1 /* $NetBSD: ptyfs_vnops.c,v 1.69 2022/08/05 10:36:02 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 1993, 1995
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Jan-Simon Pendry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95
35 */
36
37 /*
38 * Copyright (c) 1993 Jan-Simon Pendry
39 *
40 * This code is derived from software contributed to Berkeley by
41 * Jan-Simon Pendry.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 * must display the following acknowledgement:
53 * This product includes software developed by the University of
54 * California, Berkeley and its contributors.
55 * 4. Neither the name of the University nor the names of its contributors
56 * may be used to endorse or promote products derived from this software
57 * without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * SUCH DAMAGE.
70 *
71 * @(#)procfs_vnops.c 8.18 (Berkeley) 5/21/95
72 */
73
74 /*
75 * ptyfs vnode interface
76 */
77
78 #include <sys/cdefs.h>
79 __KERNEL_RCSID(0, "$NetBSD: ptyfs_vnops.c,v 1.69 2022/08/05 10:36:02 riastradh Exp $");
80
81 #include <sys/param.h>
82 #include <sys/systm.h>
83 #include <sys/time.h>
84 #include <sys/kernel.h>
85 #include <sys/file.h>
86 #include <sys/filedesc.h>
87 #include <sys/proc.h>
88 #include <sys/vnode.h>
89 #include <sys/namei.h>
90 #include <sys/malloc.h>
91 #include <sys/mount.h>
92 #include <sys/select.h>
93 #include <sys/dirent.h>
94 #include <sys/resourcevar.h>
95 #include <sys/stat.h>
96 #include <sys/conf.h>
97 #include <sys/tty.h>
98 #include <sys/pty.h>
99 #include <sys/kauth.h>
100
101 #include <uvm/uvm_extern.h> /* for PAGE_SIZE */
102
103 #include <machine/reg.h>
104
105 #include <fs/ptyfs/ptyfs.h>
106 #include <miscfs/genfs/genfs.h>
107 #include <miscfs/specfs/specdev.h>
108
109 MALLOC_DECLARE(M_PTYFSTMP);
110
111 /*
112 * Vnode Operations.
113 *
114 */
115
116 int ptyfs_lookup (void *);
117 int ptyfs_open (void *);
118 int ptyfs_close (void *);
119 int ptyfs_access (void *);
120 int ptyfs_getattr (void *);
121 int ptyfs_setattr (void *);
122 int ptyfs_read (void *);
123 int ptyfs_write (void *);
124 int ptyfs_ioctl (void *);
125 int ptyfs_poll (void *);
126 int ptyfs_kqfilter (void *);
127 int ptyfs_readdir (void *);
128 int ptyfs_reclaim (void *);
129 int ptyfs_inactive (void *);
130 int ptyfs_print (void *);
131 int ptyfs_pathconf (void *);
132 int ptyfs_advlock (void *);
133
134 static int ptyfs_update(struct vnode *, const struct timespec *,
135 const struct timespec *, int);
136 static int ptyfs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t,
137 struct lwp *);
138 static int ptyfs_chmod(struct vnode *, mode_t, kauth_cred_t, struct lwp *);
139 static int atoi(const char *, size_t);
140
141 /*
142 * ptyfs vnode operations.
