1 files changed, 89 insertions, 0 deletions
diff --git a/src/vendorcode/google/chromeos/vpd_decode.c b/src/vendorcode/google/chromeos/vpd_decode.c
new file mode 100644
index 0000000000..545fd8106f
--- /dev/null
+++ b/src/vendorcode/google/chromeos/vpd_decode.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+#include <assert.h>
+#include "lib_vpd.h"
+
+int decodeLen(
+    const int32_t max_len,
+    const uint8_t *in,
+    int32_t *length,
+    int32_t *decoded_len) {
+  uint8_t more;
+  int i = 0;
+
+  assert(length);
+  assert(decoded_len);
+
+  *length = 0;
+  do {
+    if (i >= max_len) return VPD_FAIL;
+    more = in[i] & 0x80;
+    *length <<= 7;
+    *length |= in[i] & 0x7f;
+    ++i;
+  } while (more);
+
+  *decoded_len = i;
+
+  return VPD_OK;
+}
+
+/* Sequentially decodes type, key, and value.
+ */
+int decodeVpdString(
+    const int32_t max_len,
+    const uint8_t *input_buf,
+    int32_t *consumed,
+    VpdDecodeCallback callback,
+    void *callback_arg) {
+  int type;
+  int32_t key_len, value_len;
+  int32_t decoded_len;
+  const uint8_t *key, *value;
+
+  /* type */
+  if (*consumed >= max_len)
+    return VPD_FAIL;
+
+  type = input_buf[*consumed];
+  switch (type) {
+    case VPD_TYPE_INFO:
+    case VPD_TYPE_STRING:
+      (*consumed)++;
+
+      /* key */
+      if (VPD_OK != decodeLen(max_len - *consumed, &input_buf[*consumed],
+                              &key_len, &decoded_len) ||
+          *consumed + decoded_len >= max_len) {
+        return VPD_FAIL;
+      }
+
+      *consumed += decoded_len;
+      key = &input_buf[*consumed];
+      *consumed += key_len;
+
+      /* value */
+      if (VPD_OK != decodeLen(max_len - *consumed, &input_buf[*consumed],
+                              &value_len, &decoded_len) ||
+          *consumed + decoded_len > max_len) {
+        return VPD_FAIL;
+      }
+      *consumed += decoded_len;
+      value = &input_buf[*consumed];
+      *consumed += value_len;
+
+      if (type == VPD_TYPE_STRING)
+        return callback(key, key_len, value, value_len, callback_arg);
+
+      return VPD_OK;
+
+    default:
+      return VPD_FAIL;
+      break;
+  }
+  return VPD_OK;
+}