blob: a62ec781bf20b00c30f5c84fddccae3d111c67c5 [file] [log] [blame]
// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
/*
* libfdt - Flat Device Tree manipulation
* Copyright (C) 2006 David Gibson, IBM Corporation.
*/
#include "libfdt_env.h"
#include <fdt.h>
#include <libfdt.h>
#include "libfdt_internal.h"
/* Check if a buffer contains a nul-terminated string.
* Used for checking property values which should be strings.
*/
static bool is_nul_string(const char *buf, const size_t buf_len) {
return buf_len > 0 && buf[buf_len - 1] == '\0' &&
strnlen(buf, buf_len) == buf_len - 1;
}
static int fdt_nodename_eq_(const void *fdt, int offset,
const char *s, int len)
{
int olen;
const char *p = fdt_get_name(fdt, offset, &olen);
if (!p || olen < len)
/* short match */
return 0;
if (memcmp(p, s, len) != 0)
return 0;
if (p[len] == '\0')
return 1;
else if (!memchr(s, '@', len) && (p[len] == '@'))
return 1;
else
return 0;
}
const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
{
int32_t totalsize;
uint32_t absoffset;
size_t len;
int err;
const char *s, *n;
if (can_assume(VALID_INPUT)) {
s = (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
if (lenp)
*lenp = strlen(s);
return s;
}
totalsize = fdt_ro_probe_(fdt);
err = totalsize;
if (totalsize < 0)
goto fail;
err = -FDT_ERR_BADOFFSET;
absoffset = stroffset + fdt_off_dt_strings(fdt);
if (absoffset >= (unsigned)totalsize)
goto fail;
len = totalsize - absoffset;
if (fdt_magic(fdt) == FDT_MAGIC) {
if (stroffset < 0)
goto fail;
if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
if ((unsigned)stroffset >= fdt_size_dt_strings(fdt))
goto fail;
if ((fdt_size_dt_strings(fdt) - stroffset) < len)
len = fdt_size_dt_strings(fdt) - stroffset;
}
} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
unsigned int sw_stroffset = -stroffset;
if ((stroffset >= 0) ||
(sw_stroffset > fdt_size_dt_strings(fdt)))
goto fail;
if (sw_stroffset < len)
len = sw_stroffset;
} else {
err = -FDT_ERR_INTERNAL;
goto fail;
}
s = (const char *)fdt + absoffset;
n = memchr(s, '\0', len);
if (!n) {
/* missing terminating NULL */
err = -FDT_ERR_TRUNCATED;
goto fail;
}
if (lenp)
*lenp = n - s;
return s;
fail:
if (lenp)
*lenp = err;
return NULL;
}
const char *fdt_string(const void *fdt, int stroffset)
{
return fdt_get_string(fdt, stroffset, NULL);
}
static int fdt_string_eq_(const void *fdt, int stroffset,
const char *s, int len)
{
int slen;
const char *p = fdt_get_string(fdt, stroffset, &slen);
return p && (slen == len) && (memcmp(p, s, len) == 0);
}
int fdt_find_max_phandle(const void *fdt, uint32_t *phandle)
{
uint32_t max = 0;
int offset = -1;
while (true) {
uint32_t value;
offset = fdt_next_node(fdt, offset, NULL);
if (offset < 0) {
if (offset == -FDT_ERR_NOTFOUND)
break;
return offset;
}
value = fdt_get_phandle(fdt, offset);
if (value > max)
max = value;
}
if (phandle)
*phandle = max;
return 0;
}
int fdt_generate_phandle(const void *fdt, uint32_t *phandle)
{
uint32_t max;
int err;
err = fdt_find_max_phandle(fdt, &max);
if (err < 0)
return err;
if (max == FDT_MAX_PHANDLE)
return -FDT_ERR_NOPHANDLES;
if (phandle)
