xref: /freebsd/sys/compat/linux/linux_mib.c (revision 0edc114ac0b998b06235da32bec24d55c10206cd)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1999 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/sdt.h>
35 #include <sys/systm.h>
36 #include <sys/sysctl.h>
37 #include <sys/proc.h>
38 #include <sys/malloc.h>
39 #include <sys/mount.h>
40 #include <sys/jail.h>
41 #include <sys/lock.h>
42 #include <sys/sx.h>
43 
44 #include <compat/linux/linux_mib.h>
45 #include <compat/linux/linux_misc.h>
46 
47 struct linux_prison {
48 	char	pr_osname[LINUX_MAX_UTSNAME];
49 	char	pr_osrelease[LINUX_MAX_UTSNAME];
50 	int	pr_oss_version;
51 	int	pr_osrel;
52 };
53 
54 static struct linux_prison lprison0 = {
55 	.pr_osname =		"Linux",
56 	.pr_osrelease =		LINUX_VERSION_STR,
57 	.pr_oss_version =	0x030600,
58 	.pr_osrel =		LINUX_VERSION_CODE
59 };
60 
61 static unsigned linux_osd_jail_slot;
62 
63 SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0, "Linux mode");
64 
65 static int	linux_set_osname(struct thread *td, char *osname);
66 static int	linux_set_osrelease(struct thread *td, char *osrelease);
67 static int	linux_set_oss_version(struct thread *td, int oss_version);
68 
69 static int
70 linux_sysctl_osname(SYSCTL_HANDLER_ARGS)
71 {
72 	char osname[LINUX_MAX_UTSNAME];
73 	int error;
74 
75 	linux_get_osname(req->td, osname);
76 	error = sysctl_handle_string(oidp, osname, LINUX_MAX_UTSNAME, req);
77 	if (error != 0 || req->newptr == NULL)
78 		return (error);
79 	error = linux_set_osname(req->td, osname);
80 
81 	return (error);
82 }
83 
84 SYSCTL_PROC(_compat_linux, OID_AUTO, osname,
85 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
86 	    0, 0, linux_sysctl_osname, "A",
87 	    "Linux kernel OS name");
88 
89 static int
90 linux_sysctl_osrelease(SYSCTL_HANDLER_ARGS)
91 {
92 	char osrelease[LINUX_MAX_UTSNAME];
93 	int error;
94 
95 	linux_get_osrelease(req->td, osrelease);
96 	error = sysctl_handle_string(oidp, osrelease, LINUX_MAX_UTSNAME, req);
97 	if (error != 0 || req->newptr == NULL)
98 		return (error);
99 	error = linux_set_osrelease(req->td, osrelease);
100 
101 	return (error);
102 }
103 
104 SYSCTL_PROC(_compat_linux, OID_AUTO, osrelease,
105 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
106 	    0, 0, linux_sysctl_osrelease, "A",
107 	    "Linux kernel OS release");
108 
109 static int
110 linux_sysctl_oss_version(SYSCTL_HANDLER_ARGS)
111 {
112 	int oss_version;
113 	int error;
114 
115 	oss_version = linux_get_oss_version(req->td);
116 	error = sysctl_handle_int(oidp, &oss_version, 0, req);
117 	if (error != 0 || req->newptr == NULL)
118 		return (error);
119 	error = linux_set_oss_version(req->td, oss_version);
120 
121 	return (error);
122 }
123 
124 SYSCTL_PROC(_compat_linux, OID_AUTO, oss_version,
125 	    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_MPSAFE,
126 	    0, 0, linux_sysctl_oss_version, "I",
127 	    "Linux OSS version");
128 
129 /*
130  * Map the osrelease into integer
131  */
132 static int
133 linux_map_osrel(char *osrelease, int *osrel)
134 {
135 	char *sep, *eosrelease;
136 	int len, v0, v1, v2, v;
137 
138 	len = strlen(osrelease);
139 	eosrelease = osrelease + len;
140 	v0 = strtol(osrelease, &sep, 10);
141 	if (osrelease == sep || sep + 1 >= eosrelease || *sep != '.')
142 		return (EINVAL);
143 	osrelease = sep + 1;
144 	v1 = strtol(osrelease, &sep, 10);
145 	if (osrelease == sep || sep + 1 >= eosrelease || *sep != '.')
146 		return (EINVAL);
147 	osrelease = sep + 1;
148 	v2 = strtol(osrelease, &sep, 10);
149 	if (osrelease == sep ||
150 	    (sep != eosrelease && (sep + 1 >= eosrelease || *sep != '-')))
151 		return (EINVAL);
152 
153 	v = LINUX_KERNVER(v0, v1, v2);
154 	if (v < LINUX_KERNVER(1, 0, 0))
155 		return (EINVAL);
156 
157 	if (osrel != NULL)
158 		*osrel = v;
159 
160 	return (0);
161 }
162 
163 /*
164  * Find a prison with Linux info.
