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procfs_subr.c revision 1.105.2.1
      1 /*	$NetBSD: procfs_subr.c,v 1.105.2.1 2015/01/17 12:10:54 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Andrew Doran.
      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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * This code is derived from software contributed to Berkeley by
     37  * Jan-Simon Pendry.
     38  *
     39  * Redistribution and use in source and binary forms, with or without
     40  * modification, are permitted provided that the following conditions
     41  * are met:
     42  * 1. Redistributions of source code must retain the above copyright
     43  *    notice, this list of conditions and the following disclaimer.
     44  * 2. Redistributions in binary form must reproduce the above copyright
     45  *    notice, this list of conditions and the following disclaimer in the
     46  *    documentation and/or other materials provided with the distribution.
     47  * 3. Neither the name of the University nor the names of its contributors
     48  *    may be used to endorse or promote products derived from this software
     49  *    without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     61  * SUCH DAMAGE.
     62  *
     63  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
     64  */
     65 
     66 /*
     67  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
     68  * Copyright (c) 1993 Jan-Simon Pendry
     69  *
     70  * This code is derived from software contributed to Berkeley by
     71  * Jan-Simon Pendry.
     72  *
     73  * Redistribution and use in source and binary forms, with or without
     74  * modification, are permitted provided that the following conditions
     75  * are met:
     76  * 1. Redistributions of source code must retain the above copyright
     77  *    notice, this list of conditions and the following disclaimer.
     78  * 2. Redistributions in binary form must reproduce the above copyright
     79  *    notice, this list of conditions and the following disclaimer in the
     80  *    documentation and/or other materials provided with the distribution.
     81  * 3. All advertising materials mentioning features or use of this software
     82  *    must display the following acknowledgement:
     83  *	This product includes software developed by the University of
     84  *	California, Berkeley and its contributors.
     85  * 4. Neither the name of the University nor the names of its contributors
     86  *    may be used to endorse or promote products derived from this software
     87  *    without specific prior written permission.
     88  *
     89  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     90  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     91  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     92  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     93  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     94  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     95  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     96  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     97  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     98  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     99  * SUCH DAMAGE.
    100  *
    101  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
    102  */
    103 
    104 #include <sys/cdefs.h>
    105 __KERNEL_RCSID(0, "$NetBSD: procfs_subr.c,v 1.105.2.1 2015/01/17 12:10:54 martin Exp $");
    106 
    107 #include <sys/param.h>
    108 #include <sys/systm.h>
    109 #include <sys/time.h>
    110 #include <sys/kernel.h>
    111 #include <sys/proc.h>
    112 #include <sys/vnode.h>
    113 #include <sys/stat.h>
    114 #include <sys/file.h>
    115 #include <sys/filedesc.h>
    116 #include <sys/kauth.h>
    117 
    118 #include <miscfs/procfs/procfs.h>
    119 
    120 /*
    121  * Allocate a pfsnode/vnode pair.  The vnode is referenced.
    122  * The pid, type, and file descriptor uniquely identify a pfsnode.
    123  */
    124 int
    125 procfs_allocvp(struct mount *mp, struct vnode **vpp, pid_t pid,
    126     pfstype type, int fd)
    127 {
    128 	struct pfskey key;
    129 
    130 	memset(&key, 0, sizeof(key));
    131 	key.pk_type = type;
    132 	key.pk_pid = pid;
    133 	key.pk_fd = fd;
    134 
    135 	return vcache_get(mp, &key, sizeof(key), vpp);
    136 }
    137 
    138 int
    139 procfs_rw(void *v)
    140 {
    141 	struct vop_read_args *ap = v;
    142 	struct vnode *vp = ap->a_vp;
    143 	struct uio *uio = ap->a_uio;
    144 	struct lwp *curl;
    145 	struct lwp *l;
    146 	struct pfsnode *pfs = VTOPFS(vp);
    147 	struct proc *p;
    148 	int error;
    149 
    150 	if (uio->uio_offset < 0)
    151 		return EINVAL;
    152 
    153 	if ((error = procfs_proc_lock(pfs->pfs_pid, &p, ESRCH)) != 0)
    154 		return error;
    155 
    156 	curl = curlwp;
    157 
    158 	/*
    159 	 * Do not allow init to be modified while in secure mode; it
    160 	 * could be duped into changing the security level.
