Clean up error messages

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

3 files changed, 132 insertions, 51 deletions

diff --git a/app/src/main/java/com/wireguard/android/util/ErrorMessages.java b/app/src/main/java/com/wireguard/android/util/ErrorMessages.java
new file mode 100644
index 00000000..0f49448c
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/ErrorMessages.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright © 2018 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.util;
+
+import android.content.res.Resources;
+import android.support.annotation.Nullable;
+
+import com.wireguard.android.Application;
+import com.wireguard.android.R;
+import com.wireguard.config.BadConfigException;
+import com.wireguard.config.BadConfigException.Location;
+import com.wireguard.config.BadConfigException.Reason;
+import com.wireguard.config.InetEndpoint;
+import com.wireguard.config.InetNetwork;
+import com.wireguard.config.ParseException;
+import com.wireguard.crypto.Key.Format;
+import com.wireguard.crypto.KeyFormatException;
+import com.wireguard.crypto.KeyFormatException.Type;
+
+import java.net.InetAddress;
+import java.util.EnumMap;
+import java.util.Map;
+
+import java9.util.Maps;
+
+public final class ErrorMessages {
+    private static final Map<Reason, Integer> BCE_REASON_MAP = new EnumMap<>(Maps.of(
+            Reason.INVALID_KEY, R.string.bad_config_reason_invalid_key,
+            Reason.INVALID_NUMBER, R.string.bad_config_reason_invalid_number,
+            Reason.INVALID_VALUE, R.string.bad_config_reason_invalid_value,
+            Reason.MISSING_ATTRIBUTE, R.string.bad_config_reason_missing_attribute,
+            Reason.MISSING_SECTION, R.string.bad_config_reason_missing_section,
+            Reason.MISSING_VALUE, R.string.bad_config_reason_missing_value,
+            Reason.SYNTAX_ERROR, R.string.bad_config_reason_syntax_error,
+            Reason.UNKNOWN_ATTRIBUTE, R.string.bad_config_reason_unknown_attribute,
+            Reason.UNKNOWN_SECTION, R.string.bad_config_reason_unknown_section
+    ));
+    private static final Map<Format, Integer> KFE_FORMAT_MAP = new EnumMap<>(Maps.of(
+            Format.BASE64, R.string.key_length_explanation_base64,
+            Format.BINARY, R.string.key_length_explanation_binary,
+            Format.HEX, R.string.key_length_explanation_hex
+    ));
+    private static final Map<Type, Integer> KFE_TYPE_MAP = new EnumMap<>(Maps.of(
+            Type.CONTENTS, R.string.key_contents_error,
+            Type.LENGTH, R.string.key_length_error
+    ));
+    private static final Map<Class, Integer> PE_CLASS_MAP = Maps.of(
+            InetAddress.class, R.string.parse_error_inet_address,
+            InetEndpoint.class, R.string.parse_error_inet_endpoint,
+            InetNetwork.class, R.string.parse_error_inet_network,
+            Integer.class, R.string.parse_error_integer
+    );
+
+    private ErrorMessages() {
+        // Prevent instantiation
+    }
+
+    public static String get(@Nullable final Throwable throwable) {
+        final Resources resources = Application.get().getResources();
+        if (throwable == null)
+            return resources.getString(R.string.unknown_error);
+        final Throwable rootCause = rootCause(throwable);
+        final String message;
+        if (rootCause instanceof BadConfigException) {
+            final BadConfigException bce = (BadConfigException) rootCause;
+            final String reason = getBadConfigExceptionReason(resources, bce);
+            final String context = bce.getLocation() == Location.TOP_LEVEL ?
+                    resources.getString(R.string.bad_config_context_top_level,
+                            bce.getSection().getName()) :
+                    resources.getString(R.string.bad_config_context,
+                            bce.getSection().getName(),
+                            bce.getLocation().getName());
+            final String explanation = getBadConfigExceptionExplanation(resources, bce);
+            message = resources.getString(R.string.bad_config_error, reason, context) + explanation;
+        } else if (rootCause.getMessage() != null) {
+            message = rootCause.getMessage();
+        } else {
+            final String errorType = rootCause.getClass().getSimpleName();
+            message = resources.getString(R.string.generic_error, errorType);
+        }
+        return message;
+    }
+
+    private static String getBadConfigExceptionExplanation(final Resources resources,
+                                                           final BadConfigException bce) {
+        if (bce.getCause() instanceof KeyFormatException) {
+            final KeyFormatException kfe = (KeyFormatException) bce.getCause();
+            if (kfe.getType() == Type.LENGTH)
+                return resources.getString(KFE_FORMAT_MAP.get(kfe.getFormat()));
+        } else if (bce.getCause() instanceof ParseException) {
+            final ParseException pe = (ParseException) bce.getCause();
+            if (pe.getMessage() != null)
+                return ": " + pe.getMessage();
+        } else if (bce.getLocation() == Location.LISTEN_PORT) {
+            return resources.getString(R.string.bad_config_explanation_udp_port);
+        } else if (bce.getLocation() == Location.MTU) {
+            return resources.getString(R.string.bad_config_explanation_positive_number);
+        } else if (bce.getLocation() == Location.PERSISTENT_KEEPALIVE) {
+            return resources.getString(R.string.bad_config_explanation_pka);
+        }
+        return "";
+    }
+
+    private static String getBadConfigExceptionReason(final Resources resources,
+                                                      final BadConfigException bce) {
+        if (bce.getCause() instanceof KeyFormatException) {
+            final KeyFormatException kfe = (KeyFormatException) bce.getCause();
+            return resources.getString(KFE_TYPE_MAP.get(kfe.getType()));
+        } else if (bce.getCause() instanceof ParseException) {
+            final ParseException pe = (ParseException) bce.getCause();
+            final String type = resources.getString(PE_CLASS_MAP.containsKey(pe.getParsingClass()) ?
+                    PE_CLASS_MAP.get(pe.getParsingClass()) : R.string.parse_error_generic);
+            return resources.getString(R.string.parse_error_reason, type, pe.getText());
+        }
+        return resources.getString(BCE_REASON_MAP.get(bce.getReason()), bce.getText());
+    }
+
+    private static Throwable rootCause(final Throwable throwable) {
+        Throwable cause = throwable;
+        while (cause.getCause() != null) {
+            if (cause instanceof BadConfigException)
+                break;
+            cause = cause.getCause();
+        }
+        return cause;
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
index 3cb5ca9f..5188112c 100644
--- a/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
+++ b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
@@ -5,17 +5,9 @@
 
