pktcls

Documentation

Overview

Package class implements tools for classifying and acting on network packets.

A class is a named condition that exposes an Eval method; when Eval yields true for a ClsPkt, that packet is considered to be part of that class.

The following conditions are supported: AnyOf, AllOf, Boolean true, Boolean false and IPv4. AnyOf returns true if at least one subcondition returns true. AllOf returns true if all subconditions return true. AllOf or AnyOf without subconditions return true. Boolean conditions always return their internal value. IPv4 conditions include predicates that compare the analyzed packet to preset values. Supported IPv4 conditions currently include destination network match, source network match and ToS/DSCP fields match. Multiple predicates can be checked by enumerating them under AllOf or AnyOf.

Actions are marshalable objects that describe a process. Currently, the only supported actions are Path Filters (ActionFilterPaths), which are containers for a spathmeta.PathPredicate object.

Marshalable policies can be implemented by external code by mapping Cond items to Action items.

Package class supports JSON marshaling and unmarshaling of classes and actions. Due to the custom formatting of the JSON output, marshaling must be done by first adding the classes and actions to a ClassMap or ActionMap, respectively. Unmarshaling back to the Map is guaranteed to yield an object that is identical to the initial one.

Index

• Constants
• type Action
• type ActionFilterPaths
  • func NewActionFilterPaths(name string, cond Cond) *ActionFilterPaths
  • func (a *ActionFilterPaths) Act(values interface{}) interface{}
  • func (a *ActionFilterPaths) GetName() string
  • func (a *ActionFilterPaths) MarshalJSON() ([]byte, error)
  • func (a *ActionFilterPaths) SetName(name string)
  • func (a *ActionFilterPaths) Type() string
  • func (a *ActionFilterPaths) UnmarshalJSON(b []byte) error
• type ActionMap
  • func (am ActionMap) MarshalJSON() ([]byte, error)
  • func (am *ActionMap) UnmarshalJSON(b []byte) error
• type Class
  • func NewClass(name string, cond Cond) *Class
  • func (c *Class) Eval(hpkt *Packet) bool
  • func (c *Class) GetName() string
  • func (c *Class) MarshalJSON() ([]byte, error)
  • func (c *Class) UnmarshalJSON(b []byte) error
• type ClassMap
  • func (cm ClassMap) MarshalJSON() ([]byte, error)
  • func (cm *ClassMap) UnmarshalJSON(b []byte) error
• type Cond
• type CondAllOf
  • func NewCondAllOf(children ...Cond) CondAllOf
  • func (c CondAllOf) Eval(v interface{}) bool
  • func (c CondAllOf) MarshalJSON() ([]byte, error)
  • func (c CondAllOf) String() string
  • func (c CondAllOf) Type() string
  • func (c *CondAllOf) UnmarshalJSON(b []byte) error
• type CondAnyOf
  • func NewCondAnyOf(children ...Cond) CondAnyOf
  • func (c CondAnyOf) Eval(v interface{}) bool
  • func (c CondAnyOf) MarshalJSON() ([]byte, error)
  • func (c CondAnyOf) String() string
  • func (c CondAnyOf) Type() string
  • func (c *CondAnyOf) UnmarshalJSON(b []byte) error
• type CondBool
  • func (c CondBool) Eval(v interface{}) bool
  • func (c CondBool) Type() string
• type CondIPv4
  • func NewCondIPv4(p IPv4Predicate) *CondIPv4
  • func (c *CondIPv4) Eval(v interface{}) bool
  • func (c *CondIPv4) MarshalJSON() ([]byte, error)
  • func (c *CondIPv4) Type() string
  • func (c *CondIPv4) UnmarshalJSON(b []byte) error
• type CondNot
  • func NewCondNot(operand Cond) CondNot
  • func (c CondNot) Eval(v interface{}) bool
  • func (c CondNot) MarshalJSON() ([]byte, error)
  • func (c CondNot) String() string
  • func (c CondNot) Type() string
  • func (c *CondNot) UnmarshalJSON(b []byte) error
• type CondPathPredicate
  • func NewCondPathPredicate(pp *spathmeta.PathPredicate) *CondPathPredicate
  • func (c *CondPathPredicate) Eval(v interface{}) bool
  • func (c *CondPathPredicate) Type() string
• type IPv4MatchDSCP
  • func (m *IPv4MatchDSCP) Eval(p *layers.IPv4) bool
  • func (m *IPv4MatchDSCP) MarshalJSON() ([]byte, error)
  • func (m *IPv4MatchDSCP) Type() string
  • func (m *IPv4MatchDSCP) UnmarshalJSON(b []byte) error
• type IPv4MatchDestination
  • func (m *IPv4MatchDestination) Eval(p *layers.IPv4) bool
  • func (m *IPv4MatchDestination) MarshalJSON() ([]byte, error)
  • func (m *IPv4MatchDestination) Type() string
  • func (m *IPv4MatchDestination) UnmarshalJSON(b []byte) error
• type IPv4MatchSource
  • func (m *IPv4MatchSource) Eval(p *layers.IPv4) bool
  • func (m *IPv4MatchSource) MarshalJSON() ([]byte, error)
  • func (m *IPv4MatchSource) Type() string
  • func (m *IPv4MatchSource) UnmarshalJSON(b []byte) error
• type IPv4MatchToS
  • func (m *IPv4MatchToS) Eval(p *layers.IPv4) bool
  • func (m *IPv4MatchToS) MarshalJSON() ([]byte, error)
  • func (m *IPv4MatchToS) Type() string
  • func (m *IPv4MatchToS) UnmarshalJSON(b []byte) error
• type IPv4Predicate
• type Packet
  • func NewPacket(raw common.RawBytes) *Packet
• type Typer