    161 	 */
    162 #define	M2K(m)	((m) == UIO_READ ? KAUTH_REQ_PROCESS_PROCFS_READ : \
    163 		 KAUTH_REQ_PROCESS_PROCFS_WRITE)
    164 	mutex_enter(p->p_lock);
    165 	error = kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_PROCFS,
    166 	    p, pfs, KAUTH_ARG(M2K(uio->uio_rw)), NULL);
    167 	mutex_exit(p->p_lock);
    168 	if (error) {
    169 		procfs_proc_unlock(p);
    170 		return (error);
    171 	}
    172 #undef	M2K
    173 
    174 	mutex_enter(p->p_lock);
    175 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    176 		if (l->l_stat != LSZOMB)
    177 			break;
    178 	}
    179 	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
    180 	if (l == NULL) {
    181 		mutex_exit(p->p_lock);
    182 		procfs_proc_unlock(p);
    183 		return ESRCH;
    184 	}
    185 
    186 	lwp_addref(l);
    187 	mutex_exit(p->p_lock);
    188 
    189 	switch (pfs->pfs_type) {
    190 	case PFSnote:
    191 	case PFSnotepg:
    192 		error = procfs_donote(curl, p, pfs, uio);
    193 		break;
    194 
    195 	case PFSregs:
    196 		error = procfs_doregs(curl, l, pfs, uio);
    197 		break;
    198 
    199 	case PFSfpregs:
    200 		error = procfs_dofpregs(curl, l, pfs, uio);
    201 		break;
    202 
    203 	case PFSctl:
    204 		error = procfs_doctl(curl, l, pfs, uio);
    205 		break;
    206 
    207 	case PFSstatus:
    208 		error = procfs_dostatus(curl, l, pfs, uio);
    209 		break;
    210 
    211 	case PFSstat:
    212 		error = procfs_do_pid_stat(curl, l, pfs, uio);
    213 		break;
    214 
    215 	case PFSmap:
    216 		error = procfs_domap(curl, p, pfs, uio, 0);
    217 		break;
    218 
    219 	case PFSmaps:
    220 		error = procfs_domap(curl, p, pfs, uio, 1);
    221 		break;
    222 
    223 	case PFSmem:
    224 		error = procfs_domem(curl, l, pfs, uio);
    225 		break;
    226 
    227 	case PFScmdline:
    228 		error = procfs_docmdline(curl, p, pfs, uio);
    229 		break;
    230 
    231 	case PFSmeminfo:
    232 		error = procfs_domeminfo(curl, p, pfs, uio);
    233 		break;
    234 
    235 	case PFSdevices:
    236 		error = procfs_dodevices(curl, p, pfs, uio);
    237 		break;
    238 
    239 	case PFScpuinfo:
    240 		error = procfs_docpuinfo(curl, p, pfs, uio);
    241 		break;
    242 
    243 	case PFScpustat:
    244 		error = procfs_docpustat(curl, p, pfs, uio);
    245 		break;
    246 
    247 	case PFSloadavg:
    248 		error = procfs_doloadavg(curl, p, pfs, uio);
    249 		break;
    250 
    251 	case PFSstatm:
    252 		error = procfs_do_pid_statm(curl, l, pfs, uio);
    253 		break;
    254 
    255 	case PFSfd:
    256 		error = procfs_dofd(curl, p, pfs, uio);
    257 		break;
    258 
    259 	case PFSuptime:
    260 		error = procfs_douptime(curl, p, pfs, uio);
    261 		break;
    262 
    263 	case PFSmounts:
    264 		error = procfs_domounts(curl, p, pfs, uio);
    265 		break;
    266 
    267 	case PFSemul:
    268 		error = procfs_doemul(curl, p, pfs, uio);
    269 		break;
    270 
    271 	case PFSversion:
    272 		error = procfs_doversion(curl, p, pfs, uio);
    273 		break;
    274 
    275 #ifdef __HAVE_PROCFS_MACHDEP
    276 	PROCFS_MACHDEP_NODETYPE_CASES
    277 		error = procfs_machdep_rw(curl, l, pfs, uio);
    278 		break;
    279 #endif
    280 
    281 	default:
    282 		error = EOPNOTSUPP;
    283 		break;
    284 	}
    285 
    286 	/*
    287 	 * Release the references that we acquired earlier.
