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| author | brain <brain@e03df62e-2008-0410-955e-edbf42e46eb7> | 2005-05-14 20:16:45 +0000 |
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| committer | brain <brain@e03df62e-2008-0410-955e-edbf42e46eb7> | 2005-05-14 20:16:45 +0000 |
| commit | ed503a82f41cb20795d1645190362ccbb80fa364 (patch) | |
| tree | 21159bb112098d928536b340dae15579c318ac43 /docs | |
| parent | 36127608a981c809c9b8e52980a6c23874eb633e (diff) | |
Added RFCs
git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@1379 e03df62e-2008-0410-955e-edbf42e46eb7
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| -rw-r--r-- | docs/rfc/rfc1413.txt | 451 | ||||
| -rw-r--r-- | docs/rfc/rfc1459.txt | 3643 |
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diff --git a/docs/rfc/rfc1413.txt b/docs/rfc/rfc1413.txt new file mode 100644 index 000000000..17ede58a2 --- /dev/null +++ b/docs/rfc/rfc1413.txt @@ -0,0 +1,451 @@ + + + + + + +Network Working Group M. St. Johns +Request for Comments: 1413 US Department of Defense +Obsoletes: 931 February 1993 + + + Identification Protocol + +Status of this Memo + + This RFC specifies an IAB standards track protocol for the Internet + community, and requests discussion and suggestions for improvements. + Please refer to the current edition of the "IAB Official Protocol + Standards" for the standardization state and status of this protocol. + Distribution of this memo is unlimited. + +1. INTRODUCTION + + The Identification Protocol (a.k.a., "ident", a.k.a., "the Ident + Protocol") provides a means to determine the identity of a user of a + particular TCP connection. Given a TCP port number pair, it returns + a character string which identifies the owner of that connection on + the server's system. + + The Identification Protocol was formerly called the Authentication + Server Protocol. It has been renamed to better reflect its function. + This document is a product of the TCP Client Identity Protocol + Working Group of the Internet Engineering Task Force (IETF). + +2. OVERVIEW + + This is a connection based application on TCP. A server listens for + TCP connections on TCP port 113 (decimal). Once a connection is + established, the server reads a line of data which specifies the + connection of interest. If it exists, the system dependent user + identifier of the connection of interest is sent as the reply. The + server may then either shut the connection down or it may continue to + read/respond to multiple queries. + + The server should close the connection down after a configurable + amount of time with no queries - a 60-180 second idle timeout is + recommended. The client may close the connection down at any time; + however to allow for network delays the client should wait at least + 30 seconds (or longer) after a query before abandoning the query and + closing the connection. + + + + + + + +St. Johns [Page 1] + +RFC 1413 Identification Protocol February 1993 + + +3. RESTRICTIONS + + Queries are permitted only for fully specified connections. The + query contains the local/foreign port pair -- the local/foreign + address pair used to fully specify the connection is taken from the + local and foreign address of query connection. This means a user on + address A may only query the server on address B about connections + between A and B. + +4. QUERY/RESPONSE FORMAT + + The server accepts simple text query requests of the form: + + <port-on-server> , <port-on-client> + + where <port-on-server> is the TCP port (decimal) on the target (where + the "ident" server is running) system, and <port-on-client> is the + TCP port (decimal) on the source (client) system. + + N.B - If a client on host A wants to ask a server on host B about a + connection specified locally (on the client's machine) as 23, 6191 + (an inbound TELNET connection), the client must actually ask about + 6191, 23 - which is how the connection would be specified on host B. + + For example: + + 6191, 23 + + The response is of the form + + <port-on-server> , <port-on-client> : <resp-type> : <add-info> + + where <port-on-server>,<port-on-client> are the same pair as the + query, <resp-type> is a keyword identifying the type of response, and + <add-info> is context dependent. + + The information returned is that associated with the fully specified + TCP connection identified by <server-address>, <client-address>, + <port-on-server>, <port-on-client>, where <server-address> and + <client-address> are the local and foreign IP addresses of the + querying connection -- i.e., the TCP connection to the Identification + Protocol Server. (<port-on-server> and <port-on-client> are taken + from the query.) + + For example: + + 6193, 23 : USERID : UNIX : stjohns + 6195, 23 : ERROR : NO-USER + + + +St. Johns [Page 2] + +RFC 1413 Identification Protocol February 1993 + + +5. RESPONSE TYPES + +A response can be one of two types: + +USERID + + In this case, <add-info> is a string consisting of an + operating system name (with an optional character set + identifier), followed by ":", followed by an + identification string. + + The character set (if present) is separated from the + operating system name by ",". The character set + identifier is used to indicate the character set of the + identification string. The character set identifier, + if omitted, defaults to "US-ASCII" (see below). + + Permitted operating system names and character set + names are specified in RFC 1340, "Assigned Numbers" or + its successors. + + In addition to those operating system and character set + names specified in "Assigned Numbers" there is one + special case operating system identifier - "OTHER". + + Unless "OTHER" is specified as the operating system + type, the server is expected to return the "normal" + user identification of the owner of this connection. + "Normal" in this context may be taken to mean a string + of characters which uniquely identifies the connection + owner such as a user identifier assigned by the system + administrator and used by such user as a mail + identifier, or as the "user" part of a user/password + pair used to gain access to system resources. When an + operating system is specified (e.g., anything but + "OTHER"), the user identifier is expected to be in a + more or less immediately useful form - e.g., something + that could be used as an argument to "finger" or as a + mail address. + + "OTHER" indicates the identifier is an unformatted + character string consisting of printable characters in + the specified character set. "OTHER" should be + specified if the user identifier does not meet the + constraints of the previous paragraph. Sending an + encrypted audit token, or returning other non-userid + information about a user (such as the real name and + phone number of a user from a UNIX passwd file) are + + + +St. Johns [Page 3] + +RFC 1413 Identification Protocol February 1993 + + + both examples of when "OTHER" should be used. + + Returned user identifiers are expected to be printable + in the character set indicated. + + The identifier is an unformatted octet string - - all + octets are permissible EXCEPT octal 000 (NUL), 012 (LF) + and 015 (CR). N.B. - space characters (040) following the + colon separator ARE part of the identifier string and + may not be ignored. A response string is still + terminated normally by a CR/LF. N.B. A string may be + printable, but is not *necessarily* printable. + +ERROR + + For some reason the port owner could not be determined, <add-info> + tells why. The following are the permitted values of <add-info> and + their meanings: + + INVALID-PORT + + Either the local or foreign port was improperly + specified. This should be returned if either or + both of the port ids were out of range (TCP port + numbers are from 1-65535), negative integers, reals or + in any fashion not recognized as a non-negative + integer. + + NO-USER + + The connection specified by the port pair is not + currently in use or currently not owned by an + identifiable entity. + + HIDDEN-USER + + The server was able to identify the user of this + port, but the information was not returned at the + request of the user. + + UNKNOWN-ERROR + + Can't determine connection owner; reason unknown. + Any error not covered above should return this + error code value. Optionally, this code MAY be + returned in lieu of any other specific error code + if, for example, the server desires to hide + information implied by the return of that error + + + +St. Johns [Page 4] + +RFC 1413 Identification Protocol February 1993 + + + code, or for any other reason. If a server + implements such a feature, it MUST be configurable + and it MUST default to returning the proper error + message. + + Other values may eventually be specified and defined in future + revisions to this document. If an implementer has a need to specify + a non-standard error code, that code must begin with "X". + + In addition, the server is allowed to drop the query connection + without responding. Any premature close (i.e., one where the client + does not receive the EOL, whether graceful or an abort should be + considered to have the same meaning as "ERROR : UNKNOWN-ERROR". + +FORMAL SYNTAX + + <request> ::= <port-pair> <EOL> + + <port-pair> ::= <integer> "," <integer> + + <reply> ::= <reply-text> <EOL> + + <EOL> ::= "015 012" ; CR-LF End of Line Indicator + + <reply-text> ::= <error-reply> | <ident-reply> + + <error-reply> ::= <port-pair> ":" "ERROR" ":" <error-type> + + <ident-reply> ::= <port-pair> ":" "USERID" ":" <opsys-field> + ":" <user-id> + + <error-type> ::= "INVALID-PORT" | "NO-USER" | "UNKNOWN-ERROR" + | "HIDDEN-USER" | <error-token> + + <opsys-field> ::= <opsys> [ "," <charset>] + + <opsys> ::= "OTHER" | "UNIX" | <token> ...etc. + ; (See "Assigned Numbers") + + <charset> ::= "US-ASCII" | ...etc. + ; (See "Assigned Numbers") + + <user-id> ::= <octet-string> + + <token> ::= 1*64<token-characters> ; 1-64 characters + + <error-token> ::= "X"1*63<token-characters> + ; 2-64 chars beginning w/X + + + +St. Johns [Page 5] + +RFC 1413 Identification Protocol February 1993 + + + <integer> ::= 1*5<digit> ; 1-5 digits. + + <digit> ::= "0" | "1" ... "8" | "9" ; 0-9 + + <token-characters> ::= + <Any of these ASCII characters: a-z, A-Z, + - (dash), .!@#$%^&*()_=+.,<>/?"'~`{}[]; > + ; upper and lowercase a-z plus + ; printables minus the colon ":" + ; character. + + <octet-string> ::= 1*512<octet-characters> + + <octet-characters> ::= + <any octet from 00 to 377 (octal) except for + ASCII NUL (000), CR (015) and LF (012)> + +Notes on Syntax: + + 1) To promote interoperability among variant + implementations, with respect to white space the above + syntax is understood to embody the "be conservative in + what you send and be liberal in what you accept" + philosophy. Clients and servers should not generate + unnecessary white space (space and tab characters) but + should accept white space anywhere except within a + token. In parsing responses, white space may occur + anywhere, except within a token. Specifically, any + amount of white space is permitted at the beginning or + end of a line both for queries and responses. This + does not apply for responses that contain a user ID + because everything after the colon after the operating + system type until the terminating CR/LF is taken as + part of the user ID. The terminating CR/LF is NOT + considered part of the user ID. + + 2) The above notwithstanding, servers should restrict the + amount of inter-token white space they send to the + smallest amount reasonable or useful. Clients should + feel free to abort a connection if they receive 1000 + characters without receiving an <EOL>. + + 3) The 512 character limit on user IDs and the 64 + character limit on tokens should be understood to mean + as follows: a) No new token (i.e., OPSYS or ERROR-TYPE) + token will be defined that has a length greater than 64 + and b) a server SHOULD NOT send more than 512 octets of + user ID and a client MUST accept at least 512 octets of + + + +St. Johns [Page 6] + +RFC 1413 Identification Protocol February 1993 + + + user ID. Because of this limitation, a server MUST + return the most significant portion of the user ID in + the first 512 octets. + + 4) The character sets and character set identifiers should + map directly to those defined in or referenced by RFC 1340, + "Assigned Numbers" or its successors. Character set + identifiers only apply to the user identification field + - all other fields will be defined in and must be sent + as US-ASCII. + + 5) Although <user-id> is defined as an <octet-string> + above, it must follow the format and character set + constraints implied by the <opsys-field>; see the + discussion above. + + 6) The character set provides context for the client to + print or store the returned user identification string. + If the client does not recognize or implement the + returned character set, it should handle the returned + identification string as OCTET, but should in addition + store or report the character set. An OCTET string + should be printed, stored or handled in hex notation + (0-9a-f) in addition to any other representation the + client implements - this provides a standard + representation among differing implementations. + +6. Security Considerations + + The information returned by this protocol is at most as trustworthy + as the host providing it OR the organization operating the host. For + example, a PC in an open lab has few if any controls on it to prevent + a user from having this protocol return any identifier the user + wants. Likewise, if the host has been compromised the information + returned may be completely erroneous and misleading. + + The Identification Protocol is not intended as an authorization or + access control protocol. At best, it provides some additional + auditing information with respect to TCP connections. At worst, it + can provide misleading, incorrect, or maliciously incorrect + information. + + The use of the information returned by this protocol for other than + auditing is strongly discouraged. Specifically, using Identification + Protocol information to make access control decisions - either as the + primary method (i.e., no other checks) or as an adjunct to other + methods may result in a weakening of normal host security. + + + + +St. Johns [Page 7] + +RFC 1413 Identification Protocol February 1993 + + + An Identification server may reveal information about users, + entities, objects or processes which might normally be considered + private. An Identification server provides service which is a rough + analog of the CallerID services provided by some phone companies and + many of the same privacy considerations and arguments that apply to + the CallerID service apply to Identification. If you wouldn't run a + "finger" server due to privacy considerations you may not want to run + this protocol. + +7. ACKNOWLEDGEMENTS + + Acknowledgement is given to Dan Bernstein who is primarily + responsible for renewing interest in this protocol and for pointing + out some annoying errors in RFC 931. + +References + + [1] St. Johns, M., "Authentication Server", RFC 931, TPSC, January + 1985. + + [2] Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1340, + USC/Information Sciences Institute, July 1992. + +Author's Address + + Michael C. St. Johns + DARPA/CSTO + 3701 N. Fairfax Dr + Arlington, VA 22203 + + Phone: (703) 696-2271 + EMail: stjohns@DARPA.MIL + + + + + + + + + + + + + + + + + + + +St. Johns [Page 8] +
