xref: /xnu-12377.1.9/bsd/miscfs/devfs/devfs_fdesc_support.c (revision f6217f891ac0bb64f3d375211650a4c1ff8ca1ea)
1 /*
2  * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1992, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * This code is derived from software donated to Berkeley by
34  * Jan-Simon Pendry.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *	This product includes software developed by the University of
47  *	California, Berkeley and its contributors.
48  * 4. Neither the name of the University nor the names of its contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  *
64  *	@(#)fdesc_vnops.c	8.17 (Berkeley) 5/22/95
65  *
66  */
67 
68 /*
69  * /dev/fd Filesystem
70  */
71 
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/types.h>
75 #include <sys/time.h>
76 #include <sys/proc_internal.h>
77 #include <sys/kernel.h> /* boottime */
78 #include <sys/resourcevar.h>
79 #include <sys/filedesc.h>
80 #include <sys/kauth.h>
81 #include <sys/vnode_internal.h>
82 #include <sys/malloc.h>
83 #include <sys/file_internal.h>
84 #include <sys/stat.h>
85 #include <sys/mount_internal.h>
86 #include <sys/namei.h>
87 #include <sys/dirent.h>
88 #include <sys/ubc.h>
89 #include <sys/socketvar.h>
90 #include <sys/pipe.h>
91 #include <sys/uio_internal.h>
92 #include <vfs/vfs_support.h>
93 #include <pexpert/pexpert.h>
94 #include <miscfs/devfs/fdesc.h>
95 #include <miscfs/devfs/devfs.h>
96 #include <miscfs/devfs/devfsdefs.h>
97 
98 #define FDL_WANT        0x01
99 #define FDL_LOCKED      0x02
100 static int fdcache_lock;
101 
102 
103 #if (FD_STDIN != FD_STDOUT - 1) || (FD_STDOUT != FD_STDERR - 1)
104 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n + 1, n + 2
105 #endif
106 
107 #define NFDCACHE 3
108 
109 #define FD_NHASH(ix) \
110 	(&fdhashtbl[(ix) & fdhash])
111 LIST_HEAD(fdhashhead, fdescnode) * fdhashtbl;
112 u_long fdhash;
113 
114 static int fdesc_attr(int fd, struct vnode_attr *vap, vfs_context_t a_context);
115 
116 static LCK_GRP_DECLARE(fdesc_lckgrp, "fdesc");
117 static LCK_MTX_DECLARE(fdesc_mtx, &fdesc_lckgrp);
118 
119 static void
fdesc_lock(void)120 fdesc_lock(void)
121 {
122 	lck_mtx_lock(&fdesc_mtx);
123 }
124 
125 static void
fdesc_unlock(void)126 fdesc_unlock(void)
127 {
128 	lck_mtx_unlock(&fdesc_mtx);
129 }
130 
131 
132 /*
133  * Initialise cache headers, create the devfs node
134  */
135 int
devfs_fdesc_init()136 devfs_fdesc_init()
137 {
138 	int error = 0;
139 	devnode_t *rootdir = dev_root->de_dnp;
140 	devdirent_t *direntp;
141 
142 	/* XXX Make sure you have the right path... */
143 	fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash);
144 
145 	DEVFS_LOCK();
146 	dev_add_entry("fd", rootdir, DEV_DEVFD, NULL, NULL, NULL, &direntp);
147 	devfs_fdesc_makelinks();
148 	DEVFS_UNLOCK();
149 
150 	return error;
151 }
152 
153 /*
154  * Called during early startup, no need to synchronize
155  */
156 int
devfs_fdesc_makelinks()157 devfs_fdesc_makelinks()
158 {
159 	int error = 0;
160 	devdirent_t *stdin_ent = NULL, *stdout_ent = NULL, *stderr_ent = NULL;
161 	devnode_t *root_devnode = dev_root->de_dnp;
162 
163 	/* We do this ugliness to get around some "const" warnings */
164 	char in[] = "stdin";
165 	char out[] = "stdout";
166 	char err[] = "stderr";
167 	char zero[] = "fd/0";
