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procfs_vfsops.c revision 1.88 
      1 /*	$NetBSD: procfs_vfsops.c,v 1.88 2014/02/07 15:29:22 hannken Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed 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  *	@(#)procfs_vfsops.c	8.7 (Berkeley) 5/10/95
     35  */
     36 
     37 /*
     38  * Copyright (c) 1993 Jan-Simon Pendry
     39  *
     40  * This code is derived from software contributed to Berkeley by
     41  * Jan-Simon Pendry.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by the University of
     54  *	California, Berkeley and its contributors.
     55  * 4. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  *
     71  *	@(#)procfs_vfsops.c	8.7 (Berkeley) 5/10/95
     72  */
     73 
     74 /*
     75  * procfs VFS interface
     76  */
     77 
     78 #include <sys/cdefs.h>
     79 __KERNEL_RCSID(0, "$NetBSD: procfs_vfsops.c,v 1.88 2014/02/07 15:29:22 hannken Exp $");
     80 
     81 #if defined(_KERNEL_OPT)
     82 #include "opt_compat_netbsd.h"
     83 #endif
     84 
     85 #include <sys/param.h>
     86 #include <sys/time.h>
     87 #include <sys/kernel.h>
     88 #include <sys/systm.h>
     89 #include <sys/sysctl.h>
     90 #include <sys/proc.h>
     91 #include <sys/buf.h>
     92 #include <sys/syslog.h>
     93 #include <sys/mount.h>
     94 #include <sys/dirent.h>
     95 #include <sys/signalvar.h>
     96 #include <sys/vnode.h>
     97 #include <sys/malloc.h>
     98 #include <sys/kauth.h>
     99 #include <sys/module.h>
    100 
    101 #include <miscfs/genfs/genfs.h>
    102 
    103 #include <miscfs/procfs/procfs.h>
    104 
    105 #include <uvm/uvm_extern.h>			/* for PAGE_SIZE */
    106 
    107 MODULE(MODULE_CLASS_VFS, procfs, NULL);
    108 
    109 VFS_PROTOS(procfs);
    110 
    111 static struct sysctllog *procfs_sysctl_log;
    112 
    113 static kauth_listener_t procfs_listener;
    114 
    115 /*
    116  * VFS Operations.
    117  *
    118  * mount system call
    119  */
    120 /* ARGSUSED */
    121 int
    122 procfs_mount(
    123     struct mount *mp,
    124     const char *path,
    125     void *data,
    126     size_t *data_len)
    127 {
    128 	struct lwp *l = curlwp;
    129 	struct procfsmount *pmnt;
    130 	struct procfs_args *args = data;
    131 	int error;
    132 
    133 	if (UIO_MX & (UIO_MX-1)) {
    134 		log(LOG_ERR, "procfs: invalid directory entry size");
    135 		return (EINVAL);
    136 	}
    137 
    138 	if (mp->mnt_flag & MNT_GETARGS) {
    139 		if (*data_len < sizeof *args)
    140 			return EINVAL;
    141 
    142 		pmnt = VFSTOPROC(mp);
    143 		if (pmnt == NULL)
    144 			return EIO;
    145 		args->version = PROCFS_ARGSVERSION;
    146 		args->flags = pmnt->pmnt_flags;
    147 		*data_len = sizeof *args;
    148 		return 0;
    149 	}
    150 
    151 	if (mp->mnt_flag & MNT_UPDATE)
    152 		return (EOPNOTSUPP);
    153 
    154 	if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION)
    155 		return EINVAL;
    156 
    157 	pmnt = kmem_zalloc(sizeof(struct procfsmount), KM_SLEEP);
    158 
    159 	mp->mnt_stat.f_namemax = PROCFS_MAXNAMLEN;
    160 	mp->mnt_flag |= MNT_LOCAL;
    161 	mp->mnt_data = pmnt;
    162 	vfs_getnewfsid(mp);
    163 
    164 	error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE,
    165 	    mp->mnt_op->vfs_name, mp, l);
    166 	pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp);
    167 	if (*data_len >= sizeof *args)
    168 		pmnt->pmnt_flags = args->flags;
    169 	else
    170 		pmnt->pmnt_flags = 0;
    171 
    172 	mp->mnt_iflag |= IMNT_MPSAFE;
    173 	return error;
    174 }
    175 
    176 /*
    177  * unmount system call
    178  */
    179 int
    180 procfs_unmount(struct mount *mp, int mntflags)
    181 {
    182 	int error;
    183 	int flags = 0;
    184 
    185 	if (mntflags & MNT_FORCE)
    186 		flags |= FORCECLOSE;
    187 
    188 	if ((error = vflush(mp, 0, flags)) != 0)
    189 		return (error);
    190 
    191 	exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook);
    192 
    193 	kmem_free(mp->mnt_data, sizeof(struct procfsmount));
    194 	mp->mnt_data = NULL;
    195 
    196 	return 0;
    197 }
    198 
    199 int
    200 procfs_root(struct mount *mp, struct vnode **vpp)
    201 {
    202 	int error;
    203 
    204 	error = procfs_allocvp(mp, vpp, 0, PFSroot, -1, NULL);
    205 	if (error == 0) {
    206 		error = vn_lock(*vpp, LK_EXCLUSIVE);
    207 		if (error != 0) {
    208 			vrele(*vpp);
    209 			*vpp = NULL;
    210 		}
    211 	}
    212 
    213 	return error;
    214 }
    215 
    216 /* ARGSUSED */
    217 int
    218 procfs_start(struct mount *mp, int flags)
    219 {
    220 
    221 	return (0);
    222 }
    223 
    224 /*
    225  * Get file system statistics.
    226  */
    227 int
    228 procfs_statvfs(struct mount *mp, struct statvfs *sbp)
    229 {
    230 
    231 	genfs_statvfs(mp, sbp);
    232 
    233 	sbp->f_bsize = PAGE_SIZE;
    234 	sbp->f_frsize = PAGE_SIZE;
    235 	sbp->f_iosize = PAGE_SIZE;
    236 	sbp->f_blocks = 1;
    237 	sbp->f_files = maxproc;			/* approx */
    238 	sbp->f_ffree = maxproc - nprocs;	/* approx */
    239 	sbp->f_favail = maxproc - nprocs;	/* approx */
    240 
    241 	return (0);
    242 }
    243 
    244 /*ARGSUSED*/
    245 int
    246 procfs_sync(
    247     struct mount *mp,
    248     int waitfor,
    249     kauth_cred_t uc)
    250 {
    251 
    252 	return (0);
    253 }
    254 
    255 /*ARGSUSED*/
    256 int
    257 procfs_vget(struct mount *mp, ino_t ino,
    258     struct vnode **vpp)
    259 {
    260 	return (EOPNOTSUPP);
    261 }
    262 
    263 void
    264 procfs_init(void)
    265 {
    266 	procfs_hashinit();
    267 }
    268 
    269 void
    270 procfs_reinit(void)
    271 {
    272 	procfs_hashreinit();
    273 }
    274 
    275 void
    276 procfs_done(void)
    277 {
    278 	procfs_hashdone();
    279 }
    280 
    281 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc;
    282 
    283 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = {
    284 	&procfs_vnodeop_opv_desc,
    285 	NULL,
    286 };
    287 
    288 struct vfsops procfs_vfsops = {
    289 	MOUNT_PROCFS,
    290 	sizeof (struct procfs_args),
    291 	procfs_mount,
    292 	procfs_start,
    293 	procfs_unmount,
    294 	procfs_root,
    295 	(void *)eopnotsupp,		/* vfs_quotactl */
    296 	procfs_statvfs,
    297 	procfs_sync,
    298 	procfs_vget,
    299 	(void *)eopnotsupp,		/* vfs_fhtovp */
    300 	(void *)eopnotsupp,		/* vfs_vptofh */
    301 	procfs_init,
    302 	procfs_reinit,
    303 	procfs_done,
    304 	NULL,				/* vfs_mountroot */
    305 	(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
    306 	vfs_stdextattrctl,
    307 	(void *)eopnotsupp,		/* vfs_suspendctl */
    308 	genfs_renamelock_enter,
    309 	genfs_renamelock_exit,
    310 	(void *)eopnotsupp,
    311 	procfs_vnodeopv_descs,
    312 	0,
    313 	{ NULL, NULL },
    314 };
    315 
    316 static int
    317 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    318     void *arg0, void *arg1, void *arg2, void *arg3)
    319 {
    320 	struct proc *p;
    321 	struct pfsnode *pfs;
    322 	enum kauth_process_req req;
    323 	int result;
    324 
    325 	result = KAUTH_RESULT_DEFER;
    326 	p = arg0;
    327 	pfs = arg1;
    328 	req = (enum kauth_process_req)(unsigned long)arg2;
    329 
    330 	if (action != KAUTH_PROCESS_PROCFS)
    331 		return result;
    332 
    333 	/* Privileged; let secmodel handle that. */
    334 	if (req == KAUTH_REQ_PROCESS_PROCFS_CTL)
    335 		return result;
    336 
    337 	switch (pfs->pfs_type) {
    338 	case PFSregs:
    339 	case PFSfpregs:
    340 	case PFSmem:
    341 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
    342 		    ISSET(p->p_flag, PK_SUGID))
    343 			break;
    344 
    345 		/*FALLTHROUGH*/
    346 	default:
    347 		result = KAUTH_RESULT_ALLOW;
    348 		break;
    349 	}
    350 
    351 	return result;
    352 }
    353 
    354 
    355 static int
    356 procfs_modcmd(modcmd_t cmd, void *arg)
    357 {
    358 	int error;
    359 
    360 	switch (cmd) {
    361 	case MODULE_CMD_INIT:
    362 		error = vfs_attach(&procfs_vfsops);
    363 		if (error != 0)
    364 			break;
    365 		sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
    366 			       CTLFLAG_PERMANENT,
    367 			       CTLTYPE_NODE, "vfs", NULL,
    368 			       NULL, 0, NULL, 0,
    369 			       CTL_VFS, CTL_EOL);
    370 		sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
    371 			       CTLFLAG_PERMANENT,
    372 			       CTLTYPE_NODE, "procfs",
    373 			       SYSCTL_DESCR("Process file system"),
    374 			       NULL, 0, NULL, 0,
    375 			       CTL_VFS, 12, CTL_EOL);
    376 		/*
    377 		 * XXX the "12" above could be dynamic, thereby eliminating
    378 		 * one more instance of the "number to vfs" mapping problem,
    379 		 * but "12" is the order as taken from sys/mount.h
    380 		 */
    381 
    382 		procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
    383 		    procfs_listener_cb, NULL);
    384 
    385 		break;
    386 	case MODULE_CMD_FINI:
    387 		error = vfs_detach(&procfs_vfsops);
    388 		if (error != 0)
    389 			break;
    390 		sysctl_teardown(&procfs_sysctl_log);
    391 		kauth_unlisten_scope(procfs_listener);
    392 		break;
    393 	default:
    394 		error = ENOTTY;
    395 		break;
    396 	}
    397 
    398 	return (error);
    399 }
    400