Modify FuseDaemon#DeriveVolumeName to better handle invalid paths.

Test: atest FuseUtilsTest.cpp

Bug: 378021978

Flag: EXEMPT, bug fix

Change-Id: I66c05397a1350c3fd1af52218f803e1202ed9b3d

4 files changed, 50 insertions, 17 deletions

diff --git a/jni/FuseDaemon.cpp b/jni/FuseDaemon.cpp
index e77fe5705..2a2e6310f 100644
--- a/jni/FuseDaemon.cpp
+++ b/jni/FuseDaemon.cpp
@@ -124,11 +124,6 @@ const std::regex PATTERN_BPF_BACKING_PATH("^/storage/[^/]+/[0-9]+/Android/(data|
 
 static constexpr char TRANSFORM_SYNTHETIC_DIR[] = "synthetic";
 static constexpr char TRANSFORM_TRANSCODE_DIR[] = "transcode";
-static constexpr char PRIMARY_VOLUME_PREFIX[] = "/storage/emulated";
-static constexpr char STORAGE_PREFIX[] = "/storage";
-
-static constexpr char VOLUME_INTERNAL[] = "internal";
-static constexpr char VOLUME_EXTERNAL_PRIMARY[] = "external_primary";
 
 static constexpr char OWNERSHIP_RELATION[] = "ownership";
 
@@ -282,7 +277,7 @@ struct fuse {
     inline bool IsRoot(const node* node) const { return node == root; }
 
     inline string GetEffectiveRootPath() {
-        if (android::base::StartsWith(path, PRIMARY_VOLUME_PREFIX)) {
+        if (android::base::StartsWith(path, mediaprovider::fuse::PRIMARY_VOLUME_PREFIX)) {
             return path + "/" + MY_USER_ID_STRING;
         }
         return path;
@@ -356,7 +351,7 @@ struct fuse {
             return false;
         }
 
-        if (!android::base::StartsWithIgnoreCase(path, PRIMARY_VOLUME_PREFIX)) {
+        if (!android::base::StartsWithIgnoreCase(path, mediaprovider::fuse::PRIMARY_VOLUME_PREFIX)) {
             // Uncached path config applies only to primary volumes.
             return false;
         }
@@ -2639,7 +2634,7 @@ void FuseDaemon::SetupLevelDbInstances() {
         // Setup leveldb instance for both external primary and internal volume.
         fuse->level_db_mutex.lock();
         // Create level db instance for internal volume
-        SetupLevelDbConnection(VOLUME_INTERNAL);
+        SetupLevelDbConnection(mediaprovider::fuse::VOLUME_INTERNAL);
         // Create level db instance for external primary volume
         SetupLevelDbConnection(VOLUME_EXTERNAL_PRIMARY);
         // Create level db instance to store owner id to owner package name and vice versa relation
@@ -2657,16 +2652,11 @@ void FuseDaemon::SetupPublicVolumeLevelDbInstance(const std::string& volume_name
 }
 
 std::string deriveVolumeName(const std::string& path) {
-    std::string volume_name;
-    if (!android::base::StartsWith(path, STORAGE_PREFIX)) {
-        volume_name = VOLUME_INTERNAL;
-    } else if (android::base::StartsWith(path, PRIMARY_VOLUME_PREFIX)) {
-        volume_name = VOLUME_EXTERNAL_PRIMARY;
+    std::string volume_name = mediaprovider::fuse::getVolumeNameFromPath(path);
+    if (volume_name.empty()) {
+        LOG(ERROR) << "Invalid input URI for extracting volume name." << path;
     } else {
-        // Return "C58E-1702" from the path like "/storage/C58E-1702/Download/1935694997673.png"
-        volume_name = path.substr(9, 9);
-        // Convert to lowercase
-        std::transform(volume_name.begin(), volume_name.end(), volume_name.begin(), ::tolower);
+        LOG(DEBUG) << "Volume name from input path: " << path << " ,  volName: " + volume_name;
     }
     return volume_name;
 }
diff --git a/jni/FuseUtils.cpp b/jni/FuseUtils.cpp
index 7b0816488..a74b56033 100644
--- a/jni/FuseUtils.cpp
+++ b/jni/FuseUtils.cpp
@@ -16,6 +16,7 @@
 
 #include "include/libfuse_jni/FuseUtils.h"
 
