1054 lines
22 KiB
Go
1054 lines
22 KiB
Go
package netlink
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import (
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"encoding/binary"
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"fmt"
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"net"
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"sync/atomic"
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"syscall"
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"unsafe"
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)
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const (
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IFNAMSIZ = 16
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DEFAULT_CHANGE = 0xFFFFFFFF
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IFLA_INFO_KIND = 1
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IFLA_INFO_DATA = 2
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VETH_INFO_PEER = 1
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IFLA_NET_NS_FD = 28
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SIOC_BRADDBR = 0x89a0
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SIOC_BRDELBR = 0x89a1
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SIOC_BRADDIF = 0x89a2
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)
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var nextSeqNr uint32
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type ifreqHwaddr struct {
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IfrnName [IFNAMSIZ]byte
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IfruHwaddr syscall.RawSockaddr
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}
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type ifreqIndex struct {
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IfrnName [IFNAMSIZ]byte
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IfruIndex int32
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}
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type ifreqFlags struct {
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IfrnName [IFNAMSIZ]byte
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Ifruflags uint16
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}
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func nativeEndian() binary.ByteOrder {
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var x uint32 = 0x01020304
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if *(*byte)(unsafe.Pointer(&x)) == 0x01 {
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return binary.BigEndian
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}
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return binary.LittleEndian
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}
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func getIpFamily(ip net.IP) int {
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if len(ip) <= net.IPv4len {
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return syscall.AF_INET
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}
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if ip.To4() != nil {
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return syscall.AF_INET
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}
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return syscall.AF_INET6
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}
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type NetlinkRequestData interface {
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Len() int
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ToWireFormat() []byte
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}
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type IfInfomsg struct {
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syscall.IfInfomsg
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}
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func newIfInfomsg(family int) *IfInfomsg {
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return &IfInfomsg{
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IfInfomsg: syscall.IfInfomsg{
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Family: uint8(family),
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},
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}
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}
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func newIfInfomsgChild(parent *RtAttr, family int) *IfInfomsg {
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msg := newIfInfomsg(family)
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parent.children = append(parent.children, msg)
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return msg
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}
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func (msg *IfInfomsg) ToWireFormat() []byte {
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native := nativeEndian()
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length := syscall.SizeofIfInfomsg
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b := make([]byte, length)
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b[0] = msg.Family
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b[1] = 0
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native.PutUint16(b[2:4], msg.Type)
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native.PutUint32(b[4:8], uint32(msg.Index))
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native.PutUint32(b[8:12], msg.Flags)
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native.PutUint32(b[12:16], msg.Change)
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return b
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}
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func (msg *IfInfomsg) Len() int {
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return syscall.SizeofIfInfomsg
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}
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type IfAddrmsg struct {
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syscall.IfAddrmsg
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}
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func newIfAddrmsg(family int) *IfAddrmsg {
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return &IfAddrmsg{
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IfAddrmsg: syscall.IfAddrmsg{
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Family: uint8(family),
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},
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}
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}
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func (msg *IfAddrmsg) ToWireFormat() []byte {
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native := nativeEndian()
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length := syscall.SizeofIfAddrmsg
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b := make([]byte, length)
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b[0] = msg.Family
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b[1] = msg.Prefixlen
