liblp: Move image reading/writing functions to a new cpp file.

This is in preparation for adding sparse image support, to avoid
cluttering the more critical reading and writing logic.

Bug: 79173901
Test: N/A
Change-Id: Icdddb849aebba4adf18a3e63ffbd3f36adda812d

8 files changed, 117 insertions, 59 deletions

diff --git a/fs_mgr/liblp/Android.bp b/fs_mgr/liblp/Android.bp
index 1050cf560..176671a59 100644
--- a/fs_mgr/liblp/Android.bp
+++ b/fs_mgr/liblp/Android.bp
@@ -24,6 +24,7 @@ cc_library_static {
     ],
     srcs: [
         "builder.cpp",
+        "images.cpp",
         "reader.cpp",
         "utility.cpp",
         "writer.cpp",
diff --git a/fs_mgr/liblp/images.cpp b/fs_mgr/liblp/images.cpp
new file mode 100644
index 000000000..c8d9f13d8
--- /dev/null
+++ b/fs_mgr/liblp/images.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "images.h"
+
+#include <android-base/file.h>
+#include <android-base/unique_fd.h>
+
+#include "reader.h"
+#include "utility.h"
+#include "writer.h"
+
+namespace android {
+namespace fs_mgr {
+
+std::unique_ptr<LpMetadata> ReadFromImageFile(int fd) {
+    LpMetadataGeometry geometry;
+    if (!ReadLogicalPartitionGeometry(fd, &geometry)) {
+        return nullptr;
+    }
+    if (SeekFile64(fd, LP_METADATA_GEOMETRY_SIZE, SEEK_SET) < 0) {
+        PERROR << __PRETTY_FUNCTION__ << "lseek failed: offset " << LP_METADATA_GEOMETRY_SIZE;
+        return nullptr;
+    }
+    std::unique_ptr<LpMetadata> metadata = ParseMetadata(fd);
+    if (!metadata) {
+        return nullptr;
+    }
+    metadata->geometry = geometry;
+    return metadata;
+}
+
+std::unique_ptr<LpMetadata> ReadFromImageFile(const char* file) {
+    android::base::unique_fd fd(open(file, O_RDONLY));
+    if (fd < 0) {
+        PERROR << __PRETTY_FUNCTION__ << "open failed: " << file;
+        return nullptr;
+    }
+    return ReadFromImageFile(fd);
+}
+
+bool WriteToImageFile(int fd, const LpMetadata& input) {
+    std::string geometry = SerializeGeometry(input.geometry);
+    std::string padding(LP_METADATA_GEOMETRY_SIZE - geometry.size(), '\0');
+    std::string metadata = SerializeMetadata(input);
+
+    std::string everything = geometry + padding + metadata;
+
+    if (!android::base::WriteFully(fd, everything.data(), everything.size())) {
+        PERROR << __PRETTY_FUNCTION__ << "write " << everything.size() << " bytes failed";
+        return false;
+    }
+    return true;
+}
+
+bool WriteToImageFile(const char* file, const LpMetadata& input) {
+    android::base::unique_fd fd(open(file, O_CREAT | O_RDWR | O_TRUNC, 0644));
+    if (fd < 0) {
+        PERROR << __PRETTY_FUNCTION__ << "open failed: " << file;
+        return false;
+    }
+    return WriteToImageFile(fd, input);
+}
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/liblp/images.h b/fs_mgr/liblp/images.h
new file mode 100644
index 000000000..3a999b89c
--- /dev/null
+++ b/fs_mgr/liblp/images.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <liblp/liblp.h>
+
+namespace android {
+namespace fs_mgr {
+
+// Helper function to serialize geometry and metadata to a normal file, for
+// flashing or debugging.
+std::unique_ptr<LpMetadata> ReadFromImageFile(int fd);
+bool WriteToImageFile(const char* file, const LpMetadata& metadata);
+bool WriteToImageFile(int fd, const LpMetadata& metadata);
+
+}  // namespace fs_mgr
+}  // namespace android
diff --git a/fs_mgr/liblp/io_test.cpp b/fs_mgr/liblp/io_test.cpp
index e91cc3e0a..bbbedc761 100644
--- a/fs_mgr/liblp/io_test.cpp
+++ b/fs_mgr/liblp/io_test.cpp
@@ -24,6 +24,7 @@
 #include <gtest/gtest.h>
 #include <liblp/builder.h>
 