143 */
144 int (**ptyfs_vnodeop_p)(void *);
145 const struct vnodeopv_entry_desc ptyfs_vnodeop_entries[] = {
146 { &vop_default_desc, vn_default_error },
147 { &vop_parsepath_desc, genfs_parsepath }, /* parsepath */
148 { &vop_lookup_desc, ptyfs_lookup }, /* lookup */
149 { &vop_create_desc, genfs_eopnotsupp }, /* create */
150 { &vop_mknod_desc, genfs_eopnotsupp }, /* mknod */
151 { &vop_open_desc, ptyfs_open }, /* open */
152 { &vop_close_desc, ptyfs_close }, /* close */
153 { &vop_access_desc, ptyfs_access }, /* access */
154 { &vop_accessx_desc, genfs_accessx }, /* accessx */
155 { &vop_getattr_desc, ptyfs_getattr }, /* getattr */
156 { &vop_setattr_desc, ptyfs_setattr }, /* setattr */
157 { &vop_read_desc, ptyfs_read }, /* read */
158 { &vop_write_desc, ptyfs_write }, /* write */
159 { &vop_fallocate_desc, genfs_eopnotsupp }, /* fallocate */
160 { &vop_fdiscard_desc, genfs_eopnotsupp }, /* fdiscard */
161 { &vop_ioctl_desc, ptyfs_ioctl }, /* ioctl */
162 { &vop_fcntl_desc, genfs_fcntl }, /* fcntl */
163 { &vop_poll_desc, ptyfs_poll }, /* poll */
164 { &vop_kqfilter_desc, ptyfs_kqfilter }, /* kqfilter */
165 { &vop_revoke_desc, genfs_revoke }, /* revoke */
166 { &vop_mmap_desc, genfs_eopnotsupp }, /* mmap */
167 { &vop_fsync_desc, genfs_nullop }, /* fsync */
168 { &vop_seek_desc, genfs_nullop }, /* seek */
169 { &vop_remove_desc, genfs_eopnotsupp }, /* remove */
170 { &vop_link_desc, genfs_eopnotsupp }, /* link */
171 { &vop_rename_desc, genfs_eopnotsupp }, /* rename */
172 { &vop_mkdir_desc, genfs_eopnotsupp }, /* mkdir */
173 { &vop_rmdir_desc, genfs_eopnotsupp }, /* rmdir */
174 { &vop_symlink_desc, genfs_eopnotsupp }, /* symlink */
175 { &vop_readdir_desc, ptyfs_readdir }, /* readdir */
176 { &vop_readlink_desc, genfs_eopnotsupp }, /* readlink */
177 { &vop_abortop_desc, genfs_abortop }, /* abortop */
178 { &vop_inactive_desc, ptyfs_inactive }, /* inactive */
179 { &vop_reclaim_desc, ptyfs_reclaim }, /* reclaim */
180 { &vop_lock_desc, genfs_lock }, /* lock */
181 { &vop_unlock_desc, genfs_unlock }, /* unlock */
182 { &vop_bmap_desc, genfs_eopnotsupp }, /* bmap */
183 { &vop_strategy_desc, genfs_badop }, /* strategy */
184 { &vop_print_desc, ptyfs_print }, /* print */
185 { &vop_islocked_desc, genfs_islocked }, /* islocked */
186 { &vop_pathconf_desc, ptyfs_pathconf }, /* pathconf */
187 { &vop_advlock_desc, ptyfs_advlock }, /* advlock */
188 { &vop_bwrite_desc, genfs_eopnotsupp }, /* bwrite */
189 { &vop_putpages_desc, genfs_null_putpages }, /* putpages */
190 { NULL, NULL }
191 };
192 const struct vnodeopv_desc ptyfs_vnodeop_opv_desc =
193 { &ptyfs_vnodeop_p, ptyfs_vnodeop_entries };
194
195 /*
196 * free any private data and remove the node
197 * from any private lists.
198 */
199 int
ptyfs_reclaim(void * v)200 ptyfs_reclaim(void *v)
201 {
202 struct vop_reclaim_v2_args /* {
203 struct vnode *a_vp;
204 } */ *ap = v;
205 struct vnode *vp = ap->a_vp;
206
207 VOP_UNLOCK(vp);
208
209 vp->v_data = NULL;
210 return 0;
211 }
212
213 int
ptyfs_inactive(void * v)214 ptyfs_inactive(void *v)
215 {
216 struct vop_inactive_v2_args /* {
217 struct vnode *a_vp;
218 bool *a_recycle;
219 } */ *ap = v;
220 struct vnode *vp = ap->a_vp;
221 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
222
223 if (ptyfs->ptyfs_type == PTYFSptc)
224 ptyfs_clr_active(vp->v_mount, ptyfs->ptyfs_pty);
225
226 return 0;
227 }
228
229 /*
230 * Return POSIX pathconf information applicable to special devices.