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b[2] = msg.Flags
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b[3] = msg.Scope
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native.PutUint32(b[4:8], msg.Index)
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return b
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}
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func (msg *IfAddrmsg) Len() int {
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return syscall.SizeofIfAddrmsg
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}
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type RtMsg struct {
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syscall.RtMsg
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}
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func newRtMsg() *RtMsg {
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return &RtMsg{
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RtMsg: syscall.RtMsg{
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Table: syscall.RT_TABLE_MAIN,
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Scope: syscall.RT_SCOPE_UNIVERSE,
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Protocol: syscall.RTPROT_BOOT,
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Type: syscall.RTN_UNICAST,
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},
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}
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}
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func (msg *RtMsg) ToWireFormat() []byte {
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native := nativeEndian()
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length := syscall.SizeofRtMsg
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b := make([]byte, length)
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b[0] = msg.Family
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b[1] = msg.Dst_len
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b[2] = msg.Src_len
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b[3] = msg.Tos
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b[4] = msg.Table
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b[5] = msg.Protocol
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b[6] = msg.Scope
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b[7] = msg.Type
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native.PutUint32(b[8:12], msg.Flags)
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return b
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}
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func (msg *RtMsg) Len() int {
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return syscall.SizeofRtMsg
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}
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func rtaAlignOf(attrlen int) int {
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return (attrlen + syscall.RTA_ALIGNTO - 1) & ^(syscall.RTA_ALIGNTO - 1)
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}
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type RtAttr struct {
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syscall.RtAttr
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Data []byte
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children []NetlinkRequestData
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}
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func newRtAttr(attrType int, data []byte) *RtAttr {
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return &RtAttr{
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RtAttr: syscall.RtAttr{
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Type: uint16(attrType),
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},
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children: []NetlinkRequestData{},
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Data: data,
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}
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}
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func newRtAttrChild(parent *RtAttr, attrType int, data []byte) *RtAttr {
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attr := newRtAttr(attrType, data)
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parent.children = append(parent.children, attr)
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return attr
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}
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func (a *RtAttr) Len() int {
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if len(a.children) == 0 {
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return (syscall.SizeofRtAttr + len(a.Data))
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}
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l := 0
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for _, child := range a.children {
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l += child.Len()
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}
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l += syscall.SizeofRtAttr
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return rtaAlignOf(l + len(a.Data))
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}
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func (a *RtAttr) ToWireFormat() []byte {
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native := nativeEndian()
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length := a.Len()
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buf := make([]byte, rtaAlignOf(length))
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if a.Data != nil {
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copy(buf[4:], a.Data)
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} else {
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next := 4
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for _, child := range a.children {
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childBuf := child.ToWireFormat()
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copy(buf[next:], childBuf)
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next += rtaAlignOf(len(childBuf))
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}
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}
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if l := uint16(length); l != 0 {
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native.PutUint16(buf[0:2], l)
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}
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native.PutUint16(buf[2:4], a.Type)
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return buf
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}
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type NetlinkRequest struct {
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syscall.NlMsghdr
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Data []NetlinkRequestData
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}
