protocol

irc message protocol stack

   Most of the commands which result in a change of state information
   (such as channel membership, channel mode, user status, etc) must be
   sent to all servers by default, and this distribution may not be
   changed by the client.

3.3.3 Server-to-Server.

   While most messages between servers are distributed to all 'other'
   servers, this is only required for any message that affects either a
   user, channel or server.  Since these are the basic items found in



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   IRC, nearly all messages originating from a server are broadcast to
   all other connected servers.

4. Message details

   On the following pages are descriptions of each message recognized by
   the IRC server and client.  All commands described in this section
   must be implemented by any server for this protocol.

   Where the reply ERR_NOSUCHSERVER is listed, it means that the
   <server> parameter could not be found.  The server must not send any
   other replies after this for that command.

   The server to which a client is connected is required to parse the
   complete message, returning any appropriate errors.  If the server
   encounters a fatal error while parsing a message, an error must be
   sent back to the client and the parsing terminated.  A fatal error
   may be considered to be incorrect command, a destination which is
   otherwise unknown to the server (server, nick or channel names fit
   this category), not enough parameters or incorrect privileges.

   If a full set of parameters is presented, then each must be checked
   for validity and appropriate responses sent back to the client.  In
   the case of messages which use parameter lists using the comma as an
   item separator, a reply must be sent for each item.

   In the examples below, some messages appear using the full format:

   :Name COMMAND parameter list

   Such examples represent a message from "Name" in transit between
   servers, where it is essential to include the name of the original
   sender of the message so remote servers may send back a reply along
   the correct path.

4.1 Connection Registration

   The commands described here are used to register a connection with an
   IRC server as either a user or a server as well as correctly
   disconnect.

   A "PASS" command is not required for either client or server
   connection to be registered, but it must precede the server message
   or the latter of the NICK/USER combination.  It is strongly
   recommended that all server connections have a password in order to
   give some level of security to the actual connections.  The
   recommended order for a client to register is as follows:




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           1. Pass message
           2. Nick message
           3. User message

4.1.1 Password message


      Command: PASS
   Parameters: <password>

   The PASS command is used to set a 'connection password'.  The
   password can and must be set before any attempt to register the
   connection is made.  Currently this requires that clients send a PASS
   command before sending the NICK/USER combination and servers *must*
   send a PASS command before any SERVER command.  The password supplied
   must match the one contained in the C/N lines (for servers) or I
   lines (for clients).  It is possible to send multiple PASS commands
   before registering but only the last one sent is used for
   verification and it may not be changed once registered.  Numeric
   Replies:

           ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED

   Example:

           PASS secretpasswordhere

4.1.2 Nick message

      Command: NICK
   Parameters: <nickname> [ <hopcount> ]

   NICK message is used to give user a nickname or change the previous
   one.  The <hopcount> parameter is only used by servers to indicate
   how far away a nick is from its home server.  A local connection has
   a hopcount of 0.  If supplied by a client, it must be ignored.

   If a NICK message arrives at a server which already knows about an
   identical nickname for another client, a nickname collision occurs.
   As a result of a nickname collision, all instances of the nickname
   are removed from the server's database, and a KILL command is issued
   to remove the nickname from all other server's database. If the NICK
   message causing the collision was a nickname change, then the
   original (old) nick must be removed as well.

   If the server recieves an identical NICK from a client which is
   directly connected, it may issue an ERR_NICKCOLLISION to the local
   client, drop the NICK command, and not generate any kills.



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   Numeric Replies:

           ERR_NONICKNAMEGIVEN             ERR_ERRONEUSNICKNAME
           ERR_NICKNAMEINUSE               ERR_NICKCOLLISION

   Example:

   NICK Wiz                        ; Introducing new nick "Wiz".

   :WiZ NICK Kilroy                ; WiZ changed his nickname to Kilroy.

4.1.3 User message

      Command: USER
   Parameters: <username> <hostname> <servername> <realname>

   The USER message is used at the beginning of connection to specify
   the username, hostname, servername and realname of s new user.  It is
   also used in communication between servers to indicate new user
   arriving on IRC, since only after both USER and NICK have been
   received from a client does a user become registered.

   Between servers USER must to be prefixed with client's NICKname.
   Note that hostname and servername are normally ignored by the IRC
   server when the USER command comes from a directly connected client
   (for security reasons), but they are used in server to server
   communication.  This means that a NICK must always be sent to a
   remote server when a new user is being introduced to the rest of the
   network before the accompanying USER is sent.

