Support DNS

[jbenet]

Multiaddrs like these should work:

/dns/ipfs.io
/dns/foo.bar.com/http

[ghost]

This format in ambiguous regarding IPv4/IPv6. Other options:

/ip4/ipfs.io
/dns6/foo.net
/dnsAAAA/bar.com
/dns/baz.org/ip4

All of these would roughly resolve to /ip4/1.2.3.4 and /ip6/123::4. The last one has the most appeal imo.

[jbenet]

also, which record? just A? or allow TXT to work too:

/dns/baz.org/

vs

/dns/baz.org/a/
/dns/baz.org/txt/

(hard to do defaults...)

(update: ahh i see you mentioned dnsAAAA too)

[jbenet]

i like /dns/baz.org/ip4 though that's a bit tricky.

maybe:

/dns/baz.org/ip   # either 4 or 6
/dns/baz.org/ip4  # ipv4
/dns/baz.org/ip4  # ipv6

[ghost]

maybe:

/dns/baz.org/ip   # either 4 or 6
/dns/baz.org/ip4  # ipv4
/dns/baz.org/ip4  # ipv6

yeah that's what i was after :)

A full example:

/dns/bootstrap1.ipfs.io/ip4/tcp/4001/ipfs/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ

It'd break with the quasi-rule that a protocol is a 2-tuple, but we can say that you MUST know how many segments follow once you see the first one -- e.g. you see /dns, and know there will be two more segments.

[jbenet]

@lgierth that sounds good to me

It'd break with the quasi-rule that a protocol is a 2-tuple, but we can say that you MUST know how many segments follow once you see the first one -- e.g. you see /dns, and know there will be two more segments.

Yep, i think that's fine too (deterministic)

[jbenet]

i also havent seen other multiaddr impls, so easy to change for us

[jbenet]

@lgierth we should probably support record types here.

/dns/bootstrap1.ipfs.io/A/ip4

?

[ghost]

Do you mean for SRV/TXT/etc. records? Cause A and AAAA always implicate ip4/ip6.

[jbenet]

ah right 👍

[jbenet]

Some comment i got by email is missing. for posterity:

I want to extend go-multiaddr and go-multiaddr-net to support dialing to /dns/baz.org/ws/80 and listening on /ip4/12.45.56.78/ws/80. Should I use /dns/baz.org/ip/tcp/80/ws and /ip4/12.45.56.78/tcp/80/ws instead? Also, what protocol codes you'd recommend for dns, ws and ip?

Yes you should use the /tcp/80/ws version instead.

[Gaboose]

That's my comment. Thought it was a little off topic so I deleted it 🐰

But since you mention it, I'll have you know that I got /dns/baz.org/tcp/4324 and /dns/baz.org/tcp/4324/ws/echo to work on my modest attempt to a pluggable manet, no /dns/baz.org/ip4 though, because you can't create those with this library.

[ghost]

no /dns/baz.org/ip4 though, because you can't create those with this library.

Yes we'll have to make a few changes to go-multiaddr, namely support for triplets, and some kind of resolution step that turns /dns/example.net/ip4 into /ip4/1.2.3.4

[Gaboose]

The problem with "resolving /dns/example.net/ip4 to /ip4/1.2.3.4 and be done with it" for me was that /ws needs to know the hostname to include in http request headers, otherwise cloud services refuse the connection. So those two addresses are not equivalent.

[ghost]

Your application code would be working with /dns addrs, while manet resolves these to /ip4 for internal use. Does that sound useful for your case?

[Gaboose]

Well, I have my case solved, it doesn't matter to me much. But I do like (and did in my reimplementation) manet to handle connection differences between /dns/example.net/tcp/80/ws/echo and /ip4/127.0.0.1/tcp/4324 internally and make them interchangable for the external user. It makes things like manetcat possible.

EDIT: I'm just trying to seduce you with the neatness of this, and saying that it's possible and available. Not asking for anything.

[jbenet]

@Gaboose

• very nice work with your manet fork
• have you seen the pluggability that @whyrusleeping added in-- what are your thoughts?
• Good work on manetcat i made something similar in https://github.com/multiformats/ma-pipe -- it still needs more work, but worth a look. maybe we should converge in mnc or manc

[ghost]

Closing this in favor of multiformats/multiaddr#22