openfirmio.c revision 116210
1/*	$NetBSD: openfirmio.c,v 1.4 2002/09/06 13:23:19 gehenna Exp $ */
2
3/*
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * All advertising materials mentioning features or use of this software
12 * must display the following acknowledgement:
13 *	This product includes software developed by the University of
14 *	California, Lawrence Berkeley Laboratory.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 *    notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 *    notice, this list of conditions and the following disclaimer in the
23 *    documentation and/or other materials provided with the distribution.
24 * 3. All advertising materials mentioning features or use of this software
25 *    must display the following acknowledgement:
26 *	This product includes software developed by the University of
27 *	California, Berkeley and its contributors.
28 * 4. Neither the name of the University nor the names of its contributors
29 *    may be used to endorse or promote products derived from this software
30 *    without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
35 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * SUCH DAMAGE.
43 *
44 *	@(#)openfirm.c	8.1 (Berkeley) 6/11/93
45 *
46 * $FreeBSD: head/sys/dev/ofw/openfirmio.c 116210 2003-06-11 18:33:03Z tmm $
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
61static dev_t openfirm_dev;
62
63static d_ioctl_t openfirm_ioctl;
64
65#define	OPENFIRM_MINOR	0
66
67static struct cdevsw openfirm_cdevsw = {
68	.d_open =	nullopen,
69	.d_close =	nullclose,
70	.d_ioctl =	openfirm_ioctl,
71	.d_name =	"openfirm",
72};
73
74static phandle_t lastnode;	/* speed hack */
75
76static int openfirm_checkid(phandle_t, phandle_t);
77static int openfirm_getstr(int, const char *, char **);
78
79/* Maximum accepted name length. */
80#define	OFW_NAME_MAX	8191
81
82/*
83 * Verify target ID is valid (exists in the OPENPROM tree), as
84 * listed from node ID sid forward.
85 */
86static int
87openfirm_checkid(phandle_t sid, phandle_t tid)
88{
89
90	for (; sid != 0; sid = OF_peer(sid))
91		if (sid == tid || openfirm_checkid(OF_child(sid), tid))
92			return (1);
93
94	return (0);
95}
96
97static int
98openfirm_getstr(int len, const char *user, char **cpp)
99{
100	int error;
101	char *cp;
102
103	/* Reject obvious bogus requests */
104	if ((u_int)len > OFW_NAME_MAX)
105		return (ENAMETOOLONG);
106
107	*cpp = cp = malloc(len + 1, M_TEMP, M_WAITOK);
108	if (cp == NULL)
109		return (ENOMEM);
110	error = copyin(user, cp, len);
111	cp[len] = '\0';
112	return (error);
113}
114
115int
116openfirm_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
117    struct thread *td)
118{
119	struct ofiocdesc *of;
120	phandle_t node;
121	int len, ok, error;
122	char *name, *value;
123	char newname[32];
124
125	if ((flags & FREAD) == 0)
126		return (EBADF);
127
128	of = (struct ofiocdesc *)data;
129	switch (cmd) {
130	case OFIOCGETOPTNODE:
131		*(phandle_t *) data = OF_finddevice("/options");
132		return (0);
133	case OFIOCGET:
134#if 0
135	case OFIOCSET:
136#endif
137	case OFIOCNEXTPROP:
138	case OFIOCFINDDEVICE:
139	case OFIOCGETPROPLEN:
140		node = of->of_nodeid;
141		break;
142	case OFIOCGETNEXT:
143	case OFIOCGETCHILD:
144		node = *(phandle_t *)data;
145		break;
146	default:
147		return (ENOIOCTL);
148	}
149
150	if (node != 0 && node != lastnode) {
