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