xref: /netbsd/sys/miscfs/procfs/procfs_vfsops.c (revision 6550d01e)
1 /*	$NetBSD: procfs_vfsops.c,v 1.85 2009/11/30 10:59:20 pooka 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 1.85 2009/11/30 10:59:20 pooka 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/kauth.h>
99 #include <sys/module.h>
100 
101 #include <miscfs/genfs/genfs.h>
102 
103 #include <miscfs/procfs/procfs.h>
104 
105 #include <uvm/uvm_extern.h>			/* for PAGE_SIZE */
106 
107 MODULE(MODULE_CLASS_VFS, procfs, NULL);
108 
109 VFS_PROTOS(procfs);
110 
111 static struct sysctllog *procfs_sysctl_log;
112 
113 static kauth_listener_t procfs_listener;
114 
115 /*
116  * VFS Operations.
117  *
118  * mount system call
119  */
120 /* ARGSUSED */
121 int
122 procfs_mount(
123     struct mount *mp,
124     const char *path,
125     void *data,
126     size_t *data_len)
127 {
128 	struct lwp *l = curlwp;
129 	struct procfsmount *pmnt;
130 	struct procfs_args *args = data;
131 	int error;
132 
133 	if (UIO_MX & (UIO_MX-1)) {
134 		log(LOG_ERR, "procfs: invalid directory entry size");
135 		return (EINVAL);
136 	}
137 
138 	if (mp->mnt_flag & MNT_GETARGS) {
139 		if (*data_len < sizeof *args)
140 			return EINVAL;
141 
142 		pmnt = VFSTOPROC(mp);
143 		if (pmnt == NULL)
144 			return EIO;
145 		args->version = PROCFS_ARGSVERSION;
146 		args->flags = pmnt->pmnt_flags;
147 		*data_len = sizeof *args;
148 		return 0;
149 	}
150 
151 	if (mp->mnt_flag & MNT_UPDATE)
152 		return (EOPNOTSUPP);
153 
154 	if (*data_len >= sizeof *args && args->version != PROCFS_ARGSVERSION)
155 		return EINVAL;
156 
157 	pmnt = (struct procfsmount *) malloc(sizeof(struct procfsmount),
158 	    M_UFSMNT, M_WAITOK);   /* XXX need new malloc type */
159 
160 	mp->mnt_stat.f_namemax = MAXNAMLEN;
161 	mp->mnt_flag |= MNT_LOCAL;
162 	mp->mnt_data = pmnt;
163 	vfs_getnewfsid(mp);
164 
165 	error = set_statvfs_info(path, UIO_USERSPACE, "procfs", UIO_SYSSPACE,
166 	    mp->mnt_op->vfs_name, mp, l);
167 	pmnt->pmnt_exechook = exechook_establish(procfs_revoke_vnodes, mp);
168 	if (*data_len >= sizeof *args)
169 		pmnt->pmnt_flags = args->flags;
170 	else
171 		pmnt->pmnt_flags = 0;
172 
173 	mp->mnt_iflag |= IMNT_MPSAFE;
174 	return error;
175 }
176 
177 /*
178  * unmount system call
179  */
180 int
181 procfs_unmount(struct mount *mp, int mntflags)
182 {
183 	int error;
184 	int flags = 0;
185 
186 	if (mntflags & MNT_FORCE)
187 		flags |= FORCECLOSE;
188 
189 	if ((error = vflush(mp, 0, flags)) != 0)
190 		return (error);
191 
192 	exechook_disestablish(VFSTOPROC(mp)->pmnt_exechook);
193 
194 	free(mp->mnt_data, M_UFSMNT);
195 	mp->mnt_data = NULL;
196 
197 	return (0);
198 }
199 
200 int
201 procfs_root(struct mount *mp, struct vnode **vpp)
202 {
203 
204 	return (procfs_allocvp(mp, vpp, 0, PFSroot, -1, NULL));
205 }
206 
207 /* ARGSUSED */
208 int
209 procfs_start(struct mount *mp, int flags)
210 {
211 
212 	return (0);
213 }
214 
215 /*
216  * Get file system statistics.
