Home | History | Annotate | Line # | Download | only in ptyfs
ptyfs_vfsops.c revision 1.32 
      1 /*	$NetBSD: ptyfs_vfsops.c,v 1.32 2008/04/29 18:18:08 ad 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 1.32 2008/04/29 18:18:08 ad 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/filedesc.h>
     57 #include <sys/tty.h>
     58 #include <sys/pty.h>
     59 #include <sys/kauth.h>
     60 
     61 #include <fs/ptyfs/ptyfs.h>
     62 #include <miscfs/genfs/genfs.h>
     63 #include <miscfs/specfs/specdev.h>
     64 
     65 MALLOC_JUSTDEFINE(M_PTYFSMNT, "ptyfs mount", "ptyfs mount structures");
     66 MALLOC_JUSTDEFINE(M_PTYFSTMP, "ptyfs temp", "ptyfs temporary structures");
     67 
     68 VFS_PROTOS(ptyfs);
     69 
     70 static int ptyfs__allocvp(struct ptm_pty *, struct lwp *, struct vnode **,
     71     dev_t, char);
     72 static int ptyfs__makename(struct ptm_pty *, struct lwp *, char *, size_t,
     73     dev_t, char);
     74 static void ptyfs__getvattr(struct ptm_pty *, struct lwp *, struct vattr *);
     75 
     76 /*
     77  * ptm glue: When we mount, we make ptm point to us.
     78  */
     79 struct ptm_pty *ptyfs_save_ptm;
     80 static int ptyfs_count;
     81 
     82 struct ptm_pty ptm_ptyfspty = {
     83 	ptyfs__allocvp,
     84 	ptyfs__makename,
     85 	ptyfs__getvattr,
     86 	NULL
     87 };
     88 
     89 static const char *
     90 ptyfs__getpath(struct lwp *l, const struct mount *mp)
     91 {
     92 #define MAXBUF (sizeof(mp->mnt_stat.f_mntonname) + 32)
     93 	struct cwdinfo *cwdi = l->l_proc->p_cwdi;
     94 	char *buf;
     95 	const char *rv;
     96 	size_t len;
     97 	char *bp;
     98 	int error;
     99 
    100 	rv = mp->mnt_stat.f_mntonname;
    101 	if (cwdi->cwdi_rdir == NULL)
    102 		return rv;
    103 
    104 	buf = malloc(MAXBUF, M_TEMP, M_WAITOK);
    105 	bp = buf + MAXBUF;
    106 	*--bp = '\0';
    107 	error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp,
    108 	    buf, MAXBUF / 2, 0, l);
    109 	if (error)	/* XXX */
    110 		goto out;
    111 
    112 	len = strlen(bp);
    113 	if (len < sizeof(mp->mnt_stat.f_mntonname))	/* XXX */
    114 		rv += len;
    115 out:
    116 	free(buf, M_TEMP);
    117 	return rv;
    118 }
    119 
    120 static int
    121 ptyfs__makename(struct ptm_pty *pt, struct lwp *l, char *tbuf, size_t bufsiz,
    122     dev_t dev, char ms)
    123 {
    124 	struct mount *mp = pt->arg;
    125 	size_t len;
    126 
    127 	switch (ms) {
    128 	case 'p':
    129 		/* We don't provide access to the master, should we? */
    130 		len = snprintf(tbuf, bufsiz, "/dev/null");
    131 		break;
    132 	case 't':
    133 		len = snprintf(tbuf, bufsiz, "%s/%d", ptyfs__getpath(l, mp),
    134 		    minor(dev));
    135 		break;
    136 	default:
    137 		return EINVAL;
    138 	}
    139 
    140 	return len >= bufsiz ? ENOSPC : 0;
    141 }
    142 
    143 
    144 static int
    145 /*ARGSUSED*/
    146 ptyfs__allocvp(struct ptm_pty *pt, struct lwp *l, struct vnode **vpp,
    147     dev_t dev, char ms)
    148 {
    149 	struct mount *mp = pt->arg;
    150 	ptyfstype type;
    151 
    152 	switch (ms) {
    153 	case 'p':
    154 		type = PTYFSptc;
    155 		break;
    156 	case 't':
    157 		type = PTYFSpts;
    158 		break;
    159 	default:
    160 		return EINVAL;
