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/8.4/sys/fs/pseudofs/pseudofs_vnops.c 233171 2012-03-19 11:27:54Z 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 vhold(*dvp);
414 vput(*dvp);
415 vn_lock(vp, locked | LK_RETRY);
416 vfs_unbusy(mp);
417
418 PFS_RETURN (0);
419 failed:
420 pfs_unlock(pd);
421 PFS_RETURN(error);
422 }
423
424 /*
425 * Look up a file or directory
426 */
427 static int
428 pfs_lookup(struct vop_cachedlookup_args *va)
429 {
430 struct vnode *vn = va->a_dvp;
431 struct vnode **vpp = va->a_vpp;
432 struct componentname *cnp = va->a_cnp;
433 struct pfs_vdata *pvd = vn->v_data;
434 struct pfs_node *pd = pvd->pvd_pn;
435 struct pfs_node *pn, *pdn = NULL;
436 struct mount *mp;
437 pid_t pid = pvd->pvd_pid;
438 char *pname;
439 int error, i, namelen, visible;
440
441 PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr));
442 pfs_assert_not_owned(pd);
443
444 if (vn->v_type != VDIR)
445 PFS_RETURN (ENOTDIR);
446 KASSERT_PN_IS_DIR(pd);
447
448 error = VOP_ACCESS(vn, VEXEC, cnp->cn_cred, cnp->cn_thread);
449 if (error)
450 PFS_RETURN (error);
451
452 /*
453 * Don't support DELETE or RENAME. CREATE is supported so
454 * that O_CREAT will work, but the lookup will still fail if
455 * the file does not exist.
456 */
457 if ((cnp->cn_flags & ISLASTCN) &&
458 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
459 PFS_RETURN (EOPNOTSUPP);
460
461 /* shortcut: check if the name is too long */
462 if (cnp->cn_namelen >= PFS_NAMELEN)
463 PFS_RETURN (ENOENT);
464
465 /* check that parent directory is visible... */
466 if (!pfs_visible(curthread, pd, pvd->pvd_pid, NULL))
467 PFS_RETURN (ENOENT);
468
469 /* self */
470 namelen = cnp->cn_namelen;
471 pname = cnp->cn_nameptr;
472 if (namelen == 1 && pname[0] == '.') {
473 pn = pd;
474 *vpp = vn;
475 VREF(vn);
476 PFS_RETURN (0);
477 }
478
479 mp = vn->v_mount;
480
481 /* parent */
482 if (cnp->cn_flags & ISDOTDOT) {
483 if (pd->pn_type == pfstype_root)
484 PFS_RETURN (EIO);
485 error = vfs_busy(mp, MBF_NOWAIT);
486 if (error != 0) {
487 vfs_ref(mp);
488 VOP_UNLOCK(vn, 0);
489 error = vfs_busy(mp, 0);
490 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
491 vfs_rel(mp);
492 if (error != 0)
493 PFS_RETURN(ENOENT);
494 if (vn->v_iflag & VI_DOOMED) {
495 vfs_unbusy(mp);
496 PFS_RETURN(ENOENT);
497 }
498 }
499 VOP_UNLOCK(vn, 0);
500 KASSERT(pd->pn_parent != NULL,
501 ("%s(): non-root directory has no parent", __func__));
502 /*
503 * This one is tricky. Descendents of procdir nodes
504 * inherit their parent's process affinity, but
505 * there's no easy reverse mapping. For simplicity,
506 * we assume that if this node is a procdir, its
507 * parent isn't (which is correct as long as
508 * descendents of procdir nodes are never procdir
509 * nodes themselves)
510 */
511 if (pd->pn_type == pfstype_procdir)
512 pid = NO_PID;
513 pfs_lock(pd);
514 pn = pd->pn_parent;
