peer

Documentation

Overview

Package peer implements an object used to represent peers in the libp2p network.

Package peer contains Protobuf and JSON serialization/deserialization methods for peer IDs.

Index

• Constants
• Variables
• func AddrInfoToP2pAddrs(pi *AddrInfo) ([]ma.Multiaddr, error)
• func TimestampSeq() uint64
• func ToCid(id ID) cid.Cid
• type AddrInfo
  • func AddrInfoFromP2pAddr(m ma.Multiaddr) (*AddrInfo, error)
  • func AddrInfoFromString(s string) (*AddrInfo, error)
  • func AddrInfosFromP2pAddrs(maddrs ...ma.Multiaddr) ([]AddrInfo, error)
  • func (pi *AddrInfo) Loggable() map[string]interface{}
  • func (pi AddrInfo) MarshalJSON() (res []byte, err error)
  • func (pi AddrInfo) String() string
  • func (pi *AddrInfo) UnmarshalJSON(b []byte) (err error)
• type ID
  • func AddrInfosToIDs(pis []AddrInfo) []ID
  • func Decode(s string) (ID, error)
  • func FromCid(c cid.Cid) (ID, error)
  • func IDFromBytes(b []byte) (ID, error)
  • func IDFromP2PAddr(m ma.Multiaddr) (ID, error)
  • func IDFromPrivateKey(sk ic.PrivKey) (ID, error)
  • func IDFromPublicKey(pk ic.PubKey) (ID, error)
  • func SplitAddr(m ma.Multiaddr) (transport ma.Multiaddr, id ID)
  • func (id ID) ExtractPublicKey() (ic.PubKey, error)
  • func (id ID) Loggable() map[string]interface{}
  • func (id ID) Marshal() ([]byte, error)
  • func (id ID) MarshalBinary() ([]byte, error)
  • func (id ID) MarshalJSON() ([]byte, error)
  • func (id ID) MarshalText() ([]byte, error)
  • func (id ID) MarshalTo(data []byte) (n int, err error)
  • func (id ID) MatchesPrivateKey(sk ic.PrivKey) bool
  • func (id ID) MatchesPublicKey(pk ic.PubKey) bool
  • func (id ID) ShortString() string
  • func (id ID) Size() int
  • func (id ID) String() string
  • func (id *ID) Unmarshal(data []byte) (err error)
  • func (id *ID) UnmarshalBinary(data []byte) error
  • func (id *ID) UnmarshalJSON(data []byte) (err error)
  • func (id *ID) UnmarshalText(data []byte) error
  • func (id ID) Validate() error
• type IDSlice
  • func (es IDSlice) Len() int
  • func (es IDSlice) Less(i, j int) bool
  • func (es IDSlice) String() string
  • func (es IDSlice) Swap(i, j int)
• type PeerRecord
  • func NewPeerRecord() *PeerRecord
  • func PeerRecordFromAddrInfo(info AddrInfo) *PeerRecord
  • func PeerRecordFromProtobuf(msg *pb.PeerRecord) (*PeerRecord, error)
  • func (r *PeerRecord) Codec() []byte
  • func (r *PeerRecord) Domain() string
  • func (r *PeerRecord) Equal(other *PeerRecord) bool
  • func (r *PeerRecord) MarshalRecord() (res []byte, err error)
  • func (r *PeerRecord) ToProtobuf() (*pb.PeerRecord, error)
  • func (r *PeerRecord) UnmarshalRecord(bytes []byte) (err error)

Constants

const PeerRecordEnvelopeDomain = "libp2p-peer-record"

PeerRecordEnvelopeDomain is the domain string used for peer records contained in an Envelope.

Variables

var (
	// ErrEmptyPeerID is an error for empty peer ID.
	ErrEmptyPeerID = errors.New("empty peer ID")
	// ErrNoPublicKey is an error for peer IDs that don't embed public keys
	ErrNoPublicKey = errors.New("public key is not embedded in peer ID")
)

var AdvancedEnableInlining = true

AdvancedEnableInlining enables automatically inlining keys shorter than 42 bytes into the peer ID (using the "identity" multihash function).

