There is currently serialization network namespaces exiting and
network devices exiting as the final part of netdev_run_todo does not
happen under the rtnl_lock. This is compounded by the fact that the
only list of devices unregistering in netdev_run_todo is local to the
netdev_run_todo.
This lack of serialization in extreme cases results in network devices
unregistering in netdev_run_todo after the loopback device of their
network namespace has been freed (making dst_ifdown unsafe), and after
the their network namespace has exited (making the NETDEV_UNREGISTER,
and NETDEV_UNREGISTER_FINAL callbacks unsafe).
Add the missing serialization by a per network namespace count of how
many network devices are unregistering and having a wait queue that is
woken up whenever the count is decreased. The count and wait queue
allow default_device_exit_batch to wait until all of the unregistration
activity for a network namespace has finished before proceeding to
unregister the loopback device and then allowing the network namespace
to exit.
Only a single global wait queue is used because there is a single global
lock, and there is a single waiter, per network namespace wait queues
would be a waste of resources.
The per network namespace count of unregistering devices gives a
progress guarantee because the number of network devices unregistering
in an exiting network namespace must ultimately drop to zero (assuming
network device unregistration completes).
The basic logic remains the same as in v1. This patch is now half
comment and half rtnl_lock_unregistering an expanded version of
wait_event performs no extra work in the common case where no network
devices are unregistering when we get to default_device_exit_batch.
Reported-by: Francesco Ruggeri <fruggeri@aristanetworks.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function was only used when a packet was sent to another netns. Now, it can
also be used after tunnel encapsulation or decapsulation.
Only skb_orphan() should not be done when a packet is not crossing netns.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds lower_dev_list list_head to net_device, which is the same
as upper_dev_list, only for lower devices, and begins to use it in the same
way as the upper list.
It also changes the way the whole adjacent device lists work - now they
contain *all* of upper/lower devices, not only the first level. The first
level devices are distinguished by the bool neighbour field in
netdev_adjacent, also added by this patch.
There are cases when a device can be added several times to the adjacent
list, the simplest would be:
/---- eth0.10 ---\
eth0- --- bond0
\---- eth0.20 ---/
where both bond0 and eth0 'see' each other in the adjacent lists two times.
To avoid duplication of netdev_adjacent structures ref_nr is being kept as
the number of times the device was added to the list.
The 'full view' is achieved by adding, on link creation, all of the
upper_dev's upper_dev_list devices as upper devices to all of the
lower_dev's lower_dev_list devices (and to the lower_dev itself), and vice
versa. On unlink they are removed using the same logic.
I've tested it with thousands vlans/bonds/bridges, everything works ok and
no observable lags even on a huge number of interfaces.
Memory footprint for 128 devices interconnected with each other via both
upper and lower (which is impossible, but for the comparison) lists would be:
128*128*2*sizeof(netdev_adjacent) = 1.5MB
but in the real world we usualy have at most several devices with slaves
and a lot of vlans, so the footprint will be much lower.
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_scrub_packet() was called before eth_type_trans() to let eth_type_trans()
set pkt_type.
In fact, we should force pkt_type to PACKET_HOST, so move the call after
eth_type_trans().
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a ndo for getting physical port of the device. Driver
which is aware of being virtual function of some physical port should
implement this ndo. This is applicable not only for IOV, but for other
solutions (NPAR, multichannel) as well. Basically if there is possible
to have multiple netdevs on the single hw port.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 48cc32d38a
("vlan: don't deliver frames for unknown vlans to protocols")
Florian made sure we set pkt_type to PACKET_OTHERHOST
if the vlan id is set and we could find a vlan device for this
particular id.
But we also have a problem if prio bits are set.
Steinar reported an issue on a router receiving IPv6 frames with a
vlan tag of 4000 (id 0, prio 2), and tunneled into a sit device,
because skb->vlan_tci is set.
Forwarded frame is completely corrupted : We can see (8100:4000)
being inserted in the middle of IPv6 source address :
16:48:00.780413 IP6 2001:16d8:8100:4000:ee1c:0:9d9:bc87 >
9f94:4d95:2001:67c:29f4::: ICMP6, unknown icmp6 type (0), length 64
0x0000: 0000 0029 8000 c7c3 7103 0001 a0ae e651
0x0010: 0000 0000 ccce 0b00 0000 0000 1011 1213
0x0020: 1415 1617 1819 1a1b 1c1d 1e1f 2021 2223
0x0030: 2425 2627 2829 2a2b 2c2d 2e2f 3031 3233
It seems we are not really ready to properly cope with this right now.