168 	char one[] = "fd/1";
169 	char two[] = "fd/2";
170 
171 	if ((error = devfs_make_symlink(root_devnode, in, 0555, zero, &stdin_ent))) {
172 		printf("Couldn't make stdin, err %d.\n", error);
173 		goto bad;
174 	}
175 
176 	if ((error = devfs_make_symlink(root_devnode, out, 0555, one, &stdout_ent))) {
177 		printf("Couldn't make stdout, err %d.\n", error);
178 		goto bad;
179 	}
180 
181 	if ((error = devfs_make_symlink(root_devnode, err, 0555, two, &stderr_ent))) {
182 		printf("Couldn't make stderr, err %d.\n", error);
183 		goto bad;
184 	}
185 
186 	return 0;
187 
188 bad:
189 	if (stdin_ent) {
190 		dev_free_name(stdin_ent);
191 	}
192 	if (stdout_ent) {
193 		dev_free_name(stdout_ent);
194 	}
195 	if (stderr_ent) {
196 		dev_free_name(stderr_ent);
197 	}
198 
199 	return error;
200 }
201 
202 int
fdesc_allocvp(fdntype ftype,int ix,struct mount * mp,struct vnode ** vpp,enum vtype vtype,int fdno)203 fdesc_allocvp(fdntype ftype, int ix, struct mount *mp, struct vnode **vpp, enum vtype vtype, int fdno)
204 {
205 	struct fdhashhead *fc;
206 	struct fdescnode *fd;
207 	int error = 0;
208 	int vid = 0;
209 	struct vnode_fsparam vfsp;
210 	struct vnode *vp;
211 
212 	fdesc_lock();
213 
214 	fc = FD_NHASH(ix);
215 loop:
216 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
217 		if (fd->fd_ix == ix && vnode_mount(fd->fd_vnode) == mp) {
218 			vid = vnode_vid(fd->fd_vnode);
219 			vp = fd->fd_vnode;
220 			vnode_hold(vp);
221 			fdesc_unlock();
222 
223 			if (vnode_getwithvid(vp, vid)) {
224 				vnode_drop(vp);
225 				fdesc_lock();
226 				goto loop;
227 			}
228 
229 			vnode_drop(vp);
230 			*vpp = vp;
231 			(*vpp)->v_type = (uint16_t)vtype;
232 
233 			return error;
234 		}
235 	}
236 
237 	/* Only one thread can add to the hash at a time */
238 	if (fdcache_lock & FDL_LOCKED) {
239 		fdcache_lock |= FDL_WANT;
240 		msleep((caddr_t) &fdcache_lock, &fdesc_mtx, PINOD, "fdesc_allocvp", NULL);
241 		goto loop;
242 	}
243 
244 	fdcache_lock |= FDL_LOCKED;
245 	fdesc_unlock();
246 
247 	fd = kalloc_type(struct fdescnode, Z_WAITOK);
248 
249 	vfsp.vnfs_mp = mp;
250 	vfsp.vnfs_vtype = vtype;
251 	vfsp.vnfs_str = "fdesc";
252 	vfsp.vnfs_dvp = NULL;
253 	vfsp.vnfs_fsnode = fd;
254 	vfsp.vnfs_cnp = NULL;
255 	vfsp.vnfs_vops = fdesc_vnodeop_p;
256 	vfsp.vnfs_rdev = 0;
257 	vfsp.vnfs_filesize = 0;
258 	vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE;
259 	vfsp.vnfs_marksystem = 0;
260 	vfsp.vnfs_markroot = 0;
261 
262 	error = vnode_create_ext(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, vpp,
263 	    VNODE_CREATE_DEFAULT);
264 	if (error) {
265 		kfree_type(struct fdescnode, fd);
266 		fdesc_lock();
267 		goto out;
268 	}
269 
270 	(*vpp)->v_tag = VT_FDESC;
271 	fd->fd_vnode = *vpp;
272 	fd->fd_type = ftype;
273 	fd->fd_fd = fdno;
274 	fd->fd_link = NULL;
275 	fd->fd_ix = ix;
276 
277 	fdesc_lock();
278 
279 	LIST_INSERT_HEAD(fc, fd, fd_hash);
280 out:
281 	/* Hold the lock when we get here */
282 	fdcache_lock &= ~FDL_LOCKED;
283 
284 	if (fdcache_lock & FDL_WANT) {
285 		fdcache_lock &= ~FDL_WANT;
286 		wakeup((caddr_t) &fdcache_lock);
287 	}
288 
289 	fdesc_unlock();
290 
291 	return error;
292 }
293 
294 /*
295  * vp is the current namei directory
296  * ndp is the name to locate in that directory...
