xref: /freebsd/contrib/tcpdump/parsenfsfh.c (revision 0a7e5f1f02aad2ff5fff1c60f44c6975fd07e1d9)
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 <config.h>
44 
45 #include "netdissect-stdinc.h"
46 
47 #include <stdio.h>
48 #include <string.h>
49 #include <limits.h>
50 
51 #include "netdissect-ctype.h"
52 
53 #include "netdissect.h"
54 #include "extract.h"
55 #include "nfsfh.h"
56 
57 /*
58  * This routine attempts to parse a file handle (in network byte order),
59  * using heuristics to guess what kind of format it is in.  See the
60  * file "fhandle_layouts" for a detailed description of the various
61  * patterns we know about.
62  *
63  * The file handle is parsed into our internal representation of a
64  * file-system id, and an internal representation of an inode-number.
65  */
66 
67 #define	FHT_UNKNOWN	0
68 #define	FHT_AUSPEX	1
69 #define	FHT_DECOSF	2
70 #define	FHT_IRIX4	3
71 #define	FHT_IRIX5	4
72 #define	FHT_SUNOS3	5
73 #define	FHT_SUNOS4	6
74 #define	FHT_ULTRIX	7
75 #define	FHT_VMSUCX	8
76 #define	FHT_SUNOS5	9
77 #define	FHT_AIX32	10
78 #define	FHT_HPUX9	11
79 #define	FHT_BSD44	12
80 
81 static int is_UCX(netdissect_options *, const unsigned char *, u_int);
82 
83 void
Parse_fh(netdissect_options * ndo,const unsigned char * fh,u_int len,my_fsid * fsidp,uint32_t * inop,const char ** osnamep,const char ** fsnamep,int ourself)84 Parse_fh(netdissect_options *ndo, const unsigned char *fh, u_int len,
85 	 my_fsid *fsidp, uint32_t *inop,
86 	 const char **osnamep, /* if non-NULL, return OS name here */
87 	 const char **fsnamep, /* if non-NULL, return server fs name here (for VMS) */
88 	 int ourself)	/* true if file handle was generated on this host */
89 {
90 	const unsigned char *fhp = fh;
91 	uint32_t temp;
92 	int fhtype = FHT_UNKNOWN;
93 	u_int i;
94 
95 	/*
96 	 * Require at least 16 bytes of file handle; it's variable-length
97 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
98 	 */
99 	if (len < 16/4)
100 		fhtype = FHT_UNKNOWN;
101 	else {
102 		if (ourself) {
103 		    /* File handle generated on this host, no need for guessing */
104 #if	defined(IRIX40)
105 		    fhtype = FHT_IRIX4;
106 #endif
107 #if	defined(IRIX50)
108 		    fhtype = FHT_IRIX5;
109 #endif
110 #if	defined(IRIX51)
111 		    fhtype = FHT_IRIX5;
112 #endif
113 #if	defined(SUNOS4)
114 		    fhtype = FHT_SUNOS4;
115 #endif
116 #if	defined(SUNOS5)
117 		    fhtype = FHT_SUNOS5;
118 #endif
119 #if	defined(ultrix)
120 		    fhtype = FHT_ULTRIX;
121 #endif
122 #if	defined(__osf__)
123 		    fhtype = FHT_DECOSF;
124 #endif
125 #if	defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__) \
126      || defined(__OpenBSD__)
127 		    fhtype = FHT_BSD44;
128 #endif
129 		}
130 		/*
131 		 * This is basically a big decision tree
132 		 */
133 		else if ((GET_U_1(fhp) == 0) && (GET_U_1(fhp + 1) == 0)) {
134 		    /* bytes[0,1] == (0,0); rules out Ultrix, IRIX5, SUNOS5 */
135 		    /* probably rules out HP-UX, AIX unless they allow major=0 */
