1/*-
2 * Copyright (c) 2000,2004
3 * Poul-Henning Kamp. 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 * 2. Neither the name of the University nor the names of its contributors
11 * may be used to endorse or promote products derived from this software
12 * without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
27 *
28 * $FreeBSD: head/sys/fs/devfs/devfs_devs.c 207729 2010-05-06 19:22:50Z kib $
29 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/conf.h>
34#include <sys/dirent.h>
35#include <sys/kernel.h>
36#include <sys/limits.h>
37#include <sys/lock.h>
38#include <sys/malloc.h>
39#include <sys/proc.h>
40#include <sys/sx.h>
41#include <sys/sysctl.h>
42#include <sys/vnode.h>
43
44#include <sys/kdb.h>
45
46#include <fs/devfs/devfs.h>
47#include <fs/devfs/devfs_int.h>
48
49#include <security/mac/mac_framework.h>
50
51/*
52 * The one true (but secret) list of active devices in the system.
53 * Locked by dev_lock()/devmtx
54 */
55struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
56
57struct unrhdr *devfs_inos;
58
59
60static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
61static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
62static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
63
64static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
65
66static unsigned devfs_generation;
67SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
68 &devfs_generation, 0, "DEVFS generation number");
69
70unsigned devfs_rule_depth = 1;
71SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW,
72 &devfs_rule_depth, 0, "Max depth of ruleset include");
73
74/*
75 * Helper sysctl for devname(3). We're given a dev_t and return the
76 * name, if any, registered by the device driver.
77 */
78static int
79sysctl_devname(SYSCTL_HANDLER_ARGS)
80{
81 int error;
82 dev_t ud;
83 struct cdev_priv *cdp;
84 struct cdev *dev;
85
86 error = SYSCTL_IN(req, &ud, sizeof (ud));
87 if (error)
88 return (error);
89 if (ud == NODEV)
90 return (EINVAL);
91 dev = NULL;
92 dev_lock();
93 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
94 if (cdp->cdp_inode == ud) {
95 dev = &cdp->cdp_c;
96 dev_refl(dev);
97 break;
98 }
99 dev_unlock();
100 if (dev == NULL)
101 return (ENOENT);
102 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
103 dev_rel(dev);
104 return (error);
105}
106
107SYSCTL_PROC(_kern, OID_AUTO, devname,
108 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
109 NULL, 0, sysctl_devname, "", "devname(3) handler");
110
111SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
112 0, sizeof(struct cdev), "sizeof(struct cdev)");
113
114SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
115 0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
116
117struct cdev *
118devfs_alloc(int flags)
119{
120 struct cdev_priv *cdp;
121 struct cdev *cdev;
122 struct timespec ts;
123
124 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO |
125 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
126 if (cdp == NULL)
127 return (NULL);
128
129 cdp->cdp_dirents = &cdp->cdp_dirent0;
130 cdp->cdp_dirent0 = NULL;
131 cdp->cdp_maxdirent = 0;
132 cdp->cdp_inode = 0;
133
134 cdev = &cdp->cdp_c;
135
136 cdev->si_name = cdev->__si_namebuf;
137 LIST_INIT(&cdev->si_children);
138 vfs_timestamp(&ts);
139 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
140 cdev->si_cred = NULL;
141
142 return (cdev);
143}
144
145void
146devfs_free(struct cdev *cdev)
147{
148 struct cdev_priv *cdp;
149
150 cdp = cdev2priv(cdev);
151 if (cdev->si_cred != NULL)
152 crfree(cdev->si_cred);
153 if (cdp->cdp_inode > 0)
154 free_unr(devfs_inos, cdp->cdp_inode);
155 if (cdp->cdp_maxdirent > 0)
