// 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)
route.Flags = int(msg.Flags)
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()
var res []Route
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
}
// 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
}
var res []Route
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
}
route, err := deserializeRoute(m)
if err != nil {
return nil, err
}
if link != nil && route.LinkIndex != index {
// Ignore routes from other interfaces
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()
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:
route.LinkIndex = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_IIF:
route.ILinkIndex = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_PRIORITY:
route.Priority = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_TABLE:
route.Table = int(native.Uint32(attr.Value[0:4]))
}
}
return route, 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()
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:
route.LinkIndex = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_IIF:
route.ILinkIndex = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_PRIORITY:
route.Priority = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_TABLE:
route.Table = int(native.Uint32(attr.Value[0:4]))
case syscall.RTA_MULTIPATH:
parseRtNexthop := func(value []byte) (*NexthopInfo, []byte, error) {
if len(value) < syscall.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),
}
attrs, err := nl.ParseRouteAttr(value[syscall.SizeofRtNexthop:int(nh.RtNexthop.Len)])
if err != nil {
return nil, nil, err
}
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.RTA_GATEWAY:
info.Gw = net.IP(attr.Value)
}
}
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
}
}
}
return route, nil
}
// 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(syscall.RTM_GETROUTE, syscall.NLM_F_DUMP)
infmsg := nl.NewIfInfomsg(family)
req.AddData(infmsg)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWROUTE)
if err != nil {
return nil, err
}
var res []Route
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 {
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 && 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 && filter.Dst != nil:
if route.Dst == nil {
continue
}
aMaskLen, aMaskBits := route.Dst.Mask.Size()
bMaskLen, bMaskBits := filter.Dst.Mask.Size()
if !(route.Dst.IP.Equal(filter.Dst.IP) && aMaskLen == bMaskLen && aMaskBits == bMaskBits) {
continue
}
}
}
res = append(res, route)
}
return res, nil
}
// RuleList lists rules in the system.
// Equivalent to: ip rule list
func RuleList(family int) ([]Rule, error) {
req := nl.NewNetlinkRequest(syscall.RTM_GETRULE, syscall.NLM_F_DUMP|syscall.NLM_F_REQUEST)
msg := nl.NewIfInfomsg(family)
req.AddData(msg)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWRULE)
if err != nil {
return nil, err
}
native := nl.NativeEndian()
var res = make([]Rule, 0)
for i := range msgs {
msg := nl.DeserializeRtMsg(msgs[i])
attrs, err := nl.ParseRouteAttr(msgs[i][msg.Len():])
if err != nil {
return nil, err
}
rule := NewRule()
rule.RtMsg = msg
for j := range attrs {
switch attrs[j].Attr.Type {
case syscall.RTA_TABLE:
rule.Table = int(native.Uint32(attrs[j].Value[0:4]))
case nl.FRA_SRC:
rule.Src = &net.IPNet{
IP: attrs[j].Value,
Mask: net.CIDRMask(int(msg.Src_len), 8*len(attrs[j].Value)),
}
case nl.FRA_DST:
rule.Dst = &net.IPNet{
IP: attrs[j].Value,
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(attrs[j].Value)),
}
case nl.FRA_FWMARK:
rule.Mark = int(native.Uint32(attrs[j].Value[0:4]))
case nl.FRA_FWMASK:
rule.Mask = int(native.Uint32(attrs[j].Value[0:4]))
case nl.FRA_TUN_ID:
rule.TunID = uint(native.Uint64(attrs[j].Value[0:4]))
case nl.FRA_IIFNAME:
rule.IifName = string(attrs[j].Value[:len(attrs[j].Value)-1])
case nl.FRA_OIFNAME:
rule.OifName = string(attrs[j].Value[:len(attrs[j].Value)-1])
case nl.FRA_SUPPRESS_PREFIXLEN:
i := native.Uint32(attrs[j].Value[0:4])
if i != 0xffffffff {
rule.SuppressPrefixlen = int(i)
}
case nl.FRA_SUPPRESS_IFGROUP:
i := native.Uint32(attrs[j].Value[0:4])
if i != 0xffffffff {
rule.SuppressIfgroup = int(i)
}
case nl.FRA_FLOW:
rule.Flow = int(native.Uint32(attrs[j].Value[0:4]))
case nl.FRA_GOTO:
rule.Goto = int(native.Uint32(attrs[j].Value[0:4]))
case nl.FRA_PRIORITY:
rule.Priority = int(native.Uint32(attrs[j].Value[0:4]))
}
}
res = append(res, *rule)
}
return res, nil
}
// 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()
var res []Route
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
}