WARNING: This flag will likely be set to false in the future and eventually be removed in favor of using a hash function specified by the key itself. See: https://github.com/libp2p/specs/issues/138

DO NOT change this flag unless you know what you're doing.

This currently defaults to true for backwards compatibility but will likely be set to false by default when an upgrade path is determined.

var ErrInvalidAddr = fmt.Errorf("invalid p2p multiaddr")

var PeerRecordEnvelopePayloadType = []byte{0x03, 0x01}

PeerRecordEnvelopePayloadType is the type hint used to identify peer records in an Envelope. Defined in https://github.com/multiformats/multicodec/blob/master/table.csv with name "libp2p-peer-record".

Functions

func AddrInfoToP2pAddrs

func AddrInfoToP2pAddrs(pi *AddrInfo) ([]ma.Multiaddr, error)

AddrInfoToP2pAddrs converts an AddrInfo to a list of Multiaddrs.

func TimestampSeq

func TimestampSeq() uint64

TimestampSeq is a helper to generate a timestamp-based sequence number for a PeerRecord.

func ToCid

func ToCid(id ID) cid.Cid

ToCid encodes a peer ID as a CID of the public key.

If the peer ID is invalid (e.g., empty), this will return the empty CID.

Types

type AddrInfo

type AddrInfo struct {
	ID    ID
	Addrs []ma.Multiaddr
}

AddrInfo is a small struct used to pass around a peer with a set of addresses (and later, keys?).

func AddrInfoFromP2pAddr

func AddrInfoFromP2pAddr(m ma.Multiaddr) (*AddrInfo, error)

AddrInfoFromP2pAddr converts a Multiaddr to an AddrInfo.

func AddrInfoFromString

func AddrInfoFromString(s string) (*AddrInfo, error)

AddrInfoFromString builds an AddrInfo from the string representation of a Multiaddr

func AddrInfosFromP2pAddrs

func AddrInfosFromP2pAddrs(maddrs ...ma.Multiaddr) ([]AddrInfo, error)

AddrInfosFromP2pAddrs converts a set of Multiaddrs to a set of AddrInfos.

func (*AddrInfo) Loggable

func (pi *AddrInfo) Loggable() map[string]interface{}

func (AddrInfo) MarshalJSON

func (pi AddrInfo) MarshalJSON() (res []byte, err error)

func (AddrInfo) String

func (pi AddrInfo) String() string

func (*AddrInfo) UnmarshalJSON

func (pi *AddrInfo) UnmarshalJSON(b []byte) (err error)

type ID

type ID string

ID is a libp2p peer identity.

Peer IDs are derived by hashing a peer's public key and encoding the hash output as a multihash. See IDFromPublicKey for details.

func AddrInfosToIDs

func AddrInfosToIDs(pis []AddrInfo) []ID

AddrInfosToIDs extracts the peer IDs from the passed AddrInfos and returns them in-order.

func Decode

func Decode(s string) (ID, error)

Decode accepts an encoded peer ID and returns the decoded ID if the input is valid.

The encoded peer ID can either be a CID of a key or a raw multihash (identity or sha256-256).

func FromCid

func FromCid(c cid.Cid) (ID, error)

FromCid converts a CID to a peer ID, if possible.

func IDFromBytes

func IDFromBytes(b []byte) (ID, error)

IDFromBytes casts a byte slice to the ID type, and validates the value to make sure it is a multihash.

func IDFromP2PAddr

func IDFromP2PAddr(m ma.Multiaddr) (ID, error)

IDFromP2PAddr extracts the peer ID from a p2p Multiaddr

func IDFromPrivateKey

func IDFromPrivateKey(sk ic.PrivKey) (ID, error)

IDFromPrivateKey returns the Peer ID corresponding to the secret key sk.

func IDFromPublicKey

func IDFromPublicKey(pk ic.PubKey) (ID, error)

IDFromPublicKey returns the Peer ID corresponding to the public key pk.

func SplitAddr

func SplitAddr(m ma.Multiaddr) (transport ma.Multiaddr, id ID)

SplitAddr splits a p2p Multiaddr into a transport multiaddr and a peer ID.

