What is frp?

What is frp?

frp is a fast reverse proxy to help you expose a local server behind a NAT or firewall to the internet. Now, it supports tcp, udp, http and https protocol when requests can be forwarded by domains to backward web services.

Table of Contents

• What can I do with frp?
• Status
• Architecture
• Example Usage
  • Communicate with your computer in LAN by SSH
  • Visit your web service in LAN by custom domains
  • Forward DNS query request
• Features
  • Dashboard
  • Authentication
  • Encryption and Compression
  • Reload configures without frps stopped
  • Privilege Mode
    • Port White List
  • Connection Pool
  • Rewriting the Host Header
  • Password protecting your web service
  • Custom subdomain names
  • URL routing
  • Connect frps by HTTP PROXY
• Development Plan
• Contributing
• Donation
  • AliPay
  • Paypal
• Contributors

What can I do with frp?

• Expose any http and https service behind a NAT or firewall to the internet by a server with public IP address(Name-based Virtual Host Support).
• Expose any tcp service behind a NAT or firewall to the internet by a server with public IP address.
• Inspect all http requests/responses that are transmitted over the tunnel(future).

Status

frp is under development and you can try it with latest release version. Master branch for releasing stable version when dev branch for developing.

We may change any protocol and can't promise backward compatible. Please check the release log when upgrading.

Architecture

Example Usage

Firstly, download the latest programs from Release page according to your os and arch.

Put frps and frps.ini to your server with public IP.

Put frpc and frpc.ini to your server in LAN.

Communicate with your computer in LAN by SSH

1. Modify frps.ini, configure a reverse proxy named [ssh]:

# frps.ini[common]bind_port = 7000[ssh]listen_port = 6000auth_token = 123

2. Start frps: ./frps -c ./frps.ini

3. Modify frpc.ini, set remote frps's server IP as x.x.x.x:

# frpc.ini[common]server_addr = x.x.x.xserver_port = 7000auth_token = 123[ssh]type = tcplocal_ip = 127.0.0.1local_port = 22

4. Start frpc: ./frpc -c ./frpc.ini

5. Connect to server in LAN by ssh assuming that username is test:

  ssh -oPort=6000 test@x.x.x.x

Visit your web service in LAN by custom domains

Sometimes we want to expose a local web service behind a NAT network to others for testing with your own domain name and unfortunately we can't resolve a domain name to a local ip.

However, we can expose a http or https service using frp.

1. Modify frps.ini, configure a http reverse proxy named [web] and set http port as 8080, custom domain as www.yourdomain.com:

# frps.ini[common]bind_port = 7000vhost_http_port = 8080[web]type = httpcustom_domains = www.yourdomain.comauth_token = 123

2. Start frps:  ./frps -c ./frps.ini

3. Modify frpc.ini and set remote frps server's IP as x.x.x.x. The local_port is the port of your web service:

# frpc.ini[common]server_addr = x.x.x.xserver_port = 7000auth_token = 123[web]type = httplocal_port = 80

4. Start frpc: ./frpc -c ./frpc.ini

5. Resolve A record of www.yourdomain.com to IP x.x.x.x or CNAME record to your origin domain.

6. Now visit your local web service using url http://www.yourdomain.com:8080.

Forward DNS query request

1. Modify frps.ini, configure a reverse proxy named [dns]:

# frps.ini[common]bind_port = 7000[dns]type = udplisten_port = 6000auth_token = 123

2. Start frps: ./frps -c ./frps.ini

3. Modify frpc.ini, set remote frps's server IP as x.x.x.x, forward dns query request to google dns server 8.8.8.8:53:

# frpc.ini[common]server_addr = x.x.x.xserver_port = 7000auth_token = 123[dns]type = udplocal_ip = 8.8.8.8local_port = 53

4. Start frpc: ./frpc -c ./frpc.ini

5. Send dns query request by dig:

  dig @x.x.x.x -p 6000 www.goolge.com

Features

Dashboard

Check frp's status and proxies's statistics information by Dashboard.

Configure a port for dashboard to enable this feature:

[common]dashboard_port = 7500# dashboard's username and password are both optional，if not set, default is admin.dashboard_user = admindashboard_pwd = admin

Then visit http://[server_addr]:7500 to see dashboard, default username and password are both admin.

Authentication

auth_token in frps.ini is configured for each proxy and check for authentication when frpc login in.

Client that want's to register must set a global auth_token equals to frps.ini.

Note that time duration between frpc and frps mustn't exceed 15 minutes because timestamp is used for authentication.

Howerver, this timeout duration can be modified by setting authentication_timeout in frps's configure file. It's defalut value is 900, means 15 minutes. If it is equals 0, then frps will not check authentication timeout.

Encryption and Compression

Defalut value is false, you could decide if the proxy will use encryption or compression whether the type is:

# frpc.ini[ssh]type = tcplisten_port = 6000auth_token = 123use_encryption = trueuse_gzip = true

Reload configures without frps stopped

If you want to add a new reverse proxy and avoid restarting frps, you can use this function:

1. dashboard_port should be set in frps.ini:

# frps.ini[common]bind_port = 7000dashboard_port = 7500

2. Start frps:

  ./frps -c ./frps.ini

3. Modify frps.ini to add a new proxy [new_ssh]:

# frps.ini[common]bind_port = 7000dashboard_port = 7500[new_ssh]listen_port = 6001auth_token = 123

4. Execute reload command:

  ./frps -c ./frps.ini --reload

5. Start frpc and [new_ssh] is available now.

Privilege Mode

Privilege mode is used for who don't want to do operations in frps everytime adding a new proxy.

