/
vfs_syscalls.c
3273 lines (2941 loc) · 71.9 KB
/
vfs_syscalls.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* $OpenBSD: vfs_syscalls.c,v 1.335 2019/08/31 17:59:33 beck Exp $ */
/* $NetBSD: vfs_syscalls.c,v 1.71 1996/04/23 10:29:02 mycroft Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vfs_syscalls.c 8.28 (Berkeley) 12/10/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/sysctl.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/lock.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/pledge.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/dkio.h>
#include <sys/disklabel.h>
#include <sys/ktrace.h>
#include <sys/unistd.h>
#include <sys/specdev.h>
#include <sys/syscallargs.h>
extern int suid_clear;
static int change_dir(struct nameidata *, struct proc *);
void checkdirs(struct vnode *);
int copyout_statfs(struct statfs *, void *, struct proc *);
int doopenat(struct proc *, int, const char *, int, mode_t, register_t *);
int domknodat(struct proc *, int, const char *, mode_t, dev_t);
int dolinkat(struct proc *, int, const char *, int, const char *, int);
int dosymlinkat(struct proc *, const char *, int, const char *);
int dounlinkat(struct proc *, int, const char *, int);
int dofaccessat(struct proc *, int, const char *, int, int);
int dofstatat(struct proc *, int, const char *, struct stat *, int);
int doreadlinkat(struct proc *, int, const char *, char *, size_t,
register_t *);
int dochflagsat(struct proc *, int, const char *, u_int, int);
int dovchflags(struct proc *, struct vnode *, u_int);
int dofchmodat(struct proc *, int, const char *, mode_t, int);
int dofchownat(struct proc *, int, const char *, uid_t, gid_t, int);
int dorenameat(struct proc *, int, const char *, int, const char *);
int domkdirat(struct proc *, int, const char *, mode_t);
int doutimensat(struct proc *, int, const char *, struct timespec [2], int);
int dovutimens(struct proc *, struct vnode *, struct timespec [2]);
int dofutimens(struct proc *, int, struct timespec [2]);
int dounmount_leaf(struct mount *, int, struct proc *);
/*
* Virtual File System System Calls
*/
/*
* Mount a file system.
*/
int
sys_mount(struct proc *p, void *v, register_t *retval)
{
struct sys_mount_args /* {
syscallarg(const char *) type;
syscallarg(const char *) path;
syscallarg(int) flags;
syscallarg(void *) data;
} */ *uap = v;
struct vnode *vp;
struct mount *mp;
int error, mntflag = 0;
char fstypename[MFSNAMELEN];
char fspath[MNAMELEN];
struct nameidata nd;
struct vfsconf *vfsp;
int flags = SCARG(uap, flags);
void *args = NULL;
if ((error = suser(p)))
return (error);
/*
* Mount points must fit in MNAMELEN, not MAXPATHLEN.
*/
error = copyinstr(SCARG(uap, path), fspath, MNAMELEN, NULL);
if (error)
return(error);
/*
* Get vnode to be covered
*/
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspath, p);
if ((error = namei(&nd)) != 0)
goto fail;
vp = nd.ni_vp;
if (flags & MNT_UPDATE) {
if ((vp->v_flag & VROOT) == 0) {
vput(vp);
error = EINVAL;
goto fail;
}
mp = vp->v_mount;
vfsp = mp->mnt_vfc;
args = malloc(vfsp->vfc_datasize, M_TEMP, M_WAITOK | M_ZERO);
error = copyin(SCARG(uap, data), args, vfsp->vfc_datasize);
if (error) {
vput(vp);
goto fail;
}
mntflag = mp->mnt_flag;
/*
* We only allow the filesystem to be reloaded if it
* is currently mounted read-only.
