlers);
238	handlers = NULL;
239	#else
240	LibAliasDetachHandlers(handlers);
241	#endif
242	break;
243	default:
244	error = EINVAL;
245	}
246	return (error);
247	}
248
249	#ifndef VBOX
250	#ifdef _KERNEL
251	static
252	#endif
253	moduledata_t alias_mod = {
254	"alias_nbt", mod_handler, NULL
255	};
256	#endif /* !VBOX */
257
258	#ifdef _KERNEL
259	DECLARE_MODULE(alias_nbt, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
260	MODULE_VERSION(alias_nbt, 1);
261	MODULE_DEPEND(alias_nbt, libalias, 1, 1, 1);
262	#endif
263
264	typedef struct {
265	struct in_addr oldaddr;
266	u_short oldport;
267	struct in_addr newaddr;
268	u_short newport;
269	u_short *uh_sum;
270	} NBTArguments;
271
272	typedef struct {
273	unsigned char type;
274	unsigned char flags;
275	u_short id;
276	struct in_addr source_ip;
277	u_short source_port;
278	u_short len;
279	u_short offset;
280	} NbtDataHeader;
281
282	#define OpQuery 0
283	#define OpUnknown 4
284	#define OpRegist 5
285	#define OpRelease 6
286	#define OpWACK 7
287	#define OpRefresh 8
288	typedef struct {
289	#ifndef VBOX
290	u_short nametrid;
291	u_short dir: 1, opcode:4, nmflags:7, rcode:4;
292	#else
293	unsigned nametrid:16;
294	unsigned dir: 1, opcode:4, nmflags:7, rcode:4;
295	#endif
296	u_short qdcount;
297	u_short ancount;
298	u_short nscount;
299	u_short arcount;
300	} NbtNSHeader;
301	AssertCompileSize(NbtNSHeader, 12);
302
303	#define FMT_ERR 0x1
304	#define SRV_ERR 0x2
305	#define IMP_ERR 0x4
306	#define RFS_ERR 0x5
307	#define ACT_ERR 0x6
308	#define CFT_ERR 0x7
309
310
311	#ifdef LIBALIAS_DEBUG
312	static void
313	PrintRcode(u_char rcode)
314	{
315
316	switch (rcode) {
317	case FMT_ERR:
318	printf("\nFormat Error.");
319	case SRV_ERR:
320	printf("\nSever failure.");
321	case IMP_ERR:
322	printf("\nUnsupported request error.\n");
323	case RFS_ERR:
324	printf("\nRefused error.\n");
325	case ACT_ERR:
326	printf("\nActive error.\n");
327	case CFT_ERR:
328	printf("\nName in conflict error.\n");
329	default:
330	printf("\n?%c?=%0x\n", '?', rcode);
331
332	}
333	}
334
335	#endif
336
337
338	/* Handling Name field */
339	static u_char *
340	AliasHandleName(u_char * p, char *pmax)
341	{
342
343	u_char *s;
344	#ifdef LIBALIAS_DEBUG
345	u_char c;
346	#endif
347	int compress;
348
349	/* Following length field */
350
351	if (p == NULL \|\| (char *)p >= pmax)
352	return (NULL);
353
354	if (*p & 0xc0) {
355	p = p + 2;
356	if ((char *)p > pmax)
357	return (NULL);
358	return ((u_char *) p);
359	}
360	while ((*p & 0x3f) != 0x00) {
361	s = p + 1;
362	if (*p == 0x20)
363	compress = 1;
364	else
365	compress = 0;
366
367	/* Get next length field */
368	p = (u_char ) (p + (p & 0x3f) + 1);
369	if ((char *)p > pmax) {
370	p = NULL;
371	break;
372	}
373	#ifdef LIBALIAS_DEBUG
374	printf(":");
375	#endif
376	while (s < p) {
377	if (compress == 1) {
378	#ifdef LIBALIAS_DEBUG
379	c = (u_char) (((((s & 0x0f) << 4) \| ((s + 1) & 0x0f)) - 0x11));
380	if (isprint(c))
381	printf("%c", c);
382	else
383	printf("<0x%02x>", c);
384	#endif
385	s += 2;
386	} else {
387	#ifdef LIBALIAS_DEBUG
388	printf("%c", *s);
389	#endif
390	s++;
391	}
392	}
393	#ifdef LIBALIAS_DEBUG
394	printf(":");
395	fflush(stdout);
