netconf/message/
mod.rs

1use std::{fmt::Debug, io::Write, str::from_utf8};
2
3use async_trait::async_trait;
4use quick_xml::{
5    events::{BytesStart, Event},
6    name::{Namespace, ResolveResult},
7    NsReader, Writer,
8};
9
10use crate::{
11    transport::{RecvHandle, SendHandle},
12    Error,
13};
14
15mod error;
16pub use self::error::{Read as ReadError, Write as WriteError};
17
18mod hello;
19pub(crate) use self::hello::{ClientHello, ServerHello};
20
21pub mod rpc;
22
23pub(crate) mod xmlns;
24
25pub(crate) const MARKER: &[u8] = b"]]>]]>";
26
27pub trait ReadXml: Sized {
28    fn read_xml(reader: &mut NsReader<&[u8]>, start: &BytesStart<'_>) -> Result<Self, ReadError>;
29}
30
31pub trait WriteXml {
32    fn write_xml<W: Write>(&self, writer: &mut Writer<W>) -> Result<(), WriteError>;
33}
34
35#[async_trait]
36pub trait ClientMsg: WriteXml + Debug {
37    #[tracing::instrument(skip(self), level = "debug")]
38    fn to_xml(&self) -> Result<String, WriteError> {
39        let mut buf = Vec::new();
40        let mut writer = Writer::new(&mut buf);
41        self.write_xml(&mut writer)?;
42        buf.extend_from_slice(MARKER);
43        Ok(String::from_utf8(buf)?)
44    }
45
46    #[tracing::instrument(skip(self, sender), level = "trace")]
47    async fn send<T: SendHandle>(&self, sender: &mut T) -> Result<(), Error> {
48        tracing::debug!("sending message");
49        let serialized = self.to_xml()?;
50        tracing::debug!(serialized);
51        sender.send(serialized.into()).await
52    }
53}
54
55#[async_trait]
56pub trait ServerMsg: ReadXml {
57    const TAG_NS: Namespace<'static>;
58    const TAG_NAME: &'static str;
59
60    #[tracing::instrument(skip(input), level = "debug")]
61    fn from_xml<S>(input: S) -> Result<Self, ReadError>
62    where
63        S: AsRef<str> + Debug,
64    {
65        tracing::debug!(input = input.as_ref());
66        let mut reader = NsReader::from_str(input.as_ref());
67        _ = reader.trim_text(true);
68        tracing::debug!("expecting <{}>", Self::TAG_NAME);
69        let mut this = None;
70        loop {
71            match reader.read_resolved_event()? {
72                (ResolveResult::Bound(ns), Event::Start(tag))
73                    if ns == Self::TAG_NS
74                        && tag.local_name().as_ref() == Self::TAG_NAME.as_bytes() =>
75                {
76                    this = Some(Self::read_xml(&mut reader, &tag)?);
77                }
78                (_, Event::Comment(_)) => continue,
79                (_, Event::Eof) => break,
80                (_, Event::Text(txt)) if &*txt == MARKER => break,
81                // TODO:
82                // We should save the namespace in the error too.
83                (ns, event) => {
84                    tracing::error!(?event, ?ns, "unexpected xml event");
85                    return Err(ReadError::UnexpectedXmlEvent(event.into_owned()));
86                }
87            }
88        }
89        this.ok_or_else(|| ReadError::missing_element(Self::TAG_NAME, Self::TAG_NAME))
90    }
91
92    #[tracing::instrument(skip(receiver), level = "trace")]
93    async fn recv<T: RecvHandle>(receiver: &mut T) -> Result<Self, Error> {
94        tracing::debug!("receiving message");
95        let bytes = receiver.recv().await?;
96        let serialized = from_utf8(&bytes).map_err(ReadError::DecodeMessage)?;
97        Ok(Self::from_xml(serialized)?)
98    }
99}
netconf/message/mod.rs

netconf/message/
mod.rs