165  * Return the Linux info and the (locked) prison.
166  */
167 static struct linux_prison *
168 linux_find_prison(struct prison *spr, struct prison **prp)
169 {
170 	struct prison *pr;
171 	struct linux_prison *lpr;
172 
173 	for (pr = spr;; pr = pr->pr_parent) {
174 		mtx_lock(&pr->pr_mtx);
175 		lpr = (pr == &prison0)
176 		    ? &lprison0
177 		    : osd_jail_get(pr, linux_osd_jail_slot);
178 		if (lpr != NULL)
179 			break;
180 		mtx_unlock(&pr->pr_mtx);
181 	}
182 	*prp = pr;
183 
184 	return (lpr);
185 }
186 
187 /*
188  * Ensure a prison has its own Linux info.  If lprp is non-null, point it to
189  * the Linux info and lock the prison.
190  */
191 static void
192 linux_alloc_prison(struct prison *pr, struct linux_prison **lprp)
193 {
194 	struct prison *ppr;
195 	struct linux_prison *lpr, *nlpr;
196 	void **rsv;
197 
198 	/* If this prison already has Linux info, return that. */
199 	lpr = linux_find_prison(pr, &ppr);
200 	if (ppr == pr)
201 		goto done;
202 	/*
203 	 * Allocate a new info record.  Then check again, in case something
204 	 * changed during the allocation.
205 	 */
206 	mtx_unlock(&ppr->pr_mtx);
207 	nlpr = malloc(sizeof(struct linux_prison), M_PRISON, M_WAITOK);
208 	rsv = osd_reserve(linux_osd_jail_slot);
209 	lpr = linux_find_prison(pr, &ppr);
210 	if (ppr == pr) {
211 		free(nlpr, M_PRISON);
212 		osd_free_reserved(rsv);
213 		goto done;
214 	}
215 	/* Inherit the initial values from the ancestor. */
216 	mtx_lock(&pr->pr_mtx);
217 	(void)osd_jail_set_reserved(pr, linux_osd_jail_slot, rsv, nlpr);
218 	bcopy(lpr, nlpr, sizeof(*lpr));
219 	lpr = nlpr;
220 	mtx_unlock(&ppr->pr_mtx);
221  done:
222 	if (lprp != NULL)
223 		*lprp = lpr;
224 	else
225 		mtx_unlock(&pr->pr_mtx);
226 }
227 
228 /*
229  * Jail OSD methods for Linux prison data.
230  */
231 static int
232 linux_prison_create(void *obj, void *data)
233 {
234 	struct prison *pr = obj;
235 	struct vfsoptlist *opts = data;
236 	int jsys;
237 
238 	if (vfs_copyopt(opts, "linux", &jsys, sizeof(jsys)) == 0 &&
239 	    jsys == JAIL_SYS_INHERIT)
240 		return (0);
241 	/*
242 	 * Inherit a prison's initial values from its parent
243 	 * (different from JAIL_SYS_INHERIT which also inherits changes).
244 	 */
245 	linux_alloc_prison(pr, NULL);
246 	return (0);
247 }
248 
249 static int
250 linux_prison_check(void *obj __unused, void *data)
251 {
252 	struct vfsoptlist *opts = data;
253 	char *osname, *osrelease;
254 	int error, jsys, len, oss_version;
255 
256 	/* Check that the parameters are correct. */
257 	error = vfs_copyopt(opts, "linux", &jsys, sizeof(jsys));
258 	if (error != ENOENT) {
259 		if (error != 0)
260 			return (error);
261 		if (jsys != JAIL_SYS_NEW && jsys != JAIL_SYS_INHERIT)
262 			return (EINVAL);
263 	}
264 	error = vfs_getopt(opts, "linux.osname", (void **)&osname, &len);
265 	if (error != ENOENT) {
266 		if (error != 0)
267 			return (error);
268 		if (len == 0 || osname[len - 1] != '\0')
269 			return (EINVAL);
270 		if (len > LINUX_MAX_UTSNAME) {
271 			vfs_opterror(opts, "linux.osname too long");
272 			return (ENAMETOOLONG);
273 		}
274 	}
275 	error = vfs_getopt(opts, "linux.osrelease", (void **)&osrelease, &len);
276 	if (error != ENOENT) {
277 		if (error != 0)
278 			return (error);
279 		if (len == 0 || osrelease[len - 1] != '\0')
280 			return (EINVAL);
281 		if (len > LINUX_MAX_UTSNAME) {
282 			vfs_opterror(opts, "linux.osrelease too long");
283 			return (ENAMETOOLONG);
284 		}
285 		error = linux_map_osrel(osrelease, NULL);
