alias_nbt.c@ 22452

Last change on this file since 22452 was 22452, checked in by vboxsync, 15 years ago
NAT/libalias: don't alloc to much
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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	#endif /VBOX/
74
75	#define NETBIOS_NS_PORT_NUMBER 137
76	#define NETBIOS_DGM_PORT_NUMBER 138
77
78	static int
79	AliasHandleUdpNbt(struct libalias , struct ip , struct alias_link *,
80	struct in_addr *, u_short);
81
82	static int
83	AliasHandleUdpNbtNS(struct libalias , struct ip , struct alias_link *,
84	struct in_addr , u_short , struct in_addr , u_short );
85	static int
86	fingerprint1(struct libalias la, struct ip pip, struct alias_data *ah)
87	{
88
89	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
90	ah->aaddr == NULL \|\| ah->aport == NULL)
91	return (-1);
92	if (ntohs(*ah->dport) == NETBIOS_DGM_PORT_NUMBER
93	\|\| ntohs(*ah->sport) == NETBIOS_DGM_PORT_NUMBER)
94	return (0);
95	return (-1);
96	}
97
98	static int
99	protohandler1(struct libalias la, struct ip pip, struct alias_data *ah)
100	{
101
102	AliasHandleUdpNbt(la, pip, ah->lnk, ah->aaddr, *ah->aport);
103	return (0);
104	}
105
106	static int
107	fingerprint2(struct libalias la, struct ip pip, struct alias_data *ah)
108	{
109
110	if (ah->dport == NULL \|\| ah->sport == NULL \|\| ah->lnk == NULL \|\|
111	ah->aaddr == NULL \|\| ah->aport == NULL)
112	return (-1);
113	if (ntohs(*ah->dport) == NETBIOS_NS_PORT_NUMBER
114	\|\| ntohs(*ah->sport) == NETBIOS_NS_PORT_NUMBER)
115	return (0);
116	return (-1);
117	}
118
119	static int
120	protohandler2in(struct libalias la, struct ip pip, struct alias_data *ah)
121	{
122
123	AliasHandleUdpNbtNS(la, pip, ah->lnk, ah->aaddr, ah->aport,
124	ah->oaddr, ah->dport);
125	return (0);
126	}
127
128	static int
129	protohandler2out(struct libalias la, struct ip pip, struct alias_data *ah)
130	{
131
132	AliasHandleUdpNbtNS(la, pip, ah->lnk, &pip->ip_src, ah->sport,
133	ah->aaddr, ah->aport);
134	return (0);
135	}
136
137	/* Kernel module definition. */
138	#ifndef VBOX
139	struct proto_handler handlers[] = {
140	{
141	.pri = 130,
142	.dir = IN\|OUT,
143	.proto = UDP,
144	.fingerprint = &fingerprint1,
145	.protohandler = &protohandler1
146	},
147	{
148	.pri = 140,
149	.dir = IN,
150	.proto = UDP,
151	.fingerprint = &fingerprint2,
152	.protohandler = &protohandler2in
153	},
154	{
155	.pri = 140,
156	.dir = OUT,
157	.proto = UDP,
158	.fingerprint = &fingerprint2,
159	.protohandler = &protohandler2out
160	},
161	{ EOH }
162	};
163	#else /* !VBOX */
164	#define handlers pData->nbt_module
165	#endif /VBOX/
166
167	#ifndef VBOX
168	static int
169	mod_handler(module_t mod, int type, void *data)
170	#else /!VBOX/
171	static int nbt_alias_handler(PNATState pData, int type);
172
173	int
174	nbt_alias_load(PNATState pData)
175	{
176	return nbt_alias_handler(pData, MOD_LOAD);
177	}
178
179	int
180	nbt_alias_unload(PNATState pData)
181	{
182	return nbt_alias_handler(pData, MOD_UNLOAD);
183	}
184	static int
185	nbt_alias_handler(PNATState pData, int type)
186	#endif /VBOX/
187	{
188	int error;
189	#ifdef VBOX
190	if (handlers == NULL)
191	handlers = RTMemAllocZ(4 * sizeof(struct proto_handler));
192	handlers[0].pri = 130;
193	handlers[0].dir = IN\|OUT;
194	handlers[0].proto = UDP;
