Template passtrough for dns server information

echoip_test.toml

@@ -64,5 +64,5 @@ burst = 15
 [dns.resolver.digitalcourage]
 display_name = "Digitalcourage 3"
 servers = ["5.9.164.112:853","[2a01:4f8:251:554::2]:853"]
-protocol = "Tls"
+protocol = "tls"
 tls_dns_name = "dns3.digitalcourage.de"

src/config/dns.rs

@@ -16,6 +16,7 @@ pub struct DnsConfig {
 }
 
 #[derive(Deserialize, Serialize, Clone)]
+#[serde(rename_all="lowercase")]
 pub enum DnsProtocol {
 	Udp,
 	Tcp,

src/main.rs

@@ -50,13 +50,13 @@ use crate::geoip::{
 	LocationResult,
 };
 use crate::idna::IdnaName;
-
+use crate::simple_dns::DnsLookupResult;
 use crate::templating_engine::{
 	View,
 	ResponseFormat,
 	TemplateSettings,
+	Selectable,
 };
-
 use crate::ipinfo::{AddressCast,AddressInfo,AddressScope};
 
 #[derive(Deserialize, Serialize, Clone)]
@@ -85,6 +85,7 @@ pub struct IpResult {
 	asn:      Option<AsnResult>,
 	location: Option<LocationResult>,
 	ip_info:  AddressInfo,
+	used_dns_resolver: Option<String>,
 }
 
 // We need this one to hide the partial lookup field when irelevant
@@ -97,18 +98,23 @@ pub struct DigResult {
 	idn: IdnaName,
 	#[serde(skip_serializing_if = "not")]
 	partial_lookup: bool,
+	used_dns_resolver: String,
 }
 
-
 struct ServiceSharedState {
 	templating_engine: templating_engine::Engine,
-	//dns_resolver:      TokioAsyncResolver,
 	dns_resolvers:     HashMap<String,TokioAsyncResolver>,
 	asn_db:            geoip::MMDBCarrier,
 	location_db:       geoip::MMDBCarrier,
 	config:            config::EchoIpServiceConfig,
 }
 
+// Stores configuration that is derived from the original configuration
+#[derive(Clone)]
+struct DerivedConfiguration {
+	dns_resolver_selectables: Vec<Selectable>,
+}
+
 #[derive(Parser)]
 #[command(author, version, long_about="A web service that tells you your ip-address and more …")]
 struct CliArgs {
@@ -234,6 +240,8 @@ async fn main() {
 	// Initalize DNS resolver with os defaults
 	println!("Initalizing dns resolver ...");
 
+	let mut dns_resolver_selectables = Vec::<Selectable>::new();
+
 	println!("Initalizing System resolver ...");
 	let res = TokioAsyncResolver::tokio_from_system_conf();
 	//let res = TokioAsyncResolver::tokio(ResolverConfig::default(), ResolverOpts::default());
@@ -245,22 +253,39 @@ async fn main() {
 		}
 	};
 
+	dns_resolver_selectables.push(Selectable {
+		id: "default".to_string(),
+		name: "System".to_string()
+	});
+
 	//FIXME: Not release ready,must be configurable and have better error handling.
 	println!("Initalizing Quad9 resolver ...");
 	let quad9_resolver = TokioAsyncResolver::tokio(
 		trust_dns_resolver::config::ResolverConfig::quad9_tls(),
 		Default::default()
 	).unwrap();
+	dns_resolver_selectables.push(Selectable {
+		id: "quad9".to_string(),
+		name: "Quad9".to_string()
+	});
 	println!("Initalizing Google resolver ...");
 	let google_resolver = TokioAsyncResolver::tokio(
 		trust_dns_resolver::config::ResolverConfig::google(),
 		Default::default()
 	).unwrap();
+	dns_resolver_selectables.push(Selectable {
+		id: "google".to_string(),
+		name: "Google".to_string()
+	});
 	println!("Initalizing Cloudflare resolver ...");
 	let cloudflare_resolver = TokioAsyncResolver::tokio(
 		trust_dns_resolver::config::ResolverConfig::cloudflare_tls(),
 		Default::default()
 	).unwrap();
+	dns_resolver_selectables.push(Selectable {
+		id: "cloudflare".to_string(),
+		name: "Cloudflare".to_string()
+	});
 
 	let mut dns_resolver_map: HashMap<String,TokioAsyncResolver> = HashMap::new();
 
