kernel/linux.git/drivers/net/dummy.c, branch v4.19.39

net: Do not take net_rwsem in __rtnl_link_unregister()

2018-04-01T02:24:58+00:00

This function calls call_netdevice_notifier(), which also may take net_rwsem. So, we can't use net_rwsem here. This patch makes callers of this functions take pernet_ops_rwsem, like register_netdevice_notifier() does. This will protect the modifications of net_namespace_list, and allows notifiers to take it (they won't have to care about context). Since __rtnl_link_unregister() is used on module load and unload (which are not frequent operations), this looks for me better, than make all call_netdevice_notifier() always executing in "protected net_namespace_list" context. Also, this fixes the problem we had a deal in 328fbe747ad4 "Close race between {un, }register_netdevice_notifier and ...", and guarantees __rtnl_link_unregister() does not skip exitting net. Signed-off-by: Kirill Tkhai Signed-off-by: David S. Miller

net: dummy: remove fake SR-IOV functionality

2017-12-02T23:27:58+00:00

netdevsim driver seems like a better place for fake SR-IOV functionality. Remove the code previously added to dummy. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Acked-by: Phil Sutter Signed-off-by: Daniel Borkmann

net: remove MTU limits for dummy and ifb device

2017-09-25T23:26:09+00:00

These two drivers (dummy and ifb) call ether_setup(), after commit 61e84623ace3 ("net: centralize net_device min/max MTU checking"), the range of mtu is [min_mtu, max_mtu], which is [68, 1500] by default. These two devices should not have limits on MTU. This patch set their min_mtu/max_mtu to 0. So that dev_set_mtu() will not check the mtu range, and can be set with any value. CC: Eric Dumazet CC: Sabrina Dubroca Signed-off-by: Zhang Shengju Signed-off-by: David S. Miller

dummy: declare dummy devices as enumerated devices

2017-09-18T18:28:36+00:00

Dummy device name is enumerated by the kernel, let user space be aware of the naming scheme used by dummy devices: (visible in /sys/class/net//name_assign_type). Signed-off-by: Zhang Shengju Signed-off-by: David S. Miller

dummy: Remove references to NETIF_F_UFO.

2017-07-17T16:52:57+00:00

It is going away. Signed-off-by: David S. Miller

net: add netlink_ext_ack argument to rtnl_link_ops.validate

2017-06-27T03:13:22+00:00

Add support for extended error reporting. Signed-off-by: Matthias Schiffer Acked-by: David Ahern Signed-off-by: David S. Miller

net: Fix inconsistent teardown and release of private netdev state.

2017-06-07T19:53:24+00:00

Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller

Enable tx timestamping on loopback and dummy

2017-03-21T21:40:01+00:00

This enables developing code that uses SOF_TIMESTAMPING_TX_SOFTWARE by using localhost addresses (without needing to send packets outside), as well as enabling unit and functional testing of TX timestamping code without needing hardware support or network access. It also fulfills the expectation of software network devices supporting software-based timestamping. Tested on qemu using txtimestamping.c from the kernel selftests, and ethtool -T. Signed-off-by: Ezequiel Lara Gomez Signed-off-by: David S. Miller

net: dummy: Introduce dummy virtual functions

2017-01-24T19:07:22+00:00

The idea for this was born when testing VF support in iproute2 which was impeded by hardware requirements. In fact, not every VF-capable hardware driver implements all netdev ops, so testing the interface is still hard to do even with a well-sorted hardware shelf. To overcome this and allow for testing the user-kernel interface, this patch allows to turn dummy into a PF with a configurable amount of VFs. Since my patch series 'bus-agnostic-num-vf' has been accepted, implementing the required interfaces is pretty straightforward: Iff 'num_vfs' module parameter was given a value >0, a dummy bus type is being registered which implements the 'num_vf()' callback. Additionally, a dummy parent device common to all dummy devices is registered which sits on the above dummy bus. Joint work with Sabrina Dubroca. Signed-off-by: Sabrina Dubroca Signed-off-by: Phil Sutter Signed-off-by: David S. Miller

net: make ndo_get_stats64 a void function

2017-01-08T22:51:44+00:00

The network device operation for reading statistics is only called in one place, and it ignores the return value. Having a structure return value is potentially confusing because some future driver could incorrectly assume that the return value was used. Fix all drivers with ndo_get_stats64 to have a void function. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller