feat(lwip): AutoIP trigger callback so that application can know IP changes

components/lwip/lwip/src/core/ipv4/autoip.c

@@ -67,6 +67,7 @@
 #include "lwip/autoip.h"
 #include "lwip/etharp.h"
 #include "lwip/prot/autoip.h"
+#include "lwip/dhcp.h"
 
 #include <string.h>
 
@@ -241,6 +242,13 @@ autoip_bind(struct netif *netif)
   netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr);
   /* interface is used by routing now that an address is set */
 
+#if ESP_LWIP
+  struct dhcp *dhcp = netif_dhcp_data(netif);
+  if (dhcp->cb != NULL) {
+    dhcp->cb(netif);
+  }
+#endif
+
   return ERR_OK;
 }
 

components/lwip/lwip/src/core/ipv4/dhcp.c

@@ -1954,4 +1954,23 @@ dhcp_supplied_address(const struct netif *netif)
   return 0;
 }
 
+#if ESP_LWIP
+/** Set callback for dhcp, reserved parameter for future use.
+ *
+ * @param netif the netif from which to remove the struct dhcp
+ * @param cb    callback for dhcp
+ */
+void dhcp_set_cb(struct netif *netif, void (*cb)(struct netif*))
+{
+  struct dhcp *dhcp;
+  dhcp = netif_dhcp_data(netif);
+
+  LWIP_ASSERT("netif != NULL", netif != NULL);
+
+  if (dhcp != NULL) {
+    dhcp->cb = cb;
+  }
+}
+#endif
+
 #endif /* LWIP_IPV4 && LWIP_DHCP */

components/lwip/lwip/src/include/lwip/dhcp.h

@@ -103,6 +103,10 @@ struct dhcp
   ip4_addr_t offered_si_addr;
   char boot_file_name[DHCP_BOOT_FILE_LEN];
 #endif /* LWIP_DHCP_BOOTPFILE */
+
+#if ESP_LWIP
+  void (*cb)(struct netif*); /* callback for dhcp, add a parameter to show dhcp status if needed */
+#endif
 };
 
 
@@ -134,6 +138,10 @@ extern void dhcp_set_ntp_servers(u8_t num_ntp_servers, const ip4_addr_t* ntp_ser
 
 #define netif_dhcp_data(netif) ((struct dhcp*)netif_get_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP))
 
+#ifdef ESP_LWIP
+void dhcp_set_cb(struct netif *netif, void (*cb)(struct netif*));
+#endif
+
 #ifdef __cplusplus
 }
 #endif

components/tcpip_adapter/tcpip_adapter_lwip.c

@@ -98,9 +98,17 @@ static void tcpip_adapter_dhcps_cb(u8_t client_ip[4])
 
 static err_t _dhcp_start(struct tcpip_api_call_data *p)
 {
+    err_t ret;
     struct tcpip_adapter_api_call_data *call = (struct tcpip_adapter_api_call_data *)p;
 
-    return dhcp_start(call->netif);
+    ret = dhcp_start(call->netif);
+
+#if ESP_LWIP
+    if (ret == ERR_OK)
+        dhcp_set_cb(call->netif, tcpip_adapter_dhcpc_cb);
+#endif
+
+    return ret;
 }
 
 static err_t _dhcp_stop(struct tcpip_api_call_data *p)