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func (rr *NetlinkRequest) ToWireFormat() []byte {
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native := nativeEndian()
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length := rr.Len
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dataBytes := make([][]byte, len(rr.Data))
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for i, data := range rr.Data {
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dataBytes[i] = data.ToWireFormat()
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length += uint32(len(dataBytes[i]))
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}
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b := make([]byte, length)
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native.PutUint32(b[0:4], length)
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native.PutUint16(b[4:6], rr.Type)
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native.PutUint16(b[6:8], rr.Flags)
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native.PutUint32(b[8:12], rr.Seq)
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native.PutUint32(b[12:16], rr.Pid)
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next := 16
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for _, data := range dataBytes {
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copy(b[next:], data)
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next += len(data)
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}
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return b
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}
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func (rr *NetlinkRequest) AddData(data NetlinkRequestData) {
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if data != nil {
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rr.Data = append(rr.Data, data)
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}
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}
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func newNetlinkRequest(proto, flags int) *NetlinkRequest {
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return &NetlinkRequest{
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NlMsghdr: syscall.NlMsghdr{
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Len: uint32(syscall.NLMSG_HDRLEN),
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Type: uint16(proto),
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Flags: syscall.NLM_F_REQUEST | uint16(flags),
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Seq: atomic.AddUint32(&nextSeqNr, 1),
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},
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}
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}
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type NetlinkSocket struct {
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fd int
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lsa syscall.SockaddrNetlink
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}
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func getNetlinkSocket() (*NetlinkSocket, error) {
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fd, err := syscall.Socket(syscall.AF_NETLINK, syscall.SOCK_RAW, syscall.NETLINK_ROUTE)
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if err != nil {
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return nil, err
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}
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s := &NetlinkSocket{
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fd: fd,
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}
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s.lsa.Family = syscall.AF_NETLINK
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if err := syscall.Bind(fd, &s.lsa); err != nil {
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syscall.Close(fd)
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return nil, err
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}
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return s, nil
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}
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func (s *NetlinkSocket) Close() {
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syscall.Close(s.fd)
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}
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func (s *NetlinkSocket) Send(request *NetlinkRequest) error {
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if err := syscall.Sendto(s.fd, request.ToWireFormat(), 0, &s.lsa); err != nil {
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return err
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}
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return nil
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}
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func (s *NetlinkSocket) Receive() ([]syscall.NetlinkMessage, error) {
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rb := make([]byte, syscall.Getpagesize())
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nr, _, err := syscall.Recvfrom(s.fd, rb, 0)
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if err != nil {
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return nil, err
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}
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if nr < syscall.NLMSG_HDRLEN {
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return nil, ErrShortResponse
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}
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rb = rb[:nr]
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return syscall.ParseNetlinkMessage(rb)
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}
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func (s *NetlinkSocket) GetPid() (uint32, error) {
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lsa, err := syscall.Getsockname(s.fd)
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if err != nil {
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return 0, err
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}
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switch v := lsa.(type) {
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case *syscall.SockaddrNetlink:
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return v.Pid, nil
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}
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return 0, ErrWrongSockType
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}
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func (s *NetlinkSocket) HandleAck(seq uint32) error {
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native := nativeEndian()
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pid, err := s.GetPid()
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if err != nil {
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return err
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}
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done:
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for {