195	handlers[0].fingerprint = &fingerprint1;
196	handlers[0].protohandler = &protohandler1;
197
198
199	handlers[1].pri = 140;
200	handlers[1].dir = IN;
201	handlers[1].proto = UDP;
202	handlers[1].fingerprint = &fingerprint2;
203	handlers[1].protohandler = &protohandler2in;
204
205
206	handlers[2].pri = 140;
207	handlers[2].dir = OUT;
208	handlers[2].proto = UDP;
209	handlers[2].fingerprint = &fingerprint2;
210	handlers[2].protohandler = &protohandler2out;
211
212	handlers[3].pri = EOH;
213	#endif /VBOX/
214
215	switch (type) {
216	case MOD_LOAD:
217	error = 0;
218	#ifdef VBOX
219	LibAliasAttachHandlers(pData, handlers);
220	#else
221	LibAliasAttachHandlers(handlers);
222	#endif
223	break;
224	case MOD_UNLOAD:
225	error = 0;
226	#ifdef VBOX
227	LibAliasDetachHandlers(pData, handlers);
228	RTMemFree(handlers);
229	handlers = NULL;
230	#else
231	LibAliasDetachHandlers(handlers);
232	#endif
233	break;
234	default:
235	error = EINVAL;
236	}
237	return (error);
238	}
239
240	#ifndef VBOX
241	#ifdef _KERNEL
242	static
243	#endif
244	moduledata_t alias_mod = {
245	"alias_nbt", mod_handler, NULL
246	};
247	#endif /!VBOX/
248
249	#ifdef _KERNEL
250	DECLARE_MODULE(alias_nbt, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
251	MODULE_VERSION(alias_nbt, 1);
252	MODULE_DEPEND(alias_nbt, libalias, 1, 1, 1);
253	#endif
254
255	typedef struct {
256	struct in_addr oldaddr;
257	u_short oldport;
258	struct in_addr newaddr;
259	u_short newport;
260	u_short *uh_sum;
261	} NBTArguments;
262
263	typedef struct {
264	unsigned char type;
265	unsigned char flags;
266	u_short id;
267	struct in_addr source_ip;
268	u_short source_port;
269	u_short len;
270	u_short offset;
271	} NbtDataHeader;
272
273	#define OpQuery 0
274	#define OpUnknown 4
275	#define OpRegist 5
276	#define OpRelease 6
277	#define OpWACK 7
278	#define OpRefresh 8
279	typedef struct {
280	u_short nametrid;
281	u_short dir: 1, opcode:4, nmflags:7, rcode:4;
282	u_short qdcount;
283	u_short ancount;
284	u_short nscount;
285	u_short arcount;
286	} NbtNSHeader;
287
288	#define FMT_ERR 0x1
289	#define SRV_ERR 0x2
290	#define IMP_ERR 0x4
291	#define RFS_ERR 0x5
292	#define ACT_ERR 0x6
293	#define CFT_ERR 0x7
294
295
296	#ifdef LIBALIAS_DEBUG
297	static void
298	PrintRcode(u_char rcode)
299	{
300
301	switch (rcode) {
302	case FMT_ERR:
303	printf("\nFormat Error.");
304	case SRV_ERR:
305	printf("\nSever failure.");
306	case IMP_ERR:
307	printf("\nUnsupported request error.\n");
308	case RFS_ERR:
309	printf("\nRefused error.\n");
310	case ACT_ERR:
311	printf("\nActive error.\n");
312	case CFT_ERR:
313	printf("\nName in conflict error.\n");
314	default:
315	printf("\n?%c?=%0x\n", '?', rcode);
316
317	}
318	}
319
320	#endif
321
322
323	/* Handling Name field */
324	static u_char *
325	AliasHandleName(u_char * p, char *pmax)
326	{
327
328	u_char *s;
329	u_char c;
330	int compress;
331
332	/* Following length field */
333
334	if (p == NULL \|\| (char *)p >= pmax)
335	return (NULL);
336
337	if (*p & 0xc0) {
338	p = p + 2;
339	if ((char *)p > pmax)
340	return (NULL);
341	return ((u_char *) p);
342	}
343	while ((*p & 0x3f) != 0x00) {
344	s = p + 1;
345	if (*p == 0x20)
346	compress = 1;
347	else
348	compress = 0;
349
350	/* Get next length field */