@@ -271,6 +296,10 @@ async fn main() {
 			Default::default()
 		).unwrap();
 		dns_resolver_map.insert(key.clone(), resolver);
+		dns_resolver_selectables.push(Selectable {
+			id: key.clone(),
+			name: resolver_config.display_name.clone(),
+		});
 	}
 	
 	dns_resolver_map.insert("default".to_string(), dns_resolver);
@@ -292,6 +321,10 @@ async fn main() {
 		config: config.clone(),
 	});
 
+	let derived_config = DerivedConfiguration {
+		dns_resolver_selectables: dns_resolver_selectables,
+	};
+
 	let signal_usr1_handlers_state = shared_state.clone();
 
 	task::spawn(async move {
@@ -317,6 +350,8 @@ async fn main() {
 	    .route("/", get(handle_default_route))
 	    .route("/dig/:name", get(handle_dig_route_with_path))
 	    .route("/ip/:address", get(handle_ip_route_with_path))
+	    .route("/dns_resolver/:resolver", get(handle_dns_resolver_route_with_path))
+	    .route("/dns_resolver", get(handle_dns_resolver_route))
 	    .route("/ua", get(user_agent_handler))
     	.route("/hi", get(hello_world_handler))
     	.fallback_service(
@@ -331,6 +366,7 @@ async fn main() {
 					config.ratelimit.per_minute, config.ratelimit.burst))
 				.layer(middleware::from_fn(ratelimit::rate_limit_middleware))
 				.layer(Extension(config))
+				.layer(Extension(derived_config))
 				.layer(middleware::from_fn(settings_query_middleware))
     	)
     	;
@@ -347,6 +383,7 @@ async fn main() {
 async fn settings_query_middleware<B>(
 	Query(query): Query<SettingsQuery>,
 	Extension(config): Extension<config::EchoIpServiceConfig>,
+	Extension(derived_config): Extension<DerivedConfiguration>,
 	user_agent_header: Option<TypedHeader<headers::UserAgent>>,
 	mut req: Request<B>,
 	next: Next<B>
@@ -369,6 +406,7 @@ async fn settings_query_middleware<B>(
 		template: TemplateSettings{
 			format: format.unwrap_or(ResponseFormat::TextHtml),
 			lang: query.lang.unwrap_or("en".to_string()),
+			available_dns_resolvers: derived_config.dns_resolver_selectables,
 		},
 		dns_resolver_id: query.dns.unwrap_or(config.dns.default_resolver),
 	});
@@ -377,24 +415,24 @@ async fn settings_query_middleware<B>(
 
 async fn not_found_handler(
 	State(arc_state): State<Arc<ServiceSharedState>>,
-	Extension(settings): Extension<TemplateSettings>,
+	Extension(settings): Extension<QuerySettings>,
 ) -> Response {
 	let state = Arc::clone(&arc_state);
 
 	state.templating_engine.render_view(
-		&settings,
+		&settings.template,
 		&View::NotFound,
 	).await
 }
 
 async fn hello_world_handler(
 	State(arc_state): State<Arc<ServiceSharedState>>,
-	Extension(settings): Extension<TemplateSettings>,
+	Extension(settings): Extension<QuerySettings>,
 ) -> Response {
 	let state = Arc::clone(&arc_state);
 
 	state.templating_engine.render_view(
-		&settings,
+		&settings.template,
 		&View::Message{
 			title: "Hey There!".to_string(),
 			message: "You,You are an awesome Creature!".to_string()
@@ -499,6 +537,37 @@ async fn handle_search_request(
 
