Provided by: ipp-usb_0.9.24-0ubuntu3.2_amd64 
NAME
ipp-usb - Daemon for IPP over USB printer support
DESCRIPTION
ipp-usb daemon enables driver-less printing and scanning on USB-only AirPrint-compatible printers and
MFPs.
It works by connecting to the device by USB using IPP-over-USB protocol, and exposing the device to the
network, including DNS-SD (ZeroConf) advertising.
IPP printing, eSCL scanning and web console are fully supported.
SYNOPSIS
Usage:
ipp-usb mode [options]
Modes are:
standalone
run forever, automatically discover IPP-over-USB devices and serve them all
udev like standalone, but exit when last IPP-over-USB device is disconnected
debug logs duplicated on console, -bg option is ignored
check check configuration and exit. It also prints a list of all connected devices
status print status of the running ipp-usb daemon, including information of all connected devices
Options are
-bg run in background (ignored in debug mode)
NETWORKING
Essentially, ipp-usb makes printer or scanner accessible from the network, converting network-side HTTP
operations to the USB operations.
By default, ipp-usb exposes device only to the loopback interface, using the localhost address (both
127.0.0.1 and ::1, for IPv4 and IPv6, respectively). TCP ports are allocated automatically, and
allocation is persisted in the association with the particular device, so the next time the device is
plugged on, it will get the same port. The default port range for TCP ports allocation is 60000-65535.
This default behavior can be changed, using configuration file. See CONFIGURATION section below for
details.
If you decide to publish your device to the real network, the following things should be taken into
consideration:
1. Your private device will become public and it will become accessible by other computers from the
network
2. Firewall rules needs to be updated appropriately. The ipp-usb daemon will not do it automatically by
itself
3. IPP over USB specification explicitly require that the Host field in the HTTP request is set to
localhost or localhost:port. If device is accessed from the real network, Host header will reflect
the real network address. Most of devices allow it, but some are more restrictive and will not work
in this configuration.
DNS-SD (AVAHI INTEGRATION)
IPP over USB is intended to be used with the automatic device discovery, and for this purpose ipp-usb
advertises all devices it handles, using DNS-SD protocol. On Linux, DNS-SD is handled with a help of
Avahi daemon.
DNS-SD advertising can be disabled via configuration file. Also, if Avahi is not installed or not
running, ipp-usb will still work correctly, although DNS-SD advertising will not work.
For every device the following services will be advertised:
┌────────────┬───────────────┬───────────────────────────┐
│Instance │ Type │ Subtypes │
├────────────┼───────────────┼───────────────────────────┤
│Device name │ _ipp._tcp │ _universal._sub._ipp._tcp │
├────────────┼───────────────┼───────────────────────────┤
│Device name │ _printer._tcp │ │
├────────────┼───────────────┼───────────────────────────┤
│Device name │ _uscan._tcp │ │
├────────────┼───────────────┼───────────────────────────┤
│Device name │ _http._tcp │ │
├────────────┼───────────────┼───────────────────────────┤
│BBPP │ _ipp-usb._tcp │ │
└────────────┴───────────────┴───────────────────────────┘
Notes:
○ Device name is the name under which device appears in the list of available devices, for example, in
the printing dialog (it is DNS-SD device name, in another words), and for most of devices will match
the device's model name. It is appended with the " (USB)" suffix, so if device is connected via
network and via USB simultaneously, these two connections can be easily distinguished. If there are
two devices with the same name connected simultaneously, the suffix becomes " (USB NNN)", with NNN
number unique for each device, for disambiguation. In another words, the single "Kyocera ECOSYS
M2040dn" device will be listed as "Kyocera ECOSYS M2040dn (USB)", and two such a devices will be
listed as "Kyocera ECOSYS M2040dn (USB 1)" and "Kyocera ECOSYS M2040dn (USB 2)"
○ _ipp._tcp and _printer._tcp are only advertises for printer devices and MFPs
○ _uscan._tcp is only advertised for scanner devices and MFPs
○ for the _ipp._tcp service, the _universal._sub._ipp._tcp subtype is also advertised for iOS
compatibility
○ _printer._tcp is advertised with TCP port set to 0. Other services are advertised with the actual
port number
○ _http._tcp is device web-console. It is always advertises in assumption it is always exist
○ BBPP, used for the _ipp-usb._tcp service, is the USB bus (BB) and port (PP) numbers in hex. The
purpose of this advertising is to help CUPS and other possible "clients" to guess which devices are
handled by the ipp-usb service, to avoid possible conflicts with the legacy USB drivers.
