pex

Documentation

Index

• Constants
• Variables
• type AddrBook
  • func NewAddrBook(filePath string, routabilityStrict bool) AddrBook
• type ErrAddrBookInvalidAddr
  • func (err ErrAddrBookInvalidAddr) Error() string
• type ErrAddrBookNilAddr
  • func (err ErrAddrBookNilAddr) Error() string
• type ErrAddrBookNonRoutable
  • func (err ErrAddrBookNonRoutable) Error() string
• type ErrAddrBookPrivate
  • func (err ErrAddrBookPrivate) Error() string
  • func (err ErrAddrBookPrivate) PrivateAddr() bool
• type ErrAddrBookPrivateSrc
  • func (err ErrAddrBookPrivateSrc) Error() string
  • func (err ErrAddrBookPrivateSrc) PrivateAddr() bool
• type ErrAddrBookSelf
  • func (err ErrAddrBookSelf) Error() string
• type ErrAddressBanned
  • func (err ErrAddressBanned) Error() string
• type Peer
• type Reactor
  • func NewReactor(b AddrBook, config *ReactorConfig) *Reactor
  • func (r *Reactor) AddPeer(p Peer)
  • func (r *Reactor) AttemptsToDial(addr *p2p.NetAddress) int
  • func (r *Reactor) GetChannels() []*conn.ChannelDescriptor
  • func (r *Reactor) OnStart() error
  • func (r *Reactor) OnStop()
  • func (r *Reactor) Receive(chID byte, src Peer, msgBytes []byte)
  • func (r *Reactor) ReceiveAddrs(addrs []*p2p.NetAddress, src Peer) error
  • func (r *Reactor) RemovePeer(p Peer, reason interface{})
  • func (r *Reactor) RequestAddrs(p Peer)
  • func (r *Reactor) SendAddrs(p Peer, netAddrs []*p2p.NetAddress)
  • func (r *Reactor) SetEnsurePeersPeriod(d time.Duration)
• type ReactorConfig

Constants

const (
	// PexChannel is a channel for PEX messages
	PexChannel = byte(0x00)
)

Variables

var ErrUnsolicitedList = errors.New("unsolicited pexAddrsMessage")

ErrUnsolicitedList is thrown when a peer provides a list of addresses that have not been asked for.

Types

type AddrBook

type AddrBook interface {
	service.Service

	// Add our own addresses so we don't later add ourselves
	AddOurAddress(*p2p.NetAddress)
	// Check if it is our address
	OurAddress(*p2p.NetAddress) bool

	AddPrivateIDs([]string)

	// Add and remove an address
	AddAddress(addr *p2p.NetAddress, src *p2p.NetAddress) error
	RemoveAddress(*p2p.NetAddress)

	// Check if the address is in the book
	HasAddress(*p2p.NetAddress) bool

	// Do we need more peers?
	NeedMoreAddrs() bool
	// Is Address Book Empty? Answer should not depend on being in your own
	// address book, or private peers
	Empty() bool

	// Pick an address to dial
	PickAddress(biasTowardsNewAddrs int) *p2p.NetAddress

	// Mark address
	MarkGood(p2p.ID)
	MarkAttempt(*p2p.NetAddress)
	MarkBad(*p2p.NetAddress, time.Duration) // Move peer to bad peers list
	// Add bad peers back to addrBook
	ReinstateBadPeers()

	IsGood(*p2p.NetAddress) bool
	IsBanned(*p2p.NetAddress) bool

	// Send a selection of addresses to peers
	GetSelection() []*p2p.NetAddress
	// Send a selection of addresses with bias
	GetSelectionWithBias(biasTowardsNewAddrs int) []*p2p.NetAddress

	Size() int

	// Persist to disk
	Save()
}

AddrBook is an address book used for tracking peers so we can gossip about them to others and select peers to dial. TODO: break this up?

func NewAddrBook

func NewAddrBook(filePath string, routabilityStrict bool) AddrBook

NewAddrBook creates a new address book. Use Start to begin processing asynchronous address updates.

