xref: /netbsd-src/sys/miscfs/fdesc/fdesc_vnops.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: fdesc_vnops.c,v 1.129 2017/05/26 14:21:01 riastradh Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)fdesc_vnops.c	8.17 (Berkeley) 5/22/95
35  *
36  * #Id: fdesc_vnops.c,v 1.12 1993/04/06 16:17:17 jsp Exp #
37  */
38 
39 /*
40  * /dev/fd Filesystem
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: fdesc_vnops.c,v 1.129 2017/05/26 14:21:01 riastradh Exp $");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/time.h>
49 #include <sys/proc.h>
50 #include <sys/kernel.h>	/* boottime */
51 #include <sys/resourcevar.h>
52 #include <sys/socketvar.h>
53 #include <sys/filedesc.h>
54 #include <sys/vnode.h>
55 #include <sys/malloc.h>
56 #include <sys/conf.h>
57 #include <sys/file.h>
58 #include <sys/stat.h>
59 #include <sys/mount.h>
60 #include <sys/namei.h>
61 #include <sys/buf.h>
62 #include <sys/dirent.h>
63 #include <sys/tty.h>
64 #include <sys/kauth.h>
65 #include <sys/atomic.h>
66 
67 #include <miscfs/fdesc/fdesc.h>
68 #include <miscfs/genfs/genfs.h>
69 
70 #define cttyvp(p) ((p)->p_lflag & PL_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
71 
72 dev_t devctty;
73 
74 #if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
75 FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
76 #endif
77 
78 int	fdesc_lookup(void *);
79 #define	fdesc_create	genfs_eopnotsupp
80 #define	fdesc_mknod	genfs_eopnotsupp
81 int	fdesc_open(void *);
82 #define	fdesc_close	genfs_nullop
83 #define	fdesc_access	genfs_nullop
84 int	fdesc_getattr(void *);
85 int	fdesc_setattr(void *);
86 int	fdesc_read(void *);
87 int	fdesc_write(void *);
88 int	fdesc_ioctl(void *);
89 int	fdesc_poll(void *);
90 int	fdesc_kqfilter(void *);
91 #define	fdesc_mmap	genfs_eopnotsupp
92 #define	fdesc_fcntl	genfs_fcntl
93 #define	fdesc_fsync	genfs_nullop
94 #define	fdesc_seek	genfs_seek
95 #define	fdesc_remove	genfs_eopnotsupp
96 int	fdesc_link(void *);
97 #define	fdesc_rename	genfs_eopnotsupp
98 #define	fdesc_mkdir	genfs_eopnotsupp
99 #define	fdesc_rmdir	genfs_eopnotsupp
100 int	fdesc_symlink(void *);
101 int	fdesc_readdir(void *);
102 int	fdesc_readlink(void *);
103 #define	fdesc_abortop	genfs_abortop
104 int	fdesc_inactive(void *);
105 int	fdesc_reclaim(void *);
106 #define	fdesc_lock	genfs_lock
107 #define	fdesc_unlock	genfs_unlock
108 #define	fdesc_bmap	genfs_badop
109 #define	fdesc_strategy	genfs_badop
110 int	fdesc_print(void *);
111 int	fdesc_pathconf(void *);
112 #define	fdesc_islocked	genfs_islocked
113 #define	fdesc_advlock	genfs_einval
114 #define	fdesc_bwrite	genfs_eopnotsupp
115 #define fdesc_revoke	genfs_revoke
116 #define fdesc_putpages	genfs_null_putpages
117 
118 static int fdesc_attr(int, struct vattr *, kauth_cred_t);
119 
120 int (**fdesc_vnodeop_p)(void *);
121 const struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
