xref: /illumos-gate/usr/src/uts/common/fs/hsfs/hsfs_susp_subr.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * System Use Sharing protocol subroutines for High Sierra filesystem
23  */
24 /*
25  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #include <sys/types.h>
30 #include <sys/t_lock.h>
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/sysmacros.h>
34 #include <sys/kmem.h>
35 #include <sys/signal.h>
36 #include <sys/user.h>
37 #include <sys/proc.h>
38 #include <sys/disp.h>
39 #include <sys/buf.h>
40 #include <sys/pathname.h>
41 #include <sys/vfs.h>
42 #include <sys/vnode.h>
43 #include <sys/file.h>
44 #include <sys/uio.h>
45 #include <sys/conf.h>
46 
47 #include <vm/page.h>
48 
49 #include <sys/fs/hsfs_spec.h>
50 #include <sys/fs/hsfs_isospec.h>
51 #include <sys/fs/hsfs_node.h>
52 #include <sys/fs/hsfs_impl.h>
53 #include <sys/fs/hsfs_susp.h>
54 #include <sys/fs/hsfs_rrip.h>
55 
56 #include <sys/statvfs.h>
57 #include <sys/mount.h>
58 #include <sys/swap.h>
59 #include <sys/errno.h>
60 #include <sys/debug.h>
61 #include "fs/fs_subr.h"
62 #include <sys/cmn_err.h>
63 
64 /* static declarations */
65 static void free_cont_area(uchar_t *);
66 static int get_cont_area(struct hsfs *, uchar_t **, cont_info_t *);
67 static int parse_signatures(sig_args_t *, int, uchar_t *, int);
68 
69 /*
70  * parse_sua()
71  *
72  * This is the main SUSP routine, that gets all the SUA areas and
73  * continuations.	It calls parse_signatures() to actually interpret
74  * the signature fields.
75  *
76  * XXX - need to implement signature searching to speed things up and
77  *		which is needed for the api, which isn't done yet.
78  */
79 int
80 parse_sua(
81 	uchar_t			*name_p,	/* location to copy name */
82 	int			*name_len_p,	/* location to put name len */
83 	int			*name_change_p,	/* flags to signal name chg */
84 	uchar_t			*dirp,		/* pointer to ISO dir entry */
85 	uint_t			last_offset,	/* last ind. in cur. dirblock */
86 	struct hs_direntry	*hdp,		/* loc to store dir info */
87 	struct hsfs		*fsp,		/* filesystem pointer */
88 	uchar_t			*search_sig,	/* signature to search for */
89 	int			search_num)	/* n^th sig to search for */
90 {
91 	uchar_t			*SUA_p = IDE_sys_use_area(dirp);
92 	int			SUA_len = IDE_SUA_LEN(dirp);
93 	uchar_t			*tmp_SUA_p = (SUA_p + fsp->hsfs_sua_off);
94 	int			tmp_SUA_len = (SUA_len - fsp->hsfs_sua_off);
95 	short			ret_val = -1;
96 	uchar_t			*cont_p = (uchar_t *)NULL;
97 	sig_args_t		sig_args;
98 	cont_info_t		cont_info;
99 
100 	/*
101 	 * If there is no SUA, just return, no error
102 	 */
103 
104 	if (SUA_len == 0)
105 		return (0);
106 
107 	/*
108 	 * Underflow on the length field means there's a mismatch
109 	 * between sizes of SUA and ISO directory entry. This entry
110 	 * is corrupted, return an appropriate error.
111 	 */
112 	if (SUA_len < 0) {
113 		hs_log_bogus_disk_warning(fsp, HSFS_ERR_NEG_SUA_LEN, 0);
114 		return (SUA_EINVAL);
115 	}
116 
117 	if ((tmp_SUA_p + tmp_SUA_len) > (dirp + last_offset)) {
118 		hs_log_bogus_disk_warning(fsp, HSFS_ERR_BAD_SUA_LEN, 0);
119 		return (SUA_EINVAL);
120 	}
121 
122 	/*
123 	 * Make sure that the continuation lenth is zero, as that is
124 	 * the way to tell if we must grab another continuation area.
