xref: /freebsd/sys/compat/linux/linux_util.c (revision 271171e0d97b88ba2a7c3bf750c9672b484c1c13)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1994 Christos Zoulas
5  * Copyright (c) 1995 Frank van der Linden
6  * Copyright (c) 1995 Scott Bartram
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  *	from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/conf.h>
40 #include <sys/fcntl.h>
41 #include <sys/jail.h>
42 #include <sys/malloc.h>
43 #include <sys/kernel.h>
44 #include <sys/linker_set.h>
45 #include <sys/namei.h>
46 #include <sys/proc.h>
47 #include <sys/sdt.h>
48 #include <sys/syscallsubr.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #include <sys/vnode.h>
52 
53 #include <net/if.h>
54 #include <net/if_var.h>
55 #include <net/if_types.h>
56 
57 #include <machine/stdarg.h>
58 
59 #include <compat/linux/linux_dtrace.h>
60 #include <compat/linux/linux_mib.h>
61 #include <compat/linux/linux_util.h>
62 
63 MALLOC_DEFINE(M_LINUX, "linux", "Linux mode structures");
64 MALLOC_DEFINE(M_EPOLL, "lepoll", "Linux events structures");
65 
66 FEATURE(linuxulator_v4l, "V4L ioctl wrapper support in the linuxulator");
67 FEATURE(linuxulator_v4l2, "V4L2 ioctl wrapper support in the linuxulator");
68 
69 /**
70  * Special DTrace provider for the linuxulator.
71  *
72  * In this file we define the provider for the entire linuxulator. All
73  * modules (= files of the linuxulator) use it.
74  *
75  * We define a different name depending on the emulated bitsize, see
76  * ../../<ARCH>/linux{,32}/linux.h, e.g.:
77  *      native bitsize          = linuxulator
78  *      amd64, 32bit emulation  = linuxulator32
79  */
80 LIN_SDT_PROVIDER_DEFINE(linuxulator);
81 LIN_SDT_PROVIDER_DEFINE(linuxulator32);
82 
83 char linux_emul_path[MAXPATHLEN] = "/compat/linux";
84 
85 SYSCTL_STRING(_compat_linux, OID_AUTO, emul_path, CTLFLAG_RWTUN,
86     linux_emul_path, sizeof(linux_emul_path),
87     "Linux runtime environment path");
88 
89 static bool use_real_ifnames = false;
90 SYSCTL_BOOL(_compat_linux, OID_AUTO, use_real_ifnames, CTLFLAG_RWTUN,
91     &use_real_ifnames, 0,
92     "Use FreeBSD interface names instead of generating ethN aliases");
93 
94 /*
95  * Search an alternate path before passing pathname arguments on to
96  * system calls. Useful for keeping a separate 'emulation tree'.
97  *
98  * If cflag is set, we check if an attempt can be made to create the
99  * named file, i.e. we check if the directory it should be in exists.
100  */
101 int
102 linux_emul_convpath(const char *path, enum uio_seg pathseg,
103     char **pbuf, int cflag, int dfd)
104 {
105 	int retval;
106 
107 	retval = kern_alternate_path(linux_emul_path, path, pathseg, pbuf,
108 	    cflag, dfd);
109 
110 	return (retval);
111 }
112 
113 void
114 linux_msg(const struct thread *td, const char *fmt, ...)
115 {
116 	va_list ap;
117 	struct proc *p;
118 
119 	if (linux_debug == 0)
120 		return;
121 
122 	p = td->td_proc;
123 	printf("linux: jid %d pid %d (%s): ", p->p_ucred->cr_prison->pr_id,
124 	    (int)p->p_pid, p->p_comm);
125 	va_start(ap, fmt);
126 	vprintf(fmt, ap);
127 	va_end(ap);
128 	printf("\n");
129 }
130 
131 struct device_element
132 {
133 	TAILQ_ENTRY(device_element) list;
134 	struct linux_device_handler entry;
135 };
136 
137 static TAILQ_HEAD(, device_element) devices =
138 	TAILQ_HEAD_INITIALIZER(devices);
139 
140 static struct linux_device_handler null_handler =
141 	{ "mem", "mem", "null", "null", 1, 3, 1};
142 
143 DATA_SET(linux_device_handler_set, null_handler);
144 
145 char *
146 linux_driver_get_name_dev(device_t dev)
147 {
148 	struct device_element *de;
149 	const char *device_name = device_get_name(dev);
150 
151 	if (device_name == NULL)
152 		return (NULL);
153 	TAILQ_FOREACH(de, &devices, list) {
154 		if (strcmp(device_name, de->entry.bsd_driver_name) == 0)
155 			return (de->entry.linux_driver_name);
156 	}
157 
158 	return (NULL);
159 }
160 
161 int
162 linux_driver_get_major_minor(const char *node, int *major, int *minor)
163 {
164 	struct device_element *de;
165 	unsigned long devno;
166 	size_t sz;
167 
168 	if (node == NULL || major == NULL || minor == NULL)
169 		return (1);
170 
171 	sz = sizeof("pts/") - 1;
172 	if (strncmp(node, "pts/", sz) == 0 && node[sz] != '\0') {
173 		/*
174 		 * Linux checks major and minors of the slave device
175 		 * to make sure it's a pty device, so let's make him
176 		 * believe it is.
