xref: /xnu-8020.101.4/bsd/miscfs/devfs/devfs_fdesc_support.c (revision e7776783b89a353188416a9a346c6cdb4928faad)
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 
211 	fdesc_lock();
212 
213 	fc = FD_NHASH(ix);
214 loop:
215 	for (fd = fc->lh_first; fd != 0; fd = fd->fd_hash.le_next) {
216 		if (fd->fd_ix == ix && vnode_mount(fd->fd_vnode) == mp) {
217 			vid = vnode_vid(fd->fd_vnode);
218 			fdesc_unlock();
219 
220 			if (vnode_getwithvid(fd->fd_vnode, vid)) {
221 				fdesc_lock();
222 				goto loop;
223 			}
224 
225 			*vpp = fd->fd_vnode;
226 			(*vpp)->v_type = (uint16_t)vtype;
227 
228 			return error;
229 		}
230 	}
231 
232 	/* Only one thread can add to the hash at a time */
233 	if (fdcache_lock & FDL_LOCKED) {
234 		fdcache_lock |= FDL_WANT;
235 		msleep((caddr_t) &fdcache_lock, &fdesc_mtx, PINOD, "fdesc_allocvp", NULL);
236 		goto loop;
237 	}
238 
239 	fdcache_lock |= FDL_LOCKED;
240 	fdesc_unlock();
241 
242 	fd = kalloc_type(struct fdescnode, Z_WAITOK);
243 
244 	vfsp.vnfs_mp = mp;
245 	vfsp.vnfs_vtype = vtype;
246 	vfsp.vnfs_str = "fdesc";
247 	vfsp.vnfs_dvp = NULL;
248 	vfsp.vnfs_fsnode = fd;
249 	vfsp.vnfs_cnp = NULL;
250 	vfsp.vnfs_vops = fdesc_vnodeop_p;
251 	vfsp.vnfs_rdev = 0;
252 	vfsp.vnfs_filesize = 0;
253 	vfsp.vnfs_flags = VNFS_NOCACHE | VNFS_CANTCACHE;
254 	vfsp.vnfs_marksystem = 0;
255 	vfsp.vnfs_markroot = 0;
256 
257 	error = vnode_create(VNCREATE_FLAVOR, VCREATESIZE, &vfsp, vpp);
258 	if (error) {
259 		kfree_type(struct fdescnode, fd);
260 		fdesc_lock();
261 		goto out;
262 	}
263 
264 	(*vpp)->v_tag = VT_FDESC;
265 	fd->fd_vnode = *vpp;
266 	fd->fd_type = ftype;
267 	fd->fd_fd = fdno;
268 	fd->fd_link = NULL;
269 	fd->fd_ix = ix;
270 
271 	fdesc_lock();
272 
273 	LIST_INSERT_HEAD(fc, fd, fd_hash);
274 out:
275 	/* Hold the lock when we get here */
276 	fdcache_lock &= ~FDL_LOCKED;
277 
278 	if (fdcache_lock & FDL_WANT) {
279 		fdcache_lock &= ~FDL_WANT;
280 		wakeup((caddr_t) &fdcache_lock);
281 	}
282 
283 	fdesc_unlock();
284 
285 	return error;
286 }
287 
288 /*
289  * vp is the current namei directory
290  * ndp is the name to locate in that directory...
291  *
292  * This vnop should only be called on the special directory /dev/fd.
