wasmtime_wasi/p2/
ip_name_lookup.rs

1use crate::p2::SocketError;
2use crate::p2::bindings::sockets::ip_name_lookup::{Host, HostResolveAddressStream};
3use crate::p2::bindings::sockets::network::{ErrorCode, IpAddress, Network};
4use crate::runtime::{AbortOnDropJoinHandle, spawn_blocking};
5use crate::sockets::WasiSocketsCtxView;
6use anyhow::Result;
7use std::mem;
8use std::net::ToSocketAddrs;
9use std::pin::Pin;
10use std::vec;
11use wasmtime::component::Resource;
12use wasmtime_wasi_io::poll::{DynPollable, Pollable, subscribe};
13
14use crate::sockets::util::{from_ipv4_addr, from_ipv6_addr, parse_host};
15
16pub enum ResolveAddressStream {
17    Waiting(AbortOnDropJoinHandle<Result<Vec<IpAddress>, SocketError>>),
18    Done(Result<vec::IntoIter<IpAddress>, SocketError>),
19}
20
21impl Host for WasiSocketsCtxView<'_> {
22    fn resolve_addresses(
23        &mut self,
24        network: Resource<Network>,
25        name: String,
26    ) -> Result<Resource<ResolveAddressStream>, SocketError> {
27        let network = self.table.get(&network)?;
28
29        let host = parse_host(&name)?;
30
31        if !network.allow_ip_name_lookup {
32            return Err(ErrorCode::PermanentResolverFailure.into());
33        }
34
35        let task = spawn_blocking(move || blocking_resolve(&host));
36        let resource = self.table.push(ResolveAddressStream::Waiting(task))?;
37        Ok(resource)
38    }
39}
40
41impl HostResolveAddressStream for WasiSocketsCtxView<'_> {
42    fn resolve_next_address(
43        &mut self,
44        resource: Resource<ResolveAddressStream>,
45    ) -> Result<Option<IpAddress>, SocketError> {
46        let stream: &mut ResolveAddressStream = self.table.get_mut(&resource)?;
47        loop {
48            match stream {
49                ResolveAddressStream::Waiting(future) => {
50                    match crate::runtime::poll_noop(Pin::new(future)) {
51                        Some(result) => {
52                            *stream = ResolveAddressStream::Done(result.map(|v| v.into_iter()));
53                        }
54                        None => return Err(ErrorCode::WouldBlock.into()),
55                    }
56                }
57                ResolveAddressStream::Done(slot @ Err(_)) => {
58                    mem::replace(slot, Ok(Vec::new().into_iter()))?;
59                    unreachable!();
60                }
61                ResolveAddressStream::Done(Ok(iter)) => return Ok(iter.next()),
62            }
63        }
64    }
65
66    fn subscribe(
67        &mut self,
68        resource: Resource<ResolveAddressStream>,
69    ) -> Result<Resource<DynPollable>> {
70        subscribe(self.table, resource)
71    }
72
73    fn drop(&mut self, resource: Resource<ResolveAddressStream>) -> Result<()> {
74        self.table.delete(resource)?;
75        Ok(())
76    }
77}
78
79#[async_trait::async_trait]
80impl Pollable for ResolveAddressStream {
81    async fn ready(&mut self) {
82        if let ResolveAddressStream::Waiting(future) = self {
83            *self = ResolveAddressStream::Done(future.await.map(|v| v.into_iter()));
84        }
85    }
86}
87
88fn blocking_resolve(host: &url::Host) -> Result<Vec<IpAddress>, SocketError> {
89    match host {
90        url::Host::Ipv4(v4addr) => Ok(vec![IpAddress::Ipv4(from_ipv4_addr(*v4addr))]),
91        url::Host::Ipv6(v6addr) => Ok(vec![IpAddress::Ipv6(from_ipv6_addr(*v6addr))]),
92        url::Host::Domain(domain) => {
93            // For now use the standard library to perform actual resolution through
94            // the usage of the `ToSocketAddrs` trait. This is only
95            // resolving names, not ports, so force the port to be 0.
96            let addresses = (domain.as_str(), 0)
97                .to_socket_addrs()
98                .map_err(|_| ErrorCode::NameUnresolvable)? // If/when we use `getaddrinfo` directly, map the error properly.
99                .map(|addr| addr.ip().to_canonical().into())
100                .collect();
101
102            Ok(addresses)
103        }
104    }
105}
wasmtime_wasi/p2/ip_name_lookup.rs

wasmtime_wasi/p2/
ip_name_lookup.rs
