xref: /freebsd/contrib/tcpdump/parsenfsfh.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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 #ifdef HAVE_CONFIG_H
44 #include <config.h>
45 #endif
46 
47 #include "netdissect-stdinc.h"
48 
49 #include <stdio.h>
50 #include <string.h>
51 
52 #include "netdissect-ctype.h"
53 
54 #include "netdissect.h"
55 #include "extract.h"
56 #include "nfsfh.h"
57 
58 /*
59  * This routine attempts to parse a file handle (in network byte order),
60  * using heuristics to guess what kind of format it is in.  See the
61  * file "fhandle_layouts" for a detailed description of the various
62  * patterns we know about.
63  *
64  * The file handle is parsed into our internal representation of a
65  * file-system id, and an internal representation of an inode-number.
66  */
67 
68 #define	FHT_UNKNOWN	0
69 #define	FHT_AUSPEX	1
70 #define	FHT_DECOSF	2
71 #define	FHT_IRIX4	3
72 #define	FHT_IRIX5	4
73 #define	FHT_SUNOS3	5
74 #define	FHT_SUNOS4	6
75 #define	FHT_ULTRIX	7
76 #define	FHT_VMSUCX	8
77 #define	FHT_SUNOS5	9
78 #define	FHT_AIX32	10
79 #define	FHT_HPUX9	11
80 #define	FHT_BSD44	12
81 
82 static int is_UCX(netdissect_options *, const unsigned char *, u_int);
83 
84 void
85 Parse_fh(netdissect_options *ndo, const unsigned char *fh, u_int len,
86 	 my_fsid *fsidp, uint32_t *inop,
87 	 const char **osnamep, /* if non-NULL, return OS name here */
88 	 const char **fsnamep, /* if non-NULL, return server fs name here (for VMS) */
89 	 int ourself)	/* true if file handle was generated on this host */
90 {
91 	const unsigned char *fhp = fh;
92 	uint32_t temp;
93 	int fhtype = FHT_UNKNOWN;
94 	u_int i;
95 
96 	/*
97 	 * Require at least 16 bytes of file handle; it's variable-length
98 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
99 	 */
100 	if (len < 16/4)
101 		fhtype = FHT_UNKNOWN;
102 	else {
103 		if (ourself) {
104 		    /* File handle generated on this host, no need for guessing */
105 #if	defined(IRIX40)
106 		    fhtype = FHT_IRIX4;
107 #endif
108 #if	defined(IRIX50)
109 		    fhtype = FHT_IRIX5;
110 #endif
111 #if	defined(IRIX51)
112 		    fhtype = FHT_IRIX5;
113 #endif
114 #if	defined(SUNOS4)
115 		    fhtype = FHT_SUNOS4;
116 #endif
117 #if	defined(SUNOS5)
118 		    fhtype = FHT_SUNOS5;
119 #endif
120 #if	defined(ultrix)
121 		    fhtype = FHT_ULTRIX;
122 #endif
123 #if	defined(__osf__)
124 		    fhtype = FHT_DECOSF;
125 #endif
126 #if	defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) \
127      || defined(__OpenBSD__)
128 		    fhtype = FHT_BSD44;
129 #endif
130 		}
131 		/*
132 		 * This is basically a big decision tree
133 		 */
134 		else if ((GET_U_1(fhp) == 0) && (GET_U_1(fhp + 1) == 0)) {
135 		    /* bytes[0,1] == (0,0); rules out Ultrix, IRIX5, SUNOS5 */
136 		    /* probably rules out HP-UX, AIX unless they allow major=0 */
137 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
138 			/* bytes[2,3] == (0,0); must be Auspex */
