kilo/vendor/github.com/vishvananda/netlink/route_linux.go

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2019-01-18 01:50:10 +00:00
package netlink
import (
"fmt"
"net"
"strings"
"syscall"
"github.com/vishvananda/netlink/nl"
"github.com/vishvananda/netns"
"golang.org/x/sys/unix"
)
// RtAttr is shared so it is in netlink_linux.go
const (
SCOPE_UNIVERSE Scope = unix.RT_SCOPE_UNIVERSE
SCOPE_SITE Scope = unix.RT_SCOPE_SITE
SCOPE_LINK Scope = unix.RT_SCOPE_LINK
SCOPE_HOST Scope = unix.RT_SCOPE_HOST
SCOPE_NOWHERE Scope = unix.RT_SCOPE_NOWHERE
)
const (
RT_FILTER_PROTOCOL uint64 = 1 << (1 + iota)
RT_FILTER_SCOPE
RT_FILTER_TYPE
RT_FILTER_TOS
RT_FILTER_IIF
RT_FILTER_OIF
RT_FILTER_DST
RT_FILTER_SRC
RT_FILTER_GW
RT_FILTER_TABLE
)
const (
FLAG_ONLINK NextHopFlag = unix.RTNH_F_ONLINK
FLAG_PERVASIVE NextHopFlag = unix.RTNH_F_PERVASIVE
)
var testFlags = []flagString{
{f: FLAG_ONLINK, s: "onlink"},
{f: FLAG_PERVASIVE, s: "pervasive"},
}
func listFlags(flag int) []string {
var flags []string
for _, tf := range testFlags {
if flag&int(tf.f) != 0 {
flags = append(flags, tf.s)
}
}
return flags
}
func (r *Route) ListFlags() []string {
return listFlags(r.Flags)
}
func (n *NexthopInfo) ListFlags() []string {
return listFlags(n.Flags)
}
type MPLSDestination struct {
Labels []int
}
func (d *MPLSDestination) Family() int {
return nl.FAMILY_MPLS
}
func (d *MPLSDestination) Decode(buf []byte) error {
d.Labels = nl.DecodeMPLSStack(buf)
return nil
}
func (d *MPLSDestination) Encode() ([]byte, error) {
return nl.EncodeMPLSStack(d.Labels...), nil
}
func (d *MPLSDestination) String() string {
s := make([]string, 0, len(d.Labels))
for _, l := range d.Labels {
s = append(s, fmt.Sprintf("%d", l))
}
return strings.Join(s, "/")
}
func (d *MPLSDestination) Equal(x Destination) bool {
o, ok := x.(*MPLSDestination)
if !ok {
return false
}
if d == nil && o == nil {
return true
}
if d == nil || o == nil {
return false
}
if d.Labels == nil && o.Labels == nil {
return true
}
if d.Labels == nil || o.Labels == nil {
return false
}
if len(d.Labels) != len(o.Labels) {
return false
}
for i := range d.Labels {
if d.Labels[i] != o.Labels[i] {
return false
}
}
return true
}
type MPLSEncap struct {
Labels []int
}
func (e *MPLSEncap) Type() int {
return nl.LWTUNNEL_ENCAP_MPLS
}
func (e *MPLSEncap) Decode(buf []byte) error {
if len(buf) < 4 {
return fmt.Errorf("lack of bytes")
}
native := nl.NativeEndian()
l := native.Uint16(buf)
if len(buf) < int(l) {
return fmt.Errorf("lack of bytes")
}
buf = buf[:l]
typ := native.Uint16(buf[2:])
if typ != nl.MPLS_IPTUNNEL_DST {
return fmt.Errorf("unknown MPLS Encap Type: %d", typ)
}
e.Labels = nl.DecodeMPLSStack(buf[4:])
return nil
}
func (e *MPLSEncap) Encode() ([]byte, error) {
s := nl.EncodeMPLSStack(e.Labels...)
native := nl.NativeEndian()
hdr := make([]byte, 4)
native.PutUint16(hdr, uint16(len(s)+4))
native.PutUint16(hdr[2:], nl.MPLS_IPTUNNEL_DST)
return append(hdr, s...), nil
}
func (e *MPLSEncap) String() string {
s := make([]string, 0, len(e.Labels))
for _, l := range e.Labels {
s = append(s, fmt.Sprintf("%d", l))
}
return strings.Join(s, "/")
}
func (e *MPLSEncap) Equal(x Encap) bool {
o, ok := x.(*MPLSEncap)
if !ok {
return false
}
if e == nil && o == nil {
return true
}
if e == nil || o == nil {
return false
}
if e.Labels == nil && o.Labels == nil {
return true
}
if e.Labels == nil || o.Labels == nil {
return false
}
if len(e.Labels) != len(o.Labels) {
return false
}
for i := range e.Labels {
if e.Labels[i] != o.Labels[i] {
return false
}
}
return true
}
// SEG6 definitions
type SEG6Encap struct {
Mode int
Segments []net.IP
}
func (e *SEG6Encap) Type() int {
return nl.LWTUNNEL_ENCAP_SEG6
}
func (e *SEG6Encap) Decode(buf []byte) error {
if len(buf) < 4 {
return fmt.Errorf("lack of bytes")
}
native := nl.NativeEndian()
// Get Length(l) & Type(typ) : 2 + 2 bytes
l := native.Uint16(buf)
if len(buf) < int(l) {
return fmt.Errorf("lack of bytes")
}
buf = buf[:l] // make sure buf size upper limit is Length
typ := native.Uint16(buf[2:])
if typ != nl.SEG6_IPTUNNEL_SRH {
return fmt.Errorf("unknown SEG6 Type: %d", typ)
}
var err error
e.Mode, e.Segments, err = nl.DecodeSEG6Encap(buf[4:])
return err
}
func (e *SEG6Encap) Encode() ([]byte, error) {
s, err := nl.EncodeSEG6Encap(e.Mode, e.Segments)
native := nl.NativeEndian()
hdr := make([]byte, 4)
native.PutUint16(hdr, uint16(len(s)+4))
native.PutUint16(hdr[2:], nl.SEG6_IPTUNNEL_SRH)
return append(hdr, s...), err
}
func (e *SEG6Encap) String() string {
segs := make([]string, 0, len(e.Segments))
// append segment backwards (from n to 0) since seg#0 is the last segment.
for i := len(e.Segments); i > 0; i-- {
segs = append(segs, fmt.Sprintf("%s", e.Segments[i-1]))
}
str := fmt.Sprintf("mode %s segs %d [ %s ]", nl.SEG6EncapModeString(e.Mode),
len(e.Segments), strings.Join(segs, " "))
return str
}
func (e *SEG6Encap) Equal(x Encap) bool {
o, ok := x.(*SEG6Encap)
if !ok {
return false
}
if e == o {
return true
}
if e == nil || o == nil {
return false
}
if e.Mode != o.Mode {
return false
}
if len(e.Segments) != len(o.Segments) {
return false
}
for i := range e.Segments {
if !e.Segments[i].Equal(o.Segments[i]) {
return false
}
}
return true
}
// RouteAdd will add a route to the system.
// Equivalent to: `ip route add $route`
func RouteAdd(route *Route) error {
return pkgHandle.RouteAdd(route)
}
// RouteAdd will add a route to the system.
// Equivalent to: `ip route add $route`
func (h *Handle) RouteAdd(route *Route) error {
flags := unix.NLM_F_CREATE | unix.NLM_F_EXCL | unix.NLM_F_ACK
req := h.newNetlinkRequest(unix.RTM_NEWROUTE, flags)
return h.routeHandle(route, req, nl.NewRtMsg())
}
// RouteReplace will add a route to the system.
// Equivalent to: `ip route replace $route`
func RouteReplace(route *Route) error {
return pkgHandle.RouteReplace(route)
}
// RouteReplace will add a route to the system.
// Equivalent to: `ip route replace $route`
func (h *Handle) RouteReplace(route *Route) error {
flags := unix.NLM_F_CREATE | unix.NLM_F_REPLACE | unix.NLM_F_ACK
req := h.newNetlinkRequest(unix.RTM_NEWROUTE, flags)
return h.routeHandle(route, req, nl.NewRtMsg())
}
// RouteDel will delete a route from the system.
// Equivalent to: `ip route del $route`
func RouteDel(route *Route) error {
return pkgHandle.RouteDel(route)
}
// RouteDel will delete a route from the system.