We can probably do better in future kernels :
vlan_get_ingress_priority() should be a netdev property instead of
a per vlan_dev one.
For stable kernels, lets clear vlan_tci to fix the bugs.
Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that the GRE and VXLAN tunnels can make use of Tx
checksum offload support provided by some drivers via the hw_enc_features.
Without this fix enabling GSO means sacrificing Tx checksum offload and
this actually leads to a performance regression as shown below:
Utilization
Send
Throughput local GSO
10^6bits/s % S state
6276.51 8.39 enabled
7123.52 8.42 disabled
To resolve this it was necessary to address two items. First
netif_skb_features needed to be updated so that it would correctly handle
the Trans Ether Bridging protocol without impacting the need to check for
Q-in-Q tagging. To do this it was necessary to update harmonize_features
so that it used skb_network_protocol instead of just using the outer
protocol.
Second it was necessary to update the GRE and UDP tunnel segmentation
offloads so that they would reset the encapsulation bit and inner header
offsets after the offload was complete.
As a result of this change I have seen the following results on a interface
with Tx checksum enabled for encapsulated frames:
Utilization
Send
Throughput local GSO
10^6bits/s % S state
7123.52 8.42 disabled
8321.75 5.43 enabled
v2: Instead of replacing refrence to skb->protocol with
skb_network_protocol just replace the protocol reference in
harmonize_features to allow for double VLAN tag checks.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/freescale/fec_main.c
drivers/net/ethernet/renesas/sh_eth.c
net/ipv4/gre.c
The GRE conflict is between a bug fix (kfree_skb --> kfree_skb_list)
and the splitting of the gre.c code into seperate files.
The FEC conflict was two sets of changes adding ethtool support code
in an "!CONFIG_M5272" CPP protected block.
Finally the sh_eth.c conflict was between one commit add bits set
in the .eesr_err_check mask whilst another commit removed the
.tx_error_check member and assignments.
Signed-off-by: David S. Miller <davem@davemloft.net>
The dev_forward_skb() assignment of pkt_type should be done
after the call to eth_type_trans().
ip-encapsulated packets can be handled by localhost. But skb->pkt_type
can be PACKET_OTHERHOST when packet comes via veth into ip tunnel device.
In that case, the packet is dropped by ip_rcv().
Although this example uses gretap. l2tp-eth also has same issue.
For l2tp-eth case, add dummy device for ip address and ip l2tp command.
netns A | root netns | netns B
veth<->veth=bridge=gretap <-loop back-> gretap=bridge=veth<->veth
arp packet ->
pkt_type
BROADCAST------------>ip_rcv()------------------------>
<- arp reply
pkt_type
ip_rcv()<-----------------OTHERHOST
drop
sample operations
ip link add tapa type gretap remote 172.17.107.4 local 172.17.107.3
ip link add tapb type gretap remote 172.17.107.3 local 172.17.107.4
ip link set tapa up
ip link set tapb up
ip address add 172.17.107.3 dev tapa
ip address add 172.17.107.4 dev tapb
ip route get 172.17.107.3
> local 172.17.107.3 dev lo src 172.17.107.3
> cache <local>
ip route get 172.17.107.4
> local 172.17.107.4 dev lo src 172.17.107.4
> cache <local>
ip link add vetha type veth peer name vetha-peer
ip link add vethb type veth peer name vethb-peer
brctl addbr bra
brctl addbr brb
brctl addif bra tapa
brctl addif bra vetha-peer
brctl addif brb tapb
brctl addif brb vethb-peer
brctl show
> bridge name bridge id STP enabled interfaces
> bra 8000.6ea21e758ff1 no tapa
> vetha-peer
> brb 8000.420020eb92d5 no tapb
> vethb-peer
ip link set vetha-peer up
ip link set vethb-peer up
ip link set bra up
ip link set brb up
ip netns add a
ip netns add b
ip link set vetha netns a
ip link set vethb netns b
ip netns exec a ip address add 10.0.0.3/24 dev vetha
ip netns exec b ip address add 10.0.0.4/24 dev vethb
ip netns exec a ip link set vetha up
ip netns exec b ip link set vethb up
ip netns exec a arping -I vetha 10.0.0.4
ARPING 10.0.0.4 from 10.0.0.3 vetha
^CSent 2 probes (2 broadcast(s))
Received 0 response(s)
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Hong Zhiguo <honkiko@gmail.com>
Cc: Rami Rosen <ramirose@gmail.com>
Cc: Tom Parkin <tparkin@katalix.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Jesse Gross <jesse@nicira.com>
Cc: dev@openvswitch.org
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
The goal of this new function is to perform all needed cleanup before sending
an skb into another netns.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the kernel (compiled with CONFIG_PREEMPT=n) is performing the
rename of a network interface, it can end up waiting for a workqueue
to complete. If userland is able to invoke a SIOCGIFNAME ioctl or a
SO_BINDTODEVICE getsockopt in between, the kernel will deadlock due to
the fact that read_secklock_begin() will spin forever waiting for the
writer process (the one doing the interface rename) to update the
devnet_rename_seq sequence.
