2009/235 dladm Possible Values List

[James Carlson]

Girish Moodalbail writes:
> For such drivers, which do not support "possible" values for the MTU 
> property, the <drv>_m_getprop() would return 'ENOTSUP' and we would 
> display the current value of the MTU (as cached by MAC layer) in the output.
> 
> bash-3.2$ dladm show-linkprop -p mtu mxfe0
> LINK         PROPERTY        VALUE          DEFAULT        POSSIBLE
> mxfe0      mtu             1500           1500           1500
> 
> The meaning of 'possible' value, from dladm(1m) man page, is 'list of 
> values the property can have' and in this case it will be 1500.

One of the subtleties of this project is this section:

	NOTE: MAC_PROP_POSSIBLE flag needs to be handled 'carefully'. 

The reason this project doesn't have to modify every GLDv3 driver is
that the property in question is not one that drivers actually
return.  Everyone who has a settable MTU has <name>_m_setprop set up
to handle MAC_PROP_MTU, but nobody has <name>_m_getprop for this,
because MTU is special-cased in mac_get_prop().

If it were otherwise -- that is, if this were a "normal" property and
not special-cased in mac_get_prop -- then the proposed design would
require changing all the drivers.

The next person who wants to extend this (using MAC_PROP_POSSIBLE for
some other property) may well have to bite that bullet.

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
Sun Microsystems / 35 Network Drive        71.232W   Vox +1 781 442 2084
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