xref: /illumos-gate/usr/src/uts/common/fs/hsfs/hsfs_susp_subr.c (revision fc1c62b83ed843ff61ec6521fdaa20be7b46ebb6)
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 2006 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/types.h>
32 #include <sys/t_lock.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/sysmacros.h>
36 #include <sys/kmem.h>
37 #include <sys/signal.h>
38 #include <sys/user.h>
39 #include <sys/proc.h>
40 #include <sys/disp.h>
41 #include <sys/buf.h>
42 #include <sys/pathname.h>
43 #include <sys/vfs.h>
44 #include <sys/vnode.h>
45 #include <sys/file.h>
46 #include <sys/uio.h>
47 #include <sys/conf.h>
48 
49 #include <vm/page.h>
50 
51 #include <sys/fs/hsfs_spec.h>
52 #include <sys/fs/hsfs_isospec.h>
53 #include <sys/fs/hsfs_node.h>
54 #include <sys/fs/hsfs_impl.h>
55 #include <sys/fs/hsfs_susp.h>
56 #include <sys/fs/hsfs_rrip.h>
57 
58 #include <sys/statvfs.h>
59 #include <sys/mount.h>
60 #include <sys/swap.h>
61 #include <sys/errno.h>
62 #include <sys/debug.h>
63 #include "fs/fs_subr.h"
64 #include <sys/cmn_err.h>
65 
66 /* static declarations */
67 static void free_cont_area(uchar_t *);
68 static int get_cont_area(struct hsfs *, uchar_t **, cont_info_t *);
69 static int parse_signatures(sig_args_t *, int, uchar_t *, int);
70 
71 /*
72  * parse_sua()
73  *
74  * This is the main SUSP routine, that gets all the SUA areas and
75  * continuations.	It calls parse_signatures() to actually interpret
76  * the signature fields.
77  *
78  * XXX - need to implement signature searching to speed things up and
79  *		which is needed for the api, which isn't done yet.
80  */
81 int
82 parse_sua(
83 	uchar_t			*name_p,	/* location to copy name */
84 	int			*name_len_p,	/* location to put name len */
85 	int			*name_change_p,	/* flags to signal name chg */
86 	uchar_t			*dirp,		/* pointer to ISO dir entry */
87 	struct hs_direntry	*hdp,		/* loc to store dir info */
88 	struct hsfs		*fsp,		/* filesystem pointer */
89 	uchar_t			*search_sig,	/* signature to search for */
90 	int			search_num)	/* n^th sig to search for */
91 {
92 	uchar_t			*SUA_p = IDE_sys_use_area(dirp);
93 	int			SUA_len = IDE_SUA_LEN(dirp);
94 	uchar_t			*tmp_SUA_p = (SUA_p + fsp->hsfs_sua_off);
95 	int			tmp_SUA_len = (SUA_len - fsp->hsfs_sua_off);
96 	short			ret_val = -1;
97 	uchar_t			*cont_p = (uchar_t *)NULL;
98 	sig_args_t		sig_args;
99 	cont_info_t		cont_info;
100 
101 	/*
102 	 * If there is no SUA, just return, no error
103 	 */
104 
105 	if (SUA_len == 0)
106 		return (0);
107 
108 	/*
109 	 * Underflow on the length field means there's a mismatch
110 	 * between sizes of SUA and ISO directory entry. This entry
111 	 * is corrupted, return an appropriate error.
112 	 */
113 	if (SUA_len < 0)
114 		return (SUA_EINVAL);
115 
116 	/*
117 	 * Make sure that the continuation lenth is zero, as that is
118 	 * the way to tell if we must grab another continuation area.
119 	 */
120 	bzero((char *)&cont_info, sizeof (cont_info));
121 
122 	sig_args.dirp		= dirp;
123 	sig_args.name_p		= name_p;
124 	sig_args.name_len_p	= name_len_p;
125 	sig_args.SUF_ptr	= tmp_SUA_p;
126 	sig_args.hdp		= hdp;
127 	sig_args.fsp		= fsp;
128 	sig_args.cont_info_p	= &cont_info;
129 	sig_args.flags		= 0;
130 	sig_args.name_flags	= 0;
131 
132 	/*
133 	 * Get ready to put in a new name.	 If no "NM" is found, then
134 	 * hs_namecopy will come to the rescue.  Make sure you don't
135 	 * have NULL names, also.
