QUESTION: How to special `laddr` when dialing connection?

[jjeffcaii]

In Golang, we can use codes below to specify the local addr:

    // https://cs.opensource.google/go/go/+/refs/tags/go1.21.3:src/net/udpsock.go;l=290
    srcAddr := &net.UDPAddr{IP: net.IPv4zero, Port: 9982}
    dstAddr := &net.UDPAddr{IP: net.ParseIP("207.148.70.129"), Port: 9981}
    conn, err := net.DialUDP("udp", srcAddr, dstAddr)
    if err != nil {
        fmt.Println(err)
    }

I didn't find similar methods in the socket2 pkg, can anyone help?

[the8472]

socket2 mostly provides pretty straight-forward mappings to underlying OS APIs. The operation you're looking for is bind, which is also called bind in socket2.

See the socket(7) man page or wikipedia for a high level overview of the available functions.

As socket2's top level docs say

If you don’t know how to create a socket using libc/system calls then this crate is not for you. Most, if not all, functions directly relate to the equivalent system call with no error handling applied

[Thomasdezeeuw]

laddr stands for local address. You first need to bind(2) the socket to a local address, then call connect(2).

As @the8472 mentioned If you want to use socket2 you need some knowledge of the underlying system calls, for which the linked manual pages and Wikipedia are a good starting point. Of course there is always the awesome Beej network guide: https://beej.us/guide/bgnet/ (arguably the best learning resource for using BSD sockets).

[jjeffcaii]

Thanks! ❤️