xref: /netbsd-src/sys/miscfs/procfs/procfs_subr.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /*	$NetBSD: procfs_subr.c,v 1.105 2014/07/27 16:47:26 hannken 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 2014/07/27 16:47:26 hannken 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/malloc.h>
114 #include <sys/stat.h>
115 #include <sys/file.h>
116 #include <sys/filedesc.h>
117 #include <sys/kauth.h>
118 
119 #include <miscfs/procfs/procfs.h>
120 
121 /*
122  * Allocate a pfsnode/vnode pair.  The vnode is referenced.
123  * The pid, type, and file descriptor uniquely identify a pfsnode.
124  */
125 int
126 procfs_allocvp(struct mount *mp, struct vnode **vpp, pid_t pid,
127     pfstype type, int fd)
128 {
129 	struct pfskey key;
130 
131 	memset(&key, 0, sizeof(key));
132 	key.pk_type = type;
133 	key.pk_pid = pid;
134 	key.pk_fd = fd;
135 
136 	return vcache_get(mp, &key, sizeof(key), vpp);
137 }
138 
139 int
140 procfs_rw(void *v)
141 {
142 	struct vop_read_args *ap = v;
143 	struct vnode *vp = ap->a_vp;
144 	struct uio *uio = ap->a_uio;
145 	struct lwp *curl;
146 	struct lwp *l;
147 	struct pfsnode *pfs = VTOPFS(vp);
148 	struct proc *p;
149 	int error;
150 
151 	if (uio->uio_offset < 0)
152 		return EINVAL;
153 
154 	if ((error = procfs_proc_lock(pfs->pfs_pid, &p, ESRCH)) != 0)
155 		return error;
156 
157 	curl = curlwp;
158 
159 	/*
160 	 * Do not allow init to be modified while in secure mode; it
161 	 * could be duped into changing the security level.
162 	 */
163 #define	M2K(m)	((m) == UIO_READ ? KAUTH_REQ_PROCESS_PROCFS_READ : \
164 		 KAUTH_REQ_PROCESS_PROCFS_WRITE)
165 	mutex_enter(p->p_lock);
166 	error = kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_PROCFS,
167 	    p, pfs, KAUTH_ARG(M2K(uio->uio_rw)), NULL);
168 	mutex_exit(p->p_lock);
169 	if (error) {
170 		procfs_proc_unlock(p);
171 		return (error);
172 	}
173 #undef	M2K
174 
175 	mutex_enter(p->p_lock);
176 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
177 		if (l->l_stat != LSZOMB)
178 			break;
179 	}
180 	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
181 	if (l == NULL) {
182 		mutex_exit(p->p_lock);
183 		procfs_proc_unlock(p);
184 		return ESRCH;
185 	}
186 
187 	lwp_addref(l);
188 	mutex_exit(p->p_lock);
189 
190 	switch (pfs->pfs_type) {
191 	case PFSnote:
192 	case PFSnotepg:
193 		error = procfs_donote(curl, p, pfs, uio);
194 		break;
195 
196 	case PFSregs:
197 		error = procfs_doregs(curl, l, pfs, uio);
198 		break;
199 
200 	case PFSfpregs:
201 		error = procfs_dofpregs(curl, l, pfs, uio);
202 		break;
203 
204 	case PFSctl:
205 		error = procfs_doctl(curl, l, pfs, uio);
206 		break;
207 
208 	case PFSstatus:
209 		error = procfs_dostatus(curl, l, pfs, uio);
210 		break;
211 
212 	case PFSstat:
213 		error = procfs_do_pid_stat(curl, l, pfs, uio);
214 		break;
215 
216 	case PFSmap:
217 		error = procfs_domap(curl, p, pfs, uio, 0);
218 		break;
219 
220 	case PFSmaps:
221 		error = procfs_domap(curl, p, pfs, uio, 1);
222 		break;
223 
224 	case PFSmem:
225 		error = procfs_domem(curl, l, pfs, uio);
226 		break;
227 
228 	case PFScmdline:
229 		error = procfs_docmdline(curl, p, pfs, uio);
230 		break;
231 
232 	case PFSmeminfo:
233 		error = procfs_domeminfo(curl, p, pfs, uio);
234 		break;
235 
236 	case PFSdevices:
237 		error = procfs_dodevices(curl, p, pfs, uio);
238 		break;
239 
240 	case PFScpuinfo:
241 		error = procfs_docpuinfo(curl, p, pfs, uio);
242 		break;
243 
244 	case PFScpustat:
245 		error = procfs_docpustat(curl, p, pfs, uio);
246 		break;
247 
248 	case PFSloadavg:
249 		error = procfs_doloadavg(curl, p, pfs, uio);
250 		break;
251 
252 	case PFSstatm:
253 		error = procfs_do_pid_statm(curl, l, pfs, uio);
254 		break;
255 
256 	case PFSfd:
257 		error = procfs_dofd(curl, p, pfs, uio);
258 		break;
259 
260 	case PFSuptime:
261 		error = procfs_douptime(curl, p, pfs, uio);
262 		break;
263 
264 	case PFSmounts:
265 		error = procfs_domounts(curl, p, pfs, uio);
266 		break;
267 
268 	case PFSemul:
269 		error = procfs_doemul(curl, p, pfs, uio);
270 		break;
271 
272 	case PFSversion:
273 		error = procfs_doversion(curl, p, pfs, uio);
274 		break;
275 
276 #ifdef __HAVE_PROCFS_MACHDEP
277 	PROCFS_MACHDEP_NODETYPE_CASES
278 		error = procfs_machdep_rw(curl, l, pfs, uio);
279 		break;
280 #endif
281 
282 	default:
283 		error = EOPNOTSUPP;
284 		break;
285 	}
286 
287 	/*
288 	 * Release the references that we acquired earlier.
