xref: /titanic_41/usr/src/uts/common/syscall/stat.c (revision 5203bc321053fb87d7073c7640548fab73634793)
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 /*
23  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 /*
35  * Get file attribute information through a file name or a file descriptor.
36  */
37 
38 #include <sys/param.h>
39 #include <sys/isa_defs.h>
40 #include <sys/types.h>
41 #include <sys/sysmacros.h>
42 #include <sys/cred.h>
43 #include <sys/systm.h>
44 #include <sys/errno.h>
45 #include <sys/fcntl.h>
46 #include <sys/pathname.h>
47 #include <sys/stat.h>
48 #include <sys/vfs.h>
49 #include <sys/vnode.h>
50 #include <sys/mode.h>
51 #include <sys/file.h>
52 #include <sys/proc.h>
53 #include <sys/uio.h>
54 #include <sys/debug.h>
55 #include <sys/cmn_err.h>
56 #include <c2/audit.h>
57 #include <fs/fs_subr.h>
58 
59 /*
60  * Get the vp to be stated and the cred to be used for the call
61  * to VOP_GETATTR
62  */
63 
64 static int
65 cstatat_getvp(int fd, char *name, int follow, vnode_t **vp, cred_t **cred)
66 {
67 	vnode_t *startvp;
68 	file_t *fp;
69 	int error;
70 	cred_t *cr;
71 	int estale_retry = 0;
72 
73 	*vp = NULL;
74 
75 	/*
76 	 * Only return EFAULT for fstatat when fd == AT_FDCWD && name == NULL
77 	 */
78 
79 	if (fd == AT_FDCWD) {
80 		startvp = NULL;
81 		cr = CRED();
82 		crhold(cr);
83 	} else {
84 		char startchar;
85 
86 		if (copyin(name, &startchar, sizeof (char)))
87 			return (EFAULT);
88 		if (startchar != '/') {
89 			if ((fp = getf(fd)) == NULL) {
90 				return (EBADF);
91 			}
92 			startvp = fp->f_vnode;
93 			cr = fp->f_cred;
94 			crhold(cr);
95 			VN_HOLD(startvp);
96 			releasef(fd);
97 		} else {
98 			startvp = NULL;
99 			cr = CRED();
100 			crhold(cr);
101 		}
102 	}
103 	*cred = cr;
104 
105 	if (AU_AUDITING() && startvp != NULL)
106 		audit_setfsat_path(1);
107 
108 lookup:
109 	if (error = lookupnameat(name, UIO_USERSPACE, follow, NULLVPP,
110 	    vp, startvp)) {
111 		if ((error == ESTALE) &&
112 		    fs_need_estale_retry(estale_retry++))
113 			goto lookup;
114 		if (startvp != NULL)
115 			VN_RELE(startvp);
116 		crfree(cr);
117 		return (error);
118 	}
119 	if (startvp != NULL)
120 		VN_RELE(startvp);
121 
122 	return (0);
123 }
124 
125 /*
126  * Native syscall interfaces:
127  *
128  * N-bit kernel, N-bit applications, N-bit file offsets
129  */
130 
131 static int cstatat(int, char *, struct stat *, int, int);
132 static int cstat(vnode_t *vp, struct stat *, int, cred_t *);
133 
134 /*
135  * fstat can and should be fast, do an inline implementation here.
136  */
137 #define	FSTAT_BODY(fd, sb, statfn)				\
138 	{							\
139 		file_t *fp;					\
140 		int error;					\
141 								\
142 		if (fd == AT_FDCWD)				\
143 			return (set_errno(EFAULT));		\
144 		if ((fp = getf(fd)) == NULL)			\
145 			return (set_errno(EBADF));		\
146 		error = statfn(fp->f_vnode, sb, 0, fp->f_cred);	\
147 		releasef(fd);					\
148 		if (error)					\
149 			return (set_errno(error));		\
150 		return (0);					\
151 	}
152 
153 int
154 fstat(int fd, struct stat *sb)
155 {
156 	FSTAT_BODY(fd, sb, cstat)
157 }
158 
159 int
160 fstatat(int fd, char *name, struct stat *sb, int flags)
161 {
162 	int followflag;
163 	int csflags;
164 
165 	if (name == NULL)
166 		return (fstat(fd, sb));
167 
168 	followflag = (flags & AT_SYMLINK_NOFOLLOW);
169 	csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
170 	if (followflag == 0)
171 		csflags |= ATTR_REAL;	/* flag for procfs lookups */
172 
173 	return (cstatat(fd, name, sb, followflag, csflags));
174 }
175 
176 int
177 stat(char *name, struct stat *sb)
178 {
179 	return (fstatat(AT_FDCWD, name, sb, 0));
180 }
181 
182 int
183 lstat(char *name, struct stat *sb)
184 {
185 	return (fstatat(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
186 }
187 
188 /*
189  * Common code for stat(), lstat(), and fstat().
