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/9.0/sys/fs/pseudofs/pseudofs_vnops.c 206894 2010-04-20 10:19:27Z 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 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 /* parent */
479 if (cnp->cn_flags & ISDOTDOT) {
480 if (pd->pn_type == pfstype_root)
481 PFS_RETURN (EIO);
482 VOP_UNLOCK(vn, 0);
483 KASSERT(pd->pn_parent != NULL,
484 ("%s(): non-root directory has no parent", __func__));
485 /*
486 * This one is tricky. Descendents of procdir nodes
487 * inherit their parent's process affinity, but
488 * there's no easy reverse mapping. For simplicity,
489 * we assume that if this node is a procdir, its
490 * parent isn't (which is correct as long as
491 * descendents of procdir nodes are never procdir
492 * nodes themselves)
493 */
494 if (pd->pn_type == pfstype_procdir)
495 pid = NO_PID;
496 pfs_lock(pd);
497 pn = pd->pn_parent;
498 pfs_unlock(pd);
499 goto got_pnode;
500 }
501
502 pfs_lock(pd);
503
504 /* named node */
505 for (pn = pd->pn_nodes; pn != NULL; pn = pn->pn_next)
506 if (pn->pn_type == pfstype_procdir)
507 pdn = pn;
508 else if (pn->pn_name[namelen] == '\0' &&
509 bcmp(pname, pn->pn_name, namelen) == 0) {
510 pfs_unlock(pd);
511 goto got_pnode;
512 }
513
514 /* process dependent node */
515 if ((pn = pdn) != NULL) {
516 pid = 0;
517 for (pid = 0, i = 0; i < namelen && isdigit(pname[i]); ++i)
518 if ((pid = pid * 10 + pname[i] - '') > PID_MAX)
519 break;
520 if (i == cnp->cn_namelen) {
521 pfs_unlock(pd);
522 goto got_pnode;
523 }
524 }
525
526 pfs_unlock(pd);
527
528 PFS_RETURN (ENOENT);
529
530 got_pnode:
531 pfs_assert_not_owned(pd);
532 pfs_assert_not_owned(pn);
533 visible = pfs_visible(curthread, pn, pid, NULL);
534 if (!visible) {
535 error = ENOENT;
536 goto failed;
537 }
538
539 error = pfs_vncache_alloc(vn->v_mount, vpp, pn, pid);
540 if (error)
541 goto failed;
542
543 if (cnp->cn_flags & ISDOTDOT)
544 vn_lock(vn, LK_EXCLUSIVE|LK_RETRY);
545 if (cnp->cn_flags & MAKEENTRY && !(vn->v_iflag & VI_DOOMED))
546 cache_enter(vn, *vpp, cnp);
547 PFS_RETURN (0);
548 failed:
549 if (cnp->cn_flags & ISDOTDOT)
550 vn_lock(vn, LK_EXCLUSIVE|LK_RETRY);
551 PFS_RETURN(error);
552 }
553
554 /*
555 * Open a file or directory.
556 */
557 static int
558 pfs_open(struct vop_open_args *va)
559 {
560 struct vnode *vn = va->a_vp;
561 struct pfs_vdata *pvd = vn->v_data;
562 struct pfs_node *pn = pvd->pvd_pn;
563 int mode = va->a_mode;
564
565 PFS_TRACE(("%s (mode 0x%x)", pn->pn_name, mode));
566 pfs_assert_not_owned(pn);
567
568 /* check if the requested mode is permitted */
569 if (((mode & FREAD) && !(mode & PFS_RD)) ||
570 ((mode & FWRITE) && !(mode & PFS_WR)))
571 PFS_RETURN (EPERM);
572
573 /* we don't support locking */
574 if ((mode & O_SHLOCK) || (mode & O_EXLOCK))
575 PFS_RETURN (EOPNOTSUPP);
576
577 PFS_RETURN (0);
578 }
579
580 /*
581 * Read from a file
582 */
583 static int
584 pfs_read(struct vop_read_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 struct uio *uio = va->a_uio;
590 struct proc *proc;
591 struct sbuf *sb = NULL;
592 int error, locked;
593 unsigned int buflen, offset, resid;
594
595 PFS_TRACE(("%s", pn->pn_name));
596 pfs_assert_not_owned(pn);
597
598 if (vn->v_type != VREG)
599 PFS_RETURN (EINVAL);
600 KASSERT_PN_IS_FILE(pn);
601
602 if (!(pn->pn_flags & PFS_RD))
603 PFS_RETURN (EBADF);
604
605 if (pn->pn_fill == NULL)
606 PFS_RETURN (EIO);
607
608 /*
609 * This is necessary because either process' privileges may
610 * have changed since the open() call.
