xref: /freebsd/sys/compat/linux/linux_mib.c (revision c37420b0d5b3b6ef875fbf0b84a13f6f09be56d6)
1 /*-
2  * Copyright (c) 1999 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 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/systm.h>
35 #include <sys/sysctl.h>
36 #include <sys/proc.h>
37 #include <sys/malloc.h>
38 #include <sys/jail.h>
39 #include <sys/lock.h>
40 #include <sys/mutex.h>
41 
42 #include "opt_compat.h"
43 
44 #if !COMPAT_LINUX32
45 #include <machine/../linux/linux.h>
46 #else
47 #include <machine/../linux32/linux.h>
48 #endif
49 #include <compat/linux/linux_mib.h>
50 
51 struct linux_prison {
52 	char	pr_osname[LINUX_MAX_UTSNAME];
53 	char	pr_osrelease[LINUX_MAX_UTSNAME];
54 	int	pr_oss_version;
55 };
56 
57 SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0,
58 	    "Linux mode");
59 
60 static struct mtx osname_lock;
61 MTX_SYSINIT(linux_osname, &osname_lock, "linux osname", MTX_DEF);
62 
63 static char	linux_osname[LINUX_MAX_UTSNAME] = "Linux";
64 
65 static int
66 linux_sysctl_osname(SYSCTL_HANDLER_ARGS)
67 {
68 	char osname[LINUX_MAX_UTSNAME];
69 	int error;
70 
71 	linux_get_osname(req->td, osname);
72 	error = sysctl_handle_string(oidp, osname, LINUX_MAX_UTSNAME, req);
73 	if (error || req->newptr == NULL)
74 		return (error);
75 	error = linux_set_osname(req->td, osname);
76 	return (error);
77 }
78 
79 SYSCTL_PROC(_compat_linux, OID_AUTO, osname,
80 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON,
81 	    0, 0, linux_sysctl_osname, "A",
82 	    "Linux kernel OS name");
83 
84 static char	linux_osrelease[LINUX_MAX_UTSNAME] = "2.4.2";
85 
86 static int
87 linux_sysctl_osrelease(SYSCTL_HANDLER_ARGS)
88 {
89 	char osrelease[LINUX_MAX_UTSNAME];
90 	int error;
91 
92 	linux_get_osrelease(req->td, osrelease);
93 	error = sysctl_handle_string(oidp, osrelease, LINUX_MAX_UTSNAME, req);
94 	if (error || req->newptr == NULL)
95 		return (error);
96 	error = linux_set_osrelease(req->td, osrelease);
97 	return (error);
98 }
99 
100 SYSCTL_PROC(_compat_linux, OID_AUTO, osrelease,
101 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON,
102 	    0, 0, linux_sysctl_osrelease, "A",
103 	    "Linux kernel OS release");
104 
105 static int	linux_oss_version = 0x030600;
106 
107 static int
108 linux_sysctl_oss_version(SYSCTL_HANDLER_ARGS)
109 {
110 	int oss_version;
111 	int error;
112 
113 	oss_version = linux_get_oss_version(req->td);
114 	error = sysctl_handle_int(oidp, &oss_version, 0, req);
115 	if (error || req->newptr == NULL)
116 		return (error);
117 	error = linux_set_oss_version(req->td, oss_version);
118 	return (error);
119 }
120 
121 SYSCTL_PROC(_compat_linux, OID_AUTO, oss_version,
122 	    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON,
123 	    0, 0, linux_sysctl_oss_version, "I",
124 	    "Linux OSS version");
125 
126 /*
127  * Returns holding the prison mutex if return non-NULL.