156 free(cdp->cdp_dirents, M_DEVFS2);
157 free(cdp, M_CDEVP);
158}
159
160struct devfs_dirent *
161devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
162{
163 struct devfs_dirent *de;
164
165 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
166 if (namelen != de->de_dirent->d_namlen)
167 continue;
168 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
169 continue;
170 break;
171 }
172 return (de);
173}
174
175struct devfs_dirent *
176devfs_newdirent(char *name, int namelen)
177{
178 int i;
179 struct devfs_dirent *de;
180 struct dirent d;
181
182 d.d_namlen = namelen;
183 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
184 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
185 de->de_dirent = (struct dirent *)(de + 1);
186 de->de_dirent->d_namlen = namelen;
187 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
188 bcopy(name, de->de_dirent->d_name, namelen);
189 de->de_dirent->d_name[namelen] = '\0';
190 vfs_timestamp(&de->de_ctime);
191 de->de_mtime = de->de_atime = de->de_ctime;
192 de->de_links = 1;
193 de->de_holdcnt = 1;
194#ifdef MAC
195 mac_devfs_init(de);
196#endif
197 return (de);
198}
199
200struct devfs_dirent *
201devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
202{
203 struct devfs_dirent *dd;
204 struct devfs_dirent *de;
205
206 /* Create the new directory */
207 dd = devfs_newdirent(name, namelen);
208 TAILQ_INIT(&dd->de_dlist);
209 dd->de_dirent->d_type = DT_DIR;
210 dd->de_mode = 0555;
211 dd->de_links = 2;
212 dd->de_dir = dd;
213 if (inode != 0)
214 dd->de_inode = inode;
215 else
216 dd->de_inode = alloc_unr(devfs_inos);
217
218 /* Create the "." entry in the new directory */
219 de = devfs_newdirent(".", 1);
220 de->de_dirent->d_type = DT_DIR;
221 de->de_flags |= DE_DOT;
222 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
223 de->de_dir = dd;
224
225 /* Create the ".." entry in the new directory */
226 de = devfs_newdirent("..", 2);
227 de->de_dirent->d_type = DT_DIR;
228 de->de_flags |= DE_DOTDOT;
229 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
230 if (dotdot == NULL) {
231 de->de_dir = dd;
232 } else {
233 de->de_dir = dotdot;
234 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
235 dotdot->de_links++;
236 }
237
238#ifdef MAC
239 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
240#endif
241 return (dd);
242}
243
244void
245devfs_dirent_free(struct devfs_dirent *de)
246{
247 free(de, M_DEVFS3);
248}
249
250/*
251 * The caller needs to hold the dm for the duration of the call since
252 * dm->dm_lock may be temporary dropped.
253 */
254void
255devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
256{
257 struct vnode *vp;
258
259 KASSERT((de->de_flags & DE_DOOMED) == 0,
260 ("devfs_delete doomed dirent"));
261 de->de_flags |= DE_DOOMED;
262 mtx_lock(&devfs_de_interlock);
263 vp = de->de_vnode;
264 if (vp != NULL) {
265 VI_LOCK(vp);
266 mtx_unlock(&devfs_de_interlock);
267 vholdl(vp);
268 sx_unlock(&dm->dm_lock);
269 if (!vp_locked)
270 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
271 else
272 VI_UNLOCK(vp);
273 vgone(vp);
274 if (!vp_locked)
275 VOP_UNLOCK(vp, 0);
276 vdrop(vp);
277 sx_xlock(&dm->dm_lock);
278 } else
279 mtx_unlock(&devfs_de_interlock);
280 if (de->de_symlink) {
281 free(de->de_symlink, M_DEVFS);
282 de->de_symlink = NULL;
283 }
284#ifdef MAC
285 mac_devfs_destroy(de);
286#endif
287 if (de->de_inode > DEVFS_ROOTINO) {
288 free_unr(devfs_inos, de->de_inode);
289 de->de_inode = 0;
290 }
291 if (DEVFS_DE_DROP(de))
292 devfs_dirent_free(de);
293}
294
295/*
296 * Called on unmount.
297 * Recursively removes the entire tree.
298 * The caller needs to hold the dm for the duration of the call.