 }
 
+async fn handle_dns_resolver_route(
+	Extension(settings): Extension<QuerySettings>,
+	State(arc_state): State<Arc<ServiceSharedState>>,
+) -> Response {
+	let state = Arc::clone(&arc_state);
+	state.templating_engine.render_view(
+		&settings.template,
+		&View::DnsResolverList,
+	).await	
+}
+
+
+async fn handle_dns_resolver_route_with_path(
+	Extension(settings): Extension<QuerySettings>,
+	State(arc_state): State<Arc<ServiceSharedState>>,
+	extract::Path(query): extract::Path<String>,
+) -> Response {
+	let state = Arc::clone(&arc_state);
+	if let Some(resolver) = state.config.dns.resolver.get(&query) {
+		state.templating_engine.render_view(
+			&settings.template,
+			&View::DnsResolver{ config: resolver.clone() },
+		).await
+	} else {
+		state.templating_engine.render_view(
+			&settings.template,
+			&View::NotFound,
+		).await
+	}
+}
+
 async fn handle_ip_route_with_path(
 	Extension(settings): Extension<QuerySettings>,
 	State(arc_state): State<Arc<ServiceSharedState>>,
@@ -547,20 +616,20 @@ async fn get_ip_result(
 				asn: None,
 				location: None,
 				ip_info: ip_info,
+				used_dns_resolver: None,
 			}
 		}
 	} 
 
 	// do reverse lookup
-	let hostname = if state.config.dns.allow_reverse_lookup {
+	let mut hostname: Option<String> = None;
+	let mut used_dns_resolver: Option<String> = None;
+	if state.config.dns.allow_reverse_lookup {
 		if let Some(dns_resolver) = &state.dns_resolvers.get(dns_resolver_name) {
-			simple_dns::reverse_lookup(&dns_resolver, &address).await
-		} else {
-			None
+			hostname = simple_dns::reverse_lookup(&dns_resolver, &address).await;
+			used_dns_resolver = Some(dns_resolver_name.clone());
 		}
-	} else {
-		None
-	};
+	}
 
 	// asn lookup
 	let asn_result = state.asn_db.query_asn_for_ip(address);
@@ -572,23 +641,20 @@ async fn get_ip_result(
 	);
 
 	// filter reverse lookup
-	let final_hostname = match hostname {
-		Some(name) => {
-			if match_domain_hidden_list(&name, &state.config.dns.hidden_suffixes) {
-				None
-			} else {
-				Some(name.to_owned())
-			}
-		},
-		None => None,
-	};
+	if let Some(name) = &hostname {
+		if match_domain_hidden_list(&name, &state.config.dns.hidden_suffixes) {
+			hostname = None;
+			used_dns_resolver = None;
+		}
+	}
 
 	IpResult{
 		address: *address,
-		hostname: final_hostname,
+		hostname: hostname,
 		asn: asn_result,
 		location: location_result,
 		ip_info: ip_info,
+		used_dns_resolver: used_dns_resolver,
 	}
 }
 
@@ -630,11 +696,23 @@ async fn get_dig_result(
 	do_full_lookup:     bool,
 ) -> DigResult {
 	let name = &dig_query.trim().trim_end_matches(".").to_string();
-	if match_domain_hidden_list(&name, &state.config.dns.hidden_suffixes) {
-		Default::default()
-	} else {
-		if let Some(dns_resolver) = &state.dns_resolvers.get(dns_resolver_name) {
-			let idna_name = IdnaName::from_string(&name);
+	let idna_name = IdnaName::from_string(&name);
+	if let Some(dns_resolver) = &state.dns_resolvers.get(dns_resolver_name) {
+		if match_domain_hidden_list(&name, &state.config.dns.hidden_suffixes) {
+			// Try to hide the fact that we didn't do dns resolution at all
+			// We resolve example.org as basic avoidance of timing sidechannels.
+			// WARNING: this timing sidechannel avoidance is very crude.
+			simple_dns::lookup(
+						&dns_resolver,
+						&("example.org.".to_string()),
+						do_full_lookup).await;
+			DigResult {
+				records: DnsLookupResult{ nxdomain: true , ..Default::default() },
+				idn: idna_name,
+				partial_lookup: !do_full_lookup,
+				used_dns_resolver: dns_resolver_name.clone(),
+			}
+		} else {
 			DigResult {
 				records: simple_dns::lookup(
 					&dns_resolver,
@@ -642,9 +720,10 @@ async fn get_dig_result(
 					do_full_lookup).await,
 				idn: idna_name,
 				partial_lookup: !do_full_lookup,
+				used_dns_resolver: dns_resolver_name.clone(),
 			}
-		} else {
-			return Default::default();
 		}
+	} else {
+		return Default::default();
 	}
 }

