1 files changed, 49 insertions, 0 deletions
diff --git a/src/librbd/crypto/CryptoImageDispatch.cc b/src/librbd/crypto/CryptoImageDispatch.cc
new file mode 100644
index 000000000..4d4c360dc
--- /dev/null
+++ b/src/librbd/crypto/CryptoImageDispatch.cc
@@ -0,0 +1,49 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "librbd/crypto/CryptoImageDispatch.h"
+
+namespace librbd {
+namespace crypto {
+
+CryptoImageDispatch::CryptoImageDispatch(
+        uint64_t data_offset) : m_data_offset(data_offset) {
+}
+
+void CryptoImageDispatch::remap_to_physical(io::Extents& image_extents,
+                                            io::ImageArea area) {
+  switch (area) {
+  case io::ImageArea::DATA:
+    for (auto& [off, _] : image_extents) {
+      off += m_data_offset;
+    }
+    break;
+  case io::ImageArea::CRYPTO_HEADER:
+    // direct mapping
+    break;
+  default:
+    ceph_abort();
+  }
+}
+
+io::ImageArea CryptoImageDispatch::remap_to_logical(
+    io::Extents& image_extents) {
+  bool saw_data = false;
+  bool saw_crypto_header = false;
+  for (auto& [off, _] : image_extents) {
+    if (off >= m_data_offset) {
+      off -= m_data_offset;
+      saw_data = true;
+    } else {
+      saw_crypto_header = true;
+    }
+  }
+  if (saw_crypto_header) {
+    ceph_assert(!saw_data);
+    return io::ImageArea::CRYPTO_HEADER;
+  }
+  return io::ImageArea::DATA;
+}
+
+} // namespace crypto
+} // namespace librbd