+#include <regex>
 #include <string>
 #include <vector>
 
@@ -51,5 +52,24 @@ bool containsMount(const string& path) {
            android::base::EqualsIgnoreCase(path_suffix, obb_suffix);
 }
 
+string getVolumeNameFromPath(const std::string& path) {
+    std::string volume_name = "";
+    if (!android::base::StartsWith(path, STORAGE_PREFIX)) {
+        volume_name = VOLUME_INTERNAL;
+    } else if (android::base::StartsWith(path, PRIMARY_VOLUME_PREFIX) || path == STORAGE_PREFIX) {
+        volume_name = VOLUME_EXTERNAL_PRIMARY;
+    } else {
+        // Use regex to extract volume name
+        std::regex volumeRegex(R"(/storage/([a-zA-Z0-9-]+)/)");
+        std::smatch match;
+        if (std::regex_search(path, match, volumeRegex)) {
+            volume_name = match[1].str();
+            // Convert to lowercase
+            std::transform(volume_name.begin(), volume_name.end(), volume_name.begin(), ::tolower);
+        }
+    }
+    return volume_name;
+}
+
 }  // namespace fuse
 }  // namespace mediaprovider
diff --git a/jni/FuseUtilsTest.cpp b/jni/FuseUtilsTest.cpp
index d76a89c6f..a1b03e0c2 100644
--- a/jni/FuseUtilsTest.cpp
+++ b/jni/FuseUtilsTest.cpp
@@ -59,4 +59,18 @@ TEST(FuseUtilsTest, testContainsMount_isFalseForPathWithAdditionalSlash) {
     EXPECT_FALSE(containsMount("/storage/emulated/1234//Android/data"));
 }
 
+TEST(FuseUtilsTest, getVolumeNameFromPath) {
+    EXPECT_EQ(getVolumeNameFromPath("/storage/emulated/0/Pictures"), VOLUME_EXTERNAL_PRIMARY);
+    EXPECT_EQ(getVolumeNameFromPath("/storage/emulated/0/DCIM"), VOLUME_EXTERNAL_PRIMARY);
+    EXPECT_EQ(getVolumeNameFromPath("/storage/emulated/0/"), VOLUME_EXTERNAL_PRIMARY);
+    EXPECT_EQ(getVolumeNameFromPath("/storage/emulated/0"), VOLUME_EXTERNAL_PRIMARY);
+    EXPECT_EQ(getVolumeNameFromPath("/storage/1234-5678/Music"), "1234-5678");
+    EXPECT_EQ(getVolumeNameFromPath("/storage/ABCD-EFGH/Movies"), "abcd-efgh");
+    EXPECT_EQ(getVolumeNameFromPath("/storage/AB12-E34g/Movies"), "ab12-e34g");
+    EXPECT_EQ(getVolumeNameFromPath("/storage/"), "");
+    EXPECT_EQ(getVolumeNameFromPath("/storage"), VOLUME_EXTERNAL_PRIMARY);
+    EXPECT_EQ(getVolumeNameFromPath("/data/media/0/"), VOLUME_INTERNAL);
+    EXPECT_EQ(getVolumeNameFromPath("/data/user_de/0/com.example.app/"), VOLUME_INTERNAL);
+}
+
 }  // namespace mediaprovider::fuse
diff --git a/jni/include/libfuse_jni/FuseUtils.h b/jni/include/libfuse_jni/FuseUtils.h
index 0e350995e..11f880f7a 100644
--- a/jni/include/libfuse_jni/FuseUtils.h
+++ b/jni/include/libfuse_jni/FuseUtils.h
@@ -21,6 +21,10 @@
 
 namespace mediaprovider {
 namespace fuse {
+static constexpr char STORAGE_PREFIX[] = "/storage";
+static constexpr char VOLUME_INTERNAL[] = "internal";
+static constexpr char VOLUME_EXTERNAL_PRIMARY[] = "external_primary";
+static constexpr char PRIMARY_VOLUME_PREFIX[] = "/storage/emulated";
 
 /**
  * Returns true if the given path (ignoring case) is mounted for any
@@ -31,6 +35,11 @@ namespace fuse {
  */
 bool containsMount(const std::string& path);
 
+/**
+ * Returns the volume name extracted from a given path.
+ */
+std::string getVolumeNameFromPath(const std::string& path);
+
 }  // namespace fuse
 }  // namespace mediaprovider