~singpolyma/biboumi

ref: 1c43c3af4cbefcd482f4145ee3d7553631a7485d biboumi/doc/biboumi.1.md -rw-r--r-- 14.4 KiB
1c43c3af — Florent Le Coz Include the IRC hostname in the IRC RECEIVING and SENDING debug messages 7 years ago

#BIBOUMI 1 "2014-06-02"

#NAME

biboumi - XMPP gateway to IRC

#DESCRIPTION

Biboumi is an XMPP gateway that connects to IRC servers and translates between the two protocols. It can be used to access IRC channels using any XMPP client as if these channels were XMPP MUCs.

#SYNOPSIS

biboumi [config_filename]

#OPTIONS

Available command line options:

config_filename

Specify the file to read for configuration. See CONFIG section for more details on its content.

#CONFIG

The configuration file uses a simple format of the form "option=value". Here is a description of each possible option:

hostname (mandatory)

The hostname served by the XMPP gateway. This domain must be configured in the XMPP server as an external component. See the manual for your XMPP server for more information. For prosody, see http://prosody.im/doc/components#adding_an_external_component

password (mandatory)

The password used to authenticate the XMPP component to your XMPP server. This password must be configured in the XMPP server, associated with the external component on hostname.

port

The TCP port to use to connect to the local XMPP component. The default value is 5347.

admin

The bare JID of the gateway administrator. This JID will have more privileges than other standard users (the admin thus needs to check their privileges), for example some administration ad-hoc commands will only be available to that JID.

log_file

A filename into which logs are written. If none is provided, the logs are written on standard output.

log_level

Indicate what type of log messages to write in the logs. Value can be from 0 to 3. 0 is debug, 1 is info, 2 is warning, 3 is error. The default is 0, but a more practical value for production use is 1.

The configuration can be re-read at runtime (you can for example change the log level without having to restart biboumi) by sending SIGUSR1 or SIGUSR2 (see kill(1)) to the process.

#USAGE

Biboumi acts as a server, it should be run as a daemon that lives in the background for as long as it is needed. Note that biboumi does not daemonize itself, this task should be done by your init system (SysVinit, systemd, upstart).

When started, biboumi connects, without encryption (see SECURITY), to the local XMPP server on the port 5347 and authenticates with the provided password. Biboumi then serves the configured hostname: this means that all XMPP stanza with a to JID on that domain will be forwarded to biboumi by the XMPP server, and biboumi will only send messages coming from that hostname.

When a user joins an IRC channel on an IRC server (see Join an IRC channel), biboumi connects to the remote IRC server, sets the user’s nick as requested, and then tries to join the specified channel. If the same user subsequently tries to connect to an other channel on the same server, the same IRC connection is used. If, however, an other user wants to join an IRC channel on that same IRC server, biboumi opens a new connection to that server. Biboumi connects once to each IRC server, for each user on it.

To cleanly shutdown the component, send a SIGINT or SIGTERM signal to it. It will send messages to all connected IRC and XMPP servers to indicate a reason why the users are being disconnected. Biboumi exits when the end of communication is acknowledged by all IRC servers. If one or more IRC servers do not respond, biboumi will only exit if it receives the same signal again or if a 2 seconds delay has passed.

#Addressing

IRC entities are represented by XMPP JIDs. The domain part of the JID is the domain served by biboumi (the part after the @, biboumi.example.com in the examples), and the local part (the part before the @) depends on the concerned entity.

IRC channels have a local part formed like this: channel_name%irc_server.

If the IRC channel you want to adress starts with the '#' character (or an other character, announced by the IRC server, like '&', '+' or '!'), then you must include it in the JID. Some other gateway implementations, as well as some IRC clients, do not require them to be started by one of these characters, adding an implicit '#' in that case. Biboumi does not do that because this gets confusing when trying to understand the difference between the channels #foo, and ##foo. Note that biboumi does not use the presence of these special characters to identify an IRC channel, only the presence of the separator % is used for that.

The channel name can also be empty (for example %irc.example.com), in that case this represents the virtual channel provided by biboumi. See Connect to an IRC server for more details.

