linux-stable.git/drivers/net/ipvlan, branch v4.12

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

ipvlan: use pernet operations and restrict l3s hooks to master netns

2017-04-25T14:43:22+00:00

commit 4fbae7d83c98c30efc ("ipvlan: Introduce l3s mode") added
registration of netfilter hooks via nf_register_hooks().

This API provides the illusion of 'global' netfilter hooks by placing the
hooks in all current and future network namespaces.

In case of ipvlan the hook appears to be only needed in the namespace
that contains the ipvlan master device (i.e., usually init_net), so
placing them in all namespaces is not needed.

This switches ipvlan driver to pernet operations, and then only registers
hooks in namespaces where a ipvlan master device is set to l3s mode.

Extra care has to be taken when the master device is moved to another
namespace, as we might have to 'move' the netfilter hooks too.

This is done by storing the namespace the ipvlan port was created in.
On REGISTER event, do (un)register operations in the old/new namespaces.

This will also allow removal of the nf_register_hooks() in a future patch.

Cc: Mahesh Bandewar 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

ipvtap: IP-VLAN based tap driver

2017-02-12T01:59:41+00:00

This patch adds a tap character device driver that is based on the
IP-VLAN network interface, called ipvtap. An ipvtap device can be created
in the same way as an ipvlan device, using 'type ipvtap', and then accessed
using the tap user space interface.

Signed-off-by: Sainath Grandhi 
Signed-off-by: David S. Miller

ipvlan: use netdev_is_rx_handler_busy instead of checking specific type

2017-01-20T17:22:26+00:00

IPvlan checks if the master device is already used by checking a
specific device (here it's macvlan device). This is technically not
sufficient and it should just ensure the rx_handler is busy or not.
This would be a super check that includes macvlan and any other that
has already registered rx-handler.

Signed-off-by: Mahesh Bandewar 
Signed-off-by: David S. Miller

ipvlan: fix dev_id creation corner case.

2017-01-16T19:04:43+00:00

In the last patch da36e13cf65 ("ipvlan: improvise dev_id generation
logic in IPvlan") I missed some part of Dave's suggestion and because
of that the dev_id creation could fail in a corner case scenario. This
would happen when more or less 64k devices have been already created and
several have been deleted. If the devices that are still sticking around
are the last n bits from the bitmap. So in this scenario even if lower
bits are available, the dev_id search is so narrow that it always fails.

Fixes: da36e13cf65 ("ipvlan: improvise dev_id generation logic in IPvlan")
CC: David Miller 
CC: Eric Dumazet 
Signed-off-by: Mahesh Bandewar 
Signed-off-by: David S. Miller

ipvlan: improvise dev_id generation logic in IPvlan

2017-01-11T01:47:12+00:00

The patch 009146d117b ("ipvlan: assign unique dev-id for each slave
device.") used ida_simple_get() to generate dev_ids assigned to the
slave devices. However (Eric has pointed out that) there is a shortcoming
with that approach as it always uses the first available ID. This
becomes a problem when a slave gets deleted and a new slave gets added.
The ID gets reassigned causing the new slave to get the same link-local
address. This side-effect is undesirable.

This patch adds a per-port variable that keeps track of the IDs
assigned and used as the stat-base for the IDR api. This base will be
wrapped around when it reaches the MAX (0xFFFE) value possibly on a
busy system where slaves are added and deleted routinely.

Fixes: 009146d117b ("ipvlan: assign unique dev-id for each slave device.")
Signed-off-by: Mahesh Bandewar 
CC: Eric Dumazet 
CC: David Miller 
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

ipvlan: assign unique dev-id for each slave device.

2017-01-04T18:30:42+00:00

IPvlan setup uses one mac-address (of master). The IPv6 link-local
addresses are derived using the mac-address on the link. Lack of
dev-ids makes these link-local addresses same for all slaves including
that of master device. dev-ids are necessary to add differentiation
when L2 address is shared.

Signed-off-by: Mahesh Bandewar 
Signed-off-by: David S. Miller

driver: ipvlan: Remove unnecessary ipvlan NULL check in ipvlan_count_rx

2016-12-28T19:23:22+00:00

There are three functions which would invoke the ipvlan_count_rx. They
are ipvlan_process_multicast, ipvlan_rcv_frame, and ipvlan_nf_input.
The former two functions already use the ipvlan directly before
ipvlan_count_rx, and ipvlan_nf_input gets the ipvlan from
ipvl_addr->master, it is not possible to be NULL too.
So the ipvlan pointer check is unnecessary in ipvlan_count_rx.

Signed-off-by: Gao Feng 
Signed-off-by: David S. Miller

driver: ipvlan: Define common functions to decrease duplicated codes used to add or del IP address

2016-12-28T19:23:21+00:00

There are some duplicated codes in ipvlan_add_addr6/4 and
ipvlan_del_addr6/4. Now define two common functions ipvlan_add_addr
and ipvlan_del_addr to decrease the duplicated codes.
It could be helful to maintain the codes.

Signed-off-by: Gao Feng 
Signed-off-by: David S. Miller