\ No newline at end of file diff --git a/docs/rfc/rfc1459.txt b/docs/rfc/rfc1459.txt new file mode 100644 index 000000000..09fbf34f7 --- /dev/null +++ b/docs/rfc/rfc1459.txt @@ -0,0 +1,3643 @@ + + + + + + +Network Working Group J. Oikarinen +Request for Comments: 1459 D. Reed + May 1993 + + + Internet Relay Chat Protocol + +Status of This Memo + + This memo defines an Experimental Protocol for the Internet + community. Discussion and suggestions for improvement are requested. + Please refer to the current edition of the "IAB Official Protocol + Standards" for the standardization state and status of this protocol. + Distribution of this memo is unlimited. + +Abstract + + The IRC protocol was developed over the last 4 years since it was + first implemented as a means for users on a BBS to chat amongst + themselves. Now it supports a world-wide network of servers and + clients, and is stringing to cope with growth. Over the past 2 years, + the average number of users connected to the main IRC network has + grown by a factor of 10. + + The IRC protocol is a text-based protocol, with the simplest client + being any socket program capable of connecting to the server. + +Table of Contents + + 1. INTRODUCTION ............................................... 4 + 1.1 Servers ................................................ 4 + 1.2 Clients ................................................ 5 + 1.2.1 Operators .......................................... 5 + 1.3 Channels ................................................ 5 + 1.3.1 Channel Operators .................................... 6 + 2. THE IRC SPECIFICATION ....................................... 7 + 2.1 Overview ................................................ 7 + 2.2 Character codes ......................................... 7 + 2.3 Messages ................................................ 7 + 2.3.1 Message format in 'pseudo' BNF .................... 8 + 2.4 Numeric replies ......................................... 10 + 3. IRC Concepts ................................................ 10 + 3.1 One-to-one communication ................................ 10 + 3.2 One-to-many ............................................. 11 + 3.2.1 To a list .......................................... 11 + 3.2.2 To a group (channel) ............................... 11 + 3.2.3 To a host/server mask .............................. 12 + 3.3 One to all .............................................. 12 + + + +Oikarinen & Reed [Page 1] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 3.3.1 Client to Client ................................... 12 + 3.3.2 Clients to Server .................................. 12 + 3.3.3 Server to Server ................................... 12 + 4. MESSAGE DETAILS ............................................. 13 + 4.1 Connection Registration ................................. 13 + 4.1.1 Password message ................................... 14 + 4.1.2 Nickname message ................................... 14 + 4.1.3 User message ....................................... 15 + 4.1.4 Server message ..................................... 16 + 4.1.5 Operator message ................................... 17 + 4.1.6 Quit message ....................................... 17 + 4.1.7 Server Quit message ................................ 18 + 4.2 Channel operations ...................................... 19 + 4.2.1 Join message ....................................... 19 + 4.2.2 Part message ....................................... 20 + 4.2.3 Mode message ....................................... 21 + 4.2.3.1 Channel modes ................................. 21 + 4.2.3.2 User modes .................................... 22 + 4.2.4 Topic message ...................................... 23 + 4.2.5 Names message ...................................... 24 + 4.2.6 List message ....................................... 24 + 4.2.7 Invite message ..................................... 25 + 4.2.8 Kick message ....................................... 25 + 4.3 Server queries and commands ............................. 26 + 4.3.1 Version message .................................... 26 + 4.3.2 Stats message ...................................... 27 + 4.3.3 Links message ...................................... 28 + 4.3.4 Time message ....................................... 29 + 4.3.5 Connect message .................................... 29 + 4.3.6 Trace message ...................................... 30 + 4.3.7 Admin message ...................................... 31 + 4.3.8 Info message ....................................... 31 + 4.4 Sending messages ........................................ 32 + 4.4.1 Private messages ................................... 32 + 4.4.2 Notice messages .................................... 33 + 4.5 User-based queries ...................................... 33 + 4.5.1 Who query .......................................... 33 + 4.5.2 Whois query ........................................ 34 + 4.5.3 Whowas message ..................................... 35 + 4.6 Miscellaneous messages .................................. 35 + 4.6.1 Kill message ....................................... 36 + 4.6.2 Ping message ....................................... 37 + 4.6.3 Pong message ....................................... 37 + 4.6.4 Error message ...................................... 38 + 5. OPTIONAL MESSAGES ........................................... 38 + 5.1 Away message ............................................ 38 + 5.2 Rehash command .......................................... 39 + 5.3 Restart command ......................................... 39 + + + +Oikarinen & Reed [Page 2] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 5.4 Summon message .......................................... 40 + 5.5 Users message ........................................... 40 + 5.6 Operwall command ........................................ 41 + 5.7 Userhost message ........................................ 42 + 5.8 Ison message ............................................ 42 + 6. REPLIES ..................................................... 43 + 6.1 Error Replies ........................................... 43 + 6.2 Command responses ....................................... 48 + 6.3 Reserved numerics ....................................... 56 + 7. Client and server authentication ............................ 56 + 8. Current Implementations Details ............................. 56 + 8.1 Network protocol: TCP ................................... 57 + 8.1.1 Support of Unix sockets ............................ 57 + 8.2 Command Parsing ......................................... 57 + 8.3 Message delivery ........................................ 57 + 8.4 Connection 'Liveness' ................................... 58 + 8.5 Establishing a server-client connection ................. 58 + 8.6 Establishing a server-server connection ................. 58 + 8.6.1 State information exchange when connecting ......... 59 + 8.7 Terminating server-client connections ................... 59 + 8.8 Terminating server-server connections ................... 59 + 8.9 Tracking nickname changes ............................... 60 + 8.10 Flood control of clients ............................... 60 + 8.11 Non-blocking lookups ................................... 61 + 8.11.1 Hostname (DNS) lookups ............................ 61 + 8.11.2 Username (Ident) lookups .......................... 61 + 8.12 Configuration file ..................................... 61 + 8.12.1 Allowing clients to connect ....................... 62 + 8.12.2 Operators ......................................... 62 + 8.12.3 Allowing servers to connect ....................... 62 + 8.12.4 Administrivia ..................................... 63 + 8.13 Channel membership ..................................... 63 + 9. Current problems ............................................ 63 + 9.1 Scalability ............................................. 63 + 9.2 Labels .................................................. 63 + 9.2.1 Nicknames .......................................... 63 + 9.2.2 Channels ........................................... 64 + 9.2.3 Servers ............................................ 64 + 9.3 Algorithms .............................................. 64 + 10. Support and availability ................................... 64 + 11. Security Considerations .................................... 65 + 12. Authors' Addresses ......................................... 65 + + + + + + + + + +Oikarinen & Reed [Page 3] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +1. INTRODUCTION + + The IRC (Internet Relay Chat) protocol has been designed over a + number of years for use with text based conferencing. This document + describes the current IRC protocol. + + The IRC protocol has been developed on systems using the TCP/IP + network protocol, although there is no requirement that this remain + the only sphere in which it operates. + + IRC itself is a teleconferencing system, which (through the use of + the client-server model) is well-suited to running on many machines + in a distributed fashion. A typical setup involves a single process + (the server) forming a central point for clients (or other servers) + to connect to, performing the required message delivery/multiplexing + and other functions. + +1.1 Servers + + The server forms the backbone of IRC, providing a point to which + clients may connect to to talk to each other, and a point for other + servers to connect to, forming an IRC network. The only network + configuration allowed for IRC servers is that of a spanning tree [see + Fig. 1] where each server acts as a central node for the rest of the + net it sees. + + + [ Server 15 ] [ Server 13 ] [ Server 14] + / \ / + / \ / + [ Server 11 ] ------ [ Server 1 ] [ Server 12] + / \ / + / \ / + [ Server 2 ] [ Server 3 ] + / \ \ + / \ \ + [ Server 4 ] [ Server 5 ] [ Server 6 ] + / | \ / + / | \ / + / | \____ / + / | \ / + [ Server 7 ] [ Server 8 ] [ Server 9 ] [ Server 10 ] + + : + [ etc. ] + : + + [ Fig. 1. Format of IRC server network ] + + + +Oikarinen & Reed [Page 4] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +1.2 Clients + + A client is anything connecting to a server that is not another + server. Each client is distinguished from other clients by a unique + nickname having a maximum length of nine (9) characters. See the + protocol grammar rules for what may and may not be used in a + nickname. In addition to the nickname, all servers must have the + following information about all clients: the real name of the host + that the client is running on, the username of the client on that + host, and the server to which the client is connected. + +1.2.1 Operators + + To allow a reasonable amount of order to be kept within the IRC + network, a special class of clients (operators) is allowed to perform + general maintenance functions on the network. Although the powers + granted to an operator can be considered as 'dangerous', they are + nonetheless required. Operators should be able to perform basic + network tasks such as disconnecting and reconnecting servers as + needed to prevent long-term use of bad network routing. In + recognition of this need, the protocol discussed herein provides for + operators only to be able to perform such functions. See sections + 4.1.7 (SQUIT) and 4.3.5 (CONNECT). + + A more controversial power of operators is the ability to remove a + user from the connected network by 'force', i.e. operators are able + to close the connection between any client and server. The + justification for this is delicate since its abuse is both + destructive and annoying. For further details on this type of + action, see section 4.6.1 (KILL). + +1.3 Channels + + A channel is a named group of one or more clients which will all + receive messages addressed to that channel. The channel is created + implicitly when the first client joins it, and the channel ceases to + exist when the last client leaves it. While channel exists, any + client can reference the channel using the name of the channel. + + Channels names are strings (beginning with a '&' or '#' character) of + length up to 200 characters. Apart from the the requirement that the + first character being either '&' or '#'; the only restriction on a + channel name is that it may not contain any spaces (' '), a control G + (^G or ASCII 7), or a comma (',' which is used as a list item + separator by the protocol). + + There are two types of channels allowed by this protocol. One is a + distributed channel which is known to all the servers that are + + + +Oikarinen & Reed [Page 5] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + connected to the network. These channels are marked by the first + character being a only clients on the server where it exists may join + it. These are distinguished by a leading '&' character. On top of + these two types, there are the various channel modes available to + alter the characteristics of individual channels. See section 4.2.3 + (MODE command) for more details on this. + + To create a new channel or become part of an existing channel, a user + is required to JOIN the channel. If the channel doesn't exist prior + to joining, the channel is created and the creating user becomes a + channel operator. If the channel already exists, whether or not your + request to JOIN that channel is honoured depends on the current modes + of the channel. For example, if the channel is invite-only, (+i), + then you may only join if invited. As part of the protocol, a user + may be a part of several channels at once, but a limit of ten (10) + channels is recommended as being ample for both experienced and + novice users. See section 8.13 for more information on this. + + If the IRC network becomes disjoint because of a split between two + servers, the channel on each side is only composed of those clients + which are connected to servers on the respective sides of the split, + possibly ceasing to exist on one side of the split. When the split + is healed, the connecting servers announce to each other who they + think is in each channel and the mode of that channel. If the + channel exists on both sides, the JOINs and MODEs are interpreted in + an inclusive manner so that both sides of the new connection will + agree about which clients are in the channel and what modes the + channel has. + +1.3.1 Channel Operators + + The channel operator (also referred to as a "chop" or "chanop") on a + given channel is considered to 'own' that channel. In recognition of + this status, channel operators are endowed with certain powers which + enable them to keep control and some sort of sanity in their channel. + As an owner of a channel, a channel operator is not required to have + reasons for their actions, although if their actions are generally + antisocial or otherwise abusive, it might be reasonable to ask an IRC + operator to intervene, or for the usersjust leave and go elsewhere + and form their own