1// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
2/*
3 * libfdt - Flat Device Tree manipulation
4 * Copyright (C) 2006 David Gibson, IBM Corporation.
5 */
6#include "libfdt_env.h"
7
8#include <fdt.h>
9#include <libfdt.h>
10
11#include "libfdt_internal.h"
12
13static int fdt_blocks_misordered_(const void *fdt,
14				  int mem_rsv_size, int struct_size)
15{
16	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
17		|| (fdt_off_dt_struct(fdt) <
18		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
19		|| (fdt_off_dt_strings(fdt) <
20		    (fdt_off_dt_struct(fdt) + struct_size))
21		|| (fdt_totalsize(fdt) <
22		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
23}
24
25static int fdt_rw_probe_(void *fdt)
26{
27	if (can_assume(VALID_DTB))
28		return 0;
29	FDT_RO_PROBE(fdt);
30
31	if (!can_assume(LATEST) && fdt_version(fdt) < 17)
32		return -FDT_ERR_BADVERSION;
33	if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry),
34				   fdt_size_dt_struct(fdt)))
35		return -FDT_ERR_BADLAYOUT;
36	if (!can_assume(LATEST) && fdt_version(fdt) > 17)
37		fdt_set_version(fdt, 17);
38
39	return 0;
40}
41
42#define FDT_RW_PROBE(fdt) \
43	{ \
44		int err_; \
45		if ((err_ = fdt_rw_probe_(fdt)) != 0) \
46			return err_; \
47	}
48
49static inline unsigned int fdt_data_size_(void *fdt)
50{
51	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
52}
53
54static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen)
55{
56	char *p = splicepoint;
57	unsigned int dsize = fdt_data_size_(fdt);
58	size_t soff = p - (char *)fdt;
59
60	if ((oldlen < 0) || (soff + oldlen < soff) || (soff + oldlen > dsize))
61		return -FDT_ERR_BADOFFSET;
62	if ((p < (char *)fdt) || (dsize + newlen < (unsigned)oldlen))
63		return -FDT_ERR_BADOFFSET;
64	if (dsize - oldlen + newlen > fdt_totalsize(fdt))
65		return -FDT_ERR_NOSPACE;
66	memmove(p + newlen, p + oldlen, ((char *)fdt + dsize) - (p + oldlen));
67	return 0;
68}
69
70static int fdt_splice_mem_rsv_(void *fdt, struct fdt_reserve_entry *p,
71			       int oldn, int newn)
72{
73	int delta = (newn - oldn) * sizeof(*p);
74	int err;
75	err = fdt_splice_(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
76	if (err)
77		return err;
78	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
79	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
80	return 0;
81}
82
83static int fdt_splice_struct_(void *fdt, void *p,
84			      int oldlen, int newlen)
85{
86	int delta = newlen - oldlen;
87	int err;
88
89	if ((err = fdt_splice_(fdt, p, oldlen, newlen)))
90		return err;
91
92	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
93	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
94	return 0;
95}
96
97/* Must only be used to roll back in case of error */
98static void fdt_del_last_string_(void *fdt, const char *s)
99{
100	int newlen = strlen(s) + 1;
101
102	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen);
103}
104
105static int fdt_splice_string_(void *fdt, int newlen)
106{
107	void *p = (char *)fdt
108		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
109	int err;
110
111	if ((err = fdt_splice_(fdt, p, 0, newlen)))
112		return err;
113
114	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
115	return 0;
116}
117
118/**
119 * fdt_find_add_string_() - Find or allocate a string
120 *
121 * @fdt: pointer to the device tree to check/adjust
122 * @s: string to find/add
123 * @allocated: Set to 0 if the string was found, 1 if not found and so
124 *	allocated. Ignored if can_assume(NO_ROLLBACK)
125 * @return offset of string in the string table (whether found or added)
126 */
127static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
128{
129	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
130	const char *p;
131	char *new;
132	int len = strlen(s) + 1;
133	int err;
134
135	if (!can_assume(NO_ROLLBACK))
136		*allocated = 0;
137
138	p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s);
139	if (p)
140		/* found it */
141		return (p - strtab);
142
143	new = strtab + fdt_size_dt_strings(fdt);
144	err = fdt_splice_string_(fdt, len);
145	if (err)
146		return err;
147
148	if (!can_assume(NO_ROLLBACK))
149		*allocated = 1;
150
151	memcpy(new, s, len);
152	return (new - strtab);
153}
154
155int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
156{
157	struct fdt_reserve_entry *re;
158	int err;
159
160	FDT_RW_PROBE(fdt);
161
162	re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt));
163	err = fdt_splice_mem_rsv_(fdt, re, 0, 1);
164	if (err)
