In hsr, lockdep_is_held() is needed for rcu_dereference_bh_check().
But if lockdep is not enabled, lockdep_is_held() causes a build error:
ERROR: modpost: "lockdep_is_held" [net/hsr/hsr.ko] undefined!
Thus, this patch solved by adding lockdep_hsr_is_held(). This helper
function calls the lockdep_is_held() when lockdep is enabled, and returns 1
if not defined.
Fixes: e7f2742068 ("net: hsr: fix suspicious RCU usage warning in hsr_node_get_first()")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Link: https://lore.kernel.org/r/20220220153250.5285-1-claudiajkang@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, HSR manages mac addresses of known HSR nodes by using list_head.
It takes a lot of time when there are a lot of registered nodes due to
finding specific mac address nodes by using linear search. We can be
reducing the time by using hlist. Thus, this patch moves list_head to
hlist_head for mac addresses and this allows for further improvement of
network performance.
Condition: registered 10,000 known HSR nodes
Before:
# iperf3 -c 192.168.10.1 -i 1 -t 10
Connecting to host 192.168.10.1, port 5201
[ 5] local 192.168.10.2 port 59442 connected to 192.168.10.1 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.49 sec 3.75 MBytes 21.1 Mbits/sec 0 158 KBytes
[ 5] 1.49-2.05 sec 1.25 MBytes 18.7 Mbits/sec 0 166 KBytes
[ 5] 2.05-3.06 sec 2.44 MBytes 20.3 Mbits/sec 56 16.9 KBytes
[ 5] 3.06-4.08 sec 1.43 MBytes 11.7 Mbits/sec 11 38.0 KBytes
[ 5] 4.08-5.00 sec 951 KBytes 8.49 Mbits/sec 0 56.3 KBytes
After:
# iperf3 -c 192.168.10.1 -i 1 -t 10
Connecting to host 192.168.10.1, port 5201
[ 5] local 192.168.10.2 port 36460 connected to 192.168.10.1 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 7.39 MBytes 62.0 Mbits/sec 3 130 KBytes
[ 5] 1.00-2.00 sec 5.06 MBytes 42.4 Mbits/sec 16 113 KBytes
[ 5] 2.00-3.00 sec 8.58 MBytes 72.0 Mbits/sec 42 94.3 KBytes
[ 5] 3.00-4.00 sec 7.44 MBytes 62.4 Mbits/sec 2 131 KBytes
[ 5] 4.00-5.07 sec 8.13 MBytes 63.5 Mbits/sec 38 92.9 KBytes
Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
added support for the redbox supervision frames
as defined in the IEC-62439-3:2018.
Signed-off-by: Andreas Oetken <andreas.oetken@siemens-energy.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hsr_create_self_node() may get netdev->dev_addr
passed as argument, netdev->dev_addr will be
const soon.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't check the sequence number when deciding when to update time_in in
the node table if tag removal is offloaded since the sequence number is
part of the tag. This fixes a problem where the times in the node table
wouldn't update when 0 appeared to be before or equal to seq_out when
tag removal was offloaded.
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In IEC 62439-3 EntryForgetTime is defined with a value of 400 ms. When a
node does not send any frame within this time, the sequence number check
for can be ignored. This solves communication issues with Cisco IE 2000
in Redbox mode.
Fixes: f421436a59 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Marco Wenzel <marco.wenzel@a-eberle.de>
Reviewed-by: George McCollister <george.mccollister@gmail.com>
Tested-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20210224094653.1440-1-marco.wenzel@a-eberle.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for offloading of HSR/PRP (IEC 62439-3) tag insertion
tag removal, duplicate generation and forwarding.
For HSR, insertion involves the switch adding a 6 byte HSR header after
the 14 byte Ethernet header. For PRP it adds a 6 byte trailer.
Tag removal involves automatically stripping the HSR/PRP header/trailer
in the switch. This is possible when the switch also performs auto
deduplication using the HSR/PRP header/trailer (making it no longer
required).
Forwarding involves automatically forwarding between redundant ports in
an HSR. This is crucial because delay is accumulated as a frame passes
through each node in the ring.
Duplication involves the switch automatically sending a single frame
from the CPU port to both redundant ports. This is required because the
inserted HSR/PRP header/trailer must contain the same sequence number
on the frames sent out both redundant ports.
Export is_hsr_master so DSA can tell them apart from other devices in
dsa_slave_changeupper.
