This document is "work in progress" and being continually updated :)
2. General concepts and background
2.2 Token Table.
2. General concepts and background
The undernet P10 protocol uses a scheme of "Numerics" to uniquenly identify a client or server within the network. Each server has its own unique numeric (0 -> 4095) and each client has its own numeric within that server (0->262,143).
The numerics are encoded into a Base64 stream to maintain human readable data flow and reduce the size of the messages. The Base64 character set used in ircu is included below, this defines all valid characters allowed in a Base64 numeric with "A" representing 0 and "]" representing 63.
Server numerics consist of 2 characters, with the minimum, 0, being represented by "AA", and the maximum, 4095, being represented by "]]". Client numerics are 3 characters long, with the minimum, 0, being represented by "AAA", and the maximum, 262,143, being represented by "]]]". The unique identifier of a client on the network consists of a combination of both the server and client numeric in the format SSCCC.ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
As an example, consider a server "irc.undernet.org" which has a numeric of 2, translating to "AC" in Base64. On this server exists a client, whom has been allocated the numeric 63 (which translates to "AA]" in Base64). Therefore, the unique identifier of this client on the network is "ACAA]". From this, we can determine which server the message came from, aswell as the client who sent it.
These numerics are used to prefix every message issued on the stream except for the initial "PASS" or "SERVER" message, which are not prefixed. Therefore, every message that can be recieved from a server will consist of the format:
For Example:[NUMERIC PREFIX] [TOKEN] [DATA]
2.2 Token TableA[A5j P ABAAA :Foo.
The following table lists all the acceptable messages, along with their
relevant "Token", which is used in the server<>server protocol. The
aim of tokenisation is to reduce the bandwidth used during network communication
by reducing the length of common message identifiers.
3. Registration and syncronisation
3.1 Server registration and authentication
After a TCP connection has been established, the server initally introduces itself via a "PASS" message as follows:
"PASSWORD" is simply compared with the password present in the destination servers config file, and is used to confirm credentials after the "SERVER" message has been recieved, as follows:PASS :[PASSWORD]
For Example:SERVER [SERVERNAME] [HOPCOUNT] [START TIME] [LINK TIME] [PROTOCOL] [NUMERIC/MAXCONN] :[DESCRIPTION]
Notes:1 2 3 4 5 6 7 8 SERVER irc.undernet.org 1 933022556 947908144 J10 AA]]] :[127.0.0.1] A Undernet Server.
After the connection has been established and verified, the next step is to syncronise the database of client/server/channel information between the two servers.
3.2.1 - SERVER Messages
Server details are transmitted via "SERVER" messages similar to the initial introduction message, with the following format:
[OWNING SERVER PREFIX] S [SERVERNAME] [HOPCOUNT] [START TIME] [LINK TIME] [PROTOCOL] [NUMERIC/MAXCONN] 0 :[DESCRIPTION]The syntax of this message is almost identical to the originally recieved server message, with the only exception being that the message is numeric prefixed, to indicate which server sent this message (and also therefore, which hub this new server is linked too). There is also a fixed "0" present before the Description field, this is a placeholder for future use and currently unused. [Isomer: Question, what IS this reserved for?]
3.2.2 - NICK Messages
Client information is transmitted via "NICK" messages, of the following format:
For Example:[NUMERIC PREFIX] N [NICK] [HOPCOUNT] [TIMESTAMP] [USERNAME] [HOST] <+modes> [BASE64 IP] [NUMERIC] :[USERINFO]1 2 3 4 5 6 7 8 9 10 11Notes:
AF N Client1 1 947957573 User userhost.net +oiwg DAqAoB AFAAA :Generic Client.
- The numeric of the server sending this message. (And hence, owning this client).
- The "NICK" token.
- The nickname of this client, currently max 9 chars.
- The "Hopcount" of this client, Ie: how many servers away it is on.
- The epoch timestamp indicating when the user was created.
- The "User" part of the user@host mask.
- the "Host" part of the user@host mask.
