cmd argument validation and remote hostname support

Cargo.toml

@@ -16,7 +16,7 @@ tls = ["native-tls", "tokio-tls"]
 
 [dependencies]
 base64 = "0.10"
-clap = "2"
+clap = "2.33.0"
 futures = "0.1.27"
 hyper = "0.12.30"
 jemallocator = "0"

src/main.rs

@@ -14,6 +14,7 @@ use hyper::server::conn::Http;
 use hyper::service::Service;
 use hyper::{Body, Method, Request, Response, StatusCode};
 use std::io;
+use std::net::{SocketAddr, ToSocketAddrs};
 
 #[cfg(feature = "tls")]
 use native_tls::{self, Identity};
@@ -23,7 +24,6 @@ use std::fs::File;
 
 #[cfg(feature = "tls")]
 use std::io::{self, Read};
-use std::net::SocketAddr;
 
 #[cfg(feature = "tls")]
 use std::path::{Path, PathBuf};
@@ -483,6 +483,8 @@ fn main() {
 }
 
 fn parse_opts(inner_doh: &mut InnerDoH) {
+    use crate::utils::{verify_remote_server, verify_sock_addr};
+
     let max_clients = MAX_CLIENTS.to_string();
     let timeout_sec = TIMEOUT_SEC.to_string();
     let min_ttl = MIN_TTL.to_string();
@@ -497,6 +499,7 @@ fn parse_opts(inner_doh: &mut InnerDoH) {
                 .long("listen-address")
                 .takes_value(true)
                 .default_value(LISTEN_ADDRESS)
+                .validator(verify_sock_addr)
                 .help("Address to listen to"),
         )
         .arg(
@@ -505,6 +508,7 @@ fn parse_opts(inner_doh: &mut InnerDoH) {
                 .long("server-address")
                 .takes_value(true)
                 .default_value(SERVER_ADDRESS)
+                .validator(verify_remote_server)
                 .help("Address to connect to"),
         )
         .arg(
@@ -513,6 +517,7 @@ fn parse_opts(inner_doh: &mut InnerDoH) {
                 .long("local-bind-address")
                 .takes_value(true)
                 .default_value(LOCAL_BIND_ADDRESS)
+                .validator(verify_sock_addr)
                 .help("Address to connect from"),
         )
         .arg(
@@ -595,7 +600,14 @@ fn parse_opts(inner_doh: &mut InnerDoH) {
 
     let matches = options.get_matches();
     inner_doh.listen_address = matches.value_of("listen_address").unwrap().parse().unwrap();
-    inner_doh.server_address = matches.value_of("server_address").unwrap().parse().unwrap();
+
+    inner_doh.server_address = matches
+        .value_of("server_address")
+        .unwrap()
+        .to_socket_addrs()
+        .unwrap()
+        .next()
+        .unwrap();
     inner_doh.local_bind_address = matches
         .value_of("local_bind_address")
         .unwrap()

src/utils.rs

@@ -1,5 +1,31 @@
+use std::net::{SocketAddr, ToSocketAddrs};
+
 pub(crate) fn padding_string(input_size: usize, block_size: usize) -> String {
     let block_size_ = block_size - 1;
     let padding_len = block_size_ - ((input_size + block_size_) & block_size_);
     String::from_utf8(vec![b'X'; padding_len]).unwrap()
 }
+
+// functions to verify the startup arguments as correct
+pub(crate) fn verify_sock_addr(arg_val: String) -> Result<(), String> {
+    match arg_val.parse::<SocketAddr>() {
+        Ok(_addr) => Ok(()),
+        Err(_) => Err(format!(
+            "Could not parse \"{}\" as a valid socket address (with port).",
+            arg_val
+        )),
+    }
+}
+
+pub(crate) fn verify_remote_server(arg_val: String) -> Result<(), String> {
+    match arg_val.to_socket_addrs() {
+        Ok(mut addr_iter) => match addr_iter.next() {
+            Some(_) => Ok(()),
+            None => Err(format!(
+                "Could not parse \"{}\" as a valid remote uri",
+                arg_val
+            )),
+        },
+        Err(err) => Err(format!("{}", err)),
+    }
+}