165		return err;
166
167	re->address = cpu_to_fdt64(address);
168	re->size = cpu_to_fdt64(size);
169	return 0;
170}
171
172int fdt_del_mem_rsv(void *fdt, int n)
173{
174	struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n);
175
176	FDT_RW_PROBE(fdt);
177
178	if (n >= fdt_num_mem_rsv(fdt))
179		return -FDT_ERR_NOTFOUND;
180
181	return fdt_splice_mem_rsv_(fdt, re, 1, 0);
182}
183
184static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name,
185				int len, struct fdt_property **prop)
186{
187	int oldlen;
188	int err;
189
190	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
191	if (!*prop)
192		return oldlen;
193
194	if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
195				      FDT_TAGALIGN(len))))
196		return err;
197
198	(*prop)->len = cpu_to_fdt32(len);
199	return 0;
200}
201
202static int fdt_add_property_(void *fdt, int nodeoffset, const char *name,
203			     int len, struct fdt_property **prop)
204{
205	int proplen;
206	int nextoffset;
207	int namestroff;
208	int err;
209	int allocated;
210
211	if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
212		return nextoffset;
213
214	namestroff = fdt_find_add_string_(fdt, name, &allocated);
215	if (namestroff < 0)
216		return namestroff;
217
218	*prop = fdt_offset_ptr_w_(fdt, nextoffset);
219	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
220
221	err = fdt_splice_struct_(fdt, *prop, 0, proplen);
222	if (err) {
223		/* Delete the string if we failed to add it */
224		if (!can_assume(NO_ROLLBACK) && allocated)
225			fdt_del_last_string_(fdt, name);
226		return err;
227	}
228
229	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
230	(*prop)->nameoff = cpu_to_fdt32(namestroff);
231	(*prop)->len = cpu_to_fdt32(len);
232	return 0;
233}
234
235int fdt_set_name(void *fdt, int nodeoffset, const char *name)
236{
237	char *namep;
238	int oldlen, newlen;
239	int err;
240
241	FDT_RW_PROBE(fdt);
242
243	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
244	if (!namep)
245		return oldlen;
246
247	newlen = strlen(name);
248
249	err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1),
250				 FDT_TAGALIGN(newlen+1));
251	if (err)
252		return err;
253
254	memcpy(namep, name, newlen+1);
255	return 0;
256}
257
258int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
259			    int len, void **prop_data)
260{
261	struct fdt_property *prop;
262	int err;
263
264	FDT_RW_PROBE(fdt);
265
266	err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
267	if (err == -FDT_ERR_NOTFOUND)
268		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
269	if (err)
270		return err;
271
272	*prop_data = prop->data;
273	return 0;
274}
275
276int fdt_setprop(void *fdt, int nodeoffset, const char *name,
277		const void *val, int len)
278{
279	void *prop_data;
280	int err;
281
282	err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
283	if (err)
284		return err;
285
286	if (len)
287		memcpy(prop_data, val, len);
288	return 0;
289}
290
291int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
292		   const void *val, int len)
293{
294	struct fdt_property *prop;
295	int err, oldlen, newlen;
296
297	FDT_RW_PROBE(fdt);
298
299	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
300	if (prop) {
301		newlen = len + oldlen;
302		err = fdt_splice_struct_(fdt, prop->data,
303					 FDT_TAGALIGN(oldlen),
304					 FDT_TAGALIGN(newlen));
305		if (err)
306			return err;
307		prop->len = cpu_to_fdt32(newlen);
308		memcpy(prop->data + oldlen, val, len);
309	} else {
310		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
311		if (err)
312			return err;
313		memcpy(prop->data, val, len);
314	}
315	return 0;
316}
317
318int fdt_delprop(void *fdt, int nodeoffset, const char *name)
319{
320	struct fdt_property *prop;
321	int len, proplen;
322
323	FDT_RW_PROBE(fdt);
324
325	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
326	if (!prop)
327		return len;
328
329	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
330	return fdt_splice_struct_(fdt, prop, proplen, 0);
331}
332
333int fdt_add_subnode_namelen(void *fdt, int parentoffset,
334			    const char *name, int namelen)
335{
336	struct fdt_node_header *nh;
337	int offset, nextoffset;
338	int nodelen;
339	int err;
340	uint32_t tag;
341	fdt32_t *endtag;
342
343	FDT_RW_PROBE(fdt);
344
345	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
346	if (offset >= 0)
347		return -FDT_ERR_EXISTS;
348	else if (offset != -FDT_ERR_NOTFOUND)
349		return offset;
350
351	/* Try to place the new node after the parent's properties */
