* Re: [PATCH] [RFC] bpf: tracing: new helper bpf_get_current_cgroup_ino
From: Y Song @ 2018-05-22 0:24 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Alban Crequy, netdev, linux-kernel, containers, cgroups,
Alban Crequy, tj
In-Reply-To: <20180521162609.lpdrnozowmzdn57m@ast-mbp.dhcp.thefacebook.com>
On Mon, May 21, 2018 at 9:26 AM, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
> On Sun, May 13, 2018 at 07:33:18PM +0200, Alban Crequy wrote:
>>
>> +BPF_CALL_2(bpf_get_current_cgroup_ino, u32, hierarchy, u64, flags)
>> +{
>> + // TODO: pick the correct hierarchy instead of the mem controller
>> + struct cgroup *cgrp = task_cgroup(current, memory_cgrp_id);
>> +
>> + if (unlikely(!cgrp))
>> + return -EINVAL;
>> + if (unlikely(hierarchy))
>> + return -EINVAL;
>> + if (unlikely(flags))
>> + return -EINVAL;
>> +
>> + return cgrp->kn->id.ino;
>
> ino only is not enough to identify cgroup. It needs generation number too.
> I don't quite see how hierarchy and flags can be used in the future.
> Also why limit it to memcg?
>
> How about something like this instead:
>
> BPF_CALL_2(bpf_get_current_cgroup_id)
> {
> struct cgroup *cgrp = task_dfl_cgroup(current);
>
> return cgrp->kn->id.id;
> }
> The user space can use fhandle api to get the same 64-bit id.
I think this should work. This will also be useful to bcc as user
space can encode desired id
in the bpf program and compared that id to the current cgroup id, so we can have
cgroup level tracing (esp. stat collection) support. To cope with
cgroup hierarchy, user can use
cgroup-array based approach or explicitly compare against multiple cgroup id's.
^ permalink raw reply
* Re: INFO: rcu detected stall in is_bpf_text_address
From: Marcelo Ricardo Leitner @ 2018-05-22 0:43 UTC (permalink / raw)
To: Xin Long
Cc: Eric Dumazet, syzbot, ast, Daniel Borkmann, LKML, network dev,
syzkaller-bugs, linux-sctp
In-Reply-To: <CADvbK_e7LXc7minSmaPw6iZvjWo215wG-pPAS0gr58+-VxUO7Q@mail.gmail.com>
On Sun, May 20, 2018 at 04:26:03PM +0800, Xin Long wrote:
> On Sat, May 19, 2018 at 11:57 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > SCTP experts, please take a look.
> >
> > On 05/19/2018 08:55 AM, syzbot wrote:
> >> Hello,
> >>
> >> syzbot found the following crash on:
> >>
> >> HEAD commit: 73fcb1a370c7 Merge branch 'akpm' (patches from Andrew)
> >> git tree: upstream
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=1462ec0f800000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=f3b4e30da84ec1ed
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=3dcd59a1f907245f891f
> >> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
> >> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1079cf8f800000
> Thank you.
> The Reproducer is more than helpful.
>
> setsockopt$inet_sctp6_SCTP_RTOINFO(r0, 0x84, 0x0,
> &(0x7f0000000140)={0x0, 0x6, 0x7, 0x4}, 0x10)
>
> It set rto_min=6 and rto_max=7, these are too small values.
> t3_rtx timer works fine with it. But hb_timer will get stuck there, as
> in its timer handler it starts this timer again with this value, then
> it goes to the timer handler again...
Nice, thanks Xin.
>
> HB has to repeat this and the hb timer's expire may also have to use
> 'trans->rto >> 1 ...' stuff. But we can limit the RTO's min value, like
> HZ/20, which is 'Try again later.' number used when sock lock is
> owned by others in all timer handlers.
I think a good fix for this is to not allow the application to go
below net.sctp.rto_min, and neither above net.sctp.rto_max.
Then they can even be close to each other, won't be an issue, as long
as rto_min is something sensible. Which then brings it to the second
step of a fix: to restrict rto_min to be >= HZ/5 (copying from TCP
here).
^ permalink raw reply
* Re: [PATCH 05/33] cxgb4: use match_string() helper
From: Yisheng Xie @ 2018-05-22 0:55 UTC (permalink / raw)
To: Andy Shevchenko; +Cc: Linux Kernel Mailing List, Ganesh Goudar, netdev
In-Reply-To: <CAHp75Vcpfeey_womFqoqp_gyy0=jqMHgW+30WJs-BcVTM-vHQA@mail.gmail.com>
Hi Andy,
On 2018/5/22 5:39, Andy Shevchenko wrote:
> On Mon, May 21, 2018 at 2:57 PM, Yisheng Xie <xieyisheng1@huawei.com> wrote:
>> match_string() returns the index of an array for a matching string,
>> which can be used intead of open coded variant.
>
>> - for (i = 0; i < ARRAY_SIZE(cudbg_region); i++) {
>> - if (!strcmp(cudbg_region[i], region_name)) {
>> - found = 1;
>> - idx = i;
>> - break;
>> - }
>> - }
>> - if (!found)
>> - return -EINVAL;
>> + rc = match_string(cudbg_region, ARRAY_SIZE(cudbg_region), region_name);
>> + if (rc < 0)
>> + return rc;
>>
>> - found = 0;
>> + idx = rc;
>
> Is found still in use after this?
> If so, is it initialized properly now?
it is initialized when define 'found', so no need to be initialized once more.
Thanks
Yisheng
>
^ permalink raw reply
* [PATCH net-next v11 0/5] Enable virtio_net to act as a standby for a passthru device
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
The main motivation for this patch is to enable cloud service providers
to provide an accelerated datapath to virtio-net enabled VMs in a
transparent manner with no/minimal guest userspace changes. This also
enables hypervisor controlled live migration to be supported with VMs that
have direct attached SR-IOV VF devices.
Patch 1 introduces a failover module that provides a generic interface for
paravirtual drivers to listen for netdev register/unregister/link change
events from pci ethernet devices with the same MAC and takeover their
datapath. The notifier and event handling code is based on the existing
netvsc implementation.
Patch 2 refactors netvsc to use the registration/notification framework
introduced by failover module.
Patch 3 introduces a net_failover driver that provides an automated
failover mechanism to paravirtual drivers via APIs to create and destroy
a failover master netdev and mananges a primary and standby slave netdevs
that get registered via the generic failover infrastructure.
Patch 4 introduces a new feature bit VIRTIO_NET_F_STANDBY to virtio-net
that can be used by hypervisor to indicate that virtio_net interface
should act as a standby for another device with the same MAC address.
Patch 5 extends virtio_net to use alternate datapath when available and
registered. When STANDBY feature is enabled, virtio_net driver uese the
net_failover API to create an additional 'failover' netdev that acts as
a master device and controls 2 slave devices. The original virtio_net
netdev is registered as 'standby' netdev and a passthru/vf device with
the same MAC gets registered as 'primary' netdev. Both 'standby' and
'failover' netdevs are associated with the same 'pci' device. The user
accesses the network interface via 'failover' netdev. The 'failover'
netdev chooses 'primary' netdev as default for transmits when it is
available with link up and running.
As this patch series is initially focusing on usecases where hypervisor
fully controls the VM networking and the guest is not expected to directly
configure any hardware settings, it doesn't expose all the ndo/ethtool ops
that are supported by virtio_net at this time. To support additional usecases,
it should be possible to enable additional ops later by caching the state
in failover netdev and replaying when the 'primary' netdev gets registered.
At the time of live migration, the hypervisor needs to unplug the VF device
from the guest on the source host and reset the MAC filter of the VF to
initiate failover of datapath to virtio before starting the migration. After
the migration is completed, the destination hypervisor sets the MAC filter
on the VF and plugs it back to the guest to switch over to VF datapath.
This patch is based on the discussion initiated by Jesse on this thread.
https://marc.info/?l=linux-virtualization&m=151189725224231&w=2
v11:
- Tested live migration with virtio-net/AVF(i40evf) configured in failover
mode while running iperf in background. Tried static ip and dhcp
configurations using 'network' scripts and Network Manager.
- Build tested netvsc module.
Updates:
- Split net_failover module into 2 components.
1. 'failover' module that provides generic failover infrastructure
to register a failover instance and listen for slave events.
2. 'net_failover' driver that provides APIs to create/destroy upper
netdev and supports 3-netdev model used by virtio-net.
- Added documentation
v10:
- Tested live migration with virtio-net/AVF(i40evf) configured in failover
mode while running iperf in background. Tried static ip and dhcp
configurations using 'network' scripts and Network Manager.
- To avoid dhcp requests to be sent over the lower 'standby' and 'primary'
netdevs, ifcfg-xxx scripts for the lower devices can be created.
- Build tested netvsc module.
Updates:
- fix net_failover_open() to update failover CARRIER correctly based on
standby and primary states.
- fix net_failover_handle_frame() to handle frames received on standby
when primary is present.
- replace netdev_upper_dev_link with netdev_master_upper_dev_link and
handle lower dev state changes.
- fix net_failver_create() and net_failover_register() interfaces to
use ERR_PTR and avoid arg **
- disable setting mac address when virtio-net in STANDBY mode
- document exported symbols
- added entry to MAINTAINERS file
v9:
Select NET_FAILOVER automatically when VIRTIO_NET/HYPERV_NET
are enabled. (stephen)
v8:
- Made the failover managment routines more robust by updating the feature
bits/other fields in the failover netdev when slave netdevs are
registered/unregistered. (mst)
- added support for handling vlans.
- Limited the changes in netvsc to only use the notifier/event/lookups
from the failover module. The slave register/unregister/link-change
handlers are only updated to use the getbymac routine to get the
upper netdev. There is no change in their functionality. (stephen)
- renamed structs/function/file names to use net_failover prefix. (mst)
v7
- Rename 'bypass/active/backup' terminology with 'failover/primary/standy'
(jiri, mst)
- re-arranged dev_open() and dev_set_mtu() calls in the register routines
so that they don't get called for 2-netdev model. (stephen)
- fixed select_queue() routine to do queue selection based on VF if it is
registered as primary. (stephen)
- minor bugfixes
v6 RFC:
Simplified virtio_net changes by moving all the ndo_ops of the
bypass_netdev and create/destroy of bypass_netdev to 'bypass' module.
avoided 2 phase registration(driver + instances).
introduced IFF_BYPASS/IFF_BYPASS_SLAVE dev->priv_flags
replaced mutex with a spinlock
v5 RFC:
Based on Jiri's comments, moved the common functionality to a 'bypass'
module so that the same notifier and event handlers to handle child
register/unregister/link change events can be shared between virtio_net
and netvsc.
Improved error handling based on Siwei's comments.
v4:
- Based on the review comments on the v3 version of the RFC patch and
Jakub's suggestion for the naming issue with 3 netdev solution,
proposed 3 netdev in-driver bonding solution for virtio-net.
v3 RFC:
- Introduced 3 netdev model and pointed out a couple of issues with
that model and proposed 2 netdev model to avoid these issues.
- Removed broadcast/multicast optimization and only use virtio as
backup path when VF is unplugged.
v2 RFC:
- Changed VIRTIO_NET_F_MASTER to VIRTIO_NET_F_BACKUP (mst)
- made a small change to the virtio-net xmit path to only use VF datapath
for unicasts. Broadcasts/multicasts use virtio datapath. This avoids
east-west broadcasts to go over the PCI link.
- added suppport for the feature bit in qemu
Sridhar Samudrala (5):
net: Introduce generic failover module
netvsc: refactor notifier/event handling code to use the failover
framework
net: Introduce net_failover driver
virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit
virtio_net: Extend virtio to use VF datapath when available
Documentation/networking/failover.rst | 18 +
Documentation/networking/net_failover.rst | 116 +++++
MAINTAINERS | 16 +
drivers/net/Kconfig | 13 +
drivers/net/Makefile | 1 +
drivers/net/hyperv/Kconfig | 1 +
drivers/net/hyperv/hyperv_net.h | 2 +
drivers/net/hyperv/netvsc_drv.c | 133 +----
drivers/net/net_failover.c | 836 ++++++++++++++++++++++++++++++
drivers/net/virtio_net.c | 40 +-
include/linux/netdevice.h | 16 +
include/net/failover.h | 31 ++
include/net/net_failover.h | 40 ++
include/uapi/linux/virtio_net.h | 3 +
net/Kconfig | 13 +
net/core/Makefile | 1 +
net/core/failover.c | 273 ++++++++++
17 files changed, 1440 insertions(+), 113 deletions(-)
create mode 100644 Documentation/networking/failover.rst
create mode 100644 Documentation/networking/net_failover.rst
create mode 100644 drivers/net/net_failover.c
create mode 100644 include/net/failover.h
create mode 100644 include/net/net_failover.h
create mode 100644 net/core/failover.c
--
2.14.3
^ permalink raw reply
* [PATCH net-next v11 1/5] net: Introduce generic failover module
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
In-Reply-To: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com>
The failover module provides a generic interface for paravirtual drivers
to register a netdev and a set of ops with a failover instance. The ops
are used as event handlers that get called to handle netdev register/
unregister/link change/name change events on slave pci ethernet devices
with the same mac address as the failover netdev.
This enables paravirtual drivers to use a VF as an accelerated low latency
datapath. It also allows migration of VMs with direct attached VFs by
failing over to the paravirtual datapath when the VF is unplugged.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
Documentation/networking/failover.rst | 18 +++
MAINTAINERS | 8 +
include/linux/netdevice.h | 16 ++
include/net/failover.h | 31 ++++
net/Kconfig | 13 ++
net/core/Makefile | 1 +
net/core/failover.c | 273 ++++++++++++++++++++++++++++++++++
7 files changed, 360 insertions(+)
create mode 100644 Documentation/networking/failover.rst
create mode 100644 include/net/failover.h
create mode 100644 net/core/failover.c
diff --git a/Documentation/networking/failover.rst b/Documentation/networking/failover.rst
new file mode 100644
index 000000000000..f0c8483cdbf5
--- /dev/null
+++ b/Documentation/networking/failover.rst
@@ -0,0 +1,18 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========
+FAILOVER
+========
+
+Overview
+========
+
+The failover module provides a generic interface for paravirtual drivers
+to register a netdev and a set of ops with a failover instance. The ops
+are used as event handlers that get called to handle netdev register/
+unregister/link change/name change events on slave pci ethernet devices
+with the same mac address as the failover netdev.
+
+This enables paravirtual drivers to use a VF as an accelerated low latency
+datapath. It also allows live migration of VMs with direct attached VFs by
+failing over to the paravirtual datapath when the VF is unplugged.
diff --git a/MAINTAINERS b/MAINTAINERS
index 658880464b9d..aed9575ddc53 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5413,6 +5413,14 @@ S: Maintained
F: Documentation/hwmon/f71805f
F: drivers/hwmon/f71805f.c
+FAILOVER MODULE
+M: Sridhar Samudrala <sridhar.samudrala@intel.com>
+L: netdev@vger.kernel.org
+S: Supported
+F: net/core/failover.c
+F: include/net/failover.h
+F: Documentation/networking/failover.rst
+
FANOTIFY
M: Jan Kara <jack@suse.cz>
R: Amir Goldstein <amir73il@gmail.com>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 03ed492c4e14..0f4ba52b641d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1421,6 +1421,8 @@ struct net_device_ops {
* entity (i.e. the master device for bridged veth)
* @IFF_MACSEC: device is a MACsec device
* @IFF_NO_RX_HANDLER: device doesn't support the rx_handler hook
+ * @IFF_FAILOVER: device is a failover master device
+ * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
*/
enum netdev_priv_flags {
IFF_802_1Q_VLAN = 1<<0,
@@ -1450,6 +1452,8 @@ enum netdev_priv_flags {
IFF_PHONY_HEADROOM = 1<<24,
IFF_MACSEC = 1<<25,
IFF_NO_RX_HANDLER = 1<<26,
+ IFF_FAILOVER = 1<<27,
+ IFF_FAILOVER_SLAVE = 1<<28,
};
#define IFF_802_1Q_VLAN IFF_802_1Q_VLAN
@@ -1478,6 +1482,8 @@ enum netdev_priv_flags {
#define IFF_RXFH_CONFIGURED IFF_RXFH_CONFIGURED
#define IFF_MACSEC IFF_MACSEC
#define IFF_NO_RX_HANDLER IFF_NO_RX_HANDLER
+#define IFF_FAILOVER IFF_FAILOVER
+#define IFF_FAILOVER_SLAVE IFF_FAILOVER_SLAVE
/**
* struct net_device - The DEVICE structure.
