Hello I try to use microhttpd (like <https://githu...

# kotlin-native

[aleksey.tomin]

Hello
I try to use microhttpd (like https://github.com/Kotlin/kotlinconf-spinner/blob/master/httpserver/src/hostMain/kotlin/server/HttpServer.kt)
for localhost only (https://stackoverflow.com/questions/46023399/make-local-http-server-inaccessable-from-outside).
On macOS

val portShort = 8888.toUShort()
        val loopbackAddr = alloc<sockaddr_in>()
        loopbackAddr.sin_addr.s_addr = INADDR_LOOPBACK
        loopbackAddr.sin_family = AF_INET.convert()
        loopbackAddr.sin_port = portShort
...
        val daemon = MHD_start_daemon(
            MHD_USE_POLL_INTERNALLY,
            portShort,
            null,
            null,
            staticCFunction(::processRequest), cPointer,
            MHD_OPTION_SOCK_ADDR, loopbackAddr.ptr,
            MHD_OPTION_END
        )

If I remove MHD_OPTION_SOCK_ADDR, loopbackAddr.ptr - it works.
But with this option daemon is null.
What do I wrong?

[Artyom Degtyarev [JB]]

I would guess there is a misunderstanding between K/N sending CPointer<sockaddr_in> and lib API asking for struct sockaddr * . I found a couple of similar situations in the kotlin-native/samples, the pointer was casted there as serverAddr.ptr.reinterpret() (e.g. here) . I think you can try something like that.

[aleksey.tomin]

As I know reinterpret() do nothing - it’s a shugar.
In any case _MHD_OPTION_SOCK_ADDR_, loopbackAddr._ptr_._reinterpret_<sockaddr>() leads the same problem

[Artyom Degtyarev [JB]]

IIRC it makes sense when the compiler can resolve type correctly on its own.
Have you zero’ed the structure? Sorry for such stupid questions, but for now it seems like we’re sending something incorrect here. I’m just trying to guess what.

[aleksey.tomin]

Yes, I’ve added _memset_(loopbackAddr._ptr_, 0, sockaddr_in.size._convert_()) after alloc.

Full code (with https)

val portShort = 8888.toUShort()
...
        val loopbackAddr = alloc<sockaddr_in>()
        memset(loopbackAddr.ptr, 0, sockaddr_in.size.convert())
        loopbackAddr.sin_addr.s_addr = INADDR_LOOPBACK
        loopbackAddr.sin_family = AF_INET.convert()
        loopbackAddr.sin_port = portShort
        MHD_start_daemon(
            MHD_USE_POLL_INTERNALLY or MHD_USE_SSL,
            portShort,
            null,
            null,
            staticCFunction(::processRequest), cPointer,
            MHD_OPTION_HTTPS_MEM_KEY, KEY.cstr,
            MHD_OPTION_HTTPS_MEM_CERT, CERT.cstr,
            MHD_OPTION_SOCK_ADDR, loopbackAddr.ptr.reinterpret<sockaddr>(),
            MHD_OPTION_CONNECTION_TIMEOUT, 120,
            MHD_OPTION_END
        )

It works if I remove MHD_OPTION_SOCK_ADDR, loopbackAddr.ptr.reinterpret<sockaddr>(),