139 			/* XXX or could be Ultrix+MASSBUS "hp" disk? */
140 			fhtype = FHT_AUSPEX;
141 		    }
142 		    else {
143 			/*
144 			 * bytes[2,3] != (0,0); rules out Auspex, could be
145 			 * DECOSF, SUNOS4, or IRIX4
146 			 */
147 			if ((GET_U_1(fhp + 4) != 0) && (GET_U_1(fhp + 5) == 0) &&
148 				(GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
149 			    /* seems to be DECOSF, with minor == 0 */
150 			    fhtype = FHT_DECOSF;
151 			}
152 			else {
153 			    /* could be SUNOS4 or IRIX4 */
154 			    /* XXX the test of fhp[5] == 8 could be wrong */
155 			    if ((GET_U_1(fhp + 4) == 0) && (GET_U_1(fhp + 5) == 8) && (GET_U_1(fhp + 6) == 0) &&
156 			        (GET_U_1(fhp + 7) == 0)) {
157 				/* looks like a length, not a file system typecode */
158 				fhtype = FHT_IRIX4;
159 			    }
160 			    else {
161 				/* by elimination */
162 				fhtype = FHT_SUNOS4;
163 			    }
164 			}
165 		    }
166 		}
167 		else {
168 		    /*
169 		     * bytes[0,1] != (0,0); rules out Auspex, IRIX4, SUNOS4
170 		     * could be IRIX5, DECOSF, UCX, Ultrix, SUNOS5
171 		     * could be AIX, HP-UX
172 		     */
173 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
174 			/*
175 			 * bytes[2,3] == (0,0); rules out OSF, probably not UCX
176 			 * (unless the exported device name is just one letter!),
177 			 * could be Ultrix, IRIX5, AIX, or SUNOS5
178 			 * might be HP-UX (depends on their values for minor devs)
179 			 */
180 			if ((GET_U_1(fhp + 6) == 0) && (GET_U_1(fhp + 7) == 0)) {
181 			    fhtype = FHT_BSD44;
182 			}
183 			/*XXX we probably only need to test of these two bytes */
184 			else if ((len >= 24/4) && (GET_U_1(fhp + 21) == 0) && (GET_U_1(fhp + 23) == 0)) {
185 			    fhtype = FHT_ULTRIX;
186 			}
187 			else {
188 			    /* Could be SUNOS5/IRIX5, maybe AIX */
189 			    /* XXX no obvious difference between SUNOS5 and IRIX5 */
190 			    if (GET_U_1(fhp + 9) == 10)
191 				fhtype = FHT_SUNOS5;
192 			    /* XXX what about AIX? */
193 			}
194 		    }
195 		    else {
196 			/*
197 			 * bytes[2,3] != (0,0); rules out Ultrix, could be
198 			 * DECOSF, SUNOS5, IRIX5, AIX, HP-UX, or UCX
199 			 */
200 			if ((GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
201 			    fhtype = FHT_DECOSF;
202 			}
203 			else if ((GET_U_1(fhp + 8) == 0) && (GET_U_1(fhp + 9) == 10)) {
204 			    /* could be SUNOS5/IRIX5, AIX, HP-UX */
205 			    if ((GET_U_1(fhp + 7) == 0) && (GET_U_1(fhp + 6) == 0) &&
206 				(GET_U_1(fhp + 5) == 0) && (GET_U_1(fhp + 4) == 0)) {
207 				/* XXX is this always true of HP-UX? */
208 				fhtype = FHT_HPUX9;
209 			    }
210 			    else if (GET_U_1(fhp + 7) == 2) {
211 				/* This would be MNT_NFS on AIX, which is impossible */
212 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
213 			    }
214 			    else {
215 				/*
216 				 * XXX Could be SUNOS5/IRIX5 or AIX.  I don't
217 				 * XXX see any way to disambiguate these, so
218 				 * XXX I'm going with the more likely guess.
219 				 * XXX Sorry, Big Blue.
