linux.git/drivers/net/tun.c, branch v5.2-rc2 Linux kernel source tree tuntap: synchronize through tfiles array instead of tun->numqueues 2019-05-09T16:21:42+00:00 Jason Wang jasowang@redhat.com 2019-05-09T03:20:18+00:00 9871a9e47a2646fe30ae7fd2e67668a8d30912f6 When a queue(tfile) is detached through __tun_detach(), we move the last enabled tfile to the position where detached one sit but don't NULL out last position. We expect to synchronize the datapath through tun->numqueues. Unfortunately, this won't work since we're lacking sufficient mechanism to order or synchronize the access to tun->numqueues. To fix this, NULL out the last position during detaching and check RCU protected tfile against NULL instead of checking tun->numqueues in datapath. Cc: YueHaibing <yuehaibing@huawei.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: weiyongjun (A) <weiyongjun1@huawei.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Fixes: c8d68e6be1c3b ("tuntap: multiqueue support") Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When a queue(tfile) is detached through __tun_detach(), we move the
last enabled tfile to the position where detached one sit but don't
NULL out last position. We expect to synchronize the datapath through
tun->numqueues. Unfortunately, this won't work since we're lacking
sufficient mechanism to order or synchronize the access to
tun->numqueues.

To fix this, NULL out the last position during detaching and check
RCU protected tfile against NULL instead of checking tun->numqueues in
datapath.

Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: weiyongjun (A) <weiyongjun1@huawei.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c8d68e6be1c3b ("tuntap: multiqueue support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tuntap: fix dividing by zero in ebpf queue selection 2019-05-09T16:21:42+00:00 Jason Wang jasowang@redhat.com 2019-05-09T03:20:17+00:00 a35d310f03a692bf4798eb309a1950a06a150620 We need check if tun->numqueues is zero (e.g for the persist device) before trying to use it for modular arithmetic. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Fixes: 96f84061620c6("tun: add eBPF based queue selection method") Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We need check if tun->numqueues is zero (e.g for the persist device)
before trying to use it for modular arithmetic.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 96f84061620c6("tun: add eBPF based queue selection method")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: pass net_device argument to the eth_get_headlen 2019-04-23T16:36:34+00:00 Stanislav Fomichev sdf@google.com 2019-04-22T15:55:48+00:00 c43f1255b866b423d2381f77eaa2cbc64a9c49aa Update all users of eth_get_headlen to pass network device, fetch network namespace from it and pass it down to the flow dissector. This commit is a noop until administrator inserts BPF flow dissector program. Cc: Maxim Krasnyansky <maxk@qti.qualcomm.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: intel-wired-lan@lists.osuosl.org Cc: Yisen Zhuang <yisen.zhuang@huawei.com> Cc: Salil Mehta <salil.mehta@huawei.com> Cc: Michael Chan <michael.chan@broadcom.com> Cc: Igor Russkikh <igor.russkikh@aquantia.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
Update all users of eth_get_headlen to pass network device, fetch
network namespace from it and pass it down to the flow dissector.
This commit is a noop until administrator inserts BPF flow dissector
program.

Cc: Maxim Krasnyansky <maxk@qti.qualcomm.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Cc: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
net: convert rps_needed and rfs_needed to new static branch api 2019-03-24T01:57:38+00:00 Eric Dumazet edumazet@google.com 2019-03-22T15:56:38+00:00 dc05360fee660a9dbe59824b3f7896534210432b We prefer static_branch_unlikely() over static_key_false() these days. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We prefer static_branch_unlikely() over static_key_false() these days.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tun: Remove unused first parameter of tun_get_iff() 2019-03-21T20:19:15+00:00 Kirill Tkhai ktkhai@virtuozzo.com 2019-03-20T09:16:53+00:00 12132768dc4a79be65af75ac6262117d0adf93f3 Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tun: Add ioctl() TUNGETDEVNETNS cmd to allow obtaining real net ns of tun device 2019-03-21T20:19:15+00:00 Kirill Tkhai ktkhai@virtuozzo.com 2019-03-20T09:16:42+00:00 0c3e0e3bb623c3735b8c9ab8aa8332f944f83a9f In commit f2780d6d7475 "tun: Add ioctl() SIOCGSKNS cmd to allow obtaining net ns of tun device" it was missed that tun may change its net ns, while net ns of socket remains the same as it was created initially. SIOCGSKNS returns net ns of socket, so it is not suitable for obtaining net ns of device. We may have two tun devices with the same names in two net ns, and in this case it's not possible to determ, which of them fd refers to (TUNGETIFF will return the same name). This patch adds new ioctl() cmd for obtaining net ns of a device. Reported-by: Harald Albrecht <harald.albrecht@gmx.net> Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In commit f2780d6d7475 "tun: Add ioctl() SIOCGSKNS cmd to allow
obtaining net ns of tun device" it was missed that tun may change
its net ns, while net ns of socket remains the same as it was
created initially. SIOCGSKNS returns net ns of socket, so it is
not suitable for obtaining net ns of device.