Constants

const (
	TypeCondAllOf            = "CondAllOf"
	TypeCondAnyOf            = "CondAnyOf"
	TypeCondNot              = "CondNot"
	TypeCondBool             = "CondBool"
	TypeCondIPv4             = "CondIPv4"
	TypeCondPathPredicate    = "CondPathPredicate"
	TypeActionFilterPaths    = "ActionFilterPaths"
	TypeIPv4MatchSource      = "MatchSource"
	TypeIPv4MatchDestination = "MatchDestination"
	TypeIPv4MatchToS         = "MatchToS"
	TypeIPv4MatchDSCP        = "MatchDSCP"
)

Types

type Action

type Action interface {
	Act(interface{}) interface{}
	GetName() string
	SetName(name string)
	Typer
}

Interface Action defines how paths and packets may be processed in a way that can be exported to JSON. Types implementing Action must not be marshaled to JSON directly; instead, first create an ActionMap, add the desired actions to it and then marshal the entire ActionMap.

type ActionFilterPaths

type ActionFilterPaths struct {
	Cond Cond
	Name string `json:"-"`
}

ActionFilterPaths filters paths according to the embedded Cond object. CondAnyOf, CondAllOf, CondNot and CondPathPredicate conditions can be combined to implement complex path selection policies.

func NewActionFilterPaths

func NewActionFilterPaths(name string, cond Cond) *ActionFilterPaths

func (*ActionFilterPaths) Act

func (a *ActionFilterPaths) Act(values interface{}) interface{}

Act takes an AppPathSet and returns a new AppPathSet containing only the paths permitted by the conditional predicate.

func (*ActionFilterPaths) GetName

func (a *ActionFilterPaths) GetName() string

func (*ActionFilterPaths) MarshalJSON

func (a *ActionFilterPaths) MarshalJSON() ([]byte, error)

func (*ActionFilterPaths) SetName

func (a *ActionFilterPaths) SetName(name string)

func (*ActionFilterPaths) Type

func (a *ActionFilterPaths) Type() string

func (*ActionFilterPaths) UnmarshalJSON

func (a *ActionFilterPaths) UnmarshalJSON(b []byte) error

type ActionMap

type ActionMap map[string]Action

ActionMap is a container for Actions, keyed by their unique name. ActionMap can be used to marshal Actions to JSON. Unmarshaling back to ActionMap is guaranteed to yield an object that is identical to the initial one.

