The /etc/cups/cupsd.conf file contains
configuration directives that control how the server
functions. Each directive is listed on a line by itself followed
by its value. Comments are introduced using the number sign ("#")
character at the beginning of a line.
Since the server configuration file consists of plain text,
you can use your favorite text editor to make changes to it.
After making any changes, restart the cupsd(8)
process using the startup script for your operating system:
The AccessLog directive sets the name of the
access log file. If the filename is not absolute then it is
assumed to be relative to the ServerRoot directory. The
access log file is stored in "common log format" and can be used
by any web access reporting tool to generate a report on CUPS
server activity.
The server name can be included in the filename by using
%s in the name.
The special name "syslog" can be used to send the access
information to the system log instead of a plain file.
The default access log file is
/var/log/cups/access_log.
<Location /path>
...
Allow from All
Allow from None
Allow from *.domain.com
Allow from .domain.com
Allow from host.domain.com
Allow from nnn.*
Allow from nnn.nnn.*
Allow from nnn.nnn.nnn.*
Allow from nnn.nnn.nnn.nnn
Allow from nnn.nnn.nnn.nnn/mm
Allow from nnn.nnn.nnn.nnn/mmm.mmm.mmm.mmm
Allow from [xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx]
Allow from [xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx]/mmm
Allow from @LOCAL
Allow from @IF(name)
</Location>
Description
The Allow directive specifies a hostname, IP
address, or network that is allowed access to the server.
Allow directives are cummulative, so multiple
Allow directives can be used to allow access for
multiple hosts or networks.
Host and domain name matching require that you enable the HostNameLookups
directive.
The /mm notation specifies a CIDR netmask, as shown in
Table 1.
The @LOCAL name will allow access from all local
interfaces. The @IF(name) name will allow access
from the named interface. In both cases, CUPS only allows access
from the network that the interface(s) are configured for -
requests arriving on the interface from a foreign network will
not be accepted.
The Allow directive must appear inside a Location or Limit section.
The AuthType directive defines the type of
authentication to perform:
None - No authentication should be
performed (default)
Basic - Basic authentication should be
performed using the UNIX password and group files
Digest - Digest authentication should be
performed using the /etc/cups/passwd.md5
file
BasicDigest - Basic authentication
should be performed using the
/etc/cups/passwd.md5 file
Negotiate - Kerberos authentication
should be performed
When using Basic, Digest,
BasicDigest, or Negotiate authentication,
clients connecting through the localhost interface can
also authenticate using certificates.
The AuthType directive must appear inside a Location or Limit section.
The AutoPurgeJobs directive specifies whether or
not to purge completed jobs once they are no longer required for
quotas. This option has no effect if quotas are not enabled. The
default setting is No.
The BrowseAddress directive specifies an address
to send browsing information to. Multiple
BrowseAddress directives can be specified to send
browsing information to different networks or systems.
The @LOCAL name will broadcast printer
information to all local interfaces. The @IF(name)
name will broadcast to the named interface.
There is no default browse address.
Note:
If you are using HP-UX 10.20 and a subnet that is not 24,
16, or 8 bits, printer browsing (and in fact all broadcast
reception) will not work. This problem appears to be fixed in
HP-UX 11.0.
BrowseAllow from all
BrowseAllow from none
BrowseAllow from 192.0.2
BrowseAllow from 192.0.2.0/24
BrowseAllow from 192.0.2.0/255.255.255.0
BrowseAllow from *.domain.com
BrowseAllow from @LOCAL
BrowseAllow from @IF(name)
Description
The BrowseAllow directive specifies a system or
network to accept browse packets from. The default is to accept
browse packets from all hosts.
Host and domain name matching require that you enable the HostNameLookups
directive.
IP address matching supports exact matches, partial addresses that match
networks using netmasks of 255.0.0.0, 255.255.0.0, and 255.255.255.0, or network
addresses using the specified netmask or bit count. The /mm
notation specifies a CIDR netmask, a shown in Table 1.
The @LOCAL name will allow browse data from all
local interfaces. The @IF(name) name will allow
browse data from the named interface. In both cases, CUPS only
allows data from the network that the interface(s) are configured
for - data arriving on the interface from a foreign network will
not be allowed.
