p2p/discover: add initial discovery v5 implementation (#20750)

This adds an implementation of the current discovery v5 spec.

There is full integration with cmd/devp2p and enode.Iterator in this
version. In theory we could enable the new protocol as a replacement of
discovery v4 at any time. In practice, there will likely be a few more
changes to the spec and implementation before this can happen.
This commit is contained in:
Felix Lange
2020-04-08 09:57:23 +02:00
committed by GitHub
parent 671f22be38
commit b7394d7942
19 changed files with 2976 additions and 80 deletions

View File

@ -81,6 +81,18 @@ var (
Name: "bootnodes",
Usage: "Comma separated nodes used for bootstrapping",
}
nodekeyFlag = cli.StringFlag{
Name: "nodekey",
Usage: "Hex-encoded node key",
}
nodedbFlag = cli.StringFlag{
Name: "nodedb",
Usage: "Nodes database location",
}
listenAddrFlag = cli.StringFlag{
Name: "addr",
Usage: "Listening address",
}
crawlTimeoutFlag = cli.DurationFlag{
Name: "timeout",
Usage: "Time limit for the crawl.",
@ -172,6 +184,62 @@ func discv4Crawl(ctx *cli.Context) error {
return nil
}
// startV4 starts an ephemeral discovery V4 node.
func startV4(ctx *cli.Context) *discover.UDPv4 {
ln, config := makeDiscoveryConfig(ctx)
socket := listen(ln, ctx.String(listenAddrFlag.Name))
disc, err := discover.ListenV4(socket, ln, config)
if err != nil {
exit(err)
}
return disc
}
func makeDiscoveryConfig(ctx *cli.Context) (*enode.LocalNode, discover.Config) {
var cfg discover.Config
if ctx.IsSet(nodekeyFlag.Name) {
key, err := crypto.HexToECDSA(ctx.String(nodekeyFlag.Name))
if err != nil {
exit(fmt.Errorf("-%s: %v", nodekeyFlag.Name, err))
}
cfg.PrivateKey = key
} else {
cfg.PrivateKey, _ = crypto.GenerateKey()
}
if commandHasFlag(ctx, bootnodesFlag) {
bn, err := parseBootnodes(ctx)
if err != nil {
exit(err)
}
cfg.Bootnodes = bn
}
dbpath := ctx.String(nodedbFlag.Name)
db, err := enode.OpenDB(dbpath)
if err != nil {
exit(err)
}
ln := enode.NewLocalNode(db, cfg.PrivateKey)
return ln, cfg
}
func listen(ln *enode.LocalNode, addr string) *net.UDPConn {
if addr == "" {
addr = "0.0.0.0:0"
}
socket, err := net.ListenPacket("udp4", addr)
if err != nil {
exit(err)
}
usocket := socket.(*net.UDPConn)
uaddr := socket.LocalAddr().(*net.UDPAddr)
ln.SetFallbackIP(net.IP{127, 0, 0, 1})
ln.SetFallbackUDP(uaddr.Port)
return usocket
}
func parseBootnodes(ctx *cli.Context) ([]*enode.Node, error) {
s := params.RinkebyBootnodes
if ctx.IsSet(bootnodesFlag.Name) {
@ -187,40 +255,3 @@ func parseBootnodes(ctx *cli.Context) ([]*enode.Node, error) {
}
return nodes, nil
}
// startV4 starts an ephemeral discovery V4 node.
func startV4(ctx *cli.Context) *discover.UDPv4 {
socket, ln, cfg, err := listen()
if err != nil {
exit(err)
}
if commandHasFlag(ctx, bootnodesFlag) {
bn, err := parseBootnodes(ctx)
if err != nil {
exit(err)
}
cfg.Bootnodes = bn
}
disc, err := discover.ListenV4(socket, ln, cfg)
if err != nil {
exit(err)
}
return disc
}
func listen() (*net.UDPConn, *enode.LocalNode, discover.Config, error) {
var cfg discover.Config
cfg.PrivateKey, _ = crypto.GenerateKey()
db, _ := enode.OpenDB("")
ln := enode.NewLocalNode(db, cfg.PrivateKey)
socket, err := net.ListenUDP("udp4", &net.UDPAddr{IP: net.IP{0, 0, 0, 0}})
if err != nil {
db.Close()
return nil, nil, cfg, err
}
addr := socket.LocalAddr().(*net.UDPAddr)
ln.SetFallbackIP(net.IP{127, 0, 0, 1})
ln.SetFallbackUDP(addr.Port)
return socket, ln, cfg, nil
}