func (ActionMap) MarshalJSON

func (am ActionMap) MarshalJSON() ([]byte, error)

func (*ActionMap) UnmarshalJSON

func (am *ActionMap) UnmarshalJSON(b []byte) error

type Class

type Class struct {
	Cond Cond
	// contains filtered or unexported fields
}

Type Class is used to define classes of network traffic. All packets matching Cond are said to be part of the class. Class must not be marshaled to JSON directly; instead, first create a ClassMap, add the desired classes to it and then marshal the entire ClassMap.

func NewClass

func NewClass(name string, cond Cond) *Class

func (*Class) Eval

func (c *Class) Eval(hpkt *Packet) bool

func (*Class) GetName

func (c *Class) GetName() string

func (*Class) MarshalJSON

func (c *Class) MarshalJSON() ([]byte, error)

func (*Class) UnmarshalJSON

func (c *Class) UnmarshalJSON(b []byte) error

type ClassMap

type ClassMap map[string]*Class

ClassMap is a container for Classes, keyed by their unique name. ClassMap can be used to marshal Classes to JSON. Unmarshaling back to ClassMap is guaranteed to yield an object that is identical to the initial one.

func (ClassMap) MarshalJSON

func (cm ClassMap) MarshalJSON() ([]byte, error)

func (*ClassMap) UnmarshalJSON

func (cm *ClassMap) UnmarshalJSON(b []byte) error

type Cond

type Cond interface {
	Eval(v interface{}) bool
	Typer
}

Cond is used to decide which objects match a logical predicate. Types implementing Cond should not be marshaled directly to JSON. Instead, embed them into a Class and add the Class to a ClassMap; finally, marshal the entire ClassMap.

Implemented logical operations include or (CondAnyOf), and (CondAllOf) and not (CondNot).

type CondAllOf

type CondAllOf []Cond

CondAllOf conditions return true if at least one subcondition returns true.

func NewCondAllOf

func NewCondAllOf(children ...Cond) CondAllOf

func (CondAllOf) Eval

func (c CondAllOf) Eval(v interface{}) bool

func (CondAllOf) MarshalJSON

func (c CondAllOf) MarshalJSON() ([]byte, error)

func (CondAllOf) String

func (c CondAllOf) String() string

func (CondAllOf) Type

func (c CondAllOf) Type() string

func (*CondAllOf) UnmarshalJSON

func (c *CondAllOf) UnmarshalJSON(b []byte) error

type CondAnyOf

type CondAnyOf []Cond

CondAnyOf conditions return true if all subconditions return true.

func NewCondAnyOf

func NewCondAnyOf(children ...Cond) CondAnyOf

func (CondAnyOf) Eval

func (c CondAnyOf) Eval(v interface{}) bool

func (CondAnyOf) MarshalJSON

func (c CondAnyOf) MarshalJSON() ([]byte, error)

func (CondAnyOf) String

func (c CondAnyOf) String() string

func (CondAnyOf) Type

func (c CondAnyOf) Type() string

func (*CondAnyOf) UnmarshalJSON

func (c *CondAnyOf) UnmarshalJSON(b []byte) error

type CondBool

type CondBool bool

CondBool contains a true or false value, useful for debugging and testing.

var (
	CondTrue  CondBool = true
	CondFalse CondBool = false
)

func (CondBool) Eval

func (c CondBool) Eval(v interface{}) bool

func (CondBool) Type

func (c CondBool) Type() string

type CondIPv4

type CondIPv4 struct {
	Predicate IPv4Predicate
}

CondIPv4 conditions return true if the embedded IPv4 predicate returns true.

func NewCondIPv4

func NewCondIPv4(p IPv4Predicate) *CondIPv4

func (*CondIPv4) Eval

func (c *CondIPv4) Eval(v interface{}) bool

func (*CondIPv4) MarshalJSON

func (c *CondIPv4) MarshalJSON() ([]byte, error)

func (*CondIPv4) Type

func (c *CondIPv4) Type() string

func (*CondIPv4) UnmarshalJSON

func (c *CondIPv4) UnmarshalJSON(b []byte) error

type CondNot

type CondNot struct {
	Operand Cond
}

CondNot conditions negate the result of the subcondition.

