make VirtualNetworkDNS a plain data class

java/jni/ZT_jnicache.cpp

@@ -114,8 +114,6 @@ jmethodID VirtualNetworkType_fromInt_method;
 // Instance fields
 //
 
-jfieldID VirtualNetworkDNS_domain_field;
-jfieldID VirtualNetworkDNS_servers_field;
 jfieldID VirtualNetworkRoute_flags_field;
 jfieldID VirtualNetworkRoute_metric_field;
 jfieldID VirtualNetworkRoute_target_field;
@@ -188,7 +186,7 @@ void setupJNICache(JavaVM *vm) {
     EXCEPTIONANDNULLCHECK(Version_ctor = env->GetMethodID(Version_class, "<init>", "(III)V"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkConfigListener_onNetworkConfigurationUpdated_method = env->GetMethodID(VirtualNetworkConfigListener_class, "onNetworkConfigurationUpdated", "(JLcom/zerotier/sdk/VirtualNetworkConfigOperation;Lcom/zerotier/sdk/VirtualNetworkConfig;)I"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkConfig_ctor = env->GetMethodID(VirtualNetworkConfig_class, "<init>", "(JJLjava/lang/String;Lcom/zerotier/sdk/VirtualNetworkStatus;Lcom/zerotier/sdk/VirtualNetworkType;IZZZIJ[Ljava/net/InetSocketAddress;[Lcom/zerotier/sdk/VirtualNetworkRoute;Lcom/zerotier/sdk/VirtualNetworkDNS;)V"));
-    EXCEPTIONANDNULLCHECK(VirtualNetworkDNS_ctor = env->GetMethodID(VirtualNetworkDNS_class, "<init>", "()V"));
+    EXCEPTIONANDNULLCHECK(VirtualNetworkDNS_ctor = env->GetMethodID(VirtualNetworkDNS_class, "<init>", "(Ljava/lang/String;Ljava/util/ArrayList;)V"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkFrameListener_onVirtualNetworkFrame_method = env->GetMethodID(VirtualNetworkFrameListener_class, "onVirtualNetworkFrame", "(JJJJJ[B)V"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkRoute_ctor = env->GetMethodID(VirtualNetworkRoute_class, "<init>", "()V"));
 
@@ -208,8 +206,6 @@ void setupJNICache(JavaVM *vm) {
     // Instance fields
     //
 
-    EXCEPTIONANDNULLCHECK(VirtualNetworkDNS_domain_field = env->GetFieldID(VirtualNetworkDNS_class, "domain", "Ljava/lang/String;"));
-    EXCEPTIONANDNULLCHECK(VirtualNetworkDNS_servers_field = env->GetFieldID(VirtualNetworkDNS_class, "servers", "Ljava/util/ArrayList;"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkRoute_flags_field = env->GetFieldID(VirtualNetworkRoute_class, "flags", "I"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkRoute_metric_field = env->GetFieldID(VirtualNetworkRoute_class, "metric", "I"));
     EXCEPTIONANDNULLCHECK(VirtualNetworkRoute_target_field = env->GetFieldID(VirtualNetworkRoute_class, "target", "Ljava/net/InetSocketAddress;"));

java/jni/ZT_jnicache.h

@@ -83,8 +83,6 @@ extern jmethodID VirtualNetworkType_fromInt_method;
 // Instance fields
 //
 
-extern jfieldID VirtualNetworkDNS_domain_field;
-extern jfieldID VirtualNetworkDNS_servers_field;
 extern jfieldID VirtualNetworkRoute_flags_field;
 extern jfieldID VirtualNetworkRoute_metric_field;
 extern jfieldID VirtualNetworkRoute_target_field;

java/jni/ZT_jniutils.cpp

@@ -353,37 +353,64 @@ jobject newVirtualNetworkRoute(JNIEnv *env, const ZT_VirtualNetworkRoute &route)
     return routeObj;
 }
 
+//
+// may return NULL
+//
 jobject newVirtualNetworkDNS(JNIEnv *env, const ZT_VirtualNetworkDNS &dns)
 {
-    jobject dnsObj = env->NewObject(VirtualNetworkDNS_class, VirtualNetworkDNS_ctor);
-    if(env->ExceptionCheck() || dnsObj == NULL) {
+    if (strlen(dns.domain) == 0) {
+        LOGD("dns.domain is empty; returning NULL");
         return NULL;
     }
 
