dccp

package
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This package is not in the latest version of its module.

 Go to latest Published: Jan 28, 2013 License: AGPL-3.0 Imports: 21 Imported by: 5

Documentation

Index

Constants

View Source 
const (
	CCID2 = 2 // TCP-like Congestion Control, RFC 4341
	CCID3 = 3 // TCP-Friendly Rate Control (TFRC), RFC 4342
)
View Source 
const (
	REQUEST_BACKOFF_FIRST   = 1e9  // Initial re-send period for client Request resends is 1 sec, in ns
	REQUEST_BACKOFF_FREQ    = 10e9 // Back-off Request resend every 10 secs, in ns
	REQUEST_BACKOFF_TIMEOUT = 30e9 // Request re-sends quit after 30 sec, in ns (shorter than RFC recommendation)

	RESPOND_TIMEOUT = 30e9 // Timeout in RESPOND state, 30 sec in ns

	LISTEN_TIMEOUT = REQUEST_BACKOFF_TIMEOUT // Timeout in LISTEN state

	CLOSING_BACKOFF_FREQ    = 64e9    // Backoff frequency of CLOSING timer, 64 seconds, Section 8.3
	CLOSING_BACKOFF_TIMEOUT = MSL / 4 // Maximum time in CLOSING (RFC recommends MSL, but seems too long)

	TIMEWAIT_TIMEOUT = MSL / 2 // Time to stay in TIMEWAIT, Section 8.3 recommends MSL*2

	PARTOPEN_BACKOFF_FIRST   = 200e6 // 200 miliseconds in ns, Section 8.1.5
	PARTOPEN_BACKOFF_FREQ    = 200e6 // 200 miliseconds in ns
	PARTOPEN_BACKOFF_TIMEOUT = 30e9  // 30 sec (Section 8.1.5 recommends 8 min)

	EXPIRE_INTERVAL = 1e9 // Interval for checking expiration conditions
)
View Source 
const (
	Request  = 0
	Response = 1
	Data     = 2
	Ack      = 3
	DataAck  = 4
	CloseReq = 5
	Close    = 6
	Reset    = 7
	Sync     = 8
	SyncAck  = 9
)

Packet types. Stored in the Type field of the generic header. Receivers MUST ignore any packets with reserved type. That is, packets with reserved type MUST NOT be processed, and they MUST NOT be acknowledged as received.

View Source 
const (
	ResetUnspecified       = 0
	ResetClosed            = 1
	ResetAborted           = 2
	ResetNoConnection      = 3
	ResetPacketError       = 4
	ResetOptionError       = 5
	ResetMandatoryError    = 6
	ResetConnectionRefused = 7
	ResetBadServiceCode    = 8
	ResetTooBusy           = 9
	ResetBadInitCookie     = 10
	ResetAgressionPenalty  = 11
)

Reset codes

View Source 
const (
	CsCovAllData = iota
	CsCovNoData
	CsCov4
	CsCov8
	CsCov12
)
View Source 
const (
	MuxLingerTime = 60e9  // 1 min in nanoseconds
	MuxExpireTime = 600e9 // 10 min in nanoseconds
	MuxReadSafety = 5
)
View Source 
const (
	OptionPadding         = 0
	OptionMandatory       = 1
	OptionSlowReceiver    = 2
	OptionChangeL         = 32
	OptionConfirmL        = 33
	OptionChangeR         = 34
	OptionConfirmR        = 35
	OptionInitCookie      = 36
	OptionNDPCount        = 37
	OptionAckVectorNonce0 = 38
	OptionAckVectorNonce1 = 39
	OptionDataDropped     = 40
	OptionTimestamp       = 41
	OptionTimestampEcho   = 42
	OptionElapsedTime     = 43
	OptionDataChecksum    = 44
)
View Source 
const (
	SEQWIN_INIT      = 100        // Initial value for SWAF and SWBF, Section 7.5.2
	SEQWIN_FIXED     = 700        // Large enough constant for SWAF/SWBF until the feature is implemented
	SEQWIN_MAX       = 2 ^ 46 - 1 // Maximum acceptable SWAF and SWBF value
	RoundtripDefault = 2e8        // 0.2 sec, default Round-Trip Time when no measurement is available
	RoundtripMin     = 2e6        // ...
	MSL              = 2 * 60e9   // 2 mins in nanoseconds, Maximum Segment Lifetime, Section 3.4
	MAX_OPTIONS_SIZE = 128
)
View Source 
const (
	CLOSED = iota
	LISTEN
	REQUEST
	RESPOND
	PARTOPEN
	OPEN
	CLOSEREQ
	CLOSING
	TIMEWAIT
)

The nine possible states of a DCCP socket. Listed in increasing order:

View Source 
const (
	TenMicroInNano       = 1e4         // 10 microseconds in nanoseconds
	OneSecInTenMicro     = 1e5         // 1 seconds in ten microsecond units
	MaxTenMicro          = 4294967295  // Maximum allowed time in ten microsecond units
	MaxElapsedInTenMicro = MaxTenMicro // Maximum elapsed time in ten microsecond units
)
View Source 
const (
	EventTurn  = Event(iota) // Turn events mark new information that is admissible (within expectations)
	EventMatch               // Match events mark an admissible outcome of a complex event/computation sequence
	EventCatch               // Catch events are breakpoints on conditions
	EventInfo
	EventWarn
	EventError
	EventIdle  // Idle events are emitted on the turn of the DCCP idle loop
	EventDrop  // Drop events are related to a packet drop
	EventRead  // Read events are related to a packet read
	EventWrite // Write events are related to a packet write
)
View Source 
const (
	AnyProto = iota
)

Constants for protoNo

View Source 
const BackoffMin = 100e6

BackoffMin is the minimum time before two firings of the backoff timers

View Source 
const CCID_FIXED = 0xf
View Source 
const LabelLen = 16
View Source 
const (
	SEQNOMAX = (2 << 48) - 1
)