BrowseDeny from all
BrowseDeny from none
BrowseDeny from 192.0.2
BrowseDeny from 192.0.2.0/24
BrowseDeny from 192.0.2.0/255.255.255.0
BrowseDeny from *.domain.com
BrowseDeny from @LOCAL
BrowseDeny from @IF(name)
Description
The BrowseDeny directive specifies a system or
network to reject browse packets from. The default is to not deny
browse packets from any hosts.
Host and domain name matching require that you enable the HostNameLookups
directive.
IP address matching supports exact matches, partial addresses that match
networks using netmasks of 255.0.0.0, 255.255.0.0, and 255.255.255.0, or network
addresses using the specified netmask or bit count. The /mm
notation specifies a CIDR netmask, a shown in Table 1.
The @LOCAL name will block browse data from all
local interfaces. The @IF(name) name will block
browse data from the named interface. In both cases, CUPS only
blocks data from the network that the interface(s) are configured
for - data arriving on the interface from a foreign network will
not be blocked.
The BrowseInterval directive specifies the
maximum amount of time between browsing updates. Specifying a
value of 0 seconds disables outgoing browse updates but allows a
server to receive printer information from other hosts.
The BrowseInterval value should always be less
than the BrowseTimeout
value. Otherwise printers and classes will disappear from client
systems between updates.
The BrowseLocalOptions directive specifies
additional IPP backend options to advertise with local shared
printers. The default is to not include any options.
The BrowseLocalProtocols directive specifies the
protocols to use when advertising local shared printers on the
network. Multiple protocols can be specified by separating them
with spaces. The default is "CUPS dnssd".
The BrowsePoll directive polls a server for
available printers once every BrowseInterval seconds.
Multiple BrowsePoll directives can be specified to
poll multiple servers.
If BrowseInterval is set to 0 then the server is
polled once every 30 seconds.
The BrowseProtocols directive specifies the
protocols to use when showing and advertising shared printers on
the local network. Multiple protocols can be specified by
separating them with spaces. The default protocol is
"CUPS dnssd" for
BrowseLocalProtocols and
"CUPS" for
BrowseRemoteProtocols.
Note:
When using the SLP protocol, you must have at least
one Directory Agent (DA) server on your network. Otherwise the
CUPS scheduler (cupsd) will not respond to client
requests for several seconds while polling the network.
The BrowseRelay directive specifies source and
destination addresses for relaying browsing information from one
host or network to another. Multiple BrowseRelay
directives can be specified as needed.
BrowseRelay is typically used on systems that
bridge multiple subnets using one or more network interfaces. It
can also be used to relay printer information from polled servers
with the line:
BrowseRelay 127.0.0.1 @LOCAL
This effectively provides access to printers on a WAN for all
clients on the LAN(s).
The BrowseRemoteOptions directive specifies
additional IPP backend options to include with remote shared
printers. If the options string begins with a question mark (?),
the options replace any options specified by the remote server.
The default is to not include any options.
BrowseRemoteProtocols all
BrowseRemoteProtocols none
BrowseRemoteProtocols cups
BrowseRemoteProtocols ldap
BrowseRemoteProtocols slp
Description
The BrowseRemoteProtocols directive specifies the
protocols to use when finding remote shared printers on the
network. Multiple protocols can be specified by separating them
with spaces. The default is "CUPS".
The BrowseShortNames directive specifies whether
or not short names are used for remote printers when possible.
Short names are just the remote printer name, without the server
("printer"). If more than one remote printer is detected with the
same name, the printers will have long names ("printer@server1",
"printer@server2".)
The BrowseTimeout directive sets the timeout for
printer or class information that is received in browse packets.
Once a printer or class times out it is removed from the list of
available destinations.
The BrowseTimeout value should always be greater
than the BrowseInterval value.
Otherwise printers and classes will disappear from client systems
between updates.
The Browsing directive controls whether or not
network printer browsing is enabled. The default setting is
Yes.
This directive does not enable sharing of local printers by
itself; you must also use the BrowseAddress or BrowseProtocols
directives to advertise local printers to other systems.
