Commit Graph

27 Commits

Author SHA1 Message Date
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Daniel Borkmann
c675e06a98 ipvlan: decouple l3s mode dependencies from other modes
Right now ipvlan has a hard dependency on CONFIG_NETFILTER and
otherwise it cannot be built. However, the only ipvlan operation
mode that actually depends on netfilter is l3s, everything else
is independent of it. Break this hard dependency such that users
are able to use ipvlan l3 mode on systems where netfilter is not
compiled in.

Therefore, this adds a hidden CONFIG_IPVLAN_L3S bool which is
defaulting to y when CONFIG_NETFILTER is set in order to retain
existing behavior for l3s. All l3s related code is refactored
into ipvlan_l3s.c that is compiled in when enabled.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Martynas Pumputis <m@lambda.lt>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-08 11:16:48 -08:00
Paolo Abeni
ae5799dc7e ipvlan: properly annotate rx_handler access
The rx_handler field is rcu-protected, but I forgot to use the
proper accessor while refactoring netif_is_ipvlan_port(). Such
function only check the rx_handler value, so it is safe, but we need
to properly read rx_handler via rcu_access_pointer() to avoid sparse
warnings.

Fixes: 1ec54cb44e ("net: unpollute priv_flags space")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-08 11:12:43 -05:00
Paolo Abeni
1ec54cb44e net: unpollute priv_flags space
the ipvlan device driver defines and uses 2 bits inside the priv_flags
net_device field. Such bits and the related helper are used only
inside the ipvlan device driver, and the core networking does not
need to be aware of them.

This change moves netif_is_ipvlan* helper in the ipvlan driver and
re-implement them looking for ipvlan specific symbols instead of
using priv_flags.

Overall this frees two bits inside priv_flags - and move the following
ones to avoid gaps - without any intended functional change.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-07 12:38:24 -05:00
Paolo Abeni
8230819494 ipvlan: use per device spinlock to protect addrs list updates
This changeset moves ipvlan address under RCU protection, using
a per ipvlan device spinlock to protect list mutation and RCU
read access to protect list traversal.

Also explicitly use RCU read lock to traverse the per port
ipvlans list, so that we can now perform a full address lookup
without asserting the RTNL lock.

Overall this allows the ipvlan driver to check fully for duplicate
addresses - before this commit ipv6 addresses assigned by autoconf
via prefix delegation where accepted without any check - and avoid
the following rntl assertion failure still in the same code path:

 RTNL: assertion failed at drivers/net/ipvlan/ipvlan_core.c (124)
 WARNING: CPU: 15 PID: 0 at drivers/net/ipvlan/ipvlan_core.c:124 ipvlan_addr_busy+0x97/0xa0 [ipvlan]
 Modules linked in: ipvlan(E) ixgbe
 CPU: 15 PID: 0 Comm: swapper/15 Tainted: G            E    4.16.0-rc2.ipvlan+ #1782
 Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.1.7 06/16/2016
 RIP: 0010:ipvlan_addr_busy+0x97/0xa0 [ipvlan]
 RSP: 0018:ffff881ff9e03768 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: ffff881fdf2a9000 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 00000000000000f6 RDI: 0000000000000300
 RBP: ffff881fdf2a8000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: ffff881ff9e034c0 R12: ffff881fe07bcc00
 R13: 0000000000000001 R14: ffffffffa02002b0 R15: 0000000000000001
 FS:  0000000000000000(0000) GS:ffff881ff9e00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fc5c1a4f248 CR3: 000000207e012005 CR4: 00000000001606e0
 Call Trace:
  <IRQ>
  ipvlan_addr6_event+0x6c/0xd0 [ipvlan]
  notifier_call_chain+0x49/0x90
  atomic_notifier_call_chain+0x6a/0x100
  ipv6_add_addr+0x5f9/0x720
  addrconf_prefix_rcv_add_addr+0x244/0x3c0
  addrconf_prefix_rcv+0x2f3/0x790
  ndisc_router_discovery+0x633/0xb70
  ndisc_rcv+0x155/0x180
  icmpv6_rcv+0x4ac/0x5f0
  ip6_input_finish+0x138/0x6a0
  ip6_input+0x41/0x1f0
  ipv6_rcv+0x4db/0x8d0
  __netif_receive_skb_core+0x3d5/0xe40
  netif_receive_skb_internal+0x89/0x370
  napi_gro_receive+0x14f/0x1e0
  ixgbe_clean_rx_irq+0x4ce/0x1020 [ixgbe]
  ixgbe_poll+0x31a/0x7a0 [ixgbe]
  net_rx_action+0x296/0x4f0
  __do_softirq+0xcf/0x4f5
  irq_exit+0xf5/0x110
  do_IRQ+0x62/0x110
  common_interrupt+0x91/0x91
  </IRQ>

