WARNING: BREAKS CONFIG COMPATIBILITY!
This commit changes the configuration interface of the NIC router in a way that
may break systems that use the component without proper adjustment!
How to adjust:
At each occurrence of the 'dns_server_from' attribute in a NIC router
configuration replace the attribute name with 'dns_config_from'. The attribute
value remains unaltered.
DETAILED DESCRIPTION
The new attribute name 'dns_config_from' reflects that also other aspects of
the DNS configuration of the denominated domain are used by the DHCP server
that holds the attribute. This commit is a preparation for forwarding also the
domain name (DHCP option 15) with the mechanism behind the attribute.
Ref #4246
BREAKS CONFIG COMPATIBILITY:
This commit changes the configuration interface of the NIC router in a way that
may break systems that use the component without proper adjustment!
HOW TO ADJUST:
At each occurrence of the '<uplink ...>' tag in a NIC router configuration
replace the tag name 'uplink' with 'nic-client'. The rest of the tag stays the
same.
The term "uplink" for network interfaces in the router that have a NIC session
client as back end was introduced in a time when Uplink sessions didn't yet
exist. Now, they do and, although both an uplink and an Uplink session
normally describe a network session between router and network device driver,
they are based on two different service types (NIC and Uplink). This can easily
cause confusion when integrating the router (the <uplink> is not related to
Uplink sessions) or trying to understand its functioning (an 'Uplink' object
has nothing to do with the Uplink service).
Therefore, this commit introduces the more specific term "NIC client" for an
interface that is based on a NIC session requested by the router. This doesn't
imply any semantic changes at the NIC router. However, the commit also brings a
broader update of the router's README and removes the term "downlink" that was
used only in documentation to refer to interfaces backed by a NIC session
provided by the router. The term was only associated with this meaning because
it is the natural counterpart to an uplink. This isn't appropriate anymore as
the terms for interface types have moved to a more technical level.
The commit adjusts all scenarios in the basic Genode repositories properly.
Fixes#4238
Introduce the uplink tag:
! <config>
! <uplink label="wifi" domain="uplink">
! <uplink label="wired" domain="wired_bridge">
! <uplink domain="wired_bridge">
! <config/>
For each uplink tag, the NIC router requests a NIC session with the
corresponding label or an empty label if there is no label attribute.
These NIC sessions get attached to the domain that is set in their
uplink tag as soon as the domain appears. This means their lifetime is
not bound to the domain. Uplink NIC sessions can be safely moved from
one domain to another without being closed by reconfiguring the
corresponding domain attribute.
Attention: This may render previously valid NIC router configurations
useless. A domain named "uplink" doesn't automatically request a NIC
session anymore. To fix these configurations, just add
! <uplink domain="uplink"/>
or
! <uplink label="[LABEL]" domain="uplink"/>
as direct subtag of the <config> tag.
Issue #2840