220 				 */
221 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
222 			    }
223 		        }
224 			else {
225 			    if (is_UCX(ndo, fhp, len)) {
226 				fhtype = FHT_VMSUCX;
227 			    }
228 			    else {
229 				fhtype = FHT_UNKNOWN;
230 			    }
231 			}
232 		    }
233 		}
234 	}
235 
236 	/* XXX still needs to handle SUNOS3 */
237 
238 	switch (fhtype) {
239 	case FHT_AUSPEX:
240 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 7);
241 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 6);
242 	    fsidp->fsid_code = 0;
243 
244 	    *inop = GET_BE_U_4(fhp + 12);
245 
246 	    if (osnamep)
247 		*osnamep = "Auspex";
248 	    break;
249 
250 	case FHT_BSD44:
251 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
252 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
253 	    fsidp->fsid_code = 0;
254 
255 	    *inop = GET_LE_U_4(fhp + 12);
256 
257 	    if (osnamep)
258 		*osnamep = "BSD 4.4";
259 	    break;
260 
261 	case FHT_DECOSF:
262 	    fsidp->fsid_code = GET_LE_U_4(fhp + 4);
263 			/* XXX could ignore 3 high-order bytes */
264 
265 	    temp = GET_LE_U_4(fhp);
266 	    fsidp->Fsid_dev.Minor = temp & 0xFFFFF;
267 	    fsidp->Fsid_dev.Major = (temp>>20) & 0xFFF;
268 
269 	    *inop = GET_LE_U_4(fhp + 12);
270 	    if (osnamep)
271 		*osnamep = "OSF";
272 	    break;
273 
274 	case FHT_IRIX4:
275 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
276 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
277 	    fsidp->fsid_code = 0;
278 
279 	    *inop = GET_BE_U_4(fhp + 8);
280 
281 	    if (osnamep)
282 		*osnamep = "IRIX4";
283 	    break;
284 
285 	case FHT_IRIX5:
286 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
287 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
288 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
289 
290 	    *inop = GET_BE_U_4(fhp + 12);
291 
292 	    if (osnamep)
293 		*osnamep = "IRIX5";
294 	    break;
295 
296 #ifdef notdef
297 	case FHT_SUNOS3:
298 	    /*
299 	     * XXX - none of the heuristics above return this.
300 	     * Are there any SunOS 3.x systems around to care about?
301 	     */
302 	    if (osnamep)
303 		*osnamep = "SUNOS3";
304 	    break;
305 #endif
306 
307 	case FHT_SUNOS4:
308 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
309 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
310 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
311 
312 	    *inop = GET_BE_U_4(fhp + 12);
313 
314 	    if (osnamep)
315 		*osnamep = "SUNOS4";
316 	    break;
317 
318 	case FHT_SUNOS5:
319 	    temp = GET_BE_U_2(fhp);
320 	    fsidp->Fsid_dev.Major = (temp>>2) &  0x3FFF;
321 	    temp = GET_BE_U_3(fhp + 1);
322 	    fsidp->Fsid_dev.Minor = temp & 0x3FFFF;
323 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
324 
325 	    *inop = GET_BE_U_4(fhp + 12);
326 
327 	    if (osnamep)
328 		*osnamep = "SUNOS5";
329 	    break;
330 
331 	case FHT_ULTRIX:
332 	    fsidp->fsid_code = 0;
333 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
334 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
335 
336 	    temp = GET_LE_U_4(fhp + 4);
337 	    *inop = temp;
338 	    if (osnamep)
339 		*osnamep = "Ultrix";
340 	    break;
341 
342 	case FHT_VMSUCX:
343 	    /* No numeric file system ID, so hash on the device-name */
344 	    if (sizeof(*fsidp) >= 14) {
345 		if (sizeof(*fsidp) > 14)
