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procfs_vfsops.c revision 1.92
      1 /*	$NetBSD: procfs_vfsops.c,v 1.92 2014/07/27 16:47:26 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 1.92 2014/07/27 16:47:26 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/file.h>
     99 #include <sys/filedesc.h>
    100 #include <sys/kauth.h>
    101 #include <sys/module.h>
    102 
    103 #include <miscfs/genfs/genfs.h>
    104 
    105 #include <miscfs/procfs/procfs.h>
    106 
    107 #include <uvm/uvm_extern.h>			/* for PAGE_SIZE */
    108 
    109 MODULE(MODULE_CLASS_VFS, procfs, NULL);
    110 
    111 VFS_PROTOS(procfs);
    112 
    113 static struct sysctllog *procfs_sysctl_log;
    114 
    115 static kauth_listener_t procfs_listener;
    116 
    117 /*
    118  * VFS Operations.
    119  *
    120  * mount system call
    121  */
    122 /* ARGSUSED */
    123 int
    124 procfs_mount(
    125     struct mount *mp,
    126     const char *path,
    127     void *data,
    128     size_t *data_len)
    129 {
    130 	struct lwp *l = curlwp;
    131 	struct procfsmount *pmnt;
    132 	struct procfs_args *args = data;
    133 	int error;
    134 
    135 	if (args == NULL)
    136 		return EINVAL;
    137 
    138 	if (UIO_MX & (UIO_MX-1)) {
    139 		log(LOG_ERR, "procfs: invalid directory entry size");
    140 		return (EINVAL);
    141 	}
    142 
    143 	if (mp->mnt_flag & MNT_GETARGS) {
    144 		if (*data_len < sizeof *args)
    145 			return EINVAL;
    146 
    147 		pmnt = VFSTOPROC(mp);
    148 		if (pmnt == NULL)
    149 			return EIO;
    150 		args->version = PROCFS_ARGSVERSION;
    151 		args->flags = pmnt->pmnt_flags;
    152 		*data_len = sizeof *args;
    153 		return 0;
    154 	}
    155 
    156 	if (mp->mnt_flag & MNT_UPDATE)
    157 		return (EOPNOTSUPP);
    158 
    159 	if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION)
    160 		return EINVAL;
    161 
    162 	pmnt = kmem_zalloc(sizeof(struct procfsmount), KM_SLEEP);
    163 
    164 	mp->mnt_stat.f_namemax = PROCFS_MAXNAMLEN;
    165 	mp->mnt_flag |= MNT_LOCAL;
    166 	mp->mnt_data = pmnt;
    167 	vfs_getnewfsid(mp);
    168 
    169 	error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE,
    170 	    mp->mnt_op->vfs_name, mp, l);
    171 	pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp);
    172 	if (*data_len >= sizeof *args)
    173 		pmnt->pmnt_flags = args->flags;
    174 	else
    175 		pmnt->pmnt_flags = 0;
    176 
    177 	mp->mnt_iflag |= IMNT_MPSAFE;
    178 	return error;
    179 }
    180 
    181 /*
    182  * unmount system call
    183  */
    184 int
    185 procfs_unmount(struct mount *mp, int mntflags)
    186 {
    187 	int error;
    188 	int flags = 0;
    189 
    190 	if (mntflags & MNT_FORCE)
    191 		flags |= FORCECLOSE;
    192 
    193 	if ((error = vflush(mp, 0, flags)) != 0)
    194 		return (error);
    195 
    196 	exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook);
    197 
    198 	kmem_free(mp->mnt_data, sizeof(struct procfsmount));
    199 	mp->mnt_data = NULL;
    200 
    201 	return 0;
    202 }
    203 
    204 int
    205 procfs_root(struct mount *mp, struct vnode **vpp)
    206 {
    207 	int error;
    208 
    209 	error = procfs_allocvp(mp, vpp, 0, PFSroot, -1);
    210 	if (error == 0) {
    211 		error = vn_lock(*vpp, LK_EXCLUSIVE);
    212 		if (error != 0) {
    213 			vrele(*vpp);
    214 			*vpp = NULL;
    215 		}
    216 	}
    217 
    218 	return error;
    219 }
    220 
    221 /* ARGSUSED */
    222 int
    223 procfs_start(struct mount *mp, int flags)
    224 {
    225 
    226 	return (0);
    227 }
    228 
    229 /*
    230  * Get file system statistics.