293  */
294 int
devfs_devfd_lookup(struct vnop_lookup_args * ap)295 devfs_devfd_lookup(struct vnop_lookup_args *ap)
296 {
297 	struct vnode **vpp = ap->a_vpp;
298 	struct vnode *dvp = ap->a_dvp;
299 	struct componentname *cnp = ap->a_cnp;
300 	char *pname = cnp->cn_nameptr;
301 	struct proc *p = vfs_context_proc(ap->a_context);
302 	int numfiles = p->p_fd.fd_nfiles;
303 	int fd;
304 	int error;
305 	struct vnode *fvp;
306 
307 	if (cnp->cn_namelen == 1 && *pname == '.') {
308 		*vpp = dvp;
309 
310 		if ((error = vnode_get(dvp))) {
311 			goto bad;
312 		}
313 		return 0;
314 	}
315 
316 	fd = 0;
317 	while (*pname >= '0' && *pname <= '9') {
318 		if (os_mul_and_add_overflow(fd, 10, *pname++ - '0', &fd)) {
319 			break;
320 		}
321 	}
322 
323 	if (*pname != '\0') {
324 		error = ENOENT;
325 		goto bad;
326 	}
327 
328 	if (fd < 0 || fd >= numfiles ||
329 	    *fdfile(p, fd) == NULL ||
330 	    (*fdflags(p, fd) & UF_RESERVED)) {
331 		error = EBADF;
332 		goto bad;
333 	}
334 
335 	error = fdesc_allocvp(Fdesc, FD_DESC + fd, dvp->v_mount, &fvp, VNON, fd);
336 	if (error) {
337 		goto bad;
338 	}
339 	*vpp = fvp;
340 	return 0;
341 
342 bad:
343 	*vpp = NULL;
344 	return error;
345 }
346 
347 int
fdesc_open(struct vnop_open_args * ap)348 fdesc_open(struct vnop_open_args *ap)
349 {
350 	struct vnode *vp = ap->a_vp;
351 	thread_t thr = vfs_context_thread(ap->a_context);
352 	uthread_t uu;
353 	int error = 0;
354 
355 	if (thr == NULL) {
356 		return EINVAL;
357 	}
358 
359 	uu = get_bsdthread_info(thr);
360 
361 	switch (VTOFDESC(vp)->fd_type) {
362 	case Fdesc:
363 		/*
364 		 * XXX Kludge: set uu->uu_dupfd to contain the value of the
365 		 * the file descriptor being sought for duplication. The error
366 		 * return ensures that the vnode for this device will be
367 		 * released by vn_open. Open will detect this special error and
368 		 * take the actions in dupfdopen.  Other callers of vn_open or
369 		 * vnop_open will simply report the error.
370 		 */
371 		uu->uu_dupfd = VTOFDESC(vp)->fd_fd;     /* XXX */
372 		error = ENODEV;
373 		break;
374 	default:
375 		panic("Invalid type for fdesc node!");
376 		break;
377 	}
378 
379 	return error;
380 }
381 
382 static int
fdesc_attr(int fd,struct vnode_attr * vap,vfs_context_t a_context)383 fdesc_attr(int fd, struct vnode_attr *vap, vfs_context_t a_context)
384 {
385 	struct fileproc *fp;
386 	struct proc *p = vfs_context_proc(a_context);
387 	struct stat stb;
388 	int error;
389 
390 	if ((error = fp_lookup(p, fd, &fp, 0))) {
391 		return error;
392 	}
393 	switch (FILEGLOB_DTYPE(fp->fp_glob)) {
394 	case DTYPE_VNODE:
395 		if ((error = vnode_getwithref((struct vnode *)fp_get_data(fp))) != 0) {
396 			break;
397 		}
398 		if ((error = vnode_authorize((struct vnode *)fp_get_data(fp),
399 		    NULL,
400 		    KAUTH_VNODE_READ_ATTRIBUTES | KAUTH_VNODE_READ_SECURITY,
401 		    a_context)) == 0) {
402 			error = vnode_getattr((struct vnode *)fp_get_data(fp), vap, a_context);
403 		}
404 		if (error == 0 && vap->va_type == VDIR) {
405 			/*
406 			 * directories can cause loops in the namespace,
407 			 * so turn off the 'x' bits to avoid trouble.
