Merge branch 'fix/fix_lost_ip_event_issue_v55' into 'release/v5.5'

fix(lwip): add some feature for dhcp and improve api v55

See merge request espressif/esp-idf!48105

components/esp_netif/include/esp_netif.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -682,7 +682,19 @@ esp_err_t esp_netif_dhcps_stop(esp_netif_t *esp_netif);
  */
 esp_err_t esp_netif_dhcps_get_clients_by_mac(esp_netif_t *esp_netif, int num, esp_netif_pair_mac_ip_t *mac_ip_pair);
 
-
+/**
+ * @brief  Populate IP addresses of client from the lwIP ARP cache on this interface
+ *
+ * Walks the ARP table and fills in ip when the Ethernet address matches and the entry belongs to esp_netif.
+ *
+ * @param[in] esp_netif Handle to esp-netif instance
+ * @param[in,out] mac_ip_pair MAC/IP pair to fill in the IP
+ * @return
+ *      - ESP_OK on success (including when nothing was found in ARP)
+ *      - ESP_ERR_ESP_NETIF_INVALID_PARAMS on invalid params
+ *      - ESP_ERR_NOT_SUPPORTED if ARP is disabled in lwIP
+ */
+esp_err_t esp_netif_arp_get_client_by_mac(esp_netif_t *esp_netif, esp_netif_pair_mac_ip_t *mac_ip_pair);
 
 /**
  * @brief  Set DNS Server information

components/esp_netif/lwip/esp_netif_lwip.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -1406,7 +1406,7 @@ esp_err_t esp_netif_receive(esp_netif_t *esp_netif, void *buffer, size_t len, vo
 }
 
 #if CONFIG_LWIP_IPV4
-static esp_err_t esp_netif_start_ip_lost_timer(esp_netif_t *esp_netif);
+static esp_err_t esp_netif_start_ip_lost_timer(esp_netif_t *esp_netif, bool renew);
 
 //
 // DHCP:
@@ -1469,7 +1469,7 @@ static void esp_netif_internal_dhcpc_cb(struct netif *netif)
         }
     } else {
         if (!ip4_addr_cmp(&ip_info->ip, IP4_ADDR_ANY4)) {
-            esp_netif_start_ip_lost_timer(esp_netif);
+            esp_netif_start_ip_lost_timer(esp_netif, false);
             if (esp_netif->flags & ESP_NETIF_DHCP_CLIENT && esp_netif->dhcpc_status == ESP_NETIF_DHCP_STARTED) {
                 // Only for active DHCP client (in case of static IP, we keep the last configure value in ip_info)
                 // synchronize lwip netif with esp_netif setting ip_info to 0,
@@ -1519,19 +1519,22 @@ static void esp_netif_ip_lost_timer(void *arg)
     }
 }
 
-static esp_err_t esp_netif_start_ip_lost_timer(esp_netif_t *esp_netif)
+static esp_err_t esp_netif_start_ip_lost_timer(esp_netif_t *esp_netif, bool renew)
 {
     esp_netif_ip_info_t *ip_info_old = esp_netif->ip_info;
     struct netif *netif = esp_netif->lwip_netif;
 
     ESP_LOGD(TAG, "%s esp_netif:%p", __func__, esp_netif);
 