Variables

View Source 
var (
	ErrInvalid       = NewError("invalid argument") // Invalid arguments passed to a routine
	ErrAlign         = NewError("align")
	ErrSize          = NewError("size")
	ErrSemantic      = NewError("semantic")
	ErrSyntax        = NewError("syntax")
	ErrNumeric       = NewError("numeric")
	ErrOption        = NewError("option")
	ErrOptionsTooBig = NewError("options too big")
	ErrOversize      = NewError("over size")
	ErrCsCov         = NewError("cscov")
	ErrChecksum      = NewError("checksum")
	ErrIPFormat      = NewError("ip format")
	ErrUnknownType   = NewError("unknown packet type")
	ErrUnsupported   = NewError("unsupported")
	ErrProto         = NewError("protocol error")
	ErrDrop          = NewError("dropped")
	ErrReset         = NewError("reset")
	ErrTooBig        = NewError("too big")
	ErrOverflow      = NewError("overflow")
)

TODO: Annotate each error with the circumstances that can cause it

View Source 
var (
	ErrEOF     = NewError("i/o eof")
	ErrAbort   = NewError("i/o aborted")
	ErrTimeout = NewError("i/o timeout")
	ErrBad     = NewError("i/o bad connection")
	ErrIO      = NewError("i/o error")
)

Connection errors

View Source 
var CongestionAck = NewError("cc-ack")

CongestionAck is sent from Congestion Control to Conn to advise that an Ack packet should be sent to the other side.

View Source 
var (
	LabelZero = Label{}
)
View Source 
var SampleType = TypeOf(Sample{})
View Source 
var ZeroAddr = &Addr{}

Functions

func Caller 

func Caller() string

func DecodeUint16 

func DecodeUint16(w []byte) uint16

func DecodeUint24 

func DecodeUint24(w []byte) uint32

func DecodeUint32 

func DecodeUint32(w []byte) uint32

func DecodeUint48 

func DecodeUint48(w []byte) uint64

func DecodeUint8 

func DecodeUint8(w []byte) uint8

func EncodeUint16 

func EncodeUint16(u uint16, w []byte)

func EncodeUint24 

func EncodeUint24(u uint32, w []byte)

func EncodeUint32 

func EncodeUint32(u uint32, w []byte)

func EncodeUint48 

func EncodeUint48(u uint64, w []byte)

func EncodeUint8 

func EncodeUint8(u uint8, w []byte)

func FetchCaller 

func FetchCaller(skip int) (sfile string, sline int)

FetchCaller returns a shortened (more readable) version of the source file name, as well as the source line number of the caller.

func FitsIn16Bits 

func FitsIn16Bits(x uint64) bool

func FitsIn23Bits 

func FitsIn23Bits(x uint64) bool

func FitsIn24Bits 

func FitsIn24Bits(x uint64) bool

func FitsIn32Bits 

func FitsIn32Bits(x uint64) bool

func InstallCtrlCPanic 

func InstallCtrlCPanic()

InstallCtrlCPanic installs a Ctrl-C signal handler that panics

func InstallTimeout 

func InstallTimeout(ns int64)

InstallTimeout panics the current process in ns time

func NanoFromTenMicro 

func NanoFromTenMicro(tenmicro uint32) int64

NanoFromTenMicro converts a time length given in ten microsecond units into nanoseconds, without exceeding the maximum allowed time limit of MaxTenMicro.

func NewCongestionReset 

func NewCongestionReset(resetCode byte) error

func NewError 

func NewError(s string) error

func Nstoa 

func Nstoa(ns int64) string

func ParseServiceCode 

func ParseServiceCode(p []byte) (uint32, error)

func SavePanicTrace 

func SavePanicTrace()

func ServerString 

func ServerString(isServer bool) string

func ServiceCodeString 

func ServiceCodeString(code uint32) string

func StackTrace 

func StackTrace(labels []string, skip int, sfile string, sline int) string

StackTrace formats the stack trace of the calling goroutine, excluding pointer information and including DCCP runtime-specific information, in a manner convenient for debugging DCCP

func StateString 

func StateString(state int) string

func TenMicroDiff 

func TenMicroDiff(t0, t1 uint32) uint32

TenMicroDiff returns the circular difference between t0 an t1. The arguments and the result are in ten microsecond units.

func TenMicroFromNano 

func TenMicroFromNano(ns int64) uint32

TenMicroFromNano converts a time length given in nanoseconds into units of 10 microseconds, capped by MaxTenMicro.

func TrimFuncName 

func TrimFuncName(fname string) (trimmed string, isDCCP bool)

TrimFuncName shortens DCCP function names for readability and whether this is a DCCP or anonymous function

func TrimSourceFile 

func TrimSourceFile(sfile string) string

TrimSourceFile shortens DCCP source file names for readability

func TypeOf 

func TypeOf(a interface{}) string

Types

type Addr 

type Addr struct {
	*Label
	Port uint16
}

Addr{} is a general-purpose data type intended for custom link layer addresses.

func ParseAddr 

func ParseAddr(s string) (addr *Addr, n int, err error)

ParseAddr() parses a link address from s@ in string format

func ReadAddr 

func ReadAddr(p []byte) (addr *Addr, n int, err error)

Read() reads a link address from p@ in wire format

func (*Addr) Address 

func (addr *Addr) Address() string

Address() is identical to String(), included as a method so that Addr conforms to net.Addr

func (*Addr) Network 

func (addr *Addr) Network() string

Network() returns the name of the link address namespace, included to conform to net.Addr

func (*Addr) String 

func (addr *Addr) String() string

String() returns the string represenation of the link address

func (*Addr) Write 

func (addr *Addr) Write(p []byte) (n int, err error)