408 			 *
409 			 * XXX ACLs break this, of course
410 			 */
411 			vap->va_mode &= ~((VEXEC) | (VEXEC >> 3) | (VEXEC >> 6));
412 		}
413 		(void)vnode_put((struct vnode *)fp_get_data(fp));
414 		break;
415 
416 	case DTYPE_SOCKET:
417 	case DTYPE_PIPE:
418 #if SOCKETS
419 		if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
420 			error = soo_stat((struct socket *)fp_get_data(fp), (void *)&stb, 0);
421 		} else
422 #endif /* SOCKETS */
423 		error = pipe_stat((struct pipe *)fp_get_data(fp), (void *)&stb, 0);
424 
425 		if (error == 0) {
426 			if (FILEGLOB_DTYPE(fp->fp_glob) == DTYPE_SOCKET) {
427 				VATTR_RETURN(vap, va_type, VSOCK);
428 			} else {
429 				VATTR_RETURN(vap, va_type, VFIFO);
430 			}
431 
432 			VATTR_RETURN(vap, va_mode, stb.st_mode);
433 			VATTR_RETURN(vap, va_nlink, stb.st_nlink);
434 			VATTR_RETURN(vap, va_uid, stb.st_uid);
435 			VATTR_RETURN(vap, va_gid, stb.st_gid);
436 			VATTR_RETURN(vap, va_fsid, stb.st_dev);
437 			VATTR_RETURN(vap, va_fileid, stb.st_ino);
438 			VATTR_RETURN(vap, va_data_size, stb.st_size);
439 			VATTR_RETURN(vap, va_access_time, stb.st_atimespec);
440 			VATTR_RETURN(vap, va_modify_time, stb.st_mtimespec);
441 			VATTR_RETURN(vap, va_change_time, stb.st_ctimespec);
442 			VATTR_RETURN(vap, va_gen, stb.st_gen);
443 			VATTR_RETURN(vap, va_flags, stb.st_flags);
444 			VATTR_RETURN(vap, va_rdev, stb.st_rdev);
445 			VATTR_RETURN(vap, va_total_alloc, stb.st_blocks * stb.st_blksize);
446 			VATTR_RETURN(vap, va_acl, NULL);
447 		}
448 		break;
449 
450 	default:
451 		error = EBADF;
452 	}
453 
454 	fp_drop(p, fd, fp, 0);
455 	return error;
456 }
457 
458 int
fdesc_getattr(struct vnop_getattr_args * ap)459 fdesc_getattr(struct vnop_getattr_args *ap)
460 {
461 	struct vnode *vp = ap->a_vp;
462 	struct vnode_attr *vap = ap->a_vap;
463 	unsigned fd;
464 	int error = 0;
465 
466 	switch (VTOFDESC(vp)->fd_type) {
467 	case Fdesc:
468 		fd = VTOFDESC(vp)->fd_fd;
469 		error = fdesc_attr(fd, vap, ap->a_context);
470 		break;
471 
472 	default:
473 		panic("Invalid type for an fdesc node!");
474 		break;
475 	}
476 
477 	/*
478 	 * Yes, we do this without locking, but this value is always just
479 	 * a snapshot.
480 	 */
481 	if (error == 0) {
482 		vp->v_type = (uint16_t)vap->va_type;
483 
484 		/* We need an inactive to reset type to VNON */
485 		vnode_setneedinactive(vp);
486 	}
487 
488 	return error;
489 }
490 
491 int
fdesc_setattr(struct vnop_setattr_args * ap)492 fdesc_setattr(struct vnop_setattr_args *ap)
493 {
494 	struct fileproc *fp;
495 	unsigned fd;
496 	int error;
497 	struct proc * p = vfs_context_proc(ap->a_context);
498 
499 	/*
500 	 * Can't mess with the root vnode
501 	 */
502 	switch (VTOFDESC(ap->a_vp)->fd_type) {
503 	case Fdesc:
504 		break;
505 	default:
506 		panic("Invalid type for an fdesc node!");
507 		return EACCES;
508 	}
509 
510 	fd = VTOFDESC(ap->a_vp)->fd_fd;
511 	if ((error = fp_lookup(vfs_context_proc(ap->a_context), fd, &fp, 0))) {
512 		return error;
513 	}
514 
515 	/*
516 	 * Can setattr the underlying vnode, but not sockets!