@@ -4321,6 +4327,16 @@ static inline bool netif_is_rxfh_configured(const struct net_device *dev)
return dev->priv_flags & IFF_RXFH_CONFIGURED;
}
+static inline bool netif_is_failover(const struct net_device *dev)
+{
+ return dev->priv_flags & IFF_FAILOVER;
+}
+
+static inline bool netif_is_failover_slave(const struct net_device *dev)
+{
+ return dev->priv_flags & IFF_FAILOVER_SLAVE;
+}
+
/* This device needs to keep skb dst for qdisc enqueue or ndo_start_xmit() */
static inline void netif_keep_dst(struct net_device *dev)
{
diff --git a/include/net/failover.h b/include/net/failover.h
new file mode 100644
index 000000000000..fea9d0b978c8
--- /dev/null
+++ b/include/net/failover.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, Intel Corporation. */
+
+#ifndef _FAILOVER_H
+#define _FAILOVER_H
+
+#include <linux/netdevice.h>
+
+struct failover_ops {
+ int (*slave_register)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_unregister)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_link_change)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+ int (*slave_name_change)(struct net_device *slave_dev,
+ struct net_device *failover_dev);
+};
+
+struct failover {
+ struct list_head list;
+ struct net_device __rcu *failover_dev;
+ struct failover_ops __rcu *ops;
+};
+
+struct failover *failover_register(struct net_device *dev,
+ struct failover_ops *ops);
+void failover_unregister(struct failover *failover);
+int failover_slave_unregister(struct net_device *slave_dev);
+
+#endif /* _FAILOVER_H */
diff --git a/net/Kconfig b/net/Kconfig
index df8d45ef47d8..d581c4f0f1c4 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -430,6 +430,19 @@ config MAY_USE_DEVLINK
config PAGE_POOL
bool
+config FAILOVER
+ tristate "Generic failover module"
+ help
+ The failover module provides a generic interface for paravirtual
+ drivers to register a netdev and a set of ops with a failover
+ instance. The ops are used as event handlers that get called to
+ handle netdev register/unregister/link change/name change events
+ on slave pci ethernet devices with the same mac address as the
+ failover netdev. This enables paravirtual drivers to use a
+ VF as an accelerated low latency datapath. It also allows live
+ migration of VMs with direct attached VFs by failing over to the
+ paravirtual datapath when the VF is unplugged.
+
endif # if NET
# Used by archs to tell that they support BPF JIT compiler plus which flavour.
diff --git a/net/core/Makefile b/net/core/Makefile
index 7080417f8bc8..80175e6a2eb8 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -31,3 +31,4 @@ obj-$(CONFIG_DST_CACHE) += dst_cache.o
obj-$(CONFIG_HWBM) += hwbm.o
obj-$(CONFIG_NET_DEVLINK) += devlink.o
obj-$(CONFIG_GRO_CELLS) += gro_cells.o
+obj-$(CONFIG_FAILOVER) += failover.o
diff --git a/net/core/failover.c b/net/core/failover.c
new file mode 100644
index 000000000000..48ee713a1ef4
--- /dev/null
+++ b/net/core/failover.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018, Intel Corporation. */
+
+/* A common module to handle registrations and notifications for paravirtual
+ * drivers to enable accelerated datapath and support VF live migration.
+ *
+ * The notifier and event handling code is based on netvsc driver.
+ */
+
+#include <linux/module.h>
+#include <linux/etherdevice.h>
+#include <uapi/linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <net/failover.h>
+
+static LIST_HEAD(failover_list);
+static DEFINE_SPINLOCK(failover_lock);
+
+static struct net_device *failover_get_bymac(u8 *mac, struct failover_ops **ops)
+{
+ struct net_device *failover_dev;
+ struct failover *failover;
+
+ spin_lock(&failover_lock);
+ list_for_each_entry(failover, &failover_list, list) {
+ failover_dev = rtnl_dereference(failover->failover_dev);
+ if (ether_addr_equal(failover_dev->perm_addr, mac)) {
+ *ops = rtnl_dereference(failover->ops);
+ spin_unlock(&failover_lock);
+ return failover_dev;
+ }
+ }
+ spin_unlock(&failover_lock);
+ return NULL;
+}
+
+/**
+ * failover_slave_register - Register a slave netdev
+ *
+ * @slave_dev: slave netdev that is being registered
+ *
+ * Registers a slave device to a failover instance. Only ethernet devices
+ * are supported.
+ */
+static int failover_slave_register(struct net_device *slave_dev)
+{
+ struct net_device *failover_dev;
+ struct failover_ops *fops;
+
+ if (slave_dev->type != ARPHRD_ETHER)
+ goto done;
+
+ ASSERT_RTNL();
+
+ failover_dev = failover_get_bymac(slave_dev->perm_addr, &fops);
+ if (!failover_dev)
+ goto done;
+
+ if (fops && fops->slave_register)
+ return fops->slave_register(slave_dev, failover_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+
+/**
+ * failover_slave_unregister - Unregister a slave netdev
+ *
+ * @slave_dev: slave netdev that is being unregistered
+ *
+ * Unregisters a slave device from a failover instance.
+ */
+int failover_slave_unregister(struct net_device *slave_dev)
+{
+ struct net_device *failover_dev;
+ struct failover_ops *fops;
+
+ if (!netif_is_failover_slave(slave_dev))
+ goto done;
+
+ ASSERT_RTNL();
+
+ failover_dev = failover_get_bymac(slave_dev->perm_addr, &fops);
+ if (!failover_dev)
+ goto done;
+
+ if (fops && fops->slave_unregister)
+ return fops->slave_unregister(slave_dev, failover_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+EXPORT_SYMBOL_GPL(failover_slave_unregister);
+
+static int failover_slave_link_change(struct net_device *slave_dev)
+{
+ struct net_device *failover_dev;
+ struct failover_ops *fops;
+
+ if (!netif_is_failover_slave(slave_dev))
+ goto done;
+
+ ASSERT_RTNL();
+
+ failover_dev = failover_get_bymac(slave_dev->perm_addr, &fops);
+ if (!failover_dev)
+ goto done;
+
+ if (!netif_running(failover_dev))
+ goto done;
+
+ if (fops && fops->slave_link_change)
+ return fops->slave_link_change(slave_dev, failover_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+
+static int failover_slave_name_change(struct net_device *slave_dev)
+{
+ struct net_device *failover_dev;
+ struct failover_ops *fops;
+
+ if (!netif_is_failover_slave(slave_dev))
+ goto done;
+
+ ASSERT_RTNL();
+
+ failover_dev = failover_get_bymac(slave_dev->perm_addr, &fops);
+ if (!failover_dev)
+ goto done;
+
+ if (!netif_running(failover_dev))
+ goto done;
+
+ if (fops && fops->slave_name_change)
+ return fops->slave_name_change(slave_dev, failover_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+
+static int
+failover_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+ struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
+
+ /* Skip parent events */
+ if (netif_is_failover(event_dev))
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case NETDEV_REGISTER:
+ return failover_slave_register(event_dev);
+ case NETDEV_UNREGISTER:
+ return failover_slave_unregister(event_dev);
+ case NETDEV_UP:
+ case NETDEV_DOWN:
+ case NETDEV_CHANGE:
+ return failover_slave_link_change(event_dev);
+ case NETDEV_CHANGENAME:
+ return failover_slave_name_change(event_dev);
+ default:
+ return NOTIFY_DONE;
+ }
+}
+
+static struct notifier_block failover_notifier = {
+ .notifier_call = failover_event,
+};
+
+static void
+failover_existing_slave_register(struct net_device *failover_dev)
+{
+ struct net *net = dev_net(failover_dev);
+ struct net_device *dev;
+
+ rtnl_lock();
+ for_each_netdev(net, dev) {
+ if (netif_is_failover(dev))
+ continue;
+ if (ether_addr_equal(failover_dev->perm_addr, dev->perm_addr))
+ failover_slave_register(dev);
+ }
+ rtnl_unlock();
+}
+
+/**
+ * failover_register - Register a failover instance
+ *
+ * @dev: failover netdev
+ * @ops: failover ops
+ *
+ * Allocate and register a failover instance for a failover netdev. ops
+ * provides handlers for slave device register/unregister/link change/
+ * name change events.
+ *
+ * Return: pointer to failover instance
+ */
+struct failover *failover_register(struct net_device *dev,
+ struct failover_ops *ops)
+{
+ struct failover *failover;
+
+ if (dev->type != ARPHRD_ETHER)
+ return ERR_PTR(-EINVAL);
+
+ failover = kzalloc(sizeof(*failover), GFP_KERNEL);
+ if (!failover)
+ return ERR_PTR(-ENOMEM);
+
+ rcu_assign_pointer(failover->ops, ops);
+ dev_hold(dev);
+ dev->priv_flags |= IFF_FAILOVER;
+ rcu_assign_pointer(failover->failover_dev, dev);
+
+ spin_lock(&failover_lock);
+ list_add_tail(&failover->list, &failover_list);
+ spin_unlock(&failover_lock);
+
+ netdev_info(dev, "failover master:%s registered\n", dev->name);
+
+ failover_existing_slave_register(dev);
+
+ return failover;
+}
+EXPORT_SYMBOL_GPL(failover_register);
+
+/**
+ * failover_unregister - Unregister a failover instance
+ *
+ * @failover: pointer to failover instance
+ *
+ * Unregisters and frees a failover instance.
+ */
+void failover_unregister(struct failover *failover)
+{
+ struct net_device *failover_dev;
+
+ failover_dev = rcu_dereference(failover->failover_dev);
+
+ netdev_info(failover_dev, "failover master:%s unregistered\n",
+ failover_dev->name);
+
+ failover_dev->priv_flags &= ~IFF_FAILOVER;
+ dev_put(failover_dev);
+
+ spin_lock(&failover_lock);
+ list_del(&failover->list);
+ spin_unlock(&failover_lock);
+
+ kfree(failover);
+}
+EXPORT_SYMBOL_GPL(failover_unregister);
+
+static __init int
+failover_init(void)
+{
+ register_netdevice_notifier(&failover_notifier);
+
+ return 0;
+}
+module_init(failover_init);
+
+static __exit
+void failover_exit(void)
+{
+ unregister_netdevice_notifier(&failover_notifier);
+}
+module_exit(failover_exit);
+
+MODULE_DESCRIPTION("Generic failover infrastructure/interface");
+MODULE_LICENSE("GPL v2");
--
2.14.3
^ permalink raw reply related
* [PATCH net-next v11 2/5] netvsc: refactor notifier/event handling code to use the failover framework
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
In-Reply-To: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com>
Use the registration/notification framework supported by the generic
failover infrastructure.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
drivers/net/hyperv/Kconfig | 1 +
drivers/net/hyperv/hyperv_net.h | 2 +
drivers/net/hyperv/netvsc_drv.c | 133 +++++++---------------------------------
3 files changed, 25 insertions(+), 111 deletions(-)
diff --git a/drivers/net/hyperv/Kconfig b/drivers/net/hyperv/Kconfig
index 0765d5f61714..23a2d145813a 100644
--- a/drivers/net/hyperv/Kconfig
+++ b/drivers/net/hyperv/Kconfig
@@ -2,5 +2,6 @@ config HYPERV_NET
tristate "Microsoft Hyper-V virtual network driver"
depends on HYPERV
select UCS2_STRING
+ select FAILOVER
help
Select this option to enable the Hyper-V virtual network driver.
diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 1be34d2e3563..99d8e7398a5b 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -932,6 +932,8 @@ struct net_device_context {
u32 vf_alloc;
/* Serial number of the VF to team with */
u32 vf_serial;
+
+ struct failover *failover;
};
/* Per channel data */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index da07ccdf84bf..6c77a81b7266 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -43,6 +43,7 @@
#include <net/pkt_sched.h>
#include <net/checksum.h>
#include <net/ip6_checksum.h>
+#include <net/failover.h>
#include "hyperv_net.h"
@@ -1763,46 +1764,6 @@ static void netvsc_link_change(struct work_struct *w)
rtnl_unlock();
}
-static struct net_device *get_netvsc_bymac(const u8 *mac)
-{
- struct net_device *dev;
-
- ASSERT_RTNL();
-
- for_each_netdev(&init_net, dev) {
- if (dev->netdev_ops != &device_ops)
- continue; /* not a netvsc device */
-
- if (ether_addr_equal(mac, dev->perm_addr))
- return dev;
- }
-
- return NULL;
-}
-
-static struct net_device *get_netvsc_byref(struct net_device *vf_netdev)
-{
- struct net_device *dev;
-
- ASSERT_RTNL();
-
- for_each_netdev(&init_net, dev) {
- struct net_device_context *net_device_ctx;
-
- if (dev->netdev_ops != &device_ops)
- continue; /* not a netvsc device */
-
- net_device_ctx = netdev_priv(dev);
- if (!rtnl_dereference(net_device_ctx->nvdev))
- continue; /* device is removed */
-
- if (rtnl_dereference(net_device_ctx->vf_netdev) == vf_netdev)
- return dev; /* a match */
- }
-
- return NULL;
-}
-
/* Called when VF is injecting data into network stack.
* Change the associated network device from VF to netvsc.
* note: already called with rcu_read_lock
@@ -1915,24 +1876,15 @@ static void netvsc_vf_setup(struct work_struct *w)
rtnl_unlock();
}
-static int netvsc_register_vf(struct net_device *vf_netdev)
+static int netvsc_register_vf(struct net_device *vf_netdev,
+ struct net_device *ndev)
{
- struct net_device *ndev;
struct net_device_context *net_device_ctx;
struct netvsc_device *netvsc_dev;
if (vf_netdev->addr_len != ETH_ALEN)
return NOTIFY_DONE;
- /*
- * We will use the MAC address to locate the synthetic interface to
- * associate with the VF interface. If we don't find a matching
- * synthetic interface, move on.
- */
- ndev = get_netvsc_bymac(vf_netdev->perm_addr);
- if (!ndev)
- return NOTIFY_DONE;
-
net_device_ctx = netdev_priv(ndev);
netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
if (!netvsc_dev || rtnl_dereference(net_device_ctx->vf_netdev))
@@ -1949,17 +1901,13 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
}
/* VF up/down change detected, schedule to change data path */
-static int netvsc_vf_changed(struct net_device *vf_netdev)
+static int netvsc_vf_changed(struct net_device *vf_netdev,
+ struct net_device *ndev)
{
struct net_device_context *net_device_ctx;
struct netvsc_device *netvsc_dev;
- struct net_device *ndev;
bool vf_is_up = netif_running(vf_netdev);
- ndev = get_netvsc_byref(vf_netdev);
- if (!ndev)
- return NOTIFY_DONE;
-
net_device_ctx = netdev_priv(ndev);
netvsc_dev = rtnl_dereference(net_device_ctx->nvdev);
if (!netvsc_dev)
@@ -1972,15 +1920,11 @@ static int netvsc_vf_changed(struct net_device *vf_netdev)
return NOTIFY_OK;
}
-static int netvsc_unregister_vf(struct net_device *vf_netdev)
+static int netvsc_unregister_vf(struct net_device *vf_netdev,
+ struct net_device *ndev)
{
- struct net_device *ndev;
struct net_device_context *net_device_ctx;
- ndev = get_netvsc_byref(vf_netdev);
- if (!ndev)
- return NOTIFY_DONE;
-
net_device_ctx = netdev_priv(ndev);
cancel_delayed_work_sync(&net_device_ctx->vf_takeover);
@@ -1994,6 +1938,12 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
return NOTIFY_OK;
}
+static struct failover_ops netvsc_failover_ops = {
+ .slave_register = netvsc_register_vf,
+ .slave_unregister = netvsc_unregister_vf,
+ .slave_link_change = netvsc_vf_changed,
+};
+
static int netvsc_probe(struct hv_device *dev,
const struct hv_vmbus_device_id *dev_id)
{
@@ -2083,8 +2033,14 @@ static int netvsc_probe(struct hv_device *dev,
goto register_failed;
}
+ net_device_ctx->failover = failover_register(net, &netvsc_failover_ops);
+ if (IS_ERR(net_device_ctx->failover))
+ goto err_failover;
+
return ret;
+err_failover:
+ unregister_netdev(net);
register_failed:
rndis_filter_device_remove(dev, nvdev);
rndis_failed:
@@ -2125,13 +2081,15 @@ static int netvsc_remove(struct hv_device *dev)
rtnl_lock();
vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
if (vf_netdev)
- netvsc_unregister_vf(vf_netdev);
+ failover_slave_unregister(vf_netdev);
if (nvdev)
rndis_filter_device_remove(dev, nvdev);
unregister_netdevice(net);
+ failover_unregister(ndev_ctx->failover);
+
rtnl_unlock();
rcu_read_unlock();
@@ -2158,54 +2116,8 @@ static struct hv_driver netvsc_drv = {
.remove = netvsc_remove,
};
-/*
- * On Hyper-V, every VF interface is matched with a corresponding
- * synthetic interface. The synthetic interface is presented first
- * to the guest. When the corresponding VF instance is registered,
- * we will take care of switching the data path.
