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, see <http://www.gnu.org/licenses/>.
20 *
21 * Alternatively,
22 *
23 * b) Redistribution and use in source and binary forms, with or
24 * without modification, are permitted provided that the following
25 * conditions are met:
26 *
27 * 1. Redistributions of source code must retain the above
28 * copyright notice, this list of conditions and the following
29 * disclaimer.
30 * 2. Redistributions in binary form must reproduce the above
31 * copyright notice, this list of conditions and the following
32 * disclaimer in the documentation and/or other materials
33 * provided with the distribution.
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
36 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
37 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
38 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
40 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
45 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
46 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
47 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48 */
49 #include "libfdt_env.h"
50
51 #include <fdt.h>
52 #include <libfdt.h>
53
54 #include "libfdt_internal.h"
55
fdt_check_header(const void * fdt)56 int fdt_check_header(const void *fdt)
57 {
58 if (fdt_magic(fdt) == FDT_MAGIC) {
59 /* Complete tree */
60 if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
61 return -FDT_ERR_BADVERSION;
62 if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
63 return -FDT_ERR_BADVERSION;
64 } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
65 /* Unfinished sequential-write blob */
66 if (fdt_size_dt_struct(fdt) == 0)
67 return -FDT_ERR_BADSTATE;
68 } else {
69 return -FDT_ERR_BADMAGIC;
70 }
71
72 return 0;
73 }
74
fdt_offset_ptr(const void * fdt,int offset,unsigned int len)75 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
76 {
77 const char *p;
78
79 if (fdt_version(fdt) >= 0x11)
80 if (((offset + len) < offset)
81 || ((offset + len) > fdt_size_dt_struct(fdt)))
82 return NULL;
83
84 p = _fdt_offset_ptr(fdt, offset);
85
86 if (p + len < p)
87 return NULL;
88 return p;
89 }
90
fdt_next_tag(const void * fdt,int startoffset,int * nextoffset)91 uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
92 {
93 const fdt32_t *tagp, *lenp;
94 uint32_t tag;
95 int offset = startoffset;
96 const char *p;
97
98 *nextoffset = -FDT_ERR_TRUNCATED;
99 tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
100 if (!tagp)
101 return FDT_END; /* premature end */
102 tag = fdt32_to_cpu(*tagp);
103 offset += FDT_TAGSIZE;
104
105 *nextoffset = -FDT_ERR_BADSTRUCTURE;
106 switch (tag) {
107 case FDT_BEGIN_NODE:
108 /* skip name */
109 do {
110 p = fdt_offset_ptr(fdt, offset++, 1);
111 } while (p && (*p != '\0'));
112 if (!p)
113 return FDT_END; /* premature end */
114 break;
115
116 case FDT_PROP:
117 lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp));
118 if (!lenp)
119 return FDT_END; /* premature end */
120 /* skip-name offset, length and value */
121 offset += sizeof(struct fdt_property) - FDT_TAGSIZE
122 + fdt32_to_cpu(*lenp);
123 break;
124
125 case FDT_END:
126 case FDT_END_NODE:
127 case FDT_NOP:
128 break;
129
130 default:
131 return FDT_END;
132 }
133
134 if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset))
135 return FDT_END; /* premature end */
136
137 *nextoffset = FDT_TAGALIGN(offset);
138 return tag;
139 }
140
_fdt_check_node_offset(const void * fdt,int offset)141 int _fdt_check_node_offset(const void *fdt, int offset)
142 {
143 if ((offset < 0) || (offset % FDT_TAGSIZE)
144 || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
145 return -FDT_ERR_BADOFFSET;
146
147 return offset;
148 }
149
_fdt_check_prop_offset(const void * fdt,int offset)150 int _fdt_check_prop_offset(const void *fdt, int offset)
151 {
152 if ((offset < 0) || (offset % FDT_TAGSIZE)
153 || (fdt_next_tag(fdt, offset, &offset) != FDT_PROP))
154 return -FDT_ERR_BADOFFSET;
155
156 return offset;
157 }
158
fdt_next_node(const void * fdt,int offset,int * depth)159 int fdt_next_node(const void *fdt, int offset, int *depth)
160 {
161 int nextoffset = 0;
162 uint32_t tag;
163
164 if (offset >= 0)
165 if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
166 return nextoffset;
167
168 do {
169 offset = nextoffset;
170 tag = fdt_next_tag(fdt, offset, &nextoffset);
171
172 switch (tag) {
173 case FDT_PROP:
174 case FDT_NOP:
175 break;
176
177 case FDT_BEGIN_NODE:
178 if (depth)
179 (*depth)++;
180 break;
181
182 case FDT_END_NODE:
183 if (depth && ((--(*depth)) < 0))
184 return nextoffset;
185 break;
186
187 case FDT_END:
188 if ((nextoffset >= 0)
189 || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth))
190 return -FDT_ERR_NOTFOUND;
191 else
192 return nextoffset;
193 }
194 } while (tag != FDT_BEGIN_NODE);
195
196 return offset;
197 }
198
fdt_first_subnode(const void * fdt,int offset)199 int fdt_first_subnode(const void *fdt, int offset)
200 {
201 int depth = 0;
202
203 offset = fdt_next_node(fdt, offset, &depth);
204 if (offset < 0 || depth != 1)
205 return -FDT_ERR_NOTFOUND;
206
207 return offset;
208 }
209
fdt_next_subnode(const void * fdt,int offset)210 int fdt_next_subnode(const void *fdt, int offset)
211 {
212 int depth = 1;
213
214 /*
215 * With respect to the parent, the depth of the next subnode will be
216 * the same as the last.
217 */
218 do {
219 offset = fdt_next_node(fdt, offset, &depth);
220 if (offset < 0 || depth < 1)
221 return -FDT_ERR_NOTFOUND;
222 } while (depth > 1);
223
224 return offset;
225 }
226
_fdt_find_string(const char * strtab,int tabsize,const char * s)227 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
228 {
229 int len = strlen(s) + 1;
230 const char *last = strtab + tabsize - len;
231 const char *p;
232
233 for (p = strtab; p <= last; p++)
234 if (memcmp(p, s, len) == 0)
235 return p;
236 return NULL;
237 }
238
fdt_move(const void * fdt,void * buf,int bufsize)239 int fdt_move(const void *fdt, void *buf, int bufsize)
240 {
241 FDT_CHECK_HEADER(fdt);
242
243 if (fdt_totalsize(fdt) > bufsize)
244 return -FDT_ERR_NOSPACE;
245
246 memmove(buf, fdt, fdt_totalsize(fdt));
247 return 0;
248 }
249