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|
// +build linux
package netlink
import (
"encoding/binary"
"errors"
"github.com/vishvananda/netlink/nl"
"golang.org/x/sys/unix"
)
const (
FOU_GENL_NAME = "fou"
)
const (
FOU_CMD_UNSPEC uint8 = iota
FOU_CMD_ADD
FOU_CMD_DEL
FOU_CMD_GET
FOU_CMD_MAX = FOU_CMD_GET
)
const (
FOU_ATTR_UNSPEC = iota
FOU_ATTR_PORT
FOU_ATTR_AF
FOU_ATTR_IPPROTO
FOU_ATTR_TYPE
FOU_ATTR_REMCSUM_NOPARTIAL
FOU_ATTR_MAX = FOU_ATTR_REMCSUM_NOPARTIAL
)
const (
FOU_ENCAP_UNSPEC = iota
FOU_ENCAP_DIRECT
FOU_ENCAP_GUE
FOU_ENCAP_MAX = FOU_ENCAP_GUE
)
var fouFamilyId int
func FouFamilyId() (int, error) {
if fouFamilyId != 0 {
return fouFamilyId, nil
}
fam, err := GenlFamilyGet(FOU_GENL_NAME)
if err != nil {
return -1, err
}
fouFamilyId = int(fam.ID)
return fouFamilyId, nil
}
func FouAdd(f Fou) error {
return pkgHandle.FouAdd(f)
}
func (h *Handle) FouAdd(f Fou) error {
fam_id, err := FouFamilyId()
if err != nil {
return err
}
// setting ip protocol conflicts with encapsulation type GUE
if f.EncapType == FOU_ENCAP_GUE && f.Protocol != 0 {
return errors.New("GUE encapsulation doesn't specify an IP protocol")
}
req := h.newNetlinkRequest(fam_id, unix.NLM_F_ACK)
// int to byte for port
bp := make([]byte, 2)
binary.BigEndian.PutUint16(bp[0:2], uint16(f.Port))
attrs := []*nl.RtAttr{
nl.NewRtAttr(FOU_ATTR_PORT, bp),
nl.NewRtAttr(FOU_ATTR_TYPE, []byte{uint8(f.EncapType)}),
nl.NewRtAttr(FOU_ATTR_AF, []byte{uint8(f.Family)}),
nl.NewRtAttr(FOU_ATTR_IPPROTO, []byte{uint8(f.Protocol)}),
}
raw := []byte{FOU_CMD_ADD, 1, 0, 0}
for _, a := range attrs {
raw = append(raw, a.Serialize()...)
}
req.AddRawData(raw)
_, err = req.Execute(unix.NETLINK_GENERIC, 0)
return err
}
func FouDel(f Fou) error {
return pkgHandle.FouDel(f)
}
func (h *Handle) FouDel(f Fou) error {
fam_id, err := FouFamilyId()
if err != nil {
return err
}
req := h.newNetlinkRequest(fam_id, unix.NLM_F_ACK)
// int to byte for port
bp := make([]byte, 2)
binary.BigEndian.PutUint16(bp[0:2], uint16(f.Port))
attrs := []*nl.RtAttr{
nl.NewRtAttr(FOU_ATTR_PORT, bp),
nl.NewRtAttr(FOU_ATTR_AF, []byte{uint8(f.Family)}),
}
raw := []byte{FOU_CMD_DEL, 1, 0, 0}
for _, a := range attrs {
raw = append(raw, a.Serialize()...)
}
req.AddRawData(raw)
_, err = req.Execute(unix.NETLINK_GENERIC, 0)
if err != nil {
return err
}
return nil
}
func FouList(fam int) ([]Fou, error) {
return pkgHandle.FouList(fam)
}
func (h *Handle) FouList(fam int) ([]Fou, error) {
fam_id, err := FouFamilyId()
if err != nil {
return nil, err
}
req := h.newNetlinkRequest(fam_id, unix.NLM_F_DUMP)
attrs := []*nl.RtAttr{
nl.NewRtAttr(FOU_ATTR_AF, []byte{uint8(fam)}),
}
raw := []byte{FOU_CMD_GET, 1, 0, 0}
for _, a := range attrs {
raw = append(raw, a.Serialize()...)
}
req.AddRawData(raw)
msgs, err := req.Execute(unix.NETLINK_GENERIC, 0)
if err != nil {
return nil, err
}
fous := make([]Fou, 0, len(msgs))
for _, m := range msgs {
f, err := deserializeFouMsg(m)
if err != nil {
return fous, err
}
fous = append(fous, f)
}
return fous, nil
}
func deserializeFouMsg(msg []byte) (Fou, error) {
// we'll skip to byte 4 to first attribute
msg = msg[3:]
var shift int
fou := Fou{}
for {
// attribute header is at least 16 bits
if len(msg) < 4 {
return fou, ErrAttrHeaderTruncated
}
lgt := int(binary.BigEndian.Uint16(msg[0:2]))
if len(msg) < lgt+4 {
return fou, ErrAttrBodyTruncated
}
attr := binary.BigEndian.Uint16(msg[2:4])
shift = lgt + 3
switch attr {
case FOU_ATTR_AF:
fou.Family = int(msg[5])
case FOU_ATTR_PORT:
fou.Port = int(binary.BigEndian.Uint16(msg[5:7]))
// port is 2 bytes
shift = lgt + 2
case FOU_ATTR_IPPROTO:
fou.Protocol = int(msg[5])
case FOU_ATTR_TYPE:
fou.EncapType = int(msg[5])
}
msg = msg[shift:]
if len(msg) < 4 {
break
}
}
return fou, nil
}
|