231 */
232 int
ptyfs_pathconf(void * v)233 ptyfs_pathconf(void *v)
234 {
235 struct vop_pathconf_args /* {
236 struct vnode *a_vp;
237 int a_name;
238 register_t *a_retval;
239 } */ *ap = v;
240
241 switch (ap->a_name) {
242 case _PC_LINK_MAX:
243 *ap->a_retval = LINK_MAX;
244 return 0;
245 case _PC_MAX_CANON:
246 *ap->a_retval = MAX_CANON;
247 return 0;
248 case _PC_MAX_INPUT:
249 *ap->a_retval = MAX_INPUT;
250 return 0;
251 case _PC_PIPE_BUF:
252 *ap->a_retval = PIPE_BUF;
253 return 0;
254 case _PC_CHOWN_RESTRICTED:
255 *ap->a_retval = 1;
256 return 0;
257 case _PC_VDISABLE:
258 *ap->a_retval = _POSIX_VDISABLE;
259 return 0;
260 case _PC_SYNC_IO:
261 *ap->a_retval = 1;
262 return 0;
263 default:
264 return genfs_pathconf(ap);
265 }
266 }
267
268 /*
269 * _print is used for debugging.
270 * just print a readable description
271 * of (vp).
272 */
273 int
ptyfs_print(void * v)274 ptyfs_print(void *v)
275 {
276 struct vop_print_args /* {
277 struct vnode *a_vp;
278 } */ *ap = v;
279 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
280
281 printf("tag VT_PTYFS, type %d, pty %d\n",
282 ptyfs->ptyfs_type, ptyfs->ptyfs_pty);
283 return 0;
284 }
285
286 /*
287 * support advisory locking on pty nodes
288 */
289 int
ptyfs_advlock(void * v)290 ptyfs_advlock(void *v)
291 {
292 struct vop_print_args /* {
293 struct vnode *a_vp;
294 } */ *ap = v;
295 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
296
297 switch (ptyfs->ptyfs_type) {
298 case PTYFSpts:
299 case PTYFSptc:
300 return spec_advlock(v);
301 default:
302 return EOPNOTSUPP;
303 }
304 }
305
306 /*
307 * Invent attributes for ptyfsnode (vp) and store
308 * them in (vap).
309 * Directories lengths are returned as zero since
310 * any real length would require the genuine size
311 * to be computed, and nothing cares anyway.
312 *
313 * this is relatively minimal for ptyfs.
314 */
315 int
ptyfs_getattr(void * v)316 ptyfs_getattr(void *v)
317 {
318 struct vop_getattr_args /* {
319 struct vnode *a_vp;
320 struct vattr *a_vap;
321 kauth_cred_t a_cred;
322 } */ *ap = v;
323 struct ptyfsnode *ptyfs = VTOPTYFS(ap->a_vp);
324 struct vattr *vap = ap->a_vap;
325
326 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
327
328 /* start by zeroing out the attributes */
329 vattr_null(vap);
330
331 /* next do all the common fields */
332 vap->va_type = ap->a_vp->v_type;
333 vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
334 vap->va_fileid = ptyfs->ptyfs_fileno;
335 vap->va_gen = 0;
336 vap->va_flags = 0;
337 vap->va_blocksize = PAGE_SIZE;
338
339 vap->va_atime = ptyfs->ptyfs_atime;
340 vap->va_mtime = ptyfs->ptyfs_mtime;
341 vap->va_ctime = ptyfs->ptyfs_ctime;
342 vap->va_birthtime = ptyfs->ptyfs_birthtime;
343 vap->va_mode = ptyfs->ptyfs_mode;
344 vap->va_flags = ptyfs->ptyfs_flags;
345 vap->va_uid = ptyfs->ptyfs_uid;
346 vap->va_gid = ptyfs->ptyfs_gid;
347
348 switch (ptyfs->ptyfs_type) {
349 case PTYFSpts:
350 case PTYFSptc:
351 if (pty_isfree(ptyfs->ptyfs_pty, 1))
352 return ENOENT;
353 vap->va_bytes = vap->va_size = 0;
354 vap->va_rdev = ap->a_vp->v_rdev;
355 vap->va_nlink = 1;
356 break;
357 case PTYFSroot:
358 vap->va_rdev = 0;
359 vap->va_bytes = vap->va_size = DEV_BSIZE;
360 vap->va_nlink = 2;
361 break;
362 default:
363 return EOPNOTSUPP;
364 }
365
366 return 0;
367 }
368
369 /*ARGSUSED*/
370 int
ptyfs_setattr(void * v)371 ptyfs_setattr(void *v)