There is two ways to address an IRC user, using a local part like this: nickname!irc_server or by using the in-room address of the participant, like this: channel_name%irc_server@biboumi.example.com/Nickname

The second JID is available only to be compatible with XMPP clients when the user wants to send a private message to the participant Nickname in the room channel_name%irc_server@biboumi.example.com.

On XMPP, the node part of the JID can only be lowercase. On the other hand, IRC nicknames are case-insensitive, this means that the nicknames toto, Toto, tOtO and TOTO all represent the same IRC user. This means you can talk to the user toto, and this will work.

Examples:

#foo%irc.example.com@biboumi.example.com is the #foo IRC channel, on the irc.example.com IRC server, and this is served by the biboumi instance on biboumi.example.com

toto!irc.example.com@biboumi.example.com is the IRC user named toto, or TotO, etc.

irc.example.com@biboumi.example.com is the IRC server irc.example.com.

%irc.example.com@biboumi.example.com is the virtual channel provided by biboumi, for the IRC server irc.example.com.

Note: Some JIDs are valid but make no sense in the context of biboumi:

!irc.example.com@biboumi.example.com is the empty-string nick on the irc.example.com server. It makes no sense to try to send messages to it.

#test%@biboumi.example.com, or any other JID that does not contain an IRC server is invalid. Any message to that kind of JID will trigger an error, or will be ignored.

If compiled with Libidn, an IRC channel participant has a bare JID representing the “hostname” provided by the IRC server. This JID can only be used to set IRC modes (for example to ban a user based on its IP), or to identify user. It cannot be used to contact that user using biboumi.

#Join an IRC channel

To join an IRC channel #foo on the IRC server irc.example.com, join the XMPP MUC #foo%irc.example.com@hostname.

#Connect to an IRC server

The connection to the IRC server is automatically made when the user tries to join any channel on that IRC server. The connection is closed whenever the last channel on that server is left by the user. To be able to stay connected to an IRC server without having to be in a real IRC channel, biboumi provides a virtual channel on the jid %irc.example.com@biboumi.example.com. For example if you want to join the channel #foo on the server irc.example.com, but you need to authenticate to a bot of the server before you’re allowed to join it, you can first join the room %irc.example.com@biboumi.example.com (this will effectively connect you to the IRC server without joining any room), then send your authentication message to the user bot!irc.example.com@biboumi.example.com and finally join the room #foo%irc.example.com@biboumi.example.com.

#Channel messages

On XMPP, unlike on IRC, the displayed order of the messages is the same for all participants of a MUC. Biboumi can not however provide this feature, as it cannot know whether the IRC server has received and forwarded the messages to other users. This means that the order of the messages displayed in your XMPP client may not be the same than the order on other IRC users’.

#Nicknames

On IRC, nicknames are server-wide. This means that one user only has one single nickname at one given time on all the channels of a server. This is different from XMPP where a user can have a different nick on each MUC, even if these MUCs are on the same server.

This means that the nick you choose when joining your first IRC channel on a given IRC server will be your nickname in all other channels that you join on that same IRC server. If you explicitely change your nickname on one channel, your nickname will be changed on all channels on the same server as well.

#Private messages

Private messages are handled differently on IRC and on XMPP. On IRC, you talk directly to one server-user: toto on the channel #foo is the same user as toto on the channel #bar (as long as these two channels are on the same IRC server). By default you will receive private messages from the “global” user (aka nickname!irc.example.com@biboumi.example.com), unless you previously sent a message to an in-room participant (something like #test%irc.example.com@biboumi.example.com/nickname), in which case future messages from that same user will be received from that same “in-room” JID.

#Notices

Notices are received exactly like private messages. It is not possible to send a notice.

#Kicks and bans

Kicks are transparently translated from one protocol to another. However banning an XMPP participant has no effect. To ban an user you need to set a mode +b on that user nick or host (see MODES) and then kick it.

#Encoding

On XMPP, the encoding is always UTF-8, whereas on IRC the encoding of each message can be anything.

