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164 lines
5.2 KiB

package p2p
import (
"fmt"
cmn "github.com/tendermint/tendermint/libs/common"
"strings"
)
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
// ASCIIText fields
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 ?
// JAE: It needs to be done on the client, but to prevent ambiguous
// unicode characters, maybe it's worth sanitizing it here.
// In the future we might want to validate these, once we have a
// name-resolution system up.
// International clients could then use punycode (or we could use
// url-encoding), and we just need to be careful with how we handle that in our
// clients. (e.g. off by default).
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)
}
// Sanitize ASCII text fields.
if !cmn.IsASCIIText(info.Moniker) || cmn.ASCIITrim(info.Moniker) == "" {
return fmt.Errorf("info.Moniker must be valid non-empty ASCII text without tabs, but got %v.", info.Moniker)
}
for i, s := range info.Other {
if !cmn.IsASCIIText(s) || cmn.ASCIITrim(s) == "" {
return fmt.Errorf("info.Other[%v] must be valid non-empty ASCII text without tabs, but got %v.", i, s)
}
}
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))
return err
}
// 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
}