added redirect handling, fixed some dns resolution issues

src/lib.rs

@@ -12,7 +12,7 @@ use std::{
     fmt,
     io::{BufRead, BufReader, Error as IoError, Write},
     iter,
-    net::{IpAddr, Ipv4Addr, TcpStream, ToSocketAddrs, UdpSocket},
+    net::{IpAddr, Ipv4Addr, SocketAddr, TcpStream, UdpSocket},
 };
 
 /// An HTTP request.
@@ -26,7 +26,7 @@ use std::{
 /// // ... start a local server on port 8000 ...
 /// let request = Request::get("localhost:8000");
 /// let response = request.send().unwrap();
-/// assert_eq!(response.status, 200)
+/// assert_eq!(response.status, 200);
 /// ```
 ///
 /// Adding headers:
@@ -67,6 +67,8 @@ pub struct Request<'a> {
     headers: HashMap<&'a str, &'a str>,
     /// Request body.
     body: &'a str,
+    /// How many redirects are followed before an error is emitted.
+    redirects: usize,
 }
 
 impl<'a> Request<'a> {
@@ -87,9 +89,25 @@ impl<'a> Request<'a> {
             method,
             headers: HashMap::new(),
             body: "",
+            redirects: 4,
         }
     }
 
+    /// Set the URL of the request.
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # use request::*;
+    /// let request = Request::get("http://example.org/a").url("http://example.org/b");
+    /// assert_eq!(format!("{request}"), "GET /b HTTP/1.1\r\nHost: example.org\r\n\r\n");
+    /// ```
+    pub fn url(self, url: &'a str) -> Self {
+        let mut request = self;
+        request.url = url;
+        request
+    }
+
     /// Add a body to the request.
     ///
     /// # Examples
@@ -119,6 +137,13 @@ impl<'a> Request<'a> {
         request
     }
 
+    /// Set the maximum allowed redirects.
+    pub fn redirects(self, max: usize) -> Self {
+        let mut request = self;
+        request.redirects = max;
+        request
+    }
+
     /// Construct a new GET request.
     ///
     /// # Examples
@@ -163,7 +188,8 @@ impl<'a> Request<'a> {
 
         // create the stream
         let host = resolve(host(self.url).unwrap())?;
-        let mut stream = TcpStream::connect((host, 80))?;
+        let port = port(self.url).unwrap_or("80").parse::<u16>().unwrap();
+        let mut stream = TcpStream::connect((host, port))?;
 
         // send the message
         stream.write_all(message.as_bytes())?;
@@ -175,6 +201,22 @@ impl<'a> Request<'a> {
             .collect::<Vec<_>>();
         let received = lines.join("\n");
 
+        // check for redirects
+        if lines[0].contains("301") && self.redirects > 0 {
+            assert!(self.redirects > 0, "maximum redirect limit reached"); // todo: error for maximum redirect limit reached
+
+            // find new location
+            let location = lines
+                .iter()
+                .find_map(|l| l.strip_prefix("Location: "))
+                .unwrap(); // todo: error for missing location in redirect
+            return self
+                .clone()
+                .redirects(self.redirects - 1)
+                .url(location)
+                .send();
+        }
+
         // process response
         let response = Response::parse(&received).unwrap();
 
@@ -183,13 +225,10 @@ impl<'a> Request<'a> {
 }
 impl<'a> fmt::Display for Request<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let (method, path, host, body) = (
+        let method = self.method;
-            self.method,
+        let path = path(self.url).ok_or(fmt::Error)?;
-            path(self.url).ok_or(fmt::Error)?,
+        let host = host(self.url).ok_or(fmt::Error)?;
-            host(self.url).ok_or(fmt::Error)?,
+        let body = self.body;
-            self.body,
-        );
-
         let headers = iter::once(format!("Host: {host}"))
             .chain(self.headers.iter().map(|(k, v)| format!("{k}: {v}")))
             .collect::<Vec<_>>()
@@ -248,11 +287,6 @@ impl Response {
             .map(|(a, b)| (a.to_string(), b.to_string()))
             .collect::<HashMap<String, String>>();
 
-        // check if redirect
-        if status == 301 {
-            todo!()
-        }
-
         // parse body
         let body = parts.name("body").map(|m| m.as_str().to_string());
 
@@ -270,7 +304,7 @@ impl Response {
 }
 
 static URI_REGEX: Lazy<Regex> = Lazy::new(|| {
-    Regex::new("(?:(?P<scheme>https?)://)?(?P<host>[0-9a-zA-Z:\\.\\-]+)(?P<path>/(?:.)*)?").unwrap()
+    Regex::new("(?:(?P<scheme>https?)://)?(?P<host>[0-9a-zA-Z\\.\\-]+)(?:\\:(?P<port>\\d+))?(?P<path>/(?:.)*)?").unwrap()
 });
 #[allow(dead_code)]
 fn scheme(url: &str) -> Option<&str> {
@@ -279,6 +313,9 @@ fn scheme(url: &str) -> Option<&str> {
 fn host(url: &str) -> Option<&str> {
     URI_REGEX.captures(url)?.name("host").map(|m| m.as_str())
 }
+fn port(url: &str) -> Option<&str> {
+    URI_REGEX.captures(url)?.name("port").map(|m| m.as_str())
+}
 fn path(url: &str) -> Option<&str> {
     URI_REGEX
         .captures(url)?
@@ -289,8 +326,51 @@ fn path(url: &str) -> Option<&str> {
 
