Additions to UdpContext needed for LEAmDNS2 (#7048)

* Addition to UdpContext needed for LEAmDNS2

Author: LaborEtArs

libraries/ESP8266WiFi/src/include/UdpContext.h

@@ -167,6 +167,26 @@ class UdpContext
 
 #endif // !LWIP_IPV6
 
+    /*
+     * Add a netif (by its index) as the multicast interface
+     */
+    void setMulticastInterface(netif* p_pNetIf)
+    {
+#if LWIP_VERSION_MAJOR == 1
+        udp_set_multicast_netif_addr(_pcb, (p_pNetIf ? p_pNetIf->ip_addr : ip_addr_any));
+#else
+        udp_set_multicast_netif_index(_pcb, (p_pNetIf ? netif_get_index(p_pNetIf) : NETIF_NO_INDEX));
+#endif
+    }
+
+    /*
+     * Allow access to pcb to change eg. options
+     */
+    udp_pcb* pcb(void)
+    {
+        return _pcb;
+    }
+
     void setMulticastTTL(int ttl)
     {
 #ifdef LWIP_MAYBE_XCC
@@ -205,6 +225,11 @@ class UdpContext
         return (pos <= _rx_buf->tot_len);
     }
 
+    netif* getInputNetif() const
+    {
+        return _currentAddr.input_netif;
+    }
+
     CONST IPAddress& getRemoteAddress() CONST
     {
         return _currentAddr.srcaddr;
@@ -269,7 +294,6 @@ class UdpContext
             // ref'ing it to prevent release from the below pbuf_free(deleteme)
             pbuf_ref(_rx_buf);
         }
-        // remove the already-consumed head of the chain
         pbuf_free(deleteme);
 
         _rx_buf_offset = 0;
@@ -464,11 +488,12 @@ class UdpContext
                 return;
             }
         }
-
 #if LWIP_VERSION_MAJOR == 1
     #define TEMPDSTADDR (&current_iphdr_dest)
+    #define TEMPINPUTNETIF (current_netif)
 #else
     #define TEMPDSTADDR (ip_current_dest_addr())
+    #define TEMPINPUTNETIF (ip_current_input_netif())
 #endif
 
         // chain this helper pbuf first
@@ -496,7 +521,7 @@ class UdpContext
                 return;
             }
             // construct in place
-            new(PBUF_ALIGNER(pb_helper->payload)) AddrHelper(srcaddr, TEMPDSTADDR, srcport);
+            new(PBUF_ALIGNER(pb_helper->payload)) AddrHelper(srcaddr, TEMPDSTADDR, srcport, TEMPINPUTNETIF);
             pb_helper->flags = PBUF_HELPER_FLAG; // mark helper pbuf
             // chain it
             pbuf_cat(_rx_buf, pb_helper);
@@ -510,6 +535,7 @@ class UdpContext
             _currentAddr.srcaddr = srcaddr;
             _currentAddr.dstaddr = TEMPDSTADDR;
             _currentAddr.srcport = srcport;
+            _currentAddr.input_netif = TEMPINPUTNETIF;
 
             DEBUGV(":urn %d\r\n", pb->tot_len);
             _first_buf_taken = false;
@@ -522,6 +548,7 @@ class UdpContext
         }
 
     #undef TEMPDSTADDR
+    #undef TEMPINPUTNETIF
 
     }
 
@@ -633,10 +660,11 @@ class UdpContext
     {
         IPAddress srcaddr, dstaddr;
         int16_t srcport;
+        netif* input_netif;
 
         AddrHelper() { }
-        AddrHelper(const ip_addr_t* src, const ip_addr_t* dst, uint16_t srcport):
-            srcaddr(src), dstaddr(dst), srcport(srcport) { }
+        AddrHelper(const ip_addr_t* src, const ip_addr_t* dst, uint16_t srcport, netif* input_netif):
+            srcaddr(src), dstaddr(dst), srcport(srcport), input_netif(input_netif) { }
     };
     AddrHelper _currentAddr;