136 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
137 			/* bytes[2,3] == (0,0); must be Auspex */
138 			/* XXX or could be Ultrix+MASSBUS "hp" disk? */
139 			fhtype = FHT_AUSPEX;
140 		    } else {
141 			/*
142 			 * bytes[2,3] != (0,0); rules out Auspex, could be
143 			 * DECOSF, SUNOS4, or IRIX4
144 			 */
145 			if ((GET_U_1(fhp + 4) != 0) && (GET_U_1(fhp + 5) == 0) &&
146 				(GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
147 			    /* seems to be DECOSF, with minor == 0 */
148 			    fhtype = FHT_DECOSF;
149 			} else {
150 			    /* could be SUNOS4 or IRIX4 */
151 			    /* XXX the test of fhp[5] == 8 could be wrong */
152 			    if ((GET_U_1(fhp + 4) == 0) && (GET_U_1(fhp + 5) == 8) && (GET_U_1(fhp + 6) == 0) &&
153 			        (GET_U_1(fhp + 7) == 0)) {
154 				/* looks like a length, not a file system typecode */
155 				fhtype = FHT_IRIX4;
156 			    } else {
157 				/* by elimination */
158 				fhtype = FHT_SUNOS4;
159 			    }
160 			}
161 		    }
162 		} else {
163 		    /*
164 		     * bytes[0,1] != (0,0); rules out Auspex, IRIX4, SUNOS4
165 		     * could be IRIX5, DECOSF, UCX, Ultrix, SUNOS5
166 		     * could be AIX, HP-UX
167 		     */
168 		    if ((GET_U_1(fhp + 2) == 0) && (GET_U_1(fhp + 3) == 0)) {
169 			/*
170 			 * bytes[2,3] == (0,0); rules out OSF, probably not UCX
171 			 * (unless the exported device name is just one letter!),
172 			 * could be Ultrix, IRIX5, AIX, or SUNOS5
173 			 * might be HP-UX (depends on their values for minor devs)
174 			 */
175 			if ((GET_U_1(fhp + 6) == 0) && (GET_U_1(fhp + 7) == 0)) {
176 			    fhtype = FHT_BSD44;
177 			}
178 			/*XXX we probably only need to test of these two bytes */
179 			else if ((len >= 24/4) && (GET_U_1(fhp + 21) == 0) && (GET_U_1(fhp + 23) == 0)) {
180 			    fhtype = FHT_ULTRIX;
181 			} else {
182 			    /* Could be SUNOS5/IRIX5, maybe AIX */
183 			    /* XXX no obvious difference between SUNOS5 and IRIX5 */
184 			    if (GET_U_1(fhp + 9) == 10)
185 				fhtype = FHT_SUNOS5;
186 			    /* XXX what about AIX? */
187 			}
188 		    } else {
189 			/*
190 			 * bytes[2,3] != (0,0); rules out Ultrix, could be
191 			 * DECOSF, SUNOS5, IRIX5, AIX, HP-UX, or UCX
192 			 */
193 			if ((GET_U_1(fhp + 8) == 12) && (GET_U_1(fhp + 9) == 0)) {
194 			    fhtype = FHT_DECOSF;
195 			} else if ((GET_U_1(fhp + 8) == 0) && (GET_U_1(fhp + 9) == 10)) {
196 			    /* could be SUNOS5/IRIX5, AIX, HP-UX */
197 			    if ((GET_U_1(fhp + 7) == 0) && (GET_U_1(fhp + 6) == 0) &&
198 				(GET_U_1(fhp + 5) == 0) && (GET_U_1(fhp + 4) == 0)) {
199 				/* XXX is this always true of HP-UX? */
200 				fhtype = FHT_HPUX9;
201 			    } else if (GET_U_1(fhp + 7) == 2) {
202 				/* This would be MNT_NFS on AIX, which is impossible */
203 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
204 			    } else {
205 				/*
206 				 * XXX Could be SUNOS5/IRIX5 or AIX.  I don't
207 				 * XXX see any way to disambiguate these, so
208 				 * XXX I'm going with the more likely guess.
209 				 * XXX Sorry, Big Blue.
