route

Documentation

Overview

Package route provides basic functions for the manipulation of packet routing facilities on BSD variants.

The package supports any version of Darwin, any version of DragonFly BSD, FreeBSD 7 and above, NetBSD 6 and above, and OpenBSD 5.6 and above.

Index

• func FetchRIB(af int, typ RIBType, arg int) ([]byte, error)
• type Addr
• type DefaultAddr
  • func (a *DefaultAddr) Family() int
• type Inet4Addr
  • func (a *Inet4Addr) Family() int
• type Inet6Addr
  • func (a *Inet6Addr) Family() int
• type InterfaceAddrMessage
  • func (m *InterfaceAddrMessage) Sys() []Sys
• type InterfaceAnnounceMessage
  • func (m *InterfaceAnnounceMessage) Sys() []Sys
• type InterfaceMessage
  • func (m *InterfaceMessage) Sys() []Sys
• type InterfaceMetrics
  • func (imx *InterfaceMetrics) SysType() SysType
• type InterfaceMulticastAddrMessage
  • func (m *InterfaceMulticastAddrMessage) Sys() []Sys
• type LinkAddr
  • func (a *LinkAddr) Family() int
• type Message
  • func ParseRIB(typ RIBType, b []byte) ([]Message, error)
• type RIBType
• type RouteMessage
  • func (m *RouteMessage) Marshal() ([]byte, error)
  • func (m *RouteMessage) Sys() []Sys
• type RouteMetrics
  • func (rmx *RouteMetrics) SysType() SysType
• type Sys
• type SysType

Functions

func FetchRIB

func FetchRIB(af int, typ RIBType, arg int) ([]byte, error)

FetchRIB fetches a routing information base from the operating system.

The provided af must be an address family.

The provided arg must be a RIBType-specific argument. When RIBType is related to routes, arg might be a set of route flags. When RIBType is related to network interfaces, arg might be an interface index or a set of interface flags. In most cases, zero means a wildcard.

Types

type Addr

type Addr interface {
	// Family returns an address family.
	Family() int
}

An Addr represents an address associated with packet routing.

type DefaultAddr

type DefaultAddr struct {
	Raw []byte // raw format of address
	// contains filtered or unexported fields
}

A DefaultAddr represents an address of various operating system-specific features.

func (*DefaultAddr) Family

func (a *DefaultAddr) Family() int

Family implements the Family method of Addr interface.

type Inet4Addr

type Inet4Addr struct {
	IP [4]byte // IP address
}

An Inet4Addr represents an internet address for IPv4.

func (*Inet4Addr) Family

func (a *Inet4Addr) Family() int

Family implements the Family method of Addr interface.

type Inet6Addr

type Inet6Addr struct {
	IP     [16]byte // IP address
	ZoneID int      // zone identifier
}

An Inet6Addr represents an internet address for IPv6.

func (*Inet6Addr) Family

func (a *Inet6Addr) Family() int

Family implements the Family method of Addr interface.

type InterfaceAddrMessage

type InterfaceAddrMessage struct {
	Version int    // message version
	Type    int    // message type
	Flags   int    // interface flags
	Index   int    // interface index
	Addrs   []Addr // addresses
	// contains filtered or unexported fields
}

An InterfaceAddrMessage represents an interface address message.

func (*InterfaceAddrMessage) Sys

func (m *InterfaceAddrMessage) Sys() []Sys

Sys implements the Sys method of Message interface.

type InterfaceAnnounceMessage

type InterfaceAnnounceMessage struct {
	Version int    // message version
	Type    int    // message type
	Index   int    // interface index
	Name    string // interface name
	What    int    // what type of announcement
	// contains filtered or unexported fields
}

An InterfaceAnnounceMessage represents an interface announcement message.

func (*InterfaceAnnounceMessage) Sys

func (m *InterfaceAnnounceMessage) Sys() []Sys

Sys implements the Sys method of Message interface.

type InterfaceMessage

type InterfaceMessage struct {
	Version int    // message version
	Type    int    // message type
	Flags   int    // interface flags
	Index   int    // interface index
	Name    string // interface name
	Addrs   []Addr // addresses
	// contains filtered or unexported fields
}

An InterfaceMessage represents an interface message.