351	p = (u_char ) (p + (p & 0x3f) + 1);
352	if ((char *)p > pmax) {
353	p = NULL;
354	break;
355	}
356	#ifdef LIBALIAS_DEBUG
357	printf(":");
358	#endif
359	while (s < p) {
360	if (compress == 1) {
361	c = (u_char) (((((s & 0x0f) << 4) \| ((s + 1) & 0x0f)) - 0x11));
362	#ifdef LIBALIAS_DEBUG
363	if (isprint(c))
364	printf("%c", c);
365	else
366	printf("<0x%02x>", c);
367	#endif
368	s += 2;
369	} else {
370	#ifdef LIBALIAS_DEBUG
371	printf("%c", *s);
372	#endif
373	s++;
374	}
375	}
376	#ifdef LIBALIAS_DEBUG
377	printf(":");
378	fflush(stdout);
379	#endif
380	}
381
382	/* Set up to out of Name field */
383	if (p == NULL \|\| (char *)p >= pmax)
384	p = NULL;
385	else
386	p++;
387	return ((u_char *) p);
388	}
389
390	/*
391	* NetBios Datagram Handler (IP/UDP)
392	*/
393	#define DGM_DIRECT_UNIQ 0x10
394	#define DGM_DIRECT_GROUP 0x11
395	#define DGM_BROADCAST 0x12
396	#define DGM_ERROR 0x13
397	#define DGM_QUERY 0x14
398	#define DGM_POSITIVE_RES 0x15
399	#define DGM_NEGATIVE_RES 0x16
400
401	static int
402	AliasHandleUdpNbt(
403	struct libalias *la,
404	struct ip pip, / IP packet to examine/patch */
405	struct alias_link *lnk,
406	struct in_addr *alias_address,
407	u_short alias_port
408	)
409	{
410	struct udphdr *uh;
411	NbtDataHeader *ndh;
412	u_char *p = NULL;
413	char *pmax;
414
415	(void)la;
416	(void)lnk;
417
418	/* Calculate data length of UDP packet */
419	uh = (struct udphdr *)ip_next(pip);
420	pmax = (char *)uh + ntohs(uh->uh_ulen);
421
422	ndh = (NbtDataHeader *)udp_next(uh);
423	if ((char *)(ndh + 1) > pmax)
424	return (-1);
425	#ifdef LIBALIAS_DEBUG
426	printf("\nType=%02x,", ndh->type);
427	#endif
428	switch (ndh->type) {
429	case DGM_DIRECT_UNIQ:
430	case DGM_DIRECT_GROUP:
431	case DGM_BROADCAST:
432	p = (u_char *) ndh + 14;
433	p = AliasHandleName(p, pmax); /* Source Name */
434	p = AliasHandleName(p, pmax); /* Destination Name */
435	break;
436	case DGM_ERROR:
437	p = (u_char *) ndh + 11;
438	break;
439	case DGM_QUERY:
440	case DGM_POSITIVE_RES:
441	case DGM_NEGATIVE_RES:
442	p = (u_char *) ndh + 10;
443	p = AliasHandleName(p, pmax); /* Destination Name */
444	break;
445	}
446	if (p == NULL \|\| (char *)p > pmax)
447	p = NULL;
448	#ifdef LIBALIAS_DEBUG
449	printf("%s:%d-->", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
450	#endif
451	/* Doing an IP address and Port number Translation */
452	if (uh->uh_sum != 0) {
453	int acc;
454	u_short *sptr;
455
456	acc = ndh->source_port;
457	acc -= alias_port;
458	sptr = (u_short *) & (ndh->source_ip);
459	acc += *sptr++;
460	acc += *sptr;
461	sptr = (u_short *) alias_address;
462	acc -= *sptr++;
463	acc -= *sptr;
464	ADJUST_CHECKSUM(acc, uh->uh_sum);
465	}
466	ndh->source_ip = *alias_address;
467	ndh->source_port = alias_port;
468	#ifdef LIBALIAS_DEBUG
469	printf("%s:%d\n", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port));
470	fflush(stdout);
471	#endif
472	return ((p == NULL) ? -1 : 0);
473	}
474
475	/* Question Section */
476	#define QS_TYPE_NB 0x0020
477	#define QS_TYPE_NBSTAT 0x0021
478	#define QS_CLAS_IN 0x0001
479	typedef struct {
480	u_short type; /* The type of Request */
481	u_short class; /* The class of Request */
482	} NBTNsQuestion;
483
484	static u_char *
485	AliasHandleQuestion(
486	u_short count,