515 pfs_unlock(pd);
516 goto got_pnode;
517 }
518
519 pfs_lock(pd);
520
521 /* named node */
522 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next)
523 if (pn->pn_type == pfstype_procdir)
524 pdn = pn;
525 else if (pn->pn_name[namelen] == '\0' &&
526 bcmp(pname, pn->pn_name, namelen) == 0) {
527 pfs_unlock(pd);
528 goto got_pnode;
529 }
530
531 /* process dependent node */
532 if ((pn = pdn) != NULL) {
533 pid = 0;
534 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i)
535 if ((pid = pid * 10 + pname[i] - '') > PID_MAX)
536 break;
537 if (i == cnp->cn_namelen) {
538 pfs_unlock(pd);
539 goto got_pnode;
540 }
541 }
542
543 pfs_unlock(pd);
544
545 PFS_RETURN (ENOENT);
546
547 got_pnode:
548 pfs_assert_not_owned(pd);
549 pfs_assert_not_owned(pn);
550 visible = pfs_visible(curthread, pn, pid, NULL);
551 if (!visible) {
552 error = ENOENT;
553 goto failed;
554 }
555
556 error = pfs_vncache_alloc(mp, vpp, pn, pid);
557 if (error)
558 goto failed;
559
560 if (cnp->cn_flags & ISDOTDOT) {
561 vfs_unbusy(mp);
562 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
563 if (vn->v_iflag & VI_DOOMED) {
564 vput(*vpp);
565 *vpp = NULL;
566 PFS_RETURN(ENOENT);
567 }
568 }
569 if (cnp->cn_flags & MAKEENTRY && !(vn->v_iflag & VI_DOOMED))
570 cache_enter(vn, *vpp, cnp);
571 PFS_RETURN (0);
572 failed:
573 if (cnp->cn_flags & ISDOTDOT) {
574 vfs_unbusy(mp);
575 vn_lock(vn, LK_EXCLUSIVE | LK_RETRY);
576 *vpp = NULL;
577 }
578 PFS_RETURN(error);
579 }
580
581 /*
582 * Open a file or directory.
583 */
584 static int
585 pfs_open(struct vop_open_args *va)
586 {
587 struct vnode *vn = va->a_vp;
588 struct pfs_vdata *pvd = vn->v_data;
589 struct pfs_node *pn = pvd->pvd_pn;
590 int mode = va->a_mode;
591
592 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode));
593 pfs_assert_not_owned(pn);
594
595 /* check if the requested mode is permitted */
596 if (((mode & FREAD) && !(mode & PFS_RD)) ||
597 ((mode & FWRITE) && !(mode & PFS_WR)))
598 PFS_RETURN (EPERM);
599
600 /* we don't support locking */
601 if ((mode & O_SHLOCK) || (mode & O_EXLOCK))
602 PFS_RETURN (EOPNOTSUPP);
603
604 PFS_RETURN (0);
605 }
606
607 /*
608 * Read from a file
609 */
610 static int
611 pfs_read(struct vop_read_args *va)
612 {
613 struct vnode *vn = va->a_vp;
614 struct pfs_vdata *pvd = vn->v_data;
615 struct pfs_node *pn = pvd->pvd_pn;
616 struct uio *uio = va->a_uio;
617 struct proc *proc;
618 struct sbuf *sb = NULL;
619 int error, locked;
620 unsigned int buflen, offset, resid;
621
622 PFS_TRACE(("%s", pn->pn_name));
623 pfs_assert_not_owned(pn);
624
625 if (vn->v_type != VREG)
626 PFS_RETURN (EINVAL);
627 KASSERT_PN_IS_FILE(pn);
628
629 if (!(pn->pn_flags & PFS_RD))
630 PFS_RETURN (EBADF);
631
632 if (pn->pn_fill == NULL)
633 PFS_RETURN (EIO);
634
635 /*
636 * This is necessary because either process' privileges may
637 * have changed since the open() call.