CONFIGURATION
ipp-usb searched for its configuration file in two places:
1. /etc/ipp-usb/ipp-usb.conf
2. ipp-usb.conf in the directory where executable file is located
Configuration file syntax is very similar to .INI files syntax. It consist of named sections, and each
section contains a set of named variables. Comments are started from # or ; characters and continues
until end of line:
# This is a comment
[section 1]
variable 1 = value 1 ; and another comment
variable 2 = value 2
Network parameters
Network parameters are all in the [network] section:
[network]
# TCP ports for HTTP will be automatically allocated in the
# following range
http-min-port = 60000
http-max-port = 65535
# Enable or disable DNS-SD advertisement
dns-sd = enable # enable | disable
# Network interface to use. Set to `all` if you want to expose you
# printer to the local network. This way you can share your printer
# with other computers in the network, as well as with iOS and
# Android devices.
interface = loopback # all | loopback
# Enable or disable IPv6
ipv6 = enable # enable | disable
Authentication
By default, ipp-usb exposes locally connected USB printer to all users of the system.
Though this is reasonable behavior in most cases, when computer and printer are both in personal use, for
bigger installation this approach can be too simple and primitive.
ipp-usb provides a mechanism, which allows to control local clients access based on UID the client
program runs under.
Please note, this mechanism will not work for remote connections (disabled by default but supported).
Authentication of remote users requires some different mechanism, which is under consideration but is not
yet implemented.
Authentication parameters are all in the [auth uid] section:
# Local user authentication by UID/GID
[auth uid]
# Syntax:
# operations = users
#
# Operations are comma-separated list of following operations:
# all - all operations
# config - configuration web-console
# fax - faxing
# print - printing
# scan - scanning
#
# Users have the following suntax:
# user - user name
# @group - all users that belongs to the group
#
# Users and groups may be specified either by names or by
# numbers. * means any
#
# Note, if user/group is not known in the context of request
# (for example, in the case of non-local network connection),
# "_" used for matching
#
# User/group names are resolved at the moment of request
# processing (and cached for a couple of seconds), so running
# daemon will see changes to the /etc/passwd and /etc/group
#
# Examples:
# fax, print = lp, @lp # Allow CUPS to do its work
# scan = * # Allow any user to scan
# config = @wheel # Only wheel group members can do that
all = *
Logging configuration
Logging parameters are all in the [logging] section:
[logging]
# device-log - what logs are generated per device
# main-log - what common logs are generated
# console-log - what of generated logs goes to console
#
# parameter contains a comma-separated list of
# the following keywords:
# error - error messages
# info - informative messages
# debug - debug messages
# trace-ipp, trace-escl, trace-http - very detailed
# per-protocol traces
# trace-usb - hex dump of all USB traffic
# all - all logs
# trace-all - alias to all
#
# Note, trace-* implies debug, debug implies info, info implies
# error
device-log = all
main-log = debug
console-log = debug
# Log rotation parameters:
# log-file-size - max log file before rotation. Use suffix
# M for megabytes or K for kilobytes
# log-backup-files - how many backup files to preserve during
# rotation
#
max-file-size = 256K
max-backup-files = 5
# Enable or disable ANSI colors on console
console-color = enable # enable | disable
# ipp-usb queries IPP printer attributes at the initialization time
# for its own purposes and writes received attributes to the log.
# By default, only necessary attributes are requested from device.
#
# If this parameter is set to true, all printer attributes will
# be requested. Normally, it only affects the logging. However,
# some enterprise-level HP printers returns such huge amount of
# data and do it so slowly, so it can cause initialization timeout.
# This is why this feature is not enabled by default
get-all-printer-attrs = false # false | true
Quirks
Some devices, due to their firmware bugs, require special handling, called device-specific quirks.
