(WIP) mDNS: single instance for all interfaces (udp: +multicast on all interfaces)

libraries/ESP8266WiFi/src/WiFiUdp.cpp

@@ -85,6 +85,11 @@ uint8_t WiFiUDP::begin(uint16_t port)
     return (_ctx->listen(IPAddress(), port)) ? 1 : 0;
 }
 
+uint8_t WiFiUDP::beginMulticast(IPAddress multicast, uint16_t port)
+{
+    return beginMulticast(IPAddress(IP4_ADDR_ANY), multicast, port);
+}
+
 uint8_t WiFiUDP::beginMulticast(IPAddress interfaceAddr, IPAddress multicast, uint16_t port)
 {
     if (_ctx) {
@@ -156,11 +161,7 @@ int WiFiUDP::beginPacket(IPAddress ip, uint16_t port)
 int WiFiUDP::beginPacketMulticast(IPAddress multicastAddress, uint16_t port,
     IPAddress interfaceAddress, int ttl)
 {
-    if (!_ctx) {
-        _ctx = new UdpContext;
-        _ctx->ref();
-    }
-    if (!_ctx->connect(multicastAddress, port)) {
+    if (!beginPacket(multicastAddress, port)) {
         return 0;
     }
     _ctx->setMulticastInterface(interfaceAddress);
@@ -176,6 +177,14 @@ int WiFiUDP::endPacket()
     return (_ctx->send()) ? 1 : 0;
 }
 
+int WiFiUDP::endPacketOverMulticast()
+{
+    if (!_ctx)
+        return 0;
+
+    return (_ctx->send_multicast_all()) ? 1 : 0;
+}
+
 size_t WiFiUDP::write(uint8_t byte)
 {
     return write(&byte, 1);

libraries/ESP8266WiFi/src/WiFiUdp.h

@@ -48,15 +48,18 @@ class WiFiUDP : public UDP, public SList<WiFiUDP> {
   void stop() override;
   // join a multicast group and listen on the given port
   uint8_t beginMulticast(IPAddress interfaceAddr, IPAddress multicast, uint16_t port);
+  uint8_t beginMulticast(IPAddress multicast, uint16_t port);
 
   // Sending UDP packets
 
   // Start building up a packet to send to the remote host specific in ip and port
   // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
   int beginPacket(IPAddress ip, uint16_t port) override;
+
   // Start building up a packet to send to the remote host specific in host and port
   // Returns 1 if successful, 0 if there was a problem resolving the hostname or port
   int beginPacket(const char *host, uint16_t port) override;
+
   // Start building up a packet to send to the multicast address
   // multicastAddress - muticast address to send to
   // interfaceAddress - the local IP address of the interface that should be used
@@ -67,9 +70,14 @@ class WiFiUDP : public UDP, public SList<WiFiUDP> {
                                    uint16_t port, 
                                    IPAddress interfaceAddress,
                                    int ttl = 1);
+
   // Finish off this packet and send it
   // Returns 1 if the packet was sent successfully, 0 if there was an error
   int endPacket() override;
+
+  int beginPacketOverMulticast(const IPAddress& ip, uint16_t port) { return beginPacket(ip, port); }
+  int endPacketOverMulticast();
+
   // Write a single byte into the packet
   size_t write(uint8_t) override;
   // Write size bytes from buffer into the packet

libraries/ESP8266WiFi/src/include/UdpContext.h

@@ -419,7 +419,7 @@ class UdpContext
         return size;
     }
 
-    bool send(CONST ip_addr_t* addr = 0, uint16_t port = 0)
+    bool send(CONST ip_addr_t* addr = 0, uint16_t port = 0, bool release_source = true)
     {
         size_t data_size = _tx_buf_offset;
         pbuf* tx_copy = pbuf_alloc(PBUF_TRANSPORT, data_size, PBUF_RAM);
@@ -435,39 +435,81 @@ class UdpContext
                 data_size -= will_copy;
             }
         }
-        if (_tx_buf_head)
-            pbuf_free(_tx_buf_head);
-        _tx_buf_head = 0;
-        _tx_buf_cur = 0;
-        _tx_buf_offset = 0;
+        if (release_source) {
+            reset_send_buffer();
+        }
         if(!tx_copy){
             return false;
         }
 
