Add Linux support

packages/moxdns_linux/linux/CMakeLists.txt

@@ -0,0 +1,48 @@
+# The Flutter tooling requires that developers have CMake 3.10 or later
+# installed. You should not increase this version, as doing so will cause
+# the plugin to fail to compile for some customers of the plugin.
+cmake_minimum_required(VERSION 3.10)
+
+# Project-level configuration.
+set(PROJECT_NAME "moxdns_linux")
+project(${PROJECT_NAME} LANGUAGES CXX)
+
+# This value is used when generating builds using this plugin, so it must
+# not be changed.
+set(PLUGIN_NAME "moxdns_linux_plugin")
+
+# Define the plugin library target. Its name must not be changed (see comment
+# on PLUGIN_NAME above).
+#
+# Any new source files that you add to the plugin should be added here.
+add_library(${PLUGIN_NAME} SHARED
+  "moxdns_linux_plugin.cc"
+)
+
+# Apply a standard set of build settings that are configured in the
+# application-level CMakeLists.txt. This can be removed for plugins that want
+# full control over build settings.
+apply_standard_settings(${PLUGIN_NAME})
+
+# Symbols are hidden by default to reduce the chance of accidental conflicts
+# between plugins. This should not be removed; any symbols that should be
+# exported should be explicitly exported with the FLUTTER_PLUGIN_EXPORT macro.
+set_target_properties(${PLUGIN_NAME} PROPERTIES
+  CXX_VISIBILITY_PRESET hidden)
+target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
+
+# Source include directories and library dependencies. Add any plugin-specific
+# dependencies here.
+target_include_directories(${PLUGIN_NAME} INTERFACE
+  "${CMAKE_CURRENT_SOURCE_DIR}/include")
+target_link_libraries(${PLUGIN_NAME} PRIVATE flutter)
+target_link_libraries(${PLUGIN_NAME} PRIVATE PkgConfig::GTK)
+target_link_libraries(${PLUGIN_NAME} PRIVATE resolv)
+
+# List of absolute paths to libraries that should be bundled with the plugin.
+# This list could contain prebuilt libraries, or libraries created by an
+# external build triggered from this build file.
+set(moxdns_linux_bundled_libraries
+  ""
+  PARENT_SCOPE
+)

packages/moxdns_linux/linux/include/moxdns_linux/moxdns_linux_plugin.h

@@ -0,0 +1,26 @@
+#ifndef FLUTTER_PLUGIN_MOXDNS_LINUX_PLUGIN_H_
+#define FLUTTER_PLUGIN_MOXDNS_LINUX_PLUGIN_H_
+
+#include <flutter_linux/flutter_linux.h>
+
+G_BEGIN_DECLS
+
+#ifdef FLUTTER_PLUGIN_IMPL
+#define FLUTTER_PLUGIN_EXPORT __attribute__((visibility("default")))
+#else
+#define FLUTTER_PLUGIN_EXPORT
+#endif
+
+typedef struct _MoxdnsLinuxPlugin MoxdnsLinuxPlugin;
+typedef struct {
+  GObjectClass parent_class;
+} MoxdnsLinuxPluginClass;
+
+FLUTTER_PLUGIN_EXPORT GType moxdns_linux_plugin_get_type();
+
+FLUTTER_PLUGIN_EXPORT void moxdns_linux_plugin_register_with_registrar(
+    FlPluginRegistrar* registrar);
+
+G_END_DECLS
+
+#endif  // FLUTTER_PLUGIN_MOXDNS_LINUX_PLUGIN_H_

