[net/dns] Histograms for the reasons DnsTransaction failed.
Also, do not attempt to use DnsTransaction if the hostname is in the .local (mDNS) domain.
BUG=117770
TEST=chrome://histograms
Review URL: https://chromiumcodereview.appspot.com/10562023
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@143022 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/net/base/host_resolver_impl.cc b/net/base/host_resolver_impl.cc
index 811a002c..edab00e 100644
--- a/net/base/host_resolver_impl.cc
+++ b/net/base/host_resolver_impl.cc
@@ -137,6 +137,7 @@
RESOLVE_STATUS_DNS_SUCCESS = 0,
RESOLVE_STATUS_PROC_SUCCESS,
RESOLVE_STATUS_FAIL,
+ RESOLVE_STATUS_SUSPECT_NETBIOS,
RESOLVE_STATUS_MAX
};
@@ -146,6 +147,25 @@
RESOLVE_STATUS_MAX);
}
+bool ResemblesNetBIOSName(const std::string& hostname) {
+ return (hostname.size() < 16) && (hostname.find('.') == std::string::npos);
+}
+
+// True if |hostname| ends with either ".local" or ".local.".
+bool ResemblesMulticastDNSName(const std::string& hostname) {
+ DCHECK(!hostname.empty());
+ const char kSuffix[] = ".local.";
+ const size_t kSuffixLen = sizeof(kSuffix) - 1;
+ const size_t kSuffixLenTrimmed = kSuffixLen - 1;
+ if (hostname[hostname.size() - 1] == '.') {
+ return hostname.size() > kSuffixLen &&
+ !hostname.compare(hostname.size() - kSuffixLen, kSuffixLen, kSuffix);
+ }
+ return hostname.size() > kSuffixLenTrimmed &&
+ !hostname.compare(hostname.size() - kSuffixLenTrimmed, kSuffixLenTrimmed,
+ kSuffix, kSuffixLenTrimmed);
+}
+
//-----------------------------------------------------------------------------
// Wraps call to SystemHostResolverProc as an instance of HostResolverProc.
@@ -1055,7 +1075,7 @@
: resolver_(resolver->AsWeakPtr()),
key_(key),
had_non_speculative_request_(false),
- had_dns_config_(false),
+ dns_task_error_(OK),
net_log_(BoundNetLog::Make(request_net_log.net_log(),
NetLog::SOURCE_HOST_RESOLVER_IMPL_JOB)) {
request_net_log.AddEvent(NetLog::TYPE_HOST_RESOLVER_IMPL_CREATE_JOB);
@@ -1219,9 +1239,9 @@
net_log_.AddEvent(NetLog::TYPE_HOST_RESOLVER_IMPL_JOB_STARTED);
- had_dns_config_ = resolver_->HaveDnsConfig();
- // Job::Start must not complete synchronously.
- if (had_dns_config_) {
+ // Caution: Job::Start must not complete synchronously.
+ if (resolver_->HaveDnsConfig() &&
+ !ResemblesMulticastDNSName(key_.hostname)) {
StartDnsTask();
} else {
StartProcTask();
@@ -1251,10 +1271,17 @@
void OnProcTaskComplete(int net_error, const AddressList& addr_list) {
DCHECK(is_proc_running());
- if (had_dns_config_) {
- // TODO(szym): guess if the hostname is a NetBIOS name and discount it.
+ if (dns_task_error_ != OK) {
if (net_error == OK) {
- UmaAsyncDnsResolveStatus(RESOLVE_STATUS_PROC_SUCCESS);
+ if ((dns_task_error_ == ERR_NAME_NOT_RESOLVED) &&
+ ResemblesNetBIOSName(key_.hostname)) {
+ UmaAsyncDnsResolveStatus(RESOLVE_STATUS_SUSPECT_NETBIOS);
+ } else {
+ UmaAsyncDnsResolveStatus(RESOLVE_STATUS_PROC_SUCCESS);
+ }
+ UMA_HISTOGRAM_CUSTOM_ENUMERATION("AsyncDNS.ResolveError",
+ std::abs(dns_task_error_),
+ GetAllErrorCodesForUma());
} else {
UmaAsyncDnsResolveStatus(RESOLVE_STATUS_FAIL);
}
@@ -1291,6 +1318,7 @@
DCHECK(is_dns_running());
if (net_error != OK) {
+ dns_task_error_ = net_error;
dns_task_.reset();
// TODO(szym): Run ServeFromHosts now if nsswitch.conf says so.
@@ -1413,8 +1441,8 @@
bool had_non_speculative_request_;
- // True if resolver had DnsConfig when the Job was started.
- bool had_dns_config_;
+ // Result of DnsTask.
+ int dns_task_error_;
BoundNetLog net_log_;