136 	 */
137 	if (name_p)
138 		*(name_p) = '\0';
139 	if (name_len_p)
140 		*(name_len_p) = 0;
141 
142 	while (ret_val == -1) {
143 		switch (parse_signatures(&sig_args, tmp_SUA_len, search_sig,
144 					search_num)) {
145 		case END_OF_SUA :
146 			if (cont_info.cont_len) {
147 
148 				if (get_cont_area(fsp, &cont_p, &cont_info)) {
149 					ret_val = 1;
150 					goto clean_up;
151 				}
152 
153 				sig_args.SUF_ptr = cont_p +
154 					cont_info.cont_offset;
155 
156 				tmp_SUA_len = cont_info.cont_len;
157 				cont_info.cont_len = 0;
158 
159 				continue;
160 			}
161 			sig_args.flags = 0;	/* reset */
162 			ret_val = 0;		/* keep going */
163 			break;
164 		case SUA_NULL_POINTER:
165 			ret_val = SUA_NULL_POINTER;
166 			goto clean_up;
167 		case SUA_ENOMEM:
168 			ret_val = SUA_ENOMEM;
169 			goto clean_up;
170 		case SUA_EINVAL:
171 			ret_val = SUA_EINVAL;
172 			goto clean_up;
173 		case RELOC_DIR:
174 			ret_val = RELOC_DIR;
175 			goto clean_up;
176 		}
177 	}
178 
179 	if (ret_val != 0)
180 		goto clean_up;
181 
182 	if (IS_NAME_BIT_SET(sig_args.name_flags, RRIP_NAME_CHANGE))
183 		SET_NAME_BIT(*(name_change_p), RRIP_NAME_CHANGE);
184 
185 clean_up:
186 	free_cont_area(cont_p);
187 	return (ret_val);
188 
189 }
190 
191 /*
192  * parse_signatures()
193  *
194  * Find the correct handling function for the signature string that is
195  * passed to this function.
196  *
197  * signature searching:
198  *
199  * The two arguments of search_sig and search_num are for finding the
200  * search_num^th occurance of the signature search_sig.  This will come
201  * in handy with searching for the "NM" field and is part of the api
202  * for rrip (which really can be used for any extension).
203  */
204 /*ARGSUSED*/
205 static int
206 parse_signatures(
207 	sig_args_t	*sig_args_p,
208 	int		SUA_len,
209 	uchar_t		*search_sig,	/* possible signature to search for */
210 	int		search_num)	/* n^th occurance of search_sig to */
211 					/*   search for */
212 {
213 	uchar_t			*sig_string = sig_args_p->SUF_ptr;
214 	extension_name_t	*extnp;
215 	ext_signature_t		*ext_sigp;
216 	int			impl_bit_num = 0;
217 	int			SUA_rem = SUA_len; /* SUA length */
218 					/* remaining to be parsed */
219 
220 	/* This should never happen ... just so we don't panic, literally */
221 	if (sig_string == (uchar_t *)NULL)
222 		return (SUA_NULL_POINTER);
223 
224 	if (SUA_len < 0)
225 		return (SUA_EINVAL);
226 
227 	/*
228 	 * Until the end of SUA, search for the signatures
229 	 * (check for end of SUA (2 consecutive NULL bytes)) or the
230 	 * remaining  length of the SUA is <= 3.  The minimum signature
231 	 * field  is 4.
232 	 */
233 
234 	while ((SUA_rem >= SUF_MIN_LEN) && (*sig_string != '\0') &&
235 		(*(sig_string + 1) != '\0')) {
236 
237 		/*
238 		 * Find appropriate extension and signature table
239 		 */
240 		for (extnp = extension_name_table, impl_bit_num = 0;
241 		    extnp->extension_name != (char *)NULL;
242 		    extnp++, impl_bit_num++)  {
243 
244 			/*
245 			 * look at an extension only if it is implemented
246 			 * on the CD-ROM
247 			 */
248 			if (!IS_IMPL_BIT_SET(sig_args_p->fsp, impl_bit_num))
249 				continue;
250 
251 			/*
252 			 * Find the appropriate signature
253 			 */
254 			for (ext_sigp = extnp->signature_table;
255 			    ext_sigp->ext_signature != (char *)NULL;
256 			    ext_sigp++)  {
257 
258 				if (strncmp((char *)sig_string,
259 					    ext_sigp->ext_signature,
260 					    SUF_SIG_LEN) == 0) {
261 
262 					SUA_rem -= SUF_LEN(sig_string);
263 					if (SUA_rem < 0)
264 						return (END_OF_SUA);
265 
266 					/*
267 					 * The SUA_len parameter specifies the
268 					 * length of the SUA that the kernel
269 					 * expects. There is also a length
270 					 * encoded in the SUA data. If they
271 					 * do not agree, bail out.