297  *
298  * This vnop should only be called on the special directory /dev/fd.
299  */
300 int
devfs_devfd_lookup(struct vnop_lookup_args * ap)301 devfs_devfd_lookup(struct vnop_lookup_args *ap)
302 {
303 	struct vnode **vpp = ap->a_vpp;
304 	struct vnode *dvp = ap->a_dvp;
305 	struct componentname *cnp = ap->a_cnp;
306 	char *pname = cnp->cn_nameptr;
307 	struct proc *p = vfs_context_proc(ap->a_context);
308 	int numfiles = p->p_fd.fd_nfiles;
309 	int fd;
310 	int error;
311 	struct vnode *fvp;
312 
313 	if (cnp->cn_namelen == 1 && *pname == '.') {
314 		*vpp = dvp;
315 
316 		if ((error = vnode_get(dvp))) {
317 			goto bad;
318 		}
319 		return 0;
320 	}
321 
322 	fd = 0;
323 	while (*pname >= '0' && *pname <= '9') {
324 		if (os_mul_and_add_overflow(fd, 10, *pname++ - '0', &fd)) {
325 			break;
326 		}
327 	}
328 
329 	if (*pname != '\0') {
330 		error = ENOENT;
331 		goto bad;
332 	}
333 
334 	if (fd < 0 || fd >= numfiles ||
335 	    *fdfile(p, fd) == NULL ||
336 	    (*fdflags(p, fd) & UF_RESERVED)) {
337 		error = EBADF;
338 		goto bad;
339 	}
340 
341 	/*
342 	 * For OP_SETATTR lookups, resolve the backing vnode now so we do
343 	 * MACF checks on the right thing.
344 	 *
345 	 * If there is no vnode (i.e. something else is open at that fd) then
346 	 * just return an fdescnode.
347 	 */
348 	if ((cnp->cn_ndp->ni_op == OP_SETATTR) &&
349 	    (0 == vnode_getfromfd(ap->a_context, fd, &fvp))) {
350 		cnp->cn_flags &= ~MAKEENTRY;
351 		*vpp = fvp;
352 		return 0;
353 	}
354 
355 	error = fdesc_allocvp(Fdesc, FD_DESC + fd, dvp->v_mount, &fvp, VNON, fd);
356 	if (error) {
357 		goto bad;
358 	}
359 	*vpp = fvp;
360 	return 0;
361 
362 bad:
363 	*vpp = NULL;
364 	return error;
365 }
366 
367 int
fdesc_open(struct vnop_open_args * ap)368 fdesc_open(struct vnop_open_args *ap)
369 {
370 	struct vnode *vp = ap->a_vp;
371 	thread_t thr = vfs_context_thread(ap->a_context);
372 	uthread_t uu;
373 	int error = 0;
374 
375 	if (thr == NULL) {
376 		return EINVAL;
377 	}
378 
379 	uu = get_bsdthread_info(thr);
380 
381 	switch (VTOFDESC(vp)->fd_type) {
382 	case Fdesc:
383 		/*
384 		 * XXX Kludge: set uu->uu_dupfd to contain the value of the
385 		 * the file descriptor being sought for duplication. The error
386 		 * return ensures that the vnode for this device will be
387 		 * released by vn_open. Open will detect this special error and
388 		 * take the actions in dupfdopen.  Other callers of vn_open or
389 		 * vnop_open will simply report the error.