299 */
300
301static void
302devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
303{
304 struct devfs_dirent *de;
305
306 sx_assert(&dm->dm_lock, SX_XLOCKED);
307 for (;;) {
308 de = TAILQ_FIRST(&dd->de_dlist);
309 if (de == NULL)
310 break;
311 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
312 if (de->de_flags & (DE_DOT|DE_DOTDOT))
313 devfs_delete(dm, de, 0);
314 else if (de->de_dirent->d_type == DT_DIR)
315 devfs_purge(dm, de);
316 else
317 devfs_delete(dm, de, 0);
318 }
319 devfs_delete(dm, dd, 0);
320}
321
322/*
323 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
324 * by the mount points dm_idx.
325 * This function extends the array when necessary, taking into account that
326 * the default array is 1 element and not malloc'ed.
327 */
328static void
329devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
330{
331 struct devfs_dirent **dep;
332 int siz;
333
334 siz = (dm->dm_idx + 1) * sizeof *dep;
335 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
336 dev_lock();
337 if (dm->dm_idx <= cdp->cdp_maxdirent) {
338 /* We got raced */
339 dev_unlock();
340 free(dep, M_DEVFS2);
341 return;
342 }
343 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
344 if (cdp->cdp_maxdirent > 0)
345 free(cdp->cdp_dirents, M_DEVFS2);
346 cdp->cdp_dirents = dep;
347 /*
348 * XXX: if malloc told us how much we actually got this could
349 * XXX: be optimized.
350 */
351 cdp->cdp_maxdirent = dm->dm_idx;
352 dev_unlock();
353}
354
355/*
356 * The caller needs to hold the dm for the duration of the call.
357 */
358static int
359devfs_populate_loop(struct devfs_mount *dm, int cleanup)
360{
361 struct cdev_priv *cdp;
362 struct devfs_dirent *de;
363 struct devfs_dirent *dd;
364 struct cdev *pdev;
365 int j;
366 char *q, *s;
367
368 sx_assert(&dm->dm_lock, SX_XLOCKED);
369 dev_lock();
370 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
371
372 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
373
374 /*
375 * If we are unmounting, or the device has been destroyed,
376 * clean up our dirent.
377 */
378 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
379 dm->dm_idx <= cdp->cdp_maxdirent &&
380 cdp->cdp_dirents[dm->dm_idx] != NULL) {
381 de = cdp->cdp_dirents[dm->dm_idx];
382 cdp->cdp_dirents[dm->dm_idx] = NULL;
383 KASSERT(cdp == de->de_cdp,
384 ("%s %d %s %p %p", __func__, __LINE__,
385 cdp->cdp_c.si_name, cdp, de->de_cdp));
386 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
387 dev_unlock();
388
389 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
390 de->de_cdp = NULL;
391 de->de_inode = 0;
392 devfs_delete(dm, de, 0);
393 dev_lock();
394 cdp->cdp_inuse--;
395 dev_unlock();
396 return (1);
397 }
398 /*
399 * GC any lingering devices
400 */
401 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
402 if (cdp->cdp_inuse > 0)
403 continue;
404 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
405 dev_unlock();
406 dev_rel(&cdp->cdp_c);
407 return (1);
408 }
409 /*
410 * Don't create any new dirents if we are unmounting
411 */
412 if (cleanup)
413 continue;
414 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
415
416 if (dm->dm_idx <= cdp->cdp_maxdirent &&
417 cdp->cdp_dirents[dm->dm_idx] != NULL) {
418 de = cdp->cdp_dirents[dm->dm_idx];
419 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
420 continue;
421 }
422
423
424 cdp->cdp_inuse++;
425 dev_unlock();
426
427 if (dm->dm_idx > cdp->cdp_maxdirent)
428 devfs_metoo(cdp, dm);
429
430 dd = dm->dm_rootdir;
431 s = cdp->cdp_c.si_name;
432 for (;;) {
433 for (q = s; *q != '/' && *q != '\0'; q++)
434 continue;
435 if (*q != '/')
436 break;
437 de = devfs_find(dd, s, q - s);
438 if (de == NULL)
439 de = devfs_vmkdir(dm, s, q - s, dd, 0);
