mDNS: store network interface, checking it is up

Author: d-a-v

cores/esp8266/AddrList.h

@@ -128,6 +128,7 @@ struct netifWrapper
     const char* ifmac () const      { return (const char*)_netif->hwaddr; }
     int ifnumber () const           { return _netif->num; }
     bool ifUp () const              { return !!(_netif->flags & NETIF_FLAG_UP); }
+    const netif* interface () const { return _netif; }
 
     const ip_addr_t* ipFromNetifNum () const
     {

libraries/ESP8266mDNS/src/LEAmDNS.cpp

@@ -59,11 +59,11 @@ MDNSResponder::MDNSResponder(void)
     m_pServiceQueries(0),
     m_fnServiceTxtCallback(0),
 #ifdef ENABLE_ESP_MDNS_RESPONDER_PASSIV_MODE
-    m_bPassivModeEnabled(true) {
+    m_bPassivModeEnabled(true),
 #else
-    m_bPassivModeEnabled(false) {
+    m_bPassivModeEnabled(false),
 #endif
-    
+    m_netif(nullptr) {
 }
 
 /*

libraries/ESP8266mDNS/src/LEAmDNS.h

@@ -1149,6 +1149,7 @@ class MDNSResponder {
     bool                            m_bPassivModeEnabled;
     stcProbeInformation             m_HostProbeInformation;
     IPAddress                       m_IPAddress;
+    const netif*                    m_netif; // network interface associated to m_IPAddress
 
     /** CONTROL **/
     /* MAINTENANCE */

libraries/ESP8266mDNS/src/LEAmDNS_Control.cpp

@@ -22,7 +22,6 @@
  *
  */
 
-#include <arch/cc.h>
 #include <sys/time.h>
 #include <IPAddress.h>
 #include <AddrList.h>
@@ -79,8 +78,10 @@ bool MDNSResponder::_process(bool p_bUserContext) {
         }
     }
     else {
-        bResult = _updateProbeStatus() &&           // Probing
-                  _checkServiceQueryCache();        // Service query cache check
+        bResult = (m_netif != nullptr) &&
+                  (m_netif->flags & NETIF_FLAG_UP) &&  // network interface is up and running
+                  _updateProbeStatus() &&              // Probing
+                  _checkServiceQueryCache();           // Service query cache check
     }
     return bResult;
 }
@@ -122,10 +123,12 @@ bool MDNSResponder::_restart(void) {
 
     // check existence of this IP address in the interface list
     bool found = false;
+    m_netif = nullptr;
     for (auto a: addrList)
         if (m_IPAddress == a.addr()) {
             if (a.ifUp()) {
                 found = true;
+                m_netif = a.interface();
                 break;
             }
             DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] found interface for IP '%s' but it is not UP\n"), m_IPAddress.toString().c_str()););