* Returns a nil transport if the address only contains a /p2p part. * Returns an empty peer ID if the address doesn't contain a /p2p part.

func (ID) ExtractPublicKey

func (id ID) ExtractPublicKey() (ic.PubKey, error)

ExtractPublicKey attempts to extract the public key from an ID.

This method returns ErrNoPublicKey if the peer ID looks valid, but it can't extract the public key.

func (ID) Loggable

func (id ID) Loggable() map[string]interface{}

Loggable returns a pretty peer ID string in loggable JSON format.

func (ID) Marshal

func (id ID) Marshal() ([]byte, error)

func (ID) MarshalBinary

func (id ID) MarshalBinary() ([]byte, error)

MarshalBinary returns the byte representation of the peer ID.

func (ID) MarshalJSON

func (id ID) MarshalJSON() ([]byte, error)

func (ID) MarshalText

func (id ID) MarshalText() ([]byte, error)

MarshalText returns the text encoding of the ID.

func (ID) MarshalTo

func (id ID) MarshalTo(data []byte) (n int, err error)

func (ID) MatchesPrivateKey

func (id ID) MatchesPrivateKey(sk ic.PrivKey) bool

MatchesPrivateKey tests whether this ID was derived from the secret key sk.

func (ID) MatchesPublicKey

func (id ID) MatchesPublicKey(pk ic.PubKey) bool

MatchesPublicKey tests whether this ID was derived from the public key pk.

func (ID) ShortString

func (id ID) ShortString() string

ShortString prints out the peer ID.

TODO(brian): ensure correctness at ID generation and enforce this by only exposing functions that generate IDs safely. Then any peer.ID type found in the codebase is known to be correct.

func (ID) Size

func (id ID) Size() int

func (ID) String

func (id ID) String() string

func (*ID) Unmarshal

func (id *ID) Unmarshal(data []byte) (err error)

func (*ID) UnmarshalBinary

func (id *ID) UnmarshalBinary(data []byte) error

UnmarshalBinary sets the ID from its binary representation.

func (*ID) UnmarshalJSON

func (id *ID) UnmarshalJSON(data []byte) (err error)

func (*ID) UnmarshalText

func (id *ID) UnmarshalText(data []byte) error

UnmarshalText restores the ID from its text encoding.

func (ID) Validate

func (id ID) Validate() error

Validate checks if ID is empty or not.

type IDSlice

type IDSlice []ID

IDSlice for sorting peers.

func (IDSlice) Len

func (es IDSlice) Len() int

func (IDSlice) Less

func (es IDSlice) Less(i, j int) bool

func (IDSlice) String

func (es IDSlice) String() string

func (IDSlice) Swap

func (es IDSlice) Swap(i, j int)

type PeerRecord

type PeerRecord struct {
	// PeerID is the ID of the peer this record pertains to.
	PeerID ID

	// Addrs contains the public addresses of the peer this record pertains to.
	Addrs []ma.Multiaddr

	// Seq is a monotonically-increasing sequence counter that's used to order
	// PeerRecords in time. The interval between Seq values is unspecified,
	// but newer PeerRecords MUST have a greater Seq value than older records
	// for the same peer.
	Seq uint64
}

PeerRecord contains information that is broadly useful to share with other peers, either through a direct exchange (as in the libp2p identify protocol), or through a Peer Routing provider, such as a DHT.

Currently, a PeerRecord contains the public listen addresses for a peer, but this is expected to expand to include other information in the future.