This patch fixes the problem by adding a helper (netdev_get_name())
and using it in the code handling the SIOCGIFNAME ioctl and
SO_BINDTODEVICE setsockopt.
The netdev_get_name() helper uses raw_seqcount_begin() to avoid
spinning forever, waiting for devnet_rename_seq->sequence to become
even. cond_resched() is used in the contended case, before retrying
the access to give the writer process a chance to finish.
The use of raw_seqcount_begin() will incur some unneeded work in the
reader process in the contended case, but this is better than
deadlocking the system.
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netif_alloc_netdev_queues() uses kcalloc() to allocate memory
for the "struct netdev_queue *_tx" array.
For large number of tx queues, kcalloc() might fail, so this
patch does a fallback to vzalloc().
As vmalloc() adds overhead on a critical network path, add __GFP_REPEAT
to kzalloc() flags to do this fallback only when really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds a napi_id and a hashing mechanism to lookup a napi by id.
This will be used by subsequent patches to implement low latency
Ethernet device polling.
Based on a code sample by Eric Dumazet.
Signed-off-by: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdev_create_hash() is only called from netdev_init() which is marked
__net_init.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 351638e7de (net: pass info struct via netdevice notifier)
breaks booting of my KVM guest, this is due to we still forget to pass
struct netdev_notifier_info in several places. This patch completes it.
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use new netdevice notifier infrastructure to pass along changed flags.
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
v2->v3: shortened notifier_info struct name
Signed-off-by: David S. Miller <davem@davemloft.net>
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>
The netpoll_rx_disable() will always return 0, it is no use and looks wordy,
so remove the unnecessary code and get rid of it in _dev_open and _dev_close.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the case where a non-MPLS packet is received and an MPLS stack is
added it may well be the case that the original skb is GSO but the
NIC used for transmit does not support GSO of MPLS packets.
The aim of this code is to provide GSO in software for MPLS packets
whose skbs are GSO.
SKB Usage:
When an implementation adds an MPLS stack to a non-MPLS packet it should do
the following to skb metadata:
* Set skb->inner_protocol to the old non-MPLS ethertype of the packet.
skb->inner_protocol is added by this patch.
* Set skb->protocol to the new MPLS ethertype of the packet.
* Set skb->network_header to correspond to the
end of the L3 header, including the MPLS label stack.
I have posted a patch, "[PATCH v3.29] datapath: Add basic MPLS support to
kernel" which adds MPLS support to the kernel datapath of Open vSwtich.
That patch sets the above requirements in datapath/actions.c:push_mpls()
and was used to exercise this code. The datapath patch is against the Open
vSwtich tree but it is intended that it be added to the Open vSwtich code
present in the mainline Linux kernel at some point.
Features:
I believe that the approach that I have taken is at least partially
consistent with the handling of other protocols. Jesse, I understand that
you have some ideas here. I am more than happy to change my implementation.
This patch adds dev->mpls_features which may be used by devices
to advertise features supported for MPLS packets.
A new NETIF_F_MPLS_GSO feature is added for devices which support
hardware MPLS GSO offload. Currently no devices support this
and MPLS GSO always falls back to software.
Alternate Implementation:
One possible alternate implementation is to teach netif_skb_features()
and skb_network_protocol() about MPLS, in a similar way to their
understanding of VLANs. I believe this would avoid the need
for net/mpls/mpls_gso.c and in particular the calls to
__skb_push() and __skb_push() in mpls_gso_segment().
I have decided on the implementation in this patch as it should
not introduce any overhead in the case where mpls_gso is not compiled
into the kernel or inserted as a module.
MPLS GSO suggested by Jesse Gross.
Based in part on "v4 GRE: Add TCP segmentation offload for GRE"
by Pravin B Shelar.
Cc: Jesse Gross <jesse@nicira.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