-
         if (!addr) {
             addr = &_pcb->remote_ip;
             port = _pcb->remote_port;
         }
-#ifdef LWIP_MAYBE_XCC
-        uint16_t old_ttl = _pcb->ttl;
-        if (ip_addr_ismulticast(addr)) {
-            _pcb->ttl = _mcast_ttl;
-        }
-#endif
+
         err_t err = udp_sendto(_pcb, tx_copy, addr, port);
         if (err != ERR_OK) {
             DEBUGV(":ust rc=%d\r\n", (int) err);
         }
-#ifdef LWIP_MAYBE_XCC
-        _pcb->ttl = old_ttl;
-#endif
+
         pbuf_free(tx_copy);
         return err == ERR_OK;
     }
 
+    bool send_multicast_all (CONST ip_addr_t* addr = 0, uint16_t port = 0)
+    {
+        if (!addr) {
+            addr = &_pcb->remote_ip;
+            port = _pcb->remote_port;
+        }
+        if (!ip_addr_ismulticast(addr))
+        {
+            return false;
+        }
+
+        // backup PCB multicast settings
+
+        // backup multicast IPv4 address
+        ip4_addr_t backup_mcast_addr;
+        ip4_addr_set(&backup_mcast_addr, udp_get_multicast_netif_addr(_pcb));
+        // reset it in PCB (may be useless, interface setting is used first (i set)))
+        ip4_addr_set_any(udp_get_multicast_netif_addr(_pcb));
+        // backup multicast interface (will be overwritten)
+        u8_t backup_mcast_index = udp_get_multicast_netif_index(_pcb);
+
+        // loop on all interfaces and send
+
+        bool ret = false;
+        for (netif* nif = netif_list; nif; nif = nif->next)
+            if (netif_is_up(nif))
+            {
+                // change multicast interface
+                setMulticastInterface(nif);
+                ret = ret || send(addr, port, false);
+            }
+
+        // release source
+        reset_send_buffer();
+        // ^^ optimization path: avoid tx_copy multiple times in ::send(,,false)
+
+        // restore PCB multicast settings
+        udp_set_multicast_netif_index(_pcb, backup_mcast_index);
+        udp_set_multicast_netif_addr(_pcb, &backup_mcast_addr);
+
+        return ret;
+    }
+
 private:
 
+    void reset_send_buffer ()
+    {
+        if (_tx_buf_head)
+            pbuf_free(_tx_buf_head);
+        _tx_buf_head = 0;
+        _tx_buf_cur = 0;
+        _tx_buf_offset = 0;
+    }
+
     size_t _processSize (const pbuf* pb)
     {
         size_t ret = 0;

libraries/ESP8266mDNS/src/LEAmDNS.cpp

@@ -62,11 +62,10 @@ 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)
 {
 }
 
@@ -95,89 +94,33 @@ MDNSResponder::~MDNSResponder(void)
 bool MDNSResponder::begin(const char* p_pcHostname, const IPAddress& p_IPAddress, uint32_t p_u32TTL)
 {
 
+    (void)p_IPAddress;
     (void)p_u32TTL; // ignored
     bool    bResult = false;
 
     if (0 == m_pUDPContext)
     {
         if (_setHostname(p_pcHostname))
         {
-
-            //// select interface
-
-            m_netif = nullptr;
-            IPAddress ipAddress = p_IPAddress;
-
-            if (!ipAddress.isSet())
-            {
-
-                IPAddress sta = WiFi.localIP();
-                IPAddress ap = WiFi.softAPIP();
-
-                if (sta.isSet())
-                {
-                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] STA interface selected\n")));
-                    ipAddress = sta;
-                }
-                else if (ap.isSet())
-                {
-                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] AP interface selected\n")));
-                    ipAddress = ap;
-                }
-                else
-                {
-                    DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] standard interfaces are not up, please specify one in ::begin()\n")));
-                    return false;
-                }
-
-                // continue to ensure interface is UP
-            }
-
-            // check existence of this IP address in the interface list
-            bool found = false;
-            m_netif = nullptr;
-            for (auto a : addrList)
-                if (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"), ipAddress.toString().c_str()););
-                }
-            if (!found)
-            {
-                DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] interface defined by IP '%s' not found\n"), ipAddress.toString().c_str()););
-                return false;
-            }
-
-            //// done selecting the interface
-
-            if (m_netif->num == STATION_IF)
+            m_GotIPHandler = WiFi.onStationModeGotIP([this](const WiFiEventStationModeGotIP & pEvent)
             {
-
-                m_GotIPHandler = WiFi.onStationModeGotIP([this](const WiFiEventStationModeGotIP & pEvent)
+                (void) pEvent;
+                // Ensure that _restart() runs in USER context
+                schedule_function([this]()
                 {
-                    (void) pEvent;
-                    // Ensure that _restart() runs in USER context
-                    schedule_function([this]()
-                    {
-                        MDNSResponder::_restart();
-                    });
+                    MDNSResponder::_restart();
                 });
+            });
 