    288 	 */
    289 	lwp_delref(l);
    290 	procfs_proc_unlock(p);
    291 
    292 	return (error);
    293 }
    294 
    295 /*
    296  * Get a string from userland into (bf).  Strip a trailing
    297  * nl character (to allow easy access from the shell).
    298  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
    299  * will automatically add a nul char at the end.
    300  *
    301  * Returns 0 on success or the following errors
    302  *
    303  * EINVAL:    file offset is non-zero.
    304  * EMSGSIZE:  message is longer than kernel buffer
    305  * EFAULT:    user i/o buffer is not addressable
    306  */
    307 int
    308 vfs_getuserstr(struct uio *uio, char *bf, int *buflenp)
    309 {
    310 	int xlen;
    311 	int error;
    312 
    313 	if (uio->uio_offset != 0)
    314 		return (EINVAL);
    315 
    316 	xlen = *buflenp;
    317 
    318 	/* must be able to read the whole string in one go */
    319 	if (xlen < uio->uio_resid)
    320 		return (EMSGSIZE);
    321 	xlen = uio->uio_resid;
    322 
    323 	if ((error = uiomove(bf, xlen, uio)) != 0)
    324 		return (error);
    325 
    326 	/* allow multiple writes without seeks */
    327 	uio->uio_offset = 0;
    328 
    329 	/* cleanup string and remove trailing newline */
    330 	bf[xlen] = '\0';
    331 	xlen = strlen(bf);
    332 	if (xlen > 0 && bf[xlen-1] == '\n')
    333 		bf[--xlen] = '\0';
    334 	*buflenp = xlen;
    335 
    336 	return (0);
    337 }
    338 
    339 const vfs_namemap_t *
    340 vfs_findname(const vfs_namemap_t *nm, const char *bf, int buflen)
    341 {
    342 
    343 	for (; nm->nm_name; nm++)
    344 		if (memcmp(bf, nm->nm_name, buflen+1) == 0)
    345 			return (nm);
    346 
    347 	return (0);
    348 }
    349 
    350 static bool
    351 procfs_revoke_selector(void *arg, struct vnode *vp)
    352 {
    353 	struct proc *p = arg;
    354 	struct pfsnode *pfs = VTOPFS(vp);
    355 
    356 	return (pfs != NULL && pfs->pfs_pid == p->p_pid);
    357 }
    358 
    359 void
    360 procfs_revoke_vnodes(struct proc *p, void *arg)
    361 {
    362 	struct vnode *vp;
    363 	struct vnode_iterator *marker;
    364 	struct mount *mp = (struct mount *)arg;
    365 
    366 	if (!(p->p_flag & PK_SUGID))
    367 		return;
    368 
    369 	vfs_vnode_iterator_init(mp, &marker);
    370 
    371 	while ((vp = vfs_vnode_iterator_next(marker,
    372 	    procfs_revoke_selector, p)) != NULL) {
    373 		VOP_REVOKE(vp, REVOKEALL);
    374 		vrele(vp);
    375 	}
    376 
    377 	vfs_vnode_iterator_destroy(marker);
    378 }
    379 
    380 int
    381 procfs_proc_lock(int pid, struct proc **bunghole, int notfound)
    382 {
    383 	struct proc *tp;
    384 	int error = 0;
    385 
    386 	mutex_enter(proc_lock);
    387 
    388 	if (pid == 0)
    389 		tp = &proc0;
    390 	else if ((tp = proc_find(pid)) == NULL)
    391 		error = notfound;
    392 	if (tp != NULL && !rw_tryenter(&tp->p_reflock, RW_READER))
    393 		error = EBUSY;
    394 
    395 	mutex_exit(proc_lock);
    396 
    397 	*bunghole = tp;
    398 	return error;
    399 }
    400 
    401 void
    402 procfs_proc_unlock(struct proc *p)
    403 {
    404 
    405 	rw_exit(&p->p_reflock);
    406 }
    407 
    408 int
    409 procfs_doemul(struct lwp *curl, struct proc *p,
    410     struct pfsnode *pfs, struct uio *uio)
    411 {
    412 	const char *ename = p->p_emul->e_name;
    413 	return uiomove_frombuf(__UNCONST(ename), strlen(ename), uio);
    414 }
    415