286 		if (error != 0) {
287 			vfs_opterror(opts, "linux.osrelease format error");
288 			return (error);
289 		}
290 	}
291 	error = vfs_copyopt(opts, "linux.oss_version", &oss_version,
292 	    sizeof(oss_version));
293 
294 	if (error == ENOENT)
295 		error = 0;
296 	return (error);
297 }
298 
299 static int
300 linux_prison_set(void *obj, void *data)
301 {
302 	struct linux_prison *lpr;
303 	struct prison *pr = obj;
304 	struct vfsoptlist *opts = data;
305 	char *osname, *osrelease;
306 	int error, gotversion, jsys, len, oss_version;
307 
308 	/* Set the parameters, which should be correct. */
309 	error = vfs_copyopt(opts, "linux", &jsys, sizeof(jsys));
310 	if (error == ENOENT)
311 		jsys = -1;
312 	error = vfs_getopt(opts, "linux.osname", (void **)&osname, &len);
313 	if (error == ENOENT)
314 		osname = NULL;
315 	else
316 		jsys = JAIL_SYS_NEW;
317 	error = vfs_getopt(opts, "linux.osrelease", (void **)&osrelease, &len);
318 	if (error == ENOENT)
319 		osrelease = NULL;
320 	else
321 		jsys = JAIL_SYS_NEW;
322 	error = vfs_copyopt(opts, "linux.oss_version", &oss_version,
323 	    sizeof(oss_version));
324 	if (error == ENOENT)
325 		gotversion = 0;
326 	else {
327 		gotversion = 1;
328 		jsys = JAIL_SYS_NEW;
329 	}
330 	switch (jsys) {
331 	case JAIL_SYS_INHERIT:
332 		/* "linux=inherit": inherit the parent's Linux info. */
333 		mtx_lock(&pr->pr_mtx);
334 		osd_jail_del(pr, linux_osd_jail_slot);
335 		mtx_unlock(&pr->pr_mtx);
336 		break;
337 	case JAIL_SYS_NEW:
338 		/*
339 		 * "linux=new" or "linux.*":
340 		 * the prison gets its own Linux info.
341 		 */
342 		linux_alloc_prison(pr, &lpr);
343 		if (osrelease) {
344 			(void)linux_map_osrel(osrelease, &lpr->pr_osrel);
345 			strlcpy(lpr->pr_osrelease, osrelease,
346 			    LINUX_MAX_UTSNAME);
347 		}
348 		if (osname)
349 			strlcpy(lpr->pr_osname, osname, LINUX_MAX_UTSNAME);
350 		if (gotversion)
351 			lpr->pr_oss_version = oss_version;
352 		mtx_unlock(&pr->pr_mtx);
353 	}
354 
355 	return (0);
356 }
357 
358 SYSCTL_JAIL_PARAM_SYS_NODE(linux, CTLFLAG_RW, "Jail Linux parameters");
359 SYSCTL_JAIL_PARAM_STRING(_linux, osname, CTLFLAG_RW, LINUX_MAX_UTSNAME,
360     "Jail Linux kernel OS name");
361 SYSCTL_JAIL_PARAM_STRING(_linux, osrelease, CTLFLAG_RW, LINUX_MAX_UTSNAME,
362     "Jail Linux kernel OS release");
363 SYSCTL_JAIL_PARAM(_linux, oss_version, CTLTYPE_INT | CTLFLAG_RW,
364     "I", "Jail Linux OSS version");
365 
366 static int
367 linux_prison_get(void *obj, void *data)
368 {
369 	struct linux_prison *lpr;
370 	struct prison *ppr;
371 	struct prison *pr = obj;
372 	struct vfsoptlist *opts = data;
373 	int error, i;
374 
375 	static int version0;
376 
377 	/* See if this prison is the one with the Linux info. */
378 	lpr = linux_find_prison(pr, &ppr);
379 	i = (ppr == pr) ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
380 	error = vfs_setopt(opts, "linux", &i, sizeof(i));
381 	if (error != 0 && error != ENOENT)
382 		goto done;
383 	if (i) {
384 		error = vfs_setopts(opts, "linux.osname", lpr->pr_osname);
385 		if (error != 0 && error != ENOENT)
386 			goto done;
387 		error = vfs_setopts(opts, "linux.osrelease", lpr->pr_osrelease);
388 		if (error != 0 && error != ENOENT)
389 			goto done;
390 		error = vfs_setopt(opts, "linux.oss_version",
391 		    &lpr->pr_oss_version, sizeof(lpr->pr_oss_version));
392 		if (error != 0 && error != ENOENT)
393 			goto done;
394 	} else {
395 		/*
396 		 * If this prison is inheriting its Linux info, report
397 		 * empty/zero parameters.
