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/9.1/sys/fs/pseudofs/pseudofs_vnops.c 233353 2012-03-23 11:26:54Z 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 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 offset;
620 ssize_t buflen, 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) < offset || buflen >= INT_MAX) {
662 error = EINVAL;
663 goto ret;
664 }
665 if (buflen > MAXPHYS)
666 buflen = MAXPHYS;
667
668 sb = sbuf_new(sb, NULL, buflen + 1, 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 /*
682 * XXX: If the buffer overflowed, sbuf_len() will not return
683 * the data length. Then just use the full length because an
684 * overflowed sbuf must be full.
685 */
686 if (sbuf_finish(sb) == 0)
687 buflen = sbuf_len(sb);
688 error = uiomove_frombuf(sbuf_data(sb), buflen, uio);
689 sbuf_delete(sb);
690 ret:
691 vn_lock(vn, locked | LK_RETRY);
692 vdrop(vn);
693 if (proc != NULL)
694 PRELE(proc);
695 PFS_RETURN (error);
696 }
697
698 /*
699 * Iterate through directory entries
700 */
701 static int
702 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd,
703 struct pfs_node **pn, struct proc **p)
704 {
705 int visible;
706
707 sx_assert(&allproc_lock, SX_SLOCKED);
708 pfs_assert_owned(pd);
709 again:
710 if (*pn == NULL) {
711 /* first node */
712 *pn = pd->pn_nodes;
713 } else if ((*pn)->pn_type != pfstype_procdir) {
714 /* next node */
715 *pn = (*pn)->pn_next;
716 }
717 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) {
718 /* next process */
719 if (*p == NULL)
720 *p = LIST_FIRST(&allproc);
721 else
722 *p = LIST_NEXT(*p, p_list);
723 /* out of processes: next node */
724 if (*p == NULL)
725 *pn = (*pn)->pn_next;
726 else
727 PROC_LOCK(*p);
728 }
729
730 if ((*pn) == NULL)
731 return (-1);
732
733 if (*p != NULL) {
734 visible = pfs_visible_proc(td, *pn, *p);
735 PROC_UNLOCK(*p);
736 } else if (proc != NULL) {
737 visible = pfs_visible_proc(td, *pn, proc);
738 } else {
739 visible = 1;
740 }
741 if (!visible)
742 goto again;
743
744 return (0);
745 }
746
747 /* Directory entry list */
748 struct pfsentry {
749 STAILQ_ENTRY(pfsentry) link;
750 struct dirent entry;
751 };
752 STAILQ_HEAD(pfsdirentlist, pfsentry);
753
754 /*
755 * Return directory entries.
756 */
757 static int
758 pfs_readdir(struct vop_readdir_args *va)
759 {
760 struct vnode *vn = va->a_vp;
761 struct pfs_vdata *pvd = vn->v_data;
762 struct pfs_node *pd = pvd->pvd_pn;
763 pid_t pid = pvd->pvd_pid;
764 struct proc *p, *proc;
765 struct pfs_node *pn;
766 struct uio *uio;
767 struct pfsentry *pfsent, *pfsent2;
768 struct pfsdirentlist lst;
769 off_t offset;
770 int error, i, resid;
771
772 STAILQ_INIT(&lst);
773 error = 0;
774 KASSERT(pd->pn_info == vn->v_mount->mnt_data,
775 ("%s(): pn_info does not match mountpoint", __func__));
776 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid));
777 pfs_assert_not_owned(pd);
778
779 if (vn->v_type != VDIR)
780 PFS_RETURN (ENOTDIR);
781 KASSERT_PN_IS_DIR(pd);
782 uio = va->a_uio;
783
784 /* only allow reading entire entries */
785 offset = uio->uio_offset;
786 resid = uio->uio_resid;
787 if (offset < 0 || offset % PFS_DELEN != 0 ||
788 (resid && resid < PFS_DELEN))
789 PFS_RETURN (EINVAL);
790 if (resid == 0)
791 PFS_RETURN (0);
792
793 sx_slock(&allproc_lock);
794 pfs_lock(pd);
795
796 /* check if the directory is visible to the caller */