Write() writes the link address to p@ in wire format

type Amb 

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

Amb represents a runtime context, embodied by a runtime, a stack of labels and set of options. It is also capable of emitting structured logs, that are relative to the overall context, and are consequently used for debuging and analysis purposes. It lives in the context of a shared time framework and a shared filter framework, which may filter some logs out 

var NoLogging *Amb = &Amb{}

A zero-value Amb has the special-case behavior of ignoring all emits

func NewAmb 

func NewAmb(label string, env *Env) *Amb

NewAmb creates a new Amb object with a single entry in the label stack

func (*Amb) Copy 

func (t *Amb) Copy() *Amb

Copy clones this amb into an identical new one

func (*Amb) E 

func (t *Amb) E(event Event, comment string, args ...interface{})

E emits a new log record. The arguments args are scanned in turn. The first argument of type *Header, *PreHeader, *FeedbackHeader or *FeedforwardHeader is considered the DCCP header that this log pertains to. The first argument of type Args is saved in the log record.

func (*Amb) EC 

func (t *Amb) EC(skip int, event Event, comment string, args ...interface{})

func (*Amb) Filter 

func (t *Amb) Filter() *filter.Filter

func (*Amb) Flags 

func (t *Amb) Flags() *Flags

Flags returns the flags associated with this Amb instance

func (*Amb) GetState 

func (t *Amb) GetState() string

GetState retrieves the state of the owning object, using the runtime value store

func (*Amb) Labels 

func (t *Amb) Labels() []string

Labels returns the label stack of this amb

func (*Amb) Push 

func (t *Amb) Push(l string) *Amb

Push adds the label l onto this amb's label stack

func (*Amb) Refine 

func (t *Amb) Refine(l string) *Amb

Refine clones this amb and stack the additional label l

func (*Amb) SetState 

func (t *Amb) SetState(s int)

SetState saves the state s into the runtime value store

type Bytes 

type Bytes interface {
	Bytes() []byte
}

Bytes is a type that has an equivalent representation as a byte slice We use it for addresses, since net.Addr does not require such representation

type CCFixed 

type CCFixed struct {
}

func (CCFixed) NewReceiver 

func (CCFixed) NewReceiver(env *Env, amb *Amb) ReceiverCongestionControl

func (CCFixed) NewSender 

func (CCFixed) NewSender(env *Env, amb *Amb) SenderCongestionControl

type CCID 

type CCID interface {
	NewSender(env *Env, amb *Amb, args ...interface{}) SenderCongestionControl
	NewReceiver(env *Env, amb *Amb, args ...interface{}) ReceiverCongestionControl
}

CCID is a factory type that creates instances of sender and receiver CCIDs 

type ChanLink struct {
	Mutex
	// contains filtered or unexported fields
}

ChanLink treats one side of a channel as an incoming packet link

func NewChanPipe 

func NewChanPipe() (p, q *ChanLink)

func (*ChanLink) Close 

func (l *ChanLink) Close() error

func (*ChanLink) GetMTU 

func (l *ChanLink) GetMTU() int

func (*ChanLink) ReadFrom 

func (l *ChanLink) ReadFrom(buf []byte) (n int, addr net.Addr, err error)

func (*ChanLink) SetReadDeadline 

func (l *ChanLink) SetReadDeadline(t time.Time) error

func (*ChanLink) WriteTo 

func (l *ChanLink) WriteTo(buf []byte, addr net.Addr) (n int, err error)

type CongestionReset 

type CongestionReset byte

CongestionReset is sent from Congestion Control to Conn to indicate that the connection must be reset. CongestionReset encloses the desired Reset Code.

func (CongestionReset) Error 

func (ce CongestionReset) Error() string

func (CongestionReset) ResetCode 

func (ce CongestionReset) ResetCode() byte

type Conn 

type Conn struct {
	Mutex // Protects access to socket, ccidOpen and err
	// contains filtered or unexported fields
}

Conn

func NewConnClient 

func NewConnClient(env *Env, amb *Amb, hc HeaderConn,
	scc SenderCongestionControl, rcc ReceiverCongestionControl, serviceCode uint32) *Conn

func NewConnServer 

func NewConnServer(env *Env, amb *Amb, hc HeaderConn,
	scc SenderCongestionControl, rcc ReceiverCongestionControl) *Conn

func (*Conn) Abort 

func (c *Conn) Abort()

func (*Conn) Amb 

func (c *Conn) Amb() *Amb

Amb returns the Amb instance associated with this connection

func (*Conn) ChooseISS 

func (s *Conn) ChooseISS() int64

ChooseISS chooses a safe Initial Sequence Number

func (*Conn) Close 

func (c *Conn) Close() error

Close implements SegmentConn.Close. It closes the connection, Section 8.3.

func (*Conn) Error 

func (c *Conn) Error() error

func (*Conn) GetAWLH 

func (s *Conn) GetAWLH() (AWL int64, AWH int64)

GetAWLH() computes AWL and AWH, see Section 7.5.1

func (*Conn) GetCCMPS 

func (s *Conn) GetCCMPS() int32

func (*Conn) GetGAR 

func (s *Conn) GetGAR() int64

func (*Conn) GetGSR 

func (s *Conn) GetGSR() int64

func (*Conn) GetGSS 

func (s *Conn) GetGSS() int64

func (*Conn) GetISS 

func (s *Conn) GetISS() int64

func (*Conn) GetMPS 

func (s *Conn) GetMPS() int32

func (*Conn) GetMTU 

func (c *Conn) GetMTU() int

GetMTU() returns the maximum size of an application-level data block that can be passed to Write This is an informative number. Packets are sent anyway, but they may be dropped by the link layer or a router.

func (*Conn) GetOSR 

func (s *Conn) GetOSR() int64

func (*Conn) GetPMTU 

func (s *Conn) GetPMTU() int32

func (*Conn) GetRTT 

func (s *Conn) GetRTT() int64

func (*Conn) GetSWLH 

func (s *Conn) GetSWLH() (SWL int64, SWH int64)