*/
if ((flags & MNT_RELOAD) &&
((mp->mnt_flag & MNT_RDONLY) == 0)) {
vput(vp);
error = EOPNOTSUPP; /* Needs translation */
goto fail;
}
if ((error = vfs_busy(mp, VB_READ|VB_NOWAIT)) != 0) {
vput(vp);
goto fail;
}
mp->mnt_flag |= flags & (MNT_RELOAD | MNT_UPDATE);
goto update;
}
/*
* Do not allow disabling of permission checks unless exec and access to
* device files is disabled too.
*/
if ((flags & MNT_NOPERM) &&
(flags & (MNT_NODEV | MNT_NOEXEC)) != (MNT_NODEV | MNT_NOEXEC)) {
vput(vp);
error = EPERM;
goto fail;
}
if ((error = vinvalbuf(vp, V_SAVE, p->p_ucred, p, 0, INFSLP)) != 0) {
vput(vp);
goto fail;
}
if (vp->v_type != VDIR) {
vput(vp);
goto fail;
}
error = copyinstr(SCARG(uap, type), fstypename, MFSNAMELEN, NULL);
if (error) {
vput(vp);
goto fail;
}
vfsp = vfs_byname(fstypename);
if (vfsp == NULL) {
vput(vp);
error = EOPNOTSUPP;
goto fail;
}
args = malloc(vfsp->vfc_datasize, M_TEMP, M_WAITOK | M_ZERO);
error = copyin(SCARG(uap, data), args, vfsp->vfc_datasize);
if (error) {
vput(vp);
goto fail;
}
if (vp->v_mountedhere != NULL) {
vput(vp);
error = EBUSY;
goto fail;
}
/*
* Allocate and initialize the file system.
*/
mp = vfs_mount_alloc(vp, vfsp);
mp->mnt_stat.f_owner = p->p_ucred->cr_uid;
update:
/* Ensure that the parent mountpoint does not get unmounted. */
error = vfs_busy(vp->v_mount, VB_READ|VB_NOWAIT|VB_DUPOK);
if (error) {
if (mp->mnt_flag & MNT_UPDATE) {
mp->mnt_flag = mntflag;
vfs_unbusy(mp);
} else {
vfs_unbusy(mp);
vfs_mount_free(mp);
}
vput(vp);
goto fail;
}
/*
* Set the mount level flags.
*/
if (flags & MNT_RDONLY)
mp->mnt_flag |= MNT_RDONLY;
else if (mp->mnt_flag & MNT_RDONLY)
mp->mnt_flag |= MNT_WANTRDWR;
mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_WXALLOWED | MNT_NODEV |
MNT_SYNCHRONOUS | MNT_ASYNC | MNT_SOFTDEP | MNT_NOATIME |
MNT_NOPERM | MNT_FORCE);
mp->mnt_flag |= flags & (MNT_NOSUID | MNT_NOEXEC | MNT_WXALLOWED |
MNT_NODEV | MNT_SYNCHRONOUS | MNT_ASYNC | MNT_SOFTDEP |
MNT_NOATIME | MNT_NOPERM | MNT_FORCE);
/*
* Mount the filesystem.
*/
error = VFS_MOUNT(mp, fspath, args, &nd, p);
if (!error) {
mp->mnt_stat.f_ctime = time_second;
}
if (mp->mnt_flag & MNT_UPDATE) {
vfs_unbusy(vp->v_mount);
vput(vp);
if (mp->mnt_flag & MNT_WANTRDWR)
mp->mnt_flag &= ~MNT_RDONLY;
mp->mnt_flag &=~
(MNT_UPDATE | MNT_RELOAD | MNT_FORCE | MNT_WANTRDWR);
if (error)
mp->mnt_flag = mntflag;
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
if (mp->mnt_syncer == NULL)
error = vfs_allocate_syncvnode(mp);
} else {
if (mp->mnt_syncer != NULL)
vgone(mp->mnt_syncer);
mp->mnt_syncer = NULL;
}
vfs_unbusy(mp);
goto fail;
}
vp->v_mountedhere = mp;
/*
* Put the new filesystem on the mount list after root.