- [Optional]: User modes. If present, this is always +<user modes for this client>. Note that the special +r usermode is followed by the client's account name; see the documentation for ACCOUNT.
- The real IP address of this client, a Base64 encoded 32bit int.
- This client's numeric, in SSCCC format.
- Free format user info line.
3.2.3 - BURST Messages
Channel details and membership information is synchronised in one (or more) BURST messages for each channel that exists, formatted as follows:
[NUMERIC PREFIX] B [CHANNEL] [CREATION TIMESTAMP] <+MODES> <ARG1> <ARG2> [MEMBER LIST] <:%BANS>
1 2 3 4 5 6 7 8 9 AZ B #coder-com 949217470 +tinkl key 56 AAAAA,AAAAB,AAAAC,ABAAA,ABAAB,ABAAC,ACAAA :%*!*@*.net
If the length of a BURST message exceeds the maximum lenght of a line (512 characters) then the remaining channel members/bans are sent in subsequent BURST lines. The subsequent burst lines are only used to add additional members to the channel, and if neccessary, channel bans. There will be no "Mode" parameters present. A sample additional burst line would be:
AZ BURST #coder-com 949217470 ACAAB:o,ACAAD :%*!*another@*.ban.com
Which adds two more opped members and a ban to the channel.
3.2.4 - JUPE Messages
Any currently unexpired JUPEs are transmitted via "JUPE" messages with the following format:
[NUMERIC PREFIX] JU * (+|-)[SERVER NAME] [LIFETIME] [LAST MOD] :[REASON]For example:
1 2 3 4 5 6 7Notes:
AZ JU * +juped.undernet.org 000003593 955419707 :Juped Server
The following table summarises the sequence of events that occur when a server connects to another server. S1 is our server, and S2 is a HUB on the target network.
S1: Sends Password.
S1: Sends initial SERVER message.
S2 Confirms S1 has the correct credentials, and if so, proceeds. If not, S1 is squit with a relevant reason.
S2: Sends Password.
S2: Sends initial SERVER message.
S1 Confirms S2 has the correct credentials, and if so, proceeds. If not, S2 is squit with a relevant reason.
The follow occur asynchronously, however they have been shown seperately below for simplicity.
S1: Sends all the servers it is aware of as a stream of SERVER messages.
S1: Sends all the clients it is aware of as a stream of NICK messages.
S1: Sends the database of channel states on the network, as a stream of BURST messages.
S1: Sends all the jupes it is aware of as a stream of JUPE messages.
S1: Sends a END_OF_BURST token (EB) to indicate it has finished sending.
S2: Sends all the servers it is aware of as a stream of SERVER messages.
S2: Sends all the clients it is aware of as a stream of NICK messages.
S2: Sends the database of channel states on the network, as a stream of BURST messages.
S2: Sends all the jupes it is aware of as a stream of JUPE messages.
S2: Sends a END_OF_BURST token (EB) to indicate it has finished sending.
