From 3d47e357d7626103c97d8a9abc3a64ea1f88276a Mon Sep 17 00:00:00 2001
From: Rohit Jadhav <69809379+jadhavrohit924@users.noreply.github.com>
Date: Tue, 5 Mar 2024 11:09:37 +0530
Subject: [PATCH] [ESP32] Add sntp support to get real time on esp32 (#32092)

* [ESP32] Add sntp support to get real time on esp32

* Address review comments

* Did some restructoring to address review comments

* Addressed review comments

* Again addressed review comments

* Restyled by clang-format

* Some renaming and error check

* Update sntp array to accomodate null terminating charactor

---------

Co-authored-by: Restyled.io <commits@restyled.io>
---
 config/esp32/components/chip/Kconfig          |   6 ++
 .../esp32/main/CMakeLists.txt                 |   1 +
 .../energy-management-app/esp32/main/main.cpp |  15 ++-
 .../esp32/sdkconfig.defaults                  |   3 +
 examples/platform/esp32/time/TimeSync.cpp     | 102 ++++++++++++++++++
 examples/platform/esp32/time/TimeSync.h       |  28 +++++
 src/platform/ESP32/SystemTimeSupport.cpp      |   7 +-
 7 files changed, 156 insertions(+), 6 deletions(-)
 create mode 100644 examples/platform/esp32/time/TimeSync.cpp
 create mode 100644 examples/platform/esp32/time/TimeSync.h

diff --git a/config/esp32/components/chip/Kconfig b/config/esp32/components/chip/Kconfig
index b39105d1285fac..589f33b1c70830 100644
--- a/config/esp32/components/chip/Kconfig
+++ b/config/esp32/components/chip/Kconfig
@@ -271,6 +271,12 @@ menu "CHIP Core"
                 Opens the commissioning window automatically at application boot time if
                 the node is not yet commissioned.
 
+        config ENABLE_SNTP_TIME_SYNC
+            bool "Enable SNTP time synchronization"
+            default n
+            help
+                Enable this option to enable SNTP time synchronization
+
     endmenu # "System Options"
 
     menu "Security Options"
diff --git a/examples/energy-management-app/esp32/main/CMakeLists.txt b/examples/energy-management-app/esp32/main/CMakeLists.txt
index 0c038632b4feab..a38ce499bc1ea5 100644
--- a/examples/energy-management-app/esp32/main/CMakeLists.txt
+++ b/examples/energy-management-app/esp32/main/CMakeLists.txt
@@ -31,6 +31,7 @@ set(SRC_DIRS_LIST
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/examples/energy-management-app/energy-management-common/src"
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/examples/platform/esp32/ota"
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/examples/platform/esp32/common"
+                      "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/examples/platform/esp32/time"
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/examples/platform/esp32/shell_extension"
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/src/app/server"
                       "${CMAKE_SOURCE_DIR}/third_party/connectedhomeip/src/app/util"
diff --git a/examples/energy-management-app/esp32/main/main.cpp b/examples/energy-management-app/esp32/main/main.cpp
index 8132b1ba2f3aff..e61e6cb00cca9b 100644
--- a/examples/energy-management-app/esp32/main/main.cpp
+++ b/examples/energy-management-app/esp32/main/main.cpp
@@ -22,6 +22,9 @@
 #include <common/CHIPDeviceManager.h>
 #include <common/Esp32AppServer.h>
 #include <common/Esp32ThreadInit.h>
+#if CONFIG_ENABLE_SNTP_TIME_SYNC
+#include <time/TimeSync.h>
+#endif
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 0, 0)
 #include "spi_flash_mmap.h"
 #else
@@ -126,7 +129,8 @@ static void InitServer(intptr_t context)
     PrintOnboardingCodes(chip::RendezvousInformationFlags(CONFIG_RENDEZVOUS_MODE));
 
