Serde Enums with Http-like protocol

help
1

I'm writing a parser for SSDP, which is a part of UPnP. It uses a wire format that resembels an extremely constrained HTTP1/.1 over UDP. There's only a half dozen message types, so I figured I could use an Enum to represent all messages.

I know I'm going to be writing my own serializer/deserializer, and I'm fine with that. Aside from the special case first line (the request line, i.e. `NOTIFY * HTTP/1.1", it's a pretty standard key/value mapping.

One wrinkle is that there isn't a single header that decides the message type. It's a bit more complicated, depending on the HTTP method and a header:

+-----------+
|HTTP Method|
+--+----+---+
   |    |
   |    | M-Search +----------------+
   |    +-------->-+ Message::Search|
   |               +----------------+
   |
   |      Notify   +----------------+
   +------------->-+ NTS header?    |
                   ++-----+------+--+
                    |     |      |
                    |     |      |ssdp:aliVe   +--------------------+
                    |     |      +------------>+Message::Alive      |
                    |     |                    +--------------------+
                    |     |
                    |     |       ssdp:byebye  +--------------------+
                    |     +------------------->+Message::Unavailable|
                    |                          +--------------------+
                    |
                    |             ssdp:update  +--------------------+
                    +------------------------->+Message::Update     |
                                               +--------------------+

Here's an example message, captured off my home network:

NOTIFY * HTTP/1.1 
HOST: 239.255.255.250:1900 
CACHE-CONTROL: max-age=3600 
LOCATION: http://192.168.7.238:54216/RootDevice.xml 
NT: urn:schemas-upnp-org:service:ConnectionManager:1 
NTS: ssdp:alive 
SERVER: Windows 10/10.0 UPnP/1.0 Azureus/5.7.6.0 
USN: uuid:07853410-ccef-9e3c-de6a-410b371182eb::urn:schemas-upnp-org:service:ConnectionManager:1

and here's the enum variant I want to serialize that into:

enum Message {
  Available {
        max_age: u32,

        location: String,

        secure_location: Option<String>,

        notification_type: String,

        server: String,

        unique_service_name: String,

        boot_id: i32,

        config_id: i32,

        search_port: Option<u16>,
    },
    // more message types
}

Is there any way to make this fit neatly into the serde data model? or am I trying to shove a serde peg into a round hole?

2

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.