122 	{ &vop_default_desc, vn_default_error },
123 	{ &vop_lookup_desc, fdesc_lookup },		/* lookup */
124 	{ &vop_create_desc, fdesc_create },		/* create */
125 	{ &vop_mknod_desc, fdesc_mknod },		/* mknod */
126 	{ &vop_open_desc, fdesc_open },			/* open */
127 	{ &vop_close_desc, fdesc_close },		/* close */
128 	{ &vop_access_desc, fdesc_access },		/* access */
129 	{ &vop_getattr_desc, fdesc_getattr },		/* getattr */
130 	{ &vop_setattr_desc, fdesc_setattr },		/* setattr */
131 	{ &vop_read_desc, fdesc_read },			/* read */
132 	{ &vop_write_desc, fdesc_write },		/* write */
133 	{ &vop_fallocate_desc, genfs_eopnotsupp },	/* fallocate */
134 	{ &vop_fdiscard_desc, genfs_eopnotsupp },	/* fdiscard */
135 	{ &vop_ioctl_desc, fdesc_ioctl },		/* ioctl */
136 	{ &vop_fcntl_desc, fdesc_fcntl },		/* fcntl */
137 	{ &vop_poll_desc, fdesc_poll },			/* poll */
138 	{ &vop_kqfilter_desc, fdesc_kqfilter },		/* kqfilter */
139 	{ &vop_revoke_desc, fdesc_revoke },		/* revoke */
140 	{ &vop_mmap_desc, fdesc_mmap },			/* mmap */
141 	{ &vop_fsync_desc, fdesc_fsync },		/* fsync */
142 	{ &vop_seek_desc, fdesc_seek },			/* seek */
143 	{ &vop_remove_desc, fdesc_remove },		/* remove */
144 	{ &vop_link_desc, fdesc_link },			/* link */
145 	{ &vop_rename_desc, fdesc_rename },		/* rename */
146 	{ &vop_mkdir_desc, fdesc_mkdir },		/* mkdir */
147 	{ &vop_rmdir_desc, fdesc_rmdir },		/* rmdir */
148 	{ &vop_symlink_desc, fdesc_symlink },		/* symlink */
149 	{ &vop_readdir_desc, fdesc_readdir },		/* readdir */
150 	{ &vop_readlink_desc, fdesc_readlink },		/* readlink */
151 	{ &vop_abortop_desc, fdesc_abortop },		/* abortop */
152 	{ &vop_inactive_desc, fdesc_inactive },		/* inactive */
153 	{ &vop_reclaim_desc, fdesc_reclaim },		/* reclaim */
154 	{ &vop_lock_desc, fdesc_lock },			/* lock */
155 	{ &vop_unlock_desc, fdesc_unlock },		/* unlock */
156 	{ &vop_bmap_desc, fdesc_bmap },			/* bmap */
157 	{ &vop_strategy_desc, fdesc_strategy },		/* strategy */
158 	{ &vop_print_desc, fdesc_print },		/* print */
159 	{ &vop_islocked_desc, fdesc_islocked },		/* islocked */
160 	{ &vop_pathconf_desc, fdesc_pathconf },		/* pathconf */
161 	{ &vop_advlock_desc, fdesc_advlock },		/* advlock */
162 	{ &vop_bwrite_desc, fdesc_bwrite },		/* bwrite */
163 	{ &vop_putpages_desc, fdesc_putpages },		/* putpages */
164 	{ NULL, NULL }
165 };
166 
167 const struct vnodeopv_desc fdesc_vnodeop_opv_desc =
168 	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
169 
170 /*
171  * Initialise cache headers
172  */
173 void
174 fdesc_init(void)
175 {
176 	int cttymajor;
177 
178 	/* locate the major number */
179 	cttymajor = devsw_name2chr("ctty", NULL, 0);
180 	devctty = makedev(cttymajor, 0);
181 }
182 
183 void
184 fdesc_done(void)
185 {
186 }
187 
188 /*
189  * vp is the current namei directory
190  * ndp is the name to locate in that directory...