- */
-static int netvsc_netdev_event(struct notifier_block *this,
- unsigned long event, void *ptr)
-{
- struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
-
- /* Skip our own events */
- if (event_dev->netdev_ops == &device_ops)
- return NOTIFY_DONE;
-
- /* Avoid non-Ethernet type devices */
- if (event_dev->type != ARPHRD_ETHER)
- return NOTIFY_DONE;
-
- /* Avoid Vlan dev with same MAC registering as VF */
- if (is_vlan_dev(event_dev))
- return NOTIFY_DONE;
-
- /* Avoid Bonding master dev with same MAC registering as VF */
- if ((event_dev->priv_flags & IFF_BONDING) &&
- (event_dev->flags & IFF_MASTER))
- return NOTIFY_DONE;
-
- switch (event) {
- case NETDEV_REGISTER:
- return netvsc_register_vf(event_dev);
- case NETDEV_UNREGISTER:
- return netvsc_unregister_vf(event_dev);
- case NETDEV_UP:
- case NETDEV_DOWN:
- return netvsc_vf_changed(event_dev);
- default:
- return NOTIFY_DONE;
- }
-}
-
-static struct notifier_block netvsc_netdev_notifier = {
- .notifier_call = netvsc_netdev_event,
-};
-
static void __exit netvsc_drv_exit(void)
{
- unregister_netdevice_notifier(&netvsc_netdev_notifier);
vmbus_driver_unregister(&netvsc_drv);
}
@@ -2225,7 +2137,6 @@ static int __init netvsc_drv_init(void)
if (ret)
return ret;
- register_netdevice_notifier(&netvsc_netdev_notifier);
return 0;
}
--
2.14.3
^ permalink raw reply related
* [PATCH net-next v11 3/5] net: Introduce net_failover driver
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
In-Reply-To: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com>
The net_failover driver provides an automated failover mechanism via APIs
to create and destroy a failover master netdev and mananges a primary and
standby slave netdevs that get registered via the generic failover
infrastructure.
The failover netdev acts a master device and controls 2 slave devices. The
original paravirtual interface gets registered as 'standby' slave netdev and
a passthru/vf device with the same MAC gets registered as 'primary' slave
netdev. Both 'standby' and 'failover' netdevs are associated with the same
'pci' device. The user accesses the network interface via 'failover' netdev.
The 'failover' netdev chooses 'primary' netdev as default for transmits when
it is available with link up and running.
This can be used by paravirtual drivers to enable an alternate low latency
datapath. It also enables hypervisor controlled live migration of a VM with
direct attached VF by failing over to the paravirtual datapath when the VF
is unplugged.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
Documentation/networking/net_failover.rst | 26 +
MAINTAINERS | 8 +
drivers/net/Kconfig | 12 +
drivers/net/Makefile | 1 +
drivers/net/net_failover.c | 836 ++++++++++++++++++++++++++++++
include/net/net_failover.h | 40 ++
6 files changed, 923 insertions(+)
create mode 100644 Documentation/networking/net_failover.rst
create mode 100644 drivers/net/net_failover.c
create mode 100644 include/net/net_failover.h
diff --git a/Documentation/networking/net_failover.rst b/Documentation/networking/net_failover.rst
new file mode 100644
index 000000000000..6764c3b1eec8
--- /dev/null
+++ b/Documentation/networking/net_failover.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============
+NET_FAILOVER
+============
+
+Overview
+========
+
+The net_failover driver provides an automated failover mechanism via APIs
+to create and destroy a failover master netdev and mananges a primary and
+standby slave netdevs that get registered via the generic failover
+infrastructrure.
+
+The failover netdev acts a master device and controls 2 slave devices. The
+original paravirtual interface is registered as 'standby' slave netdev and
+a passthru/vf device with the same MAC gets registered as 'primary' slave
+netdev. Both 'standby' and 'failover' netdevs are associated with the same
+'pci' device. The user accesses the network interface via 'failover' netdev.
+The 'failover' netdev chooses 'primary' netdev as default for transmits when
+it is available with link up and running.
+
+This can be used by paravirtual drivers to enable an alternate low latency
+datapath. It also enables hypervisor controlled live migration of a VM with
+direct attached VF by failing over to the paravirtual datapath when the VF
+is unplugged.
diff --git a/MAINTAINERS b/MAINTAINERS
index aed9575ddc53..ad172b1a7d57 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9642,6 +9642,14 @@ S: Maintained
F: Documentation/hwmon/nct6775
F: drivers/hwmon/nct6775.c
+NET_FAILOVER MODULE
+M: Sridhar Samudrala <sridhar.samudrala@intel.com>
+L: netdev@vger.kernel.org
+S: Supported
+F: driver/net/net_failover.c
+F: include/net/net_failover.h
+F: Documentation/networking/net_failover.rst
+
NETEFFECT IWARP RNIC DRIVER (IW_NES)
M: Faisal Latif <faisal.latif@intel.com>
L: linux-rdma@vger.kernel.org
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index a029b27fd002..1cf29c5ed510 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -510,4 +510,16 @@ config NETDEVSIM
To compile this driver as a module, choose M here: the module
will be called netdevsim.
+config NET_FAILOVER
+ tristate "Failover driver"
+ select FAILOVER
+ help
+ This provides an automated failover mechanism via APIs to create
+ and destroy a failover master netdev and manages a primary and
+ standby slave netdevs that get registered via the generic failover
+ infrastructure. This can be used by paravirtual drivers to enable
+ an alternate low latency datapath. It alsoenables live migration of
+ a VM with direct attached VF by failing over to the paravirtual
+ datapath when the VF is unplugged.
+
endif # NETDEVICES
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 91e67e375dd4..21cde7e78621 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -78,3 +78,4 @@ obj-$(CONFIG_FUJITSU_ES) += fjes/
thunderbolt-net-y += thunderbolt.o
obj-$(CONFIG_THUNDERBOLT_NET) += thunderbolt-net.o
obj-$(CONFIG_NETDEVSIM) += netdevsim/
+obj-$(CONFIG_NET_FAILOVER) += net_failover.o
diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
new file mode 100644
index 000000000000..ae47bdb363c9
--- /dev/null
+++ b/drivers/net/net_failover.c
@@ -0,0 +1,836 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018, Intel Corporation. */
+
+/* This provides a net_failover interface for paravirtual drivers to
+ * provide an alternate datapath by exporting APIs to create and
+ * destroy a upper 'net_failover' netdev. The upper dev manages the
+ * original paravirtual interface as a 'standby' netdev and uses the
+ * generic failover infrastructure to register and manage a direct
+ * attached VF as a 'primary' netdev. This enables live migration of
+ * a VM with direct attached VF by failing over to the paravirtual
+ * datapath when the VF is unplugged.
+ *
+ * Some of the netdev management routines are based on bond/team driver as
+ * this driver provides active-backup functionality similar to those drivers.
+ */
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/netpoll.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_vlan.h>
+#include <linux/pci.h>
+#include <net/sch_generic.h>
+#include <uapi/linux/if_arp.h>
+#include <net/net_failover.h>
+
+static bool net_failover_xmit_ready(struct net_device *dev)
+{
+ return netif_running(dev) && netif_carrier_ok(dev);
+}
+
+static int net_failover_open(struct net_device *dev)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev, *standby_dev;
+ int err;
+
+ primary_dev = rtnl_dereference(nfo_info->primary_dev);
+ if (primary_dev) {
+ err = dev_open(primary_dev);
+ if (err)
+ goto err_primary_open;
+ }
+
+ standby_dev = rtnl_dereference(nfo_info->standby_dev);
+ if (standby_dev) {
+ err = dev_open(standby_dev);
+ if (err)
+ goto err_standby_open;
+ }
+
+ if ((primary_dev && net_failover_xmit_ready(primary_dev)) ||
+ (standby_dev && net_failover_xmit_ready(standby_dev))) {
+ netif_carrier_on(dev);
+ netif_tx_wake_all_queues(dev);
+ }
+
+ return 0;
+
+err_standby_open:
+ dev_close(primary_dev);
+err_primary_open:
+ netif_tx_disable(dev);
+ return err;
+}
+
+static int net_failover_close(struct net_device *dev)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *slave_dev;
+
+ netif_tx_disable(dev);
+
+ slave_dev = rtnl_dereference(nfo_info->primary_dev);
+ if (slave_dev)
+ dev_close(slave_dev);
+
+ slave_dev = rtnl_dereference(nfo_info->standby_dev);
+ if (slave_dev)
+ dev_close(slave_dev);
+
+ return 0;
+}
+
+static netdev_tx_t net_failover_drop_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ atomic_long_inc(&dev->tx_dropped);
+ dev_kfree_skb_any(skb);
+ return NETDEV_TX_OK;
+}
+
+static netdev_tx_t net_failover_start_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *xmit_dev;
+
+ /* Try xmit via primary netdev followed by standby netdev */
+ xmit_dev = rcu_dereference_bh(nfo_info->primary_dev);
+ if (!xmit_dev || !net_failover_xmit_ready(xmit_dev)) {
+ xmit_dev = rcu_dereference_bh(nfo_info->standby_dev);
+ if (!xmit_dev || !net_failover_xmit_ready(xmit_dev))
+ return net_failover_drop_xmit(skb, dev);
+ }
+
+ skb->dev = xmit_dev;
+ skb->queue_mapping = qdisc_skb_cb(skb)->slave_dev_queue_mapping;
+
+ return dev_queue_xmit(skb);
+}
+
+static u16 net_failover_select_queue(struct net_device *dev,
+ struct sk_buff *skb, void *accel_priv,
+ select_queue_fallback_t fallback)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev;
+ u16 txq;
+
+ primary_dev = rcu_dereference(nfo_info->primary_dev);
+ if (primary_dev) {
+ const struct net_device_ops *ops = primary_dev->netdev_ops;
+
+ if (ops->ndo_select_queue)
+ txq = ops->ndo_select_queue(primary_dev, skb,
+ accel_priv, fallback);
+ else
+ txq = fallback(primary_dev, skb);
+
+ qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping;
+
+ return txq;
+ }
+
+ txq = skb_rx_queue_recorded(skb) ? skb_get_rx_queue(skb) : 0;
+
+ /* Save the original txq to restore before passing to the driver */
+ qdisc_skb_cb(skb)->slave_dev_queue_mapping = skb->queue_mapping;
+
+ if (unlikely(txq >= dev->real_num_tx_queues)) {
+ do {
+ txq -= dev->real_num_tx_queues;
+ } while (txq >= dev->real_num_tx_queues);
+ }
+
+ return txq;
+}
+
+/* fold stats, assuming all rtnl_link_stats64 fields are u64, but
+ * that some drivers can provide 32bit values only.
+ */
+static void net_failover_fold_stats(struct rtnl_link_stats64 *_res,
+ const struct rtnl_link_stats64 *_new,
+ const struct rtnl_link_stats64 *_old)
+{
+ const u64 *new = (const u64 *)_new;
+ const u64 *old = (const u64 *)_old;
+ u64 *res = (u64 *)_res;
+ int i;
+
+ for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) {
+ u64 nv = new[i];
+ u64 ov = old[i];
+ s64 delta = nv - ov;
+
+ /* detects if this particular field is 32bit only */
+ if (((nv | ov) >> 32) == 0)
+ delta = (s64)(s32)((u32)nv - (u32)ov);
+
+ /* filter anomalies, some drivers reset their stats
+ * at down/up events.
+ */
+ if (delta > 0)
+ res[i] += delta;
+ }
+}
+
+static void net_failover_get_stats(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ const struct rtnl_link_stats64 *new;
+ struct rtnl_link_stats64 temp;
+ struct net_device *slave_dev;
+
+ spin_lock(&nfo_info->stats_lock);
+ memcpy(stats, &nfo_info->failover_stats, sizeof(*stats));
+
+ rcu_read_lock();
+
+ slave_dev = rcu_dereference(nfo_info->primary_dev);
+ if (slave_dev) {
+ new = dev_get_stats(slave_dev, &temp);
+ net_failover_fold_stats(stats, new, &nfo_info->primary_stats);
+ memcpy(&nfo_info->primary_stats, new, sizeof(*new));
+ }
+
+ slave_dev = rcu_dereference(nfo_info->standby_dev);
+ if (slave_dev) {
+ new = dev_get_stats(slave_dev, &temp);
+ net_failover_fold_stats(stats, new, &nfo_info->standby_stats);
+ memcpy(&nfo_info->standby_stats, new, sizeof(*new));
+ }
+
+ rcu_read_unlock();
+
+ memcpy(&nfo_info->failover_stats, stats, sizeof(*stats));
+ spin_unlock(&nfo_info->stats_lock);
+}
+
+static int net_failover_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev, *standby_dev;
+ int ret = 0;
+
+ primary_dev = rcu_dereference(nfo_info->primary_dev);
+ if (primary_dev) {
+ ret = dev_set_mtu(primary_dev, new_mtu);
+ if (ret)
+ return ret;
+ }
+
+ standby_dev = rcu_dereference(nfo_info->standby_dev);
+ if (standby_dev) {
+ ret = dev_set_mtu(standby_dev, new_mtu);
+ if (ret) {
+ if (primary_dev)
+ dev_set_mtu(primary_dev, dev->mtu);
+ return ret;
+ }
+ }
+
+ dev->mtu = new_mtu;
+
+ return 0;
+}
+
+static void net_failover_set_rx_mode(struct net_device *dev)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *slave_dev;
+
+ rcu_read_lock();
+
+ slave_dev = rcu_dereference(nfo_info->primary_dev);
+ if (slave_dev) {
+ dev_uc_sync_multiple(slave_dev, dev);
+ dev_mc_sync_multiple(slave_dev, dev);
+ }
+
+ slave_dev = rcu_dereference(nfo_info->standby_dev);
+ if (slave_dev) {
+ dev_uc_sync_multiple(slave_dev, dev);
+ dev_mc_sync_multiple(slave_dev, dev);
+ }
+
+ rcu_read_unlock();
+}
+
+static int net_failover_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
+ u16 vid)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev, *standby_dev;
+ int ret = 0;
+
+ primary_dev = rcu_dereference(nfo_info->primary_dev);
+ if (primary_dev) {
+ ret = vlan_vid_add(primary_dev, proto, vid);
+ if (ret)
+ return ret;
+ }
+
+ standby_dev = rcu_dereference(nfo_info->standby_dev);
+ if (standby_dev) {
+ ret = vlan_vid_add(standby_dev, proto, vid);
+ if (ret)
+ if (primary_dev)
+ vlan_vid_del(primary_dev, proto, vid);
+ }
+
+ return ret;
+}
+
+static int net_failover_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
+ u16 vid)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *slave_dev;
+
+ slave_dev = rcu_dereference(nfo_info->primary_dev);
+ if (slave_dev)
+ vlan_vid_del(slave_dev, proto, vid);
+
+ slave_dev = rcu_dereference(nfo_info->standby_dev);
+ if (slave_dev)
+ vlan_vid_del(slave_dev, proto, vid);
+
+ return 0;
+}
+
+static const struct net_device_ops failover_dev_ops = {
+ .ndo_open = net_failover_open,
+ .ndo_stop = net_failover_close,
+ .ndo_start_xmit = net_failover_start_xmit,
+ .ndo_select_queue = net_failover_select_queue,
+ .ndo_get_stats64 = net_failover_get_stats,
+ .ndo_change_mtu = net_failover_change_mtu,
+ .ndo_set_rx_mode = net_failover_set_rx_mode,
+ .ndo_vlan_rx_add_vid = net_failover_vlan_rx_add_vid,
+ .ndo_vlan_rx_kill_vid = net_failover_vlan_rx_kill_vid,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_features_check = passthru_features_check,
+};
+
+#define FAILOVER_NAME "net_failover"
+#define FAILOVER_VERSION "0.1"
+
+static void nfo_ethtool_get_drvinfo(struct net_device *dev,
+ struct ethtool_drvinfo *drvinfo)
+{
+ strlcpy(drvinfo->driver, FAILOVER_NAME, sizeof(drvinfo->driver));
+ strlcpy(drvinfo->version, FAILOVER_VERSION, sizeof(drvinfo->version));
+}
+
+static int nfo_ethtool_get_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *cmd)
+{
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *slave_dev;
+
+ slave_dev = rtnl_dereference(nfo_info->primary_dev);
+ if (!slave_dev || !net_failover_xmit_ready(slave_dev)) {
+ slave_dev = rtnl_dereference(nfo_info->standby_dev);
+ if (!slave_dev || !net_failover_xmit_ready(slave_dev)) {
+ cmd->base.duplex = DUPLEX_UNKNOWN;
+ cmd->base.port = PORT_OTHER;
+ cmd->base.speed = SPEED_UNKNOWN;
+
+ return 0;
+ }
+ }
+
+ return __ethtool_get_link_ksettings(slave_dev, cmd);
+}
+
+static const struct ethtool_ops failover_ethtool_ops = {
+ .get_drvinfo = nfo_ethtool_get_drvinfo,
+ .get_link = ethtool_op_get_link,
+ .get_link_ksettings = nfo_ethtool_get_link_ksettings,
+};
+
+/* Called when slave dev is injecting data into network stack.
+ * Change the associated network device from lower dev to failover dev.