*/
cache_purge(vp);
if (!error) {
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
checkdirs(vp);
vfs_unbusy(vp->v_mount);
VOP_UNLOCK(vp);
if ((mp->mnt_flag & MNT_RDONLY) == 0)
error = vfs_allocate_syncvnode(mp);
vfs_unbusy(mp);
(void) VFS_STATFS(mp, &mp->mnt_stat, p);
if ((error = VFS_START(mp, 0, p)) != 0)
vrele(vp);
} else {
mp->mnt_vnodecovered->v_mountedhere = NULL;
vfs_unbusy(mp);
vfs_mount_free(mp);
vfs_unbusy(vp->v_mount);
vput(vp);
}
fail:
if (args)
free(args, M_TEMP, vfsp->vfc_datasize);
return (error);
}
/*
* Scan all active processes to see if any of them have a current
* or root directory onto which the new filesystem has just been
* mounted. If so, replace them with the new mount point, keeping
* track of how many were replaced. That's the number of references
* the old vnode had that we've replaced, so finish by vrele()'ing
* it that many times. This puts off any possible sleeping until
* we've finished walking the allprocess list.
*/
void
checkdirs(struct vnode *olddp)
{
struct filedesc *fdp;
struct vnode *newdp;
struct process *pr;
u_int free_count = 0;
if (olddp->v_usecount == 1)
return;
if (VFS_ROOT(olddp->v_mountedhere, &newdp))
panic("mount: lost mount");
LIST_FOREACH(pr, &allprocess, ps_list) {
fdp = pr->ps_fd;
if (fdp->fd_cdir == olddp) {
free_count++;
vref(newdp);
fdp->fd_cdir = newdp;
}
if (fdp->fd_rdir == olddp) {
free_count++;
vref(newdp);
fdp->fd_rdir = newdp;
}
pr->ps_uvpcwd = NULL;
}
if (rootvnode == olddp) {
free_count++;
vref(newdp);
rootvnode = newdp;
}
while (free_count-- > 0)
vrele(olddp);
vput(newdp);
}
/*
* Unmount a file system.
*
* Note: unmount takes a path to the vnode mounted on as argument,
* not special file (as before).
*/
int
sys_unmount(struct proc *p, void *v, register_t *retval)
{
struct sys_unmount_args /* {
syscallarg(const char *) path;
syscallarg(int) flags;
} */ *uap = v;
struct vnode *vp;
struct mount *mp;
int error;
struct nameidata nd;
if ((error = suser(p)) != 0)
return (error);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
SCARG(uap, path), p);
if ((error = namei(&nd)) != 0)
return (error);
vp = nd.ni_vp;
mp = vp->v_mount;
/*
* Don't allow unmounting the root file system.
*/
if (mp->mnt_flag & MNT_ROOTFS) {
vput(vp);
return (EINVAL);
}
/*
* Must be the root of the filesystem
*/
if ((vp->v_flag & VROOT) == 0) {
vput(vp);
return (EINVAL);
}
vput(vp);
if (vfs_busy(mp, VB_WRITE|VB_WAIT))
return (EBUSY);
return (dounmount(mp, SCARG(uap, flags) & MNT_FORCE, p));
}
/*
* Do the actual file system unmount.
*/
int
dounmount(struct mount *mp, int flags, struct proc *p)
{
SLIST_HEAD(, mount) mplist;
struct mount *nmp;
int error;
SLIST_INIT(&mplist);
SLIST_INSERT_HEAD(&mplist, mp, mnt_dounmount);
/*
* Collect nested mount points. This takes advantage of the mount list
* being ordered - nested mount points come after their parent.
*/
while ((mp = TAILQ_NEXT(mp, mnt_list)) != NULL) {
SLIST_FOREACH(nmp, &mplist, mnt_dounmount) {
if (mp->mnt_vnodecovered == NULLVP ||
mp->mnt_vnodecovered->v_mount != nmp)
continue;
if ((flags & MNT_FORCE) == 0) {
error = EBUSY;
goto err;
}
error = vfs_busy(mp, VB_WRITE|VB_WAIT|VB_DUPOK);
if (error) {
if ((flags & MNT_DOOMED)) {
/*
* If the mount point was busy due to
* being unmounted, it has been removed
* from the mount list already.