-    if (esp_netif->timer_running) {
-        ESP_LOGD(TAG, "if%p start ip lost tmr: already started", esp_netif);
-        return ESP_OK;
-    }
-
     if ( netif && (CONFIG_ESP_NETIF_IP_LOST_TIMER_INTERVAL > 0)) {
+        if (esp_netif->timer_running) {
+            if (renew) {
+                sys_untimeout(esp_netif_ip_lost_timer, (void *)esp_netif);
+            } else{
+                ESP_LOGD(TAG, "if%p start ip lost tmr: already started", esp_netif);
+                return ESP_OK;
+            }
+        }
         esp_netif->timer_running = true;
         sys_timeout(CONFIG_ESP_NETIF_IP_LOST_TIMER_INTERVAL * 1000, esp_netif_ip_lost_timer, (void *)esp_netif);
         ESP_LOGD(TAG, "if%p start ip lost tmr: interval=%d", esp_netif, CONFIG_ESP_NETIF_IP_LOST_TIMER_INTERVAL);
@@ -1561,7 +1564,7 @@ static esp_err_t esp_netif_dhcpc_stop_api(esp_netif_api_msg_t *msg)
         if (p_netif != NULL) {
             dhcp_stop(p_netif);
             esp_netif_reset_ip_info(esp_netif);
-            esp_netif_start_ip_lost_timer(esp_netif);
+            esp_netif_start_ip_lost_timer(esp_netif, false);
         } else {
             ESP_LOGD(TAG, "dhcp client if not ready");
             return ESP_ERR_ESP_NETIF_IF_NOT_READY;
@@ -1624,7 +1627,7 @@ static esp_err_t esp_netif_dhcpc_start_api(esp_netif_api_msg_t *msg)
             ip_addr_set_zero(&p_netif->ip_addr);
             ip_addr_set_zero(&p_netif->netmask);
             ip_addr_set_zero(&p_netif->gw);
-            esp_netif_start_ip_lost_timer(esp_netif);
+            esp_netif_start_ip_lost_timer(esp_netif, true);
         } else {
             ESP_LOGD(TAG, "dhcp client re init");
             esp_netif->dhcpc_status = ESP_NETIF_DHCP_INIT;
@@ -1875,7 +1878,7 @@ static esp_err_t esp_netif_down_api(esp_netif_api_msg_t *msg)
 
     if (esp_netif->flags & ESP_NETIF_DHCP_CLIENT) {
 #if CONFIG_LWIP_IPV4
-        esp_netif_start_ip_lost_timer(esp_netif);
+        esp_netif_start_ip_lost_timer(esp_netif, false);
 #endif
     }
 
@@ -2055,6 +2058,52 @@ esp_err_t esp_netif_dhcps_get_clients_by_mac(esp_netif_t *esp_netif, int num, es
 #endif // CONFIG_LWIP_DHCPS
 }
 
+#if CONFIG_LWIP_IPV4 && LWIP_ARP
+static esp_err_t esp_netif_arp_get_client_by_mac_api(esp_netif_api_msg_t *msg)
+{
+    esp_netif_t *esp_netif = msg->esp_netif;
+    esp_netif_pair_mac_ip_t *mac_ip_pair = msg->data;
+    struct netif *lwip_netif = esp_netif ? esp_netif->lwip_netif : NULL;
+
+    if (lwip_netif == NULL || mac_ip_pair == NULL) {
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
+    }
+
+    mac_ip_pair->ip.addr = 0;
+
+    for (size_t i = 0; i < ARP_TABLE_SIZE; i++) {
+        ip4_addr_t *ip_ptr = NULL;
+        struct netif *nif = NULL;
+        struct eth_addr *eth_ptr = NULL;
+
+        if (!etharp_get_entry(i, &ip_ptr, &nif, &eth_ptr)) {
+            continue;
+        }
+        if (nif != lwip_netif) {
+            continue;
+        }
+        if (memcmp(eth_ptr->addr, mac_ip_pair->mac, ETH_HWADDR_LEN) != 0) {
+            continue;
+        }
+        mac_ip_pair->ip.addr = ip_ptr->addr;
+        break;
+    }
+    return ESP_OK;
+}
+#endif /* CONFIG_LWIP_IPV4 && LWIP_ARP */
+
+esp_err_t esp_netif_arp_get_client_by_mac(esp_netif_t *esp_netif, esp_netif_pair_mac_ip_t *mac_ip_pair)
+{
+#if CONFIG_LWIP_IPV4 && LWIP_ARP
+    if (esp_netif == NULL || mac_ip_pair == NULL) {
+        return ESP_ERR_ESP_NETIF_INVALID_PARAMS;
+    }
+    return esp_netif_lwip_ipc_call(esp_netif_arp_get_client_by_mac_api, esp_netif, (void *)mac_ip_pair);
+#else
+    return ESP_ERR_NOT_SUPPORTED;
+#endif /* CONFIG_LWIP_IPV4 && LWIP_ARP */
+}
+
 static esp_err_t esp_netif_set_dns_info_api(esp_netif_api_msg_t *msg)
 {
     esp_netif_t *esp_netif = msg->esp_netif;

