From 237cc88b9f132a8a442645f5c98c69b11228ace4 Mon Sep 17 00:00:00 2001
From: zhangyanjiao <zhangyanjiao@espressif.com>
Date: Tue, 11 Sep 2018 14:36:42 +0800
Subject: [PATCH] lwip: add code for sending gratuitous ARP periodically

---
 components/lwip/Kconfig                       | 17 +++++++++++++++++
 components/lwip/lwip                          |  2 +-
 components/lwip/port/esp32/include/lwipopts.h |  1 +
 components/tcpip_adapter/tcpip_adapter_lwip.c |  7 +++++++
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/components/lwip/Kconfig b/components/lwip/Kconfig
index 55141ffbb3..5dfd3cade1 100644
--- a/components/lwip/Kconfig
+++ b/components/lwip/Kconfig
@@ -128,6 +128,23 @@ config LWIP_ETHARP_TRUST_IP_MAC
         So the recommendation is to disable this option. 
         Here the LAN peer means the other side to which the ESP station or soft-AP is connected.
 
+config ESP_GRATUITOUS_ARP
+    bool "Send gratuitous ARP periodically"
+    default y
+    help 
+        Enable this option allows to send gratuitous ARP periodically.
+
+        This option solve the compatibility issues.If the ARP table of the AP is old, and the AP
+        doesn't send ARP request to update it's ARP table, this will lead to the STA sending IP packet fail.
+        Thus we send gratuitous ARP periodically to let AP update it's ARP table.
+
+config GARP_TMR_INTERVAL
+    int "GARP timer interval(seconds)"
+    default 60
+    depends on ESP_GRATUITOUS_ARP
+    help
+        Set the timer interval for gratuitous ARP. The default value is 60s
+
 config TCPIP_RECVMBOX_SIZE
     int "TCPIP task receive mail box size"
     default 32
diff --git a/components/lwip/lwip b/components/lwip/lwip
index 18548d1e25..e6bb43349e 160000
--- a/components/lwip/lwip
+++ b/components/lwip/lwip
@@ -1 +1 @@
-Subproject commit 18548d1e256f7651fb4da48dbd770556e0eca8ce
+Subproject commit e6bb43349ed859eba4c1e3cae15b932627c45c4b
diff --git a/components/lwip/port/esp32/include/lwipopts.h b/components/lwip/port/esp32/include/lwipopts.h
index 6492003075..db6f982462 100644
--- a/components/lwip/port/esp32/include/lwipopts.h
+++ b/components/lwip/port/esp32/include/lwipopts.h
@@ -739,6 +739,7 @@
 #define ESP_PING                        1
 #define ESP_HAS_SELECT                  1
 #define ESP_AUTO_RECV                   1
+#define ESP_GRATUITOUS_ARP              CONFIG_ESP_GRATUITOUS_ARP
 
 #if CONFIG_LWIP_IRAM_OPTIMIZATION
 #define ESP_IRAM_ATTR                   IRAM_ATTR
diff --git a/components/tcpip_adapter/tcpip_adapter_lwip.c b/components/tcpip_adapter/tcpip_adapter_lwip.c
index a92cfd7c31..e06a2205dc 100644
--- a/components/tcpip_adapter/tcpip_adapter_lwip.c
+++ b/components/tcpip_adapter/tcpip_adapter_lwip.c
@@ -26,6 +26,7 @@
 #include "lwip/ip6_addr.h"
 #include "lwip/nd6.h"
 #include "lwip/priv/tcpip_priv.h"
+#include "lwip/netif.h"
 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
 #include "lwip/dns.h"
 #endif
@@ -184,6 +185,12 @@ static esp_err_t tcpip_adapter_start(tcpip_adapter_if_t tcpip_if, uint8_t *mac,
         netif_init = tcpip_if_to_netif_init_fn(tcpip_if);
         assert(netif_init != NULL);
         netif_add(esp_netif[tcpip_if], &ip_info->ip, &ip_info->netmask, &ip_info->gw, NULL, netif_init, tcpip_input);
+#if ESP_GRATUITOUS_ARP
+        if (tcpip_if == TCPIP_ADAPTER_IF_STA || tcpip_if == TCPIP_ADAPTER_IF_ETH) {
+            netif_set_garp_flag(esp_netif[tcpip_if]);
+        }
+#endif
+
     }
 
     if (tcpip_if == TCPIP_ADAPTER_IF_AP) {