487	NBTNsQuestion * q,
488	char *pmax,
489	NBTArguments * nbtarg)
490	{
491
492	(void)nbtarg;
493
494	while (count != 0) {
495	/* Name Filed */
496	q = (NBTNsQuestion ) AliasHandleName((u_char ) q, pmax);
497
498	if (q == NULL \|\| (char *)(q + 1) > pmax) {
499	q = NULL;
500	break;
501	}
502	/* Type and Class filed */
503	switch (ntohs(q->type)) {
504	case QS_TYPE_NB:
505	case QS_TYPE_NBSTAT:
506	q = q + 1;
507	break;
508	default:
509	#ifdef LIBALIAS_DEBUG
510	printf("\nUnknown Type on Question %0x\n", ntohs(q->type));
511	#endif
512	break;
513	}
514	count--;
515	}
516
517	/* Set up to out of Question Section */
518	return ((u_char *) q);
519	}
520
521	/* Resource Record */
522	#define RR_TYPE_A 0x0001
523	#define RR_TYPE_NS 0x0002
524	#define RR_TYPE_NULL 0x000a
525	#define RR_TYPE_NB 0x0020
526	#define RR_TYPE_NBSTAT 0x0021
527	#define RR_CLAS_IN 0x0001
528	#define SizeOfNsResource 8
529	typedef struct {
530	u_short type;
531	u_short class;
532	unsigned int ttl;
533	u_short rdlen;
534	} NBTNsResource;
535
536	#define SizeOfNsRNB 6
537	typedef struct {
538	u_short g: 1 , ont:2, resv:13;
539	struct in_addr addr;
540	} NBTNsRNB;
541
542	static u_char *
543	AliasHandleResourceNB(
544	NBTNsResource * q,
545	char *pmax,
546	NBTArguments * nbtarg)
547	{
548	NBTNsRNB *nb;
549	u_short bcount;
550
551	if (q == NULL \|\| (char *)(q + 1) > pmax)
552	return (NULL);
553	/* Check out a length */
554	bcount = ntohs(q->rdlen);
555
556	/* Forward to Resource NB position */
557	nb = (NBTNsRNB ) ((u_char ) q + SizeOfNsResource);
558
559	/* Processing all in_addr array */
560	#ifdef LIBALIAS_DEBUG
561	printf("NB rec[%s", inet_ntoa(nbtarg->oldaddr));
562	printf("->%s, %dbytes] ", inet_ntoa(nbtarg->newaddr), bcount);
563	#endif
564	while (nb != NULL && bcount != 0) {
565	if ((char *)(nb + 1) > pmax) {
566	nb = NULL;
567	break;
568	}
569	#ifdef LIBALIAS_DEBUG
570	printf("<%s>", inet_ntoa(nb->addr));
571	#endif
572	if (!bcmp(&nbtarg->oldaddr, &nb->addr, sizeof(struct in_addr))) {
573	if (*nbtarg->uh_sum != 0) {
574	int acc;
575	u_short *sptr;
576
577	sptr = (u_short *) & (nb->addr);
578	acc = *sptr++;
579	acc += *sptr;
580	sptr = (u_short *) & (nbtarg->newaddr);
581	acc -= *sptr++;
582	acc -= *sptr;
583	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
584	}
585	nb->addr = nbtarg->newaddr;
586	#ifdef LIBALIAS_DEBUG
587	printf("O");
588	#endif
589	}
590	#ifdef LIBALIAS_DEBUG
591	else {
592	printf(".");
593	}
594	#endif
595	nb = (NBTNsRNB ) ((u_char ) nb + SizeOfNsRNB);
596	bcount -= SizeOfNsRNB;
597	}
598	if (nb == NULL \|\| (char *)(nb + 1) > pmax) {
599	nb = NULL;
600	}
601	return ((u_char *) nb);
602	}
603
604	#define SizeOfResourceA 6
605	typedef struct {
606	struct in_addr addr;
607	} NBTNsResourceA;
608
609	static u_char *
610	AliasHandleResourceA(
611	NBTNsResource * q,
612	char *pmax,
613	NBTArguments * nbtarg)
614	{
615	NBTNsResourceA *a;
616	u_short bcount;
617
618	if (q == NULL \|\| (char *)(q + 1) > pmax)
619	return (NULL);
620
621	/* Forward to Resource A position */
622	a = (NBTNsResourceA ) ((u_char ) q + sizeof(NBTNsResource));
623
624	/* Check out of length */
625	bcount = ntohs(q->rdlen);
626
627	/* Processing all in_addr array */
628	#ifdef LIBALIAS_DEBUG
629	printf("Arec [%s", inet_ntoa(nbtarg->oldaddr));
