1 /* $NetBSD: openfirmio.c,v 1.4 2002/09/06 13:23:19 gehenna Exp $ */
2
3 #include <sys/cdefs.h>
4 __FBSDID("$FreeBSD: stable/12/sys/dev/ofw/openfirmio.c 369438 2021-03-08 19:08:54Z bdragon $");
5
6 /*-
7 * SPDX-License-Identifier: BSD-3-Clause
8 *
9 * Copyright (c) 1992, 1993
10 * The Regents of the University of California. All rights reserved.
11 *
12 * This software was developed by the Computer Systems Engineering group
13 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
14 * contributed to Berkeley.
15 *
16 * All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Lawrence Berkeley Laboratory.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
29 * 3. Neither the name of the University nor the names of its contributors
30 * may be used to endorse or promote products derived from this software
31 * without specific prior written permission.
32 *
33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 * SUCH DAMAGE.
44 *
45 * @(#)openfirm.c 8.1 (Berkeley) 6/11/93
46 *
47 */
48
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/conf.h>
52 #include <sys/errno.h>
53 #include <sys/fcntl.h>
54 #include <sys/ioccom.h>
55 #include <sys/kernel.h>
56 #include <sys/malloc.h>
57 #include <sys/module.h>
58
59 #include <dev/ofw/openfirmio.h>
60
61 static struct cdev *openfirm_dev;
62
63 static d_ioctl_t openfirm_ioctl;
64
65 #define OPENFIRM_MINOR 0
66
67 static struct cdevsw openfirm_cdevsw = {
68 .d_version = D_VERSION,
69 .d_flags = D_NEEDGIANT,
70 .d_ioctl = openfirm_ioctl,
71 .d_name = "openfirm",
72 };
73
74 static phandle_t lastnode; /* speed hack */
75
76 static int openfirm_checkid(phandle_t, phandle_t);
77 static int openfirm_getstr(int, const char *, char **);
78
79 /*
80 * Verify target ID is valid (exists in the OPENPROM tree), as
81 * listed from node ID sid forward.
82 */
83 static int
openfirm_checkid(phandle_t sid,phandle_t tid)84 openfirm_checkid(phandle_t sid, phandle_t tid)
85 {
86
87 for (; sid != 0; sid = OF_peer(sid))
88 if (sid == tid || openfirm_checkid(OF_child(sid), tid))
89 return (1);
90
91 return (0);
92 }
93
94 static int
openfirm_getstr(int len,const char * user,char ** cpp)95 openfirm_getstr(int len, const char *user, char **cpp)
96 {
97 int error;
98 char *cp;
99
100 /* Reject obvious bogus requests. */
101 if ((u_int)len > OFIOCMAXNAME)
102 return (ENAMETOOLONG);
103
104 *cpp = cp = malloc(len + 1, M_TEMP, M_WAITOK);
105 error = copyin(user, cp, len);
106 cp[len] = '\0';
107 return (error);
108 }
109
110 int
openfirm_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int flags,struct thread * td)111 openfirm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
112 struct thread *td)
113 {
114 struct ofiocdesc *of;
115 phandle_t node;
116 int len, ok, error;
117 char *name, *value;
118 char newname[OFIOCSUGGPROPNAMELEN];
119
120 if ((flags & FREAD) == 0)
121 return (EBADF);
122
123 of = (struct ofiocdesc *)data;
124 switch (cmd) {
125 case OFIOCGETOPTNODE:
126 *(phandle_t *) data = OF_finddevice("/options");
127 return (0);
128 case OFIOCGET:
129 case OFIOCSET:
130 case OFIOCNEXTPROP:
131 case OFIOCFINDDEVICE:
132 case OFIOCGETPROPLEN:
133 node = of->of_nodeid;
134 break;
135 case OFIOCGETNEXT:
136 case OFIOCGETCHILD:
137 node = *(phandle_t *)data;
138 break;
139 default:
140 return (ENOIOCTL);
141 }
142
143 if (node != 0 && node != lastnode) {
144 /* Not an easy one, we must search for it. */
145 ok = openfirm_checkid(OF_peer(0), node);
146 if (!ok)
147 return (EINVAL);
148 lastnode = node;
149 }
150
151 name = value = NULL;
152 error = 0;
153 switch (cmd) {
154
155 case OFIOCGET:
156 case OFIOCGETPROPLEN:
157 if (node == 0)
158 return (EINVAL);
159 error = openfirm_getstr(of->of_namelen, of->of_name, &name);
160 if (error)
161 break;
162 len = OF_getproplen(node, name);
163 if (cmd == OFIOCGETPROPLEN) {
164 of->of_buflen = len;
165 break;
166 }
167 if (len > of->of_buflen) {
168 error = ENOMEM;
169 break;
170 }
171 of->of_buflen = len;
172 /* -1 means no entry; 0 means no value. */
173 if (len <= 0)
174 break;
175 value = malloc(len, M_TEMP, M_WAITOK);
176 len = OF_getprop(node, name, (void *)value, len);
177 error = copyout(value, of->of_buf, len);
178 break;
179
180 case OFIOCSET:
181 /*
182 * Note: Text string values for at least the /options node
183 * have to be null-terminated and the length parameter must
184 * include this terminating null. However, like OF_getprop(),
185 * OF_setprop() will return the actual length of the text
186 * string, i.e. omitting the terminating null.