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
DAN-P (Dual Attached Nodes PRP) nodes are expected to receive
traditional IP packets as well as PRP (Parallel Redundancy
Protocol) tagged (trailer) packets. PRP trailer is 6 bytes
of PRP protocol unit called RCT, Redundancy Control Trailer
(RCT) similar to HSR tag. PRP network can have traditional
devices such as bridges/switches or PC attached to it and
should be able to communicate. Regular Ethernet devices treat
the RCT as pads. This patch adds logic to format L2 frames
from network stack to add a trailer (RCT) and send it as
duplicates over the slave interfaces when the protocol is
PRP as per IEC 62439-3. At the ingress, it strips the trailer,
do duplicate detection and rejection and forward a stripped
frame up the network stack. PRP device should accept frames
from Singly Attached Nodes (SAN) and thus the driver mark
the link where the frame came from in the node table.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Parallel Redundancy Protocol (PRP) is another redundancy protocol
introduced by IEC 63439 standard. It is similar to HSR in many
aspects:-
- Use a pair of Ethernet interfaces to created the PRP device
- Use a 6 byte redundancy protocol part (RCT, Redundancy Check
Trailer) similar to HSR Tag.
- Has Link Redundancy Entity (LRE) that works with RCT to implement
redundancy.
Key difference is that the protocol unit is a trailer instead of a
prefix as in HSR. That makes it inter-operable with tradition network
components such as bridges/switches which treat it as pad bytes,
whereas HSR nodes requires some kind of translators (Called redbox) to
talk to regular network devices. This features allows regular linux box
to be converted to a DAN-P box. DAN-P stands for Dual Attached Node - PRP
similar to DAN-H (Dual Attached Node - HSR).
Add a comment at the header/source code to explicitly state that the
driver files also handles PRP protocol as well.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Validate MAC address before copying the same to outgoing frame
skb destination address. Since a node can have zero mac
address for Link B until a valid frame is received over
that link, this fix address the issue of a zero MAC address
being in the packet.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Overlapping header include additions in macsec.c
A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c
Overlapping test additions in selftests Makefile
Overlapping PCI ID table adjustments in iwlwifi driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
hsr_get_node_{list/status}() are not under rtnl_lock() because
they are callback functions of generic netlink.
But they use __dev_get_by_index() without rtnl_lock().
So, it would use unsafe data.
In order to fix it, rcu_read_lock() and dev_get_by_index_rcu()
are used instead of __dev_get_by_index().
Fixes: f421436a59 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When HSR interface is sending a frame, it finds a node with
the destination ethernet address from the list.
If there is no node, it calls WARN_ONCE().
But, using WARN_ONCE() for this situation is a little bit overdoing.
So, in this patch, the netdev_err() is used instead.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
node_db is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of hsr->list_lock.
Hence, add corresponding lockdep expression to silence false-positive
warnings, and harden RCU lists.
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's never used after introduced. So maybe better to remove.
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Arvid Brodin <arvid.brodin@alten.se>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
hsr nodes are protected by RCU and there is no write side lock.
But node insertions and deletions could be being operated concurrently.
So write side locking is needed.
Test commands:
ip netns add nst
ip link add veth0 type veth peer name veth1
ip link add veth2 type veth peer name veth3
ip link set veth1 netns nst
ip link set veth3 netns nst
ip link set veth0 up
ip link set veth2 up
ip link add hsr0 type hsr slave1 veth0 slave2 veth2
ip a a 192.168.100.1/24 dev hsr0
ip link set hsr0 up
ip netns exec nst ip link set veth1 up
ip netns exec nst ip link set veth3 up
ip netns exec nst ip link add hsr1 type hsr slave1 veth1 slave2 veth3
ip netns exec nst ip a a 192.168.100.2/24 dev hsr1
ip netns exec nst ip link set hsr1 up
for i in {0..9}
do
for j in {0..9}
do
for k in {0..9}
do
for l in {0..9}
do
arping 192.168.100.2 -I hsr0 -s 00:01:3$i:4$j:5$k:6$l -c1 &
done
done
done
done
Splat looks like:
[ 236.066091][ T3286] list_add corruption. next->prev should be prev (ffff8880a5940300), but was ffff8880a5940d0.
[ 236.069617][ T3286] ------------[ cut here ]------------
[ 236.070545][ T3286] kernel BUG at lib/list_debug.c:25!