191  */
192 int
193 fdesc_lookup(void *v)
194 {
195 	struct vop_lookup_v2_args /* {
196 		struct vnode * a_dvp;
197 		struct vnode ** a_vpp;
198 		struct componentname * a_cnp;
199 	} */ *ap = v;
200 	struct vnode **vpp = ap->a_vpp;
201 	struct vnode *dvp = ap->a_dvp;
202 	struct componentname *cnp = ap->a_cnp;
203 	struct lwp *l = curlwp;
204 	const char *pname = cnp->cn_nameptr;
205 	struct proc *p = l->l_proc;
206 	unsigned fd = 0;
207 	int error, ix = -1;
208 	fdtab_t *dt;
209 
210 	dt = curlwp->l_fd->fd_dt;
211 
212 	if (cnp->cn_namelen == 1 && *pname == '.') {
213 		*vpp = dvp;
214 		vref(dvp);
215 		return (0);
216 	}
217 
218 	switch (VTOFDESC(dvp)->fd_type) {
219 	default:
220 	case Flink:
221 	case Fdesc:
222 	case Fctty:
223 		error = ENOTDIR;
224 		goto bad;
225 
226 	case Froot:
227 		if (cnp->cn_namelen == 2 && memcmp(pname, "fd", 2) == 0) {
228 			ix = FD_DEVFD;
229 			goto good;
230 		}
231 
232 		if (cnp->cn_namelen == 3 && memcmp(pname, "tty", 3) == 0) {
233 			struct vnode *ttyvp = cttyvp(p);
234 			if (ttyvp == NULL) {
235 				error = ENXIO;
236 				goto bad;
237 			}
238 			ix = FD_CTTY;
239 			goto good;
240 		}
241 
242 		switch (cnp->cn_namelen) {
243 		case 5:
244 			if (memcmp(pname, "stdin", 5) == 0) {
245 				ix = FD_STDIN;
246 				goto good;
247 			}
248 			break;
249 		case 6:
250 			if (memcmp(pname, "stdout", 6) == 0) {
251 				ix = FD_STDOUT;
252 				goto good;
253 			} else if (memcmp(pname, "stderr", 6) == 0) {
254 				ix = FD_STDERR;
255 				goto good;
256 			}
257 			break;
258 		}
259 
260 		error = ENOENT;
261 		goto bad;
262 
263 	case Fdevfd:
264 		if (cnp->cn_namelen == 2 && memcmp(pname, "..", 2) == 0) {
265 			ix = FD_ROOT;
266 			goto good;
267 		}
268 
269 		fd = 0;
270 		while (*pname >= '0' && *pname <= '9') {
271 			fd = 10 * fd + *pname++ - '0';
272 			if (fd >= dt->dt_nfiles)
273 				break;
274 		}
275 
276 		if (*pname != '\0') {
277 			error = ENOENT;
278 			goto bad;
279 		}
280 
281 		if (fd >= dt->dt_nfiles || dt->dt_ff[fd] == NULL ||
282 		    dt->dt_ff[fd]->ff_file == NULL) {
283 			error = EBADF;
284 			goto bad;
285 		}
286 
287 		ix = FD_DESC + fd;
288 		goto good;
289 	}
290 
291 bad:
292 	*vpp = NULL;
293 	return error;
294 
295 good:
296 	KASSERT(ix != -1);
297 	error = vcache_get(dvp->v_mount, &ix, sizeof(ix), vpp);
298 	if (error == 0 && ix == FD_CTTY)
299 		(*vpp)->v_type = VCHR;
300 	return error;
301 }
302 
303 int
304 fdesc_open(void *v)
305 {
306 	struct vop_open_args /* {
307 		struct vnode *a_vp;
308 		int  a_mode;
309 		kauth_cred_t a_cred;
310 	} */ *ap = v;
311 	struct vnode *vp = ap->a_vp;
312 
313 	switch (VTOFDESC(vp)->fd_type) {
314 	case Fdesc:
315 		/*
316 		 * XXX Kludge: set dupfd to contain the value of the
317 		 * the file descriptor being sought for duplication. The error
318 		 * return ensures that the vnode for this device will be
319 		 * released by vn_open. Open will detect this special error and
320 		 * take the actions in dupfdopen.  Other callers of vn_open or
321 		 * VOP_OPEN will simply report the error.