channel. + + The commands which may only be used by channel operators are: + + KICK - Eject a client from the channel + MODE - Change the channel's mode + INVITE - Invite a client to an invite-only channel (mode +i) + TOPIC - Change the channel topic in a mode +t channel + + + + +Oikarinen & Reed [Page 6] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + A channel operator is identified by the '@' symbol next to their + nickname whenever it is associated with a channel (ie replies to the + NAMES, WHO and WHOIS commands). + +2. The IRC Specification + +2.1 Overview + + The protocol as described herein is for use both with server to + server and client to server connections. There are, however, more + restrictions on client connections (which are considered to be + untrustworthy) than on server connections. + +2.2 Character codes + + No specific character set is specified. The protocol is based on a a + set of codes which are composed of eight (8) bits, making up an + octet. Each message may be composed of any number of these octets; + however, some octet values are used for control codes which act as + message delimiters. + + Regardless of being an 8-bit protocol, the delimiters and keywords + are such that protocol is mostly usable from USASCII terminal and a + telnet connection. + + Because of IRC's scandanavian origin, the characters {}| are + considered to be the lower case equivalents of the characters []\, + respectively. This is a critical issue when determining the + equivalence of two nicknames. + +2.3 Messages + + Servers and clients send eachother messages which may or may not + generate a reply. If the message contains a valid command, as + described in later sections, the client should expect a reply as + specified but it is not advised to wait forever for the reply; client + to server and server to server communication is essentially + asynchronous in nature. + + Each IRC message may consist of up to three main parts: the prefix + (optional), the command, and the command parameters (of which there + may be up to 15). The prefix, command, and all parameters are + separated by one (or more) ASCII space character(s) (0x20). + + The presence of a prefix is indicated with a single leading ASCII + colon character (':', 0x3b), which must be the first character of the + message itself. There must be no gap (whitespace) between the colon + and the prefix. The prefix is used by servers to indicate the true + + + +Oikarinen & Reed [Page 7] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + origin of the message. If the prefix is missing from the message, it + is assumed to have originated from the connection from which it was + received. Clients should not use prefix when sending a message from + themselves; if they use a prefix, the only valid prefix is the + registered nickname associated with the client. If the source + identified by the prefix cannot be found from the server's internal + database, or if the source is registered from a different link than + from which the message arrived, the server must ignore the message + silently. + + The command must either be a valid IRC command or a three (3) digit + number represented in ASCII text. + + IRC messages are always lines of characters terminated with a CR-LF + (Carriage Return - Line Feed) pair, and these messages shall not + exceed 512 characters in length, counting all characters including + the trailing CR-LF. Thus, there are 510 characters maximum allowed + for the command and its parameters. There is no provision for + continuation message lines. See section 7 for more details about + current implementations. + +2.3.1 Message format in 'pseudo' BNF + + The protocol messages must be extracted from the contiguous stream of + octets. The current solution is to designate two characters, CR and + LF, as message separators. Empty messages are silently ignored, + which permits use of the sequence CR-LF between messages + without extra problems. + + The extracted message is parsed into the components <prefix>, + <command> and list of parameters matched either by <middle> or + <trailing> components. + + The BNF representation for this is: + + +<message> ::= [':' <prefix> <SPACE> ] <command> <params> <crlf> +<prefix> ::= <servername> | <nick> [ '!' <user> ] [ '@' <host> ] +<command> ::= <letter> { <letter> } | <number> <number> <number> +<SPACE> ::= ' ' { ' ' } +<params> ::= <SPACE> [ ':' <trailing> | <middle> <params> ] + +<middle> ::= <Any *non-empty* sequence of octets not including SPACE + or NUL or CR or LF, the first of which may not be ':'> +<trailing> ::= <Any, possibly *empty*, sequence of octets not including + NUL or CR or LF> + +<crlf> ::= CR LF + + + +Oikarinen & Reed [Page 8] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +NOTES: + + 1) <SPACE> is consists only of SPACE character(s) (0x20). + Specially notice that TABULATION, and all other control + characters are considered NON-WHITE-SPACE. + + 2) After extracting the parameter list, all parameters are equal, + whether matched by <middle> or <trailing>. <Trailing> is just + a syntactic trick to allow SPACE within parameter. + + 3) The fact that CR and LF cannot appear in parameter strings is + just artifact of the message framing. This might change later. + + 4) The NUL character is not special in message framing, and + basically could end up inside a parameter, but as it would + cause extra complexities in normal C string handling. Therefore + NUL is not allowed within messages. + + 5) The last parameter may be an empty string. + + 6) Use of the extended prefix (['!' <user> ] ['@' <host> ]) must + not be used in server to server communications and is only + intended for server to client messages in order to provide + clients with more useful information about who a message is + from without the need for additional queries. + + Most protocol messages specify additional semantics and syntax for + the extracted parameter strings dictated by their position in the + list. For example, many server commands will assume that the first + parameter after the command is the list of targets, which can be + described with: + + <target> ::= <to> [ "," <target> ] + <to> ::= <channel> | <user> '@' <servername> | <nick> | <mask> + <channel> ::= ('#' | '&') <chstring> + <servername> ::= <host> + <host> ::= see RFC 952 [DNS:4] for details on allowed hostnames + <nick> ::= <letter> { <letter> | <number> | <special> } + <mask> ::= ('#' | '$') <chstring> + <chstring> ::= <any 8bit code except SPACE, BELL, NUL, CR, LF and + comma (',')> + + Other parameter syntaxes are: + + <user> ::= <nonwhite> { <nonwhite> } + <letter> ::= 'a' ... 'z' | 'A' ... 'Z' + <number> ::= '0' ... '9' + <special> ::= '-' | '[' | ']' | '\' | '`' | '^' | '{' | '}' + + + +Oikarinen & Reed [Page 9] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + <nonwhite> ::= <any 8bit code except SPACE (0x20), NUL (0x0), CR + (0xd), and LF (0xa)> + +2.4 Numeric replies + + Most of the messages sent to the server generate a reply of some + sort. The most common reply is the numeric reply, used for both + errors and normal replies. The numeric reply must be sent as one + message consisting of the sender prefix, the three digit numeric, and + the target of the reply. A numeric reply is not allowed to originate + from a client; any such messages received by a server are silently + dropped. In all other respects, a numeric reply is just like a normal + message, except that the keyword is made up of 3 numeric digits + rather than a string of letters. A list of different replies is + supplied in section 6. + +3. IRC Concepts. + + This section is devoted to describing the actual concepts behind the + organization of the IRC protocol and how the current + implementations deliver different classes of messages. + + + + 1--\ + A D---4 + 2--/ \ / + B----C + / \ + 3 E + + Servers: A, B, C, D, E Clients: 1, 2, 3, 4 + + [ Fig. 2. Sample small IRC network ] + +3.1 One-to-one communication + + Communication on a one-to-one basis is usually only performed by + clients, since most server-server traffic is not a result of servers + talking only to each other. To provide a secure means for clients to + talk to each other, it is required that all servers be able to send a + message in exactly one direction along the spanning tree in order to + reach any client. The path of a message being delivered is the + shortest path between any two points on the spanning tree. + + The following examples all refer to Figure 2 above. + + + + + +Oikarinen & Reed [Page 10] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +Example 1: + A message between clients 1 and 2 is only seen by server A, which + sends it straight to client 2. + +Example 2: + A message between clients 1 and 3 is seen by servers A & B, and + client 3. No other clients or servers are allowed see the message. + +Example 3: + A message between clients 2 and 4 is seen by servers A, B, C & D + and client 4 only. + +3.2 One-to-many + + The main goal of IRC is to provide a forum which allows easy and + efficient conferencing (one to many conversations). IRC offers + several means to achieve this, each serving its own purpose. + +3.2.1 To a list + + The least efficient style of one-to-many conversation is through + clients talking to a 'list' of users. How this is done is almost + self explanatory: the client gives a list of destinations to which + the message is to be delivered and the server breaks it up and + dispatches a separate copy of the message to each given destination. + This isn't as efficient as using a group since the destination list + is broken up and the dispatch sent without checking to make sure + duplicates aren't sent down each path. + +3.2.2 To a group (channel) + + In IRC the channel has a role equivalent to that of the multicast + group; their existence is dynamic (coming and going as people join + and leave channels) and the actual conversation carried out on a + channel is only sent to servers which are supporting users on a given + channel. If there are multiple users on a server in the same + channel, the message text is sent only once to that server and then + sent to each client on the channel. This action is then repeated for + each client-server combination until the original message has fanned + out and reached each member of the channel. + + The following examples all refer to Figure 2. + +Example 4: + Any channel with 1 client in it. Messages to the channel go to the + server and then nowhere else. + + + + + +Oikarinen & Reed [Page 11] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +Example 5: + 2 clients in a channel. All messages traverse a path as if they + were private messages between the two clients outside a channel. + +Example 6: + Clients 1, 2 and 3 in a channel. All messages to the channel are + sent to all clients and only those servers which must be traversed + by the message if it were a private message to a single client. If + client 1 sends a message, it goes back to client 2 and then via + server B to client 3. + +3.2.3 To a host/server mask + + To provide IRC operators with some mechanism to send messages to a + large body of related users, host and server mask messages are + provided. These messages are sent to users whose host or server + information match that of the mask. The messages are only sent to + locations where users are, in a fashion similar to that of channels. + +3.3 One-to-all + + The one-to-all type of message is better described as a broadcast + message, sent to all clients or servers or both. On a large network + of users and servers, a single message can result in a lot of traffic + being sent over the network in an effort to reach all of the desired + destinations. + + For some messages, there is no option but to broadcast it to all + servers so that the state information held by each server is + reasonably consistent between servers. + +3.3.1 Client-to-Client + + There is no class of message which, from a single message, results in + a message being sent to every other client. + +3.3.2 Client-to-Server + + 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 + + + +Oikarinen & Reed [Page 12] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 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: + + + + +Oikarinen & Reed [Page 13] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 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. + + + +Oikarinen & Reed [Page 14] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 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 + + + +Oikarinen & Reed [Page 15] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + ; 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: + + + + +Oikarinen & Reed [Page 16] + +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 + + + +Oikarinen & Reed [Page 17] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 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 + issue an SQUIT message for a remote server connection. In this case, + the SQUIT must be parsed by each server inbetween the operator and + the remote server, updating the view of the network held by each + server as explained below. + + The <comment> should be supplied by all operators who execute a SQUIT + for a remote server (that is not connected to the server they are + currently on) so that other operators are aware for the reason of + this action. The <comment> is also filled in by servers which may + place an error or similar message here. + + Both of the servers which are on either side of the connection being + closed are required to to send out a SQUIT message (to all its other + server connections) for all other servers which are considered to be + behind that link. + + + + +Oikarinen & Reed [Page 18] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + Similarly, a QUIT message must be sent to the other connected servers + rest of the network on behalf of all clients behind that link. In + addition to this, all channel members of a channel which lost a + member due to the split must be sent a QUIT message. + + If a server connection is terminated prematurely (e.g. the server on + the other end of the link died), the server which detects + this disconnection is required to inform the rest of the network + that the connection has closed and fill in the comment field + with something appropriate. + + Numeric replies: + + ERR_NOPRIVILEGES ERR_NOSUCHSERVER + + Example: + + SQUIT tolsun.oulu.fi :Bad Link ? ; the server link tolson.oulu.fi has + been terminated because of "Bad Link". + + :Trillian SQUIT cm22.eng.umd.edu :Server out of control + ; message from Trillian to disconnect + "cm22.eng.umd.edu" from the net + because "Server out of control". + +4.2 Channel operations + + This group of messages is concerned with manipulating channels, their + properties (channel modes), and their contents (typically clients). + In implementing these, a number of race conditions are inevitable + when clients at opposing ends of a network send commands which will + ultimately clash. It is also required that servers keep a nickname + history to ensure that wherever a <nick> parameter is given, the + server check its history in case it has recently been changed. + +4.2.1 Join message + + Command: JOIN + Parameters: <channel>{,<channel>} [<key>{,<key>}] + + The JOIN command is used by client to start listening a specific + channel. Whether or not a client is allowed to join a channel is + checked only by the server the client is connected to; all other + servers automatically add the user to the channel when it is received + from other servers. The conditions which affect this are as follows: + + 1. the user must be invited if the channel is invite-only; + + + + +Oikarinen & Reed [Page 19] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 2. the user's nick/username/hostname must not match any + active bans; + + 3. the correct key (password) must be given if it is set. + + These are discussed in more detail under the MODE command (see + section 4.2.3 for more details). + + Once a user has joined a channel, they receive notice about all + commands their server receives which affect the channel. This + includes MODE, KICK, PART, QUIT and of course PRIVMSG/NOTICE. The + JOIN command needs to be broadcast to all servers so that each server + knows where to find the users who are on the channel. This allows + optimal delivery of PRIVMSG/NOTICE messages to the channel. + + If a JOIN is successful, the user is then sent the channel's topic + (using RPL_TOPIC) and the list of users who are on the channel (using + RPL_NAMREPLY), which must include the user joining. + + Numeric Replies: + + ERR_NEEDMOREPARAMS ERR_BANNEDFROMCHAN + ERR_INVITEONLYCHAN ERR_BADCHANNELKEY + ERR_CHANNELISFULL ERR_BADCHANMASK + ERR_NOSUCHCHANNEL ERR_TOOMANYCHANNELS + RPL_TOPIC + + Examples: + + JOIN #foobar ; join channel #foobar. + + JOIN &foo fubar ; join channel &foo using key "fubar". + + JOIN #foo,&bar fubar ; join channel #foo using key "fubar" + and &bar using no key. + + JOIN #foo,#bar fubar,foobar ; join channel #foo using key "fubar". + and channel #bar using key "foobar". + + JOIN #foo,#bar ; join channels #foo and #bar. + + :WiZ JOIN #Twilight_zone ; JOIN message from WiZ + +4.2.2 Part message + + Command: PART + Parameters: <channel>{,<channel>} + + + + +Oikarinen & Reed [Page 20] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + The PART message causes the client sending the message to be removed + from the list of active users for all given channels listed in the + parameter string. + + Numeric Replies: + + ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL + ERR_NOTONCHANNEL + + Examples: + + PART #twilight_zone ; leave channel "#twilight_zone" + + PART #oz-ops,&group5 ; leave both channels "&group5" and + "#oz-ops". + +4.2.3 Mode message + + Command: MODE + + The MODE command is a dual-purpose command in IRC. It allows both + usernames and channels to have their mode changed. The rationale for + this choice is that one day nicknames will be obsolete and the + equivalent property will be the channel. + + When parsing MODE messages, it is recommended that the entire message + be parsed first and then the changes which resulted then passed on. + +4.2.3.1 Channel modes + + Parameters: <channel> {[+|-]|o|p|s|i|t|n|b|v} [<limit>] [<user>] + [<ban mask>] + + The MODE command is provided so that channel operators may change the + characteristics of `their' channel. It is also required that servers + be able to change channel modes so that channel operators may be + created. + + The various modes available for channels are as follows: + + o - give/take channel operator privileges; + p - private channel flag; + s - secret channel flag; + i - invite-only channel flag; + t - topic settable by channel operator only flag; + n - no messages to channel from clients on the outside; + m - moderated channel; + l - set the user limit to channel; + + + +Oikarinen & Reed [Page 21] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + b - set a ban mask to keep users out; + v - give/take the ability to speak on a moderated channel; + k - set a channel key (password). + + When using the 'o' and 'b' options, a restriction on a total of three + per mode command has been imposed. That is, any combination of 'o' + and + +4.2.3.2 User modes + + Parameters: <nickname> {[+|-]|i|w|s|o} + + The user MODEs are typically changes which affect either how the + client is seen by others or what 'extra' messages the client is sent. + A user MODE command may only be accepted if both the sender of the + message and the nickname given as a parameter are both the same. + + The available modes are as follows: + + i - marks a users as invisible; + s - marks a user for receipt of server notices; + w - user receives wallops; + o - operator flag. + + Additional modes may be available later on. + + If a user attempts to make themselves an operator using the "+o" + flag, the attempt should be ignored. There is no restriction, + however, on anyone `deopping' themselves (using "-o"). Numeric + Replies: + + ERR_NEEDMOREPARAMS RPL_CHANNELMODEIS + ERR_CHANOPRIVSNEEDED ERR_NOSUCHNICK + ERR_NOTONCHANNEL ERR_KEYSET + RPL_BANLIST RPL_ENDOFBANLIST + ERR_UNKNOWNMODE ERR_NOSUCHCHANNEL + + ERR_USERSDONTMATCH RPL_UMODEIS + ERR_UMODEUNKNOWNFLAG + + Examples: + + Use of Channel Modes: + +MODE #Finnish +im ; Makes #Finnish channel moderated and + 'invite-only'. + +MODE #Finnish +o Kilroy ; Gives 'chanop' privileges to Kilroy on + + + +Oikarinen & Reed [Page 22] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + channel #Finnish. + +MODE #Finnish +v Wiz ; Allow WiZ to speak on #Finnish. + +MODE #Fins -s ; Removes 'secret' flag from channel + #Fins. + +MODE #42 +k oulu ; Set the channel key to "oulu". + +MODE #eu-opers +l 10 ; Set the limit for the number of users + on channel to 10. + +MODE &oulu +b ; list ban masks set for channel. + +MODE &oulu +b *!*@* ; prevent all users from joining. + +MODE &oulu +b *!*@*.edu ; prevent any user from a hostname + matching *.edu from joining. + + Use of user Modes: + +:MODE WiZ -w ; turns reception of WALLOPS messages + off for WiZ. + +:Angel MODE Angel +i ; Message from Angel to make themselves + invisible. + +MODE WiZ -o ; WiZ 'deopping' (removing operator + status). The plain reverse of this + command ("MODE WiZ +o") must not be + allowed from users since would bypass + the OPER command. + +4.2.4 Topic message + + Command: TOPIC + Parameters: <channel> [<topic>] + + The TOPIC message is used to change or view the topic of a channel. + The topic for channel <channel> is returned if there is no <topic> + given. If the <topic> parameter is present, the topic for that + channel will be changed, if the channel modes permit this action. + + Numeric Replies: + + ERR_NEEDMOREPARAMS ERR_NOTONCHANNEL + RPL_NOTOPIC RPL_TOPIC + ERR_CHANOPRIVSNEEDED + + + +Oikarinen & Reed [Page 23] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + Examples: + + :Wiz TOPIC #test :New topic ;User Wiz setting the topic. + + TOPIC #test :another topic ;set the topic on #test to "another + topic". + + TOPIC #test ; check the topic for #test. + +4.2.5 Names message + + Command: NAMES + Parameters: [<channel>{,<channel>}] + + By using the NAMES command, a user can list all nicknames that are + visible to them on any channel that they can see. Channel names + which they can see are those which aren't private (+p) or secret (+s) + or those which they are actually on. The <channel> parameter + specifies which channel(s) to return information about if valid. + There is no error reply for bad channel names. + + If no <channel> parameter is given, a list of all channels and their + occupants is returned. At the end of this list, a list of users who + are visible but either not on any channel or not on a visible channel + are listed as being on `channel' "*". + + Numerics: + + RPL_NAMREPLY RPL_ENDOFNAMES + + Examples: + + NAMES #twilight_zone,#42 ; list visible users on #twilight_zone + and #42 if the channels are visible to + you. + + NAMES ; list all visible channels and users + +4.2.6 List message + + Command: LIST + Parameters: [<channel>{,<channel>} [<server>]] + + The list message is used to list channels and their topics. If the + <channel> parameter is used, only the status of that channel + is displayed. Private channels are listed (without their + topics) as channel "Prv" unless the client generating the query is + actually on that channel. Likewise, secret channels are not listed + + + +Oikarinen & Reed [Page 24] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + at all unless the client is a member of the channel in question. + + Numeric Replies: + + ERR_NOSUCHSERVER RPL_LISTSTART + RPL_LIST RPL_LISTEND + + Examples: + + LIST ; List all channels. + + LIST #twilight_zone,#42 ; List channels #twilight_zone and #42 + +4.2.7 Invite message + + Command: INVITE + Parameters: <nickname> <channel> + + The INVITE message is used to invite users to a channel. The + parameter <nickname> is the nickname of the person to be invited to + the target channel <channel>. There is no requirement that the + channel the target user is being invited to must exist or be a valid + channel. To invite a user to a channel which is invite only (MODE + +i), the client sending the invite must be recognised as being a + channel operator on the given channel. + + Numeric Replies: + + ERR_NEEDMOREPARAMS ERR_NOSUCHNICK + ERR_NOTONCHANNEL ERR_USERONCHANNEL + ERR_CHANOPRIVSNEEDED + RPL_INVITING RPL_AWAY + + Examples: + + :Angel INVITE Wiz #Dust ; User Angel inviting WiZ to channel + #Dust + + INVITE Wiz #Twilight_Zone ; Command to invite WiZ to + #Twilight_zone + +4.2.8 Kick command + + Command: KICK + Parameters: <channel> <user> [<comment>] + + The KICK command can be used to forcibly remove a user from a + channel. It 'kicks them out' of the channel (forced PART). + + + +Oikarinen & Reed [Page 25] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + Only a channel operator may kick another user out of a channel. + Each server that receives a KICK message checks that it is valid + (ie the sender is actually a channel operator) before removing + the victim from the channel. + + Numeric Replies: + + ERR_NEEDMOREPARAMS ERR_NOSUCHCHANNEL + ERR_BADCHANMASK ERR_CHANOPRIVSNEEDED + ERR_NOTONCHANNEL + + Examples: + +KICK &Melbourne Matthew ; Kick Matthew from &Melbourne + +KICK #Finnish John :Speaking English + ; Kick John from #Finnish using + "Speaking English" as the reason + (comment). + +:WiZ KICK #Finnish John ; KICK message from WiZ to remove John + from channel #Finnish + +NOTE: + It is possible to extend the KICK command parameters to the +following: + +<channel>{,<channel>} <user>{,<user>} [<comment>] + +4.3 Server queries and commands + + The server query group of commands has been designed to return + information about any server which is connected to the network. All + servers connected must respond to these queries and respond + correctly. Any invalid response (or lack thereof) must be considered + a sign of a broken server and it must be disconnected/disabled as + soon as possible until the situation is remedied. + + In these queries, where a parameter appears as "<server>", it will + usually mean it can be a nickname or a server or a wildcard name of + some sort. For each parameter, however, only one query and set of + replies is to be generated. + +4.3.1 Version message + + Command: VERSION + Parameters: [<server>] + + + + +Oikarinen & Reed [Page 26] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + The VERSION message is used to query the version of the server + program. An optional parameter <server> is used to query the version + of the server program which a client is not directly connected to. + + Numeric Replies: + + ERR_NOSUCHSERVER RPL_VERSION + + Examples: + + :Wiz VERSION *.se ; message from Wiz to check the version + of a server matching "*.se" + + VERSION tolsun.oulu.fi ; check the version of server + "tolsun.oulu.fi". + +4.3.2 Stats message + + Command: STATS + Parameters: [<query> [<server>]] + + The stats message is used to query statistics of certain server. If + <server> parameter is omitted, only the end of stats reply is sent + back. The implementation of this command is highly dependent on the + server which replies, although the server must be able to supply + information as described by the queries below (or similar). + + A query may be given by any single letter which is only checked by + the destination server (if given as the <server> parameter) and is + otherwise passed on by intermediate servers, ignored and unaltered. + The following queries are those found in the current IRC + implementation and provide a large portion of the setup information + for that server. Although these may not be supported in the same way + by other versions, all servers should be able to supply a valid reply + to a STATS query which is consistent with the reply formats currently + used and the purpose of the query. + + The currently supported queries are: + + c - returns a list of servers which the server may connect + to or allow connections from; + h - returns a list of servers which are either forced to be + treated as leaves or allowed to act as hubs; + i - returns a list of hosts which the server allows a client + to connect from; + k - returns a list of banned username/hostname combinations + for that server; + l - returns a list of the server's connections, showing how + + + +Oikarinen & Reed [Page 27] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + long each connection has been established and the traffic + over that connection in bytes and messages for each + direction; + m - returns a list of commands supported by the server and + the usage count for each if the usage count is non zero; + o - returns a list of hosts from which normal clients may + become operators; + y - show Y (Class) lines from server's configuration file; + u - returns a string showing how long the server has been up. + + Numeric Replies: + + ERR_NOSUCHSERVER + RPL_STATSCLINE RPL_STATSNLINE + RPL_STATSILINE RPL_STATSKLINE + RPL_STATSQLINE RPL_STATSLLINE + RPL_STATSLINKINFO RPL_STATSUPTIME + RPL_STATSCOMMANDS RPL_STATSOLINE + RPL_STATSHLINE RPL_ENDOFSTATS + + Examples: + +STATS m ; check the command usage for the server + you are connected to + +:Wiz STATS c eff.org ; request by WiZ for C/N line + information from server eff.org + +4.3.3 Links message + + Command: LINKS + Parameters: [[<remote server>] <server mask>] + + With LINKS, a user can list all servers which are known by the server + answering the query. The returned list of servers must match the + mask, or if no mask is given, the full list is returned. + + If <remote server> is given in addition to <server mask>, the LINKS + command is forwarded to the first server found that matches that name + (if any), and that server is then required to answer the query. + + Numeric Replies: + + ERR_NOSUCHSERVER + RPL_LINKS RPL_ENDOFLINKS + + Examples: + + + + +Oikarinen & Reed [Page 28] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +LINKS *.au ; list all servers which have a name + that matches *.au; + +:WiZ LINKS *.bu.edu *.edu ; LINKS message from WiZ to the first + server matching *.edu for a list of + servers matching *.bu.edu. + +4.3.4 Time message + + Command: TIME + Parameters: [<server>] + + The time message is used to query local time from the specified + server. If the server parameter is not given, the server handling the + command must reply