components/esp_wifi/include/esp_wifi_ap_get_sta_list.h

@@ -36,7 +36,8 @@ typedef struct {
 /**
  * @brief  Get IP information for stations connected to the Wi-Fi AP interface
  *
- * @note   If `CONFIG_LWIP_DHCPS` is disabled then `ip` address field will not be populated in sta list
+ * @note   If `CONFIG_LWIP_DHCPS` is disabled then DHCP lookup is skipped; IPv4 may still be filled from the lwIP ARP cache when available.
+ *         After DHCP (when enabled), any station still without an IP is resolved via ARP table on the same interface.
  *
  * @warning This API works only for the default Wi-Fi AP interface, i.e. esp-netif with key="WIFI_AP_DEF"
  *

components/esp_wifi/remote/include/injected/esp_wifi_ap_get_sta_list.h

@@ -0,0 +1,56 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include "esp_netif_types.h"
+#include "esp_wifi_types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef ESP_WIFI_MAX_CONN_NUM
+// Number of maximum wifi connection may be undefined if we have no native wifi support on this target
+//   and at the same time there's no native interface injected by the wifi_remote component.
+// In this case, we just let the header compilable, since no wifi API could be used (let's make a sanity check)
+#if !CONFIG_SOC_WIFI_SUPPORTED && !CONFIG_ESP_WIFI_REMOTE_ENABLED && !CONFIG_ESP_HOST_WIFI_ENABLED
+#define ESP_WIFI_MAX_CONN_NUM  (15)
+typedef struct wifi_sta_list_t wifi_sta_list_t;
+#else
+#error WiFi header mismatch! Please make sure you use the correct version of WiFi API
+#endif
+#endif // ESP_WIFI_MAX_CONN_NUM
+
+/**
+ * @brief station list structure
+ */
+typedef struct {
+    int num;                                                /**< Number of connected stations */
+    esp_netif_pair_mac_ip_t sta[ESP_WIFI_MAX_CONN_NUM];     /**< Connected stations */
+} wifi_sta_mac_ip_list_t;
+
+/**
+ * @brief  Get IP information for stations connected to the Wi-Fi AP interface
+ *
+ * @note   If `CONFIG_LWIP_DHCPS` is disabled then DHCP lookup is skipped; IPv4 may still be filled from the lwIP ARP cache when available.
+ *         After DHCP (when enabled), any station still without an IP is resolved via ARP table on the same interface.
+ *
+ * @warning This API works only for the default Wi-Fi AP interface, i.e. esp-netif with key="WIFI_AP_DEF"
+ *
+ * @param[in]   wifi_sta_list Wi-Fi station info list, returned from esp_wifi_ap_get_sta_list()
+ * @param[out]  wifi_sta_ip_mac_list IP layer station info list, corresponding to MAC addresses provided in wifi_sta_list
+ *
+ * @return
+ *         - ESP_OK
+ *         - ESP_ERR_ESP_NETIF_NO_MEM
+ *         - ESP_ERR_ESP_NETIF_INVALID_PARAMS
+ */
+esp_err_t esp_wifi_ap_get_sta_list_with_ip(const wifi_sta_list_t *wifi_sta_list, wifi_sta_mac_ip_list_t *wifi_sta_ip_mac_list);
+
+#ifdef __cplusplus
+}
+#endif

