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Forwarding Chain

Dynamic configuration

Forwarding chain supports dynamic configuration via Web API.

Forwarding chain is a list of node groups formed by several nodes grouped according to a specific level. Each level of node group is a hop, and data is forwarded through each hop in turn. Forwarding chain is an important module in GOST, it is the link for establishing connections between services.

The nodes in the forwarding chain are independent of each other, and each node can use different data channels and data processing protocols independently.

gost -L http://:8080 -F https://192.168.1.1:8080 -F socks5+ws://192.168.1.2:1080
All -F parameters on the command line form a forwarding chain, and all services use this forwarding chain.

services:
- name: service-0
  addr: ":8080"
  handler:
    type: http
    chain: chain-0
  listener:
    type: tcp
chains:
- name: chain-0
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: 192.168.1.1:8080
      connector:
        type: http
      dialer:
        type: tls
  - name: hop-1
    nodes:
    - name: node-0
      addr: 192.168.1.2:1080
      connector:
        type: socks5
      dialer:
        type: ws
Listeners or handlers of a service use the specified forwarding chain by referring to the forwarding chain's name via the chain property.

Node Group

Each hop level can add multiple nodes to form a node group.

gost -L http://:8080 -F https://192.168.1.1:8080,192.168.1.1:8081,192.168.1.2:8082 -F socks5+ws://192.168.0.1:1080,192.168.0.1:1081,192.168.0.2:1082
services:
- name: service-0
  addr: ":8080"
  handler:
    type: http
    chain: chain-0
  listener:
    type: tcp
chains:
- name: chain-0
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: 192.168.1.1:8080
      connector:
        type: http
      dialer:
        type: tls
    - name: node-1
      addr: 192.168.1.1:8081
      connector:
        type: http
      dialer:
        type: tls
    - name: node-2
      addr: 192.168.1.2:8082
      connector:
        type: http
      dialer:
        type: tls
  - name: hop-1
    nodes:
    - name: node-0
      addr: 192.168.0.1:1080
      connector:
        type: socks5
      dialer:
        type: ws
    - name: node-1
      addr: 192.168.0.1:1081
      connector:
        type: socks5
      dialer:
        type: ws
    - name: node-2
      addr: 192.168.0.2:1082
      connector:
        type: socks5
      dialer:
        type: ws

There are three nodes in the first hop level (hop-0): 192.168.1.1:8080(node-0), 192.168.1.1:8081(node-1), 192.168.1.2:8082(node-2). They use the same node configuration.

There are three nodes in the second hop level (hop-1): 192.168.0.1:1080(node-0),192.168.0.1:1081(node-1),192.168.0.2:1082(node-2). They use the same node configuration.

If you need to configure each node freely, you can use the configuration file.

Multiple types

services:
- name: service-0
  addr: ":8080"
  handler:
    type: http
    chain: chain-0
  listener:
    type: tcp
chains:
- name: chain-0
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: 192.168.1.1:8080
      connector:
        type: http
      dialer:
        type: tls
    - name: node-1
      addr: 192.168.1.1:8081
      connector:
        type: socks5
      dialer:
        type: ws
    - name: node-2
      addr: 192.168.1.2:8082
      connector:
        type: relay
      dialer:
        type: tls
  - name: hop-1
    nodes:
    - name: node-0
      addr: 192.168.0.1:1080
      connector:
        type: socks5
      dialer:
        type: ws
    - name: node-1
      addr: 192.168.0.1:1081
      connector:
        type: relay
      dialer:
        type: tls
    - name: node-2
      addr: 192.168.0.2:1082
      connector:
        type: http
      dialer:
        type: h2

Multiple Forwarding Chains

Multiple forwarding chains can be set in the configuration file, and different services can use different forwarding chains according to the chain names.

Example

services:
- name: service-0
  addr: ":8080"
  handler:
    type: http
    chain: chain-0
  listener:
    type: tcp
- name: service-1
  addr: ":1080"
  handler:
    type: socks5
    chain: chain-1
  listener:
    type: tcp
chains:
- name: chain-0
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: 192.168.1.1:8080
      connector:
        type: http
      dialer:
        type: tls
- name: chain-1
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: 192.168.1.2:8082
      connector:
        type: relay
      dialer:
        type: tls
  - name: hop-1
    nodes:
    - name: node-0
      addr: 192.168.0.1:1080
      connector:
        type: socks5
      dialer:
        type: ws
    - name: node-1
      addr: 192.168.0.1:1081
      connector:
        type: relay
      dialer:
        type: tls

The service service-0 uses the forwarding chain chain-0, and the service service-1 uses the forwarding chain chain-1.

Chain Group

Listener or handler of a service can also use the chainGroup parameter to specify a chain group to use multiple chains. You can also set a Selector to specify the usage of the chains, the default selector strategy is round-robin.

Chain Group

services:
- name: service-0
  addr: ":8080"
  handler:
    type: http
    chainGroup:
      chains:
      - chain-0
      - chain-1
      selector:
        strategy: round
        maxFails: 1
        failTimeout: 10s
  listener:
    type: tcp
chains:
- name: chain-0
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: :8081
      connector:
        type: http
      dialer:
        type: tcp
- name: chain-1
  hops:
  - name: hop-0
    nodes:
    - name: node-0
      addr: :8082
      connector:
        type: http
      dialer:
        type: tcp

The service service-0 uses two chains chain-0 and chain-1 in a round-robin manner.

Direct Connection Node

If the service does not need to use an upper-stream proxy, a special direct connection node (connector.type and dialer.type are both direct) can be used to directly connect to the target address, and the node does not require a corresponding server, so the addr parameter of the node is ignored.

gost -L :8080 -F direct://:0?interface=eth0
services:
- name: service-0
  addr: ":8080"
  handler:
    type: auto
    chain: chain-0
  listener:
    type: tcp
  chains:
  - name: chain-0
    hops:
    - name: hop-0
      nodes:
      - name: node-0
        addr: :0
        interface: eth0
        connector:
          type: direct
        dialer:
          type: direct
      - name: node-1
        addr: :0
        interface: eth1
        connector:
          type: direct
        dialer:
          type: direct

Here node-0 and node-1 are direct connection nodes. When the host is [multi-homed] (/en/tutorials/multi-homed/), you can specify different interfaces for each node through the interface parameter, so that achieve load balancing at the network egress level.

Limitation

If the data channel of the node uses the UDP protocol, such as QUIC, KCP, etc., this node can only be used for the first level of the forwarding chain.