* Restart the iteration from the last
* collected busy entry.
*/
mp = SLIST_FIRST(&mplist);
break;
}
goto err;
}
SLIST_INSERT_HEAD(&mplist, mp, mnt_dounmount);
break;
}
}
/*
* Nested mount points cannot appear during this loop as mounting
* requires a read lock for the parent mount point.
*/
while ((mp = SLIST_FIRST(&mplist)) != NULL) {
SLIST_REMOVE(&mplist, mp, mount, mnt_dounmount);
error = dounmount_leaf(mp, flags, p);
if (error)
goto err;
}
return (0);
err:
while ((mp = SLIST_FIRST(&mplist)) != NULL) {
SLIST_REMOVE(&mplist, mp, mount, mnt_dounmount);
vfs_unbusy(mp);
}
return (error);
}
int
dounmount_leaf(struct mount *mp, int flags, struct proc *p)
{
struct vnode *coveredvp;
struct vnode *vp, *nvp;
int error;
int hadsyncer = 0;
mp->mnt_flag &=~ MNT_ASYNC;
cache_purgevfs(mp); /* remove cache entries for this file sys */
if (mp->mnt_syncer != NULL) {
hadsyncer = 1;
vgone(mp->mnt_syncer);
mp->mnt_syncer = NULL;
}
/*
* Before calling file system unmount, make sure
* all unveils to vnodes in here are dropped.
*/
LIST_FOREACH_SAFE(vp , &mp->mnt_vnodelist, v_mntvnodes, nvp) {
unveil_removevnode(vp);
}
if (((mp->mnt_flag & MNT_RDONLY) ||
(error = VFS_SYNC(mp, MNT_WAIT, 0, p->p_ucred, p)) == 0) ||
(flags & MNT_FORCE))
error = VFS_UNMOUNT(mp, flags, p);
if (error && !(flags & MNT_DOOMED)) {
if ((mp->mnt_flag & MNT_RDONLY) == 0 && hadsyncer)
(void) vfs_allocate_syncvnode(mp);
vfs_unbusy(mp);
return (error);
}
TAILQ_REMOVE(&mountlist, mp, mnt_list);
if ((coveredvp = mp->mnt_vnodecovered) != NULLVP) {
coveredvp->v_mountedhere = NULL;
vrele(coveredvp);
}
if (!LIST_EMPTY(&mp->mnt_vnodelist))
panic("unmount: dangling vnode");
vfs_unbusy(mp);
vfs_mount_free(mp);
return (0);
}
/*
* Sync each mounted filesystem.
*/
#ifdef DEBUG
int syncprt = 0;
struct ctldebug debug0 = { "syncprt", &syncprt };
#endif
int
sys_sync(struct proc *p, void *v, register_t *retval)
{
struct mount *mp;
int asyncflag;
TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
if (vfs_busy(mp, VB_READ|VB_NOWAIT))
continue;
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
asyncflag = mp->mnt_flag & MNT_ASYNC;
mp->mnt_flag &= ~MNT_ASYNC;
uvm_vnp_sync(mp);
VFS_SYNC(mp, MNT_NOWAIT, 0, p->p_ucred, p);
if (asyncflag)
mp->mnt_flag |= MNT_ASYNC;
}
vfs_unbusy(mp);
}
return (0);
}
/*
* Change filesystem quotas.
