xref: /netbsd-src/sys/miscfs/procfs/procfs_subr.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: procfs_subr.c,v 1.106 2014/11/10 18:46:34 maxv 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 1.106 2014/11/10 18:46:34 maxv 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