components/esp_wifi/src/wifi_default_ap.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -30,7 +30,17 @@ esp_err_t esp_wifi_ap_get_sta_list_with_ip(const wifi_sta_list_t *wifi_sta_list,
         memcpy(wifi_sta_ip_mac_list->sta[i].mac, wifi_sta_list->sta[i].mac, 6);
         memset(&wifi_sta_ip_mac_list->sta[i].ip, 0, sizeof(esp_ip4_addr_t));
     }
-    return esp_netif_dhcps_get_clients_by_mac(ap, num, wifi_sta_ip_mac_list->sta);
+    esp_err_t err = esp_netif_dhcps_get_clients_by_mac(ap, num, wifi_sta_ip_mac_list->sta);
+    if (err != ESP_OK && err != ESP_ERR_NOT_SUPPORTED) {
+        return err;
+    }
+    for (int i = 0; i < num; i++) {
+        if (wifi_sta_ip_mac_list->sta[i].ip.addr == 0) {
+            // Try to get the IP from the ARP table, and not care about the result
+            esp_netif_arp_get_client_by_mac(ap, &wifi_sta_ip_mac_list->sta[i]);
+        }
+    }
+    return ESP_OK;
 #else
     return ESP_ERR_NOT_SUPPORTED;
 #endif

components/lwip/apps/dhcpserver/dhcpserver.c

@@ -5,6 +5,7 @@
  */
 #include <stdlib.h>
 #include <string.h>
+#include <stdbool.h>
 #include <assert.h>
 #include "lwip/dhcp.h"
 #include "lwip/err.h"
@@ -48,6 +49,7 @@
 #define DHCPACK       5
 #define DHCPNAK       6
 #define DHCPRELEASE   7
+#define DHCPINFORM    8
 
 #define DHCP_OPTION_PAD           0
 #define DHCP_OPTION_SUBNET_MASK   1
@@ -101,6 +103,7 @@
 #define DHCPS_STATE_NAK 4
 #define DHCPS_STATE_IDLE 5
 #define DHCPS_STATE_RELEASE 6
+#define DHCPS_STATE_INFORM_ACK 7
 
 typedef enum {
     DHCPS_HANDLE_CREATED = 0,
@@ -428,7 +431,7 @@ static u8_t *add_msg_type(u8_t *optptr, u8_t type)
  * Parameters   : optptr -- the addr of DHCP message option
  * Returns      : the addr of DHCP message option
 *******************************************************************************/
-static u8_t *add_offer_options(dhcps_t *dhcps, u8_t *optptr)
+static u8_t *add_offer_options(dhcps_t *dhcps, u8_t *optptr, bool include_lease_time)
 {
     u32_t i;
     ip4_addr_t ipadd;
@@ -439,12 +442,14 @@ static u8_t *add_offer_options(dhcps_t *dhcps, u8_t *optptr)
     *optptr++ = 4;
     optptr = dhcps_option_ip(optptr, &dhcps->dhcps_mask);
 
-    *optptr++ = DHCP_OPTION_LEASE_TIME;
+    if (include_lease_time) {
-    *optptr++ = 4;
+        *optptr++ = DHCP_OPTION_LEASE_TIME;
-    *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 24) & 0xFF;
+        *optptr++ = 4;
-    *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 16) & 0xFF;
+        *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 24) & 0xFF;
-    *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 8) & 0xFF;
+        *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 16) & 0xFF;
-    *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 0) & 0xFF;
+        *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 8) & 0xFF;
+        *optptr++ = ((dhcps->dhcps_lease_time * DHCPS_LEASE_UNIT) >> 0) & 0xFF;
+    }
 
     *optptr++ = DHCP_OPTION_SERVER_ID;
     *optptr++ = 4;
@@ -535,6 +540,44 @@ static u8_t *add_end(u8_t *optptr)
     return optptr;
 }
 
