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Merge pull request #8 from creack/implement_create_veth
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Simplify code + Allow more generic attr children + remove prefix
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@crosbymichael
crosbymichael committed Feb 12, 2014
2 parents e941111 + 38e5b4e commit 9fd44cb
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Showing 2 changed files with 79 additions and 62 deletions.
10 changes: 9 additions & 1 deletion pkg/netlink/netlink.go
View file
Expand Up @@ -5,7 +5,15 @@
// netlink_darwin.go
package netlink

import "net"
import (
"errors"
"net"
)

var (
ErrWrongSockType = errors.New("Wrong socket type")
ErrShortResponse = errors.New("Got short response from netlink")
)

// A Route is a subnet associated with the interface to reach it.
type Route struct {
Expand Down
131 changes: 70 additions & 61 deletions pkg/netlink/netlink_linux.go
View file
Expand Up @@ -45,6 +45,7 @@ func getIpFamily(ip net.IP) int {
}

type NetlinkRequestData interface {
Len() int
ToWireFormat() []byte
}

Expand All @@ -53,21 +54,24 @@ type IfInfomsg struct {
}

func newIfInfomsg(family int) *IfInfomsg {
msg := &IfInfomsg{}
msg.Family = uint8(family)
msg.Type = uint16(0)
msg.Index = int32(0)
msg.Flags = uint32(0)
msg.Change = uint32(0)
return &IfInfomsg{
IfInfomsg: syscall.IfInfomsg{
Family: uint8(family),
},
}
}

func newIfInfomsgChild(parent *RtAttr, family int) *IfInfomsg {
msg := newIfInfomsg(family)
parent.children = append(parent.children, msg)
return msg
}

func (msg *IfInfomsg) ToWireFormat() []byte {
native := nativeEndian()

len := syscall.SizeofIfInfomsg
b := make([]byte, len)
length := syscall.SizeofIfInfomsg
b := make([]byte, length)
b[0] = msg.Family
b[1] = 0
native.PutUint16(b[2:4], msg.Type)
Expand All @@ -77,26 +81,27 @@ func (msg *IfInfomsg) ToWireFormat() []byte {
return b
}

func (msg *IfInfomsg) Len() int {
return syscall.SizeofIfInfomsg
}

type IfAddrmsg struct {
syscall.IfAddrmsg
}

func newIfAddrmsg(family int) *IfAddrmsg {
msg := &IfAddrmsg{}
msg.Family = uint8(family)
msg.Prefixlen = uint8(0)
msg.Flags = uint8(0)
msg.Scope = uint8(0)
msg.Index = uint32(0)

return msg
return &IfAddrmsg{
IfAddrmsg: syscall.IfAddrmsg{
Family: uint8(family),
},
}
}

func (msg *IfAddrmsg) ToWireFormat() []byte {
native := nativeEndian()

len := syscall.SizeofIfAddrmsg
b := make([]byte, len)
length := syscall.SizeofIfAddrmsg
b := make([]byte, length)
b[0] = msg.Family
b[1] = msg.Prefixlen
b[2] = msg.Flags
Expand All @@ -105,26 +110,31 @@ func (msg *IfAddrmsg) ToWireFormat() []byte {
return b
}

func (msg *IfAddrmsg) Len() int {
return syscall.SizeofIfAddrmsg
}

type RtMsg struct {
syscall.RtMsg
}

func newRtMsg(family int) *RtMsg {
msg := &RtMsg{}
msg.Family = uint8(family)
msg.Table = syscall.RT_TABLE_MAIN
msg.Scope = syscall.RT_SCOPE_UNIVERSE
msg.Protocol = syscall.RTPROT_BOOT
msg.Type = syscall.RTN_UNICAST

return msg
return &RtMsg{
RtMsg: syscall.RtMsg{
Family: uint8(family),
Table: syscall.RT_TABLE_MAIN,
Scope: syscall.RT_SCOPE_UNIVERSE,
Protocol: syscall.RTPROT_BOOT,
Type: syscall.RTN_UNICAST,
},
}
}

func (msg *RtMsg) ToWireFormat() []byte {
native := nativeEndian()

len := syscall.SizeofRtMsg
b := make([]byte, len)
length := syscall.SizeofRtMsg
b := make([]byte, length)
b[0] = msg.Family
b[1] = msg.Dst_len
b[2] = msg.Src_len
Expand All @@ -137,25 +147,28 @@ func (msg *RtMsg) ToWireFormat() []byte {
return b
}

func (msg *RtMsg) Len() int {
return syscall.SizeofRtMsg
}

func rtaAlignOf(attrlen int) int {
return (attrlen + syscall.RTA_ALIGNTO - 1) & ^(syscall.RTA_ALIGNTO - 1)
}

type RtAttr struct {
syscall.RtAttr
Data []byte
children []*RtAttr
prefix int
children []NetlinkRequestData
}