    231  */
    232 int
    233 procfs_statvfs(struct mount *mp, struct statvfs *sbp)
    234 {
    235 
    236 	genfs_statvfs(mp, sbp);
    237 
    238 	sbp->f_bsize = PAGE_SIZE;
    239 	sbp->f_frsize = PAGE_SIZE;
    240 	sbp->f_iosize = PAGE_SIZE;
    241 	sbp->f_blocks = 1;
    242 	sbp->f_files = maxproc;			/* approx */
    243 	sbp->f_ffree = maxproc - nprocs;	/* approx */
    244 	sbp->f_favail = maxproc - nprocs;	/* approx */
    245 
    246 	return (0);
    247 }
    248 
    249 /*ARGSUSED*/
    250 int
    251 procfs_sync(
    252     struct mount *mp,
    253     int waitfor,
    254     kauth_cred_t uc)
    255 {
    256 
    257 	return (0);
    258 }
    259 
    260 /*ARGSUSED*/
    261 int
    262 procfs_vget(struct mount *mp, ino_t ino,
    263     struct vnode **vpp)
    264 {
    265 	return (EOPNOTSUPP);
    266 }
    267 
    268 int
    269 procfs_loadvnode(struct mount *mp, struct vnode *vp,
    270     const void *key, size_t key_len, const void **new_key)
    271 {
    272 	int error;
    273 	struct pfskey pfskey;
    274 	struct pfsnode *pfs;
    275 
    276 	KASSERT(key_len == sizeof(pfskey));
    277 	memcpy(&pfskey, key, key_len);
    278 
    279 	pfs = kmem_alloc(sizeof(*pfs), KM_SLEEP);
    280 	pfs->pfs_pid = pfskey.pk_pid;
    281 	pfs->pfs_type = pfskey.pk_type;
    282 	pfs->pfs_fd = pfskey.pk_fd;
    283 	pfs->pfs_vnode = vp;
    284 	pfs->pfs_flags = 0;
    285 	pfs->pfs_fileno =
    286 	    PROCFS_FILENO(pfs->pfs_pid, pfs->pfs_type, pfs->pfs_fd);
    287 	vp->v_tag = VT_PROCFS;
    288 	vp->v_op = procfs_vnodeop_p;
    289 	vp->v_data = pfs;
    290 
    291 	switch (pfs->pfs_type) {
    292 	case PFSroot:	/* /proc = dr-xr-xr-x */
    293 		vp->v_vflag |= VV_ROOT;
    294 		/*FALLTHROUGH*/
    295 	case PFSproc:	/* /proc/N = dr-xr-xr-x */
    296 		pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
    297 		vp->v_type = VDIR;
    298 		break;
    299 
    300 	case PFStask:	/* /proc/N/task = dr-xr-xr-x */
    301 		if (pfs->pfs_fd == -1) {
    302 			pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|
    303 			    S_IROTH|S_IXOTH;
    304 			vp->v_type = VDIR;
    305 			break;
    306 		}
    307 		/*FALLTHROUGH*/
    308 	case PFScurproc:	/* /proc/curproc = lr-xr-xr-x */
    309 	case PFSself:	/* /proc/self    = lr-xr-xr-x */
    310 	case PFScwd:	/* /proc/N/cwd = lr-xr-xr-x */
    311 	case PFSchroot:	/* /proc/N/chroot = lr-xr-xr-x */
    312 	case PFSexe:	/* /proc/N/exe = lr-xr-xr-x */
    313 		pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
    314 		vp->v_type = VLNK;
    315 		break;
    316 
    317 	case PFSfd:
    318 		if (pfs->pfs_fd == -1) {	/* /proc/N/fd = dr-x------ */
    319 			pfs->pfs_mode = S_IRUSR|S_IXUSR;
    320 			vp->v_type = VDIR;
    321 		} else {	/* /proc/N/fd/M = [ps-]rw------- */
    322 			file_t *fp;
    323 			vnode_t *vxp;
    324 			struct proc *p;
    325 
    326 			mutex_enter(proc_lock);
    327 			p = proc_find(pfs->pfs_pid);
    328 			mutex_exit(proc_lock);
    329 			if (p == NULL) {
    330 				error = ENOENT;
    331 				goto bad;
    332 			}
    333 			KASSERT(rw_read_held(&p->p_reflock));
    334 			if ((fp = fd_getfile2(p, pfs->pfs_fd)) == NULL) {
    335 				error = EBADF;
    336 				goto bad;
    337 			}
    338 
    339 			pfs->pfs_mode = S_IRUSR|S_IWUSR;
    340 			switch (fp->f_type) {
    341 			case DTYPE_VNODE:
    342 				vxp = fp->f_data;
    343 
    344 				/*
    345 				 * We make symlinks for directories
    346 				 * to avoid cycles.