190  * (32-bit kernel, 32-bit applications, 32-bit files)
191  * (64-bit kernel, 64-bit applications, 64-bit files)
192  */
193 static int
194 cstat(vnode_t *vp, struct stat *ubp, int flag, cred_t *cr)
195 {
196 	struct vfssw *vswp;
197 	struct stat sb;
198 	vattr_t vattr;
199 	int error;
200 
201 	vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
202 	if ((error = VOP_GETATTR(vp, &vattr, flag, cr, NULL)) != 0)
203 		return (error);
204 #ifdef	_ILP32
205 	/*
206 	 * (32-bit kernel, 32-bit applications, 32-bit files)
207 	 * NOTE: 32-bit kernel maintains a 64-bit unsigend va_size.
208 	 *
209 	 * st_size of devices (VBLK and VCHR special files) is a special case.
210 	 * POSIX does not define size behavior for special files, so the
211 	 * following Solaris specific behavior is not a violation. Solaris
212 	 * returns the size of the device.
213 	 *
214 	 * For compatibility with 32-bit programs which happen to do stat() on
215 	 * a (mknod) bigger than 2GB we suppress the large file EOVERFLOW and
216 	 * instead we return the value MAXOFF32_T (LONG_MAX).
217 	 *
218 	 * 32-bit applications that care about the size of devices should be
219 	 * built 64-bit or use a large file interface (lfcompile(5) or lf64(5)).
220 	 */
221 	if ((vattr.va_size > MAXOFF32_T) &&
222 	    ((vp->v_type == VBLK) || (vp->v_type == VCHR))) {
223 		/* OVERFLOW | UNKNOWN_SIZE */
224 		vattr.va_size = MAXOFF32_T;
225 	}
226 #endif	/* _ILP32 */
227 	if (vattr.va_size > MAXOFF_T || vattr.va_nblocks > LONG_MAX ||
228 	    vattr.va_nodeid > ULONG_MAX)
229 		return (EOVERFLOW);
230 
231 	bzero(&sb, sizeof (sb));
232 	sb.st_dev = vattr.va_fsid;
233 	sb.st_ino = (ino_t)vattr.va_nodeid;
234 	sb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
235 	sb.st_nlink = vattr.va_nlink;
236 	sb.st_uid = vattr.va_uid;
237 	sb.st_gid = vattr.va_gid;
238 	sb.st_rdev = vattr.va_rdev;
239 	sb.st_size = (off_t)vattr.va_size;
240 	sb.st_atim = vattr.va_atime;
241 	sb.st_mtim = vattr.va_mtime;
242 	sb.st_ctim = vattr.va_ctime;
243 	sb.st_blksize = vattr.va_blksize;
244 	sb.st_blocks = (blkcnt_t)vattr.va_nblocks;
245 	if (vp->v_vfsp != NULL) {
246 		vswp = &vfssw[vp->v_vfsp->vfs_fstype];
247 		if (vswp->vsw_name && *vswp->vsw_name)
248 			(void) strcpy(sb.st_fstype, vswp->vsw_name);
249 	}
250 	if (copyout(&sb, ubp, sizeof (sb)))
251 		return (EFAULT);
252 	return (0);
253 }
254 
255 static int
256 cstatat(int fd, char *name, struct stat *sb, int follow, int flags)
257 {
258 	vnode_t *vp;
259 	int error;
260 	cred_t *cred;
261 	int link_follow;
262 	int estale_retry = 0;
263 
264 	link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
265 lookup:
266 	if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
267 		return (set_errno(error));
268 	error = cstat(vp, sb, flags, cred);
269 	crfree(cred);
270 	VN_RELE(vp);
271 	if (error != 0) {
272 		if (error == ESTALE &&
273 		    fs_need_estale_retry(estale_retry++))
274 			goto lookup;
275 		return (set_errno(error));
276 	}
277 	return (0);
278 }
279 
280 #if defined(_SYSCALL32_IMPL)
281 
282 /*
283  * 64-bit kernel, 32-bit applications, 32-bit file offsets
284  */
285 static int cstatat32(int, char *, struct stat32 *, int, int);
286 static int cstat32(vnode_t *, struct stat32 *, int, cred_t *);
287 
288 int
289 fstat32(int fd, struct stat32 *sb)
290 {
291 	FSTAT_BODY(fd, sb, cstat32)
292 }
293 
294 int