GetSWLH() computes SWL and SWH, see Section 7.5.1

func (*Conn) GetServiceCode 

func (s *Conn) GetServiceCode() uint32

func (*Conn) GetState 

func (s *Conn) GetState() int

func (*Conn) InAckWindow 

func (s *Conn) InAckWindow(x int64) bool

func (*Conn) IsServer 

func (s *Conn) IsServer() bool

func (*Conn) Joiner 

func (c *Conn) Joiner() Joiner

Joiner returns a Joiner instance that can wait until all goroutines associated with the connection have completed.

func (*Conn) LocalLabel 

func (c *Conn) LocalLabel() Bytes

LocalLabel implements SegmentConn.LocalLabel

func (*Conn) PlaceSeqAck 

func (c *Conn) PlaceSeqAck(h *Header)

PlaceSeqAck() updates the socket registers upon receiving a header from the other side.

func (*Conn) Read 

func (c *Conn) Read() (b []byte, err error)

Read blocks until the next packet of application data is received. Successfuly read data is returned in a slice. The error returned by Read behaves according to io.Reader. If the connection was never established or was aborted, Read returns ErrIO. If the connection was closed normally, Read returns io.EOF. In the event of a non-nil error, successive calls to Read return the same error.

func (*Conn) RemoteLabel 

func (c *Conn) RemoteLabel() Bytes

RemoteLabel implements SegmentConn.RemoteLabel

func (*Conn) SetCCIDA 

func (s *Conn) SetCCIDA(v byte)

func (*Conn) SetCCIDB 

func (s *Conn) SetCCIDB(v byte)

func (*Conn) SetCCMPS 

func (s *Conn) SetCCMPS(v int32)

func (*Conn) SetGAR 

func (s *Conn) SetGAR(v int64)

func (*Conn) SetGSR 

func (s *Conn) SetGSR(v int64)

func (*Conn) SetGSS 

func (s *Conn) SetGSS(v int64)

func (*Conn) SetISR 

func (s *Conn) SetISR(v int64)

func (*Conn) SetOSR 

func (s *Conn) SetOSR(v int64)

func (*Conn) SetPMTU 

func (s *Conn) SetPMTU(v int32)

func (*Conn) SetRTT 

func (s *Conn) SetRTT(v int64)

func (*Conn) SetReadExpire 

func (c *Conn) SetReadExpire(nsec int64) error

SetReadExpire implements SegmentConn.SetReadExpire

func (*Conn) SetSWAF 

func (s *Conn) SetSWAF(v int64)

func (*Conn) SetSWBF 

func (s *Conn) SetSWBF(v int64)

func (*Conn) SetServer 

func (s *Conn) SetServer(v bool)

func (*Conn) SetServiceCode 

func (s *Conn) SetServiceCode(v uint32)

func (*Conn) SetState 

func (s *Conn) SetState(v int)

func (*Conn) String 

func (s *Conn) String() string

func (*Conn) UpdateGAR 

func (s *Conn) UpdateGAR(v int64)

func (*Conn) UpdateGSR 

func (s *Conn) UpdateGSR(v int64)

func (*Conn) Write 

func (c *Conn) Write(data []byte) error

Write blocks until the slice b is sent.

func (*Conn) WriteCC 

func (c *Conn) WriteCC(h *Header, timeWrite int64)

func (*Conn) WriteSeqAck 

func (c *Conn) WriteSeqAck(h *writeHeader)

type ElapsedTimeOption 

type ElapsedTimeOption struct {
	Elapsed uint32
}

ElapsedTimeOption, Section 13.2 This option is permitted in any DCCP packet that contains an Acknowledgement Number; such options received on other packet types MUST be ignored. It indicates how much time has elapsed since the packet being acknowledged -- the packet with the given Acknowledgement Number -- was received.

The option data, Elapsed Time, represents an estimated lower bound on the amount of time elapsed since the packet being acknowledged was received, with units of hundredths of milliseconds (10 microseconds granularity).

func DecodeElapsedTimeOption 

func DecodeElapsedTimeOption(opt *Option) *ElapsedTimeOption

func (*ElapsedTimeOption) Encode 

func (opt *ElapsedTimeOption) Encode() (*Option, error)

type Env 

type Env struct {
	sync.Mutex
	// contains filtered or unexported fields
}

Env encapsulates the runtime environment of a DCCP endpoint. It includes a pluggable time interface, in order to allow for use of real as well as synthetic (accelerated) time (for testing purposes), as well as a amb interface.

func NewEnv 

func NewEnv(guzzle TraceWriter) *Env

func (*Env) Close 

func (t *Env) Close() error

func (*Env) Expire 

func (t *Env) Expire(test func() bool, onexpire func(), timeout, interval int64, fmt_ string, args_ ...interface{})

Expire periodically, on every interval duration, checks if the test condition has been met. If the condition is met within the timeout period, no further action is taken. Otherwise, the onexpire function is invoked.

func (*Env) Filter 

func (t *Env) Filter() *filter.Filter

func (*Env) Go 

func (t *Env) Go(f func(), fmt_ string, args_ ...interface{})

Go runs f in a new GoRoutine. The GoRoutine is also added to the GoJoin of the Env.

func (*Env) Joiner 

func (t *Env) Joiner() Joiner

func (*Env) NewGoJoin 

func (t *Env) NewGoJoin(annotation string, group ...Joiner) *GoJoin

func (*Env) Now 

func (t *Env) Now() int64

func (*Env) Sleep 

func (t *Env) Sleep(ns int64)

func (*Env) Snap 

func (t *Env) Snap() (sinceZero int64, sinceLast int64)

func (*Env) Sync 

func (t *Env) Sync() error

func (*Env) TraceWriter 

func (t *Env) TraceWriter() TraceWriter

type Event 

type Event int

Event is the type of logging event. Events are wrapped in a special type to make sure that modifications/additions to the set of events impose respective modifications in the reducer and the inspector.

