Add docs and refactor for readability

README.md

@@ -1,3 +1,16 @@
 # Proxima
 
 Proxima is a simple gateway server.
+
+## Configuring
+
+Proxima reads the first config file it sees in the following order of preference:
+
+- `./config`
+- `/etc/proxima`
+
+In these files, each line is a rule consisting of a pattern (consisting of a
+hostname and a portspec) and an effect: either a number indicating a port on
+`0.0.0.0` to proxy the request to or a string that is used as the `location`
+header's value. If the latter effect is specified, Proxima redirects clients
+to that location.

src/main.rs

@@ -1,5 +1,10 @@
 use std::net::SocketAddr;
-use hyper::{service::{make_service_fn, service_fn}, Client, Error, Server, Response, StatusCode, Body, Request, Uri};
+use hyper::{service::{make_service_fn, service_fn}, Error, Server, Response, StatusCode, Body, Request, Uri, client::HttpConnector};
+
+pub mod parse;
+
+/// An alias for a [`hyper::Client`] with an [`HttpConnector`].
+pub type Client<C = HttpConnector> = hyper::Client<C>;
 
 #[tokio::main(flavor = "current_thread")]
 async fn main() {
@@ -22,7 +27,6 @@ async fn main() {
     };
 
     let addr   = SocketAddr::from(([127, 0, 0, 1], 8100));
-
     let client = Client::new();
 
     let make_service = make_service_fn(move |_| {
@@ -33,15 +37,175 @@ async fn main() {
             // This is the `Service` that will handle the connection.
             // `service_fn` is a helper to convert a function that
             // returns a Response into a `Service`.
-            Ok::<_, Error>(service_fn(move |mut req| {
+            Ok::<_, Error>(service_fn(move |req| {
                 let config = config.clone();
                 let client = client.clone();
 