packages/moxdns_linux/linux/moxdns_linux_plugin.cc

@@ -0,0 +1,114 @@
+#include "include/moxdns_linux/moxdns_linux_plugin.h"
+
+#include <flutter_linux/flutter_linux.h>
+#include <gtk/gtk.h>
+#include <netinet/in.h>
+#include <resolv.h>
+#include <arpa/nameser.h>
+
+#include <cstring>
+#include <iostream>
+
+#define MOXDNS_LINUX_PLUGIN(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), moxdns_linux_plugin_get_type(), \
+                              MoxdnsLinuxPlugin))
+
+struct _MoxdnsLinuxPlugin {
+  GObject parent_instance;
+};
+
+G_DEFINE_TYPE(MoxdnsLinuxPlugin, moxdns_linux_plugin, g_object_get_type())
+
+// Convert the data field at offset [offset] of the RR [record] into an integer
+// [FlValue].
+FlValue *rr_data_field_to_value(ns_rr &record, int offset) {
+  auto data = ntohs(*((unsigned short*)ns_rr_rdata(record) + offset));
+  return fl_value_new_int(data);
+}
+
+// Called when a method call is received from Flutter.
+static void moxdns_linux_plugin_handle_method_call(
+    MoxdnsLinuxPlugin* self,
+    FlMethodCall* method_call) {
+  g_autoptr(FlMethodResponse) response = nullptr;
+
+  const gchar* method = fl_method_call_get_name(method_call);
+  if (strcmp(method, "srvQuery") == 0) {
+    FlValue* args = fl_method_call_get_args(method_call);
+    gchar *domain = fl_value_to_string(fl_value_lookup_string(args, "domain"));
+    //bool dnssec = fl_value_get_bool(fl_value_lookup_string(args, "dnssec"));
+
+    res_init();
+
+    // This is based on this gist: https://gist.githubusercontent.com/ajdavis/e5f5ddbf50b5aecdc5e1d686d72a8a7a/raw/31ec3c642d5ca4a3d0688dde8cc4a6ef8bd97146/dnssd.cpp
+    unsigned char query_buffer[1024];
+    int result = res_query(domain, C_IN, ns_t_srv, query_buffer, sizeof(query_buffer));
+    ns_msg records;
+    ns_initparse(query_buffer, result, &records);
+
+    FlValue *results = fl_value_new_list();
+    for (int i = 0; i < ns_msg_count(records, ns_s_an); i++) {
+      ns_rr record;
+      ns_parserr(&records, ns_s_an, i, &record);
+
+      char target[1024];
+      dn_expand(ns_msg_base(records),
+		ns_msg_end(records),
+		ns_rr_rdata(record) + 6,
+		target, sizeof(target));
+      FlValue *map = fl_value_new_map();
+      fl_value_set(map,
+		   fl_value_new_string("target"),
+		   fl_value_new_string(target));
+      fl_value_set(map,
+		   fl_value_new_string("port"), 
+		   rr_data_field_to_value(record, 2));
+      fl_value_set(map,
+		   fl_value_new_string("priority"),
+		   rr_data_field_to_value(record, 0));
+      fl_value_set(map,
+		   fl_value_new_string("weight"),
+		   rr_data_field_to_value(record, 1));
+
+      fl_value_append(results, map);
+    }
+
+    response = FL_METHOD_RESPONSE(fl_method_success_response_new(results));
+  } else {
+    response = FL_METHOD_RESPONSE(fl_method_not_implemented_response_new());
+  }
+  
+  fl_method_call_respond(method_call, response, nullptr);
+}
+
+static void moxdns_linux_plugin_dispose(GObject* object) {
+  G_OBJECT_CLASS(moxdns_linux_plugin_parent_class)->dispose(object);
+}
+
+static void moxdns_linux_plugin_class_init(MoxdnsLinuxPluginClass* klass) {
+  G_OBJECT_CLASS(klass)->dispose = moxdns_linux_plugin_dispose;
+}
+
+static void moxdns_linux_plugin_init(MoxdnsLinuxPlugin* self) {}
+
+static void method_call_cb(FlMethodChannel* channel, FlMethodCall* method_call,
+                           gpointer user_data) {
+  MoxdnsLinuxPlugin* plugin = MOXDNS_LINUX_PLUGIN(user_data);
+  moxdns_linux_plugin_handle_method_call(plugin, method_call);
+}
+
+void moxdns_linux_plugin_register_with_registrar(FlPluginRegistrar* registrar) {
+  MoxdnsLinuxPlugin* plugin = MOXDNS_LINUX_PLUGIN(
+      g_object_new(moxdns_linux_plugin_get_type(), nullptr));
+
+  g_autoptr(FlStandardMethodCodec) codec = fl_standard_method_codec_new();
+  g_autoptr(FlMethodChannel) channel =
+      fl_method_channel_new(fl_plugin_registrar_get_messenger(registrar),
+                            "me.polynom.moxdns_linux",
+                            FL_METHOD_CODEC(codec));
+  fl_method_channel_set_method_call_handler(channel, method_call_cb,
+                                            g_object_ref(plugin),
+                                            g_object_unref);
+
+  g_object_unref(plugin);
+}