-    if (strlen(dns.domain) > 0) {
+    jstring domain = env->NewStringUTF(dns.domain);
+    if (env->ExceptionCheck() || domain == NULL) {
+        LOGE("Exception creating new string");
+        return NULL;
+    }
 
-        jstring domain = env->NewStringUTF(dns.domain);
+    jobject addrList = env->NewObject(ArrayList_class, ArrayList_ctor, 0);
+    if (env->ExceptionCheck() || addrList == NULL) {
+        LOGE("Exception creating new ArrayList");
+        return NULL;
+    }
 
-        jobject addrArray = env->NewObject(ArrayList_class, ArrayList_ctor, 0);
+    for (int i = 0; i < ZT_MAX_DNS_SERVERS; ++i) { //NOLINT
 
-        struct sockaddr_storage nullAddr;
-        memset(&nullAddr, 0, sizeof(struct sockaddr_storage));
-        for(int i = 0; i < ZT_MAX_DNS_SERVERS; ++i) {
-            struct sockaddr_storage tmp = dns.server_addr[i];
+        struct sockaddr_storage tmp = dns.server_addr[i];
 
-            if (memcmp(&tmp, &nullAddr, sizeof(struct sockaddr_storage)) != 0) {
-                jobject addr = newInetSocketAddress(env, tmp);
-                env->CallBooleanMethod(addrArray, ArrayList_add_method, addr);
-                env->DeleteLocalRef(addr);
-            }
+        //
+        // may be NULL
+        //
+        jobject addr = newInetSocketAddress(env, tmp);
+        if (env->ExceptionCheck()) {
+            return NULL;
         }
 
-        env->SetObjectField(dnsObj, VirtualNetworkDNS_domain_field, domain);
-        env->SetObjectField(dnsObj, VirtualNetworkDNS_servers_field, addrArray);
+        if (addr == NULL) {
+            continue;
+        }
 
-        return dnsObj;
+        env->CallBooleanMethod(addrList, ArrayList_add_method, addr);
+        if(env->ExceptionCheck())
+        {
+            LOGE("Exception calling add");
+            return NULL;
+        }
+
+        env->DeleteLocalRef(addr);
+    }
+
+    jobject dnsObj = env->NewObject(
+            VirtualNetworkDNS_class,
+            VirtualNetworkDNS_ctor,
+            domain,
+            addrList);
+    if (env->ExceptionCheck() || dnsObj == NULL) {
+        LOGE("Exception creating new VirtualNetworkDNS");
+        return NULL;
     }
-    return NULL;
+    return dnsObj;
 }
 
 jobject newNodeStatus(JNIEnv *env, const ZT_NodeStatus &status) {

java/src/com/zerotier/sdk/VirtualNetworkDNS.java

@@ -8,11 +8,25 @@ package com.zerotier.sdk;
 import java.net.InetSocketAddress;
 import java.util.ArrayList;
 
+/**
+ * DNS configuration to be pushed on a virtual network
+ *
+ * Defined in ZeroTierOne.h as ZT_VirtualNetworkDNS
+ */
 public class VirtualNetworkDNS implements Comparable<VirtualNetworkDNS> {
-    private String domain;
-    private ArrayList<InetSocketAddress> servers;
 
-    public VirtualNetworkDNS() {}
+    private final String domain;
+    private final ArrayList<InetSocketAddress> servers;
+
+    public VirtualNetworkDNS(String domain, ArrayList<InetSocketAddress> servers) {
+        this.domain = domain;
+        this.servers = servers;
+    }
+
+    @Override
+    public String toString() {
+        return "VirtualNetworkDNS(" + domain + ", " + servers + ")";
+    }
 
     @Override
     public boolean equals(Object o) {
@@ -53,7 +67,11 @@ public class VirtualNetworkDNS implements Comparable<VirtualNetworkDNS> {
         return result;
     }
 
-    public String getSearchDomain() { return domain; }
+    public String getDomain() {
+        return domain;
+    }
 
-    public ArrayList<InetSocketAddress> getServers() { return servers; }
+    public ArrayList<InetSocketAddress> getServers() {
+        return servers;
+    }
 }