630	printf("->%s]", inet_ntoa(nbtarg->newaddr));
631	#endif
632	while (bcount != 0) {
633	if (a == NULL \|\| (char *)(a + 1) > pmax)
634	return (NULL);
635	#ifdef LIBALIAS_DEBUG
636	printf("..%s", inet_ntoa(a->addr));
637	#endif
638	if (!bcmp(&nbtarg->oldaddr, &a->addr, sizeof(struct in_addr))) {
639	if (*nbtarg->uh_sum != 0) {
640	int acc;
641	u_short *sptr;
642
643	sptr = (u_short ) & (a->addr); / Old */
644	acc = *sptr++;
645	acc += *sptr;
646	sptr = (u_short ) & nbtarg->newaddr; / New */
647	acc -= *sptr++;
648	acc -= *sptr;
649	ADJUST_CHECKSUM(acc, *nbtarg->uh_sum);
650	}
651	a->addr = nbtarg->newaddr;
652	}
653	a++; /* XXXX */
654	bcount -= SizeOfResourceA;
655	}
656	if (a == NULL \|\| (char *)(a + 1) > pmax)
657	a = NULL;
658	return ((u_char *) a);
659	}
660
661	typedef struct {
662	u_short opcode:4, flags:8, resv:4;
663	} NBTNsResourceNULL;
664
665	static u_char *
666	AliasHandleResourceNULL(
667	NBTNsResource * q,
668	char *pmax,
669	NBTArguments * nbtarg)
670	{
671	NBTNsResourceNULL *n;
672	u_short bcount;
673
674	(void)nbtarg;
675
676	if (q == NULL \|\| (char *)(q + 1) > pmax)
677	return (NULL);
678
679	/* Forward to Resource NULL position */
680	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
681
682	/* Check out of length */
683	bcount = ntohs(q->rdlen);
684
685	/* Processing all in_addr array */
686	while (bcount != 0) {
687	if ((char *)(n + 1) > pmax) {
688	n = NULL;
689	break;
690	}
691	n++;
692	bcount -= sizeof(NBTNsResourceNULL);
693	}
694	if ((char *)(n + 1) > pmax)
695	n = NULL;
696
697	return ((u_char *) n);
698	}
699
700	static u_char *
701	AliasHandleResourceNS(
702	NBTNsResource * q,
703	char *pmax,
704	NBTArguments * nbtarg)
705	{
706	NBTNsResourceNULL *n;
707	u_short bcount;
708
709	(void)nbtarg;
710
711	if (q == NULL \|\| (char *)(q + 1) > pmax)
712	return (NULL);
713
714	/* Forward to Resource NULL position */
715	n = (NBTNsResourceNULL ) ((u_char ) q + sizeof(NBTNsResource));
716
717	/* Check out of length */
718	bcount = ntohs(q->rdlen);
719
720	/* Resource Record Name Filed */
721	q = (NBTNsResource ) AliasHandleName((u_char ) n, pmax); /* XXX */
722
723	if (q == NULL \|\| (char )((u_char ) n + bcount) > pmax)
724	return (NULL);
725	else
726	return ((u_char *) n + bcount);
727	}
728
729	typedef struct {
730	u_short numnames;
731	} NBTNsResourceNBSTAT;
732
733	static u_char *
734	AliasHandleResourceNBSTAT(
735	NBTNsResource * q,
736	char *pmax,
737	NBTArguments * nbtarg)
738	{
739	NBTNsResourceNBSTAT *n;
740	u_short bcount;
741
742	(void)nbtarg;
743
744	if (q == NULL \|\| (char *)(q + 1) > pmax)
745	return (NULL);
746
747	/* Forward to Resource NBSTAT position */
748	n = (NBTNsResourceNBSTAT ) ((u_char ) q + sizeof(NBTNsResource));
749
750	/* Check out of length */
751	bcount = ntohs(q->rdlen);
752
753	if (q == NULL \|\| (char )((u_char ) n + bcount) > pmax)
754	return (NULL);
755	else
756	return ((u_char *) n + bcount);
757	}
758
759	static u_char *
760	AliasHandleResource(
761	u_short count,
762	NBTNsResource * q,
763	char *pmax,
764	NBTArguments
765	* nbtarg)
766	{
767	while (count != 0) {
768	/* Resource Record Name Filed */
769	q = (NBTNsResource ) AliasHandleName((u_char ) q, pmax);
770
771	if (q == NULL \|\| (char *)(q + 1) > pmax)