372 {
373 struct vop_setattr_args /* {
374 struct vnodeop_desc *a_desc;
375 struct vnode *a_vp;
376 struct vattr *a_vap;
377 kauth_cred_t a_cred;
378 } */ *ap = v;
379 struct vnode *vp = ap->a_vp;
380 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
381 struct vattr *vap = ap->a_vap;
382 kauth_cred_t cred = ap->a_cred;
383 struct lwp *l = curlwp;
384 int error;
385 kauth_action_t action = KAUTH_VNODE_WRITE_FLAGS;
386 bool changing_sysflags = false;
387
388 if (vap->va_size != VNOVALSIZE) {
389 switch (ptyfs->ptyfs_type) {
390 case PTYFSroot:
391 return EISDIR;
392 case PTYFSpts:
393 case PTYFSptc:
394 break;
395 default:
396 return EINVAL;
397 }
398 }
399
400 if (vap->va_flags != VNOVALFLAGS) {
401 if (vp->v_mount->mnt_flag & MNT_RDONLY)
402 return EROFS;
403
404 /* Immutable and append-only flags are not supported on ptyfs. */
405 if (vap->va_flags & (IMMUTABLE | APPEND))
406 return EINVAL;
407
408 /* Snapshot flag cannot be set or cleared */
409 if ((vap->va_flags & SF_SNAPSHOT) != (ptyfs->ptyfs_flags & SF_SNAPSHOT))
410 return EPERM;
411
412 if ((ptyfs->ptyfs_flags & SF_SETTABLE) != (vap->va_flags & SF_SETTABLE)) {
413 changing_sysflags = true;
414 action |= KAUTH_VNODE_WRITE_SYSFLAGS;
415 }
416
417 error = kauth_authorize_vnode(cred, action, vp, NULL,
418 genfs_can_chflags(vp, cred, ptyfs->ptyfs_uid,
419 changing_sysflags));
420 if (error)
421 return error;
422
423 if (changing_sysflags) {
424 ptyfs->ptyfs_flags = vap->va_flags;
425 } else {
426 ptyfs->ptyfs_flags &= SF_SETTABLE;
427 ptyfs->ptyfs_flags |= (vap->va_flags & UF_SETTABLE);
428 }
429 ptyfs->ptyfs_status |= PTYFS_CHANGE;
430 }
431
432 /*
433 * Go through the fields and update iff not VNOVAL.
434 */
435 if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
436 if (vp->v_mount->mnt_flag & MNT_RDONLY)
437 return EROFS;
438 error = ptyfs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
439 if (error)
440 return error;
441 }
442
443 if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL ||
444 vap->va_birthtime.tv_sec != VNOVAL) {
445 if (vp->v_mount->mnt_flag & MNT_RDONLY)
446 return EROFS;
447 if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0)
448 return EPERM;
449 error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_TIMES, vp,
450 NULL, genfs_can_chtimes(vp, cred, ptyfs->ptyfs_uid,
451 vap->va_vaflags));
452 if (error)
453 return (error);
454 if (vap->va_atime.tv_sec != VNOVAL)
455 if (!(vp->v_mount->mnt_flag & MNT_NOATIME))
456 ptyfs->ptyfs_status |= PTYFS_ACCESS;
457 if (vap->va_mtime.tv_sec != VNOVAL) {
458 ptyfs->ptyfs_status |= PTYFS_CHANGE | PTYFS_MODIFY;
459 if (vp->v_mount->mnt_flag & MNT_RELATIME)
460 ptyfs->ptyfs_status |= PTYFS_ACCESS;
461 }
462 if (vap->va_birthtime.tv_sec != VNOVAL)
463 ptyfs->ptyfs_birthtime = vap->va_birthtime;
464 ptyfs->ptyfs_status |= PTYFS_CHANGE;
465 error = ptyfs_update(vp, &vap->va_atime, &vap->va_mtime, 0);
466 if (error)
467 return error;
468 }
469 if (vap->va_mode != (mode_t)VNOVAL) {
470 if (vp->v_mount->mnt_flag & MNT_RDONLY)
471 return EROFS;
472 if ((ptyfs->ptyfs_flags & SF_SNAPSHOT) != 0 &&
473 (vap->va_mode &
474 (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IXOTH|S_IWOTH)))
475 return EPERM;
476 error = ptyfs_chmod(vp, vap->va_mode, cred, l);
477 if (error)
478 return error;
479 }
480 return 0;
481 }
482
483 /*
484 * Change the mode on a file.
