xref: /freebsd/sys/compat/linux/linux_mib.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 <machine/../linux/linux.h>
43 #include <compat/linux/linux_mib.h>
44 
45 struct linux_prison {
46 	char	pr_osname[LINUX_MAX_UTSNAME];
47 	char	pr_osrelease[LINUX_MAX_UTSNAME];
48 	int	pr_oss_version;
49 };
50 
51 SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0,
52 	    "Linux mode");
53 
54 static struct mtx osname_lock;
55 MTX_SYSINIT(linux_osname, &osname_lock, "linux osname", MTX_DEF);
56 
57 static char	linux_osname[LINUX_MAX_UTSNAME] = "Linux";
58 
59 static int
60 linux_sysctl_osname(SYSCTL_HANDLER_ARGS)
61 {
62 	char osname[LINUX_MAX_UTSNAME];
63 	int error;
64 
65 	linux_get_osname(req->td, osname);
66 	error = sysctl_handle_string(oidp, osname, LINUX_MAX_UTSNAME, req);
67 	if (error || req->newptr == NULL)
68 		return (error);
69 	error = linux_set_osname(req->td, osname);
70 	return (error);
71 }
72 
73 SYSCTL_PROC(_compat_linux, OID_AUTO, osname,
74 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON,
75 	    0, 0, linux_sysctl_osname, "A",
76 	    "Linux kernel OS name");
77 
78 static char	linux_osrelease[LINUX_MAX_UTSNAME] = "2.4.2";
79 
80 static int
81 linux_sysctl_osrelease(SYSCTL_HANDLER_ARGS)
82 {
83 	char osrelease[LINUX_MAX_UTSNAME];
84 	int error;
85 
86 	linux_get_osrelease(req->td, osrelease);
87 	error = sysctl_handle_string(oidp, osrelease, LINUX_MAX_UTSNAME, req);
88 	if (error || req->newptr == NULL)
89 		return (error);
90 	error = linux_set_osrelease(req->td, osrelease);
91 	return (error);
92 }
93 
94 SYSCTL_PROC(_compat_linux, OID_AUTO, osrelease,
95 	    CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_PRISON,
96 	    0, 0, linux_sysctl_osrelease, "A",
97 	    "Linux kernel OS release");
98 
99 static int	linux_oss_version = 0x030600;
100 
101 static int
102 linux_sysctl_oss_version(SYSCTL_HANDLER_ARGS)
103 {
104 	int oss_version;
105 	int error;
106 
107 	oss_version = linux_get_oss_version(req->td);
108 	error = sysctl_handle_int(oidp, &oss_version, 0, req);
109 	if (error || req->newptr == NULL)
110 		return (error);
111 	error = linux_set_oss_version(req->td, oss_version);
112 	return (error);
113 }
114 
115 SYSCTL_PROC(_compat_linux, OID_AUTO, oss_version,
116 	    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_PRISON,
117 	    0, 0, linux_sysctl_oss_version, "I",
118 	    "Linux OSS version");
119 
120 /*
121  * Returns holding the prison mutex if return non-NULL.
122  */
123 static struct prison *
124 linux_get_prison(struct thread *td)
125 {
126 	register struct prison *pr;
127 	register struct linux_prison *lpr;
128 
129 	KASSERT(td == curthread, ("linux_get_prison() called on !curthread"));
130 	if (!jailed(td->td_ucred))
131 		return (NULL);
132 	pr = td->td_ucred->cr_prison;
133 	mtx_lock(&pr->pr_mtx);
134 	if (pr->pr_linux == NULL) {
135 		/*
136 		 * If we don't have a linux prison structure yet, allocate
137 		 * one.  We have to handle the race where another thread
138 		 * could be adding a linux prison to this process already.
139 		 */
140 		mtx_unlock(&pr->pr_mtx);
141 		lpr = malloc(sizeof(struct linux_prison), M_PRISON,
142 		    M_WAITOK | M_ZERO);
143 		mtx_lock(&pr->pr_mtx);
144 		if (pr->pr_linux == NULL)
145 			pr->pr_linux = lpr;
146 		else
147 			free(lpr, M_PRISON);
148 	}
149 	return (pr);
150 }
151 
152 void
153 linux_mib_destroy(void)
154 {
155 
156 	mtx_destroy(&osname_lock);
157 }
158 
159 void
160 linux_get_osname(struct thread *td, char *dst)
161 {
162 	register struct prison *pr;
163 	register struct linux_prison *lpr;
164 
165 	pr = td->td_ucred->cr_prison;
166 	if (pr != NULL) {
167 		mtx_lock(&pr->pr_mtx);
168 		if (pr->pr_linux != NULL) {
169 			lpr = (struct linux_prison *)pr->pr_linux;
170 			if (lpr->pr_osname[0]) {
171 				bcopy(lpr->pr_osname, dst, LINUX_MAX_UTSNAME);
172 				mtx_unlock(&pr->pr_mtx);
173 				return;
174 			}
175 		}
176 		mtx_unlock(&pr->pr_mtx);
177 	}
178 
179 	mtx_lock(&osname_lock);
180 	bcopy(linux_osname, dst, LINUX_MAX_UTSNAME);
181 	mtx_unlock(&osname_lock);
182 }
183 
184 int
185 linux_set_osname(struct thread *td, char *osname)
186 {
187 	struct prison *pr;
188 	struct linux_prison *lpr;