272 					 */
273 					if (SUA_len < SUF_LEN(sig_string)) {
274 						cmn_err(CE_NOTE,
275 					"parse_signatures: SUA length too big: "
276 					"expected=%d, found=%d",
277 						    SUA_len,
278 						    SUF_LEN(sig_string));
279 						return (SUA_EINVAL);
280 					}
281 
282 					sig_args_p->SUF_ptr = sig_string;
283 					sig_string =
284 					    (ext_sigp->sig_handler)(sig_args_p);
285 
286 					switch (sig_args_p->flags) {
287 					case END_OF_SUA :
288 						return (END_OF_SUA);
289 					case SUA_ENOMEM :
290 						return (SUA_ENOMEM);
291 					case SUA_EINVAL :
292 						return (SUA_EINVAL);
293 					case RELOC_DIR :
294 						return (RELOC_DIR);
295 					default :
296 #if NAME_SEARCH
297 						case NAME_CONTINUE :
298 							/* nothing for now */
299 						case NAME_CHANGE :
300 							/* nothing for now */
301 #endif
302 						break;
303 					}
304 
305 					/* reset to be zero */
306 
307 					sig_args_p->flags = 0;
308 					goto next_signature;
309 				}
310 
311 				/* off to the next signature .... */
312 
313 			} /* for ext_sigp */
314 
315 		} /* for extnp	(extension parsing) */
316 
317 		/*
318 		 * Opps, did not find this signature. We must
319 		 * advance on the the next signature in the SUA
320 		 * and pray to persumedly omniscient, omnipresent,
321 		 * almighty transcendental being(s) that the next
322 		 * record is in the susp format, or we get hosed.
323 		 */
324 		if (SUA_rem < SUF_MIN_LEN)
325 			return (END_OF_SUA);
326 
327 		SUA_rem -= SUF_LEN(sig_string);
328 		sig_string += SUF_LEN(sig_string);
329 
330 next_signature:
331 		/*
332 		 * Failsafe
333 		 */
334 		if (SUA_rem < SUF_MIN_LEN ||
335 		    sig_string == NULL || SUF_LEN(sig_string) <= 0) {
336 			return (END_OF_SUA);
337 		}
338 
339 	} /* while */
340 
341 	return (END_OF_SUA);
342 }
343 
344 /*
345  * hs_fill_root_dirent()
346  *
347  *
348  * This function reads the root directory extent to get to the SUA of
349  * the "." entry of the root directory.  It the checks to see if the
350  * susp is implemented.
351  */
352 void
353 hs_check_root_dirent(struct vnode *vp, struct hs_direntry *hdp)
354 {
355 	struct buf	*secbp;
356 	uchar_t		*root_ptr;
357 	uchar_t		*secp;
358 	uint_t		secno;
359 	offset_t	secoff;
360 	sig_args_t	sig_args;
361 	struct hsfs	*fsp;
362 	int		error;
363 
364 	if (vp->v_type != VDIR) {
365 		cmn_err(CE_NOTE,
366 		    "hs_check_root_dirent: vp (0x%p) not a directory",
367 		    (void *)vp);
368 		return;
369 	}
370 
371 	bzero((caddr_t)&sig_args, sizeof (sig_args));
372 
373 	fsp = VFS_TO_HSFS(vp->v_vfsp);
374 	secno = LBN_TO_SEC(hdp->ext_lbn+hdp->xar_len, vp->v_vfsp);
375 	secoff = LBN_TO_BYTE(hdp->ext_lbn+hdp->xar_len, vp->v_vfsp) &
376 		MAXHSOFFSET;
377 	secbp = bread(fsp->hsfs_devvp->v_rdev, secno * 4, HS_SECTOR_SIZE);
378 	error = geterror(secbp);
379 
380 	if (error != 0) {
381 		cmn_err(CE_NOTE,
382 			"hs_check_root_dirent: bread: error=(%d)", error);
383 		goto end;
384 	}
385 
386 	secp = (uchar_t *)secbp->b_un.b_addr;
387 	root_ptr = &secp[secoff];
388 
389 	/* quick check */
390 	if (hdp->ext_lbn != HDE_EXT_LBN(root_ptr)) {
391 		cmn_err(CE_NOTE, "hs_check_root_dirent: dirent not match\n");
392 		/* keep on going */
393 	}
394 
395 	/*
396 	 * Here, we know that the "." entry is the first in the sector
397 	 * just read (ISO 9660).  Let's now check for the sharing
398 	 * protocol and set call the susp sig_handler() if we should.
399 	 * Then we run through the hs_parsedir() function to catch all
400 	 * the other possibilities of SUSP fields and continuations.
401 	 *
402 	 * If there is no SUA area, just return, and assume ISO.
403 	 *
404 	 * If the SUA area length is invalid (negative, due to a mismatch
405 	 * between dirent size and SUA size), return and hope for the best.
406 	 */
407 
408 	if (IDE_SUA_LEN(root_ptr) <= 0)
409 		goto end;
410 
411 	if (strncmp(SUSP_SP, (char *)IDE_sys_use_area(root_ptr),
412 		    SUF_SIG_LEN) == 0) {
413 		/*
414 		 * We have a match of the sharing signature, so let's
415 		 * call the sig_handler to do what is necessary. We can
416 		 * ignore the return value, as implemented bits are set.