128  */
129 static struct prison *
130 linux_get_prison(struct thread *td)
131 {
132 	register struct prison *pr;
133 	register struct linux_prison *lpr;
134 
135 	KASSERT(td == curthread, ("linux_get_prison() called on !curthread"));
136 	if (!jailed(td->td_ucred))
137 		return (NULL);
138 	pr = td->td_ucred->cr_prison;
139 	mtx_lock(&pr->pr_mtx);
140 	if (pr->pr_linux == NULL) {
141 		/*
142 		 * If we don't have a linux prison structure yet, allocate
143 		 * one.  We have to handle the race where another thread
144 		 * could be adding a linux prison to this process already.
145 		 */
146 		mtx_unlock(&pr->pr_mtx);
147 		lpr = malloc(sizeof(struct linux_prison), M_PRISON,
148 		    M_WAITOK | M_ZERO);
149 		mtx_lock(&pr->pr_mtx);
150 		if (pr->pr_linux == NULL)
151 			pr->pr_linux = lpr;
152 		else
153 			free(lpr, M_PRISON);
154 	}
155 	return (pr);
156 }
157 
158 void
159 linux_mib_destroy(void)
160 {
161 
162 	mtx_destroy(&osname_lock);
163 }
164 
165 void
166 linux_get_osname(struct thread *td, char *dst)
167 {
168 	register struct prison *pr;
169 	register struct linux_prison *lpr;
170 
171 	pr = td->td_ucred->cr_prison;
172 	if (pr != NULL) {
173 		mtx_lock(&pr->pr_mtx);
174 		if (pr->pr_linux != NULL) {
175 			lpr = (struct linux_prison *)pr->pr_linux;
176 			if (lpr->pr_osname[0]) {
177 				bcopy(lpr->pr_osname, dst, LINUX_MAX_UTSNAME);
178 				mtx_unlock(&pr->pr_mtx);
179 				return;
180 			}
181 		}
182 		mtx_unlock(&pr->pr_mtx);
183 	}
184 
185 	mtx_lock(&osname_lock);
186 	bcopy(linux_osname, dst, LINUX_MAX_UTSNAME);
187 	mtx_unlock(&osname_lock);
188 }
189 
190 int
191 linux_set_osname(struct thread *td, char *osname)
192 {
193 	struct prison *pr;
194 	struct linux_prison *lpr;
195 
196 	pr = linux_get_prison(td);
197 	if (pr != NULL) {
198 		lpr = (struct linux_prison *)pr->pr_linux;
199 		strcpy(lpr->pr_osname, osname);
200 		mtx_unlock(&pr->pr_mtx);
201 	} else {
202 		mtx_lock(&osname_lock);
203 		strcpy(linux_osname, osname);
204 		mtx_unlock(&osname_lock);
205 	}
206 
207 	return (0);
208 }
209 
210 void
211 linux_get_osrelease(struct thread *td, char *dst)
212 {
213 	register struct prison *pr;
214 	struct linux_prison *lpr;
215 
216 	pr = td->td_ucred->cr_prison;
217 	if (pr != NULL) {
218 		mtx_lock(&pr->pr_mtx);
219 		if (pr->pr_linux != NULL) {
220 			lpr = (struct linux_prison *)pr->pr_linux;
221 			if (lpr->pr_osrelease[0]) {
222 				bcopy(lpr->pr_osrelease, dst,
223 				    LINUX_MAX_UTSNAME);
224 				mtx_unlock(&pr->pr_mtx);
225 				return;
226 			}
227 		}
228 		mtx_unlock(&pr->pr_mtx);
229 	}
230 
231 	mtx_lock(&osname_lock);
232 	bcopy(linux_osrelease, dst, LINUX_MAX_UTSNAME);
233 	mtx_unlock(&osname_lock);
234 }
235 
236 int
237 linux_set_osrelease(struct thread *td, char *osrelease)
238 {
239 	struct prison *pr;
240 	struct linux_prison *lpr;
241 
242 	pr = linux_get_prison(td);
243 	if (pr != NULL) {
244 		lpr = (struct linux_prison *)pr->pr_linux;