     DeviceCallbacksDelegate::Instance().SetAppDelegate(&sAppDeviceCallbacksDelegate);
-    Esp32AppServer::Init(); // Init ZCL Data Model and CHIP App Server AND Initialize device attestation config
+    Esp32AppServer::Init(); // Init ZCL Data Model and CHIP App Server AND
+                            // Initialize device attestation config
 #if CONFIG_ENABLE_ESP_INSIGHTS_TRACE
     esp_insights_config_t config = {
         .log_type = ESP_DIAG_LOG_TYPE_ERROR | ESP_DIAG_LOG_TYPE_WARNING | ESP_DIAG_LOG_TYPE_EVENT,
@@ -144,8 +148,15 @@ static void InitServer(intptr_t context)
     Tracing::Register(backend);
 #endif
 
-    // Application code should always be initialised after the initialisation of server.
+    // Application code should always be initialised after the initialisation of
+    // server.
     ApplicationInit();
+
+#if CONFIG_ENABLE_SNTP_TIME_SYNC
+    const char kNtpServerUrl[]             = "pool.ntp.org";
+    const uint16_t kSyncNtpTimeIntervalDay = 1;
+    chip::Esp32TimeSync::Init(kNtpServerUrl, kSyncNtpTimeIntervalDay);
+#endif
 }
 
 extern "C" void app_main()
diff --git a/examples/energy-management-app/esp32/sdkconfig.defaults b/examples/energy-management-app/esp32/sdkconfig.defaults
index a8833c13a1a23b..c78a8751c9440a 100644
--- a/examples/energy-management-app/esp32/sdkconfig.defaults
+++ b/examples/energy-management-app/esp32/sdkconfig.defaults
@@ -64,3 +64,6 @@ CONFIG_DISABLE_READ_CLIENT=y
 