// Equivalent to: `ip route del $route`
func (h *Handle) RouteDel(route *Route) error {
req := h.newNetlinkRequest(unix.RTM_DELROUTE, unix.NLM_F_ACK)
return h.routeHandle(route, req, nl.NewRtDelMsg())
}
func (h *Handle) routeHandle(route *Route, req *nl.NetlinkRequest, msg *nl.RtMsg) error {
if (route.Dst == nil || route.Dst.IP == nil) && route.Src == nil && route.Gw == nil && route.MPLSDst == nil {
return fmt.Errorf("one of Dst.IP, Src, or Gw must not be nil")
}
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(unix.RTA_DST, dstData))
} else if route.MPLSDst != nil {
family = nl.FAMILY_MPLS
msg.Dst_len = uint8(20)
msg.Type = unix.RTN_UNICAST
rtAttrs = append(rtAttrs, nl.NewRtAttr(unix.RTA_DST, nl.EncodeMPLSStack(*route.MPLSDst)))
}
if route.NewDst != nil {
if family != -1 && family != route.NewDst.Family() {
return fmt.Errorf("new destination and destination are not the same address family")
}
buf, err := route.NewDst.Encode()
if err != nil {
return err
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(nl.RTA_NEWDST, buf))
}
if route.Encap != nil {
buf := make([]byte, 2)
native.PutUint16(buf, uint16(route.Encap.Type()))
rtAttrs = append(rtAttrs, nl.NewRtAttr(nl.RTA_ENCAP_TYPE, buf))
buf, err := route.Encap.Encode()
if err != nil {
return err
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(nl.RTA_ENCAP, buf))
}
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(unix.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(unix.RTA_GATEWAY, gwData))
}
if len(route.MultiPath) > 0 {
buf := []byte{}
for _, nh := range route.MultiPath {
rtnh := &nl.RtNexthop{
RtNexthop: unix.RtNexthop{
Hops: uint8(nh.Hops),
Ifindex: int32(nh.LinkIndex),
Flags: uint8(nh.Flags),
},
}
children := []nl.NetlinkRequestData{}
if nh.Gw != nil {
gwFamily := nl.GetIPFamily(nh.Gw)
if family != -1 && family != gwFamily {
return fmt.Errorf("gateway, source, and destination ip are not the same IP family")
}
if gwFamily == FAMILY_V4 {
children = append(children, nl.NewRtAttr(unix.RTA_GATEWAY, []byte(nh.Gw.To4())))
} else {
children = append(children, nl.NewRtAttr(unix.RTA_GATEWAY, []byte(nh.Gw.To16())))
}
}
if nh.NewDst != nil {
if family != -1 && family != nh.NewDst.Family() {
return fmt.Errorf("new destination and destination are not the same address family")
}
buf, err := nh.NewDst.Encode()
if err != nil {
return err
}
children = append(children, nl.NewRtAttr(nl.RTA_NEWDST, buf))
}
if nh.Encap != nil {
buf := make([]byte, 2)
native.PutUint16(buf, uint16(nh.Encap.Type()))
rtAttrs = append(rtAttrs, nl.NewRtAttr(nl.RTA_ENCAP_TYPE, buf))
buf, err := nh.Encap.Encode()
if err != nil {
return err
}
children = append(children, nl.NewRtAttr(nl.RTA_ENCAP, buf))
}
rtnh.Children = children
buf = append(buf, rtnh.Serialize()...)
