Improvements in network boot (#2916)

***NO_CI***

Author: antoniofagundes

src/PAL/Lwip/lwIP_Sockets.cpp

@@ -1311,7 +1311,7 @@ HRESULT LWIP_SOCKETS_Driver::UpdateAdapterConfiguration(
         else
         {
             // stop DHCP
-            dhcp_stop(networkInterface);
+            dhcp_release_and_stop(networkInterface);
 
             // need to convert these first
             ip_addr_t ipAddress, mask, gateway;
@@ -1333,15 +1333,9 @@ HRESULT LWIP_SOCKETS_Driver::UpdateAdapterConfiguration(
 
     if (enableDHCP)
     {
-        // developer note: on legacy source there was a hack of trying to renew before release and
-        // also setting the release flag in managed call when the intent was to renew only
-        // nowadays lwIP seems to be doing what is told, so no need for these hacks anymore
-        // also it's NOT possible to renew & release on the same pass, so adding an extra else-if for that
-        // just in case it's request from the managed code
-
         if (0 != (updateFlags & NetworkInterface_UpdateOperation_DhcpRelease))
         {
-            dhcp_release(networkInterface);
+            dhcp_release_and_stop(networkInterface);
         }
         else if (0 != (updateFlags & NetworkInterface_UpdateOperation_DhcpRenew))
         {

targets/ChibiOS/_lwIP/nf_lwipthread.c

@@ -275,7 +275,7 @@ void lwipDefaultLinkDownCB(void *p)
 #if LWIP_DHCP
     if (addressMode == NET_ADDRESS_DHCP)
     {
-        dhcp_stop(ifc);
+        dhcp_release_and_stop(ifc);
     }
 #endif
 
@@ -500,7 +500,9 @@ static void do_reconfigure(void *p)
         case NET_ADDRESS_DHCP:
         {
             if (netif_is_up(&thisif))
-                dhcp_stop(&thisif);
+            {
+                dhcp_release_and_stop(&thisif);
+            }
             break;
         }
 #endif
@@ -532,8 +534,7 @@ static void do_reconfigure(void *p)
 #if LWIP_DHCP
         case NET_ADDRESS_DHCP:
         {
-            if (netif_is_up(&thisif))
-                dhcp_start(&thisif);
+            dhcp_start(&thisif);
             break;
         }
 #endif