*phandle = max + 1;
return 0;
}
static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
{
unsigned int offset = n * sizeof(struct fdt_reserve_entry);
unsigned int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
if (!can_assume(VALID_INPUT)) {
if (absoffset < fdt_off_mem_rsvmap(fdt))
return NULL;
if (absoffset > fdt_totalsize(fdt) -
sizeof(struct fdt_reserve_entry))
return NULL;
}
return fdt_mem_rsv_(fdt, n);
}
int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
const struct fdt_reserve_entry *re;
FDT_RO_PROBE(fdt);
re = fdt_mem_rsv(fdt, n);
if (!can_assume(VALID_INPUT) && !re)
return -FDT_ERR_BADOFFSET;
*address = fdt64_ld_(&re->address);
*size = fdt64_ld_(&re->size);
return 0;
}
int fdt_num_mem_rsv(const void *fdt)
{
int i;
const struct fdt_reserve_entry *re;
for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
if (fdt64_ld_(&re->size) == 0)
return i;
}
return -FDT_ERR_TRUNCATED;
}
static int nextprop_(const void *fdt, int offset)
{
uint32_t tag;
int nextoffset;
do {
tag = fdt_next_tag(fdt, offset, &nextoffset);
switch (tag) {
case FDT_END:
if (nextoffset >= 0)
return -FDT_ERR_BADSTRUCTURE;
else
return nextoffset;
case FDT_PROP:
return offset;
}
offset = nextoffset;
} while (tag == FDT_NOP);
return -FDT_ERR_NOTFOUND;
}
int fdt_subnode_offset_namelen(const void *fdt, int offset,
const char *name, int namelen)
{
int depth;
FDT_RO_PROBE(fdt);
for (depth = 0;
(offset >= 0) && (depth >= 0);
offset = fdt_next_node(fdt, offset, &depth))
if ((depth == 1)
&& fdt_nodename_eq_(fdt, offset, name, namelen))
return offset;
if (depth < 0)
return -FDT_ERR_NOTFOUND;
return offset; /* error */
}
int fdt_subnode_offset(const void *fdt, int parentoffset,
const char *name)
{
return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
}
int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
{
const char *end = path + namelen;
const char *p = path;
int offset = 0;
FDT_RO_PROBE(fdt);
if (namelen < 1)
return -FDT_ERR_BADPATH;
if (namelen < 1)
return -FDT_ERR_BADPATH;
/* see if we have an alias */
if (*path != '/') {
const char *q = memchr(path, '/', end - p);
if (!q)
q = end;
p = fdt_get_alias_namelen(fdt, p, q - p);
if (!p)
return -FDT_ERR_BADPATH;
offset = fdt_path_offset(fdt, p);
p = q;
}
while (p < end) {
const char *q;
while (*p == '/') {
p++;
if (p == end)
return offset;
}
q = memchr(p, '/', end - p);
if (! q)
q = end;
offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
if (offset < 0)
return offset;
p = q;
}
return offset;
}
int fdt_path_offset(const void *fdt, const char *path)
{
return fdt_path_offset_namelen(fdt, path, strlen(path));
}
const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
{
const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset);
const char *nameptr;
int err;
if (((err = fdt_ro_probe_(fdt)) < 0)
|| ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
goto fail;
nameptr = nh->name;
if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
/*
* For old FDT versions, match the naming conventions of V16:
* give only the leaf name (after all /). The actual tree
* contents are loosely checked.
