xref: /netbsd-src/external/bsd/tcpdump/dist/parsenfsfh.c (revision 26ba0b503b498a5194a71ac319838b7f5497f3fe)
1 /*
2  * Copyright (c) 1993, 1994 Jeffrey C. Mogul, Digital Equipment Corporation,
3  * Western Research Laboratory. All rights reserved.
4  * Copyright (c) 2001 Compaq Computer Corporation. All rights reserved.
5  *
6  *  Permission to use, copy, and modify this software and its
7  *  documentation is hereby granted only under the following terms and
8  *  conditions.  Both the above copyright notice and this permission
9  *  notice must appear in all copies of the software, derivative works
10  *  or modified versions, and any portions thereof, and both notices
11  *  must appear in supporting documentation.
12  *
13  *  Redistribution and use in source and binary forms, with or without
14  *  modification, are permitted provided that the following conditions
15  *  are met:
16  *    1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  *    2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in
20  *    the documentation and/or other materials provided with the
21  *    distribution.
22  *
23  *  THE SOFTWARE IS PROVIDED "AS IS" AND COMPAQ COMPUTER CORPORATION
24  *  DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
25  *  ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.   IN NO
26  *  EVENT SHALL COMPAQ COMPUTER CORPORATION BE LIABLE FOR ANY
27  *  SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
28  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
29  *  AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
30  *  OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
31  *  SOFTWARE.
32  */
33 
34 /*
35  * parsenfsfh.c - portable parser for NFS file handles
36  *			uses all sorts of heuristics
37  *
38  * Jeffrey C. Mogul
39  * Digital Equipment Corporation
40  * Western Research Laboratory
41  */
42 
43 #include <sys/cdefs.h>
44 #ifndef lint
45 __RCSID("$NetBSD: parsenfsfh.c,v 1.11 2024/09/02 16:15:30 christos Exp $");
46 #endif
47 
48 #include <config.h>
49 
50 #include "netdissect-stdinc.h"
51 
52 #include <stdio.h>
53 #include <string.h>
54 #include <limits.h>
55 
56 #include "netdissect-ctype.h"
57 
58 #include "netdissect.h"
59 #include "extract.h"
60 #include "nfsfh.h"
61 
62 /*
63  * This routine attempts to parse a file handle (in network byte order),
64  * using heuristics to guess what kind of format it is in.  See the
65  * file "fhandle_layouts" for a detailed description of the various
66  * patterns we know about.
67  *
68  * The file handle is parsed into our internal representation of a
69  * file-system id, and an internal representation of an inode-number.
70  */
71 
72 #define	FHT_UNKNOWN	0
73 #define	FHT_AUSPEX	1
74 #define	FHT_DECOSF	2
75 #define	FHT_IRIX4	3
76 #define	FHT_IRIX5	4
77 #define	FHT_SUNOS3	5
78 #define	FHT_SUNOS4	6
79 #define	FHT_ULTRIX	7
80 #define	FHT_VMSUCX	8
81 #define	FHT_SUNOS5	9
82 #define	FHT_AIX32	10
83 #define	FHT_HPUX9	11
84 #define	FHT_BSD44	12
85 #define	FHT_NETBSD	13
86 
87 static int is_UCX(netdissect_options *, const unsigned char *, u_int);
88 
89 void
90 Parse_fh(netdissect_options *ndo, const unsigned char *fh, u_int len,
91 	 my_fsid *fsidp, uint32_t *inop,
92 	 const char **osnamep, /* if non-NULL, return OS name here */
93 	 const char **fsnamep, /* if non-NULL, return server fs name here (for VMS) */
94 	 int ourself)	/* true if file handle was generated on this host */
95 {
96 	const unsigned char *fhp = fh;
97 	uint32_t temp;
98 	int fhtype = FHT_UNKNOWN;
99 	u_int i;
100 
101 	/*
102 	 * Require at least 16 bytes of file handle; it's variable-length
103 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
104 	 */
105 	if (len < 16/4)
106 	    fhtype = FHT_UNKNOWN;
107 	else {
108 	    if (ourself) {
109 		/* File handle generated on this host, no need for guessing */
110 #if	defined(IRIX40)
111 		fhtype = FHT_IRIX4;
112 #endif
113 #if	defined(IRIX50)
114 		fhtype = FHT_IRIX5;
115 #endif
116 #if	defined(IRIX51)
117 		fhtype = FHT_IRIX5;
118 #endif
119 #if	defined(SUNOS4)
120 		fhtype = FHT_SUNOS4;
