kaspad/dnsseed/seed.go
Svarog b42b8b16fd
[NOD-1120] Connection Manager (#796)
* [NOD-1120] Removed closure in NetAdapter.onConnectedHanlder

* [NOD-1120] Implement all connection manager methods

* [NOD-1120] Integrated connmanager into kaspad + added call for dnsseeder

* [NOD-1120] Allow buffer to not be bytes.Buffer

* [NOD-1120] Added timeout to connect

* [NOD-1120] Don't enter connections to  add loop if none needed

* [NOD-1120] Add call for addressManager.Good

* [NOD-1120] Minor bug fixes

* [NOD-1120] Remove errChan from grpcConnection

* [NOD-1120] Add comments to exported methods

* [NOD-1120] cancel the context for DialContext in gRPCServer.Connect

* [NOD-1120] Don't try to remove from connSet a connection that doesn't exist

* [NOD-1120] add ok bool to connectionSet.get

* [NOD-1120] Remove overuse of if-else in checkConnectionRequests

* [NOD-1120] Made some order in ConnectionManager

* [NOD-1120] Moved checkIncomingConnections to it's own file

* [NOD-1120] cleanup in checkOutgoingConnections

* [NOD-1120] Cleanup in SeedDNS, and move call outside of connection manager

* [NOD-1120] Add check that both --connect and --addpeer aren't used

* [NOD-1120] Move dial timeout to constant

* [NOD-1120] Enhance comment

* [NOD-1120] Log connection failure out of initiateConnection

* [NOD-1148] Reshuffle checkRequestedConnections to make more sense

* [NOD-1120] Move continue to correct place + reshuffle logging code

* [NOD-1120] Don't expose server.Connection outside netAdapter - expose a wrapper instead

* [NOD-1120] Add comments

* [NOD-1120] Don't return the connection from netAdapter.Connect()

* [NOD-1120] Use .Address as key for connectionSet

* [NOD-1120] Fix minRetryDuration usage

* [NOD-1120] Remove the correct number of incoming connections

* [NOD-1120] Add comment

* [NOD-1120] Rename connSet -> incomingConnectionSet

* [NOD-1120] fix grammar
2020-07-16 17:15:58 +03:00

102 lines
2.8 KiB
Go

// Copyright (c) 2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package dnsseed
import (
"fmt"
"math/rand"
"net"
"strconv"
"time"
"github.com/kaspanet/kaspad/util/mstime"
"github.com/kaspanet/kaspad/config"
"github.com/kaspanet/kaspad/util/subnetworkid"
"github.com/kaspanet/kaspad/dagconfig"
"github.com/kaspanet/kaspad/wire"
)
const (
// These constants are used by the DNS seed code to pick a random last
// seen time.
secondsIn3Days int32 = 24 * 60 * 60 * 3
secondsIn4Days int32 = 24 * 60 * 60 * 4
// SubnetworkIDPrefixChar is the prefix of subnetworkID, when building a DNS seed request
SubnetworkIDPrefixChar byte = 'n'
// ServiceFlagPrefixChar is the prefix of service flag, when building a DNS seed request
ServiceFlagPrefixChar byte = 'x'
)
// OnSeed is the signature of the callback function which is invoked when DNS
// seeding is successful.
type OnSeed func(addrs []*wire.NetAddress)
// LookupFunc is the signature of the DNS lookup function.
type LookupFunc func(string) ([]net.IP, error)
// SeedFromDNS uses DNS seeding to populate the address manager with peers.
func SeedFromDNS(dagParams *dagconfig.Params, reqServices wire.ServiceFlag, includeAllSubnetworks bool,
subnetworkID *subnetworkid.SubnetworkID, lookupFn LookupFunc, seedFn OnSeed) {
var dnsSeeds []string
cfg := config.ActiveConfig()
if cfg != nil && cfg.DNSSeed != "" {
dnsSeeds = []string{cfg.DNSSeed}
} else {
dnsSeeds = dagParams.DNSSeeds
}
for _, dnsseed := range dnsSeeds {
var host string
if reqServices == wire.SFNodeNetwork {
host = dnsseed
} else {
host = fmt.Sprintf("%c%x.%s", ServiceFlagPrefixChar, uint64(reqServices), dnsseed)
}
if !includeAllSubnetworks {
if subnetworkID != nil {
host = fmt.Sprintf("%c%s.%s", SubnetworkIDPrefixChar, subnetworkID, host)
} else {
host = fmt.Sprintf("%c.%s", SubnetworkIDPrefixChar, host)
}
}
spawn(func() {
randSource := rand.New(rand.NewSource(time.Now().UnixNano()))
seedPeers, err := lookupFn(host)
if err != nil {
log.Infof("DNS discovery failed on seed %s: %s", host, err)
return
}
numPeers := len(seedPeers)
log.Infof("%d addresses found from DNS seed %s", numPeers, host)
if numPeers == 0 {
return
}
addresses := make([]*wire.NetAddress, len(seedPeers))
// if this errors then we have *real* problems
intPort, _ := strconv.Atoi(dagParams.DefaultPort)
for i, peer := range seedPeers {
addresses[i] = wire.NewNetAddressTimestamp(
// seed with addresses from a time randomly selected
// between 3 and 7 days ago.
mstime.Now().Add(-1*time.Second*time.Duration(secondsIn3Days+
randSource.Int31n(secondsIn4Days))),
0, peer, uint16(intPort))
}
seedFn(addresses)
})
}
}