289 	 */
290 	lwp_delref(l);
291 	procfs_proc_unlock(p);
292 
293 	return (error);
294 }
295 
296 /*
297  * Get a string from userland into (bf).  Strip a trailing
298  * nl character (to allow easy access from the shell).
299  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
300  * will automatically add a nul char at the end.
301  *
302  * Returns 0 on success or the following errors
303  *
304  * EINVAL:    file offset is non-zero.
305  * EMSGSIZE:  message is longer than kernel buffer
306  * EFAULT:    user i/o buffer is not addressable
307  */
308 int
309 vfs_getuserstr(struct uio *uio, char *bf, int *buflenp)
310 {
311 	int xlen;
312 	int error;
313 
314 	if (uio->uio_offset != 0)
315 		return (EINVAL);
316 
317 	xlen = *buflenp;
318 
319 	/* must be able to read the whole string in one go */
320 	if (xlen < uio->uio_resid)
321 		return (EMSGSIZE);
322 	xlen = uio->uio_resid;
323 
324 	if ((error = uiomove(bf, xlen, uio)) != 0)
325 		return (error);
326 
327 	/* allow multiple writes without seeks */
328 	uio->uio_offset = 0;
329 
330 	/* cleanup string and remove trailing newline */
331 	bf[xlen] = '\0';
332 	xlen = strlen(bf);
333 	if (xlen > 0 && bf[xlen-1] == '\n')
334 		bf[--xlen] = '\0';
335 	*buflenp = xlen;
336 
337 	return (0);
338 }
339 
340 const vfs_namemap_t *
341 vfs_findname(const vfs_namemap_t *nm, const char *bf, int buflen)
342 {
343 
344 	for (; nm->nm_name; nm++)
345 		if (memcmp(bf, nm->nm_name, buflen+1) == 0)
346 			return (nm);
347 
348 	return (0);
349 }
350 
351 static bool
352 procfs_revoke_selector(void *arg, struct vnode *vp)
353 {
354 	struct proc *p = arg;
355 	struct pfsnode *pfs = VTOPFS(vp);
356 
357 	return (pfs != NULL && pfs->pfs_pid == p->p_pid);
358 }
359 
360 void
361 procfs_revoke_vnodes(struct proc *p, void *arg)
362 {
363 	struct vnode *vp;
364 	struct vnode_iterator *marker;
365 	struct mount *mp = (struct mount *)arg;
366 
367 	if (!(p->p_flag & PK_SUGID))
368 		return;
369 
370 	vfs_vnode_iterator_init(mp, &marker);
371 
372 	while ((vp = vfs_vnode_iterator_next(marker,
373 	    procfs_revoke_selector, p)) != NULL) {
374 		VOP_REVOKE(vp, REVOKEALL);
375 		vrele(vp);
376 	}
377 
378 	vfs_vnode_iterator_destroy(marker);
379 }
380 
381 int
382 procfs_proc_lock(int pid, struct proc **bunghole, int notfound)
383 {
384 	struct proc *tp;
385 	int error = 0;
386 
387 	mutex_enter(proc_lock);
388 
389 	if (pid == 0)
390 		tp = &proc0;
391 	else if ((tp = proc_find(pid)) == NULL)
392 		error = notfound;
393 	if (tp != NULL && !rw_tryenter(&tp->p_reflock, RW_READER))
394 		error = EBUSY;
395 
396 	mutex_exit(proc_lock);
397 
398 	*bunghole = tp;
399 	return error;
400 }
401 
402 void
403 procfs_proc_unlock(struct proc *p)
404 {
405 
406 	rw_exit(&p->p_reflock);
407 }
408 
409 int
410 procfs_doemul(struct lwp *curl, struct proc *p,
411     struct pfsnode *pfs, struct uio *uio)
412 {
413 	const char *ename = p->p_emul->e_name;
414 	return uiomove_frombuf(__UNCONST(ename), strlen(ename), uio);
415 }
416