322 		 */
323 		curlwp->l_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
324 		return EDUPFD;
325 
326 	case Fctty:
327 		return cdev_open(devctty, ap->a_mode, 0, curlwp);
328 	case Froot:
329 	case Fdevfd:
330 	case Flink:
331 		break;
332 	}
333 
334 	return (0);
335 }
336 
337 static int
338 fdesc_attr(int fd, struct vattr *vap, kauth_cred_t cred)
339 {
340 	file_t *fp;
341 	struct stat stb;
342 	int error;
343 
344 	if ((fp = fd_getfile(fd)) == NULL)
345 		return (EBADF);
346 
347 	switch (fp->f_type) {
348 	case DTYPE_VNODE:
349 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
350 		error = VOP_GETATTR(fp->f_vnode, vap, cred);
351 		VOP_UNLOCK(fp->f_vnode);
352 		if (error == 0 && vap->va_type == VDIR) {
353 			/*
354 			 * directories can cause loops in the namespace,
355 			 * so turn off the 'x' bits to avoid trouble.
356 			 */
357 			vap->va_mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
358 		}
359 		break;
360 
361 	default:
362 		memset(&stb, 0, sizeof(stb));
363 		error = (*fp->f_ops->fo_stat)(fp, &stb);
364 		if (error)
365 			break;
366 
367 		vattr_null(vap);
368 		switch(fp->f_type) {
369 		case DTYPE_SOCKET:
370 			vap->va_type = VSOCK;
371 			break;
372 		case DTYPE_PIPE:
373 			vap->va_type = VFIFO;
374 			break;
375 		default:
376 			/* use VNON perhaps? */
377 			vap->va_type = VBAD;
378 			break;
379 		}
380 		vap->va_mode = stb.st_mode;
381 		vap->va_nlink = stb.st_nlink;
382 		vap->va_uid = stb.st_uid;
383 		vap->va_gid = stb.st_gid;
384 		vap->va_fsid = stb.st_dev;
385 		vap->va_fileid = stb.st_ino;
386 		vap->va_size = stb.st_size;
387 		vap->va_blocksize = stb.st_blksize;
388 		vap->va_atime = stb.st_atimespec;
389 		vap->va_mtime = stb.st_mtimespec;
390 		vap->va_ctime = stb.st_ctimespec;
391 		vap->va_gen = stb.st_gen;
392 		vap->va_flags = stb.st_flags;
393 		vap->va_rdev = stb.st_rdev;
394 		vap->va_bytes = stb.st_blocks * stb.st_blksize;
395 		break;
396 	}
397 
398 	fd_putfile(fd);
399 	return (error);
400 }
401 
402 int
403 fdesc_getattr(void *v)
404 {
405 	struct vop_getattr_args /* {
406 		struct vnode *a_vp;
407 		struct vattr *a_vap;
408 		kauth_cred_t a_cred;
409 		struct lwp *a_l;
410 	} */ *ap = v;
411 	struct vnode *vp = ap->a_vp;
412 	struct vattr *vap = ap->a_vap;
413 	unsigned fd;
414 	int error = 0;
415 
416 	switch (VTOFDESC(vp)->fd_type) {
417 	case Froot:
418 	case Fdevfd:
419 	case Flink:
420 	case Fctty:
421 		vattr_null(vap);
422 		vap->va_fileid = VTOFDESC(vp)->fd_ix;
423 
424 #define R_ALL (S_IRUSR|S_IRGRP|S_IROTH)
425 #define W_ALL (S_IWUSR|S_IWGRP|S_IWOTH)
426 #define X_ALL (S_IXUSR|S_IXGRP|S_IXOTH)
427 
428 		switch (VTOFDESC(vp)->fd_type) {
429 		case Flink:
430 			vap->va_mode = R_ALL|X_ALL;
431 			vap->va_type = VLNK;
432 			vap->va_rdev = 0;
433 			vap->va_nlink = 1;
434 			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
435 			break;
436 
437 		case Fctty:
438 			vap->va_mode = R_ALL|W_ALL;
439 			vap->va_type = VCHR;
440 			vap->va_rdev = devctty;
441 			vap->va_nlink = 1;
442 			vap->va_size = 0;
443 			break;
444 