517 	 */
518 	switch (FILEGLOB_DTYPE(fp->fp_glob)) {
519 	case DTYPE_VNODE:
520 	{
521 		if ((error = vnode_getwithref((struct vnode *)fp_get_data(fp))) != 0) {
522 			break;
523 		}
524 		error = vnode_setattr((struct vnode *)fp_get_data(fp), ap->a_vap, ap->a_context);
525 		(void)vnode_put((struct vnode *)fp_get_data(fp));
526 		break;
527 	}
528 
529 	case DTYPE_SOCKET:
530 	case DTYPE_PIPE:
531 		error = 0;
532 		break;
533 
534 	default:
535 		error = EBADF;
536 		break;
537 	}
538 
539 	fp_drop(p, fd, fp, 0);
540 	return error;
541 }
542 
543 #define UIO_MX 16
544 
545 /*
546  *  static struct dirtmp {
547  *       u_int32_t d_fileno;
548  *       u_short d_reclen;
549  *       u_short d_namlen;
550  *       char d_name[8];
551  *  } rootent[] = {
552  *       { FD_DEVFD, UIO_MX, 2, "fd" },
553  *       { FD_STDIN, UIO_MX, 5, "stdin" },
554  *       { FD_STDOUT, UIO_MX, 6, "stdout" },
555  *       { FD_STDERR, UIO_MX, 6, "stderr" },
556  *       { 0, 0, 0, "" }
557  *  };
558  */
559 
560 /* Only called on /dev/fd */
561 int
devfs_devfd_readdir(struct vnop_readdir_args * ap)562 devfs_devfd_readdir(struct vnop_readdir_args *ap)
563 {
564 	struct uio *uio = ap->a_uio;
565 	struct proc *p = current_proc();
566 	off_t i;
567 	int error;
568 
569 	/*
570 	 * We don't allow exporting fdesc mounts, and currently local
571 	 * requests do not need cookies.
572 	 */
573 	if (ap->a_flags & (VNODE_READDIR_EXTENDED | VNODE_READDIR_REQSEEKOFF)) {
574 		return EINVAL;
575 	}
576 
577 	/*
578 	 * There needs to be space for at least one entry.
579 	 */
580 	if (uio_resid(uio) < UIO_MX) {
581 		return EINVAL;
582 	}
583 
584 	i = uio->uio_offset / UIO_MX;
585 	error = 0;
586 	while (uio_resid(uio) >= UIO_MX) {
587 		if (i >= p->p_fd.fd_nfiles || i < 0) {
588 			break;
589 		}
590 
591 		if (*fdfile(p, i) != NULL && !(*fdflags(p, i) & UF_RESERVED)) {
592 			struct dirent d;
593 			struct dirent *dp = &d;
594 
595 			bzero((caddr_t) dp, UIO_MX);
596 
597 			dp->d_namlen = (__uint8_t)scnprintf(dp->d_name, sizeof(dp->d_name),
598 			    "%lld", i);
599 			dp->d_reclen = UIO_MX;
600 			dp->d_type = DT_UNKNOWN;
601 			dp->d_fileno = (ino_t)i + FD_STDIN;
602 			/*
603 			 * And ship to userland
604 			 */
605 			error = uiomove((caddr_t) dp, UIO_MX, uio);
606 			if (error) {
607 				break;
608 			}
609 		}
610 		i++;
611 	}
612 
613 	uio->uio_offset = i * UIO_MX;
614 	return error;
615 }
616 
617 int
fdesc_read(__unused struct vnop_read_args * ap)618 fdesc_read(__unused struct vnop_read_args *ap)
619 {
620 	return ENOTSUP;
621 }
622 
623 int
fdesc_write(__unused struct vnop_write_args * ap)624 fdesc_write(__unused struct vnop_write_args *ap)
625 {
626 	return ENOTSUP;
627 }
628 
629 int
fdesc_ioctl(__unused struct vnop_ioctl_args * ap)630 fdesc_ioctl(__unused struct vnop_ioctl_args *ap)
631 {
632 	return ENOTSUP;
633 }
634 
635 int
fdesc_select(__unused struct vnop_select_args * ap)636 fdesc_select(__unused struct vnop_select_args *ap)
637 {
638 	return ENOTSUP;
639 }
640 
641 int
fdesc_inactive(struct vnop_inactive_args * ap)642 fdesc_inactive(struct vnop_inactive_args *ap)
643 {
644 	struct vnode *vp = ap->a_vp;
645 
646 	/*
647 	 * Clear out the v_type field to avoid
648 	 * nasty things happening in vgone().
649 	 */
650 	vp->v_type = VNON;
651 
652 	return 0;
653 }
654 
655 int
fdesc_reclaim(struct vnop_reclaim_args * ap)656 fdesc_reclaim(struct vnop_reclaim_args *ap)
657 {
658 	struct vnode *vp = ap->a_vp;
659 	struct fdescnode *fd = VTOFDESC(vp);
660 
661 	fdesc_lock();
662 
663 	LIST_REMOVE(fd, fd_hash);
664 	kfree_type(struct fdescnode, vp->v_data);
665 
666 	fdesc_unlock();
667 
668 	return 0;
669 }
670 
671 /*
672  * Return POSIX pathconf information applicable to special devices.