210 				 */
211 				fhtype = FHT_SUNOS5;	/* or maybe IRIX5 */
212 			    }
213 		        } else {
214 			    if (is_UCX(ndo, fhp, len)) {
215 				fhtype = FHT_VMSUCX;
216 			    } else {
217 				fhtype = FHT_UNKNOWN;
218 			    }
219 			}
220 		    }
221 		}
222 	}
223 
224 	/* XXX still needs to handle SUNOS3 */
225 
226 	switch (fhtype) {
227 	case FHT_AUSPEX:
228 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 7);
229 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 6);
230 	    fsidp->fsid_code = 0;
231 
232 	    *inop = GET_BE_U_4(fhp + 12);
233 
234 	    if (osnamep)
235 		*osnamep = "Auspex";
236 	    break;
237 
238 	case FHT_BSD44:
239 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
240 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
241 	    fsidp->fsid_code = 0;
242 
243 	    *inop = GET_LE_U_4(fhp + 12);
244 
245 	    if (osnamep)
246 		*osnamep = "BSD 4.4";
247 	    break;
248 
249 	case FHT_DECOSF:
250 	    fsidp->fsid_code = GET_LE_U_4(fhp + 4);
251 			/* XXX could ignore 3 high-order bytes */
252 
253 	    temp = GET_LE_U_4(fhp);
254 	    fsidp->Fsid_dev.Minor = temp & 0xFFFFF;
255 	    fsidp->Fsid_dev.Major = (temp>>20) & 0xFFF;
256 
257 	    *inop = GET_LE_U_4(fhp + 12);
258 	    if (osnamep)
259 		*osnamep = "OSF";
260 	    break;
261 
262 	case FHT_IRIX4:
263 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
264 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
265 	    fsidp->fsid_code = 0;
266 
267 	    *inop = GET_BE_U_4(fhp + 8);
268 
269 	    if (osnamep)
270 		*osnamep = "IRIX4";
271 	    break;
272 
273 	case FHT_IRIX5:
274 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
275 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
276 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
277 
278 	    *inop = GET_BE_U_4(fhp + 12);
279 
280 	    if (osnamep)
281 		*osnamep = "IRIX5";
282 	    break;
283 
284 #ifdef notdef
285 	case FHT_SUNOS3:
286 	    /*
287 	     * XXX - none of the heuristics above return this.
288 	     * Are there any SunOS 3.x systems around to care about?
289 	     */
290 	    if (osnamep)
291 		*osnamep = "SUNOS3";
292 	    break;
293 #endif
294 
295 	case FHT_SUNOS4:
296 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp + 3);
297 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 2);
298 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
299 
300 	    *inop = GET_BE_U_4(fhp + 12);
301 
302 	    if (osnamep)
303 		*osnamep = "SUNOS4";
304 	    break;
305 
306 	case FHT_SUNOS5:
307 	    temp = GET_BE_U_2(fhp);
308 	    fsidp->Fsid_dev.Major = (temp>>2) &  0x3FFF;
309 	    temp = GET_BE_U_3(fhp + 1);
310 	    fsidp->Fsid_dev.Minor = temp & 0x3FFFF;
311 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
312 
313 	    *inop = GET_BE_U_4(fhp + 12);
314 
315 	    if (osnamep)
316 		*osnamep = "SUNOS5";
317 	    break;
318 
319 	case FHT_ULTRIX:
320 	    fsidp->fsid_code = 0;
321 	    fsidp->Fsid_dev.Minor = GET_U_1(fhp);
322 	    fsidp->Fsid_dev.Major = GET_U_1(fhp + 1);
323 
324 	    temp = GET_LE_U_4(fhp + 4);
325 	    *inop = temp;
326 	    if (osnamep)
327 		*osnamep = "Ultrix";
328 	    break;
329 
330 	case FHT_VMSUCX:
331 	    /* No numeric file system ID, so hash on the device-name */
332 	    if (sizeof(*fsidp) >= 14) {
333 		if (sizeof(*fsidp) > 14)
334 		    memset((char *)fsidp, 0, sizeof(*fsidp));
335 		/* just use the whole thing */