to the query. + + Numeric Replies: + + ERR_NOSUCHSERVER RPL_TIME + + Examples: + + TIME tolsun.oulu.fi ; check the time on the server + "tolson.oulu.fi" + + Angel TIME *.au ; user angel checking the time on a + server matching "*.au" + +4.3.5 Connect message + + Command: CONNECT + Parameters: <target server> [<port> [<remote server>]] + + The CONNECT command can be used to force a server to try to establish + a new connection to another server immediately. CONNECT is a + privileged command and is to be available only to IRC Operators. If + a remote server is given then the CONNECT attempt is made by that + server to <target server> and <port>. + + Numeric Replies: + + ERR_NOSUCHSERVER ERR_NOPRIVILEGES + ERR_NEEDMOREPARAMS + + Examples: + +CONNECT tolsun.oulu.fi ; Attempt to connect a server to + tolsun.oulu.fi + + + +Oikarinen & Reed [Page 29] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +:WiZ CONNECT eff.org 6667 csd.bu.edu + ; CONNECT attempt by WiZ to get servers + eff.org and csd.bu.edu connected on port + 6667. + +4.3.6 Trace message + + Command: TRACE + Parameters: [<server>] + + TRACE command is used to find the route to specific server. Each + server that processes this message must tell the sender about it by + sending a reply indicating it is a pass-through link, forming a chain + of replies similar to that gained from using "traceroute". After + sending this reply back, it must then send the TRACE message to the + next server until given server is reached. If the <server> parameter + is omitted, it is recommended that TRACE command send a message to + the sender telling which servers the current server has direct + connection to. + + If the destination given by "<server>" is an actual server, then the + destination server is required to report all servers and users which + are connected to it, although only operators are permitted to see + users present. If the destination given by <server> is a nickname, + they only a reply for that nickname is given. + + Numeric Replies: + + ERR_NOSUCHSERVER + + If the TRACE message is destined for another server, all intermediate + servers must return a RPL_TRACELINK reply to indicate that the TRACE + passed through it and where its going next. + + RPL_TRACELINK + A TRACE reply may be composed of any number of the following numeric + replies. + + RPL_TRACECONNECTING RPL_TRACEHANDSHAKE + RPL_TRACEUNKNOWN RPL_TRACEOPERATOR + RPL_TRACEUSER RPL_TRACESERVER + RPL_TRACESERVICE RPL_TRACENEWTYPE + RPL_TRACECLASS + + Examples: + +TRACE *.oulu.fi ; TRACE to a server matching *.oulu.fi + + + + +Oikarinen & Reed [Page 30] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +:WiZ TRACE AngelDust ; TRACE issued by WiZ to nick AngelDust + +4.3.7 Admin command + + Command: ADMIN + Parameters: [<server>] + + The admin message is used to find the name of the administrator of + the given server, or current server if <server> parameter is omitted. + Each server must have the ability to forward ADMIN messages to other + servers. + + Numeric Replies: + + ERR_NOSUCHSERVER + RPL_ADMINME RPL_ADMINLOC1 + RPL_ADMINLOC2 RPL_ADMINEMAIL + + Examples: + + ADMIN tolsun.oulu.fi ; request an ADMIN reply from + tolsun.oulu.fi + + :WiZ ADMIN *.edu ; ADMIN request from WiZ for first + server found to match *.edu. + +4.3.8 Info command + + Command: INFO + Parameters: [<server>] + + The INFO command is required to return information which describes + the server: its version, when it was compiled, the patchlevel, when + it was started, and any other miscellaneous information which may be + considered to be relevant. + + Numeric Replies: + + ERR_NOSUCHSERVER + RPL_INFO RPL_ENDOFINFO + + Examples: + + INFO csd.bu.edu ; request an INFO reply from + csd.bu.edu + + :Avalon INFO *.fi ; INFO request from Avalon for first + server found to match *.fi. + + + +Oikarinen & Reed [Page 31] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + INFO Angel ; request info from the server that + Angel is connected to. + +4.4 Sending messages + + The main purpose of the IRC protocol is to provide a base for clients + to communicate with each other. PRIVMSG and NOTICE are the only + messages available which actually perform delivery of a text message + from one client to another - the rest just make it possible and try + to ensure it happens in a reliable and structured manner. + +4.4.1 Private messages + + Command: PRIVMSG + Parameters: <receiver>{,<receiver>} <text to be sent> + + PRIVMSG is used to send private messages between users. <receiver> + is the nickname of the receiver of the message. <receiver> can also + be a list of names or channels separated with commas. + + The <receiver> parameter may also me a host mask (#mask) or server + mask ($mask). In both cases the server will only send the PRIVMSG + to those who have a server or host matching the mask. The mask must + have at least 1 (one) "." in it and no wildcards following the + last ".". This requirement exists to prevent people sending messages + to "#*" or "$*", which would broadcast to all users; from + experience, this is abused more than used responsibly and properly. + Wildcards are the '*' and '?' characters. This extension to + the PRIVMSG command is only available to Operators. + + Numeric Replies: + + ERR_NORECIPIENT ERR_NOTEXTTOSEND + ERR_CANNOTSENDTOCHAN ERR_NOTOPLEVEL + ERR_WILDTOPLEVEL ERR_TOOMANYTARGETS + ERR_NOSUCHNICK + RPL_AWAY + + Examples: + +:Angel PRIVMSG Wiz :Hello are you receiving this message ? + ; Message from Angel to Wiz. + +PRIVMSG Angel :yes I'm receiving it !receiving it !'u>(768u+1n) .br ; + Message to Angel. + +PRIVMSG jto@tolsun.oulu.fi :Hello ! + ; Message to a client on server + + + +Oikarinen & Reed [Page 32] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + tolsun.oulu.fi with username of "jto". + +PRIVMSG $*.fi :Server tolsun.oulu.fi rebooting. + ; Message to everyone on a server which + has a name matching *.fi. + +PRIVMSG #*.edu :NSFNet is undergoing work, expect interruptions + ; Message to all users who come from a + host which has a name matching *.edu. + +4.4.2 Notice + + Command: NOTICE + Parameters: <nickname> <text> + + The NOTICE message is used similarly to PRIVMSG. The difference + between NOTICE and PRIVMSG is that automatic replies must never be + sent in response to a NOTICE message. This rule applies to servers + too - they must not send any error reply back to the client on + receipt of a notice. The object of this rule is to avoid loops + between a client automatically sending something in response to + something it received. This is typically used by automatons (clients + with either an AI or other interactive program controlling their + actions) which are always seen to be replying lest they end up in a + loop with another automaton. + + See PRIVMSG for more details on replies and examples. + +4.5 User based queries + + User queries are a group of commands which are primarily concerned + with finding details on a particular user or group users. When using + wildcards with any of these commands, if they match, they will only + return information on users who are 'visible' to you. The visibility + of a user is determined as a combination of the user's mode and the + common set of channels you are both on. + +4.5.1 Who query + + Command: WHO + Parameters: [<name> [<o>]] + + The WHO message is used by a client to generate a query which returns + a list of information which 'matches' the <name> parameter given by + the client. In the absence of the <name> parameter, all visible + (users who aren't invisible (user mode +i) and who don't have a + common channel with the requesting client) are listed. The same + result can be achieved by using a <name> of "0" or any wildcard which + + + +Oikarinen & Reed [Page 33] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + will end up matching every entry possible. + + The <name> passed to WHO is matched against users' host, server, real + name and nickname if the channel <name> cannot be found. + + If the "o" parameter is passed only operators are returned according + to the name mask supplied. + + Numeric Replies: + + ERR_NOSUCHSERVER + RPL_WHOREPLY RPL_ENDOFWHO + + Examples: + + WHO *.fi ; List all users who match against + "*.fi". + + WHO jto* o ; List all users with a match against + "jto*" if they are an operator. + +4.5.2 Whois query + + Command: WHOIS + Parameters: [<server>] <nickmask>[,<nickmask>[,...]] + + This message is used to query information about particular user. The + server will answer this message with several numeric messages + indicating different statuses of each user which matches the nickmask + (if you are entitled to see them). If no wildcard is present in the + <nickmask>, any information about that nick which you are allowed to + see is presented. A comma (',') separated list of nicknames may be + given. + + The latter version sends the query to a specific server. It is + useful if you want to know how long the user in question has been + idle as only local server (ie. the server the user is directly + connected to) knows that information, while everything else is + globally known. + + Numeric Replies: + + ERR_NOSUCHSERVER ERR_NONICKNAMEGIVEN + RPL_WHOISUSER RPL_WHOISCHANNELS + RPL_WHOISCHANNELS RPL_WHOISSERVER + RPL_AWAY RPL_WHOISOPERATOR + RPL_WHOISIDLE ERR_NOSUCHNICK + RPL_ENDOFWHOIS + + + +Oikarinen & Reed [Page 34] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + Examples: + + WHOIS wiz ; return available user information + about nick WiZ + + WHOIS eff.org trillian ; ask server eff.org for user + information about trillian + +4.5.3 Whowas + + Command: WHOWAS + Parameters: <nickname> [<count> [<server>]] + + Whowas asks for information about a nickname which no longer exists. + This may either be due to a nickname change or the user leaving IRC. + In response to this query, the server searches through its nickname + history, looking for any nicks which are lexically the same (no wild + card matching here). The history is searched backward, returning the + most recent entry first. If there are multiple entries, up to + <count> replies will be returned (or all of them if no <count> + parameter is given). If a non-positive number is passed as being + <count>, then a full search is done. + + Numeric Replies: + + ERR_NONICKNAMEGIVEN ERR_WASNOSUCHNICK + RPL_WHOWASUSER RPL_WHOISSERVER + RPL_ENDOFWHOWAS + + Examples: + + WHOWAS Wiz ; return all information in the nick + history about nick "WiZ"; + + WHOWAS Mermaid 9 ; return at most, the 9 most recent + entries in the nick history for + "Mermaid"; + + WHOWAS Trillian 1 *.edu ; return the most recent history for + "Trillian" from the first server found + to match "*.edu". + +4.6 Miscellaneous messages + + Messages in this category do not fit into any of the above categories + but are nonetheless still a part of and required by the protocol. + + + + + +Oikarinen & Reed [Page 35] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +4.6.1 Kill message + + Command: KILL + Parameters: <nickname> <comment> + + The KILL message is used to cause a client-server connection to be + closed by the server which has the actual connection. KILL is used + by servers when they encounter a duplicate entry in the list of valid + nicknames and is used to remove both entries. It is also available + to operators. + + Clients which have automatic reconnect algorithms effectively make + this command useless since the disconnection is only brief. It does + however break the flow of data and can be used to stop large amounts + of being abused, any user may elect to receive KILL messages + generated for others to keep an 'eye' on would be trouble spots. + + In an arena where nicknames are required to be globally unique at all + times, KILL messages are sent whenever 'duplicates' are detected + (that is an attempt to register two users with the same nickname) in + the hope that both of them will disappear and only 1 reappear. + + The comment given must reflect the actual reason for the KILL. For + server-generated KILLs it usually is made up of details concerning + the origins of the two conflicting nicknames. For users it is left + up to them to provide an adequate reason to satisfy others who see + it. To prevent/discourage fake KILLs from being generated to hide + the identify of the KILLer, the comment also shows a 'kill-path' + which is updated by each server it passes through, each prepending + its name to the path. + + Numeric Replies: + + ERR_NOPRIVILEGES ERR_NEEDMOREPARAMS + ERR_NOSUCHNICK ERR_CANTKILLSERVER + + + KILL David (csd.bu.edu <- tolsun.oulu.fi) + ; Nickname collision between csd.bu.edu + and tolson.oulu.fi + + + NOTE: + It is recommended that only Operators be allowed to kill other users + with KILL message. In an ideal world not even operators would need + to do this and it would be left to servers to deal with. + + + + + +Oikarinen & Reed [Page 36] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +4.6.2 Ping message + + Command: PING + Parameters: <server1> [<server2>] + + The PING message is used to test the presence of an active client at + the other end of the connection. A PING message is sent at regular + intervals if no other activity detected coming from a connection. If + a connection fails to respond to a PING command within a set amount + of time, that connection is closed. + + Any client which receives a PING message must respond to <server1> + (server which sent the PING message out) as quickly as possible with + an appropriate PONG message to indicate it is still there and alive. + Servers should not respond to PING commands but rely on PINGs from + the other end of the connection to indicate the connection is alive. + If the <server2> parameter is specified, the PING message gets + forwarded there. + + Numeric Replies: + + ERR_NOORIGIN ERR_NOSUCHSERVER + + Examples: + + PING tolsun.oulu.fi ; server sending a PING message to + another server to indicate it is still + alive. + + PING WiZ ; PING message being sent to nick WiZ + +4.6.3 Pong message + + Command: PONG + Parameters: <daemon> [<daemon2>] + + PONG message is a reply to ping message. If parameter <daemon2> is + given this message must be forwarded to given daemon. The <daemon> + parameter is the name of the daemon who has responded to PING message + and generated this message. + + Numeric Replies: + + ERR_NOORIGIN ERR_NOSUCHSERVER + + Examples: + + PONG csd.bu.edu tolsun.oulu.fi ; PONG message from csd.bu.edu to + + + +Oikarinen & Reed [Page 37] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + tolsun.oulu.fi + +4.6.4 Error + + Command: ERROR + Parameters: <error message> + + The ERROR command is for use by servers when reporting a serious or + fatal error to its operators. It may also be sent from one server to + another but must not be accepted from any normal unknown clients. + + An ERROR message is for use for reporting errors which occur with a + server-to-server link only. An ERROR message is sent to the server + at the other end (which sends it to all of its connected operators) + and to all operators currently connected. It is not to be passed + onto any other servers by a server if it is received from a server. + + When a server sends a received ERROR message to its operators, the + message should be