125 	 */
126 	bzero((char *)&cont_info, sizeof (cont_info));
127 
128 	sig_args.dirp		= dirp;
129 	sig_args.name_p		= name_p;
130 	sig_args.name_len_p	= name_len_p;
131 	sig_args.SUF_ptr	= tmp_SUA_p;
132 	sig_args.hdp		= hdp;
133 	sig_args.fsp		= fsp;
134 	sig_args.cont_info_p	= &cont_info;
135 	sig_args.flags		= 0;
136 	sig_args.name_flags	= 0;
137 
138 	/*
139 	 * Get ready to put in a new name.	 If no "NM" is found, then
140 	 * hs_namecopy will come to the rescue.  Make sure you don't
141 	 * have NULL names, also.
142 	 */
143 	if (name_p)
144 		*(name_p) = '\0';
145 	if (name_len_p)
146 		*(name_len_p) = 0;
147 
148 	while (ret_val == -1) {
149 		switch (parse_signatures(&sig_args, tmp_SUA_len, search_sig,
150 		    search_num)) {
151 		case END_OF_SUA :
152 			if (cont_info.cont_len) {
153 
154 				if (get_cont_area(fsp, &cont_p, &cont_info)) {
155 					ret_val = 1;
156 					goto clean_up;
157 				}
158 
159 				sig_args.SUF_ptr =
160 				    cont_p + cont_info.cont_offset;
161 
162 				tmp_SUA_len = cont_info.cont_len;
163 				cont_info.cont_len = 0;
164 
165 				continue;
166 			}
167 			sig_args.flags = 0;	/* reset */
168 			ret_val = 0;		/* keep going */
169 			break;
170 		case SUA_NULL_POINTER:
171 			ret_val = SUA_NULL_POINTER;
172 			goto clean_up;
173 		case SUA_ENOMEM:
174 			ret_val = SUA_ENOMEM;
175 			goto clean_up;
176 		case SUA_EINVAL:
177 			ret_val = SUA_EINVAL;
178 			goto clean_up;
179 		case RELOC_DIR:
180 			ret_val = RELOC_DIR;
181 			goto clean_up;
182 		}
183 	}
184 
185 	if (ret_val != 0)
186 		goto clean_up;
187 
188 	if (IS_NAME_BIT_SET(sig_args.name_flags, RRIP_NAME_CHANGE))
189 		SET_NAME_BIT(*(name_change_p), RRIP_NAME_CHANGE);
190 
191 clean_up:
192 	free_cont_area(cont_p);
193 	return (ret_val);
194 
195 }
196 
197 /*
198  * parse_signatures()
199  *
200  * Find the correct handling function for the signature string that is
201  * passed to this function.
202  *
203  * signature searching:
204  *
205  * The two arguments of search_sig and search_num are for finding the
206  * search_num^th occurance of the signature search_sig.  This will come
207  * in handy with searching for the "NM" field and is part of the api
208  * for rrip (which really can be used for any extension).
209  */
210 /*ARGSUSED*/
211 static int
212 parse_signatures(
213 	sig_args_t	*sig_args_p,
214 	int		SUA_len,
215 	uchar_t		*search_sig,	/* possible signature to search for */
216 	int		search_num)	/* n^th occurance of search_sig to */
217 					/*   search for */
218 {
219 	uchar_t			*sig_string = sig_args_p->SUF_ptr;
220 	extension_name_t	*extnp;
221 	ext_signature_t		*ext_sigp;
222 	int			impl_bit_num = 0;
223 	int			SUA_rem = SUA_len; /* SUA length */
224 					/* remaining to be parsed */
225 
226 	/* This should never happen ... just so we don't panic, literally */
227 	if (sig_string == (uchar_t *)NULL)
228 		return (SUA_NULL_POINTER);
229 
230 	if (SUA_len < 0)
231 		return (SUA_EINVAL);
232 
233 	/*
234 	 * Until the end of SUA, search for the signatures
235 	 * (check for end of SUA (2 consecutive NULL bytes)) or the
236 	 * remaining  length of the SUA is <= 3.  The minimum signature
237 	 * field  is 4.
