1/*
2 * libfdt - Flat Device Tree manipulation
3 * Copyright (C) 2006 David Gibson, IBM Corporation.
4 *
5 * libfdt is dual licensed: you can use it either under the terms of
6 * the GPL, or the BSD license, at your option.
7 *
8 *  a) This library is free software; you can redistribute it and/or
9 *     modify it under the terms of the GNU General Public License as
10 *     published by the Free Software Foundation; either version 2 of the
11 *     License, or (at your option) any later version.
12 *
13 *     This library is distributed in the hope that it will be useful,
14 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *     GNU General Public License for more details.
17 *
18 *     You should have received a copy of the GNU General Public
19 *     License along with this library; if not, write to the Free
20 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21 *     MA 02110-1301 USA
22 *
23 * Alternatively,
24 *
25 *  b) Redistribution and use in source and binary forms, with or
26 *     without modification, are permitted provided that the following
27 *     conditions are met:
28 *
29 *     1. Redistributions of source code must retain the above
30 *        copyright notice, this list of conditions and the following
31 *        disclaimer.
32 *     2. Redistributions in binary form must reproduce the above
33 *        copyright notice, this list of conditions and the following
34 *        disclaimer in the documentation and/or other materials
35 *        provided with the distribution.
36 *
37 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50 */
51#include "libfdt_env.h"
52
53#include <fdt.h>
54#include <libfdt.h>
55
56#include "libfdt_internal.h"
57
58int fdt_check_header(const void *fdt)
59{
60	if (fdt_magic(fdt) == FDT_MAGIC) {
61		/* Complete tree */
62		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
63			return -FDT_ERR_BADVERSION;
64		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
65			return -FDT_ERR_BADVERSION;
66	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
67		/* Unfinished sequential-write blob */
68		if (fdt_size_dt_struct(fdt) == 0)
69			return -FDT_ERR_BADSTATE;
70	} else {
71		return -FDT_ERR_BADMAGIC;
72	}
73
74	return 0;
75}
76
77const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
78{
79	const char *p;
80
81	if (fdt_version(fdt) >= 0x11)
82		if (((offset + len) < offset)
83		    || ((offset + len) > fdt_size_dt_struct(fdt)))
84			return NULL;
85
86	p = _fdt_offset_ptr(fdt, offset);
87
88	if (p + len < p)
89		return NULL;
90	return p;
91}
92
93uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
94{
95	const uint32_t *tagp, *lenp;
96	uint32_t tag;
97	int offset = startoffset;
98	const char *p;
99
100	*nextoffset = -FDT_ERR_TRUNCATED;
101	tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
102	if (!tagp)
103		return FDT_END; /* premature end */
104	tag = fdt32_to_cpu(*tagp);
105	offset += FDT_TAGSIZE;
106
107	*nextoffset = -FDT_ERR_BADSTRUCTURE;
108	switch (tag) {
109	case FDT_BEGIN_NODE:
110		/* skip name */
111		do {
112			p = fdt_offset_ptr(fdt, offset++, 1);
113		} while (p && (*p != '\0'));
114		if (!p)
115			return FDT_END; /* premature end */
116		break;
117
118	case FDT_PROP:
119		lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
120		if (!lenp)
121			return FDT_END; /* premature end */
122		/* skip-name offset, length and value */
123		offset += sizeof(struct fdt_property) - FDT_TAGSIZE
124			+ fdt32_to_cpu(*lenp);
125		break;
126
127	case FDT_END:
128	case FDT_END_NODE:
129	case FDT_NOP:
130		break;
131
132	default:
133		return FDT_END;
134	}
135
136	if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
137		return FDT_END; /* premature end */
138
139	*nextoffset = FDT_TAGALIGN(offset);
140	return tag;
141}
142
143int _fdt_check_node_offset(const void *fdt, int offset)
144{
145	if ((offset < 0) || (offset % FDT_TAGSIZE)
146	    || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
147		return -FDT_ERR_BADOFFSET;
148
149	return offset;
150}
151
152int _fdt_check_prop_offset(const void *fdt, int offset)
153{
154	if ((offset < 0) || (offset % FDT_TAGSIZE)
155	    || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
156		return -FDT_ERR_BADOFFSET;
157
158	return offset;
159}
160
161int fdt_next_node(const void *fdt, int offset, int *depth)
162{
163	int nextoffset = 0;
164	uint32_t tag;
165
166	if (offset >= 0)
167		if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
168			return nextoffset;
169
170	do {
171		offset = nextoffset;
172		tag = fdt_next_tag(fdt, offset, &nextoffset);
173
174		switch (tag) {
175		case FDT_PROP:
176		case FDT_NOP:
177			break;
178
179		case FDT_BEGIN_NODE:
180			if (depth)
181				(*depth)++;
182			break;
183
184		case FDT_END_NODE:
185			if (depth && ((--(*depth)) < 0))
186				return nextoffset;
187			break;
188
189		case FDT_END:
190			if ((nextoffset >= 0)
191			    || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
192				return -FDT_ERR_NOTFOUND;
193			else
194				return nextoffset;
195		}
196	} while (tag != FDT_BEGIN_NODE);
197
198	return offset;
199}
200
201const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
202{
203	int len = strlen(s) + 1;
204	const char *last = strtab + tabsize - len;
205	const char *p;
206
207	for (p = strtab; p <= last; p++)
208		if (memcmp(p, s, len) == 0)
209			return p;
210	return NULL;
211}
212
213int fdt_move(const void *fdt, void *buf, int bufsize)
214{
215	FDT_CHECK_HEADER(fdt);
216
217	if (fdt_totalsize(fdt) > bufsize)
218		return -FDT_ERR_NOSPACE;
219
220	memmove(buf, fdt, fdt_totalsize(fdt));
221	return 0;
222}
223