}
rtAttrs = append(rtAttrs, nl.NewRtAttr(unix.RTA_MULTIPATH, buf))
}
if route.Table > 0 {
if route.Table >= 256 {
msg.Table = unix.RT_TABLE_UNSPEC
b := make([]byte, 4)
native.PutUint32(b, uint32(route.Table))
rtAttrs = append(rtAttrs, nl.NewRtAttr(unix.RTA_TABLE, b))
} else {
msg.Table = uint8(route.Table)
}
}
if route.Priority > 0 {
b := make([]byte, 4)
native.PutUint32(b, uint32(route.Priority))
rtAttrs = append(rtAttrs, nl.NewRtAttr(unix.RTA_PRIORITY, b))
}
if route.Tos > 0 {
msg.Tos = uint8(route.Tos)
}
if route.Protocol > 0 {
msg.Protocol = uint8(route.Protocol)
}
if route.Type > 0 {
msg.Type = uint8(route.Type)
}
var metrics []*nl.RtAttr
// TODO: support other rta_metric values
if route.MTU > 0 {
b := nl.Uint32Attr(uint32(route.MTU))
metrics = append(metrics, nl.NewRtAttr(unix.RTAX_MTU, b))
}
if route.AdvMSS > 0 {
b := nl.Uint32Attr(uint32(route.AdvMSS))
metrics = append(metrics, nl.NewRtAttr(unix.RTAX_ADVMSS, b))
}
if metrics != nil {
attr := nl.NewRtAttr(unix.RTA_METRICS, nil)
for _, metric := range metrics {
attr.AddChild(metric)
}
rtAttrs = append(rtAttrs, attr)
}
msg.Flags = uint32(route.Flags)
msg.Scope = uint8(route.Scope)
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(unix.RTA_OIF, b))
_, err := req.Execute(unix.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) {
return pkgHandle.RouteList(link, family)
}
// 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 (h *Handle) RouteList(link Link, family int) ([]Route, error) {
var routeFilter *Route
if link != nil {
routeFilter = &Route{
LinkIndex: link.Attrs().Index,
}
}
return h.RouteListFiltered(family, routeFilter, RT_FILTER_OIF)
}
// RouteListFiltered gets a list of routes in the system filtered with specified rules.
// All rules must be defined in RouteFilter struct
func RouteListFiltered(family int, filter *Route, filterMask uint64) ([]Route, error) {
return pkgHandle.RouteListFiltered(family, filter, filterMask)
}
// RouteListFiltered gets a list of routes in the system filtered with specified rules.
// All rules must be defined in RouteFilter struct
func (h *Handle) RouteListFiltered(family int, filter *Route, filterMask uint64) ([]Route, error) {
req := h.newNetlinkRequest(unix.RTM_GETROUTE, unix.NLM_F_DUMP)
infmsg := nl.NewIfInfomsg(family)
req.AddData(infmsg)
msgs, err := req.Execute(unix.NETLINK_ROUTE, unix.RTM_NEWROUTE)
if err != nil {
return nil, err
}
var res []Route
for _, m := range msgs {
msg := nl.DeserializeRtMsg(m)
if msg.Flags&unix.RTM_F_CLONED != 0 {
// Ignore cloned routes
continue
}
if msg.Table != unix.RT_TABLE_MAIN {
if filter == nil || filter != nil && filterMask&RT_FILTER_TABLE == 0 {
// Ignore non-main tables
continue
}
}
route, err := deserializeRoute(m)
if err != nil {
return nil, err
}
if filter != nil {
switch {
case filterMask&RT_FILTER_TABLE != 0 && filter.Table != unix.RT_TABLE_UNSPEC && route.Table != filter.Table:
continue
case filterMask&RT_FILTER_PROTOCOL != 0 && route.Protocol != filter.Protocol:
continue
case filterMask&RT_FILTER_SCOPE != 0 && route.Scope != filter.Scope:
continue
case filterMask&RT_FILTER_TYPE != 0 && route.Type != filter.Type:
continue
case filterMask&RT_FILTER_TOS != 0 && route.Tos != filter.Tos:
continue
case filterMask&RT_FILTER_OIF != 0 && route.LinkIndex != filter.LinkIndex:
continue
case filterMask&RT_FILTER_IIF != 0 && route.ILinkIndex != filter.ILinkIndex:
continue
case filterMask&RT_FILTER_GW != 0 && !route.Gw.Equal(filter.Gw):
continue
case filterMask&RT_FILTER_SRC != 0 && !route.Src.Equal(filter.Src):
continue
case filterMask&RT_FILTER_DST != 0:
if filter.MPLSDst == nil || route.MPLSDst == nil || (*filter.MPLSDst) != (*route.MPLSDst) {
if !ipNetEqual(route.Dst, filter.Dst) {
continue
}
}
}
}
res = append(res, route)
}
return res, nil
}