217  */
218 int
219 procfs_statvfs(struct mount *mp, struct statvfs *sbp)
220 {
221 
222 	genfs_statvfs(mp, sbp);
223 
224 	sbp->f_bsize = PAGE_SIZE;
225 	sbp->f_frsize = PAGE_SIZE;
226 	sbp->f_iosize = PAGE_SIZE;
227 	sbp->f_blocks = 1;
228 	sbp->f_files = maxproc;			/* approx */
229 	sbp->f_ffree = maxproc - nprocs;	/* approx */
230 	sbp->f_favail = maxproc - nprocs;	/* approx */
231 
232 	return (0);
233 }
234 
235 /*ARGSUSED*/
236 int
237 procfs_sync(
238     struct mount *mp,
239     int waitfor,
240     kauth_cred_t uc)
241 {
242 
243 	return (0);
244 }
245 
246 /*ARGSUSED*/
247 int
248 procfs_vget(struct mount *mp, ino_t ino,
249     struct vnode **vpp)
250 {
251 	return (EOPNOTSUPP);
252 }
253 
254 void
255 procfs_init(void)
256 {
257 	procfs_hashinit();
258 }
259 
260 void
261 procfs_reinit(void)
262 {
263 	procfs_hashreinit();
264 }
265 
266 void
267 procfs_done(void)
268 {
269 	procfs_hashdone();
270 }
271 
272 extern const struct vnodeopv_desc procfs_vnodeop_opv_desc;
273 
274 const struct vnodeopv_desc * const procfs_vnodeopv_descs[] = {
275 	&procfs_vnodeop_opv_desc,
276 	NULL,
277 };
278 
279 struct vfsops procfs_vfsops = {
280 	MOUNT_PROCFS,
281 	sizeof (struct procfs_args),
282 	procfs_mount,
283 	procfs_start,
284 	procfs_unmount,
285 	procfs_root,
286 	(void *)eopnotsupp,		/* vfs_quotactl */
287 	procfs_statvfs,
288 	procfs_sync,
289 	procfs_vget,
290 	(void *)eopnotsupp,		/* vfs_fhtovp */
291 	(void *)eopnotsupp,		/* vfs_vptofh */
292 	procfs_init,
293 	procfs_reinit,
294 	procfs_done,
295 	NULL,				/* vfs_mountroot */
296 	(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
297 	vfs_stdextattrctl,
298 	(void *)eopnotsupp,		/* vfs_suspendctl */
299 	genfs_renamelock_enter,
300 	genfs_renamelock_exit,
301 	(void *)eopnotsupp,
302 	procfs_vnodeopv_descs,
303 	0,
304 	{ NULL, NULL },
305 };
306 
307 static int
308 procfs_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
309     void *arg0, void *arg1, void *arg2, void *arg3)
310 {
311 	struct proc *p;
312 	struct pfsnode *pfs;
313 	enum kauth_process_req req;
314 	int result;
315 
316 	result = KAUTH_RESULT_DEFER;
317 	p = arg0;
318 	pfs = arg1;
319 	req = (enum kauth_process_req)(unsigned long)arg2;
320 
321 	if (action != KAUTH_PROCESS_PROCFS)
322 		return result;
323 
324 	/* Privileged; let secmodel handle that. */
325 	if (req == KAUTH_REQ_PROCESS_PROCFS_CTL)
326 		return result;
327 
328 	switch (pfs->pfs_type) {
329 	case PFSregs:
330 	case PFSfpregs:
331 	case PFSmem:
332 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
333 		    ISSET(p->p_flag, PK_SUGID))
334 			break;
335 
336 		/*FALLTHROUGH*/
337 	default:
338 		result = KAUTH_RESULT_ALLOW;
339 		break;
340 	}
341 
342 	return result;
343 }
344 
345 
346 static int
347 procfs_modcmd(modcmd_t cmd, void *arg)
348 {
349 	int error;
350 
351 	switch (cmd) {
352 	case MODULE_CMD_INIT:
353 		error = vfs_attach(&procfs_vfsops);
354 		if (error != 0)
355 			break;
356 		sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
357 			       CTLFLAG_PERMANENT,
358 			       CTLTYPE_NODE, "vfs", NULL,
359 			       NULL, 0, NULL, 0,
360 			       CTL_VFS, CTL_EOL);
361 		sysctl_createv(&procfs_sysctl_log, 0, NULL, NULL,
362 			       CTLFLAG_PERMANENT,
363 			       CTLTYPE_NODE, "procfs",
364 			       SYSCTL_DESCR("Process file system"),
365 			       NULL, 0, NULL, 0,
366 			       CTL_VFS, 12, CTL_EOL);
367 		/*
368 		 * XXX the "12" above could be dynamic, thereby eliminating
369 		 * one more instance of the "number to vfs" mapping problem,
370 		 * but "12" is the order as taken from sys/mount.h
371 		 */
372 
373 		procfs_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
374 		    procfs_listener_cb, NULL);
375 
376 		break;
377 	case MODULE_CMD_FINI:
378 		error = vfs_detach(&procfs_vfsops);
379 		if (error != 0)
380 			break;
381 		sysctl_teardown(&procfs_sysctl_log);
382 		kauth_unlisten_scope(procfs_listener);
383 		break;
384 	default:
385 		error = ENOTTY;
386 		break;
387 	}
388 
389 	return (error);
390 }
391