Note:
If you are using HP-UX 10.20 and a subnet that is not 24,
16, or 8 bits, printer browsing (and in fact all broadcast
reception) will not work. This problem appears to be fixed in
HP-UX 11.0.
The Classification directive sets the
classification level on the server. When this option is set, at
least one of the banner pages is forced to the classification
level, and the classification is placed on each page of output.
The default is no classification level.
The ClassifyOverride directive specifies whether
users can override the default classification level on the
server. When the server classification is set, users can change
the classification using the job-sheets option and
can choose to only print one security banner before or after the
job. If the job-sheets option is set to
none then the server default classification is
used.
The default is to not allow classification overrides.
DefaultLanguage de
DefaultLanguage en
DefaultLanguage es
DefaultLanguage fr
DefaultLanguage it
Description
The DefaultLanguage directive specifies the
default language to use for client connections. Setting the
default language also sets the default character set if a
language localization file exists for it. The default language
is "en" for English.
DefaultPaperSize Letter
DefaultPaperSize A4
DefaultPaperSize Auto
DefaultPaperSize None
Description
The DefaultPaperSize directive specifies the default paper
size to use when creating new printers. The default is Auto
which uses a paper size appropriate for the system default locale. A value
of None tells the scheduler to not set the default paper
size.
<Location /path>
..
Deny from All
Deny from None
Deny from *.domain.com
Deny from .domain.com
Deny from host.domain.com
Deny from nnn.*
Deny from nnn.nnn.*
Deny from nnn.nnn.nnn.*
Deny from nnn.nnn.nnn.nnn
Deny from nnn.nnn.nnn.nnn/mm
Deny from nnn.nnn.nnn.nnn/mmm.mmm.mmm.mmm
Deny from [xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx]
Deny from [xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx]/mmm
Deny from @LOCAL
Deny from @IF(name)
</Location>
Description
The Deny directive specifies a hostname, IP
address, or network that is denied access to the server.
Deny directives are cummulative, so multiple
Deny directives can be used to allow access for
multiple hosts or networks.
Host and domain name matching require that you enable the HostNameLookups
directive.
The /mm notation specifies a CIDR netmask, a shown in
Table 1.
The @LOCAL name will deny access from all local
interfaces. The @IF(name) name will deny access from
the named interface. In both cases, CUPS only denies access from
the network that the interface(s) are configured for - requests
arriving on the interface from a foreign network will
not be denied.
The Deny directive must appear inside a Location or Limit section.
The DirtyCleanInterval directive specifies the number of
seconds to wait before updating configuration and state files for printers,
classes, subscriptions, and jobs. The default is 30 seconds. A value of 0
causes the update to occur as soon as possible, typically within a few
milliseconds.
The DocumentRoot directive specifies the location
of web content for the HTTP server in CUPS. If an absolute path
is not specified then it is assumed to be relative to the ServerRoot directory. The
default directory is /usr/share/cups/doc-root.
Documents are first looked up in a sub-directory for the
primary language requested by the client (e.g.
/usr/share/cups/doc-root/fr/...) and then directly under
the DocumentRoot directory (e.g.
/usr/share/cups/doc-root/...), so it is possible to
localize the web content by providing subdirectories for each
language needed.
<Location /path>
...
Encryption Never
Encryption IfRequested
Encryption Required
</Location>
Description
The Encryption directive must appear instead a Location or Limit section and specifies the
encryption settings for that location. The default setting is
IfRequested for all locations.
The ErrorLog directive sets the name of the error
log file. If the filename is not absolute then it is assumed to
be relative to the ServerRoot directory. The
default error log file is /var/log/cups/error_log.
The server name can be included in the filename by using
%s in the name.
The special name "syslog" can be used to send the error
information to the system log instead of a plain file.
The FileDevice directive determines whether the
scheduler allows new printers to be added using device URIs of
the form file:/filename. File devices are most often
used to test new printer drivers and do not support raw file
printing.
The default setting is No.
Note:
File devices are managed by the scheduler. Since the
scheduler normally runs as the root user, file devices
can be used to overwrite system files and potentially
gain unauthorized access to the system. If you must
create printers using file devices, we recommend that
you set the FileDevice directive to
Yes for only as long as you need to add the
printers to the system, and then reset the directive to
No.