611 */
612 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
613 PFS_RETURN (EIO);
614 if (proc != NULL) {
615 _PHOLD(proc);
616 PROC_UNLOCK(proc);
617 }
618
619 vhold(vn);
620 locked = VOP_ISLOCKED(vn);
621 VOP_UNLOCK(vn, 0);
622
623 if (pn->pn_flags & PFS_RAWRD) {
624 PFS_TRACE(("%zd resid", uio->uio_resid));
625 error = pn_fill(curthread, proc, pn, NULL, uio);
626 PFS_TRACE(("%zd resid", uio->uio_resid));
627 goto ret;
628 }
629
630 /* beaucoup sanity checks so we don't ask for bogus allocation */
631 if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
632 (offset = uio->uio_offset) != uio->uio_offset ||
633 (resid = uio->uio_resid) != uio->uio_resid ||
634 (buflen = offset + resid + 1) < offset || buflen > INT_MAX) {
635 if (proc != NULL)
636 PRELE(proc);
637 error = EINVAL;
638 goto ret;
639 }
640 if (buflen > MAXPHYS + 1)
641 buflen = MAXPHYS + 1;
642
643 sb = sbuf_new(sb, NULL, buflen, 0);
644 if (sb == NULL) {
645 error = EIO;
646 goto ret;
647 }
648
649 error = pn_fill(curthread, proc, pn, sb, uio);
650
651 if (error) {
652 sbuf_delete(sb);
653 goto ret;
654 }
655
656 sbuf_finish(sb);
657 error = uiomove_frombuf(sbuf_data(sb), sbuf_len(sb), uio);
658 sbuf_delete(sb);
659 ret:
660 vn_lock(vn, locked | LK_RETRY);
661 vdrop(vn);
662 if (proc != NULL)
663 PRELE(proc);
664 PFS_RETURN (error);
665 }
666
667 /*
668 * Iterate through directory entries
669 */
670 static int
671 pfs_iterate(struct thread *td, struct proc *proc, struct pfs_node *pd,
672 struct pfs_node **pn, struct proc **p)
673 {
674 int visible;
675
676 sx_assert(&allproc_lock, SX_SLOCKED);
677 pfs_assert_owned(pd);
678 again:
679 if (*pn == NULL) {
680 /* first node */
681 *pn = pd->pn_nodes;
682 } else if ((*pn)->pn_type != pfstype_procdir) {
683 /* next node */
684 *pn = (*pn)->pn_next;
685 }
686 if (*pn != NULL && (*pn)->pn_type == pfstype_procdir) {
687 /* next process */
688 if (*p == NULL)
689 *p = LIST_FIRST(&allproc);
690 else
691 *p = LIST_NEXT(*p, p_list);
692 /* out of processes: next node */
693 if (*p == NULL)
694 *pn = (*pn)->pn_next;
695 else
696 PROC_LOCK(*p);
697 }
698
699 if ((*pn) == NULL)
700 return (-1);
701
702 if (*p != NULL) {
703 visible = pfs_visible_proc(td, *pn, *p);
704 PROC_UNLOCK(*p);
705 } else if (proc != NULL) {
706 visible = pfs_visible_proc(td, *pn, proc);
707 } else {
708 visible = 1;
709 }
710 if (!visible)
711 goto again;
712
713 return (0);
714 }
715
716 /*
717 * Return directory entries.
718 */
719 static int
720 pfs_readdir(struct vop_readdir_args *va)
721 {
722 struct vnode *vn = va->a_vp;
723 struct pfs_vdata *pvd = vn->v_data;
724 struct pfs_node *pd = pvd->pvd_pn;
725 pid_t pid = pvd->pvd_pid;
726 struct proc *p, *proc;
727 struct pfs_node *pn;
728 struct dirent *entry;
729 struct uio *uio;
730 off_t offset;
731 int error, i, resid;
732 char *buf, *ent;
733
734 KASSERT(pd->pn_info == vn->v_mount->mnt_data,
735 ("%s(): pn_info does not match mountpoint", __func__));
736 PFS_TRACE(("%s pid %lu", pd->pn_name, (unsigned long)pid));
737 pfs_assert_not_owned(pd);
738
739 if (vn->v_type != VDIR)
740 PFS_RETURN (ENOTDIR);
741 KASSERT_PN_IS_DIR(pd);
742 uio = va->a_uio;
743
744 /* only allow reading entire entries */
745 offset = uio->uio_offset;
746 resid = uio->uio_resid;
747 if (offset < 0 || offset % PFS_DELEN != 0 ||