This means that biboumi has to convert everything coming from IRC into UTF-8 without knowing the encoding of the received messages. To do so, it checks if each message is UTF-8 valid, if not it tries to convert from iso_8859-1 (because this appears to be the most common case, at least on the channels I visit) to UTF-8. If that conversion fails at some point, a placeholder character '�' is inserted to indicate this decoding error.

Messages are always sent in UTF-8 over IRC, no conversion is done in that direction.

#IRC modes

One feature that doesn’t exist on XMPP but does on IRC is the modes. Although some of these modes have a correspondance in the XMPP world (for example the +o mode on a user corresponds to the moderator role in XMPP), it is impossible to map all these modes to an XMPP feature. To circumvent this problem, biboumi provides a raw notification when modes are changed, and lets the user change the modes directly.

To change modes, simply send a message starting with “/mode” followed by the modes and the arguments you want to send to the IRC server. For example “/mode +aho louiz”. Note that your XMPP client may interprete messages begining with “/” like a command. To actually send a message starting with a slash, you may need to start your message with “//mode” or “/say /mode”, depending on your client.

When a mode is changed, the user is notified by a message coming from the MUC bare JID, looking like “Mode #foo [+ov] [toto tutu]”. In addition, if the mode change can be translated to an XMPP feature, the user will be notified of this XMPP event as well. For example if a mode “+o toto” is received, then toto’s role will be changed to moderator. The mapping between IRC modes and XMPP features is as follow:

+q

Sets the participant’s role to moderator and its affiliation to owner.

+a

Sets the participant’s role to moderator and its affiliation to owner.

+o

Sets the participant’s role to moderator and its affiliation to admin.

+h

Sets the participant’s role to moderator and its affiliation to member.

+v

Sets the participant’s role to participant and its affiliation to member.

Similarly, when a biboumi user changes some participant's affiliation or role, biboumi translates that in an IRC mode change.

Affiliation set to none

Sets mode to -vhoaq

Affiliation set to member

Sets mode to +v-hoaq

Role set to moderator

Sets mode to +h-oaq

Affiliation set to admin

Sets mode to +o-aq

Affiliation set to owner

Sets mode to +a-q

#Ad-hoc commands

Biboumi supports a few ad-hoc commands, as described in the XEP 0050.

  • ping: Just respond “pong”

  • hello: Provide a form, where the user enters their name, and biboumi responds with a nice greeting.

  • disconnect-user: Only available to the administrator. The user provides a list of JIDs, and a quit message. All the selected users are disconnected from all the IRC servers to which they were connected, using the provided quit message. Sending SIGINT to biboumi is equivalent to using this command by selecting all the connected JIDs and using the “Gateway shutdown” quit message, except that biboumi does not exit when using this ad-hoc command.

#SECURITY

The connection to the XMPP server can only be made on localhost. The XMPP server is not supposed to accept non-local connections from components. Thus, encryption is not used to connect to the local XMPP server because it is useless.

If compiled with the Botan library, biboumi can use TLS when communicating with the IRC serveres. It will first try ports 6697 and 6670 and use TLS if it succeeds, if connection fails on both these ports, the connection is established on port 6667 without any encryption.

Biboumi does not check if the received JIDs are properly formatted using nodeprep. This must be done by the XMPP server to which biboumi is directly connected.

Note if you use a biboumi that you have no control on: remember that the administrator of the gateway you use is able to view all your IRC conversations, whether you’re using encryption or not. This is exactly as if you were running your IRC client on someone else’s server. Only use biboumi if you trust its administrator (or, better, if you are the administrator) or if you don’t intend to have any private conversation.

Biboumi does not provide a way to ban users from connecting to it, has no protection against flood or any sort of abuse that your users may cause on the IRC servers. Some XMPP server however offer the possibility to restrict what JID can access a gateway. Use that feature if you wish to grant access to your biboumi instance only to a list of trusted users.

#AUTHORS

This software and man page are both written by Florent Le Coz.

#LICENSE

Biboumi is released under the zlib license.