blob: 55a2825ff69bec7c202321a791e191e870cc5f96 [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.
#include "net/dns/dns_config_service_win.h"
#include <algorithm>
#include <string>
#include "base/bind.h"
#include "base/callback.h"
#include "base/compiler_specific.h"
#include "base/files/file_path.h"
#include "base/files/file_path_watcher.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/histogram.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/synchronization/lock.h"
#include "base/threading/non_thread_safe.h"
#include "base/threading/thread_restrictions.h"
#include "base/time/time.h"
#include "base/win/object_watcher.h"
#include "base/win/registry.h"
#include "base/win/windows_version.h"
#include "net/base/net_util.h"
#include "net/base/network_change_notifier.h"
#include "net/dns/dns_hosts.h"
#include "net/dns/dns_protocol.h"
#include "net/dns/serial_worker.h"
#include "url/url_canon.h"
#pragma comment(lib, "iphlpapi.lib")
namespace net {
namespace internal {
namespace {
// Interval between retries to parse config. Used only until parsing succeeds.
const int kRetryIntervalSeconds = 5;
// Registry key paths.
const wchar_t* const kTcpipPath =
L"SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters";
const wchar_t* const kTcpip6Path =
L"SYSTEM\\CurrentControlSet\\Services\\Tcpip6\\Parameters";
const wchar_t* const kDnscachePath =
L"SYSTEM\\CurrentControlSet\\Services\\Dnscache\\Parameters";
const wchar_t* const kPolicyPath =
L"SOFTWARE\\Policies\\Microsoft\\Windows NT\\DNSClient";
const wchar_t* const kPrimaryDnsSuffixPath =
L"SOFTWARE\\Policies\\Microsoft\\System\\DNSClient";
const wchar_t* const kNRPTPath =
L"SOFTWARE\\Policies\\Microsoft\\Windows NT\\DNSClient\\DnsPolicyConfig";
enum HostsParseWinResult {
HOSTS_PARSE_WIN_OK = 0,
HOSTS_PARSE_WIN_UNREADABLE_HOSTS_FILE,
HOSTS_PARSE_WIN_COMPUTER_NAME_FAILED,
HOSTS_PARSE_WIN_IPHELPER_FAILED,
HOSTS_PARSE_WIN_BAD_ADDRESS,
HOSTS_PARSE_WIN_MAX // Bounding values for enumeration.
};
// Convenience for reading values using RegKey.
class RegistryReader : public base::NonThreadSafe {
public:
explicit RegistryReader(const wchar_t* key) {
// Ignoring the result. |key_.Valid()| will catch failures.
key_.Open(HKEY_LOCAL_MACHINE, key, KEY_QUERY_VALUE);
}
bool ReadString(const wchar_t* name,
DnsSystemSettings::RegString* out) const {
DCHECK(CalledOnValidThread());
out->set = false;
if (!key_.Valid()) {
// Assume that if the |key_| is invalid then the key is missing.
return true;
}
LONG result = key_.ReadValue(name, &out->value);
if (result == ERROR_SUCCESS) {
out->set = true;
return true;
}
return (result == ERROR_FILE_NOT_FOUND);
}
bool ReadDword(const wchar_t* name,
DnsSystemSettings::RegDword* out) const {
DCHECK(CalledOnValidThread());
out->set = false;
if (!key_.Valid()) {
// Assume that if the |key_| is invalid then the key is missing.
return true;
}
LONG result = key_.ReadValueDW(name, &out->value);
if (result == ERROR_SUCCESS) {
out->set = true;
return true;
}
return (result == ERROR_FILE_NOT_FOUND);
}
private:
base::win::RegKey key_;
DISALLOW_COPY_AND_ASSIGN(RegistryReader);
};
// Wrapper for GetAdaptersAddresses. Returns NULL if failed.
scoped_ptr<IP_ADAPTER_ADDRESSES, base::FreeDeleter> ReadIpHelper(ULONG flags) {
base::ThreadRestrictions::AssertIOAllowed();
scoped_ptr<IP_ADAPTER_ADDRESSES, base::FreeDeleter> out;
ULONG len = 15000; // As recommended by MSDN for GetAdaptersAddresses.