748 (resid && resid < PFS_DELEN))
749 PFS_RETURN (EINVAL);
750 if (resid == 0)
751 PFS_RETURN (0);
752
753 /* can't do this while holding the proc lock... */
754 buf = malloc(resid, M_IOV, M_WAITOK | M_ZERO);
755 sx_slock(&allproc_lock);
756 pfs_lock(pd);
757
758 /* check if the directory is visible to the caller */
759 if (!pfs_visible(curthread, pd, pid, &proc)) {
760 sx_sunlock(&allproc_lock);
761 pfs_unlock(pd);
762 free(buf, M_IOV);
763 PFS_RETURN (ENOENT);
764 }
765 KASSERT(pid == NO_PID || proc != NULL,
766 ("%s(): no process for pid %lu", __func__, (unsigned long)pid));
767
768 /* skip unwanted entries */
769 for (pn = NULL, p = NULL; offset > 0; offset -= PFS_DELEN) {
770 if (pfs_iterate(curthread, proc, pd, &pn, &p) == -1) {
771 /* nothing left... */
772 if (proc != NULL)
773 PROC_UNLOCK(proc);
774 pfs_unlock(pd);
775 sx_sunlock(&allproc_lock);
776 free(buf, M_IOV);
777 PFS_RETURN (0);
778 }
779 }
780
781 /* fill in entries */
782 ent = buf;
783 while (pfs_iterate(curthread, proc, pd, &pn, &p) != -1 &&
784 resid >= PFS_DELEN) {
785 entry = (struct dirent *)ent;
786 entry->d_reclen = PFS_DELEN;
787 entry->d_fileno = pn_fileno(pn, pid);
788 /* PFS_DELEN was picked to fit PFS_NAMLEN */
789 for (i = 0; i < PFS_NAMELEN - 1 && pn->pn_name[i] != '\0'; ++i)
790 entry->d_name[i] = pn->pn_name[i];
791 entry->d_name[i] = 0;
792 entry->d_namlen = i;
793 switch (pn->pn_type) {
794 case pfstype_procdir:
795 KASSERT(p != NULL,
796 ("reached procdir node with p == NULL"));
797 entry->d_namlen = snprintf(entry->d_name,
798 PFS_NAMELEN, "%d", p->p_pid);
799 /* fall through */
800 case pfstype_root:
801 case pfstype_dir:
802 case pfstype_this:
803 case pfstype_parent:
804 entry->d_type = DT_DIR;
805 break;
806 case pfstype_file:
807 entry->d_type = DT_REG;
808 break;
809 case pfstype_symlink:
810 entry->d_type = DT_LNK;
811 break;
812 default:
813 panic("%s has unexpected node type: %d", pn->pn_name, pn->pn_type);
814 }
815 PFS_TRACE(("%s", entry->d_name));
816 offset += PFS_DELEN;
817 resid -= PFS_DELEN;
818 ent += PFS_DELEN;
819 }
820 if (proc != NULL)
821 PROC_UNLOCK(proc);
822 pfs_unlock(pd);
823 sx_sunlock(&allproc_lock);
824 PFS_TRACE(("%zd bytes", ent - buf));
825 error = uiomove(buf, ent - buf, uio);
826 free(buf, M_IOV);
827 PFS_RETURN (error);
828 }
829
830 /*
831 * Read a symbolic link
832 */
833 static int
834 pfs_readlink(struct vop_readlink_args *va)
835 {
836 struct vnode *vn = va->a_vp;
837 struct pfs_vdata *pvd = vn->v_data;
838 struct pfs_node *pn = pvd->pvd_pn;
839 struct uio *uio = va->a_uio;
840 struct proc *proc = NULL;
841 char buf[PATH_MAX];
842 struct sbuf sb;
843 int error, locked;
844
845 PFS_TRACE(("%s", pn->pn_name));
846 pfs_assert_not_owned(pn);
847
848 if (vn->v_type != VLNK)
849 PFS_RETURN (EINVAL);
850 KASSERT_PN_IS_LINK(pn);
851
852 if (pn->pn_fill == NULL)
853 PFS_RETURN (EIO);
854
855 if (pvd->pvd_pid != NO_PID) {
856 if ((proc = pfind(pvd->pvd_pid)) == NULL)
857 PFS_RETURN (EIO);
858 if (proc->p_flag & P_WEXIT) {
859 PROC_UNLOCK(proc);
860 PFS_RETURN (EIO);
861 }
862 _PHOLD(proc);
863 PROC_UNLOCK(proc);
864 }
865 vhold(vn);
866 locked = VOP_ISLOCKED(vn);
867 VOP_UNLOCK(vn, 0);
868
869 /* sbuf_new() can't fail with a static buffer */
870 sbuf_new(&sb, buf, sizeof buf, 0);
871
872 error = pn_fill(curthread, proc, pn, &sb, NULL);
873