src/simple_dns.rs

@@ -27,20 +27,20 @@ use std::net::IpAddr;
 
 #[derive(serde::Deserialize, serde::Serialize, Default, Clone)]
 pub struct DnsLookupResult {
-	a:     Option<Vec<IpAddr>>,
-	aaaa:  Option<Vec<IpAddr>>,
-	aname: Option<Vec<String>>,
-	cname: Option<Vec<String>>,
-	mx:    Option<Vec<MxRecord>>,
-	ns:    Option<Vec<String>>,
-	soa:   Option<Vec<SoaRecord>>,
-	txt:   Option<Vec<String>>,
-	srv:   Option<Vec<SrvRecord>>,
-	caa:   Option<Vec<String>>,
-	other_error: bool,
-	dns_error:   bool,
-	nxdomain:    bool,
-	timeout:     bool,
+	pub a:     Option<Vec<IpAddr>>,
+	pub aaaa:  Option<Vec<IpAddr>>,
+	pub aname: Option<Vec<String>>,
+	pub cname: Option<Vec<String>>,
+	pub mx:    Option<Vec<MxRecord>>,
+	pub ns:    Option<Vec<String>>,
+	pub soa:   Option<Vec<SoaRecord>>,
+	pub txt:   Option<Vec<String>>,
+	pub srv:   Option<Vec<SrvRecord>>,
+	pub caa:   Option<Vec<String>>,
+	pub other_error: bool,
+	pub dns_error:   bool,
+	pub nxdomain:    bool,
+	pub timeout:     bool,
 }
 
 #[derive(serde::Deserialize, serde::Serialize, Clone, PartialEq)]

src/templating_engine.rs

@@ -15,6 +15,7 @@ use toml::Table;
 
 use crate::DigResult;
 use crate::IpResult;
+use crate::config::DnsResolverConfig;
 
 /* Response format */
 
@@ -54,6 +55,13 @@ impl ResponseFormat {
 pub struct TemplateSettings {
 	pub format: ResponseFormat,
 	pub lang: String,
+	pub available_dns_resolvers: Vec<Selectable>,
+}
+
+#[derive(serde::Deserialize, serde::Serialize, Clone)]
+pub struct Selectable {
+	pub id: String,
+	pub name: String,
 }
 
 /* The echoip view */
@@ -63,6 +71,8 @@ pub struct TemplateSettings {
 pub enum View {
 	Asn { asn: u32 },
 	Dig { query: String, result: DigResult },
+	DnsResolver{ config: DnsResolverConfig },
+	DnsResolverList,
 	Index { result: IpResult, user_agent: Option<String> },
 	Ip { result: IpResult },
 	Message{ title: String, message: String },
@@ -75,6 +85,8 @@ impl View {
 		match self {
 			View::Asn{..} => "asn",
 			View::Dig{..} => "dig",
+			View::DnsResolver{..} => "dns_resolver",
+			View::DnsResolverList => "dns_resolver_list",
 			View::Index{..} => "index",
 			View::Ip{..} => "ip",
 			View::Message{..} => "message",
@@ -133,6 +145,12 @@ impl Engine {
 					View::Index{result, ..} | View::Ip{result, ..} => {
 						Json(result).into_response()
 					},
+					View::DnsResolverList => {
+						Json(settings.available_dns_resolvers.clone()).into_response()
+					},
+					View::DnsResolver{ config } => {
+						Json(config).into_response()
+					}
 					_ => Json(view).into_response(),
 				}
 			}