DNS branch

[FreshXOpenSource]

i started to work on a basic DNS implementation at https://github.com/FreshXOpenSource/seaduk/tree/dns (for now only _sync name lookups to ip-strings or arrays work).

i realize that im not yet that fit to implement an async version and would like to request help here for one async resolve example. furthermore there are several issues not yet addressed:

• can you create a DNS branch in nucleus-js to merge to or whats the best way here?
• i would like to implement relevant parts of the NodeJS DNS Module https://nodejs.org/api/dns.html and be as compatible to this as possible
• i have not yet a clue how to create duv internal structures that the lookups can be used within the networking c-code directly (not converting them as to duktape string before)

any input welcome...

[creationix]

I like how dns was done in luvit. I simply bound the libuv methods directly and then implemented the node dns APIs on top of the libuv udp bindings.

• https://github.com/luvit/luv/blob/master/src/dns.c
• https://github.com/luvit/luvit/blob/master/deps/dns.lua

[creationix]

I can work on the C part tonight if you need dns in seaduk. It covers the main case of resolving a domain name to a dns address.

[creationix]

I've added the dns bindings to seaduk.

There are two new functions uv.getnameinfo(options, callback) and uv.getaddrinfo(options, callback)

uv.getnameinfo(options, callback)

address-to-name translation in protocol-independent manner

• options.ip - optionally provide an IP address
• options.port - optionally provide a port (it will try to guess service name)
• options.family - optionally provide a family

The callback will have (err, hostname, servicename).

uv.getaddrinfo(options, callback)

network address and service translation

• options.node - the hostname you want to resolve
• options.service - an optional servicename to resolve to port
• options.family - a family like inet or inet6
• options.socktype
• options.protocol
• options.addrconfig
• options.v4mapped
• options.all
• options.numerichost
• options.passive
• options.numericserv
• options.canonname

---

To simply resolve a hostname to an IPv4 address, do something like:

uv.getaddrinfo({
  node: "luvit.io",
  socktype: "stream", // Only show TCP results
  family: "inet",  // Only show IPv4 results
}, function (err, results) {
  assert(!err, err);
  p("Dns results for luvit.io", results);
});

[creationix]

I believe libuv supports sync mode and I can add it with more work (same as the uv.fs_* functions). Currently it runs in async mode and you must pass in a callback.

[FreshXOpenSource]

that looks pretty nice to me! the sync functionality is not really needed.

[prust]

Nice! Thanks for doing this @creationix!