+ * note: already called with rcu_read_lock
+ */
+static rx_handler_result_t net_failover_handle_frame(struct sk_buff **pskb)
+{
+ struct sk_buff *skb = *pskb;
+ struct net_device *dev = rcu_dereference(skb->dev->rx_handler_data);
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev, *standby_dev;
+
+ primary_dev = rcu_dereference(nfo_info->primary_dev);
+ standby_dev = rcu_dereference(nfo_info->standby_dev);
+
+ if (primary_dev && skb->dev == standby_dev)
+ return RX_HANDLER_EXACT;
+
+ skb->dev = dev;
+
+ return RX_HANDLER_ANOTHER;
+}
+
+static void net_failover_compute_features(struct net_device *dev)
+{
+ u32 vlan_features = FAILOVER_VLAN_FEATURES & NETIF_F_ALL_FOR_ALL;
+ netdev_features_t enc_features = FAILOVER_ENC_FEATURES;
+ unsigned short max_hard_header_len = ETH_HLEN;
+ unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE |
+ IFF_XMIT_DST_RELEASE_PERM;
+ struct net_failover_info *nfo_info = netdev_priv(dev);
+ struct net_device *primary_dev, *standby_dev;
+
+ primary_dev = rcu_dereference(nfo_info->primary_dev);
+ if (primary_dev) {
+ vlan_features =
+ netdev_increment_features(vlan_features,
+ primary_dev->vlan_features,
+ FAILOVER_VLAN_FEATURES);
+ enc_features =
+ netdev_increment_features(enc_features,
+ primary_dev->hw_enc_features,
+ FAILOVER_ENC_FEATURES);
+
+ dst_release_flag &= primary_dev->priv_flags;
+ if (primary_dev->hard_header_len > max_hard_header_len)
+ max_hard_header_len = primary_dev->hard_header_len;
+ }
+
+ standby_dev = rcu_dereference(nfo_info->standby_dev);
+ if (standby_dev) {
+ vlan_features =
+ netdev_increment_features(vlan_features,
+ standby_dev->vlan_features,
+ FAILOVER_VLAN_FEATURES);
+ enc_features =
+ netdev_increment_features(enc_features,
+ standby_dev->hw_enc_features,
+ FAILOVER_ENC_FEATURES);
+
+ dst_release_flag &= standby_dev->priv_flags;
+ if (standby_dev->hard_header_len > max_hard_header_len)
+ max_hard_header_len = standby_dev->hard_header_len;
+ }
+
+ dev->vlan_features = vlan_features;
+ dev->hw_enc_features = enc_features | NETIF_F_GSO_ENCAP_ALL;
+ dev->hard_header_len = max_hard_header_len;
+
+ dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+ if (dst_release_flag == (IFF_XMIT_DST_RELEASE |
+ IFF_XMIT_DST_RELEASE_PERM))
+ dev->priv_flags |= IFF_XMIT_DST_RELEASE;
+
+ netdev_change_features(dev);
+}
+
+static void net_failover_lower_state_changed(struct net_device *slave_dev,
+ struct net_device *primary_dev,
+ struct net_device *standby_dev)
+{
+ struct netdev_lag_lower_state_info info;
+
+ if (netif_carrier_ok(slave_dev))
+ info.link_up = true;
+ else
+ info.link_up = false;
+
+ if (slave_dev == primary_dev) {
+ if (netif_running(primary_dev))
+ info.tx_enabled = true;
+ else
+ info.tx_enabled = false;
+ } else {
+ if ((primary_dev && netif_running(primary_dev)) ||
+ (!netif_running(standby_dev)))
+ info.tx_enabled = false;
+ else
+ info.tx_enabled = true;
+ }
+
+ netdev_lower_state_changed(slave_dev, &info);
+}
+
+static int net_failover_slave_register(struct net_device *slave_dev,
+ struct net_device *failover_dev)
+{
+ struct net_device *standby_dev, *primary_dev;
+ struct netdev_lag_upper_info lag_upper_info;
+ struct net_failover_info *nfo_info;
+ bool slave_is_standby;
+ u32 orig_mtu;
+ int err;
+
+ nfo_info = netdev_priv(failover_dev);
+ standby_dev = rtnl_dereference(nfo_info->standby_dev);
+ primary_dev = rtnl_dereference(nfo_info->primary_dev);
+ slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent;
+ if (slave_is_standby ? standby_dev : primary_dev) {
+ netdev_err(failover_dev, "%s attempting to register as slave dev when %s already present\n",
+ slave_dev->name,
+ slave_is_standby ? "standby" : "primary");
+ goto done;
+ }
+
+ /* We want to allow only a direct attached VF device as a primary
+ * netdev. As there is no easy way to check for a VF device, restrict
+ * this to a pci device.
+ */
+ if (!slave_is_standby && (!slave_dev->dev.parent ||
+ !dev_is_pci(slave_dev->dev.parent)))
+ goto done;
+
+ if (failover_dev->features & NETIF_F_VLAN_CHALLENGED &&
+ vlan_uses_dev(failover_dev)) {
+ netdev_err(failover_dev, "Device %s is VLAN challenged and failover device has VLAN set up\n",
+ failover_dev->name);
+ goto done;
+ }
+
+ /* Align MTU of slave with failover dev */
+ orig_mtu = slave_dev->mtu;
+ err = dev_set_mtu(slave_dev, failover_dev->mtu);
+ if (err) {
+ netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n",
+ slave_dev->name, failover_dev->mtu);
+ goto done;
+ }
+
+ dev_hold(slave_dev);
+
+ if (netif_running(failover_dev)) {
+ err = dev_open(slave_dev);
+ if (err && (err != -EBUSY)) {
+ netdev_err(failover_dev, "Opening slave %s failed err:%d\n",
+ slave_dev->name, err);
+ goto err_dev_open;
+ }
+ }
+
+ netif_addr_lock_bh(failover_dev);
+ dev_uc_sync_multiple(slave_dev, failover_dev);
+ dev_uc_sync_multiple(slave_dev, failover_dev);
+ netif_addr_unlock_bh(failover_dev);
+
+ err = vlan_vids_add_by_dev(slave_dev, failover_dev);
+ if (err) {
+ netdev_err(failover_dev, "Failed to add vlan ids to device %s err:%d\n",
+ slave_dev->name, err);
+ goto err_vlan_add;
+ }
+
+ err = netdev_rx_handler_register(slave_dev, net_failover_handle_frame,
+ failover_dev);
+ if (err) {
+ netdev_err(slave_dev, "can not register failover rx handler (err = %d)\n",
+ err);
+ goto err_handler_register;
+ }
+
+ lag_upper_info.tx_type = NETDEV_LAG_TX_TYPE_ACTIVEBACKUP;
+ err = netdev_master_upper_dev_link(slave_dev, failover_dev, NULL,
+ &lag_upper_info, NULL);
+ if (err) {
+ netdev_err(slave_dev, "can not set failover device %s (err = %d)\n",
+ failover_dev->name, err);
+ goto err_upper_link;
+ }
+
+ slave_dev->priv_flags |= IFF_FAILOVER_SLAVE;
+
+ if (slave_is_standby) {
+ rcu_assign_pointer(nfo_info->standby_dev, slave_dev);
+ standby_dev = slave_dev;
+ dev_get_stats(standby_dev, &nfo_info->standby_stats);
+ } else {
+ rcu_assign_pointer(nfo_info->primary_dev, slave_dev);
+ primary_dev = slave_dev;
+ dev_get_stats(primary_dev, &nfo_info->primary_stats);
+ failover_dev->min_mtu = slave_dev->min_mtu;
+ failover_dev->max_mtu = slave_dev->max_mtu;
+ }
+
+ net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev);
+ net_failover_compute_features(failover_dev);
+
+ call_netdevice_notifiers(NETDEV_JOIN, slave_dev);
+
+ netdev_info(failover_dev, "failover %s slave:%s registered\n",
+ slave_is_standby ? "standby" : "primary", slave_dev->name);
+
+ goto done;
+
+err_upper_link:
+ netdev_rx_handler_unregister(slave_dev);
+err_handler_register:
+ vlan_vids_del_by_dev(slave_dev, failover_dev);
+err_vlan_add:
+ dev_uc_unsync(slave_dev, failover_dev);
+ dev_mc_unsync(slave_dev, failover_dev);
+ dev_close(slave_dev);
+err_dev_open:
+ dev_put(slave_dev);
+ dev_set_mtu(slave_dev, orig_mtu);
+done:
+ return NOTIFY_DONE;
+}
+
+static int net_failover_slave_unregister(struct net_device *slave_dev,
+ struct net_device *failover_dev)
+{
+ struct net_device *standby_dev, *primary_dev;
+ struct net_failover_info *nfo_info;
+ bool slave_is_standby;
+
+ nfo_info = netdev_priv(failover_dev);
+ primary_dev = rtnl_dereference(nfo_info->primary_dev);
+ standby_dev = rtnl_dereference(nfo_info->standby_dev);
+
+ if (slave_dev != primary_dev && slave_dev != standby_dev)
+ goto done;
+
+ slave_is_standby = slave_dev->dev.parent == failover_dev->dev.parent;
+
+ netdev_rx_handler_unregister(slave_dev);
+ netdev_upper_dev_unlink(slave_dev, failover_dev);
+ vlan_vids_del_by_dev(slave_dev, failover_dev);
+ dev_uc_unsync(slave_dev, failover_dev);
+ dev_mc_unsync(slave_dev, failover_dev);
+ dev_close(slave_dev);
+ slave_dev->priv_flags &= ~IFF_FAILOVER_SLAVE;
+
+ nfo_info = netdev_priv(failover_dev);
+ dev_get_stats(failover_dev, &nfo_info->failover_stats);
+
+ if (slave_is_standby) {
+ RCU_INIT_POINTER(nfo_info->standby_dev, NULL);
+ } else {
+ RCU_INIT_POINTER(nfo_info->primary_dev, NULL);
+ if (standby_dev) {
+ failover_dev->min_mtu = standby_dev->min_mtu;
+ failover_dev->max_mtu = standby_dev->max_mtu;
+ }
+ }
+
+ dev_put(slave_dev);
+
+ net_failover_compute_features(failover_dev);
+
+ netdev_info(failover_dev, "failover %s slave:%s unregistered\n",
+ slave_is_standby ? "standby" : "primary", slave_dev->name);
+
+done:
+ return NOTIFY_DONE;
+}
+
+static int net_failover_slave_link_change(struct net_device *slave_dev,
+ struct net_device *failover_dev)
+{
+ struct net_device *primary_dev, *standby_dev;
+ struct net_failover_info *nfo_info;
+
+ nfo_info = netdev_priv(failover_dev);
+
+ primary_dev = rtnl_dereference(nfo_info->primary_dev);
+ standby_dev = rtnl_dereference(nfo_info->standby_dev);
+
+ if (slave_dev != primary_dev && slave_dev != standby_dev)
+ goto done;
+
+ if ((primary_dev && net_failover_xmit_ready(primary_dev)) ||
+ (standby_dev && net_failover_xmit_ready(standby_dev))) {
+ netif_carrier_on(failover_dev);
+ netif_tx_wake_all_queues(failover_dev);
+ } else {
+ dev_get_stats(failover_dev, &nfo_info->failover_stats);
+ netif_carrier_off(failover_dev);
+ netif_tx_stop_all_queues(failover_dev);
+ }
+
+ net_failover_lower_state_changed(slave_dev, primary_dev, standby_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+
+static int net_failover_slave_name_change(struct net_device *slave_dev,
+ struct net_device *failover_dev)
+{
+ struct net_device *primary_dev, *standby_dev;
+ struct net_failover_info *nfo_info;
+
+ nfo_info = netdev_priv(failover_dev);
+
+ primary_dev = rtnl_dereference(nfo_info->primary_dev);
+ standby_dev = rtnl_dereference(nfo_info->standby_dev);
+
+ if (slave_dev != primary_dev && slave_dev != standby_dev)
+ goto done;
+
+ /* We need to bring up the slave after the rename by udev in case
+ * open failed with EBUSY when it was registered.
+ */
+ dev_open(slave_dev);
+
+done:
+ return NOTIFY_DONE;
+}
+
+static struct failover_ops net_failover_ops = {
+ .slave_register = net_failover_slave_register,
+ .slave_unregister = net_failover_slave_unregister,
+ .slave_link_change = net_failover_slave_link_change,
+ .slave_name_change = net_failover_slave_name_change,
+};
+
+/**
+ * net_failover_create - Create and register a failover instance
+ *
+ * @dev: standby netdev
+ *
+ * Creates a failover netdev and registers a failover instance for a standby
+ * netdev. Used by paravirtual drivers that use 3-netdev model.
+ * The failover netdev acts as a master device and controls 2 slave devices -
+ * the original standby netdev and a VF netdev with the same MAC gets
+ * registered as primary netdev.
+ *
+ * Return: pointer to failover instance
+ */
+struct failover *net_failover_create(struct net_device *standby_dev)
+{
+ struct device *dev = standby_dev->dev.parent;
+ struct net_device *failover_dev;
+ struct failover *failover;
+ int err;
+
+ /* Alloc at least 2 queues, for now we are going with 16 assuming
+ * that VF devices being enslaved won't have too many queues.
+ */
+ failover_dev = alloc_etherdev_mq(sizeof(struct net_failover_info), 16);
+ if (!failover_dev) {
+ dev_err(dev, "Unable to allocate failover_netdev!\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ dev_net_set(failover_dev, dev_net(standby_dev));
+ SET_NETDEV_DEV(failover_dev, dev);
+
+ failover_dev->netdev_ops = &failover_dev_ops;
+ failover_dev->ethtool_ops = &failover_ethtool_ops;
+
+ /* Initialize the device options */
+ failover_dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
+ failover_dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE |
+ IFF_TX_SKB_SHARING);
+
+ /* don't acquire failover netdev's netif_tx_lock when transmitting */
+ failover_dev->features |= NETIF_F_LLTX;
+
+ /* Don't allow failover devices to change network namespaces. */
+ failover_dev->features |= NETIF_F_NETNS_LOCAL;
+
+ failover_dev->hw_features = FAILOVER_VLAN_FEATURES |
+ NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_CTAG_RX |
+ NETIF_F_HW_VLAN_CTAG_FILTER;
+
+ failover_dev->hw_features |= NETIF_F_GSO_ENCAP_ALL;
+ failover_dev->features |= failover_dev->hw_features;
+
+ memcpy(failover_dev->dev_addr, standby_dev->dev_addr,
+ failover_dev->addr_len);
+
+ failover_dev->min_mtu = standby_dev->min_mtu;
+ failover_dev->max_mtu = standby_dev->max_mtu;
+
+ err = register_netdev(failover_dev);
+ if (err) {
+ dev_err(dev, "Unable to register failover_dev!\n");
+ goto err_register_netdev;
+ }
+
+ netif_carrier_off(failover_dev);
+
+ failover = failover_register(failover_dev, &net_failover_ops);
+ if (IS_ERR(failover))
+ goto err_failover_register;
+
+ return failover;
+
+err_failover_register:
+ unregister_netdev(failover_dev);
+err_register_netdev:
+ free_netdev(failover_dev);
+
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(net_failover_create);
+
+/**
+ * net_failover_destroy - Destroy a failover instance
+ *
+ * @failover: pointer to failover instance
+ *
+ * Unregisters any slave netdevs associated with the failover instance by
+ * calling failover_slave_unregister().
+ * unregisters the failover instance itself and finally frees the failover
+ * netdev. Used by paravirtual drivers that use 3-netdev model.
+ *
+ */
+void net_failover_destroy(struct failover *failover)
+{
+ struct net_failover_info *nfo_info;
+ struct net_device *failover_dev;
+ struct net_device *slave_dev;
+
+ if (!failover)
+ return;
+
+ failover_dev = rcu_dereference(failover->failover_dev);
+ nfo_info = netdev_priv(failover_dev);
+
+ netif_device_detach(failover_dev);
+
+ rtnl_lock();
+
+ slave_dev = rtnl_dereference(nfo_info->primary_dev);
+ if (slave_dev)
+ failover_slave_unregister(slave_dev);
+
+ slave_dev = rtnl_dereference(nfo_info->standby_dev);
+ if (slave_dev)
+ failover_slave_unregister(slave_dev);
+
+ failover_unregister(failover);
+
+ unregister_netdevice(failover_dev);
+
+ rtnl_unlock();
+
+ free_netdev(failover_dev);
+}
+EXPORT_SYMBOL_GPL(net_failover_destroy);
+
+static __init int
+net_failover_init(void)
+{
+ return 0;
+}
+module_init(net_failover_init);
+
+static __exit
+void net_failover_exit(void)
+{
+}
+module_exit(net_failover_exit);
+
+MODULE_DESCRIPTION("Failover driver for Paravirtual drivers");
+MODULE_LICENSE("GPL v2");
diff --git a/include/net/net_failover.h b/include/net/net_failover.h
new file mode 100644
index 000000000000..b12a1c469d1c
--- /dev/null
+++ b/include/net/net_failover.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, Intel Corporation. */
+
+#ifndef _NET_FAILOVER_H
+#define _NET_FAILOVER_H
+
+#include <net/failover.h>
+
+/* failover state */
+struct net_failover_info {
+ /* primary netdev with same MAC */
+ struct net_device __rcu *primary_dev;
+
+ /* standby netdev */
+ struct net_device __rcu *standby_dev;
+
+ /* primary netdev stats */
+ struct rtnl_link_stats64 primary_stats;
+
+ /* standby netdev stats */
+ struct rtnl_link_stats64 standby_stats;
+
+ /* aggregated stats */
+ struct rtnl_link_stats64 failover_stats;
+
+ /* spinlock while updating stats */
+ spinlock_t stats_lock;
+};
+
+struct failover *net_failover_create(struct net_device *standby_dev);
+void net_failover_destroy(struct failover *failover);
+
+#define FAILOVER_VLAN_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | \
+ NETIF_F_FRAGLIST | NETIF_F_ALL_TSO | \
+ NETIF_F_HIGHDMA | NETIF_F_LRO)
+
+#define FAILOVER_ENC_FEATURES (NETIF_F_HW_CSUM | NETIF_F_SG | \
+ NETIF_F_RXCSUM | NETIF_F_ALL_TSO)
+
+#endif /* _NET_FAILOVER_H */
--
2.14.3
^ permalink raw reply related
* [PATCH net-next v11 4/5] virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
In-Reply-To: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com>
This feature bit can be used by hypervisor to indicate virtio_net device to
act as a standby for another device with the same MAC address.
