[Qemu-devel] [PATCH 1/6] device_tree.c: Introduce a function to check multiple strings for dts

["john.liuli" <john.liuli@huawei.com>]

From: Li Liu <john.liuli@huawei.com>

dts property's value can be multiple strings. So introduce a function
to check a data with a given length to see if it is all printable and
has a valid terminator. It can contain either a single string, or
multiple strings each of non-zero length.

Signed-off-by: Li Liu <john.liuli@huawei.com>
---
 device_tree.c |   32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/device_tree.c b/device_tree.c
index ca83504..29d9acc 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -345,3 +345,35 @@ int qemu_fdt_setprop_sized_cells_from_array(void *fdt,
     return qemu_fdt_setprop(fdt, node_path, property, propcells,
                             cellnum * sizeof(uint32_t));
 }
+
+/*
+ * Check a data of a given length to see if it is all printable and
+ * has a valid terminator. The data can contain either a single string,
+ * or multiple strings each of non-zero length.
+ */
+static int dts_is_printable_strings(const void *data, int len)
+{
+    const char *str = (char *)data;
+    int substrs = 0;
+    int substr_len = 0;
+    int i;
+
+    for (i = 0; i < len; i++) {
+        if (str[i] == '\0') {
+            if (substr_len) {
+                substr_len = 0;
+                substrs++;
+                continue;
+            } else {
+                /* substr is empty */
+                return 0;
+            }
+        } else if (isprint(str[i])) {
+            substr_len++;
+        } else {
+            return 0;
+        }
+    }
+
+    return substrs && !substr_len;
+}
-- 
1.7.9.5