From 49202b7f03e1c8dd63ccbb8a9bce7f01949e2973 Mon Sep 17 00:00:00 2001
From: xueyunfei <xueyunfei@espressif.com>
Date: Fri, 27 Mar 2020 17:19:03 +0800
Subject: [PATCH] backport bugfix lwip for v3.2

---
 components/lwip/lwip                          |  2 +-
 components/lwip/port/esp32/include/lwipopts.h |  7 +++++++
 components/tcpip_adapter/tcpip_adapter_lwip.c | 10 +++++++++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/components/lwip/lwip b/components/lwip/lwip
index 39f338547..da2740fa8 160000
--- a/components/lwip/lwip
+++ b/components/lwip/lwip
@@ -1 +1 @@
-Subproject commit 39f338547ab344e855f94eb922421036bee8e417
+Subproject commit da2740fa8d56b9b9e8a10602f38df1ea4dbd9b74
diff --git a/components/lwip/port/esp32/include/lwipopts.h b/components/lwip/port/esp32/include/lwipopts.h
index 7d48f7bdd..be04739a7 100644
--- a/components/lwip/port/esp32/include/lwipopts.h
+++ b/components/lwip/port/esp32/include/lwipopts.h
@@ -655,6 +655,13 @@
  */
 #define LWIP_IPV6                       1
 
+/**
+ * LWIP_ND6_RDNSS_MAX_DNS_SERVERS: Allow IPv6 DNS servers to be retrieved from
+ * NDP, up to the maximum number of allowed DNS servers (minus fallback slot)
+ */
+#define LWIP_ND6_RDNSS_MAX_DNS_SERVERS  0
+
+
 /*
    ---------------------------------------
    ---------- Hook options ---------------
diff --git a/components/tcpip_adapter/tcpip_adapter_lwip.c b/components/tcpip_adapter/tcpip_adapter_lwip.c
index 16f80a9a3..153dd5dff 100644
--- a/components/tcpip_adapter/tcpip_adapter_lwip.c
+++ b/components/tcpip_adapter/tcpip_adapter_lwip.c
@@ -323,6 +323,9 @@ esp_err_t tcpip_adapter_down(tcpip_adapter_if_t tcpip_if)
             tcpip_adapter_reset_ip_info(tcpip_if);
         }
 
+        for(int8_t i = 0 ;i < LWIP_IPV6_NUM_ADDRESSES ;i++) {
+            netif_ip6_addr_set(esp_netif[tcpip_if] ,i ,IP6_ADDR_ANY6);
+        }
         netif_set_addr(esp_netif[tcpip_if], IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4);
         netif_set_down(esp_netif[tcpip_if]);
         tcpip_adapter_start_ip_lost_timer(tcpip_if);
@@ -771,6 +774,7 @@ esp_err_t tcpip_adapter_get_dns_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_
 
     dns_param.dns_type =  type;
     dns_param.dns_info =  dns;
+    const ip_addr_t*  dns_ip = NULL;
     
     TCPIP_ADAPTER_IPC_CALL(tcpip_if, type,  0, &dns_param, tcpip_adapter_get_dns_info_api);
     if (!dns) {
@@ -789,7 +793,10 @@ esp_err_t tcpip_adapter_get_dns_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_
     }
 
     if (tcpip_if == TCPIP_ADAPTER_IF_STA || tcpip_if == TCPIP_ADAPTER_IF_ETH) {
-        dns->ip = dns_getserver(type);
+        dns_ip = dns_getserver(type);
+        if (dns_ip != NULL) {
+            dns->ip = *dns_ip;
+        }
     } else {
         dns->ip.u_addr.ip4 = dhcps_dns_getserver();
     }
@@ -827,6 +834,7 @@ esp_err_t tcpip_adapter_dhcps_start(tcpip_adapter_if_t tcpip_if)
         if (p_netif != NULL && netif_is_up(p_netif)) {
             tcpip_adapter_ip_info_t default_ip;
             tcpip_adapter_get_ip_info(ESP_IF_WIFI_AP, &default_ip);
+            dhcps_set_new_lease_cb(tcpip_adapter_dhcps_cb);
             dhcps_start(p_netif, default_ip.ip);
             dhcps_status = TCPIP_ADAPTER_DHCP_STARTED;
             ESP_LOGD(TAG, "dhcp server start successfully");