implement mDNS support and hostname configuration (#1632)

Co-authored-by: Copilot <copilot@github.com>

Author: Pelsin

headers/gp2040.h

@@ -6,6 +6,10 @@
 #ifndef GP2040_H_
 #define GP2040_H_
 
+#ifndef WEB_CONFIG_HOSTNAME
+#define WEB_CONFIG_HOSTNAME "gp2040-ce"
+#endif
+
 #include <map>
 
 // GP2040 Classes

lib/lwip-port/CMakeLists.txt

@@ -2,15 +2,17 @@ add_library(lwip-port
 ${PICO_SDK_PATH}/lib/tinyusb/lib/networking/dhserver.c
 ${PICO_SDK_PATH}/lib/tinyusb/lib/networking/dnserver.c
 )
-target_include_directories(lwip-port INTERFACE 
+target_include_directories(lwip-port INTERFACE
 .
 arch
 ${PICO_SDK_PATH}/lib/tinyusb/lib/networking
 )
-target_link_libraries(lwip-port 
+target_link_libraries(lwip-port
 pico_stdlib
 pico_lwip
+pico_lwip_mdns
+pico_rand
 )
 target_include_directories(pico_lwip INTERFACE
 .
-)
+)

lib/lwip-port/lwipopts.h

@@ -32,6 +32,8 @@
 #ifndef __LWIPOPTS_H__
 #define __LWIPOPTS_H__
 
+#include "pico/rand.h"
+
 /* Prevent having to link sys_arch.c (we don't test the API layers in unit tests) */
 #define NO_SYS                          1
 #define MEM_ALIGNMENT                   4
@@ -63,4 +65,11 @@
 
 #define LWIP_SINGLE_NETIF               1
 
+#define LWIP_IGMP                       1
+#define LWIP_MDNS_RESPONDER             1
+#define MDNS_MAX_SERVICES               1
+#define LWIP_NUM_NETIF_CLIENT_DATA      1
+
+#define LWIP_RAND()                     ((uint32_t)get_rand_32())
+
 #endif /* __LWIPOPTS_H__ */

lib/rndis/rndis.c

@@ -49,6 +49,7 @@ try changing the first byte of tud_network_mac_address[] below from 0x02 to 0x00
 #include "lwip/init.h"
 #include "lwip/timeouts.h"
 #include "lwip/apps/httpd.h"
+#include "lwip/apps/mdns.h"
 
 #define INIT_IP4(a,b,c,d) { PP_HTONL(LWIP_MAKEU32(a,b,c,d)) }
 
@@ -117,7 +118,7 @@ static err_t netif_init_cb(struct netif *netif)
 {
   LWIP_ASSERT("netif != NULL", (netif != NULL));
   netif->mtu = CFG_TUD_NET_MTU;
-  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP | NETIF_FLAG_UP;
+  netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP | NETIF_FLAG_UP | NETIF_FLAG_IGMP;
   netif->state = NULL;
   netif->name[0] = 'E';
   netif->name[1] = 'X';
@@ -154,7 +155,7 @@ bool dns_query_proc(const char *name, ip4_addr_t *addr)
 
 bool tud_network_recv_cb(const uint8_t *src, uint16_t size)
 {
-  /* this shouldn't happen, but if we get another packet before 
+  /* this shouldn't happen, but if we get another packet before
   parsing the previous, we must signal our inability to accept it */
   if (received_frame)
     return false;
@@ -209,9 +210,12 @@ void tud_network_init_cb(void)
     pbuf_free(received_frame);
     received_frame = NULL;
   }
+
+  /* re-announce mDNS, so hostname resolves after reconnect, getting issues on windows on hard-refresh without this */
+  mdns_resp_announce(&netif_data);
 }
 
-int rndis_init(void)
+int rndis_init(const char *hostname)
 {
   // Removed as rndis defect 07-08-2025 as we need to setup TinyUSB to non-default values
   ///* initialize TinyUSB */
@@ -225,6 +229,8 @@ int rndis_init(void)
     ;
   while (dnserv_init(&ipaddr, 53, dns_query_proc) != ERR_OK)
     ;
+  mdns_resp_init();
+  mdns_resp_add_netif(&netif_data, hostname);
   httpd_init();
 
   return 0;

lib/rndis/rndis.h

@@ -5,7 +5,7 @@
 extern "C" {
 #endif
 
-int rndis_init(void);
+int rndis_init(const char *hostname);
 void rndis_task(void);
 
 #ifdef __cplusplus

src/gp2040.cpp

@@ -245,7 +245,7 @@ void GP2040::run() {
 	USBHostManager::getInstance().start();
 
 	if (configMode == true ) {
-		rndis_init();
+		rndis_init(WEB_CONFIG_HOSTNAME);
 	}
 
 	while (1) { // LOOP