1 /*-
2 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/10.2/sys/fs/pseudofs/pseudofs_vnops.c 259506 2013-12-17 13:10:28Z kib $");
31
32 #include "opt_pseudofs.h"
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/systm.h>
37 #include <sys/ctype.h>
38 #include <sys/dirent.h>
39 #include <sys/fcntl.h>
40 #include <sys/limits.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mount.h>
44 #include <sys/mutex.h>
45 #include <sys/namei.h>
46 #include <sys/proc.h>
47 #include <sys/sbuf.h>
48 #include <sys/sx.h>
49 #include <sys/sysctl.h>
50 #include <sys/vnode.h>
51
52 #include <fs/pseudofs/pseudofs.h>
53 #include <fs/pseudofs/pseudofs_internal.h>
54
55 #define KASSERT_PN_IS_DIR(pn) \
56 KASSERT((pn)->pn_type == pfstype_root || \
57 (pn)->pn_type == pfstype_dir || \
58 (pn)->pn_type == pfstype_procdir, \
59 ("%s(): VDIR vnode refers to non-directory pfs_node", __func__))
60
61 #define KASSERT_PN_IS_FILE(pn) \
62 KASSERT((pn)->pn_type == pfstype_file, \
63 ("%s(): VREG vnode refers to non-file pfs_node", __func__))
64
65 #define KASSERT_PN_IS_LINK(pn) \
66 KASSERT((pn)->pn_type == pfstype_symlink, \
67 ("%s(): VLNK vnode refers to non-link pfs_node", __func__))
68
69 /*
70 * Returns the fileno, adjusted for target pid
71 */
72 static uint32_t
73 pn_fileno(struct pfs_node *pn, pid_t pid)
74 {
75
76 KASSERT(pn->pn_fileno > 0,
77 ("%s(): no fileno allocated", __func__));
78 if (pid != NO_PID)
79 return (pn->pn_fileno * NO_PID + pid);
80 return (pn->pn_fileno);
81 }
82
83 /*
84 * Returns non-zero if given file is visible to given thread.
85 */
86 static int
87 pfs_visible_proc(struct thread *td, struct pfs_node *pn, struct proc *proc)
88 {
89 int visible;
90
91 if (proc == NULL)
92 return (0);
93
94 PROC_LOCK_ASSERT(proc, MA_OWNED);
95
96 visible = ((proc->p_flag & P_WEXIT) == 0);
97 if (visible)
98 visible = (p_cansee(td, proc) == 0);
99 if (visible && pn->pn_vis != NULL)
100 visible = pn_vis(td, proc, pn);
101 if (!visible)
102 return (0);
103 return (1);
104 }
105
106 static int
107 pfs_visible(struct thread *td, struct pfs_node *pn, pid_t pid, struct proc **p)
108 {
109 struct proc *proc;
110
111 PFS_TRACE(("%s (pid: %d, req: %d)",
112 pn->pn_name, pid, td->td_proc->p_pid));
113
114 if (p)
115 *p = NULL;
116 if (pid == NO_PID)
117 PFS_RETURN (1);
118 if ((proc = pfind(pid)) == NULL)
119 PFS_RETURN (0);
120 if (pfs_visible_proc(td, pn, proc)) {
121 if (p)
122 *p = proc;
123 else
124 PROC_UNLOCK(proc);
125 PFS_RETURN (1);
126 }
127 PROC_UNLOCK(proc);
128 PFS_RETURN (0);
129 }
130
131 /*
132 * Verify permissions
133 */
134 static int
135 pfs_access(struct vop_access_args *va)
136 {
137 struct vnode *vn = va->a_vp;
138 struct pfs_vdata *pvd = vn->v_data;
139 struct vattr vattr;
140 int error;
141
142 PFS_TRACE(("%s", pvd->pvd_pn->pn_name));
143 (void)pvd;
144
145 error = VOP_GETATTR(vn, &vattr, va->a_cred);
146 if (error)
147 PFS_RETURN (error);
148 error = vaccess(vn->v_type, vattr.va_mode, vattr.va_uid,
149 vattr.va_gid, va->a_accmode, va->a_cred, NULL);
150 PFS_RETURN (error);
151 }
152
153 /*
154 * Close a file or directory
155 */
156 static int
157 pfs_close(struct vop_close_args *va)
158 {
159 struct vnode *vn = va->a_vp;
160 struct pfs_vdata *pvd = vn->v_data;
161 struct pfs_node *pn = pvd->pvd_pn;
162 struct proc *proc;
163 int error;
164
165 PFS_TRACE(("%s", pn->pn_name));
166 pfs_assert_not_owned(pn);
167
168 /*
169 * Do nothing unless this is the last close and the node has a
170 * last-close handler.
171 */
172 if (vrefcnt(vn) > 1 || pn->pn_close == NULL)
173 PFS_RETURN (0);
174
175 if (pvd->pvd_pid != NO_PID) {
176 proc = pfind(pvd->pvd_pid);
177 } else {
178 proc = NULL;
179 }
180
181 error = pn_close(va->a_td, proc, pn);
182
183 if (proc != NULL)
184 PROC_UNLOCK(proc);
185
186 PFS_RETURN (error);
187 }
188
189 /*
190 * Get file attributes
191 */
192 static int
193 pfs_getattr(struct vop_getattr_args *va)
194 {
195 struct vnode *vn = va->a_vp;
196 struct pfs_vdata *pvd = vn->v_data;
197 struct pfs_node *pn = pvd->pvd_pn;
198 struct vattr *vap = va->a_vap;
199 struct proc *proc;
200 int error = 0;
201
202 PFS_TRACE(("%s", pn->pn_name));
203 pfs_assert_not_owned(pn);
204
205 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
206 PFS_RETURN (ENOENT);
207
208 vap->va_type = vn->v_type;
209 vap->va_fileid = pn_fileno(pn, pvd->pvd_pid);
210 vap->va_flags = 0;
211 vap->va_blocksize = PAGE_SIZE;
212 vap->va_bytes = vap->va_size = 0;
213 vap->va_filerev = 0;
214 vap->va_fsid = vn->v_mount->mnt_stat.f_fsid.val[0];
215 vap->va_nlink = 1;
216 nanotime(&vap->va_ctime);
217 vap->va_atime = vap->va_mtime = vap->va_ctime;
218
219 switch (pn->pn_type) {
220 case pfstype_procdir:
221 case pfstype_root:
222 case pfstype_dir:
223 #if 0
224 pfs_lock(pn);
225 /* compute link count */
226 pfs_unlock(pn);
227 #endif
228 vap->va_mode = 0555;
229 break;
230 case pfstype_file:
231 case pfstype_symlink:
232 vap->va_mode = 0444;
233 break;
234 default:
235 printf("shouldn't be here!\n");
236 vap->va_mode = 0;
237 break;
238 }
239
240 if (proc != NULL) {
241 vap->va_uid = proc->p_ucred->cr_ruid;
242 vap->va_gid = proc->p_ucred->cr_rgid;
243 } else {
244 vap->va_uid = 0;
245 vap->va_gid = 0;
246 }
247
248 if (pn->pn_attr != NULL)
249 error = pn_attr(curthread, proc, pn, vap);
250
251 if(proc != NULL)
252 PROC_UNLOCK(proc);
253
254 PFS_RETURN (error);
255 }
256
257 /*
258 * Perform an ioctl
259 */
260 static int
261 pfs_ioctl(struct vop_ioctl_args *va)
262 {
263 struct vnode *vn;
264 struct pfs_vdata *pvd;
265 struct pfs_node *pn;
266 struct proc *proc;
267 int error;
268
269 vn = va->a_vp;
270 vn_lock(vn, LK_SHARED | LK_RETRY);
271 if (vn->v_iflag & VI_DOOMED) {
272 VOP_UNLOCK(vn, 0);
273 return (EBADF);
274 }
275 pvd = vn->v_data;
276 pn = pvd->pvd_pn;
277
278 PFS_TRACE(("%s: %lx", pn->pn_name, va->a_command));
279 pfs_assert_not_owned(pn);
280
281 if (vn->v_type != VREG) {
282 VOP_UNLOCK(vn, 0);
283 PFS_RETURN (EINVAL);
284 }
285 KASSERT_PN_IS_FILE(pn);
286
287 if (pn->pn_ioctl == NULL) {
288 VOP_UNLOCK(vn, 0);
289 PFS_RETURN (ENOTTY);
290 }
291
292 /*
293 * This is necessary because process' privileges may
294 * have changed since the open() call.