238 	 */
239 
240 	while ((SUA_rem >= SUF_MIN_LEN) && (*sig_string != '\0') &&
241 		(*(sig_string + 1) != '\0')) {
242 
243 		/*
244 		 * Find appropriate extension and signature table
245 		 */
246 		for (extnp = extension_name_table, impl_bit_num = 0;
247 		    extnp->extension_name != (char *)NULL;
248 		    extnp++, impl_bit_num++)  {
249 
250 			/*
251 			 * look at an extension only if it is implemented
252 			 * on the CD-ROM
253 			 */
254 			if (!IS_IMPL_BIT_SET(sig_args_p->fsp, impl_bit_num))
255 				continue;
256 
257 			/*
258 			 * Find the appropriate signature
259 			 */
260 			for (ext_sigp = extnp->signature_table;
261 			    ext_sigp->ext_signature != (char *)NULL;
262 			    ext_sigp++)  {
263 
264 				if (strncmp((char *)sig_string,
265 					    ext_sigp->ext_signature,
266 					    SUF_SIG_LEN) == 0) {
267 
268 					SUA_rem -= SUF_LEN(sig_string);
269 					if (SUA_rem < 0)
270 						return (END_OF_SUA);
271 
272 					/*
273 					 * The SUA_len parameter specifies the
274 					 * length of the SUA that the kernel
275 					 * expects. There is also a length
276 					 * encoded in the SUA data. If they
277 					 * do not agree, bail out.
278 					 */
279 					if (SUA_len < SUF_LEN(sig_string)) {
280 						cmn_err(CE_NOTE,
281 					"parse_signatures: SUA length too big: "
282 					"expected=%d, found=%d",
283 						    SUA_len,
284 						    SUF_LEN(sig_string));
285 						return (SUA_EINVAL);
286 					}
287 
288 					sig_args_p->SUF_ptr = sig_string;
289 					sig_string =
290 					    (ext_sigp->sig_handler)(sig_args_p);
291 
292 					switch (sig_args_p->flags) {
293 					case END_OF_SUA :
294 						return (END_OF_SUA);
295 					case SUA_ENOMEM :
296 						return (SUA_ENOMEM);
297 					case SUA_EINVAL :
298 						return (SUA_EINVAL);
299 					case RELOC_DIR :
300 						return (RELOC_DIR);
301 					default :
302 #if NAME_SEARCH
303 						case NAME_CONTINUE :
304 							/* nothing for now */
305 						case NAME_CHANGE :
306 							/* nothing for now */
307 #endif
308 						break;
309 					}
310 
311 					/* reset to be zero */
312 
313 					sig_args_p->flags = 0;
314 					goto next_signature;
315 				}
316 
317 				/* off to the next signature .... */
318 
319 			} /* for ext_sigp */
320 
321 		} /* for extnp	(extension parsing) */
322 
323 		/*
324 		 * Opps, did not find this signature. We must
325 		 * advance on the the next signature in the SUA
326 		 * and pray to persumedly omniscient, omnipresent,
327 		 * almighty transcendental being(s) that the next
328 		 * record is in the susp format, or we get hosed.
329 		 */
330 		if (SUA_rem < SUF_MIN_LEN)
331 			return (END_OF_SUA);
332 
333 		SUA_rem -= SUF_LEN(sig_string);
334 		sig_string += SUF_LEN(sig_string);
335 
336 next_signature:
337 		/*
338 		 * Failsafe
339 		 */
340 		if (SUA_rem < SUF_MIN_LEN ||
341 		    sig_string == NULL || SUF_LEN(sig_string) <= 0) {
342 			return (END_OF_SUA);
343 		}
344 
345 	} /* while */
346 
347 	return (END_OF_SUA);
348 }
349 
350 /*
351  * hs_fill_root_dirent()
352  *
353  *
354  * This function reads the root directory extent to get to the SUA of
355  * the "." entry of the root directory.  It the checks to see if the
356  * susp is implemented.