encapsulated inside a NOTICE message, indicating + that the client was not responsible for the error. + + Numerics: + + None. + + Examples: + + ERROR :Server *.fi already exists; ERROR message to the other server + which caused this error. + + NOTICE WiZ :ERROR from csd.bu.edu -- Server *.fi already exists + ; Same ERROR message as above but sent + to user WiZ on the other server. + +5. OPTIONALS + + This section describes OPTIONAL messages. They are not required in a + working server implementation of the protocol described herein. In + the absence of the option, an error reply message must be generated + or an unknown command error. If the message is destined for another + server to answer then it must be passed on (elementary parsing + required) The allocated numerics for this are listed with the + messages below. + +5.1 Away + + Command: AWAY + Parameters: [message] + + + +Oikarinen & Reed [Page 38] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + With the AWAY message, clients can set an automatic reply string for + any PRIVMSG commands directed at them (not to a channel they are on). + The automatic reply is sent by the server to client sending the + PRIVMSG command. The only replying server is the one to which the + sending client is connected to. + + The AWAY message is used either with one parameter (to set an AWAY + message) or with no parameters (to remove the AWAY message). + + Numeric Replies: + + RPL_UNAWAY RPL_NOWAWAY + + Examples: + + AWAY :Gone to lunch. Back in 5 ; set away message to "Gone to lunch. + Back in 5". + + :WiZ AWAY ; unmark WiZ as being away. + + +5.2 Rehash message + + Command: REHASH + Parameters: None + + The rehash message can be used by the operator to force the server to + re-read and process its configuration file. + + Numeric Replies: + + RPL_REHASHING ERR_NOPRIVILEGES + +Examples: + +REHASH ; message from client with operator + status to server asking it to reread its + configuration file. + +5.3 Restart message + + Command: RESTART + Parameters: None + + The restart message can only be used by an operator to force a server + restart itself. This message is optional since it may be viewed as a + risk to allow arbitrary people to connect to a server as an operator + and execute this command, causing (at least) a disruption to service. + + + +Oikarinen & Reed [Page 39] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + The RESTART command must always be fully processed by the server to + which the sending client is connected and not be passed onto other + connected servers. + + Numeric Replies: + + ERR_NOPRIVILEGES + + Examples: + + RESTART ; no parameters required. + +5.4 Summon message + + Command: SUMMON + Parameters: <user> [<server>] + + The SUMMON command can be used to give users who are on a host + running an IRC server a message asking them to please join IRC. This + message is only sent if the target server (a) has SUMMON enabled, (b) + the user is logged in and (c) the server process can write to the + user's tty (or similar). + + If no <server> parameter is given it tries to summon <user> from the + server the client is connected to is assumed as the target. + + If summon is not enabled in a server, it must return the + ERR_SUMMONDISABLED numeric and pass the summon message onwards. + + Numeric Replies: + + ERR_NORECIPIENT ERR_FILEERROR + ERR_NOLOGIN ERR_NOSUCHSERVER + RPL_SUMMONING + + Examples: + + SUMMON jto ; summon user jto on the server's host + + SUMMON jto tolsun.oulu.fi ; summon user jto on the host which a + server named "tolsun.oulu.fi" is + running. + + +5.5 Users + + Command: USERS + Parameters: [<server>] + + + +Oikarinen & Reed [Page 40] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + The USERS command returns a list of users logged into the server in a + similar format to who(1), rusers(1) and finger(1). Some people + may disable this command on their server for security related + reasons. If disabled, the correct numeric must be returned to + indicate this. + + Numeric Replies: + + ERR_NOSUCHSERVER ERR_FILEERROR + RPL_USERSSTART RPL_USERS + RPL_NOUSERS RPL_ENDOFUSERS + ERR_USERSDISABLED + + Disabled Reply: + + ERR_USERSDISABLED + + Examples: + +USERS eff.org ; request a list of users logged in on + server eff.org + +:John USERS tolsun.oulu.fi ; request from John for a list of users + logged in on server tolsun.oulu.fi + +5.6 Operwall message + + Command: WALLOPS + Parameters: Text to be sent to all operators currently online + + Sends a message to all operators currently online. After + implementing WALLOPS as a user command it was found that it was + often and commonly abused as a means of sending a message to a lot + of people (much similar to WALL). Due to this it is recommended + that the current implementation of WALLOPS be used as an + example by allowing and recognising only servers as the senders of + WALLOPS. + + Numeric Replies: + + ERR_NEEDMOREPARAMS + + Examples: + + :csd.bu.edu WALLOPS :Connect '*.uiuc.edu 6667' from Joshua; WALLOPS + message from csd.bu.edu announcing a + CONNECT message it received and acted + upon from Joshua. + + + +Oikarinen & Reed [Page 41] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +5.7 Userhost message + + Command: USERHOST + Parameters: <nickname>{<space><nickname>} + + The USERHOST command takes a list of up to 5 nicknames, each + separated by a space character and returns a list of information + about each nickname that it found. The returned list has each reply + separated by a space. + + Numeric Replies: + + RPL_USERHOST ERR_NEEDMOREPARAMS + + Examples: + + USERHOST Wiz Michael Marty p ;USERHOST request for information on + nicks "Wiz", "Michael", "Marty" and "p" + +5.8 Ison message + + Command: ISON + Parameters: <nickname>{<space><nickname>} + + The ISON command was implemented to provide a quick and efficient + means to get a response about whether a given nickname was currently + on IRC. ISON only takes one (1) parameter: a space-separated list of + nicks. For each nickname in the list that is present, the server + adds that to its reply string. Thus the reply string may return + empty (none of the given nicks are present), an exact copy of the + parameter string (all of them present) or as any other subset of the + set of nicks given in the parameter. The only limit on the number + of nicks that may be checked is that the combined length must not be + too large as to cause the server to chop it off so it fits in 512 + characters. + + ISON is only be processed by the server local to the client sending + the command and thus not passed onto other servers for further + processing. + + Numeric Replies: + + RPL_ISON ERR_NEEDMOREPARAMS + + Examples: + + ISON phone trillian WiZ jarlek Avalon Angel Monstah + ; Sample ISON request for 7 nicks. + + + +Oikarinen & Reed [Page 42] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +6. REPLIES + + The following is a list of numeric replies which are generated in + response to the commands given above. Each numeric is given with its + number, name and reply string. + +6.1 Error Replies. + + 401 ERR_NOSUCHNICK + "<nickname> :No such nick/channel" + + - Used to indicate the nickname parameter supplied to a + command is currently unused. + + 402 ERR_NOSUCHSERVER + "<server name> :No such server" + + - Used to indicate the server name given currently + doesn't exist. + + 403 ERR_NOSUCHCHANNEL + "<channel name> :No such channel" + + - Used to indicate the given channel name is invalid. + + 404 ERR_CANNOTSENDTOCHAN + "<channel name> :Cannot send to channel" + + - Sent to a user who is either (a) not on a channel + which is mode +n or (b) not a chanop (or mode +v) on + a channel which has mode +m set and is trying to send + a PRIVMSG message to that channel. + + 405 ERR_TOOMANYCHANNELS + "<channel name> :You have joined too many \ + channels" + - Sent to a user when they have joined the maximum + number of allowed channels and they try to join + another channel. + + 406 ERR_WASNOSUCHNICK + "<nickname> :There was no such nickname" + + - Returned by WHOWAS to indicate there is no history + information for that nickname. + + 407 ERR_TOOMANYTARGETS + "<target> :Duplicate recipients. No message \ + + + +Oikarinen & Reed [Page 43] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + delivered" + + - Returned to a client which is attempting to send a + PRIVMSG/NOTICE using the user@host destination format + and for a user@host which has several occurrences. + + 409 ERR_NOORIGIN + ":No origin specified" + + - PING or PONG message missing the originator parameter + which is required since these commands must work + without valid prefixes. + + 411 ERR_NORECIPIENT + ":No recipient given (<command>)" + 412 ERR_NOTEXTTOSEND + ":No text to send" + 413 ERR_NOTOPLEVEL + "<mask> :No toplevel domain specified" + 414 ERR_WILDTOPLEVEL + "<mask> :Wildcard in toplevel domain" + + - 412 - 414 are returned by PRIVMSG to indicate that + the message wasn't delivered for some reason. + ERR_NOTOPLEVEL and ERR_WILDTOPLEVEL are errors that + are returned when an invalid use of + "PRIVMSG $<server>" or "PRIVMSG #<host>" is attempted. + + 421 ERR_UNKNOWNCOMMAND + "<command> :Unknown command" + + - Returned to a registered client to indicate that the + command sent is unknown by the server. + + 422 ERR_NOMOTD + ":MOTD File is missing" + + - Server's MOTD file could not be opened by the server. + + 423 ERR_NOADMININFO + "<server> :No administrative info available" + + - Returned by a server in response to an ADMIN message + when there is an error in finding the appropriate + information. + + 424 ERR_FILEERROR + ":File error doing <file op> on <file>" + + + +Oikarinen & Reed [Page 44] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + - Generic error message used to report a failed file + operation during the processing of a message. + + 431 ERR_NONICKNAMEGIVEN + ":No nickname given" + + - Returned when a nickname parameter expected for a + command and isn't found. + + 432 ERR_ERRONEUSNICKNAME + "<nick> :Erroneus nickname" + + - Returned after receiving a NICK message which contains + characters which do not fall in the defined set. See + section x.x.x for details on valid nicknames. + + 433 ERR_NICKNAMEINUSE + "<nick> :Nickname is already in use" + + - Returned when a NICK message is processed that results + in an attempt to change to a currently existing + nickname. + + 436 ERR_NICKCOLLISION + "<nick> :Nickname collision KILL" + + - Returned by a server to a client when it detects a + nickname collision (registered of a NICK that + already exists by another server). + + 441 ERR_USERNOTINCHANNEL + "<nick> <channel> :They aren't on that channel" + + - Returned by the server to indicate that the target + user of the command is not on the given channel. + + 442 ERR_NOTONCHANNEL + "<channel> :You're not on that channel" + + - Returned by the server whenever a client tries to + perform a channel effecting command for which the + client isn't a member. + + 443 ERR_USERONCHANNEL + "<user> <channel> :is already on channel" + + - Returned when a client tries to invite a user to a + channel they are already on. + + + +Oikarinen & Reed [Page 45] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 444 ERR_NOLOGIN + "<user> :User not logged in" + + - Returned by the summon after a SUMMON command for a + user was unable to be performed since they were not + logged in. + + 445 ERR_SUMMONDISABLED + ":SUMMON has been disabled" + + - Returned as a response to the SUMMON command. Must be + returned by any server which does not implement it. + + 446 ERR_USERSDISABLED + ":USERS has been disabled" + + - Returned as a response to the USERS command. Must be + returned by any server which does not implement it. + + 451 ERR_NOTREGISTERED + ":You have not registered" + + - Returned by the server to indicate that the client + must be registered before the server will allow it + to be parsed in detail. + + 461 ERR_NEEDMOREPARAMS + "<command> :Not enough parameters" + + - Returned by the server by numerous commands to + indicate to the client that it didn't supply enough + parameters. + + 462 ERR_ALREADYREGISTRED + ":You may not reregister" + + - Returned by the server to any link which tries to + change part of the registered details (such as + password or user details from second USER message). + + + 463 ERR_NOPERMFORHOST + ":Your host isn't among the privileged" + + - Returned to a client which attempts to register with + a server which does not been setup to allow + connections from the host the attempted connection + is tried. + + + +Oikarinen & Reed [Page 46] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 464 ERR_PASSWDMISMATCH + ":Password incorrect" + + - Returned to indicate a failed attempt at registering + a connection for which a password was required and + was either not given or incorrect. + + 465 ERR_YOUREBANNEDCREEP + ":You are banned from this server" + + - Returned after an attempt to connect and register + yourself with a server which has been setup to + explicitly deny connections to you. + + 467 ERR_KEYSET + "<channel> :Channel key already set" + 471 ERR_CHANNELISFULL + "<channel> :Cannot join channel (+l)" + 472 ERR_UNKNOWNMODE + "<char> :is unknown mode char to me" + 473 ERR_INVITEONLYCHAN + "<channel> :Cannot join channel (+i)" + 474 ERR_BANNEDFROMCHAN + "<channel> :Cannot join channel (+b)" + 475 ERR_BADCHANNELKEY + "<channel> :Cannot join channel (+k)" + 481 ERR_NOPRIVILEGES + ":Permission Denied- You're not an IRC operator" + + - Any command requiring operator privileges to operate + must return this error to indicate the attempt was + unsuccessful. + + 482 ERR_CHANOPRIVSNEEDED + "<channel> :You're not channel operator" + + - Any command requiring 'chanop' privileges (such as + MODE messages) must return this error if the client + making the attempt is not a chanop on the specified + channel. + + 483 ERR_CANTKILLSERVER + ":You cant kill a server!" + + - Any attempts to use the KILL command on a server + are to be refused and this error returned directly + to the client. + + + + +Oikarinen & Reed [Page 47] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 491 ERR_NOOPERHOST + ":No O-lines for your host" + + - If a client sends an OPER message and the server has + not been configured to allow connections from the + client's host as an operator, this error must be + returned. + + 501 ERR_UMODEUNKNOWNFLAG + ":Unknown MODE flag" + + - Returned by the server to indicate that a MODE + message was sent with a nickname parameter and that + the a mode flag sent was not recognized. + + 502 ERR_USERSDONTMATCH + ":Cant change mode for other users" + + - Error sent to any user trying to view or change the + user mode for a user other than themselves. + +6.2 Command responses. + + 300 RPL_NONE + Dummy reply number. Not used. + + 302 RPL_USERHOST + ":[<reply>{<space><reply>}]" + + - Reply format used by USERHOST to list replies to + the query list. The reply string is composed as + follows: + + <reply> ::= <nick>['*'] '=' <'+'|'-'><hostname> + + The '*' indicates whether the client has registered + as an Operator. The '-' or '+' characters represent + whether the client has set an AWAY message or not + respectively. + + 303 RPL_ISON + ":[<nick> {<space><nick>}]" + + - Reply format used by ISON