Fix SGX delayed host lookup via ToSocketAddr

Author: Jethro Beekman

library/std/src/net/mod.rs

@@ -70,3 +70,7 @@ pub enum Shutdown {
     #[stable(feature = "rust1", since = "1.0.0")]
     Both,
 }
+
+// allow(unused_imports): This function is only used on some targets
+#[allow(unused_imports)]
+pub(crate) use socket_addr::lookup_host_string;

library/std/src/net/socket_addr.rs

@@ -189,9 +189,23 @@ impl ToSocketAddrs for (Ipv6Addr, u16) {
     }
 }
 
-fn lookup_host(host: &str, port: u16) -> io::Result<vec::IntoIter<SocketAddr>> {
-    let addrs = crate::sys::net::lookup_host(host, port)?;
-    Ok(Vec::from_iter(addrs).into_iter())
+// Default implementation, this shouldn't be called directly by the function's
+// path in this module. Instead, use the platform-specific implementation
+// (which may be this one).
+//
+// allow(dead_code): This function is only used on some targets
+#[allow(dead_code)]
+pub(crate) fn lookup_host_string(addr: &str) -> io::Result<impl Iterator<Item = SocketAddr>> {
+    // Split the string by ':' and convert the second part to u16...
+    let Some((host, port_str)) = addr.rsplit_once(':') else {
+        return Err(io::const_error!(io::ErrorKind::InvalidInput, "invalid socket address"));
+    };
+    let Ok(port) = port_str.parse::<u16>() else {
+        return Err(io::const_error!(io::ErrorKind::InvalidInput, "invalid port value"));
+    };
+
+    // ... and make the system look up the host.
+    crate::sys::net::lookup_host(host, port)
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -207,7 +221,7 @@ impl ToSocketAddrs for (&str, u16) {
         }
 
         // Otherwise, make the system look it up.
-        lookup_host(host, port)
+        crate::sys::net::lookup_host(host, port).map(|addrs| Vec::from_iter(addrs).into_iter())
     }
 }
 
@@ -229,16 +243,8 @@ impl ToSocketAddrs for str {
             return Ok(vec![addr].into_iter());
         }
 
-        // Otherwise, split the string by ':' and convert the second part to u16...
-        let Some((host, port_str)) = self.rsplit_once(':') else {
-            return Err(io::const_error!(io::ErrorKind::InvalidInput, "invalid socket address"));
-        };
-        let Ok(port) = port_str.parse::<u16>() else {
-            return Err(io::const_error!(io::ErrorKind::InvalidInput, "invalid port value"));
-        };
-
-        // ... and make the system look up the host.
-        lookup_host(host, port)
+        // Otherwise, make the system look it up.
+        crate::sys::net::lookup_host_string(self).map(|addrs| Vec::from_iter(addrs).into_iter())
     }
 }
 

library/std/src/sys/net/connection/motor.rs

@@ -395,6 +395,8 @@ pub struct LookupHost {
     addresses: alloc::collections::VecDeque<netc::sockaddr>,
 }
 
+pub(crate) use crate::net::lookup_host_string;
+
 pub fn lookup_host(host: &str, port: u16) -> io::Result<LookupHost> {
     let (_port, addresses) = moto_rt::net::lookup_host(host, port).map_err(map_motor_error)?;
     Ok(LookupHost { addresses })

library/std/src/sys/net/connection/sgx.rs

@@ -506,11 +506,12 @@ impl Iterator for LookupHost {
     }
 }
 
+pub fn lookup_host_string(addr: impl Into<String>) -> io::Result<LookupHost> {
+    Err(io::Error::new(io::ErrorKind::Uncategorized, NonIpSockAddr { host: addr.into() }))
+}
+
 pub fn lookup_host(host: &str, port: u16) -> io::Result<LookupHost> {
-    Err(io::Error::new(
-        io::ErrorKind::Uncategorized,
-        NonIpSockAddr { host: format!("{host}:{port}") },
-    ))
+    lookup_host_string(format!("{host}:{port}"))
 }
 
 #[cfg(test)]

library/std/src/sys/net/connection/socket/mod.rs

@@ -340,6 +340,8 @@ impl Drop for LookupHost {
     }
 }
 
+pub(crate) use crate::net::lookup_host_string;
+
 pub fn lookup_host(host: &str, port: u16) -> io::Result<LookupHost> {
     init();
     run_with_cstr(host.as_bytes(), &|c_host| {

library/std/src/sys/net/connection/uefi/mod.rs

@@ -345,6 +345,8 @@ impl Iterator for LookupHost {
     }
 }
 
+pub(crate) use crate::net::lookup_host_string;
+
 pub fn lookup_host(_host: &str, _port: u16) -> io::Result<LookupHost> {
     unsupported()
 }

library/std/src/sys/net/connection/unsupported.rs

@@ -311,6 +311,8 @@ impl Iterator for LookupHost {
     }
 }
 
+pub(crate) use crate::net::lookup_host_string;
+
 pub fn lookup_host(_host: &str, _port: u16) -> io::Result<LookupHost> {
     unsupported()
 }

library/std/src/sys/net/connection/wasip1.rs

@@ -483,6 +483,8 @@ impl Iterator for LookupHost {
     }
 }
 
+pub(crate) use crate::net::lookup_host_string;
+
 pub fn lookup_host(_host: &str, _port: u16) -> io::Result<LookupHost> {
     unsupported()
 }

library/std/src/sys/net/connection/xous/mod.rs

@@ -46,3 +46,5 @@ pub struct GetAddress {
 }
 
 pub use dns::lookup_host;
+
+pub(crate) use crate::net::lookup_host_string;