638 */
639 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
640 PFS_RETURN (EIO);
641 if (proc != NULL) {
642 _PHOLD(proc);
643 PROC_UNLOCK(proc);
644 }
645
646 vhold(vn);
647 locked = VOP_ISLOCKED(vn);
648 VOP_UNLOCK(vn, 0);
649
650 if (pn->pn_flags & PFS_RAWRD) {
651 PFS_TRACE(("%zd resid", uio->uio_resid));
652 error = pn_fill(curthread, proc, pn, NULL, uio);
653 PFS_TRACE(("%zd resid", uio->uio_resid));
654 goto ret;
655 }
656
657 /* beaucoup sanity checks so we don't ask for bogus allocation */
658 if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
659 (offset = uio->uio_offset) != uio->uio_offset ||
660 (resid = uio->uio_resid) != uio->uio_resid ||
661 (buflen = offset + resid + 1) < offset || buflen > INT_MAX) {
662 error = EINVAL;
663 goto ret;
664 }
665 if (buflen > MAXPHYS + 1)
666 buflen = MAXPHYS + 1;
667
668 sb = sbuf_new(sb, NULL, buflen, 0);
669 if (sb == NULL) {
670 error = EIO;
671 goto ret;
672 }
673
674 error = pn_fill(curthread, proc, pn, sb, uio);
675
676 if (error) {
677 sbuf_delete(sb);
678 goto ret;
679 }
680
681 sbuf_finish(sb);
682 error = uiomove_frombuf(sbuf_data(sb), sbuf_len(sb), uio);
683 sbuf_delete(sb);
684 ret:
685 vn_lock(vn, locked | LK_RETRY);
686 vdrop(vn);
687 if (proc != NULL)
688 PRELE(proc);
689 PFS_RETURN (error);
690 }
691
692 /*
693 * Iterate through directory entries
694 */
695 static int
696 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd,
697 struct pfs_node **pn, struct proc **p)
698 {
699 int visible;
700
701 sx_assert(&allproc_lock, SX_SLOCKED);
702 pfs_assert_owned(pd);
703 again:
704 if (*pn == NULL) {
705 /* first node */
706 *pn = pd->pn_nodes;
707 } else if ((*pn)->pn_type != pfstype_procdir) {
708 /* next node */
709 *pn = (*pn)->pn_next;
710 }
711 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) {
712 /* next process */
713 if (*p == NULL)
714 *p = LIST_FIRST(&allproc);
715 else
716 *p = LIST_NEXT(*p, p_list);
717 /* out of processes: next node */
718 if (*p == NULL)
719 *pn = (*pn)->pn_next;
720 else
721 PROC_LOCK(*p);
722 }
723
724 if ((*pn) == NULL)
725 return (-1);
726
727 if (*p != NULL) {
728 visible = pfs_visible_proc(td, *pn, *p);
729 PROC_UNLOCK(*p);
730 } else if (proc != NULL) {
731 visible = pfs_visible_proc(td, *pn, proc);
732 } else {
733 visible = 1;
734 }
735 if (!visible)
736 goto again;
737
738 return (0);
739 }
740
741 /* Directory entry list */
742 struct pfsentry {
743 STAILQ_ENTRY(pfsentry) link;
744 struct dirent entry;
745 };
746 STAILQ_HEAD(pfsdirentlist, pfsentry);
747
748 /*
749 * Return directory entries.
750 */
751 static int
752 pfs_readdir(struct vop_readdir_args *va)
753 {
754 struct vnode *vn = va->a_vp;
755 struct pfs_vdata *pvd = vn->v_data;
756 struct pfs_node *pd = pvd->pvd_pn;
757 pid_t pid = pvd->pvd_pid;
758 struct proc *p, *proc;
759 struct pfs_node *pn;
760 struct uio *uio;
761 struct pfsentry *pfsent, *pfsent2;
762 struct pfsdirentlist lst;
763 off_t offset;
764 int error, i, resid;
765
766 STAILQ_INIT(&lst);
767 error = 0;
768 KASSERT(pd->pn_info == vn->v_mount->mnt_data,
769 ("%s(): pn_info does not match mountpoint", __func__));
770 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid));
771 pfs_assert_not_owned(pd);
772
773 if (vn->v_type != VDIR)
774 PFS_RETURN (ENOTDIR);
775 KASSERT_PN_IS_DIR(pd);
776 uio = va->a_uio;
777
778 /* only allow reading entire entries */
779 offset = uio->uio_offset;
780 resid = uio->uio_resid;
781 if (offset < 0 || offset % PFS_DELEN != 0 ||