+/**
+ * Read DHCP message type (option 53) from the variable-length option area
+ * (starts after the magic cookie at options[4]).
+ */
+static u8_t dhcps_get_option_msg_type(u8_t *optptr, u16_t len)
+{
+    u8_t *end;
+
+    if (len <= 0) {
+        return 0;
+    }
+    end = optptr + len;
+
+    while (optptr < end) {
+        u8_t code = *optptr;
+        if (code == DHCP_OPTION_END) {
+            break;
+        }
+        if (code == 0) {
+            /* Pad */
+            optptr++;
+            continue;
+        }
+        if (optptr + 1 >= end) {
+            break;
+        }
+        u8_t optlen = optptr[1];
+        if ((optptr + 2 + optlen) > end) {
+            break;
+        }
+        if (code == DHCP_OPTION_MSG_TYPE && optlen >= 1) {
+            return optptr[2];
+        }
+        optptr += (u16_t)optlen + 2;
+    }
+    return 0;
+}
+
 /******************************************************************************
  * FunctionName : create_msg
  * Description  : create response message
@@ -592,7 +635,11 @@ static void dhcps_response_ip_set(dhcps_t *dhcps, struct dhcps_msg *m, ip4_addr_
             /* If the 'giaddr' field is zero and the 'ciaddr' is nonzero,
              * the server unicasts DHCPOFFER and DHCPACK message to the address in 'ciaddr'*/
             ip4_addr_set(ip4_out, &ip4_ciaddr);
-            etharp_add_static_entry(&ip4_ciaddr, &chaddr);
+            /* when 'yiaddr' is zero, means DHCPACK INFO, no need to add static entry */
+            if (!ip4_addr_isany_val(ip4_yiaddr)) {
+                /* add the IP<->MAC as static entry into the arp table. */
+                etharp_add_static_entry(&ip4_ciaddr, &chaddr);
+            }
         } else if (!BROADCAST_BIT_IS_SET(htons(m->flags))) {
             /* If the 'giaddr' is zero and 'ciaddr' is zero, and the broadcast bit is not set,
              * the server unicasts DHCPOFFER and DHCPACK message to the client's hardware address and
@@ -643,7 +690,7 @@ static void send_offer(dhcps_t *dhcps, struct dhcps_msg *m, u16_t len)
     create_msg(dhcps, m);
 
     end = add_msg_type(&m->options[4], DHCPOFFER);
-    end = add_offer_options(dhcps, end);
+    end = add_offer_options(dhcps, end, true);
     LWIP_HOOK_DHCPS_POST_APPEND_OPTS(dhcps->dhcps_netif, dhcps, DHCPOFFER, &end)
     end = add_end(end);
 
@@ -826,7 +873,7 @@ static void send_ack(dhcps_t *dhcps, struct dhcps_msg *m, u16_t len)
     create_msg(dhcps, m);
 
     end = add_msg_type(&m->options[4], DHCPACK);
-    end = add_offer_options(dhcps, end);
+    end = add_offer_options(dhcps, end, true);
     LWIP_HOOK_DHCPS_POST_APPEND_OPTS(dhcps->dhcps_netif, dhcps, DHCPACK, &end)
     end = add_end(end);
 
@@ -893,6 +940,50 @@ static void send_ack(dhcps_t *dhcps, struct dhcps_msg *m, u16_t len)
     }
 }
 