673  */
674 int
fdesc_pathconf(struct vnop_pathconf_args * ap)675 fdesc_pathconf(struct vnop_pathconf_args *ap)
676 {
677 	switch (ap->a_name) {
678 	case _PC_LINK_MAX:
679 		*ap->a_retval = LINK_MAX;
680 		return 0;
681 	case _PC_MAX_CANON:
682 		*ap->a_retval = MAX_CANON;
683 		return 0;
684 	case _PC_MAX_INPUT:
685 		*ap->a_retval = MAX_INPUT;
686 		return 0;
687 	case _PC_PIPE_BUF:
688 		*ap->a_retval = PIPE_BUF;
689 		return 0;
690 	case _PC_CHOWN_RESTRICTED:
691 		*ap->a_retval = 200112;         /* _POSIX_CHOWN_RESTRICTED */
692 		return 0;
693 	case _PC_VDISABLE:
694 		*ap->a_retval = _POSIX_VDISABLE;
695 		return 0;
696 	default:
697 		return EINVAL;
698 	}
699 	/* NOTREACHED */
700 }
701 
702 /*
703  * /dev/fd "should never get here" operation
704  */
705 int
fdesc_badop(void)706 fdesc_badop(void)
707 {
708 	return ENOTSUP;
709 	/* NOTREACHED */
710 }
711 
712 #define VOPFUNC int (*)(void *)
713 
714 #define fdesc_create (int (*) (struct  vnop_create_args *))eopnotsupp
715 #define fdesc_mknod (int (*) (struct  vnop_mknod_args *))eopnotsupp
716 #define fdesc_close (int (*) (struct  vnop_close_args *))nullop
717 #define fdesc_access (int (*) (struct  vnop_access_args *))nullop
718 #define fdesc_mmap (int (*) (struct  vnop_mmap_args *))eopnotsupp
719 #define fdesc_revoke nop_revoke
720 #define fdesc_fsync (int (*) (struct  vnop_fsync_args *))nullop
721 #define fdesc_remove (int (*) (struct  vnop_remove_args *))eopnotsupp
722 #define fdesc_link (int (*) (struct  vnop_link_args *))eopnotsupp
723 #define fdesc_rename (int (*) (struct  vnop_rename_args *))eopnotsupp
724 #define fdesc_mkdir (int (*) (struct  vnop_mkdir_args *))eopnotsupp
725 #define fdesc_rmdir (int (*) (struct  vnop_rmdir_args *))eopnotsupp
726 #define fdesc_symlink (int (*) (struct vnop_symlink_args *))eopnotsupp
727 #define fdesc_strategy (int (*) (struct  vnop_strategy_args *))fdesc_badop
728 #define fdesc_advlock (int (*) (struct vnop_advlock_args *))eopnotsupp
729 #define fdesc_bwrite (int (*) (struct  vnop_bwrite_args *))eopnotsupp
730 #define fdesc_blktooff (int (*) (struct  vnop_blktooff_args *))eopnotsupp
731 #define fdesc_offtoblk (int (*) (struct  vnop_offtoblk_args *))eopnotsupp
732 #define fdesc_blockmap (int (*) (struct  vnop_blockmap_args *))eopnotsupp
733 
734 int(**fdesc_vnodeop_p)(void *);
735 const struct vnodeopv_entry_desc devfs_fdesc_vnodeop_entries[] = {
736 	{ .opve_op = &vnop_default_desc, .opve_impl = (VOPFUNC)vn_default_error },
737 	{ .opve_op = &vnop_lookup_desc, .opve_impl = (VOPFUNC)vn_default_error},        /* lookup */
738 	{ .opve_op = &vnop_create_desc, .opve_impl = (VOPFUNC)fdesc_create },   /* create */
739 	{ .opve_op = &vnop_mknod_desc, .opve_impl = (VOPFUNC)fdesc_mknod },     /* mknod */
740 	{ .opve_op = &vnop_open_desc, .opve_impl = (VOPFUNC)fdesc_open },       /* open */
741 	{ .opve_op = &vnop_close_desc, .opve_impl = (VOPFUNC)fdesc_close },     /* close */