445 		default:
446 			vap->va_mode = R_ALL|X_ALL;
447 			vap->va_type = VDIR;
448 			vap->va_rdev = 0;
449 			vap->va_nlink = 2;
450 			vap->va_size = DEV_BSIZE;
451 			break;
452 		}
453 		vap->va_uid = 0;
454 		vap->va_gid = 0;
455 		vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
456 		vap->va_blocksize = DEV_BSIZE;
457 		vap->va_atime.tv_sec = boottime.tv_sec;
458 		vap->va_atime.tv_nsec = 0;
459 		vap->va_mtime = vap->va_atime;
460 		vap->va_ctime = vap->va_mtime;
461 		vap->va_gen = 0;
462 		vap->va_flags = 0;
463 		vap->va_bytes = 0;
464 		break;
465 
466 	case Fdesc:
467 		fd = VTOFDESC(vp)->fd_fd;
468 		error = fdesc_attr(fd, vap, ap->a_cred);
469 		break;
470 
471 	default:
472 		panic("fdesc_getattr");
473 		break;
474 	}
475 
476 	if (error == 0)
477 		vp->v_type = vap->va_type;
478 
479 	return (error);
480 }
481 
482 int
483 fdesc_setattr(void *v)
484 {
485 	struct vop_setattr_args /* {
486 		struct vnode *a_vp;
487 		struct vattr *a_vap;
488 		kauth_cred_t a_cred;
489 	} */ *ap = v;
490 	file_t *fp;
491 	unsigned fd;
492 
493 	/*
494 	 * Can't mess with the root vnode
495 	 */
496 	switch (VTOFDESC(ap->a_vp)->fd_type) {
497 	case Fdesc:
498 		break;
499 
500 	case Fctty:
501 		return (0);
502 
503 	default:
504 		return (EACCES);
505 	}
506 
507 	fd = VTOFDESC(ap->a_vp)->fd_fd;
508 	if ((fp = fd_getfile(fd)) == NULL)
509 		return (EBADF);
510 
511 	/*
512 	 * XXX: Can't reasonably set the attr's on any types currently.
513 	 *      On vnode's this will cause truncation and socket/pipes make
514 	 *      no sense.
515 	 */
516 	fd_putfile(fd);
517 	return (0);
518 }
519 
520 
521 struct fdesc_target {
522 	ino_t ft_fileno;
523 	u_char ft_type;
524 	u_char ft_namlen;
525 	const char *ft_name;
526 } fdesc_targets[] = {
527 #define N(s) sizeof(s)-1, s
528 	{ FD_DEVFD,  DT_DIR,     N("fd")     },
529 	{ FD_STDIN,  DT_LNK,     N("stdin")  },
530 	{ FD_STDOUT, DT_LNK,     N("stdout") },
531 	{ FD_STDERR, DT_LNK,     N("stderr") },
532 	{ FD_CTTY,   DT_UNKNOWN, N("tty")    },
533 #undef N
534 #define UIO_MX _DIRENT_RECLEN((struct dirent *)NULL, sizeof("stderr") - 1)
535 };
536 static int nfdesc_targets = sizeof(fdesc_targets) / sizeof(fdesc_targets[0]);
537 
538 int
539 fdesc_readdir(void *v)
540 {
541 	struct vop_readdir_args /* {
542 		struct vnode *a_vp;
543 		struct uio *a_uio;
544 		kauth_cred_t a_cred;
545 		int *a_eofflag;
546 		off_t **a_cookies;
547 		int *a_ncookies;
548 	} */ *ap = v;
549 	struct uio *uio = ap->a_uio;
550 	struct dirent d;
551 	off_t i;
552 	int j;
553 	int error;
554 	off_t *cookies = NULL;
555 	int ncookies;
556 	fdtab_t *dt;
557 
558 	switch (VTOFDESC(ap->a_vp)->fd_type) {
559 	case Fctty:
560 		return 0;
561 
562 	case Fdesc:
563 		return ENOTDIR;
564 
565 	default:
566 		break;
567 	}
568 
569 	dt = curlwp->l_fd->fd_dt;
570 
571 	if (uio->uio_resid < UIO_MX)
572 		return EINVAL;
573 	if (uio->uio_offset < 0)
574 		return EINVAL;
575 
576 	error = 0;
577 	i = uio->uio_offset;
578 	(void)memset(&d, 0, UIO_MX);
579 	d.d_reclen = UIO_MX;
580 	if (ap->a_ncookies)
