From ee59f77d77dc13830fb64e370ff45d569935fa3a Mon Sep 17 00:00:00 2001
From: yuanjm <yuanjianmin@espressif.com>
Date: Tue, 12 Oct 2021 20:11:42 +0800
Subject: [PATCH] dns: Add API to clear dns cache

---
 src/core/dns.c         | 6 ++++++
 src/include/lwip/dns.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/src/core/dns.c b/src/core/dns.c
index e758aca5..0517c2a2 100644
--- a/src/core/dns.c
+++ b/src/core/dns.c
@@ -396,6 +396,12 @@ dns_clear_servers(bool keep_fallback)
     dns_setserver(numdns, NULL);
   }
 }
+
+void
+dns_clear_cache(void)
+{
+  memset(dns_table, 0, sizeof(struct dns_table_entry) * DNS_TABLE_SIZE);
+}
 #endif
 
 /**
diff --git a/src/include/lwip/dns.h b/src/include/lwip/dns.h
index db52fedd..7c9933ea 100644
--- a/src/include/lwip/dns.h
+++ b/src/include/lwip/dns.h
@@ -113,6 +113,7 @@ err_t            dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *add
                                    u8_t dns_addrtype);
 #if ESP_DNS
 void             dns_clear_servers(bool keep_fallback);
+void             dns_clear_cache(void);
 #endif
 
 #if DNS_LOCAL_HOSTLIST