xref: /illumos-kvm-cmd/kvm/libfdt/fdt_rw.c (revision 68396ea9)
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 
_blocks_misordered(const void * fdt,int mem_rsv_size,int struct_size)58 static int _blocks_misordered(const void *fdt,
59 			      int mem_rsv_size, int struct_size)
60 {
61 	return (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(struct fdt_header), 8))
62 		|| (fdt_off_dt_struct(fdt) <
63 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
64 		|| (fdt_off_dt_strings(fdt) <
65 		    (fdt_off_dt_struct(fdt) + struct_size))
66 		|| (fdt_totalsize(fdt) <
67 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
68 }
69 
rw_check_header(void * fdt)70 static int rw_check_header(void *fdt)
71 {
72 	CHECK_HEADER(fdt);
73 
74 	if (fdt_version(fdt) < 17)
75 		return -FDT_ERR_BADVERSION;
76 	if (_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
77 			       fdt_size_dt_struct(fdt)))
78 		return -FDT_ERR_BADLAYOUT;
79 	if (fdt_version(fdt) > 17)
80 		fdt_set_version(fdt, 17);
81 
82 	return 0;
83 }
84 
85 #define RW_CHECK_HEADER(fdt) \
86 	{ \
87 		int err; \
88 		if ((err = rw_check_header(fdt)) != 0) \
89 			return err; \
90 	}
91 
_blob_data_size(void * fdt)92 static inline int _blob_data_size(void *fdt)
93 {
94 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
95 }
96 
_blob_splice(void * fdt,void * p,int oldlen,int newlen)97 static int _blob_splice(void *fdt, void *p, int oldlen, int newlen)
98 {
99 	void *end = fdt + _blob_data_size(fdt);
100 
101 	if (((p + oldlen) < p) || ((p + oldlen) > end))
102 		return -FDT_ERR_BADOFFSET;
103 	if ((end - oldlen + newlen) > (fdt + fdt_totalsize(fdt)))
104 		return -FDT_ERR_NOSPACE;
105 	memmove(p + newlen, p + oldlen, end - p - oldlen);
106 	return 0;
107 }
108 
_blob_splice_mem_rsv(void * fdt,struct fdt_reserve_entry * p,int oldn,int newn)109 static int _blob_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
110 				int oldn, int newn)
111 {
112 	int delta = (newn - oldn) * sizeof(*p);
113 	int err;
114 	err = _blob_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
115 	if (err)
116 		return err;
117 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
118 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
119 	return 0;
120 }
121 
_blob_splice_struct(void * fdt,void * p,int oldlen,int newlen)122 static int _blob_splice_struct(void *fdt, void *p,
123 			       int oldlen, int newlen)
124 {
125 	int delta = newlen - oldlen;
126 	int err;
127 
128 	if ((err = _blob_splice(fdt, p, oldlen, newlen)))
129 		return err;
130 
131 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
132 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
133 	return 0;
134 }
135 
_blob_splice_string(void * fdt,int newlen)136 static int _blob_splice_string(void *fdt, int newlen)
137 {
138 	void *p = fdt + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
139 	int err;
140 
141 	if ((err = _blob_splice(fdt, p, 0, newlen)))
142 		return err;
143 
144 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
145 	return 0;
146 }
147 
_find_add_string(void * fdt,const char * s)148 static int _find_add_string(void *fdt, const char *s)
149 {
150 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
151 	const char *p;
152 	char *new;
153 	int len = strlen(s) + 1;
154 	int err;
155 
156 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
157 	if (p)
158 		/* found it */
159 		return (p - strtab);
160 
161 	new = strtab + fdt_size_dt_strings(fdt);
162 	err = _blob_splice_string(fdt, len);
163 	if (err)
164 		return err;
165 
166 	memcpy(new, s, len);
167 	return (new - strtab);
168 }
169 
fdt_add_mem_rsv(void * fdt,uint64_t address,uint64_t size)170 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
171 {
172 	struct fdt_reserve_entry *re;
173 	int err;
174 
175 	if ((err = rw_check_header(fdt)))
176 		return err;
177 
178 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
179 	err = _blob_splice_mem_rsv(fdt, re, 0, 1);
180 	if (err)
181 		return err;
182 
183 	re->address = cpu_to_fdt64(address);
184 	re->size = cpu_to_fdt64(size);
185 	return 0;
186 }
187 
fdt_del_mem_rsv(void * fdt,int n)188 int fdt_del_mem_rsv(void *fdt, int n)
189 {
190 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
191 	int err;
192 
193 	if ((err = rw_check_header(fdt)))
194 		return err;
195 	if (n >= fdt_num_mem_rsv(fdt))
196 		return -FDT_ERR_NOTFOUND;
197 
198 	err = _blob_splice_mem_rsv(fdt, re, 1, 0);
199 	if (err)
200 		return err;
201 	return 0;
202 }
203 
_resize_property(void * fdt,int nodeoffset,const char * name,int len,struct fdt_property ** prop)204 static int _resize_property(void *fdt, int nodeoffset, const char *name, int len,
205 			    struct fdt_property **prop)
206 {
207 	int oldlen;
208 	int err;
209 
210 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
211 	if (! (*prop))
212 		return oldlen;
213 
214 	if ((err = _blob_splice_struct(fdt, (*prop)->data,
215 				       ALIGN(oldlen, FDT_TAGSIZE),
216 				       ALIGN(len, FDT_TAGSIZE))))
217 		return err;
218 
219 	(*prop)->len = cpu_to_fdt32(len);
220 	return 0;
221 }
222 
_add_property(void * fdt,int nodeoffset,const char * name,int len,struct fdt_property ** prop)223 static int _add_property(void *fdt, int nodeoffset, const char *name, int len,
224 			 struct fdt_property **prop)
225 {
226 	uint32_t tag;
227 	int proplen;
228 	int nextoffset;
229 	int namestroff;
230 	int err;
231 
232 	tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
233 	if (tag != FDT_BEGIN_NODE)
234 		return -FDT_ERR_BADOFFSET;
235 
236 	namestroff = _find_add_string(fdt, name);
237 	if (namestroff < 0)
238 		return namestroff;
239 
240 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
241 	proplen = sizeof(**prop) + ALIGN(len, FDT_TAGSIZE);
242 
243 	err = _blob_splice_struct(fdt, *prop, 0, proplen);
244 	if (err)
245 		return err;
246 
247 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
248 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
249 	(*prop)->len = cpu_to_fdt32(len);
250 	return 0;
251 }
252 
fdt_set_name(void * fdt,int nodeoffset,const char * name)253 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
254 {
255 	char *namep;
256 	int oldlen, newlen;
257 	int err;
258 
259 	if ((err = rw_check_header(fdt)))
260 		return err;
261 
262 	namep = (char *)fdt_get_name(fdt, nodeoffset, &oldlen);
263 	if (!namep)
264 		return oldlen;
265 
266 	newlen = strlen(name);
267 
268 	err = _blob_splice_struct(fdt, namep, ALIGN(oldlen+1, FDT_TAGSIZE),
269 				  ALIGN(newlen+1, FDT_TAGSIZE));
270 	if (err)
271 		return err;
272 
273 	memcpy(namep, name, newlen+1);
274 	return 0;
275 }
276 
fdt_setprop(void * fdt,int nodeoffset,const char * name,const void * val,int len)277 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
278 		const void *val, int len)
279 {
280 	struct fdt_property *prop;
281 	int err;
282 
283 	if ((err = rw_check_header(fdt)))
284 		return err;
285 
286 	err = _resize_property(fdt, nodeoffset, name, len, &prop);
287 	if (err == -FDT_ERR_NOTFOUND)
288 		err = _add_property(fdt, nodeoffset, name, len, &prop);
289 	if (err)
290 		return err;
291 
292 	memcpy(prop->data, val, len);
293 	return 0;
294 }
295 
fdt_delprop(void * fdt,int nodeoffset,const char * name)296 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
297 {
298 	struct fdt_property *prop;
299 	int len, proplen;
300 
301 	RW_CHECK_HEADER(fdt);
302 
303 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
304 	if (! prop)
305 		return len;
306 
307 	proplen = sizeof(*prop) + ALIGN(len, FDT_TAGSIZE);
308 	return _blob_splice_struct(fdt, prop, proplen, 0);
309 }
310 
fdt_add_subnode_namelen(void * fdt,int parentoffset,const char * name,int namelen)311 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
312 			    const char *name, int namelen)
313 {
314 	struct fdt_node_header *nh;
315 	int offset, nextoffset;
316 	int nodelen;
317 	int err;
318 	uint32_t tag;
319 	uint32_t *endtag;
320 
321 	RW_CHECK_HEADER(fdt);
322 
323 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
324 	if (offset >= 0)
325 		return -FDT_ERR_EXISTS;
326 	else if (offset != -FDT_ERR_NOTFOUND)
327 		return offset;
328 
329 	/* Try to place the new node after the parent's properties */
330 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
331 	do {
332 		offset = nextoffset;
333 		tag = fdt_next_tag(fdt, offset, &nextoffset);
334 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
335 
336 	nh = _fdt_offset_ptr_w(fdt, offset);
337 	nodelen = sizeof(*nh) + ALIGN(namelen+1, FDT_TAGSIZE) + FDT_TAGSIZE;
338 
339 	err = _blob_splice_struct(fdt, nh, 0, nodelen);
340 	if (err)
341 		return err;
342 
343 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
344 	memset(nh->name, 0, ALIGN(namelen+1, FDT_TAGSIZE));
345 	memcpy(nh->name, name, namelen);
346 	endtag = (uint32_t *)((void *)nh + nodelen - FDT_TAGSIZE);
347 	*endtag = cpu_to_fdt32(FDT_END_NODE);
348 
349 	return offset;
350 }
351 
fdt_add_subnode(void * fdt,int parentoffset,const char * name)352 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
353 {
354 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
355 }
356 
fdt_del_node(void * fdt,int nodeoffset)357 int fdt_del_node(void *fdt, int nodeoffset)
358 {
359 	int endoffset;
360 
361 	RW_CHECK_HEADER(fdt);
362 
363 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
364 	if (endoffset < 0)
365 		return endoffset;
366 
367 	return _blob_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
368 				   endoffset - nodeoffset, 0);
369 }
370 
_packblocks(const void * fdt,void * buf,int mem_rsv_size,int struct_size)371 static void _packblocks(const void *fdt, void *buf,
372 		       int mem_rsv_size, int struct_size)
373 {
374 	int mem_rsv_off, struct_off, strings_off;
375 
376 	mem_rsv_off = ALIGN(sizeof(struct fdt_header), 8);
377 	struct_off = mem_rsv_off + mem_rsv_size;
378 	strings_off = struct_off + struct_size;
379 
380 	memmove(buf + mem_rsv_off, fdt + fdt_off_mem_rsvmap(fdt), mem_rsv_size);
381 	fdt_set_off_mem_rsvmap(buf, mem_rsv_off);
382 
383 	memmove(buf + struct_off, fdt + fdt_off_dt_struct(fdt), struct_size);
384 	fdt_set_off_dt_struct(buf, struct_off);
385 	fdt_set_size_dt_struct(buf, struct_size);
386 
387 	memmove(buf + strings_off, fdt + fdt_off_dt_strings(fdt),
388 		fdt_size_dt_strings(fdt));
389 	fdt_set_off_dt_strings(buf, strings_off);
390 	fdt_set_size_dt_strings(buf, fdt_size_dt_strings(fdt));
391 }
392 
fdt_open_into(const void * fdt,void * buf,int bufsize)393 int fdt_open_into(const void *fdt, void *buf, int bufsize)
394 {
395 	int err;
396 	int mem_rsv_size, struct_size;
397 	int newsize;
398 	void *tmp;
399 
400 	CHECK_HEADER(fdt);
401 
402 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
403 		* sizeof(struct fdt_reserve_entry);
404 
405 	if (fdt_version(fdt) >= 17) {
406 		struct_size = fdt_size_dt_struct(fdt);
407 	} else {
408 		struct_size = 0;
409 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
410 			;
411 	}
412 
413 	if (!_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
414 		/* no further work necessary */
415 		err = fdt_move(fdt, buf, bufsize);
416 		if (err)
417 			return err;
418 		fdt_set_version(buf, 17);
419 		fdt_set_size_dt_struct(buf, struct_size);
420 		fdt_set_totalsize(buf, bufsize);
421 		return 0;
422 	}
423 
424 	/* Need to reorder */
425 	newsize = ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
426 		+ struct_size + fdt_size_dt_strings(fdt);
427 
428 	if (bufsize < newsize)
429 		return -FDT_ERR_NOSPACE;
430 
431 	if (((buf + newsize) <= fdt)
432 	    || (buf >= (fdt + fdt_totalsize(fdt)))) {
433 		tmp = buf;
434 	} else {
435 		tmp = (void *)fdt + fdt_totalsize(fdt);
436 		if ((tmp + newsize) > (buf + bufsize))
437 			return -FDT_ERR_NOSPACE;
438 	}
439 
440 	_packblocks(fdt, tmp, mem_rsv_size, struct_size);
441 	memmove(buf, tmp, newsize);
442 
443 	fdt_set_magic(buf, FDT_MAGIC);
444 	fdt_set_totalsize(buf, bufsize);
445 	fdt_set_version(buf, 17);
446 	fdt_set_last_comp_version(buf, 16);
447 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
448 
449 	return 0;
450 }
451 
fdt_pack(void * fdt)452 int fdt_pack(void *fdt)
453 {
454 	int mem_rsv_size;
455 	int err;
456 
457 	err = rw_check_header(fdt);
458 	if (err)
459 		return err;
460 
461 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
462 		* sizeof(struct fdt_reserve_entry);
463 	_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
464 	fdt_set_totalsize(fdt, _blob_data_size(fdt));
465 
466 	return 0;
467 }
468