189 
190 	pr = linux_get_prison(td);
191 	if (pr != NULL) {
192 		lpr = (struct linux_prison *)pr->pr_linux;
193 		strcpy(lpr->pr_osname, osname);
194 		mtx_unlock(&pr->pr_mtx);
195 	} else {
196 		mtx_lock(&osname_lock);
197 		strcpy(linux_osname, osname);
198 		mtx_unlock(&osname_lock);
199 	}
200 
201 	return (0);
202 }
203 
204 void
205 linux_get_osrelease(struct thread *td, char *dst)
206 {
207 	register struct prison *pr;
208 	struct linux_prison *lpr;
209 
210 	pr = td->td_ucred->cr_prison;
211 	if (pr != NULL) {
212 		mtx_lock(&pr->pr_mtx);
213 		if (pr->pr_linux != NULL) {
214 			lpr = (struct linux_prison *)pr->pr_linux;
215 			if (lpr->pr_osrelease[0]) {
216 				bcopy(lpr->pr_osrelease, dst,
217 				    LINUX_MAX_UTSNAME);
218 				mtx_unlock(&pr->pr_mtx);
219 				return;
220 			}
221 		}
222 		mtx_unlock(&pr->pr_mtx);
223 	}
224 
225 	mtx_lock(&osname_lock);
226 	bcopy(linux_osrelease, dst, LINUX_MAX_UTSNAME);
227 	mtx_unlock(&osname_lock);
228 }
229 
230 int
231 linux_set_osrelease(struct thread *td, char *osrelease)
232 {
233 	struct prison *pr;
234 	struct linux_prison *lpr;
235 
236 	pr = linux_get_prison(td);
237 	if (pr != NULL) {
238 		lpr = (struct linux_prison *)pr->pr_linux;
239 		strcpy(lpr->pr_osrelease, osrelease);
240 		mtx_unlock(&pr->pr_mtx);
241 	} else {
242 		mtx_lock(&osname_lock);
243 		strcpy(linux_osrelease, osrelease);
244 		mtx_unlock(&osname_lock);
245 	}
246 
247 	return (0);
248 }
249 
250 int
251 linux_get_oss_version(struct thread *td)
252 {
253 	register struct prison *pr;
254 	register struct linux_prison *lpr;
255 	int version;
256 
257 	pr = td->td_ucred->cr_prison;
258 	if (pr != NULL) {
259 		mtx_lock(&pr->pr_mtx);
260 		if (pr->pr_linux != NULL) {
261 			lpr = (struct linux_prison *)pr->pr_linux;
262 			if (lpr->pr_oss_version) {
263 				version = lpr->pr_oss_version;
264 				mtx_unlock(&pr->pr_mtx);
265 				return (version);
266 			}
267 		}
268 		mtx_unlock(&pr->pr_mtx);
269 	}
270 
271 	mtx_lock(&osname_lock);
272 	version = linux_oss_version;
273 	mtx_unlock(&osname_lock);
274 	return (version);
275 }
276 
277 int
278 linux_set_oss_version(struct thread *td, int oss_version)
279 {
280 	struct prison *pr;
281 	struct linux_prison *lpr;
282 
283 	pr = linux_get_prison(td);
284 	if (pr != NULL) {
285 		lpr = (struct linux_prison *)pr->pr_linux;
286 		lpr->pr_oss_version = oss_version;
287 		mtx_unlock(&pr->pr_mtx);
288 	} else {
289 		mtx_lock(&osname_lock);
290 		linux_oss_version = oss_version;
291 		mtx_unlock(&osname_lock);
292 	}
293 
294 	return (0);
295 }
296 
297 #ifdef DEBUG
298 
299 u_char linux_debug_map[howmany(LINUX_SYS_MAXSYSCALL, sizeof(u_char))];
300 
301 static int
302 linux_debug(int syscall, int toggle, int global)
303 {
304 
305 	if (global) {
306 		char c = toggle ? 0 : 0xff;
307 
308 		memset(linux_debug_map, c, sizeof(linux_debug_map));
309 		return (0);
310 	}
311 	if (syscall < 0 || syscall >= LINUX_SYS_MAXSYSCALL)
312 		return (EINVAL);
313 	if (toggle)
314 		clrbit(linux_debug_map, syscall);
315 	else
316 		setbit(linux_debug_map, syscall);
317 	return (0);
318 }
319 
320 /*
321  * Usage: sysctl linux.debug=<syscall_nr>.<0/1>
322  *
323  *    E.g.: sysctl linux.debug=21.0
324  *
325  * As a special case, syscall "all" will apply to all syscalls globally.
326  */
327 #define LINUX_MAX_DEBUGSTR	16
328 static int
329 linux_sysctl_debug(SYSCTL_HANDLER_ARGS)
330 {
331 	char value[LINUX_MAX_DEBUGSTR], *p;
332 	int error, sysc, toggle;
333 	int global = 0;
334 
335 	value[0] = '\0';
336 	error = sysctl_handle_string(oidp, value, LINUX_MAX_DEBUGSTR, req);
337 	if (error || req->newptr == NULL)
338 		return (error);
339 	for (p = value; *p != '\0' && *p != '.'; p++);
340 	if (*p == '\0')
341 		return (EINVAL);
342 	*p++ = '\0';
343 	sysc = strtol(value, NULL, 0);
344 	toggle = strtol(p, NULL, 0);
345 	if (strcmp(value, "all") == 0)
346 		global = 1;
347 	error = linux_debug(sysc, toggle, global);
348 	return (error);
349 }
350 
351 SYSCTL_PROC(_compat_linux, OID_AUTO, debug,
352             CTLTYPE_STRING | CTLFLAG_RW,
353             0, 0, linux_sysctl_debug, "A",
354             "Linux debugging control");
355 
356 #endif /* DEBUG */
357