xref: /netbsd-src/sys/miscfs/procfs/procfs_subr.c (revision 0124a94134087629ad3d7bd4f7a3282d20839f3d)
1 /*	$NetBSD: procfs_subr.c,v 1.120 2024/07/01 01:35:53 christos 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 1.120 2024/07/01 01:35:53 christos 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/fstrans.h>
113 #include <sys/vnode.h>
114 #include <sys/stat.h>
115 #include <sys/file.h>
116 #include <sys/filedesc.h>
117 #include <sys/kauth.h>
118 #include <sys/sysctl.h>
119 
120 #include <miscfs/procfs/procfs.h>
121 
122 /*
123  * Allocate a pfsnode/vnode pair.  The vnode is referenced.
124  * The pid, type, and file descriptor uniquely identify a pfsnode.
125  */
126 int
procfs_allocvp(struct mount * mp,struct vnode ** vpp,pid_t pid,pfstype type,int fd)127 procfs_allocvp(struct mount *mp, struct vnode **vpp, pid_t pid,
128     pfstype type, int fd)
129 {
130 	struct pfskey key;
131 
132 	memset(&key, 0, sizeof(key));
133 	key.pk_type = type;
134 	key.pk_pid = pid;
135 	key.pk_fd = fd;
136 
137 	return vcache_get(mp, &key, sizeof(key), vpp);
138 }
139 
140 int
procfs_rw(void * v)141 procfs_rw(void *v)
142 {
143 	struct vop_read_args *ap = v;
144 	struct vnode *vp = ap->a_vp;
145 	struct uio *uio = ap->a_uio;
146 	struct lwp *curl;
147 	struct lwp *l;
148 	struct pfsnode *pfs = VTOPFS(vp);
149 	struct proc *p;
150 	int error;
151 
152 	if (uio->uio_offset < 0)
153 		return EINVAL;
154 
155 	if ((error =
156 	     procfs_proc_lock(vp->v_mount, pfs->pfs_pid, &p, ESRCH)) != 0)
157 		return error;
158 
159 	curl = curlwp;
160 
161 	/*
162 	 * Do not allow init to be modified while in secure mode; it
163 	 * could be duped into changing the security level.
164 	 */
165 #define	M2K(m)	((m) == UIO_READ ? KAUTH_REQ_PROCESS_PROCFS_READ : \
166 		 KAUTH_REQ_PROCESS_PROCFS_WRITE)
167 	mutex_enter(p->p_lock);
168 	error = kauth_authorize_process(curl->l_cred, KAUTH_PROCESS_PROCFS,
169 	    p, pfs, KAUTH_ARG(M2K(uio->uio_rw)), NULL);
170 	mutex_exit(p->p_lock);
171 	if (error) {
172 		procfs_proc_unlock(p);
173 		return (error);
174 	}
175 #undef	M2K
176 
177 	mutex_enter(p->p_lock);
178 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
179 		if (l->l_stat != LSZOMB)
180 			break;
181 	}
182 	/* Process is exiting if no-LWPS or all LWPs are LSZOMB */
183 	if (l == NULL) {
184 		mutex_exit(p->p_lock);
185 		procfs_proc_unlock(p);
186 		return ESRCH;
187 	}
188 
189 	lwp_addref(l);
190 	mutex_exit(p->p_lock);
191 
192 	switch (pfs->pfs_type) {
193 	case PFSnote:
194 	case PFSnotepg:
195 		error = procfs_donote(curl, p, pfs, uio);
196 		break;
197 
198 	case PFSregs:
199 		error = procfs_doregs(curl, l, pfs, uio);
200 		break;
201 
202 	case PFSfpregs:
203 		error = procfs_dofpregs(curl, l, pfs, uio);
204 		break;
205 
206 	case PFSstatus:
207 		error = procfs_dostatus(curl, l, pfs, uio);
208 		break;
209 