485 * Inode must be locked before calling.
486 */
487 static int
ptyfs_chmod(struct vnode * vp,mode_t mode,kauth_cred_t cred,struct lwp * l)488 ptyfs_chmod(struct vnode *vp, mode_t mode, kauth_cred_t cred, struct lwp *l)
489 {
490 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
491 int error;
492
493 error = kauth_authorize_vnode(cred, KAUTH_VNODE_WRITE_SECURITY, vp,
494 NULL, genfs_can_chmod(vp, cred, ptyfs->ptyfs_uid, ptyfs->ptyfs_gid,
495 mode));
496 if (error)
497 return (error);
498
499 ptyfs->ptyfs_mode &= ~ALLPERMS;
500 ptyfs->ptyfs_mode |= (mode & ALLPERMS);
501 return 0;
502 }
503
504 /*
505 * Perform chown operation on inode ip;
506 * inode must be locked prior to call.
507 */
508 static int
ptyfs_chown(struct vnode * vp,uid_t uid,gid_t gid,kauth_cred_t cred,struct lwp * l)509 ptyfs_chown(struct vnode *vp, uid_t uid, gid_t gid, kauth_cred_t cred,
510 struct lwp *l)
511 {
512 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
513 int error;
514
515 if (uid == (uid_t)VNOVAL)
516 uid = ptyfs->ptyfs_uid;
517 if (gid == (gid_t)VNOVAL)
518 gid = ptyfs->ptyfs_gid;
519
520 error = kauth_authorize_vnode(cred, KAUTH_VNODE_CHANGE_OWNERSHIP, vp,
521 NULL, genfs_can_chown(vp, cred, ptyfs->ptyfs_uid, ptyfs->ptyfs_gid,
522 uid, gid));
523 if (error)
524 return (error);
525
526 ptyfs->ptyfs_gid = gid;
527 ptyfs->ptyfs_uid = uid;
528 return 0;
529 }
530
531 /*
532 * implement access checking.
533 *
534 * actually, the check for super-user is slightly
535 * broken since it will allow read access to write-only
536 * objects. this doesn't cause any particular trouble
537 * but does mean that the i/o entry points need to check
538 * that the operation really does make sense.
539 */
540 int
ptyfs_access(void * v)541 ptyfs_access(void *v)
542 {
543 struct vop_access_args /* {
544 struct vnode *a_vp;
545 accmode_t a_accmode;
546 kauth_cred_t a_cred;
547 } */ *ap = v;
548 struct vattr va;
549 int error;
550
551 if ((error = VOP_GETATTR(ap->a_vp, &va, ap->a_cred)) != 0)
552 return error;
553
554 return kauth_authorize_vnode(ap->a_cred,
555 KAUTH_ACCESS_ACTION(ap->a_accmode, ap->a_vp->v_type, va.va_mode),
556 ap->a_vp, NULL, genfs_can_access(ap->a_vp, ap->a_cred, va.va_uid,
557 va.va_gid, va.va_mode, NULL, ap->a_accmode));
558 }
559
560 /*
561 * lookup. this is incredibly complicated in the
562 * general case, however for most pseudo-filesystems
563 * very little needs to be done.
564 *
565 * Locking isn't hard here, just poorly documented.
566 *
567 * If we're looking up ".", just vref the parent & return it.
568 *
569 * If we're looking up "..", unlock the parent, and lock "..". If everything
570 * went ok, try to re-lock the parent. We do this to prevent lock races.
571 *
572 * For anything else, get the needed node.
573 *
574 * We try to exit with the parent locked in error cases.