396	#endif
397	}
398
399	/* Set up to out of Name field */
400	if (p == NULL \|\| (char *)p >= pmax)
401	p = NULL;
402	else
403	p++;
404	return ((u_char *) p);
405	}
406
407	/*
408	* NetBios Datagram Handler (IP/UDP)
409	*/
410	#define DGM_DIRECT_UNIQ 0x10
411	#define DGM_DIRECT_GROUP 0x11
412	#define DGM_BROADCAST 0x12
413	#define DGM_ERROR 0x13
414	#define DGM_QUERY 0x14
415	#define DGM_POSITIVE_RES 0x15
416	#define DGM_NEGATIVE_RES 0x16
417
418	static int
419	AliasHandleUdpNbt(
420	struct libalias *la,
421	struct ip pip, / IP packet to examine/patch */
422	struct alias_link *lnk,
423	struct in_addr *alias_address,
424	u_short alias_port
425	)
426	{
427	struct udphdr *uh;
428	NbtDataHeader *ndh;
429	u_char *p = NULL;
430	char *pmax;
431
432	(void)la;
433	(void)lnk;
434
435	/* Calculate data length of UDP packet */
436	uh = (struct udphdr *)ip_next(pip);
437	pmax = (char *)uh + ntohs(uh->uh_ulen);
438
439	ndh = (NbtDataHeader *)udp_next(uh);
440	if ((char *)(ndh + 1) > pmax)
441	return (-1);
442	#ifdef LIBALIAS_DEBUG
443	printf("\nType=%02x,", ndh->type);
444	#endif
445	switch (ndh->type) {
446	case DGM_DIRECT_UNIQ:
447	case DGM_DIRECT_GROUP:
448	case DGM_BROADCAST:
449	p = (u_char *) ndh + 14;
450	p = AliasHandleName(p, pmax); /* Source Name */
451	p = AliasHandleName(p, pmax); /* Destination Name */
452	break;
453	case DGM_ERROR:
454	p = (u_char *) ndh + 11;
455	break;
456	case DGM_QUERY:
457	case DGM_POSITIVE_RES:
458	case DGM_NEGATIVE_RES:
459	p = (u_char *) ndh + 10;
460	p = AliasHandleName(p, pmax); /* Destination Name */
461	break;
462	}
463	if (p == NULL \|\| (char *)p > pmax)
464	p = NULL;
465	#ifdef LIBALIAS_DEBUG
466	printf("%s:%d-->", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
467	#endif
468	/* Doing an IP address and Port number Translation */
469	if (uh->uh_sum != 0) {
470	int acc;
471	u_short *sptr;
472
473	acc = ndh->source_port;
474	acc -= alias_port;
475	sptr = (u_short *) & (ndh->source_ip);
476	acc += *sptr++;
477	acc += *sptr;
478	sptr = (u_short *) alias_address;
479	acc -= *sptr++;
480	acc -= *sptr;
481	ADJUST_CHECKSUM(acc, uh->uh_sum);
482	}
483	ndh->source_ip = *alias_address;
484	ndh->source_port = alias_port;
485	#ifdef LIBALIAS_DEBUG
486	printf("%s:%d\n", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
487	fflush(stdout);
488	#endif
489	return ((p == NULL) ? -1 : 0);
490	}
491
492	/* Question Section */
493	#define QS_TYPE_NB 0x0020
494	#define QS_TYPE_NBSTAT 0x0021
495	#define QS_CLAS_IN 0x0001
496	typedef struct {
497	u_short type; /* The type of Request */
498	u_short class; /* The class of Request */
499	} NBTNsQuestion;
500
501	static u_char *
502	AliasHandleQuestion(
503	u_short count,
504	NBTNsQuestion * q,
505	char *pmax,
506	NBTArguments * nbtarg)
507	{
508
509	(void)nbtarg;
510
511	while (count != 0) {
512	/* Name Filed */
513	q = (NBTNsQuestion ) AliasHandleName((u_char ) q, pmax);
514
515	if (q == NULL \|\| (char *)(q + 1) > pmax) {
516	q = NULL;
517	break;
518	}
519	/* Type and Class filed */
520	switch (ntohs(q->type)) {
521	case QS_TYPE_NB:
522	case QS_TYPE_NBSTAT:
523	q = q + 1;
524	break;
525	default:
526	#ifdef LIBALIAS_DEBUG