390 		 */
391 		uu->uu_dupfd = VTOFDESC(vp)->fd_fd;     /* XXX */
392 		error = ENODEV;
393 		break;
394 	default:
395 		panic("Invalid type for fdesc node!");
396 		break;
397 	}
398 
399 	return error;
400 }
401 
402 static int
fdesc_attr(int fd,struct vnode_attr * vap,vfs_context_t a_context)403 fdesc_attr(int fd, struct vnode_attr *vap, vfs_context_t a_context)
404 {
405 	struct fileproc *fp;
406 	struct proc *p = vfs_context_proc(a_context);
407 	struct stat stb;
408 	int error;
409 
410 	if ((error = fp_lookup(p, fd, &fp, 0))) {
411 		return error;
412 	}
413 	switch (FILEGLOB_DTYPE(fp->fp_glob)) {
414 	case DTYPE_VNODE: {
415 		vnode_t vp = (vnode_t)fp_get_data(fp);
416 
417 		if ((error = vnode_getwithref(vp)) != 0) {
418 			break;
419 		}
420 		if ((error = vnode_authorize(vp,
421 		    NULL,
422 		    KAUTH_VNODE_READ_ATTRIBUTES | KAUTH_VNODE_READ_SECURITY,
423 		    a_context)) == 0) {
424 			error = vnode_getattr(vp, vap, a_context);
425 		}
426 		if (error == 0 && vap->va_type == VDIR) {
427 			/*
428 			 * directories can cause loops in the namespace,
429 			 * so turn off the 'x' bits to avoid trouble.
430 			 *
431 			 * XXX ACLs break this, of course
432 			 */
433 			vap->va_mode &= ~((VEXEC) | (VEXEC >> 3) | (VEXEC >> 6));
434 		}
435 		(void)vnode_put(vp);
436 		break;
437 	}
438 	case DTYPE_SOCKET:
439 	case DTYPE_PIPE:
440 #if SOCKETS
441 		if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
442 			error = soo_stat((struct socket *)fp_get_data(fp), (void *)&stb, 0);
443 		} else
444 #endif /* SOCKETS */
445 		error = pipe_stat((struct pipe *)fp_get_data(fp), (void *)&stb, 0);
446 
447 		if (error == 0) {
448 			if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
449 				VATTR_RETURN(vap, va_type, VSOCK);
450 			} else {
451 				VATTR_RETURN(vap, va_type, VFIFO);
452 			}
453 
454 			VATTR_RETURN(vap, va_mode, stb.st_mode);
455 			VATTR_RETURN(vap, va_nlink, stb.st_nlink);
456 			VATTR_RETURN(vap, va_uid, stb.st_uid);
457 			VATTR_RETURN(vap, va_gid, stb.st_gid);
458 			VATTR_RETURN(vap, va_fsid, stb.st_dev);
459 			VATTR_RETURN(vap, va_fileid, stb.st_ino);
460 			VATTR_RETURN(vap, va_data_size, stb.st_size);
461 			VATTR_RETURN(vap, va_access_time, stb.st_atimespec);
462 			VATTR_RETURN(vap, va_modify_time, stb.st_mtimespec);
463 			VATTR_RETURN(vap, va_change_time, stb.st_ctimespec);
464 			VATTR_RETURN(vap, va_gen, stb.st_gen);
465 			VATTR_RETURN(vap, va_flags, stb.st_flags);
466 			VATTR_RETURN(vap, va_rdev, stb.st_rdev);
467 			VATTR_RETURN(vap, va_total_alloc, stb.st_blocks * stb.st_blksize);
468 			VATTR_RETURN(vap, va_acl, NULL);
469 		}
470 		break;
471 
472 	default:
473 		error = EBADF;
474 	}
475 
476 	/* Update 'va_mode' to take into account the bits on the fd. */
477 	if (error == 0 && VATTR_IS_SUPPORTED(vap, va_mode)) {
478 		int flags;
479 
480 		flags = fp->fp_glob->fg_flag;
481 		if (!(flags & FREAD)) {
482 			vap->va_mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
483 		}
484 		if (!(flags & FWRITE)) {