295 fstatat32(int fd, char *name, struct stat32 *sb, int flags)
296 {
297 	int followflag;
298 	int csflags;
299 
300 	if (name == NULL)
301 		return (fstat32(fd, sb));
302 
303 	followflag = (flags & AT_SYMLINK_NOFOLLOW);
304 	csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
305 	if (followflag == 0)
306 		csflags |= ATTR_REAL;	/* flag for procfs lookups */
307 
308 	return (cstatat32(fd, name, sb, followflag, csflags));
309 }
310 
311 int
312 stat32(char *name, struct stat32 *sb)
313 {
314 	return (fstatat32(AT_FDCWD, name, sb, 0));
315 }
316 
317 int
318 lstat32(char *name, struct stat32 *sb)
319 {
320 	return (fstatat32(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
321 }
322 
323 static int
324 cstat32(vnode_t *vp, struct stat32 *ubp, int flag, struct cred *cr)
325 {
326 	struct vfssw *vswp;
327 	struct stat32 sb;
328 	vattr_t vattr;
329 	int error;
330 	dev32_t st_dev, st_rdev;
331 
332 	vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
333 	if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
334 		return (error);
335 
336 	/* devices are a special case, see comments in cstat */
337 	if ((vattr.va_size > MAXOFF32_T) &&
338 	    ((vp->v_type == VBLK) || (vp->v_type == VCHR))) {
339 		/* OVERFLOW | UNKNOWN_SIZE */
340 		vattr.va_size = MAXOFF32_T;
341 	}
342 
343 	/* check for large values */
344 	if (!cmpldev(&st_dev, vattr.va_fsid) ||
345 	    !cmpldev(&st_rdev, vattr.va_rdev) ||
346 	    vattr.va_size > MAXOFF32_T ||
347 	    vattr.va_nblocks > INT32_MAX ||
348 	    vattr.va_nodeid > UINT32_MAX ||
349 	    TIMESPEC_OVERFLOW(&(vattr.va_atime)) ||
350 	    TIMESPEC_OVERFLOW(&(vattr.va_mtime)) ||
351 	    TIMESPEC_OVERFLOW(&(vattr.va_ctime)))
352 		return (EOVERFLOW);
353 
354 	bzero(&sb, sizeof (sb));
355 	sb.st_dev = st_dev;
356 	sb.st_ino = (ino32_t)vattr.va_nodeid;
357 	sb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
358 	sb.st_nlink = vattr.va_nlink;
359 	sb.st_uid = vattr.va_uid;
360 	sb.st_gid = vattr.va_gid;
361 	sb.st_rdev = st_rdev;
362 	sb.st_size = (off32_t)vattr.va_size;
363 	TIMESPEC_TO_TIMESPEC32(&(sb.st_atim), &(vattr.va_atime));
364 	TIMESPEC_TO_TIMESPEC32(&(sb.st_mtim), &(vattr.va_mtime));
365 	TIMESPEC_TO_TIMESPEC32(&(sb.st_ctim), &(vattr.va_ctime));
366 	sb.st_blksize = vattr.va_blksize;
367 	sb.st_blocks = (blkcnt32_t)vattr.va_nblocks;
368 	if (vp->v_vfsp != NULL) {
369 		vswp = &vfssw[vp->v_vfsp->vfs_fstype];
370 		if (vswp->vsw_name && *vswp->vsw_name)
371 			(void) strcpy(sb.st_fstype, vswp->vsw_name);
372 	}
373 	if (copyout(&sb, ubp, sizeof (sb)))
374 		return (EFAULT);
375 	return (0);
376 }
377 
378 static int
379 cstatat32(int fd, char *name, struct stat32 *sb, int follow, int flags)
380 {
381 	vnode_t *vp;
382 	int error;
383 	cred_t *cred;
384 	int link_follow;
385 	int estale_retry = 0;
386 
387 	link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
388 lookup:
389 	if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
390 		return (set_errno(error));
391 	error = cstat32(vp, sb, flags, cred);
392 	crfree(cred);
393 	VN_RELE(vp);
394 	if (error != 0) {
395 		if (error == ESTALE &&
396 		    fs_need_estale_retry(estale_retry++))
397 			goto lookup;
398 		return (set_errno(error));
399 	}
400 	return (0);
401 }
402 
403 #endif	/* _SYSCALL32_IMPL */
404 
405 #if defined(_ILP32)
406 
407 /*
408  * 32-bit kernel, 32-bit applications, 64-bit file offsets.