797 if (!pfs_visible(curthread, pd, pid, &proc)) {
798 sx_sunlock(&allproc_lock);
799 pfs_unlock(pd);
800 PFS_RETURN (ENOENT);
801 }
802 KASSERT(pid == NO_PID || proc != NULL,
803 ("%s(): no process for pid %lu", __func__, (unsigned long)pid));
804
805 /* skip unwanted entries */
806 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) {
807 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) {
808 /* nothing left... */
809 if (proc != NULL)
810 PROC_UNLOCK(proc);
811 pfs_unlock(pd);
812 sx_sunlock(&allproc_lock);
813 PFS_RETURN (0);
814 }
815 }
816
817 /* fill in entries */
818 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 &&
819 resid >= PFS_DELEN) {
820 if ((pfsent = malloc(sizeof(struct pfsentry), M_IOV,
821 M_NOWAIT | M_ZERO)) == NULL) {
822 error = ENOMEM;
823 break;
824 }
825 pfsent->entry.d_reclen = PFS_DELEN;
826 pfsent->entry.d_fileno = pn_fileno(pn, pid);
827 /* PFS_DELEN was picked to fit PFS_NAMLEN */
828 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i)
829 pfsent->entry.d_name[i] = pn->pn_name[i];
830 pfsent->entry.d_name[i] = 0;
831 pfsent->entry.d_namlen = i;
832 switch (pn->pn_type) {
833 case pfstype_procdir:
834 KASSERT(p != NULL,
835 ("reached procdir node with p == NULL"));
836 pfsent->entry.d_namlen = snprintf(pfsent->entry.d_name,
837 PFS_NAMELEN, "%d", p->p_pid);
838 /* fall through */
839 case pfstype_root:
840 case pfstype_dir:
841 case pfstype_this:
842 case pfstype_parent:
843 pfsent->entry.d_type = DT_DIR;
844 break;
845 case pfstype_file:
846 pfsent->entry.d_type = DT_REG;
847 break;
848 case pfstype_symlink:
849 pfsent->entry.d_type = DT_LNK;
850 break;
851 default:
852 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type);
853 }
854 PFS_TRACE(("%s", pfsent->entry.d_name));
855 STAILQ_INSERT_TAIL(&lst, pfsent, link);
856 offset += PFS_DELEN;
857 resid -= PFS_DELEN;
858 }
859 if (proc != NULL)
860 PROC_UNLOCK(proc);
861 pfs_unlock(pd);
862 sx_sunlock(&allproc_lock);
863 i = 0;
864 STAILQ_FOREACH_SAFE(pfsent, &lst, link, pfsent2) {
865 if (error == 0)
866 error = uiomove(&pfsent->entry, PFS_DELEN, uio);
867 free(pfsent, M_IOV);
868 i++;
869 }
870 PFS_TRACE(("%d bytes", i * PFS_DELEN));
871 PFS_RETURN (error);
872 }
873
874 /*
875 * Read a symbolic link
876 */
877 static int
878 pfs_readlink(struct vop_readlink_args *va)
879 {
880 struct vnode *vn = va->a_vp;
881 struct pfs_vdata *pvd = vn->v_data;
882 struct pfs_node *pn = pvd->pvd_pn;
883 struct uio *uio = va->a_uio;
884 struct proc *proc = NULL;
885 char buf[PATH_MAX];
886 struct sbuf sb;
887 int error, locked;
888
889 PFS_TRACE(("%s", pn->pn_name));
890 pfs_assert_not_owned(pn);
891
892 if (vn->v_type != VLNK)
893 PFS_RETURN (EINVAL);
894 KASSERT_PN_IS_LINK(pn);
895
896 if (pn->pn_fill == NULL)
897 PFS_RETURN (EIO);
898
899 if (pvd->pvd_pid != NO_PID) {
900 if ((proc = pfind(pvd->pvd_pid)) == NULL)
901 PFS_RETURN (EIO);
902 if (proc->p_flag & P_WEXIT) {
903 PROC_UNLOCK(proc);
904 PFS_RETURN (EIO);
905 }
906 _PHOLD(proc);
907 PROC_UNLOCK(proc);
908 }
909 vhold(vn);
910 locked = VOP_ISLOCKED(vn);
911 VOP_UNLOCK(vn, 0);
912
913 /* sbuf_new() can't fail with a static buffer */
914 sbuf_new(&sb, buf, sizeof buf, 0);
915
916 error = pn_fill(curthread, proc, pn, &sb, NULL);
917
918 if (proc != NULL)
919 PRELE(proc);
920 vn_lock(vn, locked | LK_RETRY);
921 vdrop(vn);
