[ircu2.10.12-pk.git] / doc / readme.features

Many of the old compile-time options are now configured through the
server configuration file, ircd.conf.  This file is intended to
document each of these features.  Logging, although also configured
through the use of F-lines, is documented in doc/readme.log.

DOMAINNAME
 * Type: string
 * Default: picked by ./configure from /etc/resolv.conf

This option allows you to specify what you consider to be "local."  It
is only used for statistics.  When you issue the IRC command /STATS w,
the server will respond with statistics of how many clients have been
connecting to your server in the last minute, hour and day.  It will
give these statistics for all connections (including the servers), all
clients (from anywhere) and also for clients whose hostname ends on
the domain you specify here.  So if you are an ISP and you want to
know what the client load from your own domain is, specify that domain
here.  If you are unsure what to do, then it isn't really important
what you give here, just don't give an empty string.  A good guess is
the last two parts of your own hostname (i.e., if your hostname is
foo.bar.nowhere.org, specify "nowhere.org").  Note that the string you
give should NOT start with a "." and you should not use quotes.

RELIABLE_CLOCK
 * Type: boolean
 * Default: FALSE

You should really ONLY specify "TRUE" here when your system clock is
stable and accurate at all times (within a few seconds).  If you are
running ntpdate on a regular basis, or an equivalent like xntpd, to
keep your system clock synchronized over the network, then you might
have an accurate clock.  However, this is not guaranteed; for example,
it is known that xntpd gives unstable results on Linux in some cases.
Note that an unstable clock is worse then an clock that has a constant
offset, because the servers attempt to correct for a constant offset,
but do not correct jumps of your system clock!  In general you SHOULD
be running ntpdate or equivalent AND make sure it works when you run a
production server on Undernet.  Otherwise leave your clock alone and
specify "FALSE" here.  If unsure specify "FALSE"!

BUFFERPOOL
 * Type: integer
 * Default: 27000000

This specifies the maximum amount of RAM that your server will
allocate for buffering sendQs.  Small leafs can use a value as little
as 1000000, while large HUBs need to specify a value as high as
20000000.  If you run out of memory, clients and/or servers are
dropped with the error "Buffer allocation error"; then you will have
to increase this number (and install more RAM if appropriate).  If you
want a more educated guess for this value then realize that any value
is good if you _really_ would rather drop servers and clients than
allocate more memory; this will be the case when there is the danger
you may run out of memory for other allocations.  Even if you run the
daemon on a dedicated machine, specifying all of the RAM you have is a
bad thing, because running out of memory is a lot worse than dropping
clients in a controlled way; if possible you should have memory left
for all the internal structures (channels, clients, ban lists, receive
buffers) at all times.  On average, clients seem to use 150 bytes of
sendQ, but at peak moments this can easily increase to 2032 bytes per
client (sendQs are allocated in chunks of 2032 bytes).  The maximum
possible amount that can be allocated for sendQs is the number of
connected clients times whatever you specified as the maximum sendQ in
your Y: lines in the ircd.conf file.  That value will likely be larger
then the amount of RAM you have.  The educated guess I talked about
earlier would be "number of clients" times * 2048 bytes + "size of
net.burst" * n, where "n" is 1 for leafs and up to 5 for HUBs.  The
"size of net.burst" is about 125 bytes per online client (on the whole
network).  For large HUBs with 4000 clients on a network with 30,000
users, this results in 27 Mb.  Leafs could use 12 Mb.  Of course you
can use less when you have less than 4000 local clients.  This value
is in bytes.

HAS_FERGUSON_FLUSHER
 * Type: boolean
 * Default: FALSE

If you have a server with a lot of resources available, this option
will cause the server to attempt to flush its internal buffers before
dropping clients during a net break.  Don't define this if you don't
know for certain; if you're not careful this can end up rebooting
FreeBSD boxes.  For more information, refer to freebsd.txt, also in
this directory.

CLIENT_FLOOD
 * Type: integer
 * Default: 1024

Currently, everything that a client sends to a server is read by the
server and stored in a buffer (the clients receive queue).  The server
will process messages from this queue one by one (running over all
clients each time).  When a client sends new messages faster they get
processed, and the size of its receive buffer reaches this value, the
client is dropped with the error "Excess flood."  A reasonable value
is 1024 bytes.  The maximum size is 8000 bytes.

SERVER_PORT
 * Type: integer
 * Default: 4400

When an IRC operator attempts a connect to another server, he or she
may not know which port the connect should go to.  In this server
version, that operator may use the special port 0, in which case the
server will take the port from the C-line.  If no port is specified in
the C-line, however, the port specified by this option will be used
instead.

