hplip tools use localhost in HTTP request when addressing printer over network

[Erik Devriendt]

HPLIP 3.23.5
Printer: OfficeJet Pro 9010 All-in-one, connected on local network.
OS: Linux Mint 21.2

HPLIP tools such as hp-info send HTTP GET requests to the printer but the HTTP header contains a Host:localhost line, which is refused by the EWS of the printer. It returns 403 Forbidden.

My device URI: hp:/net/HP_OfficeJet_Pro_9010_series?ip=192.168.0.219

The failing requests:
GET /DevMgmt/ConsumableConfigDyn.xml HTTP/1.1
Accept: text/plain
Host:localhost
User-Agent:hplip

and

GET /DevMgmt/MediaHandlingDyn.xml HTTP/1.1
Accept: text/plain
Host:localhost
User-Agent:hplip

and

GET /DevMgmt/ProductStatusDyn.xml HTTP/1.1
Accept: text/plain
Host:localhost
User-Agent:hplip

The HPLIP Status service then erroneously reports the state of the printer as Busy, powered down or unplugged. No Supplies info was shown either.

I was able to correct the software for my printer by editing the /usr/share/hplip/base/device.py file. See the attachment.
In essence the correction consists of replacing the fixed string 'localhost' by the value of the http_host field of the device object.

I replaced all occurrences of localhost, but I might have replaced too many of them. I leave that to you to judge.
Although the comment above the methods indicate a "hp:/usb/..." uri, these methods get also called for "hp:/net/..." uris.

[brian_p (claremont102)]

Your detailed report seems to indicate a deficiency in
HPLIP. We assume you can still print and scan.

What is the connection method to the printer?

[Erik Devriendt (erik-devriendt)]

Yes, I can still print and scan, using the CUPS subsystem.
In CUPS I see two printers:
1. implicitclass://HP_OfficeJet_Pro_9010_series_5FE742/
2. hp:/net/HP_OfficeJet_Pro_9010_series?ip=192.168.0.219

I usually print using printer 1. because I see a lot of pauses when printing with printer 2.

I'm not sure that I understand your question regarding the connection method.
I now the printer supports LPD protocol on port 515, IPP on port 631 and jetdirect on port 9100.
But I did not yet figure out what CUPS is using in case of the hp:/net/... URI.

[Erik Devriendt (erik-devriendt)]

And there is of course some SNMP communication for printer status.

[brian_p (claremont102)]

> 1. implicitclass://HP_OfficeJet_Pro_9010_series_5FE742/

This is a driverless URI. Linux Mint 21.2 is focused on providing
a user with a driverless printing system; that is, a system that
does not need vendor (HPLIP) drivers.

The EWS should be accessible with

  http://192.168.0.219

and should display supply levels.

I am unable to offer an explanation for your observations.

[Erik Devriendt (erik-devriendt)]

@brian_p: the implicitclass URI is not the subject of this issue. It is the hp://net/... URI processing that is the issue.

Note that similar corrections already took place in the libsane-hpaio.so library somewhere between 3.21.12 and 3.23.5.

[Ivan Prokudin (iprok83)]

I confirm the issue with hplip 3.23.12 and HP LaserJet Pro MFP M428fdn on Gentoo Linux.

Device URI: hp:/net/HP_LaserJet_Pro_M428f-M429f?ip=192.168.21.36

I have temporary fixed it by changing hostname of the printer (in its settings) to localhost.