PeerRecords are ordered in time by their Seq field. Newer PeerRecords must have greater Seq values than older records. The NewPeerRecord function will create a PeerRecord with a timestamp-based Seq value. The other PeerRecord fields should be set by the caller:

rec := peer.NewPeerRecord()
rec.PeerID = aPeerID
rec.Addrs = someAddrs

Alternatively, you can construct a PeerRecord struct directly and use the TimestampSeq helper to set the Seq field:

rec := peer.PeerRecord{PeerID: aPeerID, Addrs: someAddrs, Seq: peer.TimestampSeq()}

Failing to set the Seq field will not result in an error, however, a PeerRecord with a Seq value of zero may be ignored or rejected by other peers.

PeerRecords are intended to be shared with other peers inside a signed routing.Envelope, and PeerRecord implements the routing.Record interface to facilitate this.

To share a PeerRecord, first call Sign to wrap the record in an Envelope and sign it with the local peer's private key:

rec := &PeerRecord{PeerID: myPeerId, Addrs: myAddrs}
envelope, err := rec.Sign(myPrivateKey)

The resulting record.Envelope can be marshalled to a []byte and shared publicly. As a convenience, the MarshalSigned method will produce the Envelope and marshal it to a []byte in one go:

rec := &PeerRecord{PeerID: myPeerId, Addrs: myAddrs}
recordBytes, err := rec.MarshalSigned(myPrivateKey)

To validate and unmarshal a signed PeerRecord from a remote peer, "consume" the containing envelope, which will return both the routing.Envelope and the inner Record. The Record must be cast to a PeerRecord pointer before use:

envelope, untypedRecord, err := ConsumeEnvelope(envelopeBytes, PeerRecordEnvelopeDomain)
if err != nil {
  handleError(err)
  return
}
peerRec := untypedRecord.(*PeerRecord)

func NewPeerRecord

func NewPeerRecord() *PeerRecord

NewPeerRecord returns a PeerRecord with a timestamp-based sequence number. The returned record is otherwise empty and should be populated by the caller.

func PeerRecordFromAddrInfo

func PeerRecordFromAddrInfo(info AddrInfo) *PeerRecord

PeerRecordFromAddrInfo creates a PeerRecord from an AddrInfo struct. The returned record will have a timestamp-based sequence number.

func PeerRecordFromProtobuf

func PeerRecordFromProtobuf(msg *pb.PeerRecord) (*PeerRecord, error)

PeerRecordFromProtobuf creates a PeerRecord from a protobuf PeerRecord struct.

func (*PeerRecord) Codec

func (r *PeerRecord) Codec() []byte

Codec is a binary identifier for the PeerRecord type. It is constant for all PeerRecord instances.

func (*PeerRecord) Domain

func (r *PeerRecord) Domain() string

Domain is used when signing and validating PeerRecords contained in Envelopes. It is constant for all PeerRecord instances.

func (*PeerRecord) Equal

func (r *PeerRecord) Equal(other *PeerRecord) bool

Equal returns true if the other PeerRecord is identical to this one.

func (*PeerRecord) MarshalRecord

func (r *PeerRecord) MarshalRecord() (res []byte, err error)

MarshalRecord serializes a PeerRecord to a byte slice. This method is called automatically when constructing a routing.Envelope using Seal or PeerRecord.Sign.

func (*PeerRecord) ToProtobuf

func (r *PeerRecord) ToProtobuf() (*pb.PeerRecord, error)

ToProtobuf returns the equivalent Protocol Buffer struct object of a PeerRecord.

func (*PeerRecord) UnmarshalRecord

func (r *PeerRecord) UnmarshalRecord(bytes []byte) (err error)

UnmarshalRecord parses a PeerRecord from a byte slice. This method is called automatically when consuming a record.Envelope whose PayloadType indicates that it contains a PeerRecord. It is generally not necessary or recommended to call this method directly.