# libzt
*Embed ZeroTier directly into your app*
***

<a href="https://www.zerotier.com/?pk_campaign=github_libzt"><img src="https://raw.githubusercontent.com/zerotier/ZeroTierOne/master/artwork/ZeroTierIcon.png" width="128" height="128" align="left" hspace="20" vspace="9"></a>

A library version of [ZeroTier](https://github.com/zerotier/ZeroTierOne), **libzt** makes it easy to securely connect devices, servers, cloud VMs, containers, and apps everywhere and manage them at scale. Now you can bake this ability directly into your app or service using your preferred language. We provide a POSIX-like socket API supporting `SOCK_STREAM`, `SOCK_DGRAM`, and `SOCK_RAW` to make the integration simple. There's no need for system-wide virtual interfaces. This connection is exclusive to your app and fully encrypted via the [Salsa20](https://en.wikipedia.org/wiki/Salsa20) cipher. For a more in-depth discussion on the technical side of ZeroTier, check out our [Manual](https://www.zerotier.com/manual.shtml?pk_campaign=github_libzt)

<hr>

[![irc](https://img.shields.io/badge/IRC-%23zerotier%20on%20freenode-orange.svg)](https://webchat.freenode.net/?channels=zerotier)

 - Pre-Built binaries will soon be placed here: [zerotier.com/download.shtml](https://zerotier.com/download.shtml?pk_campaign=github_libzt)
 - Windows DLL (x64) can be found here: [libzt_win_x64_1.1.5.zip](https://download.zerotier.com/dist/libzt_win_x64_1.1.5.zip)
 - Bindings for popular languages like [Scala](examples/bindings/scala), [Swift](examples/bindings/swift), [Java](examples/bindings/java), [Python](examples/bindings/python), etc. can be found [here](examples/bindings)

*** 

### C++ Example

```
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>

#include "libzt.h"

int main() 
{
	char *str = "welcome to the machine";
	char *ip = "10.8.8.42";               // remote address
	int port = 8080;                      // remote port

	struct sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = inet_addr(ip);
	addr.sin_port = htons(port);	

	zts_startjoin("path", 0xc7cd7c981b0f52a2); // config path, nwid

	int fd, err = 0;
	if ((fd = zts_socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		printf("error creating socket\n");
	}
	if ((err = zts_connect(fd, (const struct sockaddr *)&addr, sizeof(addr))) < 0) {
		printf("error connecting to remote host\n");
	}
	if ((err = zts_write(fd, str, strlen(str))) < 0) {
		printf("error writing to socket\n");
	}
	if ((err = zts_close(fd)) < 0) {
		printf("error closing socket\n");
	}
	zts_stop();
	return 0;
}
```

For an example using only the [Virtual Layer 2](https://www.zerotier.com/manual.shtml#2_2?pk_campaign=github_libzt), see [test/layer2.cpp](test/layer2.cpp)

***

### Build

We recommend using [CMake](https://cmake.org/) for its extensive cross-platform build support. 

```
git submodule init
git submodule update
cmake -H. -Bbuild -DCMAKE_BUILD_TYPE=DEBUG
cmake --build -build 
```

Builds are placed in `bin` and `bin\lib`. Change `CMAKE_BUILD_TYPE` to `RELEASE` for a smaller and optmized build.

### Install

 - Install: `make install`
 - Uninstall: `xargs rm < install_manifest.txt`

***

### Testing and Debugging
 - See [TESTING.md](TESTING.md)


### Contributing

Please make pull requests against the `dev` branch. The `master` branch is release, and `edge` is for unstable and work in progress changes and is not likely to work.

### Commercial License
 - To be released from GPLv3, contact us directly via `contact@zerotier.com` to discuss commercial licensing.

### Adding a custom network stack
 - If you wish to use something other than lwIP or picoTCP, you can easily add your own API function calls in `src/libzt.cpp` or `src/VirtualSocket.cpp` depending on whether your stack's API exposes a POSIX-socket API or a raw API, respectively.