// deserializeRoute decodes a binary netlink message into a Route struct
func deserializeRoute(m []byte) (Route, error) {
msg := nl.DeserializeRtMsg(m)
attrs, err := nl.ParseRouteAttr(m[msg.Len():])
if err != nil {
return Route{}, err
}
route := Route{
Scope: Scope(msg.Scope),
Protocol: int(msg.Protocol),
Table: int(msg.Table),
Type: int(msg.Type),
Tos: int(msg.Tos),
Flags: int(msg.Flags),
}
native := nl.NativeEndian()
var encap, encapType syscall.NetlinkRouteAttr
for _, attr := range attrs {
switch attr.Attr.Type {
case unix.RTA_GATEWAY:
route.Gw = net.IP(attr.Value)
case unix.RTA_PREFSRC:
route.Src = net.IP(attr.Value)
case unix.RTA_DST:
if msg.Family == nl.FAMILY_MPLS {
stack := nl.DecodeMPLSStack(attr.Value)
if len(stack) == 0 || len(stack) > 1 {
return route, fmt.Errorf("invalid MPLS RTA_DST")
}
route.MPLSDst = &stack[0]
} else {
route.Dst = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attr.Value)),
}
}
case unix.RTA_OIF:
route.LinkIndex = int(native.Uint32(attr.Value[0:4]))
case unix.RTA_IIF:
route.ILinkIndex = int(native.Uint32(attr.Value[0:4]))
case unix.RTA_PRIORITY:
route.Priority = int(native.Uint32(attr.Value[0:4]))
case unix.RTA_TABLE:
route.Table = int(native.Uint32(attr.Value[0:4]))
case unix.RTA_MULTIPATH:
parseRtNexthop := func(value []byte) (*NexthopInfo, []byte, error) {
if len(value) < unix.SizeofRtNexthop {
return nil, nil, fmt.Errorf("lack of bytes")
}
nh := nl.DeserializeRtNexthop(value)
if len(value) < int(nh.RtNexthop.Len) {
return nil, nil, fmt.Errorf("lack of bytes")
}
info := &NexthopInfo{
LinkIndex: int(nh.RtNexthop.Ifindex),
Hops: int(nh.RtNexthop.Hops),
Flags: int(nh.RtNexthop.Flags),
}
attrs, err := nl.ParseRouteAttr(value[unix.SizeofRtNexthop:int(nh.RtNexthop.Len)])
if err != nil {
return nil, nil, err
}
var encap, encapType syscall.NetlinkRouteAttr
for _, attr := range attrs {
switch attr.Attr.Type {
case unix.RTA_GATEWAY:
info.Gw = net.IP(attr.Value)
case nl.RTA_NEWDST:
var d Destination
switch msg.Family {
case nl.FAMILY_MPLS:
d = &MPLSDestination{}
}
if err := d.Decode(attr.Value); err != nil {
return nil, nil, err
}
info.NewDst = d
case nl.RTA_ENCAP_TYPE:
encapType = attr
case nl.RTA_ENCAP:
encap = attr
}
}
if len(encap.Value) != 0 && len(encapType.Value) != 0 {
typ := int(native.Uint16(encapType.Value[0:2]))
var e Encap
switch typ {
case nl.LWTUNNEL_ENCAP_MPLS:
e = &MPLSEncap{}
if err := e.Decode(encap.Value); err != nil {
return nil, nil, err
}
}
info.Encap = e
}
return info, value[int(nh.RtNexthop.Len):], nil
}
rest := attr.Value
for len(rest) > 0 {
info, buf, err := parseRtNexthop(rest)
if err != nil {
return route, err
}
route.MultiPath = append(route.MultiPath, info)
rest = buf
}
case nl.RTA_NEWDST:
var d Destination
switch msg.Family {
case nl.FAMILY_MPLS:
d = &MPLSDestination{}
}
if err := d.Decode(attr.Value); err != nil {
return route, err
}
route.NewDst = d
case nl.RTA_ENCAP_TYPE:
encapType = attr
case nl.RTA_ENCAP:
encap = attr
case unix.RTA_METRICS:
metrics, err := nl.ParseRouteAttr(attr.Value)
if err != nil {
return route, err
}
for _, metric := range metrics {
switch metric.Attr.Type {
case unix.RTAX_MTU:
route.MTU = int(native.Uint32(metric.Value[0:4]))
case unix.RTAX_ADVMSS:
route.AdvMSS = int(native.Uint32(metric.Value[0:4]))
}
}
}
}
if len(encap.Value) != 0 && len(encapType.Value) != 0 {
typ := int(native.Uint16(encapType.Value[0:2]))
var e Encap
switch typ {
case nl.LWTUNNEL_ENCAP_MPLS:
e = &MPLSEncap{}
if err := e.Decode(encap.Value); err != nil {
return route, err
}
case nl.LWTUNNEL_ENCAP_SEG6:
e = &SEG6Encap{}
if err := e.Decode(encap.Value); err != nil {
return route, err
}
}
route.Encap = e
}
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) {
return pkgHandle.RouteGet(destination)
}
// RouteGet gets a route to a specific destination from the host system.