func newRtAttr(attrType int, data []byte) *RtAttr {
attr := &RtAttr{
children: []*RtAttr{},
return &RtAttr{
RtAttr: syscall.RtAttr{
Type: uint16(attrType),
},
children: []NetlinkRequestData{},
Data: data,
}
attr.Type = uint16(attrType)
attr.Data = data

return attr
}

func newRtAttrChild(parent *RtAttr, attrType int, data []byte) *RtAttr {
Expand All @@ -164,10 +177,10 @@ func newRtAttrChild(parent *RtAttr, attrType int, data []byte) *RtAttr {
return attr
}

func (a *RtAttr) length() int {
func (a *RtAttr) Len() int {
l := 0
for _, child := range a.children {
l += child.length() + syscall.SizeofRtAttr + child.prefix
l += child.Len() + syscall.SizeofRtAttr
}
if l == 0 {
l++
Expand All @@ -178,7 +191,7 @@ func (a *RtAttr) length() int {
func (a *RtAttr) ToWireFormat() []byte {
native := nativeEndian()

length := a.length()
length := a.Len()
buf := make([]byte, rtaAlignOf(length+syscall.SizeofRtAttr))

if a.Data != nil {
Expand All @@ -187,7 +200,7 @@ func (a *RtAttr) ToWireFormat() []byte {
next := 4
for _, child := range a.children {
childBuf := child.ToWireFormat()
copy(buf[next+child.prefix:], childBuf)
copy(buf[next:], childBuf)
next += rtaAlignOf(len(childBuf))
}
}
Expand All @@ -212,7 +225,7 @@ func (rr *NetlinkRequest) ToWireFormat() []byte {
dataBytes := make([][]byte, len(rr.Data))
for i, data := range rr.Data {
dataBytes[i] = data.ToWireFormat()
length = length + uint32(len(dataBytes[i]))
length += uint32(len(dataBytes[i]))
}
b := make([]byte, length)
native.PutUint32(b[0:4], length)
Expand All @@ -221,12 +234,10 @@ func (rr *NetlinkRequest) ToWireFormat() []byte {
native.PutUint32(b[8:12], rr.Seq)
native.PutUint32(b[12:16], rr.Pid)

i := 16
next := 16
for _, data := range dataBytes {
for _, dataByte := range data {
b[i] = dataByte
i = i + 1
}
copy(b[next:], data)
next += len(data)
}
return b
}
Expand All @@ -238,12 +249,14 @@ func (rr *NetlinkRequest) AddData(data NetlinkRequestData) {
}

func newNetlinkRequest(proto, flags int) *NetlinkRequest {
rr := &NetlinkRequest{}
rr.Len = uint32(syscall.NLMSG_HDRLEN)
rr.Type = uint16(proto)
rr.Flags = syscall.NLM_F_REQUEST | uint16(flags)
rr.Seq = uint32(getSeq())
return rr
return &NetlinkRequest{
NlMsghdr: syscall.NlMsghdr{
Len: uint32(syscall.NLMSG_HDRLEN),
Type: uint16(proto),
Flags: syscall.NLM_F_REQUEST | uint16(flags),
Seq: uint32(getSeq()),
},
}
}

type NetlinkSocket struct {
Expand Down Expand Up @@ -286,7 +299,7 @@ func (s *NetlinkSocket) Receive() ([]syscall.NetlinkMessage, error) {
return nil, err
}
if nr < syscall.NLMSG_HDRLEN {
return nil, fmt.Errorf("Got short response from netlink")
return nil, ErrShortResponse
}
rb = rb[:nr]
return syscall.ParseNetlinkMessage(rb)
Expand All @@ -301,7 +314,7 @@ func (s *NetlinkSocket) GetPid() (uint32, error) {
case *syscall.SockaddrNetlink:
return v.Pid, nil
}
return 0, fmt.Errorf("Wrong socket type")
return 0, ErrWrongSockType
}

func (s *NetlinkSocket) HandleAck(seq uint32) error {
Expand Down Expand Up @@ -592,11 +605,7 @@ func zeroTerminated(s string) []byte {
}

func nonZeroTerminated(s string) []byte {
bytes := make([]byte, len(s))
for i := 0; i < len(s); i++ {
bytes[i] = s[i]
}
return bytes
return []byte(s)
}

// Add a new network link of a specified type. This is identical to
Expand Down Expand Up @@ -789,8 +798,8 @@ func NetworkCreateVethPair(name1, name2 string) error {
nest2 := newRtAttrChild(nest1, IFLA_INFO_DATA, nil)
nest3 := newRtAttrChild(nest2, VETH_INFO_PEER, nil)

last := newRtAttrChild(nest3, syscall.IFLA_IFNAME, zeroTerminated(name2))
last.prefix = syscall.SizeofIfInfomsg
newIfInfomsgChild(nest3, syscall.AF_UNSPEC)
newRtAttrChild(nest3, syscall.IFLA_IFNAME, zeroTerminated(name2))

wb.AddData(nest1)

Expand Down

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