+#include "images.h"
 #include "reader.h"
 #include "utility.h"
 #include "writer.h"
diff --git a/fs_mgr/liblp/reader.cpp b/fs_mgr/liblp/reader.cpp
index 7fbf8e6c0..117da5991 100644
--- a/fs_mgr/liblp/reader.cpp
+++ b/fs_mgr/liblp/reader.cpp
@@ -171,7 +171,7 @@ static bool ValidateMetadataHeader(const LpMetadataHeader& header) {
 
 // Parse and validate all metadata at the current position in the given file
 // descriptor.
-static std::unique_ptr<LpMetadata> ParseMetadata(int fd) {
+std::unique_ptr<LpMetadata> ParseMetadata(int fd) {
     // First read and validate the header.
     std::unique_ptr<LpMetadata> metadata = std::make_unique<LpMetadata>();
     if (!android::base::ReadFully(fd, &metadata->header, sizeof(metadata->header))) {
@@ -286,32 +286,6 @@ std::unique_ptr<LpMetadata> ReadMetadata(const char* block_device, uint32_t slot
     return ReadMetadata(fd, slot_number);
 }
 
-std::unique_ptr<LpMetadata> ReadFromImageFile(int fd) {
-    LpMetadataGeometry geometry;
-    if (!ReadLogicalPartitionGeometry(fd, &geometry)) {
-        return nullptr;
-    }
-    if (SeekFile64(fd, LP_METADATA_GEOMETRY_SIZE, SEEK_SET) < 0) {
-        PERROR << __PRETTY_FUNCTION__ << "lseek failed: offset " << LP_METADATA_GEOMETRY_SIZE;
-        return nullptr;
-    }
-    std::unique_ptr<LpMetadata> metadata = ParseMetadata(fd);
-    if (!metadata) {
-        return nullptr;
-    }
-    metadata->geometry = geometry;
-    return metadata;
-}
-
-std::unique_ptr<LpMetadata> ReadFromImageFile(const char* file) {
-    android::base::unique_fd fd(open(file, O_RDONLY));
-    if (fd < 0) {
-        PERROR << __PRETTY_FUNCTION__ << "open failed: " << file;
-        return nullptr;
-    }
-    return ReadFromImageFile(fd);
-}
-
 static std::string NameFromFixedArray(const char* name, size_t buffer_size) {
     // If the end of the buffer has a null character, it's safe to assume the
     // buffer is null terminated. Otherwise, we cap the string to the input
diff --git a/fs_mgr/liblp/reader.h b/fs_mgr/liblp/reader.h
index c4cac8fcb..843b2f25b 100644
--- a/fs_mgr/liblp/reader.h
+++ b/fs_mgr/liblp/reader.h
@@ -30,6 +30,7 @@ std::unique_ptr<LpMetadata> ReadMetadata(int fd, uint32_t slot_number);
 
 // Helper functions for manually reading geometry and metadata.
 bool ReadLogicalPartitionGeometry(int fd, LpMetadataGeometry* geometry);
+std::unique_ptr<LpMetadata> ParseMetadata(int fd);
 
 // These functions assume a valid geometry and slot number.
 std::unique_ptr<LpMetadata> ReadPrimaryMetadata(int fd, const LpMetadataGeometry& geometry,
@@ -37,8 +38,6 @@ std::unique_ptr<LpMetadata> ReadPrimaryMetadata(int fd, const LpMetadataGeometry
 std::unique_ptr<LpMetadata> ReadBackupMetadata(int fd, const LpMetadataGeometry& geometry,
                                                uint32_t slot_number);
 
