fix: handle router mappings of mixed IP version (#2858)

Handle the case where the router has an external IPv4 address but
the internal network is IPv6 only, and vice versa.

Author: achingbrain

packages/libp2p/package.json

@@ -85,6 +85,7 @@
     "test:webkit": "aegir test -t browser -- --browser webkit"
   },
   "dependencies": {
+    "@chainsafe/is-ip": "^2.0.2",
     "@libp2p/crypto": "^5.0.7",
     "@libp2p/interface": "^2.2.1",
     "@libp2p/interface-internal": "^2.1.1",

packages/libp2p/src/address-manager.ts

@@ -1,3 +1,4 @@
+import { isIPv4 } from '@chainsafe/is-ip'
 import { peerIdFromString } from '@libp2p/peer-id'
 import { debounce } from '@libp2p/utils/debounce'
 import { multiaddr, protocols } from '@multiformats/multiaddr'
@@ -149,7 +150,9 @@ export class AddressManager implements AddressManagerInterface {
     this.components.peerStore.patch(this.components.peerId, {
       multiaddrs: addrs
     })
-      .catch(err => { this.log.error('error updating addresses', err) })
+      .catch(err => {
+        this.log.error('error updating addresses', err)
+      })
   }
 
   /**
@@ -267,6 +270,7 @@ export class AddressManager implements AddressManagerInterface {
       }
 
       mappings.forEach(mapping => {
+        tuples[0][0] = isIPv4(mapping.externalIp) ? CODEC_IP4 : CODEC_IP6
         tuples[0][1] = mapping.externalIp
         tuples[1][1] = `${mapping.externalPort}`
 

packages/libp2p/test/addresses/address-manager.spec.ts

@@ -427,4 +427,76 @@ describe('Address Manager', () => {
       multiaddr(`/ip6/${internalIp}/${protocol}/${internalPort}/p2p/${peerId.toString()}`)
     ])
   })
+
+  it('should add a public IPv4 address mapping when only local IPv6 addresses are present', () => {
+    const transportManager = stubInterface<TransportManager>()
+    const am = new AddressManager({
+      peerId,
+      transportManager,
+      peerStore,
+      events,
+      logger: defaultLogger()
+    })
+
+    const internalIp = '2a00:23c6:14b1:7e00:28b8:30d:944e:27f3'
+    const internalPort = 4567
+    const externalIp = '81.12.12.1'
+    const externalPort = 8910
+    const protocol = 'tcp'
+
+    am.addPublicAddressMapping(internalIp, internalPort, externalIp, externalPort, protocol)
+
+    // one loopback, one LAN address
+    transportManager.getAddrs.returns([
+      multiaddr(`/ip6/${internalIp}/${protocol}/${internalPort}`)
+    ])
+
+    // should have mapped the LAN address to the external IP
+    expect(am.getAddresses()).to.deep.equal([
+      multiaddr(`/ip6/${internalIp}/${protocol}/${internalPort}/p2p/${peerId.toString()}`),
+      multiaddr(`/ip4/${externalIp}/${protocol}/${externalPort}/p2p/${peerId.toString()}`)
+    ])
+
+    am.removePublicAddressMapping(internalIp, internalPort, externalIp, externalPort, protocol)
+
+    expect(am.getAddresses()).to.deep.equal([
+      multiaddr(`/ip6/${internalIp}/${protocol}/${internalPort}/p2p/${peerId.toString()}`)
+    ])
+  })
+
+  it('should add a public IPv6 address mapping when only local IPv4 addresses are present', () => {
+    const transportManager = stubInterface<TransportManager>()
+    const am = new AddressManager({
+      peerId,
+      transportManager,
+      peerStore,
+      events,
+      logger: defaultLogger()
+    })
+
+    const internalIp = '192.168.1.123'
+    const internalPort = 4567
+    const externalIp = '2a00:23c6:14b1:7e00:28b8:30d:944e:27f3'
+    const externalPort = 8910
+    const protocol = 'tcp'
+
+    am.addPublicAddressMapping(internalIp, internalPort, externalIp, externalPort, protocol)
+
+    // one loopback, one LAN address
+    transportManager.getAddrs.returns([
+      multiaddr(`/ip4/${internalIp}/${protocol}/${internalPort}`)
+    ])
+
+    // should have mapped the LAN address to the external IP
+    expect(am.getAddresses()).to.deep.equal([
+      multiaddr(`/ip4/${internalIp}/${protocol}/${internalPort}/p2p/${peerId.toString()}`),
+      multiaddr(`/ip6/${externalIp}/${protocol}/${externalPort}/p2p/${peerId.toString()}`)
+    ])
+
+    am.removePublicAddressMapping(internalIp, internalPort, externalIp, externalPort, protocol)
+
+    expect(am.getAddresses()).to.deep.equal([
+      multiaddr(`/ip4/${internalIp}/${protocol}/${internalPort}/p2p/${peerId.toString()}`)
+    ])
+  })
 })