ipp-usb loads quirks from the /usr/share/ipp-usb/quirks/*.conf files and from the
/etc/ipp-usb/quirks/*.conf files. The /etc/ipp-usb/quirks directory is for system quirks overrides or
admin changes. These files have .INI-file syntax with the content that looks like this:
[HP LaserJet MFP M28-M31]
http-connection = keep-alive
[HP OfficeJet Pro 8730]
http-connection = close
[HP Inc. HP Laser MFP 135a]
blacklist = true
# Default configuration
[*]
http-connection = ""
For each discovered device, its model name is matched against sections of the quirks files. Section names
may contain glob-style wildcards: * that matches any sequence of characters and ? , that matches any
single character. To match one of these characters (* and ?) literally, use backslash as escape.
Note, the simplest way to guess the exact model name for the particular device is to use ipp-usb check
command, which prints a list of all connected devices.
All matching sections from all quirks files are taken in consideration, and applied in priority order.
Priority is computed using the following algorithm:
○ When matching model name against section name, amount of non-wildcard matched characters is counted,
and the longer match wins
○ Otherwise, section loaded first wins. Files are loaded in alphabetical order, sections read
sequentially
If some parameter exist in multiple sections, used its value from the most priority section
The following parameters are defined:
○ blacklist = true | false
If true, the matching device is ignored by the ipp-usb
○ http-XXX = YYY
Set XXX header of the HTTP requests forwarded to device to YYY. If YYY is empty string, XXX header is
removed
○ usb-max-interfaces = N
Don't use more that N USB interfaces, even if more is available
○ disable-fax = true | false
If true, the matching device's fax capability is ignored
○ init-reset = none | soft | hard
How to reset device during initialization. Default is none
○ init-delay = NNN
Delay, in milliseconds, between device is opened and, optionally, reset, and the first request is
sent to device
○ request-delay = NNN
Delay, in milliseconds, between subsequent requests
○ ignore-ipp-status = true | false
If true, IPP status of IPP requests sent by the ipp-usb by itself will be ignored. This quirk is
useful, when device correctly handles IPP request but returned status is not reliable. Affects only
ipp-usb initialization.
If you found out about your device that it needs a quirk to work properly or it does not work with
ipp-usb at all, although it provides IPP-over-USB interface, please report the issue at
https://github.com/OpenPrinting/ipp-usb. It will let us to update our collection of quirks, so helping
other owners of such a device.
FILES
○ /etc/ipp-usb/ipp-usb.conf: the daemon configuration file
○ /var/log/ipp-usb/main.log: the main log file
○ /var/log/ipp-usb/<DEVICE>.log: per-device log files
○ /var/ipp-usb/dev/<DEVICE>.state: device state (HTTP port allocation, DNS-SD name)
○ /var/ipp-usb/lock/ipp-usb.lock: lock file, that helps to prevent multiple copies of daemon to run
simultaneously
○ /var/ipp-usb/ctrl: ipp-usb control socket. Currently only used to obtain the per-device status
(printed by ipp-usb status), but its functionality may be extended in a future
○ /usr/share/ipp-usb/quirks/*.conf: device-specific quirks (see above)
○ /etc/ipp-usb/quirks/*.conf: device-specific quirks defined by sysadmin (see above)
COPYRIGHT
Copyright (c) by Alexander Pevzner (pzz@apevzner.com, pzz@pzz.msk.ru)
All rights reserved.
This program is licensed under 2-Clause BSD license. See LICENSE file for details.
SEE ALSO
cups(1)
October 2024 IPP-USB(8)