// Equivalent to: 'ip route get'.
func (h *Handle) RouteGet(destination net.IP) ([]Route, error) {
req := h.newNetlinkRequest(unix.RTM_GETROUTE, unix.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(unix.RTA_DST, destinationData)
req.AddData(rtaDst)
msgs, err := req.Execute(unix.NETLINK_ROUTE, unix.RTM_NEWROUTE)
if err != nil {
return nil, err
}
var res []Route
for _, m := range msgs {
route, err := deserializeRoute(m)
if err != nil {
return nil, err
}
res = append(res, route)
}
return res, nil
}
// RouteSubscribe takes a chan down which notifications will be sent
// when routes are added or deleted. Close the 'done' chan to stop subscription.
func RouteSubscribe(ch chan<- RouteUpdate, done <-chan struct{}) error {
return routeSubscribeAt(netns.None(), netns.None(), ch, done, nil, false)
}
// RouteSubscribeAt works like RouteSubscribe plus it allows the caller
// to choose the network namespace in which to subscribe (ns).
func RouteSubscribeAt(ns netns.NsHandle, ch chan<- RouteUpdate, done <-chan struct{}) error {
return routeSubscribeAt(ns, netns.None(), ch, done, nil, false)
}
// RouteSubscribeOptions contains a set of options to use with
// RouteSubscribeWithOptions.
type RouteSubscribeOptions struct {
Namespace *netns.NsHandle
ErrorCallback func(error)
ListExisting bool
}
// RouteSubscribeWithOptions work like RouteSubscribe but enable to
// provide additional options to modify the behavior. Currently, the
// namespace can be provided as well as an error callback.
func RouteSubscribeWithOptions(ch chan<- RouteUpdate, done <-chan struct{}, options RouteSubscribeOptions) error {
if options.Namespace == nil {
none := netns.None()
options.Namespace = &none
}
return routeSubscribeAt(*options.Namespace, netns.None(), ch, done, options.ErrorCallback, options.ListExisting)
}
func routeSubscribeAt(newNs, curNs netns.NsHandle, ch chan<- RouteUpdate, done <-chan struct{}, cberr func(error), listExisting bool) error {
s, err := nl.SubscribeAt(newNs, curNs, unix.NETLINK_ROUTE, unix.RTNLGRP_IPV4_ROUTE, unix.RTNLGRP_IPV6_ROUTE)
if err != nil {
return err
}
if done != nil {
go func() {
<-done
s.Close()
}()
}
if listExisting {
req := pkgHandle.newNetlinkRequest(unix.RTM_GETROUTE,
unix.NLM_F_DUMP)
infmsg := nl.NewIfInfomsg(unix.AF_UNSPEC)
req.AddData(infmsg)
if err := s.Send(req); err != nil {
return err
}
}
go func() {
defer close(ch)
for {
msgs, err := s.Receive()
if err != nil {
if cberr != nil {
cberr(err)
}
return
}
for _, m := range msgs {
if m.Header.Type == unix.NLMSG_DONE {
continue
}
if m.Header.Type == unix.NLMSG_ERROR {
native := nl.NativeEndian()
error := int32(native.Uint32(m.Data[0:4]))
if error == 0 {
continue
}
if cberr != nil {
cberr(syscall.Errno(-error))
}
return
}
route, err := deserializeRoute(m.Data)
if err != nil {
if cberr != nil {
cberr(err)
}
return
}
ch <- RouteUpdate{Type: m.Header.Type, Route: route}
}
}
}()
return nil
}