net: hsr: Add __packed to struct hsr_sup_tlv.

Struct hsr_sup_tlv describes HW layout and therefore it needs a __packed
attribute to ensure the compiler does not add any padding.
Due to the size and __packed attribute of the structs that use
hsr_sup_tlv it has no functional impact.

Add __packed to struct hsr_sup_tlv.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: Disable promiscuous mode in offload mode

When port-to-port forwarding for interfaces in HSR node is enabled,
disable promiscuous mode since L2 frame forward happens at the
offloaded hardware.

Signed-off-by: Ravi Gunasekaran <r-gunasekaran@ti.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230614114710.31400-1-r-gunasekaran@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

hsr: Use a single struct for self_node.

self_node_db is a list_head with one entry of struct hsr_node. The
purpose is to hold the two MAC addresses of the node itself.
It is convenient to recycle the structure. However having a list_head
and fetching always the first entry is not really optimal.

Created a new data strucure contaning the two MAC addresses named
hsr_self_node. Access that structure like an RCU protected pointer so
it can be replaced on the fly without blocking the reader.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Revert "net: hsr: use hlist_head instead of list_head for mac addresses"

The hlist optimisation (which not only uses hlist_head instead of
list_head but also splits hsr_priv::node_db into an array of 256 slots)
does not consider the "node merge":
Upon starting the hsr network (with three nodes) a packet that is
sent from node1 to node3 will also be sent from node1 to node2 and then
forwarded to node3.
As a result node3 will receive 2 packets because it is not able
to filter out the duplicate. Each packet received will create a new
struct hsr_node with macaddress_A only set the MAC address it received
from (the two MAC addesses from node1).
At some point (early in the process) two supervision frames will be
received from node1. They will be processed by hsr_handle_sup_frame()
and one frame will leave early ("Node has already been merged") and does
nothing. The other frame will be merged as portB and have its MAC
address written to macaddress_B and the hsr_node (that was created for
it as macaddress_A) will be removed.
From now on HSR is able to identify a duplicate because both packets
sent from one node will result in the same struct hsr_node because
hsr_get_node() will find the MAC address either on macaddress_A or
macaddress_B.

Things get tricky with the optimisation: If sender's MAC address is
saved as macaddress_A then the lookup will work as usual. If the MAC
address has been merged into macaddress_B of another hsr_node then the
lookup won't work because it is likely that the data structure is in
another bucket. This results in creating a new struct hsr_node and not
recognising a possible duplicate.

A way around it would be to add another hsr_node::mac_list_B and attach
it to the other bucket to ensure that this hsr_node will be looked up
either via macaddress_A _or_ macaddress_B.

I however prefer to revert it because it sounds like an academic problem
rather than real life workload plus it adds complexity. I'm not an HSR
expert with what is usual size of a network but I would guess 40 to 60
nodes. With 10.000 nodes and assuming 60us for pass-through (from node
to node) then it would take almost 600ms for a packet to almost wrap
around which sounds a lot.

Revert the hash MAC addresses optimisation.

Fixes: 4acc45db71158 ("net: hsr: use hlist_head instead of list_head for mac addresses")
Cc: Juhee Kang <claudiajkang@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

flow_dissector: Add support for HSR

Network drivers such as igb or igc call eth_get_headlen() to determine the
header length for their to be constructed skbs in receive path.

When running HSR on top of these drivers, it results in triggering BUG_ON() in
skb_pull(). The reason is the skb headlen is not sufficient for HSR to work
correctly. skb_pull() notices that.

For instance, eth_get_headlen() returns 14 bytes for TCP traffic over HSR which
is not correct. The problem is, the flow dissection code does not take HSR into
account. Therefore, add support for it.

Reported-by: Anthony Harivel <anthony.harivel@linutronix.de>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20220228195856.88187-1-kurt@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: hsr: use hlist_head instead of list_head for mac addresses

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>

hsr: remove get_prp_lan_id()

get_prp_lan_id() has never been used.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: Add support for redbox supervision frames

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>

net: hsr: fix mac_len checks

Commit 2e9f60932a2c ("net: hsr: check skb can contain struct hsr_ethhdr
in fill_frame_info") added the following which resulted in -EINVAL
always being returned:
if (skb->mac_len < sizeof(struct hsr_ethhdr))
return -EINVAL;

mac_len was not being set correctly so this check completely broke
HSR/PRP since it was always 14, not 20.

Set mac_len correctly and modify the mac_len checks to test in the
correct places since sometimes it is legitimately 14.

Fixes: 2e9f60932a2c ("net: hsr: check skb can contain struct hsr_ethhdr in fill_frame_info")
Signed-off-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: add support for EntryForgetTime

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: f421436a591d ("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>

net: hsr: add offloading support

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>

net: hsr: align sup_multicast_addr in struct hsr_priv to u16 boundary

sup_multicast_addr is passed to ether_addr_equal for address comparison
which casts the address inputs to u16 leading to an unaligned access.
Aligning the sup_multicast_addr to u16 boundary fixes the issue.