440 s = q + 1;
441 dd = de;
442 }
443
444 de = devfs_newdirent(s, q - s);
445 if (cdp->cdp_c.si_flags & SI_ALIAS) {
446 de->de_uid = 0;
447 de->de_gid = 0;
448 de->de_mode = 0755;
449 de->de_dirent->d_type = DT_LNK;
450 pdev = cdp->cdp_c.si_parent;
451 j = strlen(pdev->si_name) + 1;
452 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
453 bcopy(pdev->si_name, de->de_symlink, j);
454 } else {
455 de->de_uid = cdp->cdp_c.si_uid;
456 de->de_gid = cdp->cdp_c.si_gid;
457 de->de_mode = cdp->cdp_c.si_mode;
458 de->de_dirent->d_type = DT_CHR;
459 }
460 de->de_inode = cdp->cdp_inode;
461 de->de_cdp = cdp;
462#ifdef MAC
463 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
464 &cdp->cdp_c, de);
465#endif
466 de->de_dir = dd;
467 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
468 devfs_rules_apply(dm, de);
469 dev_lock();
470 /* XXX: could check that cdp is still active here */
471 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
472 ("%s %d\n", __func__, __LINE__));
473 cdp->cdp_dirents[dm->dm_idx] = de;
474 KASSERT(de->de_cdp != (void *)0xdeadc0de,
475 ("%s %d\n", __func__, __LINE__));
476 dev_unlock();
477 return (1);
478 }
479 dev_unlock();
480 return (0);
481}
482
483/*
484 * The caller needs to hold the dm for the duration of the call.
485 */
486void
487devfs_populate(struct devfs_mount *dm)
488{
489
490 sx_assert(&dm->dm_lock, SX_XLOCKED);
491 if (dm->dm_generation == devfs_generation)
492 return;
493 while (devfs_populate_loop(dm, 0))
494 continue;
495 dm->dm_generation = devfs_generation;
496}
497
498/*
499 * The caller needs to hold the dm for the duration of the call.
500 */
501void
502devfs_cleanup(struct devfs_mount *dm)
503{
504
505 sx_assert(&dm->dm_lock, SX_XLOCKED);
506 while (devfs_populate_loop(dm, 1))
507 continue;
508 devfs_purge(dm, dm->dm_rootdir);
509}
510
511/*
512 * devfs_create() and devfs_destroy() are called from kern_conf.c and
513 * in both cases the devlock() mutex is held, so no further locking
514 * is necesary and no sleeping allowed.
515 */
516
517void
518devfs_create(struct cdev *dev)
519{
520 struct cdev_priv *cdp;
521
522 mtx_assert(&devmtx, MA_OWNED);
523 cdp = cdev2priv(dev);
524 cdp->cdp_flags |= CDP_ACTIVE;
525 cdp->cdp_inode = alloc_unrl(devfs_inos);
526 dev_refl(dev);
527 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
528 devfs_generation++;
529}
530
531void
532devfs_destroy(struct cdev *dev)
533{
534 struct cdev_priv *cdp;
535
536 mtx_assert(&devmtx, MA_OWNED);
537 cdp = cdev2priv(dev);
538 cdp->cdp_flags &= ~CDP_ACTIVE;
539 devfs_generation++;
540}
541
542static void
543devfs_devs_init(void *junk __unused)
544{
545
546 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
547}
548
549SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);
2 * Copyright (c) 2000,2004
3 * Poul-Henning Kamp. 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 * 2. Neither the name of the University nor the names of its contributors
11 * may be used to endorse or promote products derived from this software
12 * without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
27 *
28 * $FreeBSD: head/sys/fs/devfs/devfs_devs.c 207729 2010-05-06 19:22:50Z kib $
29 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/conf.h>
34#include <sys/dirent.h>
35#include <sys/kernel.h>
36#include <sys/limits.h>
37#include <sys/lock.h>
38#include <sys/malloc.h>
39#include <sys/proc.h>
40#include <sys/sx.h>
41#include <sys/sysctl.h>
42#include <sys/vnode.h>
43
44#include <sys/kdb.h>
45
46#include <fs/devfs/devfs.h>
47#include <fs/devfs/devfs_int.h>
48
49#include <security/mac/mac_framework.h>
50
51/*
52 * The one true (but secret) list of active devices in the system.