575 */
576 int
ptyfs_lookup(void * v)577 ptyfs_lookup(void *v)
578 {
579 struct vop_lookup_v2_args /* {
580 struct vnode * a_dvp;
581 struct vnode ** a_vpp;
582 struct componentname * a_cnp;
583 } */ *ap = v;
584 struct componentname *cnp = ap->a_cnp;
585 struct vnode **vpp = ap->a_vpp;
586 struct vnode *dvp = ap->a_dvp;
587 const char *pname = cnp->cn_nameptr;
588 struct ptyfsnode *ptyfs;
589 int pty, error;
590
591 *vpp = NULL;
592
593 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)
594 return EROFS;
595
596 if (cnp->cn_namelen == 1 && *pname == '.') {
597 *vpp = dvp;
598 vref(dvp);
599 return 0;
600 }
601
602 ptyfs = VTOPTYFS(dvp);
603 switch (ptyfs->ptyfs_type) {
604 case PTYFSroot:
605 /*
606 * Shouldn't get here with .. in the root node.
607 */
608 if (cnp->cn_flags & ISDOTDOT)
609 return EIO;
610
611 pty = atoi(pname, cnp->cn_namelen);
612 if (pty < 0 || ptyfs_next_active(dvp->v_mount, pty) != pty)
613 break;
614 error = ptyfs_allocvp(dvp->v_mount, vpp, PTYFSpts, pty);
615 if (error)
616 return error;
617 if (ptyfs_next_active(dvp->v_mount, pty) != pty) {
618 vrele(*vpp);
619 *vpp = NULL;
620 return ENOENT;
621 }
622 return 0;
623
624 default:
625 return ENOTDIR;
626 }
627
628 return cnp->cn_nameiop == LOOKUP ? ENOENT : EROFS;
629 }
630
631 /*
632 * readdir returns directory entries from ptyfsnode (vp).
633 *
634 * the strategy here with ptyfs is to generate a single
635 * directory entry at a time (struct dirent) and then
636 * copy that out to userland using uiomove. a more efficient
637 * though more complex implementation, would try to minimize
638 * the number of calls to uiomove(). for ptyfs, this is
639 * hardly worth the added code complexity.
640 *
641 * this should just be done through read()
642 */
643 int
ptyfs_readdir(void * v)644 ptyfs_readdir(void *v)
645 {
646 struct vop_readdir_args /* {
647 struct vnode *a_vp;
648 struct uio *a_uio;
649 kauth_cred_t a_cred;
650 int *a_eofflag;
651 off_t **a_cookies;
652 int *a_ncookies;
653 } */ *ap = v;
654 struct uio *uio = ap->a_uio;
655 struct dirent *dp;
656 struct ptyfsnode *ptyfs;
657 off_t i;
658 int error;
659 off_t *cookies = NULL;
660 int ncookies;
661 struct vnode *vp;
662 int n, nc = 0;
663
664 vp = ap->a_vp;
665 ptyfs = VTOPTYFS(vp);
666
667 if (uio->uio_resid < UIO_MX)
668 return EINVAL;
669 if (uio->uio_offset < 0)
670 return EINVAL;
671
672 dp = malloc(sizeof(struct dirent), M_PTYFSTMP, M_WAITOK | M_ZERO);
673
674 error = 0;
675 i = uio->uio_offset;
676 dp->d_reclen = UIO_MX;
677 ncookies = uio->uio_resid / UIO_MX;
678
679 if (ptyfs->ptyfs_type != PTYFSroot) {
680 error = ENOTDIR;
681 goto out;
682 }
683
684 if (i >= npty)
685 goto out;
686
687 if (ap->a_ncookies) {
688 ncookies = uimin(ncookies, (npty + 2 - i));
689 cookies = malloc(ncookies * sizeof (off_t),
690 M_TEMP, M_WAITOK);
691 *ap->a_cookies = cookies;
692 }
693
694 for (; i < 2 && uio->uio_resid >= UIO_MX; i++) {
695 /* `.' and/or `..' */
696 dp->d_fileno = PTYFS_FILENO(PTYFSroot, 0);
697 dp->d_namlen = i + 1;
698 (void)memcpy(dp->d_name, "..", dp->d_namlen);
699 dp->d_name[i + 1] = '\0';
700 dp->d_type = DT_DIR;
701 if ((error = uiomove(dp, UIO_MX, uio)) != 0)
702 goto out;
