// deserializeRoute decodes a binary netlink message into a Route struct
func deserializeRoute(m []byte) (Route, error) {
route := Route{}
msg := nl.DeserializeRtMsg(m)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return route, err
}
route.Scope = Scope(msg.Scope)
native := nl.NativeEndian()
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.RTA_GATEWAY:
route.Gw = net.IP(attr.Value)
case syscall.RTA_PREFSRC:
route.Src = net.IP(attr.Value)
case syscall.RTA_DST:
route.Dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
}
case syscall.RTA_OIF:
routeIndex := int(native.Uint32(attr.Value[0:4]))
route.LinkIndex = routeIndex
}
}
return route, nil
}
// RouteGet gets a route to a specific destination from the host system.
// Equivalent to: 'ip route get'.
func RouteGet(destination net.IP) ([]Route, error) {
req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_REQUEST)
family := nl.GetIPFamily(destination)
var destinationData []byte
var bitlen uint8
if family == FAMILY_V4 {
destinationData = destination.To4()
bitlen = 32
} else {
destinationData = destination.To16()
bitlen = 128
}
msg := &nl.RtMsg{}
msg.Family = uint8(family)
msg.Dst_len = bitlen
req.AddData(msg)
rtaDst := nl.NewRtAttr(syscall.RTA_DST, destinationData)
req.AddData(rtaDst)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
if err != nil {
return nil, err
}
native := nl.NativeEndian()
res := make([]Route, 0)
for _, m := range msgs {
msg := nl.DeserializeRtMsg(m)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
route := Route{}
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.RTA_GATEWAY:
route.Gw = net.IP(attr.Value)
case syscall.RTA_PREFSRC:
route.Src = net.IP(attr.Value)
case syscall.RTA_DST:
route.Dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
}
case syscall.RTA_OIF:
routeIndex := int(native.Uint32(attr.Value[0:4]))
route.LinkIndex = routeIndex
}
}
res = append(res, route)
}
return res, nil
}
func parseU32Data(filter Filter, data []syscall.NetlinkRouteAttr) (bool, error) {
native = nl.NativeEndian()
u32 := filter.(*U32)
detailed := false
for _, datum := range data {
switch datum.Attr.Type {
case nl.TCA_U32_SEL:
detailed = true
sel := nl.DeserializeTcU32Sel(datum.Value)
// only parse if we have a very basic redirect
if sel.Flags&nl.TC_U32_TERMINAL == 0 || sel.Nkeys != 1 {
return detailed, nil
}
case nl.TCA_U32_ACT:
table, err := nl.ParseRouteAttr(datum.Value)
if err != nil {
return detailed, err
}
if len(table) != 1 || table[0].Attr.Type != nl.TCA_ACT_TAB {
return detailed, fmt.Errorf("Action table not formed properly")
}
aattrs, err := nl.ParseRouteAttr(table[0].Value)
for _, aattr := range aattrs {
switch aattr.Attr.Type {
case nl.TCA_KIND:
actionType := string(aattr.Value[:len(aattr.Value)-1])
// only parse if the action is mirred
if actionType != "mirred" {
return detailed, nil
}
case nl.TCA_OPTIONS:
adata, err := nl.ParseRouteAttr(aattr.Value)
if err != nil {
return detailed, err
}
for _, adatum := range adata {
switch adatum.Attr.Type {
case nl.TCA_MIRRED_PARMS:
mir := nl.DeserializeTcMirred(adatum.Value)
u32.RedirIndex = int(mir.Ifindex)
}
}
}
}
}
}
return detailed, nil
}
func parseTbfData(qdisc Qdisc, data []syscall.NetlinkRouteAttr) error {
native = nl.NativeEndian()
tbf := qdisc.(*Tbf)
for _, datum := range data {
switch datum.Attr.Type {
case nl.TCA_TBF_PARMS:
opt := nl.DeserializeTcTbfQopt(datum.Value)
tbf.Rate = uint64(opt.Rate.Rate)
tbf.Limit = opt.Limit
tbf.Buffer = opt.Buffer
case nl.TCA_TBF_RATE64:
tbf.Rate = native.Uint64(datum.Value[0:4])
}
}
return nil
}
func parseHtbData(qdisc Qdisc, data []syscall.NetlinkRouteAttr) error {
native = nl.NativeEndian()
htb := qdisc.(*Htb)
for _, datum := range data {
switch datum.Attr.Type {
case nl.TCA_HTB_INIT:
opt := nl.DeserializeTcHtbGlob(datum.Value)
htb.Version = opt.Version