295 */
296 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc)) {
297 VOP_UNLOCK(vn, 0);
298 PFS_RETURN (EIO);
299 }
300
301 error = pn_ioctl(curthread, proc, pn, va->a_command, va->a_data);
302
303 if (proc != NULL)
304 PROC_UNLOCK(proc);
305
306 VOP_UNLOCK(vn, 0);
307 PFS_RETURN (error);
308 }
309
310 /*
311 * Perform getextattr
312 */
313 static int
314 pfs_getextattr(struct vop_getextattr_args *va)
315 {
316 struct vnode *vn = va->a_vp;
317 struct pfs_vdata *pvd = vn->v_data;
318 struct pfs_node *pn = pvd->pvd_pn;
319 struct proc *proc;
320 int error;
321
322 PFS_TRACE(("%s", pn->pn_name));
323 pfs_assert_not_owned(pn);
324
325 /*
326 * This is necessary because either process' privileges may
327 * have changed since the open() call.
328 */
329 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
330 PFS_RETURN (EIO);
331
332 if (pn->pn_getextattr == NULL)
333 error = EOPNOTSUPP;
334 else
335 error = pn_getextattr(curthread, proc, pn,
336 va->a_attrnamespace, va->a_name, va->a_uio,
337 va->a_size, va->a_cred);
338
339 if (proc != NULL)
340 PROC_UNLOCK(proc);
341
342 PFS_RETURN (error);
343 }
344
345 /*
346 * Convert a vnode to its component name
347 */
348 static int
349 pfs_vptocnp(struct vop_vptocnp_args *ap)
350 {
351 struct vnode *vp = ap->a_vp;
352 struct vnode **dvp = ap->a_vpp;
353 struct pfs_vdata *pvd = vp->v_data;
354 struct pfs_node *pd = pvd->pvd_pn;
355 struct pfs_node *pn;
356 struct mount *mp;
357 char *buf = ap->a_buf;
358 int *buflen = ap->a_buflen;
359 char pidbuf[PFS_NAMELEN];
360 pid_t pid = pvd->pvd_pid;
361 int len, i, error, locked;
362
363 i = *buflen;
364 error = 0;
365
366 pfs_lock(pd);
367
368 if (vp->v_type == VDIR && pd->pn_type == pfstype_root) {
369 *dvp = vp;
370 vhold(*dvp);
371 pfs_unlock(pd);
372 PFS_RETURN (0);
373 } else if (vp->v_type == VDIR && pd->pn_type == pfstype_procdir) {
374 len = snprintf(pidbuf, sizeof(pidbuf), "%d", pid);
375 i -= len;
376 if (i < 0) {
377 error = ENOMEM;
378 goto failed;
379 }
380 bcopy(pidbuf, buf + i, len);
381 } else {
382 len = strlen(pd->pn_name);
383 i -= len;
384 if (i < 0) {
385 error = ENOMEM;
386 goto failed;
387 }
388 bcopy(pd->pn_name, buf + i, len);
389 }
390
391 pn = pd->pn_parent;
392 pfs_unlock(pd);
393
394 mp = vp->v_mount;
395 error = vfs_busy(mp, 0);
396 if (error)
397 return (error);
398
399 /*
400 * vp is held by caller.
401 */
402 locked = VOP_ISLOCKED(vp);
403 VOP_UNLOCK(vp, 0);
404
405 error = pfs_vncache_alloc(mp, dvp, pn, pid);
406 if (error) {
407 vn_lock(vp, locked | LK_RETRY);
408 vfs_unbusy(mp);
409 PFS_RETURN(error);
410 }
411
412 *buflen = i;
413 VOP_UNLOCK(*dvp, 0);
414 vn_lock(vp, locked | LK_RETRY);
415 vfs_unbusy(mp);
416
417 PFS_RETURN (0);
418 failed:
419 pfs_unlock(pd);
420 PFS_RETURN(error);
421 }
422
423 /*
424 * Look up a file or directory
425 */
426 static int
427 pfs_lookup(struct vop_cachedlookup_args *va)
428 {
429 struct vnode *vn = va->a_dvp;
430 struct vnode **vpp = va->a_vpp;
431 struct componentname *cnp = va->a_cnp;
432 struct pfs_vdata *pvd = vn->v_data;
433 struct pfs_node *pd = pvd->pvd_pn;
434 struct pfs_node *pn, *pdn = NULL;
435 struct mount *mp;
436 pid_t pid = pvd->pvd_pid;
437 char *pname;
438 int error, i, namelen, visible;
439
440 PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr));
441 pfs_assert_not_owned(pd);
442
443 if (vn->v_type != VDIR)
444 PFS_RETURN (ENOTDIR);
445 KASSERT_PN_IS_DIR(pd);
446
447 error = VOP_ACCESS(vn, VEXEC, cnp->cn_cred, cnp->cn_thread);
448 if (error)
449 PFS_RETURN (error);
450
451 /*
452 * Don't support DELETE or RENAME. CREATE is supported so
453 * that O_CREAT will work, but the lookup will still fail if
454 * the file does not exist.