+/******************************************************************************
+ * FunctionName : send_ack_inform
+ * Description  : DHCPACK response to DHCPINFORM (RFC 2131: yiaddr = 0, no lease time)
+ * Parameters   : m -- DHCP message info
+ * Returns      : none
+*******************************************************************************/
+static void send_ack_inform(dhcps_t *dhcps, struct dhcps_msg *m, u16_t len)
+{
+    u8_t *end;
+    struct pbuf *p, *q;
+    u8_t *data;
+    u16_t cnt = 0;
+    u16_t i;
+    create_msg(dhcps, m);
+    memset(m->yiaddr, 0, sizeof(m->yiaddr));
+
+    end = add_msg_type(&m->options[4], DHCPACK);
+    end = add_offer_options(dhcps, end, false);
+    LWIP_HOOK_DHCPS_POST_APPEND_OPTS(dhcps->dhcps_netif, dhcps, DHCPACK, &end)
+    end = add_end(end);
+
+    p = dhcps_pbuf_alloc(len);
+    if (p == NULL) {
+        return;
+    }
+
+    q = p;
+    while (q != NULL) {
+        data = (u8_t *)q->payload;
+        for (i = 0; i < q->len; i++) {
+            data[i] = ((u8_t *) m)[cnt++];
+        }
+        q = q->next;
+    }
+
+    ip_addr_t ip_temp = IPADDR4_INIT(0x0);
+    dhcps_response_ip_set(dhcps, m, ip_2_ip4(&ip_temp));
+    udp_sendto(dhcps->dhcps_pcb, p, &ip_temp, DHCPS_CLIENT_PORT);
+
+    if (p->ref != 0) {
+        pbuf_free(p);
+    }
+}
+
 /******************************************************************************
  * FunctionName : parse_options
  * Description  : parse DHCP message options
@@ -1025,6 +1116,23 @@ static s16_t parse_msg(dhcps_t *dhcps, struct dhcps_msg *m, u16_t len)
 #if DHCPS_DEBUG
         DHCPS_LOG("dhcps: len = %d\n", len);
 #endif
+        {
+            u8_t msg_type = dhcps_get_option_msg_type(&m->options[4], (s16_t)len);
+            if (msg_type == DHCPINFORM) {
+                ip4_addr_t ciaddr;
+                memcpy(&ciaddr.addr, m->ciaddr, sizeof(ciaddr.addr));
+                if (ip4_addr_isany(&ciaddr)) {
+                    /* RFC 2131: client MUST set ciaddr to its configured address */
+                    return 0;
+                }
+                if (!ip4_addr_netcmp(&ciaddr, &dhcps->server_address, &dhcps->dhcps_mask)) {
+                    /* No configuration for this client */
+                    return 0;
+                }
+                return DHCPS_STATE_INFORM_ACK;
+            }
+        }
+
         ip4_addr_t addr_tmp;
 
         struct dhcps_pool *pdhcps_pool = NULL;
@@ -1276,6 +1384,13 @@ static void handle_dhcp(void *arg,
             send_nak(dhcps, pmsg_dhcps, malloc_len);
             break;
 
+        case DHCPS_STATE_INFORM_ACK://7
+#if DHCPS_DEBUG
+            DHCPS_LOG("dhcps: handle_dhcp-> DHCPD_STATE_INFORM_ACK\n");
+#endif
+            send_ack_inform(dhcps, pmsg_dhcps, malloc_len);
+            break;
+
         default :
             break;
     }

components/lwip/include/apps/dhcpserver/dhcpserver.h

@@ -61,6 +61,7 @@ typedef enum
  * - MAX_STATION_NUM: Maximum number of clients, set to Kconfig value CONFIG_LWIP_DHCPS_MAX_STATION_NUM
  * - LWIP_HOOK_DHCPS_POST_STATE: Used to inject user code after parsing DHCP message, not defined
  *      - could be enabled in lwipopts.h or via CC_FLAGS
+ *      - parse states include DHCPS_STATE_OFFER (1), ACK (3), NAK (4), INFORM_ACK (7), etc.
  *      - basic usage of the hook to print hex representation of the entire option field is below:
  *          #define LWIP_HOOK_DHCPS_POST_STATE(msg, len, state) \
  *          ({ s16_t ret = state; if (state == DHCPS_STATE_ACK) { ESP_LOG_BUFFER_HEXDUMP("DHCPS",msg->options, 312, ESP_LOG_INFO);} ret; })