417 		 */
418 		sig_args.SUF_ptr = IDE_sys_use_area(root_ptr);
419 		sig_args.fsp	 = fsp;
420 
421 		if ((susp_sp->sig_handler)(&sig_args) == (uchar_t *)NULL) {
422 			goto end;
423 		}
424 	} else
425 		goto end;
426 
427 	(void) hs_parsedir(fsp, root_ptr, hdp, (char *)NULL, (int *)NULL,
428 					HS_SECTOR_SIZE - secoff);
429 
430 	/*
431 	 * If we did not get at least 1 extension, let's assume ISO and
432 	 * NULL out the implementation bits.
433 	 */
434 	if (fsp->hsfs_ext_impl <= 1L)
435 		fsp->hsfs_ext_impl = 0L;
436 
437 end:
438 	brelse(secbp);
439 }
440 
441 
442 /*
443  * get_cont_area()
444  *
445  * This function allocates a memory block, if necessary, and reads the
446  * continuation area into the allocated space.
447  *
448  * Return value : 	0 if the read and allocation went OK.
449  * 			1 if there was an error.
450  */
451 static int
452 get_cont_area(struct hsfs *fsp, uchar_t **buf_pp, cont_info_t *cont_info_p)
453 {
454 	struct buf	*secbp;
455 	int		error;
456 	uint_t		secno;
457 
458 	/*
459 	 * Guard against invalid continuation area records.
460 	 * Both cont_offset and cont_len must be no longer than
461 	 * HS_SECTOR_SIZE. If they are, return an error.
462 	 */
463 	if (cont_info_p->cont_offset > HS_SECTOR_SIZE ||
464 	    cont_info_p->cont_len > HS_SECTOR_SIZE) {
465 		cmn_err(CE_NOTE, "get_cont_area: invalid offset/length");
466 		return (1);
467 	}
468 
469 	if (*buf_pp == (uchar_t *)NULL)
470 		*buf_pp = kmem_alloc((size_t)HS_SECTOR_SIZE, KM_SLEEP);
471 
472 	secno = (uint_t)LBN_TO_SEC(cont_info_p->cont_lbn, fsp->hsfs_vfs);
473 	secbp = bread(fsp->hsfs_devvp->v_rdev, secno * 4, HS_SECTOR_SIZE);
474 	error = geterror(secbp);
475 
476 	if (error != 0) {
477 		cmn_err(CE_NOTE, "get_cont_area: bread: error=(%d)", error);
478 		brelse(secbp);
479 		return (1);
480 	}
481 
482 	/*
483 	 * This continuation area does not extend into the next sector
484 	 * so just copy the data to the buffer.
485 	 */
486 	if ((cont_info_p->cont_offset + cont_info_p->cont_len) <=
487 	    HS_SECTOR_SIZE) {
488 		bcopy(secbp->b_un.b_addr, (char *)*buf_pp, HS_SECTOR_SIZE);
489 	}
490 	/*
491 	 * This continuation area extends into the next sector so we
492 	 * need to do some dancing:
493 	 *
494 	 * - zero the return buffer so nothing random is returned
495 	 * - copy the partial data to the *beginning* of the return buffer
496 	 * - release the first sector's buffer
497 	 * - read the next sector
498 	 * - copy the remainder of the data to the return buffer
499 	 */
500 	else {
501 		uint_t	partial_size;
502 
503 		bzero((char *)*buf_pp, HS_SECTOR_SIZE);
504 		partial_size = HS_SECTOR_SIZE - cont_info_p->cont_offset;
505 		bcopy(&secbp->b_un.b_addr[cont_info_p->cont_offset],
506 			(char *)*buf_pp, partial_size);
507 		cont_info_p->cont_offset = 0;
508 		brelse(secbp);
509 
510 		secbp = bread(fsp->hsfs_devvp->v_rdev, (secno + 1) * 4,
511 				HS_SECTOR_SIZE);
512 		error = geterror(secbp);
513 		if (error != 0) {
514 			cmn_err(CE_NOTE, "get_cont_area: bread(2): error=(%d)",
515 				error);
516 			brelse(secbp);
517 			return (1);
518 		}
519 		bcopy(secbp->b_un.b_addr, (char *)&(*buf_pp)[partial_size],
520 			cont_info_p->cont_len - partial_size);
521 	}
522 
523 	brelse(secbp);
524 	return (0);
525 }
526 
527 
528 /*
529  * free_cont_area
530  *
531  * simple function to just free up memory, if it exists
532  *
533  */
534 static void
535 free_cont_area(uchar_t *cont_p)
536 {
537 	if (cont_p)
538 		(void) kmem_free((caddr_t)cont_p, (size_t)HS_SECTOR_SIZE);
539 	cont_p = (uchar_t *)NULL;
540 }
541