455 */
456 if ((cnp->cn_flags & ISLASTCN) &&
457 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
458 PFS_RETURN (EOPNOTSUPP);
459
460 /* shortcut: check if the name is too long */
461 if (cnp->cn_namelen >= PFS_NAMELEN)
462 PFS_RETURN (ENOENT);
463
464 /* check that parent directory is visible... */
465 if (!pfs_visible(curthread, pd, pvd->pvd_pid, NULL))
466 PFS_RETURN (ENOENT);
467
468 /* self */
469 namelen = cnp->cn_namelen;
470 pname = cnp->cn_nameptr;
471 if (namelen == 1 && pname[0] == '.') {
472 pn = pd;
473 *vpp = vn;
474 VREF(vn);
475 PFS_RETURN (0);
476 }
477
478 mp = vn->v_mount;
479
480 /* parent */
481 if (cnp->cn_flags & ISDOTDOT) {
482 if (pd->pn_type == pfstype_root)
483 PFS_RETURN (EIO);
484 error = vfs_busy(mp, MBF_NOWAIT);
485 if (error != 0) {
486 vfs_ref(mp);
487 VOP_UNLOCK(vn, 0);
488 error = vfs_busy(mp, 0);
489 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
490 vfs_rel(mp);
491 if (error != 0)
492 PFS_RETURN(ENOENT);
493 if (vn->v_iflag & VI_DOOMED) {
494 vfs_unbusy(mp);
495 PFS_RETURN(ENOENT);
496 }
497 }
498 VOP_UNLOCK(vn, 0);
499 KASSERT(pd->pn_parent != NULL,
500 ("%s(): non-root directory has no parent", __func__));
501 /*
502 * This one is tricky. Descendents of procdir nodes
503 * inherit their parent's process affinity, but
504 * there's no easy reverse mapping. For simplicity,
505 * we assume that if this node is a procdir, its
506 * parent isn't (which is correct as long as
507 * descendents of procdir nodes are never procdir
508 * nodes themselves)
509 */
510 if (pd->pn_type == pfstype_procdir)
511 pid = NO_PID;
512 pfs_lock(pd);
513 pn = pd->pn_parent;
514 pfs_unlock(pd);
515 goto got_pnode;
516 }
517
518 pfs_lock(pd);
519
520 /* named node */
521 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next)
522 if (pn->pn_type == pfstype_procdir)
523 pdn = pn;
524 else if (pn->pn_name[namelen] == '\0' &&
525 bcmp(pname, pn->pn_name, namelen) == 0) {
526 pfs_unlock(pd);
527 goto got_pnode;
528 }
529
530 /* process dependent node */
531 if ((pn = pdn) != NULL) {
532 pid = 0;
533 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i)
534 if ((pid = pid * 10 + pname[i] - '') > PID_MAX)
535 break;
536 if (i == cnp->cn_namelen) {
537 pfs_unlock(pd);
538 goto got_pnode;
539 }
540 }
541
542 pfs_unlock(pd);
543
544 PFS_RETURN (ENOENT);
545
546 got_pnode:
547 pfs_assert_not_owned(pd);
548 pfs_assert_not_owned(pn);
549 visible = pfs_visible(curthread, pn, pid, NULL);
550 if (!visible) {
551 error = ENOENT;
552 goto failed;
553 }
554
555 error = pfs_vncache_alloc(mp, vpp, pn, pid);
556 if (error)
557 goto failed;
558
559 if (cnp->cn_flags & ISDOTDOT) {
560 vfs_unbusy(mp);
561 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
562 if (vn->v_iflag & VI_DOOMED) {
563 vput(*vpp);
564 *vpp = NULL;
565 PFS_RETURN(ENOENT);
566 }
567 }
568 if (cnp->cn_flags & MAKEENTRY && !(vn->v_iflag & VI_DOOMED))
569 cache_enter(vn, *vpp, cnp);
570 PFS_RETURN (0);
571 failed:
572 if (cnp->cn_flags & ISDOTDOT) {
573 vfs_unbusy(mp);
574 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
575 *vpp = NULL;
576 }
577 PFS_RETURN(error);
578 }
579
580 /*
581 * Open a file or directory.