357  */
358 void
359 hs_check_root_dirent(struct vnode *vp, struct hs_direntry *hdp)
360 {
361 	struct buf	*secbp;
362 	uchar_t		*root_ptr;
363 	uchar_t		*secp;
364 	uint_t		secno;
365 	offset_t	secoff;
366 	sig_args_t	sig_args;
367 	struct hsfs	*fsp;
368 	int		error;
369 
370 	if (vp->v_type != VDIR) {
371 		cmn_err(CE_NOTE,
372 		    "hs_check_root_dirent: vp (0x%p) not a directory",
373 		    (void *)vp);
374 		return;
375 	}
376 
377 	bzero((caddr_t)&sig_args, sizeof (sig_args));
378 
379 	fsp = VFS_TO_HSFS(vp->v_vfsp);
380 	secno = LBN_TO_SEC(hdp->ext_lbn+hdp->xar_len, vp->v_vfsp);
381 	secoff = LBN_TO_BYTE(hdp->ext_lbn+hdp->xar_len, vp->v_vfsp) &
382 	    MAXHSOFFSET;
383 	secbp = bread(fsp->hsfs_devvp->v_rdev, secno * 4, HS_SECTOR_SIZE);
384 	error = geterror(secbp);
385 
386 	if (error != 0) {
387 		cmn_err(CE_NOTE,
388 		    "hs_check_root_dirent: bread: error=(%d)", error);
389 		goto end;
390 	}
391 
392 	secp = (uchar_t *)secbp->b_un.b_addr;
393 	root_ptr = &secp[secoff];
394 
395 	/* quick check */
396 	if (hdp->ext_lbn != HDE_EXT_LBN(root_ptr)) {
397 		cmn_err(CE_NOTE, "hs_check_root_dirent: dirent not match\n");
398 		/* keep on going */
399 	}
400 
401 	/*
402 	 * Here, we know that the "." entry is the first in the sector
403 	 * just read (ISO 9660).  Let's now check for the sharing
404 	 * protocol and set call the susp sig_handler() if we should.
405 	 * Then we run through the hs_parsedir() function to catch all
406 	 * the other possibilities of SUSP fields and continuations.
407 	 *
408 	 * If there is no SUA area, just return, and assume ISO.
409 	 *
410 	 * If the SUA area length is invalid (negative, due to a mismatch
411 	 * between dirent size and SUA size), return and hope for the best.
412 	 */
413 
414 	if (IDE_SUA_LEN(root_ptr) <= 0)
415 		goto end;
416 
417 	if (strncmp(SUSP_SP, (char *)IDE_sys_use_area(root_ptr),
418 	    SUF_SIG_LEN) == 0) {
419 		/*
420 		 * We have a match of the sharing signature, so let's
421 		 * call the sig_handler to do what is necessary. We can
422 		 * ignore the return value, as implemented bits are set.
423 		 */
424 		sig_args.SUF_ptr = IDE_sys_use_area(root_ptr);
425 		sig_args.fsp	 = fsp;
426 
427 		if ((susp_sp->sig_handler)(&sig_args) == (uchar_t *)NULL) {
428 			goto end;
429 		}
430 	} else {
431 		goto end;
432 	}
433 
434 	/*
435 	 * If the "ER" signature in the root directory is past any non SU
436 	 * signature, the Rock Ridge signatures will be ignored. This happens
437 	 * e.g. for filesystems created by mkisofs. In this case,
438 	 * IS_RRIP_IMPLEMENTED(fsp) will return 0 when the "ER" signature is
439 	 * parsed. Unfortunately, the results of this run will be cached for
440 	 * the root vnode. The solution is to run hs_parsedir() a second time
441 	 * for the root directory.
442 	 */
443 	if (hs_parsedir(fsp, root_ptr, hdp, (char *)NULL, (int *)NULL,
444 	    HS_SECTOR_SIZE - secoff) == 0) {
445 		(void) hs_parsedir(fsp, root_ptr, hdp, (char *)NULL,
446 		    (int *)NULL, HS_SECTOR_SIZE - secoff);
447 	}
448 
449 	/*
450 	 * If we did not get at least 1 extension, let's assume ISO and
451 	 * NULL out the implementation bits.