*/
int
sys_quotactl(struct proc *p, void *v, register_t *retval)
{
struct sys_quotactl_args /* {
syscallarg(const char *) path;
syscallarg(int) cmd;
syscallarg(int) uid;
syscallarg(char *) arg;
} */ *uap = v;
struct mount *mp;
int error;
struct nameidata nd;
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
if ((error = namei(&nd)) != 0)
return (error);
mp = nd.ni_vp->v_mount;
vrele(nd.ni_vp);
return (VFS_QUOTACTL(mp, SCARG(uap, cmd), SCARG(uap, uid),
SCARG(uap, arg), p));
}
int
copyout_statfs(struct statfs *sp, void *uaddr, struct proc *p)
{
size_t co_sz1 = offsetof(struct statfs, f_fsid);
size_t co_off2 = co_sz1 + sizeof(fsid_t);
size_t co_sz2 = sizeof(struct statfs) - co_off2;
char *s, *d;
int error;
/* Don't let non-root see filesystem id (for NFS security) */
if (suser(p)) {
fsid_t fsid;
s = (char *)sp;
d = (char *)uaddr;
memset(&fsid, 0, sizeof(fsid));
if ((error = copyout(s, d, co_sz1)) != 0)
return (error);
if ((error = copyout(&fsid, d + co_sz1, sizeof(fsid))) != 0)
return (error);
return (copyout(s + co_off2, d + co_off2, co_sz2));
}
return (copyout(sp, uaddr, sizeof(*sp)));
}
/*
* Get filesystem statistics.
*/
int
sys_statfs(struct proc *p, void *v, register_t *retval)
{
struct sys_statfs_args /* {
syscallarg(const char *) path;
syscallarg(struct statfs *) buf;
} */ *uap = v;
struct mount *mp;
struct statfs *sp;
int error;
struct nameidata nd;
NDINIT(&nd, LOOKUP, FOLLOW | BYPASSUNVEIL, UIO_USERSPACE,
SCARG(uap, path), p);
nd.ni_pledge = PLEDGE_RPATH;
nd.ni_unveil = UNVEIL_READ;
if ((error = namei(&nd)) != 0)
return (error);
mp = nd.ni_vp->v_mount;
sp = &mp->mnt_stat;
vrele(nd.ni_vp);
if ((error = VFS_STATFS(mp, sp, p)) != 0)
return (error);
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
return (copyout_statfs(sp, SCARG(uap, buf), p));
}
/*
* Get filesystem statistics.
*/
int
sys_fstatfs(struct proc *p, void *v, register_t *retval)
{
struct sys_fstatfs_args /* {
syscallarg(int) fd;
syscallarg(struct statfs *) buf;
} */ *uap = v;
struct file *fp;
struct mount *mp;
struct statfs *sp;
int error;
if ((error = getvnode(p, SCARG(uap, fd), &fp)) != 0)
return (error);
mp = ((struct vnode *)fp->f_data)->v_mount;
if (!mp) {
FRELE(fp, p);
return (ENOENT);
}
sp = &mp->mnt_stat;
error = VFS_STATFS(mp, sp, p);
FRELE(fp, p);
if (error)
return (error);
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
return (copyout_statfs(sp, SCARG(uap, buf), p));
}
/*
* Get statistics on all filesystems.
*/
int
sys_getfsstat(struct proc *p, void *v, register_t *retval)
{
struct sys_getfsstat_args /* {
syscallarg(struct statfs *) buf;
syscallarg(size_t) bufsize;
syscallarg(int) flags;
} */ *uap = v;
struct mount *mp;
struct statfs *sp;
struct statfs *sfsp;
size_t count, maxcount;
int error, flags = SCARG(uap, flags);
maxcount = SCARG(uap, bufsize) / sizeof(struct statfs);
sfsp = SCARG(uap, buf);
count = 0;
TAILQ_FOREACH(mp, &mountlist, mnt_list) {
if (vfs_busy(mp, VB_READ|VB_NOWAIT))
continue;
if (sfsp && count < maxcount) {
sp = &mp->mnt_stat;
/* Refresh stats unless MNT_NOWAIT is specified */
if (flags != MNT_NOWAIT &&
flags != MNT_LAZY &&
(flags == MNT_WAIT ||
flags == 0) &&
(error = VFS_STATFS(mp, sp, p))) {
vfs_unbusy(mp);
continue;
}
sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
#if notyet
if (mp->mnt_flag & MNT_SOFTDEP)
sp->f_eflags = STATFS_SOFTUPD;
#endif
error = (copyout_statfs(sp, sfsp, p));
if (error) {
vfs_unbusy(mp);
return (error);
}
sfsp++;
}
count++;
vfs_unbusy(mp);
}
if (sfsp && count > maxcount)
*retval = maxcount;
else
*retval = count;
return (0);
}
/*
* Change current working directory to a given file descriptor.