The FilterLimit directive sets the maximum cost
of all running job filters. It can be used to limit the number of
filter programs that are run on a server to minimize disk,
memory, and CPU resource problems. A limit of 0 disables filter
limiting.
An average print to a non-PostScript printer needs a filter
limit of about 200. A PostScript printer needs about half that
(100). Setting the limit below these thresholds will effectively
limit the scheduler to printing a single job at any time.
The FilterNice directive sets the nice(1)
value to assign to filter processes. The nice value ranges from
0, the highest priority, to 19, the lowest priority. The default
is 0.
HostNameLookups On
HostNameLookups Off
HostNameLookups Double
Description
The HostNameLookups directive controls whether or
not CUPS looks up the hostname for connecting clients. The
Double setting causes CUPS to verify that the
hostname resolved from the address matches one of the addresses
returned for that hostname. Double lookups also
prevent clients with unregistered addresses from connecting to
your server.
The default is Off to avoid the potential server
performance problems with hostname lookups. Set this option to
On or Double only if absolutely
required.
The ImplicitAnyClasses directive controls
whether implicit classes for local and remote printers are
created with the name AnyPrinter. The default
setting is Off.
ImplicitClasses
must be enabled for this directive to have any effect.
The ImplicitClasses directive controls whether
implicit classes are created based upon the available network
printers and classes. The default setting is
Yes but is automatically turned
Off if Browsing is turned
Off.
The Include directive includes the named file in
the cupsd.conf file. If no leading path is provided,
the file is assumed to be relative to the ServerRoot directory.
The JobRetryInterval directive specifies the
number of seconds to wait before retrying a job. This is
typically used for fax queues but can also be used with normal
print queues whose error policy is retry-job. The
default is 30 seconds.
The JobKillDelay directive specifies the number of seconds to
wait before killing the filters and backend associated with a canceled or held
job. The default is 30 seconds.
The JobRetryLimit directive specifies the maximum
number of times the scheduler will try to print a job. This is
typically used for fax queues but can also be used with normal
print queues whose error policy is retry-job. The
default is 5 times.
The KeepAlive directive controls whether or not
to support persistent HTTP connections. The default is
On.
HTTP/1.1 clients automatically support persistent connections,
while HTTP/1.0 clients must specifically request them using the
Keep-Alive attribute in the Connection:
field of each request.
The Limit directive groups access control
directives for specific types of HTTP requests and must appear
inside a Location section.
Access can be limited for individual request types
(DELETE, GET, HEAD,
OPTIONS, POST, PUT, and
TRACE) or for all request types (ALL).
The request type names are case-sensitive for compatibility with
Apache.
When included in Policy
sections, the Limit directive groups access control
directives for specific IPP operations. Multiple operations can
be listed, separated by spaces. Table 2 lists the supported
operations.
<Location /path>
<LimitExcept GET POST>
...
</LimitExcept>
</Location>
Description
The LimitExcept directive groups access control
directives for specific types of HTTP requests and must appear
inside a Location section.
Unlike the Limit directive,
LimitExcept restricts access for all requests
except those listed on the LimitExcept
line.
The LimitRequestBody directive controls the
maximum size of print files, IPP requests, and HTML form data in
HTTP POST requests. The default limit is 0 which disables the
limit check.
The Listen directive specifies a network address
and port to listen for connections. Multiple Listen
directives can be provided to listen on multiple addresses.
The Listen directive is similar to the Port directive but allows you to
restrict access to specific interfaces or networks.
The ListenBackLog directive sets the maximum
number of pending connections the scheduler will allow. This
normally only affects very busy servers that have reached the MaxClients limit, but can
also be triggered by large numbers of simultaneous connections.
When the limit is reached, the operating system will refuse
additional connections until the scheduler can accept the pending
ones. The default is the OS-defined default limit, typically
either 5 for older operating systems or 128 for newer operating
systems.
Note that more specific resources override the less specific
ones. So the directives inside the /printers/name
location will override ones from /printers.
Directives inside /printers will override ones from
/. None of the directives are inherited.