VIRTIO_NET_F_STANDBY is defined as bit 62 as it is a device feature bit.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
drivers/net/virtio_net.c | 2 +-
include/uapi/linux/virtio_net.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f34794a76c4d..213fddc70fd0 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2999,7 +2999,7 @@ static struct virtio_device_id id_table[] = {
VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
VIRTIO_NET_F_CTRL_MAC_ADDR, \
VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
- VIRTIO_NET_F_SPEED_DUPLEX
+ VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
static unsigned int features[] = {
VIRTNET_FEATURES,
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 5de6ed37695b..a3715a3224c1 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -57,6 +57,9 @@
* Steering */
#define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */
+#define VIRTIO_NET_F_STANDBY 62 /* Act as standby for another device
+ * with the same MAC.
+ */
#define VIRTIO_NET_F_SPEED_DUPLEX 63 /* Device set linkspeed and duplex */
#ifndef VIRTIO_NET_NO_LEGACY
--
2.14.3
^ permalink raw reply related
* [PATCH net-next v11 5/5] virtio_net: Extend virtio to use VF datapath when available
From: Sridhar Samudrala @ 2018-05-22 2:06 UTC (permalink / raw)
To: mst, stephen, davem, netdev, virtualization, virtio-dev,
jesse.brandeburg, alexander.h.duyck, kubakici, sridhar.samudrala,
jasowang, loseweigh, jiri, aaron.f.brown, anjali.singhai
In-Reply-To: <1526954781-35359-1-git-send-email-sridhar.samudrala@intel.com>
This patch enables virtio_net to switch over to a VF datapath when STANDBY
feature is enabled and a VF netdev is present with the same MAC address.
It allows live migration of a VM with a direct attached VF without the need
to setup a bond/team between a VF and virtio net device in the guest.
It uses the API that is exported by the net_failover driver to create and
and destroy a master failover netdev. When STANDBY feature is enabled, an
additional netdev(failover netdev) is created that acts as a master device
and tracks the state of the 2 lower netdevs. The original virtio_net netdev
is marked as 'standby' netdev and a passthru device with the same MAC is
registered as 'primary' netdev.
The hypervisor needs to unplug the VF device from the guest on the source
host and reset the MAC filter of the VF to initiate failover of datapath
to virtio before starting the migration. After the migration is completed,
the destination hypervisor sets the MAC filter on the VF and plugs it back
to the guest to switch over to VF datapath.
This patch is based on the discussion initiated by Jesse on this thread.
https://marc.info/?l=linux-virtualization&m=151189725224231&w=2
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
---
Documentation/networking/net_failover.rst | 90 +++++++++++++++++++++++++++++++
drivers/net/Kconfig | 1 +
drivers/net/virtio_net.c | 38 ++++++++++++-
3 files changed, 128 insertions(+), 1 deletion(-)
diff --git a/Documentation/networking/net_failover.rst b/Documentation/networking/net_failover.rst
index 6764c3b1eec8..3ad8376f8fa7 100644
--- a/Documentation/networking/net_failover.rst
+++ b/Documentation/networking/net_failover.rst
@@ -24,3 +24,93 @@ This can be used by paravirtual drivers to enable an alternate low latency
datapath. It also enables hypervisor controlled live migration of a VM with
direct attached VF by failing over to the paravirtual datapath when the VF
is unplugged.
+
+virtio-net accelerated datapath: STANDBY mode
+=============================================
+
+net_failover enables hypervisor controlled accelerated datapath to virtio-net
+enabled VMs in a transparent manner with no/minimal guest userspace chanages.
+
+To support this, the hypervisor needs to enable VIRTIO_NET_F_STANDBY
+feature on the virtio-net interface and assign the same MAC address to both
+virtio-net and VF interfaces.
+
+Here is an example XML snippet that shows such configuration.
+
+ <interface type='network'>
+ <mac address='52:54:00:00:12:53'/>
+ <source network='enp66s0f0_br'/>
+ <target dev='tap01'/>
+ <model type='virtio'/>
+ <driver name='vhost' queues='4'/>
+ <link state='down'/>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
+ </interface>
+ <interface type='hostdev' managed='yes'>
+ <mac address='52:54:00:00:12:53'/>
+ <source>
+ <address type='pci' domain='0x0000' bus='0x42' slot='0x02' function='0x5'/>
+ </source>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/>
+ </interface>
+
+Booting a VM with the above configuration will result in the following 3
+netdevs created in the VM.
+
+4: ens10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
+ link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff
+ inet 192.168.12.53/24 brd 192.168.12.255 scope global dynamic ens10
+ valid_lft 42482sec preferred_lft 42482sec
+ inet6 fe80::97d8:db2:8c10:b6d6/64 scope link
+ valid_lft forever preferred_lft forever
+5: ens10nsby: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master ens10 state UP group default qlen 1000
+ link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff
+7: ens11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master ens10 state UP group default qlen 1000
+ link/ether 52:54:00:00:12:53 brd ff:ff:ff:ff:ff:ff
+
+ens10 is the 'failover' master netdev, ens10nsby and ens11 are the slave
+'standby' and 'primary' netdevs respectively.
+
+Live Migration of a VM with SR-IOV VF & virtio-net in STANDBY mode
+==================================================================
+
+net_failover also enables hypervisor controlled live migration to be supported
+with VMs that have direct attached SR-IOV VF devices by automatic failover to
+the paravirtual datapath when the VF is unplugged.
+
+Here is a sample script that shows the steps to initiate live migration on
+the source hypervisor.
+
+# cat vf_xml
+<interface type='hostdev' managed='yes'>
+ <mac address='52:54:00:00:12:53'/>
+ <source>
+ <address type='pci' domain='0x0000' bus='0x42' slot='0x02' function='0x5'/>
+ </source>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/>
+</interface>
+
+# Source Hypervisor
+#!/bin/bash
+
+DOMAIN=fedora27-tap01
+PF=enp66s0f0
+VF_NUM=5
+TAP_IF=tap01
+VF_XML=
+
+MAC=52:54:00:00:12:53
+ZERO_MAC=00:00:00:00:00:00
+
+virsh domif-setlink $DOMAIN $TAP_IF up
+bridge fdb del $MAC dev $PF master
+virsh detach-device $DOMAIN $VF_XML
+ip link set $PF vf $VF_NUM mac $ZERO_MAC
+
+virsh migrate --live $DOMAIN qemu+ssh://$REMOTE_HOST/system
+
+# Destination Hypervisor
+#!/bin/bash
+
+virsh attach-device $DOMAIN $VF_XML
+virsh domif-setlink $DOMAIN $TAP_IF down
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 1cf29c5ed510..148bcf1b4bf9 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -332,6 +332,7 @@ config VETH
config VIRTIO_NET
tristate "Virtio network driver"
depends on VIRTIO
+ select NET_FAILOVER
---help---
This is the virtual network driver for virtio. It can be used with
QEMU based VMMs (like KVM or Xen). Say Y or M.
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 213fddc70fd0..370828c3d114 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -30,8 +30,11 @@
#include <linux/cpu.h>
#include <linux/average.h>
#include <linux/filter.h>
+#include <linux/netdevice.h>
+#include <linux/pci.h>
#include <net/route.h>
#include <net/xdp.h>
+#include <net/net_failover.h>
static int napi_weight = NAPI_POLL_WEIGHT;
module_param(napi_weight, int, 0444);
@@ -210,6 +213,9 @@ struct virtnet_info {
u32 speed;
unsigned long guest_offloads;
+
+ /* failover when STANDBY feature enabled */
+ struct failover *failover;
};
struct padded_vnet_hdr {
@@ -1523,6 +1529,9 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
struct sockaddr *addr;
struct scatterlist sg;
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
+ return -EOPNOTSUPP;
+
addr = kmemdup(p, sizeof(*addr), GFP_KERNEL);
if (!addr)
return -ENOMEM;
@@ -2306,6 +2315,22 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
}
}
+static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
+ size_t len)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ int ret;
+
+ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STANDBY))
+ return -EOPNOTSUPP;
+
+ ret = snprintf(buf, len, "sby");
+ if (ret >= len)
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
static const struct net_device_ops virtnet_netdev = {
.ndo_open = virtnet_open,
.ndo_stop = virtnet_close,
@@ -2323,6 +2348,7 @@ static const struct net_device_ops virtnet_netdev = {
.ndo_xdp_xmit = virtnet_xdp_xmit,
.ndo_xdp_flush = virtnet_xdp_flush,
.ndo_features_check = passthru_features_check,
+ .ndo_get_phys_port_name = virtnet_get_phys_port_name,
};
static void virtnet_config_changed_work(struct work_struct *work)
@@ -2876,10 +2902,16 @@ static int virtnet_probe(struct virtio_device *vdev)
virtnet_init_settings(dev);
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
+ vi->failover = net_failover_create(vi->dev);
+ if (IS_ERR(vi->failover))
+ goto free_vqs;
+ }
+
err = register_netdev(dev);
if (err) {
pr_debug("virtio_net: registering device failed\n");
- goto free_vqs;
+ goto free_failover;
}
virtio_device_ready(vdev);
@@ -2916,6 +2948,8 @@ static int virtnet_probe(struct virtio_device *vdev)
vi->vdev->config->reset(vdev);
unregister_netdev(dev);
+free_failover:
+ net_failover_destroy(vi->failover);
free_vqs:
cancel_delayed_work_sync(&vi->refill);
free_receive_page_frags(vi);
@@ -2950,6 +2984,8 @@ static void virtnet_remove(struct virtio_device *vdev)
unregister_netdev(vi->dev);
+ net_failover_destroy(vi->failover);
+
remove_vq_common(vi);
free_netdev(vi->dev);
--
2.14.3
^ permalink raw reply related
* [PATCH v3 net-next 1/2] umh: introduce fork_usermode_blob() helper
From: Alexei Starovoitov @ 2018-05-22 2:22 UTC (permalink / raw)
To: David S . Miller
Cc: daniel, torvalds, gregkh, luto, mcgrof, keescook, netdev,
linux-kernel, kernel-team
In-Reply-To: <20180522022230.2492505-1-ast@kernel.org>
Introduce helper:
int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
struct umh_info {
struct file *pipe_to_umh;
struct file *pipe_from_umh;
pid_t pid;
};
that GPLed kernel modules (signed or unsigned) can use it to execute part
of its own data as swappable user mode process.
The kernel will do:
- allocate a unique file in tmpfs
- populate that file with [data, data + len] bytes
- user-mode-helper code will do_execve that file and, before the process
starts, the kernel will create two unix pipes for bidirectional
communication between kernel module and umh
- close tmpfs file, effectively deleting it
- the fork_usermode_blob will return zero on success and populate
'struct umh_info' with two unix pipes and the pid of the user process
As the first step in the development of the bpfilter project
the fork_usermode_blob() helper is introduced to allow user mode code
to be invoked from a kernel module. The idea is that user mode code plus
normal kernel module code are built as part of the kernel build
and installed as traditional kernel module into distro specified location,
such that from a distribution point of view, there is
no difference between regular kernel modules and kernel modules + umh code.
Such modules can be signed, modprobed, rmmod, etc. The use of this new helper
by a kernel module doesn't make it any special from kernel and user space
tooling point of view.
Such approach enables kernel to delegate functionality traditionally done
by the kernel modules into the user space processes (either root or !root) and
reduces security attack surface of the new code. The buggy umh code would crash
the user process, but not the kernel. Another advantage is that umh code
of the kernel module can be debugged and tested out of user space
(e.g. opening the possibility to run clang sanitizers, fuzzers or
user space test suites on the umh code).
In case of the bpfilter project such architecture allows complex control plane
to be done in the user space while bpf based data plane stays in the kernel.
Since umh can crash, can be oom-ed by the kernel, killed by the admin,
the kernel module that uses them (like bpfilter) needs to manage life
time of umh on its own via two unix pipes and the pid of umh.
The exit code of such kernel module should kill the umh it started,
so that rmmod of the kernel module will cleanup the corresponding umh.
Just like if the kernel module does kmalloc() it should kfree() it
in the exit code.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
fs/exec.c | 38 +++++++++++----
include/linux/binfmts.h | 1 +
include/linux/umh.h | 12 +++++
kernel/umh.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++--
4 files changed, 164 insertions(+), 12 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 183059c427b9..30a36c2a39bf 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1706,14 +1706,13 @@ static int exec_binprm(struct linux_binprm *bprm)
/*
* sys_execve() executes a new program.
*/
-static int do_execveat_common(int fd, struct filename *filename,
- struct user_arg_ptr argv,
- struct user_arg_ptr envp,
- int flags)
+static int __do_execve_file(int fd, struct filename *filename,
+ struct user_arg_ptr argv,
+ struct user_arg_ptr envp,
+ int flags, struct file *file)
{
char *pathbuf = NULL;
struct linux_binprm *bprm;
- struct file *file;
struct files_struct *displaced;
int retval;
@@ -1752,7 +1751,8 @@ static int do_execveat_common(int fd, struct filename *filename,
check_unsafe_exec(bprm);
current->in_execve = 1;
- file = do_open_execat(fd, filename, flags);
+ if (!file)
+ file = do_open_execat(fd, filename, flags);
retval = PTR_ERR(file);
if (IS_ERR(file))
goto out_unmark;
@@ -1760,7 +1760,9 @@ static int do_execveat_common(int fd, struct filename *filename,
sched_exec();
bprm->file = file;
- if (fd == AT_FDCWD || filename->name[0] == '/') {
+ if (!filename) {
+ bprm->filename = "none";
+ } else if (fd == AT_FDCWD || filename->name[0] == '/') {
bprm->filename = filename->name;
} else {
if (filename->name[0] == '\0')
@@ -1826,7 +1828,8 @@ static int do_execveat_common(int fd, struct filename *filename,
task_numa_free(current);
free_bprm(bprm);
kfree(pathbuf);
- putname(filename);
+ if (filename)
+ putname(filename);
if (displaced)
put_files_struct(displaced);
return retval;
@@ -1849,10 +1852,27 @@ static int do_execveat_common(int fd, struct filename *filename,
if (displaced)
reset_files_struct(displaced);
out_ret:
- putname(filename);
+ if (filename)
+ putname(filename);
return retval;
}
+static int do_execveat_common(int fd, struct filename *filename,
+ struct user_arg_ptr argv,
+ struct user_arg_ptr envp,
+ int flags)
+{
+ return __do_execve_file(fd, filename, argv, envp, flags, NULL);
+}
+
+int do_execve_file(struct file *file, void *__argv, void *__envp)
+{
+ struct user_arg_ptr argv = { .ptr.native = __argv };
+ struct user_arg_ptr envp = { .ptr.native = __envp };
+
+ return __do_execve_file(AT_FDCWD, NULL, argv, envp, 0, file);
+}
+
int do_execve(struct filename *filename,
const char __user *const __user *__argv,
const char __user *const __user *__envp)
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 4955e0863b83..c05f24fac4f6 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -150,5 +150,6 @@ extern int do_execveat(int, struct filename *,
const char __user * const __user *,
const char __user * const __user *,
int);
+int do_execve_file(struct file *file, void *__argv, void *__envp);
#endif /* _LINUX_BINFMTS_H */
diff --git a/include/linux/umh.h b/include/linux/umh.h
index 244aff638220..5c812acbb80a 100644
--- a/include/linux/umh.h
+++ b/include/linux/umh.h
@@ -22,8 +22,10 @@ struct subprocess_info {
const char *path;
char **argv;
char **envp;
+ struct file *file;
int wait;
int retval;
+ pid_t pid;
int (*init)(struct subprocess_info *info, struct cred *new);
void (*cleanup)(struct subprocess_info *info);
void *data;
@@ -38,6 +40,16 @@ call_usermodehelper_setup(const char *path, char **argv, char **envp,
int (*init)(struct subprocess_info *info, struct cred *new),
void (*cleanup)(struct subprocess_info *), void *data);
+struct subprocess_info *call_usermodehelper_setup_file(struct file *file,
+ int (*init)(struct subprocess_info *info, struct cred *new),
+ void (*cleanup)(struct subprocess_info *), void *data);
+struct umh_info {
+ struct file *pipe_to_umh;
+ struct file *pipe_from_umh;
+ pid_t pid;
+};
+int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
+
extern int
call_usermodehelper_exec(struct subprocess_info *info, int wait);
diff --git a/kernel/umh.c b/kernel/umh.c
index f76b3ff876cf..30db93fd7e39 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c
@@ -25,6 +25,8 @@
#include <linux/ptrace.h>
#include <linux/async.h>
#include <linux/uaccess.h>
+#include <linux/shmem_fs.h>
+#include <linux/pipe_fs_i.h>
#include <trace/events/module.h>
@@ -97,9 +99,13 @@ static int call_usermodehelper_exec_async(void *data)
commit_creds(new);
- retval = do_execve(getname_kernel(sub_info->path),
- (const char __user *const __user *)sub_info->argv,
- (const char __user *const __user *)sub_info->envp);
+ if (sub_info->file)
+ retval = do_execve_file(sub_info->file,
+ sub_info->argv, sub_info->envp);
+ else
+ retval = do_execve(getname_kernel(sub_info->path),
+ (const char __user *const __user *)sub_info->argv,
+ (const char __user *const __user *)sub_info->envp);
out:
sub_info->retval = retval;
/*
@@ -185,6 +191,8 @@ static void call_usermodehelper_exec_work(struct work_struct *work)
if (pid < 0) {
sub_info->retval = pid;
umh_complete(sub_info);
+ } else {
+ sub_info->pid = pid;
}
}
}
@@ -393,6 +401,117 @@ struct subprocess_info *call_usermodehelper_setup(const char *path, char **argv,
}
EXPORT_SYMBOL(call_usermodehelper_setup);
+struct subprocess_info *call_usermodehelper_setup_file(struct file *file,
+ int (*init)(struct subprocess_info *info, struct cred *new),
+ void (*cleanup)(struct subprocess_info *info), void *data)
+{
+ struct subprocess_info *sub_info;
+
+ sub_info = kzalloc(sizeof(struct subprocess_info), GFP_KERNEL);
+ if (!sub_info)
+ return NULL;
+
+ INIT_WORK(&sub_info->work, call_usermodehelper_exec_work);
+ sub_info->path = "none";
+ sub_info->file = file;
+ sub_info->init = init;
+ sub_info->cleanup = cleanup;
+ sub_info->data = data;
+ return sub_info;
+}
+
+static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
+{
+ struct umh_info *umh_info = info->data;
+ struct file *from_umh[2];
+ struct file *to_umh[2];
+ int err;
+
+ /* create pipe to send data to umh */
+ err = create_pipe_files(to_umh, 0);
+ if (err)
+ return err;
+ err = replace_fd(0, to_umh[0], 0);
+ fput(to_umh[0]);
+ if (err < 0) {
+ fput(to_umh[1]);
+ return err;
+ }
+
+ /* create pipe to receive data from umh */
+ err = create_pipe_files(from_umh, 0);
+ if (err) {
+ fput(to_umh[1]);
+ replace_fd(0, NULL, 0);
+ return err;
+ }
+ err = replace_fd(1, from_umh[1], 0);
+ fput(from_umh[1]);
+ if (err < 0) {
+ fput(to_umh[1]);
+ replace_fd(0, NULL, 0);
+ fput(from_umh[0]);
+ return err;
+ }
+
+ umh_info->pipe_to_umh = to_umh[1];
+ umh_info->pipe_from_umh = from_umh[0];
+ return 0;
+}
+
+static void umh_save_pid(struct subprocess_info *info)
+{
+ struct umh_info *umh_info = info->data;
+
+ umh_info->pid = info->pid;
+}
+
+/**
+ * fork_usermode_blob - fork a blob of bytes as a usermode process
+ * @data: a blob of bytes that can be do_execv-ed as a file
+ * @len: length of the blob
+ * @info: information about usermode process (shouldn't be NULL)
+ *
+ * Returns either negative error or zero which indicates success
+ * in executing a blob of bytes as a usermode process. In such
+ * case 'struct umh_info *info' is populated with two pipes
+ * and a pid of the process. The caller is responsible for health
+ * check of the user process, killing it via pid, and closing the
+ * pipes when user process is no longer needed.
