net: make IP address selection work correctly on IPv6-only kernel
Update #3610
Update #5267
Update #5707
R=golang-dev, bradfitz, dave, fvbommel
CC=golang-dev
https://golang.org/cl/11958043
diff --git a/src/pkg/net/ipsock_posix.go b/src/pkg/net/ipsock_posix.go
index d1940a4..f0c575a 100644
--- a/src/pkg/net/ipsock_posix.go
+++ b/src/pkg/net/ipsock_posix.go
@@ -13,6 +13,17 @@
"time"
)
+func probeIPv4Stack() bool {
+ s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_TCP)
+ switch err {
+ case syscall.EAFNOSUPPORT, syscall.EPROTONOSUPPORT:
+ return false
+ case nil:
+ closesocket(s)
+ }
+ return true
+}
+
// Should we try to use the IPv4 socket interface if we're
// only dealing with IPv4 sockets? As long as the host system
// understands IPv6, it's okay to pass IPv4 addresses to the IPv6
