Adopted Storage support

 -Detects, decrypts, and mounts an adopted SD card if a
  secondary block device is defined (usually mmcblk1)
 -Handles unified storage
 -Displays the adopted storage in MTP along with internal
 -Factory Reset - wiped just like a data media device, we
  retain the keys folder and the storage.xml during a
  factory reset
 -Backup / Restore
 -Disable mass storage when adopted storage is present
 -Read storage nickname from storage.xml and apply it to
  display names in the GUI
 -Read storage.xml and determine what storage location is in
  use for /sdcard and remap accordingly

libgpt_twrp is source code mostly kanged from an efimanager
project. It is GPL v2 or higher, so we will opt for GPL v3.

Change-Id: Ieda0030bec5155ba8d2b9167dc0016cebbf39d55

Android.mk

@@ -284,7 +284,7 @@ ifeq ($(TW_INCLUDE_L_CRYPTO), true)
 endif
 ifeq ($(TW_INCLUDE_CRYPTO), true)
     LOCAL_CFLAGS += -DTW_INCLUDE_CRYPTO
-    LOCAL_SHARED_LIBRARIES += libcryptfslollipop
+    LOCAL_SHARED_LIBRARIES += libcryptfslollipop libgpt_twrp
     LOCAL_C_INCLUDES += external/boringssl/src/include
 endif
 ifeq ($(TW_USE_MODEL_HARDWARE_ID_FOR_DEVICE_ID), true)
@@ -592,6 +592,7 @@ include $(commands_recovery_local_path)/injecttwrp/Android.mk \
 ifeq ($(TW_INCLUDE_CRYPTO), true)
     include $(commands_recovery_local_path)/crypto/lollipop/Android.mk
     include $(commands_recovery_local_path)/crypto/scrypt/Android.mk
+    include $(commands_recovery_local_path)/gpt/Android.mk
 endif
 ifeq ($(BUILD_ID), GINGERBREAD)
     TW_NO_EXFAT := true

crypto/lollipop/cryptfs.c

@@ -1060,6 +1060,7 @@ static int load_crypto_mapping_table(struct crypt_mnt_ftr *crypt_ftr, unsigned c
     if (! ioctl(fd, DM_TABLE_LOAD, io)) {
       break;
     }
+    printf("%i\n", errno);
     usleep(500000);
   }
 
@@ -1145,7 +1146,7 @@ static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char
 
   ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
   if (ioctl(fd, DM_DEV_CREATE, io)) {
-    printf("Cannot create dm-crypt device\n");
+    printf("Cannot create dm-crypt device %i\n", errno);
     goto errout;
   }
 
@@ -2017,3 +2018,45 @@ int cryptfs_get_password_type(void)
 
     return crypt_ftr.crypt_type;
 }
+
+/*
+ * Called by vold when it's asked to mount an encrypted external
+ * storage volume. The incoming partition has no crypto header/footer,
+ * as any metadata is been stored in a separate, small partition.
+ *
+ * out_crypto_blkdev must be MAXPATHLEN.
+ */
+int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev,
+        const unsigned char* key, int keysize, char* out_crypto_blkdev) {
+    int fd = open(real_blkdev, O_RDONLY|O_CLOEXEC);
+    if (fd == -1) {
+        printf("Failed to open %s: %s", real_blkdev, strerror(errno));
+        return -1;
+    }
+
+    unsigned long nr_sec = 0;
+    nr_sec = get_blkdev_size(fd);
+    close(fd);
+
+    if (nr_sec == 0) {
+        printf("Failed to get size of %s: %s", real_blkdev, strerror(errno));
+        return -1;
+    }
+
+    struct crypt_mnt_ftr ext_crypt_ftr;
+    memset(&ext_crypt_ftr, 0, sizeof(ext_crypt_ftr));
+    ext_crypt_ftr.fs_size = nr_sec;
+    ext_crypt_ftr.keysize = keysize;
+    strcpy((char*) ext_crypt_ftr.crypto_type_name, "aes-cbc-essiv:sha256");
+
+    return create_crypto_blk_dev(&ext_crypt_ftr, key, real_blkdev,
+            out_crypto_blkdev, label);
+}
+
+/*
+ * Called by vold when it's asked to unmount an encrypted external
+ * storage volume.
+ */
+int cryptfs_revert_ext_volume(const char* label) {
+    return delete_crypto_blk_dev((char*) label);
+}

crypto/lollipop/cryptfs.h

@@ -221,6 +221,9 @@ extern "C" {
   int cryptfs_verify_passwd(char *newpw);
   int cryptfs_get_password_type(void);
   int delete_crypto_blk_dev(char *name);
+  int cryptfs_setup_ext_volume(const char* label, const char* real_blkdev,
+          const unsigned char* key, int keysize, char* out_crypto_blkdev);
+  int cryptfs_revert_ext_volume(const char* label);
 #ifdef __cplusplus
 }
 #endif

data.cpp

@@ -744,7 +744,7 @@ void DataManager::SetDefaultValues()
 		mConstValues.insert(make_pair(TW_HAS_USB_STORAGE, "0"));
 	} else {
 		LOGINFO("Lun file '%s'\n", Lun_File_str.c_str());
-		mConstValues.insert(make_pair(TW_HAS_USB_STORAGE, "1"));
+		mValues.insert(make_pair(TW_HAS_USB_STORAGE, make_pair("1", 0)));
 	}
 #endif
 #ifdef TW_INCLUDE_INJECTTWRP
@@ -923,6 +923,8 @@ void DataManager::SetDefaultValues()
 	mValues.insert(make_pair("tw_language", make_pair(EXPAND(TW_DEFAULT_LANGUAGE), 1)));
 	LOGINFO("LANG: %s\n", EXPAND(TW_DEFAULT_LANGUAGE));
 
+	mValues.insert(make_pair("tw_has_adopted_storage", make_pair("0", 0)));
+
 	pthread_mutex_unlock(&m_valuesLock);
 }
 

gpt/Android.mk

@@ -0,0 +1,15 @@
+LOCAL_PATH := $(call my-dir)
+
+# Build libgpt_twrp library
+
+include $(CLEAR_VARS)
+LOCAL_CLANG := false
+LOCAL_MODULE := libgpt_twrp
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES = \
+    gpt.c \
+    gptcrc32.c
+
+LOCAL_SHARED_LIBRARIES := libc
+include $(BUILD_SHARED_LIBRARY)