From d5f086f43233c01d8ba7cb967b7167a08940e99a Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Tue, 23 Jan 2024 17:10:19 +0100
Subject: [PATCH 1/2] fix(netif): Add missing SNTP get-reachablitiy API

---
 components/esp_netif/include/esp_netif_sntp.h | 13 ++++++++-
 components/esp_netif/lwip/esp_netif_sntp.c    | 14 +++++++++-
 .../test_app_esp_netif/main/esp_netif_test.c  | 15 ++++++++++-
 components/lwip/apps/sntp/sntp.c              | 16 ++++++++++-
 components/lwip/include/apps/esp_sntp.h       | 27 ++++++++++++++++++-
 components/lwip/test_apps/main/lwip_test.c    | 10 ++++++-
 6 files changed, 89 insertions(+), 6 deletions(-)

diff --git a/components/esp_netif/include/esp_netif_sntp.h b/components/esp_netif/include/esp_netif_sntp.h
index 87f1245d5a..51d7e42bd4 100644
--- a/components/esp_netif/include/esp_netif_sntp.h
+++ b/components/esp_netif/include/esp_netif_sntp.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -107,6 +107,17 @@ void esp_netif_sntp_deinit(void);
  */
 esp_err_t esp_netif_sntp_sync_wait(TickType_t tout);
 
+/**
+ * @brief Returns SNTP server's reachability shift register as described in RFC 5905.
+ *
+ * @param index Index of the SERVER
+ * @param reachability reachability shift register
+ * @return ESP_OK on success,
+ *         ESP_ERR_INVALID_STATE if SNTP not initialized
+ *         ESP_ERR_INVALID_ARG if invalid arguments
+ */
+esp_err_t esp_netif_sntp_reachability(unsigned int index, unsigned int *reachability);
+
 /**
  * @}
  */
diff --git a/components/esp_netif/lwip/esp_netif_sntp.c b/components/esp_netif/lwip/esp_netif_sntp.c
index 1aadcbef69..e6fe54f37f 100644
--- a/components/esp_netif/lwip/esp_netif_sntp.c
+++ b/components/esp_netif/lwip/esp_netif_sntp.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -177,3 +177,15 @@ esp_err_t esp_netif_sntp_start(void)
 {
     return esp_netif_tcpip_exec(sntp_start_api, NULL);
 }
+
+esp_err_t esp_netif_sntp_reachability(unsigned int index, unsigned int *reachability)
+{
+    if (index >= SNTP_MAX_SERVERS || reachability == NULL) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (s_storage == NULL || sntp_enabled() == 0) {
+        return ESP_ERR_INVALID_STATE;
+    }
+    *reachability = sntp_getreachability(index);
+    return ESP_OK;
+}
diff --git a/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c b/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
index 472a8de7ad..79f70ac27a 100644
--- a/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
+++ b/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
@@ -48,7 +48,20 @@ TEST(esp_netif, init_and_destroy_sntp)
 {
     esp_sntp_config_t config = ESP_NETIF_SNTP_DEFAULT_CONFIG("127.0.0.1");
     config.start = false;
-    esp_netif_sntp_init(&config);
+    TEST_ESP_OK(esp_netif_sntp_init(&config));
+    // Cannot initialize multiple times
+    TEST_ASSERT_NOT_EQUAL(ESP_OK, esp_netif_sntp_init(&config));
+    // Try again to see that the state didn't change
+    TEST_ASSERT_NOT_EQUAL(ESP_OK, esp_netif_sntp_init(&config));
+    esp_netif_sntp_deinit();
+
+    // Can initialize again once it's destroyed
+    TEST_ESP_OK(esp_netif_sntp_init(&config));
+
+    // Test the reachability API
+    size_t reachability = 0;
+    // Invalid state is expected since SNTP service didn't start
+    TEST_ASSERT_EQUAL(ESP_ERR_INVALID_STATE, esp_netif_sntp_reachability(0, &reachability));
     esp_netif_sntp_deinit();
 }
 
diff --git a/components/lwip/apps/sntp/sntp.c b/components/lwip/apps/sntp/sntp.c
index 3b8cf283ae..8d8fbfbe90 100644
--- a/components/lwip/apps/sntp/sntp.c
+++ b/components/lwip/apps/sntp/sntp.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -243,6 +243,20 @@ const ip_addr_t* esp_sntp_getserver(u8_t idx)
     return sntp_getserver(idx);
 }
 
+uint8_t esp_sntp_getreachability(uint8_t idx)
+{
+#if SNTP_MONITOR_SERVER_REACHABILITY
+    return sntp_getreachability(idx);
+#endif
+    LWIP_ERROR("sntp_getreachability() in not enabled in lwipopts", false, );
+    return 0;
+}
+
+esp_sntp_operatingmode_t esp_sntp_getoperatingmode(void)
+{
+    return (esp_sntp_operatingmode_t)sntp_getoperatingmode();
+}
+
 #if LWIP_DHCP_GET_NTP_SRV
 static void do_servermode_dhcp(void* ctx)
 {
diff --git a/components/lwip/include/apps/esp_sntp.h b/components/lwip/include/apps/esp_sntp.h
index 80d2a88129..6aad345d00 100644
--- a/components/lwip/include/apps/esp_sntp.h
+++ b/components/lwip/include/apps/esp_sntp.h
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2021 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -218,6 +218,20 @@ const ip_addr_t* esp_sntp_getserver(u8_t idx);
  */
 bool esp_sntp_enabled(void);
 
+/**
+ * @brief Gets the server reachability shift register as described in RFC 5905.
+ * @param idx Index of the SNTP server
+ * @return reachability shift register
+ */
+uint8_t esp_sntp_getreachability(uint8_t idx);
+
+/**
+ * @brief Get the configured operating mode
+ *
+ * @return operating mode enum
+ */
+esp_sntp_operatingmode_t esp_sntp_getoperatingmode(void);
+
 #if LWIP_DHCP_GET_NTP_SRV
 /**
  * @brief Enable acquiring SNTP server from DHCP
@@ -269,6 +283,17 @@ const ip_addr_t* sntp_getserver(u8_t idx)
     return esp_sntp_getserver(idx);
 }
 
+static inline uint8_t sntp_getreachability(uint8_t idx)
+{
+    return esp_sntp_getreachability(idx);
+}
+
+static inline __attribute__((deprecated("use esp_sntp_getoperatingmode() instead")))
+esp_sntp_operatingmode_t sntp_getoperatingmode(void)
+{
+    return esp_sntp_getoperatingmode();
+}
+
 #endif /* ESP_LWIP_COMPONENT_BUILD */
 
 
diff --git a/components/lwip/test_apps/main/lwip_test.c b/components/lwip/test_apps/main/lwip_test.c
index 6a34edeb43..a738c87611 100644
--- a/components/lwip/test_apps/main/lwip_test.c
+++ b/components/lwip/test_apps/main/lwip_test.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -294,8 +294,16 @@ void test_sntp_timestamps(int year, bool msb_flag)
     localtime_r(&now, &timeinfo);
     TEST_ASSERT_EQUAL(year, 1900 + timeinfo.tm_year);
 
+    // Check that the server 0 was reachable
+    TEST_ASSERT_EQUAL(1, esp_sntp_getreachability(0));
     // close the SNTP and the fake server
     esp_sntp_stop();
+
+    // Test some other SNTP APIs
+    TEST_ASSERT_EQUAL(0, esp_sntp_getreachability(0));
+    TEST_ASSERT_EQUAL(ESP_SNTP_OPMODE_POLL, esp_sntp_getoperatingmode());
+    const ip_addr_t *server_ip = esp_sntp_getserver(0);
+    TEST_ASSERT_EQUAL(PP_HTONL(IPADDR_LOOPBACK), server_ip->u_addr.ip4.addr);
     close(sock);
 }
 

From d750d067e512cdc1b275516ea922bc1016f09741 Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Mon, 8 Jan 2024 11:09:35 +0100
Subject: [PATCH 2/2] fix(esp_netif): Prevent running esp_netif_sntp_init()
 multiple times