177 		 */
178 		devno = strtoul(node + sz, NULL, 10);
179 		*major = 136 + (devno / 256);
180 		*minor = devno % 256;
181 		return (0);
182 	}
183 
184 	sz = sizeof("dri/card") - 1;
185 	if (strncmp(node, "dri/card", sz) == 0 && node[sz] != '\0') {
186 		devno = strtoul(node + sz, NULL, 10);
187 		*major = 226 + (devno / 256);
188 		*minor = devno % 256;
189 		return (0);
190 	}
191 	sz = sizeof("dri/controlD") - 1;
192 	if (strncmp(node, "dri/controlD", sz) == 0 && node[sz] != '\0') {
193 		devno = strtoul(node + sz, NULL, 10);
194 		*major = 226 + (devno / 256);
195 		*minor = devno % 256;
196 		return (0);
197 	}
198 	sz = sizeof("dri/renderD") - 1;
199 	if (strncmp(node, "dri/renderD", sz) == 0 && node[sz] != '\0') {
200 		devno = strtoul(node + sz, NULL, 10);
201 		*major = 226 + (devno / 256);
202 		*minor = devno % 256;
203 		return (0);
204 	}
205 	sz = sizeof("drm/") - 1;
206 	if (strncmp(node, "drm/", sz) == 0 && node[sz] != '\0') {
207 		devno = strtoul(node + sz, NULL, 10);
208 		*major = 226 + (devno / 256);
209 		*minor = devno % 256;
210 		return (0);
211 	}
212 
213 	TAILQ_FOREACH(de, &devices, list) {
214 		if (strcmp(node, de->entry.bsd_device_name) == 0) {
215 			*major = de->entry.linux_major;
216 			*minor = de->entry.linux_minor;
217 			return (0);
218 		}
219 	}
220 
221 	return (1);
222 }
223 
224 int
225 linux_vn_get_major_minor(const struct vnode *vp, int *major, int *minor)
226 {
227 	int error;
228 
229 	if (vp->v_type != VCHR)
230 		return (ENOTBLK);
231 	dev_lock();
232 	if (vp->v_rdev == NULL) {
233 		dev_unlock();
234 		return (ENXIO);
235 	}
236 	error = linux_driver_get_major_minor(devtoname(vp->v_rdev),
237 	    major, minor);
238 	dev_unlock();
239 	return (error);
240 }
241 
242 char *
243 linux_get_char_devices(void)
244 {
245 	struct device_element *de;
246 	char *temp, *string, *last;
247 	char formated[256];
248 	int current_size = 0, string_size = 1024;
249 
250 	string = malloc(string_size, M_LINUX, M_WAITOK);
251 	string[0] = '\000';
252 	last = "";
253 	TAILQ_FOREACH(de, &devices, list) {
254 		if (!de->entry.linux_char_device)
255 			continue;
256 		temp = string;
257 		if (strcmp(last, de->entry.bsd_driver_name) != 0) {
258 			last = de->entry.bsd_driver_name;
259 
260 			snprintf(formated, sizeof(formated), "%3d %s\n",
261 				 de->entry.linux_major,
262 				 de->entry.linux_device_name);
263 			if (strlen(formated) + current_size
264 			    >= string_size) {
265 				string_size *= 2;
266 				string = malloc(string_size,
267 				    M_LINUX, M_WAITOK);
268 				bcopy(temp, string, current_size);
269 				free(temp, M_LINUX);
270 			}
271 			strcat(string, formated);
272 			current_size = strlen(string);
273 		}
274 	}
275 
276 	return (string);
277 }
278 
279 void
280 linux_free_get_char_devices(char *string)
281 {
282 
283 	free(string, M_LINUX);
284 }
285 
286 static int linux_major_starting = 200;
287 
288 int
289 linux_device_register_handler(struct linux_device_handler *d)
290 {
291 	struct device_element *de;
292 
293 	if (d == NULL)
294 		return (EINVAL);
295 
296 	de = malloc(sizeof(*de), M_LINUX, M_WAITOK);
297 	if (d->linux_major < 0) {
298 		d->linux_major = linux_major_starting++;
299 	}
300 	bcopy(d, &de->entry, sizeof(*d));
301 
302 	/* Add the element to the list, sorted on span. */
303 	TAILQ_INSERT_TAIL(&devices, de, list);
304 
305 	return (0);
306 }
307 
308 int
309 linux_device_unregister_handler(struct linux_device_handler *d)
310 {
311 	struct device_element *de;
312 
313 	if (d == NULL)
314 		return (EINVAL);
315 
316 	TAILQ_FOREACH(de, &devices, list) {
317 		if (bcmp(d, &de->entry, sizeof(*d)) == 0) {
318 			TAILQ_REMOVE(&devices, de, list);
319 			free(de, M_LINUX);
320 
321 			return (0);
322 		}
323 	}
324 
325 	return (EINVAL);
326 }
327 
328 bool
329 linux_use_real_ifname(const struct ifnet *ifp)
330 {
331 	return (use_real_ifnames || !IFP_IS_ETH(ifp));
332 }
333