func (*InterfaceMessage) Sys

func (m *InterfaceMessage) Sys() []Sys

Sys implements the Sys method of Message interface.

type InterfaceMetrics

type InterfaceMetrics struct {
	Type int // interface type
	MTU  int // maximum transmission unit
}

InterfaceMetrics represents interface metrics.

func (*InterfaceMetrics) SysType

func (imx *InterfaceMetrics) SysType() SysType

SysType implements the SysType method of Sys interface.

type InterfaceMulticastAddrMessage

type InterfaceMulticastAddrMessage struct {
	Version int    // message version
	Type    int    // message type
	Flags   int    // interface flags
	Index   int    // interface index
	Addrs   []Addr // addresses
	// contains filtered or unexported fields
}

An InterfaceMulticastAddrMessage represents an interface multicast address message.

func (*InterfaceMulticastAddrMessage) Sys

func (m *InterfaceMulticastAddrMessage) Sys() []Sys

Sys implements the Sys method of Message interface.

type LinkAddr

type LinkAddr struct {
	Index int    // interface index when attached
	Name  string // interface name when attached
	Addr  []byte // link-layer address when attached
}

A LinkAddr represents a link-layer address.

func (*LinkAddr) Family

func (a *LinkAddr) Family() int

Family implements the Family method of Addr interface.

type Message

type Message interface {
	// Sys returns operating system-specific information.
	Sys() []Sys
}

A Message represents a routing message.

func ParseRIB

func ParseRIB(typ RIBType, b []byte) ([]Message, error)

ParseRIB parses b as a routing information base and returns a list of routing messages.

type RIBType

type RIBType int

A RIBType reprensents a type of routing information base.

const (
	RIBTypeRoute     RIBType = syscall.NET_RT_DUMP
	RIBTypeInterface RIBType = syscall.NET_RT_IFLIST
)

type RouteMessage

type RouteMessage struct {
	Version int     // message version
	Type    int     // message type
	Flags   int     // route flags
	Index   int     // interface index when atatched
	ID      uintptr // sender's identifier; usually process ID
	Seq     int     // sequence number
	Err     error   // error on requested operation
	Addrs   []Addr  // addresses
	// contains filtered or unexported fields
}

A RouteMessage represents a message conveying an address prefix, a nexthop address and an output interface.

Unlike other messages, this message can be used to query adjacency information for the given address prefix, to add a new route, and to delete or modify the existing route from the routing information base inside the kernel by writing and reading route messages on a routing socket.

For the manipulation of routing information, the route message must contain appropriate fields that include:

Version       = <must be specified>
Type          = <must be specified>
Flags         = <must be specified>
Index         = <must be specified if necessary>
ID            = <must be specified>
Seq           = <must be specified>
Addrs         = <must be specified>

The Type field specifies a type of manipulation, the Flags field specifies a class of target information and the Addrs field specifies target information like the following:

route.RouteMessage{
	Version: RTM_VERSION,
	Type: RTM_GET,
	Flags: RTF_UP | RTF_HOST,
	ID: uintptr(os.Getpid()),
	Seq: 1,
	Addrs: []route.Addrs{
		RTAX_DST: &route.Inet4Addr{ ... },
		RTAX_IFP: &route.LinkAddr{ ... },
		RTAX_BRD: &route.Inet4Addr{ ... },
	},
}

The values for the above fields depend on the implementation of each operating system.

The Err field on a response message contains an error value on the requested operation. If non-nil, the requested operation is failed.

func (*RouteMessage) Marshal

func (m *RouteMessage) Marshal() ([]byte, error)

Marshal returns the binary encoding of m.

func (*RouteMessage) Sys

func (m *RouteMessage) Sys() []Sys

Sys implements the Sys method of Message interface.

type RouteMetrics

type RouteMetrics struct {
	PathMTU int // path maximum transmission unit
}

RouteMetrics represents route metrics.

func (*RouteMetrics) SysType

func (rmx *RouteMetrics) SysType() SysType

SysType implements the SysType method of Sys interface.

type Sys

type Sys interface {
	// SysType returns a type of operating system-specific
	// information.
	SysType() SysType
}

A Sys reprensents operating system-specific information.

type SysType

type SysType int

A SysType represents a type of operating system-specific information.

const (
	SysMetrics SysType = iota
	SysStats
)