121 #endif
122 #if	defined(SUNOS5)
123 		fhtype = FHT_SUNOS5;
124 #endif
125 #if	defined(ultrix)
126 		fhtype = FHT_ULTRIX;
127 #endif
128 #if	defined(__osf__)
129 		fhtype = FHT_DECOSF;
130 #endif
131 #if	defined(__FreeBSD__) || defined(__DragonFly__) || defined(__OpenBSD__)
132 		fhtype = FHT_BSD44;
133 #endif
134 #if	defined(__NetBSD__)
135 		fhtype = FHT_NETBSD;
136 #endif
137 	    }
138 	    /*
139 	     * This is basically a big decision tree
140 	     */
141 	    else if ((fhp[0] == 0) && (fhp[1] == 0)) {
142 		/* bytes[0,1] == (0,0); rules out Ultrix, IRIX5, SUNOS5 */
143 		/* probably rules out HP-UX, AIX unless they allow major=0 */
144 		if ((fhp[2] == 0) && (fhp[3] == 0)) {
145 		    /* bytes[2,3] == (0,0); must be Auspex */
146 		    /* XXX or could be Ultrix+MASSBUS "hp" disk? */
147 		    fhtype = FHT_AUSPEX;
148 		}
149 		/*
150 		 * This is basically a big decision tree
151 		 */
152 		else if ((GET_U_1(fhp) == 0) && (GET_U_1(fhp + 1) == 0)) {
153 		    /* bytes[0,1] == (0,0); rules out Ultrix, IRIX5, SUNOS5 */
154 		    /* probably rules out HP-UX, AIX unless they allow major=0 */
155 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
156 			/* bytes[2,3] == (0,0); must be Auspex */
157 			/* XXX or could be Ultrix+MASSBUS "hp" disk? */
158 			fhtype = FHT_AUSPEX;
159 		    } else {
160 			/*
161 			 * bytes[2,3] != (0,0); rules out Auspex, could be
162 			 * DECOSF, SUNOS4, or IRIX4
163 			 */
164 			if ((GET_U_1(fhp + 4) != 0) && (GET_U_1(fhp + 5) == 0) &&
165 				(GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
166 			    /* seems to be DECOSF, with minor == 0 */
167 			    fhtype = FHT_DECOSF;
168 			} else {
169 			    /* could be SUNOS4 or IRIX4 */
170 			    /* XXX the test of fhp[5] == 8 could be wrong */
171 			    if ((GET_U_1(fhp + 4) == 0) && (GET_U_1(fhp + 5) == 8) && (GET_U_1(fhp + 6) == 0) &&
172 			        (GET_U_1(fhp + 7) == 0)) {
173 				/* looks like a length, not a file system typecode */
174 				fhtype = FHT_IRIX4;
175 			    } else {
176 				/* by elimination */
177 				fhtype = FHT_SUNOS4;
178 			    }
179 			}
180 		    }
181 		} else {
182 		    /*
183 		     * bytes[2,3] != (0,0); rules out Ultrix, could be
184 		     * DECOSF, SUNOS5, IRIX5, AIX, HP-UX, or UCX
185 		     */
186 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
187 			/*
188 			 * bytes[2,3] == (0,0); rules out OSF, probably not UCX
189 			 * (unless the exported device name is just one letter!),
190 			 * could be Ultrix, IRIX5, AIX, or SUNOS5
191 			 * might be HP-UX (depends on their values for minor devs)
192 			 */
193 			if ((GET_U_1(fhp + 6) == 0) && (GET_U_1(fhp + 7) == 0)) {
194 			    fhtype = FHT_BSD44;
195 			}
196 			/*XXX we probably only need to test of these two bytes */
197 			else if ((len >= 24/4) && (GET_U_1(fhp + 21) == 0) && (GET_U_1(fhp + 23) == 0)) {
198 			    fhtype = FHT_ULTRIX;
199 			} else {
200 			    /* Could be SUNOS5/IRIX5, maybe AIX */
201 			    /* XXX no obvious difference between SUNOS5 and IRIX5 */
202 			    if (GET_U_1(fhp + 9) == 10)
203 				fhtype = FHT_SUNOS5;
204 			    /* XXX what about AIX? */
205 			}
206 		    } else {
207 			/*
208 			 * bytes[2,3] != (0,0); rules out Ultrix, could be
209 			 * DECOSF, SUNOS5, IRIX5, AIX, HP-UX, or UCX
210 			 */
211 			if ((GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
212 			    fhtype = FHT_DECOSF;
213 			} else if ((GET_U_1(fhp + 8) == 0) && (GET_U_1(fhp + 9) == 10)) {
214 			    /* could be SUNOS5/IRIX5, AIX, HP-UX */
215 			    if ((GET_U_1(fhp + 7) == 0) && (GET_U_1(fhp + 6) == 0) &&
216 				(GET_U_1(fhp + 5) == 0) && (GET_U_1(fhp + 4) == 0)) {
217 				/* XXX is this always true of HP-UX? */
218 				fhtype = FHT_HPUX9;
219 			    } else if (GET_U_1(fhp + 7) == 2) {
220 				/* This would be MNT_NFS on AIX, which is impossible */
221 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
222 			    } else {
223 				/*
224 				 * XXX Could be SUNOS5/IRIX5 or AIX.  I don't
225 				 * XXX see any way to disambiguate these, so
226 				 * XXX I'm going with the more likely guess.
