Add more information to os.networkInterfaces() output?

[cwalther]

I had a need to get some detail information about the system’s IPv6 addresses, specifically whether they were temporary. It turned out that this was not extremely hard to add to the built-in os.networkInterfaces() function. Because I would rather not have to ship and maintain a patched node, I extracted the relevant code from node and libuv and put it into a module, then made my additions there: network-interfaces-plus.

Would there be interest in having this functionality added back to the original os.networkInterfaces()?

I don’t mind if the answer is “no” – I have seen similar requests declined in the past on the grounds that having os.networkInterfaces() in core is borderline feature-creep already.

My changes modify the libuv ABI (added struct fields) and would probably need to be coordinated with libuv/libuv#1371.

Example output

with node v6.11.2 on macOS 10.12.6

> os.networkInterfaces() // before
{ lo0: 
   [ { address: '127.0.0.1',
       netmask: '255.0.0.0',
       family: 'IPv4',
       mac: '00:00:00:00:00:00',
       internal: true },
     { address: '::1',
       netmask: 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 0,
       internal: true },
     { address: 'fe80::1',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 1,
       internal: true } ],
  en0: 
   [ { address: 'fe80::1ce9:2f8c:6663:ab03',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 4,
       internal: false },
     { address: 'fd49:351c:437d:0:4b6:e152:cd43:74af',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 0,
       internal: false },
     { address: 'fd49:351c:437d:0:449b:78a2:7370:4d3b',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 0,
       internal: false },
     { address: '192.168.1.59',
       netmask: '255.255.128.0',
       family: 'IPv4',
       mac: '00:25:00:f4:d8:75',
       internal: false } ],
  utun0: 
   [ { address: 'fe80::a9bf:ce39:e4f:2c53',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 7,
       internal: false } ],
  vnic0: 
   [ { address: '10.211.55.2',
       netmask: '255.255.255.0',
       family: 'IPv4',
       mac: '00:1c:42:00:00:08',
       internal: false } ],
  vnic1: 
   [ { address: '10.37.129.2',
       netmask: '255.255.255.0',
       family: 'IPv4',
       mac: '00:1c:42:00:00:09',
       internal: false } ] }
> require('network-interfaces-plus').networkInterfaces() // after
{ lo0: 
   [ { address: '127.0.0.1',
       netmask: '255.0.0.0',
       family: 'IPv4',
       mac: '00:00:00:00:00:00',
       internal: true,
       cidr: '127.0.0.1/8' },
     { address: '::1',
       netmask: 'ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 0,
       internal: true,
       temporary: false,
       valid_lifetime: 4294967295,
       preferred_lifetime: 4294967295,
       cidr: '::1/128' },
     { address: 'fe80::1',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 1,
       internal: true,
       temporary: false,
       valid_lifetime: 4294967295,
       preferred_lifetime: 4294967295,
       cidr: 'fe80::1/64' } ],
  en0: 
   [ { address: 'fe80::1ce9:2f8c:6663:ab03',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 4,
       internal: false,
       temporary: false,
       valid_lifetime: 4294967295,
       preferred_lifetime: 4294967295,
       cidr: 'fe80::1ce9:2f8c:6663:ab03/64' },
     { address: 'fd49:351c:437d:0:4b6:e152:cd43:74af',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 0,
       internal: false,
       temporary: false,
       valid_lifetime: 2591982,
       preferred_lifetime: 604782,
       cidr: 'fd49:351c:437d:0:4b6:e152:cd43:74af/64' },
     { address: 'fd49:351c:437d:0:449b:78a2:7370:4d3b',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:25:00:f4:d8:75',
       scopeid: 0,
       internal: false,
       temporary: true,
       valid_lifetime: 596355,
       preferred_lifetime: 77955,
       cidr: 'fd49:351c:437d:0:449b:78a2:7370:4d3b/64' },
     { address: '192.168.1.59',
       netmask: '255.255.128.0',
       family: 'IPv4',
       mac: '00:25:00:f4:d8:75',
       internal: false,
       cidr: '192.168.1.59/17' } ],
  utun0: 
   [ { address: 'fe80::a9bf:ce39:e4f:2c53',
       netmask: 'ffff:ffff:ffff:ffff::',
       family: 'IPv6',
       mac: '00:00:00:00:00:00',
       scopeid: 7,
       internal: false,
       temporary: false,
       valid_lifetime: 4294967295,
       preferred_lifetime: 4294967295,
       cidr: 'fe80::a9bf:ce39:e4f:2c53/64' } ],
  vnic0: 
   [ { address: '10.211.55.2',
       netmask: '255.255.255.0',
       family: 'IPv4',
       mac: '00:1c:42:00:00:08',
       internal: false,
       cidr: '10.211.55.2/24' } ],
  vnic1: 
   [ { address: '10.37.129.2',
       netmask: '255.255.255.0',
       family: 'IPv4',
       mac: '00:1c:42:00:00:09',
       internal: false,
       cidr: '10.37.129.2/24' } ] }

[Fishrock123]

related to and possibly a duplicate of #498?

[cwalther]

Definitely related in that it touches the same code (like mentioned libuv/libuv#1371, which is basically its implementation), but not a duplicate in my opinion, but orthogonal – it is asking for more interfaces, while my implementation adds more information inside each interface.

[bzoz]

PRs to libuv are always welcomed, feel free to open one. ABI stability is very important in libuv though. If your code changes structs then it will have hard time being accepted into the v1.x branch.

[refack]

Put into https://github.com/nodejs/node/projects/13 backlog