James Carlson wrote:
> Artem Kachitchkine writes:
>   
>> In order to better support these devices, this case seeks to extend the
>> current HAL offering by adding a network attached device discovery
>> service addon module and a probe module to probe network attached
>> printers for identifying data.  These modules will be connected to HAL
>> via .fdi files.
>>     
>
> Just to clarify: we're only discovering printers on the network.  If
> we have a printer (attached via some other method, such as USB), we
> won't be advertising that device to others, right?
>   
That is correct.
>   
>> Since virtually all network attached printers (or attachment devices)
>> seem to support SNMP v1, the initial implementation will support an
>> SNMP_GET broadcast mechanism for device discovery.  The SNMP discovery
>> method will use the following SMF service instance/properties, and
>> D-BUS methods/arguments
>>     
>
> I didn't see a reference here to RFC 1759 or 3805.  Will this project
> use any of the standardized Printer MIB interfaces, or does it only
> support the enumerated vendor MIB entries and Host Resources?
>   
The Printer-MIB prtInputVendorName, prtInputModel, prtInputSerialNumber, 
and prtInputDescription didn't appear to be in use in the printers that 
I tried so I took them out.  I can add them back in as a fallback.  That 
will add

  SNMPv2-SMI::mib-2.43.8.2.1.14         Committed    Printer MIB 
Manufacturer
  SNMPv2-SMI::mib-2.43.8.2.1.15         Committed    Printer MIB Model
  SNMPv2-SMI::mib-2.43.8.2.1.17         Committed    Printer MIB Serial 
Number
  SNMPv2-SMI::mib-2.43.8.2.1.18         Committed    Printer MIB Description

To the Imported interfaces.
> What about Avahi?
>   
Most of the printers that I have come across don't support mDNS.  A 
couple of the newer ones that I have tested with do.  I am looking at 
incorporating it as a discovery method.  mDNS support should introduce a 
relatively small incremental change to this case to import the necessary 
interfaces and introduce an interface to control the discovery method.

>> svc:/network/device-discovery:snmp  org.freedesktop.Hal.Device.
>>     
>
> Enabled or disabled by default?  And under what system profile?
>   
Disabled by default.
>   
>>   interval specifies the number of seconds to wait between active SNMP
>>   scans. community specifies the SNMP community string to use in
>>   SNMP_GET requests. network specifies the network broadcast address to
>>   use in the SNMP_GET request.
>>     
>
> What's the default for config/network?
>
> Why does that need to be specified anyway?  You should be able to use
> SIOCGIF* ioctls to get every bit of information needed to perform
> broadcast-based queries.
>   
The default is currently all 1s, but could be auto-detected.  The reason 
I put in config/network was to allow for the possibility of limiting the 
scope.
>   
>> libnetsnmp                           Stable        Core SNMP library
>>     
>
> Nit: should be Committed.
>
>   
>>    PSARC/2006/467  Printers Devfs Events
>>     
>
> How is this related to devfs?  (Is it just because of the reference to
> USB printers, or is there something deeper here?)
>   
It's not related to devfs.  This is only because of the reference to USB 
printer support.


Reply via email to