+ */
+int fork_usermode_blob(void *data, size_t len, struct umh_info *info)
+{
+ struct subprocess_info *sub_info;
+ struct file *file;
+ ssize_t written;
+ loff_t pos = 0;
+ int err;
+
+ file = shmem_kernel_file_setup("", len, 0);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+
+ written = kernel_write(file, data, len, &pos);
+ if (written != len) {
+ err = written;
+ if (err >= 0)
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = -ENOMEM;
+ sub_info = call_usermodehelper_setup_file(file, umh_pipe_setup,
+ umh_save_pid, info);
+ if (!sub_info)
+ goto out;
+
+ err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
+out:
+ fput(file);
+ return err;
+}
+EXPORT_SYMBOL_GPL(fork_usermode_blob);
+
/**
* call_usermodehelper_exec - start a usermode application
* @sub_info: information about the subprocessa
--
2.9.5
^ permalink raw reply related
* [PATCH v3 net-next 2/2] net: add skeleton of bpfilter kernel module
From: Alexei Starovoitov @ 2018-05-22 2:22 UTC (permalink / raw)
To: David S . Miller
Cc: daniel, torvalds, gregkh, luto, mcgrof, keescook, netdev,
linux-kernel, kernel-team
In-Reply-To: <20180522022230.2492505-1-ast@kernel.org>
bpfilter.ko consists of bpfilter_kern.c (normal kernel module code)
and user mode helper code that is embedded into bpfilter.ko
The steps to build bpfilter.ko are the following:
- main.c is compiled by HOSTCC into the bpfilter_umh elf executable file
- with quite a bit of objcopy and Makefile magic the bpfilter_umh elf file
is converted into bpfilter_umh.o object file
with _binary_net_bpfilter_bpfilter_umh_start and _end symbols
Example:
$ nm ./bld_x64/net/bpfilter/bpfilter_umh.o
0000000000004cf8 T _binary_net_bpfilter_bpfilter_umh_end
0000000000004cf8 A _binary_net_bpfilter_bpfilter_umh_size
0000000000000000 T _binary_net_bpfilter_bpfilter_umh_start
- bpfilter_umh.o and bpfilter_kern.o are linked together into bpfilter.ko
bpfilter_kern.c is a normal kernel module code that calls
the fork_usermode_blob() helper to execute part of its own data
as a user mode process.
Notice that _binary_net_bpfilter_bpfilter_umh_start - end
is placed into .init.rodata section, so it's freed as soon as __init
function of bpfilter.ko is finished.
As part of __init the bpfilter.ko does first request/reply action
via two unix pipe provided by fork_usermode_blob() helper to
make sure that umh is healthy. If not it will kill it via pid.
Later bpfilter_process_sockopt() will be called from bpfilter hooks
in get/setsockopt() to pass iptable commands into umh via bpfilter.ko
If admin does 'rmmod bpfilter' the __exit code bpfilter.ko will
kill umh as well.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
include/linux/bpfilter.h | 15 ++++++
include/uapi/linux/bpfilter.h | 21 ++++++++
net/Kconfig | 2 +
net/Makefile | 1 +
net/bpfilter/Kconfig | 16 ++++++
net/bpfilter/Makefile | 30 ++++++++++++
net/bpfilter/bpfilter_kern.c | 111 ++++++++++++++++++++++++++++++++++++++++++
net/bpfilter/main.c | 63 ++++++++++++++++++++++++
net/bpfilter/msgfmt.h | 17 +++++++
net/ipv4/Makefile | 2 +
net/ipv4/bpfilter/Makefile | 2 +
net/ipv4/bpfilter/sockopt.c | 42 ++++++++++++++++
net/ipv4/ip_sockglue.c | 17 +++++++
13 files changed, 339 insertions(+)
create mode 100644 include/linux/bpfilter.h
create mode 100644 include/uapi/linux/bpfilter.h
create mode 100644 net/bpfilter/Kconfig
create mode 100644 net/bpfilter/Makefile
create mode 100644 net/bpfilter/bpfilter_kern.c
create mode 100644 net/bpfilter/main.c
create mode 100644 net/bpfilter/msgfmt.h
create mode 100644 net/ipv4/bpfilter/Makefile
create mode 100644 net/ipv4/bpfilter/sockopt.c
diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h
new file mode 100644
index 000000000000..687b1760bb9f
--- /dev/null
+++ b/include/linux/bpfilter.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_BPFILTER_H
+#define _LINUX_BPFILTER_H
+
+#include <uapi/linux/bpfilter.h>
+
+struct sock;
+int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char *optval,
+ unsigned int optlen);
+int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char *optval,
+ int *optlen);
+extern int (*bpfilter_process_sockopt)(struct sock *sk, int optname,
+ char __user *optval,
+ unsigned int optlen, bool is_set);
+#endif
diff --git a/include/uapi/linux/bpfilter.h b/include/uapi/linux/bpfilter.h
new file mode 100644
index 000000000000..2ec3cc99ea4c
--- /dev/null
+++ b/include/uapi/linux/bpfilter.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _UAPI_LINUX_BPFILTER_H
+#define _UAPI_LINUX_BPFILTER_H
+
+#include <linux/if.h>
+
+enum {
+ BPFILTER_IPT_SO_SET_REPLACE = 64,
+ BPFILTER_IPT_SO_SET_ADD_COUNTERS = 65,
+ BPFILTER_IPT_SET_MAX,
+};
+
+enum {
+ BPFILTER_IPT_SO_GET_INFO = 64,
+ BPFILTER_IPT_SO_GET_ENTRIES = 65,
+ BPFILTER_IPT_SO_GET_REVISION_MATCH = 66,
+ BPFILTER_IPT_SO_GET_REVISION_TARGET = 67,
+ BPFILTER_IPT_GET_MAX,
+};
+
+#endif /* _UAPI_LINUX_BPFILTER_H */
diff --git a/net/Kconfig b/net/Kconfig
index df8d45ef47d8..ba554cedb615 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -202,6 +202,8 @@ source "net/bridge/netfilter/Kconfig"
endif
+source "net/bpfilter/Kconfig"
+
source "net/dccp/Kconfig"
source "net/sctp/Kconfig"
source "net/rds/Kconfig"
diff --git a/net/Makefile b/net/Makefile
index 77aaddedbd29..bdaf53925acd 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_TLS) += tls/
obj-$(CONFIG_XFRM) += xfrm/
obj-$(CONFIG_UNIX) += unix/
obj-$(CONFIG_NET) += ipv6/
+obj-$(CONFIG_BPFILTER) += bpfilter/
obj-$(CONFIG_PACKET) += packet/
obj-$(CONFIG_NET_KEY) += key/
obj-$(CONFIG_BRIDGE) += bridge/
diff --git a/net/bpfilter/Kconfig b/net/bpfilter/Kconfig
new file mode 100644
index 000000000000..60725c5f79db
--- /dev/null
+++ b/net/bpfilter/Kconfig
@@ -0,0 +1,16 @@
+menuconfig BPFILTER
+ bool "BPF based packet filtering framework (BPFILTER)"
+ default n
+ depends on NET && BPF
+ help
+ This builds experimental bpfilter framework that is aiming to
+ provide netfilter compatible functionality via BPF
+
+if BPFILTER
+config BPFILTER_UMH
+ tristate "bpfilter kernel module with user mode helper"
+ default m
+ help
+ This builds bpfilter kernel module with embedded user mode helper
+endif
+
diff --git a/net/bpfilter/Makefile b/net/bpfilter/Makefile
new file mode 100644
index 000000000000..2af752c8ef5e
--- /dev/null
+++ b/net/bpfilter/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux BPFILTER layer.
+#
+
+hostprogs-y := bpfilter_umh
+bpfilter_umh-objs := main.o
+HOSTCFLAGS += -I. -Itools/include/
+ifeq ($(CONFIG_BPFILTER_UMH), y)
+# builtin bpfilter_umh should be compiled with -static
+# since rootfs isn't mounted at the time of __init
+# function is called and do_execv won't find elf interpreter
+HOSTLDFLAGS += -static
+endif
+
+# a bit of elf magic to convert bpfilter_umh binary into a binary blob
+# inside bpfilter_umh.o elf file referenced by
+# _binary_net_bpfilter_bpfilter_umh_start symbol
+# which bpfilter_kern.c passes further into umh blob loader at run-time
+quiet_cmd_copy_umh = GEN $@
+ cmd_copy_umh = echo ':' > $(obj)/.bpfilter_umh.o.cmd; \
+ $(OBJCOPY) -I binary -O $(CONFIG_OUTPUT_FORMAT) \
+ -B `$(OBJDUMP) -f $<|grep architecture|cut -d, -f1|cut -d' ' -f2` \
+ --rename-section .data=.init.rodata $< $@
+
+$(obj)/bpfilter_umh.o: $(obj)/bpfilter_umh
+ $(call cmd,copy_umh)
+
+obj-$(CONFIG_BPFILTER_UMH) += bpfilter.o
+bpfilter-objs += bpfilter_kern.o bpfilter_umh.o
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
new file mode 100644
index 000000000000..7596314b61c7
--- /dev/null
+++ b/net/bpfilter/bpfilter_kern.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/umh.h>
+#include <linux/bpfilter.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include "msgfmt.h"
+
+#define UMH_start _binary_net_bpfilter_bpfilter_umh_start
+#define UMH_end _binary_net_bpfilter_bpfilter_umh_end
+
+extern char UMH_start;
+extern char UMH_end;
+
+static struct umh_info info;
+/* since ip_getsockopt() can run in parallel, serialize access to umh */
+static DEFINE_MUTEX(bpfilter_lock);
+
+static void shutdown_umh(struct umh_info *info)
+{
+ struct task_struct *tsk;
+
+ tsk = pid_task(find_vpid(info->pid), PIDTYPE_PID);
+ if (tsk)
+ force_sig(SIGKILL, tsk);
+ fput(info->pipe_to_umh);
+ fput(info->pipe_from_umh);
+}
+
+static void __stop_umh(void)
+{
+ if (bpfilter_process_sockopt) {
+ bpfilter_process_sockopt = NULL;
+ shutdown_umh(&info);
+ }
+}
+
+static void stop_umh(void)
+{
+ mutex_lock(&bpfilter_lock);
+ __stop_umh();
+ mutex_unlock(&bpfilter_lock);
+}
+
+static int __bpfilter_process_sockopt(struct sock *sk, int optname,
+ char __user *optval,
+ unsigned int optlen, bool is_set)
+{
+ struct mbox_request req;
+ struct mbox_reply reply;
+ loff_t pos;
+ ssize_t n;
+ int ret;
+
+ req.is_set = is_set;
+ req.pid = current->pid;
+ req.cmd = optname;
+ req.addr = (long)optval;
+ req.len = optlen;
+ mutex_lock(&bpfilter_lock);
+ n = __kernel_write(info.pipe_to_umh, &req, sizeof(req), &pos);
+ if (n != sizeof(req)) {
+ pr_err("write fail %zd\n", n);
+ __stop_umh();
+ ret = -EFAULT;
+ goto out;
+ }
+ pos = 0;
+ n = kernel_read(info.pipe_from_umh, &reply, sizeof(reply), &pos);
+ if (n != sizeof(reply)) {
+ pr_err("read fail %zd\n", n);
+ __stop_umh();
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = reply.status;
+out:
+ mutex_unlock(&bpfilter_lock);
+ return ret;
+}
+
+static int __init load_umh(void)
+{
+ int err;
+
+ /* fork usermode process */
+ err = fork_usermode_blob(&UMH_start, &UMH_end - &UMH_start, &info);
+ if (err)
+ return err;
+ pr_info("Loaded bpfilter_umh pid %d\n", info.pid);
+
+ /* health check that usermode process started correctly */
+ if (__bpfilter_process_sockopt(NULL, 0, 0, 0, 0) != 0) {
+ stop_umh();
+ return -EFAULT;
+ }
+ bpfilter_process_sockopt = &__bpfilter_process_sockopt;
+ return 0;
+}
+
+static void __exit fini_umh(void)
+{
+ stop_umh();
+}
+module_init(load_umh);
+module_exit(fini_umh);
+MODULE_LICENSE("GPL");
diff --git a/net/bpfilter/main.c b/net/bpfilter/main.c
new file mode 100644
index 000000000000..81bbc1684896
--- /dev/null
+++ b/net/bpfilter/main.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <sys/uio.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "include/uapi/linux/bpf.h"
+#include <asm/unistd.h>
+#include "msgfmt.h"
+
+int debug_fd;
+
+static int handle_get_cmd(struct mbox_request *cmd)
+{
+ switch (cmd->cmd) {
+ case 0:
+ return 0;
+ default:
+ break;
+ }
+ return -ENOPROTOOPT;
+}
+
+static int handle_set_cmd(struct mbox_request *cmd)
+{
+ return -ENOPROTOOPT;
+}
+
+static void loop(void)
+{
+ while (1) {
+ struct mbox_request req;
+ struct mbox_reply reply;
+ int n;
+
+ n = read(0, &req, sizeof(req));
+ if (n != sizeof(req)) {
+ dprintf(debug_fd, "invalid request %d\n", n);
+ return;
+ }
+
+ reply.status = req.is_set ?