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msgs, err := s.Receive()
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if err != nil {
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return err
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}
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for _, m := range msgs {
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if m.Header.Seq != seq {
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return fmt.Errorf("Wrong Seq nr %d, expected %d", m.Header.Seq, seq)
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}
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if m.Header.Pid != pid {
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return fmt.Errorf("Wrong pid %d, expected %d", m.Header.Pid, pid)
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}
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if m.Header.Type == syscall.NLMSG_DONE {
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break done
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}
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if m.Header.Type == syscall.NLMSG_ERROR {
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error := int32(native.Uint32(m.Data[0:4]))
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if error == 0 {
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break done
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}
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return syscall.Errno(-error)
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}
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}
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}
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return nil
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}
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// Add a new route table entry.
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func AddRoute(destination, source, gateway, device string) error {
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if destination == "" && source == "" && gateway == "" {
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return fmt.Errorf("one of destination, source or gateway must not be blank")
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}
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s, err := getNetlinkSocket()
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if err != nil {
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return err
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}
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defer s.Close()
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wb := newNetlinkRequest(syscall.RTM_NEWROUTE, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
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msg := newRtMsg()
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currentFamily := -1
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var rtAttrs []*RtAttr
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if destination != "" {
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destIP, destNet, err := net.ParseCIDR(destination)
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if err != nil {
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return fmt.Errorf("destination CIDR %s couldn't be parsed", destination)
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}
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destFamily := getIpFamily(destIP)
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currentFamily = destFamily
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destLen, bits := destNet.Mask.Size()
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if destLen == 0 && bits == 0 {
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return fmt.Errorf("destination CIDR %s generated a non-canonical Mask", destination)
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}
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msg.Family = uint8(destFamily)
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msg.Dst_len = uint8(destLen)
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var destData []byte
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if destFamily == syscall.AF_INET {
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destData = destIP.To4()
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} else {
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destData = destIP.To16()
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}
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rtAttrs = append(rtAttrs, newRtAttr(syscall.RTA_DST, destData))
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}
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if source != "" {
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srcIP, srcNet, err := net.ParseCIDR(source)
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if err != nil {
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return fmt.Errorf("source CIDR %s couldn't be parsed", source)
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}
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srcFamily := getIpFamily(srcIP)
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if currentFamily != -1 && currentFamily != srcFamily {
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return fmt.Errorf("source and destination ip were not the same IP family")
|
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}
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currentFamily = srcFamily
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srcLen, bits := srcNet.Mask.Size()
|
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if srcLen == 0 && bits == 0 {
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return fmt.Errorf("source CIDR %s generated a non-canonical Mask", source)
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}
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msg.Family = uint8(srcFamily)
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msg.Src_len = uint8(srcLen)
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var srcData []byte
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if srcFamily == syscall.AF_INET {
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srcData = srcIP.To4()
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} else {
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srcData = srcIP.To16()
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}
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rtAttrs = append(rtAttrs, newRtAttr(syscall.RTA_SRC, srcData))
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}
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|
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if gateway != "" {
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gwIP := net.ParseIP(gateway)
|
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if gwIP == nil {
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return fmt.Errorf("gateway IP %s couldn't be parsed", gateway)
|