581 		ncookies = uio->uio_resid / UIO_MX;
582 	else
583 		ncookies = 0;
584 
585 	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
586 		struct fdesc_target *ft;
587 
588 		if (i >= nfdesc_targets)
589 			return 0;
590 
591 		if (ap->a_ncookies) {
592 			ncookies = min(ncookies, (nfdesc_targets - i));
593 			cookies = malloc(ncookies * sizeof(off_t),
594 			    M_TEMP, M_WAITOK);
595 			*ap->a_cookies = cookies;
596 			*ap->a_ncookies = ncookies;
597 		}
598 
599 		for (ft = &fdesc_targets[i]; uio->uio_resid >= UIO_MX &&
600 		    i < nfdesc_targets; ft++, i++) {
601 			switch (ft->ft_fileno) {
602 			case FD_CTTY:
603 				if (cttyvp(curproc) == NULL)
604 					continue;
605 				break;
606 
607 			case FD_STDIN:
608 			case FD_STDOUT:
609 			case FD_STDERR:
610 				if ((ft->ft_fileno - FD_STDIN) >=
611 				    dt->dt_nfiles)
612 					continue;
613 				if (dt->dt_ff[ft->ft_fileno - FD_STDIN]
614 				    == NULL || dt->dt_ff[ft->ft_fileno -
615 				    FD_STDIN]->ff_file == NULL)
616 					continue;
617 				break;
618 			}
619 
620 			d.d_fileno = ft->ft_fileno;
621 			d.d_namlen = ft->ft_namlen;
622 			(void)memcpy(d.d_name, ft->ft_name, ft->ft_namlen + 1);
623 			d.d_type = ft->ft_type;
624 
625 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
626 				break;
627 			if (cookies)
628 				*cookies++ = i + 1;
629 		}
630 	} else {
631 		membar_consumer();
632 		if (ap->a_ncookies) {
633 			ncookies = min(ncookies, dt->dt_nfiles + 2);
634 			cookies = malloc(ncookies * sizeof(off_t),
635 			    M_TEMP, M_WAITOK);
636 			*ap->a_cookies = cookies;
637 			*ap->a_ncookies = ncookies;
638 		}
639 		for (; i - 2 < dt->dt_nfiles && uio->uio_resid >= UIO_MX; i++) {
640 			switch (i) {
641 			case 0:
642 			case 1:
643 				d.d_fileno = FD_ROOT;		/* XXX */
644 				d.d_namlen = i + 1;
645 				(void)memcpy(d.d_name, "..", d.d_namlen);
646 				d.d_name[i + 1] = '\0';
647 				d.d_type = DT_DIR;
648 				break;
649 
650 			default:
651 				j = (int)i - 2;
652 				if (dt->dt_ff[j] == NULL ||
653 				    dt->dt_ff[j]->ff_file == NULL)
654 					continue;
655 				d.d_fileno = j + FD_STDIN;
656 				d.d_namlen = snprintf(d.d_name,
657 				    sizeof(d.d_name), "%d", j);
658 				d.d_type = DT_UNKNOWN;
659 				break;
660 			}
661 
662 			if ((error = uiomove(&d, UIO_MX, uio)) != 0)
663 				break;
664 			if (cookies)
665 				*cookies++ = i + 1;
666 		}
667 	}
668 
669 	if (ap->a_ncookies && error) {
670 		free(*ap->a_cookies, M_TEMP);
671 		*ap->a_ncookies = 0;
672 		*ap->a_cookies = NULL;
673 	}
674 
675 	uio->uio_offset = i;
676 	return error;
677 }
678 
679 int
680 fdesc_readlink(void *v)
681 {
682 	struct vop_readlink_args /* {
683 		struct vnode *a_vp;
684 		struct uio *a_uio;
685 		kauth_cred_t a_cred;
686 	} */ *ap = v;
687 	struct vnode *vp = ap->a_vp;
688 	int error;
689 
690 	if (vp->v_type != VLNK)
691 		return (EPERM);
692 
693 	if (VTOFDESC(vp)->fd_type == Flink) {
694 		const char *ln = VTOFDESC(vp)->fd_link;
695 		error = uiomove(__UNCONST(ln), strlen(ln), ap->a_uio);
696 	} else {
697 		error = EOPNOTSUPP;
698 	}