UINT rv = ERROR_BUFFER_OVERFLOW;
// Try up to three times.
for (unsigned tries = 0; (tries < 3) && (rv == ERROR_BUFFER_OVERFLOW);
tries++) {
out.reset(static_cast<PIP_ADAPTER_ADDRESSES>(malloc(len)));
memset(out.get(), 0, len);
rv = GetAdaptersAddresses(AF_UNSPEC, flags, NULL, out.get(), &len);
}
if (rv != NO_ERROR)
out.reset();
return out.Pass();
}
// Converts a base::string16 domain name to ASCII, possibly using punycode.
// Returns true if the conversion succeeds and output is not empty. In case of
// failure, |domain| might become dirty.
bool ParseDomainASCII(const base::string16& widestr, std::string* domain) {
DCHECK(domain);
if (widestr.empty())
return false;
// Check if already ASCII.
if (base::IsStringASCII(widestr)) {
*domain = base::UTF16ToASCII(widestr);
return true;
}
// Otherwise try to convert it from IDN to punycode.
const int kInitialBufferSize = 256;
url::RawCanonOutputT<base::char16, kInitialBufferSize> punycode;
if (!url::IDNToASCII(widestr.data(), widestr.length(), &punycode))
return false;
// |punycode_output| should now be ASCII; convert it to a std::string.
// (We could use UTF16ToASCII() instead, but that requires an extra string
// copy. Since ASCII is a subset of UTF8 the following is equivalent).
bool success = base::UTF16ToUTF8(punycode.data(), punycode.length(), domain);
DCHECK(success);
DCHECK(base::IsStringASCII(*domain));
return success && !domain->empty();
}
bool ReadDevolutionSetting(const RegistryReader& reader,
DnsSystemSettings::DevolutionSetting* setting) {
return reader.ReadDword(L"UseDomainNameDevolution", &setting->enabled) &&
reader.ReadDword(L"DomainNameDevolutionLevel", &setting->level);
}
// Reads DnsSystemSettings from IpHelper and registry.
ConfigParseWinResult ReadSystemSettings(DnsSystemSettings* settings) {
settings->addresses = ReadIpHelper(GAA_FLAG_SKIP_ANYCAST |
GAA_FLAG_SKIP_UNICAST |
GAA_FLAG_SKIP_MULTICAST |
GAA_FLAG_SKIP_FRIENDLY_NAME);
if (!settings->addresses.get())
return CONFIG_PARSE_WIN_READ_IPHELPER;
RegistryReader tcpip_reader(kTcpipPath);
RegistryReader tcpip6_reader(kTcpip6Path);
RegistryReader dnscache_reader(kDnscachePath);
RegistryReader policy_reader(kPolicyPath);
RegistryReader primary_dns_suffix_reader(kPrimaryDnsSuffixPath);
if (!policy_reader.ReadString(L"SearchList",
&settings->policy_search_list)) {
return CONFIG_PARSE_WIN_READ_POLICY_SEARCHLIST;
}
if (!tcpip_reader.ReadString(L"SearchList", &settings->tcpip_search_list))
return CONFIG_PARSE_WIN_READ_TCPIP_SEARCHLIST;
if (!tcpip_reader.ReadString(L"Domain", &settings->tcpip_domain))
return CONFIG_PARSE_WIN_READ_DOMAIN;
if (!ReadDevolutionSetting(policy_reader, &settings->policy_devolution))
return CONFIG_PARSE_WIN_READ_POLICY_DEVOLUTION;
if (!ReadDevolutionSetting(dnscache_reader, &settings->dnscache_devolution))
return CONFIG_PARSE_WIN_READ_DNSCACHE_DEVOLUTION;
if (!ReadDevolutionSetting(tcpip_reader, &settings->tcpip_devolution))
return CONFIG_PARSE_WIN_READ_TCPIP_DEVOLUTION;
if (!policy_reader.ReadDword(L"AppendToMultiLabelName",
&settings->append_to_multi_label_name)) {
return CONFIG_PARSE_WIN_READ_APPEND_MULTILABEL;
}
if (!primary_dns_suffix_reader.ReadString(L"PrimaryDnsSuffix",
&settings->primary_dns_suffix)) {
return CONFIG_PARSE_WIN_READ_PRIMARY_SUFFIX;
}
base::win::RegistryKeyIterator nrpt_rules(HKEY_LOCAL_MACHINE, kNRPTPath);
settings->have_name_resolution_policy = (nrpt_rules.SubkeyCount() > 0);
return CONFIG_PARSE_WIN_OK;
}
// Default address of "localhost" and local computer name can be overridden
// by the HOSTS file, but if it's not there, then we need to fill it in.
