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ptyfs_vfsops.c revision 1.3 
      1 /*	$NetBSD: ptyfs_vfsops.c,v 1.3 2004/11/25 05:15:10 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993, 1995
      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  */
     35 
     36 /*
     37  * Pseudo-tty Filesystem
     38  */
     39 
     40 #include <sys/cdefs.h>
     41 __KERNEL_RCSID(0, "$NetBSD: ptyfs_vfsops.c,v 1.3 2004/11/25 05:15:10 christos Exp $");
     42 
     43 #include <sys/param.h>
     44 #include <sys/systm.h>
     45 #include <sys/sysctl.h>
     46 #include <sys/conf.h>
     47 #include <sys/proc.h>
     48 #include <sys/vnode.h>
     49 #include <sys/mount.h>
     50 #include <sys/namei.h>
     51 #include <sys/stat.h>
     52 #include <sys/dirent.h>
     53 #include <sys/malloc.h>
     54 #include <sys/syslog.h>
     55 #include <sys/select.h>
     56 #include <sys/tty.h>
     57 #include <sys/pty.h>
     58 
     59 #include <fs/ptyfs/ptyfs.h>
     60 #include <miscfs/specfs/specdev.h>
     61 
     62 MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures");
     63 
     64 void	ptyfs_init(void);
     65 void	ptyfs_reinit(void);
     66 void	ptyfs_done(void);
     67 int	ptyfs_mount(struct mount *, const char *, void *, struct nameidata *,
     68     struct proc *);
     69 int	ptyfs_start(struct mount *, int, struct proc *);
     70 int	ptyfs_unmount(struct mount *, int, struct proc *);
     71 int	ptyfs_statvfs(struct mount *, struct statvfs *, struct proc *);
     72 int	ptyfs_quotactl(struct mount *, int, uid_t, void *, struct proc *);
     73 int	ptyfs_sync(struct mount *, int, struct ucred *, struct proc *);
     74 int	ptyfs_vget(struct mount *, ino_t, struct vnode **);
     75 int	ptyfs_fhtovp(struct mount *, struct fid *, struct vnode **);
     76 int	ptyfs_checkexp(struct mount *, struct mbuf *, int *, struct ucred **);
     77 int	ptyfs_vptofh(struct vnode *, struct fid *);
     78 
     79 static int ptyfs__allocvp(struct ptm_pty *, struct proc *, struct vnode **,
     80     dev_t, char);
     81 static int ptyfs__makename(struct ptm_pty *, char *, size_t, dev_t, char);
     82 static void ptyfs__getvattr(struct ptm_pty *, struct proc *, struct vattr *);
     83 
     84 /*
     85  * ptm glue: When we mount, we make ptm point to us.
     86  */
     87 struct ptm_pty *ptyfs_save_ptm;
     88 
     89 struct ptm_pty ptm_ptyfspty = {
     90 	ptyfs__allocvp,
     91 	ptyfs__makename,
     92 	ptyfs__getvattr,
     93 	NULL
     94 };
     95 
     96 static int
     97 ptyfs__makename(struct ptm_pty *pt, char *buf, size_t bufsiz, dev_t dev,
     98     char ms)
     99 {
    100 	struct mount *mp = pt->arg;
    101 	size_t len;
    102 
    103 	switch (ms) {
    104 	case 'p':
    105 		/* We don't provide access to the master, should we? */
    106 		len = snprintf(buf, bufsiz, "/dev/null");
    107 		break;
    108 	case 't':
    109 		len = snprintf(buf, bufsiz, "%s/%d", mp->mnt_stat.f_mntonname,
    110 		    minor(dev));
    111 		break;
    112 	default:
    113 		return EINVAL;
    114 	}
    115 
    116 	return len >= bufsiz ? ENOSPC : 0;
    117 }
    118 
    119 
    120 static int
    121 /*ARGSUSED*/
    122 ptyfs__allocvp(struct ptm_pty *pt, struct proc *p, struct vnode **vpp,
    123     dev_t dev, char ms)
    124 {
    125 	struct mount *mp = pt->arg;
    126 	ptyfstype type;
    127 
    128 	switch (ms) {
    129 	case 'p':
    130 		type = PTYFSptc;
    131 		break;
    132 	case 't':
    133 		type = PTYFSpts;
    134 		break;
    135 	default:
    136 		return EINVAL;
    137 	}
    138 
    139 	return ptyfs_allocvp(mp, vpp, type, minor(dev), p);
    140 }
    141 
    142 
    143 static void
    144 ptyfs__getvattr(struct ptm_pty *pt, struct proc *p, struct vattr *vattr)
    145 {
    146 	struct mount *mp = pt->arg;
    147 	struct ptyfsmount *pmnt = VFSTOPTY(mp);
    148 	VATTR_NULL(vattr);
    149 	/* get real uid */
    150 	vattr->va_uid = p->p_cred->p_ruid;
    151 	vattr->va_gid = pmnt->pmnt_gid;
    152 	vattr->va_mode = pmnt->pmnt_mode;
    153 }
    154 
    155 
    156 void
    157 ptyfs_init(void)
    158 {
    159 #ifdef _LKM
    160 	malloc_type_attach(M_PTYFSMNT);
    161 #endif
    162 	ptyfs_hashinit();
    163 }
    164 
    165 void
    166 ptyfs_reinit(void)
    167 {
    168 	ptyfs_hashreinit();
    169 }
    170 
    171 void
    172 ptyfs_done(void)
    173 {
    174 #ifdef _LKM
    175 	malloc_type_detach(M_PTYFSMNT);
    176 #endif
    177 	ptyfs_hashdone();
    178 }
    179 
    180 /*
    181  * Mount the Pseudo tty params filesystem
    182  */
    183 int
    184 ptyfs_mount(struct mount *mp, const char *path, void *data,
    185     struct nameidata *ndp, struct proc *p)
    186 {
    187 	int error = 0;
    188 	struct ptyfsmount *pmnt;
    189 	struct ptyfs_args args;
    190 
    191 	if (UIO_MX & (UIO_MX - 1)) {
    192 		log(LOG_ERR, "ptyfs: invalid directory entry size");
    193 		return EINVAL;
    194 	}
    195 
    196 	if (mp->mnt_flag & MNT_GETARGS) {
    197 		pmnt = VFSTOPTY(mp);
    198 		if (pmnt == NULL)
    199 			return EIO;
    200 		args.version = PTYFS_ARGSVERSION;
    201 		args.mode = pmnt->pmnt_mode;
    202 		args.gid = pmnt->pmnt_gid;
    203 		return copyout(&args, data, sizeof(args));
    204 	}
    205 
    206 	if (mp->mnt_flag & MNT_UPDATE)
    207 		return EOPNOTSUPP;
    208 
    209 	if (data != NULL) {
    210 		error = copyin(data, &args, sizeof args);
    211 		if (error != 0)
    212 			return error;
    213 
    214 		if (args.version != PTYFS_ARGSVERSION)
    215 			return EINVAL;
    216 	} else {
    217 		/* Compat code; remove and return an error */
    218 		args.gid = 4;	/* XXX tty gid */
    219 		args.mode = S_IRUSR|S_IWUSR|S_IWGRP;
    220 	}
    221 
    222 	pmnt = malloc(sizeof(struct ptyfsmount), M_UFSMNT, M_WAITOK);
    223 
    224 	mp->mnt_data = pmnt;
    225 	pmnt->pmnt_gid = args.gid;
    226 	pmnt->pmnt_mode = args.mode;
    227 	mp->mnt_flag |= MNT_LOCAL;
    228 	vfs_getnewfsid(mp);
    229 
    230 	if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs",
    231 	    UIO_SYSSPACE, mp, p)) != 0) {
    232 		return error;
    233 	}
    234 
    235 	/* Point pty access to us */
    236 	if (ptyfs_save_ptm != NULL)
    237 		return EBUSY;
    238 
    239 	ptm_ptyfspty.arg = mp;
    240 	ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
    241 	return 0;
    242 }
    243 
    244 /*ARGSUSED*/
    245 int
    246 ptyfs_start(struct mount *mp, int flags, struct proc *p)
    247 {
    248 	return 0;
    249 }
    250 
    251 /*ARGSUSED*/
    252 int
    253 ptyfs_unmount(struct mount *mp, int mntflags, struct proc *p)
    254 {
    255 	int error;
    256 	int flags = 0;
    257 
    258 	if (mntflags & MNT_FORCE)
    259 		flags |= FORCECLOSE;
    260 
    261 	if ((error = vflush(mp, 0, flags)) != 0)
    262 		return (error);
    263 
    264 	/* Restore where pty access was pointing */
    265 	ptm_ptyfspty.arg = NULL;
    266 	(void)pty_sethandler(ptyfs_save_ptm);
    267 	ptyfs_save_ptm = NULL;
    268 
    269 	/*