NODEFAULTMOTD
 * Type: boolean
 * Default: TRUE

Every time a client connects to your server, the full Message of the
Day (as specified by the T-lines or by the file specified by the MPATH
option) is sent to the client.  The server sends the Message of the
Day even though many clients permit the user to ignore it.  Many users
never read the message of the day anyway, making it a huge waste of
bandwidth.  If you specify "TRUE" here, then the server won't send the
MOTD to the client by default; instead, it will only tell the client
when the MOTD was last changed, and give instructions on how to obtain
it by typing /MOTD.

MOTD_BANNER
 * Type: string
 * Default: NULL

If you enable NODEFAULTMOTD, this specifies a one-line banner to be sent
to the client in addition to the instructions mentioned above.

KILL_IPMISMATCH
 * Type: boolean
 * Default: FALSE

When a client connects to your server, the IP address of the client is
reverse-resolved to obtain a hostname.  Then that hostname is resolved
to an IP address and compared with the IP address of the client.  If
they don't match, the client will appear with the IP address instead
of the hostname, unless KILL_IPMISMATCH is "TRUE," in which case the
client is simply disconnected.

IDLE_FROM_MSG
 * Type: boolean
 * Default: TRUE

The IRC command WHOIS gives an idle time for clients.  If you want
this idle time to be set to zero only when the client sends a PRIVMSG,
then you should specify "TRUE" here.  If you specify "FALSE," then the
idle time will be nullified on all messages except the server
PING/PONG.

HUB
 * Type: boolean
 * Default: FALSE

All servers of an IRC "network" are connected in a "tree" (no loops).
Servers that are only connected to one other server (called the
"uplink") are called "leafs"; servers that are connected to more than
one other server are called HUBs.  If you specify "FALSE" here then
your server will prevent itself from accidentally connecting to two
servers at once, thus keeping servers in poor network locations from
routing traffic.  Note that on Undernet, all newly linked servers are
linked as leafs during their test phase, and should specify "FALSE"
here.

WALLOPS_OPER_ONLY
 * Type: boolean
 * Default: FALSE

Setting this option removes the ability for clients that are not IRC
operators to see wallops messages.

NODNS
 * Type: boolean
 * Default: FALSE

If you are playing with the server off-line, and no DNS is available,
then long delays occur before the server starts up because it tries to
resolve the name given on the M-line (which usually isn't given in
/etc/hosts) and for each connecting client.  If you specify "TRUE"
here, then a call to gethostbyname() will be done only for the real
hostname, and the server will not try to resolve clients that connect
to "localhost."  Note that other calls to gethostbyname() are still
done if you use VIRTUAL_HOST; also note that the server still tries to
resolve clients that connect to the real IP address of the server.

RANDOM_SEED
 * Type: string
 * Default: none

When a client connects, the server sends the client a "cookie,"
consisting of a random number.  The client must return the cookie to
the server verbatim.  This is done to prevent IP spoofing.  The cookie
is generated by a pseudorandom number generator included in ircd.
This generator must be seeded with a phrase that is kept secret, to
ensure that the numbers it generates are not easily guessed.  The
value given to RANDOM_SEED may be a string of any length.  It should
not contain any characters that are considered special by the
configuration file system, such as ":" or "#"; the string should be at
least 8 characters long, but longer strings are better.  The
RANDOM_SEED may not be retrieved online.

DEFAULT_LIST_PARAM
 * Type: string
 * Default: none

The LIST command takes a single optional argument.  If given, that
argument is either a channel or a filter.  If that argument is not
given, then by default, /LIST will list all channels on the network.
Needless to say, this can generate a large amount of data on large
networks with many channels, as well as chewing up a lot of CPU time.
Server administrators can therefore set a default filter to be applied
to the channel list if the optional argument to LIST is omitted.

NICKNAMEHISTORYLENGTH
 * Type: integer
 * Default: 800

This value specifies the length of the nick name history list, which
is used for /WHOWAS and some nickname chasing in /KILL and /KICK.  It
uses about 300 to 400 bytes per entry.  Note that at a net break, so
many client disappear that the whole "whowas" list is refreshed a few
times (unless you make it rather large).  A reasonable value is "total
number of clients" / 25.

HOST_HIDING
 * Type: boolean
 * Default: FALSE

This selects whether local users can set umode +x, thus allowing them
to hide their hostname if they have also registered with a channel
service (i.e. they have the ACCOUNT flag set).

HIDDEN_HOST
 * Type: string
 * Default: users.undernet.org

This selects the suffix for the hidden hostmask (see HOST_HIDING).

