Index: net/dns/dns_client.h |
diff --git a/net/dns/dns_client.h b/net/dns/dns_client.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..af75cf6ef57eff37f7ad1e76eb2153cf8fba5dc7 |
--- /dev/null |
+++ b/net/dns/dns_client.h |
@@ -0,0 +1,93 @@ |
+// Copyright (c) 2011 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef NET_DNS_DNS_CLIENT_H_ |
+#define NET_DNS_DNS_CLIENT_H_ |
+#pragma once |
+ |
+#include <string> |
+ |
+#include "base/basictypes.h" |
+#include "base/callback.h" |
+#include "base/memory/weak_ptr.h" |
+#include "net/base/net_export.h" |
+ |
+namespace base { |
+class StringPiece; |
+} |
+ |
+namespace net { |
+ |
+class BoundNetLog; |
+class ClientSocketFactory; |
+class DnsResponse; |
+class DnsSession; |
+ |
+// DnsClient performs asynchronous DNS queries. DnsClient takes care of |
+// retransmissions, DNS server fallback (or round-robin), suffix search, and |
+// simple response validation ("does it match the query") to fight poisoning. |
+// It does NOT perform caching, aggregation or prioritization of requests. |
+// |
+// Destroying DnsClient does NOT affect any already created Requests. |
+// |
+// TODO(szym): consider adding flags to MakeRequest to indicate options: |
+// -- don't perform suffix search |
+// -- query both A and AAAA at once |
+// -- accept truncated response (and/or forbid TCP) |
+class NET_EXPORT_PRIVATE DnsClient { |
+ public: |
+ class Request; |
+ // Callback for complete requests. Note that DnsResponse might be NULL if |
+ // the DNS server(s) could not be reached. |
+ typedef base::Callback<void(Request* req, |
+ int result, |
+ const DnsResponse* resp)> RequestCallback; |
+ |
+ // A data-holder for a request made to the DnsClient. |
+ // Destroying the request cancels the underlying network effort. |
+ class NET_EXPORT_PRIVATE Request { |
+ public: |
+ Request(const base::StringPiece& qname, |
+ uint16 qtype, |
+ const RequestCallback& callback); |
+ virtual ~Request(); |
+ |
+ const std::string& qname() const { return qname_; } |
+ |
+ uint16 qtype() const { return qtype_; } |
+ |
+ virtual int Start() = 0; |
+ |
+ void DoCallback(int result, const DnsResponse* response) { |
+ callback_.Run(this, result, response); |
+ } |
+ |
+ private: |
+ std::string qname_; |
+ uint16 qtype_; |
+ RequestCallback callback_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(Request); |
+ }; |
+ |
+ virtual ~DnsClient() {} |
+ |
+ // Makes asynchronous DNS query for the given |qname| and |qtype| (assuming |
+ // QCLASS == IN). The caller is responsible for destroying the returned |
+ // request whether to cancel it or after its completion. |
+ // (Destroying DnsClient does not abort the requests.) |
+ virtual Request* CreateRequest( |
+ const base::StringPiece& qname, |
+ uint16 qtype, |
+ const RequestCallback& callback, |
+ const BoundNetLog& source_net_log) WARN_UNUSED_RESULT = 0; |
+ |
+ // Creates a socket-based DnsClient using the |session|. |
+ static DnsClient* CreateClient(DnsSession* session) WARN_UNUSED_RESULT; |
+}; |
+ |
+} // namespace net |
+ |
+#endif // NET_DNS_DNS_CLIENT_H_ |
+ |