func (Event) String 

func (e Event) String() string

String returns a textual representation of the event

type FeedbackHeader 

type FeedbackHeader struct {
	Type    byte
	X       bool
	SeqNo   int64
	Options []*Option
	AckNo   int64

	// Time when header received
	Time int64
}

FeedbackHeader contains information that is shown to the sender congesion control at packet reception. FeedbackHeader encloses the parts of the packet header that are sent by the HC-Receiver and received by the HC-Sender

type FeedforwardHeader 

type FeedforwardHeader struct {

	// These fields are copied directly from the header
	Type    byte
	X       bool
	SeqNo   int64
	CCVal   int8
	Options []*Option

	// Time when header received
	Time int64

	// Length of application data in bytes
	DataLen int
}

FeedforwardHeader contains information that is shown to the receiver congesion control at packet reception. FeedforwardHeader encloses the parts of the packet header that are sent by the HC-Sender and received by the HC-Receiver

type FileTraceWriter 

type FileTraceWriter struct {
	sync.Mutex
	// contains filtered or unexported fields
}

FileTraceWriter saves all log entries to a file in JSON format

func NewFileTraceWriter 

func NewFileTraceWriter(filename string) *FileTraceWriter

func NewFileTraceWriterDup 

func NewFileTraceWriterDup(filename string, dup TraceWriter) *FileTraceWriter

NewFileTraceWriterDup creates a TraceWriter that saves logs in a file and also passes them to dup.

func (*FileTraceWriter) Close 

func (t *FileTraceWriter) Close() error

func (*FileTraceWriter) Sync 

func (t *FileTraceWriter) Sync() error

func (*FileTraceWriter) Write 

func (t *FileTraceWriter) Write(r *Trace)

type Flags 

type Flags struct {
	sync.Mutex
	// contains filtered or unexported fields
}

Flags is a general purpose key-value map, which is used inside Amb to allow an Amb and all of its refinements to share a collection of debug flags.

func NewFlags 

func NewFlags() *Flags

NewFlags creates and initializes a new Flags instance

func (*Flags) GetInt64 

func (x *Flags) GetInt64(key string) (value int64, present bool)

func (*Flags) GetUint32 

func (x *Flags) GetUint32(key string) (value uint32, present bool)

func (*Flags) Has 

func (x *Flags) Has(key string) bool

func (*Flags) Init 

func (x *Flags) Init()

Init clears a Flags instance for fresh use

func (*Flags) Set 

func (x *Flags) Set(key string, value interface{})

func (*Flags) SetUint32 

func (x *Flags) SetUint32(key string, value uint32)

type GoJoin 

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

GoJoin waits until a set of GoRoutines all complete. It also allows new routines to be added dynamically before the completion event.

func NewGoJoin 

func NewGoJoin(annotation string, group ...Joiner) *GoJoin

func NewGoJoinCaller 

func NewGoJoinCaller(skip int, annotation string, group ...Joiner) *GoJoin

NewGoJoinCaller creates an object capable of waiting until all supplied GoRoutines complete.

func (*GoJoin) Add 

func (t *GoJoin) Add(u Joiner)

Add adds a Joiner to the group. It can be called at any time as long as the current set of goroutines hasn't completed. For instance, as long as you call Add from a GoRoutine which is waited on by this object, the condtion will be met.

func (*GoJoin) Go 

func (t *GoJoin) Go(f func(), fmt_ string, args_ ...interface{})

Go is a convenience method which forks f into a new GoRoutine and adds the latter to the waiting queue. fmt is a formatted annotation with arguments args.

func (*GoJoin) Join 

func (t *GoJoin) Join()

Join blocks until all goroutines in the group have completed. Join can be called concurrently. If called post-completion of the goroutine group, Join returns immediately.

func (*GoJoin) String 

func (t *GoJoin) String() string

String returns a unique, readable string representation of this instance.

type GoRoutine 

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

GoRoutine represents a running goroutine.

func Go 

func Go(f func(), fmt_ string, args_ ...interface{}) *GoRoutine

func GoCaller 

func GoCaller(f func(), skip int, fmt_ string, args_ ...interface{}) *GoRoutine

Go runs f in a new goroutine and returns a handle object, which can then be used for various synchronization mechanisms.

func (*GoRoutine) Join 

func (g *GoRoutine) Join()

Join blocks until the goroutine completes; otherwise, if the goroutine has completed, it returns immediately. Join can be called concurrently.

func (*GoRoutine) Source 

func (g *GoRoutine) Source() (sfile string, sline int)

Source returns the file and line where the goroutine was forked.

func (*GoRoutine) String 

func (g *GoRoutine) String() string

Strings returns a unique and readable string representation of this instance. 

type Header struct {
	SourcePort  uint16    // Sender port
	DestPort    uint16    // Receiver port
	CCVal       int8      // Used by the HC-Sender's CCID to transmit 4-bit values
	CsCov       byte      // Specifies the parts of packet covered by the checksum
	Type        byte      // Packet type: Data, Ack, Sync, etc.
	X           bool      // Extended seq numbers: generally always true (for us)
	SeqNo       int64     // 48-bit if X=1
	AckNo       int64     // 48-bit if X=1
	ServiceCode uint32    // ServiceCode: Applicaton level service (in Req,Resp pkts)
	ResetCode   byte      // ResetCode: Reason for reset (in Reset pkts)
	ResetData   []byte    // ResetData: Additional reset info (in Reset pkts)
	Options     []*Option // Used for feature negotiation, padding, mandatory flags
	Data        []byte    // Application data (in Req, Resp, Data, DataAck pkts)