    161 	}
    162 
    163 	return ptyfs_allocvp(mp, vpp, type, minor(dev), l);
    164 }
    165 
    166 
    167 static void
    168 ptyfs__getvattr(struct ptm_pty *pt, struct lwp *l, struct vattr *vattr)
    169 {
    170 	struct mount *mp = pt->arg;
    171 	struct ptyfsmount *pmnt = VFSTOPTY(mp);
    172 	VATTR_NULL(vattr);
    173 	/* get real uid */
    174 	vattr->va_uid = kauth_cred_getuid(l->l_cred);
    175 	vattr->va_gid = pmnt->pmnt_gid;
    176 	vattr->va_mode = pmnt->pmnt_mode;
    177 }
    178 
    179 
    180 void
    181 ptyfs_init(void)
    182 {
    183 
    184 	malloc_type_attach(M_PTYFSMNT);
    185 	malloc_type_attach(M_PTYFSTMP);
    186 	ptyfs_hashinit();
    187 }
    188 
    189 void
    190 ptyfs_reinit(void)
    191 {
    192 	ptyfs_hashreinit();
    193 }
    194 
    195 void
    196 ptyfs_done(void)
    197 {
    198 
    199 	ptyfs_hashdone();
    200 	malloc_type_detach(M_PTYFSTMP);
    201 	malloc_type_detach(M_PTYFSMNT);
    202 }
    203 
    204 /*
    205  * Mount the Pseudo tty params filesystem
    206  */
    207 int
    208 ptyfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
    209 {
    210 	struct lwp *l = curlwp;
    211 	int error = 0;
    212 	struct ptyfsmount *pmnt;
    213 	struct ptyfs_args *args = data;
    214 
    215 	if (*data_len < sizeof *args)
    216 		return EINVAL;
    217 
    218 	if (UIO_MX & (UIO_MX - 1)) {
    219 		log(LOG_ERR, "ptyfs: invalid directory entry size");
    220 		return EINVAL;
    221 	}
    222 
    223 	if (mp->mnt_flag & MNT_GETARGS) {
    224 		pmnt = VFSTOPTY(mp);
    225 		if (pmnt == NULL)
    226 			return EIO;
    227 		args->version = PTYFS_ARGSVERSION;
    228 		args->mode = pmnt->pmnt_mode;
    229 		args->gid = pmnt->pmnt_gid;
    230 		*data_len = sizeof *args;
    231 		return 0;
    232 	}
    233 
    234 	/* Don't allow more than one mount */
    235 	if (ptyfs_count)
    236 		return EBUSY;
    237 
    238 	if (mp->mnt_flag & MNT_UPDATE)
    239 		return EOPNOTSUPP;
    240 
    241 	if (args->version != PTYFS_ARGSVERSION)
    242 		return EINVAL;
    243 
    244 	pmnt = malloc(sizeof(struct ptyfsmount), M_PTYFSMNT, M_WAITOK);
    245 
    246 	mp->mnt_data = pmnt;
    247 	pmnt->pmnt_gid = args->gid;
    248 	pmnt->pmnt_mode = args->mode;
    249 	mp->mnt_flag |= MNT_LOCAL;
    250 	vfs_getnewfsid(mp);
    251 
    252 	if ((error = set_statvfs_info(path, UIO_USERSPACE, "ptyfs",
    253 	    UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) {
    254 		free(pmnt, M_UFSMNT);
    255 		return error;
    256 	}
    257 
    258 	/* Point pty access to us */
    259 
    260 	ptm_ptyfspty.arg = mp;
    261 	ptyfs_save_ptm = pty_sethandler(&ptm_ptyfspty);
    262 	ptyfs_count++;
    263 	return 0;
    264 }
    265 
    266 /*ARGSUSED*/
    267 int
    268 ptyfs_start(struct mount *mp, int flags)
    269 {
    270 	return 0;
    271 }
    272 
    273 /*ARGSUSED*/
    274 int
    275 ptyfs_unmount(struct mount *mp, int mntflags)
    276 {
    277 	int error;
    278 	int flags = 0;
    279 
    280 	if (mntflags & MNT_FORCE)
    281 		flags |= FORCECLOSE;
    282 
    283 	if ((error = vflush(mp, 0, flags)) != 0)
    284 		return (error);
    285 
    286 	/* Restore where pty access was pointing */
    287 	(void)pty_sethandler(ptyfs_save_ptm);
    288 	ptyfs_save_ptm = NULL;