HIDDEN_IP
 * Type: string
 * Default: 127.0.0.1

This selects a fake IP to be shown on /USERIP and /WHO %i when the
target has a hidden host (see HOST_HIDING).

KILLCHASETIMELIMIT
 * Type: integer
 * Default: 30

If a user changes his or her nickname just before an operator issues a
/KILL, the /KILL will be changed to follow the user the operator
intended to get.  This option specifies the time limit, in seconds,
for this nickname change; if the user changed his or her nickname more
than this many seconds ago, the /KILL will not be changed.  Don't
change this unless you really need to.

MAXCHANNELSPERUSER
 * Type: integer
 * Default: 10

This is the maximum number of channels a user can be in at a time.
The "mandatory" value on Undernet is currently 10.  Since it only
influences the local server when you decrease it, its up to you to
decide if you want to use a smaller value.  Do not use a larger value
however, because it DOES cost more memory and bandwidth on all other
servers when you allow users to join more channels simultaneously.
One of the most important reasons to choose a smaller value is the
fact that the "GUI" clients tend to stay on every channel they join
(they aren't bothered by flooding in other channels).  It DOES take
your bandwidth however to send all those messages for 10 different
channels to all your users.

AVBANLEN
 * Type: integer
 * Default: 40

This is the expected average ban mask length.  Leave it at 40.

MAXBANS
 * Type: integer
 * Default: 30

This is the maximum number of bans a user may set on a given channel.

MAXSILES
 * Type: integer
 * Default: 15

This is the maximum number of masks a user can silence at a time.  The
silence command allows users to filter messages directed at them from
certain users or domains, at the source server.  Increasing this
number allows users to use up more memory with inefficient use of the
command.  If you're not sure, don't change this.

HANGONGOODLINK
 * Type: integer
 * Default: 300

Often the net breaks for a short time and it is useful to try to
reestablish the same connection faster than CONNECTFREQUENCY would
allow, but to keep from trying again on a bad connection, we require
that the connection be open for a certain minimum time. The
recommended value is 300 seconds.

HANGONRETRYDELAY
 * Type: integer
 * Default: 10

When attempting to quickly reestablish a connection to a good link, we
give the net a few seconds to calm down. This time must be long enough
for the other end to also notice that the connection is broken. The
recommended value is 10 seconds.

CONNECTTIMEOUT
 * Type: integer
 * Default: 90

Number of seconds to wait for a connect(2) call to complete.  NOTE:
this must be at *LEAST* 10.  When a client connects, it has
CONNECTTIMEOUT - 10 seconds for its host to respond to an ident lookup
query and for a DNS lookup to complete. It is recommended that you not
change this value, but if you do, consider the fact that users whose
clients do not support NOSPOOF will have to type /QUOTE PING <big
number> before registration.

TIMESEC
 * Type: integer
 * Default: 60

This is the maximum idle time for the server. If no messages are
received in TIMESEC seconds, PINGFREQUENCY and CONNECTFREQUENCY are
checked.  Recommended value is 60 seconds.

MAXIMUM_LINKS
 * Type: integer
 * Default: 1

This is the maximum number of links for the built-in client class 0.
Leave this value at 1.

PINGFREQUENCY
 * Type: integer
 * Default: 120

If the daemon doesn't receive anything from any of its links within
PINGFREQUENCY seconds, then the it will attempt to check for an active
link with a PING message.  If no reply is received within
(PINGFREQUENCY * 2) seconds, then the connection will be closed.  This
value may be overridden by a Y-line in "ircd.conf" if the connection's
I- or C-line in "ircd.conf" assigns a specific class to the connection
(recommended).

CONNECTFREQUENCY
 * Type: integer
 * Default: 600

This is the default frequency that the server attempts to reconnect
with its uplink server if it is set to auto connect to it. Note that
this value is overridden by a Y-line in ircd.conf if the C-lines in
ircd.conf assign a specific class to the connection (recommended).

DEFAULTMAXSENDQLENGTH
 * Type: integer
 * Default: 40000

This is the default value of the maximum sendQ length of Y-line
classes (see doc/example.conf for details on Y-lines).  You will
probably always override this value in your "ircd.conf" with the
Y-lines.  The given value used to be an often used value for client
sendQs.

GLINEMAXUSERCOUNT
 * Type: integer
 * Default: 20

G-lines that affect too many users have to be set with a special
command, to prevent accidental G-lines of large blocks of users.  This
feature sets that particular threshold.

