PyLink/docs/technical/hooks-reference.md

PyLink hooks reference

Introduction

In PyLink, protocol modules communicate with plugins through a system of hooks. This has the benefit of being IRCd-independent, allowing most plugins to function regardless of the IRCd being used. Each hook payload is formatted as a Python list, with three arguments: numeric, command, and args.

1. numeric: The sender of the hook payload (normally a UID or SID).

2. command: The command name (hook name) of the payload. These are always UPPERCASE, and those starting with “PYLINK_” indicate hooks sent out by PyLink IRC objects themselves (i.e. they don’t require protocol modules to handle them).

3. args: The hook data (args), a Python dict, with different data keys and values depending on the command given.

Note: the ts key is automatically added (using the current time) to all hook data dicts that don’t include it - such a key should only be provided if the command the uplink IRCd sends a TS value itself.

Example syntax

The command :42XAAAAAB PRIVMSG #dev :test would result in the following raw hook data:

• ['42XAAAAAB', 'PRIVMSG', {'target': '#dev', 'text': 'test', 'ts': 1451174041}]

On UnrealIRCd, because SETHOST is mapped to CHGHOST, :GL SETHOST blah would return the raw hook data of this (with the nick converted into UID automatically by the protocol module):

• ['001ZJZW01', 'CHGHOST', {'ts': 1451174512, 'target': '001ZJZW01', 'newhost': 'blah'}]

Some hooks, like MODE, are more complex and can include the entire state of a channel. This will be further described later. :GL MODE #chat +o PyLink-devel is converted into (pretty-printed for readability):

['001ZJZW01',
 'MODE',
 {'modes': [('+o', '38QAAAAAA')],
  'channeldata': IrcChannel({'modes': set(),
                             'prefixmodes': {'admin': set(),
                                             'halfop': set(),
                                             'op': set(),
                                             'owner': set(),
                                             'voice': set()},
                             'topic': '',
                             'topicset': False,
                             'ts': 1451169448,
                             'users': {'38QAAAAAA', '001ZJZW01'}}),
  'target': '#chat',
  'ts': 1451174702}]

Core hooks

These following hooks, sent with their correct data keys, are required for PyLink’s basic functioning.

• ENDBURST: {}
  • The hook data here is empty.
  • This payload should be sent whenever a server finishes its burst, with the SID of the bursted server as the sender.
  • The service bot API and plugins like relay use this to make sure networks are properly connected. Should ENDBURST not be sent or emulated, they will likely fail to spawn users entirely.
• PYLINK_DISCONNECT: {}
  • This is sent to plugins by IRC object instances whenever their network has disconnected. The sender here is always None.

IRC command hooks

The following hooks represent regular IRC commands sent between servers.

Basic commands

• JOIN: {'channel': '#channel', 'users': ['UID1', 'UID2', 'UID3'], 'modes': [('n', None), ('t', None), ('k', 'somesecretkey')], 'ts': 1234567890}

  • This hook handles both SJOIN and JOIN commands, to make writing plugins slightly easier (they only need to listen to one hook).
  • channel sends the channel name, users sends a list of joining UIDs, and ts returns the TS (an int) that we have for the channel.
  • modes returns a list of parsed modes: (mode character, mode argument) tuples, where the mode argument is either None (for modes without arguments), or a string.
  • The sender of this hook payload is IRCd-dependent, and is determined by whether the command was originally a SJOIN or regular JOIN - SJOIN is only sent by servers, and JOIN is only sent by users.
  • For IRCds that support joining multiple channels in one command (/join #channel1,#channel2), consecutive JOIN hook payloads of this format will be sent (one per channel).
  • For SJOIN, the channeldata key may also be sent, with a copy of the IrcChannel object BEFORE any mode changes from this burst command were processed.

• KICK: {'channel': '#channel', 'target': 'UID1', 'text': 'some reason'}

  • text refers to the kick reason. The target and channel fields send the target’s UID and the channel they were kicked from, and the sender of the hook payload is the kicker.

• KILL: {'target': killed, 'text': args[1], 'userdata': data}

  • text refers to the kill reason. target is the target’s UID.
  • The userdata key may include an IrcUser instance, depending on the IRCd. On IRCds where QUITs are explicitly sent (InspIRCd), userdata will be None. Other IRCds do not explicitly send QUIT messages for KILLed clients, so the daemon must assume that they’ve quit, and deliver their last state to plugins that require this info.

• MODE: {'target': '#channel', 'modes': [('+m', None), ('+i', None), ('+t', None), ('+l', '3'), ('-o', 'person')], 'channeldata': IrcChannel(...)}

  • target is the target the mode is being set on: it may be either a channel (for channel modes) OR a UID (for user modes).
  • modes is a list of prefixed parsed modes: (mode character, mode argument) tuples, but with +/- prefixes to denote whether each mode is being set or unset.
  • For channels, the channeldata key is also sent, with a copy of the IrcChannel BEFORE this MODE hook was processed.
    • One use for this is to prevent oper-override hacks: checks for whether a sender is opped have to be done before the MODE is processed; otherwise, someone can simply op themselves and circumvent this detection.

• NICK: {'newnick': 'Alakazam', 'oldnick': 'Abracadabra', 'ts': 1234567890}

• NOTICE: {'target': 'UID3', 'text': 'hi there!'}

  • Note: target can not only be a channel or a UID, but also a channel with a prefix attached (e.g. @#lounge). These cases should not be overlooked!