-std::unique_ptr<LpMetadata> ReadFromImageFile(int fd);
-
 }  // namespace fs_mgr
 }  // namespace android
 
diff --git a/fs_mgr/liblp/writer.cpp b/fs_mgr/liblp/writer.cpp
index 3ec76a970..74c03bf2f 100644
--- a/fs_mgr/liblp/writer.cpp
+++ b/fs_mgr/liblp/writer.cpp
@@ -30,7 +30,7 @@
 namespace android {
 namespace fs_mgr {
 
-static std::string SerializeGeometry(const LpMetadataGeometry& input) {
+std::string SerializeGeometry(const LpMetadataGeometry& input) {
     LpMetadataGeometry geometry = input;
     memset(geometry.checksum, 0, sizeof(geometry.checksum));
     SHA256(&geometry, sizeof(geometry), geometry.checksum);
@@ -44,7 +44,7 @@ static bool CompareGeometry(const LpMetadataGeometry& g1, const LpMetadataGeomet
            g1.last_logical_sector == g2.last_logical_sector;
 }
 
-static std::string SerializeMetadata(const LpMetadata& input) {
+std::string SerializeMetadata(const LpMetadata& input) {
     LpMetadata metadata = input;
     LpMetadataHeader& header = metadata.header;
 
@@ -318,28 +318,5 @@ bool UpdatePartitionTable(int fd, const LpMetadata& metadata, uint32_t slot_numb
     return UpdatePartitionTable(fd, metadata, slot_number, DefaultWriter);
 }
 
-bool WriteToImageFile(int fd, const LpMetadata& input) {
-    std::string geometry = SerializeGeometry(input.geometry);
-    std::string padding(LP_METADATA_GEOMETRY_SIZE - geometry.size(), '\0');
-    std::string metadata = SerializeMetadata(input);
-
-    std::string everything = geometry + padding + metadata;
-
-    if (!android::base::WriteFully(fd, everything.data(), everything.size())) {
-        PERROR << __PRETTY_FUNCTION__ << "write " << everything.size() << " bytes failed";
-        return false;
-    }
-    return true;
-}
-
-bool WriteToImageFile(const char* file, const LpMetadata& input) {
-    android::base::unique_fd fd(open(file, O_CREAT | O_RDWR | O_TRUNC, 0644));
-    if (fd < 0) {
-        PERROR << __PRETTY_FUNCTION__ << "open failed: " << file;
-        return false;
-    }
-    return WriteToImageFile(fd, input);
-}
-
 }  // namespace fs_mgr
 }  // namespace android
diff --git a/fs_mgr/liblp/writer.h b/fs_mgr/liblp/writer.h
index 94c1d3195..adbbebf66 100644
--- a/fs_mgr/liblp/writer.h
+++ b/fs_mgr/liblp/writer.h
@@ -25,6 +25,9 @@
 namespace android {
 namespace fs_mgr {
 
+std::string SerializeGeometry(const LpMetadataGeometry& input);
+std::string SerializeMetadata(const LpMetadata& input);
+
 // These variants are for testing only. The path-based functions should be used
 // for actual operation, so that open() is called with the correct flags.
 bool FlashPartitionTable(int fd, const LpMetadata& metadata, uint32_t slot_number);
@@ -33,11 +36,6 @@ bool UpdatePartitionTable(int fd, const LpMetadata& metadata, uint32_t slot_numb
 bool UpdatePartitionTable(int fd, const LpMetadata& metadata, uint32_t slot_number,
                           const std::function<bool(int, const std::string&)>& writer);
 
-// Helper function to serialize geometry and metadata to a normal file, for
-// flashing or debugging.
-bool WriteToImageFile(const char* file, const LpMetadata& metadata);
-bool WriteToImageFile(int fd, const LpMetadata& metadata);
-
 }  // namespace fs_mgr
 }  // namespace android