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}
|
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gwFamily := getIpFamily(gwIP)
|
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if currentFamily != -1 && currentFamily != gwFamily {
|
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return fmt.Errorf("gateway, source, and destination ip were not the same IP family")
|
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}
|
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msg.Family = uint8(gwFamily)
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var gwData []byte
|
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if gwFamily == syscall.AF_INET {
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gwData = gwIP.To4()
|
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} else {
|
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gwData = gwIP.To16()
|
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}
|
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rtAttrs = append(rtAttrs, newRtAttr(syscall.RTA_GATEWAY, gwData))
|
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}
|
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|
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wb.AddData(msg)
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for _, attr := range rtAttrs {
|
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wb.AddData(attr)
|
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}
|
|
|
|
var (
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native = nativeEndian()
|
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b = make([]byte, 4)
|
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)
|
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iface, err := net.InterfaceByName(device)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
native.PutUint32(b, uint32(iface.Index))
|
|
|
|
wb.AddData(newRtAttr(syscall.RTA_OIF, b))
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// Add a new default gateway. Identical to:
|
|
// ip route add default via $ip
|
|
func AddDefaultGw(ip, device string) error {
|
|
return AddRoute("", "", ip, device)
|
|
}
|
|
|
|
// Bring up a particular network interface
|
|
func NetworkLinkUp(iface *net.Interface) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Change = syscall.IFF_UP
|
|
msg.Flags = syscall.IFF_UP
|
|
msg.Index = int32(iface.Index)
|
|
wb.AddData(msg)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
func NetworkLinkDown(iface *net.Interface) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Change = syscall.IFF_UP
|
|
msg.Flags = 0 & ^syscall.IFF_UP
|
|
msg.Index = int32(iface.Index)
|
|
wb.AddData(msg)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
func NetworkSetMTU(iface *net.Interface, mtu int) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Type = syscall.RTM_SETLINK
|
|
msg.Flags = syscall.NLM_F_REQUEST
|
|
msg.Index = int32(iface.Index)
|
|
msg.Change = DEFAULT_CHANGE
|
|
wb.AddData(msg)
|
|
|
|
var (
|
|
b = make([]byte, 4)
|
|
native = nativeEndian()
|
|
)
|
|
native.PutUint32(b, uint32(mtu))
|
|
|
|
data := newRtAttr(syscall.IFLA_MTU, b)
|
|
wb.AddData(data)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// same as ip link set $name master $master
|
|
func NetworkSetMaster(iface, master *net.Interface) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Type = syscall.RTM_SETLINK
|
|
msg.Flags = syscall.NLM_F_REQUEST
|
|
msg.Index = int32(iface.Index)
|
|
msg.Change = DEFAULT_CHANGE
|
|
wb.AddData(msg)
|
|
|
|
var (
|
|
b = make([]byte, 4)
|
|
native = nativeEndian()
|
|
)
|
|
native.PutUint32(b, uint32(master.Index))
|
|
|
|
data := newRtAttr(syscall.IFLA_MASTER, b)
|
|
wb.AddData(data)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
func NetworkSetNsPid(iface *net.Interface, nspid int) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Type = syscall.RTM_SETLINK
|
|
msg.Flags = syscall.NLM_F_REQUEST
|
|
msg.Index = int32(iface.Index)
|
|
msg.Change = DEFAULT_CHANGE
|
|
wb.AddData(msg)
|
|
|
|
var (
|
|
b = make([]byte, 4)
|
|
native = nativeEndian()
|
|
)
|
|
native.PutUint32(b, uint32(nspid))
|
|
|
|
data := newRtAttr(syscall.IFLA_NET_NS_PID, b)
|
|
wb.AddData(data)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
func NetworkSetNsFd(iface *net.Interface, fd int) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Type = syscall.RTM_SETLINK
|
|
msg.Flags = syscall.NLM_F_REQUEST
|
|
msg.Index = int32(iface.Index)
|
|
msg.Change = DEFAULT_CHANGE
|
|
wb.AddData(msg)
|
|
|
|
var (
|
|
b = make([]byte, 4)
|
|
native = nativeEndian()
|
|
)
|
|
native.PutUint32(b, uint32(fd))
|
|
|
|
data := newRtAttr(IFLA_NET_NS_FD, b)
|
|
wb.AddData(data)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
func networkLinkIpAction(action, flags int, ifa IfAddr) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
family := getIpFamily(ifa.IP)
|
|
|
|
wb := newNetlinkRequest(action, flags)
|
|
|
|
msg := newIfAddrmsg(family)
|
|
msg.Index = uint32(ifa.Iface.Index)
|
|
prefixLen, _ := ifa.IPNet.Mask.Size()
|
|
msg.Prefixlen = uint8(prefixLen)
|
|
wb.AddData(msg)
|
|
|
|
var ipData []byte
|
|
if family == syscall.AF_INET {
|
|
ipData = ifa.IP.To4()
|
|
} else {
|
|
ipData = ifa.IP.To16()
|
|
}
|
|
|
|
localData := newRtAttr(syscall.IFA_LOCAL, ipData)
|
|
wb.AddData(localData)
|
|
|
|
addrData := newRtAttr(syscall.IFA_ADDRESS, ipData)
|
|
wb.AddData(addrData)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// Delete an IP address from an interface. This is identical to:
|
|
// ip addr del $ip/$ipNet dev $iface
|
|
func NetworkLinkDelIp(iface *net.Interface, ip net.IP, ipNet *net.IPNet) error {
|
|
return networkLinkIpAction(
|
|
syscall.RTM_DELADDR,
|
|
syscall.NLM_F_ACK,
|
|
IfAddr{iface, ip, ipNet},
|
|
)
|
|
}
|
|
|
|
// Add an Ip address to an interface. This is identical to:
|
|
// ip addr add $ip/$ipNet dev $iface
|
|
func NetworkLinkAddIp(iface *net.Interface, ip net.IP, ipNet *net.IPNet) error {
|
|
return networkLinkIpAction(
|
|
syscall.RTM_NEWADDR,
|
|
syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK,
|
|
IfAddr{iface, ip, ipNet},
|
|
)
|
|
}
|
|
|
|
func zeroTerminated(s string) []byte {
|
|
return []byte(s + "\000")
|
|
}
|
|
|
|
func nonZeroTerminated(s string) []byte {
|
|
return []byte(s)
|
|
}
|
|
|
|
// Add a new network link of a specified type. This is identical to
|
|
// running: ip add link $name type $linkType
|
|
func NetworkLinkAdd(name string, linkType string) error {
|
|
if name == "" || linkType == "" {
|
|
return fmt.Errorf("Neither link name nor link type can be empty!")
|
|
}
|
|
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
wb.AddData(msg)
|
|
|
|
linkInfo := newRtAttr(syscall.IFLA_LINKINFO, nil)
|
|
newRtAttrChild(linkInfo, IFLA_INFO_KIND, nonZeroTerminated(linkType))
|
|
wb.AddData(linkInfo)
|
|
|
|
nameData := newRtAttr(syscall.IFLA_IFNAME, zeroTerminated(name))
|
|
wb.AddData(nameData)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// Delete a network link. This is identical to
|
|
// running: ip link del $name
|
|
func NetworkLinkDel(name string) error {
|
|
if name == "" {
|
|
return fmt.Errorf("Network link name can not be empty!")
