gRPC

[!NOTE] This document is partially generated by AI.

gRPC is a high-performance transport protocol based on HTTP/2 and Protocol Buffers. In yuhaiin, it is used to tunnel proxy traffic through bi-directional gRPC streams.

Network Support

• TCP: Supported (Stream-based).
• UDP: Not supported. gRPC is inherently stream-oriented.

Client Configuration (Outbound)

When used as an outbound transport, the grpc block uses the following simplified configuration:

Configuration Fields

• tls: A nested TLS configuration block. gRPC requires a TLS layer for connection establishment.
  • enable (bool): (Required) Set to true.
  • servernames (string array): SNI for the gRPC server.

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Server Configuration (Inbound)

For an inbound gRPC server, the configuration is typically handled at the listener level.

Configuration Fields

• The grpc Inbound does not have dedicated configuration fields in the grpc block itself; it relies on the underlying TLS and listener setup.

Example Configuration

{
  "grpc": {
    "tls": {
      "enable": true,
      "servernames": ["grpc.example.com"]
    }
  }
}

Developer Details

Implementation

yuhaiin implements a specific gRPC service that allows for streaming raw binary data (TCP/UDP) over HTTP/2 streams. This is often more resilient to detection in environments that already use heavy gRPC traffic.

Package

Located in pkg/net/proxy/grpc. It utilizes the official google.golang.org/grpc library.