*/
const char *leaf;
leaf = strrchr(nameptr, '/');
if (leaf == NULL) {
err = -FDT_ERR_BADSTRUCTURE;
goto fail;
}
nameptr = leaf+1;
}
if (len)
*len = strlen(nameptr);
return nameptr;
fail:
if (len)
*len = err;
return NULL;
}
int fdt_first_property_offset(const void *fdt, int nodeoffset)
{
int offset;
if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
return offset;
return nextprop_(fdt, offset);
}
int fdt_next_property_offset(const void *fdt, int offset)
{
if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0)
return offset;
return nextprop_(fdt, offset);
}
static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
int offset,
int *lenp)
{
int err;
const struct fdt_property *prop;
if (!can_assume(VALID_INPUT) &&
(err = fdt_check_prop_offset_(fdt, offset)) < 0) {
if (lenp)
*lenp = err;
return NULL;
}
prop = fdt_offset_ptr_(fdt, offset);
if (lenp)
*lenp = fdt32_ld_(&prop->len);
return prop;
}
const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
int offset,
int *lenp)
{
/* Prior to version 16, properties may need realignment
* and this API does not work. fdt_getprop_*() will, however. */
if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
if (lenp)
*lenp = -FDT_ERR_BADVERSION;
return NULL;
}
return fdt_get_property_by_offset_(fdt, offset, lenp);
}
static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
int offset,
const char *name,
int namelen,
int *lenp,
int *poffset)
{
for (offset = fdt_first_property_offset(fdt, offset);
(offset >= 0);
(offset = fdt_next_property_offset(fdt, offset))) {
const struct fdt_property *prop;
prop = fdt_get_property_by_offset_(fdt, offset, lenp);
if (!can_assume(LIBFDT_FLAWLESS) && !prop) {
offset = -FDT_ERR_INTERNAL;
break;
}
if (fdt_string_eq_(fdt, fdt32_ld_(&prop->nameoff),
name, namelen)) {
if (poffset)
*poffset = offset;
return prop;
}
}
if (lenp)
*lenp = offset;
return NULL;
}
const struct fdt_property *fdt_get_property_namelen(const void *fdt,
int offset,
const char *name,
int namelen, int *lenp)
{
/* Prior to version 16, properties may need realignment
* and this API does not work. fdt_getprop_*() will, however. */
if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) {
if (lenp)
*lenp = -FDT_ERR_BADVERSION;
return NULL;
}
return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp,
NULL);
}
const struct fdt_property *fdt_get_property(const void *fdt,
int nodeoffset,
const char *name, int *lenp)
{
return fdt_get_property_namelen(fdt, nodeoffset, name,
strlen(name), lenp);
}
const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
const char *name, int namelen, int *lenp)
{
int poffset;
const struct fdt_property *prop;
prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp,
&poffset);
if (!prop)
return NULL;
/* Handle realignment */
if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
(poffset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
return prop->data + 4;
return prop->data;
}
const void *fdt_getprop_by_offset(const void *fdt, int offset,
const char **namep, int *lenp)
{
const struct fdt_property *prop;
prop = fdt_get_property_by_offset_(fdt, offset, lenp);
if (!prop)
return NULL;
if (namep) {
const char *name;
int namelen;
if (!can_assume(VALID_INPUT)) {
name = fdt_get_string(fdt, fdt32_ld_(&prop->nameoff),
&namelen);
*namep = name;
if (!name) {
if (lenp)
*lenp = namelen;
return NULL;
}
} else {
*namep = fdt_string(fdt, fdt32_ld_(&prop->nameoff));
}
}
/* Handle realignment */
if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 &&
(offset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8)
return prop->data + 4;
return prop->data;
}
const void *fdt_getprop(const void *fdt, int nodeoffset,
const char *name, int *lenp)
{
return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
}
uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
{
const fdt32_t *php;
int len;
/* FIXME: This is a bit sub-optimal, since we potentially scan
* over all the properties twice. */
php = fdt_getprop(fdt, nodeoffset, "phandle", &len);
if (!php || (len != sizeof(*php))) {
php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len);
if (!php || (len != sizeof(*php)))
return 0;
}
return fdt32_ld_(php);
}
const char *fdt_get_alias_namelen(const void *fdt,
const char *name, int namelen)
{
const char *prop;
int aliasoffset;
int prop_len;
aliasoffset = fdt_path_offset(fdt, "/aliases");
if (aliasoffset < 0)
return NULL;
prop = fdt_getprop_namelen(fdt, aliasoffset, name, namelen, &prop_len);
if (prop && !can_assume(VALID_INPUT)) {
/* Validate the alias value. From the devicetree spec v0.3:
* "An alias value is a device path and is encoded as a string.
