[netboot] use rtnl package

After adding the higher-level [rtnl package](https://github.com/jsimonetti/rtnetlink/pull/44)
let's switch to it.

Pending https://github.com/jsimonetti/rtnetlink/pull/50

Signed-off-by: Andrea Barberio <insomniac@slackware.it>

1 files changed, 4 insertions, 150 deletions

diff --git a/netboot/rtnetlink_linux.go b/netboot/rtnetlink_linux.go
index 949f7e5..41f5b3e 100644
--- a/netboot/rtnetlink_linux.go
+++ b/netboot/rtnetlink_linux.go
@@ -1,162 +1,16 @@
 package netboot
 
-import (
-	"encoding/binary"
-	"net"
+import "github.com/jsimonetti/rtnetlink"
 
-	"github.com/jsimonetti/rtnetlink"
-	"golang.org/x/sys/unix"
-)
-
-// RTNL is a rtnetlink object with a high-level interface.
-type RTNL struct {
-	conn *rtnetlink.Conn
-}
-
-func (r *RTNL) init() error {
-	if r.conn != nil {
-		return nil
-	}
+// getOperState returns the operational state for the given interface index.
+func getOperState(iface int) (rtnetlink.OperationalState, error) {
 	conn, err := rtnetlink.Dial(nil)
 	if err != nil {
-		return err
-	}
-	r.conn = conn
-	return nil
-}
-
-// Close closes the netlink connection. Must be called to avoid leaks!
-func (r *RTNL) Close() {
-	if r.conn != nil {
-		r.conn.Close()
-		r.conn = nil
-	}
-}
-
-// GetLinkState returns the operational state for the given interface index.
-func (r *RTNL) GetLinkState(iface int) (rtnetlink.OperationalState, error) {
-	if err := r.init(); err != nil {
 		return 0, err
 	}
-	msg, err := r.conn.Link.Get(uint32(iface))
+	msg, err := conn.Link.Get(uint32(iface))
 	if err != nil {
 		return 0, err
 	}
 	return msg.Attributes.OperationalState, nil
 }
-
-// SetLinkState sets the operational state up or down for the given interface
-// index.
-func (r *RTNL) SetLinkState(iface int, up bool) error {
-	if err := r.init(); err != nil {
-		return err
-	}
-	var state uint32
-	if up {
-		state = unix.IFF_UP
-	}
-	msg := rtnetlink.LinkMessage{
-		Family: unix.AF_UNSPEC,
-		Type:   unix.ARPHRD_NETROM,
-		Index:  uint32(iface),
-		Flags:  state,
-		Change: unix.IFF_UP,
-	}
-	if err := r.conn.Link.Set(&msg); err != nil {
-		return err
-	}
-	return nil
-}
-
-func getFamily(ip net.IP) int {
-	if ip.To4() != nil {
-		return unix.AF_INET
-	}
-	return unix.AF_INET6
-}
-
-// SetAddr sets the interface address.
-func (r *RTNL) SetAddr(iface int, a net.IPNet) error {
-	if err := r.init(); err != nil {
-		return err
-	}
-	ones, _ := a.Mask.Size()
-	msg := rtnetlink.AddressMessage{
-		Family:       uint8(getFamily(a.IP)),
-		PrefixLength: uint8(ones),
-		// TODO detect the right scope to set, or get it as input argument
-		Scope: unix.RT_SCOPE_UNIVERSE,
-		Index: uint32(iface),
-		Attributes: rtnetlink.AddressAttributes{
-			Address: a.IP,
-			Local:   a.IP,
-		},
-	}
-	if a.IP.To4() != nil {
-		// Broadcast is only required for IPv4
-		ip := make(net.IP, net.IPv4len)
-		binary.BigEndian.PutUint32(
-			ip,
-			binary.BigEndian.Uint32(a.IP.To4())|
-				^binary.BigEndian.Uint32(net.IP(a.Mask).To4()))
-		msg.Attributes.Broadcast = ip
-	}
-	if err := r.conn.Address.New(&msg); err != nil {
-		return err
-	}
-	return nil
-}
-
-// RouteDel deletes a route to the given destination
-func (r *RTNL) RouteDel(dst net.IP) error {
-	if err := r.init(); err != nil {
-		return err
-	}
-	msg := rtnetlink.RouteMessage{
-		Family: uint8(getFamily(dst)),
-		Table:  unix.RT_TABLE_MAIN,
-		// TODO make this configurable?
-		Protocol: unix.RTPROT_UNSPEC,
-		// TODO make this configurable?
-		Scope: unix.RT_SCOPE_NOWHERE,
-		Type:  unix.RTN_UNSPEC,
-		Attributes: rtnetlink.RouteAttributes{
-			Dst: dst,
-		},
-	}
-	if err := r.conn.Route.Delete(&msg); err != nil {
-		return err
-	}
-	return nil
-}
-
-// RouteAdd adds a route to dst, from src (if set), via gw.
-func (r *RTNL) RouteAdd(iface int, dst, src net.IPNet, gw net.IP) error {
-	if err := r.init(); err != nil {
-		return err
-	}
-	dstLen, _ := dst.Mask.Size()
-	srcLen, _ := src.Mask.Size()
-	msg := rtnetlink.RouteMessage{
-		Family: uint8(getFamily(dst.IP)),
-		Table:  unix.RT_TABLE_MAIN,
-		// TODO make this configurable?
-		Protocol: unix.RTPROT_BOOT,
-		// TODO make this configurable?
-		Scope:     unix.RT_SCOPE_UNIVERSE,
-		Type:      unix.RTN_UNICAST,
-		DstLength: uint8(dstLen),
-		SrcLength: uint8(srcLen),
-		Attributes: rtnetlink.RouteAttributes{
-			Dst:      dst.IP,
-			Src:      src.IP,
-			Gateway:  gw,
-			OutIface: uint32(iface),
-		},
-	}
-	if err := r.conn.Route.Add(&msg); err != nil {
-		return err
-	}
-	return nil
-
-}