alias_nbt.c@ 22451

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

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source: vbox/trunk/src/VBox/Devices/Network/slirp/libalias/alias_nbt.c@ 22451

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