From 2fd5b6c4eaed4b3a1e4a23e794956381d8ad2f3f Mon Sep 17 00:00:00 2001
From: Hanno Cornelius <68783915+jm-clius@users.noreply.github.com>
Date: Fri, 18 Feb 2022 12:10:38 +0100
Subject: [PATCH] Domain name config for `nwaku` node (#852)

---
 tests/v2/test_wakunode.nim | 19 +++++++++++++++
 waku/v2/node/config.nim    |  5 ++++
 waku/v2/node/wakunode2.nim | 48 +++++++++++++++++++++++++++++---------
 3 files changed, 61 insertions(+), 11 deletions(-)

diff --git a/tests/v2/test_wakunode.nim b/tests/v2/test_wakunode.nim
index 2eef23576..1e4cb66c5 100644
--- a/tests/v2/test_wakunode.nim
+++ b/tests/v2/test_wakunode.nim
@@ -1482,3 +1482,22 @@ procSuite "WakuNode":
       node.switch.peerInfo.addrs.contains(announcedEndpoint)
 
     await node.stop()
+
+  asyncTest "Node can use dns4 in announced addresses":
+    let
+      nodeKey = crypto.PrivateKey.random(Secp256k1, rng[])[]
+      bindIp = ValidIpAddress.init("0.0.0.0")
+      bindPort = Port(60000)
+      extIp = some(ValidIpAddress.init("127.0.0.1"))
+      extPort = some(Port(60002))
+      domainName = "example.com"
+      expectedDns4Addr = MultiAddress.init("/dns4/" & domainName & "/tcp/" & $(extPort.get())).get()
+      node = WakuNode.new(
+        nodeKey,
+        bindIp, bindPort,
+        extIp, extPort,
+        dns4DomainName = some(domainName))
+    
+    check:
+      node.announcedAddresses.len == 1
+      node.announcedAddresses.contains(expectedDns4Addr)
diff --git a/waku/v2/node/config.nim b/waku/v2/node/config.nim
index c5a3d6acb..b38449a53 100644
--- a/waku/v2/node/config.nim
+++ b/waku/v2/node/config.nim
@@ -76,6 +76,11 @@ type
       desc: "DNS name server IPs to query for DNS multiaddrs resolution. Argument may be repeated."
       defaultValue: @[ValidIpAddress.init("1.1.1.1"), ValidIpAddress.init("1.0.0.1")]
       name: "dns-addrs-name-server" }: seq[ValidIpAddress]
+    
+    dns4DomainName* {.
+      desc: "The domain name resolving to the node's public IPv4 address",
+      defaultValue: ""
+      name: "dns4-domain-name" }: string
 
     ## Relay config
     
diff --git a/waku/v2/node/wakunode2.nim b/waku/v2/node/wakunode2.nim
index 5e0519042..36468ccbe 100644
--- a/waku/v2/node/wakunode2.nim
+++ b/waku/v2/node/wakunode2.nim
@@ -142,10 +142,19 @@ proc updateSwitchPeerInfo(node: WakuNode) =
   if node.announcedAddresses.len > 0:
     node.switch.peerInfo.addrs = node.announcedAddresses
 
-template tcpEndPoint(address, port): auto =
+template ip4TcpEndPoint(address, port): MultiAddress =
   MultiAddress.init(address, tcpProtocol, port)
 
-func wsFlag(wssEnabled: bool): MultiAddress {.raises: [Defect, LPError]} =
+template dns4Ma(dns4DomainName: string): MultiAddress =
+  MultiAddress.init("/dns4/" & dns4DomainName).tryGet()
+
+template tcpPortMa(port: Port): MultiAddress =
+  MultiAddress.init("/tcp/" & $port).tryGet()
+
+template dns4TcpEndPoint(dns4DomainName: string, port: Port): MultiAddress =
+  dns4Ma(dns4DomainName) & tcpPortMa(port)
+
+template wsFlag(wssEnabled: bool): MultiAddress =
   if wssEnabled: MultiAddress.init("/wss").tryGet()
   else: MultiAddress.init("/ws").tryGet()
 
@@ -161,6 +170,7 @@ proc new*(T: type WakuNode, nodeKey: crypto.PrivateKey,
     secureCert: string = "",
     wakuFlags = none(WakuEnrBitfield),
     nameResolver: NameResolver = nil,
+    dns4DomainName = none(string)
     ): T 
     {.raises: [Defect, LPError, IOError, TLSStreamProtocolError].} =
   ## Creates a Waku Node.
@@ -171,16 +181,28 @@ proc new*(T: type WakuNode, nodeKey: crypto.PrivateKey,
   ## Initialize addresses
   let
     # Bind addresses
-    hostAddress = tcpEndPoint(bindIp, bindPort)
-    wsHostAddress = if wsEnabled or wssEnabled: some(tcpEndPoint(bindIp, wsbindPort) & wsFlag(wssEnabled))
+    hostAddress = ip4TcpEndPoint(bindIp, bindPort)
+    wsHostAddress = if wsEnabled or wssEnabled: some(ip4TcpEndPoint(bindIp, wsbindPort) & wsFlag(wssEnabled))
                     else: none(MultiAddress)
 
-    # External addresses
-    hostExtAddress = if extIp.isNone() or extPort.isNone(): none(MultiAddress)
-                     else: some(tcpEndPoint(extIp.get(), extPort.get()))
-    wsExtAddress = if wsHostAddress.isNone(): none(MultiAddress)
-                   elif hostExtAddress.isNone(): none(MultiAddress)
-                   else: some(tcpEndPoint(extIp.get(), wsBindPort) & wsFlag(wssEnabled))
+  # Setup external addresses, if available
+  var
+    hostExtAddress, wsExtAddress = none(MultiAddress)
+  
+  if (dns4DomainName.isSome()):
+    # Use dns4 for externally announced addresses
+    
+    hostExtAddress = some(dns4TcpEndPoint(dns4DomainName.get(), extPort.get()))
+
+    if (wsHostAddress.isSome()):
+      wsExtAddress = some(dns4TcpEndPoint(dns4DomainName.get(), wsBindPort) & wsFlag(wssEnabled))
+  else:
+    # No public domain name, use ext IP if available
+    if extIp.isSome() and extPort.isSome():
+      hostExtAddress = some(ip4TcpEndPoint(extIp.get(), extPort.get()))
+
+      if (wsHostAddress.isSome()):
+        wsExtAddress = some(ip4TcpEndPoint(extIp.get(), wsBindPort) & wsFlag(wssEnabled))
 
   var announcedAddresses: seq[MultiAddress]
   if hostExtAddress.isSome:
@@ -1030,6 +1052,9 @@ when isMainModule:
                 else:
                   extTcpPort
       
+      dns4DomainName = if conf.dns4DomainName != "": some(conf.dns4DomainName)
+                       else: none(string)
+      
       wakuFlags = initWakuFlags(conf.lightpush,
                                 conf.filter,
                                 conf.store,
@@ -1046,7 +1071,8 @@ when isMainModule:
                           conf.websocketSecureKeyPath,
                           conf.websocketSecureCertPath,
                           some(wakuFlags),
-                          dnsResolver
+                          dnsResolver,
+                          dns4DomainName
                           )
     
     if conf.discv5Discovery: