BIBOUMI 1 "2014-02-17" ====================== NAME ---- biboumi - XMPP gateway to IRC SYNOPSIS -------- `biboumi` [`config_filename`] 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. OPTIONS ------- Available 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. `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*. `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. Values 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 ----- When started, biboumi connects, without encryption (see *SECURITY*), to the local XMPP server on the port `5347` and provides the configured password to authenticate. Biboumi then serves the configured `hostname`, this means that all XMPP stanza with a `to` JID on that domain will be sent to biboumi, and biboumi will send only send messages coming from this hostname. When an 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 the SIGINT or SIGTERM signals 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 all connections are closed because the remote acknowledged the end of communication. If the remote server does not respond, biboumi does not exit, unless SIGINT or SIGTERM is received again, in which case biboumi closes the TCP connections and exits immediately. ### Addressing IRC entities are represented by XMPP JIDs. The domain part of the JID is the domain served by biboumi, and the local part depends on the concerned entity. IRC channels and IRC users JIDs have a localpart formed like this: `name`, the `'%'` separator and the `irc_server`. If the IRC channel you want to adress starts with the `'#'` character (or less frequently, but still valid, one of `'&'`, `'+'` 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*, *#foo*, and *##foo*. If compiled with Libidn, an IRC user has a bare JID representing the “hostname” provided by the IRC server. ### 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_serve@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 can join it, you can first join the room `%irc.example.com@biboumi.example.net` (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.net" and finally join the room `#foo%irc.example.com@biboumi.example.net`. ### 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 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 an 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). Using biboumi, there is no way to receive a message from a room participant (from a jid like #test%irc.example.com/nickname). Instead, private messages are received from and sent to the user (using a jid like nickname%irc.example.com). For conveniance and compatibility with XMPP clients sending private messages to the MUC participants, a message sent to #chan%irc.example.com@irc.example.net/Nickname will be redirected to Nickname%irc.example.com@irc.example.net, although this is not the prefered way to do it. ### 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 an 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`. SECURITY -------- Biboumi does not provide any encryption mechanism: connection to the XMPP server MUST be made on localhost. The XMPP server is not supposed to accept non-local connection from components, thus encryption is useless. IRC SSL/TLS is also not yet implemented. Biboumi also does not check if received JIDs are properly formatted using nodeprep. This must be done by the XMPP server to which biboumi is directly connected. AUTHORS ------- This software and man page are both written by Florent Le Coz. LICENSE ------- Biboumi is released under the zlib license.