    347 				 */
    348 				if (vxp->v_type == VDIR)
    349 					goto symlink;
    350 				vp->v_type = vxp->v_type;
    351 				break;
    352 			case DTYPE_PIPE:
    353 				vp->v_type = VFIFO;
    354 				break;
    355 			case DTYPE_SOCKET:
    356 				vp->v_type = VSOCK;
    357 				break;
    358 			case DTYPE_KQUEUE:
    359 			case DTYPE_MISC:
    360 			case DTYPE_SEM:
    361 			symlink:
    362 				pfs->pfs_mode = S_IRUSR|S_IXUSR|S_IRGRP|
    363 				    S_IXGRP|S_IROTH|S_IXOTH;
    364 				vp->v_type = VLNK;
    365 				break;
    366 			default:
    367 				error = EOPNOTSUPP;
    368 				closef(fp);
    369 				goto bad;
    370 			}
    371 			closef(fp);
    372 		}
    373 		break;
    374 
    375 	case PFSfile:	/* /proc/N/file = -rw------- */
    376 	case PFSmem:	/* /proc/N/mem = -rw------- */
    377 	case PFSregs:	/* /proc/N/regs = -rw------- */
    378 	case PFSfpregs:	/* /proc/N/fpregs = -rw------- */
    379 		pfs->pfs_mode = S_IRUSR|S_IWUSR;
    380 		vp->v_type = VREG;
    381 		break;
    382 
    383 	case PFSctl:	/* /proc/N/ctl = --w------ */
    384 	case PFSnote:	/* /proc/N/note = --w------ */
    385 	case PFSnotepg:	/* /proc/N/notepg = --w------ */
    386 		pfs->pfs_mode = S_IWUSR;
    387 		vp->v_type = VREG;
    388 		break;
    389 
    390 	case PFSmap:	/* /proc/N/map = -r--r--r-- */
    391 	case PFSmaps:	/* /proc/N/maps = -r--r--r-- */
    392 	case PFSstatus:	/* /proc/N/status = -r--r--r-- */
    393 	case PFSstat:	/* /proc/N/stat = -r--r--r-- */
    394 	case PFScmdline:	/* /proc/N/cmdline = -r--r--r-- */
    395 	case PFSemul:	/* /proc/N/emul = -r--r--r-- */
    396 	case PFSmeminfo:	/* /proc/meminfo = -r--r--r-- */
    397 	case PFScpustat:	/* /proc/stat = -r--r--r-- */
    398 	case PFSdevices:	/* /proc/devices = -r--r--r-- */
    399 	case PFScpuinfo:	/* /proc/cpuinfo = -r--r--r-- */
    400 	case PFSuptime:	/* /proc/uptime = -r--r--r-- */
    401 	case PFSmounts:	/* /proc/mounts = -r--r--r-- */
    402 	case PFSloadavg:	/* /proc/loadavg = -r--r--r-- */
    403 	case PFSstatm:	/* /proc/N/statm = -r--r--r-- */
    404 	case PFSversion:	/* /proc/version = -r--r--r-- */
    405 		pfs->pfs_mode = S_IRUSR|S_IRGRP|S_IROTH;
    406 		vp->v_type = VREG;
    407 		break;
    408 
    409 #ifdef __HAVE_PROCFS_MACHDEP
    410 	PROCFS_MACHDEP_NODETYPE_CASES
    411 		procfs_machdep_allocvp(vp);
    412 		break;
    413 #endif
    414 
    415 	default:
    416 		panic("procfs_allocvp");
    417 	}
    418 
    419 	uvm_vnp_setsize(vp, 0);
    420 	*new_key = &pfs->pfs_key;
    421 
    422 	return 0;
    423 
    424 bad:
    425 	vp->v_tag =VT_NON;
    426 	vp->v_type = VNON;
    427 	vp->v_op = NULL;
    428 	vp->v_data = NULL;
    429 	kmem_free(pfs, sizeof(*pfs));
    430 	return error;
    431 }
    432 
    433 void
    434 procfs_init(void)
    435 {
    436 
    437 }
    438 
    439 void
    440 procfs_reinit(void)
    441 {
    442 
    443 }
    444 
    445 void
    446 procfs_done(void)
    447 {
    448 
    449 }
    450 
    451 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc;
    452 
    453 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = {
    454 	&procfs_vnodeop_opv_desc,
    455 	NULL,
    456 };
    457 
    458 struct vfsops procfs_vfsops = {