to list replies to the + query list. + + 301 RPL_AWAY + "<nick> :<away message>" + + + +Oikarinen & Reed [Page 48] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + 305 RPL_UNAWAY + ":You are no longer marked as being away" + 306 RPL_NOWAWAY + ":You have been marked as being away" + + - These replies are used with the AWAY command (if + allowed). RPL_AWAY is sent to any client sending a + PRIVMSG to a client which is away. RPL_AWAY is only + sent by the server to which the client is connected. + Replies RPL_UNAWAY and RPL_NOWAWAY are sent when the + client removes and sets an AWAY message. + + 311 RPL_WHOISUSER + "<nick> <user> <host> * :<real name>" + 312 RPL_WHOISSERVER + "<nick> <server> :<server info>" + 313 RPL_WHOISOPERATOR + "<nick> :is an IRC operator" + 317 RPL_WHOISIDLE + "<nick> <integer> :seconds idle" + 318 RPL_ENDOFWHOIS + "<nick> :End of /WHOIS list" + 319 RPL_WHOISCHANNELS + "<nick> :{[@|+]<channel><space>}" + + - Replies 311 - 313, 317 - 319 are all replies + generated in response to a WHOIS message. Given that + there are enough parameters present, the answering + server must either formulate a reply out of the above + numerics (if the query nick is found) or return an + error reply. The '*' in RPL_WHOISUSER is there as + the literal character and not as a wild card. For + each reply set, only RPL_WHOISCHANNELS may appear + more than once (for long lists of channel names). + The '@' and '+' characters next to the channel name + indicate whether a client is a channel operator or + has been granted permission to speak on a moderated + channel. The RPL_ENDOFWHOIS reply is used to mark + the end of processing a WHOIS message. + + 314 RPL_WHOWASUSER + "<nick> <user> <host> * :<real name>" + 369 RPL_ENDOFWHOWAS + "<nick> :End of WHOWAS" + + - When replying to a WHOWAS message, a server must use + the replies RPL_WHOWASUSER, RPL_WHOISSERVER or + ERR_WASNOSUCHNICK for each nickname in the presented + + + +Oikarinen & Reed [Page 49] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + list. At the end of all reply batches, there must + be RPL_ENDOFWHOWAS (even if there was only one reply + and it was an error). + + 321 RPL_LISTSTART + "Channel :Users Name" + 322 RPL_LIST + "<channel> <# visible> :<topic>" + 323 RPL_LISTEND + ":End of /LIST" + + - Replies RPL_LISTSTART, RPL_LIST, RPL_LISTEND mark + the start, actual replies with data and end of the + server's response to a LIST command. If there are + no channels available to return, only the start + and end reply must be sent. + + 324 RPL_CHANNELMODEIS + "<channel> <mode> <mode params>" + + 331 RPL_NOTOPIC + "<channel> :No topic is set" + 332 RPL_TOPIC + "<channel> :<topic>" + + - When sending a TOPIC message to determine the + channel topic, one of two replies is sent. If + the topic is set, RPL_TOPIC is sent back else + RPL_NOTOPIC. + + 341 RPL_INVITING + "<channel> <nick>" + + - Returned by the server to indicate that the + attempted INVITE message was successful and is + being passed onto the end client. + + 342 RPL_SUMMONING + "<user> :Summoning user to IRC" + + - Returned by a server answering a SUMMON message to + indicate that it is summoning that user. + + 351 RPL_VERSION + "<version>.<debuglevel> <server> :<comments>" + + - Reply by the server showing its version details. + The <version> is the version of the software being + + + +Oikarinen & Reed [Page 50] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + used (including any patchlevel revisions) and the + <debuglevel> is used to indicate if the server is + running in "debug mode". + + The "comments" field may contain any comments about + the version or further version details. + + 352 RPL_WHOREPLY + "<channel> <user> <host> <server> <nick> \ + <H|G>[*][@|+] :<hopcount> <real name>" + 315 RPL_ENDOFWHO + "<name> :End of /WHO list" + + - The RPL_WHOREPLY and RPL_ENDOFWHO pair are used + to answer a WHO message. The RPL_WHOREPLY is only + sent if there is an appropriate match to the WHO + query. If there is a list of parameters supplied + with a WHO message, a RPL_ENDOFWHO must be sent + after processing each list item with <name> being + the item. + + 353 RPL_NAMREPLY + "<channel> :[[@|+]<nick> [[@|+]<nick> [...]]]" + 366 RPL_ENDOFNAMES + "<channel> :End of /NAMES list" + + - To reply to a NAMES message, a reply pair consisting + of RPL_NAMREPLY and RPL_ENDOFNAMES is sent by the + server back to the client. If there is no channel + found as in the query, then only RPL_ENDOFNAMES is + returned. The exception to this is when a NAMES + message is sent with no parameters and all visible + channels and contents are sent back in a series of + RPL_NAMEREPLY messages with a RPL_ENDOFNAMES to mark + the end. + + 364 RPL_LINKS + "<mask> <server> :<hopcount> <server info>" + 365 RPL_ENDOFLINKS + "<mask> :End of /LINKS list" + + - In replying to the LINKS message, a server must send + replies back using the RPL_LINKS numeric and mark the + end of the list using an RPL_ENDOFLINKS reply. + + 367 RPL_BANLIST + "<channel> <banid>" + 368 RPL_ENDOFBANLIST + + + +Oikarinen & Reed [Page 51] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + "<channel> :End of channel ban list" + + - When listing the active 'bans' for a given channel, + a server is required to send the list back using the + RPL_BANLIST and RPL_ENDOFBANLIST messages. A separate + RPL_BANLIST is sent for each active banid. After the + banids have been listed (or if none present) a + RPL_ENDOFBANLIST must be sent. + + 371 RPL_INFO + ":<string>" + 374 RPL_ENDOFINFO + ":End of /INFO list" + + - A server responding to an INFO message is required to + send all its 'info' in a series of RPL_INFO messages + with a RPL_ENDOFINFO reply to indicate the end of the + replies. + + 375 RPL_MOTDSTART + ":- <server> Message of the day - " + 372 RPL_MOTD + ":- <text>" + 376 RPL_ENDOFMOTD + ":End of /MOTD command" + + - When responding to the MOTD message and the MOTD file + is found, the file is displayed line by line, with + each line no longer than 80 characters, using + RPL_MOTD format replies. These should be surrounded + by a RPL_MOTDSTART (before the RPL_MOTDs) and an + RPL_ENDOFMOTD (after). + + 381 RPL_YOUREOPER + ":You are now an IRC operator" + + - RPL_YOUREOPER is sent back to a client which has + just successfully issued an OPER message and gained + operator status. + + 382 RPL_REHASHING + "<config file> :Rehashing" + + - If the REHASH option is used and an operator sends + a REHASH message, an RPL_REHASHING is sent back to + the operator. + + 391 RPL_TIME + + + +Oikarinen & Reed [Page 52] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + "<server> :<string showing server's local time>" + + - When replying to the TIME message, a server must send + the reply using the RPL_TIME format above. The string + showing the time need only contain the correct day and + time there. There is no further requirement for the + time string. + + 392 RPL_USERSSTART + ":UserID Terminal Host" + 393 RPL_USERS + ":%-8s %-9s %-8s" + 394 RPL_ENDOFUSERS + ":End of users" + 395 RPL_NOUSERS + ":Nobody logged in" + + - If the USERS message is handled by a server, the + replies RPL_USERSTART, RPL_USERS, RPL_ENDOFUSERS and + RPL_NOUSERS are used. RPL_USERSSTART must be sent + first, following by either a sequence of RPL_USERS + or a single RPL_NOUSER. Following this is + RPL_ENDOFUSERS. + + 200 RPL_TRACELINK + "Link <version & debug level> <destination> \ + <next server>" + 201 RPL_TRACECONNECTING + "Try. <class> <server>" + 202 RPL_TRACEHANDSHAKE + "H.S. <class> <server>" + 203 RPL_TRACEUNKNOWN + "???? <class> [<client IP address in dot form>]" + 204 RPL_TRACEOPERATOR + "Oper <class> <nick>" + 205 RPL_TRACEUSER + "User <class> <nick>" + 206 RPL_TRACESERVER + "Serv <class> <int>S <int>C <server> \ + <nick!user|*!*>@<host|server>" + 208 RPL_TRACENEWTYPE + "<newtype> 0 <client name>" + 261 RPL_TRACELOG + "File <logfile> <debug level>" + + - The RPL_TRACE* are all returned by the server in + response to the TRACE message. How many are + returned is dependent on the the TRACE message and + + + +Oikarinen & Reed [Page 53] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + whether it was sent by an operator or not. There + is no predefined order for which occurs first. + Replies RPL_TRACEUNKNOWN, RPL_TRACECONNECTING and + RPL_TRACEHANDSHAKE are all used for connections + which have not been fully established and are either + unknown, still attempting to connect or in the + process of completing the 'server handshake'. + RPL_TRACELINK is sent by any server which handles + a TRACE message and has to pass it on to another + server. The list of RPL_TRACELINKs sent in + response to a TRACE command traversing the IRC + network should reflect the actual connectivity of + the servers themselves along that path. + RPL_TRACENEWTYPE is to be used for any connection + which does not fit in the other categories but is + being displayed anyway. + + 211 RPL_STATSLINKINFO + "<linkname> <sendq> <sent messages> \ + <sent bytes> <received messages> \ + <received bytes> <time open>" + 212 RPL_STATSCOMMANDS + "<command> <count>" + 213 RPL_STATSCLINE + "C <host> * <name> <port> <class>" + 214 RPL_STATSNLINE + "N <host> * <name> <port> <class>" + 215 RPL_STATSILINE + "I <host> * <host> <port> <class>" + 216 RPL_STATSKLINE + "K <host> * <username> <port> <class>" + 218 RPL_STATSYLINE + "Y <class> <ping frequency> <connect \ + frequency> <max sendq>" + 219 RPL_ENDOFSTATS + "<stats letter> :End of /STATS report" + 241 RPL_STATSLLINE + "L <hostmask> * <servername> <maxdepth>" + 242 RPL_STATSUPTIME + ":Server Up %d days %d:%02d:%02d" + 243 RPL_STATSOLINE + "O <hostmask> * <name>" + 244 RPL_STATSHLINE + "H <hostmask> * <servername>" + + 221 RPL_UMODEIS + "<user mode string>" + + + + +Oikarinen & Reed [Page 54] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + - To answer a query about a client's own mode, + RPL_UMODEIS is sent back. + + 251 RPL_LUSERCLIENT + ":There are <integer> users and <integer> \ + invisible on <integer> servers" + 252 RPL_LUSEROP + "<integer> :operator(s) online" + 253 RPL_LUSERUNKNOWN + "<integer> :unknown connection(s)" + 254 RPL_LUSERCHANNELS + "<integer> :channels formed" + 255 RPL_LUSERME + ":I have <integer> clients and <integer> \ + servers" + + - In processing an LUSERS message, the server + sends a set of replies from RPL_LUSERCLIENT, + RPL_LUSEROP, RPL_USERUNKNOWN, + RPL_LUSERCHANNELS and RPL_LUSERME. When + replying, a server must send back + RPL_LUSERCLIENT and RPL_LUSERME. The other + replies are only sent back if a non-zero count + is found for them. + + 256 RPL_ADMINME + "<server> :Administrative info" + 257 RPL_ADMINLOC1 + ":<admin info>" + 258 RPL_ADMINLOC2 + ":<admin info>" + 259 RPL_ADMINEMAIL + ":<admin info>" + + - When replying to an ADMIN message, a server + is expected to use replies RLP_ADMINME + through to RPL_ADMINEMAIL and provide a text + message with each. For RPL_ADMINLOC1 a + description of what city, state and country + the server is in is expected, followed by + details of the university and department + (RPL_ADMINLOC2) and finally the administrative + contact for the server (an email address here + is required) in RPL_ADMINEMAIL. + + + + + + + +Oikarinen & Reed [Page 55] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +6.3 Reserved numerics. + + These numerics are not described above since they fall into one of + the following categories: + + 1. no longer in use; + + 2. reserved for future planned use; + + 3. in current use but are part of a non-generic 'feature' of + the current IRC server. + + 209 RPL_TRACECLASS 217 RPL_STATSQLINE + 231 RPL_SERVICEINFO 232 RPL_ENDOFSERVICES + 233 RPL_SERVICE 234 RPL_SERVLIST + 235 RPL_SERVLISTEND + 316 RPL_WHOISCHANOP 361 RPL_KILLDONE + 362 RPL_CLOSING 363 RPL_CLOSEEND + 373 RPL_INFOSTART 384 RPL_MYPORTIS + 466 ERR_YOUWILLBEBANNED 476 ERR_BADCHANMASK + 492 ERR_NOSERVICEHOST + +7. Client and server authentication + + Clients and servers are both subject to the same level of + authentication. For both, an IP number to hostname lookup (and + reverse check on this) is performed for all connections made to the + server. Both connections are then subject to a password check (if + there is a password set for that connection). These checks are + possible on all connections although the password check is only + commonly used with servers. + + An additional check that is becoming of more and more common is that + of the username responsible for making the connection. Finding the + username of the other end of the connection typically involves + connecting to an authentication server such as IDENT as described in + RFC 1413. + + Given that without passwords it is not easy to reliably determine who + is on the other end of a network connection, use of passwords is + strongly recommended on inter-server connections in addition to any + other measures such as using an ident server. + +8. Current implementations + + The only current implementation of this protocol is the IRC server, + version 2.8. Earlier versions may implement some or all of the + commands described by this document with NOTICE messages replacing + + + +Oikarinen & Reed [Page 56] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + many of the numeric replies. Unfortunately, due to backward + compatibility requirements, the implementation of some parts of this + document varies with what is laid out. On notable difference is: + + * recognition that any LF or CR anywhere in a message marks the + end of that message (instead of requiring CR-LF); + + The rest of this section deals with issues that are mostly of + importance to those who wish to implement a server but some parts + also apply directly to clients as well. + +8.1 Network protocol: TCP - why it is best used here. + + IRC has been implemented on top of TCP since TCP supplies a reliable + network protocol which is well suited to this scale of conferencing. + The use of multicast IP is an alternative, but it is not widely + available or supported at the present time. + +8.1.1 Support of Unix sockets + + Given that Unix domain sockets allow listen/connect operations, the + current implementation can be configured to listen and accept both + client and server connections on a Unix domain socket. These are + recognized as sockets where the hostname starts with a '/'. + + When providing any information about the connections on a Unix domain + socket, the server is required to supplant the actual hostname in + place of the pathname unless the actual socket name is being asked + for. + +8.2 Command Parsing + + To provide useful 'non-buffered' network IO for clients and servers, + each connection is given its own private 'input buffer' in which the + results of the most recent read and parsing are kept. A buffer size + of 512 bytes is used so as to hold 1 full message, although, this + will usually hold several commands. The private buffer is parsed + after every read operation for valid messages. When dealing with + multiple messages from one client in the buffer, care should be taken + in case one happens to cause the client to be 'removed'. + +8.3 Message delivery + + It is common to find network links saturated or hosts to which you + are sending data unable to send data. Although Unix typically + handles