• PART: {'channels': ['#channel1', '#channel2'], 'text': 'some reason'}

  • text can also be an empty string, as part messages are optional on IRC.
  • Unlike the JOIN hook, multiple channels can be specified in a list for PART. This means that a user PARTing one channel will cause a payload to be sent with channels as a one-length list with the channel name.

• PRIVMSG: {'target': 'UID3', 'text': 'hi there!'}

  • Ditto with NOTICE: target can be a channel or a UID, or a channel with a prefix attached (e.g. @#lounge).

• QUIT: {'text': 'Quit: Bye everyone!'}

  • text corresponds to the quit reason.

• SQUIT: {'target': '800', 'users': ['UID1', 'UID2', 'UID6'], 'name': 'some.server', 'uplink': '24X', 'nicks': {'#channel1: ['tester1', 'tester2'], '#channel3': ['somebot']}, 'serverdata': IrcServer(...)

  • target is the SID of the server being split, while name is the server’s name.
  • users is a list of all UIDs affected by the netsplit. nicks maps channels to lists of nicks affected.
  • serverdata provides the IrcServer object of the server that was split.
  • channeldata provides the channel index of the network before the netsplit was processed, allowing plugins to track who was affected by a netsplit in a channel specific way.

• TOPIC: {'channel': channel, 'setter': numeric, 'text': 'Welcome to #Lounge!, 'oldtopic': 'Welcome to#Lounge!'}

  • oldtopic denotes the original topic, and text indicates the new one being set.
  • setter is the raw sender field given to us by the IRCd; it may be a nick!user@host, a UID, a SID, a server name, or a nick. This is not processed any further.

• UID: {'uid': 'UID1', 'ts': 1234567891, 'nick': 'supercoder', 'realhost': 'localhost', 'host': 'admin.testnet.local', 'ident': ident, 'ip': '127.0.0.1'}

  • This command is used to introduce users; the sender of the message should be the server bursting or announcing the connection.
  • ts refers to the user’s signon time.

Extra commands (where supported by the IRCd)

• AWAY: {'text': text}

  • text denotes the away reason. It is an empty string ('') when a user is unsetting their away status.

• CHGHOST: {'target': 'UID2', 'newhost': 'some.silly.host'}

  • SETHOST, CHGHOST, and any other events that cause host changes should return a CHGHOST hook payload. The point of this is to track changes in users’ hostmasks.

• CHGIDENT: {'target': 'UID2', 'newident': 'evilone'}

  • SETIDENT and CHGIDENT commands, where available, both share this hook name.

• CHGNAME: {'target': 'UID2', 'newgecos': "I ain't telling you!"}

  • SETNAME and CHGNAME commands, where available, both share this hook name.

• INVITE: {'target': 'UID3', 'channel': '#myroom'}

• KNOCK: {'text': 'let me in please!', 'channel': '#myroom'}

  • This is not actually implemented by any protocol module as of writing.

• SAVE: {'target': 'UID8', 'ts': 1234567892, 'oldnick': 'Abracadabra'}

  • For protocols that use TS6-style nick saving. During nick collisions, instead of killing the losing client, servers that support SAVE will send such a command targeting the losing client, which forces that user’s nick to their UID.
  • As of 1.1.x, SAVE is also used internally to alert plugins of nick collisions, when protocol modules receive a user introduction for a nick that already exists.

• SVSNICK: {'target': 'UID1', 'newnick': 'abcd'}

  • PyLink does not comply with SVSNICK requests, but instead forwards it to plugins that listen for it.
  • Relay, for example, treats SVSNICK as a cue to force tag nicks.

• VERSION: {}

  • This is used for protocols that send VERSION requests between servers when a client requests it (e.g. /raw version pylink.local).
  • coremods/handlers.py automatically handles this by responding with a 351 numeric, with the data being the output of irc.fullVersion().

• WHOIS: {'target': 'UID1'}

  • On protocols supporting it (everything except InspIRCd), the WHOIS command is sent between servers for remote WHOIS requests.
  • PyLink has built-in handling for this via coremods/handlers.py - plugins wishing to add custom WHOIS text should use the PYLINK_CUSTOM_WHOIS hook below.

Hooks that don’t map to IRC commands

Some hooks do not map directly to IRC commands, but to events that protocol modules should handle.

• CLIENT_SERVICES_LOGIN: {'text': 'supercoder'}
  • This hook is sent whenever a user logs in to a services account, where text is the account name. The sender of the hook is the UID of the user logging in.
• CLIENT_OPERED: {'text': 'IRC_Operator'}
  • This hook is sent whenever an oper-up is successful: when a user with umode +o is bursted, when umode +o is set, etc.
  • The text field denotes the oper type (not the SWHOIS), which is used for WHOIS replies on different IRCds.
• PYLINK_NEW_SERVICE: {'name': "servicename"}
  • This hook is sent when a new service is introduced. It replaces the old PYLINK_SPAWNMAIN hook.
  • The sender here is always None.
• PYLINK_CUSTOM_WHOIS: {'target': UID1, 'server': SID1}
  • This hook is called by coremods/handlers.py during its WHOIS handling process, to allow plugins to provide custom WHOIS information. The target field represents the target UID, while the server field represents the SID that should be replying to the WHOIS request. The source of the payload is the user using /whois.
  • Plugins wishing to implement this should use the standard WHOIS numerics, using irc.proto.numeric() to reply to the source from the given server.
  • This hook replaces the pre-0.8.x fashion of defining custom WHOIS handlers, which was non-standard and poorly documented.

Commands handled WITHOUT hooks

At this time, commands that are handled by protocol modules without returning any hook data include PING, PONG, and various commands sent during the initial server linking phase.