772	break;
773	#ifdef LIBALIAS_DEBUG
774	printf("type=%02x, count=%d\n", ntohs(q->type), count);
775	#endif
776
777	/* Type and Class filed */
778	switch (ntohs(q->type)) {
779	case RR_TYPE_NB:
780	q = (NBTNsResource *) AliasHandleResourceNB(
781	q,
782	pmax,
783	nbtarg
784	);
785	break;
786	case RR_TYPE_A:
787	q = (NBTNsResource *) AliasHandleResourceA(
788	q,
789	pmax,
790	nbtarg
791	);
792	break;
793	case RR_TYPE_NS:
794	q = (NBTNsResource *) AliasHandleResourceNS(
795	q,
796	pmax,
797	nbtarg
798	);
799	break;
800	case RR_TYPE_NULL:
801	q = (NBTNsResource *) AliasHandleResourceNULL(
802	q,
803	pmax,
804	nbtarg
805	);
806	break;
807	case RR_TYPE_NBSTAT:
808	q = (NBTNsResource *) AliasHandleResourceNBSTAT(
809	q,
810	pmax,
811	nbtarg
812	);
813	break;
814	default:
815	#ifdef LIBALIAS_DEBUG
816	printf(
817	"\nUnknown Type of Resource %0x\n",
818	ntohs(q->type)
819	);
820	fflush(stdout);
821	#endif
822	break;
823	}
824	count--;
825	}
826	return ((u_char *) q);
827	}
828
829	static int
830	AliasHandleUdpNbtNS(
831	struct libalias *la,
832	struct ip pip, / IP packet to examine/patch */
833	struct alias_link *lnk,
834	struct in_addr *alias_address,
835	u_short * alias_port,
836	struct in_addr *original_address,
837	u_short * original_port)
838	{
839	struct udphdr *uh;
840	NbtNSHeader *nsh;
841	u_char *p;
842	char *pmax;
843	NBTArguments nbtarg;
844
845	(void)la;
846	(void)lnk;
847
848	/* Set up Common Parameter */
849	nbtarg.oldaddr = *alias_address;
850	nbtarg.oldport = *alias_port;
851	nbtarg.newaddr = *original_address;
852	nbtarg.newport = *original_port;
853
854	/* Calculate data length of UDP packet */
855	uh = (struct udphdr *)ip_next(pip);
856	nbtarg.uh_sum = &(uh->uh_sum);
857	nsh = (NbtNSHeader *)udp_next(uh);
858	p = (u_char *) (nsh + 1);
859	pmax = (char *)uh + ntohs(uh->uh_ulen);
860
861	if ((char *)(nsh + 1) > pmax)
862	return (-1);
863
864	#ifdef LIBALIAS_DEBUG
865	printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x"
866	", an=%04x, ns=%04x, ar=%04x, [%d]-->",
867	nsh->dir ? "Response" : "Request",
868	nsh->nametrid,
869	nsh->opcode,
870	nsh->nmflags,
871	nsh->rcode,
872	ntohs(nsh->qdcount),
873	ntohs(nsh->ancount),
874	ntohs(nsh->nscount),
875	ntohs(nsh->arcount),
876	(u_char ) p - (u_char ) nsh
877	);
878	#endif
879
880	/* Question Entries */
881	if (ntohs(nsh->qdcount) != 0) {
882	p = AliasHandleQuestion(
883	ntohs(nsh->qdcount),
884	(NBTNsQuestion *) p,
885	pmax,
886	&nbtarg
887	);
888	}
889	/* Answer Resource Records */
890	if (ntohs(nsh->ancount) != 0) {
891	p = AliasHandleResource(
892	ntohs(nsh->ancount),
893	(NBTNsResource *) p,
894	pmax,
895	&nbtarg
896	);
897	}
898	/* Authority Resource Recodrs */
899	if (ntohs(nsh->nscount) != 0) {
900	p = AliasHandleResource(
901	ntohs(nsh->nscount),
902	(NBTNsResource *) p,
903	pmax,
904	&nbtarg
905	);
906	}
907	/* Additional Resource Recodrs */
908	if (ntohs(nsh->arcount) != 0) {
909	p = AliasHandleResource(
910	ntohs(nsh->arcount),
911	(NBTNsResource *) p,
912	pmax,
913	&nbtarg
914	);
915	}
916	#ifdef LIBALIAS_DEBUG
917	PrintRcode(nsh->rcode);
918	#endif
919	return ((p == NULL) ? -1 : 0);
920	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/libalias/alias_nbt.c@ 22452

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