Fix error handling and cleanup of netlink listener

diff --git a/tun_linux.go b/tun_linux.go
index 1abc86fd884335536dcd0a3f646fcf845022f2fc..0672b5e2227a51f7f2a0ea961245ba88a22a6c95 100644 (file)
--- a/tun_linux.go
+++ b/tun_linux.go
@@ -36,31 +36,15 @@ type NativeTun struct {
        closingWriter *os.File
 }
 
-func toRTMGRP(sc uint) uint {
-       return 1 << (sc - 1)
-}
-
-func (tun *NativeTun) bindRTMGRP() (int, error) {
-       groups := toRTMGRP(unix.RTNLGRP_LINK)
-       groups |= toRTMGRP(unix.RTNLGRP_IPV4_IFADDR)
-       groups |= toRTMGRP(unix.RTNLGRP_IPV6_IFADDR)
-       sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE)
-       if err != nil {
-               return 0, err
-       }
-       saddr := &unix.SockaddrNetlink{
-               Family: unix.AF_NETLINK,
-               Pid:    uint32(os.Getpid()),
-               Groups: uint32(groups),
-       }
-       return sock, unix.Bind(sock, saddr)
-}
-
 func (tun *NativeTun) File() *os.File {
        return tun.fd
 }
 
 func (tun *NativeTun) RoutineHackListener() {
+       // TODO: This function never actually exits in response to anything,
+       // a go routine that goes forever. We'll want to fix that if this is
+       // to ever be used as any sort of library.
+
        /* This is needed for the detection to work across network namespaces
         * If you are reading this and know a better method, please get in touch.
         */
@@ -78,12 +62,35 @@ func (tun *NativeTun) RoutineHackListener() {
        }
 }
 
+func toRTMGRP(sc uint) uint {
+       return 1 << (sc - 1)
+}
+
 func (tun *NativeTun) RoutineNetlinkListener() {
-       sock, err := tun.bindRTMGRP()
+
+       groups := toRTMGRP(unix.RTNLGRP_LINK)
+       groups |= toRTMGRP(unix.RTNLGRP_IPV4_IFADDR)
+       groups |= toRTMGRP(unix.RTNLGRP_IPV6_IFADDR)
+       sock, err := unix.Socket(unix.AF_NETLINK, unix.SOCK_RAW, unix.NETLINK_ROUTE)
        if err != nil {
-               tun.errors <- errors.New("Failed to create netlink event listener")
+               tun.errors <- errors.New("Failed to create netlink event listener socket")
                return
        }
+       defer unix.Close(sock)
+       saddr := &unix.SockaddrNetlink{
+               Family: unix.AF_NETLINK,
+               Pid:    uint32(os.Getpid()),
+               Groups: uint32(groups),
+       }
+       err = unix.Bind(sock, saddr)
+       if err != nil {
+               tun.errors <- errors.New("Failed to bind netlink event listener socket")
+               return
+       }
+
+       // TODO: This function never actually exits in response to anything,
+       // a go routine that goes forever. We'll want to fix that if this is
+       // to ever be used as any sort of library.
 
        for msg := make([]byte, 1<<16); ; {