}

func ReadHeader 

func ReadHeader(buf []byte,
	sourceIP, destIP []byte,
	protoNo byte,
	allowShortSeqNoFeature bool) (header *Header, err error)

func (*Header) HasAckNo 

func (h *Header) HasAckNo() bool

func (*Header) InitAckHeader 

func (h *Header) InitAckHeader()

InitAckHeader() creates a new Ack header

func (*Header) InitCloseHeader 

func (h *Header) InitCloseHeader()

InitCloseHeader() creates a new Close header

func (*Header) InitDataAckHeader 

func (h *Header) InitDataAckHeader(data []byte)

InitDataAckHeader() creates a new DataAck header

func (*Header) InitDataHeader 

func (h *Header) InitDataHeader(data []byte)

InitDataHeader() creates a new Data header

func (*Header) InitRequestHeader 

func (h *Header) InitRequestHeader(serviceCode uint32)

InitRequestHeader() creates a new Request header

func (*Header) InitResetHeader 

func (h *Header) InitResetHeader(resetCode byte)

InitResetHeader() creates a new Reset header

func (*Header) InitResponseHeader 

func (h *Header) InitResponseHeader(serviceCode uint32)

InitResponseHeader() creates a new Response header

func (*Header) InitSyncAckHeader 

func (h *Header) InitSyncAckHeader()

InitSyncAckHeader() creates a new Sync header

func (*Header) InitSyncHeader 

func (h *Header) InitSyncHeader()

InitSyncHeader() creates a new Sync header

func (*Header) String 

func (h *Header) String() string

func (*Header) Write 

func (gh *Header) Write(sourceIP, destIP []byte,
	protoNo byte,
	allowShortSeqNoFeature bool) (header []byte, err error)

Write() writes the DCCP header to two return buffers. The first one is the header part, and the second one is the data part which simply equals the slice Header.Data

type HeaderConn 

type HeaderConn interface {
	// GetMTU() returns the Maximum Transmission Unit size. This is the maximum
	// byte size of the header and app data wire-format footprint.
	GetMTU() int

	// Read returns ErrTimeout in the event of timeout. See SetReadExpire.
	Read() (h *Header, err error)

	// Write can return ErrTooBig, if the wire-format of h exceeds the MTU
	Write(h *Header) (err error)

	LocalLabel() Bytes

	RemoteLabel() Bytes

	// SetReadExpire behaves similarly to SegmentConn.SetReadExpire
	SetReadExpire(nsec int64) error

	Close() error
}

Implementors of this interface MUST only return i/o errors defined in the dccp package (ErrEOF, ErrBad, ErrTimeout, etc.)

func NewHeaderConn 

func NewHeaderConn(bc SegmentConn) HeaderConn

————— NewHeaderConn creates a HeaderConn on top of a SegmentConn

type Joiner 

type Joiner interface {
	// Join blocks until an underlying event occurs.
	// It returns immediately if called post-event.
	// It is re-entrant.
	Join()
	String() string
}

Joiner is an interface to objects that can wait for some event.

type Label 

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

Label{} is an immutable object, representing a general-purpose address similar to IPv6 in that it consists of 16 opaque bytes.

func ChooseLabel 

func ChooseLabel() *Label

ChooseLabel() creates a new label by choosing its bytes randomly

func ParseLabel 

func ParseLabel(s string) (label *Label, n int, err error)

ParseLabel() parses and creates a new label from the string representation in s@

func ReadLabel 

func ReadLabel(p []byte) (label *Label, n int, err error)

ReadLabel() reads and creates a new label from a wire format representation in p@

func (*Label) Address 

func (label *Label) Address() string

func (*Label) Bytes 

func (label *Label) Bytes() []byte

func (*Label) Equal 

func (label *Label) Equal(q *Label) bool

Equal() performs a deep check for equality with q@

func (*Label) Hash 

func (label *Label) Hash() uint64

Hash() returns the hash code of this label

func (*Label) String 

func (label *Label) String() string

String() returns a string representation of the label

func (*Label) Write 

func (label *Label) Write(p []byte) (n int, err error)

Write() writes the wire format representation of the label into p@ 

type Link interface {

	// Returns the Maximum Transmission Unit
	// Writes smaller than this are guaranteed to be sent whole
	GetMTU() int

	// ReadFrom receives the next packet of data. It returns net.Error errors. So in the event
	// of a timeout e.g. it will return a net.Error with Timeout() true, rather than an
	// ErrTimeout. The latter is used internally to DCCP in types that implement HeaderConn and
	// SegmentConn.
	ReadFrom(buf []byte) (n int, addr net.Addr, err error)

	// WriteTo sends a packet of data
	WriteTo(buf []byte, addr net.Addr) (n int, err error)

	// SetReadDeadline has the same meaning as net.Conn.SetReadDeadline
	SetReadDeadline(t time.Time) error

	// Close terminates the link gracefully
	Close() error
}

Link is an abstract interface to a physical connection-less packet layer which sends and receives packets

type Mutex 

type Mutex struct {
	sync.Mutex
}

func (*Mutex) AssertLocked 

func (m *Mutex) AssertLocked()

func (*Mutex) Lock 

func (m *Mutex) Lock()

func (*Mutex) Unlock 

func (m *Mutex) Unlock()

type Mux 

type Mux struct {
	Mutex
	// contains filtered or unexported fields
}

Mux is a thin protocol layer that works on top of a connection-less packet layer, like UDP. Mux multiplexes packets into flows. A flow is a point-to-point connection, which has no congestion or reliability mechanism.

Mux implements a mechanism for dropping packets that linger (are received) for up to one minute after their respective flow has been closed.