703 if (cookies)
704 *cookies++ = i + 1;
705 nc++;
706 }
707 while (uio->uio_resid >= UIO_MX) {
708 /* check for used ptys */
709 n = ptyfs_next_active(vp->v_mount, i - 2);
710 if (n < 0)
711 break;
712 dp->d_fileno = PTYFS_FILENO(PTYFSpts, n);
713 dp->d_namlen = snprintf(dp->d_name, sizeof(dp->d_name),
714 "%lld", (long long)(n));
715 dp->d_type = DT_CHR;
716 if ((error = uiomove(dp, UIO_MX, uio)) != 0)
717 goto out;
718 i = n + 3;
719 if (cookies)
720 *cookies++ = i;
721 nc++;
722 }
723
724 out:
725 /* not pertinent in error cases */
726 ncookies = nc;
727
728 if (ap->a_ncookies) {
729 if (error) {
730 if (cookies)
731 free(*ap->a_cookies, M_TEMP);
732 *ap->a_ncookies = 0;
733 *ap->a_cookies = NULL;
734 } else
735 *ap->a_ncookies = ncookies;
736 }
737 uio->uio_offset = i;
738 free(dp, M_PTYFSTMP);
739 return error;
740 }
741
742 int
ptyfs_open(void * v)743 ptyfs_open(void *v)
744 {
745 struct vop_open_args /* {
746 struct vnode *a_vp;
747 int a_mode;
748 kauth_cred_t a_cred;
749 } */ *ap = v;
750 struct vnode *vp = ap->a_vp;
751 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
752
753 switch (ptyfs->ptyfs_type) {
754 case PTYFSpts:
755 case PTYFSptc:
756 return spec_open(v);
757 case PTYFSroot:
758 return 0;
759 default:
760 return EINVAL;
761 }
762 }
763
764 int
ptyfs_close(void * v)765 ptyfs_close(void *v)
766 {
767 struct vop_close_args /* {
768 struct vnode *a_vp;
769 int a_fflag;
770 kauth_cred_t a_cred;
771 } */ *ap = v;
772 struct vnode *vp = ap->a_vp;
773 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
774
775 mutex_enter(vp->v_interlock);
776 if (vrefcnt(vp) > 1)
777 PTYFS_ITIMES(ptyfs, NULL, NULL, NULL);
778 mutex_exit(vp->v_interlock);
779
780 switch (ptyfs->ptyfs_type) {
781 case PTYFSpts:
782 case PTYFSptc:
783 return spec_close(v);
784 case PTYFSroot:
785 return 0;
786 default:
787 return EINVAL;
788 }
789 }
790
791 int
ptyfs_read(void * v)792 ptyfs_read(void *v)
793 {
794 struct vop_read_args /* {
795 struct vnode *a_vp;
796 struct uio *a_uio;
797 int a_ioflag;
798 kauth_cred_t a_cred;
799 } */ *ap = v;
800 struct timespec ts;
801 struct vnode *vp = ap->a_vp;
802 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
803 int error;
804
805 if (vp->v_type == VDIR)
806 return EISDIR;
807
808 ptyfs->ptyfs_status |= PTYFS_ACCESS;
809 /* hardclock() resolution is good enough for ptyfs */
810 getnanotime(&ts);
811 (void)ptyfs_update(vp, &ts, &ts, 0);
812
813 switch (ptyfs->ptyfs_type) {
814 case PTYFSpts:
815 case PTYFSptc:
816 VOP_UNLOCK(vp);
817 error = cdev_read(vp->v_rdev, ap->a_uio, ap->a_ioflag);
818 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
819 return error;
820 default:
821 return EOPNOTSUPP;
822 }
823 }
824
825 int
ptyfs_write(void * v)826 ptyfs_write(void *v)
827 {
828 struct vop_write_args /* {
829 struct vnode *a_vp;
830 struct uio *a_uio;
831 int a_ioflag;
832 kauth_cred_t a_cred;
833 } */ *ap = v;
834 struct timespec ts;
835 struct vnode *vp = ap->a_vp;
836 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
837 int error;
838
839 ptyfs->ptyfs_status |= PTYFS_MODIFY;
840 getnanotime(&ts);
841 (void)ptyfs_update(vp, &ts, &ts, 0);
842
843 switch (ptyfs->ptyfs_type) {