 # Increase LwIP IPv6 address number
 CONFIG_LWIP_IPV6_NUM_ADDRESSES=6
+
+# Enable sntp time sync
+CONFIG_ENABLE_SNTP_TIME_SYNC=y
diff --git a/examples/platform/esp32/time/TimeSync.cpp b/examples/platform/esp32/time/TimeSync.cpp
new file mode 100644
index 00000000000000..e5086b834ed4b2
--- /dev/null
+++ b/examples/platform/esp32/time/TimeSync.cpp
@@ -0,0 +1,102 @@
+/*
+ *
+ *    Copyright (c) 2024 Project CHIP Authors
+ *    All rights reserved.
+ *
+ *    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 "TimeSync.h"
+#include <esp_sntp.h>
+#include <lib/support/CHIPMemString.h>
+#include <lib/support/logging/CHIPLogging.h>
+
+static constexpr time_t kMinValidTimeStampEpoch = 1704067200; // 1 Jan 2019
+static constexpr uint32_t kSecondsInADay        = 24 * 60 * 60;
+
+namespace {
+const uint8_t kMaxNtpServerStringSize = 128;
+char sSntpServerName[kMaxNtpServerStringSize + 1];
+
+CHIP_ERROR GetLocalTimeString(char * buf, size_t buf_len)
+{
+    VerifyOrReturnError(buf_len > 0, CHIP_ERROR_INVALID_ARGUMENT);
+    struct tm timeinfo;
+    char strftime_buf[64];
+    time_t now;
+    time(&now);
+    localtime_r(&now, &timeinfo);
+    if (strftime(strftime_buf, sizeof(strftime_buf), "%Y-%m-%dT%H:%M:%S%z", &timeinfo) == 0)
+    {
+        ChipLogError(DeviceLayer, "Buffer too small");
+        return CHIP_ERROR_BUFFER_TOO_SMALL;
+    }
+    size_t print_size = snprintf(buf, buf_len, "%s, DST: %s", strftime_buf, timeinfo.tm_isdst ? "Yes" : "No");
+    if (print_size >= (buf_len - 1))
+    {
+        ChipLogError(DeviceLayer, "Buffer size %d insufficient for localtime string. Required size: %d", static_cast<int>(buf_len),
+                     static_cast<int>(print_size));
+        return CHIP_ERROR_BUFFER_TOO_SMALL;
+    }
+    return CHIP_NO_ERROR;
+}
+
+bool ValidateTime()
+{
+    time_t now;
+    time(&now);
+    return (now > kMinValidTimeStampEpoch);
+}
+
+CHIP_ERROR PrintCurrentTime()
+{
+    char local_time[64] = { 0 };
+    ReturnErrorOnFailure(GetLocalTimeString(local_time, sizeof(local_time)));
+    if (!ValidateTime())
+    {
+        ChipLogProgress(DeviceLayer, "Time not synchronised yet.");
+        return CHIP_ERROR_INCORRECT_STATE;
+    }
+    ChipLogProgress(DeviceLayer, "The current time is: %s.", local_time);
+    return CHIP_NO_ERROR;
+}
+
+void TimeSyncCallback(struct timeval * tv)
+{
+    ChipLogProgress(DeviceLayer, "SNTP Synchronised.");
+    if (PrintCurrentTime() != CHIP_NO_ERROR)
+    {
+        ChipLogError(DeviceLayer, "SNTP time is not synchronised.");
+    }
+}
+
+} // anonymous namespace
+
+namespace chip {
+namespace Esp32TimeSync {
+void Init(const char * aSntpServerName, const uint16_t aSyncSntpIntervalDay)
+{
+    chip::Platform::CopyString(sSntpServerName, aSntpServerName);
+    if (esp_sntp_enabled())
+    {
+        ChipLogProgress(DeviceLayer, "SNTP already initialized.");
+    }
+    ChipLogProgress(DeviceLayer, "Initializing SNTP. Using the SNTP server: %s", sSntpServerName);
+    esp_sntp_setoperatingmode(SNTP_OPMODE_POLL);
+    esp_sntp_setservername(0, sSntpServerName);
+    esp_sntp_set_sync_interval(kSecondsInADay * aSyncSntpIntervalDay);
+    esp_sntp_init();
+    sntp_set_time_sync_notification_cb(TimeSyncCallback);
+}
+} // namespace Esp32TimeSync
+} // namespace chip
diff --git a/examples/platform/esp32/time/TimeSync.h b/examples/platform/esp32/time/TimeSync.h
new file mode 100644
index 00000000000000..1009955d320400
--- /dev/null
+++ b/examples/platform/esp32/time/TimeSync.h
@@ -0,0 +1,28 @@
+/*
+ *
+ *    Copyright (c) 2024 Project CHIP Authors
+ *    All rights reserved.
+ *
+ *    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.
+ */
+
+#pragma once
+#include <esp_sntp.h>
+#include <lib/core/CHIPError.h>
+#include <lib/support/Span.h>
+
+namespace chip {
+namespace Esp32TimeSync {
+void Init(const char * aSntpServerName, uint16_t aSyncSntpIntervalDay);
+} // namespace Esp32TimeSync
+} // namespace chip
diff --git a/src/platform/ESP32/SystemTimeSupport.cpp b/src/platform/ESP32/SystemTimeSupport.cpp
index 2dc288145ce497..c303c7420c42c0 100644
--- a/src/platform/ESP32/SystemTimeSupport.cpp
+++ b/src/platform/ESP32/SystemTimeSupport.cpp
@@ -50,10 +50,7 @@ Milliseconds64 ClockImpl::GetMonotonicMilliseconds64(void)
 
 CHIP_ERROR ClockImpl::GetClock_RealTime(Microseconds64 & aCurTime)
 {
-    // TODO(19081): This platform does not properly error out if wall clock has
-    //              not been set.  For now, short circuit this.
-    return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE;
-#if 0
+#if CONFIG_ENABLE_SNTP_TIME_SYNC
     struct timeval tv;
     if (gettimeofday(&tv, nullptr) != 0)
     {
@@ -70,6 +67,8 @@ CHIP_ERROR ClockImpl::GetClock_RealTime(Microseconds64 & aCurTime)
     static_assert(CHIP_SYSTEM_CONFIG_VALID_REAL_TIME_THRESHOLD >= 0, "We might be letting through negative tv_sec values!");
     aCurTime = Microseconds64((static_cast<uint64_t>(tv.tv_sec) * UINT64_C(1000000)) + static_cast<uint64_t>(tv.tv_usec));
     return CHIP_NO_ERROR;
+#else
+    return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE;
 #endif
 }