/* * Copyright (c) 2014 Kevin Smith and Remko Tronçon * Licensed under the GNU General Public License v3. * See Documentation/Licenses/GPLv3.txt for more information. */ #include "dns_android.h" #include <vector> #include <string> #include <jni.h> JavaVM* javaVM = 0; JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* vm, void* /*aReserved*/) { javaVM = vm; return JNI_VERSION_1_6; } std::vector<std::string> get_servers() { std::vector<std::string> servers; if (javaVM == 0) { return servers; } JNIEnv* env = 0; int result = javaVM->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6); if (result == JNI_EDETACHED) { if (javaVM->AttachCurrentThread(&env, 0) != 0) { return servers; } } else if (result != JNI_OK) { return servers; } jclass systemProperties = env->FindClass("android.os.SystemProperties"); if (!systemProperties) { return servers; } jmethodID method = env->GetStaticMethodID(systemProperties, "get", "(Ljava/lang/String;)Ljava/lang/String;"); if (!method) { return servers; } const char* parameters[] = { "net.dns1", "net.dns2", "net.dns3", "net.dns4" }; for (size_t i = 0; i < sizeof(parameters)/sizeof(*parameters); ++i) { jstring parameter = env->NewStringUTF(parameters[i]); jstring value = jstring(env->CallStaticObjectMethod(systemProperties, method, parameter)); const char* server = env->GetStringUTFChars(value, JNI_FALSE); if (strcmp(server, "")) { servers.push_back(server); } env->ReleaseStringUTFChars(value, server); } return servers; } size_t dns_android_server_count() { std::vector<std::string> servers = get_servers(); return servers.size(); } dns_android_result dns_android_server_get(size_t index, char* buffer, size_t length) { std::vector<std::string> servers = get_servers(); if (index >= servers.size()) { return DNS_ANDROID_FAILURE; /* invalid server index */ } if (length < servers[index].length() + 1) { return DNS_ANDROID_FAILURE; /* insufficient buffer space */ } strncpy(buffer, servers[index].c_str(), length); return DNS_ANDROID_SUCCESS; }