platform/common/http_server/lib/src/virtual_host.dart

141 lines
4.3 KiB
Dart

// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
import 'dart:async';
import 'dart:io';
/// A utility for handling multiple hosts on multiple sources using a
/// named-based approach.
abstract class VirtualHost {
/// The [Stream] of [HttpRequest] not matching any hosts.
///
/// If this field is not read the default implementation will result in a
/// [HttpStatus.forbidden] response.
Stream<HttpRequest> get unhandled;
/// Construct an [VirtualHost] with an optional initial source.
///
/// The optional [source] is a shortcut for calling [addSource].
///
/// ## Example
///
/// ```dart
/// var server = await HttpServer.bind(..., 80);
/// var virtualHost = VirtualHost(server);
/// virtualServer.addHost('static.myserver.com').listen(...);
/// virtualServer.addHost('cache.myserver.com').listen(...);
/// ```
factory VirtualHost([Stream<HttpRequest>? source]) => _VirtualHost(source);
/// Provide another source of [HttpRequest]s in the form of a [Stream].
void addSource(Stream<HttpRequest> source);
/// Add a host to the [VirtualHost] instance.
///
/// The host can be either a specific domain (`my.domain.name`) or a
/// wildcard-based domain name (`*.domain.name`). The former will only match
/// the specific domain name while the latter will match any series of
/// sub-domains.
///
/// If both `my.domain.name` and `*.domain.name` is specified, the most
/// qualified will take precedence, `my.domain.name` in this case.
Stream<HttpRequest> addHost(String host);
}
class _VirtualHostDomain {
StreamController<HttpRequest>? any;
StreamController<HttpRequest>? exact;
Map<String, _VirtualHostDomain> subDomains = {};
}
class _VirtualHost implements VirtualHost {
final _VirtualHostDomain _topDomain = _VirtualHostDomain();
StreamController<HttpRequest>? _unhandledController;
@override
Stream<HttpRequest> get unhandled {
_unhandledController ??= StreamController<HttpRequest>();
return _unhandledController!.stream;
}
_VirtualHost([Stream<HttpRequest>? source]) {
if (source != null) addSource(source);
}
@override
void addSource(Stream<HttpRequest> source) {
source.listen((request) {
var host = request.headers.host;
if (host == null) {
_unhandled(request);
return;
}
var domains = host.split('.');
var current = _topDomain;
StreamController? any;
for (var i = domains.length - 1; i >= 0; i--) {
if (current.any != null) any = current.any;
if (i == 0) {
var last = current.subDomains[domains[i]];
if (last != null && last.exact != null) {
last.exact!.add(request);
return;
}
} else {
if (!current.subDomains.containsKey(domains[i])) {
break;
}
current = current.subDomains[domains[i]]!;
}
}
if (any != null) {
any.add(request);
return;
}
_unhandled(request);
});
}
@override
Stream<HttpRequest> addHost(String host) {
if (host.lastIndexOf('*') > 0) {
throw ArgumentError(
'Wildcards are only allowed in the beginning of a host');
}
var controller = StreamController<HttpRequest>();
var domains = host.split('.');
var current = _topDomain;
for (var i = domains.length - 1; i >= 0; i--) {
if (domains[i] == '*') {
if (current.any != null) {
throw ArgumentError('Host is already provided');
}
current.any = controller;
} else {
if (!current.subDomains.containsKey(domains[i])) {
current.subDomains[domains[i]] = _VirtualHostDomain();
}
if (i > 0) {
current = current.subDomains[domains[i]]!;
} else {
if (current.subDomains[domains[i]]!.exact != null) {
throw ArgumentError('Host is already provided');
}
current.subDomains[domains[i]]!.exact = controller;
}
}
}
return controller.stream;
}
void _unhandled(HttpRequest request) {
if (_unhandledController != null) {
_unhandledController!.add(request);
return;
}
request.response.statusCode = HttpStatus.forbidden;
request.response.close();
}
}