LEAmDNS: announce IPv6 addresses (AAAA) and use the IPv6 transport

libraries/ESP8266mDNS/src/LEAmDNS.cpp

@@ -29,6 +29,9 @@
 #include "LEAmDNS_Priv.h"
 #include <LwipIntf.h>
 #include <lwip/igmp.h>
+#if LWIP_IPV6
+#include <lwip/mld6.h>
+#endif
 #include <lwip/prot/dns.h>
 
 // should be defined at build time
@@ -1298,9 +1301,13 @@ namespace MDNSImplementation
         // Join multicast group(s)
         for (netif* pNetIf = netif_list; pNetIf; pNetIf = pNetIf->next)
         {
-            if (netif_is_up(pNetIf) && IPAddress(pNetIf->ip_addr).isSet())
+            if (!netif_is_up(pNetIf))
             {
+                continue;
+            }
 #ifdef MDNS_IP4_SUPPORT
+            if (IPAddress(pNetIf->ip_addr).isSet())
+            {
                 ip_addr_t multicast_addr_V4 = DNS_MQUERY_IPV4_GROUP_INIT;
                 if (!(pNetIf->flags & NETIF_FLAG_IGMP))
                 {
@@ -1326,21 +1333,22 @@ namespace MDNSImplementation
                              ": %s) FAILED!\n"),
                         NETIFID_VAL(pNetIf), IPAddress(multicast_addr_V4).toString().c_str()););
                 }
+            }
 #endif
-
-#ifdef MDNS_IPV6_SUPPORT
-                ip_addr_t multicast_addr_V6 = DNS_MQUERY_IPV6_GROUP_INIT;
-                bResult
-                    = ((bResult)
-                       && (ERR_OK == mld6_joingroup_netif(pNetIf, ip_2_ip6(&multicast_addr_V6))));
-                DEBUG_EX_ERR_IF(
-                    !bResult,
-                    DEBUG_OUTPUT.printf_P(
-                        PSTR("[MDNSResponder] _createHost: mld6_joingroup_netif (" NETIFID_STR
-                             ") FAILED!\n"),
-                        NETIFID_VAL(pNetIf)));
-#endif
+#if defined(MDNS_IP6_SUPPORT) || defined(MDNS_IP6_RESPONDER)
+            ip_addr_t multicast_addr_V6 = DNS_MQUERY_IPV6_GROUP_INIT;
+            if (ERR_OK == mld6_joingroup_netif(pNetIf, ip_2_ip6(&multicast_addr_V6)))
+            {
+                bResult = true;
+            }
+            else
+            {
+                DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(
+                    PSTR("[MDNSResponder] _createHost: mld6_joingroup_netif (" NETIFID_STR
+                         ") FAILED!\n"),
+                    NETIFID_VAL(pNetIf)););
             }
+#endif
         }
         return bResult;
     }
@@ -1354,19 +1362,20 @@ namespace MDNSImplementation
 
         for (netif* pNetIf = netif_list; pNetIf; pNetIf = pNetIf->next)
         {
-            if (netif_is_up(pNetIf) && IPAddress(pNetIf->ip_addr).isSet())
+            if (netif_is_up(pNetIf))
             {
                 bResult = true;
 
                 // Leave multicast group(s)
 #ifdef MDNS_IP4_SUPPORT
                 ip_addr_t multicast_addr_V4 = DNS_MQUERY_IPV4_GROUP_INIT;
-                if (ERR_OK != igmp_leavegroup_netif(pNetIf, ip_2_ip4(&multicast_addr_V4)))
+                if ((IPAddress(pNetIf->ip_addr).isSet())
+                    && (ERR_OK != igmp_leavegroup_netif(pNetIf, ip_2_ip4(&multicast_addr_V4))))
                 {
                     DEBUG_EX_ERR(DEBUG_OUTPUT.printf_P(PSTR("\n")););
                 }
 #endif
-#ifdef MDNS_IPV6_SUPPORT
+#if defined(MDNS_IP6_SUPPORT) || defined(MDNS_IP6_RESPONDER)
                 ip_addr_t multicast_addr_V6 = DNS_MQUERY_IPV6_GROUP_INIT;
                 if (ERR_OK
                     != mld6_leavegroup_netif(

libraries/ESP8266mDNS/src/LEAmDNS.h

@@ -135,12 +135,14 @@ namespace MDNSImplementation
 #define MDNS_IP4_SUPPORT
 #if LWIP_IPV6
 //#define MDNS_IP6_SUPPORT
+// Answer AAAA questions and announce the IPv6 addresses (over the IPv4 transport)
+#define MDNS_IP6_RESPONDER
 #endif
 
 #ifdef MDNS_IP4_SUPPORT
 #define MDNS_IP4_SIZE 4
 #endif
-#ifdef MDNS_IP6_SUPPORT
+#if defined(MDNS_IP6_SUPPORT) || defined(MDNS_IP6_RESPONDER)
 #define MDNS_IP6_SIZE 16
 #endif
 /*
@@ -1173,8 +1175,11 @@ namespace MDNSImplementation
         stcMDNSServiceQuery*              m_pServiceQueries;
         MDNSDynamicServiceTxtCallbackFunc m_fnServiceTxtCallback;
         stcProbeInformation               m_HostProbeInformation;
-        bool                              m_bLwipCb;
-        bool                              m_bRestarting;
+#ifdef MDNS_IP6_RESPONDER
+        uint8_t m_u8IP6AddressCount = 0;  // re-announce when it changes (SLAAC comes after DHCP)
+#endif
+        bool m_bLwipCb;
+        bool m_bRestarting;
 
