Tribblix: manual page: cupsd.conf.5

cupsd.conf(5) OpenPrinting cupsd.conf(5)

NAME

cupsd.conf - server configuration file for cups

DESCRIPTION

The cupsd.conf file configures the CUPS scheduler, cupsd(8). It is
normally located in the /etc/cups directory. Each line in the file
can be a configuration directive, a blank line, or a comment.
Configuration directives typically consist of a name and zero or more
values separated by whitespace. The configuration directive name and
values are case-insensitive. Comment lines start with the #
character.

TOP-LEVEL DIRECTIVES
The following top-level directives are understood by cupsd(8):

AccessLogLevel config

AccessLogLevel actions

AccessLogLevel all
Specifies the logging level for the AccessLog file. The
"config" level logs when printers and classes are added,
deleted, or modified and when configuration files are accessed
or updated. The "actions" level logs when print jobs are
submitted, held, released, modified, or canceled, and any of the
conditions for "config". The "all" level logs all requests.
The default access log level is "actions".

AutoPurgeJobs Yes

AutoPurgeJobs No
Specifies whether to purge job history data automatically when
it is no longer required for quotas. The default is "No".

BrowseDNSSDSubTypes_subtype[,...]
Specifies a list of Bonjour sub-types to advertise for each
shared printer. For example, "BrowseDNSSDSubTypes _cups,_print"
will tell network clients that both CUPS sharing and IPP
Everywhere are supported. The default is "_cups" which is
necessary for printer sharing to work between systems using
CUPS.

BrowseLocalProtocols all

BrowseLocalProtocols dnssd

BrowseLocalProtocols none
Specifies which protocols to use for local printer sharing. The
default is "dnssd" on systems that support Bonjour and "none"
otherwise.

BrowseWebIF Yes

BrowseWebIF No
Specifies whether the CUPS web interface is advertised. The
default is "No".

Browsing Yes

Browsing No
Specifies whether shared printers are advertised. The default
is "No".

DefaultAuthType Basic
Specifies the default type of authentication to use. The
default is "Basic".

DefaultEncryption Never

DefaultEncryption IfRequested

DefaultEncryption Required
Specifies whether encryption will be used for authenticated
requests. The default is "Required".

DefaultLanguage locale
Specifies the default language to use for text and web content.
The default is "en".

DefaultPaperSize Auto

DefaultPaperSize None

DefaultPaperSize sizename
Specifies the default paper size for new print queues. "Auto"
uses a locale-specific default, while "None" specifies there is
no default paper size. Specific size names are typically
"Letter" or "A4". The default is "Auto". Note: The default
paper size must use a size name from the PPD file and not a PWG
self-describing media size name.

DefaultPolicy policy-name
Specifies the default access policy to use. The default access
policy is "default".

DefaultShared Yes

DefaultShared No
Specifies whether local printers are shared by default. The
default is "Yes".

DirtyCleanInterval seconds
Specifies the delay for updating of configuration and state
files. A value of 0 causes the update to happen as soon as
possible, typically within a few milliseconds. The default
value is "30".

DNSSDHostNamehostname.example.com
Specifies the fully-qualified domain name for the server that is
used for Bonjour sharing. The default is typically the server's
".local" hostname.

ErrorPolicy abort-job
Specifies that a failed print job should be aborted (discarded)
unless otherwise specified for the printer.

ErrorPolicy retry-current-job
Specifies that a failed print job should be retried immediately
unless otherwise specified for the printer.

ErrorPolicy retry-job
Specifies that a failed print job should be retried at a later
time unless otherwise specified for the printer.

ErrorPolicy stop-printer
Specifies that a failed print job should stop the printer unless
otherwise specified for the printer. The 'stop-printer' error
policy is the default.

FilterLimit limit
Specifies the maximum cost of filters that are run concurrently,
which can be used 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 default
limit is "0".

FilterNice nice-value
Specifies the scheduling priority ( nice(8) value) of filters
that are run to print a job. The nice value ranges from 0, the
highest priority, to 19, the lowest priority. The default is 0.

