commit 985ad14555769dd80abad766dffad4ecfd5fb04f
author Paul Crowley <paulcrowley@google.com> Sun Mar 22 08:10:58 2020 -0700
committer Paul Crowley <paulcrowley@google.com> Tue Apr 07 07:33:05 2020 -0700
tree 5b8f4c04595ae0d98a55139b8c61c7b6fdbb3ae5
parent 60ba46a93e70b82ec7ce8f9506480fc67e11a1d7

Abolish DmTargetDefaultKey::IsLegacy

To make it easier to support disk formats created using old versions
of dm-default-key with new kernels, stop checking the kernel module
version; instead, the caller decides whether to use the old or new
options format.

Bug: 150761030
Test: crosshatch and cuttlefish boot normally; cuttlefish
    fails with "default-key: Not enough arguments" as expected when
    option is set to 1
Cherry-Picked-From: 539b98fb58cd0efa278336139d8f4ba963dad285
Merged-In: I810bb7e085b9b8648858de1a02165162d1fd163e
Change-Id: I810bb7e085b9b8648858de1a02165162d1fd163e

fs_mgr/libdm/dm_target.cpp

diff --git a/fs_mgr/libdm/dm_target.cpp b/fs_mgr/libdm/dm_target.cpp
index 29b1032..a594198 100644
--- a/fs_mgr/libdm/dm_target.cpp
+++ b/fs_mgr/libdm/dm_target.cpp
@@ -243,20 +243,8 @@
     return android::base::Join(argv, " ");
 }
 
-bool DmTargetDefaultKey::IsLegacy(bool* result) {
-    DeviceMapper& dm = DeviceMapper::Instance();
-    DmTargetTypeInfo info;
-    if (!dm.GetTargetByName(kName, &info)) return false;
-    // dm-default-key was modified to be like dm-crypt with version 2
-    *result = !info.IsAtLeast(2, 0, 0);
-    return true;
-}
-
 bool DmTargetDefaultKey::Valid() const {
-    bool real_is_legacy;
-    if (!DmTargetDefaultKey::IsLegacy(&real_is_legacy)) return false;
-    if (real_is_legacy != is_legacy_) return false;
-    if (!is_legacy_ && !set_dun_) return false;
+    if (!use_legacy_options_format_ && !set_dun_) return false;
     return true;
 }
 
@@ -264,13 +252,13 @@
     std::vector<std::string> argv;
     argv.emplace_back(cipher_);
     argv.emplace_back(key_);
-    if (!is_legacy_) {
+    if (!use_legacy_options_format_) {
         argv.emplace_back("0");  // iv_offset
     }
     argv.emplace_back(blockdev_);
     argv.push_back(std::to_string(start_sector_));
     std::vector<std::string> extra_argv;
-    if (is_legacy_) {
+    if (use_legacy_options_format_) {
         if (set_dun_) {  // v2 always sets the DUN.
             extra_argv.emplace_back("set_dun");
         }

fs_mgr/libdm/dm_test.cpp

diff --git a/fs_mgr/libdm/dm_test.cpp b/fs_mgr/libdm/dm_test.cpp
index 67af59a..41d3145 100644
--- a/fs_mgr/libdm/dm_test.cpp
+++ b/fs_mgr/libdm/dm_test.cpp
@@ -516,32 +516,22 @@
 }
 
 TEST(libdm, DefaultKeyArgs) {
-    DmTargetTypeInfo info;
-
-    DeviceMapper& dm = DeviceMapper::Instance();
-    if (!dm.GetTargetByName("default-key", &info)) {
-        cout << "default-key module not enabled; skipping test" << std::endl;
-        return;
-    }
-    bool is_legacy;
-    ASSERT_TRUE(DmTargetDefaultKey::IsLegacy(&is_legacy));
-    // set_dun only in the non-is_legacy case
-    DmTargetDefaultKey target(0, 4096, "AES-256-XTS", "abcdef0123456789", "/dev/loop0", 0);
-    if (is_legacy) {
-        target.SetIsLegacy();
-    } else {
-        target.SetSetDun();
-    }
+    DmTargetDefaultKey target(0, 4096, "aes-xts-plain64", "abcdef0123456789", "/dev/loop0", 0);
+    target.SetSetDun();
     ASSERT_EQ(target.name(), "default-key");
     ASSERT_TRUE(target.Valid());
-    if (is_legacy) {
-        ASSERT_EQ(target.GetParameterString(), "AES-256-XTS abcdef0123456789 /dev/loop0 0");
-    } else {
-        // TODO: Add case for wrapped key enabled
-        ASSERT_EQ(target.GetParameterString(),
-                  "AES-256-XTS abcdef0123456789 0 /dev/loop0 0 3 allow_discards sector_size:4096 "
-                  "iv_large_sectors");
-    }
+    // TODO: Add case for wrapped key enabled
+    ASSERT_EQ(target.GetParameterString(),
+              "aes-xts-plain64 abcdef0123456789 0 /dev/loop0 0 3 allow_discards sector_size:4096 "
+              "iv_large_sectors");
+}
+
+TEST(libdm, DefaultKeyLegacyArgs) {
+    DmTargetDefaultKey target(0, 4096, "AES-256-XTS", "abcdef0123456789", "/dev/loop0", 0);
+    target.SetUseLegacyOptionsFormat();
+    ASSERT_EQ(target.name(), "default-key");
+    ASSERT_TRUE(target.Valid());
+    ASSERT_EQ(target.GetParameterString(), "AES-256-XTS abcdef0123456789 /dev/loop0 0");
 }
 
 TEST(libdm, DeleteDeviceWithTimeout) {

fs_mgr/libdm/include/libdm/dm_target.h

diff --git a/fs_mgr/libdm/include/libdm/dm_target.h b/fs_mgr/libdm/include/libdm/dm_target.h
index 050d0b6..57096ce 100644
--- a/fs_mgr/libdm/include/libdm/dm_target.h
+++ b/fs_mgr/libdm/include/libdm/dm_target.h
@@ -290,8 +290,7 @@
     std::string name() const override { return kName; }
     bool Valid() const override;
     std::string GetParameterString() const override;
-    static bool IsLegacy(bool* result);
-    void SetIsLegacy() { is_legacy_ = true; }
+    void SetUseLegacyOptionsFormat() { use_legacy_options_format_ = true; }
     void SetSetDun() { set_dun_ = true; }
     void SetWrappedKeyV0() { is_hw_wrapped_ = true; }
 
@@ -302,7 +301,7 @@
     std::string key_;
     std::string blockdev_;
     uint64_t start_sector_;
-    bool is_legacy_ = false;
+    bool use_legacy_options_format_ = false;
     bool set_dun_ = false;
     bool is_hw_wrapped_ = false;
 };