 v1 -> v2: drop unneeded in_softirq check in ipvlan_addr6_validator_event()

Fixes: e9997c2938 ("ipvlan: fix check for IP addresses in control path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-28 12:20:13 -05:00
Mahesh Bandewar
fe89aa6b25 ipvlan: implement VEPA mode
This is very similar to the Macvlan VEPA mode, however, there is some
difference. IPvlan uses the mac-address of the lower device, so the VEPA
mode has implications of ICMP-redirects for packets destined for its
immediate neighbors sharing same master since the packets will have same
source and dest mac. The external switch/router will send redirect msg.

Having said that, this will be useful tool in terms of debugging
since IPvlan will not switch packets within its slaves and rely completely
on the external entity as intended in 802.1Qbg.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 18:39:57 +09:00
Mahesh Bandewar
a190d04db9 ipvlan: introduce 'private' attribute for all existing modes.
IPvlan has always operated in bridge mode. However there are scenarios
where each slave should be able to talk through the master device but
not necessarily across each other. Think of an environment where each
of a namespace is a private and independant customer. In this scenario
the machine which is hosting these namespaces neither want to tell who
their neighbor is nor the individual namespaces care to talk to neighbor
on short-circuited network path.

This patch implements the mode that is very similar to the 'private' mode
in macvlan where individual slaves can send and receive traffic through
the master device, just that they can not talk among slave devices.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 18:39:57 +09:00
Matthias Schiffer
7a3f4a1851 net: add netlink_ext_ack argument to rtnl_link_ops.newlink
Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-26 23:13:21 -04:00
Florian Westphal
3133822f5a ipvlan: use pernet operations and restrict l3s hooks to master netns
commit 4fbae7d83c ("ipvlan: Introduce l3s mode") added
registration of netfilter hooks via nf_register_hooks().

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

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

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

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

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

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

Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-25 10:43:22 -04:00
Sainath Grandhi
235a9d89da ipvtap: IP-VLAN based tap driver
This patch adds a tap character device driver that is based on the
IP-VLAN network interface, called ipvtap. An ipvtap device can be created
in the same way as an ipvlan device, using 'type ipvtap', and then accessed
using the tap user space interface.

Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11 20:59:41 -05:00
Mahesh Bandewar
da36e13cf6 ipvlan: improvise dev_id generation logic in IPvlan
The patch 009146d117 ("ipvlan: assign unique dev-id for each slave
device.") used ida_simple_get() to generate dev_ids assigned to the
slave devices. However (Eric has pointed out that) there is a shortcoming
with that approach as it always uses the first available ID. This
becomes a problem when a slave gets deleted and a new slave gets added.
The ID gets reassigned causing the new slave to get the same link-local
address. This side-effect is undesirable.

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

Fixes: 009146d117 ("ipvlan: assign unique dev-id for each slave device.")
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: Eric Dumazet <edumazet@google.com>
CC: David Miller <davem@davemloft.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-10 20:47:12 -05:00
Mahesh Bandewar
009146d117 ipvlan: assign unique dev-id for each slave device.
IPvlan setup uses one mac-address (of master). The IPv6 link-local
addresses are derived using the mac-address on the link. Lack of
dev-ids makes these link-local addresses same for all slaves including
that of master device. dev-ids are necessary to add differentiation
when L2 address is shared.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-04 13:30:42 -05:00
Mahesh Bandewar
e252536068 ipvlan: fix multicast processing
In an IPvlan setup when master is set in loopback mode e.g.

  ethtool -K eth0 set loopback on

  where eth0 is master device for IPvlan setup.