HostNameLookups On

HostNameLookups Off

HostNameLookups Double
Specifies whether to do reverse lookups on connecting clients.
The "Double" setting causes cupsd(8) 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. Only set this option to "On" or
"Double" if absolutely required.

IdleExitTimeout seconds
Specifies the length of time to wait before shutting down due to
inactivity. The default is "60" seconds. Note: Only applicable
when cupsd(8) is run on-demand (e.g., with -l).

JobKillDelay seconds
Specifies the number of seconds to wait before killing the
filters and backend associated with a canceled or held job. The
default is "30".

JobRetryInterval seconds
Specifies the interval between retries of jobs in seconds. This
is typically used for fax queues but can also be used with
normal print queues whose error policy is "retry-job" or "retry-
current-job". The default is "30".

JobRetryLimit count
Specifies the number of retries that are done for jobs. This is
typically used for fax queues but can also be used with normal
print queues whose error policy is "retry-job" or "retry-
current-job". The default is "5".

KeepAlive Yes

KeepAlive No
Specifies whether to support HTTP keep-alive connections. The
default is "Yes".

<Limit operation ...> ... </Limit>
Specifies the IPP operations that are being limited inside a
Policy section. IPP operation names are listed below in the
section "IPP OPERATION NAMES".

<Limit method ...> ... </Limit>

<LimitExcept method ...> ... </LimitExcept>
Specifies the HTTP methods that are being limited inside a
Location section. HTTP method names are listed below in the
section "HTTP METHOD NAMES".

LimitRequestBody size
Specifies the maximum size of print files, IPP requests, and
HTML form data. The default is "0" which disables the limit
check.

Listen ipv4-address:port

Listen [ipv6-address]:port

Listen *:port

Listen /path/to/domain/socket
Listens to the specified address and port or domain socket path
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. Note: "Listen *:port" and
"Port port" effectively listen on all IP addresses, so you
cannot combine them with Listen directives for explicit IPv4 or
IPv6 addresses on the same port.

<Location /path> ... </Location>
Specifies access control for the named location. Paths are
documented below in the section "LOCATION PATHS".

LogDebugHistory number
Specifies the number of debugging messages that are retained for
logging if an error occurs in a print job. Debug messages are
logged regardless of the LogLevel setting.

LogLevel none

LogLevel emerg

LogLevel alert

LogLevel crit

LogLevel error

LogLevel warn

LogLevel notice

LogLevel info

LogLevel debug

LogLevel debug2
Specifies the level of logging for the ErrorLog file. The value
"none" stops all logging while "debug2" logs everything. The
default is "warn".

LogTimeFormat standard

LogTimeFormat usecs
Specifies the format of the date and time in the log files. The
value "standard" is the default and logs whole seconds while
"usecs" logs microseconds.

MaxClients number
Specifies the maximum number of simultaneous clients that are
allowed by the scheduler. The default is "100".

MaxClientsPerHost number
Specifies the maximum number of simultaneous clients that are
allowed from a single address. The default is the MaxClients
value.

MaxCopies number
Specifies the maximum number of copies that a user can print of
each job. The default is "9999".

MaxHoldTime seconds
Specifies the maximum time a job may remain in the "indefinite"
hold state before it is canceled. The default is "0" which
disables cancellation of held jobs.

MaxJobs number
Specifies the maximum number of simultaneous jobs that are
allowed. Set to "0" to allow an unlimited number of jobs. The
default is "500".

MaxJobsPerPrinter number
Specifies the maximum number of simultaneous jobs that are
allowed per printer. The default is "0" which allows up to
MaxJobs jobs per printer.

MaxJobsPerUser number
Specifies the maximum number of simultaneous jobs that are
allowed per user. The default is "0" which allows up to MaxJobs
jobs per user.

MaxJobTime seconds
Specifies the maximum time a job may take to print before it is
canceled. Set to "0" to disable cancellation of "stuck" jobs.
The default is "10800" (3 hours).