187 */
188 if ((flags & FWRITE) == 0)
189 return (EBADF);
190 if (node == 0)
191 return (EINVAL);
192 if ((u_int)of->of_buflen > OFIOCMAXVALUE)
193 return (ENAMETOOLONG);
194 error = openfirm_getstr(of->of_namelen, of->of_name, &name);
195 if (error)
196 break;
197 value = malloc(of->of_buflen, M_TEMP, M_WAITOK);
198 error = copyin(of->of_buf, value, of->of_buflen);
199 if (error)
200 break;
201 len = OF_setprop(node, name, value, of->of_buflen);
202 if (len < 0)
203 error = EINVAL;
204 of->of_buflen = len;
205 break;
206
207 case OFIOCNEXTPROP:
208 if (node == 0 || of->of_buflen < 0)
209 return (EINVAL);
210 if (of->of_namelen != 0) {
211 error = openfirm_getstr(of->of_namelen, of->of_name,
212 &name);
213 if (error)
214 break;
215 }
216 ok = OF_nextprop(node, name, newname, sizeof(newname));
217 if (ok == 0) {
218 error = ENOENT;
219 break;
220 }
221 if (ok == -1) {
222 error = EINVAL;
223 break;
224 }
225 len = strlen(newname) + 1;
226 if (len > of->of_buflen) {
227 /*
228 * Passed buffer was insufficient.
229 *
230 * Instead of returning an error here, truncate the
231 * property name to fit the buffer.
232 *
233 * This allows us to retain compatibility with old
234 * tools which always pass a 32 character buffer.
235 */
236 len = of->of_buflen;
237 newname[len - 1] = '\0';
238 }
239 else
240 of->of_buflen = len;
241 error = copyout(newname, of->of_buf, len);
242 break;
243
244 case OFIOCGETNEXT:
245 node = OF_peer(node);
246 *(phandle_t *)data = lastnode = node;
247 break;
248
249 case OFIOCGETCHILD:
250 if (node == 0)
251 return (EINVAL);
252 node = OF_child(node);
253 *(phandle_t *)data = lastnode = node;
254 break;
255
256 case OFIOCFINDDEVICE:
257 error = openfirm_getstr(of->of_namelen, of->of_name, &name);
258 if (error)
259 break;
260 node = OF_finddevice(name);
261 if (node == -1) {
262 error = ENOENT;
263 break;
264 }
265 of->of_nodeid = lastnode = node;
266 break;
267 }
268
269 if (name != NULL)
270 free(name, M_TEMP);
271 if (value != NULL)
272 free(value, M_TEMP);
273
274 return (error);
275 }
276
277 static int
openfirm_modevent(module_t mod,int type,void * data)278 openfirm_modevent(module_t mod, int type, void *data)
279 {
280
281 switch(type) {
282 case MOD_LOAD:
283 if (bootverbose)
284 printf("openfirm: <Open Firmware control device>\n");
285 /*
286 * Allow only root access by default; this device may allow
287 * users to peek into firmware passwords, and likely to crash
288 * the machine on some boxen due to firmware quirks.
289 */
290 openfirm_dev = make_dev(&openfirm_cdevsw, OPENFIRM_MINOR,
291 UID_ROOT, GID_WHEEL, 0600, "openfirm");
292 return 0;
293
294 case MOD_UNLOAD:
295 destroy_dev(openfirm_dev);
296 return 0;
297
298 case MOD_SHUTDOWN:
299 return 0;
300
301 default:
302 return EOPNOTSUPP;
303 }
304 }
305
306 DEV_MODULE(openfirm, openfirm_modevent, NULL);
307