582 */
583 static int
584 pfs_open(struct vop_open_args *va)
585 {
586 struct vnode *vn = va->a_vp;
587 struct pfs_vdata *pvd = vn->v_data;
588 struct pfs_node *pn = pvd->pvd_pn;
589 int mode = va->a_mode;
590
591 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode));
592 pfs_assert_not_owned(pn);
593
594 /* check if the requested mode is permitted */
595 if (((mode & FREAD) && !(mode & PFS_RD)) ||
596 ((mode & FWRITE) && !(mode & PFS_WR)))
597 PFS_RETURN (EPERM);
598
599 /* we don't support locking */
600 if ((mode & O_SHLOCK) || (mode & O_EXLOCK))
601 PFS_RETURN (EOPNOTSUPP);
602
603 PFS_RETURN (0);
604 }
605
606 /*
607 * Read from a file
608 */
609 static int
610 pfs_read(struct vop_read_args *va)
611 {
612 struct vnode *vn = va->a_vp;
613 struct pfs_vdata *pvd = vn->v_data;
614 struct pfs_node *pn = pvd->pvd_pn;
615 struct uio *uio = va->a_uio;
616 struct proc *proc;
617 struct sbuf *sb = NULL;
618 int error, locked;
619 off_t buflen;
620
621 PFS_TRACE(("%s", pn->pn_name));
622 pfs_assert_not_owned(pn);
623
624 if (vn->v_type != VREG)
625 PFS_RETURN (EINVAL);
626 KASSERT_PN_IS_FILE(pn);
627
628 if (!(pn->pn_flags & PFS_RD))
629 PFS_RETURN (EBADF);
630
631 if (pn->pn_fill == NULL)
632 PFS_RETURN (EIO);
633
634 /*
635 * This is necessary because either process' privileges may
636 * have changed since the open() call.
637 */
638 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
639 PFS_RETURN (EIO);
640 if (proc != NULL) {
641 _PHOLD(proc);
642 PROC_UNLOCK(proc);
643 }
644
645 vhold(vn);
646 locked = VOP_ISLOCKED(vn);
647 VOP_UNLOCK(vn, 0);
648
649 if (pn->pn_flags & PFS_RAWRD) {
650 PFS_TRACE(("%zd resid", uio->uio_resid));
651 error = pn_fill(curthread, proc, pn, NULL, uio);
652 PFS_TRACE(("%zd resid", uio->uio_resid));
653 goto ret;
654 }
655
656 if (uio->uio_resid < 0 || uio->uio_offset < 0 ||
657 uio->uio_resid > OFF_MAX - uio->uio_offset) {
658 error = EINVAL;
659 goto ret;
660 }
661 buflen = uio->uio_offset + uio->uio_resid;
662 if (buflen > MAXPHYS)
663 buflen = MAXPHYS;
664
665 sb = sbuf_new(sb, NULL, buflen + 1, 0);
666 if (sb == NULL) {
667 error = EIO;
668 goto ret;
669 }
670
671 error = pn_fill(curthread, proc, pn, sb, uio);
672
673 if (error) {
674 sbuf_delete(sb);
675 goto ret;
676 }
677
678 /*
679 * XXX: If the buffer overflowed, sbuf_len() will not return
680 * the data length. Then just use the full length because an
681 * overflowed sbuf must be full.