874 if (proc != NULL)
875 PRELE(proc);
876 vn_lock(vn, locked | LK_RETRY);
877 vdrop(vn);
878
879 if (error) {
880 sbuf_delete(&sb);
881 PFS_RETURN (error);
882 }
883
884 sbuf_finish(&sb);
885 error = uiomove_frombuf(sbuf_data(&sb), sbuf_len(&sb), uio);
886 sbuf_delete(&sb);
887 PFS_RETURN (error);
888 }
889
890 /*
891 * Reclaim a vnode
892 */
893 static int
894 pfs_reclaim(struct vop_reclaim_args *va)
895 {
896 struct vnode *vn = va->a_vp;
897 struct pfs_vdata *pvd = vn->v_data;
898 struct pfs_node *pn = pvd->pvd_pn;
899
900 PFS_TRACE(("%s", pn->pn_name));
901 pfs_assert_not_owned(pn);
902
903 return (pfs_vncache_free(va->a_vp));
904 }
905
906 /*
907 * Set attributes
908 */
909 static int
910 pfs_setattr(struct vop_setattr_args *va)
911 {
912 struct vnode *vn = va->a_vp;
913 struct pfs_vdata *pvd = vn->v_data;
914 struct pfs_node *pn = pvd->pvd_pn;
915
916 PFS_TRACE(("%s", pn->pn_name));
917 pfs_assert_not_owned(pn);
918
919 PFS_RETURN (EOPNOTSUPP);
920 }
921
922 /*
923 * Write to a file
924 */
925 static int
926 pfs_write(struct vop_write_args *va)
927 {
928 struct vnode *vn = va->a_vp;
929 struct pfs_vdata *pvd = vn->v_data;
930 struct pfs_node *pn = pvd->pvd_pn;
931 struct uio *uio = va->a_uio;
932 struct proc *proc;
933 struct sbuf sb;
934 int error;
935
936 PFS_TRACE(("%s", pn->pn_name));
937 pfs_assert_not_owned(pn);
938
939 if (vn->v_type != VREG)
940 PFS_RETURN (EINVAL);
941 KASSERT_PN_IS_FILE(pn);
942
943 if (!(pn->pn_flags & PFS_WR))
944 PFS_RETURN (EBADF);
945
946 if (pn->pn_fill == NULL)
947 PFS_RETURN (EIO);
948
949 /*
950 * This is necessary because either process' privileges may
951 * have changed since the open() call.
952 */
953 if (!pfs_visible(curthread, pn, pvd->pvd_pid, &proc))
954 PFS_RETURN (EIO);
955 if (proc != NULL) {
956 _PHOLD(proc);
957 PROC_UNLOCK(proc);
958 }
959
960 if (pn->pn_flags & PFS_RAWWR) {
961 error = pn_fill(curthread, proc, pn, NULL, uio);
962 if (proc != NULL)
963 PRELE(proc);
964 PFS_RETURN (error);
965 }
966
967 sbuf_uionew(&sb, uio, &error);
968 if (error) {
969 if (proc != NULL)
970 PRELE(proc);
971 PFS_RETURN (error);
972 }
973
974 error = pn_fill(curthread, proc, pn, &sb, uio);
975
976 sbuf_delete(&sb);
977 if (proc != NULL)
978 PRELE(proc);
979 PFS_RETURN (error);
980 }
981
982 /*
983 * Vnode operations
984 */
985 struct vop_vector pfs_vnodeops = {
986 .vop_default = &default_vnodeops,
987
988 .vop_access = pfs_access,
989 .vop_cachedlookup = pfs_lookup,
990 .vop_close = pfs_close,
991 .vop_create = VOP_EOPNOTSUPP,
992 .vop_getattr = pfs_getattr,
993 .vop_getextattr = pfs_getextattr,
994 .vop_ioctl = pfs_ioctl,
995 .vop_link = VOP_EOPNOTSUPP,
996 .vop_lookup = vfs_cache_lookup,
997 .vop_mkdir = VOP_EOPNOTSUPP,
998 .vop_mknod = VOP_EOPNOTSUPP,
999 .vop_open = pfs_open,
1000 .vop_read = pfs_read,
1001 .vop_readdir = pfs_readdir,
1002 .vop_readlink = pfs_readlink,
1003 .vop_reclaim = pfs_reclaim,
1004 .vop_remove = VOP_EOPNOTSUPP,
1005 .vop_rename = VOP_EOPNOTSUPP,
1006 .vop_rmdir = VOP_EOPNOTSUPP,
1007 .vop_setattr = pfs_setattr,
1008 .vop_symlink = VOP_EOPNOTSUPP,
1009 .vop_vptocnp = pfs_vptocnp,
1010 .vop_write = pfs_write,
1011 /* XXX I've probably forgotten a few that need VOP_EOPNOTSUPP */
1012 };
Cache object: cae56346e47f6e3784661a453c48a5b4
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