Mux force-closes flows that have experienced no activity for 10 mins

func NewMux 

func NewMux(link Link) *Mux

NewMux creates a new Mux object, using the connection-less packet interface link

func (*Mux) Accept 

func (m *Mux) Accept() (c SegmentConn, err error)

Accept() returns the first incoming flow request

func (*Mux) Close 

func (m *Mux) Close() error

Close() closes the mux and signals all outstanding connections that it is time to terminate

func (*Mux) Dial 

func (m *Mux) Dial(addr net.Addr) (c SegmentConn, err error)

Dial opens a packet-based connection to the Link-layer addr

type Option 

type Option struct {
	Type      byte
	Data      []byte
	Mandatory bool
}

type PreHeader 

type PreHeader struct {
	Type  byte
	X     bool
	SeqNo int64
	AckNo int64

	// TimeWrite is the time just before the packet is handed off to the
	// network layer.  The bulk of the time difference between TimeWrite and
	// TimeMake reflects the duration that the packet spends in the write
	// queue before it is pulled for sending, which itself is a function of
	// the send rate. TimeWrite is currently used by the CC logic to measure
	// the roundtrip time without factoring rate-related wait times in
	// endpoint queues.
	TimeWrite int64
}

PreHeader contains information that is shown to the sender and receiver congesion controls before a packet is sent. PreHeader contains the parts of the DCCP header than are fixed before the CCID has made its changes to CCVal and Options.

type ProtoError 

type ProtoError string

ProtoError is a type that wraps all DCCP-specific errors. It is utilized to distinguish these errors from others, using type checks.

func (ProtoError) Error 

func (e ProtoError) Error() string

type ReceiverCongestionControl 

type ReceiverCongestionControl interface {

	// GetID() returns the CCID of this congestion control algorithm
	GetID() byte

	// Open tells the Congestion Control that the connection has entered
	// OPEN or PARTOPEN state and that the CC can now kick in.
	Open()

	// Conn calls OnWrite before a packet is sent to give CongestionControl
	// an opportunity to add CCVal and options to an outgoing packet
	// NOTE: If the CC is not active, OnWrite MUST return nil.
	OnWrite(ph *PreHeader) (options []*Option)

	// Conn calls OnRead after a packet has been accepted and validated
	// If OnRead returns ErrDrop, the packet will be dropped and no further processing
	// will occur.
	// NOTE: If the CC is not active, OnRead MUST return nil.
	OnRead(ff *FeedforwardHeader) error

	// OnIdle behaves identically to the same method of the HC-Sender CCID
	OnIdle(now int64) error

	// Close terminates the half-connection congestion control when it is not needed any longer
	Close()
}

ReceiverCongestionControl specifies the interface for the congestion control logic of a DCCP receiver (aka Half-Connection Receiver CCID)

type Sample 

type Sample struct {
	Series string
	Value  float64
	Unit   string
}

One Sample argument can be attached to a log. The inspector interprets it as a data point in a time series where: 

(i)   The time series name is given by the label stack of the amb
(ii)  The X-value of the data point equals the time the log was emitted
(iii) The Y-value of the data point is stored inside the Sample object

func NewSample 

func NewSample(name string, value float64, unit string) Sample

type SegmentConn 

type SegmentConn interface {
	// GetMTU returns th he largest allowable block size (for read and write). The MTU may vary.
	GetMTU() int

	// Read returns an ErrTimeout in the event of a timeout. See SetReadExpire.
	Read() (block []byte, err error)

	// If the user attempts to write a block that is too big, an ErrTooBig is returned
	// and the block is not sent.
	Write(block []byte) (err error)

	LocalLabel() Bytes

	RemoteLabel() Bytes

	// SetReadExpire sets the expiration time for any blocked calls to Read
	// as a time represented in nanoseconds from now. It's semantics are similar to that
	// of net.Conn.SetReadDeadline except that the deadline is specified in time from now,
	// rather than absolute time. Also note that Read is expected to return
	// an ErrTimeout in the event of timeouts.
	SetReadExpire(nsec int64) error

	Close() error
}

A SegmentConn is an I/O facility that explicitly reads/writes data in the form of indivisible blocks of data. Implementors of this interface MUST only return i/o errors defined in the dccp package (ErrEOF, ErrBad, ErrTimeout, etc.)

type SegmentDialAccepter 

type SegmentDialAccepter interface {
	Accept() (c SegmentConn, err error)
	Dial(addr net.Addr) (c SegmentConn, err error)
	Close() error
}

SegmentDialAccepter represents a type that can accept and dial lossy packet connections

type SenderCongestionControl 

type SenderCongestionControl interface {

	// GetID() returns the CCID of this congestion control algorithm
	GetID() byte

	// GetCCMPS returns the Congestion Control Maximum Packet Size, CCMPS. Generally, PMTU <= CCMPS
	GetCCMPS() int32

	// GetRTT returns the Round-Trip Time as measured by this CCID
	GetRTT() int64

	// Open tells the Congestion Control that the connection has entered
	// OPEN or PARTOPEN state and that the CC can now kick in. Before the
	// call to Open and after the call to Close, the Strobe function is
	// expected to return immediately.
	Open()

	// Conn calls OnWrite before a packet is sent to give CongestionControl
	// an opportunity to add CCVal and options to an outgoing packet
	// NOTE: If the CC is not active, OnWrite should return 0, nil.
	OnWrite(ph *PreHeader) (ccval int8, options []*Option)

	// Conn calls OnRead after a packet has been accepted and validated
	// If OnRead returns ErrDrop, the packet will be dropped and no further processing
	// will occur. If OnRead returns ResetError, the connection will be reset.
	// NOTE: If the CC is not active, OnRead MUST return nil.
	OnRead(fb *FeedbackHeader) error

	// Strobe blocks until a new packet can be sent without violating the
	// congestion control rate limit.
	// NOTE: If the CC is not active, Strobe MUST return immediately.
	Strobe()

	// OnIdle is called periodically, giving the CC a chance to:
	// (a) Request a connection reset by returning a CongestionReset, or
	// (b) Request the injection of an Ack packet by returning a CongestionAck
	// NOTE: If the CC is not active, OnIdle MUST to return nil.
	OnIdle(now int64) error