782 (resid && resid < PFS_DELEN))
783 PFS_RETURN (EINVAL);
784 if (resid == 0)
785 PFS_RETURN (0);
786
787 sx_slock(&allproc_lock);
788 pfs_lock(pd);
789
790 /* check if the directory is visible to the caller */
791 if (!pfs_visible(curthread, pd, pid, &proc)) {
792 sx_sunlock(&allproc_lock);
793 pfs_unlock(pd);
794 PFS_RETURN (ENOENT);
795 }
796 KASSERT(pid == NO_PID || proc != NULL,
797 ("%s(): no process for pid %lu", __func__, (unsigned long)pid));
798
799 /* skip unwanted entries */
800 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) {
801 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) {
802 /* nothing left... */
803 if (proc != NULL)
804 PROC_UNLOCK(proc);
805 pfs_unlock(pd);
806 sx_sunlock(&allproc_lock);
807 PFS_RETURN (0);
808 }
809 }
810
811 /* fill in entries */
812 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 &&
813 resid >= PFS_DELEN) {
814 if ((pfsent = malloc(sizeof(struct pfsentry), M_IOV,
815 M_NOWAIT | M_ZERO)) == NULL) {
816 error = ENOMEM;
817 break;
818 }
819 pfsent->entry.d_reclen = PFS_DELEN;
820 pfsent->entry.d_fileno = pn_fileno(pn, pid);
821 /* PFS_DELEN was picked to fit PFS_NAMLEN */
822 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i)
823 pfsent->entry.d_name[i] = pn->pn_name[i];
824 pfsent->entry.d_name[i] = 0;
825 pfsent->entry.d_namlen = i;
826 switch (pn->pn_type) {
827 case pfstype_procdir:
828 KASSERT(p != NULL,
829 ("reached procdir node with p == NULL"));
830 pfsent->entry.d_namlen = snprintf(pfsent->entry.d_name,
831 PFS_NAMELEN, "%d", p->p_pid);
832 /* fall through */
833 case pfstype_root:
834 case pfstype_dir:
835 case pfstype_this:
836 case pfstype_parent:
837 pfsent->entry.d_type = DT_DIR;
838 break;
839 case pfstype_file:
840 pfsent->entry.d_type = DT_REG;
841 break;
842 case pfstype_symlink:
843 pfsent->entry.d_type = DT_LNK;
844 break;
845 default:
846 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type);
847 }
848 PFS_TRACE(("%s", pfsent->entry.d_name));
849 STAILQ_INSERT_TAIL(&lst, pfsent, link);
850 offset += PFS_DELEN;
851 resid -= PFS_DELEN;
852 }
853 if (proc != NULL)
854 PROC_UNLOCK(proc);
855 pfs_unlock(pd);
856 sx_sunlock(&allproc_lock);
857 i = 0;
858 STAILQ_FOREACH_SAFE(pfsent, &lst, link, pfsent2) {
859 if (error == 0)
860 error = uiomove(&pfsent->entry, PFS_DELEN, uio);
861 free(pfsent, M_IOV);
862 i++;
863 }
864 PFS_TRACE(("%d bytes", i * PFS_DELEN));
865 PFS_RETURN (error);
866 }
867
868 /*
869 * Read a symbolic link
870 */
871 static int
872 pfs_readlink(struct vop_readlink_args *va)
873 {
874 struct vnode *vn = va->a_vp;
875 struct pfs_vdata *pvd = vn->v_data;
876 struct pfs_node *pn = pvd->pvd_pn;
877 struct uio *uio = va->a_uio;
878 struct proc *proc = NULL;
879 char buf[PATH_MAX];
880 struct sbuf sb;
881 int error, locked;
882
883 PFS_TRACE(("%s", pn->pn_name));
884 pfs_assert_not_owned(pn);
885
886 if (vn->v_type != VLNK)
887 PFS_RETURN (EINVAL);
888 KASSERT_PN_IS_LINK(pn);
889
890 if (pn->pn_fill == NULL)
891 PFS_RETURN (EIO);
892
893 if (pvd->pvd_pid != NO_PID) {
894 if ((proc = pfind(pvd->pvd_pid)) == NULL)
895 PFS_RETURN (EIO);
896 if (proc->p_flag & P_WEXIT) {
897 PROC_UNLOCK(proc);
898 PFS_RETURN (EIO);
899 }
900 _PHOLD(proc);
901 PROC_UNLOCK(proc);
902 }
903 vhold(vn);
904 locked = VOP_ISLOCKED(vn);
905 VOP_UNLOCK(vn, 0);
906
907 /* sbuf_new() can't fail with a static buffer */
908 sbuf_new(&sb, buf, sizeof buf, 0);
909
910 error = pn_fill(curthread, proc, pn, &sb, NULL);