MPATH
 * Type: string
 * Default: "ircd.motd"

MPATH is the filename (relative to DPATH) or the full path of the
"Message of the Day" file.  The contents of this file will be sent to
every client that connects to the server, after registration.

RPATH
 * Type: string
 * Default: "remote.motd"

RPATH is the filename (relative to DPATH) or the full path of the
"Remote Message of the Day" file.  The contents of this file will be
sent to every remote client that issues a /MOTD <your server name>.
Only the first three lines are sent, so you might want to keep that in
mind while writing the file.

PPATH
 * Type: string
 * Default: "ircd.pid"

PPATH is the filename (relative to DPATH) or the full path of the
"PID" file.  It is used for storing the server's process ID so that a
ps(1) isn't necessary.

VIRTUAL_HOST
 * Type: boolean
 * Default: FALSE

This option is only needed when you wish to run multiple IRC servers
on the same machine, and they must share at least one port.  This will
require having multiple IP addresses for the machine that will be
hosting the servers.  If you specify "TRUE" here, you can cause the
server to bind to one of these IP addresses.  Use the second field of
the M-line (the "password" field) to specify the IP address.  If you
are unsure, stick with "FALSE."

TOS_SERVER
 * Type: integer
 * Default: 0x08

This option is used to specify the type of service that will be
requested for connections to other servers.  The value may be given as
a hexadecimal integer.

TOS_CLIENT
 * Type: integer
 * Default: 0x08

This option is used to specify the type of service that will be
requested for connections to users.  The value may be given as a
hexadecimal integer.

POLLS_PER_LOOP
 * Type: integer
 * Default: 200

Some of the engines used by the event interface get a number of events
from the kernel at once.  Since the number retrieved can impact
performance, it can be tuned by modifying this value.  The engines
enforce a lower limit of 20.

CRYPT_OPER_PASSWORD
 * Type: boolean
 * Default: TRUE

In order to allow certain users to become IRC operators, they must
authenticate themselves with a password.  This password is matched
against an O-line in the "ircd.conf" configuration file; see
doc/example.conf for more details.  If you specify "TRUE" here, you
must use the crypted form of these passwords in your "ircd.conf" file.
Since compromises of the "ircd.conf" file have happened in the past,
you are highly encouraged to use this option.  You can find a program
called "mkpasswd" in the tools directory that will allow you to
generate crypted passwords.

OPER_NO_CHAN_LIMIT
 * Type: boolean
 * Default: TRUE

If this option is set to "TRUE," IRC operators may join as many
channels as they need to.  This is primarily intended to permit
administrators to run a channel service for local ("&") channels.

OPER_MODE_LCHAN
 * Type: boolean
 * Default: TRUE

If this option is set to "TRUE," IRC operators may change the channel
modes on local ("&") channels.  This is primarily intended to permit
administrators to run a channel service for local channels.

OPER_WALK_THROUGH_LMODES
 * Type: boolean
 * Default: FALSE

If this option is set to "TRUE," IRC operators may join local ("&")
channels regardless of any restrictive modes, including bans.  This
requires giving the special password "OVERRIDE."  This is primarily
intended to permit administrators to run a channel service for local
channels.

NO_OPER_DEOP_LCHAN
 * Type: boolean
 * Default: FALSE

If this option is set to "TRUE," IRC operators may not be deopped on
local ("&") channels.  This is primarily intended to permit
administrators to run a channel service for local channels.

SHOW_INVISIBLE_USERS
 * Type: boolean
 * Default: TRUE

If you specify "TRUE" here, then your (local) IRC Operators will be
able to see all local invisible users (clients connected to your own
server).  This should be used only for investigating instances of
abuse; make sure your operators do not use this for spying on
individuals.

SHOW_ALL_INVISIBLE_USERS
 * Type: boolean
 * Default: TRUE

If you specify "TRUE" here, then your global IRC Operators will be
able to see ALL invisible users.  This should be used only for
investigating instances of abuse; make sure your operators do not use
this for spying on individuals.

UNLIMIT_OPER_QUERY
 * Type: boolean
 * Default: FALSE

A /WHO command can sometimes return several hundred lines of
information.  To reduce the flood potential, the output is truncated.
By setting this option to "TRUE," when an IRC Operator uses /WHO, the
output will not be truncated, no matter how much data is returned.

LOCAL_KILL_ONLY
 * Type: boolean
 * Default: FALSE

If this option is set to "TRUE," operators of this server may only
KILL clients directly connected to this server.  Operators will not be
able to issue KILLs for clients on other servers.  Some networks may
require that this be turned on for newly linking servers.