+ handle_set_cmd(&req) :
+ handle_get_cmd(&req);
+
+ n = write(1, &reply, sizeof(reply));
+ if (n != sizeof(reply)) {
+ dprintf(debug_fd, "reply failed %d\n", n);
+ return;
+ }
+ }
+}
+
+int main(void)
+{
+ debug_fd = open("/dev/console", 00000002 | 00000100);
+ dprintf(debug_fd, "Started bpfilter\n");
+ loop();
+ close(debug_fd);
+ return 0;
+}
diff --git a/net/bpfilter/msgfmt.h b/net/bpfilter/msgfmt.h
new file mode 100644
index 000000000000..98d121c62945
--- /dev/null
+++ b/net/bpfilter/msgfmt.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _NET_BPFILTER_MSGFMT_H
+#define _NET_BPFILTER_MSGFMT_H
+
+struct mbox_request {
+ __u64 addr;
+ __u32 len;
+ __u32 is_set;
+ __u32 cmd;
+ __u32 pid;
+};
+
+struct mbox_reply {
+ __u32 status;
+};
+
+#endif
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index b379520f9133..7018f91c5a39 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -16,6 +16,8 @@ obj-y := route.o inetpeer.o protocol.o \
inet_fragment.o ping.o ip_tunnel_core.o gre_offload.o \
metrics.o
+obj-$(CONFIG_BPFILTER) += bpfilter/
+
obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
obj-$(CONFIG_PROC_FS) += proc.o
diff --git a/net/ipv4/bpfilter/Makefile b/net/ipv4/bpfilter/Makefile
new file mode 100644
index 000000000000..ce262d76cc48
--- /dev/null
+++ b/net/ipv4/bpfilter/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_BPFILTER) += sockopt.o
+
diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c
new file mode 100644
index 000000000000..42a96d2d8d05
--- /dev/null
+++ b/net/ipv4/bpfilter/sockopt.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/uaccess.h>
+#include <linux/bpfilter.h>
+#include <uapi/linux/bpf.h>
+#include <linux/wait.h>
+#include <linux/kmod.h>
+
+int (*bpfilter_process_sockopt)(struct sock *sk, int optname,
+ char __user *optval,
+ unsigned int optlen, bool is_set);
+EXPORT_SYMBOL_GPL(bpfilter_process_sockopt);
+
+int bpfilter_mbox_request(struct sock *sk, int optname, char __user *optval,
+ unsigned int optlen, bool is_set)
+{
+ if (!bpfilter_process_sockopt) {
+ int err = request_module("bpfilter");
+
+ if (err)
+ return err;
+ if (!bpfilter_process_sockopt)
+ return -ECHILD;
+ }
+ return bpfilter_process_sockopt(sk, optname, optval, optlen, is_set);
+}
+
+int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval,
+ unsigned int optlen)
+{
+ return bpfilter_mbox_request(sk, optname, optval, optlen, true);
+}
+
+int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
+ int __user *optlen)
+{
+ int len;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+
+ return bpfilter_mbox_request(sk, optname, optval, len, false);
+}
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 5ad2d8ed3a3f..e0791faacb24 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -47,6 +47,8 @@
#include <linux/errqueue.h>
#include <linux/uaccess.h>
+#include <linux/bpfilter.h>
+
/*
* SOL_IP control messages.
*/
@@ -1244,6 +1246,11 @@ int ip_setsockopt(struct sock *sk, int level,
return -ENOPROTOOPT;
err = do_ip_setsockopt(sk, level, optname, optval, optlen);
+#ifdef CONFIG_BPFILTER
+ if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
+ optname < BPFILTER_IPT_SET_MAX)
+ err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
+#endif
#ifdef CONFIG_NETFILTER
/* we need to exclude all possible ENOPROTOOPTs except default case */
if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
@@ -1552,6 +1559,11 @@ int ip_getsockopt(struct sock *sk, int level,
int err;
err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
+#ifdef CONFIG_BPFILTER
+ if (optname >= BPFILTER_IPT_SO_GET_INFO &&
+ optname < BPFILTER_IPT_GET_MAX)
+ err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
+#endif
#ifdef CONFIG_NETFILTER
/* we need to exclude all possible ENOPROTOOPTs except default case */
if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
@@ -1584,6 +1596,11 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
err = do_ip_getsockopt(sk, level, optname, optval, optlen,
MSG_CMSG_COMPAT);
+#ifdef CONFIG_BPFILTER
+ if (optname >= BPFILTER_IPT_SO_GET_INFO &&
+ optname < BPFILTER_IPT_GET_MAX)
+ err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
+#endif
#ifdef CONFIG_NETFILTER
/* we need to exclude all possible ENOPROTOOPTs except default case */
if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
--
2.9.5
^ permalink raw reply related
* [PATCH v3 net-next 0/2] bpfilter
From: Alexei Starovoitov @ 2018-05-22 2:22 UTC (permalink / raw)
To: David S . Miller
Cc: daniel, torvalds, gregkh, luto, mcgrof, keescook, netdev,
linux-kernel, kernel-team
Hi All,
v2->v3:
- followed Luis's suggestion and significantly simplied first patch
with shmem_kernel_file_setup+kernel_write. Added kdoc for new helper
- fixed typos and race to access pipes with mutex
- tested with bpfilter being 'builtin'. CONFIG_BPFILTER_UMH=y|m both work.
Interesting to see a usermode executable being embedded inside vmlinux.
- it doesn't hurt to enable bpfilter in .config.
ip_setsockopt commands sent to usermode via pipes and -ENOPROTOOPT is
returned from userspace, so kernel falls back to original iptables code
v1->v2:
this patch set is almost a full rewrite of the earlier umh modules approach
The v1 of patches and follow up discussion was covered by LWN:
https://lwn.net/Articles/749108/
I believe the v2 addresses all issues brought up by Andy and others.
Mainly there are zero changes to kernel/module.c
Instead of teaching module loading logic to recognize special
umh module, let normal kernel modules execute part of its own
.init.rodata as a new user space process (Andy's idea)
Patch 1 introduces this new helper:
int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
Input:
data + len == executable file
Output:
struct umh_info {
struct file *pipe_to_umh;
struct file *pipe_from_umh;
pid_t pid;
};
Advantages vs v1:
- the embedded user mode executable is stored as .init.rodata inside
normal kernel module. These pages are freed when .ko finishes loading
- the elf file is copied into tmpfs file. The user mode process is swappable.
- the communication between user mode process and 'parent' kernel module
is done via two unix pipes, hence protocol is not exposed to
user space
- impossible to launch umh on its own (that was the main issue of v1)
and impossible to be man-in-the-middle due to pipes
- bpfilter.ko consists of tiny kernel part that passes the data
between kernel and umh via pipes and much bigger umh part that
doing all the work
- 'lsmod' shows bpfilter.ko as usual.
'rmmod bpfilter' removes kernel module and kills corresponding umh
- signed bpfilter.ko covers the whole image including umh code
Few issues:
- the user can still attach to the process and debug it with
'gdb /proc/pid/exe pid', but 'gdb -p pid' doesn't work.
(a bit worse comparing to v1)
- tinyconfig will notice a small increase in .text
+766 | TEXT | 7c8b94806bec umh: introduce fork_usermode_blob() helper
Alexei Starovoitov (2):
umh: introduce fork_usermode_blob() helper
net: add skeleton of bpfilter kernel module
fs/exec.c | 38 ++++++++++---
include/linux/binfmts.h | 1 +
include/linux/bpfilter.h | 15 +++++
include/linux/umh.h | 12 ++++
include/uapi/linux/bpfilter.h | 21 +++++++
kernel/umh.c | 125 +++++++++++++++++++++++++++++++++++++++++-
net/Kconfig | 2 +
net/Makefile | 1 +
net/bpfilter/Kconfig | 16 ++++++
net/bpfilter/Makefile | 30 ++++++++++
net/bpfilter/bpfilter_kern.c | 111 +++++++++++++++++++++++++++++++++++++
net/bpfilter/main.c | 63 +++++++++++++++++++++
net/bpfilter/msgfmt.h | 17 ++++++
net/ipv4/Makefile | 2 +
net/ipv4/bpfilter/Makefile | 2 +
net/ipv4/bpfilter/sockopt.c | 42 ++++++++++++++
net/ipv4/ip_sockglue.c | 17 ++++++
17 files changed, 503 insertions(+), 12 deletions(-)
create mode 100644 include/linux/bpfilter.h
create mode 100644 include/uapi/linux/bpfilter.h
create mode 100644 net/bpfilter/Kconfig
create mode 100644 net/bpfilter/Makefile
create mode 100644 net/bpfilter/bpfilter_kern.c
create mode 100644 net/bpfilter/main.c
create mode 100644 net/bpfilter/msgfmt.h
create mode 100644 net/ipv4/bpfilter/Makefile
create mode 100644 net/ipv4/bpfilter/sockopt.c
--
2.9.5
^ permalink raw reply
* Re: [PATCH net] tuntap: raise EPOLLOUT on device up
From: Jason Wang @ 2018-05-22 3:22 UTC (permalink / raw)
To: Michael S. Tsirkin, David Miller; +Cc: netdev, linux-kernel, hannes, edumazet
In-Reply-To: <20180522010700-mutt-send-email-mst@kernel.org>
On 2018年05月22日 06:08, Michael S. Tsirkin wrote:
> On Mon, May 21, 2018 at 11:47:42AM -0400, David Miller wrote:
>> From: Jason Wang <jasowang@redhat.com>
>> Date: Fri, 18 May 2018 21:00:43 +0800
>>
>>> We return -EIO on device down but can not raise EPOLLOUT after it was
>>> up. This may confuse user like vhost which expects tuntap to raise
>>> EPOLLOUT to re-enable its TX routine after tuntap is down. This could
>>> be easily reproduced by transmitting packets from VM while down and up
>>> the tap device. Fixing this by set SOCKWQ_ASYNC_NOSPACE on -EIO.
>>>
>>> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
>>> Cc: Eric Dumazet <edumazet@google.com>
>>> Fixes: 1bd4978a88ac2 ("tun: honor IFF_UP in tun_get_user()")
>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> I'm no so sure what to do with this patch.
>>
>> Like Michael says, this flag bit is only checks upon transmit which
>> may or may not happen after this point. It doesn't seem to be
>> guaranteed.
The flag is checked in tun_chr_poll() as well.
> Jason, can't we detect a link up transition and respond accordingly?
> What do you think?
>
I think we've already tried to do this, in tun_net_open() we call
write_space(). But the problem is the bit may not be set at that time.
A second thought is to set the bit in tun_chr_poll() instead of -EIO like:
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d45ac37..46a1573 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1423,6 +1423,13 @@ static void tun_net_init(struct net_device *dev)
dev->max_mtu = MAX_MTU - dev->hard_header_len;
}
+static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file
*tfile)
+{
+ struct sock *sk = tfile->socket.sk;
+
+ return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
+}
+
/* Character device part */
/* Poll */
@@ -1445,10 +1452,9 @@ static __poll_t tun_chr_poll(struct file *file,
poll_table *wait)
if (!ptr_ring_empty(&tfile->tx_ring))
mask |= EPOLLIN | EPOLLRDNORM;
- if (tun->dev->flags & IFF_UP &&
- (sock_writeable(sk) ||
- (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE,
&sk->sk_socket->flags) &&
- sock_writeable(sk))))
+ if (tun_sock_writeable(tun, tfile) ||
+ (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE,
&sk->sk_socket->flags) &&
+ tun_sock_writeable(tun, tfile)));
mask |= EPOLLOUT | EPOLLWRNORM;
if (tun->dev->reg_state != NETREG_REGISTERED)
Does this make more sense?
Thanks
^ permalink raw reply related
* Re: [PATCH] bpf: check NULL for sk_to_full_sk()
From: YueHaibing @ 2018-05-22 3:29 UTC (permalink / raw)
To: Eric Dumazet, ast, daniel; +Cc: linux-kernel, netdev
In-Reply-To: <5490b571-7881-c5eb-6acf-8f45634cd2b1@gmail.com>
On 2018/5/21 23:17, Eric Dumazet wrote:
>
>
> On 05/21/2018 12:55 AM, YueHaibing wrote:
>> like commit df39a9f106d5 ("bpf: check NULL for sk_to_full_sk() return value"),
>> we should check sk_to_full_sk return value against NULL.
>>
>> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
>> ---
>> include/linux/bpf-cgroup.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
>> index 30d15e6..fd3fbeb 100644
>> --- a/include/linux/bpf-cgroup.h
>> +++ b/include/linux/bpf-cgroup.h
>> @@ -91,7 +91,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
>> int __ret = 0; \
>> if (cgroup_bpf_enabled && sk && sk == skb->sk) { \
>> typeof(sk) __sk = sk_to_full_sk(sk); \
>> - if (sk_fullsock(__sk)) \
>> + if (__sk && sk_fullsock(__sk)) \
>> __ret = __cgroup_bpf_run_filter_skb(__sk, skb, \
>> BPF_CGROUP_INET_EGRESS); \
>> } \
>>
>
> Why is this needed ???
BPF_CGROUP_RUN_PROG_INET_EGRESS is called in ip_output
I just misunderstood, sorry for noise.
>
>
^ permalink raw reply
* Re: [PATCH 07/33] iwlwifi: mvm: use match_string() helper
From: Yisheng Xie @ 2018-05-22 3:30 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Linux Kernel Mailing List, Kalle Valo, Intel Linux Wireless,
Johannes Berg, Emmanuel Grumbach, open list:TI WILINK WIRELES...,
netdev
In-Reply-To: <CAHp75VeFiEMN+q0FPuk4qTVEW_1oovHzVkV_Ydcm22SEMarvUA@mail.gmail.com>
Hi Andy,
On 2018/5/22 5:43, Andy Shevchenko wrote:
> On Mon, May 21, 2018 at 2:57 PM, Yisheng Xie <xieyisheng1@huawei.com> wrote:
>> match_string() returns the index of an array for a matching string,
>> which can be used intead of open coded variant.
>
>> int ret, bt_force_ant_mode;
>>
>> - for (bt_force_ant_mode = 0;
>> - bt_force_ant_mode < ARRAY_SIZE(modes_str);
>> - bt_force_ant_mode++) {
>> - if (!strcmp(buf, modes_str[bt_force_ant_mode]))
>> - break;
>> - }
>> -
>> - if (bt_force_ant_mode >= ARRAY_SIZE(modes_str))
>
>> + bt_force_ant_mode = match_string(modes_str,
>> + ARRAY_SIZE(modes_str), buf);
>
> One line?
hmm, if use ret instead it will no over 80 chars.
>
>> + if (bt_force_ant_mode < 0)
>> return -EINVAL;
>
> I would rather use
>
> ret = match_string();
> if (ret < 0)
> return ret;
>
> bt_force_... = ret;
>
> But it's up tu Loca.
OK, I will change it if Loca agree your opinion.
Thanks
Yisheng
>
>>
>> ret = 0;
>
>
>
^ permalink raw reply
* Re: [PATCH net 3/4] virtio-net: reset num_buf to 1 after linearizing packet
From: Jason Wang @ 2018-05-22 3:36 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: virtualization, netdev, linux-kernel
In-Reply-To: <20180521174725-mutt-send-email-mst@kernel.org>
On 2018年05月21日 22:59, Michael S. Tsirkin wrote:
> On Mon, May 21, 2018 at 04:35:05PM +0800, Jason Wang wrote:
>> If we successfully linearize the packets, num_buf were set to zero
>> which was wrong since we now have only 1 buffer to be used for e.g in
>> the error path of receive_mergeable(). Zero num_buf will lead the code
>> try to pop the buffers of next packet and drop it. Fixing this by set
>> num_buf to 1 if we successfully linearize the packet.
>>
>> Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> drivers/net/virtio_net.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 6260d65..165a922 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -722,6 +722,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>> &len);
>> if (!xdp_page)
>> goto err_xdp;
>> + num_buf = 1;
> So this is tweaked here for the benefit of err_skb below.
> That's confusing and we won't remember to change it
> if we change the error handling.
>
> How about fixing the error path?
>
>
> - while (--num_buf) {
> + while (num_buf-- > 1) {
>
> Seems more robust to me.
Looks good, will do this in V2.
Thanks
>
>> offset = VIRTIO_XDP_HEADROOM;
>> } else {
>> xdp_page = page;
>> --
>> 2.7.4
^ permalink raw reply
* Re: [PATCH net 4/4] virito-net: fix leaking page for gso packet during mergeable XDP
From: Jason Wang @ 2018-05-22 3:37 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: virtualization, netdev, linux-kernel, John Fastabend
In-Reply-To: <20180521175919-mutt-send-email-mst@kernel.org>
On 2018年05月21日 23:01, Michael S. Tsirkin wrote:
> On Mon, May 21, 2018 at 04:35:06PM +0800, Jason Wang wrote:
>> We need to drop refcnt to xdp_page if we see a gso packet. Otherwise
>> it will be leaked. Fixing this by moving the check of gso packet above
>> the linearizing logic.
>>
>> Cc: John Fastabend <john.fastabend@gmail.com>
>> Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> typo in subject
Let me fix it in V2.
>> ---
>> drivers/net/virtio_net.c | 16 ++++++++--------
>> 1 file changed, 8 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 165a922..f8db809 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -707,6 +707,14 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>> void *data;
>> u32 act;
>>
>> + /* Transient failure which in theory could occur if
>> + * in-flight packets from before XDP was enabled reach
>> + * the receive path after XDP is loaded. In practice I
>> + * was not able to create this condition.