352	tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
353	/* the fdt_subnode_offset_namelen() should ensure this never hits */
354	if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE))
355		return -FDT_ERR_INTERNAL;
356	do {
357		offset = nextoffset;
358		tag = fdt_next_tag(fdt, offset, &nextoffset);
359	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
360
361	nh = fdt_offset_ptr_w_(fdt, offset);
362	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
363
364	err = fdt_splice_struct_(fdt, nh, 0, nodelen);
365	if (err)
366		return err;
367
368	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
369	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
370	memcpy(nh->name, name, namelen);
371	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
372	*endtag = cpu_to_fdt32(FDT_END_NODE);
373
374	return offset;
375}
376
377int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
378{
379	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
380}
381
382int fdt_del_node(void *fdt, int nodeoffset)
383{
384	int endoffset;
385
386	FDT_RW_PROBE(fdt);
387
388	endoffset = fdt_node_end_offset_(fdt, nodeoffset);
389	if (endoffset < 0)
390		return endoffset;
391
392	return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset),
393				  endoffset - nodeoffset, 0);
394}
395
396static void fdt_packblocks_(const char *old, char *new,
397			    int mem_rsv_size,
398			    int struct_size,
399			    int strings_size)
400{
401	int mem_rsv_off, struct_off, strings_off;
402
403	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
404	struct_off = mem_rsv_off + mem_rsv_size;
405	strings_off = struct_off + struct_size;
406
407	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
408	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
409
410	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
411	fdt_set_off_dt_struct(new, struct_off);
412	fdt_set_size_dt_struct(new, struct_size);
413
414	memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size);
415	fdt_set_off_dt_strings(new, strings_off);
416	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
417}
418
419int fdt_open_into(const void *fdt, void *buf, int bufsize)
420{
421	int err;
422	int mem_rsv_size, struct_size;
423	int newsize;
424	const char *fdtstart = fdt;
425	const char *fdtend = fdtstart + fdt_totalsize(fdt);
426	char *tmp;
427
428	FDT_RO_PROBE(fdt);
429
430	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
431		* sizeof(struct fdt_reserve_entry);
432
433	if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
434		struct_size = fdt_size_dt_struct(fdt);
435	} else if (fdt_version(fdt) == 16) {
436		struct_size = 0;
437		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
438			;
439		if (struct_size < 0)
440			return struct_size;
441	} else {
442		return -FDT_ERR_BADVERSION;
443	}
444
445	if (can_assume(LIBFDT_ORDER) ||
446	    !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) {
447		/* no further work necessary */
448		err = fdt_move(fdt, buf, bufsize);
449		if (err)
450			return err;
451		fdt_set_version(buf, 17);
452		fdt_set_size_dt_struct(buf, struct_size);
453		fdt_set_totalsize(buf, bufsize);
454		return 0;
455	}
456
457	/* Need to reorder */
458	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
459		+ struct_size + fdt_size_dt_strings(fdt);
460
461	if (bufsize < newsize)
462		return -FDT_ERR_NOSPACE;
463
464	/* First attempt to build converted tree at beginning of buffer */
465	tmp = buf;
466	/* But if that overlaps with the old tree... */
467	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
468		/* Try right after the old tree instead */
469		tmp = (char *)(uintptr_t)fdtend;
470		if ((tmp + newsize) > ((char *)buf + bufsize))
471			return -FDT_ERR_NOSPACE;
472	}
473
474	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size,
475			fdt_size_dt_strings(fdt));
476	memmove(buf, tmp, newsize);
477
478	fdt_set_magic(buf, FDT_MAGIC);
479	fdt_set_totalsize(buf, bufsize);
480	fdt_set_version(buf, 17);
481	fdt_set_last_comp_version(buf, 16);
482	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
483
484	return 0;
485}
486
487int fdt_pack(void *fdt)
488{
489	int mem_rsv_size;
490
491	FDT_RW_PROBE(fdt);
492
493	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
494		* sizeof(struct fdt_reserve_entry);
495	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt),
496			fdt_size_dt_strings(fdt));
497	fdt_set_totalsize(fdt, fdt_data_size_(fdt));
498
499	return 0;
500}
501