922
923 if (error) {
924 sbuf_delete(&sb);
925 PFS_RETURN (error);
926 }
927
928 if (sbuf_finish(&sb) != 0) {
929 sbuf_delete(&sb);
930 PFS_RETURN (ENAMETOOLONG);
931 }
932
933 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio);
934 sbuf_delete(&sb);
935 PFS_RETURN (error);
936 }
937
938 /*
939 * Reclaim a vnode
940 */
941 static int
942 pfs_reclaim(struct vop_reclaim_args *va)
943 {
944 struct vnode *vn = va->a_vp;
945 struct pfs_vdata *pvd = vn->v_data;
946 struct pfs_node *pn = pvd->pvd_pn;
947
948 PFS_TRACE(("%s", pn->pn_name));
949 pfs_assert_not_owned(pn);
950
951 return (pfs_vncache_free(va->a_vp));
952 }
953
954 /*
955 * Set attributes
956 */
957 static int
958 pfs_setattr(struct vop_setattr_args *va)
959 {
960 struct vnode *vn = va->a_vp;
961 struct pfs_vdata *pvd = vn->v_data;
962 struct pfs_node *pn = pvd->pvd_pn;
963
964 PFS_TRACE(("%s", pn->pn_name));
965 pfs_assert_not_owned(pn);
966
967 PFS_RETURN (EOPNOTSUPP);
968 }
969
970 /*
971 * Write to a file
972 */
973 static int
974 pfs_write(struct vop_write_args *va)
975 {
976 struct vnode *vn = va->a_vp;
977 struct pfs_vdata *pvd = vn->v_data;
978 struct pfs_node *pn = pvd->pvd_pn;
979 struct uio *uio = va->a_uio;
980 struct proc *proc;
981 struct sbuf sb;
982 int error;
983
984 PFS_TRACE(("%s", pn->pn_name));
985 pfs_assert_not_owned(pn);
986
987 if (vn->v_type != VREG)
988 PFS_RETURN (EINVAL);
989 KASSERT_PN_IS_FILE(pn);
990
991 if (!(pn->pn_flags & PFS_WR))
992 PFS_RETURN (EBADF);
993
994 if (pn->pn_fill == NULL)
995 PFS_RETURN (EIO);
996
997 /*
998 * This is necessary because either process' privileges may
999 * have changed since the open() call.
1000 */
1001 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
1002 PFS_RETURN (EIO);
1003 if (proc != NULL) {
1004 _PHOLD(proc);
1005 PROC_UNLOCK(proc);
1006 }
1007
1008 if (pn->pn_flags & PFS_RAWWR) {
1009 error = pn_fill(curthread, proc, pn, NULL, uio);
1010 if (proc != NULL)
1011 PRELE(proc);
1012 PFS_RETURN (error);
1013 }
1014
1015 sbuf_uionew(&sb, uio, &error);
1016 if (error) {
1017 if (proc != NULL)
1018 PRELE(proc);
1019 PFS_RETURN (error);
1020 }
1021
1022 error = pn_fill(curthread, proc, pn, &sb, uio);
1023
1024 sbuf_delete(&sb);
1025 if (proc != NULL)
1026 PRELE(proc);
1027 PFS_RETURN (error);
1028 }
1029
1030 /*
1031 * Vnode operations
1032 */
1033 struct vop_vector pfs_vnodeops = {
1034 .vop_default = &default_vnodeops,
1035
1036 .vop_access = pfs_access,
1037 .vop_cachedlookup = pfs_lookup,
1038 .vop_close = pfs_close,
1039 .vop_create = VOP_EOPNOTSUPP,
1040 .vop_getattr = pfs_getattr,
1041 .vop_getextattr = pfs_getextattr,
1042 .vop_ioctl = pfs_ioctl,
1043 .vop_link = VOP_EOPNOTSUPP,
1044 .vop_lookup = vfs_cache_lookup,
1045 .vop_mkdir = VOP_EOPNOTSUPP,
1046 .vop_mknod = VOP_EOPNOTSUPP,
1047 .vop_open = pfs_open,
1048 .vop_read = pfs_read,
1049 .vop_readdir = pfs_readdir,
1050 .vop_readlink = pfs_readlink,
1051 .vop_reclaim = pfs_reclaim,
1052 .vop_remove = VOP_EOPNOTSUPP,
1053 .vop_rename = VOP_EOPNOTSUPP,
1054 .vop_rmdir = VOP_EOPNOTSUPP,
1055 .vop_setattr = pfs_setattr,
1056 .vop_symlink = VOP_EOPNOTSUPP,
1057 .vop_vptocnp = pfs_vptocnp,
1058 .vop_write = pfs_write,
1059 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */
1060 };
Cache object: 749e97058b23d76411af9f6dcf57aa13
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