2 ngIRCd - Next Generation IRC Server
3 http://ngircd.barton.de/
5 (c)2001-2019 Alexander Barton and Contributors.
6 ngIRCd is free software and published under the
7 terms of the GNU General Public License.
15 The ngIRCd implements the Internet Relay Chat (IRC) protocol version 2.10
16 as defined in RFC ("request for comment") 1459 and 2810-2813. These (and
17 probably further relevant RFCs) are listed in doc/RFC.txt.
19 Unfortunately, even the "original" ircd doesn't follow these specifications
20 in all details. But because the ngIRCd should be a fully compatible
21 replacement for this server ("ircd") it tries to emulate these differences.
23 If you don't like this behavior please ./configure the ngIRCd using the
24 "--enable-strict-rfc" command line option. But keep in mind: not all IRC
25 clients are compatible with a server configured that way, some can't even
26 connect at all! Therefore this option usually isn't desired for "normal
29 In addition, ngIRCd implements some "IRCv3" features. This includes:
30 - IRCv3 Client Capability Negotiation
31 - IRCv3.1 multi-prefix Extension
32 - IRCv3.2 userhost-in-names Extension
33 Please see the IRCv3 homepage for more information: <https://ircv3.net>.
39 Starting with version 0.5.0, the ngIRCd extends the original IRC protocol
40 as defined in RFC 2810-2813. This enhanced protocol is named "IRC+". It is
41 backwards compatible to the "plain" IRC protocol and will only be used by
42 the ngIRCd if it detects that the peer supports it as well.
44 The "PASS" command is used to detect the protocol and peer versions see
45 RFC 2813 (section 4.1.1) and below.
48 II.1 Register new server link
51 Parameters: <password> <version> <flags> [<options>]
52 Used by: servers only (with these parameters)
54 <password> is the password for this new server link as defined in the server
55 configuration which is sent to the peer or received from it.
57 <version> consists of two parts and is at least 4, at most 14 characters
58 long: the first four bytes contain the IRC protocol version number, whereas
59 the first two bytes represent the major version, the last two bytes the
60 minor version (the string "0210" indicates version 2.10, e.g.).
62 The following optional(!) 10 bytes contain an implementation-dependent
63 version number. Servers supporting the IRC+ protocol as defined in this
64 document provide the string "-IRC+" here.
66 Example for <version>: "0210-IRC+".
68 <flags> consists of two parts separated with the character "|" and is at
69 most 100 bytes long. The first part contains the name of the implementation
70 (ngIRCd sets this to "ngircd", the original ircd to "IRC", e.g.). The second
71 part is implementation-dependent and should only be parsed if the peer
72 supports the IRC+ protocol as well. In this case the following syntax is
73 used: "<serverversion>[:<serverflags>]".
75 <serverversion> is an ASCII representation of the clear-text server version
76 number, <serverflags> indicates the supported IRC+ protocol extensions (and
79 The following <serverflags> are defined at the moment:
81 - C: The server supports the CHANINFO command.
83 - L: INVITE- and BAN-lists should be synchronized between servers: if the
84 peer understands this flag, it will send "MODE +I" and "MODE +b"
85 commands after the server link has been established.
87 - H: The server supports the "enhanced server handshake", see section II.2
88 for a detailed description.
90 - M: Changing client "metadata" (hostname, real name, ...) using the
91 METADATA command is supported.
93 - o: IRC operators are allowed to change channel- and channel-user-modes
94 even if they aren't channel-operator of the affected channel.
96 - S: The server supports the SERVICE command (on this link).
98 - X: Server supports XOP channel modes (owner, admin, halfop) and supports
99 these user prefixes in CHANINFO commands, for example.
101 - Z: Compressed server links are supported by the server.
103 Example for a complete <flags> string: "ngircd|0.7.5:CZ".
105 The optional parameter <options> is used to propagate server options as
106 defined in RFC 2813, section 4.1.1.
109 II.2 Enhanced Server Handshake
111 The "enhanced server handshake" is used when both servers support this IRC+
112 extension, which is indicated by the 'H' flag in the <serverflags> sent with
113 the PASS command, see section II.1.
115 It basically means, that after exchanging the PASS and SERVER commands the
116 server is not registered in the network (as usual), but that IRC numerics
117 are exchanged until the numeric 376 (ENDOFMOTD) is received. Afterwards the
118 peer is registered in the network as with the regular IRC protocol.
120 A server implementing the enhanced server handshake (and indicating this
121 using 'H' in the <serverflags>) MUST ignore all unknown numerics to it
124 In addition, such a server should at least send the numeric 005 (ISUPPORT)
125 to its peer, containing the following information. Syntax: <key>=<value>,
126 one token per IRC parameter. If the server has to send more than 12 token
127 it must send separate ISUPPORT numerics (this is a limitation of the IRC
128 protocol which allows at max 15 arguments per command).
130 - NICKLEN: Maximum nickname length. Default: 9.
131 - CASEMAPPING: Case mapping used for nick- and channel name comparing.
