From ff506ccf072db9d85b7bf3c19b3d610de01efeda Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Wed, 18 Dec 2019 07:16:20 +0100
Subject: [PATCH] pkg/lwip: start DHCP for a netif with lwip_dhcp

The NETDEV_EVENT_LINK_UP is used to start DHCP for a network interface
---
 Makefile.dep                          |  4 ++++
 pkg/lwip/Makefile.include             |  1 +
 pkg/lwip/contrib/netdev/lwip_netdev.c | 11 ++++++++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Makefile.dep b/Makefile.dep
index a89a5d2547..c2f6b5bd7f 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -568,6 +568,10 @@ ifneq (,$(filter lwip_contrib,$(USEMODULE)))
   USEMODULE += xtimer
 endif
 
+ifneq (,$(filter lwip_dhcp_auto,$(USEMODULE)))
+  USEMODULE += lwip_dhcp
+endif
+
 ifneq (,$(filter sema,$(USEMODULE)))
   USEMODULE += xtimer
 endif
diff --git a/pkg/lwip/Makefile.include b/pkg/lwip/Makefile.include
index a51c7b94df..3cd5a28a02 100644
--- a/pkg/lwip/Makefile.include
+++ b/pkg/lwip/Makefile.include
@@ -4,6 +4,7 @@ INCLUDES += -I$(RIOTBASE)/pkg/lwip/include \
 PSEUDOMODULES += lwip_arp
 PSEUDOMODULES += lwip_autoip
 PSEUDOMODULES += lwip_dhcp
+PSEUDOMODULES += lwip_dhcp_auto
 PSEUDOMODULES += lwip_ethernet
 PSEUDOMODULES += lwip_igmp
 PSEUDOMODULES += lwip_ipv6_autoconfig
diff --git a/pkg/lwip/contrib/netdev/lwip_netdev.c b/pkg/lwip/contrib/netdev/lwip_netdev.c
index dbc3b59e5b..dab163495f 100644
--- a/pkg/lwip/contrib/netdev/lwip_netdev.c
+++ b/pkg/lwip/contrib/netdev/lwip_netdev.c
@@ -17,6 +17,9 @@
 #include <sys/uio.h>
 #include <inttypes.h>
 
+#if MODULE_LWIP_DHCP_AUTO
+#include "lwip/dhcp.h"
+#endif
 #include "lwip/err.h"
 #include "lwip/ethip6.h"
 #include "lwip/netif.h"
@@ -280,8 +283,14 @@ static void _event_cb(netdev_t *dev, netdev_event_t event)
                     DEBUG("lwip_netdev: error inputing packet\n");
                     return;
                 }
+                break;
             }
-            break;
+#ifdef MODULE_LWIP_DHCP_AUTO
+            case NETDEV_EVENT_LINK_UP: {
+                dhcp_start(netif);
+                break;
+            }
+#endif
             default:
                 break;
         }