htb.Rate2Quantum = opt.Rate2Quantum
htb.Defcls = opt.Defcls
htb.Debug = opt.Debug
htb.DirectPkts = opt.DirectPkts
case nl.TCA_HTB_DIRECT_QLEN:
// TODO
//htb.DirectQlen = native.uint32(datum.Value)
}
}
return nil
}
package netlink
import (
"bytes"
"encoding/binary"
"fmt"
"net"
"syscall"
"github.com/coreos/rkt/Godeps/_workspace/src/github.com/vishvananda/netlink/nl"
)
var native = nl.NativeEndian()
var lookupByDump = false
var macvlanModes = [...]uint32{
0,
nl.MACVLAN_MODE_PRIVATE,
nl.MACVLAN_MODE_VEPA,
nl.MACVLAN_MODE_BRIDGE,
nl.MACVLAN_MODE_PASSTHRU,
nl.MACVLAN_MODE_SOURCE,
}
func ensureIndex(link *LinkAttrs) {
if link != nil && link.Index == 0 {
newlink, _ := LinkByName(link.Name)
if newlink != nil {
link.Index = newlink.Attrs().Index
}
}
func routeHandle(route *Route, req *nl.NetlinkRequest) error {
if (route.Dst == nil || route.Dst.IP == nil) && route.Src == nil && route.Gw == nil {
return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
}
msg := nl.NewRtMsg()
msg.Scope = uint8(route.Scope)
family := -1
var rtAttrs []*nl.RtAttr
if route.Dst != nil && route.Dst.IP != nil {
dstLen, _ := route.Dst.Mask.Size()
msg.Dst_len = uint8(dstLen)
dstFamily := nl.GetIPFamily(route.Dst.IP)
family = dstFamily
var dstData []byte
if dstFamily == FAMILY_V4 {
dstData = route.Dst.IP.To4()
} else {
dstData = route.Dst.IP.To16()
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
}
if route.Src != nil {
srcFamily := nl.GetIPFamily(route.Src)
if family != -1 && family != srcFamily {
return fmt.Errorf("source and destination ip are not the same IP family")
}
family = srcFamily
var srcData []byte
if srcFamily == FAMILY_V4 {
srcData = route.Src.To4()
} else {
srcData = route.Src.To16()
}
// The commonly used src ip for routes is actually PREFSRC
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_PREFSRC, srcData))
}
if route.Gw != nil {
gwFamily := nl.GetIPFamily(route.Gw)
if family != -1 && family != gwFamily {
return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
}
family = gwFamily
var gwData []byte
if gwFamily == FAMILY_V4 {
gwData = route.Gw.To4()
} else {
gwData = route.Gw.To16()
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_GATEWAY, gwData))
}
msg.Family = uint8(family)
req.AddData(msg)
for _, attr := range rtAttrs {
req.AddData(attr)
}
var (
b = make([]byte, 4)
native = nl.NativeEndian()
)
native.PutUint32(b, uint32(route.LinkIndex))
req.AddData(nl.NewRtAttr(syscall.RTA_OIF, b))
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}
// RouteList gets a list of routes in the system.
// Equivalent to: `ip route show`.
// The list can be filtered by link and ip family.
func RouteList(link Link, family int) ([]Route, error) {
req := nl.NewNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_DUMP)
msg := nl.NewIfInfomsg(family)
req.AddData(msg)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
if err != nil {
return nil, err
}
index := 0
if link != nil {
base := link.Attrs()
ensureIndex(base)
index = base.Index
}
native := nl.NativeEndian()
res := make([]Route, 0)
for _, m := range msgs {
msg := nl.DeserializeRtMsg(m)
if msg.Flags&syscall.RTM_F_CLONED != 0 {
// Ignore cloned routes
continue
}
if msg.Table != syscall.RT_TABLE_MAIN {
// Ignore non-main tables
continue
}
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
route := Route{Scope: Scope(msg.Scope)}
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.RTA_GATEWAY:
route.Gw = net.IP(attr.Value)
case syscall.RTA_PREFSRC:
route.Src = net.IP(attr.Value)
case syscall.RTA_DST:
route.Dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
}
case syscall.RTA_OIF:
routeIndex := int(native.Uint32(attr.Value[0:4]))
if link != nil && routeIndex != index {
// Ignore routes from other interfaces
continue
}
route.LinkIndex = routeIndex
}
}
res = append(res, route)
}
return res, nil
}