336 		memcpy((char *)fsidp, (const char *)fh, 14);
337 	    } else {
338 		uint32_t tempa[4];	/* at least 16 bytes, maybe more */
339 
340 		memset((char *)tempa, 0, sizeof(tempa));
341 		memcpy((char *)tempa, (const char *)fh, 14); /* ensure alignment */
342 		fsidp->Fsid_dev.Minor = tempa[0] + (tempa[1]<<1);
343 		fsidp->Fsid_dev.Major = tempa[2] + (tempa[3]<<1);
344 		fsidp->fsid_code = 0;
345 	    }
346 
347 	    /* VMS file ID is: (RVN, FidHi, FidLo) */
348 	    *inop = (((uint32_t) GET_U_1(fhp + 26)) << 24) |
349 		    (((uint32_t) GET_U_1(fhp + 27)) << 16) |
350 		    (GET_LE_U_2(fhp + 22) << 0);
351 
352 	    /* Caller must save (and null-terminate?) this value */
353 	    if (fsnamep)
354 		*fsnamep = (const char *)(fhp + 1);
355 
356 	    if (osnamep)
357 		*osnamep = "VMS";
358 	    break;
359 
360 	case FHT_AIX32:
361 	    fsidp->Fsid_dev.Minor = GET_BE_U_2(fhp + 2);
362 	    fsidp->Fsid_dev.Major = GET_BE_U_2(fhp);
363 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
364 
365 	    *inop = GET_BE_U_4(fhp + 12);
366 
367 	    if (osnamep)
368 		*osnamep = "AIX32";
369 	    break;
370 
371 	case FHT_HPUX9:
372 	    fsidp->Fsid_dev.Major = GET_U_1(fhp);
373 	    temp = GET_BE_U_3(fhp + 1);
374 	    fsidp->Fsid_dev.Minor = temp;
375 	    fsidp->fsid_code = GET_BE_U_4(fhp + 4);
376 
377 	    *inop = GET_BE_U_4(fhp + 12);
378 
379 	    if (osnamep)
380 		*osnamep = "HPUX9";
381 	    break;
382 
383 	case FHT_UNKNOWN:
384 #ifdef DEBUG
385 	    /* XXX debugging */
386 	    for (i = 0; i < len*4; i++)
387 		(void)fprintf(stderr, "%x.", GET_U_1(fhp + i));
388 	    (void)fprintf(stderr, "\n");
389 #endif
390 	    /* Save the actual handle, so it can be display with -u */
391 	    /* XXX really ? When -u is used this function is not called */
392 	    for (i = 0; i < len*4 && i*2 < sizeof(fsidp->Opaque_Handle) - 1; i++)
393 		(void)snprintf(&(fsidp->Opaque_Handle[i*2]), 3, "%.2X",
394 			       GET_U_1(fhp + i));
395 	    fsidp->Opaque_Handle[i*2] = '\0';
396 
397 	    /* XXX for now, give "bogus" values to aid debugging */
398 	    fsidp->fsid_code = 0;
399 	    fsidp->Fsid_dev.Minor = UINT_MAX;
400 	    fsidp->Fsid_dev.Major = UINT_MAX;
401 	    *inop = 1;
402 
403 	    /* display will show this string instead of (UINT_MAX,UINT_MAX) */
404 	    /* XXX really ? */
405 	    if (fsnamep)
406 		*fsnamep = "Unknown";
407 
408 	    if (osnamep)
409 		*osnamep = "Unknown";
410 	    break;
411 
412 	}
413 }
414 
415 /*
416  * Is this a VMS UCX file handle?
417  *	Check for:
418  *	(1) leading code byte	[XXX not yet]
419  *	(2) followed by string of printing chars & spaces
420  *	(3) followed by string of nulls
421  */
422 static int
is_UCX(netdissect_options * ndo,const unsigned char * fhp,u_int len)423 is_UCX(netdissect_options *ndo, const unsigned char *fhp, u_int len)
424 {
425 	u_int i;
426 	int seen_null = 0;
427 
428 	/*
429 	 * Require at least 28 bytes of file handle; it's variable-length
430 	 * in NFSv3.  "len" is in units of 32-bit words, not bytes.
431 	 */
432 	if (len < 28/4)
433 		return(0);
434 
435 	for (i = 1; i < 14; i++) {
436 	    if (ND_ASCII_ISPRINT(GET_U_1(fhp + i))) {
437 		if (seen_null)
438 		   return(0);
439 		else
440 		   continue;
441 	    } else if (GET_U_1(fhp + i) == 0) {
442 		seen_null = 1;
443 		continue;
444 	    } else
445 		return(0);
446 	}
447 
448 	return(1);
449 }
450