*/
int
sys_fchdir(struct proc *p, void *v, register_t *retval)
{
struct sys_fchdir_args /* {
syscallarg(int) fd;
} */ *uap = v;
struct filedesc *fdp = p->p_fd;
struct vnode *vp, *tdp, *old_cdir;
struct mount *mp;
struct file *fp;
int error;
if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL)
return (EBADF);
vp = fp->f_data;
if (fp->f_type != DTYPE_VNODE || vp->v_type != VDIR) {
FRELE(fp, p);
return (ENOTDIR);
}
vref(vp);
FRELE(fp, p);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p);
while (!error && (mp = vp->v_mountedhere) != NULL) {
if (vfs_busy(mp, VB_READ|VB_WAIT))
continue;
error = VFS_ROOT(mp, &tdp);
vfs_unbusy(mp);
if (error)
break;
vput(vp);
vp = tdp;
}
if (error) {
vput(vp);
return (error);
}
VOP_UNLOCK(vp);
old_cdir = fdp->fd_cdir;
fdp->fd_cdir = vp;
vrele(old_cdir);
return (0);
}
/*
* Change current working directory (``.'').
*/
int
sys_chdir(struct proc *p, void *v, register_t *retval)
{
struct sys_chdir_args /* {
syscallarg(const char *) path;
} */ *uap = v;
struct filedesc *fdp = p->p_fd;
struct vnode *old_cdir;
int error;
struct nameidata nd;
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
SCARG(uap, path), p);
nd.ni_pledge = PLEDGE_RPATH;
nd.ni_unveil = UNVEIL_READ;
if ((error = change_dir(&nd, p)) != 0)
return (error);
p->p_p->ps_uvpcwd = nd.ni_unveil_match;
old_cdir = fdp->fd_cdir;
fdp->fd_cdir = nd.ni_vp;
vrele(old_cdir);
return (0);
}
/*
* Change notion of root (``/'') directory.
*/
int
sys_chroot(struct proc *p, void *v, register_t *retval)
{
struct sys_chroot_args /* {
syscallarg(const char *) path;
} */ *uap = v;
struct filedesc *fdp = p->p_fd;
struct vnode *old_cdir, *old_rdir;
int error;
struct nameidata nd;
if ((error = suser(p)) != 0)
return (error);
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
SCARG(uap, path), p);
if ((error = change_dir(&nd, p)) != 0)
return (error);
if (fdp->fd_rdir != NULL) {
/*
* A chroot() done inside a changed root environment does
* an automatic chdir to avoid the out-of-tree experience.
*/
vref(nd.ni_vp);
old_rdir = fdp->fd_rdir;
old_cdir = fdp->fd_cdir;
fdp->fd_rdir = fdp->fd_cdir = nd.ni_vp;
vrele(old_rdir);
vrele(old_cdir);
} else
fdp->fd_rdir = nd.ni_vp;
return (0);
}
/*
* Common routine for chroot and chdir.