* The value representes the full path to a node, ..."
* A full path must start at the root to prevent recursion.
*/
if (prop_len == 0 || *prop != '/' || !is_nul_string(prop, prop_len)) {
prop = NULL;
}
}
return prop;
}
const char *fdt_get_alias(const void *fdt, const char *name)
{
return fdt_get_alias_namelen(fdt, name, strlen(name));
}
int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
{
int pdepth = 0, p = 0;
int offset, depth, namelen;
const char *name;
FDT_RO_PROBE(fdt);
if (buflen < 2)
return -FDT_ERR_NOSPACE;
for (offset = 0, depth = 0;
(offset >= 0) && (offset <= nodeoffset);
offset = fdt_next_node(fdt, offset, &depth)) {
while (pdepth > depth) {
do {
p--;
} while (buf[p-1] != '/');
pdepth--;
}
if (pdepth >= depth) {
name = fdt_get_name(fdt, offset, &namelen);
if (!name)
return namelen;
if ((p + namelen + 1) <= buflen) {
memcpy(buf + p, name, namelen);
p += namelen;
buf[p++] = '/';
pdepth++;
}
}
if (offset == nodeoffset) {
if (pdepth < (depth + 1))
return -FDT_ERR_NOSPACE;
if (p > 1) /* special case so that root path is "/", not "" */
p--;
buf[p] = '\0';
return 0;
}
}
if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
return -FDT_ERR_BADOFFSET;
else if (offset == -FDT_ERR_BADOFFSET)
return -FDT_ERR_BADSTRUCTURE;
return offset; /* error from fdt_next_node() */
}
int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
int supernodedepth, int *nodedepth)
{
int offset, depth;
int supernodeoffset = -FDT_ERR_INTERNAL;
FDT_RO_PROBE(fdt);
if (supernodedepth < 0)
return -FDT_ERR_NOTFOUND;
for (offset = 0, depth = 0;
(offset >= 0) && (offset <= nodeoffset);
offset = fdt_next_node(fdt, offset, &depth)) {
if (depth == supernodedepth)
supernodeoffset = offset;
if (offset == nodeoffset) {
if (nodedepth)
*nodedepth = depth;
if (supernodedepth > depth)
return -FDT_ERR_NOTFOUND;
else
return supernodeoffset;
}
}
if (!can_assume(VALID_INPUT)) {
if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0))
return -FDT_ERR_BADOFFSET;
else if (offset == -FDT_ERR_BADOFFSET)
return -FDT_ERR_BADSTRUCTURE;
}
return offset; /* error from fdt_next_node() */
}
int fdt_node_depth(const void *fdt, int nodeoffset)
{
int nodedepth;
int err;
err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth);
if (err)
return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err :
-FDT_ERR_INTERNAL;
return nodedepth;
}
int fdt_parent_offset(const void *fdt, int nodeoffset)
{
int nodedepth = fdt_node_depth(fdt, nodeoffset);
if (nodedepth < 0)
return nodedepth;
return fdt_supernode_atdepth_offset(fdt, nodeoffset,
nodedepth - 1, NULL);
}
int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
const char *propname,
const void *propval, int proplen)
{
int offset;
const void *val;
int len;
FDT_RO_PROBE(fdt);
/* FIXME: The algorithm here is pretty horrible: we scan each
* property of a node in fdt_getprop(), then if that didn't
* find what we want, we scan over them again making our way
* to the next node. Still it's the easiest to implement
* approach; performance can come later. */
for (offset = fdt_next_node(fdt, startoffset, NULL);
offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
val = fdt_getprop(fdt, offset, propname, &len);
if (val && (len == proplen)
&& (memcmp(val, propval, len) == 0))
return offset;
}
return offset; /* error from fdt_next_node() */
}
int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
{
int offset;
if ((phandle == 0) || (phandle == ~0U))