func NewCondNot

func NewCondNot(operand Cond) CondNot

func (CondNot) Eval

func (c CondNot) Eval(v interface{}) bool

func (CondNot) MarshalJSON

func (c CondNot) MarshalJSON() ([]byte, error)

func (CondNot) String

func (c CondNot) String() string

func (CondNot) Type

func (c CondNot) Type() string

func (*CondNot) UnmarshalJSON

func (c *CondNot) UnmarshalJSON(b []byte) error

type CondPathPredicate

type CondPathPredicate struct {
	PP *spathmeta.PathPredicate
}

CondPathPredicate implements interface Cond, and is designed for use in conditions for ActionFilterPaths. CondPathPredicate returns true if the argument to eval is a *sciond.PathReplyEntry that satisfies the embedded predicate PP.

func NewCondPathPredicate

func NewCondPathPredicate(pp *spathmeta.PathPredicate) *CondPathPredicate

func (*CondPathPredicate) Eval

func (c *CondPathPredicate) Eval(v interface{}) bool

func (*CondPathPredicate) Type

func (c *CondPathPredicate) Type() string

type IPv4MatchDSCP

type IPv4MatchDSCP struct {
	DSCP uint8
}

IPv4MatchDSCP checks whether the DSCP subset of the TOS field matches.

func (*IPv4MatchDSCP) Eval

func (m *IPv4MatchDSCP) Eval(p *layers.IPv4) bool

func (*IPv4MatchDSCP) MarshalJSON

func (m *IPv4MatchDSCP) MarshalJSON() ([]byte, error)

func (*IPv4MatchDSCP) Type

func (m *IPv4MatchDSCP) Type() string

func (*IPv4MatchDSCP) UnmarshalJSON

func (m *IPv4MatchDSCP) UnmarshalJSON(b []byte) error

type IPv4MatchDestination

type IPv4MatchDestination struct {
	Net *net.IPNet
}

IPv4MatchDestination checks whether the destination IPv4 address is contained in Net.

func (*IPv4MatchDestination) Eval

func (m *IPv4MatchDestination) Eval(p *layers.IPv4) bool

func (*IPv4MatchDestination) MarshalJSON

func (m *IPv4MatchDestination) MarshalJSON() ([]byte, error)

func (*IPv4MatchDestination) Type

func (m *IPv4MatchDestination) Type() string

func (*IPv4MatchDestination) UnmarshalJSON

func (m *IPv4MatchDestination) UnmarshalJSON(b []byte) error

type IPv4MatchSource

type IPv4MatchSource struct {
	Net *net.IPNet
}

IPv4MatchSource checks whether the source IPv4 address is contained in Net.

func (*IPv4MatchSource) Eval

func (m *IPv4MatchSource) Eval(p *layers.IPv4) bool

func (*IPv4MatchSource) MarshalJSON

func (m *IPv4MatchSource) MarshalJSON() ([]byte, error)

func (*IPv4MatchSource) Type

func (m *IPv4MatchSource) Type() string

func (*IPv4MatchSource) UnmarshalJSON

func (m *IPv4MatchSource) UnmarshalJSON(b []byte) error

type IPv4MatchToS

type IPv4MatchToS struct {
	TOS uint8
}

IPv4MatchToS checks whether the ToS field matches.

func (*IPv4MatchToS) Eval

func (m *IPv4MatchToS) Eval(p *layers.IPv4) bool

func (*IPv4MatchToS) MarshalJSON

func (m *IPv4MatchToS) MarshalJSON() ([]byte, error)

func (*IPv4MatchToS) Type

func (m *IPv4MatchToS) Type() string

func (*IPv4MatchToS) UnmarshalJSON

func (m *IPv4MatchToS) UnmarshalJSON(b []byte) error

type IPv4Predicate

type IPv4Predicate interface {
	// Eval returns true if the IPv4 packet matched the predicate
	Eval(*layers.IPv4) bool
	Typer
}

IPv4Predicate describes a single test on various IPv4 packet fields.

type Packet

type Packet struct {
	// contains filtered or unexported fields
}

Packet is a wrapper around common.RawBytes which is used to store additional metadata relating to packet classification and processing.

func NewPacket

func NewPacket(raw common.RawBytes) *Packet

type Typer

type Typer interface {
	Type() string
}