HostsParseWinResult AddLocalhostEntries(DnsHosts* hosts) {
const unsigned char kIPv4Localhost[] = { 127, 0, 0, 1 };
const unsigned char kIPv6Localhost[] = { 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1 };
IPAddressNumber loopback_ipv4(kIPv4Localhost,
kIPv4Localhost + arraysize(kIPv4Localhost));
IPAddressNumber loopback_ipv6(kIPv6Localhost,
kIPv6Localhost + arraysize(kIPv6Localhost));
// This does not override any pre-existing entries from the HOSTS file.
hosts->insert(std::make_pair(DnsHostsKey("localhost", ADDRESS_FAMILY_IPV4),
loopback_ipv4));
hosts->insert(std::make_pair(DnsHostsKey("localhost", ADDRESS_FAMILY_IPV6),
loopback_ipv6));
WCHAR buffer[MAX_PATH];
DWORD size = MAX_PATH;
std::string localname;
if (!GetComputerNameExW(ComputerNameDnsHostname, buffer, &size) ||
!ParseDomainASCII(buffer, &localname)) {
return HOSTS_PARSE_WIN_COMPUTER_NAME_FAILED;
}
base::StringToLowerASCII(&localname);
bool have_ipv4 =
hosts->count(DnsHostsKey(localname, ADDRESS_FAMILY_IPV4)) > 0;
bool have_ipv6 =
hosts->count(DnsHostsKey(localname, ADDRESS_FAMILY_IPV6)) > 0;
if (have_ipv4 && have_ipv6)
return HOSTS_PARSE_WIN_OK;
scoped_ptr<IP_ADAPTER_ADDRESSES, base::FreeDeleter> addresses =
ReadIpHelper(GAA_FLAG_SKIP_ANYCAST |
GAA_FLAG_SKIP_DNS_SERVER |
GAA_FLAG_SKIP_MULTICAST |
GAA_FLAG_SKIP_FRIENDLY_NAME);
if (!addresses.get())
return HOSTS_PARSE_WIN_IPHELPER_FAILED;
// The order of adapters is the network binding order, so stick to the
// first good adapter for each family.
for (const IP_ADAPTER_ADDRESSES* adapter = addresses.get();
adapter != NULL && (!have_ipv4 || !have_ipv6);
adapter = adapter->Next) {
if (adapter->OperStatus != IfOperStatusUp)
continue;
if (adapter->IfType == IF_TYPE_SOFTWARE_LOOPBACK)
continue;
for (const IP_ADAPTER_UNICAST_ADDRESS* address =
adapter->FirstUnicastAddress;
address != NULL;
address = address->Next) {
IPEndPoint ipe;
if (!ipe.FromSockAddr(address->Address.lpSockaddr,
address->Address.iSockaddrLength)) {
return HOSTS_PARSE_WIN_BAD_ADDRESS;
}
if (!have_ipv4 && (ipe.GetFamily() == ADDRESS_FAMILY_IPV4)) {
have_ipv4 = true;
(*hosts)[DnsHostsKey(localname, ADDRESS_FAMILY_IPV4)] = ipe.address();
} else if (!have_ipv6 && (ipe.GetFamily() == ADDRESS_FAMILY_IPV6)) {
have_ipv6 = true;
(*hosts)[DnsHostsKey(localname, ADDRESS_FAMILY_IPV6)] = ipe.address();
}
}
}
return HOSTS_PARSE_WIN_OK;
}
// Watches a single registry key for changes.