type ErrAddrBookInvalidAddr

type ErrAddrBookInvalidAddr struct {
	Addr    *p2p.NetAddress
	AddrErr error
}

func (ErrAddrBookInvalidAddr) Error

func (err ErrAddrBookInvalidAddr) Error() string

type ErrAddrBookNilAddr

type ErrAddrBookNilAddr struct {
	Addr *p2p.NetAddress
	Src  *p2p.NetAddress
}

func (ErrAddrBookNilAddr) Error

func (err ErrAddrBookNilAddr) Error() string

type ErrAddrBookNonRoutable

type ErrAddrBookNonRoutable struct {
	Addr *p2p.NetAddress
}

func (ErrAddrBookNonRoutable) Error

func (err ErrAddrBookNonRoutable) Error() string

type ErrAddrBookPrivate

type ErrAddrBookPrivate struct {
	Addr *p2p.NetAddress
}

func (ErrAddrBookPrivate) Error

func (err ErrAddrBookPrivate) Error() string

func (ErrAddrBookPrivate) PrivateAddr

func (err ErrAddrBookPrivate) PrivateAddr() bool

type ErrAddrBookPrivateSrc

type ErrAddrBookPrivateSrc struct {
	Src *p2p.NetAddress
}

func (ErrAddrBookPrivateSrc) Error

func (err ErrAddrBookPrivateSrc) Error() string

func (ErrAddrBookPrivateSrc) PrivateAddr

func (err ErrAddrBookPrivateSrc) PrivateAddr() bool

type ErrAddrBookSelf

type ErrAddrBookSelf struct {
	Addr *p2p.NetAddress
}

func (ErrAddrBookSelf) Error

func (err ErrAddrBookSelf) Error() string

type ErrAddressBanned

type ErrAddressBanned struct {
	Addr *p2p.NetAddress
}

ErrAddressBanned is thrown when the address has been banned and therefore cannot be used

func (ErrAddressBanned) Error

func (err ErrAddressBanned) Error() string

type Peer

type Peer = p2p.Peer

type Reactor

type Reactor struct {
	p2p.BaseReactor
	// contains filtered or unexported fields
}

Reactor handles PEX (peer exchange) and ensures that an adequate number of peers are connected to the switch.

It uses `AddrBook` (address book) to store `NetAddress`es of the peers.

## Preventing abuse

Only accept pexAddrsMsg from peers we sent a corresponding pexRequestMsg too. Only accept one pexRequestMsg every ~defaultEnsurePeersPeriod.

func NewReactor

func NewReactor(b AddrBook, config *ReactorConfig) *Reactor

NewReactor creates new PEX reactor.

func (*Reactor) AddPeer

func (r *Reactor) AddPeer(p Peer)

AddPeer implements Reactor by adding peer to the address book (if inbound) or by requesting more addresses (if outbound).

func (*Reactor) AttemptsToDial

func (r *Reactor) AttemptsToDial(addr *p2p.NetAddress) int

AttemptsToDial returns the number of attempts to dial specific address. It returns 0 if never attempted or successfully connected.

func (*Reactor) GetChannels

func (r *Reactor) GetChannels() []*conn.ChannelDescriptor

GetChannels implements Reactor

func (*Reactor) OnStart

func (r *Reactor) OnStart() error

OnStart implements BaseService

func (*Reactor) OnStop

func (r *Reactor) OnStop()

OnStop implements BaseService

func (*Reactor) Receive

func (r *Reactor) Receive(chID byte, src Peer, msgBytes []byte)

Receive implements Reactor by handling incoming PEX messages.

func (*Reactor) ReceiveAddrs

func (r *Reactor) ReceiveAddrs(addrs []*p2p.NetAddress, src Peer) error

ReceiveAddrs adds the given addrs to the addrbook if theres an open request for this peer and deletes the open request. If there's no open request for the src peer, it returns an error.

func (*Reactor) RemovePeer

func (r *Reactor) RemovePeer(p Peer, reason interface{})

RemovePeer implements Reactor by resetting peer's requests info.

func (*Reactor) RequestAddrs

func (r *Reactor) RequestAddrs(p Peer)

RequestAddrs asks peer for more addresses if we do not already have a request out for this peer.

func (*Reactor) SendAddrs

func (r *Reactor) SendAddrs(p Peer, netAddrs []*p2p.NetAddress)

SendAddrs sends addrs to the peer.

func (*Reactor) SetEnsurePeersPeriod

func (r *Reactor) SetEnsurePeersPeriod(d time.Duration)

SetEnsurePeersPeriod sets period to ensure peers connected.

type ReactorConfig

type ReactorConfig struct {
	// Seed/Crawler mode
	SeedMode bool

	// We want seeds to only advertise good peers. Therefore they should wait at
	// least as long as we expect it to take for a peer to become good before
	// disconnecting.
	SeedDisconnectWaitPeriod time.Duration

	// Maximum pause when redialing a persistent peer (if zero, exponential backoff is used)
	PersistentPeersMaxDialPeriod time.Duration

	// Seeds is a list of addresses reactor may use
	// if it can't connect to peers in the addrbook.
	Seeds []string
}

ReactorConfig holds reactor specific configuration data.