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
fdt_check_header(const void * fdt)58 int 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
fdt_offset_ptr(const void * fdt,int offset,unsigned int len)77 const 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
fdt_next_tag(const void * fdt,int startoffset,int * nextoffset)93 uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset)
94 {
95 const fdt32_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
_fdt_check_node_offset(const void * fdt,int offset)143 int _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
_fdt_check_prop_offset(const void * fdt,int offset)152 int _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
fdt_next_node(const void * fdt,int offset,int * depth)161 int 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
fdt_first_subnode(const void * fdt,int offset)201 int fdt_first_subnode(const void *fdt, int offset)
202 {
203 int depth = 0;
204
205 offset = fdt_next_node(fdt, offset, &depth);
206 if (offset < 0 || depth != 1)
207 return -FDT_ERR_NOTFOUND;
208
209 return offset;
210 }
211
fdt_next_subnode(const void * fdt,int offset)212 int fdt_next_subnode(const void *fdt, int offset)
213 {
214 int depth = 1;
215
216 /*
217 * With respect to the parent, the depth of the next subnode will be
218 * the same as the last.
219 */
220 do {
221 offset = fdt_next_node(fdt, offset, &depth);
222 if (offset < 0 || depth < 1)
223 return -FDT_ERR_NOTFOUND;
224 } while (depth > 1);
225
226 return offset;
227 }
228
_fdt_find_string(const char * strtab,int tabsize,const char * s)229 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
230 {
231 int len = strlen(s) + 1;
232 const char *last = strtab + tabsize - len;
233 const char *p;
234
235 for (p = strtab; p <= last; p++)
236 if (memcmp(p, s, len) == 0)
237 return p;
238 return NULL;
239 }
240
fdt_move(const void * fdt,void * buf,int bufsize)241 int fdt_move(const void *fdt, void *buf, int bufsize)
242 {
243 FDT_CHECK_HEADER(fdt);
244
245 if (fdt_totalsize(fdt) > bufsize)
246 return -FDT_ERR_NOSPACE;
247
248 memmove(buf, fdt, fdt_totalsize(fdt));
249 return 0;
250 }
251