151		/* Not an easy one, must search for it */
152		ok = openfirm_checkid(OF_peer(0), node);
153		if (!ok)
154			return (EINVAL);
155		lastnode = node;
156	}
157
158	name = value = NULL;
159	error = 0;
160	switch (cmd) {
161
162	case OFIOCGET:
163	case OFIOCGETPROPLEN:
164		if (node == 0)
165			return (EINVAL);
166		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
167		if (error)
168			break;
169		len = OF_getproplen(node, name);
170		if (cmd == OFIOCGETPROPLEN) {
171			of->of_buflen = len;
172			break;
173		}
174		if (len > of->of_buflen) {
175			error = ENOMEM;
176			break;
177		}
178		of->of_buflen = len;
179		/* -1 means no entry; 0 means no value */
180		if (len <= 0)
181			break;
182		value = malloc(len, M_TEMP, M_WAITOK);
183		if (value == NULL) {
184			error = ENOMEM;
185			break;
186		}
187		len = OF_getprop(node, name, (void *)value, len);
188		error = copyout(value, of->of_buf, len);
189		break;
190
191#if 0
192	case OFIOCSET:
193		if ((flags & FWRITE) == 0)
194			return (EBADF);
195		if (node == 0)
196			return (EINVAL);
197		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
198		if (error)
199			break;
200		error = openfirm_getstr(of->of_buflen, of->of_buf, &value);
201		if (error)
202			break;
203		len = OF_setprop(node, name, value, of->of_buflen);
204		if (len != of->of_buflen)
205			error = EINVAL;
206		break;
207#endif
208
209	case OFIOCNEXTPROP:
210		if (node == 0 || of->of_buflen < 0)
211			return (EINVAL);
212		if (of->of_namelen != 0) {
213			error = openfirm_getstr(of->of_namelen, of->of_name,
214			    &name);
215			if (error)
216				break;
217		}
218		ok = OF_nextprop(node, name, newname);
219		if (ok == 0) {
220			error = ENOENT;
221			break;
222		}
223		if (ok == -1) {
224			error = EINVAL;
225			break;
226		}
227		len = strlen(newname) + 1;
228		if (len > of->of_buflen)
229			len = of->of_buflen;
230		else
231			of->of_buflen = len;
232		error = copyout(newname, of->of_buf, len);
233		break;
234
235	case OFIOCGETNEXT:
236		node = OF_peer(node);
237		*(phandle_t *)data = lastnode = node;
238		break;
239
240	case OFIOCGETCHILD:
241		if (node == 0)
242			return (EINVAL);
243		node = OF_child(node);
244		*(phandle_t *)data = lastnode = node;
245		break;
246
247	case OFIOCFINDDEVICE:
248		error = openfirm_getstr(of->of_namelen, of->of_name, &name);
249		if (error)
250			break;
251		node = OF_finddevice(name);
252		if (node == 0 || node == -1) {
253			error = ENOENT;
254			break;
255		}
256		of->of_nodeid = lastnode = node;
257		break;
258	}
259
260	if (name != NULL)
261		free(name, M_TEMP);
262	if (value != NULL)
263		free(value, M_TEMP);
264
265	return (error);
266}
267
268static int
269openfirm_modevent(module_t mod, int type, void *data)
270{
271	switch(type) {
272	case MOD_LOAD:
273		if (bootverbose)
274			printf("openfirm: <OpenFirmware control device>\n");
275		/*
276		 * Allow only root access by default; this device may allow
277		 * users to peek into firmware passwords, and likely to crash
278		 * the machine on some boxen due to firmware quirks.
279		 */
280		openfirm_dev = make_dev(&openfirm_cdevsw, OPENFIRM_MINOR,
281		    UID_ROOT, GID_WHEEL, 0600, "openfirm");
282		return 0;
283
284	case MOD_UNLOAD:
285		destroy_dev(openfirm_dev);
286		return 0;
287
288	case MOD_SHUTDOWN:
289		return 0;
290
291	default:
292		return EOPNOTSUPP;
293	}
294}
295
296DEV_MODULE(openfirm, openfirm_modevent, NULL);
297