blob: 11d8531cf38b7c218f25c35f8df604052c967f9e [file] [log] [blame]
// Copyright (c) 2012 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_TRANSACTION_H_
#define NET_DNS_DNS_TRANSACTION_H_
#include <stdint.h>
#include <memory>
#include <string>
#include "net/base/request_priority.h"
#include "net/dns/record_rdata.h"
#include "url/gurl.h"
namespace net {
class DnsResponse;
class DnsSession;
class NetLogWithSource;
class URLRequestContext;
// DnsTransaction implements a stub DNS resolver as defined in RFC 1034.
// The DnsTransaction takes care of retransmissions, name server fallback (or
// round-robin), suffix search, and simple response validation ("does it match
// the query") to fight poisoning.
//
// Destroying DnsTransaction cancels the underlying network effort.
class NET_EXPORT_PRIVATE DnsTransaction {
public:
virtual ~DnsTransaction() {}
// Returns the original |hostname|.
virtual const std::string& GetHostname() const = 0;
// Returns the |qtype|.
virtual uint16_t GetType() const = 0;
// Starts the transaction. Always completes asynchronously.
virtual void Start() = 0;
virtual void SetRequestContext(URLRequestContext*) = 0;
virtual void SetRequestPriority(RequestPriority priority) = 0;
};
// Creates DnsTransaction which performs asynchronous DNS search.
// It does NOT perform caching, aggregation or prioritization of transactions.
//
// Destroying the factory does NOT affect any already created DnsTransactions.
class NET_EXPORT_PRIVATE DnsTransactionFactory {
public:
// Called with the response or NULL if no matching response was received.
// Note that the |GetDottedName()| of the response may be different than the
// original |hostname| as a result of suffix search.
typedef base::Callback<void(DnsTransaction* transaction,
int neterror,
const DnsResponse* response)> CallbackType;
virtual ~DnsTransactionFactory() {}
// Creates DnsTransaction for the given |hostname| and |qtype| (assuming
// QCLASS is IN). |hostname| should be in the dotted form. A dot at the end
// implies the domain name is fully-qualified and will be exempt from suffix
// search. |hostname| should not be an IP literal.
//
// The transaction will run |callback| upon asynchronous completion.
// The |net_log| is used as the parent log.
virtual std::unique_ptr<DnsTransaction> CreateTransaction(
const std::string& hostname,
uint16_t qtype,
const CallbackType& callback,
const NetLogWithSource& net_log) WARN_UNUSED_RESULT = 0;
// The given EDNS0 option will be included in all DNS queries performed by
// transactions from this factory.
virtual void AddEDNSOption(const OptRecordRdata::Opt& opt) = 0;
// Creates a DnsTransactionFactory which creates DnsTransactionImpl using the
// |session|.
static std::unique_ptr<DnsTransactionFactory> CreateFactory(
DnsSession* session) WARN_UNUSED_RESULT;
};
} // namespace net
#endif // NET_DNS_DNS_TRANSACTION_H_