> BTW we should probably drop the last sentence. It says in theory, should be enough.
Ok.
Thanks
>> + */
>> + if (unlikely(hdr->hdr.gso_type))
>> + goto err_xdp;
>> +
>> /* This happens when rx buffer size is underestimated
>> * or headroom is not enough because of the buffer
>> * was refilled before XDP is set. This should only
>> @@ -728,14 +736,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>> xdp_page = page;
>> }
>>
>> - /* Transient failure which in theory could occur if
>> - * in-flight packets from before XDP was enabled reach
>> - * the receive path after XDP is loaded. In practice I
>> - * was not able to create this condition.
>> - */
>> - if (unlikely(hdr->hdr.gso_type))
>> - goto err_xdp;
>> -
>> /* Allow consuming headroom but reserve enough space to push
>> * the descriptor on if we get an XDP_TX return code.
>> */
>> --
>> 2.7.4
^ permalink raw reply
* [PATCH net V2 0/4] Fix several issues of virtio-net mergeable XDP
From: Jason Wang @ 2018-05-22 3:44 UTC (permalink / raw)
To: mst, jasowang; +Cc: virtualization, netdev, linux-kernel
Hi:
Please review the patches that tries to fix sevreal issues of
virtio-net mergeable XDP.
Changes from V1:
- check against 1 before decreasing instead of resetting to 1
- typoe fixes
Jason Wang (4):
virtio-net: correctly redirect linearized packet
virtio-net: correctly transmit XDP buff after linearizing
virtio-net: correctly check num_buf during err path
virtio-net: fix leaking page for gso packet during mergeable XDP
drivers/net/virtio_net.c | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
--
2.7.4
^ permalink raw reply
* [PATCH net V2 1/4] virtio-net: correctly redirect linearized packet
From: Jason Wang @ 2018-05-22 3:44 UTC (permalink / raw)
To: mst, jasowang; +Cc: virtualization, netdev, linux-kernel
In-Reply-To: <1526960671-11782-1-git-send-email-jasowang@redhat.com>
After a linearized packet was redirected by XDP, we should not go for
the err path which will try to pop buffers for the next packet and
increase the drop counter. Fixing this by just drop the page refcnt
for the original page.
Fixes: 186b3c998c50 ("virtio-net: support XDP_REDIRECT")
Reported-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 770422e..c15d240 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -787,7 +787,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
}
*xdp_xmit = true;
if (unlikely(xdp_page != page))
- goto err_xdp;
+ put_page(page);
rcu_read_unlock();
goto xdp_xmit;
default:
--
2.7.4
^ permalink raw reply related
* [PATCH net V2 2/4] virtio-net: correctly transmit XDP buff after linearizing
From: Jason Wang @ 2018-05-22 3:44 UTC (permalink / raw)
To: mst, jasowang; +Cc: virtualization, netdev, linux-kernel, John Fastabend
In-Reply-To: <1526960671-11782-1-git-send-email-jasowang@redhat.com>
We should not go for the error path after successfully transmitting a
XDP buffer after linearizing. Since the error path may try to pop and
drop next packet and increase the drop counters. Fixing this by simply
drop the refcnt of original page and go for xmit path.
Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
Cc: John Fastabend <john.fastabend@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c15d240..6260d65 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -775,7 +775,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
}
*xdp_xmit = true;
if (unlikely(xdp_page != page))
- goto err_xdp;
+ put_page(page);
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
--
2.7.4
^ permalink raw reply related
* [PATCH net V2 3/4] virtio-net: correctly check num_buf during err path
From: Jason Wang @ 2018-05-22 3:44 UTC (permalink / raw)
To: mst, jasowang; +Cc: virtualization, netdev, linux-kernel
In-Reply-To: <1526960671-11782-1-git-send-email-jasowang@redhat.com>
If we successfully linearize the packet, num_buf will be set to zero
which may confuse error handling path which assumes num_buf is at
least 1 and this can lead the code tries to pop the descriptor of next
buffer. Fixing this by checking num_buf against 1 before decreasing.
Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6260d65..326e247 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -875,7 +875,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
rcu_read_unlock();
err_skb:
put_page(page);
- while (--num_buf) {
+ while (num_buf-- > 1) {
buf = virtqueue_get_buf(rq->vq, &len);
if (unlikely(!buf)) {
pr_debug("%s: rx error: %d buffers missing\n",
--
2.7.4
^ permalink raw reply related
* [PATCH net V2 4/4] virtio-net: fix leaking page for gso packet during mergeable XDP
From: Jason Wang @ 2018-05-22 3:44 UTC (permalink / raw)
To: mst, jasowang; +Cc: virtualization, netdev, linux-kernel, John Fastabend
In-Reply-To: <1526960671-11782-1-git-send-email-jasowang@redhat.com>
We need to drop refcnt to xdp_page if we see a gso packet. Otherwise
it will be leaked. Fixing this by moving the check of gso packet above
the linearizing logic. While at it, remove useless comment as well.
Cc: John Fastabend <john.fastabend@gmail.com>
Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/virtio_net.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 326e247..032e1ac 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -707,6 +707,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
void *data;
u32 act;
+ /* Transient failure which in theory could occur if
+ * in-flight packets from before XDP was enabled reach
+ * the receive path after XDP is loaded.
+ */
+ if (unlikely(hdr->hdr.gso_type))
+ goto err_xdp;
+
/* This happens when rx buffer size is underestimated
* or headroom is not enough because of the buffer
* was refilled before XDP is set. This should only
@@ -727,14 +734,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
xdp_page = page;
}
- /* Transient failure which in theory could occur if
- * in-flight packets from before XDP was enabled reach
- * the receive path after XDP is loaded. In practice I
- * was not able to create this condition.
- */
- if (unlikely(hdr->hdr.gso_type))
- goto err_xdp;
-
/* Allow consuming headroom but reserve enough space to push
* the descriptor on if we get an XDP_TX return code.
*/
--
2.7.4
^ permalink raw reply related
* Re: [PATCH net] tuntap: raise EPOLLOUT on device up
From: Michael S. Tsirkin @ 2018-05-22 3:45 UTC (permalink / raw)
To: Jason Wang; +Cc: David Miller, netdev, linux-kernel, hannes, edumazet
In-Reply-To: <358628f8-a296-ad0e-985b-307895ed5520@redhat.com>
On Tue, May 22, 2018 at 11:22:11AM +0800, Jason Wang wrote:
>
>
> On 2018年05月22日 06:08, Michael S. Tsirkin wrote:
> > On Mon, May 21, 2018 at 11:47:42AM -0400, David Miller wrote:
> > > From: Jason Wang <jasowang@redhat.com>
> > > Date: Fri, 18 May 2018 21:00:43 +0800
> > >
> > > > We return -EIO on device down but can not raise EPOLLOUT after it was
> > > > up. This may confuse user like vhost which expects tuntap to raise
> > > > EPOLLOUT to re-enable its TX routine after tuntap is down. This could
> > > > be easily reproduced by transmitting packets from VM while down and up
> > > > the tap device. Fixing this by set SOCKWQ_ASYNC_NOSPACE on -EIO.
> > > >
> > > > Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
> > > > Cc: Eric Dumazet <edumazet@google.com>
> > > > Fixes: 1bd4978a88ac2 ("tun: honor IFF_UP in tun_get_user()")
> > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > I'm no so sure what to do with this patch.
> > >
> > > Like Michael says, this flag bit is only checks upon transmit which
> > > may or may not happen after this point. It doesn't seem to be
> > > guaranteed.
>
> The flag is checked in tun_chr_poll() as well.
>
> > Jason, can't we detect a link up transition and respond accordingly?
> > What do you think?
> >
>
> I think we've already tried to do this, in tun_net_open() we call
> write_space(). But the problem is the bit may not be set at that time.
Which bit? __dev_change_flags seems to set IFF_UP before calling
ndo_open. The issue I think is that tun_sock_write_space
exits if SOCKWQ_ASYNC_NOSPACE is clear.
And now I think I understand what is going on:
When link is down, writes to the device might fail with -EIO.
Userspace needs an indication when the status is resolved. As a fix,
tun_net_open attempts to wake up writers - but that is only effective if
SOCKWQ_ASYNC_NOSPACE has been set in the past. As a quick hack, set
SOCKWQ_ASYNC_NOSPACE when write fails because of the link down status.
If no writes failed, userspace does not know that interface
was down so should not care that it's going up.
does this describe what this line of code does?
If yes feel free to include this info in a code comment and commit log.
> A second thought is to set the bit in tun_chr_poll() instead of -EIO like:
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index d45ac37..46a1573 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1423,6 +1423,13 @@ static void tun_net_init(struct net_device *dev)
> dev->max_mtu = MAX_MTU - dev->hard_header_len;
> }
>
> +static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file
> *tfile)
> +{
> + struct sock *sk = tfile->socket.sk;
> +
> + return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
> +}
> +
> /* Character device part */
>
> /* Poll */
> @@ -1445,10 +1452,9 @@ static __poll_t tun_chr_poll(struct file *file,
> poll_table *wait)
> if (!ptr_ring_empty(&tfile->tx_ring))
> mask |= EPOLLIN | EPOLLRDNORM;
>
> - if (tun->dev->flags & IFF_UP &&
> - (sock_writeable(sk) ||
> - (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)
> &&
> - sock_writeable(sk))))
> + if (tun_sock_writeable(tun, tfile) ||
> + (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)
> &&
> + tun_sock_writeable(tun, tfile)));
> mask |= EPOLLOUT | EPOLLWRNORM;
>
> if (tun->dev->reg_state != NETREG_REGISTERED)
>
> Does this make more sense?
>
> Thanks
^ permalink raw reply
* Re: [PATCH net] tuntap: raise EPOLLOUT on device up
From: Michael S. Tsirkin @ 2018-05-22 3:46 UTC (permalink / raw)
To: Jason Wang; +Cc: David Miller, netdev, linux-kernel, hannes, edumazet
In-Reply-To: <358628f8-a296-ad0e-985b-307895ed5520@redhat.com>
On Tue, May 22, 2018 at 11:22:11AM +0800, Jason Wang wrote:
>
>
> On 2018年05月22日 06:08, Michael S. Tsirkin wrote:
> > On Mon, May 21, 2018 at 11:47:42AM -0400, David Miller wrote:
> > > From: Jason Wang <jasowang@redhat.com>
> > > Date: Fri, 18 May 2018 21:00:43 +0800
> > >
> > > > We return -EIO on device down but can not raise EPOLLOUT after it was
> > > > up. This may confuse user like vhost which expects tuntap to raise
> > > > EPOLLOUT to re-enable its TX routine after tuntap is down. This could
> > > > be easily reproduced by transmitting packets from VM while down and up
> > > > the tap device. Fixing this by set SOCKWQ_ASYNC_NOSPACE on -EIO.
> > > >
> > > > Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
> > > > Cc: Eric Dumazet <edumazet@google.com>
> > > > Fixes: 1bd4978a88ac2 ("tun: honor IFF_UP in tun_get_user()")
> > > > Signed-off-by: Jason Wang <jasowang@redhat.com>
> > > I'm no so sure what to do with this patch.
> > >
> > > Like Michael says, this flag bit is only checks upon transmit which
> > > may or may not happen after this point. It doesn't seem to be
> > > guaranteed.
>
> The flag is checked in tun_chr_poll() as well.
>
> > Jason, can't we detect a link up transition and respond accordingly?
> > What do you think?
> >
>
> I think we've already tried to do this, in tun_net_open() we call
> write_space(). But the problem is the bit may not be set at that time.
>
> A second thought is to set the bit in tun_chr_poll() instead of -EIO like:
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index d45ac37..46a1573 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -1423,6 +1423,13 @@ static void tun_net_init(struct net_device *dev)
> dev->max_mtu = MAX_MTU - dev->hard_header_len;
> }
>
> +static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file
> *tfile)
> +{
> + struct sock *sk = tfile->socket.sk;
> +
> + return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
> +}
> +
> /* Character device part */
>
> /* Poll */
> @@ -1445,10 +1452,9 @@ static __poll_t tun_chr_poll(struct file *file,
> poll_table *wait)
> if (!ptr_ring_empty(&tfile->tx_ring))
> mask |= EPOLLIN | EPOLLRDNORM;
>
> - if (tun->dev->flags & IFF_UP &&
> - (sock_writeable(sk) ||
> - (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)
> &&
> - sock_writeable(sk))))
> + if (tun_sock_writeable(tun, tfile) ||
> + (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)
> &&
> + tun_sock_writeable(tun, tfile)));
> mask |= EPOLLOUT | EPOLLWRNORM;
>
> if (tun->dev->reg_state != NETREG_REGISTERED)
>
> Does this make more sense?
>
> Thanks
I just understood the motivation for doing it on EIO.
Maybe there's a reason it makes sense here as well,
but it's far from obvious. I suggest you repost adding
an explanation in the comment. The original patch will
be fine with an explanation as well.
^ permalink raw reply
* Re: KASAN: use-after-free Read in vhost_chr_write_iter
From: Jason Wang @ 2018-05-22 3:50 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: DaeRyong Jeong, kvm, virtualization, netdev, linux-kernel,
byoungyoung, kt0755, bammanag
In-Reply-To: <20180521173645-mutt-send-email-mst@kernel.org>
On 2018年05月21日 22:42, Michael S. Tsirkin wrote:
> On Mon, May 21, 2018 at 10:38:10AM +0800, Jason Wang wrote:
>> On 2018年05月18日 17:24, Jason Wang wrote:
>>> On 2018年05月17日 21:45, DaeRyong Jeong wrote:
>>>> We report the crash: KASAN: use-after-free Read in vhost_chr_write_iter
>>>>
>>>> This crash has been found in v4.17-rc1 using RaceFuzzer (a modified
>>>> version of Syzkaller), which we describe more at the end of this
>>>> report. Our analysis shows that the race occurs when invoking two
>>>> syscalls concurrently, write$vnet and ioctl$VHOST_RESET_OWNER.
>>>>
>>>>
>>>> Analysis:
>>>> We think the concurrent execution of vhost_process_iotlb_msg() and
>>>> vhost_dev_cleanup() causes the crash.
>>>> Both of functions can run concurrently (please see call sequence below),
>>>> and possibly, there is a race on dev->iotlb.
>>>> If the switch occurs right after vhost_dev_cleanup() frees
>>>> dev->iotlb, vhost_process_iotlb_msg() still sees the non-null value
>>>> and it
>>>> keep executing without returning -EFAULT. Consequently, use-after-free
>>>> occures
>>>>
>>>>
>>>> Thread interleaving:
>>>> CPU0 (vhost_process_iotlb_msg) CPU1 (vhost_dev_cleanup)
>>>> (In the case of both VHOST_IOTLB_UPDATE and
>>>> VHOST_IOTLB_INVALIDATE)
>>>> ===== =====
>>>> vhost_umem_clean(dev->iotlb);
>>>> if (!dev->iotlb) {
>>>> ret = -EFAULT;
>>>> break;
>>>> }
>>>> dev->iotlb = NULL;
>>>>
>>>>
>>>> Call Sequence:
>>>> CPU0
>>>> =====
>>>> vhost_net_chr_write_iter
>>>> vhost_chr_write_iter
>>>> vhost_process_iotlb_msg
>>>>
>>>> CPU1
>>>> =====
>>>> vhost_net_ioctl
>>>> vhost_net_reset_owner
>>>> vhost_dev_reset_owner
>>>> vhost_dev_cleanup
>>> Thanks a lot for the analysis.
>>>
>>> This could be addressed by simply protect it with dev mutex.
>>>
>>> Will post a patch.
>>>
>> Could you please help to test the attached patch? I've done some smoking
>> test.
>>
>> Thanks
>> >From 88328386f3f652e684ee33dc4cf63dcaed871aea Mon Sep 17 00:00:00 2001
>> From: Jason Wang<jasowang@redhat.com>
>> Date: Fri, 18 May 2018 17:33:27 +0800
>> Subject: [PATCH] vhost: synchronize IOTLB message with dev cleanup
>>
>> DaeRyong Jeong reports a race between vhost_dev_cleanup() and
>> vhost_process_iotlb_msg():
>>
>> Thread interleaving:
>> CPU0 (vhost_process_iotlb_msg) CPU1 (vhost_dev_cleanup)
>> (In the case of both VHOST_IOTLB_UPDATE and
>> VHOST_IOTLB_INVALIDATE)
>> ===== =====
>> vhost_umem_clean(dev->iotlb);
>> if (!dev->iotlb) {
>> ret = -EFAULT;
>> break;
>> }
>> dev->iotlb = NULL;
>>
>> The reason is we don't synchronize between them, fixing by protecting
>> vhost_process_iotlb_msg() with dev mutex.
>>
>> Reported-by: DaeRyong Jeong<threeearcat@gmail.com>
>> Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
>> Reported-by: DaeRyong Jeong<threeearcat@gmail.com>
> Long terms we might want to move iotlb into vqs
> so that messages can be processed in parallel.
> Not sure how to do it yet.
>
Then we probably need to extend IOTLB msg to have a queue idx. But I
thinkit was probably only help if we split tx/rx into separate processes.
Thanks
^ permalink raw reply
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