Closes https://github.com/espressif/esp-idf/issues/12854
---
 components/esp_netif/lwip/esp_netif_sntp.c                      | 1 +
 .../test_apps/test_app_esp_netif/main/esp_netif_test.c          | 2 +-
 docs/en/api-reference/network/esp_netif.rst                     | 2 +-
 docs/zh_CN/api-reference/network/esp_netif.rst                  | 2 +-
 4 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/components/esp_netif/lwip/esp_netif_sntp.c b/components/esp_netif/lwip/esp_netif_sntp.c
index e6fe54f37f..1a7da5e442 100644
--- a/components/esp_netif/lwip/esp_netif_sntp.c
+++ b/components/esp_netif/lwip/esp_netif_sntp.c
@@ -91,6 +91,7 @@ void esp_netif_sntp_renew_servers(void *handler_args, esp_event_base_t base, int
 esp_err_t esp_netif_sntp_init(const esp_sntp_config_t * config)
 {
     esp_err_t ret = ESP_OK;
+    ESP_RETURN_ON_FALSE(s_storage == NULL, ESP_ERR_INVALID_STATE, TAG, "esp_netif_sntp already initialized");
     s_storage = calloc(1, sizeof(sntp_storage_t) + // allocate space for servers only if we are supposed to refresh the settings
                           (config->renew_servers_after_new_IP ? config->num_of_servers * sizeof(char*) : 0));
     ESP_GOTO_ON_FALSE(s_storage != NULL, ESP_ERR_NO_MEM, err, TAG, "Failed to allocate SNTP storage");
diff --git a/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c b/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
index 79f70ac27a..84705bc784 100644
--- a/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
+++ b/components/esp_netif/test_apps/test_app_esp_netif/main/esp_netif_test.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
diff --git a/docs/en/api-reference/network/esp_netif.rst b/docs/en/api-reference/network/esp_netif.rst
index 2ff9b9f3ff..d1fff7e542 100644
--- a/docs/en/api-reference/network/esp_netif.rst
+++ b/docs/en/api-reference/network/esp_netif.rst
@@ -264,7 +264,7 @@ You can find a brief introduction to SNTP in general, its initialization code, a
 
 This section provides more details about specific use cases of the SNTP service, with statically configured servers, or use the DHCP-provided servers, or both. The workflow is usually very simple:
 
-1) Initialize and configure the service using :cpp:func:`esp_netif_sntp_init()`.
+1) Initialize and configure the service using :cpp:func:`esp_netif_sntp_init()`. This operations can only be called once (unless the SNTP service has been destroyed by :cpp:func:`esp_netif_sntp_deinit()`)
 2) Start the service via :cpp:func:`esp_netif_sntp_start()`. This step is not needed if we auto-started the service in the previous step (default). It is useful to start the service explicitly after connecting if we want to use the DHCP-obtained NTP servers. Please note, this option needs to be enabled before connecting, but the SNTP service should be started after.
 3) Wait for the system time to synchronize using :cpp:func:`esp_netif_sntp_sync_wait()` (only if needed).
 4) Stop and destroy the service using :cpp:func:`esp_netif_sntp_deinit()`.
diff --git a/docs/zh_CN/api-reference/network/esp_netif.rst b/docs/zh_CN/api-reference/network/esp_netif.rst
index 3eb9bfe3e8..0b6a9a34fd 100644
--- a/docs/zh_CN/api-reference/network/esp_netif.rst
+++ b/docs/zh_CN/api-reference/network/esp_netif.rst
@@ -264,7 +264,7 @@ SNTP 的简要介绍、初始化代码和基本模式请参阅 :doc:`系统时
 
 本节介绍了使用 SNTP 服务特定用例的详细信息，包括静态配置的服务器、使用 DHCP 提供的服务器或两者兼备的情况，操作流程如下：
 
-1) 调用 :cpp:func:`esp_netif_sntp_init()` 初始化服务并完成配置。
+1) 调用 :cpp:func:`esp_netif_sntp_init()` 初始化服务并完成配置。此操作只能执行一次（除非已调用 :cpp:func:`esp_netif_sntp_deinit()` 销毁 SNTP 服务）。
 2) 调用 :cpp:func:`esp_netif_sntp_start()` 启动服务。如果在前一步中已经默认启动了服务，则不需要此步骤。如果需使用通过 DHCP 获取的 NTP 服务器，推荐在完成连接后显式启动该服务。注意，应在连接前启用通过 DHCP 获取的 NTP 服务器选项，并在连接后再启用 SNTP 服务。
 3) 需要时，可调用 :cpp:func:`esp_netif_sntp_sync_wait()` 等待系统时间同步。
 4) 调用 :cpp:func:`esp_netif_sntp_deinit()` 停止并销毁服务。