webfinger: Use the subject field to determine the canonical name of the subject

acrate-core/migrations/2024-11-14-031744_meta/up.sql

@@ -2,8 +2,14 @@ CREATE TABLE IF NOT EXISTS meta_subjects (
 	id UUID DEFAULT gen_random_uuid(),
 	document BPCHAR NOT NULL,
 	pattern BPCHAR NOT NULL,
+	subject BPCHAR,
 	redirect BPCHAR,
 
+	CONSTRAINT either_subject_or_redirect_not_null CHECK (
+		(subject IS NOT NULL AND redirect IS NULL)
+		OR
+		(subject IS NULL AND redirect IS NOT NULL)
+	),
 	PRIMARY KEY (id)
 );
 

acrate-core/src/meta.rs

@@ -11,6 +11,7 @@ pub struct MetaSubject {
 	pub id: Uuid,
 	pub document: String,
 	pub pattern: String,
+	pub subject: Option<String>,
 	pub redirect: Option<String>,
 }
 
@@ -71,13 +72,13 @@ pub struct MetaProperty {
 }
 
 impl MetaSubject {
-	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject: &str) -> QueryResult<Vec<Self>> {
+	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject_: &str) -> QueryResult<Vec<Self>> {
 		use diesel::prelude::*;
 		use diesel_async::RunQueryDsl;
 		use schema::meta_subjects::dsl::*;
 		
 		let document_is_equal = document.eq(doc);
-		let subject_matches_pattern = subject.into_sql::<diesel::sql_types::Text>().ilike(pattern);
+		let subject_matches_pattern = subject_.into_sql::<diesel::sql_types::Text>().ilike(pattern);
 		
 		meta_subjects
 			.filter(document_is_equal)

acrate-core/src/schema.rs

@@ -55,6 +55,7 @@ diesel::table! {
         id -> Uuid,
         document -> Bpchar,
         pattern -> Bpchar,
+        subject -> Nullable<Bpchar>,
         redirect -> Nullable<Bpchar>,
     }
 }

acrate-webfinger/src/route.rs

@@ -74,6 +74,8 @@ pub async fn webfinger_handler(
 		return Ok(response);
 	}
 
+	let subject = subject.subject.clone();
+
 	let aliases = MetaAlias::query_matching(&mut conn, WEBFINGER_DOC, &resource)
 		.await
 		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
@@ -127,8 +129,6 @@ pub async fn webfinger_handler(
 
 		match mime {
 			"*/*" | "application/json" | "application/jrd+json" => {
-				let subject = Some(resource);
-				
 				let aliases = aliases
 					.into_iter()
 					.map(|alias| alias.alias)
@@ -175,8 +175,6 @@ pub async fn webfinger_handler(
 				return Ok(response);
 			},
 			"application/xml" | "application/xrd+xml" => {
-				let subject = Some(resource);
-				
 				let aliases = aliases
 					.into_iter()
 					.map(|alias| alias.alias)
@@ -265,7 +263,7 @@ pub async fn webfinger_handler(
 					.expect("webfinger.html.j2 to exist")
 					.render(
 						minijinja::context!(
-							subject => resource,
+							subject => subject,
 							aliases => aliases,
 							properties => properties,
 							links => links,