699 
700 	return (error);
701 }
702 
703 int
704 fdesc_read(void *v)
705 {
706 	struct vop_read_args /* {
707 		struct vnode *a_vp;
708 		struct uio *a_uio;
709 		int  a_ioflag;
710 		kauth_cred_t a_cred;
711 	} */ *ap = v;
712 	int error = EOPNOTSUPP;
713 	struct vnode *vp = ap->a_vp;
714 
715 	switch (VTOFDESC(vp)->fd_type) {
716 	case Fctty:
717 		VOP_UNLOCK(vp);
718 		error = cdev_read(devctty, ap->a_uio, ap->a_ioflag);
719 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
720 		break;
721 
722 	default:
723 		error = EOPNOTSUPP;
724 		break;
725 	}
726 
727 	return (error);
728 }
729 
730 int
731 fdesc_write(void *v)
732 {
733 	struct vop_write_args /* {
734 		struct vnode *a_vp;
735 		struct uio *a_uio;
736 		int  a_ioflag;
737 		kauth_cred_t a_cred;
738 	} */ *ap = v;
739 	int error = EOPNOTSUPP;
740 	struct vnode *vp = ap->a_vp;
741 
742 	switch (VTOFDESC(vp)->fd_type) {
743 	case Fctty:
744 		VOP_UNLOCK(vp);
745 		error = cdev_write(devctty, ap->a_uio, ap->a_ioflag);
746 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
747 		break;
748 
749 	default:
750 		error = EOPNOTSUPP;
751 		break;
752 	}
753 
754 	return (error);
755 }
756 
757 int
758 fdesc_ioctl(void *v)
759 {
760 	struct vop_ioctl_args /* {
761 		struct vnode *a_vp;
762 		u_long a_command;
763 		void *a_data;
764 		int  a_fflag;
765 		kauth_cred_t a_cred;
766 	} */ *ap = v;
767 	int error = EOPNOTSUPP;
768 
769 	switch (VTOFDESC(ap->a_vp)->fd_type) {
770 	case Fctty:
771 		error = cdev_ioctl(devctty, ap->a_command, ap->a_data,
772 		    ap->a_fflag, curlwp);
773 		break;
774 
775 	default:
776 		error = EOPNOTSUPP;
777 		break;
778 	}
779 
780 	return (error);
781 }
782 
783 int
784 fdesc_poll(void *v)
785 {
786 	struct vop_poll_args /* {
787 		struct vnode *a_vp;
788 		int a_events;
789 	} */ *ap = v;
790 	int revents;
791 
792 	switch (VTOFDESC(ap->a_vp)->fd_type) {
793 	case Fctty:
794 		revents = cdev_poll(devctty, ap->a_events, curlwp);
795 		break;
796 
797 	default:
798 		revents = genfs_poll(v);
799 		break;
800 	}
801 
802 	return (revents);
803 }
804 
805 int
806 fdesc_kqfilter(void *v)
807 {
808 	struct vop_kqfilter_args /* {
809 		struct vnode *a_vp;
810 		struct knote *a_kn;
811 	} */ *ap = v;
812 	int error, fd;
813 	file_t *fp;
814 
815 	switch (VTOFDESC(ap->a_vp)->fd_type) {
816 	case Fctty:
817 		error = cdev_kqfilter(devctty, ap->a_kn);
818 		break;
819 
820 	case Fdesc:
821 		/* just invoke kqfilter for the underlying descriptor */
822 		fd = VTOFDESC(ap->a_vp)->fd_fd;
823 		if ((fp = fd_getfile(fd)) == NULL)
824 			return (1);
825 		error = (*fp->f_ops->fo_kqfilter)(fp, ap->a_kn);
826 		fd_putfile(fd);
827 		break;
828 
829 	default:
830 		return (genfs_kqfilter(v));
831 	}
832 
833 	return (error);
834 }
835 
836 int
837 fdesc_inactive(void *v)
838 {
839 	struct vop_inactive_v2_args /* {
840 		struct vnode *a_vp;
841 	} */ *ap = v;
842 	struct vnode *vp = ap->a_vp;
843 	struct fdescnode *fd = VTOFDESC(vp);
844 
845 	/*
846 	 * Clear out the v_type field to avoid
847 	 * nasty things happening on reclaim.