346 		    memset((char *)fsidp, 0, sizeof(*fsidp));
347 		/* just use the whole thing */
348 		memcpy((char *)fsidp, (const char *)fh, 14);
349 	    }
350 	    else {
351 		uint32_t tempa[4];	/* at least 16 bytes, maybe more */
352 
353 		memset((char *)tempa, 0, sizeof(tempa));
354 		memcpy((char *)tempa, (const char *)fh, 14); /* ensure alignment */
355 		fsidp->Fsid_dev.Minor = tempa[0] + (tempa[1]<<1);
356 		fsidp->Fsid_dev.Major = tempa[2] + (tempa[3]<<1);
357 		fsidp->fsid_code = 0;
358 	    }
359 
360 	    /* VMS file ID is: (RVN, FidHi, FidLo) */
361 	    *inop = (((uint32_t) GET_U_1(fhp + 26)) << 24) |
362 		    (((uint32_t) GET_U_1(fhp + 27)) << 16) |
363 		    (GET_LE_U_2(fhp + 22) << 0);
364 
365 	    /* Caller must save (and null-terminate?) this value */
366 	    if (fsnamep)
367 		*fsnamep = (const char *)(fhp + 1);
368 
369 	    if (osnamep)
370 		*osnamep = "VMS";
371 	    break;
372 
373 	case FHT_AIX32:
374 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
375 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
376 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
377 
378 	    *inop = GET_BE_U_4(fhp + 12);
379 
380 	    if (osnamep)
381 		*osnamep = "AIX32";
382 	    break;
383 
384 	case FHT_HPUX9:
385 	    fsidp->Fsid_dev.Major = GET_U_1(fhp);
386 	    temp = GET_BE_U_3(fhp + 1);
387 	    fsidp->Fsid_dev.Minor = temp;
388 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
389 
390 	    *inop = GET_BE_U_4(fhp + 12);
391 
392 	    if (osnamep)
393 		*osnamep = "HPUX9";
394 	    break;
395 
396 	case FHT_UNKNOWN:
397 #ifdef DEBUG
398 	    /* XXX debugging */
399 	    for (i = 0; i < len*4; i++)
400 		(void)fprintf(stderr, "%x.", GET_U_1(fhp + i));
401 	    (void)fprintf(stderr, "\n");
402 #endif
403 	    /* Save the actual handle, so it can be display with -u */
404 	    for (i = 0; i < len*4 && i*2 < sizeof(fsidp->Opaque_Handle) - 1; i++)
405 		(void)snprintf(&(fsidp->Opaque_Handle[i*2]), 3, "%.2X",
406 			       GET_U_1(fhp + i));
407 	    fsidp->Opaque_Handle[i*2] = '\0';
408 
409 	    /* XXX for now, give "bogus" values to aid debugging */
410 	    fsidp->fsid_code = 0;
411 	    fsidp->Fsid_dev.Minor = 257;
412 	    fsidp->Fsid_dev.Major = 257;
413 	    *inop = 1;
414 
415 	    /* display will show this string instead of (257,257) */
416 	    if (fsnamep)
417 		*fsnamep = "Unknown";
418 
419 	    if (osnamep)
420 		*osnamep = "Unknown";
421 	    break;
422 
423 	}
424 }
425 
426 /*
427  * Is this a VMS UCX file handle?
428  *	Check for:
429  *	(1) leading code byte	[XXX not yet]
430  *	(2) followed by string of printing chars & spaces
431  *	(3) followed by string of nulls
432  */
433 static int
434 is_UCX(netdissect_options *ndo, const unsigned char *fhp, u_int len)
435 {
436 	u_int i;
437 	int seen_null = 0;
438 
439 	/*
440 	 * Require at least 28 bytes of file handle; it's variable-length
441 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
442 	 */
443 	if (len < 28/4)
444 		return(0);
445 
446 	for (i = 1; i < 14; i++) {
447 	    if (ND_ASCII_ISPRINT(GET_U_1(fhp + i))) {
448 		if (seen_null)
449 		   return(0);
450 		else
451 		   continue;
452 	    }
453 	    else if (GET_U_1(fhp + i) == 0) {
454 		seen_null = 1;
455 		continue;
456 	    }
457 	    else
458 		return(0);
459 	}
460 
461 	return(1);
462 }
463