 package com.wireguard.android.util;
 
-import android.content.res.Resources;
 import android.support.annotation.Nullable;
 import android.util.Log;
 
-import com.wireguard.android.Application;
-import com.wireguard.android.R;
-import com.wireguard.config.BadConfigException;
-import com.wireguard.config.ParseException;
-import com.wireguard.crypto.KeyFormatException;
-
-import java9.util.concurrent.CompletionException;
 import java9.util.function.BiConsumer;
 
 /**
@@ -28,53 +20,12 @@ public enum ExceptionLoggers implements BiConsumer<Object, Throwable> {
     E(Log.ERROR);
 
     private static final String TAG = "WireGuard/" + ExceptionLoggers.class.getSimpleName();
-
     private final int priority;
 
     ExceptionLoggers(final int priority) {
         this.priority = priority;
     }
 
-    public static Throwable unwrap(final Throwable throwable) {
-        if (throwable instanceof CompletionException && throwable.getCause() != null)
-            return throwable.getCause();
-        if (throwable instanceof ParseException && throwable.getCause() != null)
-            return throwable.getCause();
-        return throwable;
-    }
-
-    public static String unwrapMessage(final Throwable throwable) {
-        final Throwable innerThrowable = unwrap(throwable);
-        final Resources resources = Application.get().getResources();
-        String message;
-        if (innerThrowable instanceof BadConfigException) {
-            final BadConfigException configException = (BadConfigException) innerThrowable;
-            message = resources.getString(R.string.parse_error, configException.getText(), configException.getLocation());
-            final Throwable cause = unwrap(configException);
-            if (cause.getMessage() != null)
-                message += ": " + cause.getMessage();
-        } else if (innerThrowable instanceof KeyFormatException) {
-            final KeyFormatException keyFormatException = (KeyFormatException) innerThrowable;
-            switch (keyFormatException.getFormat()) {
-                case BASE64:
-                    message = resources.getString(R.string.key_length_base64_exception_message);
-                    break;
-                case BINARY:
-                    message = resources.getString(R.string.key_length_exception_message);
-                    break;
-                case HEX:
-                    message = resources.getString(R.string.key_length_hex_exception_message);
-                    break;
-                default:
-                    // Will never happen, as getFormat is not nullable.
-                    message = null;
-            }
-        } else {
-            message = innerThrowable.getMessage();
-        }
-        return message != null ? message : innerThrowable.getClass().getSimpleName();
-    }
-
     @Override
     public void accept(final Object result, @Nullable final Throwable throwable) {
         if (throwable != null)
diff --git a/app/src/main/java/com/wireguard/android/util/RootShell.java b/app/src/main/java/com/wireguard/android/util/RootShell.java
index e48e3564..2dc02b56 100644
--- a/app/src/main/java/com/wireguard/android/util/RootShell.java
+++ b/app/src/main/java/com/wireguard/android/util/RootShell.java
@@ -123,9 +123,9 @@ public class RootShell {
                 }
             }
             if (markersSeen != 4)
-                throw new IOException(context.getString(R.string.marker_count_error, markersSeen));
+                throw new IOException(context.getString(R.string.shell_marker_count_error, markersSeen));
             if (errnoStdout != errnoStderr)
-                throw new IOException(context.getString(R.string.exit_status_read_error));
+                throw new IOException(context.getString(R.string.shell_exit_status_read_error));
             Log.v(TAG, "exit: " + errnoStdout);
             return errnoStdout;
         }