-                async move {
-                    for Rule (pattern, effect) in config.rules() {
                 println!("{} {}", req.method(), req.uri());
+
+                async move {
+
+                    // Perform the first matching rule
+                    for Rule (pattern, effect) in config.rules() {
                         if pattern.matches(&req) {
-                            return match effect {
+                            let res = effect.perform(client, req).await;
+                            return res
+                        }
+                    }
+
+                    println!("No matching rule found, returning error");
+
+                    // Return an empty response with a Bad Gateway status code
+                    // if no rules matched (and thus caused the loop to short-
+                    // circuit).
+                    let res = Response::builder()
+                        .status(StatusCode::BAD_GATEWAY)
+                        .body(Body::empty())
+                        .expect("Failed to construct response");
+
+                    Ok (res)
+
+                }
+            }))
+        }
+    });
+
+    let server = Server::bind(&addr).serve(make_service);
+
+    if let Err (e) = server.await {
+        eprintln!("server error: {}", e);
+    }
+
+}
+
+/// A config consists of a set of [`Rule`]s.
+#[derive(Clone, Debug)]
+pub struct Config (Vec<Rule>);
+
+impl Config {
+    /// Get the rules in the config.
+    pub fn rules (&self) -> impl Iterator <Item = &Rule> {
+        self.0.iter()
+    }
+}
+
+/// Load a config from a path.
+pub fn load (p: impl AsRef<std::path::Path>) -> std::io::Result<String> {
+    std::fs::read_to_string(p.as_ref())
+}
+
+/// Parse a config string.
+///
+/// Example config string:
+///
+/// ```text
+/// api.riley.lgbt : (80 | 443) --> 6000           # --> is proxy_pass
+///     riley.lgbt : (80 | 443) --> 3000 [ssl]     # add [ssl] to automate ssl for this domain
+///     rly.cx     : *          ==> riley.lgbt     # ==> is HTTP redirect
+/// ```
+pub fn parse (data: String) -> Config {
+    let rules = data
+        .lines()
+        .map(parse::rule)
+        .filter_map(|x| match x {
+            Ok ((_, rule)) => Some (rule),
+            Err (e) => {
+                eprintln!("Error parsing rule: {:?}", e);
+                None
+            },
+        })
+        .collect();
+
+    Config (rules)
+}
+/// A rule consists of a [`Pattern`] and an [`Effect`]. If the pattern matches,
+/// the effect is performed.
+#[derive(Clone, Debug)]
+pub struct Rule (Pattern, Effect);
+
+impl Rule {
+    /// Get the domain of the pattern.
+    pub fn host (&self) -> &str {
+        &self.0.host
+    }
+
+    /// Get the portspec.
+    pub fn ports (&self) -> &Ports {
+        &self.0.ports
+    }
+
+    /// Get the associated effect.
+    pub fn effect (&self) -> &Effect {
+        &self.1
+    }
+}
+
+/// A pattern consists of a host and a [portspec][Ports].
+#[derive(Clone, Debug)]
+pub struct Pattern {
+    host: String,
+    ports: Ports,
+}
+
+impl Pattern {
+
+    /// Determine whether the given [`Request`] matches this pattern.
+    ///
+    /// For a request to match, it needs a `host` header.
+    pub fn matches <T> (&self, req: &Request<T>) -> bool {
+        let (host, port) = {
+            // We need to parse the `host` header.
+            if let Some (uri) = req
+                .headers()
+                .get("host")
+                .and_then(|x| x.to_str().ok())
+                .and_then(|x| x.parse::<Uri>().ok())
+            {
+                let host = uri.host().map(str::to_string);
+                let port = uri.port_u16();
+                (host, port.unwrap_or(80))
+            } else {
+                (None, 80)
+            }
+        };
+        
+        match host {
+            // The domain needs to match in all cases
+            Some (h) if &h == &self.host => match &self.ports {
+                // We don't care about the port from the header if the
+                // portspec is a wildcard
+                Ports::Any => true,
+                // Check if the port is included in the spec. If the
+                // port couldn't be parsed, it defaults to `80`.
+                spec => spec.includes(port),
+            },
+            // If no host header or the host header does not equal
+            // the specified domain, the request does not match
+            _ => false,
+        }
+
+    }
+
+}
+
+/// What to do with a matched request.
+#[derive(Clone, Debug)]
+pub enum Effect {
+    /// Redirect to the given URI.
+    Redirect (String),
+    /// Proxy the request, optionally with managed SSL.
+    Proxy {
+        /// The port on `0.0.0.0` to proxy to.
+        port: u16,
+        /// Whether to manage SSL for this rule.
+        ssl: bool,
+    },
+}
+
+impl Effect {
+    /// Perform the effect.
+    pub async fn perform (&self, client: Client, mut req: Request<Body>) -> hyper::Result<Response<Body>> {
+        match self {
             Effect::Proxy { port, .. } => {
                 let host = "0.0.0.0"; // Support for custom hosts added later
                 let path = req.uri().path_and_query().map(|x| x.as_str()).unwrap_or("");
@@ -66,109 +230,14 @@ async fn main() {
     }
 }
 