   It must be noted that realname parameter must be the last parameter,
   because it may contain space characters and must be prefixed with a
   colon (':') to make sure this is recognised as such.

   Since it is easy for a client to lie about its username by relying
   solely on the USER message, the use of an "Identity Server" is
   recommended.  If the host which a user connects from has such a
   server enabled the username is set to that as in the reply from the
   "Identity Server".

   Numeric Replies:

           ERR_NEEDMOREPARAMS              ERR_ALREADYREGISTRED

   Examples:


   USER guest tolmoon tolsun :Ronnie Reagan



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                                   ; User registering themselves with a
                                   username of "guest" and real name
                                   "Ronnie Reagan".


   :testnick USER guest tolmoon tolsun :Ronnie Reagan
                                   ; message between servers with the
                                   nickname for which the USER command
                                   belongs to

4.1.4 Server message

      Command: SERVER
   Parameters: <servername> <hopcount> <info>

   The server message is used to tell a server that the other end of a
   new connection is a server. This message is also used to pass server
   data over whole net.  When a new server is connected to net,
   information about it be broadcast to the whole network.  <hopcount>
   is used to give all servers some internal information on how far away
   all servers are.  With a full server list, it would be possible to
   construct a map of the entire server tree, but hostmasks prevent this
   from being done.

   The SERVER message must only be accepted from either (a) a connection
   which is yet to be registered and is attempting to register as a
   server, or (b) an existing connection to another server, in  which
   case the SERVER message is introducing a new server behind that
   server.

   Most errors that occur with the receipt of a SERVER command result in
   the connection being terminated by the destination host (target
   SERVER).  Error replies are usually sent using the "ERROR" command
   rather than the numeric since the ERROR command has several useful
   properties which make it useful here.

   If a SERVER message is parsed and attempts to introduce a server
   which is already known to the receiving server, the connection from
   which that message must be closed (following the correct procedures),
   since a duplicate route to a server has formed and the acyclic nature
   of the IRC tree broken.

   Numeric Replies:

           ERR_ALREADYREGISTRED

   Example:




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RFC 1459              Internet Relay Chat Protocol              May 1993


SERVER test.oulu.fi 1 :[tolsun.oulu.fi] Experimental server
                                ; New server test.oulu.fi introducing
                                itself and attempting to register.  The
                                name in []'s is the hostname for the
                                host running test.oulu.fi.


:tolsun.oulu.fi SERVER csd.bu.edu 5 :BU Central Server
                                ; Server tolsun.oulu.fi is our uplink
                                for csd.bu.edu which is 5 hops away.

4.1.5 Oper

      Command: OPER
   Parameters: <user> <password>

   OPER message is used by a normal user to obtain operator privileges.
   The combination of <user> and <password> are required to gain
   Operator privileges.

   If the client sending the OPER command supplies the correct password
   for the given user, the server then informs the rest of the network
   of the new operator by issuing a "MODE +o" for the clients nickname.

   The OPER message is client-server only.

   Numeric Replies:

           ERR_NEEDMOREPARAMS              RPL_YOUREOPER
           ERR_NOOPERHOST                  ERR_PASSWDMISMATCH

   Example:

   OPER foo bar                    ; Attempt to register as an operator
                                   using a username of "foo" and "bar" as
                                   the password.

4.1.6 Quit

      Command: QUIT
   Parameters: [<Quit message>]

   A client session is ended with a quit message.  The server must close
   the connection to a client which sends a QUIT message. If a "Quit
   Message" is given, this will be sent instead of the default message,
   the nickname.

   When netsplits (disconnecting of two servers) occur, the quit message



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   is composed of the names of two servers involved, separated by a
   space.  The first name is that of the server which is still connected
   and the second name is that of the server that has become
   disconnected.

   If, for some other reason, a client connection is closed without  the
   client  issuing  a  QUIT  command  (e.g.  client  dies and EOF occurs
   on socket), the server is required to fill in the quit  message  with
   some sort  of  message  reflecting the nature of the event which
   caused it to happen.

   Numeric Replies:

           None.

   Examples:

   QUIT :Gone to have lunch        ; Preferred message format.

4.1.7 Server quit message

      Command: SQUIT
   Parameters: <server> <comment>

   The SQUIT message is needed to tell about quitting or dead servers.
   If a server wishes to break the connection to another server it must
   send a SQUIT message to the other server, using the the name of the
   other server as the server parameter, which then closes its
   connection to the quitting server.

   This command is also available operators to help keep a network of
   IRC servers connected in an orderly fashion.  Operators may also