envoy attempt to match istio wildcard port listener

source/common/network/utility.cc

@@ -281,6 +281,44 @@ bool Utility::isLocalConnection(const Network::ConnectionSocket& socket) {
   return false;
 }
 
+bool Utility::isLocalIpAddress(const Address::Instance& address) {
+  if (address.type() != Envoy::Network::Address::Type::Ip) {
+    return false;
+  }
+
+  if (isLoopbackAddress(address)) {
+    return false;
+  }
+
+  struct ifaddrs* ifaddr;
+  const int rc = getifaddrs(&ifaddr);
+  Cleanup ifaddr_cleanup([ifaddr] {
+    if (ifaddr) {
+      freeifaddrs(ifaddr);
+    }
+  });
+  RELEASE_ASSERT(rc == 0, "");
+
+  auto af_look_up = (address.ip()->version() == Address::IpVersion::v4) ? AF_INET : AF_INET6;
+
+  for (struct ifaddrs* ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next) {
+    if (ifa->ifa_addr == nullptr) {
+      continue;
+    }
+
+    if (ifa->ifa_addr->sa_family == af_look_up) {
+      const auto* addr = reinterpret_cast<const struct sockaddr_storage*>(ifa->ifa_addr);
+      auto local_address = Address::addressFromSockAddr(
+          *addr, (af_look_up == AF_INET) ? sizeof(sockaddr_in) : sizeof(sockaddr_in6));
+
+      if (address == *local_address) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 bool Utility::isInternalAddress(const Address::Instance& address) {
   if (address.type() != Address::Type::Ip) {
     return false;

source/common/network/utility.h

@@ -139,6 +139,12 @@ class Utility {
    */
   static bool isLocalConnection(const Network::ConnectionSocket& socket);
 
+  /**
+   * Determine whether this is a local address.
+   * @return bool the address is a local address.
+   */
+  static bool isLocalIpAddress(const Address::Instance& address);
+
   /**
    * Determine whether this is an internal (RFC1918) address.
    * @return bool the address is an RFC1918 address.

source/server/connection_handler_impl.cc

@@ -126,6 +126,27 @@ ConnectionHandlerImpl::findActiveListenerByAddress(const Network::Address::Insta
     return listener_it->second.get();
   }
 
+  /*
+   * istio: if the ip is local pod ip, select the predefined listener
+   * 1. where can I find the pod ip?
+   * env:      INSTANCE_IP:                        (v1:status.podIP)
+   *
+   * 2. What the predefined listener should be?
+   */
+  if (Network::Utility::isLocalIpAddress(address)) {
+    ENVOY_LOG_TO_LOGGER(
+        logger_, error,
+        "dest ip {} is local address but hit no listener, try using blackhole listener",
+        address.ip()->addressAsString());
+    listener_it = std::find_if(
+        listeners_.begin(), listeners_.end(),
+        [](const std::pair<Network::Address::InstanceConstSharedPtr, ActiveListenerPtr>& p) {
+          return p.second->config_.name() == "ISTIO_WILDCARD_PORT_LISTENER";
+        });
+    if (listener_it != listeners_.end()) {
+      return listener_it->second.get();
+    }
+  }
   // Otherwise, we need to look for the wild card match, i.e., 0.0.0.0:[address_port].
   // We do not return stopped listeners.
   // TODO(wattli): consolidate with previous search for more efficiency.