-                    Ok (Response::builder()
+/// A specification of ports.
-                        .status(StatusCode::BAD_REQUEST)
-                        .body(Body::empty())
-                        .unwrap())
-                }
-            }))
-        }
-    });
-
-    let server = Server::bind(&addr).serve(make_service);
-
-    if let Err(e) = server.await {
-        eprintln!("server error: {}", e);
-    }
-
-}
-
-#[derive(Clone, Debug)]
-pub struct Rule (Pattern, Effect);
-
-impl Rule {
-    /// Get the domain of the pattern.
-    pub fn domain (&self) -> &str {
-        &self.0.domain
-    }
-
-    /// Get the portspec
-    pub fn ports (&self) -> &Ports {
-        &self.0.ports
-    }
-
-    pub fn effect (&self) -> &Effect {
-        &self.1
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct Pattern {
-    domain: String,
-    ports: Ports,
-}
-
-impl Pattern {
-    pub fn matches <T> (&self, req: &Request<T>) -> bool {
-        let uri = req.uri();
-        let (host, port) = {
-            let host = req
-                .headers()
-                .get("host")
-                .and_then(|x| x.to_str().ok())
-                .and_then(|x| x.parse::<Uri>().ok());
-
-            let h = uri
-                .host()
-                .map(|x| x.to_string())
-                .or_else(|| {
-                    host.clone().and_then(|x| {
-                        x.host().map(|x| x.to_string())
-                    })
-                });
-
-            let p = uri
-                .port_u16()
-                .or_else(|| {
-                    host.and_then(|x| x.port_u16())
-                });
-
-            (h, p)
-        };
-        
-        match host {
-            Some (h) if &h == &self.domain => match &self.ports {
-                Ports::Any => true,
-                spec => match port {
-                    Some (p) => spec.includes(p),
-                    None => false,
-                }
-            },
-            _ => false,
-        }
-
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum Effect {
-    Redirect (String),
-    Proxy {
-        port: u16,
-        ssl: bool,
-    },
-}
-
-impl Effect {
-    pub async fn perform (&self) -> Response<Body> {
-        todo!()
-    }
-}
-
 #[derive(Clone, Debug)]
 pub enum Ports {
+    /// Just this one port.
     Single (u16),
+    /// Any of the specified ports.
     Either (Vec<u16>),
+    /// Wildcard, skip port check.
     Any
 }
 