*/
static int
change_dir(struct nameidata *ndp, struct proc *p)
{
struct vnode *vp;
int error;
if ((error = namei(ndp)) != 0)
return (error);
vp = ndp->ni_vp;
if (vp->v_type != VDIR)
error = ENOTDIR;
else
error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p);
if (error)
vput(vp);
else
VOP_UNLOCK(vp);
return (error);
}
int
sys___realpath(struct proc *p, void *v, register_t *retval)
{
struct sys___realpath_args /* {
syscallarg(const char *) pathname;
syscallarg(char *) resolved;
} */ *uap = v;
char *pathname, *c;
char *rpbuf;
struct nameidata nd;
size_t pathlen;
int error = 0;
if (SCARG(uap, pathname) == NULL)
return (EINVAL);
pathname = pool_get(&namei_pool, PR_WAITOK);
rpbuf = pool_get(&namei_pool, PR_WAITOK);
if ((error = copyinstr(SCARG(uap, pathname), pathname, MAXPATHLEN,
&pathlen)))
goto end;
if (pathlen == 1) { /* empty string "" */
error = ENOENT;
goto end;
}
if (pathlen < 2) {
error = EINVAL;
goto end;
}
/* Get cwd for relative path if needed, prepend to rpbuf */
rpbuf[0] = '\0';
if (pathname[0] != '/') {
int cwdlen = MAXPATHLEN * 4; /* for vfs_getcwd_common */
char *cwdbuf, *bp;
cwdbuf = malloc(cwdlen, M_TEMP, M_WAITOK);
/* vfs_getcwd_common fills this in backwards */
bp = &cwdbuf[cwdlen - 1];
*bp = '\0';
error = vfs_getcwd_common(p->p_fd->fd_cdir, NULL, &bp, cwdbuf,
cwdlen/2, GETCWD_CHECK_ACCESS, p);
if (error) {
free(cwdbuf, M_TEMP, cwdlen);
goto end;
}
if (strlcpy(rpbuf, bp, MAXPATHLEN) >= MAXPATHLEN) {
free(cwdbuf, M_TEMP, cwdlen);
error = ENAMETOOLONG;
goto end;
}
free(cwdbuf, M_TEMP, cwdlen);
}
/* find root "/" or "//" */
for (c = pathname; *c != '\0'; c++) {
if (*c != '/')
break;
}
if (*c == '\0')
/* root directory */
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | SAVENAME | REALPATH,
UIO_SYSSPACE, pathname, p);
else
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | LOCKPARENT | SAVENAME |
REALPATH, UIO_SYSSPACE, pathname, p);
nd.ni_cnd.cn_rpbuf = rpbuf;
nd.ni_cnd.cn_rpi = strlen(rpbuf);
nd.ni_pledge = PLEDGE_RPATH;
nd.ni_unveil = UNVEIL_READ;
if ((error = namei(&nd)) != 0)
goto end;
/* release lock and reference from namei */
if (nd.ni_vp) {
VOP_UNLOCK(nd.ni_vp);
vrele(nd.ni_vp);
}
if (nd.ni_dvp && nd.ni_dvp != nd.ni_vp)
VOP_UNLOCK(nd.ni_dvp);
if (nd.ni_dvp)
vrele(nd.ni_dvp);
error = copyoutstr(nd.ni_cnd.cn_rpbuf, SCARG(uap, resolved),
MAXPATHLEN, NULL);
#ifdef KTRACE
if (KTRPOINT(p, KTR_NAMEI))
ktrnamei(p, nd.ni_cnd.cn_rpbuf);
#endif
pool_put(&namei_pool, nd.ni_cnd.cn_pnbuf);
end:
pool_put(&namei_pool, rpbuf);
pool_put(&namei_pool, pathname);
return (error);
}
int
sys_unveil(struct proc *p, void *v, register_t *retval)
{
struct sys_unveil_args /* {
syscallarg(const char *) path;
syscallarg(const char *) permissions;
} */ *uap = v;
char *pathname, *c;
struct nameidata nd;
size_t pathlen;
char permissions[5];
int error, allow;
if (SCARG(uap, path) == NULL && SCARG(uap, permissions) == NULL) {
p->p_p->ps_uvdone = 1;
return (0);
}
if (p->p_p->ps_uvdone != 0)
return EPERM;
error = copyinstr(SCARG(uap, permissions), permissions,
sizeof(permissions), NULL);
if (error)
return (error);
pathname = pool_get(&namei_pool, PR_WAITOK);
error = copyinstr(SCARG(uap, path), pathname, MAXPATHLEN, &pathlen);
if (error)
goto end;