We may have two tun devices with the same names in two net ns,
and in this case it's not possible to determ, which of them
fd refers to (TUNGETIFF will return the same name).

This patch adds new ioctl() cmd for obtaining net ns of a device.

Reported-by: Harald Albrecht <harald.albrecht@gmx.net>
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: remove 'fallback' argument from dev->ndo_select_queue() 2019-03-20T18:18:55+00:00 Paolo Abeni pabeni@redhat.com 2019-03-20T10:02:06+00:00 a350eccee5830d9a1f29e393a88dc05a15326d44 After the previous patch, all the callers of ndo_select_queue() provide as a 'fallback' argument netdev_pick_tx. The only exceptions are nested calls to ndo_select_queue(), which pass down the 'fallback' available in the current scope - still netdev_pick_tx. We can drop such argument and replace fallback() invocation with netdev_pick_tx(). This avoids an indirect call per xmit packet in some scenarios (TCP syn, UDP unconnected, XDP generic, pktgen) with device drivers implementing such ndo. It also clean the code a bit. Tested with ixgbe and CONFIG_FCOE=m With pktgen using queue xmit: threads vanilla patched (kpps) (kpps) 1 2334 2428 2 4166 4278 4 7895 8100 v1 -> v2: - rebased after helper's name change Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
After the previous patch, all the callers of ndo_select_queue()
provide as a 'fallback' argument netdev_pick_tx.
The only exceptions are nested calls to ndo_select_queue(),
which pass down the 'fallback' available in the current scope
- still netdev_pick_tx.

We can drop such argument and replace fallback() invocation with
netdev_pick_tx(). This avoids an indirect call per xmit packet
in some scenarios (TCP syn, UDP unconnected, XDP generic, pktgen)
with device drivers implementing such ndo. It also clean the code
a bit.

Tested with ixgbe and CONFIG_FCOE=m

With pktgen using queue xmit:
threads		vanilla 	patched
		(kpps)		(kpps)
1		2334		2428
2		4166		4278
4		7895		8100

 v1 -> v2:
 - rebased after helper's name change

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tun: add a missing rcu_read_unlock() in error path 2019-03-16T20:16:37+00:00 Eric Dumazet edumazet@google.com 2019-03-16T20:09:53+00:00 9180bb4f046064dfa4541488102703b402bb04e1 In my latest patch I missed one rcu_read_unlock(), in case device is down. Fixes: 4477138fa0ae ("tun: properly test for IFF_UP") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In my latest patch I missed one rcu_read_unlock(), in case
device is down.

Fixes: 4477138fa0ae ("tun: properly test for IFF_UP")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tun: properly test for IFF_UP 2019-03-15T22:42:11+00:00 Eric Dumazet edumazet@google.com 2019-03-15T03:19:47+00:00 4477138fa0ae4e1b699786ef0600863ea6e6c61c Same reasons than the ones explained in commit 4179cb5a4c92 ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx_ni() or napi_gro_frags() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro layer. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Fixes: 1bd4978a88ac ("tun: honor IFF_UP in tun_get_user()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Same reasons than the ones explained in commit 4179cb5a4c92
("vxlan: test dev->flags & IFF_UP before calling netif_rx()")

netif_rx_ni() or napi_gro_frags() must be called under a strict contract.

At device dismantle phase, core networking clears IFF_UP
and flush_all_backlogs() is called after rcu grace period
to make sure no incoming packet might be in a cpu backlog
and still referencing the device.

A similar protocol is used for gro layer.

Most drivers call netif_rx() from their interrupt handler,
and since the interrupts are disabled at device dismantle,
netif_rx() does not have to check dev->flags & IFF_UP

Virtual drivers do not have this guarantee, and must
therefore make the check themselves.

Fixes: 1bd4978a88ac ("tun: honor IFF_UP in tun_get_user()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-02T20:54:35+00:00 David S. Miller davem@davemloft.net 2019-03-02T20:54:35+00:00 9eb359140cd307f8a14f61c19b155ffca5291057