682 */
683 if (sbuf_finish(sb) == 0)
684 buflen = sbuf_len(sb);
685 error = uiomove_frombuf(sbuf_data(sb), buflen, uio);
686 sbuf_delete(sb);
687 ret:
688 vn_lock(vn, locked | LK_RETRY);
689 vdrop(vn);
690 if (proc != NULL)
691 PRELE(proc);
692 PFS_RETURN (error);
693 }
694
695 /*
696 * Iterate through directory entries
697 */
698 static int
699 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd,
700 struct pfs_node **pn, struct proc **p)
701 {
702 int visible;
703
704 sx_assert(&allproc_lock, SX_SLOCKED);
705 pfs_assert_owned(pd);
706 again:
707 if (*pn == NULL) {
708 /* first node */
709 *pn = pd->pn_nodes;
710 } else if ((*pn)->pn_type != pfstype_procdir) {
711 /* next node */
712 *pn = (*pn)->pn_next;
713 }
714 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) {
715 /* next process */
716 if (*p == NULL)
717 *p = LIST_FIRST(&allproc);
718 else
719 *p = LIST_NEXT(*p, p_list);
720 /* out of processes: next node */
721 if (*p == NULL)
722 *pn = (*pn)->pn_next;
723 else
724 PROC_LOCK(*p);
725 }
726
727 if ((*pn) == NULL)
728 return (-1);
729
730 if (*p != NULL) {
731 visible = pfs_visible_proc(td, *pn, *p);
732 PROC_UNLOCK(*p);
733 } else if (proc != NULL) {
734 visible = pfs_visible_proc(td, *pn, proc);
735 } else {
736 visible = 1;
737 }
738 if (!visible)
739 goto again;
740
741 return (0);
742 }
743
744 /* Directory entry list */
745 struct pfsentry {
746 STAILQ_ENTRY(pfsentry) link;
747 struct dirent entry;
748 };
749 STAILQ_HEAD(pfsdirentlist, pfsentry);
750
751 /*
752 * Return directory entries.
753 */
754 static int
755 pfs_readdir(struct vop_readdir_args *va)
756 {
757 struct vnode *vn = va->a_vp;
758 struct pfs_vdata *pvd = vn->v_data;
759 struct pfs_node *pd = pvd->pvd_pn;
760 pid_t pid = pvd->pvd_pid;
761 struct proc *p, *proc;
762 struct pfs_node *pn;
763 struct uio *uio;
764 struct pfsentry *pfsent, *pfsent2;
765 struct pfsdirentlist lst;
766 off_t offset;
767 int error, i, resid;
768
769 STAILQ_INIT(&lst);
770 error = 0;
771 KASSERT(pd->pn_info == vn->v_mount->mnt_data,
772 ("%s(): pn_info does not match mountpoint", __func__));
773 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid));
774 pfs_assert_not_owned(pd);
775
776 if (vn->v_type != VDIR)
777 PFS_RETURN (ENOTDIR);
778 KASSERT_PN_IS_DIR(pd);
779 uio = va->a_uio;
780
781 /* only allow reading entire entries */
782 offset = uio->uio_offset;
783 resid = uio->uio_resid;
784 if (offset < 0 || offset % PFS_DELEN != 0 ||
785 (resid && resid < PFS_DELEN))
786 PFS_RETURN (EINVAL);
787 if (resid == 0)
788 PFS_RETURN (0);
789
790 sx_slock(&allproc_lock);
791 pfs_lock(pd);
792
793 /* check if the directory is visible to the caller */
794 if (!pfs_visible(curthread, pd, pid, &proc)) {
795 sx_sunlock(&allproc_lock);
796 pfs_unlock(pd);
797 PFS_RETURN (ENOENT);
798 }
799 KASSERT(pid == NO_PID || proc != NULL,
800 ("%s(): no process for pid %lu", __func__, (unsigned long)pid));
801
802 /* skip unwanted entries */
803 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) {
804 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) {
805 /* nothing left... */
806 if (proc != NULL)