|
|
}
|
|
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
iface, err := net.InterfaceByName(name)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_DELLINK, syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
msg.Index = int32(iface.Index)
|
|
wb.AddData(msg)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// Returns an array of IPNet for all the currently routed subnets on ipv4
|
|
// This is similar to the first column of "ip route" output
|
|
func NetworkGetRoutes() ([]Route, error) {
|
|
native := nativeEndian()
|
|
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_GETROUTE, syscall.NLM_F_DUMP)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
wb.AddData(msg)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
pid, err := s.GetPid()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
res := make([]Route, 0)
|
|
|
|
done:
|
|
for {
|
|
msgs, err := s.Receive()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
for _, m := range msgs {
|
|
if m.Header.Seq != wb.Seq {
|
|
return nil, fmt.Errorf("Wrong Seq nr %d, expected 1", m.Header.Seq)
|
|
}
|
|
if m.Header.Pid != pid {
|
|
return nil, fmt.Errorf("Wrong pid %d, expected %d", m.Header.Pid, pid)
|
|
}
|
|
if m.Header.Type == syscall.NLMSG_DONE {
|
|
break done
|
|
}
|
|
if m.Header.Type == syscall.NLMSG_ERROR {
|
|
error := int32(native.Uint32(m.Data[0:4]))
|
|
if error == 0 {
|
|
break done
|
|
}
|
|
return nil, syscall.Errno(-error)
|
|
}
|
|
if m.Header.Type != syscall.RTM_NEWROUTE {
|
|
continue
|
|
}
|
|
|
|
var r Route
|
|
|
|
msg := (*RtMsg)(unsafe.Pointer(&m.Data[0:syscall.SizeofRtMsg][0]))
|
|
|
|
if msg.Flags&syscall.RTM_F_CLONED != 0 {
|
|
// Ignore cloned routes
|
|
continue
|
|
}
|
|
|
|
if msg.Table != syscall.RT_TABLE_MAIN {
|
|
// Ignore non-main tables
|
|
continue
|
|
}
|
|
|
|
if msg.Family != syscall.AF_INET {
|
|
// Ignore non-ipv4 routes
|
|
continue
|
|
}
|
|
|
|
if msg.Dst_len == 0 {
|
|
// Default routes
|
|
r.Default = true
|
|
}
|
|
|
|
attrs, err := syscall.ParseNetlinkRouteAttr(&m)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
for _, attr := range attrs {
|
|
switch attr.Attr.Type {
|
|
case syscall.RTA_DST:
|
|
ip := attr.Value
|
|
r.IPNet = &net.IPNet{
|
|
IP: ip,
|
|
Mask: net.CIDRMask(int(msg.Dst_len), 8*len(ip)),
|
|
}
|
|
case syscall.RTA_OIF:
|
|
index := int(native.Uint32(attr.Value[0:4]))
|
|
r.Iface, _ = net.InterfaceByIndex(index)
|
|
}
|
|
}
|
|
if r.Default || r.IPNet != nil {
|
|
res = append(res, r)
|
|
}
|
|
}
|
|
}
|
|
|
|
return res, nil
|
|
}
|
|
|
|
func getIfSocket() (fd int, err error) {
|
|
for _, socket := range []int{
|
|
syscall.AF_INET,
|
|
syscall.AF_PACKET,
|
|
syscall.AF_INET6,
|
|
} {
|
|
if fd, err = syscall.Socket(socket, syscall.SOCK_DGRAM, 0); err == nil {
|
|
break
|
|
}
|
|
}
|
|
if err == nil {
|
|
return fd, nil
|
|
}
|
|
return -1, err
|
|
}
|
|
|
|
func NetworkChangeName(iface *net.Interface, newName string) error {
|
|
if len(newName) >= IFNAMSIZ {
|
|
return fmt.Errorf("Interface name %s too long", newName)
|
|
}
|
|
|
|
fd, err := getIfSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer syscall.Close(fd)
|
|
|
|
data := [IFNAMSIZ * 2]byte{}
|
|
// the "-1"s here are very important for ensuring we get proper null
|
|
// termination of our new C strings
|
|
copy(data[:IFNAMSIZ-1], iface.Name)
|
|
copy(data[IFNAMSIZ:IFNAMSIZ*2-1], newName)
|
|
|
|
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), syscall.SIOCSIFNAME, uintptr(unsafe.Pointer(&data[0]))); errno != 0 {
|
|
return errno
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func NetworkCreateVethPair(name1, name2 string) error {
|
|
s, err := getNetlinkSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer s.Close()
|
|
|
|
wb := newNetlinkRequest(syscall.RTM_NEWLINK, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
|
|
|
|
msg := newIfInfomsg(syscall.AF_UNSPEC)
|
|
wb.AddData(msg)
|
|
|
|
nameData := newRtAttr(syscall.IFLA_IFNAME, zeroTerminated(name1))
|
|
wb.AddData(nameData)
|
|
|
|
nest1 := newRtAttr(syscall.IFLA_LINKINFO, nil)
|
|
newRtAttrChild(nest1, IFLA_INFO_KIND, zeroTerminated("veth"))
|
|
nest2 := newRtAttrChild(nest1, IFLA_INFO_DATA, nil)
|
|
nest3 := newRtAttrChild(nest2, VETH_INFO_PEER, nil)
|
|
|
|
newIfInfomsgChild(nest3, syscall.AF_UNSPEC)
|
|
newRtAttrChild(nest3, syscall.IFLA_IFNAME, zeroTerminated(name2))
|
|
|
|
wb.AddData(nest1)
|
|
|
|
if err := s.Send(wb); err != nil {
|
|
return err
|
|
}
|
|
return s.HandleAck(wb.Seq)
|
|
}
|
|
|
|
// Create the actual bridge device. This is more backward-compatible than
|
|
// netlink.NetworkLinkAdd and works on RHEL 6.
