xref: /freebsd/sys/dev/ofw/openfirmio.c (revision 6137b5f7b8c183ee8806d79b3f1d8e5e3ddb3df3)
1 /*	$NetBSD: openfirmio.c,v 1.4 2002/09/06 13:23:19 gehenna Exp $ */
2 
3 #include <sys/cdefs.h>
4 /*-
5  * SPDX-License-Identifier: BSD-3-Clause
6  *
7  * Copyright (c) 1992, 1993
8  *	The Regents of the University of California.  All rights reserved.
9  *
10  * This software was developed by the Computer Systems Engineering group
11  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
12  * contributed to Berkeley.
13  *
14  * All advertising materials mentioning features or use of this software
15  * must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Lawrence Berkeley Laboratory.
18  *
19  * Redistribution and use in source and binary forms, with or without
20  * modification, are permitted provided that the following conditions
21  * are met:
22  * 1. Redistributions of source code must retain the above copyright
23  *    notice, this list of conditions and the following disclaimer.
24  * 2. Redistributions in binary form must reproduce the above copyright
25  *    notice, this list of conditions and the following disclaimer in the
26  *    documentation and/or other materials provided with the distribution.
27  * 3. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  */
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/conf.h>
48 #include <sys/errno.h>
49 #include <sys/fcntl.h>
50 #include <sys/ioccom.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
53 #include <sys/module.h>
54 
55 #include <dev/ofw/openfirmio.h>
56 
57 static struct cdev *openfirm_dev;
58 
59 static d_ioctl_t openfirm_ioctl;
60 
61 #define	OPENFIRM_MINOR	0
62 
63 static struct cdevsw openfirm_cdevsw = {
64 	.d_version =	D_VERSION,
65 	.d_flags =	D_NEEDGIANT | D_GIANTOK,
66 	.d_ioctl =	openfirm_ioctl,
67 	.d_name =	"openfirm",
68 };
69 
70 static phandle_t lastnode;	/* speed hack */
71 
72 static int openfirm_checkid(phandle_t, phandle_t);
73 static int openfirm_getstr(int, const char *, char **);
74 
75 /*
76  * Verify target ID is valid (exists in the OPENPROM tree), as
77  * listed from node ID sid forward.
78  */
79 static int
80 openfirm_checkid(phandle_t sid, phandle_t tid)
81 {
82 
83 	for (; sid != 0; sid = OF_peer(sid))
84 		if (sid == tid || openfirm_checkid(OF_child(sid), tid))
85 			return (1);
86 
87 	return (0);
88 }
89 
90 static int
91 openfirm_getstr(int len, const char *user, char **cpp)
92 {
93 	int error;
94 	char *cp;
95 
96 	/* Reject obvious bogus requests. */
97 	if ((u_int)len > OFIOCMAXNAME)
98 		return (ENAMETOOLONG);
99 
100 	*cpp = cp = malloc(len + 1, M_TEMP, M_WAITOK);
101 	error = copyin(user, cp, len);
102 	cp[len] = '\0';
103 	return (error);
104 }
105 
106 int
107 openfirm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
108     struct thread *td)
109 {
110 	struct ofiocdesc *of;
111 	phandle_t node;
112 	int len, ok, error;
113 	char *name, *value;
114 	char newname[OFIOCSUGGPROPNAMELEN];
115 
116 	if ((flags & FREAD) == 0)
117 		return (EBADF);
118 
119 	of = (struct ofiocdesc *)data;
120 	switch (cmd) {
121 	case OFIOCGETOPTNODE:
122 		*(phandle_t *) data = OF_finddevice("/options");
123 		return (0);
124 	case OFIOCGET:
125 	case OFIOCSET:
126 	case OFIOCNEXTPROP:
127 	case OFIOCFINDDEVICE:
128 	case OFIOCGETPROPLEN:
129 		node = of->of_nodeid;
130 		break;
131 	case OFIOCGETNEXT:
132 	case OFIOCGETCHILD:
133 		node = *(phandle_t *)data;
134 		break;
135 	default:
136 		return (ENOIOCTL);
137 	}
138 
139 	if (node != 0 && node != lastnode) {
140 		/* Not an easy one, we must search for it. */
141 		ok = openfirm_checkid(OF_peer(0), node);
142 		if (!ok)
143 			return (EINVAL);
144 		lastnode = node;
145 	}
146 
147 	name = value = NULL;
148 	error = 0;
149 	switch (cmd) {
150 	case OFIOCGET:
151 	case OFIOCGETPROPLEN:
152 		if (node == 0)
153 			return (EINVAL);
154 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
155 		if (error)
156 			break;
157 		len = OF_getproplen(node, name);
158 		if (cmd == OFIOCGETPROPLEN) {
159 			of->of_buflen = len;
160 			break;
161 		}
162 		if (len > of->of_buflen) {
163 			error = ENOMEM;
164 			break;
165 		}
166 		of->of_buflen = len;
167 		/* -1 means no entry; 0 means no value. */
168 		if (len <= 0)
169 			break;
170 		value = malloc(len, M_TEMP, M_WAITOK);
171 		len = OF_getprop(node, name, (void *)value, len);
172 		error = copyout(value, of->of_buf, len);
173 		break;
174 
175 	case OFIOCSET:
176 		/*
177 		 * Note: Text string values for at least the /options node
178 		 * have to be null-terminated and the length parameter must
179 		 * include this terminating null.  However, like OF_getprop(),
180 		 * OF_setprop() will return the actual length of the text
181 		 * string, i.e. omitting the terminating null.