227 				 * XXX Sorry, Big Blue.
228 				 */
229 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
230 			    }
231 		        } else {
232 			    if (is_UCX(ndo, fhp, len)) {
233 				fhtype = FHT_VMSUCX;
234 			    } else {
235 				fhtype = FHT_UNKNOWN;
236 			    }
237 			}
238 		    }
239 		}
240 	    }
241 	}
242 
243 	/* XXX still needs to handle SUNOS3 */
244 
245 	switch (fhtype) {
246 	case FHT_AUSPEX:
247 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 7);
248 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 6);
249 	    fsidp->fsid_code = 0;
250 
251 	    *inop = GET_BE_U_4(fhp + 12);
252 
253 	    if (osnamep)
254 		*osnamep = "Auspex";
255 	    break;
256 
257 	case FHT_BSD44:
258 	case FHT_NETBSD:
259 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
260 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
261 	    fsidp->fsid_code = 0;
262 
263 	    /*
264 	     * NetBSD puts the generation number before the inode; inode
265 	     * is 64 bits, but only 32 are typically used; XXX endian issues?
266 	     */
267 	    if (fhtype == FHT_NETBSD)
268 		    *inop = GET_LE_U_4(fhp + 16);
269 	    else
270 		    *inop = GET_LE_U_4(fhp + 12);
271 
272 	    if (osnamep)
273 		*osnamep = "BSD 4.4";
274 	    break;
275 
276 	case FHT_DECOSF:
277 	    fsidp->fsid_code = GET_LE_U_4(fhp + 4);
278 			/* XXX could ignore 3 high-order bytes */
279 
280 	    temp = GET_LE_U_4(fhp);
281 	    fsidp->Fsid_dev.Minor = temp & 0xFFFFF;
282 	    fsidp->Fsid_dev.Major = (temp>>20) & 0xFFF;
283 
284 	    *inop = GET_LE_U_4(fhp + 12);
285 	    if (osnamep)
286 		*osnamep = "OSF";
287 	    break;
288 
289 	case FHT_IRIX4:
290 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
291 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
292 	    fsidp->fsid_code = 0;
293 
294 	    *inop = GET_BE_U_4(fhp + 8);
295 
296 	    if (osnamep)
297 		*osnamep = "IRIX4";
298 	    break;
299 
300 	case FHT_IRIX5:
301 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
302 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
303 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
304 
305 	    *inop = GET_BE_U_4(fhp + 12);
306 
307 	    if (osnamep)
308 		*osnamep = "IRIX5";
309 	    break;
310 
311 #ifdef notdef
312 	case FHT_SUNOS3:
313 	    /*
314 	     * XXX - none of the heuristics above return this.
315 	     * Are there any SunOS 3.x systems around to care about?