CONFIG_OPERCMDS
 * Type: boolean
 * Default: FALSE

For u2.10.11, several new oper-only features have been added that
involve changes to the server<->server protocol.  Until the entire
network is running the new version, these features cannot be enabled.
This configuration option provides a single switch to prevent the use
of these features until the entire network has been upgraded.  It is
not required that all servers set this to "TRUE" in order for the
features to be used.

OPER_KILL
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue the /KILL command.

OPER_REHASH
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue the /REHASH command.

OPER_RESTART
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue the /RESTART command.

OPER_DIE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue the /DIE command.

OPER_GLINE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue global G-lines.

OPER_LGLINE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue local G-lines.

OPER_JUPE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue global jupes.

OPER_LJUPE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to issue local jupes.

OPER_OPMODE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to use /OPMODE and /CLEARMODE on ordinary ("#") channels.

OPER_LOPMODE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to use /OPMODE and /CLEARMODE on local ("&") channels.

OPER_BADCHAN
 * Type: boolean
 * Default: FALSE

This selects whether global IRC operators on this server are permitted
to issue global BADCHANs.  USE OF THIS ON THE UNDERNET IS STRICTLY
REGULATED BY THE UNDERNET ADMINISTRATION.

OPER_LBADCHAN
 * Type: boolean
 * Default: FALSE

This selects whether global IRC operators on this server are permitted
to issue local BADCHANs.  USE OF THIS ON THE UNDERNET IS STRICTLY
REGULATED BY THE UNDERNET ADMINISTRATION.

OPER_SET
 * Type: boolean
 * Default: FALSE

This selects whether global IRC operators on this server are permitted
to use the /SET command to set various feature values.

OPERS_SEE_IN_SECRET_CHANNELS
 * Type: boolean
 * Default: TRUE

If you specify "TRUE" here, then your global IRC Operators will be
able to see who is on a specified secret channel, without joining
themselves.  This can be used to make a reasonable judgment in the
case of a "channel takeover" being reported, while the channel is set
invite-only.  See doc/readme.who for more details.

OPER_WIDE_GLINE
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators on this server are permitted
to use the /GLINE command with the ! flag to force slightly wide
G-lines to be set.

OPER_LIST_CHAN 
 * Type: boolean
 * Default: TRUE

This selects whether global IRC operators are permitted to list secret 
(+s) channels.

LOCOP_KILL
 * Type: boolean
 * Default: TRUE

This selects whether local IRC operators are permitted to use the
/KILL command on local clients.

LOCOP_REHASH
 * Type: boolean
 * Default: TRUE

This selects whether local IRC operators are permitted to use the
/REHASH command.

LOCOP_RESTART
 * Type: boolean
 * Default: FALSE

This selects whether local IRC operators are permitted to use the
/RESTART command.

LOCOP_DIE
 * Type: boolean
 * Default: FALSE

This selects whether local IRC operators are permitted to use the /DIE
command.

LOCOP_LGLINE
 * Type: boolean
 * Default: TRUE

This selects whether local IRC operators are permitted to issue local
G-lines.

LOCOP_LJUPE
 * Type: boolean
 * Default: TRUE

This selects whether local IRC operators are permitted to issue local
jupes.

LOCOP_LOPMODE
 * Type: boolean
 * Default: TRUE

This selects whether local IRC operators are permitted to use /OPMODE
and /CLEARMODE on local ("&") channels.

LOCOP_LBADCHAN
 * Type: boolean
 * Default: FALSE

This selects whether local IRC operators are permitted to issue local
BADCHANs.  USE OF THIS ON THE UNDERNET IS STRICTLY REGULATED BY THE
UNDERNET ADMINISTRATION.

LOCOP_SET
 * Type: boolean
 * Default: FALSE

This selects whether local IRC operators are permitted to use the /SET
command to set various feature values.

LOCOP_SEE_IN_SECRET_CHANNELS
 * Type: boolean
 * Default: FALSE

If you specify "TRUE" here, then your local IRC Operators will be
able to see who is on a specified secret channel, without joining
themselves.  This can be used to make a reasonable judgment in the
case of a "channel takeover" being reported, while the channel is set
invite-only.  See doc/readme.who for more details.

LOCOP_WIDE_GLINE
 * Type: boolean
 * Default: FALSE

This selects whether local IRC operators are permitted to use the
/GLINE command with the ! flag to force slightly wide G-lines to be
set.

LOCOP_LIST_CHAN
 * Type: boolean
 * Default: FALSE
 
This selects whether local IRC operators are permitted to list secret 
(+s) channels.