how to forward everything from one connection to another in golang

To forward everything from one connection to another in Go, you can follow these steps:

Import the necessary packages:

import (
    "io"
    "log"
    "net"
)

Create a function to handle the forwarding:

func forward(src, dst net.Conn) {
    defer src.Close()
    defer dst.Close()

    _, err := io.Copy(src, dst)
    if err != nil {
        log.Fatal(err)
    }
}

Create a function to accept incoming connections and start forwarding:

func startForwarding(src net.Conn, dstAddress string) {
    dst, err := net.Dial("tcp", dstAddress)
    if err != nil {
        log.Fatal(err)
    }

    go forward(src, dst)
    go forward(dst, src)
}

In your main function, listen for incoming connections and start forwarding:

func main() {
    listener, err := net.Listen("tcp", "localhost:8080")
    if err != nil {
        log.Fatal(err)
    }
    defer listener.Close()

    for {
        src, err := listener.Accept()
        if err != nil {
            log.Fatal(err)
        }

        go startForwarding(src, "destination-address:port")
    }
}

In this code, we first import the necessary packages: "io" for input/output operations, "log" for logging errors, and "net" for networking.

Next, we create a function named "forward" that takes two connections as parameters: "src" for the source connection and "dst" for the destination connection. Inside this function, we use the "io.Copy" function to copy data from the source connection to the destination connection. If any error occurs, we log it using "log.Fatal".

Then, we create another function named "startForwarding" that takes the source connection and a destination address as parameters. Inside this function, we use the "net.Dial" function to establish a connection to the destination address. We then call the "forward" function twice, once to forward data from the source to the destination, and once to forward data from the destination back to the source.

Finally, in the main function, we listen for incoming connections using "net.Listen" on localhost port 8080. For each incoming connection, we call the "startForwarding" function to start forwarding data.

Please note that this is a basic example, and you may need to modify the code to fit your specific use case.