The failure is caused by the faulty logic that determines if the
packet is from TX-path vs. RX-path by just looking at the mac-
addresses on the packet while processing multicast packets.

In the loopback-mode where this crash was happening, the packets
that are sent out are reflected by the NIC and are processed on
the RX path, but mac-address check tricks into thinking this
packet is from TX path and falsely uses dev_forward_skb() to pass
packets to the slave (virtual) devices.

This patch records the path while queueing packets and eliminates
logic of looking at mac-addresses for the same decision.

------------[ cut here ]------------
kernel BUG at include/linux/skbuff.h:1737!
Call Trace:
 [<ffffffff921fbbc2>] dev_forward_skb+0x92/0xd0
 [<ffffffffc031ac65>] ipvlan_process_multicast+0x395/0x4c0 [ipvlan]
 [<ffffffffc031a9a7>] ? ipvlan_process_multicast+0xd7/0x4c0 [ipvlan]
 [<ffffffff91cdfea7>] ? process_one_work+0x147/0x660
 [<ffffffff91cdff09>] process_one_work+0x1a9/0x660
 [<ffffffff91cdfea7>] ? process_one_work+0x147/0x660
 [<ffffffff91ce086d>] worker_thread+0x11d/0x360
 [<ffffffff91ce0750>] ? rescuer_thread+0x350/0x350
 [<ffffffff91ce960b>] kthread+0xdb/0xe0
 [<ffffffff91c05c70>] ? _raw_spin_unlock_irq+0x30/0x50
 [<ffffffff91ce9530>] ? flush_kthread_worker+0xc0/0xc0
 [<ffffffff92348b7a>] ret_from_fork+0x9a/0xd0
 [<ffffffff91ce9530>] ? flush_kthread_worker+0xc0/0xc0

Fixes: ba35f8588f ("ipvlan: Defer multicast / broadcast processing to a work-queue")
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-23 17:53:47 -05:00
Gao Feng
48140a210b driver: ipvlan: Free ipvl_port directly with kfree instead of kfree_rcu
There are two functions which would free the ipvl_port now. The first
is ipvlan_port_create. It frees the ipvl_port in the error handler,
so it could kfree it directly. The second is ipvlan_port_destroy. It
invokes netdev_rx_handler_unregister which enforces one grace period
by synchronize_net firstly, so it also could kfree the ipvl_port
directly and safely.

So it is unnecessary to use kfree_rcu to free ipvl_port.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07 13:21:21 -05:00
Gao Feng
8f679ed88f driver: ipvlan: Remove useless member mtu_adj of struct ipvl_dev
The mtu_adj is initialized to zero when alloc mem, there is no any
assignment to mtu_adj. It is only used in ipvlan_adjust_mtu as one
right value.
So it is useless member of struct ipvl_dev, then remove it.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 15:01:32 -05:00
Mahesh Bandewar
4fbae7d83c ipvlan: Introduce l3s mode
In a typical IPvlan L3 setup where master is in default-ns and
each slave is into different (slave) ns. In this setup egress
packet processing for traffic originating from slave-ns will
hit all NF_HOOKs in slave-ns as well as default-ns. However same
is not true for ingress processing. All these NF_HOOKs are
hit only in the slave-ns skipping them in the default-ns.
IPvlan in L3 mode is restrictive and if admins want to deploy
iptables rules in default-ns, this asymmetric data path makes it
impossible to do so.

