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
57static struct cdev *openfirm_dev;
58
59static d_ioctl_t openfirm_ioctl;
60
61#define	OPENFIRM_MINOR	0
62
63static 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
70static phandle_t lastnode;	/* speed hack */
71
72static int openfirm_checkid(phandle_t, phandle_t);
73static 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 */
79static int
80openfirm_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
90static int
91openfirm_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
106int
107openfirm_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
272static int
273openfirm_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
301DEV_MODULE(openfirm, openfirm_modevent, NULL);
302