53 * Locked by dev_lock()/devmtx
54 */
55struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
56
57struct unrhdr *devfs_inos;
58
59
60static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
61static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
62static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
63
64static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
65
66static unsigned devfs_generation;
67SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
68 &devfs_generation, 0, "DEVFS generation number");
69
70unsigned devfs_rule_depth = 1;
71SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW,
72 &devfs_rule_depth, 0, "Max depth of ruleset include");
73
74/*
75 * Helper sysctl for devname(3). We're given a dev_t and return the
76 * name, if any, registered by the device driver.
77 */
78static int
79sysctl_devname(SYSCTL_HANDLER_ARGS)
80{
81 int error;
82 dev_t ud;
83 struct cdev_priv *cdp;
84 struct cdev *dev;
85
86 error = SYSCTL_IN(req, &ud, sizeof (ud));
87 if (error)
88 return (error);
89 if (ud == NODEV)
90 return (EINVAL);
91 dev = NULL;
92 dev_lock();
93 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
94 if (cdp->cdp_inode == ud) {
95 dev = &cdp->cdp_c;
96 dev_refl(dev);
97 break;
98 }
99 dev_unlock();
100 if (dev == NULL)
101 return (ENOENT);
102 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
103 dev_rel(dev);
104 return (error);
105}
106
107SYSCTL_PROC(_kern, OID_AUTO, devname,
108 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY|CTLFLAG_MPSAFE,
109 NULL, 0, sysctl_devname, "", "devname(3) handler");
110
111SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
112 0, sizeof(struct cdev), "sizeof(struct cdev)");
113
114SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
115 0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
116
117struct cdev *
118devfs_alloc(int flags)
119{
120 struct cdev_priv *cdp;
121 struct cdev *cdev;
122 struct timespec ts;
123
124 cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO |
125 ((flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK));
126 if (cdp == NULL)
127 return (NULL);
128
129 cdp->cdp_dirents = &cdp->cdp_dirent0;
130 cdp->cdp_dirent0 = NULL;
131 cdp->cdp_maxdirent = 0;
132 cdp->cdp_inode = 0;
133
134 cdev = &cdp->cdp_c;
135
136 cdev->si_name = cdev->__si_namebuf;
137 LIST_INIT(&cdev->si_children);
138 vfs_timestamp(&ts);
139 cdev->si_atime = cdev->si_mtime = cdev->si_ctime = ts;
140 cdev->si_cred = NULL;
141
142 return (cdev);
143}
144
145void
146devfs_free(struct cdev *cdev)
147{
148 struct cdev_priv *cdp;
149
150 cdp = cdev2priv(cdev);
151 if (cdev->si_cred != NULL)
152 crfree(cdev->si_cred);
153 if (cdp->cdp_inode > 0)
154 free_unr(devfs_inos, cdp->cdp_inode);
155 if (cdp->cdp_maxdirent > 0)
156 free(cdp->cdp_dirents, M_DEVFS2);
157 free(cdp, M_CDEVP);
158}
159
160struct devfs_dirent *
161devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
162{
163 struct devfs_dirent *de;
164
165 TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
166 if (namelen != de->de_dirent->d_namlen)
167 continue;
168 if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
169 continue;
170 break;
171 }
172 return (de);
173}
174
175struct devfs_dirent *
