[wpinet] Add callback for mDNS service resolver (#7986)

wpinet/src/main/native/include/wpinet/MulticastServiceResolver.h

@@ -21,9 +21,9 @@ class MulticastServiceResolver {
   explicit MulticastServiceResolver(std::string_view serviceType);
   ~MulticastServiceResolver() noexcept;
   struct ServiceData {
-    /// IPv4 address.
+    /// IPv4 address in host order.
     unsigned int ipv4Address;
-    /// Port number.
+    /// Port number in host order.
     int port;
     /// Service name.
     std::string serviceName;
@@ -32,6 +32,17 @@ class MulticastServiceResolver {
     /// Service data payload.
     std::vector<std::pair<std::string, std::string>> txt;
   };
+  /**
+   * Set a copy callback to be called when a service is resolved.
+   * Takes presidence over the move callback. Return true to
+   * not send the data to the event queue.
+   */
+  bool SetCopyCallback(std::function<bool(const ServiceData&)> callback);
+  /**
+   * Set a move callback to be called when a service is resolved.
+   * Data is moved into the function and cannot be added to the event queue.
+   */
+  bool SetMoveCallback(std::function<void(ServiceData&&)> callback);
   /**
    * Starts multicast service resolver.
    */
@@ -72,12 +83,23 @@ class MulticastServiceResolver {
  private:
   void PushData(ServiceData&& data) {
     std::scoped_lock lock{mutex};
-    queue.emplace_back(std::forward<ServiceData>(data));
-    event.Set();
+    if (copyCallback) {
+      if (!copyCallback(data)) {
+        queue.emplace_back(std::forward<ServiceData>(data));
+        event.Set();
+      }
+    } else if (moveCallback) {
+      moveCallback(std::move(data));
+    } else {
+      queue.emplace_back(std::forward<ServiceData>(data));
+      event.Set();
+    }
   }
   wpi::Event event{true};
   std::vector<ServiceData> queue;
   wpi::mutex mutex;
+  std::function<bool(const ServiceData&)> copyCallback;
+  std::function<void(ServiceData&&)> moveCallback;
   std::unique_ptr<Impl> pImpl;
 };
 }  // namespace wpi

wpinet/src/main/native/linux/MulticastServiceResolver.cpp

@@ -4,6 +4,8 @@
 
 #include "wpinet/MulticastServiceResolver.h"
 
+#include <arpa/inet.h>
+
 #include <memory>
 #include <string>
 #include <utility>
@@ -44,6 +46,26 @@ bool MulticastServiceResolver::HasImplementation() const {
   return pImpl->table.IsValid();
 }
 
+bool MulticastServiceResolver::SetCopyCallback(
+    std::function<bool(const ServiceData&)> callback) {
+  std::scoped_lock lock{*pImpl->thread};
+  if (pImpl->client) {
+    return false;
+  }
+  copyCallback = std::move(callback);
+  return true;
+}
+
+bool MulticastServiceResolver::SetMoveCallback(
+    std::function<void(ServiceData&&)> callback) {
+  std::scoped_lock lock{*pImpl->thread};
+  if (pImpl->client) {
+    return false;
+  }
+  moveCallback = std::move(callback);
+  return true;
+}
+
 static void ResolveCallback(AvahiServiceResolver* r, AvahiIfIndex interface,
                             AvahiProtocol protocol, AvahiResolverEvent event,
                             const char* name, const char* type,
@@ -83,8 +105,8 @@ static void ResolveCallback(AvahiServiceResolver* r, AvahiIfIndex interface,
         outputHostName.append(".");
       } while (true);
 
-      data.ipv4Address = address->data.ipv4.address;
-      data.port = port;
+      data.ipv4Address = ntohl(address->data.ipv4.address);
+      data.port = ntohs(port);
       data.serviceName = name;
       data.hostName = std::string{outputHostName};
 

wpinet/src/main/native/macOS/MulticastServiceResolver.cpp

@@ -72,8 +72,8 @@ void ServiceGetAddrInfoReply(DNSServiceRef sdRef, DNSServiceFlags flags,
   DnsResolveState* resolveState = static_cast<DnsResolveState*>(context);
 
   resolveState->data.hostName = hostname;
-  resolveState->data.ipv4Address =
-      reinterpret_cast<const struct sockaddr_in*>(address)->sin_addr.s_addr;
+  resolveState->data.ipv4Address = ntohl(
+      reinterpret_cast<const struct sockaddr_in*>(address)->sin_addr.s_addr);
 
   resolveState->pImpl->onFound(std::move(resolveState->data));
 
@@ -179,6 +179,24 @@ bool MulticastServiceResolver::HasImplementation() const {
   return true;
 }
 
+bool MulticastServiceResolver::SetCopyCallback(
+    std::function<bool(const ServiceData&)> callback) {
+  if (pImpl->serviceRef) {
+    return false;
+  }
+  copyCallback = std::move(callback);
+  return true;
+}
+
+bool MulticastServiceResolver::SetMoveCallback(
+    std::function<void(ServiceData&&)> callback) {
+  if (pImpl->serviceRef) {
+    return false;
+  }
+  moveCallback = std::move(callback);
+  return true;
+}
+
 void MulticastServiceResolver::Start() {
   if (pImpl->serviceRef) {
     return;

wpinet/src/main/native/windows/MulticastServiceResolver.cpp

@@ -65,9 +65,31 @@ bool MulticastServiceResolver::HasImplementation() const {
   return pImpl->dynamicDns.CanDnsResolve;
 }
 
+bool MulticastServiceResolver::SetCopyCallback(
+    std::function<bool(const ServiceData&)> callback) {
+  if (pImpl->serviceCancel.reserved != nullptr) {
+    return false;
+  }
+  copyCallback = std::move(callback);
+  return true;
+}
+
+bool MulticastServiceResolver::SetMoveCallback(
+    std::function<void(ServiceData&&)> callback) {
+  if (pImpl->serviceCancel.reserved != nullptr) {
+    return false;
+  }
+  moveCallback = std::move(callback);
+  return true;
+}
+
 static _Function_class_(DNS_QUERY_COMPLETION_ROUTINE) VOID WINAPI
     DnsCompletion(_In_ PVOID pQueryContext,
                   _Inout_ PDNS_QUERY_RESULT pQueryResults) {
+  if (pQueryResults->QueryStatus != ERROR_SUCCESS) {
+    return;
+  }
+
   MulticastServiceResolver::Impl* impl =
       reinterpret_cast<MulticastServiceResolver::Impl*>(pQueryContext);
 
@@ -167,8 +189,8 @@ static _Function_class_(DNS_QUERY_COMPLETION_ROUTINE) VOID WINAPI
         wpi::convertUTF16ToUTF8String(wideServiceName, storage);
 
         data.serviceName = std::string{storage};
-        data.port = foundSrv->Data.Srv.wPort;
-        data.ipv4Address = A->Data.A.IpAddress;
+        data.port = ntohs(foundSrv->Data.Srv.wPort);
+        data.ipv4Address = ntohl(A->Data.A.IpAddress);
 
         impl->onFound(std::move(data));
       }