TS6 bans not implemented

[cooper]

Kline/Dline/etc. are not yet implemented in TS6. The Ban::TS6 module exists and is loaded automatically whenever Ban and TS6 are both loaded.

[cooper]

Problem

juno bans are global and negotiated during burst with the bursting server as the command source. TS6 remote ban commands have to come from a user source.

Solution

Created a ban agent user which opers up and is used for the source of the K/DLINE commands. It quits immediately after burst.

Critical response

@glolol

<mad> SEND(ts6.notroll.net): :000 EUID 000AAAAFJ 0 1469308191 +io juno k.notroll.net  000AAAAFJ * * :juno-ircd ban agent
<GL|ovd> ??
<GL|ovd> oh my god
<GL|ovd> what is this hack

Everyone else

<everyone> Wow! What a modern and elegant solution to a bewildering issue!

[cooper]

Update: Reverted a change to wait until end burst; now the QUIT is sent during burst. Sounds bad, but it works better. This prevents the bot from generating annoying oper notices on every connect.

[cooper]

Need to improve notices in Ban. Need proto-inspecific methods for that rather than using gnotice() in JELP.pm.

[cooper]

Summary of the TS6 ban implementation

Bans are sent to TS6 servers on burst. Because certain ban commands only support a user source, a ban agent bot may be introduced to set the bans and then exit.

The duration sent to TS6 servers is variable based on the difference between the expiration time and the duration, since we cannot propagate an expiration time. The TS6 server will ignore any bans which already exist for the given mask, which is perfect for our purposes. An exception to this is the newer BAN command which does allow propagation of expiry times and is used when available.

Ban::TS6 uses the charybdis-style BAN command when possible. Alternatively KLINE and INCLINE may be used when the KLN and UKLN capabilities are available. Otherwise, it uses ENCAP KLINE and ENCAP UNKLINE. DLINEs always use ENCAP and therefore always require a ban agent during burst.

Note that, because some charybdis server bans are local-only, the TS6 server may not burst its own bans (such as D-Lines, or even K-Lines if the BAN capability is not available). However, ban commands are handled such that AKILLs (which have target *) will be effective across an entire mixed charybdis/juno network. AKILL is considered the most reliable way to ensure global ban propagation.

Other changes in Ban

• Bans are now enforced immediately upon hostname and ident resolve, speeding up the process.
• Bans can do things besides kill users now. Different actions can be registered.
• Notices for bans are now handled locally, which is a much safer way of doing it.
• More ban validation. validate_ban(), etc.
• New high-level functions like add_update_enforce_activate_ban() which simplify Ban protocol implementations.
• Significant changes in BAN::JELP. It is much safer now; it actually checks that required keys are present and ignores unknown ones.