452 	 */
453 	if (fsp->hsfs_ext_impl <= 1L)
454 		fsp->hsfs_ext_impl = 0L;
455 
456 end:
457 	brelse(secbp);
458 }
459 
460 
461 /*
462  * get_cont_area()
463  *
464  * This function allocates a memory block, if necessary, and reads the
465  * continuation area into the allocated space.
466  *
467  * Return value : 	0 if the read and allocation went OK.
468  * 			1 if there was an error.
469  */
470 static int
471 get_cont_area(struct hsfs *fsp, uchar_t **buf_pp, cont_info_t *cont_info_p)
472 {
473 	struct buf	*secbp;
474 	int		error;
475 	uint_t		secno;
476 
477 	/*
478 	 * Guard against invalid continuation area records.
479 	 * Both cont_offset and cont_len must be no longer than
480 	 * HS_SECTOR_SIZE. If they are, return an error.
481 	 */
482 	if (cont_info_p->cont_offset > HS_SECTOR_SIZE ||
483 	    cont_info_p->cont_len > HS_SECTOR_SIZE) {
484 		cmn_err(CE_NOTE, "get_cont_area: invalid offset/length");
485 		return (1);
486 	}
487 
488 	if (*buf_pp == (uchar_t *)NULL)
489 		*buf_pp = kmem_alloc((size_t)HS_SECTOR_SIZE, KM_SLEEP);
490 
491 	secno = (uint_t)LBN_TO_SEC(cont_info_p->cont_lbn, fsp->hsfs_vfs);
492 	secbp = bread(fsp->hsfs_devvp->v_rdev, secno * 4, HS_SECTOR_SIZE);
493 	error = geterror(secbp);
494 
495 	if (error != 0) {
496 		cmn_err(CE_NOTE, "get_cont_area: bread: error=(%d)", error);
497 		brelse(secbp);
498 		return (1);
499 	}
500 
501 	/*
502 	 * This continuation area does not extend into the next sector
503 	 * so just copy the data to the buffer.
504 	 */
505 	if ((cont_info_p->cont_offset + cont_info_p->cont_len) <=
506 	    HS_SECTOR_SIZE) {
507 		bcopy(secbp->b_un.b_addr, (char *)*buf_pp, HS_SECTOR_SIZE);
508 	}
509 	/*
510 	 * This continuation area extends into the next sector so we
511 	 * need to do some dancing:
512 	 *
513 	 * - zero the return buffer so nothing random is returned
514 	 * - copy the partial data to the *beginning* of the return buffer
515 	 * - release the first sector's buffer
516 	 * - read the next sector
517 	 * - copy the remainder of the data to the return buffer
518 	 */
519 	else {
520 		uint_t	partial_size;
521 
522 		bzero((char *)*buf_pp, HS_SECTOR_SIZE);
523 		partial_size = HS_SECTOR_SIZE - cont_info_p->cont_offset;
524 		bcopy(&secbp->b_un.b_addr[cont_info_p->cont_offset],
525 		    (char *)*buf_pp, partial_size);
526 		cont_info_p->cont_offset = 0;
527 		brelse(secbp);
528 
529 		secbp = bread(fsp->hsfs_devvp->v_rdev, (secno + 1) * 4,
530 		    HS_SECTOR_SIZE);
531 		error = geterror(secbp);
532 		if (error != 0) {
533 			cmn_err(CE_NOTE, "get_cont_area: bread(2): error=(%d)",
534 			    error);
535 			brelse(secbp);
536 			return (1);
537 		}
538 		bcopy(secbp->b_un.b_addr, (char *)&(*buf_pp)[partial_size],
539 		    cont_info_p->cont_len - partial_size);
540 	}
541 
542 	brelse(secbp);
543 	return (0);
544 }
545 
546 
547 /*
548  * free_cont_area
549  *
550  * simple function to just free up memory, if it exists
551  *
552  */
553 static void
554 free_cont_area(uchar_t *cont_p)
555 {
556 	if (cont_p)
557 		(void) kmem_free((caddr_t)cont_p, (size_t)HS_SECTOR_SIZE);
558 	cont_p = (uchar_t *)NULL;
559 }
560