return -FDT_ERR_BADPHANDLE;
FDT_RO_PROBE(fdt);
/* FIXME: The algorithm here is pretty horrible: we
* potentially scan each property of a node in
* fdt_get_phandle(), then if that didn't find what
* we want, we scan over them again making our way to the next
* node. Still it's the easiest to implement approach;
* performance can come later. */
for (offset = fdt_next_node(fdt, -1, NULL);
offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
if (fdt_get_phandle(fdt, offset) == phandle)
return offset;
}
return offset; /* error from fdt_next_node() */
}
int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
{
int len = strlen(str);
const char *p;
while (listlen >= len) {
if (memcmp(str, strlist, len+1) == 0)
return 1;
p = memchr(strlist, '\0', listlen);
if (!p)
return 0; /* malformed strlist.. */
listlen -= (p-strlist) + 1;
strlist = p + 1;
}
return 0;
}
int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
{
const char *list, *end;
int length, count = 0;
list = fdt_getprop(fdt, nodeoffset, property, &length);
if (!list)
return length;
end = list + length;
while (list < end) {
length = strnlen(list, end - list) + 1;
/* Abort if the last string isn't properly NUL-terminated. */
if (list + length > end)
return -FDT_ERR_BADVALUE;
list += length;
count++;
}
return count;
}
int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
const char *string)
{
int length, len, idx = 0;
const char *list, *end;
list = fdt_getprop(fdt, nodeoffset, property, &length);
if (!list)
return length;
len = strlen(string) + 1;
end = list + length;
while (list < end) {
length = strnlen(list, end - list) + 1;
/* Abort if the last string isn't properly NUL-terminated. */
if (list + length > end)
return -FDT_ERR_BADVALUE;
if (length == len && memcmp(list, string, length) == 0)
return idx;
list += length;
idx++;
}
return -FDT_ERR_NOTFOUND;
}
const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
const char *property, int idx,
int *lenp)
{
const char *list, *end;
int length;
list = fdt_getprop(fdt, nodeoffset, property, &length);
if (!list) {
if (lenp)
*lenp = length;
return NULL;
}
end = list + length;
while (list < end) {
length = strnlen(list, end - list) + 1;
/* Abort if the last string isn't properly NUL-terminated. */
if (list + length > end) {
if (lenp)
*lenp = -FDT_ERR_BADVALUE;
return NULL;
}
if (idx == 0) {
if (lenp)
*lenp = length - 1;
return list;
}
list += length;
idx--;
}
if (lenp)
*lenp = -FDT_ERR_NOTFOUND;
return NULL;
}
int fdt_node_check_compatible(const void *fdt, int nodeoffset,
const char *compatible)
{
const void *prop;
int len;
prop = fdt_getprop(fdt, nodeoffset, "compatible", &len);
if (!prop)
return len;
return !fdt_stringlist_contains(prop, len, compatible);
}
int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
const char *compatible)
{
int offset, err;
FDT_RO_PROBE(fdt);
/* FIXME: The algorithm here is pretty horrible: we scan each
* property of a node in fdt_node_check_compatible(), then if
* that didn't find what we want, we scan over them again
* making our way to the next node. Still it's the easiest to
* implement approach; performance can come later. */
for (offset = fdt_next_node(fdt, startoffset, NULL);
offset >= 0;
offset = fdt_next_node(fdt, offset, NULL)) {
err = fdt_node_check_compatible(fdt, offset, compatible);
if ((err < 0) && (err != -FDT_ERR_NOTFOUND))
return err;
else if (err == 0)
return offset;
}
return offset; /* error from fdt_next_node() */
}