-                m_DisconnectedHandler = WiFi.onStationModeDisconnected([this](const WiFiEventStationModeDisconnected & pEvent)
+            m_DisconnectedHandler = WiFi.onStationModeDisconnected([this](const WiFiEventStationModeDisconnected & pEvent)
+            {
+                (void) pEvent;
+                // Ensure that _restart() runs in USER context
+                schedule_function([this]()
                 {
-                    (void) pEvent;
-                    // Ensure that _restart() runs in USER context
-                    schedule_function([this]()
-                    {
-                        MDNSResponder::_restart();
-                    });
+                    MDNSResponder::_restart();
                 });
-            }
+            });
 
             bResult = _restart();
         }

libraries/ESP8266mDNS/src/LEAmDNS.h

@@ -1203,7 +1203,6 @@ class MDNSResponder
     MDNSDynamicServiceTxtCallbackFunc m_fnServiceTxtCallback;
     bool                            m_bPassivModeEnabled;
     stcProbeInformation             m_HostProbeInformation;
-    CONST netif*                    m_netif; // network interface to run on
 
     /** CONTROL **/
     /* MAINTENANCE */
@@ -1260,7 +1259,7 @@ class MDNSResponder
 
     const IPAddress _getResponseMulticastInterface() const
     {
-        return IPAddress(m_netif->ip_addr);
+        return IPAddress(IP4_ADDR_ANY);
     }
 
     uint8_t _replyMaskForHost(const stcMDNS_RRHeader& p_RRHeader,

libraries/ESP8266mDNS/src/LEAmDNS_Control.cpp

@@ -84,9 +84,7 @@ bool MDNSResponder::_process(bool p_bUserContext)
     }
     else
     {
-        bResult = (m_netif != nullptr) &&
-                  (m_netif->flags & NETIF_FLAG_UP) &&  // network interface is up and running
-                  _updateProbeStatus() &&              // Probing
+        bResult = _updateProbeStatus() &&              // Probing
                   _checkServiceQueryCache();           // Service query cache check
     }
     return bResult;
@@ -98,9 +96,7 @@ bool MDNSResponder::_process(bool p_bUserContext)
 bool MDNSResponder::_restart(void)
 {
 
-    return ((m_netif != nullptr) &&
-            (m_netif->flags & NETIF_FLAG_UP) &&  // network interface is up and running
-            (_resetProbeStatus(true)) &&         // Stop and restart probing
+    return ((_resetProbeStatus(true)) &&         // Stop and restart probing
             (_allocUDPContext()));               // Restart UDP
 }
 

libraries/ESP8266mDNS/src/LEAmDNS_Helpers.cpp

@@ -221,7 +221,7 @@ bool MDNSResponder::_allocUDPContext(void)
     //TODO: set multicast address (lwip_joingroup() is IPv4 only at the time of writing)
     multicast_addr.addr = DNS_MQUERY_IPV6_GROUP_INIT;
 #endif
-    if (ERR_OK == igmp_joingroup(ip_2_ip4(&m_netif->ip_addr), ip_2_ip4(&multicast_addr)))
+    if (ERR_OK == igmp_joingroup(IP4_ADDR_ANY4, ip_2_ip4(&multicast_addr)))
     {
         m_pUDPContext = new UdpContext;
         m_pUDPContext->ref();

libraries/ESP8266mDNS/src/LEAmDNS_Transfer.cpp

@@ -133,7 +133,7 @@ bool MDNSResponder::_sendMDNSMessage_Multicast(MDNSResponder::stcMDNSSendParamet
 #endif
     DEBUG_EX_INFO(DEBUG_OUTPUT.printf_P(PSTR("[MDNSResponder] _sendMDNSMessage_Multicast: Will send to '%s'.\n"), toMulticastAddress.toString().c_str()););
     bResult = ((_prepareMDNSMessage(p_rSendParameter, fromIPAddress)) &&
-               (m_pUDPContext->send(toMulticastAddress, DNS_MQUERY_PORT)));
+               (m_pUDPContext->send_multicast_all(toMulticastAddress, DNS_MQUERY_PORT)));
 
     DEBUG_EX_ERR(if (!bResult)
 {