ip: Add helpers to determine if an IP address is private

[sjoerdsimons]

Add IsPrivate methods to IP4 and IP6 to determine if a ip address is in
the private range. similar to IsPrivate of net.IP in newer golang
versions.

Signed-off-by: Sjoerd Simons [email protected]

Description

Add some helpers for determining of address are in a private range or not; useful for determining if masquarading should be enabled.

Todos

• Tests
• Documentation
• Release note

Release Note

None required

[manuelbuil]

Are you planning on implementing the code that will apply masq if it is private?

[sjoerdsimons]

fwiw here is an example usage: sjoerdsimons/k3s@f53921d

that's my old k3s branch for the previous rounds of wireguard dualstacking; I was submitting as i was prepping an MR to k3s for what is now merged in flannel which will also use this commit ;).

[luthermonson]

@sjoerdsimons can we just upgrade go however needed and use the net.IP functionaliry?

[sjoerdsimons]

@sjoerdsimons can we just upgrade go however needed and use the net.IP functionaliry?

I don't know what flannels policy is for updating the Go version. But iirc (it's been a while) if that's updated to a new enough version most if not all of this patch would unneeded indeed

[sjoerdsimons]

looks like i accidentally closed this one; woops

[sjoerdsimons]

Sorry for the noise; now i remember why i deleted the relevant branch; the branch name ending in .go confuses the flannel testsuite and on cannot change the source branch of an MR in github 🤦