libfdt: Add fdt_path_offset_namelen()
Properties may contain path names which are not NUL-terminated.
For example, the 'stdout-path' property allows the form 'path:options',
where the ':' character terminates the path specifier.
Allow these path names to be used in-place for path descending;
add fdt_path_offset_namelen(), which limits the path name to 'namelen'
characters.
Reimplement fdt_path_offset() as a trivial wrapper.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 50007f6..a65e4b5 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -154,9 +154,9 @@
return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name));
}
-int fdt_path_offset(const void *fdt, const char *path)
+int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
{
- const char *end = path + strlen(path);
+ const char *end = path + namelen;
const char *p = path;
int offset = 0;
@@ -164,7 +164,7 @@
/* see if we have an alias */
if (*path != '/') {
- const char *q = strchr(path, '/');
+ const char *q = memchr(path, '/', end - p);
if (!q)
q = end;
@@ -177,14 +177,15 @@
p = q;
}
- while (*p) {
+ while (p < end) {
const char *q;
- while (*p == '/')
+ while (*p == '/') {
p++;
- if (! *p)
- return offset;
- q = strchr(p, '/');
+ if (p == end)
+ return offset;
+ }
+ q = memchr(p, '/', end - p);
if (! q)
q = end;
@@ -198,6 +199,11 @@
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);
diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
index 32d5227..1054512 100644
--- a/libfdt/libfdt.h
+++ b/libfdt/libfdt.h
@@ -323,6 +323,17 @@
int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
/**
+ * fdt_path_offset_namelen - find a tree node by its full path
+ * @fdt: pointer to the device tree blob
+ * @path: full path of the node to locate
+ * @namelen: number of characters of path to consider
+ *
+ * Identical to fdt_path_offset(), but only consider the first namelen
+ * characters of path as the path name.
+ */
+int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
+
+/**
* fdt_path_offset - find a tree node by its full path
* @fdt: pointer to the device tree blob
* @path: full path of the node to locate
diff --git a/libfdt/version.lds b/libfdt/version.lds
index 941208e..f19f157 100644
--- a/libfdt/version.lds
+++ b/libfdt/version.lds
@@ -8,6 +8,7 @@
fdt_get_mem_rsv;
fdt_subnode_offset_namelen;
fdt_subnode_offset;
+ fdt_path_offset_namelen;
fdt_path_offset;
fdt_get_name;
fdt_get_property_namelen;
