Channel ACLs

[S-S-X]

Add simple access control lists for channels.

Possible roles are:

• deny Access to channel is denied.
• read Can read messages sent to channel.
• write Can send messages to channel.
• manager Can manage deny, read and write ACLs for channel.
• owner Can manage all ACLs, including channel owners.

Default role, when ACLs are not used for channel, is write.

Possible identities for ACL lookup are:

• Player name. Matches individual players.
• Privilege prefixed with $, for example $interact. Matches players who has that privilege.
• Special identity *. Default privilege for channel, used when no better match found.
• More special identities can be added, for example faction membership or such.

Password handling have been mostly moved from core to ACL plugin.
Beerchat now asks for password when attempting to join channel with password, /jc wont accept password at all (however it could still do that but access checks still requires ACL plugin).

[S-S-X]

ACL	Password	Outcome
allow	allow	✔️
undef	allow	✔️
deny	allow	⛔
allow	undef	✔️
undef	undef	✔️
deny	undef	⛔
allow	deny	⛔
undef	deny	⛔
deny	deny	⛔

That is how event handlers work by default. By default access is always granted and must be explicitly denied: if any handler denies access then access is denied completely. If nothing denies access then access is granted.

Explicit grants however are possible, if event handler returns true instead of nil then propagation is stopped and access granted immediately without checking any other rules. This however also requires extra care with event handler registration order and is way harder to manage.

[S-S-X]

This is going to need some play testing on actual server.

Things to test:

• Basic chatting / channel switching / joining / creating channels.
• Channels with password, is there any issues with existing protected channels or password functionality.
• Do player based ACLs work?
• Do privilege based ACLs work?
• Do owner and manager roles work correctly?
• ACLs should not affect channels where there's no ACLs.

It does also change basic message formatting parameters channel_name -> channel and channel_password -> password so custom format strings might break.
Currently however only main channel format string is actually configurable and even if formatting breaks it'll be easy to fix (in configuration) and chat should work just fine.

Stats:
spec/** 5 files changed, 249 insertions(+), 16 deletions(-)
!spec/** 12 files changed, 342 insertions(+), 145 deletions(-)
plugin/acl** 2 files changed, 270 insertions(+)

[S-S-X]

• Reorder chat command args Get rid of channel ban plugin #107 (comment)