    459 	.vfs_name = MOUNT_PROCFS,
    460 	.vfs_min_mount_data = sizeof (struct procfs_args),
    461 	.vfs_mount = procfs_mount,
    462 	.vfs_start = procfs_start,
    463 	.vfs_unmount = procfs_unmount,
    464 	.vfs_root = procfs_root,
    465 	.vfs_quotactl = (void *)eopnotsupp,
    466 	.vfs_statvfs = procfs_statvfs,
    467 	.vfs_sync = procfs_sync,
    468 	.vfs_vget = procfs_vget,
    469 	.vfs_loadvnode = procfs_loadvnode,
    470 	.vfs_fhtovp = (void *)eopnotsupp,
    471 	.vfs_vptofh = (void *)eopnotsupp,
    472 	.vfs_init = procfs_init,
    473 	.vfs_reinit = procfs_reinit,
    474 	.vfs_done = procfs_done,
    475 	.vfs_snapshot = (void *)eopnotsupp,
    476 	.vfs_extattrctl = vfs_stdextattrctl,
    477 	.vfs_suspendctl = (void *)eopnotsupp,
    478 	.vfs_renamelock_enter = genfs_renamelock_enter,
    479 	.vfs_renamelock_exit = genfs_renamelock_exit,
    480 	.vfs_fsync = (void *)eopnotsupp,
    481 	.vfs_opv_descs = procfs_vnodeopv_descs
    482 };
    483 
    484 static int
    485 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
    486     void *arg0, void *arg1, void *arg2, void *arg3)
    487 {
    488 	struct proc *p;
    489 	struct pfsnode *pfs;
    490 	enum kauth_process_req req;
    491 	int result;
    492 
    493 	result = KAUTH_RESULT_DEFER;
    494 	p = arg0;
    495 	pfs = arg1;
    496 	req = (enum kauth_process_req)(unsigned long)arg2;
    497 
    498 	if (action != KAUTH_PROCESS_PROCFS)
    499 		return result;
    500 
    501 	/* Privileged; let secmodel handle that. */
    502 	if (req == KAUTH_REQ_PROCESS_PROCFS_CTL)
    503 		return result;
    504 
    505 	switch (pfs->pfs_type) {
    506 	case PFSregs:
    507 	case PFSfpregs:
    508 	case PFSmem:
    509 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
    510 		    ISSET(p->p_flag, PK_SUGID))
    511 			break;
    512 
    513 		/*FALLTHROUGH*/
    514 	default:
    515 		result = KAUTH_RESULT_ALLOW;
    516 		break;
    517 	}
    518 
    519 	return result;
    520 }
    521 
    522 
    523 static int
    524 procfs_modcmd(modcmd_t cmd, void *arg)
    525 {
    526 	int error;
    527 
    528 	switch (cmd) {
    529 	case MODULE_CMD_INIT:
    530 		error = vfs_attach(&procfs_vfsops);
    531 		if (error != 0)
    532 			break;
    533 		sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
    534 			       CTLFLAG_PERMANENT,
    535 			       CTLTYPE_NODE, "procfs",
    536 			       SYSCTL_DESCR("Process file system"),
    537 			       NULL, 0, NULL, 0,
    538 			       CTL_VFS, 12, CTL_EOL);
    539 		/*
    540 		 * XXX the "12" above could be dynamic, thereby eliminating
    541 		 * one more instance of the "number to vfs" mapping problem,
    542 		 * but "12" is the order as taken from sys/mount.h
    543 		 */
    544 
    545 		procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
    546 		    procfs_listener_cb, NULL);
    547 
    548 		break;
    549 	case MODULE_CMD_FINI:
    550 		error = vfs_detach(&procfs_vfsops);
    551 		if (error != 0)
    552 			break;
    553 		sysctl_teardown(&procfs_sysctl_log);
    554 		kauth_unlisten_scope(procfs_listener);
    555 		break;
    556 	default:
    557 		error = ENOTTY;
    558 		break;
    559 	}
    560 
    561 	return (error);
    562 }
    563