316 	     */
317 	    if (osnamep)
318 		*osnamep = "SUNOS3";
319 	    break;
320 #endif
321 
322 	case FHT_SUNOS4:
323 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
324 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
325 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
326 
327 	    *inop = GET_BE_U_4(fhp + 12);
328 
329 	    if (osnamep)
330 		*osnamep = "SUNOS4";
331 	    break;
332 
333 	case FHT_SUNOS5:
334 	    temp = GET_BE_U_2(fhp);
335 	    fsidp->Fsid_dev.Major = (temp>>2) &  0x3FFF;
336 	    temp = GET_BE_U_3(fhp + 1);
337 	    fsidp->Fsid_dev.Minor = temp & 0x3FFFF;
338 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
339 
340 	    *inop = GET_BE_U_4(fhp + 12);
341 
342 	    if (osnamep)
343 		*osnamep = "SUNOS5";
344 	    break;
345 
346 	case FHT_ULTRIX:
347 	    fsidp->fsid_code = 0;
348 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
349 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
350 
351 	    temp = GET_LE_U_4(fhp + 4);
352 	    *inop = temp;
353 	    if (osnamep)
354 		*osnamep = "Ultrix";
355 	    break;
356 
357 	case FHT_VMSUCX:
358 	    /* No numeric file system ID, so hash on the device-name */
359 	    if (sizeof(*fsidp) >= 14) {
360 		if (sizeof(*fsidp) > 14)
361 		    memset((char *)fsidp, 0, sizeof(*fsidp));
362 		/* just use the whole thing */
363 		memcpy((char *)fsidp, (const char *)fh, 14);
364 	    } else {
365 		uint32_t tempa[4];	/* at least 16 bytes, maybe more */
366 
367 		memset((char *)tempa, 0, sizeof(tempa));
368 		memcpy((char *)tempa, (const char *)fh, 14); /* ensure alignment */
369 		fsidp->Fsid_dev.Minor = tempa[0] + (tempa[1]<<1);
370 		fsidp->Fsid_dev.Major = tempa[2] + (tempa[3]<<1);
371 		fsidp->fsid_code = 0;
372 	    }
373 
374 	    /* VMS file ID is: (RVN, FidHi, FidLo) */
375 	    *inop = (((uint32_t) GET_U_1(fhp + 26)) << 24) |
376 		    (((uint32_t) GET_U_1(fhp + 27)) << 16) |
377 		    (GET_LE_U_2(fhp + 22) << 0);
378 
379 	    /* Caller must save (and null-terminate?) this value */
380 	    if (fsnamep)
381 		*fsnamep = (const char *)(fhp + 1);
382 
383 	    if (osnamep)
384 		*osnamep = "VMS";
385 	    break;
386 
387 	case FHT_AIX32:
388 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
389 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
390 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
391 
392 	    *inop = GET_BE_U_4(fhp + 12);
393 
394 	    if (osnamep)
395 		*osnamep = "AIX32";
396 	    break;
397 
398 	case FHT_HPUX9:
399 	    fsidp->Fsid_dev.Major = GET_U_1(fhp);
400 	    temp = GET_BE_U_3(fhp + 1);
401 	    fsidp->Fsid_dev.Minor = temp;
402 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
403 
404 	    *inop = GET_BE_U_4(fhp + 12);
405 
406 	    if (osnamep)
407 		*osnamep = "HPUX9";
408 	    break;
409 
410 	case FHT_UNKNOWN:
411 #ifdef DEBUG
412 	    /* XXX debugging */
413 	    for (i = 0; i < len*4; i++)
414 		(void)fprintf(stderr, "%x.", GET_U_1(fhp + i));
415 	    (void)fprintf(stderr, "\n");
416 #endif
417 	    /* Save the actual handle, so it can be display with -u */
418 	    /* XXX really ? When -u is used this function is not called */
419 	    for (i = 0; i < len*4 && i*2 < sizeof(fsidp->Opaque_Handle) - 1; i++)
420 		(void)snprintf(&(fsidp->Opaque_Handle[i*2]), 3, "%.2X",
421 			       GET_U_1(fhp + i));
422 	    fsidp->Opaque_Handle[i*2] = '\0';
423 
424 	    /* XXX for now, give "bogus" values to aid debugging */
425 	    fsidp->fsid_code = 0;
426 	    fsidp->Fsid_dev.Minor = UINT_MAX;
427 	    fsidp->Fsid_dev.Major = UINT_MAX;
428 	    *inop = 1;
429 
430 	    /* display will show this string instead of (UINT_MAX,UINT_MAX) */
431 	    /* XXX really ? */
432 	    if (fsnamep)
433 		*fsnamep = "Unknown";
434 
435 	    if (osnamep)
436 		*osnamep = "Unknown";
437 	    break;
438 
439 	}
440 }
441 
442 /*
443  * Is this a VMS UCX file handle?
444  *	Check for:
445  *	(1) leading code byte	[XXX not yet]
446  *	(2) followed by string of printing chars & spaces
447  *	(3) followed by string of nulls
448  */
449 static int
450 is_UCX(netdissect_options *ndo, const unsigned char *fhp, u_int len)
451 {
452 	u_int i;
453 	int seen_null = 0;
454 
455 	/*
456 	 * Require at least 28 bytes of file handle; it's variable-length
457 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
458 	 */
459 	if (len < 28/4)
460 		return(0);
461 
462 	for (i = 1; i < 14; i++) {
463 	    if (ND_ASCII_ISPRINT(GET_U_1(fhp + i))) {
464 		if (seen_null)
465 		   return(0);
466 		else
467 		   continue;
468 	    } else if (GET_U_1(fhp + i) == 0) {
469 		seen_null = 1;
470 		continue;
471 	    } else
472 		return(0);
473 	}
474 
475 	return(1);
476 }
477