Packets in transmit path could potentially be dropped if there were
errors while adding the MAP header or the checksum header.
Increment the tx_drops stats in these cases.
Additionally, refactor the code to free the packet and increment
the tx_drops stat under a single label.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define new netlink attributes for rmnet mux_id and flags. These
flags / mux_id were earlier using vlan flags / id respectively.
The flag bits are also moved to uapi and are renamed with
prefix RMNET_FLAG_*.
Also add the rmnet policy to handle the new netlink attributes.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TX checksum offload applies to TCP / UDP packets which are not
fragmented using the MAPv4 checksum trailer. The following needs to be
done to have checksum computed in hardware -
1. Set the checksum start offset and inset offset.
2. Set the csum_enabled bit
3. Compute and set 1's complement of partial checksum field in
transport header.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using the MAPv4 packet format, receive checksum offload can be
enabled in hardware. The checksum computation over pseudo header is
not offloaded but the rest of the checksum computation over
the payload is offloaded. This applies only for TCP / UDP packets
which are not fragmented.
rmnet validates the TCP/UDP checksum for the packet using the checksum
from the checksum trailer added to the packet by hardware. The
validation performed is as following -
1. Perform 1's complement over the checksum value from the trailer
2. Compute 1's complement checksum over IPv4 / IPv6 header and
subtracts it from the value from step 1
3. Computes 1's complement checksum over IPv4 / IPv6 pseudo header and
adds it to the value from step 2
4. Subtracts the checksum value from the TCP / UDP header from the
value from step 3.
5. Compares the value from step 4 to the checksum value from the
TCP / UDP header.
6. If the comparison in step 5 succeeds, CHECKSUM_UNNECESSARY is set
and the packet is passed on to network stack. If there is a
failure, then the packet is passed on as such without modifying
the ip_summed field.
The checksum field is also checked for UDP checksum 0 as per RFC 768
and for unexpected TCP checksum of 0.
If checksum offload is disabled when using MAPv4 packet format in
receive path, the packet is queued as is to network stack without
the validations above.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The real device over which the rmnet devices are installed also
aggregate multiple IP packets and sends them as a single large
aggregate frame to the hardware. This causes degraded throughput
for TCP TX due to bufferbloat.
To overcome this problem, pacing shift value of 8 is set using the
sk_pacing_shift_update() helper. This value was determined based
on experiments with a single stream TCP TX using iperf for a
duration of 30s.
Pacing shift | Observed data rate (Mbps)
10 | 9
9 | 140
8 | 146 (Max link rate)
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done so that we can use this field for both ingress and
egress flags.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
rmnet devices cannot have a mux id of 255. This is validated when
assigning the mux id to the rmnet devices. As a result, checking for
mux id 255 does not apply in egress path.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support to send and receive packets over ethernet.
An example of usage is testing the data path on UML. This can be
achieved by setting up two UML instances in multicast mode and
associating rmnet over the UML ethernet device.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Multiplexing is always enabled when transmiting from a rmnet device,
so remove the redundant egress macros. De-multiplexing is always
enabled when receiving packets from a rmnet device, so remove those
ingress macros.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only the success and consumed entries were actually in use.
Use standard error codes instead.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a skb in transmit path does not have sufficient headroom to add
the map header, the skb is not sent out and is never freed.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add gro_cells so that rmnet devices can call gro_cells_receive
instead of netif_receive_skb.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rmnet device needs to assigned for all packets in the
deaggregation path based on the mux id, so the check is not needed.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since packet is always consumed by rmnet_rx_handler(), we always
return RX_HANDLER_CONSUMED. There is no need to pass on this
value through multiple functions.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support to bridge two devices which can send multiplexing and
aggregation (MAP) data. This is done only when the data itself is
not going to be consumed in the stack but is being passed on to a
different endpoint. This is mainly used for testing.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than using a static array, use a hlist to store the muxed
endpoints and use the mux id to query the rmnet_device.
This is useful as usually very few mux ids are used.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The end point is set twice in the local_ep as well as the mux_id and
the real_dev in the rmnet private structure. Remove the local_ep.
While these elements are equivalent, rmnet_endpoint will be
used only as part of the rmnet_port for muxed scenarios in VND mode.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mode information on the real device makes it easier to route packets
to rmnet device or bridged device based on the configuration.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This will be rewritten in the following patches.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make it similar to drivers like ipvlan / macvlan so it is easier to read.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RmNet driver provides a transport agnostic MAP (multiplexing and
aggregation protocol) support in embedded module. Module provides
virtual network devices which can be attached to any IP-mode
physical device. This will be used to provide all MAP functionality
on future hardware in a single consistent location.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Subash Abhinov Kasiviswanathan