fix(#8): file path check, pack.mcmeta check

src/main/java/net/iceice666/resourcepackserver/Mod.kt

@@ -6,11 +6,13 @@ import net.fabricmc.fabric.api.command.v2.CommandRegistrationCallback
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents.ServerStarted
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents.ServerStopping
+import net.fabricmc.loader.api.FabricLoader
 import net.minecraft.command.CommandRegistryAccess
 import net.minecraft.server.command.CommandManager.RegistrationEnvironment
 import net.minecraft.server.command.ServerCommandSource
 import org.slf4j.Logger
 import org.slf4j.LoggerFactory
+import java.nio.file.Path
 
 class Mod : DedicatedServerModInitializer {
     override fun onInitializeServer() {
@@ -27,5 +29,8 @@ class Mod : DedicatedServerModInitializer {
 
         @JvmField
         val LOGGER: Logger = LoggerFactory.getLogger("resourcepack-server")
+
+        @JvmField
+        val GAME_DIR: Path = FabricLoader.getInstance().gameDir
     }
 }

src/main/java/net/iceice666/resourcepackserver/ResourcePackFileServer.kt

@@ -3,14 +3,18 @@ package net.iceice666.resourcepackserver
 import com.sun.net.httpserver.HttpExchange
 import com.sun.net.httpserver.HttpHandler
 import com.sun.net.httpserver.HttpServer
+import net.iceice666.resourcepackserver.Mod.Companion.GAME_DIR
 import net.iceice666.resourcepackserver.lib.ConfigLoader
 import org.slf4j.Logger
 import java.io.*
 import java.net.InetSocketAddress
 import java.net.URL
 import java.net.URLConnection
+import java.nio.file.Paths
 import java.security.MessageDigest
 import java.util.*
+import java.util.zip.ZipFile
+import kotlin.io.path.isReadable
 
 
 // Object declaration for a singleton pattern that manages a resource pack file server.
@@ -28,6 +32,9 @@ object ResourcePackFileServer {
     // resolved
     private var resPath = ""
 
+    private val gameAbsDir = GAME_DIR.toAbsolutePath()
+        .toString().removeSuffix(".")
+
     // Getter for the server path.
     @JvmStatic
     fun getOriginPath(): String = originPath
@@ -43,77 +50,106 @@ object ResourcePackFileServer {
     fun isServerRunning(): Boolean = server != null
 
     // Setter for the path of the resource pack, with string normalization.
-    fun setPath(location: String) {
-        path = location.trim()
-        resPath = path
-
-        if (path.startsWith("http://") || path.startsWith("https://")) {
+    fun setPath(location: String): String {
+        val tmpPath = location.trim()
+        // Nothing changed, return
+        if (originPath == tmpPath) return "Nothing changed."
 
+        // A remote source
+        if (tmpPath.startsWith("http://") || tmpPath.startsWith("https://")) {
             try {
                 downloadFile(resPath, "tmpfile-res.zip")
-                resPath = "tmpfile-res.zip"
             } catch (e: IOException) {
-                LOGGER.error("Failed to download file", e)
-                return
+                return "Failed to download file: \n" + e.message
+            }
+            resPath = "tmpfile-res.zip"
+        } else {
+            val tmpPath = Paths.get(tmpPath)
+            if (!tmpPath.toAbsolutePath().startsWith(gameAbsDir)) {
+                return "Cannot resolve the file path.\n" +
+                        "Please ensure the file is under the game directory(${
+                            gameAbsDir
+                        })\n" +
+                        "and ends with '.zip'."
+            }
+
+            if (!tmpPath.isReadable()) {
+                return "Cannot read the file.\n" +
+                        "Please ensure the file exists and is readable."
             }
+
+            resPath = tmpPath.toString()
+        }
+
+        if (!containsPackMcmeta()) {
+            return "File is not a valid resource pack."
         }
 
-        calculateSha1(resPath)
+        return calculateSha1()
 
     }
 
-    // Calculates the SHA-1 checksum of the file at the given path.
-    fun calculateSha1(path: String = resPath) {
-        try {
-            FileInputStream(path).use { fis ->
-                val sha1Digest = MessageDigest.getInstance("SHA-1")
-                val buffer = ByteArray(1024)
-                var bytesRead: Int
-                while (fis.read(buffer).also { bytesRead = it } != -1) {
-                    sha1Digest.update(buffer, 0, bytesRead)
-                }
-                val sha1Hash = sha1Digest.digest()
-                sha1 = sha1Hash.joinToString("") { "%02x".format(it) }
-                LOGGER.info("Path of resourcepack is $path")
-                LOGGER.info("SHA-1 of server resourcepack is $sha1")
+    private fun containsPackMcmeta(path: String = resPath): Boolean {
+        val zipFile = ZipFile(path)
+        val entries = zipFile.entries()
+
+        var res = false
+
+        while (entries.hasMoreElements()) {
+            if ("pack.mcmeta" == entries.nextElement().name) {
+                res = true
+                break
             }
-        } catch (e: FileNotFoundException) {
-            LOGGER.error(
-                """
-                Resourcepack not found. 
-                Please check your config file or run the command '/rps set' to set the correct resourcepack.
-                """.trimIndent()
-            )
-        } catch (e: Exception) {
-            LOGGER.error("An error occurred while calculating SHA-1: ${e.message}")
         }
+
+        zipFile.close()
+
+        return res
+    }
+
+    // Calculates the SHA-1 checksum of the file at the given path.
+    fun calculateSha1(path: String = resPath): String {
+
+        val fis = FileInputStream(path)
+        val sha1Digest = MessageDigest.getInstance("SHA-1")
+        val buffer = ByteArray(1024)
+        var bytesRead: Int
+
+        while (fis.read(buffer).also { bytesRead = it } != -1) {
+            sha1Digest.update(buffer, 0, bytesRead)
+        }
+
+        val sha1Hash = sha1Digest.digest()
+        sha1 = sha1Hash.joinToString("") { "%02x".format(it) }
+
+        return "Path of resourcepack is $path\n" +
+                "SHA-1 of server resourcepack is $sha1"
+
     }
 
     // Starts the HTTP server if needed.
     fun start(force: Boolean = false) {
         if (!force && !CONFIG.enabled) {
-
             LOGGER.info("Resourcepack server is disabled")
             return
 
         }
+        val port = CONFIG.serverPort
 
         try {
-            val port = CONFIG.serverPort
             server = HttpServer.create(InetSocketAddress(port), 0).apply {
                 createContext("/", FileHandler())
                 executor = null // Use the default executor
                 start()
             }
-            LOGGER.info("Resourcepack server is running on port $port")
-
         } catch (e: IOException) {
             LOGGER.error("Failed to start file server", e)
             return
         }
 
-        setPath(CONFIG.path)
-
+        LOGGER.info("Resourcepack server is running on port $port")
+        val msg = setPath(CONFIG.path)
+        LOGGER.info(msg)
 
 
     }
@@ -145,6 +181,7 @@ fun downloadFile(fileUrl: String, destinationPath: String) {
         }
     }
 }
+
 // Handler class that responds to HTTP requests with the resource pack file.
 internal class FileHandler : HttpHandler {
     @Throws(IOException::class)