lbry.go/dht/contact.go
Alex Grintsvayg 0a54d4da56 fixed some linting errors
found them using

```
gometalinter --skip=vendor --disable-all --enable=megacheck --enable=deadcode --enable=ineffassign --enable=interfacer --enable=errcheck ./...
```
2018-08-07 11:38:56 -04:00

118 lines
3.3 KiB
Go

package dht
import (
"bytes"
"net"
"sort"
"strconv"
"github.com/lbryio/lbry.go/errors"
"github.com/lbryio/reflector.go/dht/bits"
"github.com/lyoshenka/bencode"
)
// TODO: if routing table is ever empty (aka the node is isolated), it should re-bootstrap
// Contact contains information for contacting another node on the network
type Contact struct {
ID bits.Bitmap
IP net.IP
Port int // the udp port used for the dht
PeerPort int // the tcp port a peer can be contacted on for blob requests
}
// Equals returns true if two contacts are the same.
func (c Contact) Equals(other Contact, checkID bool) bool {
return c.IP.Equal(other.IP) && c.Port == other.Port && (!checkID || c.ID == other.ID)
}
// Addr returns the address of the contact.
func (c Contact) Addr() *net.UDPAddr {
return &net.UDPAddr{IP: c.IP, Port: c.Port}
}
// String returns a short string representation of the contact
func (c Contact) String() string {
str := c.ID.HexShort() + "@" + c.Addr().String()
if c.PeerPort != 0 {
str += "(" + strconv.Itoa(c.PeerPort) + ")"
}
return str
}
// MarshalCompact returns a compact byteslice representation of the contact
// NOTE: The compact representation always uses the tcp PeerPort, not the udp Port. This is dumb, but that's how the python daemon does it
func (c Contact) MarshalCompact() ([]byte, error) {
if c.IP.To4() == nil {
return nil, errors.Err("ip not set")
}
if c.PeerPort < 0 || c.PeerPort > 65535 {
return nil, errors.Err("invalid port")
}
var buf bytes.Buffer
buf.Write(c.IP.To4())
buf.WriteByte(byte(c.PeerPort >> 8))
buf.WriteByte(byte(c.PeerPort))
buf.Write(c.ID[:])
if buf.Len() != compactNodeInfoLength {
return nil, errors.Err("i dont know how this happened")
}
return buf.Bytes(), nil
}
// UnmarshalCompact unmarshals the compact byteslice representation of a contact.
// NOTE: The compact representation always uses the tcp PeerPort, not the udp Port. This is dumb, but that's how the python daemon does it
func (c *Contact) UnmarshalCompact(b []byte) error {
if len(b) != compactNodeInfoLength {
return errors.Err("invalid compact length")
}
c.IP = net.IPv4(b[0], b[1], b[2], b[3]).To4()
c.PeerPort = int(uint16(b[5]) | uint16(b[4])<<8)
c.ID = bits.FromBytesP(b[6:])
return nil
}
// MarshalBencode returns the serialized byte slice representation of a contact.
func (c Contact) MarshalBencode() ([]byte, error) {
return bencode.EncodeBytes([]interface{}{c.ID, c.IP.String(), c.Port})
}
// UnmarshalBencode unmarshals the serialized byte slice into the appropriate fields of the contact.
func (c *Contact) UnmarshalBencode(b []byte) error {
var raw []bencode.RawMessage
err := bencode.DecodeBytes(b, &raw)
if err != nil {
return err
}
if len(raw) != 3 {
return errors.Err("contact must have 3 elements; got %d", len(raw))
}
err = bencode.DecodeBytes(raw[0], &c.ID)
if err != nil {
return err
}
var ipStr string
err = bencode.DecodeBytes(raw[1], &ipStr)
if err != nil {
return err
}
c.IP = net.ParseIP(ipStr).To4()
if c.IP == nil {
return errors.Err("invalid IP")
}
return bencode.DecodeBytes(raw[2], &c.Port)
}
func sortByDistance(contacts []Contact, target bits.Bitmap) {
sort.Slice(contacts, func(i, j int) bool {
return contacts[i].ID.Xor(target).Cmp(contacts[j].ID.Xor(target)) < 0
})
}