When LogLevel is not set to
debug or debug2, the LogDebugHistory
directive specifies the number of debugging messages that are logged when an
error occurs during printing. The default is 200 messages. A value of 0
disables debugging history entirely and is not recommended.
The LogLevel directive specifies the level of
logging for the ErrorLog
file. The following values are recognized (each level logs
everything under the preceding levels):
none - Log nothing
emerg - Log emergency conditions that
prevent the server from running
alert - Log alerts that must be handled
immediately
crit - Log critical errors that don't
prevent the server from running
The LogTimeFormat directive specifies the format used for the
date and time in the log files. Standard uses the standard Apache
Common Log Format date and time while usecs adds microseconds.
The default is standard.
The MaxClients directive controls the maximum
number of simultaneous clients that will be allowed by the
server. The default is 100 clients.
Note:
Since each print job requires a file descriptor for the status
pipe, the scheduler internally limits the MaxClients
value to 1/3 of the available file descriptors to avoid possible
problems when printing large numbers of jobs.
The MaxClientsPerHost directive controls the
maximum number of simultaneous clients that will be allowed from
a single host by the server. The default is the
MaxClients value.
This directive provides a small measure of protection against
Denial of Service attacks from a single host.
The MaxJobs directive controls the maximum number
of jobs that are kept in memory. Once the number of jobs reaches
the limit, the oldest completed job is automatically purged from
the system to make room for the new one. If all of the known jobs
are still pending or active then the new job will be
rejected.
Setting the maximum size to 0 disables this functionality. The
default setting is 500.
The MaxJobsPerPrinter directive controls the
maximum number of active jobs that are allowed for each printer
or class. Once a printer or class reaches the limit, new jobs
will be rejected until one of the active jobs is completed,
stopped, aborted, or canceled.
Setting the maximum to 0 disables this functionality. The
default setting is 0.
The MaxJobsPerUser directive controls the maximum
number of active jobs that are allowed for each user. Once a user
reaches the limit, new jobs will be rejected until one of the
active jobs is completed, stopped, aborted, or canceled.
Setting the maximum to 0 disables this functionality. The
default setting is 0.
The MaxLogSize directive controls the maximum
size of each log file. Once a log file reaches or exceeds the
maximum size it is closed and renamed to filename.O.
This allows you to rotate the logs automatically. The default
size is 1048576 bytes (1MB).
Setting the maximum size to 0 disables log rotation.
The MaxRequestSize directive controls the maximum
size of print files, IPP requests, and HTML form data in HTTP
POST requests. The default limit is 0 which disables the limit
check.
This directive is deprecated and will be removed in a
future CUPS release. Use the LimitRequestBody
directive instead.
The PageLog directive sets the name of the page
log file. If the filename is not absolute then it is assumed to
be relative to the ServerRoot directory. The
default page log file is /var/log/cups/page_log.
The server name can be included in the filename by using
%s in the name.
The special name "syslog" can be used to send the page
information to the system log instead of a plain file.
The PageLogFormat directive sets the format of lines
that are logged to the page log file. Sequences beginning with percent (%)
characters are replaced with the corresponding information, while all other
characters are copied literally. The following percent sequences are
recognized:
%%: Inserts a single percent character.
%{name}: Inserts the value of the specified IPP
attribute.
%C: Inserts the number of copies for the current page.
%P: Inserts the current page number.
%T: Inserts the current date and time in common log
format.
%j: Inserts the job ID.
%p: Inserts the printer name.
%u: Inserts the username.
The default is "%p %j %u %T %P %C %{job-billing} %{job-originating-host-name} %{job-name} %{media} %{sides}".
The PassEnv directive specifies an environment
variable that should be passed to child processes. Normally, the
scheduler only passes the DYLD_LIBRARY_PATH,
LD_ASSUME_KERNEL, LD_LIBRARY_PATH,
LD_PRELOAD, NLSPATH,
SHLIB_PATH, TZ, and VGARGS
environment variables to child processes.
The Policy directive specifies IPP operation
access control limits. Each policy contains 1 or more Limit sections to set the
access control limits for specific operations - user limits,
authentication, encryption, and allowed/denied addresses,
domains, or hosts. The <Limit All> section
specifies the default access control limits for operations that
are not listed.