class RegistryWatcher : public base::win::ObjectWatcher::Delegate,
public base::NonThreadSafe {
public:
typedef base::Callback<void(bool succeeded)> CallbackType;
RegistryWatcher() {}
bool Watch(const wchar_t* key, const CallbackType& callback) {
DCHECK(CalledOnValidThread());
DCHECK(!callback.is_null());
DCHECK(callback_.is_null());
callback_ = callback;
if (key_.Open(HKEY_LOCAL_MACHINE, key, KEY_NOTIFY) != ERROR_SUCCESS)
return false;
if (key_.StartWatching() != ERROR_SUCCESS)
return false;
if (!watcher_.StartWatching(key_.watch_event(), this))
return false;
return true;
}
virtual void OnObjectSignaled(HANDLE object) OVERRIDE {
DCHECK(CalledOnValidThread());
bool succeeded = (key_.StartWatching() == ERROR_SUCCESS) &&
watcher_.StartWatching(key_.watch_event(), this);
if (!succeeded && key_.Valid()) {
watcher_.StopWatching();
key_.StopWatching();
key_.Close();
}
if (!callback_.is_null())
callback_.Run(succeeded);
}
private:
CallbackType callback_;
base::win::RegKey key_;
base::win::ObjectWatcher watcher_;
DISALLOW_COPY_AND_ASSIGN(RegistryWatcher);
};
// Returns true iff |address| is DNS address from IPv6 stateless discovery,
// i.e., matches fec0:0:0:ffff::{1,2,3}.
// http://tools.ietf.org/html/draft-ietf-ipngwg-dns-discovery
bool IsStatelessDiscoveryAddress(const IPAddressNumber& address) {
if (address.size() != kIPv6AddressSize)
return false;
const uint8 kPrefix[] = {
0xfe, 0xc0, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};
return std::equal(kPrefix, kPrefix + arraysize(kPrefix),
address.begin()) && (address.back() < 4);
}
// Returns the path to the HOSTS file.
base::FilePath GetHostsPath() {
TCHAR buffer[MAX_PATH];
UINT rc = GetSystemDirectory(buffer, MAX_PATH);
DCHECK(0 < rc && rc < MAX_PATH);
return base::FilePath(buffer).Append(
FILE_PATH_LITERAL("drivers\\etc\\hosts"));
}
void ConfigureSuffixSearch(const DnsSystemSettings& settings,
DnsConfig* config) {
// SearchList takes precedence, so check it first.
if (settings.policy_search_list.set) {
std::vector<std::string> search;
if (ParseSearchList(settings.policy_search_list.value, &search)) {
config->search.swap(search);
return;
}
// Even if invalid, the policy disables the user-specified setting below.
} else if (settings.tcpip_search_list.set) {
std::vector<std::string> search;
if (ParseSearchList(settings.tcpip_search_list.value, &search)) {
config->search.swap(search);
return;
}
}
// In absence of explicit search list, suffix search is:
// [primary suffix, connection-specific suffix, devolution of primary suffix].
// Primary suffix can be set by policy (primary_dns_suffix) or
// user setting (tcpip_domain).
//
// The policy (primary_dns_suffix) can be edited via Group Policy Editor
// (gpedit.msc) at Local Computer Policy => Computer Configuration
// => Administrative Template => Network => DNS Client => Primary DNS Suffix.
//
// The user setting (tcpip_domain) can be configurred at Computer Name in
// System Settings
std::string primary_suffix;
if ((settings.primary_dns_suffix.set &&
ParseDomainASCII(settings.primary_dns_suffix.value, &primary_suffix)) ||
(settings.tcpip_domain.set &&
ParseDomainASCII(settings.tcpip_domain.value, &primary_suffix))) {
// Primary suffix goes in front.
config->search.insert(config->search.begin(), primary_suffix);
} else {
return; // No primary suffix, hence no devolution.
}
// Devolution is determined by precedence: policy > dnscache > tcpip.
// |enabled|: UseDomainNameDevolution and |level|: DomainNameDevolutionLevel
// are overridden independently.
DnsSystemSettings::DevolutionSetting devolution = settings.policy_devolution;
if (!devolution.enabled.set)
devolution.enabled = settings.dnscache_devolution.enabled;
if (!devolution.enabled.set)
devolution.enabled = settings.tcpip_devolution.enabled;
if (devolution.enabled.set && (devolution.enabled.value == 0))
return; // Devolution disabled.
// By default devolution is enabled.
if (!devolution.level.set)
devolution.level = settings.dnscache_devolution.level;
if (!devolution.level.set)
devolution.level = settings.tcpip_devolution.level;
// After the recent update, Windows will try to determine a safe default
// value by comparing the forest root domain (FRD) to the primary suffix.
