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ptyfs_vfsops.c revision 1.1 
      1 /*	$NetBSD: ptyfs_vfsops.c,v 1.1 2004/11/11 18:56:25 jdolecek 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 1.1 2004/11/11 18:56:25 jdolecek 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/dirent.h>
     52 #include <sys/malloc.h>
     53 #include <sys/syslog.h>
     54 #include <sys/select.h>
     55 #include <sys/tty.h>
     56 #include <sys/pty.h>
     57 
     58 #include <miscfs/specfs/specdev.h>
     59 #include <miscfs/ptyfs/ptyfs.h>
     60 
     61 MALLOC_DEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures");
     62 
     63 void	ptyfs_init(void);
     64 void	ptyfs_reinit(void);
     65 void	ptyfs_done(void);
     66 int	ptyfs_mount(struct mount *, const char *, void *, struct nameidata *,
     67     struct proc *);
     68 int	ptyfs_start(struct mount *, int, struct proc *);
     69 int	ptyfs_unmount(struct mount *, int, struct proc *);
     70 int	ptyfs_statvfs(struct mount *, struct statvfs *, struct proc *);
     71 int	ptyfs_quotactl(struct mount *, int, uid_t, void *, struct proc *);
     72 int	ptyfs_sync(struct mount *, int, struct ucred *, struct proc *);
     73 int	ptyfs_vget(struct mount *, ino_t, struct vnode **);
     74 int	ptyfs_fhtovp(struct mount *, struct fid *, struct vnode **);
     75 int	ptyfs_checkexp(struct mount *, struct mbuf *, int *, struct ucred **);
     76 int	ptyfs_vptofh(struct vnode *, struct fid *);
     77 
     78 static int ptyfs__allocvp(struct ptm_pty *, struct proc *, struct vnode **,
     79     dev_t, char);
     80 static int ptyfs__makename(struct ptm_pty *, char *, size_t, dev_t, char);
     81 
     82 /*
     83  * ptm glue: When we mount, we make ptm point to us.
     84  */
     85 struct ptm_pty *ptyfs_save_ptm;
     86 
     87 struct ptm_pty ptm_ptyfspty = {
     88 	ptyfs__allocvp,
     89 	ptyfs__makename,
     90 	NULL
     91 };
     92 
     93 static int
     94 ptyfs__makename(struct ptm_pty *pt, char *buf, size_t bufsiz, dev_t dev,
     95     char ms)
     96 {
     97 	struct mount *mp = pt->arg;
     98 	size_t len;
     99 
    100 	switch (ms) {
    101 	case 'p':
    102 		/* We don't provide access to the master, should we? */
    103 		len = snprintf(buf, bufsiz, "/dev/null");
    104 		break;
    105 	case 't':
    106 		len = snprintf(buf, bufsiz, "%s/%d", mp->mnt_stat.f_mntonname,
    107 		    minor(dev));
    108 		break;
    109 	default:
    110 		return EINVAL;
    111 	}
    112 
    113 	return len >= bufsiz ? ENOSPC : 0;
    114 }
    115 
    116 static int
    117 /*ARGSUSED*/
    118 ptyfs__allocvp(struct ptm_pty *pt, struct proc *p, struct vnode **vpp,
    119     dev_t dev, char ms)
    120 {
    121 	struct mount *mp = pt->arg;
    122 	ptyfstype type;
    123 
    124 	switch (ms) {
    125 	case 'p':
    126 		type = PTYFSptc;
    127 		break;
    128 	case 't':
    129 		type = PTYFSpts;
    130 		break;
    131 	default:
    132 		return EINVAL;
    133 	}
    134 
    135 	return ptyfs_allocvp(mp, vpp, type, minor(dev), p);
    136 }
    137 
    138 void
    139 ptyfs_init(void)
    140 {
    141 #ifdef _LKM
    142 	malloc_type_attach(M_PTYFSMNT);
    143 #endif
    144 	ptyfs_hashinit();
    145 }
    146 
    147 void
    148 ptyfs_reinit(void)
    149 {
    150 	ptyfs_hashreinit();
    151 }
    152 
    153 void
    154 ptyfs_done(void)
    155 {
    156 #ifdef _LKM
    157 	malloc_type_detach(M_PTYFSMNT);
    158 #endif
    159 	ptyfs_hashdone();
    160 }
    161 
    162 /*
    163  * Mount the Pseudo tty params filesystem
    164  */
    165 int
    166 ptyfs_mount(struct mount *mp, const char *path, void *data,
    167     struct nameidata *ndp, struct proc *p)
    168 {
    169 	int error = 0;
    170 
    171 	if (UIO_MX & (UIO_MX - 1)) {
    172 		log(LOG_ERR, "ptyfs: invalid directory entry size");
    173 		return EINVAL;
    174 	}
    175 
    176 	if (mp->mnt_flag & MNT_GETARGS)
    177 		return 0;
    178 	/*
    179 	 * Update is a no-op
    180 	 */
    181 	if (mp->mnt_flag & MNT_UPDATE)
    182 		return EOPNOTSUPP;
    183 
    184 	mp->mnt_data = NULL;
    185 	mp->mnt_flag |= MNT_LOCAL;
    186 	vfs_getnewfsid(mp);
    187 
    188 	if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs",
    189 	    UIO_SYSSPACE, mp, p)) != 0) {
    190 		return error;
    191 	}
    192 
    193 	/* Point pty access to us */