527	printf("\nUnknown Type on Question %0x\n", ntohs(q->type));
528	#endif
529	break;
530	}
531	count--;
532	}
533
534	/* Set up to out of Question Section */
535	return ((u_char *) q);
536	}
537
538	/* Resource Record */
539	#define RR_TYPE_A 0x0001
540	#define RR_TYPE_NS 0x0002
541	#define RR_TYPE_NULL 0x000a
542	#define RR_TYPE_NB 0x0020
543	#define RR_TYPE_NBSTAT 0x0021
544	#define RR_CLAS_IN 0x0001
545	#define SizeOfNsResource 8
546	typedef struct {
547	u_short type;
548	u_short class;
549	unsigned int ttl;
550	u_short rdlen;
551	} NBTNsResource;
552
553	#define SizeOfNsRNB 6
554	typedef struct {
555	#ifndef VBOX
556	u_short g: 1 , ont:2, resv:13;
557	#else
558	unsigned g: 1 , ont:2, resv:13;
559	#endif
560	struct in_addr addr;
561	} NBTNsRNB;
562	AssertCompileSize(NBTNsRNB, 8);
563
564	static u_char *
565	AliasHandleResourceNB(
566	NBTNsResource * q,
567	char *pmax,
568	NBTArguments * nbtarg)
569	{
570	NBTNsRNB *nb;
571	u_short bcount;
572
573	if (q == NULL \|\| (char *)(q + 1) > pmax)
574	return (NULL);
575	/* Check out a length */
576	bcount = ntohs(q->rdlen);
577
578	/* Forward to Resource NB position */
579	nb = (NBTNsRNB ) ((u_char ) q + SizeOfNsResource);
580
581	/* Processing all in_addr array */
582	#ifdef LIBALIAS_DEBUG
583	printf("NB rec[%s", inet_ntoa(nbtarg->oldaddr));
584	printf("->%s, %dbytes] ", inet_ntoa(nbtarg->newaddr), bcount);
585	#endif
586	while (nb != NULL && bcount != 0) {
587	if ((char *)(nb + 1) > pmax) {
588	nb = NULL;
589	break;
590	}
591	#ifdef LIBALIAS_DEBUG
592	printf("<%s>", inet_ntoa(nb->addr));
593	#endif
594	if (!bcmp(&nbtarg->oldaddr, &nb->addr, sizeof(struct in_addr))) {
595	if (*nbtarg->uh_sum != 0) {
596	int acc;
597	u_short *sptr;
598
599	sptr = (u_short *) & (nb->addr);
600	acc = *sptr++;
601	acc += *sptr;
602	sptr = (u_short *) & (nbtarg->newaddr);
603	acc -= *sptr++;
604	acc -= *sptr;
605	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
606	}
607	nb->addr = nbtarg->newaddr;
608	#ifdef LIBALIAS_DEBUG
609	printf("O");
610	#endif
611	}
612	#ifdef LIBALIAS_DEBUG
613	else {
614	printf(".");
615	}
616	#endif
617	nb = (NBTNsRNB ) ((u_char ) nb + SizeOfNsRNB);
618	bcount -= SizeOfNsRNB;
619	}
620	if (nb == NULL \|\| (char *)(nb + 1) > pmax) {
621	nb = NULL;
622	}
623	return ((u_char *) nb);
624	}
625
626	#define SizeOfResourceA 6
627	typedef struct {
628	struct in_addr addr;
629	} NBTNsResourceA;
630
631	static u_char *
632	AliasHandleResourceA(
633	NBTNsResource * q,
634	char *pmax,
635	NBTArguments * nbtarg)
636	{
637	NBTNsResourceA *a;
638	u_short bcount;
639
640	if (q == NULL \|\| (char *)(q + 1) > pmax)
641	return (NULL);
642
643	/* Forward to Resource A position */
644	a = (NBTNsResourceA ) ((u_char ) q + sizeof(NBTNsResource));
645
646	/* Check out of length */
647	bcount = ntohs(q->rdlen);
648
649	/* Processing all in_addr array */
650	#ifdef LIBALIAS_DEBUG
651	printf("Arec [%s", inet_ntoa(nbtarg->oldaddr));
652	printf("->%s]", inet_ntoa(nbtarg->newaddr));
653	#endif
654	while (bcount != 0) {
655	if (a == NULL \|\| (char *)(a + 1) > pmax)
656	return (NULL);
657	#ifdef LIBALIAS_DEBUG
658	printf("..%s", inet_ntoa(a->addr));
659	#endif
660	if (!bcmp(&nbtarg->oldaddr, &a->addr, sizeof(struct in_addr))) {
