Add ethtool private stats handler to debug the handling of packets
with checksum offload header / trailer. This allows to keep track of
the number of packets for which hardware computes the checksum and
counts and reasons where checksum computation was skipped in hardware
and was done in the network stack.
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>
Device of the de-aggregated skb is correctly assigned after inspecting
the mux_id, so remove the assignment in rmnet_map_deaggregate().
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>
We already check the headroom once in rmnet_map_egress_handler(),
so this is not needed.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a typo here so we accidentally free "skb" instead of "skbn".
It leads to a double free and a leak. After discussing with Subash,
it's better to just move the check before the allocation and avoid the
need to free.
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-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>