this through the TCP window and internal buffers, the server + often has large amounts of data to send (especially when a new + server-server link forms) and the small buffers provided in the + + + +Oikarinen & Reed [Page 57] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + kernel are not enough for the outgoing queue. To alleviate this + problem, a "send queue" is used as a FIFO queue for data to be sent. + A typical "send queue" may grow to 200 Kbytes on a large IRC network + with a slow network connection when a new server connects. + + When polling its connections, a server will first read and parse all + incoming data, queuing any data to be sent out. When all available + input is processed, the queued data is sent. This reduces the number + of write() system calls and helps TCP make bigger packets. + +8.4 Connection 'Liveness' + + To detect when a connection has died or become unresponsive, the + server must ping each of its connections that it doesn't get a + response from in a given amount of time. + + If a connection doesn't respond in time, its connection is closed + using the appropriate procedures. A connection is also dropped if + its sendq grows beyond the maximum allowed, because it is better to + close a slow connection than have a server process block. + +8.5 Establishing a server to client connection + + Upon connecting to an IRC server, a client is sent the MOTD (if + present) as well as the current user/server count (as per the LUSER + command). The server is also required to give an unambiguous message + to the client which states its name and version as well as any other + introductory messages which may be deemed appropriate. + + After dealing with this, the server must then send out the new user's + nickname and other information as supplied by itself (USER command) + and as the server could discover (from DNS/authentication servers). + The server must send this information out with NICK first followed by + USER. + +8.6 Establishing a server-server connection. + + The process of establishing of a server-to-server connection is + fraught with danger since there are many possible areas where + problems can occur - the least of which are race conditions. + + After a server has received a connection following by a PASS/SERVER + pair which were recognised as being valid, the server should then + reply with its own PASS/SERVER information for that connection as + well as all of the other state information it knows about as + described below. + + When the initiating server receives a PASS/SERVER pair, it too then + + + +Oikarinen & Reed [Page 58] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + checks that the server responding is authenticated properly before + accepting the connection to be that server. + +8.6.1 Server exchange of state information when connecting + + The order of state information being exchanged between servers is + essential. The required order is as follows: + + * all known other servers; + + * all known user information; + + * all known channel information. + + Information regarding servers is sent via extra SERVER messages, user + information with NICK/USER/MODE/JOIN messages and channels with MODE + messages. + + NOTE: channel topics are *NOT* exchanged here because the TOPIC + command overwrites any old topic information, so at best, the two + sides of the connection would exchange topics. + + By passing the state information about servers first, any collisions + with servers that already exist occur before nickname collisions due + to a second server introducing a particular nickname. Due to the IRC + network only being able to exist as an acyclic graph, it may be + possible that the network has already reconnected in another + location, the place where the collision occurs indicating where the + net needs to split. + +8.7 Terminating server-client connections + + When a client connection closes, a QUIT message is generated on + behalf of the client by the server to which the client connected. No + other message is to be generated or used. + +8.8 Terminating server-server connections + + If a server-server connection is closed, either via a remotely + generated SQUIT or 'natural' causes, the rest of the connected IRC + network must have its information updated with by the server which + detected the closure. The server then sends a list of SQUITs (one + for each server behind that connection) and a list of QUITs (again, + one for each client behind that connection). + + + + + + + +Oikarinen & Reed [Page 59] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +8.9 Tracking nickname changes + + All IRC servers are required to keep a history of recent nickname + changes. This is required to allow the server to have a chance of + keeping in touch of things when nick-change race conditions occur + with commands which manipulate them. Commands which must trace nick + changes are: + + * KILL (the nick being killed) + + * MODE (+/- o,v) + + * KICK (the nick being kicked) + + No other commands are to have nick changes checked for. + + In the above cases, the server is required to first check for the + existence of the nickname, then check its history to see who that + nick currently belongs to (if anyone!). This reduces the chances of + race conditions but they can still occur with the server ending up + affecting the wrong client. When performing a change trace for an + above command it is recommended that a time range be given and + entries which are too old ignored. + + For a reasonable history, a server should be able to keep previous + nickname for every client it knows about if they all decided to + change. This size is limited by other factors (such as memory, etc). + +8.10 Flood control of clients + + With a large network of interconnected IRC servers, it is quite easy + for any single client attached to the network to supply a continuous + stream of messages that result in not only flooding the network, but + also degrading the level of service provided to others. Rather than + require every 'victim' to be provide their own protection, flood + protection was written into the server and is applied to all clients + except services. The current algorithm is as follows: + + * check to see if client's `message timer' is less than + current time (set to be equal if it is); + + * read any data present from the client; + + * while the timer is less than ten seconds ahead of the current + time, parse any present messages and penalize the client by + 2 seconds for each message; + + which in essence means that the client may send 1 message every 2 + + + +Oikarinen & Reed [Page 60] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + seconds without being adversely affected. + +8.11 Non-blocking lookups + + In a real-time environment, it is essential that a server process do + as little waiting as possible so that all the clients are serviced + fairly. Obviously this requires non-blocking IO on all network + read/write operations. For normal server connections, this was not + difficult, but there are other support operations that may cause the + server to block (such as disk reads). Where possible, such activity + should be performed with a short timeout. + +8.11.1 Hostname (DNS) lookups + + Using the standard resolver libraries from Berkeley and others has + meant large delays in some cases where replies have timed out. To + avoid this, a separate set of DNS routines were written which were + setup for non-blocking IO operations and then polled from within the + main server IO loop. + +8.11.2 Username (Ident) lookups + + Although there are numerous ident libraries for use and inclusion + into other programs, these caused problems since they operated in a + synchronous manner and resulted in frequent delays. Again the + solution was to write a set of routines which would cooperate with + the rest of the server and work using non-blocking IO. + +8.12 Configuration File + + To provide a flexible way of setting up and running the server, it is + recommended that a configuration file be used which contains + instructions to the server on the following: + + * which hosts to accept client connections from; + + * which hosts to allow to connect as servers; + + * which hosts to connect to (both actively and + passively); + + * information about where the server is (university, + city/state, company are examples of this); + + * who is responsible for the server and an email address + at which they can be contacted; + + * hostnames and passwords for clients which wish to be given + + + +Oikarinen & Reed [Page 61] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + access to restricted operator commands. + + In specifying hostnames, both domain names and use of the 'dot' + notation (127.0.0.1) should both be accepted. It must be possible to + specify the password to be used/accepted for all outgoing and + incoming connections (although the only outgoing connections are + those to other servers). + + The above list is the minimum requirement for any server which wishes + to make a connection with another server. Other items which may be + of use are: + + * specifying which servers other server may introduce; + + * how deep a server branch is allowed to become; + + * hours during which clients may connect. + +8.12.1 Allowing clients to connect + + A server should use some sort of 'access control list' (either in the + configuration file or elsewhere) that is read at startup and used to + decide what hosts clients may use to connect to it. + + Both 'deny' and 'allow' should be implemented to provide the required + flexibility for host access control. + +8.12.2 Operators + + The granting of operator privileges to a disruptive person can have + dire consequences for the well-being of the IRC net in general due to + the powers given to them. Thus, the acquisition of such powers + should not be very easy. The current setup requires two 'passwords' + to be used although one of them is usually easy guessed. Storage of + oper passwords in configuration files is preferable to hard coding + them in and should be stored in a crypted format (ie using crypt(3) + from Unix) to prevent easy theft. + +8.12.3 Allowing servers to connect + + The interconnection of server is not a trivial matter: a bad + connection can have a large impact on the usefulness of IRC. Thus, + each server should have a list of servers to which it may connect and + which servers may connect to it. Under no circumstances should a + server allow an arbitrary host to connect as a server. In addition + to which servers may and may not connect, the configuration file + should also store the password and other characteristics of that + link. + + + +Oikarinen & Reed [Page 62] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +8.12.4 Administrivia + + To provide accurate and valid replies to the ADMIN command (see + section 4.3.7), the server should find the relevant details in the + configuration. + +8.13 Channel membership + + The current server allows any registered local user to join upto 10 + different channels. There is no limit imposed on non-local users so + that the server remains (reasonably) consistant with all others on a + channel membership basis + +9. Current problems + + There are a number of recognized problems with this protocol, all of + which hope to be solved sometime in the near future during its + rewrite. Currently, work is underway to find working solutions to + these problems. + +9.1 Scalability + + It is widely recognized that this protocol does not scale + sufficiently well when used in a large arena. The main problem comes + from the requirement that all servers know about all other servers + and users and that information regarding them be updated as soon as + it changes. It is also desirable to keep the number of servers low + so that the path length between any two points is kept minimal and + the spanning tree as strongly branched as possible. + +9.2 Labels + + The current IRC protocol has 3 types of labels: the nickname, the + channel name and the server name. Each of the three types has its + own domain and no duplicates are allowed inside that domain. + Currently, it is possible for users to pick the label for any of the + three, resulting in collisions. It is widely recognized that this + needs reworking, with a plan for unique names for channels and nicks + that don't collide being desirable as well as a solution allowing a + cyclic tree. + +9.2.1 Nicknames + + The idea of the nickname on IRC is very convenient for users to use + when talking to each other outside of a channel, but there is only a + finite nickname space and being what they are, its not uncommon for + several people to want to use the same nick. If a nickname is chosen + by two people using this protocol, either one will not succeed or + + + +Oikarinen & Reed [Page 63] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + + both will removed by use of KILL (4.6.1). + +9.2.2 Channels + + The current channel layout requires that all servers know about all + channels, their inhabitants and properties. Besides not scaling + well, the issue of privacy is also a concern. A collision of + channels is treated as an inclusive event (both people who create the + new channel are considered to be members of it) rather than an + exclusive one such as used to solve nickname collisions. + +9.2.3 Servers + + Although the number of servers is usually small relative to the + number of users and channels, they two currently required to be known + globally, either each one separately or hidden behind a mask. + +9.3 Algorithms + + In some places within the server code, it has not been possible to + avoid N^2 algorithms such as checking the channel list of a set + of clients. + + In current server versions, there are no database consistency checks, + each server assumes that a neighbouring server is correct. This + opens the door to large problems if a connecting server is buggy or + otherwise tries to introduce contradictions to the existing net. + + Currently, because of the lack of unique internal and global labels, + there are a multitude of race conditions that exist. These race + conditions generally arise from the problem of it taking time for + messages to traverse and effect the IRC network. Even by changing to + unique labels, there are problems with channel-related commands being + disrupted. + +10. Current support and availability + + Mailing lists for IRC related discussion: + Future protocol: ircd-three-request@eff.org + General discussion: operlist-request@eff.org + + Software implemenations + cs.bu.edu:/irc + nic.funet.fi:/pub/irc + coombs.anu.edu.au:/pub/irc + + Newsgroup: alt.irc + + + + +Oikarinen & Reed [Page 64] + +RFC 1459 Internet Relay Chat Protocol May 1993 + + +Security Considerations + + Security issues are discussed in sections 4.1, 4.1.1, 4.1.3, 5.5, and + 7. + +12. Authors' Addresses + + Jarkko Oikarinen + Tuirantie 17 as 9 + 90500 OULU + FINLAND + + Email: jto@tolsun.oulu.fi + + + Darren Reed + 4 Pateman Street + Watsonia, Victoria 3087 + Australia + + Email: avalon@coombs.anu.edu.au + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Oikarinen & Reed [Page 65] +
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