661	if (*nbtarg->uh_sum != 0) {
662	int acc;
663	u_short *sptr;
664
665	sptr = (u_short ) & (a->addr); / Old */
666	acc = *sptr++;
667	acc += *sptr;
668	sptr = (u_short ) & nbtarg->newaddr; / New */
669	acc -= *sptr++;
670	acc -= *sptr;
671	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
672	}
673	a->addr = nbtarg->newaddr;
674	}
675	a++; /* XXXX */
676	bcount -= SizeOfResourceA;
677	}
678	if (a == NULL \|\| (char *)(a + 1) > pmax)
679	a = NULL;
680	return ((u_char *) a);
681	}
682
683	typedef struct {
684	#ifndef VBOX
685	u_short opcode:4, flags:8, resv:4;
686	#else
687	u_short hidden; /* obviously not needed */
688	#endif
689	} NBTNsResourceNULL;
690	AssertCompileSize(NBTNsResourceNULL, 2);
691
692	static u_char *
693	AliasHandleResourceNULL(
694	NBTNsResource * q,
695	char *pmax,
696	NBTArguments * nbtarg)
697	{
698	NBTNsResourceNULL *n;
699	u_short bcount;
700
701	(void)nbtarg;
702
703	if (q == NULL \|\| (char *)(q + 1) > pmax)
704	return (NULL);
705
706	/* Forward to Resource NULL position */
707	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
708
709	/* Check out of length */
710	bcount = ntohs(q->rdlen);
711
712	/* Processing all in_addr array */
713	while (bcount != 0) {
714	if ((char *)(n + 1) > pmax) {
715	n = NULL;
716	break;
717	}
718	n++;
719	bcount -= sizeof(NBTNsResourceNULL);
720	}
721	if ((char *)(n + 1) > pmax)
722	n = NULL;
723
724	return ((u_char *) n);
725	}
726
727	static u_char *
728	AliasHandleResourceNS(
729	NBTNsResource * q,
730	char *pmax,
731	NBTArguments * nbtarg)
732	{
733	NBTNsResourceNULL *n;
734	u_short bcount;
735
736	(void)nbtarg;
737
738	if (q == NULL \|\| (char *)(q + 1) > pmax)
739	return (NULL);
740
741	/* Forward to Resource NULL position */
742	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
743
744	/* Check out of length */
745	bcount = ntohs(q->rdlen);
746
747	/* Resource Record Name Filed */
748	q = (NBTNsResource ) AliasHandleName((u_char ) n, pmax); /* XXX */
749
750	if (q == NULL \|\| (char )((u_char ) n + bcount) > pmax)
751	return (NULL);
752	else
753	return ((u_char *) n + bcount);
754	}
755
756	typedef struct {
757	u_short numnames;
758	} NBTNsResourceNBSTAT;
759
760	static u_char *
761	AliasHandleResourceNBSTAT(
762	NBTNsResource * q,
763	char *pmax,
764	NBTArguments * nbtarg)
765	{
766	NBTNsResourceNBSTAT *n;
767	u_short bcount;
768
769	(void)nbtarg;
770
771	if (q == NULL \|\| (char *)(q + 1) > pmax)
772	return (NULL);
773
774	/* Forward to Resource NBSTAT position */
775	n = (NBTNsResourceNBSTAT ) ((u_char ) q + sizeof(NBTNsResource));
776
777	/* Check out of length */
778	bcount = ntohs(q->rdlen);
779
780	if ((char )((u_char ) n + bcount) > pmax)
781	return (NULL);
782	else
783	return ((u_char *) n + bcount);
784	}
785
786	static u_char *
787	AliasHandleResource(
788	u_short count,
789	NBTNsResource * q,
790	char *pmax,
791	NBTArguments
792	* nbtarg)
793	{
794	while (count != 0) {
795	/* Resource Record Name Filed */
796	q = (NBTNsResource ) AliasHandleName((u_char ) q, pmax);
797
798	if (q == NULL \|\| (char *)(q + 1) > pmax)
799	break;
800	#ifdef LIBALIAS_DEBUG
801	printf("type=%02x, count=%d\n", ntohs(q->type), count);