176devfs_newdirent(char *name, int namelen)
177{
178 int i;
179 struct devfs_dirent *de;
180 struct dirent d;
181
182 d.d_namlen = namelen;
183 i = sizeof (*de) + GENERIC_DIRSIZ(&d);
184 de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
185 de->de_dirent = (struct dirent *)(de + 1);
186 de->de_dirent->d_namlen = namelen;
187 de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
188 bcopy(name, de->de_dirent->d_name, namelen);
189 de->de_dirent->d_name[namelen] = '\0';
190 vfs_timestamp(&de->de_ctime);
191 de->de_mtime = de->de_atime = de->de_ctime;
192 de->de_links = 1;
193 de->de_holdcnt = 1;
194#ifdef MAC
195 mac_devfs_init(de);
196#endif
197 return (de);
198}
199
200struct devfs_dirent *
201devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
202{
203 struct devfs_dirent *dd;
204 struct devfs_dirent *de;
205
206 /* Create the new directory */
207 dd = devfs_newdirent(name, namelen);
208 TAILQ_INIT(&dd->de_dlist);
209 dd->de_dirent->d_type = DT_DIR;
210 dd->de_mode = 0555;
211 dd->de_links = 2;
212 dd->de_dir = dd;
213 if (inode != 0)
214 dd->de_inode = inode;
215 else
216 dd->de_inode = alloc_unr(devfs_inos);
217
218 /* Create the "." entry in the new directory */
219 de = devfs_newdirent(".", 1);
220 de->de_dirent->d_type = DT_DIR;
221 de->de_flags |= DE_DOT;
222 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
223 de->de_dir = dd;
224
225 /* Create the ".." entry in the new directory */
226 de = devfs_newdirent("..", 2);
227 de->de_dirent->d_type = DT_DIR;
228 de->de_flags |= DE_DOTDOT;
229 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
230 if (dotdot == NULL) {
231 de->de_dir = dd;
232 } else {
233 de->de_dir = dotdot;
234 TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
235 dotdot->de_links++;
236 }
237
238#ifdef MAC
239 mac_devfs_create_directory(dmp->dm_mount, name, namelen, dd);
240#endif
241 return (dd);
242}
243
244void
245devfs_dirent_free(struct devfs_dirent *de)
246{
247 free(de, M_DEVFS3);
248}
249
250/*
251 * The caller needs to hold the dm for the duration of the call since
252 * dm->dm_lock may be temporary dropped.
253 */
254void
255devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
256{
257 struct vnode *vp;
258
259 KASSERT((de->de_flags & DE_DOOMED) == 0,
260 ("devfs_delete doomed dirent"));
261 de->de_flags |= DE_DOOMED;
262 mtx_lock(&devfs_de_interlock);
263 vp = de->de_vnode;
264 if (vp != NULL) {
265 VI_LOCK(vp);
266 mtx_unlock(&devfs_de_interlock);
267 vholdl(vp);
268 sx_unlock(&dm->dm_lock);
269 if (!vp_locked)
270 vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
271 else
272 VI_UNLOCK(vp);
273 vgone(vp);
274 if (!vp_locked)
275 VOP_UNLOCK(vp, 0);
276 vdrop(vp);
277 sx_xlock(&dm->dm_lock);
278 } else
279 mtx_unlock(&devfs_de_interlock);
280 if (de->de_symlink) {
281 free(de->de_symlink, M_DEVFS);
282 de->de_symlink = NULL;
283 }
284#ifdef MAC
285 mac_devfs_destroy(de);
286#endif
287 if (de->de_inode > DEVFS_ROOTINO) {
288 free_unr(devfs_inos, de->de_inode);
289 de->de_inode = 0;
290 }
291 if (DEVFS_DE_DROP(de))
292 devfs_dirent_free(de);
293}
294
295/*
296 * Called on unmount.
297 * Recursively removes the entire tree.
298 * The caller needs to hold the dm for the duration of the call.