485 			vap->va_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
486 		}
487 		if (!(flags & O_EXEC)) {
488 			vap->va_mode &= ~(S_IXUSR | S_IXGRP | S_IXOTH);
489 		}
490 	}
491 
492 	fp_drop(p, fd, fp, 0);
493 	return error;
494 }
495 
496 int
fdesc_getattr(struct vnop_getattr_args * ap)497 fdesc_getattr(struct vnop_getattr_args *ap)
498 {
499 	struct vnode *vp = ap->a_vp;
500 	struct vnode_attr *vap = ap->a_vap;
501 	unsigned fd;
502 	int error = 0;
503 
504 	switch (VTOFDESC(vp)->fd_type) {
505 	case Fdesc:
506 		fd = VTOFDESC(vp)->fd_fd;
507 		error = fdesc_attr(fd, vap, ap->a_context);
508 		break;
509 
510 	default:
511 		panic("Invalid type for an fdesc node!");
512 		break;
513 	}
514 
515 	/*
516 	 * Yes, we do this without locking, but this value is always just
517 	 * a snapshot.
518 	 */
519 	if (error == 0) {
520 		vp->v_type = (uint16_t)vap->va_type;
521 
522 		/* We need an inactive to reset type to VNON */
523 		vnode_setneedinactive(vp);
524 	}
525 
526 	return error;
527 }
528 
529 int
fdesc_setattr(struct vnop_setattr_args * ap)530 fdesc_setattr(struct vnop_setattr_args *ap)
531 {
532 	struct fileproc *fp;
533 	unsigned fd;
534 	int error;
535 	struct proc * p = vfs_context_proc(ap->a_context);
536 
537 	/*
538 	 * Can't mess with the root vnode
539 	 */
540 	switch (VTOFDESC(ap->a_vp)->fd_type) {
541 	case Fdesc:
542 		break;
543 	default:
544 		panic("Invalid type for an fdesc node!");
545 		return EACCES;
546 	}
547 
548 	fd = VTOFDESC(ap->a_vp)->fd_fd;
549 	if ((error = fp_lookup(vfs_context_proc(ap->a_context), fd, &fp, 0))) {
550 		return error;
551 	}
552 
553 	switch (FILEGLOB_DTYPE(fp->fp_glob)) {
554 	case DTYPE_VNODE:
555 	/*
556 	 * We shouldn't get here unless we were raced with close/open.
557 	 * In that case, shenanigans are happening and it's unsafe to
558 	 * take action on the `setattr`; the MACF and UNIX permission
559 	 * checks are no longer valid (TOCTOU).
560 	 *
561 	 * Fall through to report success.
562 	 */
563 	case DTYPE_SOCKET:
564 	case DTYPE_PIPE:
565 		error = 0;
566 		break;
567 
568 	default:
569 		error = EBADF;
570 		break;
571 	}
572 
573 	fp_drop(p, fd, fp, 0);
574 	return error;
575 }
576 
577 #define UIO_MX 16
578 
579 /*
580  *  static struct dirtmp {
581  *       u_int32_t d_fileno;
582  *       u_short d_reclen;
583  *       u_short d_namlen;
584  *       char d_name[8];
585  *  } rootent[] = {
586  *       { FD_DEVFD, UIO_MX, 2, "fd" },
587  *       { FD_STDIN, UIO_MX, 5, "stdin" },
588  *       { FD_STDOUT, UIO_MX, 6, "stdout" },
589  *       { FD_STDERR, UIO_MX, 6, "stderr" },
590  *       { 0, 0, 0, "" }
591  *  };
592  */
593 
594 /* Only called on /dev/fd */
595 int
devfs_devfd_readdir(struct vnop_readdir_args * ap)596 devfs_devfd_readdir(struct vnop_readdir_args *ap)
597 {
598 	struct uio *uio = ap->a_uio;
599 	struct proc *p = current_proc();
600 	off_t i;
601 	int error;
602 
603 	/*
604 	 * We don't allow exporting fdesc mounts, and currently local
605 	 * requests do not need cookies.