409  *
410  * These routines are implemented differently on 64-bit kernels.
411  */
412 static int cstatat64(int, char *, struct stat64 *, int, int);
413 static int cstat64(vnode_t *, struct stat64 *, int, cred_t *);
414 
415 int
416 fstat64(int fd, struct stat64 *sb)
417 {
418 	FSTAT_BODY(fd, sb, cstat64)
419 }
420 
421 int
422 fstatat64(int fd, char *name, struct stat64 *sb, int flags)
423 {
424 	int followflag;
425 	int csflags;
426 
427 	if (name == NULL)
428 		return (fstat64(fd, sb));
429 
430 	followflag = (flags & AT_SYMLINK_NOFOLLOW);
431 	csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
432 	if (followflag == 0)
433 		csflags |= ATTR_REAL;	/* flag for procfs lookups */
434 
435 	return (cstatat64(fd, name, sb, followflag, csflags));
436 }
437 
438 int
439 stat64(char *name, struct stat64 *sb)
440 {
441 	return (fstatat64(AT_FDCWD, name, sb, 0));
442 }
443 
444 int
445 lstat64(char *name, struct stat64 *sb)
446 {
447 	return (fstatat64(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
448 }
449 
450 static int
451 cstat64(vnode_t *vp, struct stat64 *ubp, int flag, cred_t *cr)
452 {
453 	struct vfssw *vswp;
454 	struct stat64 lsb;
455 	vattr_t vattr;
456 	int error;
457 
458 	vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
459 	if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
460 		return (error);
461 
462 	bzero(&lsb, sizeof (lsb));
463 	lsb.st_dev = vattr.va_fsid;
464 	lsb.st_ino = vattr.va_nodeid;
465 	lsb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
466 	lsb.st_nlink = vattr.va_nlink;
467 	lsb.st_uid = vattr.va_uid;
468 	lsb.st_gid = vattr.va_gid;
469 	lsb.st_rdev = vattr.va_rdev;
470 	lsb.st_size = vattr.va_size;
471 	lsb.st_atim = vattr.va_atime;
472 	lsb.st_mtim = vattr.va_mtime;
473 	lsb.st_ctim = vattr.va_ctime;
474 	lsb.st_blksize = vattr.va_blksize;
475 	lsb.st_blocks = vattr.va_nblocks;
476 	if (vp->v_vfsp != NULL) {
477 		vswp = &vfssw[vp->v_vfsp->vfs_fstype];
478 		if (vswp->vsw_name && *vswp->vsw_name)
479 			(void) strcpy(lsb.st_fstype, vswp->vsw_name);
480 	}
481 	if (copyout(&lsb, ubp, sizeof (lsb)))
482 		return (EFAULT);
483 	return (0);
484 }
485 
486 static int
487 cstatat64(int fd, char *name, struct stat64 *sb, int follow, int flags)
488 {
489 	vnode_t *vp;
490 	int error;
491 	cred_t *cred;
492 	int link_follow;
493 	int estale_retry = 0;
494 
495 	link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
496 lookup:
497 	if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
498 		return (set_errno(error));
499 	error = cstat64(vp, sb, flags, cred);
500 	crfree(cred);
501 	VN_RELE(vp);
502 	if (error != 0) {
503 		if (error == ESTALE &&
504 		    fs_need_estale_retry(estale_retry++))
505 			goto lookup;
506 		return (set_errno(error));
507 	}
508 	return (0);
509 }
510 
511 #endif	/* _ILP32 */
512 
513 #if defined(_SYSCALL32_IMPL)
514 
515 /*
516  * 64-bit kernel, 32-bit applications, 64-bit file offsets.
517  *
518  * We'd really like to call the "native" stat calls for these ones,
519  * but the problem is that the 64-bit ABI defines the 'stat64' structure
520  * differently from the way the 32-bit ABI defines it.