911
912 if (proc != NULL)
913 PRELE(proc);
914 vn_lock(vn, locked | LK_RETRY);
915 vdrop(vn);
916
917 if (error) {
918 sbuf_delete(&sb);
919 PFS_RETURN (error);
920 }
921
922 if (sbuf_finish(&sb) != 0) {
923 sbuf_delete(&sb);
924 PFS_RETURN (ENAMETOOLONG);
925 }
926
927 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio);
928 sbuf_delete(&sb);
929 PFS_RETURN (error);
930 }
931
932 /*
933 * Reclaim a vnode
934 */
935 static int
936 pfs_reclaim(struct vop_reclaim_args *va)
937 {
938 struct vnode *vn = va->a_vp;
939 struct pfs_vdata *pvd = vn->v_data;
940 struct pfs_node *pn = pvd->pvd_pn;
941
942 PFS_TRACE(("%s", pn->pn_name));
943 pfs_assert_not_owned(pn);
944
945 return (pfs_vncache_free(va->a_vp));
946 }
947
948 /*
949 * Set attributes
950 */
951 static int
952 pfs_setattr(struct vop_setattr_args *va)
953 {
954 struct vnode *vn = va->a_vp;
955 struct pfs_vdata *pvd = vn->v_data;
956 struct pfs_node *pn = pvd->pvd_pn;
957
958 PFS_TRACE(("%s", pn->pn_name));
959 pfs_assert_not_owned(pn);
960
961 PFS_RETURN (EOPNOTSUPP);
962 }
963
964 /*
965 * Write to a file
966 */
967 static int
968 pfs_write(struct vop_write_args *va)
969 {
970 struct vnode *vn = va->a_vp;
971 struct pfs_vdata *pvd = vn->v_data;
972 struct pfs_node *pn = pvd->pvd_pn;
973 struct uio *uio = va->a_uio;
974 struct proc *proc;
975 struct sbuf sb;
976 int error;
977
978 PFS_TRACE(("%s", pn->pn_name));
979 pfs_assert_not_owned(pn);
980
981 if (vn->v_type != VREG)
982 PFS_RETURN (EINVAL);
983 KASSERT_PN_IS_FILE(pn);
984
985 if (!(pn->pn_flags & PFS_WR))
986 PFS_RETURN (EBADF);
987
988 if (pn->pn_fill == NULL)
989 PFS_RETURN (EIO);
990
991 /*
992 * This is necessary because either process' privileges may
993 * have changed since the open() call.
994 */
995 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
996 PFS_RETURN (EIO);
997 if (proc != NULL) {
998 _PHOLD(proc);
999 PROC_UNLOCK(proc);
1000 }
1001
1002 if (pn->pn_flags & PFS_RAWWR) {
1003 error = pn_fill(curthread, proc, pn, NULL, uio);
1004 if (proc != NULL)
1005 PRELE(proc);
1006 PFS_RETURN (error);
1007 }
1008
1009 sbuf_uionew(&sb, uio, &error);
1010 if (error) {
1011 if (proc != NULL)
1012 PRELE(proc);
1013 PFS_RETURN (error);
1014 }
1015
1016 error = pn_fill(curthread, proc, pn, &sb, uio);
1017
1018 sbuf_delete(&sb);
1019 if (proc != NULL)
1020 PRELE(proc);
1021 PFS_RETURN (error);
1022 }
1023
1024 /*
1025 * Vnode operations
1026 */
1027 struct vop_vector pfs_vnodeops = {
1028 .vop_default = &default_vnodeops,
1029
1030 .vop_access = pfs_access,
1031 .vop_cachedlookup = pfs_lookup,
1032 .vop_close = pfs_close,
1033 .vop_create = VOP_EOPNOTSUPP,
1034 .vop_getattr = pfs_getattr,
1035 .vop_getextattr = pfs_getextattr,
1036 .vop_ioctl = pfs_ioctl,
1037 .vop_link = VOP_EOPNOTSUPP,
1038 .vop_lookup = vfs_cache_lookup,
1039 .vop_mkdir = VOP_EOPNOTSUPP,
1040 .vop_mknod = VOP_EOPNOTSUPP,
1041 .vop_open = pfs_open,
1042 .vop_read = pfs_read,
1043 .vop_readdir = pfs_readdir,
1044 .vop_readlink = pfs_readlink,
1045 .vop_reclaim = pfs_reclaim,
1046 .vop_remove = VOP_EOPNOTSUPP,
1047 .vop_rename = VOP_EOPNOTSUPP,
1048 .vop_rmdir = VOP_EOPNOTSUPP,
1049 .vop_setattr = pfs_setattr,
1050 .vop_symlink = VOP_EOPNOTSUPP,
1051 .vop_vptocnp = pfs_vptocnp,
1052 .vop_write = pfs_write,
1053 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */
1054 };
Cache object: 23316740610e51a66d2bb0a910324297
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