245 		strcpy(lpr->pr_osrelease, osrelease);
246 		mtx_unlock(&pr->pr_mtx);
247 	} else {
248 		mtx_lock(&osname_lock);
249 		strcpy(linux_osrelease, osrelease);
250 		mtx_unlock(&osname_lock);
251 	}
252 
253 	return (0);
254 }
255 
256 int
257 linux_get_oss_version(struct thread *td)
258 {
259 	register struct prison *pr;
260 	register struct linux_prison *lpr;
261 	int version;
262 
263 	pr = td->td_ucred->cr_prison;
264 	if (pr != NULL) {
265 		mtx_lock(&pr->pr_mtx);
266 		if (pr->pr_linux != NULL) {
267 			lpr = (struct linux_prison *)pr->pr_linux;
268 			if (lpr->pr_oss_version) {
269 				version = lpr->pr_oss_version;
270 				mtx_unlock(&pr->pr_mtx);
271 				return (version);
272 			}
273 		}
274 		mtx_unlock(&pr->pr_mtx);
275 	}
276 
277 	mtx_lock(&osname_lock);
278 	version = linux_oss_version;
279 	mtx_unlock(&osname_lock);
280 	return (version);
281 }
282 
283 int
284 linux_set_oss_version(struct thread *td, int oss_version)
285 {
286 	struct prison *pr;
287 	struct linux_prison *lpr;
288 
289 	pr = linux_get_prison(td);
290 	if (pr != NULL) {
291 		lpr = (struct linux_prison *)pr->pr_linux;
292 		lpr->pr_oss_version = oss_version;
293 		mtx_unlock(&pr->pr_mtx);
294 	} else {
295 		mtx_lock(&osname_lock);
296 		linux_oss_version = oss_version;
297 		mtx_unlock(&osname_lock);
298 	}
299 
300 	return (0);
301 }
302 
303 #ifdef DEBUG
304 
305 u_char linux_debug_map[howmany(LINUX_SYS_MAXSYSCALL, sizeof(u_char))];
306 
307 static int
308 linux_debug(int syscall, int toggle, int global)
309 {
310 
311 	if (global) {
312 		char c = toggle ? 0 : 0xff;
313 
314 		memset(linux_debug_map, c, sizeof(linux_debug_map));
315 		return (0);
316 	}
317 	if (syscall < 0 || syscall >= LINUX_SYS_MAXSYSCALL)
318 		return (EINVAL);
319 	if (toggle)
320 		clrbit(linux_debug_map, syscall);
321 	else
322 		setbit(linux_debug_map, syscall);
323 	return (0);
324 }
325 
326 /*
327  * Usage: sysctl linux.debug=<syscall_nr>.<0/1>
328  *
329  *    E.g.: sysctl linux.debug=21.0
330  *
331  * As a special case, syscall "all" will apply to all syscalls globally.
332  */
333 #define LINUX_MAX_DEBUGSTR	16
334 static int
335 linux_sysctl_debug(SYSCTL_HANDLER_ARGS)
336 {
337 	char value[LINUX_MAX_DEBUGSTR], *p;
338 	int error, sysc, toggle;
339 	int global = 0;
340 
341 	value[0] = '\0';
342 	error = sysctl_handle_string(oidp, value, LINUX_MAX_DEBUGSTR, req);
343 	if (error || req->newptr == NULL)
344 		return (error);
345 	for (p = value; *p != '\0' && *p != '.'; p++);
346 	if (*p == '\0')
347 		return (EINVAL);
348 	*p++ = '\0';
349 	sysc = strtol(value, NULL, 0);
350 	toggle = strtol(p, NULL, 0);
351 	if (strcmp(value, "all") == 0)
352 		global = 1;
353 	error = linux_debug(sysc, toggle, global);
354 	return (error);
355 }
356 
357 SYSCTL_PROC(_compat_linux, OID_AUTO, debug,
358             CTLTYPE_STRING | CTLFLAG_RW,
359             0, 0, linux_sysctl_debug, "A",
360             "Linux debugging control");
361 
362 #endif /* DEBUG */
363