    289 	ptm_ptyfspty.arg = NULL;
    290 
    291 	/*
    292 	 * Finally, throw away the ptyfsmount structure
    293 	 */
    294 	free(mp->mnt_data, M_UFSMNT);
    295 	mp->mnt_data = 0;
    296 	ptyfs_count--;
    297 
    298 	return 0;
    299 }
    300 
    301 int
    302 ptyfs_root(struct mount *mp, struct vnode **vpp)
    303 {
    304 	/* setup "." */
    305 	return ptyfs_allocvp(mp, vpp, PTYFSroot, 0, NULL);
    306 }
    307 
    308 /*ARGSUSED*/
    309 int
    310 ptyfs_statvfs(struct mount *mp, struct statvfs *sbp)
    311 {
    312 	sbp->f_bsize = DEV_BSIZE;
    313 	sbp->f_frsize = DEV_BSIZE;
    314 	sbp->f_iosize = DEV_BSIZE;
    315 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    316 	sbp->f_bfree = 0;
    317 	sbp->f_bavail = 0;
    318 	sbp->f_bresvd = 0;
    319 	sbp->f_files = 1024;	/* XXX lie */
    320 	sbp->f_ffree = 128;	/* XXX lie */
    321 	sbp->f_favail = 128;	/* XXX lie */
    322 	sbp->f_fresvd = 0;
    323 	sbp->f_namemax = MAXNAMLEN;
    324 	copy_statvfs_info(sbp, mp);
    325 	return 0;
    326 }
    327 
    328 /*ARGSUSED*/
    329 int
    330 ptyfs_sync(struct mount *mp, int waitfor,
    331     kauth_cred_t uc)
    332 {
    333 	return 0;
    334 }
    335 
    336 /*
    337  * Kernfs flat namespace lookup.
    338  * Currently unsupported.
    339  */
    340 /*ARGSUSED*/
    341 int
    342 ptyfs_vget(struct mount *mp, ino_t ino,
    343     struct vnode **vpp)
    344 {
    345 	return EOPNOTSUPP;
    346 }
    347 
    348 SYSCTL_SETUP(sysctl_vfs_ptyfs_setup, "sysctl vfs.ptyfs subtree setup")
    349 {
    350 
    351 	sysctl_createv(clog, 0, NULL, NULL,
    352 		       CTLFLAG_PERMANENT,
    353 		       CTLTYPE_NODE, "vfs", NULL,
    354 		       NULL, 0, NULL, 0,
    355 		       CTL_VFS, CTL_EOL);
    356 	sysctl_createv(clog, 0, NULL, NULL,
    357 		       CTLFLAG_PERMANENT,
    358 		       CTLTYPE_NODE, "ptyfs",
    359 		       SYSCTL_DESCR("Pty file system"),
    360 		       NULL, 0, NULL, 0,
    361 		       CTL_VFS, 23, CTL_EOL);
    362 	/*
    363 	 * XXX the "23" above could be dynamic, thereby eliminating
    364 	 * one more instance of the "number to vfs" mapping problem,
    365 	 * but "23" is the order as taken from sys/mount.h
    366 	 */
    367 }
    368 
    369 
    370 extern const struct vnodeopv_desc ptyfs_vnodeop_opv_desc;
    371 
    372 const struct vnodeopv_desc * const ptyfs_vnodeopv_descs[] = {
    373 	&ptyfs_vnodeop_opv_desc,
    374 	NULL,
    375 };
    376 
    377 struct vfsops ptyfs_vfsops = {
    378 	MOUNT_PTYFS,
    379 	sizeof (struct ptyfs_args),
    380 	ptyfs_mount,
    381 	ptyfs_start,
    382 	ptyfs_unmount,
    383 	ptyfs_root,
    384 	(void *)eopnotsupp,		/* vfs_quotactl */
    385 	ptyfs_statvfs,
    386 	ptyfs_sync,
    387 	ptyfs_vget,
    388 	(void *)eopnotsupp,		/* vfs_fhtovp */
    389 	(void *)eopnotsupp,		/* vfs_vptofp */
    390 	ptyfs_init,
    391 	ptyfs_reinit,
    392 	ptyfs_done,
    393 	NULL,				/* vfs_mountroot */
    394 	(void *)eopnotsupp,
    395 	(void *)eopnotsupp,
    396 	(void *)eopnotsupp,		/* vfs_suspendctl */
    397 	genfs_renamelock_enter,
    398 	genfs_renamelock_exit,
    399 	(void *)eopnotsupp,
    400 	ptyfs_vnodeopv_descs,
    401 	0,
    402 	{ NULL, NULL },
    403 };
    404 VFS_ATTACH(ptyfs_vfsops);
    405