From a890f18e9aa26470d435b875c826a2bf1966ee35 Mon Sep 17 00:00:00 2001 From: "Guillaume J. Charmes" Date: Wed, 12 Feb 2014 09:29:06 -0800 Subject: [PATCH] Simplify code + Allow more generic attr children + remove prefix Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes (github: creack) --- netlink/netlink.go | 10 ++- netlink/netlink_linux.go | 131 +++++++++++++++++++++------------------ 2 files changed, 79 insertions(+), 62 deletions(-) diff --git a/netlink/netlink.go b/netlink/netlink.go index 5098b4b..5cc7562 100644 --- a/netlink/netlink.go +++ b/netlink/netlink.go @@ -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 { diff --git a/netlink/netlink_linux.go b/netlink/netlink_linux.go index 1f48a64..f8bb6ba 100644 --- a/netlink/netlink_linux.go +++ b/netlink/netlink_linux.go @@ -45,6 +45,7 @@ func getIpFamily(ip net.IP) int { } type NetlinkRequestData interface { + Len() int ToWireFormat() []byte } @@ -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) @@ -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 @@ -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 @@ -137,6 +147,10 @@ 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) } @@ -144,18 +158,17 @@ func rtaAlignOf(attrlen int) int { 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 { @@ -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++ @@ -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 { @@ -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)) } } @@ -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) @@ -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 } @@ -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 { @@ -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) @@ -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 { @@ -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 @@ -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)