@@ -183,200 +252,3 @@ impl Ports {
     }
 }
 
-/// A config consists of a set if [`Rule`].
-#[derive(Clone, Debug)]
-pub struct Config (Vec<Rule>);
-
-impl Config {
-    pub fn rules (&self) -> impl Iterator <Item = &Rule> {
-        self.0.iter()
-    }
-}
-
-/// Load a config from a path.
-pub fn load (p: impl AsRef<std::path::Path>) -> std::io::Result<String> {
-    std::fs::read_to_string(p.as_ref())
-}
-
-/// Parse a config string.
-///
-/// Example config string:
-///
-/// ```text
-/// hmt.riley.lgbt : (80 | 443) --> 6000           # --> is proxy_pass
-///     riley.lgbt : (80 | 443) --> 3000 [ssl]     # add [ssl] to automate ssl for this domain
-///     rly.cx     : any        ==> riley.lgbt     # ==> is HTTP redirect
-/// ```
-pub fn parse (data: String) -> Config {
-    let rules = data
-        .lines()
-        .map(parse::rule)
-        .filter_map(|x| match x {
-            Ok ((_, rule)) => Some (rule),
-            Err (e) => {
-                eprintln!("Error parsing rule: {:?}", e);
-                None
-            },
-        })
-        .collect();
-
-    Config (rules)
-}
-pub mod parse {
-
-    use super::{ Ports, Effect, Pattern, Rule };
-    use nom::{
-        sequence as seq,
-        multi as mul,
-        character::complete as chr,
-        bytes::complete::{self as byt, tag, take_till},
-        Parser, error::ParseError, combinator::opt,
-    };
-
-    pub type PResult<'i, T> = nom::IResult<&'i str, T>;
-
-    fn around <I, O, P, E, A, B> (a: A, b: B) -> impl Parser<I, O, E>
-    where E: ParseError<I>,
-          A: Parser<I, P, E> + Clone,
-          B: Parser<I, O, E>,
-    {
-        seq::delimited(a.clone(), b, a)
-    }
-
-    /// Parse a [`Portspec`].
-    pub (super) fn portspec (s: &str) -> PResult<'_, Ports> {
-        let single = chr::u16;
-        let either = {
-            let delim = around(chr::space1, chr::char('|'));
-            seq::delimited(
-                chr::char('('),
-                mul::separated_list1(delim, single),
-                chr::char(')'),
-            )
-        };
-        let any = byt::tag("any");
-
-        let single = single.map(Ports::Single);
-        let either = either.map(Ports::Either);
-        let any    = any.map(|_| Ports::Any);
-
-        single.or(either)
-              .or(any)
-              .parse(s)
-    }
-
-    /// Parse an [`Effect`].
-    pub fn effect (s: &str) -> PResult<'_, Effect> {
-
-        let redirect = {
-            let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
-            let internal = domain;
-
-            seq::preceded(
-                spaced(tag("==>")),
-                internal,
-            ).map(Effect::Redirect)
-        };
-
-        let proxy = {
-            let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
-            let ssl = opt(seq::delimited(
-                seq::preceded(chr::space1, chr::char('[')),
-                tag("ssl"),
-                chr::char(']'),
-            )).map(|o| o.is_some());
-            let internal = seq::terminated(chr::u16, chr::space0);
-
-            seq::preceded(
-                spaced(tag("-->")),
-                internal.and(ssl),
-            ).map(|(port, ssl)| Effect::Proxy { ssl, port })
-        };
-
-        redirect.or(proxy)
-                .parse(s)
-
-    }
-
-    fn domain (s: &str) -> PResult<'_, String> {
-        take_till(|c: char| !(c == '.' || c.is_alphanumeric()))
-            .map(str::to_string)
-            .parse(s)
-    }
-
-    /// Parse a [`Pattern`].
-    ///
-    /// ```
-    /// use proxima::parse;
-    ///
-    /// # fn main () -> parse::PResult<'static, ()> {
-    /// let (_, pattern) = parse::pattern("example.com : any")?;
-    /// # Ok ("", ())
-    /// # }
-    /// ```
-    pub fn pattern (s: &str) -> PResult<'_, Pattern> {
-        let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
-        seq::separated_pair(domain, spaced(chr::char(':')), portspec)
-            .map(|(domain, ports)| Pattern { domain, ports })
-            .parse(s)
-    }
-
-    /// Parse a [`Rule`].
-    pub fn rule (s: &str) -> PResult<'_, Rule> {
-        pattern.and(effect)
-               .map(|(p, e)| Rule (p, e))
-               .parse(s)
-    }
-
-    #[cfg(test)]
-    mod tests {
-
-        use super::*;
-
-        /// Test whether a pattern containing an Any portspec gets parsed
-        /// correctly.
-        #[test]
-        fn simple_pattern () {
-            let input = "example.com : any";
-            let (_, Pattern { domain, ports }) = pattern(input).unwrap();
-            assert!(domain == "example.com");
-            assert!(match ports {
-                Ports::Any => true,
-                _ => false,
-            })
-        }
-
-        /// Test whether an Either portspec is parsed correctly.
-        #[test]
-        fn either_portspec () {
-            let input = "(69 | 420)";
-            assert!(match portspec(input).unwrap() {
-                ("", Ports::Either(p)) => p == [69, 420],
-                _ => false,
-            })
-        }
-
-        /// Test whether domain names are parsed correctly.
-        #[test]
-        fn domains () {
-            let inputs = ["example.com", "im.badat.dev", "riley.lgbt", "toot.site", "a.b.c.d.e.f.g.h"];
-            // Each of these should be considered valid
-            for input in inputs {
-                domain(input).unwrap();
-            }
-        }
-
-        /// Test whether a simple rule gets parsed correctly.
-        #[test]
-        fn simple_rule () {
-            let input = "example.gay : any --> 3000";
-            let (_, Rule (_, effect)) = rule(input).unwrap();
-            assert!(match effect {
-                Effect::Proxy { port: 3000, ssl } if !ssl => true,
-                _ => false,
-            });
-        }
-    }
-
-}
-

