package p2p import ( "fmt" "strings" cmn "github.com/tendermint/tmlibs/common" ) const ( maxNodeInfoSize = 10240 // 10Kb maxNumChannels = 16 // plenty of room for upgrades, for now ) // Max size of the NodeInfo struct func MaxNodeInfoSize() int { return maxNodeInfoSize } // NodeInfo is the basic node information exchanged // between two peers during the Tendermint P2P handshake. type NodeInfo struct { // Authenticate // TODO: replace with NetAddress ID ID `json:"id"` // authenticated identifier ListenAddr string `json:"listen_addr"` // accepting incoming // Check compatibility. // Channels are HexBytes so easier to read as JSON Network string `json:"network"` // network/chain ID Version string `json:"version"` // major.minor.revision Channels cmn.HexBytes `json:"channels"` // channels this node knows about // Sanitize Moniker string `json:"moniker"` // arbitrary moniker Other []string `json:"other"` // other application specific data } // Validate checks the self-reported NodeInfo is safe. // It returns an error if there // are too many Channels, if there are any duplicate Channels, // if the ListenAddr is malformed, or if the ListenAddr is a host name // that can not be resolved to some IP. // TODO: constraints for Moniker/Other? Or is that for the UI ? func (info NodeInfo) Validate() error { if len(info.Channels) > maxNumChannels { return fmt.Errorf("info.Channels is too long (%v). Max is %v", len(info.Channels), maxNumChannels) } channels := make(map[byte]struct{}) for _, ch := range info.Channels { _, ok := channels[ch] if ok { return fmt.Errorf("info.Channels contains duplicate channel id %v", ch) } channels[ch] = struct{}{} } // ensure ListenAddr is good _, err := NewNetAddressString(IDAddressString(info.ID, info.ListenAddr)) if err != nil { return err } return nil } // CompatibleWith checks if two NodeInfo are compatible with eachother. // CONTRACT: two nodes are compatible if the major version matches and network match // and they have at least one channel in common. func (info NodeInfo) CompatibleWith(other NodeInfo) error { iMajor, iMinor, _, iErr := splitVersion(info.Version) oMajor, oMinor, _, oErr := splitVersion(other.Version) // if our own version number is not formatted right, we messed up if iErr != nil { return iErr } // version number must be formatted correctly ("x.x.x") if oErr != nil { return oErr } // major version must match if iMajor != oMajor { return fmt.Errorf("Peer is on a different major version. Got %v, expected %v", oMajor, iMajor) } // minor version can differ if iMinor != oMinor { // ok } // nodes must be on the same network if info.Network != other.Network { return fmt.Errorf("Peer is on a different network. Got %v, expected %v", other.Network, info.Network) } // if we have no channels, we're just testing if len(info.Channels) == 0 { return nil } // for each of our channels, check if they have it found := false OUTER_LOOP: for _, ch1 := range info.Channels { for _, ch2 := range other.Channels { if ch1 == ch2 { found = true break OUTER_LOOP // only need one } } } if !found { return fmt.Errorf("Peer has no common channels. Our channels: %v ; Peer channels: %v", info.Channels, other.Channels) } return nil } // NetAddress returns a NetAddress derived from the NodeInfo - // it includes the authenticated peer ID and the self-reported // ListenAddr. Note that the ListenAddr is not authenticated and // may not match that address actually dialed if its an outbound peer. func (info NodeInfo) NetAddress() *NetAddress { netAddr, err := NewNetAddressString(IDAddressString(info.ID, info.ListenAddr)) if err != nil { switch err.(type) { case ErrNetAddressLookup: // XXX If the peer provided a host name and the lookup fails here // we're out of luck. // TODO: use a NetAddress in NodeInfo default: panic(err) // everything should be well formed by now } } return netAddr } func (info NodeInfo) String() string { return fmt.Sprintf("NodeInfo{id: %v, moniker: %v, network: %v [listen %v], version: %v (%v)}", info.ID, info.Moniker, info.Network, info.ListenAddr, info.Version, info.Other) } func splitVersion(version string) (string, string, string, error) { spl := strings.Split(version, ".") if len(spl) != 3 { return "", "", "", fmt.Errorf("Invalid version format %v", version) } return spl[0], spl[1], spl[2], nil }