Initial commit

1 files changed, 30 insertions, 0 deletions

diff --git a/dhcpv6/iputils.go b/dhcpv6/iputils.go
new file mode 100644
index 0000000..c3ac3aa
--- /dev/null
+++ b/dhcpv6/iputils.go
@@ -0,0 +1,30 @@
+package dhcpv6
+
+import (
+	"fmt"
+	"net"
+)
+
+func GetLinkLocalAddr(ifname string) (*net.IP, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+	for _, iface := range ifaces {
+		if iface.Name != ifname {
+			continue
+		}
+		ifaddrs, err := iface.Addrs()
+		if err != nil {
+			return nil, err
+		}
+		for _, ifaddr := range ifaddrs {
+			if ifaddr, ok := ifaddr.(*net.IPNet); ok {
+				if ifaddr.IP.To4() == nil && ifaddr.IP.IsLinkLocalUnicast() {
+					return &ifaddr.IP, nil
+				}
+			}
+		}
+	}
+	return nil, fmt.Errorf("No link-local address found for interface %v", ifname)
+}