210 	case PFSstat:
211 		error = procfs_do_pid_stat(curl, l, pfs, uio);
212 		break;
213 
214 	case PFSlimit:
215 		error = procfs_dolimit(curl, p, pfs, uio);
216 		break;
217 
218 	case PFSlimits:
219 		error = procfs_dolimits(curl, p, pfs, uio);
220 		break;
221 
222 	case PFSmap:
223 		error = procfs_domap(curl, p, pfs, uio, 0);
224 		break;
225 
226 	case PFSmaps:
227 		error = procfs_domap(curl, p, pfs, uio, 1);
228 		break;
229 
230 	case PFSmem:
231 		error = procfs_domem(curl, l, pfs, uio);
232 		break;
233 
234 	case PFScmdline:
235 		error = procfs_doprocargs(curl, p, pfs, uio, KERN_PROC_ARGV);
236 		break;
237 
238 	case PFSenviron:
239 		error = procfs_doprocargs(curl, p, pfs, uio, KERN_PROC_ENV);
240 		break;
241 
242 	case PFSmeminfo:
243 		error = procfs_domeminfo(curl, p, pfs, uio);
244 		break;
245 
246 	case PFSdevices:
247 		error = procfs_dodevices(curl, p, pfs, uio);
248 		break;
249 
250 	case PFScpuinfo:
251 		error = procfs_docpuinfo(curl, p, pfs, uio);
252 		break;
253 
254 	case PFScpustat:
255 		error = procfs_docpustat(curl, p, pfs, uio);
256 		break;
257 
258 	case PFSloadavg:
259 		error = procfs_doloadavg(curl, p, pfs, uio);
260 		break;
261 
262 	case PFSstatm:
263 		error = procfs_do_pid_statm(curl, l, pfs, uio);
264 		break;
265 
266 	case PFSfd:
267 		error = procfs_dofd(curl, p, pfs, uio);
268 		break;
269 
270 	case PFSuptime:
271 		error = procfs_douptime(curl, p, pfs, uio);
272 		break;
273 
274 	case PFSmounts:
275 		error = procfs_domounts(curl, p, pfs, uio);
276 		break;
277 
278 	case PFSemul:
279 		error = procfs_doemul(curl, p, pfs, uio);
280 		break;
281 
282 	case PFSversion:
283 		error = procfs_doversion(curl, p, pfs, uio);
284 		break;
285 
286 	case PFSauxv:
287 		error = procfs_doauxv(curl, p, pfs, uio);
288 		break;
289 
290 	case PFSsysvipc_msg:
291 		error = procfs_dosysvipc_msg(curl, p, pfs, uio);
292 		break;
293 
294 	case PFSsysvipc_sem:
295 		error = procfs_dosysvipc_sem(curl, p, pfs, uio);
296 		break;
297 
298 	case PFSsysvipc_shm:
299 		error = procfs_dosysvipc_shm(curl, p, pfs, uio);
300 		break;
301 
302 	case PFSmq_msg_def:
303 		error = procfs_domq_msg_def(curl, p, pfs, uio);
304 		break;
305 
306 	case PFSmq_msg_max:
307 		error = procfs_domq_msg_max(curl, p, pfs, uio);
308 		break;
309 
310 	case PFSmq_siz_def:
311 		error = procfs_domq_siz_def(curl, p, pfs, uio);
312 		break;
313 
314 	case PFSmq_siz_max:
315 		error = procfs_domq_siz_max(curl, p, pfs, uio);
316 		break;
317 
318 	case PFSmq_qmax:
319 		error = procfs_domq_qmax(curl, p, pfs, uio);
320 		break;
321 
322 #ifdef __HAVE_PROCFS_MACHDEP
323 	PROCFS_MACHDEP_NODETYPE_CASES
324 		error = procfs_machdep_rw(curl, l, pfs, uio);
325 		break;
326 #endif
327 
328 	default:
329 		error = EOPNOTSUPP;
330 		break;
331 	}
332 
333 	/*
334 	 * Release the references that we acquired earlier.