MaxLogSize size
Specifies the maximum size of the log files before they are
rotated. The value "0" disables log rotation. The default is
"1048576" (1MB).

MaxSubscriptions number
Specifies the maximum number of simultaneous event subscriptions
that are allowed. Set to "0" to allow an unlimited number of
subscriptions. The default is "100".

MaxSubscriptionsPerJob number
Specifies the maximum number of simultaneous event subscriptions
that are allowed per job. The default is "0" which allows up to
MaxSubscriptions subscriptions per job.

MaxSubscriptionsPerPrinter number
Specifies the maximum number of simultaneous event subscriptions
that are allowed per printer. The default is "0" which allows
up to MaxSubscriptions subscriptions per printer.

MaxSubscriptionsPerUser number
Specifies the maximum number of simultaneous event subscriptions
that are allowed per user. The default is "0" which allows up
to MaxSubscriptions subscriptions per user.

MultipleOperationTimeout seconds
Specifies the maximum amount of time to allow between files in a
multiple file print job. The default is "900" (15 minutes).

<Policy name> ... </Policy>
Specifies access control for the named policy.

Port number
Listens to the specified port number for connections.

PreserveJobFiles Yes

PreserveJobFiles No

PreserveJobFiles seconds
Specifies whether job files (documents) are preserved after a
job is printed. If a numeric value is specified, job files are
preserved for the indicated number of seconds after printing.
The default is "86400" (preserve 1 day).

PreserveJobHistory Yes

PreserveJobHistory No

PreserveJobHistory seconds
Specifies whether the job history is preserved after a job is
printed. If a numeric value is specified, the job history is
preserved for the indicated number of seconds after printing.
If "Yes", the job history is preserved until the MaxJobs limit
is reached. The default is "Yes".

ReadyPaperSizes sizename[,...]
Specifies a list of potential paper sizes that are reported as
"ready" (loaded). The actual list will only contain sizes that
each printer supports. The default is
"Letter,Legal,Tabloid,4x6,Env10" when the default paper size is
"Letter" and "A3,A4,A5,A6,EnvDL" otherwise. Note: Paper sizes
must use the size names from the PPD file and not PWG self-
describing media size names.

ReloadTimeout seconds
Specifies the amount of time to wait for job completion before
restarting the scheduler. The default is "30".

ServerAdmin email-address
Specifies the email address of the server administrator. The
default value is "root@ServerName".

ServerAlias hostname [ ... hostname ]

ServerAlias *
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
"*".

ServerName hostname
Specifies the fully-qualified hostname of the server. The
default is the value reported by the hostname(1) command.

ServerTokens None

ServerTokens ProductOnly

ServerTokens Major

ServerTokens Minor

ServerTokens Minimal

ServerTokens OS

ServerTokens Full
Specifies what information is included in the Server header of
HTTP responses. "None" disables the Server header.
"ProductOnly" reports "CUPS". "Major" reports "CUPS/major
IPP/2". "Minor" reports "CUPS/major.minor IPP/2.1". "Minimal"
reports "CUPS/major.minor.patch IPP/2.1". "OS" reports
"CUPS/major.minor.path (osname osversion) IPP/2.1". "Full"
reports "CUPS/major.minor.path (osname osversion; architecture)
IPP/2.1". The default is "Minimal".

SSLListen ipv4-address:port

SSLListen [ipv6-address]:port

SSLListen *:port
Listens on the specified address and port for encrypted
connections.