299 */
300
301static void
302devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
303{
304 struct devfs_dirent *de;
305
306 sx_assert(&dm->dm_lock, SX_XLOCKED);
307 for (;;) {
308 de = TAILQ_FIRST(&dd->de_dlist);
309 if (de == NULL)
310 break;
311 TAILQ_REMOVE(&dd->de_dlist, de, de_list);
312 if (de->de_flags & (DE_DOT|DE_DOTDOT))
313 devfs_delete(dm, de, 0);
314 else if (de->de_dirent->d_type == DT_DIR)
315 devfs_purge(dm, de);
316 else
317 devfs_delete(dm, de, 0);
318 }
319 devfs_delete(dm, dd, 0);
320}
321
322/*
323 * Each cdev_priv has an array of pointers to devfs_dirent which is indexed
324 * by the mount points dm_idx.
325 * This function extends the array when necessary, taking into account that
326 * the default array is 1 element and not malloc'ed.
327 */
328static void
329devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
330{
331 struct devfs_dirent **dep;
332 int siz;
333
334 siz = (dm->dm_idx + 1) * sizeof *dep;
335 dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
336 dev_lock();
337 if (dm->dm_idx <= cdp->cdp_maxdirent) {
338 /* We got raced */
339 dev_unlock();
340 free(dep, M_DEVFS2);
341 return;
342 }
343 memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
344 if (cdp->cdp_maxdirent > 0)
345 free(cdp->cdp_dirents, M_DEVFS2);
346 cdp->cdp_dirents = dep;
347 /*
348 * XXX: if malloc told us how much we actually got this could
349 * XXX: be optimized.
350 */
351 cdp->cdp_maxdirent = dm->dm_idx;
352 dev_unlock();
353}
354
355/*
356 * The caller needs to hold the dm for the duration of the call.
357 */
358static int
359devfs_populate_loop(struct devfs_mount *dm, int cleanup)
360{
361 struct cdev_priv *cdp;
362 struct devfs_dirent *de;
363 struct devfs_dirent *dd;
364 struct cdev *pdev;
365 int j;
366 char *q, *s;
367
368 sx_assert(&dm->dm_lock, SX_XLOCKED);
369 dev_lock();
370 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
371
372 KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
373
374 /*
375 * If we are unmounting, or the device has been destroyed,
376 * clean up our dirent.
377 */
378 if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
379 dm->dm_idx <= cdp->cdp_maxdirent &&
380 cdp->cdp_dirents[dm->dm_idx] != NULL) {
381 de = cdp->cdp_dirents[dm->dm_idx];
382 cdp->cdp_dirents[dm->dm_idx] = NULL;
383 KASSERT(cdp == de->de_cdp,
384 ("%s %d %s %p %p", __func__, __LINE__,
385 cdp->cdp_c.si_name, cdp, de->de_cdp));
386 KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
387 dev_unlock();
388
389 TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
390 de->de_cdp = NULL;
391 de->de_inode = 0;
392 devfs_delete(dm, de, 0);
393 dev_lock();
394 cdp->cdp_inuse--;
395 dev_unlock();
396 return (1);
397 }
398 /*
399 * GC any lingering devices
400 */
401 if (!(cdp->cdp_flags & CDP_ACTIVE)) {
402 if (cdp->cdp_inuse > 0)
403 continue;
404 TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
405 dev_unlock();
406 dev_rel(&cdp->cdp_c);
407 return (1);
408 }
409 /*
410 * Don't create any new dirents if we are unmounting
411 */
412 if (cleanup)
413 continue;
414 KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
415
416 if (dm->dm_idx <= cdp->cdp_maxdirent &&
417 cdp->cdp_dirents[dm->dm_idx] != NULL) {
418 de = cdp->cdp_dirents[dm->dm_idx];