398 		 */
399 		error = vfs_setopts(opts, "linux.osname", "");
400 		if (error != 0 && error != ENOENT)
401 			goto done;
402 		error = vfs_setopts(opts, "linux.osrelease", "");
403 		if (error != 0 && error != ENOENT)
404 			goto done;
405 		error = vfs_setopt(opts, "linux.oss_version", &version0,
406 		    sizeof(lpr->pr_oss_version));
407 		if (error != 0 && error != ENOENT)
408 			goto done;
409 	}
410 	error = 0;
411 
412  done:
413 	mtx_unlock(&ppr->pr_mtx);
414 
415 	return (error);
416 }
417 
418 static void
419 linux_prison_destructor(void *data)
420 {
421 
422 	free(data, M_PRISON);
423 }
424 
425 void
426 linux_osd_jail_register(void)
427 {
428 	struct prison *pr;
429 	osd_method_t methods[PR_MAXMETHOD] = {
430 	    [PR_METHOD_CREATE] =	linux_prison_create,
431 	    [PR_METHOD_GET] =		linux_prison_get,
432 	    [PR_METHOD_SET] =		linux_prison_set,
433 	    [PR_METHOD_CHECK] =		linux_prison_check
434 	};
435 
436 	linux_osd_jail_slot =
437 	    osd_jail_register(linux_prison_destructor, methods);
438 	/* Copy the system Linux info to any current prisons. */
439 	sx_slock(&allprison_lock);
440 	TAILQ_FOREACH(pr, &allprison, pr_list)
441 		linux_alloc_prison(pr, NULL);
442 	sx_sunlock(&allprison_lock);
443 }
444 
445 void
446 linux_osd_jail_deregister(void)
447 {
448 
449 	osd_jail_deregister(linux_osd_jail_slot);
450 }
451 
452 void
453 linux_get_osname(struct thread *td, char *dst)
454 {
455 	struct prison *pr;
456 	struct linux_prison *lpr;
457 
458 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
459 	bcopy(lpr->pr_osname, dst, LINUX_MAX_UTSNAME);
460 	mtx_unlock(&pr->pr_mtx);
461 }
462 
463 static int
464 linux_set_osname(struct thread *td, char *osname)
465 {
466 	struct prison *pr;
467 	struct linux_prison *lpr;
468 
469 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
470 	strlcpy(lpr->pr_osname, osname, LINUX_MAX_UTSNAME);
471 	mtx_unlock(&pr->pr_mtx);
472 
473 	return (0);
474 }
475 
476 void
477 linux_get_osrelease(struct thread *td, char *dst)
478 {
479 	struct prison *pr;
480 	struct linux_prison *lpr;
481 
482 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
483 	bcopy(lpr->pr_osrelease, dst, LINUX_MAX_UTSNAME);
484 	mtx_unlock(&pr->pr_mtx);
485 }
486 
487 int
488 linux_kernver(struct thread *td)
489 {
490 	struct prison *pr;
491 	struct linux_prison *lpr;
492 	int osrel;
493 
494 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
495 	osrel = lpr->pr_osrel;
496 	mtx_unlock(&pr->pr_mtx);
497 
498 	return (osrel);
499 }
500 
501 static int
502 linux_set_osrelease(struct thread *td, char *osrelease)
503 {
504 	struct prison *pr;
505 	struct linux_prison *lpr;
506 	int error;
507 
508 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
509 	error = linux_map_osrel(osrelease, &lpr->pr_osrel);
510 	if (error == 0)
511 		strlcpy(lpr->pr_osrelease, osrelease, LINUX_MAX_UTSNAME);
512 	mtx_unlock(&pr->pr_mtx);
513 
514 	return (error);
515 }
516 
517 int
518 linux_get_oss_version(struct thread *td)
519 {
520 	struct prison *pr;
521 	struct linux_prison *lpr;
522 	int version;
523 
524 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
525 	version = lpr->pr_oss_version;
526 	mtx_unlock(&pr->pr_mtx);
527 
528 	return (version);
529 }
530 
531 static int
532 linux_set_oss_version(struct thread *td, int oss_version)
533 {
534 	struct prison *pr;
535 	struct linux_prison *lpr;
536 
537 	lpr = linux_find_prison(td->td_ucred->cr_prison, &pr);
538 	lpr->pr_oss_version = oss_version;
539 	mtx_unlock(&pr->pr_mtx);
540 
541 	return (0);
542 }
543