UnhandledPromiseRejectionWarning caused by this module not catching validation errors

[achingbrain]

(node:19077) UnhandledPromiseRejectionWarning: Error: invalid ip
    at module.exports (/Users/alex/.nvm/versions/node/v10.17.0/lib/node_modules/ipfs/node_modules/libp2p-utils/src/ip-port-to-multiaddr.js:8:11)
    at module.exports (/Users/alex/.nvm/versions/node/v10.17.0/lib/node_modules/ipfs/node_modules/libp2p-tcp/src/socket-to-conn.js:55:39)
    at Server.net.createServer (/Users/alex/.nvm/versions/node/v10.17.0/lib/node_modules/ipfs/node_modules/libp2p-tcp/src/listener.js:23:20)
    at Server.emit (events.js:198:13)
    at TCP.onconnection (net.js:1520:8)

This can cause applications to crash.

[jacobheun]

My assumption is that we're getting a DNS address causing the invalid ip error. We need to wrap the calls to the utils function. Ideally we'd just use multiaddr.fromNodeAddress, but that doesn't support non ip addresses at the moment.

[vasco-santos]

@jacobheun I am not sure if this is because of getting a DNS address, since this throws on parameter validation and not on ip validation.

The stack trace is:

• https://github.com/libp2p/js-libp2p-tcp/blob/master/src/socket-to-conn.js#L55
• https://github.com/libp2p/js-libp2p-utils/blob/master/src/ip-port-to-multiaddr.js#L8

So, this immediately failing on the parameter validation, which makes me think that ip-port-to-multiaddr is receiving undefined. Anyway, I will PR shortly a better error support for the util

[jacobheun]

I believe the issue is related to a client disconnecting before the listener converts the connection. From the nodejs docs for remoteAddress

Value may be undefined if the socket is destroyed (for example, if the client disconnected).

This is likely what we're seeing. I am adding a general catch in the listener for converting the socket to a MultiaddrConnection. Dial errors are caught in libp2p, but there is nothing to handle listener errors, so it can't throw.