 /// Resolve DNS request using system nameservers.
 fn resolve(query: &str) -> Result<IpAddr, IoError> {
+    // todo: local overrides
+    if query.starts_with("localhost") {
+        return Ok(IpAddr::V4(Ipv4Addr::LOCALHOST));
+    }
+
+    // todo: dns caching
+    // create dns query header: [id, flags, questions, answers, authority, additional]
+    let header: [u16; 6] = [0xabcd, 0x0100, 0x0001, 0x0000, 0x0000, 0x0000].map(|b: u16| b.to_be());
+    let question: [u16; 2] = [0x0001, 0x0001].map(|b: u16| b.to_be()); // [qtype, qclass] = [A, IN(ternet)]
+
+    // convert query to standard dns name notation (max 63 characters for each label)
+    let ascii = query.chars().filter(char::is_ascii).collect::<String>();
+    let name = ascii
+        .split('.')
+        .flat_map(|l| {
+            iter::once(u8::try_from(l.len()).unwrap_or(63).min(63)).chain(l.bytes().take(63))
+        })
+        .chain(iter::once(0))
+        .collect::<Vec<u8>>();
+
+    // construct the message
+    let mut message = bytemuck::cast::<[u16; 6], [u8; 12]>(header).to_vec();
+    message.extend(&name[..]);
+    message.extend(bytemuck::cast_slice(&question));
+
+    // create the socket
+    let socket = UdpSocket::bind("0.0.0.0:0")?;
+    socket.connect(&DNS_SERVERS[..])?;
+
+    // write dns lookup message
+    socket.send_to(&message, &DNS_SERVERS[..]).unwrap();
+
+    // read dns response
+    let mut buf = vec![0; 1024];
+    let (n, _addr) = socket.recv_from(&mut buf)?;
+    buf.resize(n, 0);
+
+    // parse out the address
+    let ip = &buf.get(message.len()..).unwrap()[12..];
+    let address = IpAddr::V4(Ipv4Addr::new(ip[0], ip[1], ip[2], ip[3]));
+
+    Ok(address)
+}
+static DNS_SERVERS: Lazy<Vec<SocketAddr>> = Lazy::new(|| {
     // find name servers (platform-dependent)
-    let servers = {
     #[cfg(unix)]
     {
         use std::fs;
@@ -304,43 +384,11 @@ fn resolve(query: &str) -> Result<IpAddr, IoError> {
     }
     #[cfg(windows)]
     {
-            ("8.8.8.8", 53).to_socket_addrs()?.collect::<Vec<_>>()
+        // todo: get windows name servers
+        vec![SocketAddr::new(IpAddr::V4(Ipv4Addr::new(8, 8, 8, 8)), 53)]
     }
-    };
+    #[cfg(not(any(unix, windows)))]
-
+    {
-    // request dns resolution from nameservers
+        vec![SocketAddr::new(IpAddr::V4(Ipv4Addr::new(8, 8, 8, 8)), 53)]
-    let header: [u16; 6] = [0xabcd, 0x0100, 0x0001, 0x0000, 0x0000, 0x0000].map(|b: u16| b.to_be());
-    let question: [u16; 2] = [0x0001, 0x0001].map(|b: u16| b.to_be());
-
-    // convert query to standard dns name notation
-    let ascii = query.chars().filter(char::is_ascii).collect::<String>();
-    let name = ascii
-        .split('.')
-        .flat_map(|l| iter::once(u8::try_from(l.len()).unwrap_or(63)).chain(l.bytes().take(63)))
-        .chain(iter::once(0))
-        .collect::<Vec<u8>>();
-
-    // construct the message
-    let mut message = bytemuck::cast::<[u16; 6], [u8; 12]>(header).to_vec();
-    message.extend(&name[..]);
-    message.extend(bytemuck::cast_slice(&question));
-
-    // create the socket
-    let socket = UdpSocket::bind("0.0.0.0:0")?;
-    socket.connect(&servers[..])?;
-
-    // write dns lookup message
-    socket.send_to(&message, &servers[..]).unwrap();
-
-    // read dns response
-    let mut buf = vec![0; 1024];
-    let (n, _addr) = socket.recv_from(&mut buf)?;
-    buf.resize(n, 0);
-
-    // parse out the address
-    let answers = &buf[message.len()..];
-    let ip = &answers[12..];
-    let address = IpAddr::V4(Ipv4Addr::new(ip[0], ip[1], ip[2], ip[3]));
-
-    Ok(address)
     }
+});