[ 236.071391][ T3286] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 236.072343][ T3286] CPU: 0 PID: 3286 Comm: arping Tainted: G W 5.5.0-rc1+ #209
[ 236.073463][ T3286] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 236.074695][ T3286] RIP: 0010:__list_add_valid+0x74/0xd0
[ 236.075499][ T3286] Code: 48 39 da 75 27 48 39 f5 74 36 48 39 dd 74 31 48 83 c4 08 b8 01 00 00 00 5b 5d c3 48 b
[ 236.078277][ T3286] RSP: 0018:ffff8880aaa97648 EFLAGS: 00010286
[ 236.086991][ T3286] RAX: 0000000000000075 RBX: ffff8880d4624c20 RCX: 0000000000000000
[ 236.088000][ T3286] RDX: 0000000000000075 RSI: 0000000000000008 RDI: ffffed1015552ebf
[ 236.098897][ T3286] RBP: ffff88809b53d200 R08: ffffed101b3c04f9 R09: ffffed101b3c04f9
[ 236.099960][ T3286] R10: 00000000308769a1 R11: ffffed101b3c04f8 R12: ffff8880d4624c28
[ 236.100974][ T3286] R13: ffff8880d4624c20 R14: 0000000040310100 R15: ffff8880ce17ee02
[ 236.138967][ T3286] FS: 00007f23479fa680(0000) GS:ffff8880d9c00000(0000) knlGS:0000000000000000
[ 236.144852][ T3286] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 236.145720][ T3286] CR2: 00007f4a14bab210 CR3: 00000000a61c6001 CR4: 00000000000606f0
[ 236.146776][ T3286] Call Trace:
[ 236.147222][ T3286] hsr_add_node+0x314/0x490 [hsr]
[ 236.153633][ T3286] hsr_forward_skb+0x2b6/0x1bc0 [hsr]
[ 236.154362][ T3286] ? rcu_read_lock_sched_held+0x90/0xc0
[ 236.155091][ T3286] ? rcu_read_lock_bh_held+0xa0/0xa0
[ 236.156607][ T3286] hsr_dev_xmit+0x70/0xd0 [hsr]
[ 236.157254][ T3286] dev_hard_start_xmit+0x160/0x740
[ 236.157941][ T3286] __dev_queue_xmit+0x1961/0x2e10
[ 236.158565][ T3286] ? netdev_core_pick_tx+0x2e0/0x2e0
[ ... ]
Reported-by: syzbot+3924327f9ad5f4d2b343@syzkaller.appspotmail.com
Fixes: f421436a59 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hsr_link_ops implements ->newlink() but not ->dellink(),
which leads that resources not released after removing the device,
particularly the entries in self_node_db and node_db.
So add ->dellink() implementation to replace the priv_destructor.
This also makes the code slightly easier to understand.
Reported-by: syzbot+c6167ec3de7def23d1e8@syzkaller.appspotmail.com
Cc: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't prune the master node in the hsr_prune_nodes function.
Neither time_in[HSR_PT_SLAVE_A] nor time_in[HSR_PT_SLAVE_B]
will ever be updated by hsr_register_frame_in for the master port.
Thus, the master node will be repeatedly pruned leading to
repeated packet loss.
This bug never appeared because the hsr_prune_nodes function
was only called once. Since commit 5150b45fd3
("net: hsr: Fix node prune function for forget time expiry") this issue
is fixed unveiling the issue described above.
Fixes: 5150b45fd3 ("net: hsr: Fix node prune function for forget time expiry")
Signed-off-by: Andreas Oetken <andreas.oetken@siemens.com>
Tested-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
HSR should forget nodes after configured node forget time expiry based
on HSR_NODE_FORGET_TIME. As part of hsr_prune_nodes(), code checks to
see if entries are to be flushed out if not heard for longer than forget
time. But currently hsr_prune_nodes() is called only once during device
creation. Restart the timer at the end of hsr_prune_nodes() so that
hsr_prune_nodes() gets called periodically and forgotten entries are
removed from node table.
Signed-off-by: Aaron Kramer <a-kramer@ti.com>
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds a debugfs interface to allow display the nodes learned
by the hsr master.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use SPDX-License-Identifier instead of a verbose license text.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a blank line after function declaration as suggested by
checkpatch.pl -f
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current driver code uses camel case in many places. This is
seen when ran checkpatch.pl -f on files under net/hsr. This
patch fixes the code to remove camel case usage.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch add missing space around operator in code. This is
seen when ran checkpatch.pl -f on files under net/hsr.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In a multi-line statement exceeding 80 characters, logical operator
should be at the end of a line instead of being at the start. This
is seen when ran checkpatch.pl -f on files under net/hsr. The change
is per suggestion from checkpatch.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes unnecessary space after a cast. This is seen
when ran checkpatch.pl -f on files under net/hsr.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch replaces all instance of NULL checks such as
if (foo == NULL) with if (!foo)
Also
if (foo != NULL) with if (foo)
This is seen when ran checkpatch.pl -f on files under net/hsr
and suggestion is to replace as above.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes alignment issues in code for functions. This is
seen when ran checkpatch.pl -f option on files under net/hsr.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes multiple blank lines in the code. This is seen
when ran checkpatch.pl -f option for files under net/hsr
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes lines exceeding 80 characters. This is seen