|
|
func CreateBridge(name string, setMacAddr bool) error {
|
|
if len(name) >= IFNAMSIZ {
|
|
return fmt.Errorf("Interface name %s too long", name)
|
|
}
|
|
|
|
s, err := getIfSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer syscall.Close(s)
|
|
|
|
nameBytePtr, err := syscall.BytePtrFromString(name)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(s), SIOC_BRADDBR, uintptr(unsafe.Pointer(nameBytePtr))); err != 0 {
|
|
return err
|
|
}
|
|
if setMacAddr {
|
|
return setBridgeMacAddress(s, name)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Delete the actual bridge device.
|
|
func DeleteBridge(name string) error {
|
|
s, err := getIfSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer syscall.Close(s)
|
|
|
|
nameBytePtr, err := syscall.BytePtrFromString(name)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
var ifr ifreqFlags
|
|
copy(ifr.IfrnName[:len(ifr.IfrnName)-1], []byte(name))
|
|
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(s),
|
|
syscall.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&ifr))); err != 0 {
|
|
return err
|
|
}
|
|
|
|
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(s),
|
|
SIOC_BRDELBR, uintptr(unsafe.Pointer(nameBytePtr))); err != 0 {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Add a slave to abridge device. This is more backward-compatible than
|
|
// netlink.NetworkSetMaster and works on RHEL 6.
|
|
func AddToBridge(iface, master *net.Interface) error {
|
|
if len(master.Name) >= IFNAMSIZ {
|
|
return fmt.Errorf("Interface name %s too long", master.Name)
|
|
}
|
|
|
|
s, err := getIfSocket()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
defer syscall.Close(s)
|
|
|
|
ifr := ifreqIndex{}
|
|
copy(ifr.IfrnName[:len(ifr.IfrnName)-1], master.Name)
|
|
ifr.IfruIndex = int32(iface.Index)
|
|
|
|
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(s), SIOC_BRADDIF, uintptr(unsafe.Pointer(&ifr))); err != 0 {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func setBridgeMacAddress(s int, name string) error {
|
|
if len(name) >= IFNAMSIZ {
|
|
return fmt.Errorf("Interface name %s too long", name)
|
|
}
|
|
|
|
ifr := ifreqHwaddr{}
|
|
ifr.IfruHwaddr.Family = syscall.ARPHRD_ETHER
|
|
copy(ifr.IfrnName[:len(ifr.IfrnName)-1], name)
|
|
|
|
for i := 0; i < 6; i++ {
|
|
ifr.IfruHwaddr.Data[i] = randIfrDataByte()
|
|
}
|
|
|
|
ifr.IfruHwaddr.Data[0] &^= 0x1 // clear multicast bit
|
|
ifr.IfruHwaddr.Data[0] |= 0x2 // set local assignment bit (IEEE802)
|
|
|
|
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, uintptr(s), syscall.SIOCSIFHWADDR, uintptr(unsafe.Pointer(&ifr))); err != 0 {
|
|
return err
|
|
}
|
|
return nil
|
|
}
|