All proxies's configurations are set in frpc.ini when privilege mode is enabled.

1. Enable privilege mode and set privilege_token.Client with the same privilege_token can create proxy automaticly:

# frps.ini[common]bind_port = 7000privilege_mode = trueprivilege_token = 1234

2. Start frps:

  ./frps -c ./frps.ini

3. Enable privilege mode for proxy [ssh]:

# frpc.ini[common]server_addr = x.x.x.xserver_port = 7000privilege_token = 1234[ssh]privilege_mode = truelocal_port = 22remote_port = 6000

4. Start frpc:

  ./frpc -c ./frpc.ini

5. Connect to server in LAN by ssh assuming username is test:

  ssh -oPort=6000 test@x.x.x.x

Port White List

privilege_allow_ports in frps.ini is used for preventing abuse of ports in privilege mode:

# frps.ini[common]privilege_mode = trueprivilege_token = 1234privilege_allow_ports = 2000-3000,3001,3003,4000-50000

privilege_allow_ports consists of a specific port or a range of ports divided by ,.

Connection Pool

By default, frps send message to frpc for create a new connection to backward service when getting an user request.If a proxy's connection pool is enabled, there will be a specified number of connections pre-established.

This feature is fit for a large number of short connections.

1. Configure the limit of pool count each proxy can use in frps.ini:

# frps.ini[common]max_pool_count = 50

2. Enable and specify the number of connection pool:

# frpc.ini[ssh]type = tcplocal_port = 22pool_count = 10

Rewriting the Host Header

When forwarding to a local port, frp does not modify the tunneled HTTP requests at all, they are copied to your server byte-for-byte as they are received. Some application servers use the Host header for determining which development site to display. For this reason, frp can rewrite your requests with a modified Host header. Use the host_header_rewrite switch to rewrite incoming HTTP requests.

# frpc.ini                                                         [web]privilege_mode = truetype = httplocal_port = 80custom_domains = test.yourdomain.comhost_header_rewrite = dev.yourdomain.com

If host_header_rewrite is specified, the Host header will be rewritten to match the hostname portion of the forwarding address.

Password protecting your web service

Anyone who can guess your tunnel URL can access your local web server unless you protect it with a password.

This enforces HTTP Basic Auth on all requests with the username and password you specify in frpc's configure file.

It can be only enabled when proxy type is http.

# frpc.ini[web]privilege_mode = truetype = httplocal_port = 80custom_domains = test.yourdomain.comhttp_user = abchttp_pwd = abc

Visit test.yourdomain.com and now you need to input username and password.

Custom subdomain names

It is convenient to use subdomain configure for http、https type when many people use one frps server together.

# frps.inisubdomain_host = frps.com

Resolve *.frps.com to the frps server's IP.

# frpc.ini[web]privilege_mode = truetype = httplocal_port = 80subdomain = test

Now you can visit your web service by host test.frps.com.

Note that if subdomain_host is not empty, custom_domains should not be the subdomain of subdomain_host.

URL routing

frp support forward http requests to different backward web services by url routing.

locations specify the prefix of URL used for routing. frps first searches for the most specific prefix location given by literal strings regardless of the listed order.

# frpc.ini[web01]privilege_mode = truetype = httplocal_port = 80custom_domains = web.yourdomain.comlocations = /[web02]privilege_mode = truetype = httplocal_port = 81custom_domains = web.yourdomain.comlocations = /news,/about

Http requests with url prefix /news and /about will be forwarded to web02 and others to web01.

Connect frps by HTTP PROXY

frpc can connect frps using HTTP PROXY if you set os environment HTTP_PROXY or configure http_proxy param in frpc.ini file.

# frpc.iniserver_addr = x.x.x.xserver_port = 7000http_proxy = http://user:pwd@192.168.1.128:8080

Development Plan

• Log http request information in frps.
• Direct reverse proxy, like haproxy.
• Load balance to different service in frpc.
• Debug mode for frpc, prestent proxy status in terminal.
• Inspect all http requests/responses that are transmitted over the tunnel.
• Frpc can directly be a webserver for static files.
• Full control mode, dynamically modify frpc's configure with dashboard in frps.
• P2p communicate by make udp hole to penetrate NAT.

Contributing

Interested in getting involved? We would like to help you!

• Take a look at our issues list and consider sending a Pull Request to dev branch.
• If you want to add a new feature, please create an issue first to describe the new feature, as well as the implementation approach. Once a proposal is accepted, create an implementation of the new features and submit it as a pull request.
• Sorry for my poor english and improvement for this document is welcome even some typo fix.
• If you have some wanderful ideas, send email to [e-mail].

Note: We prefer you to give your advise in issues, so others with a same question can search it quickly and we don't need to answer them repeatly.