848 	 */
849 	if (fd->fd_type == Fctty || fd->fd_type == Fdesc)
850 		vp->v_type = VNON;
851 
852 	return (0);
853 }
854 
855 int
856 fdesc_reclaim(void *v)
857 {
858 	struct vop_reclaim_v2_args /* {
859 		struct vnode *a_vp;
860 	} */ *ap = v;
861 	struct vnode *vp = ap->a_vp;
862 	struct fdescnode *fd = VTOFDESC(vp);
863 
864 	VOP_UNLOCK(vp);
865 
866 	vp->v_data = NULL;
867 	kmem_free(fd, sizeof(struct fdescnode));
868 
869 	return (0);
870 }
871 
872 /*
873  * Return POSIX pathconf information applicable to special devices.
874  */
875 int
876 fdesc_pathconf(void *v)
877 {
878 	struct vop_pathconf_args /* {
879 		struct vnode *a_vp;
880 		int a_name;
881 		register_t *a_retval;
882 	} */ *ap = v;
883 
884 	switch (ap->a_name) {
885 	case _PC_LINK_MAX:
886 		*ap->a_retval = LINK_MAX;
887 		return (0);
888 	case _PC_MAX_CANON:
889 		*ap->a_retval = MAX_CANON;
890 		return (0);
891 	case _PC_MAX_INPUT:
892 		*ap->a_retval = MAX_INPUT;
893 		return (0);
894 	case _PC_PIPE_BUF:
895 		*ap->a_retval = PIPE_BUF;
896 		return (0);
897 	case _PC_CHOWN_RESTRICTED:
898 		*ap->a_retval = 1;
899 		return (0);
900 	case _PC_VDISABLE:
901 		*ap->a_retval = _POSIX_VDISABLE;
902 		return (0);
903 	case _PC_SYNC_IO:
904 		*ap->a_retval = 1;
905 		return (0);
906 	default:
907 		return (EINVAL);
908 	}
909 	/* NOTREACHED */
910 }
911 
912 /*
913  * Print out the contents of a /dev/fd vnode.
914  */
915 /* ARGSUSED */
916 int
917 fdesc_print(void *v)
918 {
919 	printf("tag VT_NON, fdesc vnode\n");
920 	return (0);
921 }
922 
923 int
924 fdesc_link(void *v)
925 {
926 	struct vop_link_v2_args /* {
927 		struct vnode *a_dvp;
928 		struct vnode *a_vp;
929 		struct componentname *a_cnp;
930 	} */ *ap = v;
931 
932 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
933 	return (EROFS);
934 }
935 
936 int
937 fdesc_symlink(void *v)
938 {
939 	struct vop_symlink_v3_args /* {
940 		struct vnode *a_dvp;
941 		struct vnode **a_vpp;
942 		struct componentname *a_cnp;
943 		struct vattr *a_vap;
944 		char *a_target;
945 	} */ *ap = v;
946 
947 	VOP_ABORTOP(ap->a_dvp, ap->a_cnp);
948 	return (EROFS);
949 }
950