521  */
522 
523 static int cstatat64_32(int, char *, struct stat64_32 *, int, int);
524 static int cstat64_32(vnode_t *, struct stat64_32 *, int, cred_t *);
525 
526 int
527 fstat64_32(int fd, struct stat64_32 *sb)
528 {
529 	FSTAT_BODY(fd, sb, cstat64_32)
530 }
531 
532 int
533 fstatat64_32(int fd, char *name, struct stat64_32 *sb, int flags)
534 {
535 	int followflag;
536 	int csflags;
537 
538 	if (name == NULL)
539 		return (fstat64_32(fd, sb));
540 
541 	followflag = (flags & AT_SYMLINK_NOFOLLOW);
542 	csflags = (flags & _AT_TRIGGER ? ATTR_TRIGGER : 0);
543 	if (followflag == 0)
544 		csflags |= ATTR_REAL;	/* flag for procfs lookups */
545 
546 	return (cstatat64_32(fd, name, sb, followflag, csflags));
547 }
548 
549 int
550 stat64_32(char *name, struct stat64_32 *sb)
551 {
552 	return (fstatat64_32(AT_FDCWD, name, sb, 0));
553 }
554 
555 int
556 lstat64_32(char *name, struct stat64_32 *sb)
557 {
558 	return (fstatat64_32(AT_FDCWD, name, sb, AT_SYMLINK_NOFOLLOW));
559 }
560 
561 static int
562 cstat64_32(vnode_t *vp, struct stat64_32 *ubp, int flag, cred_t *cr)
563 {
564 	struct vfssw *vswp;
565 	struct stat64_32 lsb;
566 	vattr_t vattr;
567 	int error;
568 	dev32_t st_dev, st_rdev;
569 
570 	vattr.va_mask = AT_STAT | AT_NBLOCKS | AT_BLKSIZE | AT_SIZE;
571 	if (error = VOP_GETATTR(vp, &vattr, flag, cr, NULL))
572 		return (error);
573 
574 	if (!cmpldev(&st_dev, vattr.va_fsid) ||
575 	    !cmpldev(&st_rdev, vattr.va_rdev) ||
576 	    TIMESPEC_OVERFLOW(&(vattr.va_atime)) ||
577 	    TIMESPEC_OVERFLOW(&(vattr.va_mtime)) ||
578 	    TIMESPEC_OVERFLOW(&(vattr.va_ctime)))
579 		return (EOVERFLOW);
580 
581 	bzero(&lsb, sizeof (lsb));
582 	lsb.st_dev = st_dev;
583 	lsb.st_ino = vattr.va_nodeid;
584 	lsb.st_mode = VTTOIF(vattr.va_type) | vattr.va_mode;
585 	lsb.st_nlink = vattr.va_nlink;
586 	lsb.st_uid = vattr.va_uid;
587 	lsb.st_gid = vattr.va_gid;
588 	lsb.st_rdev = st_rdev;
589 	lsb.st_size = vattr.va_size;
590 	TIMESPEC_TO_TIMESPEC32(&(lsb.st_atim), &(vattr.va_atime));
591 	TIMESPEC_TO_TIMESPEC32(&(lsb.st_mtim), &(vattr.va_mtime));
592 	TIMESPEC_TO_TIMESPEC32(&(lsb.st_ctim), &(vattr.va_ctime));
593 	lsb.st_blksize = vattr.va_blksize;
594 	lsb.st_blocks = vattr.va_nblocks;
595 	if (vp->v_vfsp != NULL) {
596 		vswp = &vfssw[vp->v_vfsp->vfs_fstype];
597 		if (vswp->vsw_name && *vswp->vsw_name)
598 			(void) strcpy(lsb.st_fstype, vswp->vsw_name);
599 	}
600 	if (copyout(&lsb, ubp, sizeof (lsb)))
601 		return (EFAULT);
602 	return (0);
603 }
604 
605 static int
606 cstatat64_32(int fd, char *name, struct stat64_32 *sb, int follow, int flags)
607 {
608 	vnode_t  *vp;
609 	int error;
610 	cred_t *cred;
611 	int link_follow;
612 	int estale_retry = 0;
613 
614 	link_follow = (follow == AT_SYMLINK_NOFOLLOW) ? NO_FOLLOW : FOLLOW;
615 lookup:
616 	if (error = cstatat_getvp(fd, name, link_follow, &vp, &cred))
617 		return (set_errno(error));
618 	error = cstat64_32(vp, sb, flags, cred);
619 	crfree(cred);
620 	VN_RELE(vp);
621 	if (error != 0) {
622 		if (error == ESTALE &&
623 		    fs_need_estale_retry(estale_retry++))
624 			goto lookup;
625 		return (set_errno(error));
626 	}
627 	return (0);
628 }
629 
630 #endif /* _SYSCALL32_IMPL */
631