From 9c0c0ce994ab6263316e16a55714e34c9284323e Mon Sep 17 00:00:00 2001
From: zwx <zhangwenxu@espressif.com>
Date: Mon, 29 Jul 2024 21:01:49 +0800
Subject: [PATCH] feat(esp_netif): add an API to get all preferred ip6
 addresses

---
 components/esp_netif/include/esp_netif.h   | 13 +++++++++++-
 components/esp_netif/lwip/esp_netif_lwip.c | 24 ++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/components/esp_netif/include/esp_netif.h b/components/esp_netif/include/esp_netif.h
index df4beee605..657c6303fa 100644
--- a/components/esp_netif/include/esp_netif.h
+++ b/components/esp_netif/include/esp_netif.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2019-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2019-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -821,6 +821,17 @@ esp_err_t esp_netif_get_ip6_global(esp_netif_t *esp_netif, esp_ip6_addr_t *if_ip
  *      number of returned IPv6 addresses
  */
 int esp_netif_get_all_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[]);
+
+/**
+ * @brief  Get all preferred IPv6 addresses of the specified interface
+ *
+ * @param[in]  esp_netif Handle to esp-netif instance
+ * @param[out] if_ip6 Array of IPv6 addresses will be copied to the argument
+ *
+ * @return
+ *      number of returned IPv6 addresses
+ */
+int esp_netif_get_all_preferred_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[]);
 #endif
 
 /**
diff --git a/components/esp_netif/lwip/esp_netif_lwip.c b/components/esp_netif/lwip/esp_netif_lwip.c
index 264e214d72..c117daff94 100644
--- a/components/esp_netif/lwip/esp_netif_lwip.c
+++ b/components/esp_netif/lwip/esp_netif_lwip.c
@@ -2159,6 +2159,30 @@ int esp_netif_get_all_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[])
     }
     return addr_count;
 }
+
+int esp_netif_get_all_preferred_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[])
+{
+    ESP_LOGV(TAG, "%s esp-netif:%p", __func__, esp_netif);
+
+    if (esp_netif == NULL || if_ip6 == NULL) {
+        return 0;
+    }
+
+    int addr_count = 0;
+    struct netif *p_netif = esp_netif->lwip_netif;
+
+    if (p_netif != NULL && netif_is_up(p_netif)) {
+        for (int i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
+            // Only return the IPs which are:
+            // 1. the state is preferred
+            // 2. not the IP6_ADDR_ANY(all bits are `0`)
+            if (ip6_addr_ispreferred(netif_ip6_addr_state(p_netif, i)) && !ip_addr_cmp(&p_netif->ip6_addr[i], IP6_ADDR_ANY)) {
+                memcpy(&if_ip6[addr_count++], &p_netif->ip6_addr[i], sizeof(ip6_addr_t));
+            }
+        }
+    }
+    return addr_count;
+}
 #endif
 
 esp_netif_flags_t esp_netif_get_flags(esp_netif_t *esp_netif)