when ran checkpatch.pl with -f option for files under
net/hsr.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Arvid Brodin <arvid.brodin@alten.se>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When HSR interface is setup using ip link command, an annoying warning
appears with the trace as below:-
[ 203.019828] hsr_get_node: Non-HSR frame
[ 203.019833] Modules linked in:
[ 203.019848] CPU: 0 PID: 158 Comm: sd-resolve Tainted: G W 4.12.0-rc3-00052-g9fa6bf70 #2
[ 203.019853] Hardware name: Generic DRA74X (Flattened Device Tree)
[ 203.019869] [<c0110280>] (unwind_backtrace) from [<c010c2f4>] (show_stack+0x10/0x14)
[ 203.019880] [<c010c2f4>] (show_stack) from [<c04b9f64>] (dump_stack+0xac/0xe0)
[ 203.019894] [<c04b9f64>] (dump_stack) from [<c01374e8>] (__warn+0xd8/0x104)
[ 203.019907] [<c01374e8>] (__warn) from [<c0137548>] (warn_slowpath_fmt+0x34/0x44)
root@am57xx-evm:~# [ 203.019921] [<c0137548>] (warn_slowpath_fmt) from [<c081126c>] (hsr_get_node+0x148/0x170)
[ 203.019932] [<c081126c>] (hsr_get_node) from [<c0814240>] (hsr_forward_skb+0x110/0x7c0)
[ 203.019942] [<c0814240>] (hsr_forward_skb) from [<c0811d64>] (hsr_dev_xmit+0x2c/0x34)
[ 203.019954] [<c0811d64>] (hsr_dev_xmit) from [<c06c0828>] (dev_hard_start_xmit+0xc4/0x3bc)
[ 203.019963] [<c06c0828>] (dev_hard_start_xmit) from [<c06c13d8>] (__dev_queue_xmit+0x7c4/0x98c)
[ 203.019974] [<c06c13d8>] (__dev_queue_xmit) from [<c0782f54>] (ip6_finish_output2+0x330/0xc1c)
[ 203.019983] [<c0782f54>] (ip6_finish_output2) from [<c0788f0c>] (ip6_output+0x58/0x454)
[ 203.019994] [<c0788f0c>] (ip6_output) from [<c07b16cc>] (mld_sendpack+0x420/0x744)
As this is an expected path to hsr_get_node() with frame coming from
the master interface, add a check to ensure packet is not from the
master port and then warn.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for the newer version 1 of the HSR
networking standard. Version 0 is still default and the new
version has to be selected via iproute2.
Main changes are in the supervision frame handling and its
ethertype field.
Signed-off-by: Peter Heise <peter.heise@airbus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
MacAddressB is an array (unsigned char MacAddressB[ETH_ALEN]) and is allocated
as a part of *node_dst (which is a struct hsr_node). So the condition is always
false.
Detected by Dan Carpenter.
Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the separate paths for frames coming from the outside, and
frames sent from the HSR device, and instead makes all frames go through
hsr_forward_skb() in hsr_forward.c. This greatly improves code readability and
also opens up the possibility for future support of the HSR Interlink device
that is the basis for HSR RedBoxes and HSR QuadBoxes, as well as VLAN
compatibility.
Other improvements:
* A reduction in the number of times an skb is copied on machines without
HAVE_EFFICIENT_UNALIGNED_ACCESS, which improves throughput somewhat.
* Headers are now created using the standard eth_header(), and using the
standard hard_header_len.
* Each HSR slave now gets its own private skb, so slave-specific fields can be
correctly set.
Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also try to prevent some possible slave dereference race conditions. This is
finalized in the next patch, which abandons the slave array in favour of
a list_head list and list RCU.
Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/wireless/ath/ath9k/recv.c
drivers/net/wireless/mwifiex/pcie.c
net/ipv6/sit.c
The SIT driver conflict consists of a bug fix being done by hand
in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper
was created (netdev_alloc_pcpu_stats()) which takes care of this.
The two wireless conflicts were overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a sanity check and we never pass invalid values so this patch
doesn't change anything. However the node->time_in[] array has
HSR_MAX_SLAVE (2) elements and not HSR_MAX_DEV (3).
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's slightly smaller/faster for some architectures.
Make sure def_multicast_addr is __aligned(2)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The callback function of call_rcu() just calls a kfree(), so we
can use kfree_rcu() instead of call_rcu() + callback function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
High-availability Seamless Redundancy ("HSR") provides instant failover
redundancy for Ethernet networks. It requires a special network topology where
all nodes are connected in a ring (each node having two physical network
interfaces). It is suited for applications that demand high availability and
very short reaction time.
HSR acts on the Ethernet layer, using a registered Ethernet protocol type to
send special HSR frames in both directions over the ring. The driver creates
virtual network interfaces that can be used just like any ordinary Linux
network interface, for IP/TCP/UDP traffic etc. All nodes in the network ring
must be HSR capable.
This code is a "best effort" to comply with the HSR standard as described in
IEC 62439-3:2010 (HSRv0).
Signed-off-by: Arvid Brodin <arvid.brodin@xdin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