807 PROC_UNLOCK(proc);
808 pfs_unlock(pd);
809 sx_sunlock(&allproc_lock);
810 PFS_RETURN (0);
811 }
812 }
813
814 /* fill in entries */
815 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 &&
816 resid >= PFS_DELEN) {
817 if ((pfsent = malloc(sizeof(struct pfsentry), M_IOV,
818 M_NOWAIT | M_ZERO)) == NULL) {
819 error = ENOMEM;
820 break;
821 }
822 pfsent->entry.d_reclen = PFS_DELEN;
823 pfsent->entry.d_fileno = pn_fileno(pn, pid);
824 /* PFS_DELEN was picked to fit PFS_NAMLEN */
825 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i)
826 pfsent->entry.d_name[i] = pn->pn_name[i];
827 pfsent->entry.d_name[i] = 0;
828 pfsent->entry.d_namlen = i;
829 switch (pn->pn_type) {
830 case pfstype_procdir:
831 KASSERT(p != NULL,
832 ("reached procdir node with p == NULL"));
833 pfsent->entry.d_namlen = snprintf(pfsent->entry.d_name,
834 PFS_NAMELEN, "%d", p->p_pid);
835 /* fall through */
836 case pfstype_root:
837 case pfstype_dir:
838 case pfstype_this:
839 case pfstype_parent:
840 pfsent->entry.d_type = DT_DIR;
841 break;
842 case pfstype_file:
843 pfsent->entry.d_type = DT_REG;
844 break;
845 case pfstype_symlink:
846 pfsent->entry.d_type = DT_LNK;
847 break;
848 default:
849 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type);
850 }
851 PFS_TRACE(("%s", pfsent->entry.d_name));
852 STAILQ_INSERT_TAIL(&lst, pfsent, link);
853 offset += PFS_DELEN;
854 resid -= PFS_DELEN;
855 }
856 if (proc != NULL)
857 PROC_UNLOCK(proc);
858 pfs_unlock(pd);
859 sx_sunlock(&allproc_lock);
860 i = 0;
861 STAILQ_FOREACH_SAFE(pfsent, &lst, link, pfsent2) {
862 if (error == 0)
863 error = uiomove(&pfsent->entry, PFS_DELEN, uio);
864 free(pfsent, M_IOV);
865 i++;
866 }
867 PFS_TRACE(("%d bytes", i * PFS_DELEN));
868 PFS_RETURN (error);
869 }
870
871 /*
872 * Read a symbolic link
873 */
874 static int
875 pfs_readlink(struct vop_readlink_args *va)
876 {
877 struct vnode *vn = va->a_vp;
878 struct pfs_vdata *pvd = vn->v_data;
879 struct pfs_node *pn = pvd->pvd_pn;
880 struct uio *uio = va->a_uio;
881 struct proc *proc = NULL;
882 char buf[PATH_MAX];
883 struct sbuf sb;
884 int error, locked;
885
886 PFS_TRACE(("%s", pn->pn_name));
887 pfs_assert_not_owned(pn);
888
889 if (vn->v_type != VLNK)
890 PFS_RETURN (EINVAL);
891 KASSERT_PN_IS_LINK(pn);
892
893 if (pn->pn_fill == NULL)
894 PFS_RETURN (EIO);
895
896 if (pvd->pvd_pid != NO_PID) {
897 if ((proc = pfind(pvd->pvd_pid)) == NULL)
898 PFS_RETURN (EIO);
899 if (proc->p_flag & P_WEXIT) {
900 PROC_UNLOCK(proc);
901 PFS_RETURN (EIO);
902 }
903 _PHOLD(proc);
904 PROC_UNLOCK(proc);
905 }
906 vhold(vn);
907 locked = VOP_ISLOCKED(vn);
908 VOP_UNLOCK(vn, 0);
909
910 /* sbuf_new() can't fail with a static buffer */
911 sbuf_new(&sb, buf, sizeof buf, 0);
912
913 error = pn_fill(curthread, proc, pn, &sb, NULL);
914
915 if (proc != NULL)
916 PRELE(proc);
917 vn_lock(vn, locked | LK_RETRY);
918 vdrop(vn);
919
920 if (error) {
921 sbuf_delete(&sb);
922 PFS_RETURN (error);
923 }
924
925 if (sbuf_finish(&sb) != 0) {
926 sbuf_delete(&sb);
927 PFS_RETURN (ENAMETOOLONG);
928 }
929
930 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio);