         /** CONTROL **/
         /* MAINTENANCE */
@@ -1220,7 +1225,7 @@ namespace MDNSImplementation
         /* SENDING */
         bool _sendMDNSMessage(stcMDNSSendParameter& p_SendParameter);
         bool _sendMDNSMessage_Multicast(MDNSResponder::stcMDNSSendParameter& p_rSendParameter);
-        bool _prepareMDNSMessage(stcMDNSSendParameter& p_SendParameter, IPAddress p_IPAddress);
+        bool _prepareMDNSMessage(stcMDNSSendParameter& p_SendParameter, const netif* p_pNetIf);
         bool _sendMDNSServiceQuery(const stcMDNSServiceQuery& p_ServiceQuery);
         bool _sendMDNSQuery(const stcMDNS_RRDomain& p_QueryDomain, uint16_t p_u16QueryType,
                             stcMDNSServiceQuery::stcAnswer* p_pKnownAnswers = 0);
@@ -1316,8 +1321,11 @@ namespace MDNSImplementation
                                        stcMDNSSendParameter& p_rSendParameter);
         bool _writeMDNSAnswer_TXT(stcMDNSService&       p_rService,
                                   stcMDNSSendParameter& p_rSendParameter);
+#if defined(MDNS_IP6_SUPPORT) || defined(MDNS_IP6_RESPONDER)
+        static uint8_t _ip6AddressCount(const netif* p_pNetIf);
+        bool _writeMDNSAnswer_AAAA(const netif* p_pNetIf, stcMDNSSendParameter& p_rSendParameter);
+#endif
 #ifdef MDNS_IP6_SUPPORT
-        bool _writeMDNSAnswer_AAAA(IPAddress p_IPAddress, stcMDNSSendParameter& p_rSendParameter);
         bool _writeMDNSAnswer_PTR_IP6(IPAddress             p_IPAddress,
                                       stcMDNSSendParameter& p_rSendParameter);
 #endif

libraries/ESP8266mDNS/src/LEAmDNS_Control.cpp

@@ -86,6 +86,16 @@ namespace MDNSImplementation
         {
             bResult = _updateProbeStatus() &&     // Probing
                       _checkServiceQueryCache();  // Service query cache check
+#ifdef MDNS_IP6_RESPONDER
+            // IP6 addresses (SLAAC) usually come after the IP4 one, announce them once they do
+            const uint8_t u8IP6Count = _ip6AddressCount(0);
+            if ((ProbingStatus_Done == m_HostProbeInformation.m_ProbingStatus)
+                && (u8IP6Count != m_u8IP6AddressCount))
+            {
+                m_u8IP6AddressCount = u8IP6Count;
+                _announce(true, true);  // Services too, in an IP6 only net nothing went out yet
+            }
+#endif
         }
         return bResult;
     }
@@ -1778,6 +1788,9 @@ namespace MDNSImplementation
             sendParameter.m_u8HostReplyMask |= ContentFlag_A;        // A answer
             sendParameter.m_u8HostReplyMask |= ContentFlag_PTR_IP4;  // PTR_IP4 answer
 #endif
+#ifdef MDNS_IP6_RESPONDER
+            sendParameter.m_u8HostReplyMask |= ContentFlag_AAAA;  // AAAA answer
+#endif
 #ifdef MDNS_IP6_SUPPORT
             sendParameter.m_u8HostReplyMask |= ContentFlag_AAAA;     // AAAA answer
             sendParameter.m_u8HostReplyMask |= ContentFlag_PTR_IP6;  // PTR_IP6 answer
@@ -2258,7 +2271,7 @@ namespace MDNSImplementation
                     u8ReplyMask |= ContentFlag_A;
                 }
 #endif
-#ifdef MDNS_IP6_SUPPORT
+#if defined(MDNS_IP6_SUPPORT) || defined(MDNS_IP6_RESPONDER)
                 if ((DNS_RRTYPE_AAAA == p_RRHeader.m_Attributes.m_u16Type)
                     || (DNS_RRTYPE_ANY == p_RRHeader.m_Attributes.m_u16Type))
                 {

libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp

@@ -180,7 +180,11 @@ namespace MDNSImplementation
         m_pUDPContext = new UdpContext;
         m_pUDPContext->ref();
 
+#ifdef MDNS_IP6_RESPONDER
+        if (m_pUDPContext->listen(IP_ANY_TYPE, DNS_MQUERY_PORT))  // IP4 and IP6
+#else
         if (m_pUDPContext->listen(IP4_ADDR_ANY, DNS_MQUERY_PORT))
+#endif
         {
             m_pUDPContext->setMulticastTTL(MDNS_MULTICAST_TTL);
             m_pUDPContext->onRx(std::bind(&MDNSResponder::_callProcess, this));