419 KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
420 continue;
421 }
422
423
424 cdp->cdp_inuse++;
425 dev_unlock();
426
427 if (dm->dm_idx > cdp->cdp_maxdirent)
428 devfs_metoo(cdp, dm);
429
430 dd = dm->dm_rootdir;
431 s = cdp->cdp_c.si_name;
432 for (;;) {
433 for (q = s; *q != '/' && *q != '\0'; q++)
434 continue;
435 if (*q != '/')
436 break;
437 de = devfs_find(dd, s, q - s);
438 if (de == NULL)
439 de = devfs_vmkdir(dm, s, q - s, dd, 0);
440 s = q + 1;
441 dd = de;
442 }
443
444 de = devfs_newdirent(s, q - s);
445 if (cdp->cdp_c.si_flags & SI_ALIAS) {
446 de->de_uid = 0;
447 de->de_gid = 0;
448 de->de_mode = 0755;
449 de->de_dirent->d_type = DT_LNK;
450 pdev = cdp->cdp_c.si_parent;
451 j = strlen(pdev->si_name) + 1;
452 de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
453 bcopy(pdev->si_name, de->de_symlink, j);
454 } else {
455 de->de_uid = cdp->cdp_c.si_uid;
456 de->de_gid = cdp->cdp_c.si_gid;
457 de->de_mode = cdp->cdp_c.si_mode;
458 de->de_dirent->d_type = DT_CHR;
459 }
460 de->de_inode = cdp->cdp_inode;
461 de->de_cdp = cdp;
462#ifdef MAC
463 mac_devfs_create_device(cdp->cdp_c.si_cred, dm->dm_mount,
464 &cdp->cdp_c, de);
465#endif
466 de->de_dir = dd;
467 TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
468 devfs_rules_apply(dm, de);
469 dev_lock();
470 /* XXX: could check that cdp is still active here */
471 KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
472 ("%s %d\n", __func__, __LINE__));
473 cdp->cdp_dirents[dm->dm_idx] = de;
474 KASSERT(de->de_cdp != (void *)0xdeadc0de,
475 ("%s %d\n", __func__, __LINE__));
476 dev_unlock();
477 return (1);
478 }
479 dev_unlock();
480 return (0);
481}
482
483/*
484 * The caller needs to hold the dm for the duration of the call.
485 */
486void
487devfs_populate(struct devfs_mount *dm)
488{
489
490 sx_assert(&dm->dm_lock, SX_XLOCKED);
491 if (dm->dm_generation == devfs_generation)
492 return;
493 while (devfs_populate_loop(dm, 0))
494 continue;
495 dm->dm_generation = devfs_generation;
496}
497
498/*
499 * The caller needs to hold the dm for the duration of the call.
500 */
501void
502devfs_cleanup(struct devfs_mount *dm)
503{
504
505 sx_assert(&dm->dm_lock, SX_XLOCKED);
506 while (devfs_populate_loop(dm, 1))
507 continue;
508 devfs_purge(dm, dm->dm_rootdir);
509}
510
511/*
512 * devfs_create() and devfs_destroy() are called from kern_conf.c and
513 * in both cases the devlock() mutex is held, so no further locking
514 * is necesary and no sleeping allowed.
515 */
516
517void
518devfs_create(struct cdev *dev)
519{
520 struct cdev_priv *cdp;
521
522 mtx_assert(&devmtx, MA_OWNED);
523 cdp = cdev2priv(dev);
524 cdp->cdp_flags |= CDP_ACTIVE;
525 cdp->cdp_inode = alloc_unrl(devfs_inos);
526 dev_refl(dev);
527 TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
528 devfs_generation++;
529}
530
531void
532devfs_destroy(struct cdev *dev)
533{
534 struct cdev_priv *cdp;
535
536 mtx_assert(&devmtx, MA_OWNED);
537 cdp = cdev2priv(dev);
538 cdp->cdp_flags &= ~CDP_ACTIVE;
539 devfs_generation++;
540}
541
542static void
543devfs_devs_init(void *junk __unused)
544{
545
546 devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
547}
548
549SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);