606 	 */
607 	if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF)) {
608 		return EINVAL;
609 	}
610 
611 	/*
612 	 * There needs to be space for at least one entry.
613 	 */
614 	if (uio_resid(uio) < UIO_MX) {
615 		return EINVAL;
616 	}
617 
618 	i = uio->uio_offset / UIO_MX;
619 	error = 0;
620 	while (uio_resid(uio) >= UIO_MX) {
621 		if (i >= p->p_fd.fd_nfiles || i < 0) {
622 			break;
623 		}
624 
625 		if (*fdfile(p, i) != NULL && !(*fdflags(p, i) & UF_RESERVED)) {
626 			struct dirent d;
627 			struct dirent *dp = &d;
628 
629 			bzero((caddr_t) dp, UIO_MX);
630 
631 			dp->d_namlen = (__uint8_t)scnprintf(dp->d_name, sizeof(dp->d_name),
632 			    "%lld", i);
633 			dp->d_reclen = UIO_MX;
634 			dp->d_type = DT_UNKNOWN;
635 			dp->d_fileno = (ino_t)i + FD_STDIN;
636 			/*
637 			 * And ship to userland
638 			 */
639 			error = uiomove((caddr_t) dp, UIO_MX, uio);
640 			if (error) {
641 				break;
642 			}
643 		}
644 		i++;
645 	}
646 
647 	uio->uio_offset = i * UIO_MX;
648 	return error;
649 }
650 
651 int
fdesc_read(__unused struct vnop_read_args * ap)652 fdesc_read(__unused struct vnop_read_args *ap)
653 {
654 	return ENOTSUP;
655 }
656 
657 int
fdesc_write(__unused struct vnop_write_args * ap)658 fdesc_write(__unused struct vnop_write_args *ap)
659 {
660 	return ENOTSUP;
661 }
662 
663 int
fdesc_ioctl(__unused struct vnop_ioctl_args * ap)664 fdesc_ioctl(__unused struct vnop_ioctl_args *ap)
665 {
666 	return ENOTSUP;
667 }
668 
669 int
fdesc_select(__unused struct vnop_select_args * ap)670 fdesc_select(__unused struct vnop_select_args *ap)
671 {
672 	return ENOTSUP;
673 }
674 
675 int
fdesc_inactive(struct vnop_inactive_args * ap)676 fdesc_inactive(struct vnop_inactive_args *ap)
677 {
678 	struct vnode *vp = ap->a_vp;
679 
680 	/*
681 	 * Clear out the v_type field to avoid
682 	 * nasty things happening in vgone().
683 	 */
684 	vp->v_type = VNON;
685 
686 	return 0;
687 }
688 
689 int
fdesc_reclaim(struct vnop_reclaim_args * ap)690 fdesc_reclaim(struct vnop_reclaim_args *ap)
691 {
692 	struct vnode *vp = ap->a_vp;
693 	struct fdescnode *fd = VTOFDESC(vp);
694 
695 	fdesc_lock();
696 
697 	LIST_REMOVE(fd, fd_hash);
698 	kfree_type(struct fdescnode, vp->v_data);
699 
700 	fdesc_unlock();
701 
702 	return 0;
703 }
704 
705 /*
706  * Return POSIX pathconf information applicable to special devices.