742 	{ .opve_op = &vnop_access_desc, .opve_impl = (VOPFUNC)fdesc_access },   /* access */
743 	{ .opve_op = &vnop_getattr_desc, .opve_impl = (VOPFUNC)fdesc_getattr }, /* getattr */
744 	{ .opve_op = &vnop_setattr_desc, .opve_impl = (VOPFUNC)fdesc_setattr }, /* setattr */
745 	{ .opve_op = &vnop_read_desc, .opve_impl = (VOPFUNC)fdesc_read },       /* read */
746 	{ .opve_op = &vnop_write_desc, .opve_impl = (VOPFUNC)fdesc_write },     /* write */
747 	{ .opve_op = &vnop_ioctl_desc, .opve_impl = (VOPFUNC)fdesc_ioctl },     /* ioctl */
748 	{ .opve_op = &vnop_select_desc, .opve_impl = (VOPFUNC)fdesc_select },   /* select */
749 	{ .opve_op = &vnop_revoke_desc, .opve_impl = (VOPFUNC)fdesc_revoke },   /* revoke */
750 	{ .opve_op = &vnop_mmap_desc, .opve_impl = (VOPFUNC)fdesc_mmap },       /* mmap */
751 	{ .opve_op = &vnop_fsync_desc, .opve_impl = (VOPFUNC)fdesc_fsync },     /* fsync */
752 	{ .opve_op = &vnop_remove_desc, .opve_impl = (VOPFUNC)fdesc_remove },   /* remove */
753 	{ .opve_op = &vnop_link_desc, .opve_impl = (VOPFUNC)fdesc_link },       /* link */
754 	{ .opve_op = &vnop_rename_desc, .opve_impl =  (VOPFUNC)fdesc_rename },   /* rename */
755 	{ .opve_op = &vnop_mkdir_desc, .opve_impl = (VOPFUNC)fdesc_mkdir },     /* mkdir */
756 	{ .opve_op = &vnop_rmdir_desc, .opve_impl = (VOPFUNC)fdesc_rmdir },     /* rmdir */
757 	{ .opve_op = &vnop_symlink_desc, .opve_impl = (VOPFUNC)fdesc_symlink }, /* symlink */
758 	{ .opve_op = &vnop_readdir_desc, .opve_impl = (VOPFUNC)vn_default_error},/* readdir */
759 	{ .opve_op = &vnop_readlink_desc, .opve_impl = (VOPFUNC)err_readlink}, /* readlink */
760 	{ .opve_op = &vnop_inactive_desc, .opve_impl = (VOPFUNC)fdesc_inactive },/* inactive */
761 	{ .opve_op = &vnop_reclaim_desc, .opve_impl = (VOPFUNC)fdesc_reclaim }, /* reclaim */
762 	{ .opve_op = &vnop_strategy_desc, .opve_impl = (VOPFUNC)fdesc_strategy },       /* strategy */
763 	{ .opve_op = &vnop_pathconf_desc, .opve_impl = (VOPFUNC)fdesc_pathconf },       /* pathconf */
764 	{ .opve_op = &vnop_advlock_desc, .opve_impl = (VOPFUNC)fdesc_advlock }, /* advlock */
765 	{ .opve_op = &vnop_bwrite_desc, .opve_impl = (VOPFUNC)fdesc_bwrite },   /* bwrite */
766 	{ .opve_op = &vnop_pagein_desc, .opve_impl = (VOPFUNC)err_pagein },     /* pagein */
767 	{ .opve_op = &vnop_pageout_desc, .opve_impl = (VOPFUNC)err_pageout },   /* pageout */
768 	{ .opve_op = &vnop_copyfile_desc, .opve_impl = (VOPFUNC)err_copyfile }, /* Copyfile */
769 	{ .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)fdesc_blktooff },       /* blktooff */
770 	{ .opve_op = &vnop_blktooff_desc, .opve_impl = (VOPFUNC)fdesc_offtoblk },       /* offtoblk */
771 	{ .opve_op = &vnop_blockmap_desc, .opve_impl = (VOPFUNC)fdesc_blockmap },       /* blockmap */
772 	{ .opve_op = (struct vnodeop_desc*)NULL, .opve_impl = (VOPFUNC)NULL }
773 };
774 
775 const struct vnodeopv_desc devfs_fdesc_vnodeop_opv_desc =
776 { .opv_desc_vector_p = &fdesc_vnodeop_p, .opv_desc_ops = devfs_fdesc_vnodeop_entries };
777