https://github.com/freertos/coresntp
SNTPv4 client designed for embedded devices.
https://github.com/freertos/coresntp
Last synced: 5 months ago
JSON representation
SNTPv4 client designed for embedded devices.
- Host: GitHub
- URL: https://github.com/freertos/coresntp
- Owner: FreeRTOS
- License: mit
- Created: 2021-03-25T23:09:20.000Z (about 5 years ago)
- Default Branch: main
- Last Pushed: 2025-04-15T09:11:39.000Z (about 1 year ago)
- Last Synced: 2025-04-15T10:25:07.390Z (about 1 year ago)
- Language: C
- Homepage:
- Size: 1.15 MB
- Stars: 21
- Watchers: 16
- Forks: 25
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: .github/CONTRIBUTING.md
- License: LICENSE
- Codeowners: .github/CODEOWNERS
- Security: SECURITY.md
Awesome Lists containing this project
README
## coreSNTP Library
**[API Documentation Pages for current and previous releases of this library can be found here](https://freertos.github.io/coreSNTP/)**
This repository contains the coreSNTP library, a client library to use Simple
Network Time Protocol (SNTP) to synchronize device clocks with internet time.
This library implements the SNTPv4 specification defined in
[RFC 4330](https://tools.ietf.org/html/rfc4330).
An SNTP client can request time from both NTP and SNTP servers. According to the
SNTPv4 specification, "_To an NTP or SNTP server, NTP and SNTP clients are
indistinguishable; to an NTP or SNTP client, NTP and SNTP servers are
indistinguishable._", thereby, allowing SNTP clients to request time from NTP
servers.
This library has gone through code quality checks including verification that no
function has a
[GNU Complexity](https://www.gnu.org/software/complexity/manual/complexity.html)
score over 10, and checks against deviations from mandatory rules in the
[MISRA coding standard](https://www.misra.org.uk). Deviations from the MISRA
C:2012 guidelines are documented under [MISRA Deviations](MISRA.md). This
library has also undergone both static code analysis from
[Coverity static analysis](https://scan.coverity.com/), and validation of memory
safety through the
[CBMC automated reasoning tool](https://www.cprover.org/cbmc/).
See memory requirements for this library
[here](./docs/doxygen/include/size_table.md).
**coreSNTP v1.3.1
[source code](https://github.com/FreeRTOS/coreSNTP/tree/v1.3.1/source) is part
of the
[FreeRTOS 202406.00 LTS](https://github.com/FreeRTOS/FreeRTOS-LTS/tree/202406.00-LTS)
release.**
### Documentation
The API reference documentation for the coreSNTP library version released in
[FreeRTOS/FreeRTOS](https://github.com/FreeRTOS/FreeRTOS) can be viewed from the
[freertos.org website](https://freertos.org/coresntp/index.html).
## Cloning this repository
This repo uses
[Git Submodules](https://git-scm.com/book/en/v2/Git-Tools-Submodules) to bring
in dependent components.
To clone using HTTPS:
```sh
git clone https://github.com/FreeRTOS/coreSNTP.git --recurse-submodules
```
Using SSH:
```sh
git clone git@github.com:FreeRTOS/coreSNTP.git --recurse-submodules
```
If you have downloaded the repo without using the `--recurse-submodules`
argument, you need to run:
```sh
git submodule update --init --recursive
```
## Building the library
You can build the coreSNTP source files that are in the [source](source/)
directory, and add [source/include](source/include) to your compiler's include
path.
If using CMake, the [coreSntpFilePaths.cmake](coreSntpFilePaths.cmake) file
contains the above information of the source files and the header include path
from this repository.
## Reference Example
A reference example of using the coreSNTP library can be viewed in the
`FreeRTOS/FreeRTOS` repository
[here](https://github.com/FreeRTOS/FreeRTOS/tree/main/FreeRTOS-Plus/Demo/coreSNTP_Windows_Simulator).
The demo application showcases use of the library in order to create an SNTP
client for periodic time synchronization of the system clock.
## Building Unit Tests
The unit tests for the library use CMock/Unity unit testing framework.
### Checkout CMock Submodule
To build unit tests, the submodule dependency of CMock is required. Use the
following command to clone the submodule:
```
git submodule update --checkout --init --recursive test/unit-test/CMock
```
### Unit Test Platform Prerequisites
- For running unit tests
- **C90 compiler** like gcc
- **CMake 3.13.0 or later**
- **Ruby 2.0.0 or later** is additionally required for the CMock test
framework (that we use).
- For running the coverage target, **gcov** and **lcov** are additionally
required.
### Steps to build **Unit Tests**
1. Go to the root directory of this repository. (Make sure that the **CMock**
submodule is cloned as described [above](#checkout-cmock-submodule))
1. Run the _cmake_ command: `cmake -S test -B build -DUNITTEST=ON`
1. Run this command to build the library and unit tests: `make -C build all`
1. The generated test executables will be present in `build/bin/tests` folder.
1. Run `cd build && ctest` to execute all tests and view the test run summary.
## CBMC proofs
To learn more about CBMC and proofs specifically, review the training material
[here](https://model-checking.github.io/cbmc-training).
The `test/cbmc/proofs` directory contains CBMC proofs.
In order to run these proofs you will need to install CBMC and other tools by
following the instructions
[here](https://model-checking.github.io/cbmc-training/installation.html).
## Generating documentation
The Doxygen references were created using Doxygen version 1.9.6. To generate the
Doxygen pages, please run the following command from the root of this
repository:
```sh
doxygen docs/doxygen/config.doxyfile
```
## Contributing
See [CONTRIBUTING.md](./.github/CONTRIBUTING.md) for information on
contributing.
## License
This library is licensed under the MIT License. See the [LICENSE](LICENSE) file.