libgo: Update to current version of master library.

From-SVN: r193688

1 files changed, 46 insertions, 0 deletions

diff --git a/libgo/go/net/lookup.go b/libgo/go/net/lookup.go
index 3a44e528eb2..bec93ec08cd 100644
--- a/libgo/go/net/lookup.go
+++ b/libgo/go/net/lookup.go
@@ -4,12 +4,53 @@
 
 package net
 
+import (
+	"time"
+)
+
 // LookupHost looks up the given host using the local resolver.
 // It returns an array of that host's addresses.
 func LookupHost(host string) (addrs []string, err error) {
 	return lookupHost(host)
 }
 
+func lookupHostDeadline(host string, deadline time.Time) (addrs []string, err error) {
+	if deadline.IsZero() {
+		return lookupHost(host)
+	}
+
+	// TODO(bradfitz): consider pushing the deadline down into the
+	// name resolution functions. But that involves fixing it for
+	// the native Go resolver, cgo, Windows, etc.
+	//
+	// In the meantime, just use a goroutine. Most users affected
+	// by http://golang.org/issue/2631 are due to TCP connections
+	// to unresponsive hosts, not DNS.
+	timeout := deadline.Sub(time.Now())
+	if timeout <= 0 {
+		err = errTimeout
+		return
+	}
+	t := time.NewTimer(timeout)
+	defer t.Stop()
+	type res struct {
+		addrs []string
+		err   error
+	}
+	resc := make(chan res, 1)
+	go func() {
+		a, err := lookupHost(host)
+		resc <- res{a, err}
+	}()
+	select {
+	case <-t.C:
+		err = errTimeout
+	case r := <-resc:
+		addrs, err = r.addrs, r.err
+	}
+	return
+}
+
 // LookupIP looks up host using the local resolver.
 // It returns an array of that host's IPv4 and IPv6 addresses.
 func LookupIP(host string) (addrs []IP, err error) {
@@ -47,6 +88,11 @@ func LookupMX(name string) (mx []*MX, err error) {
 	return lookupMX(name)
 }
 
+// LookupNS returns the DNS NS records for the given domain name.
+func LookupNS(name string) (ns []*NS, err error) {
+	return lookupNS(name)
+}
+
 // LookupTXT returns the DNS TXT records for the given domain name.
 func LookupTXT(name string) (txt []string, err error) {
 	return lookupTXT(name)