Signed-off-by: Andreas Oetken <andreas.oetken@siemens.com>
Link: https://lore.kernel.org/r/20210202090304.2740471-1-ennoerlangen@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: prp: add packet handling support

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>

net: hsr: define and use proto_ops ptrs to handle hsr specific frames

As a preparatory patch to introduce PRP, refactor the code specific to
handling HSR frames into separate functions and call them through
proto_ops function pointers.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: prp: add supervision frame generation utility function

Add support for generation of PRP supervision frames. For PRP,
supervision frame format is similar to HSR version 0, but have
a PRP Redundancy Control Trailer (RCT) added and uses a different
message type, PRP_TLV_LIFE_CHECK_DD. Also update
is_supervision_frame() to include the new message type used for
PRP supervision frame.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: introduce protocol specific function pointers

As a preparatory patch to introduce support for PRP protocol, add a
protocol ops ptr in the private hsr structure to hold function
pointers as some of the functions at protocol level packet
handling is different for HSR vs PRP. It is expected that PRP will
add its of set of functions for protocol handling. Modify existing
hsr_announce() function to call proto_ops->send_sv_frame() to send
supervision frame for HSR. This is expected to be different for PRP.
So introduce a ops function ptr, send_sv_frame() for the same and
initialize it to send_hsr_supervsion_frame(). Modify hsr_announce()
to call proto_ops->send_sv_frame().

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: enhance netlink socket interface to support PRP

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>

net: hsr: remove unused inline functions

There's no callers in-tree anymore.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: use debugfs_remove_recursive() instead of debugfs_remove()

If it uses debugfs_remove_recursive() instead of debugfs_remove(),
hsr_priv() doesn't need to have "node_tbl_file" pointer variable.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: Fix a compilation error

A compliation error happen when building branch 5.5-rc7

In file included from net/hsr/hsr_main.c:12:0:
net/hsr/hsr_main.h:194:20: error: two or more data types in declaration specifiers
static inline void void hsr_debugfs_rename(struct net_device *dev)

So Removed one void.

Fixes: 4c2d5e33dcd3 ("hsr: rename debugfs file when interface name is changed")
Signed-off-by: xiaofeng.yan <yanxiaofeng7@jd.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: fix dummy hsr_debugfs_rename() declaration

The hsr_debugfs_rename prototype got an extra 'void' that needs to
be removed again:

In file included from /git/arm-soc/net/hsr/hsr_main.c:12:
net/hsr/hsr_main.h:194:20: error: two or more data types in declaration specifiers
static inline void void hsr_debugfs_rename(struct net_device *dev)

Fixes: 4c2d5e33dcd3 ("hsr: rename debugfs file when interface name is changed")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: fix a race condition in node list insertion and deletion

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: f421436a591d ("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: rename debugfs file when interface name is changed

hsr interface has own debugfs file, which name is same with interface name.
So, interface name is changed, debugfs file name should be changed too.

Fixes: fc4ecaeebd26 ("net: hsr: add debugfs support for display node list")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: add hsr root debugfs directory

In current hsr code, when hsr interface is created, it creates debugfs
directory /sys/kernel/debug/<interface name>.
If there is same directory or file name in there, it fails.
In order to reduce possibility of failure of creation of debugfs,
this patch adds root directory.

Test commands:
ip link add dummy0 type dummy
ip link add dummy1 type dummy
ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1

Before this patch:
/sys/kernel/debug/hsr0/node_table

After this patch:
/sys/kernel/debug/hsr/hsr0/node_table

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hsr: fix error handling routine in hsr_dev_finalize()

hsr_dev_finalize() is called to create new hsr interface.
There are some wrong error handling codes.

1. wrong checking return value of debugfs_create_{dir/file}.
These function doesn't return NULL. If error occurs in there,
it returns error pointer.
So, it should check error pointer instead of NULL.

2. It doesn't unregister interface if it fails to setup hsr interface.
If it fails to initialize hsr interface after register_netdevice(),
it should call unregister_netdevice().

3. Ignore failure of creation of debugfs
If creating of debugfs dir and file is failed, creating hsr interface
will be failed. But debugfs doesn't affect actual logic of hsr module.
So, ignoring this is more correct and this behavior is more general.

Fixes: c5a759117210 ("net/hsr: Use list_head (and rcu) instead of array for slave devices.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: fix debugfs path to support multiple interfaces

Fix the path of hsr debugfs root directory to use the net device
name so that it can work with multiple interfaces. While at it,
also fix some typos.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: fix naming of file and functions

Fix the file name and functions to match with existing implementation.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: hsr: add debugfs support for display node list

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>

net: hsr: convert to SPDX identifier

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>

net: hsr: remove camel case usage in the code

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>

net: hsr: remove unnecessary space after a cast

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>

net: hsr: fix lines that ends with a '('

This patch fixes function calls that ends with '(' in a line.
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>

net: hsr: fix multiple blank lines in the code

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>

net: hsr: fix lines exceeding 80 characters

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>

net/hsr: Added support for HSR v1

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>

net/hsr: Better frame dispatch

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>

net/hsr: Use list_head (and rcu) instead of array for slave devices.

Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr: Move to per-hsr device prune timer.

Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr: Switch from dev_add_pack() to netdev_rx_handler_register()

Also move the frame receive handler to hsr_slave.c.

Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr: Better variable names and update of contact info.

Signed-off-by: Arvid Brodin <arvid.brodin@alten.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)

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>