xref: /freebsd/sys/dev/ofw/openfirmio.c (revision e8d8bef961a50d4dc22501cde4fb9fb0be1b2532)
1 /*	$NetBSD: openfirmio.c,v 1.4 2002/09/06 13:23:19 gehenna Exp $ */
2 
3 #include <sys/cdefs.h>
4 __FBSDID("$FreeBSD$");
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 | D_GIANTOK,
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
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
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
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 	case OFIOCGET:
155 	case OFIOCGETPROPLEN:
156 		if (node == 0)
157 			return (EINVAL);
158 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
159 		if (error)
160 			break;
161 		len = OF_getproplen(node, name);
162 		if (cmd == OFIOCGETPROPLEN) {
163 			of->of_buflen = len;
164 			break;
165 		}
166 		if (len > of->of_buflen) {
167 			error = ENOMEM;
168 			break;
169 		}
170 		of->of_buflen = len;
171 		/* -1 means no entry; 0 means no value. */
172 		if (len <= 0)
173 			break;
174 		value = malloc(len, M_TEMP, M_WAITOK);
175 		len = OF_getprop(node, name, (void *)value, len);
176 		error = copyout(value, of->of_buf, len);
177 		break;
178 
179 	case OFIOCSET:
180 		/*
181 		 * Note: Text string values for at least the /options node
182 		 * have to be null-terminated and the length parameter must
183 		 * include this terminating null.  However, like OF_getprop(),
184 		 * OF_setprop() will return the actual length of the text
185 		 * string, i.e. omitting the terminating null.
186 		 */
187 		if ((flags & FWRITE) == 0)
188 			return (EBADF);
189 		if (node == 0)
190 			return (EINVAL);
191 		if ((u_int)of->of_buflen > OFIOCMAXVALUE)
192 			return (ENAMETOOLONG);
193 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
194 		if (error)
195 			break;
196 		value = malloc(of->of_buflen, M_TEMP, M_WAITOK);
197 		error = copyin(of->of_buf, value, of->of_buflen);
198 		if (error)
199 			break;
200 		len = OF_setprop(node, name, value, of->of_buflen);
201 		if (len < 0)
202 			error = EINVAL;
203 		of->of_buflen = len;
204 		break;
205 
206 	case OFIOCNEXTPROP:
207 		if (node == 0 || of->of_buflen < 0)
208 			return (EINVAL);
209 		if (of->of_namelen != 0) {
210 			error = openfirm_getstr(of->of_namelen, of->of_name,
211 			    &name);
212 			if (error)
213 				break;
214 		}
215 		ok = OF_nextprop(node, name, newname, sizeof(newname));
216 		if (ok == 0) {
217 			error = ENOENT;
218 			break;
219 		}
220 		if (ok == -1) {
221 			error = EINVAL;
222 			break;
223 		}
224 		len = strlen(newname) + 1;
225 		if (len > of->of_buflen) {
226 			/*
227 			 * Passed buffer was insufficient.
228 			 *
229 			 * Instead of returning an error here, truncate the
230 			 * property name to fit the buffer.
231 			 *
232 			 * This allows us to retain compatibility with old
233 			 * tools which always pass a 32 character buffer.
234 			 */
235 			len = of->of_buflen;
236 			newname[len - 1] = '\0';
237 		}
238 		else
239 			of->of_buflen = len;
240 		error = copyout(newname, of->of_buf, len);
241 		break;
242 
243 	case OFIOCGETNEXT:
244 		node = OF_peer(node);
245 		*(phandle_t *)data = lastnode = node;
246 		break;
247 
248 	case OFIOCGETCHILD:
249 		if (node == 0)
250 			return (EINVAL);
251 		node = OF_child(node);
252 		*(phandle_t *)data = lastnode = node;
253 		break;
254 
255 	case OFIOCFINDDEVICE:
256 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
257 		if (error)
258 			break;
259 		node = OF_finddevice(name);
260 		if (node == -1) {
261 			error = ENOENT;
262 			break;
263 		}
264 		of->of_nodeid = lastnode = node;
265 		break;
266 	}
267 
268 	if (name != NULL)
269 		free(name, M_TEMP);
270 	if (value != NULL)
271 		free(value, M_TEMP);
272 
273 	return (error);
274 }
275 
276 static int
277 openfirm_modevent(module_t mod, int type, void *data)
278 {
279 
280 	switch(type) {
281 	case MOD_LOAD:
282 		if (bootverbose)
283 			printf("openfirm: <Open Firmware control device>\n");
284 		/*
285 		 * Allow only root access by default; this device may allow
286 		 * users to peek into firmware passwords, and likely to crash
287 		 * the machine on some boxen due to firmware quirks.
288 		 */
289 		openfirm_dev = make_dev(&openfirm_cdevsw, OPENFIRM_MINOR,
290 		    UID_ROOT, GID_WHEEL, 0600, "openfirm");
291 		return 0;
292 
293 	case MOD_UNLOAD:
294 		destroy_dev(openfirm_dev);
295 		return 0;
296 
297 	case MOD_SHUTDOWN:
298 		return 0;
299 
300 	default:
301 		return EOPNOTSUPP;
302 	}
303 }
304 
305 DEV_MODULE(openfirm, openfirm_modevent, NULL);
306