Merge pull request #432 from davidalo/add-targethostip-option

 Add targetHostIp option, support concurrent STA in Android

Author: RonRadtke

android/src/main/java/com/ReactNativeBlobUtil/ReactNativeBlobUtilConfig.java

@@ -14,6 +14,7 @@ class ReactNativeBlobUtilConfig {
     public ReadableMap addAndroidDownloads;
     public Boolean trusty;
     public Boolean wifiOnly = false;
+    public String targetHostIp;
     public String key;
     public String mime;
     public Boolean auto;
@@ -32,6 +33,7 @@ class ReactNativeBlobUtilConfig {
         this.appendExt = options.hasKey("appendExt") ? options.getString("appendExt") : "";
         this.trusty = options.hasKey("trusty") && options.getBoolean("trusty");
         this.wifiOnly = options.hasKey("wifiOnly") && options.getBoolean("wifiOnly");
+        this.targetHostIp = options.hasKey("targetHostIp") ? options.getString("targetHostIp") : "";
         if (options.hasKey("addAndroidDownloads")) {
             this.addAndroidDownloads = options.getMap("addAndroidDownloads");
         }

android/src/main/java/com/ReactNativeBlobUtil/ReactNativeBlobUtilReq.java

@@ -11,6 +11,9 @@
 import android.net.NetworkCapabilities;
 import android.net.NetworkInfo;
 import android.net.Uri;
+import android.net.LinkProperties;
+import android.net.LinkAddress;
+import java.net.Inet4Address;  
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
@@ -388,33 +391,43 @@ else if (this.options.fileCache)
 
             // wifi only, need ACCESS_NETWORK_STATE permission
             // and API level >= 21
+            boolean targetHostIpAvailable = (this.options.targetHostIp != null && !this.options.targetHostIp.isEmpty());
             if (this.options.wifiOnly) {
-
                 boolean found = false;
 
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                     ConnectivityManager connectivityManager = (ConnectivityManager) ReactNativeBlobUtilImpl.RCTContext.getSystemService(ReactNativeBlobUtilImpl.RCTContext.CONNECTIVITY_SERVICE);
                     Network[] networks = connectivityManager.getAllNetworks();
-
+                    Network selectedNetwork;
+                    
                     for (Network network : networks) {
 
-                        NetworkInfo netInfo = connectivityManager.getNetworkInfo(network);
-                        NetworkCapabilities caps = connectivityManager.getNetworkCapabilities(network);
-
-                        if (caps == null || netInfo == null) {
+                        if (!isValidWifiNetwork(connectivityManager, network)) {
                             continue;
                         }
 
-                        if (!netInfo.isConnected()) {
-                            continue;
-                        }
+                        // if targetHostIpAvailable does not match, fallback to any wifi
+                        if (targetHostIpAvailable) {
+                            String targetHostIp = this.options.targetHostIp;
 
-                        if (caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
+                            if (networkMatchesTargetIp(connectivityManager, network, targetHostIp)) {
+                                clientBuilder.proxy(Proxy.NO_PROXY);
+                                clientBuilder.socketFactory(network.getSocketFactory());
+                                found = true;
+                                break;
+                            }
+                        } 
+                        
+                        // wifiOnly. selects the first interface with wifi transport
+                        // if targetHostIp is available and it matches, this selection will be overriden
+                        if (!found) {
                             clientBuilder.proxy(Proxy.NO_PROXY);
                             clientBuilder.socketFactory(network.getSocketFactory());
                             found = true;
-                            break;
 
+                            if (!targetHostIpAvailable) {
+                                break;
+                            }
                         }
                     }
 
@@ -423,10 +436,12 @@ else if (this.options.fileCache)
                         releaseTaskResource();
                         return;
                     }
+
+
                 } else {
-                    ReactNativeBlobUtilUtils.emitWarningEvent("ReactNativeBlobUtil: wifiOnly was set, but SDK < 21. wifiOnly was ignored.");
+                    ReactNativeBlobUtilUtils.emitWarningEvent("ReactNativeBlobUtil: wifiOnly or targetHostIp was set, but SDK < 21. wifiOnly was ignored.");
                 }
-            }
+            } 
 
             final Request.Builder builder = new Request.Builder();
             try {
@@ -1011,4 +1026,50 @@ public static OkHttpClient.Builder enableTls12OnPreLollipop(OkHttpClient.Builder
 
         return client;
     }
+
+    /**
+     * Check if a network is a valid connected WiFi network
+     */
+    private boolean isValidWifiNetwork(ConnectivityManager cm, Network network) {
+        NetworkInfo netInfo = cm.getNetworkInfo(network);
+        NetworkCapabilities caps = cm.getNetworkCapabilities(network);
+        
+        if (caps == null || netInfo == null) {
+            return false;
+        }
+        
+        if (!netInfo.isConnected()) {
+            return false;
+        }
+        
+        return caps.hasTransport(NetworkCapabilities.TRANSPORT_WIFI);
+    }
+
+    /**
+     * Check if a network matches the target host IP address
+     */
+    private boolean networkMatchesTargetIp(ConnectivityManager cm, Network network, String targetHostIp) {
+        LinkProperties lp = cm.getLinkProperties(network);
+        if (lp == null) return false;
+        
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            // For Android R and above, use DHCP server address
+            Inet4Address dhcpServer = lp.getDhcpServerAddress();
+            if (dhcpServer != null && dhcpServer.getHostAddress().equals(targetHostIp)) {
+                return true;
+            }
+        }
+        
+        // Always fall back to linkAddresses check
+        List<LinkAddress> linkAddresses = lp.getLinkAddresses();
+        if (linkAddresses != null && !linkAddresses.isEmpty()) {
+            for (LinkAddress la : linkAddresses) {
+                if (la.getAddress().getHostAddress().equals(targetHostIp)) {
+                    return true;
+                }
+            }
+        }
+        
+        return false;
+    }
 }