SSLOptions [AllowDH] [AllowRC4] [AllowSSL3] [DenyCBC] [DenyTLS1.0]
[MaxTLS1.0] [MaxTLS1.1] [MaxTLS1.2] [MaxTLS1.3] [MinTLS1.0]
[MinTLS1.1] [MinTLS1.2] [MinTLS1.3]

SSLOptions None
Sets encryption options (only in /etc/cups/client.conf). By
default, CUPS only supports encryption using TLS v1.0 or higher
using known secure cipher suites. Security is reduced when
Allow options are used. Security is enhanced when Deny options
are used. The AllowDH option enables cipher suites using plain
Diffie-Hellman key negotiation (not supported on systems using
GNU TLS). The AllowRC4 option enables the 128-bit RC4 cipher
suites, which are required for some older clients. The
AllowSSL3 option enables SSL v3.0, which is required for some
older clients that do not support TLS v1.0. The DenyCBC option
disables all CBC cipher suites. The DenyTLS1.0 option disables
TLS v1.0 support - this sets the minimum protocol version to TLS
v1.1. The MinTLS options set the minimum TLS version to
support. The MaxTLS options set the maximum TLS version to
support. Not all operating systems support TLS 1.3 at this
time.

SSLPort port
Listens on the specified port for encrypted connections.

StrictConformance Yes

StrictConformance No
Specifies whether the scheduler requires clients to strictly
adhere to the IPP specifications. The default is "No".

Timeout seconds
Specifies the HTTP request timeout. The default is "900" (15
minutes).

WebInterface yes

WebInterface no
Specifies whether the web interface is enabled. The default is
"No".

HTTP METHOD NAMES

The following HTTP methods are supported by cupsd(8):

GET Used by a client to download icons and other printer resources
and to access the CUPS web interface.

HEAD Used by a client to get the type, size, and modification date of
resources.

OPTIONS
Used by a client to establish a secure (SSL/TLS) connection.

POST Used by a client to submit IPP requests and HTML forms from the
CUPS web interface.

PUT Used by a client to upload configuration files.

IPP OPERATION NAMES

The following IPP operations are supported by cupsd(8):

CUPS-Accept-Jobs
Allows a printer to accept new jobs.

CUPS-Add-Modify-Class
Adds or modifies a printer class.

CUPS-Add-Modify-Printer
Adds or modifies a printer.

CUPS-Authenticate-Job
Releases a job that is held for authentication.

CUPS-Delete-Class
Deletes a printer class.

CUPS-Delete-Printer
Deletes a printer.

CUPS-Get-Classes
Gets a list of printer classes.

CUPS-Get-Default
Gets the server default printer or printer class.

CUPS-Get-Devices
Gets a list of devices that are currently available.

CUPS-Get-Document
Gets a document file for a job.

CUPS-Get-PPD
Gets a PPD file.

CUPS-Get-PPDs
Gets a list of installed PPD files.

CUPS-Get-Printers
Gets a list of printers.

CUPS-Move-Job
Moves a job.

CUPS-Reject-Jobs
Prevents a printer from accepting new jobs.

CUPS-Set-Default
Sets the server default printer or printer class.

Cancel-Job
Cancels a job.

Cancel-Jobs
Cancels one or more jobs.

Cancel-My-Jobs
Cancels one or more jobs creates by a user.

Cancel-Subscription
Cancels a subscription.

Close-Job
Closes a job that is waiting for more documents.

Create-Job
Creates a new job with no documents.

Create-Job-Subscriptions
Creates a subscription for job events.

Create-Printer-Subscriptions
Creates a subscription for printer events.

Get-Job-Attributes
Gets information about a job.

Get-Jobs
Gets a list of jobs.

Get-Notifications
Gets a list of event notifications for a subscription.

Get-Printer-Attributes
Gets information about a printer or printer class.

Get-Subscription-Attributes
Gets information about a subscription.

Get-Subscriptions
Gets a list of subscriptions.

Hold-Job
Holds a job from printing.

Hold-New-Jobs
Holds all new jobs from printing.

Pause-Printer
Stops processing of jobs by a printer or printer class.

Pause-Printer-After-Current-Job
Stops processing of jobs by a printer or printer class after the
current job is finished.

Print-Job
Creates a new job with a single document.

Purge-Jobs
Cancels one or more jobs and deletes the job history.

Release-Held-New-Jobs
Allows previously held jobs to print.

