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fa4a7063 | 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 | ||
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 | ||
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 | ||
93 | uint32_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 | ||
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 | ||
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 | ||
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 | ||
201 | const 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 | ||
213 | int 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 | } |