// See http://support.microsoft.com/kb/957579 for details.
// For now, if the level is not set, we disable devolution, assuming that
// we will fallback to the system getaddrinfo anyway. This might cause
// performance loss for resolutions which depend on the system default
// devolution setting.
//
// If the level is explicitly set below 2, devolution is disabled.
if (!devolution.level.set || devolution.level.value < 2)
return; // Devolution disabled.
// Devolve the primary suffix. This naive logic matches the observed
// behavior (see also ParseSearchList). If a suffix is not valid, it will be
// discarded when the fully-qualified name is converted to DNS format.
unsigned num_dots = std::count(primary_suffix.begin(),
primary_suffix.end(), '.');
for (size_t offset = 0; num_dots >= devolution.level.value; --num_dots) {
offset = primary_suffix.find('.', offset + 1);
config->search.push_back(primary_suffix.substr(offset + 1));
}
}
} // namespace
bool ParseSearchList(const base::string16& value,
std::vector<std::string>* output) {
DCHECK(output);
if (value.empty())
return false;
output->clear();
// If the list includes an empty hostname (",," or ", ,"), it is terminated.
// Although nslookup and network connection property tab ignore such
// fragments ("a,b,,c" becomes ["a", "b", "c"]), our reference is getaddrinfo
// (which sees ["a", "b"]). WMI queries also return a matching search list.
std::vector<base::string16> woutput;
base::SplitString(value, ',', &woutput);
for (size_t i = 0; i < woutput.size(); ++i) {
// Convert non-ASCII to punycode, although getaddrinfo does not properly
// handle such suffixes.
const base::string16& t = woutput[i];
std::string parsed;
if (!ParseDomainASCII(t, &parsed))
break;
output->push_back(parsed);
}
return !output->empty();
}
ConfigParseWinResult ConvertSettingsToDnsConfig(
const DnsSystemSettings& settings,
DnsConfig* config) {
*config = DnsConfig();
// Use GetAdapterAddresses to get effective DNS server order and
// connection-specific DNS suffix. Ignore disconnected and loopback adapters.
// The order of adapters is the network binding order, so stick to the
// first good adapter.
for (const IP_ADAPTER_ADDRESSES* adapter = settings.addresses.get();
adapter != NULL && config->nameservers.empty();
adapter = adapter->Next) {
if (adapter->OperStatus != IfOperStatusUp)
continue;
if (adapter->IfType == IF_TYPE_SOFTWARE_LOOPBACK)
continue;
for (const IP_ADAPTER_DNS_SERVER_ADDRESS* address =
adapter->FirstDnsServerAddress;
address != NULL;
address = address->Next) {
IPEndPoint ipe;
if (ipe.FromSockAddr(address->Address.lpSockaddr,
address->Address.iSockaddrLength)) {
if (IsStatelessDiscoveryAddress(ipe.address()))
continue;
// Override unset port.
if (!ipe.port())
ipe = IPEndPoint(ipe.address(), dns_protocol::kDefaultPort);
config->nameservers.push_back(ipe);
} else {
return CONFIG_PARSE_WIN_BAD_ADDRESS;
}
}
// IP_ADAPTER_ADDRESSES in Vista+ has a search list at |FirstDnsSuffix|,
// but it came up empty in all trials.
// |DnsSuffix| stores the effective connection-specific suffix, which is
// obtained via DHCP (regkey: Tcpip\Parameters\Interfaces\{XXX}\DhcpDomain)
// or specified by the user (regkey: Tcpip\Parameters\Domain).
std::string dns_suffix;
if (ParseDomainASCII(adapter->DnsSuffix, &dns_suffix))
config->search.push_back(dns_suffix);
}
if (config->nameservers.empty())
return CONFIG_PARSE_WIN_NO_NAMESERVERS; // No point continuing.