335 	 */
336 	lwp_delref(l);
337 	procfs_proc_unlock(p);
338 
339 	return (error);
340 }
341 
342 /*
343  * Get a string from userland into (bf).  Strip a trailing
344  * nl character (to allow easy access from the shell).
345  * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
346  * will automatically add a nul char at the end.
347  *
348  * Returns 0 on success or the following errors
349  *
350  * EINVAL:    file offset is non-zero.
351  * EMSGSIZE:  message is longer than kernel buffer
352  * EFAULT:    user i/o buffer is not addressable
353  */
354 int
vfs_getuserstr(struct uio * uio,char * bf,int * buflenp)355 vfs_getuserstr(struct uio *uio, char *bf, int *buflenp)
356 {
357 	size_t xlen;
358 	int error;
359 
360 	if (uio->uio_offset != 0)
361 		return (EINVAL);
362 
363 	xlen = *buflenp;
364 
365 	/* must be able to read the whole string in one go */
366 	if (xlen < uio->uio_resid)
367 		return (EMSGSIZE);
368 	xlen = uio->uio_resid;
369 
370 	if ((error = uiomove(bf, xlen, uio)) != 0)
371 		return (error);
372 
373 	/* allow multiple writes without seeks */
374 	uio->uio_offset = 0;
375 
376 	/* cleanup string and remove trailing newline */
377 	bf[xlen] = '\0';
378 	xlen = strlen(bf);
379 	if (xlen > 0 && bf[xlen-1] == '\n')
380 		bf[--xlen] = '\0';
381 	*buflenp = xlen;
382 
383 	return (0);
384 }
385 
386 const vfs_namemap_t *
vfs_findname(const vfs_namemap_t * nm,const char * bf,int buflen)387 vfs_findname(const vfs_namemap_t *nm, const char *bf, int buflen)
388 {
389 
390 	for (; nm->nm_name; nm++)
391 		if (memcmp(bf, nm->nm_name, buflen+1) == 0)
392 			return (nm);
393 
394 	return (0);
395 }
396 
397 bool
procfs_use_linux_compat(struct mount * mp)398 procfs_use_linux_compat(struct mount *mp)
399 {
400 	const int flags = VFSTOPROC(mp)->pmnt_flags;
401 
402 	return (flags & PROCFSMNT_LINUXCOMPAT) ? true : false;
403 }
404 
405 struct proc *
procfs_proc_find(struct mount * mp,pid_t pid)406 procfs_proc_find(struct mount *mp, pid_t pid)
407 {
408 
409 	KASSERT(mutex_owned(&proc_lock));
410 	return procfs_use_linux_compat(mp) ? proc_find_lwpid(pid)
411 					   : proc_find(pid);
412 }
413 
414 int
procfs_proc_lock(struct mount * mp,int pid,struct proc ** bunghole,int notfound)415 procfs_proc_lock(struct mount *mp, int pid, struct proc **bunghole,
416 		 int notfound)
417 {
418 	struct proc *tp;
419 	int error = 0;
420 
421 	mutex_enter(&proc_lock);
422 
423 	if (pid == 0)
424 		tp = &proc0;
425 	else if ((tp = procfs_proc_find(mp, pid)) == NULL)
426 		error = notfound;
427 	if (tp != NULL && !rw_tryenter(&tp->p_reflock, RW_READER))
428 		error = EBUSY;
429 
430 	mutex_exit(&proc_lock);
431 
432 	*bunghole = tp;
433 	return error;
434 }
435 
436 void
procfs_proc_unlock(struct proc * p)437 procfs_proc_unlock(struct proc *p)
438 {
439 
440 	rw_exit(&p->p_reflock);
441 }
442 
443 int
procfs_doemul(struct lwp * curl,struct proc * p,struct pfsnode * pfs,struct uio * uio)444 procfs_doemul(struct lwp *curl, struct proc *p,
445     struct pfsnode *pfs, struct uio *uio)
446 {
447 	const char *ename = p->p_emul->e_name;
448 	return uiomove_frombuf(__UNCONST(ename), strlen(ename), uio);
449 }
450