132 Default: "ascii", the chars [a-z] are lowercase of [A-Z].
133 - PREFIX: List of channel modes a person can get and the respective prefix
134 a channel or nickname will get in case the person has it. The order of the
135 modes goes from most powerful to least powerful. Default: "(ov)@+"
136 - CHANTYPES: Supported channel prefixes. Default: "#".
137 - CHANMODES: List of channel modes for 4 types, separated by comma (","):
138 Mode that adds or removes a nick or address to a list, mode that changes
139 a setting (both have always has a parameter), mode that changes a setting
140 and only has a parameter when set, and mode that changes a setting and
141 never has a parameter. For example "bI,k,l,imnPst".
142 - CHANLIMIT: Maximum number of channels allowed to join by channel prefix,
145 Please see <http://www.irc.org/tech_docs/005.html> for details.
147 The information exchanged using ISUPPORT can be used to detect configuration
148 incompatibilities (different maximum nickname length, for example) and
149 therefore to disconnect the peer prior to registering it in the network.
152 II.3 Exchange channel-modes, topics, and persistent channels
155 Parameters: <channel> +<modes> [[<key> <limit>] <topic>]
156 Used by: servers only
158 CHANINFO is used by servers to inform each other about a channel: its
159 modes, channel key, user limits and its topic. The parameter combination
160 <key> and <limit> is optional, as well as the <topic> parameter, so that
161 there are three possible forms of this command:
163 CHANINFO <channel> +<modes>
164 CHANINFO <channel> +<modes> <topic>
165 CHANINFO <channel> +<modes> <key> <limit> <topic>
167 If the channel already exists on the server receiving the CHANINFO command,
168 it only adopts the <modes> (or the <topic>) if there are no modes (or topic)
169 already set. It there are already values set the server ignores the
170 corresponding parameter.
172 If the channel doesn't exists at all it will be created.
174 The parameter <key> must be ignored if a channel has no key (the parameter
175 <modes> doesn't list the "k" channel mode). In this case <key> should
176 contain "*" because the parameter <key> is required by the CHANINFO syntax
177 and therefore can't be omitted. The parameter <limit> must be ignored when
178 a channel has no user limit (the parameter <modes> doesn't list the "l"
179 channel mode). In this case <limit> should be "0".
182 II.4 Update webchat/proxy client information
185 Parameters: <password> <username> <hostname> <ip-address> [<ignored>]
186 Used by: unregistered clients only
188 The WEBIRC command is used by some Web-to-IRC gateways to set the correct
189 user name and host name of users instead of their own. It must be the very
190 first command sent to the server, even before USER and NICK commands!
192 The <password> must be set in the server configuration file to prevent
193 unauthorized clients to fake their identity; it is an arbitrary string.
195 Optionally, a 5th parameter is accepted to comply with an IRCv3 extension,
196 see <https://github.com/ircv3/ircv3-ideas/issues/12>, but ignored.
199 II.5 Client character encoding conversion
202 Parameters: <client-charset>
203 Used by: registered clients
204 Replies: RPL_IP_CHARCONV, ERR_IP_CHARCONV
206 A client can set its character set encoding using the CHARCONV command:
207 after receiving such a command, the server translates all message data
208 received from the client using the set <client-charset> to the server
209 encoding (UTF-8), and all message data which is to be sent to the client
210 from the server encoding (UTF-8) to <client-charset>.
212 The list of supported client character sets is implementation dependent.
214 If a client sets its <client-charset> to the server encoding (UTF-8),
215 it disables all conversions; the connection behaves as if no CHARCONV
216 command has been sent at all in this session.
219 II.6 Update client "metadata"
222 Parameters: <target> <key> <value>
223 Used by: servers only
225 The METADATA command is used on server-links to update "metadata" information
226 of clients, like the hostname, the info text ("real name"), or the user name.
228 The server updates its client database according to the received <key> and
229 <value> parameters, and passes the METADATA command on to all the other
230 servers in the network that support this command (see section II.1 "Register
231 new server link", <serverflag> "M"), even if it doesn't support the given
232 <key> itself: unknown <key> names are ignored silently!
234 The following <key> names are defined:
236 - "accountname": the account name of a client (can't be empty)
237 - "certfp": the certificate fingerprint of a client (can't be empty)
238 - "cloakhost": the cloaked hostname of a client
239 - "host": the hostname of a client (can't be empty)
240 - "info": info text ("real name") of a client
241 - "user": the user name of a client (can't be empty)
244 III. Numerics used by IRC+ Protocol
245 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
247 The IRC+ protocol uses numerics in the range 800-899 which aren't used by
248 RFC 2812 and hopefully don't clash with other implementations ...
250 Numerics 800-849 are used for status and success messages, and numerics
251 850-899 are failure and error messages.
254 III.1 IRC+ status and success numerics
256 801 - RPL_IP_CHARCONV
257 %1 :Client encoding set"
259 %1 client character set
262 III.2 IRC+ failure and error numerics
264 851 - ERR_IP_CHARCONV
265 :Can't initialize client encoding