931 sbuf_delete(&sb);
932 PFS_RETURN (error);
933 }
934
935 /*
936 * Reclaim a vnode
937 */
938 static int
939 pfs_reclaim(struct vop_reclaim_args *va)
940 {
941 struct vnode *vn = va->a_vp;
942 struct pfs_vdata *pvd = vn->v_data;
943 struct pfs_node *pn = pvd->pvd_pn;
944
945 PFS_TRACE(("%s", pn->pn_name));
946 pfs_assert_not_owned(pn);
947
948 return (pfs_vncache_free(va->a_vp));
949 }
950
951 /*
952 * Set attributes
953 */
954 static int
955 pfs_setattr(struct vop_setattr_args *va)
956 {
957 struct vnode *vn = va->a_vp;
958 struct pfs_vdata *pvd = vn->v_data;
959 struct pfs_node *pn = pvd->pvd_pn;
960
961 PFS_TRACE(("%s", pn->pn_name));
962 pfs_assert_not_owned(pn);
963
964 PFS_RETURN (EOPNOTSUPP);
965 }
966
967 /*
968 * Write to a file
969 */
970 static int
971 pfs_write(struct vop_write_args *va)
972 {
973 struct vnode *vn = va->a_vp;
974 struct pfs_vdata *pvd = vn->v_data;
975 struct pfs_node *pn = pvd->pvd_pn;
976 struct uio *uio = va->a_uio;
977 struct proc *proc;
978 struct sbuf sb;
979 int error;
980
981 PFS_TRACE(("%s", pn->pn_name));
982 pfs_assert_not_owned(pn);
983
984 if (vn->v_type != VREG)
985 PFS_RETURN (EINVAL);
986 KASSERT_PN_IS_FILE(pn);
987
988 if (!(pn->pn_flags & PFS_WR))
989 PFS_RETURN (EBADF);
990
991 if (pn->pn_fill == NULL)
992 PFS_RETURN (EIO);
993
994 /*
995 * This is necessary because either process' privileges may
996 * have changed since the open() call.
997 */
998 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
999 PFS_RETURN (EIO);
1000 if (proc != NULL) {
1001 _PHOLD(proc);
1002 PROC_UNLOCK(proc);
1003 }
1004
1005 if (pn->pn_flags & PFS_RAWWR) {
1006 error = pn_fill(curthread, proc, pn, NULL, uio);
1007 if (proc != NULL)
1008 PRELE(proc);
1009 PFS_RETURN (error);
1010 }
1011
1012 sbuf_uionew(&sb, uio, &error);
1013 if (error) {
1014 if (proc != NULL)
1015 PRELE(proc);
1016 PFS_RETURN (error);
1017 }
1018
1019 error = pn_fill(curthread, proc, pn, &sb, uio);
1020
1021 sbuf_delete(&sb);
1022 if (proc != NULL)
1023 PRELE(proc);
1024 PFS_RETURN (error);
1025 }
1026
1027 /*
1028 * Vnode operations
1029 */
1030 struct vop_vector pfs_vnodeops = {
1031 .vop_default = &default_vnodeops,
1032
1033 .vop_access = pfs_access,
1034 .vop_cachedlookup = pfs_lookup,
1035 .vop_close = pfs_close,
1036 .vop_create = VOP_EOPNOTSUPP,
1037 .vop_getattr = pfs_getattr,
1038 .vop_getextattr = pfs_getextattr,
1039 .vop_ioctl = pfs_ioctl,
1040 .vop_link = VOP_EOPNOTSUPP,
1041 .vop_lookup = vfs_cache_lookup,
1042 .vop_mkdir = VOP_EOPNOTSUPP,
1043 .vop_mknod = VOP_EOPNOTSUPP,
1044 .vop_open = pfs_open,
1045 .vop_read = pfs_read,
1046 .vop_readdir = pfs_readdir,
1047 .vop_readlink = pfs_readlink,
1048 .vop_reclaim = pfs_reclaim,
1049 .vop_remove = VOP_EOPNOTSUPP,
1050 .vop_rename = VOP_EOPNOTSUPP,
1051 .vop_rmdir = VOP_EOPNOTSUPP,
1052 .vop_setattr = pfs_setattr,
1053 .vop_symlink = VOP_EOPNOTSUPP,
1054 .vop_vptocnp = pfs_vptocnp,
1055 .vop_write = pfs_write,
1056 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */
1057 };
Cache object: 8722556661e74b6ef2524c929018a9ce
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