// Windows always tries a multi-label name "as is" before using suffixes.
config->ndots = 1;
if (!settings.append_to_multi_label_name.set) {
// The default setting is true for XP, false for Vista+.
if (base::win::GetVersion() >= base::win::VERSION_VISTA) {
config->append_to_multi_label_name = false;
} else {
config->append_to_multi_label_name = true;
}
} else {
config->append_to_multi_label_name =
(settings.append_to_multi_label_name.value != 0);
}
ConfigParseWinResult result = CONFIG_PARSE_WIN_OK;
if (settings.have_name_resolution_policy) {
config->unhandled_options = true;
// TODO(szym): only set this to true if NRPT has DirectAccess rules.
config->use_local_ipv6 = true;
result = CONFIG_PARSE_WIN_UNHANDLED_OPTIONS;
}
ConfigureSuffixSearch(settings, config);
return result;
}
// Watches registry and HOSTS file for changes. Must live on a thread which
// allows IO.
class DnsConfigServiceWin::Watcher
: public NetworkChangeNotifier::IPAddressObserver {
public:
explicit Watcher(DnsConfigServiceWin* service) : service_(service) {}
~Watcher() {
NetworkChangeNotifier::RemoveIPAddressObserver(this);
}
bool Watch() {
RegistryWatcher::CallbackType callback =
base::Bind(&DnsConfigServiceWin::OnConfigChanged,
base::Unretained(service_));
bool success = true;
// The Tcpip key must be present.
if (!tcpip_watcher_.Watch(kTcpipPath, callback)) {
LOG(ERROR) << "DNS registry watch failed to start.";
success = false;
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.WatchStatus",
DNS_CONFIG_WATCH_FAILED_TO_START_CONFIG,
DNS_CONFIG_WATCH_MAX);
}
// Watch for IPv6 nameservers.
tcpip6_watcher_.Watch(kTcpip6Path, callback);
// DNS suffix search list and devolution can be configured via group
// policy which sets this registry key. If the key is missing, the policy
// does not apply, and the DNS client uses Tcpip and Dnscache settings.
// If a policy is installed, DnsConfigService will need to be restarted.
// BUG=99509
dnscache_watcher_.Watch(kDnscachePath, callback);
policy_watcher_.Watch(kPolicyPath, callback);
if (!hosts_watcher_.Watch(GetHostsPath(), false,
base::Bind(&Watcher::OnHostsChanged,
base::Unretained(this)))) {
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.WatchStatus",
DNS_CONFIG_WATCH_FAILED_TO_START_HOSTS,
DNS_CONFIG_WATCH_MAX);
LOG(ERROR) << "DNS hosts watch failed to start.";
success = false;
} else {
// Also need to observe changes to local non-loopback IP for DnsHosts.
NetworkChangeNotifier::AddIPAddressObserver(this);
}
return success;
}
private:
void OnHostsChanged(const base::FilePath& path, bool error) {
if (error)
NetworkChangeNotifier::RemoveIPAddressObserver(this);
service_->OnHostsChanged(!error);
}
// NetworkChangeNotifier::IPAddressObserver:
virtual void OnIPAddressChanged() OVERRIDE {
// Need to update non-loopback IP of local host.
service_->OnHostsChanged(true);
}
DnsConfigServiceWin* service_;
RegistryWatcher tcpip_watcher_;
RegistryWatcher tcpip6_watcher_;
RegistryWatcher dnscache_watcher_;
RegistryWatcher policy_watcher_;
base::FilePathWatcher hosts_watcher_;
DISALLOW_COPY_AND_ASSIGN(Watcher);
};
// Reads config from registry and IpHelper. All work performed on WorkerPool.
class DnsConfigServiceWin::ConfigReader : public SerialWorker {
public:
explicit ConfigReader(DnsConfigServiceWin* service)
: service_(service),
success_(false) {}
private:
virtual ~ConfigReader() {}
virtual void DoWork() OVERRIDE {
// Should be called on WorkerPool.
base::TimeTicks start_time = base::TimeTicks::Now();
DnsSystemSettings settings = {};
ConfigParseWinResult result = ReadSystemSettings(&settings);
if (result == CONFIG_PARSE_WIN_OK)
result = ConvertSettingsToDnsConfig(settings, &dns_config_);
success_ = (result == CONFIG_PARSE_WIN_OK ||
result == CONFIG_PARSE_WIN_UNHANDLED_OPTIONS);
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.ConfigParseWin",
result, CONFIG_PARSE_WIN_MAX);
UMA_HISTOGRAM_BOOLEAN("AsyncDNS.ConfigParseResult", success_);
UMA_HISTOGRAM_TIMES("AsyncDNS.ConfigParseDuration",
base::TimeTicks::Now() - start_time);
}
virtual void OnWorkFinished() OVERRIDE {
DCHECK(loop()->BelongsToCurrentThread());
DCHECK(!IsCancelled());
if (success_) {
service_->OnConfigRead(dns_config_);
} else {
LOG(WARNING) << "Failed to read DnsConfig.";
// Try again in a while in case DnsConfigWatcher missed the signal.