S2: Sends an EOB_ACK token (EA) to indicate it has succesfully recieved
the END_OF_BURST from S1
S1: Sends an EOB_ACK token (EA) to indicate it has succesfully recieved the END_OF_BURST from S2
[WRITE]: PASS :54321 [WRITE]: SERVER irc.undernet.org 1 947957852 947957852 J10 AB]]] :Undernet Client Server. [WRITE]: AB N MrFoo 1 947957852 ~me myhost.foobar.net +diksw DAqAoB ABAAA :Mr Foo (email@example.com). [WRITE]: AB B #mychannel 946101324 ABAAA:o [WRITE]: AB EB [ READ]: PASS :54321 [ READ]: SERVER server1.undernet.org 1 947901540 947958150 J10 AFAD] :A Generic Server. [ READ]: AF S server2.undernet.org 2 0 947957585 P10 AZAD] 0 :[192.168.10.3] A Generic Server. [ READ]: AZ S server3.undernet.org 3 0 947957607 P10 AIAD] 0 :[192.168.10.5] A Generic Server. [ READ]: AF N Client1 1 947957573 Ident userhost.net +oiwg DAqAoB AFAAA :Generic Client. [ READ]: AZ N Client2 2 947957719 Ident userhost.net +iwg DAqAoB AZAAA :Generic Client. [ READ]: AI N Client3 3 947957742 Ident userhost.net +iwg DAqAoB AIAAA :Generic Client. [ READ]: AI N Client4 3 947958121 Ident userhost.net +iwg DAqAoB AIAAB :Generic Client. [ READ]: AF B #foobar 947957734 +tink akey AIAAB,AIAAA:v,AZAAA:o :%*!*another@*.ban.com *!*firstname.lastname@example.org [ READ]: AF B #coder-com 947957727 AIAAB,AZAAA:o [ READ]: AF B #another 946101321 AFAAA [ READ]: AF JU * +juped.undernet.org 3600 947958100 :Broken, please fix [ READ]: AF EB [WRITE]: AB EA [ READ]: AF EA[Back]
This chapter provides details of the messages that can be sent after successfully linking to a network, and synchronising the channel/user database.
4.1 Channel state operations
There are a number of messages that can modify the state of a channel, these are:
The MODE message can modify channel modes and bans, and also give or take operator/voice status from channel members.
|p||Sets/Unsets 'Private' Flag.||None.|
|s||Sets/Unsets 'Secret' Flag.||None.|
|m||Sets/Unsets 'Moderated' Flag.||None.|
|n||Sets/Unsets 'External Messages' Flag.||None.|
|t||Sets/Unsets 'Topic Limit' Flag.||None.|
|i||Sets/Unsets 'Invite only' Flag.||None.|
|l||Sets/Unsets 'Channel Limit' Flag.||The channel limit.|
|k||Sets/Unsets 'Channel Key' Flag.||The channel keyword (Password).|
|o||Ops and Deops users.||Numeric of user to be opped.|
|v||Voice||Numeric of user to be voiced.|
N.B: The "MODE" message is also used to modify a client's user modes, not just channel modes. See section 4.2 for details.
The OPMODE message is identical in syntax to the MODE message, however it will only ever have an operator as the source. It is likely that the source of this mode will not have ops in the target channel, but it should succeed never the less.
4.1.3 - JOIN
4.1.4 - PART
4.1.5 - KICK
4.1.6 - TOPIC
4.1.7 - CLEARMODE
4.2.1 - NICK4.3 Channel/Client Messaging.AZAAA N Nick2 9554232304.2.2 - MODEAZAAA M Nick2 :+odi4.2.3 - ACCOUNTAX AC AZAAA oper
The ACCOUNT message provides a way for servers, such as the channel service server, to set the account name information that is associated with a client. Once set, it cannot be unset or changed, and will be propagated in NICK during net bursts using the special user mode +r followed by the account name.
4.3.1 - PRIVMSG[Back]
4.3.2 - NOTICE
4.3.3 - CNOTICE
4.3.4 - CPRIVMSG
5. Programmers reference: Client/Server Structures
This section provides information on the standard Client/Server structures, for easy reference during development.
[..Link to autogenerated struct.html..]
Frequently asked questions.
8. Update History
[2000-01-20]: Initial draft, structure, background info.
[2000-02-13]: Added initial BURST documentation.
[2000-02-14]: Continued BURST documentation / Begin NICK and SERVER documentation.
[2000-02-26]: Continued chapter 5, few example fixes, added token table from msg.h. -Gte.
[2000-03-02]: Added NICK spec. -Gte.
[2000-03-18]: Added JUPE spec. -Kev
[2000-04-10]: Added information about OPMODE and CLEARMODE tokens. -Kev
[2000-04-11]: Started work on chapter 4. -Gte
[2000-06-01]: Changed some info about the max number of clients -Isomer
[2002-01-11]: Wrote a specification for ACCOUNT and noted that a usermode in a NICK message may have an argument. -Kev