707  */
708 int
fdesc_pathconf(struct vnop_pathconf_args * ap)709 fdesc_pathconf(struct vnop_pathconf_args *ap)
710 {
711 	switch (ap->a_name) {
712 	case _PC_LINK_MAX:
713 		*ap->a_retval = LINK_MAX;
714 		return 0;
715 	case _PC_MAX_CANON:
716 		*ap->a_retval = MAX_CANON;
717 		return 0;
718 	case _PC_MAX_INPUT:
719 		*ap->a_retval = MAX_INPUT;
720 		return 0;
721 	case _PC_PIPE_BUF:
722 		*ap->a_retval = PIPE_BUF;
723 		return 0;
724 	case _PC_CHOWN_RESTRICTED:
725 		*ap->a_retval = 200112;         /* _POSIX_CHOWN_RESTRICTED */
726 		return 0;
727 	case _PC_VDISABLE:
728 		*ap->a_retval = _POSIX_VDISABLE;
729 		return 0;
730 	default:
731 		return EINVAL;
732 	}
733 	/* NOTREACHED */
734 }
735 
736 /*
737  * /dev/fd "should never get here" operation
738  */
739 int
fdesc_badop(void)740 fdesc_badop(void)
741 {
742 	return ENOTSUP;
743 	/* NOTREACHED */
744 }
745 
746 #define VOPFUNC int (*)(void *)
747 
748 #define fdesc_revoke nop_revoke
749 #define fdesc_strategy (void (*)(void))fdesc_badop
750 
751 #define fdesc_nullop (void (*)(void ))nullop
752 #define fdesc_error (void (*)(void ))vn_default_error
753 #define fdesc_notsupp (void (*)(void ))eopnotsupp
754 
755 int(**fdesc_vnodeop_p)(void *);
756 const struct vnodeopv_entry_desc devfs_fdesc_vnodeop_entries[] = {
757 	{ .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)fdesc_error },
758 	{ .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)fdesc_error},        /* lookup */
759 	{ .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },   /* create */
760 	{ .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },     /* mknod */
761 	{ .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)fdesc_open },       /* open */
762 	{ .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)fdesc_nullop },     /* close */
763 	{ .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)fdesc_nullop },   /* access */
764 	{ .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)fdesc_getattr }, /* getattr */
765 	{ .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)fdesc_setattr }, /* setattr */
766 	{ .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)fdesc_read },       /* read */
767 	{ .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)fdesc_write },     /* write */
768 	{ .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)fdesc_ioctl },     /* ioctl */
769 	{ .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)fdesc_select },   /* select */
770 	{ .opve_op = &vnop_revoke_desc, .opve_impl = (VOPFUNC)fdesc_revoke },   /* revoke */
771 	{ .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },       /* mmap */
772 	{ .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)fdesc_nullop },     /* fsync */
773 	{ .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },   /* remove */
774 	{ .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },       /* link */
775 	{ .opve_op = &vnop_rename_desc, .opve_impl =  (VOPFUNC)fdesc_notsupp },   /* rename */
776 	{ .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },     /* mkdir */
777 	{ .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },     /* rmdir */
778 	{ .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)fdesc_notsupp }, /* symlink */
779 	{ .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)fdesc_error},/* readdir */
780 	{ .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)err_readlink}, /* readlink */
781 	{ .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)fdesc_inactive },/* inactive */
782 	{ .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)fdesc_reclaim }, /* reclaim */
783 	{ .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)fdesc_strategy },       /* strategy */
784 	{ .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)fdesc_pathconf },       /* pathconf */
785 	{ .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)fdesc_notsupp }, /* advlock */
786 	{ .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },   /* bwrite */
787 	{ .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein },     /* pagein */
788 	{ .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout },   /* pageout */
789 	{ .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */
790 	{ .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },       /* blktooff */
791 	{ .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },       /* offtoblk */
792 	{ .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)fdesc_notsupp },       /* blockmap */
793 	{ .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (VOPFUNC)NULL }
794 };
795 
796 const struct vnodeopv_desc devfs_fdesc_vnodeop_opv_desc =
797 { .opv_desc_vector_p = &fdesc_vnodeop_p, .opv_desc_ops = devfs_fdesc_vnodeop_entries };
798