844 case PTYFSpts:
845 case PTYFSptc:
846 VOP_UNLOCK(vp);
847 error = cdev_write(vp->v_rdev, ap->a_uio, ap->a_ioflag);
848 vn_lock(vp, LK_RETRY|LK_EXCLUSIVE);
849 return error;
850 default:
851 return EOPNOTSUPP;
852 }
853 }
854
855 int
ptyfs_ioctl(void * v)856 ptyfs_ioctl(void *v)
857 {
858 struct vop_ioctl_args /* {
859 struct vnode *a_vp;
860 u_long a_command;
861 void *a_data;
862 int a_fflag;
863 kauth_cred_t a_cred;
864 } */ *ap = v;
865 struct vnode *vp = ap->a_vp;
866 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
867
868 switch (ptyfs->ptyfs_type) {
869 case PTYFSpts:
870 case PTYFSptc:
871 return cdev_ioctl(vp->v_rdev, ap->a_command,
872 ap->a_data, ap->a_fflag, curlwp);
873 default:
874 return EOPNOTSUPP;
875 }
876 }
877
878 int
ptyfs_poll(void * v)879 ptyfs_poll(void *v)
880 {
881 struct vop_poll_args /* {
882 struct vnode *a_vp;
883 int a_events;
884 } */ *ap = v;
885 struct vnode *vp = ap->a_vp;
886 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
887
888 switch (ptyfs->ptyfs_type) {
889 case PTYFSpts:
890 case PTYFSptc:
891 return cdev_poll(vp->v_rdev, ap->a_events, curlwp);
892 default:
893 return genfs_poll(v);
894 }
895 }
896
897 int
ptyfs_kqfilter(void * v)898 ptyfs_kqfilter(void *v)
899 {
900 struct vop_kqfilter_args /* {
901 struct vnode *a_vp;
902 struct knote *a_kn;
903 } */ *ap = v;
904 struct vnode *vp = ap->a_vp;
905 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
906
907 switch (ptyfs->ptyfs_type) {
908 case PTYFSpts:
909 case PTYFSptc:
910 return cdev_kqfilter(vp->v_rdev, ap->a_kn);
911 default:
912 return genfs_kqfilter(v);
913 }
914 }
915
916 static int
ptyfs_update(struct vnode * vp,const struct timespec * acc,const struct timespec * mod,int flags)917 ptyfs_update(struct vnode *vp, const struct timespec *acc,
918 const struct timespec *mod, int flags)
919 {
920 struct ptyfsnode *ptyfs = VTOPTYFS(vp);
921
922 if (vp->v_mount->mnt_flag & MNT_RDONLY)
923 return 0;
924
925 PTYFS_ITIMES(ptyfs, acc, mod, NULL);
926 return 0;
927 }
928
929 void
ptyfs_itimes(struct ptyfsnode * ptyfs,const struct timespec * acc,const struct timespec * mod,const struct timespec * cre)930 ptyfs_itimes(struct ptyfsnode *ptyfs, const struct timespec *acc,
931 const struct timespec *mod, const struct timespec *cre)
932 {
933 struct timespec now;
934
935 KASSERT(ptyfs->ptyfs_status & (PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY));
936
937 getnanotime(&now);
938 if (ptyfs->ptyfs_status & PTYFS_ACCESS) {
939 if (acc == NULL)
940 acc = &now;
941 ptyfs->ptyfs_atime = *acc;
942 }
943 if (ptyfs->ptyfs_status & PTYFS_MODIFY) {
944 if (mod == NULL)
945 mod = &now;
946 ptyfs->ptyfs_mtime = *mod;
947 }
948 if (ptyfs->ptyfs_status & PTYFS_CHANGE) {
949 if (cre == NULL)
950 cre = &now;
951 ptyfs->ptyfs_ctime = *cre;
952 }
953 ptyfs->ptyfs_status &= ~(PTYFS_ACCESS|PTYFS_CHANGE|PTYFS_MODIFY);
954 }
955
956 /*
957 * convert decimal ascii to int
958 */
959 static int
atoi(const char * b,size_t len)960 atoi(const char *b, size_t len)
961 {
962 int p = 0;
963
964 while (len--) {
965 char c = *b++;
966 if (c < '0' || c > '9')
967 return -1;
968 p = 10 * p + (c - '0');
969 }
970
971 return p;
972 }
973