Keyboard support + data requests via tcp server

src/dns.rs

@@ -0,0 +1,40 @@
+use std::{net::IpAddr, error::Error, fmt::Display};
+
+use trust_dns_resolver::Resolver;
+
+#[derive(Debug, Clone)]
+struct InvalidConfigError;
+
+#[derive(Debug, Clone)]
+struct DnsError{
+    host: String,
+}
+
+
+impl Error for InvalidConfigError {}
+
+impl Display for InvalidConfigError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "No hostname specified!")
+    }
+}
+
+impl Error for DnsError {}
+
+impl Display for DnsError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "couldn't resolve host \"{}\"", self.host)
+    }
+}
+
+pub fn resolve(host: &Option<String>) -> Result<IpAddr, Box<dyn Error>> {
+    let host = match host {
+        Some(host) => host,
+        None => return Err(InvalidConfigError.into()),
+    };
+    let response = Resolver::from_system_conf()?.lookup_ip(host)?;
+    match response.iter().next() {
+        Some(ip) => Ok(ip),
+        None => Err(DnsError{host: host.clone()}.into()),
+    }
+}