802	#endif
803
804	/* Type and Class filed */
805	switch (ntohs(q->type)) {
806	case RR_TYPE_NB:
807	q = (NBTNsResource *) AliasHandleResourceNB(
808	q,
809	pmax,
810	nbtarg
811	);
812	break;
813	case RR_TYPE_A:
814	q = (NBTNsResource *) AliasHandleResourceA(
815	q,
816	pmax,
817	nbtarg
818	);
819	break;
820	case RR_TYPE_NS:
821	q = (NBTNsResource *) AliasHandleResourceNS(
822	q,
823	pmax,
824	nbtarg
825	);
826	break;
827	case RR_TYPE_NULL:
828	q = (NBTNsResource *) AliasHandleResourceNULL(
829	q,
830	pmax,
831	nbtarg
832	);
833	break;
834	case RR_TYPE_NBSTAT:
835	q = (NBTNsResource *) AliasHandleResourceNBSTAT(
836	q,
837	pmax,
838	nbtarg
839	);
840	break;
841	default:
842	#ifdef LIBALIAS_DEBUG
843	printf(
844	"\nUnknown Type of Resource %0x\n",
845	ntohs(q->type)
846	);
847	fflush(stdout);
848	#endif
849	break;
850	}
851	count--;
852	}
853	return ((u_char *) q);
854	}
855
856	static int
857	AliasHandleUdpNbtNS(
858	struct libalias *la,
859	struct ip pip, / IP packet to examine/patch */
860	struct alias_link *lnk,
861	struct in_addr *alias_address,
862	u_short * alias_port,
863	struct in_addr *original_address,
864	u_short * original_port)
865	{
866	struct udphdr *uh;
867	NbtNSHeader *nsh;
868	u_char *p;
869	char *pmax;
870	NBTArguments nbtarg;
871
872	(void)la;
873	(void)lnk;
874
875	/* Set up Common Parameter */
876	nbtarg.oldaddr = *alias_address;
877	nbtarg.oldport = *alias_port;
878	nbtarg.newaddr = *original_address;
879	nbtarg.newport = *original_port;
880
881	/* Calculate data length of UDP packet */
882	uh = (struct udphdr *)ip_next(pip);
883	nbtarg.uh_sum = &(uh->uh_sum);
884	nsh = (NbtNSHeader *)udp_next(uh);
885	p = (u_char *) (nsh + 1);
886	pmax = (char *)uh + ntohs(uh->uh_ulen);
887
888	if ((char *)(nsh + 1) > pmax)
889	return (-1);
890
891	#ifdef LIBALIAS_DEBUG
892	printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x"
893	", an=%04x, ns=%04x, ar=%04x, [%d]-->",
894	nsh->dir ? "Response" : "Request",
895	nsh->nametrid,
896	nsh->opcode,
897	nsh->nmflags,
898	nsh->rcode,
899	ntohs(nsh->qdcount),
900	ntohs(nsh->ancount),
901	ntohs(nsh->nscount),
902	ntohs(nsh->arcount),
903	(u_char ) p - (u_char ) nsh
904	);
905	#endif
906
907	/* Question Entries */
908	if (ntohs(nsh->qdcount) != 0) {
909	p = AliasHandleQuestion(
910	ntohs(nsh->qdcount),
911	(NBTNsQuestion *) p,
912	pmax,
913	&nbtarg
914	);
915	}
916	/* Answer Resource Records */
917	if (ntohs(nsh->ancount) != 0) {
918	p = AliasHandleResource(
919	ntohs(nsh->ancount),
920	(NBTNsResource *) p,
921	pmax,
922	&nbtarg
923	);
924	}
925	/* Authority Resource Recodrs */
926	if (ntohs(nsh->nscount) != 0) {
927	p = AliasHandleResource(
928	ntohs(nsh->nscount),
929	(NBTNsResource *) p,
930	pmax,
931	&nbtarg
932	);
933	}
934	/* Additional Resource Recodrs */
935	if (ntohs(nsh->arcount) != 0) {
936	p = AliasHandleResource(
937	ntohs(nsh->arcount),
938	(NBTNsResource *) p,
939	pmax,
940	&nbtarg
941	);
942	}
943	#ifdef LIBALIAS_DEBUG
944	PrintRcode(nsh->rcode);
945	#endif
946	return ((p == NULL) ? -1 : 0);
947	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/libalias/alias_nbt.c@ 64808

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