Policies are named and associated with printers via the
printer's operation policy setting
(printer-op-policy). The default policy for the
scheduler is specified using the DefaultPolicy
directive.
The Port directive specifies a port to listen on.
Multiple Port lines can be specified to listen on
multiple ports. The Port directive is equivalent to
"Listen *:nnn". The default port is 631.
Note:
On systems that support IPv6, this directive will bind to both
the IPv4 and IPv6 wildcard address.
The PreserveJobFiles directive controls whether
the document files of completed, canceled, or aborted print jobs
are stored on disk.
A value of On preserves job files until the
administrator purges them with the cancel command.
Jobs can be restarted (and reprinted) as desired until they are
purged.
A value of Off (the default) removes the job
files as soon as each job is completed, canceled, or aborted.
The ReloadTimeout directive specifies the number
of seconds the scheduler will wait for active jobs to complete
before doing a restart. The default is 30 seconds.
<Location /path>
...
Require group foo bar
Require user john mary
Require valid-user
Require user @groupname
Require user @SYSTEM
Require user @OWNER
</Location>
Description
The Require directive specifies that
authentication is required for the resource. The
group keyword specifies that the authenticated user
must be a member of one or more of the named groups that
follow.
The user keyword specifies that the
authenticated user must be one of the named users or groups that
follow. Group names are specified using the "@" prefix.
The valid-user keyword specifies that any
authenticated user may access the resource.
The default is to do no authentication. This directive must
appear inside a Location or
Limit section.
The RIPCache directive sets the size of the
memory cache used by Raster Image Processor ("RIP") filters such
as imagetoraster and pstoraster. The
size can be suffixed with a "k" for kilobytes, "m" for megabytes,
or "g" for gigabytes. The default cache size is "8m", or 8
megabytes.
The RootCertDuration directive specifies the
number of seconds the root certificate remains valid.
The scheduler will generate a new certificate as needed when the
number of seconds has expired. If set to 0, the root certificate
is generated only once on startup or on a restart. The default is
300 seconds.
<Location /path>
...
Satisfy all
Satisfy any
</Location>
Description
The Satisfy directive specifies whether all
conditions must be satisfied to allow access to the resource. If
set to all, then all authentication and access
control conditions must be satified to allow access.
Setting Satisfy to any allows a user
to gain access if the authentication or access control
requirements are satisfied. For example, you might require
authentication for remote access, but allow local access without
authentication.
The default is all. This directive must appear
inside a Location or Limit section.
The ServerAdmin directive identifies the email
address for the administrator on the system. By default the
administrator email address is root@server, where
server is the ServerName.
The ServerAlias directive specifies alternate names that the
server is known by. By default it contains a list of all aliases associated
with the ServerName. The special name
"*" can be used to allow any hostname when accessing CUPS via an external
network interfaces.
Note
The ServerAlias directive is used for HTTP Host header
validation when clients connect to the scheduler from external interfaces.
Using the special name "*" can expose your system to known browser-based
DNS rebinding attacks, even when accessing sites through a firewall. If the
auto-discovery of alternate names does not work, we recommend listing each
alternate name with a ServerAlias directive instead of using "*".
ServerTokens None
ServerTokens ProductOnly
ServerTokens Major
ServerTokens Minor
ServerTokens Minimal
ServerTokens OS
ServerTokens Full
Description
The ServerTokens directive specifies the
information that is included in the Server: header
of all HTTP responses. Table 4 lists the token name along with
the text that is returned. The default is
Minimal.
The SSLOptions directive specifies a network
address and port to listen for secure connections. Multiple
SSLOptions directives can be provided to listen on
multiple addresses.
The SSLOptions directive is similar to the SSLPort directive but allows you
to restrict access to specific interfaces or networks.
The SSLOptions directive specifies additional SSL/TLS
protocol options to use for encrypted connected. Currently only two
options are supported - None (the default) for the most
secure mode and NoEmptyFragments to allow CUPS to work with
Microsoft Windows with the FIPS conformance mode enabled.