    270 	 * Finally, throw away the ptyfsmount structure
    271 	 */
    272 	free(mp->mnt_data, M_UFSMNT);
    273 	mp->mnt_data = 0;
    274 
    275 	return 0;
    276 }
    277 
    278 int
    279 ptyfs_root(struct mount *mp, struct vnode **vpp)
    280 {
    281 	/* setup "." */
    282 	return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL);
    283 }
    284 
    285 /*ARGSUSED*/
    286 int
    287 ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, struct proc *p)
    288 {
    289 	return EOPNOTSUPP;
    290 }
    291 
    292 /*ARGSUSED*/
    293 int
    294 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p)
    295 {
    296 	sbp->f_bsize = DEV_BSIZE;
    297 	sbp->f_frsize = DEV_BSIZE;
    298 	sbp->f_iosize = DEV_BSIZE;
    299 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    300 	sbp->f_bfree = 0;
    301 	sbp->f_bavail = 0;
    302 	sbp->f_bresvd = 0;
    303 	sbp->f_files = 1024;	/* XXX lie */
    304 	sbp->f_ffree = 128;	/* XXX lie */
    305 	sbp->f_favail = 128;	/* XXX lie */
    306 	sbp->f_fresvd = 0;
    307 	sbp->f_namemax = MAXNAMLEN;
    308 	copy_statvfs_info(sbp, mp);
    309 	return 0;
    310 }
    311 
    312 /*ARGSUSED*/
    313 int
    314 ptyfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct proc *p)
    315 {
    316 	return 0;
    317 }
    318 
    319 /*
    320  * Kernfs flat namespace lookup.
    321  * Currently unsupported.
    322  */
    323 /*ARGSUSED*/
    324 int
    325 ptyfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
    326 {
    327 	return EOPNOTSUPP;
    328 }
    329 
    330 /*ARGSUSED*/
    331 int
    332 ptyfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
    333 {
    334 	return EOPNOTSUPP;
    335 }
    336 
    337 /*ARGSUSED*/
    338 int
    339 ptyfs_checkexp(struct mount *mp, struct mbuf *mb, int *wh, struct ucred **anon)
    340 {
    341 	return EOPNOTSUPP;
    342 }
    343 
    344 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup")
    345 {
    346 
    347 	sysctl_createv(clog, 0, NULL, NULL,
    348 		       CTLFLAG_PERMANENT,
    349 		       CTLTYPE_NODE, "vfs", NULL,
    350 		       NULL, 0, NULL, 0,
    351 		       CTL_VFS, CTL_EOL);
    352 	sysctl_createv(clog, 0, NULL, NULL,
    353 		       CTLFLAG_PERMANENT,
    354 		       CTLTYPE_NODE, "ptyfs",
    355 		       SYSCTL_DESCR("Pty file system"),
    356 		       NULL, 0, NULL, 0,
    357 		       CTL_VFS, 23, CTL_EOL);
    358 	/*
    359 	 * XXX the "23" above could be dynamic, thereby eliminating
    360 	 * one more instance of the "number to vfs" mapping problem,
    361 	 * but "23" is the order as taken from sys/mount.h
    362 	 */
    363 }
    364 
    365 
    366 /*ARGSUSED*/
    367 int
    368 ptyfs_vptofh(struct vnode *vp, struct fid *fhp)
    369 {
    370 	return EOPNOTSUPP;
    371 }
    372 
    373 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc;
    374 
    375 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = {
    376 	&ptyfs_vnodeop_opv_desc,
    377 	NULL,
    378 };
    379 
    380 struct vfsops ptyfs_vfsops = {
    381 	MOUNT_PTYFS,
    382 	ptyfs_mount,
    383 	ptyfs_start,
    384 	ptyfs_unmount,
    385 	ptyfs_root,
    386 	ptyfs_quotactl,
    387 	ptyfs_statvfs,
    388 	ptyfs_sync,
    389 	ptyfs_vget,
    390 	ptyfs_fhtovp,
    391 	ptyfs_vptofh,
    392 	ptyfs_init,
    393 	ptyfs_reinit,
    394 	ptyfs_done,
    395 	NULL,
    396 	NULL,				/* vfs_mountroot */
    397 	ptyfs_checkexp,
    398 	(int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp,
    399 	ptyfs_vnodeopv_descs,
    400 };
    401