This patch makes use of the l3_rcv() (added as part of l3mdev
enhancements) to perform input route lookup on RX packets without
changing the skb->dev and then uses nf_hook at NF_INET_LOCAL_IN
to change the skb->dev just before handing over skb to L4.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
CC: David Ahern <dsa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-19 01:25:22 -04:00
Mahesh Bandewar
ab5b7013db ipvlan: misc changes
1. scope correction for few functions that are used in single file.
2. Adjust variables that are used in fast-path to fit into single cacheline
3. Update rcv_frame() to skip shared check for frames coming over wire

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-21 22:43:24 -05:00
Mahesh Bandewar
e93fbc5a15 ipvlan: mode is u16
The mode argument was erronusly defined as u32 but it has always
been u16. Also use ipvlan_set_mode() helper to set the mode instead
of assigning directly. This should avoid future erronus assignments /
updates.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-21 22:43:24 -05:00
WANG Cong
0fba37a3af ipvlan: use rcu_deference_bh() in ipvlan_queue_xmit()
In tx path rcu_read_lock_bh() is held, so we need rcu_deference_bh().
This fixes the following warning:

 ===============================
 [ INFO: suspicious RCU usage. ]
 4.1.0-rc1+ #1007 Not tainted
 -------------------------------
 drivers/net/ipvlan/ipvlan.h:106 suspicious rcu_dereference_check() usage!

 other info that might help us debug this:

 rcu_scheduler_active = 1, debug_locks = 0
 1 lock held by dhclient/1076:
  #0:  (rcu_read_lock_bh){......}, at: [<ffffffff817e8d84>] rcu_lock_acquire+0x0/0x26

 stack backtrace:
 CPU: 2 PID: 1076 Comm: dhclient Not tainted 4.1.0-rc1+ #1007
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000001 ffff8800d381bac8 ffffffff81a4154f 000000003c1a3c19
  ffff8800d4d0a690 ffff8800d381baf8 ffffffff810b849f ffff880117d41148
  ffff880117d40000 ffff880117d40068 0000000000000156 ffff8800d381bb18
 Call Trace:
  [<ffffffff81a4154f>] dump_stack+0x4c/0x65
  [<ffffffff810b849f>] lockdep_rcu_suspicious+0x107/0x110
  [<ffffffff8165a522>] ipvlan_port_get_rcu+0x47/0x4e
  [<ffffffff8165ad14>] ipvlan_queue_xmit+0x35/0x450
  [<ffffffff817ea45d>] ? rcu_read_unlock+0x3e/0x5f
  [<ffffffff810a20bf>] ? local_clock+0x19/0x22
  [<ffffffff810b4781>] ? __lock_is_held+0x39/0x52
  [<ffffffff8165b64c>] ipvlan_start_xmit+0x1b/0x44
  [<ffffffff817edf7f>] dev_hard_start_xmit+0x2ae/0x467
  [<ffffffff817ee642>] __dev_queue_xmit+0x50a/0x60c
  [<ffffffff817ee7a7>] dev_queue_xmit_sk+0x13/0x15
  [<ffffffff81997596>] dev_queue_xmit+0x10/0x12
  [<ffffffff8199b41c>] packet_sendmsg+0xb6b/0xbdf
  [<ffffffff810b5ea7>] ? mark_lock+0x2e/0x226
  [<ffffffff810a1fcc>] ? sched_clock_cpu+0x9e/0xb7
  [<ffffffff817d56f9>] sock_sendmsg_nosec+0x12/0x1d
  [<ffffffff817d7257>] sock_sendmsg+0x29/0x2e
  [<ffffffff817d72cc>] sock_write_iter+0x70/0x91
  [<ffffffff81199563>] __vfs_write+0x7e/0xa7
  [<ffffffff811996bc>] vfs_write+0x92/0xe8
  [<ffffffff811997d7>] SyS_write+0x47/0x7e
  [<ffffffff81a4d517>] system_call_fastpath+0x12/0x6f

Fixes: 2ad7bf3638 ("ipvlan: Initial check-in of the IPVLAN driver.")
Cc: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15 21:33:40 -07:00
Konstantin Khlebnikov
6640e673c6 ipvlan: unhash addresses without synchronize_rcu
All structures used in traffic forwarding are rcu-protected:
ipvl_addr, ipvl_dev and ipvl_port. Thus we can unhash addresses
without synchronization. We'll anyway hash it back into the same
bucket: in worst case lockless lookup will scan hash once again.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15 21:33:39 -07:00
Konstantin Khlebnikov
515866f818 ipvlan: remove counters of ipv4 and ipv6 addresses
They are unused after commit f631c44bbe ("ipvlan: Always set broadcast bit in
multicast filter").

