Enabling this option performs a check (via ARP request) if the offered IP address
is not already in use by another host on the network.
+config LWIP_DHCP_RESTORE_LAST_IP
+ bool "DHCP: Restore last IP obtained from DHCP server"
+ default n
+ help
+ When this option is enabled, DHCP client tries to re-obtain last valid IP address obtained from DHCP server.
+ Last valid DHCP configuration is stored in nvs and restored afrer reset/power-up. If IP is still available,
+ there is no need for sending discovery message to DHCP server and save some time.
+
menu "DHCP server"
config LWIP_DHCPS_LEASE_UNIT
#include "esp_system.h"
#include "sdkconfig.h"
+#include "netif/dhcp_state.h"
+
/* Enable all Espressif-only options */
/*
*/
#define DHCP_DOES_ARP_CHECK CONFIG_LWIP_DHCP_DOES_ARP_CHECK
+
+/**
+ * CONFIG_LWIP_DHCP_RESTORE_LAST_IP==1: Last valid IP address obtained from DHCP server
+ * is restored after reset/power-up.
+ */
+#if CONFIG_LWIP_DHCP_RESTORE_LAST_IP
+
+#define LWIP_DHCP_IP_ADDR_RESTORE() dhcp_ip_addr_restore(netif)
+#define LWIP_DHCP_IP_ADDR_STORE() dhcp_ip_addr_store(netif)
+#define LWIP_DHCP_IP_ADDR_ERASE() dhcp_ip_addr_erase(esp_netif[tcpip_if])
+
+#endif
+
/*
------------------------------------
---------- AUTOIP options ----------
--- /dev/null
+// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#ifndef _DHCP_STATE_H_
+#define _DHCP_STATE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+bool dhcp_ip_addr_restore(void *netif);
+
+void dhcp_ip_addr_store(void *netif);
+
+void dhcp_ip_addr_erase(void *netif);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _DHCP_STATE_H_ */
\ No newline at end of file
--- /dev/null
+// Copyright 2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <stdio.h>
+#include <assert.h>
+#include "nvs.h"
+#include "lwip/opt.h"
+#include "lwip/dhcp.h"
+#include "lwip/netif.h"
+#include "esp_interface.h"
+#include "tcpip_adapter.h"
+#include "netif/dhcp_state.h"
+
+#define DHCP_NAMESPACE "dhcp_state"
+#define VALID_NETIF_ID(id) ((id < ESP_IF_MAX) && (id != ESP_IF_WIFI_AP))
+
+static uint32_t restored_ip_addr[TCPIP_ADAPTER_IF_MAX];
+static const char *interface_key[] = {"IF_STA", "IF_AP", "IF_ETH"};
+
+_Static_assert(sizeof(interface_key) / sizeof(char*) == TCPIP_ADAPTER_IF_MAX,
+ "Number interface keys differs from number of interfaces");
+
+bool dhcp_ip_addr_restore(void *netif)
+{
+ nvs_handle nvs;
+ bool err = false;
+ struct netif *net = (struct netif *)netif;
+ struct dhcp *dhcp = netif_dhcp_data(net);
+ esp_interface_t netif_id = tcpip_adapter_get_esp_if(net);
+
+ if(VALID_NETIF_ID(netif_id)) {
+ uint32_t *ip_addr = &dhcp->offered_ip_addr.addr;
+ if (nvs_open(DHCP_NAMESPACE, NVS_READONLY, &nvs) == ESP_OK) {
+ if (nvs_get_u32(nvs, interface_key[netif_id], ip_addr) == ESP_OK) {
+ restored_ip_addr[netif_id] = *ip_addr;
+ err = true;
+ }
+ nvs_close(nvs);
+ }
+ }
+ return err;
+}
+
+void dhcp_ip_addr_store(void *netif)
+{
+ nvs_handle nvs;
+ struct netif *net = (struct netif *)netif;
+ struct dhcp *dhcp = netif_dhcp_data(net);
+ uint32_t ip_addr = dhcp->offered_ip_addr.addr;
+ esp_interface_t netif_id = tcpip_adapter_get_esp_if(net);
+
+ if(VALID_NETIF_ID(netif_id)) {
+ if (restored_ip_addr[netif_id] != ip_addr) {
+ if (nvs_open(DHCP_NAMESPACE, NVS_READWRITE, &nvs) == ESP_OK) {
+ nvs_set_u32(nvs, interface_key[netif_id], ip_addr);
+ nvs_commit(nvs);
+ nvs_close(nvs);
+ }
+ }
+ }
+}
+
+void dhcp_ip_addr_erase(void *netif)
+{
+ nvs_handle nvs;
+ struct netif *net = (struct netif *)netif;
+ esp_interface_t netif_id = tcpip_adapter_get_esp_if(net);
+
+ if(VALID_NETIF_ID(netif_id)) {
+ if (nvs_open(DHCP_NAMESPACE, NVS_READWRITE, &nvs) == ESP_OK) {
+ nvs_erase_key(nvs, interface_key[netif_id]);
+ nvs_commit(nvs);
+ nvs_close(nvs);
+ }
+ }
+}
\ No newline at end of file