src/parse.rs

@@ -0,0 +1,149 @@
+//! Parsers for parts of the config file.
+
+// TODO: comments
+
+use super::{ Ports, Effect, Pattern, Rule };
+use nom::{
+    sequence as seq,
+    multi as mul,
+    character::complete as chr,
+    bytes::complete::{self as byt, tag, take_till},
+    Parser, error::ParseError, combinator::opt,
+};
+
+/// The result of running a parser.
+pub type PResult<'i, T> = nom::IResult<&'i str, T>;
+
+fn around <I, O, P, E, A, B> (a: A, b: B) -> impl Parser<I, O, E>
+where E: ParseError<I>,
+      A: Parser<I, P, E> + Clone,
+      B: Parser<I, O, E>,
+{
+    seq::delimited(a.clone(), b, a)
+}
+
+/// Parse a set of [`Ports`].
+pub fn ports (s: &str) -> PResult<'_, Ports> {
+    let single = chr::u16;
+    let either = {
+        let delim = around(chr::space1, chr::char('|'));
+        seq::delimited(
+            chr::char('('),
+            mul::separated_list1(delim, single),
+            chr::char(')'),
+        )
+    };
+    let any = byt::tag("*");
+
+    let single = single.map(Ports::Single);
+    let either = either.map(Ports::Either);
+    let any    = any.map(|_| Ports::Any);
+
+    single.or(either)
+          .or(any)
+          .parse(s)
+}
+
+/// Parse an [`Effect`].
+pub fn effect (s: &str) -> PResult<'_, Effect> {
+
+    let redirect = {
+        let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
+
+        seq::preceded(
+            spaced(tag("==>")),
+            target,
+        ).map(Effect::Redirect)
+    };
+
+    let proxy = {
+        let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
+        let ssl = opt(seq::delimited(
+            seq::preceded(chr::space1, chr::char('[')),
+            tag("ssl"),
+            chr::char(']'),
+        )).map(|o| o.is_some());
+        let internal = seq::terminated(chr::u16, chr::space0);
+
+        seq::preceded(
+            spaced(tag("-->")),
+            internal.and(ssl),
+        ).map(|(port, ssl)| Effect::Proxy { ssl, port })
+    };
+
+    redirect.or(proxy)
+            .parse(s)
+
+}
+
+fn target (s: &str) -> PResult<'_, String> {
+    take_till(|c: char| !(c == '.' || c.is_alphanumeric()))
+        .map(str::to_string)
+        .parse(s)
+}
+
+/// Parse a [`Pattern`].
+pub fn pattern (s: &str) -> PResult<'_, Pattern> {
+    let spaced = |x| seq::delimited(chr::space1, x, chr::space1);
+    seq::separated_pair(target, spaced(chr::char(':')), ports)
+        .map(|(domain, ports)| Pattern { host: domain, ports })
+        .parse(s)
+}
+
+/// Parse a [`Rule`].
+pub fn rule (s: &str) -> PResult<'_, Rule> {
+    pattern.and(effect)
+           .map(|(p, e)| Rule (p, e))
+           .parse(s)
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    /// Test whether a pattern containing an Any portspec gets parsed
+    /// correctly.
+    #[test]
+    fn simple_pattern () {
+        let input = "example.com : *";
+        let (_, Pattern { host: domain, ports }) = pattern(input).unwrap();
+        assert!(domain == "example.com");
+        assert!(match ports {
+            Ports::Any => true,
+            _ => false,
+        })
+    }
+
+    /// Test whether an Either portspec is parsed correctly.
+    #[test]
+    fn either_ports () {
+        let input = "(69 | 420)";
+        assert!(match ports(input).unwrap() {
+            ("", Ports::Either(p)) => p == [69, 420],
+            _ => false,
+        })
+    }
+
+    /// Test whether target names are parsed correctly.
+    #[test]
+    fn targets () {
+        let inputs = ["example.com", "im.badat.dev", "riley.lgbt", "toot.site", "a.b.c.d.e.f.g.h"];
+        // Each of these should be considered valid
+        for input in inputs {
+            target(input).unwrap();
+        }
+    }
+
+    /// Test whether a simple rule gets parsed correctly.
+    #[test]
+    fn simple_rule () {
+        let input = "example.gay : * --> 3000";
+        let (_, Rule (_, effect)) = rule(input).unwrap();
+        assert!(match effect {
+            Effect::Proxy { port: 3000, ssl } if !ssl => true,
+            _ => false,
+        });
+    }
+}
+