182 		 */
183 		if ((flags & FWRITE) == 0)
184 			return (EBADF);
185 		if (node == 0)
186 			return (EINVAL);
187 		if ((u_int)of->of_buflen > OFIOCMAXVALUE)
188 			return (ENAMETOOLONG);
189 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
190 		if (error)
191 			break;
192 		value = malloc(of->of_buflen, M_TEMP, M_WAITOK);
193 		error = copyin(of->of_buf, value, of->of_buflen);
194 		if (error)
195 			break;
196 		len = OF_setprop(node, name, value, of->of_buflen);
197 		if (len < 0)
198 			error = EINVAL;
199 		of->of_buflen = len;
200 		break;
201 
202 	case OFIOCNEXTPROP:
203 		if (node == 0 || of->of_buflen < 0)
204 			return (EINVAL);
205 		if (of->of_namelen != 0) {
206 			error = openfirm_getstr(of->of_namelen, of->of_name,
207 			    &name);
208 			if (error)
209 				break;
210 		}
211 		ok = OF_nextprop(node, name, newname, sizeof(newname));
212 		if (ok == 0) {
213 			error = ENOENT;
214 			break;
215 		}
216 		if (ok == -1) {
217 			error = EINVAL;
218 			break;
219 		}
220 		len = strlen(newname) + 1;
221 		if (len > of->of_buflen) {
222 			/*
223 			 * Passed buffer was insufficient.
224 			 *
225 			 * Instead of returning an error here, truncate the
226 			 * property name to fit the buffer.
227 			 *
228 			 * This allows us to retain compatibility with old
229 			 * tools which always pass a 32 character buffer.
230 			 */
231 			len = of->of_buflen;
232 			newname[len - 1] = '\0';
233 		}
234 		else
235 			of->of_buflen = len;
236 		error = copyout(newname, of->of_buf, len);
237 		break;
238 
239 	case OFIOCGETNEXT:
240 		node = OF_peer(node);
241 		*(phandle_t *)data = lastnode = node;
242 		break;
243 
244 	case OFIOCGETCHILD:
245 		if (node == 0)
246 			return (EINVAL);
247 		node = OF_child(node);
248 		*(phandle_t *)data = lastnode = node;
249 		break;
250 
251 	case OFIOCFINDDEVICE:
252 		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
253 		if (error)
254 			break;
255 		node = OF_finddevice(name);
256 		if (node == -1) {
257 			error = ENOENT;
258 			break;
259 		}
260 		of->of_nodeid = lastnode = node;
261 		break;
262 	}
263 
264 	if (name != NULL)
265 		free(name, M_TEMP);
266 	if (value != NULL)
267 		free(value, M_TEMP);
268 
269 	return (error);
270 }
271 
272 static int
273 openfirm_modevent(module_t mod, int type, void *data)
274 {
275 
276 	switch(type) {
277 	case MOD_LOAD:
278 		if (bootverbose)
279 			printf("openfirm: <Open Firmware control device>\n");
280 		/*
281 		 * Allow only root access by default; this device may allow
282 		 * users to peek into firmware passwords, and likely to crash
283 		 * the machine on some boxen due to firmware quirks.
284 		 */
285 		openfirm_dev = make_dev(&openfirm_cdevsw, OPENFIRM_MINOR,
286 		    UID_ROOT, GID_WHEEL, 0600, "openfirm");
287 		return 0;
288 
289 	case MOD_UNLOAD:
290 		destroy_dev(openfirm_dev);
291 		return 0;
292 
293 	case MOD_SHUTDOWN:
294 		return 0;
295 
296 	default:
297 		return EOPNOTSUPP;
298 	}
299 }
300 
301 DEV_MODULE(openfirm, openfirm_modevent, NULL);
302