base::MessageLoop::current()->PostDelayedTask(
FROM_HERE,
base::Bind(&ConfigReader::WorkNow, this),
base::TimeDelta::FromSeconds(kRetryIntervalSeconds));
}
}
DnsConfigServiceWin* service_;
// Written in DoWork(), read in OnWorkFinished(). No locking required.
DnsConfig dns_config_;
bool success_;
};
// Reads hosts from HOSTS file and fills in localhost and local computer name if
// necessary. All work performed on WorkerPool.
class DnsConfigServiceWin::HostsReader : public SerialWorker {
public:
explicit HostsReader(DnsConfigServiceWin* service)
: path_(GetHostsPath()),
service_(service),
success_(false) {
}
private:
virtual ~HostsReader() {}
virtual void DoWork() OVERRIDE {
base::TimeTicks start_time = base::TimeTicks::Now();
HostsParseWinResult result = HOSTS_PARSE_WIN_UNREADABLE_HOSTS_FILE;
if (ParseHostsFile(path_, &hosts_))
result = AddLocalhostEntries(&hosts_);
success_ = (result == HOSTS_PARSE_WIN_OK);
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.HostsParseWin",
result, HOSTS_PARSE_WIN_MAX);
UMA_HISTOGRAM_BOOLEAN("AsyncDNS.HostParseResult", success_);
UMA_HISTOGRAM_TIMES("AsyncDNS.HostsParseDuration",
base::TimeTicks::Now() - start_time);
}
virtual void OnWorkFinished() OVERRIDE {
DCHECK(loop()->BelongsToCurrentThread());
if (success_) {
service_->OnHostsRead(hosts_);
} else {
LOG(WARNING) << "Failed to read DnsHosts.";
}
}
const base::FilePath path_;
DnsConfigServiceWin* service_;
// Written in DoWork, read in OnWorkFinished, no locking necessary.
DnsHosts hosts_;
bool success_;
DISALLOW_COPY_AND_ASSIGN(HostsReader);
};
DnsConfigServiceWin::DnsConfigServiceWin()
: config_reader_(new ConfigReader(this)),
hosts_reader_(new HostsReader(this)) {}
DnsConfigServiceWin::~DnsConfigServiceWin() {
config_reader_->Cancel();
hosts_reader_->Cancel();
}
void DnsConfigServiceWin::ReadNow() {
config_reader_->WorkNow();
hosts_reader_->WorkNow();
}
bool DnsConfigServiceWin::StartWatching() {
// TODO(szym): re-start watcher if that makes sense. http://crbug.com/116139
watcher_.reset(new Watcher(this));
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.WatchStatus", DNS_CONFIG_WATCH_STARTED,
DNS_CONFIG_WATCH_MAX);
return watcher_->Watch();
}
void DnsConfigServiceWin::OnConfigChanged(bool succeeded) {
InvalidateConfig();
if (succeeded) {
config_reader_->WorkNow();
} else {
LOG(ERROR) << "DNS config watch failed.";
set_watch_failed(true);
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.WatchStatus",
DNS_CONFIG_WATCH_FAILED_CONFIG,
DNS_CONFIG_WATCH_MAX);
}
}
void DnsConfigServiceWin::OnHostsChanged(bool succeeded) {
InvalidateHosts();
if (succeeded) {
hosts_reader_->WorkNow();
} else {
LOG(ERROR) << "DNS hosts watch failed.";
set_watch_failed(true);
UMA_HISTOGRAM_ENUMERATION("AsyncDNS.WatchStatus",
DNS_CONFIG_WATCH_FAILED_HOSTS,
DNS_CONFIG_WATCH_MAX);
}
}
} // namespace internal
// static
scoped_ptr<DnsConfigService> DnsConfigService::CreateSystemService() {
return scoped_ptr<DnsConfigService>(new internal::DnsConfigServiceWin());
}
} // namespace net