Release-Job
Allows a job to print.

Renew-Subscription
Renews a subscription.

Restart-Job
Reprints a job, if possible.

Send-Document
Adds a document to a job.

Set-Job-Attributes
Changes job information.

Set-Printer-Attributes
Changes printer or printer class information.

Validate-Job
Validates options for a new job.

LOCATION PATHS

The following paths are commonly used when configuring cupsd(8):

/ The path for all get operations (get-printers, get-jobs, etc.)

/admin
The path for all administration operations (add-printer, delete-
printer, start-printer, etc.)

/admin/conf
The path for access to the CUPS configuration files (cupsd.conf,
client.conf, etc.)

/admin/log
The path for access to the CUPS log files (access_log,
error_log, page_log)

/classes
The path for all printer classes

/classes/name
The resource for the named printer class

/jobs
The path for all jobs (hold-job, release-job, etc.)

/jobs/id
The path for the specified job

/printers
The path for all printers

/printers/name
The path for the named printer

/printers/name.png
The icon file path for the named printer

/printers/name.ppd
The PPD file path for the named printer

DIRECTIVES VALID WITHIN LOCATION AND LIMIT SECTIONS

The following directives may be placed inside Location and Limit
sections in the cupsd.conf file:

Allow all

Allow none

Allow host.domain.com

Allow *.domain.com

Allow ipv4-address

Allow ipv4-address/netmask

Allow ipv4-address/mm

Allow [ipv6-address]

Allow [ipv6-address]/mm

Allow @IF(name)

Allow @LOCAL
Allows access from the named hosts, domains, addresses, or
interfaces. The @IF(name) form uses the current subnets
configured for the named interface. The @LOCAL form uses the
current subnets configured for all interfaces that are not
point-to-point, for example Ethernet and Wi-Fi interfaces are
used but DSL and VPN interfaces are not. The Order directive
controls whether Allow lines are evaluated before or after Deny
lines.

AuthType None

AuthType Basic

AuthType Default
Specifies the type of authentication required. The value
"Default" corresponds to the DefaultAuthType value.

Deny all

Deny none

Deny host.domain.com

Deny *.domain.com

Deny ipv4-address

Deny ipv4-address/netmask

Deny ipv4-address/mm

Deny [ipv6-address]

Deny [ipv6-address]/mm

Deny @IF(name)

Deny @LOCAL
Denies access from the named hosts, domains, addresses, or
interfaces. The @IF(name) form uses the current subnets
configured for the named interface. The @LOCAL form uses the
current subnets configured for all interfaces that are not
point-to-point, for example Ethernet and Wi-Fi interfaces are
used but DSL and VPN interfaces are not. The Order directive
controls whether Deny lines are evaluated before or after Allow
lines.

Encryption IfRequested

Encryption Never

Encryption Required
Specifies the level of encryption that is required for a
particular location. The default value is "IfRequested".

Order allow,deny
Specifies that access is denied by default. Allow lines are then
processed followed by Deny lines to determine whether a client
may access a particular resource.

Order deny,allow
Specifies that access is allowed by default. Deny lines are then
processed followed by Allow lines to determine whether a client
may access a particular resource.

Require group group-name [ group-name ... ]
Specifies that an authenticated user must be a member of one of
the named groups.

Require user {user-name|@group-name} ...
Specifies that an authenticated user must match one of the named
users or be a member of one of the named groups. The group name
"@SYSTEM" corresponds to the list of groups defined by the
SystemGroup directive in the cups-files.conf(5) file. The group
name "@OWNER" corresponds to the owner of the resource, for
example the person that submitted a print job. Note: The 'root'
user is not special and must be granted privileges like any
other user account.

Require valid-user
Specifies that any authenticated user is acceptable.

Satisfy all
Specifies that all Allow, AuthType, Deny, Order, and Require
conditions must be satisfied to allow access.