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15 21:33:39 -07:00
Mahesh Bandewar
ba35f8588f ipvlan: Defer multicast / broadcast processing to a work-queue
Processing multicast / broadcast in fast path is performance draining
and having more links means more cloning and bringing performance
down further.

Broadcast; in particular, need to be given to all the virtual links.
Earlier tricks of enabling broadcast bit for IPv4 only interfaces are not
really working since it fails autoconf. Which means enabling broadcast
for all the links if protocol specific hacks do not have to be added into
the driver.

This patch defers all (incoming as well as outgoing) multicast traffic to
a work-queue leaving only the unicast traffic in the fast-path. Now if we
need to apply any additional tricks to further reduce the impact of this
(multicast / broadcast) type of traffic, it can be implemented while
processing this work without affecting the fast-path.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-05 19:29:49 -04:00
Jiri Benc
e9997c2938 ipvlan: fix check for IP addresses in control path
When an ipvlan interface is down, its addresses are not on the hash list.
Fix checks for existence of addresses not to depend on the hash list, walk
through all interface addresses instead.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-31 13:28:33 -04:00
Eric Dumazet
6aa6395ff3 ipvlan: add a missing __percpu pcpu_stats
Cosmetic patch to add __percpu qualifier to pcpu_stats

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-11 20:03:23 -08:00
Mahesh Bandewar
5933fea7aa ipvlan: move the device check function into netdevice.h
Move the port check [ipvlan_dev_master()] and device check
[ipvlan_dev_slave()] functions to netdevice.h and rename them
netif_is_ipvlan_port() and netif_is_ipvlan() resp. to be
consistent with macvlan api naming.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-09 16:10:06 -05:00
Mahesh Bandewar
265de6d19c ipvlan: ipvlan depends on INET and IPV6
This driver uses ip_out_local() and ip6_route_output() which are
defined only if CONFIG_INET and CONFIG_IPV6 are enabled respectively.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-29 20:53:05 -08:00
Mahesh Bandewar
2ad7bf3638 ipvlan: Initial check-in of the IPVLAN driver.
This driver is very similar to the macvlan driver except that it
uses L3 on the frame to determine the logical interface while
functioning as packet dispatcher. It inherits L2 of the master
device hence the packets on wire will have the same L2 for all
the packets originating from all virtual devices off of the same
master device.

This driver was developed keeping the namespace use-case in
mind. Hence most of the examples given here take that as the
base setup where main-device belongs to the default-ns and
virtual devices are assigned to the additional namespaces.

The device operates in two different modes and the difference
in these two modes in primarily in the TX side.

(a) L2 mode : In this mode, the device behaves as a L2 device.
TX processing upto L2 happens on the stack of the virtual device
associated with (namespace). Packets are switched after that
into the main device (default-ns) and queued for xmit.

RX processing is simple and all multicast, broadcast (if
applicable), and unicast belonging to the address(es) are
delivered to the virtual devices.

(b) L3 mode : In this mode, the device behaves like a L3 device.
TX processing upto L3 happens on the stack of the virtual device
associated with (namespace). Packets are switched to the
main-device (default-ns) for the L2 processing. Hence the routing
table of the default-ns will be used in this mode.

RX processins is somewhat similar to the L2 mode except that in
this mode only Unicast packets are delivered to the virtual device
while main-dev will handle all other packets.

The devices can be added using the "ip" command from the iproute2
package -

	ip link add link <master> <virtual> type ipvlan mode [ l2 | l3 ]

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Laurent Chavey <chavey@google.com>
Cc: Tim Hockin <thockin@google.com>
Cc: Brandon Philips <brandon.philips@coreos.com>
Cc: Pavel Emelianov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-24 15:29:18 -05:00