This builds on earlier work that implemented netdev object refcounting.
However, rather than requiring explicit create and destroy calls,
these operations are now performed automatically based on the referenece
count. This is important because in certain situations it is not
possible to know whether a netdev has already been created. A
workaround existed (which looked fairly similar to this paradigm) but
introduced it's own issues. This simplifies and unifies the API.
The latest version of GCC flags a common socket convention as breaking
strict-aliasing rules. This commit removes the aliasing and gets rid of
the scary warning.
This implements the userspace portion of GRE on Linux. It communicates
with the kernel module to setup tunnels using either Netlink or ioctls
as appropriate based on the kernel version.
Significant portions of this commit were actually written by
Justin Pettit.
This change adds netdev_create() and netdev_destroy() functions to allow
the creation of network devices through the netdev library. Previously,
network devices had to already exist or be created on demand through
netdev_open(). This caused problems such as not being able to specify
TAP devices as ports in ovs-vswitchd, which this patch fixes.
This also lays the groundwork for adding GRE and VDE support.
The comment on netdev_get_features() claimed that all of the passed-in
values were set to 0 on failure, but the implementation didn't live up
to the promise.
CC: Paul Ingram <paul@nicira.com>
Fixes a bug whereby netdev_linux_set_etheraddr() would update the cached
Ethernet address but not mark it valid. (This potentially wasted a system
call later but wasn't harmful.)
As an added optimization, don't set the Ethernet address at all if the
new address is the same as the current address.
netdev_linux_receive was returning positive error codes while the
interface specifies that it should be returning negative errors.
This difference causes a huge increase in (non-existant) packet
processing with the userspace datapath.
Whether a port is internal is cached to avoid requerying the kernel
every time stats are requested. However, the cache vality bit was
never being set so the cache wasn't used. This corrects that
oversight.
Thanks to Ben Pfaff for noticing.
Internal ports appear to have their transmit and receive stats swapped
because from the kernel's point of view these ports are acting like
the machine connected to the switch, not the switch itself. This swaps
the stats for consistency with other ports.
It was getting to be too confusing to have both netdev_linux_* functions
and linux_netdev_* functions. Rename the latter to make the distinction
more obvious. "rtnetlink" seems to be a fairly good name because that's
what the kernel calls it, so the name will be familiar at least to people
who know about rtnetlink.
This new abstraction layer allows multiple implementations of network
devices in a single running process. This will be useful, for example, to
support network devices that are simulated entirely in the running process
or that communicate with other processes over Unix domain sockets, etc.
The reimplemented tap device support in this commit has not been tested.
The dpif and netdev code has had various ways to check for changes to
dpifs and netdevs over the course of Open vSwitch development. All of
these have been thus far fairly specific to the Linux implementation. This
commit is the start of a more general API for watching for such changes.
The dpif-related parts seem fairly mature and so they are documented,
the netdev parts will probably need to change somewhat and so they are
not documented yet.