Satisfy any
Specifies that any a client may access a resource if either the
authentication (AuthType/Require) or address (Allow/Deny/Order)
conditions are satisfied. For example, this can be used to
require authentication only for remote accesses.

DIRECTIVES VALID WITHIN POLICY SECTIONS

The following directives may be placed inside Policy sections in the
cupsd.conf file:

JobPrivateAccess all

JobPrivateAccess default

JobPrivateAccess {user|@group|@ACL|@OWNER|@SYSTEM} ...
Specifies an access list for a job's private values. The
"default" access list is "@OWNER @SYSTEM". "@ACL" maps to the
printer's requesting-user-name-allowed or requesting-user-name-
denied values. "@OWNER" maps to the job's owner. "@SYSTEM"
maps to the groups listed for the SystemGroup directive in the
cups-files.conf(5) file.

JobPrivateValues all

JobPrivateValues default

JobPrivateValues none

JobPrivateValues attribute-name [ ... attribute-name ]
Specifies the list of job values to make private. The "default"
values are "job-name", "job-originating-host-name", "job-
originating-user-name", and "phone".

SubscriptionPrivateAccess all

SubscriptionPrivateAccess default

SubscriptionPrivateAccess {user|@group|@ACL|@OWNER|@SYSTEM} ...
Specifies an access list for a subscription's private values.
The "default" access list is "@OWNER @SYSTEM". "@ACL" maps to
the printer's requesting-user-name-allowed or requesting-user-
name-denied values. "@OWNER" maps to the job's owner.
"@SYSTEM" maps to the groups listed for the SystemGroup
directive in the cups-files.conf(5) file.

SubscriptionPrivateValues all

SubscriptionPrivateValues default

SubscriptionPrivateValues none

SubscriptionPrivateValues attribute-name [ ... attribute-name ]
Specifies the list of subscription values to make private. The
"default" values are "notify-events", "notify-pull-method",
"notify-recipient-uri", "notify-subscriber-user-name", and
"notify-user-data".

DEPRECATED DIRECTIVES

The following directives are deprecated and will be removed in a
future release of CUPS:

AuthType Negotiate
Specifies Kerberos authentication is required.

Classification banner
Specifies the security classification of the server. Any valid
banner name can be used, including "classified", "confidential",
"secret", "topsecret", and "unclassified", or the banner can be
omitted to disable secure printing functions. The default is no
classification banner.

ClassifyOverride Yes

ClassifyOverride No
Specifies whether users may override the classification (cover
page) of individual print jobs using the "job-sheets" option.
The default is "No".

DefaultAuthType Negotiate
Specifies that Kerberos authentication is required by default.

GSSServiceName name
Specifies the service name when using Kerberos authentication.
The default service name is "http."

PageLogFormat format-string
Specifies the format of PageLog lines. 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 the empty string, which disables page logging.
The string "%p %u %j %T %P %C %{job-billing} %{job-originating-
host-name} %{job-name} %{media} %{sides}" creates a page log
with the standard items. Use "%{job-impressions-completed}" to
insert the number of pages (sides) that were printed, or "%{job-
media-sheets-completed}" to insert the number of sheets that
were printed.

NOTES

File, directory, and user configuration directives that used to be
allowed in the cupsd.conf file are now stored in the
cups-files.conf(5) file instead in order to prevent certain types of
privilege escalation attacks.

The scheduler MUST be restarted manually after making changes to the
cupsd.conf file. On Linux this is typically done using the
systemctl(8) command, while on macOS the launchctl(8) command is used
instead.

The @LOCAL macro name can be confusing since the system running cupsd
often belongs to a different set of subnets from its clients.

CONFORMING TO

The cupsd.conf file format is based on the Apache HTTP Server
configuration file format.

EXAMPLES

Log everything with a maximum log file size of 32 megabytes:

AccessLogLevel all
LogLevel debug2
MaxLogSize 32m

Require authentication for accesses from outside the 10. network:

<Location />
Order allow,deny
Allow from 10./8
AuthType Basic
Require valid-user
Satisfy any
</Location>