host_resolver.h revision 3551c9c881056c480085172ff9840cab31610854
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 52a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#ifndef NET_DNS_HOST_RESOLVER_H_ 62a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#define NET_DNS_HOST_RESOLVER_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <string> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/scoped_ptr.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/address_family.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/completion_callback.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/host_port_pair.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/net_export.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/net_util.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "net/base/request_priority.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base { 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class Value; 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace net { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class AddressList; 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class BoundNetLog; 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class HostCache; 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class HostResolverProc; 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class NetLog; 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This class represents the task of resolving hostnames (or IP address 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// literal) to an AddressList object. 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// HostResolver can handle multiple requests at a time, so when cancelling a 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// request the RequestHandle that was returned by Resolve() needs to be 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// given. A simpler alternative for consumers that only have 1 outstanding 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// request at a time is to create a SingleRequestHostResolver wrapper around 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// HostResolver (which will automatically cancel the single request when it 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// goes out of scope). 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class NET_EXPORT HostResolver { 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |max_concurrent_resolves| is how many resolve requests will be allowed to 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // run in parallel. Pass HostResolver::kDefaultParallelism to choose a 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // default value. 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |max_retry_attempts| is the maximum number of times we will retry for host 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // resolution. Pass HostResolver::kDefaultRetryAttempts to choose a default 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // value. 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |enable_caching| controls whether a HostCache is used. 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) struct NET_EXPORT Options { 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Options(); 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t max_concurrent_resolves; 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) size_t max_retry_attempts; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool enable_caching; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 563551c9c881056c480085172ff9840cab31610854Torne (Richard Coles) // The parameters for doing a Resolve(). A hostname and port are 573551c9c881056c480085172ff9840cab31610854Torne (Richard Coles) // required; the rest are optional (and have reasonable defaults). 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class NET_EXPORT RequestInfo { 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) explicit RequestInfo(const HostPortPair& host_port_pair); 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const HostPortPair& host_port_pair() const { return host_port_pair_; } 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void set_host_port_pair(const HostPortPair& host_port_pair) { 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) host_port_pair_ = host_port_pair; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int port() const { return host_port_pair_.port(); } 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const std::string& hostname() const { return host_port_pair_.host(); } 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AddressFamily address_family() const { return address_family_; } 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void set_address_family(AddressFamily address_family) { 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) address_family_ = address_family; 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HostResolverFlags host_resolver_flags() const { 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return host_resolver_flags_; 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void set_host_resolver_flags(HostResolverFlags host_resolver_flags) { 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) host_resolver_flags_ = host_resolver_flags; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool allow_cached_response() const { return allow_cached_response_; } 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void set_allow_cached_response(bool b) { allow_cached_response_ = b; } 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool is_speculative() const { return is_speculative_; } 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void set_is_speculative(bool b) { is_speculative_ = b; } 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The hostname to resolve, and the port to use in resulting sockaddrs. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HostPortPair host_port_pair_; 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The address family to restrict results to. 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AddressFamily address_family_; 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Flags to use when resolving this request. 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HostResolverFlags host_resolver_flags_; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Whether it is ok to return a result from the host cache. 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool allow_cached_response_; 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Whether this request was started by the DNS prefetcher. 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool is_speculative_; 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Opaque type used to cancel a request. 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) typedef void* RequestHandle; 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This value can be passed into CreateSystemResolver as the 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |max_concurrent_resolves| parameter. It will select a default level of 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // concurrency. 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static const size_t kDefaultParallelism = 0; 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This value can be passed into CreateSystemResolver as the 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |max_retry_attempts| parameter. 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static const size_t kDefaultRetryAttempts = -1; 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If any completion callbacks are pending when the resolver is destroyed, 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the host resolutions are cancelled, and the completion callbacks will not 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be called. 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~HostResolver(); 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Resolves the given hostname (or IP address literal), filling out the 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // |addresses| object upon success. The |info.port| parameter will be set as 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the sin(6)_port field of the sockaddr_in{6} struct. Returns OK if 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // successful or an error code upon failure. Returns 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ERR_NAME_NOT_RESOLVED if hostname is invalid, or if it is an 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // incompatible IP literal (e.g. IPv6 is disabled and it is an IPv6 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // literal). 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If the operation cannot be completed synchronously, ERR_IO_PENDING will 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be returned and the real result code will be passed to the completion 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // callback. Otherwise the result code is returned immediately from this 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // call. 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If |out_req| is non-NULL, then |*out_req| will be filled with a handle to 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // the async request. This handle is not valid after the request has 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // completed. 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Profiling information for the request is saved to |net_log| if non-NULL. 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual int Resolve(const RequestInfo& info, 1413551c9c881056c480085172ff9840cab31610854Torne (Richard Coles) RequestPriority priority, 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AddressList* addresses, 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const CompletionCallback& callback, 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) RequestHandle* out_req, 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const BoundNetLog& net_log) = 0; 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Resolves the given hostname (or IP address literal) out of cache or HOSTS 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // file (if enabled) only. This is guaranteed to complete synchronously. 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This acts like |Resolve()| if the hostname is IP literal, or cached value 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // or HOSTS entry exists. Otherwise, ERR_DNS_CACHE_MISS is returned. 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual int ResolveFromCache(const RequestInfo& info, 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AddressList* addresses, 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const BoundNetLog& net_log) = 0; 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Cancels the specified request. |req| is the handle returned by Resolve(). 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // After a request is canceled, its completion callback will not be called. 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // CancelRequest must NOT be called after the request's completion callback 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // has already run or the request was canceled. 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void CancelRequest(RequestHandle req) = 0; 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Sets the default AddressFamily to use when requests have left it 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // unspecified. For example, this could be used to restrict resolution 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // results to AF_INET by passing in ADDRESS_FAMILY_IPV4, or to 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // AF_INET6 by passing in ADDRESS_FAMILY_IPV6. 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void SetDefaultAddressFamily(AddressFamily address_family) {} 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual AddressFamily GetDefaultAddressFamily() const; 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Enable or disable the built-in asynchronous DnsClient. 1692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) virtual void SetDnsClientEnabled(bool enabled); 1702a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns the HostResolverCache |this| uses, or NULL if there isn't one. 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Used primarily to clear the cache and for getting debug information. 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual HostCache* GetHostCache(); 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns the current DNS configuration |this| is using, as a Value, or NULL 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // if it's configured to always use the system host resolver. Caller takes 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ownership of the returned Value. 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual base::Value* GetDnsConfigAsValue() const; 1795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Creates a HostResolver implementation that queries the underlying system. 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // (Except if a unit-test has changed the global HostResolverProc using 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // ScopedHostResolverProc to intercept requests to the system). 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static scoped_ptr<HostResolver> CreateSystemResolver( 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Options& options, 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) NetLog* net_log); 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // As above, but uses default parameters. 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) static scoped_ptr<HostResolver> CreateDefaultResolver(NetLog* net_log); 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 1915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HostResolver(); 1925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(HostResolver); 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace net 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1992a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)#endif // NET_DNS_HOST_RESOLVER_H_ 200