	// SetHeartbeat advices the CCID of the desired frequency of heartbeat packets.
	// A heartbeat interval value of zero indicates that no heartbeat is needed.
	SetHeartbeat(interval int64)

	// Close terminates the half-connection congestion control when it is not needed any longer
	Close()
}

SenderCongestionControl specifies the interface for the congestion control logic of a DCCP sender (aka Half-Connection Sender CCID)

type Stack 

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

func NewStack 

func NewStack(link Link, ccid CCID) *Stack

NewStack creates a new connection-handling object.

func (*Stack) Accept 

func (s *Stack) Accept() (c SegmentConn, err error)

Accept blocks until a new connecion is established. It then returns the connection.

func (*Stack) Dial 

func (s *Stack) Dial(addr net.Addr, serviceCode uint32) (c SegmentConn, err error)

Dial initiates a new connection to the specified Link-layer address.

type TimestampEchoOption 

type TimestampEchoOption struct {
	// The timestamp echo option value in 10 microsecond circular units
	Timestamp uint32
	// The elapsed time in nanoseconds
	Elapsed uint32
}

————— TimestampEchoOption, Section 13.3 Time values are based on a circular uint32 value at 10 microseconds granularity

func DecodeTimestampEchoOption 

func DecodeTimestampEchoOption(opt *Option) *TimestampEchoOption

func (*TimestampEchoOption) Encode 

func (opt *TimestampEchoOption) Encode() (*Option, error)

type TimestampOption 

type TimestampOption struct {
	// Timestamp is given in 10 microsecond circular units
	Timestamp uint32
}

TimestampOption, Section 13.1 Time values are based on a circular uint32 value at 10 microseconds granularity

func DecodeTimestampOption 

func DecodeTimestampOption(opt *Option) *TimestampOption

func (*TimestampOption) Encode 

func (opt *TimestampOption) Encode() (*Option, error)

type Trace 

type Trace struct {

	// Time is the DCCP runtime time when the log was emitted
	Time int64 `json:"t"`

	// Labels is a list of runtime labels that identify some dynamic
	// instance of the DCCP stack.  For example, if two instances of Conn
	// are available at runtime (as in the case of tests in the sandbox),
	// one can be labeled "client" and the other "server". The labels slice
	// is kept as a field inside the Amb object, so that it can be
	// filled in automatically upon calls to the Amb's E method.
	Labels []string `json:"l"`

	// Event is an identifier representing the type of event that this trace represents. It
	// can be something like "Warn", "Info", etc.
	Event Event `json:"e"`

	// If applicable, State is the DCCP state of the runtime instance (or system) that this log
	// record pertains to. This is typically used only if the system is a dccp.Conn.
	State string `json:"s"`

	// Comment is a free-form textual comment
	Comment string `json:"c"`

	// Args are any additional arguments in the form of string keys mapped to open-ended values.
	// See documentation of E method for details how it is typically used.
	Args map[string]interface{} `json:"a"`

	// If this trace pertains to a DCCP header, Type is the DCCP type of this header.
	Type string `json:"ht"`

	// If this trace pertains to a DCCP header, SeqNo is the DCCP sequence number of this header.
	SeqNo int64 `json:"hs"`

	// If this trace pertains to a DCCP header, AckNo is the DCCP acknowledgement number of
	// this header.
	AckNo int64 `json:"ha"`

	// SourceFile is the name of the source file where this trace was emitted.
	SourceFile string `json:"sf"`

	// SourceLine is the line number in the source file where this trace was emitted.
	SourceLine int `json:"sl"`

	// Trace is the stack trace at the log entry's creation point
	Trace string `json:"st"`

	// Highlight indicates whether this record is of particular interest. Used for visualization purposes.
	// Currently, the inspector draws time series only for highlighted records.
	Highlight bool
}

Trace stores a log event. It can be used to marshal to JSON and pass to external visualisation tools.

func (*Trace) ArgOfType 

func (x *Trace) ArgOfType(example interface{}) interface{}

ArgOfType returns an argument of the same type as example, if one is present in the log, or nil otherwise

func (*Trace) IsHighlighted 

func (x *Trace) IsHighlighted() bool

func (*Trace) LabelString 

func (x *Trace) LabelString() string

LabelString returns a textual representation of the label stack of this log

func (*Trace) Sample 

func (x *Trace) Sample() (sample *Sample, present bool)

Sample returns the value of a sample embedded in this trace, if it exists

func (*Trace) SetHighlight 

func (x *Trace) SetHighlight()

Highlight sets the highlight flag on this Trace. This is used in test-specific TraceWriters to indicate to the inspector that this record is of particular interest for visualization purposes.

type TraceWriter 

type TraceWriter interface {
	Write(*Trace)
	Sync() error
	Close() error
}

TraceWriter is a type that consumes log entries. 

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

UDPLink binds to a UDP port and acts as a Link. 

func BindUDPLink(netw string, laddr *net.UDPAddr) (link *UDPLink, err error)

func (*UDPLink) Close 

func (u *UDPLink) Close() error

func (*UDPLink) GetMTU 

func (u *UDPLink) GetMTU() int

func (*UDPLink) ReadFrom 

func (u *UDPLink) ReadFrom(buf []byte) (n int, addr net.Addr, err error)

func (*UDPLink) SetReadDeadline 

func (u *UDPLink) SetReadDeadline(t time.Time) error

func (*UDPLink) WriteTo 

func (u *UDPLink) WriteTo(buf []byte, addr net.Addr) (n int, err error)

Source Files

View all Source files

Directories

Path Synopsis
This package contains utilities for testing DCCP and CCID in a controlled, simulated environment.
 This package contains utilities for testing DCCP and CCID in a controlled, simulated environment.

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