    194 	if (ptyfs_save_ptm != NULL)
    195 		return EBUSY;
    196 
    197 	ptm_ptyfspty.arg = mp;
    198 	ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
    199 	return 0;
    200 }
    201 
    202 /*ARGSUSED*/
    203 int
    204 ptyfs_start(struct mount *mp, int flags, struct proc *p)
    205 {
    206 	return 0;
    207 }
    208 
    209 /*ARGSUSED*/
    210 int
    211 ptyfs_unmount(struct mount *mp, int mntflags, struct proc *p)
    212 {
    213 	int error;
    214 	int flags = 0;
    215 
    216 	if (mntflags & MNT_FORCE)
    217 		flags |= FORCECLOSE;
    218 
    219 	if ((error = vflush(mp, 0, flags)) != 0)
    220 		return (error);
    221 
    222 	/* Restore where pty access was pointing */
    223 	ptm_ptyfspty.arg = NULL;
    224 	(void)pty_sethandler(ptyfs_save_ptm);
    225 	ptyfs_save_ptm = NULL;
    226 	/*
    227 	 * Finally, throw away the ptyfs_mount structure
    228 	 */
    229 	return 0;
    230 }
    231 
    232 int
    233 ptyfs_root(struct mount *mp, struct vnode **vpp)
    234 {
    235 	/* setup "." */
    236 	return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL);
    237 }
    238 
    239 /*ARGSUSED*/
    240 int
    241 ptyfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg, struct proc *p)
    242 {
    243 	return EOPNOTSUPP;
    244 }
    245 
    246 /*ARGSUSED*/
    247 int
    248 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp, struct proc *p)
    249 {
    250 	sbp->f_bsize = DEV_BSIZE;
    251 	sbp->f_frsize = DEV_BSIZE;
    252 	sbp->f_iosize = DEV_BSIZE;
    253 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    254 	sbp->f_bfree = 0;
    255 	sbp->f_bavail = 0;
    256 	sbp->f_bresvd = 0;
    257 	sbp->f_files = 1024;	/* XXX lie */
    258 	sbp->f_ffree = 128;	/* XXX lie */
    259 	sbp->f_favail = 128;	/* XXX lie */
    260 	sbp->f_fresvd = 0;
    261 	sbp->f_namemax = MAXNAMLEN;
    262 	copy_statvfs_info(sbp, mp);
    263 	return 0;
    264 }
    265 
    266 /*ARGSUSED*/
    267 int
    268 ptyfs_sync(struct mount *mp, int waitfor, struct ucred *uc, struct proc *p)
    269 {
    270 	return 0;
    271 }
    272 
    273 /*
    274  * Kernfs flat namespace lookup.
    275  * Currently unsupported.
    276  */
    277 /*ARGSUSED*/
    278 int
    279 ptyfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
    280 {
    281 	return EOPNOTSUPP;
    282 }
    283 
    284 /*ARGSUSED*/
    285 int
    286 ptyfs_fhtovp(struct mount *mp, struct fid *fhp, struct vnode **vpp)
    287 {
    288 	return EOPNOTSUPP;
    289 }
    290 
    291 /*ARGSUSED*/
    292 int
    293 ptyfs_checkexp(struct mount *mp, struct mbuf *mb, int *wh, struct ucred **anon)
    294 {
    295 	return EOPNOTSUPP;
    296 }
    297 
    298 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup")
    299 {
    300 
    301 	sysctl_createv(clog, 0, NULL, NULL,
    302 		       CTLFLAG_PERMANENT,
    303 		       CTLTYPE_NODE, "vfs", NULL,
    304 		       NULL, 0, NULL, 0,
    305 		       CTL_VFS, CTL_EOL);
    306 	sysctl_createv(clog, 0, NULL, NULL,
    307 		       CTLFLAG_PERMANENT,
    308 		       CTLTYPE_NODE, "ptyfs",
    309 		       SYSCTL_DESCR("Pty file system"),
    310 		       NULL, 0, NULL, 0,
    311 		       CTL_VFS, 23, CTL_EOL);
    312 	/*
    313 	 * XXX the "23" above could be dynamic, thereby eliminating
    314 	 * one more instance of the "number to vfs" mapping problem,
    315 	 * but "23" is the order as taken from sys/mount.h
    316 	 */
    317 }
    318 
    319 
    320 /*ARGSUSED*/
    321 int
    322 ptyfs_vptofh(struct vnode *vp, struct fid *fhp)
    323 {
    324 	return EOPNOTSUPP;
    325 }
    326 
    327 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc;
    328 
    329 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = {
    330 	&ptyfs_vnodeop_opv_desc,
    331 	NULL,
    332 };
    333 
    334 struct vfsops ptyfs_vfsops = {
    335 	MOUNT_PTYFS,
    336 	ptyfs_mount,
    337 	ptyfs_start,
    338 	ptyfs_unmount,
    339 	ptyfs_root,
    340 	ptyfs_quotactl,
    341 	ptyfs_statvfs,
    342 	ptyfs_sync,
    343 	ptyfs_vget,
    344 	ptyfs_fhtovp,
    345 	ptyfs_vptofh,
    346 	ptyfs_init,
    347 	ptyfs_reinit,
    348 	ptyfs_done,
    349 	NULL,
    350 	NULL,				/* vfs_mountroot */
    351 	ptyfs_checkexp,
    352 	(int (*)(struct mount *, struct vnode *, struct timespec *))eopnotsupp,
    353 	ptyfs_vnodeopv_descs,
    354 };
    355