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Author SHA1 Message Date
Dan Carpenter
753ba09aa3 net: qualcomm: rmnet: fix two pointer math bugs
We recently changed these two pointers from void pointers to struct
pointers and it breaks the pointer math so now the "txphdr" points
beyond the end of the buffer.

Fixes: 56a967c4f7 ("net: qualcomm: rmnet: Remove some unneeded casts")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-21 12:19:19 -07:00
Subash Abhinov Kasiviswanathan
56a967c4f7 net: qualcomm: rmnet: Remove some unneeded casts
Remove the explicit casts in the checksum complement functions
and pass the actual protocol specific headers instead.

Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-16 12:19:50 -07:00
Alex Elder
b84b53ee83 net: qualcomm: rmnet: always expose a few functions
A recent change tidied up some conditional code, avoiding the use of
some #ifdefs.  Unfortunately, if CONFIG_IPV6 was not enabled, it
meant that two functions were referenced but never defined.

The easiest fix is to just define stubs for these functions if
CONFIG_IPV6 is not defined.  This will soon be simplified further
by some other development in the works...

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 75db5b07f8 ("net: qualcomm: rmnet: eliminate some ifdefs")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-14 12:43:45 -07:00
Alex Elder
185a108fe0 net: qualcomm: rmnet: IPv6 payload length is simple
We don't support any extension headers for IPv6 packets.  Extension
headers therefore contribute 0 bytes to the payload length.  As a
result we can just use the IPv6 payload length as the length used to
compute the pseudo header checksum for both UDP and TCP messages.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:49 -07:00
Alex Elder
411a795e14 net: qualcomm: rmnet: drop some unary NOTs
We compare a payload checksum with a pseudo checksum value for
equality in rmnet_map_ipv4_dl_csum_trailer().  Both of those values
are computed with a unary NOT (~) operation.  The result of the
comparison is the same if we omit that NOT for both values.

Remove these operations in rmnet_map_ipv6_dl_csum_trailer() also.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:49 -07:00
Alex Elder
be754f6435 net: qualcomm: rmnet: trailer value is a checksum
The csum_value field in the rmnet_map_dl_csum_trailer structure is a
"real" Internet checksum.  It is a 16 bit value, in big endian format,
which represents an inverted ones' complement sum over pairs of bytes.

Make that clear by changing its type to __sum16.

This makes a typecast in rmnet_map_ipv4_dl_csum_trailer() and
another in rmnet_map_ipv6_dl_csum_trailer() unnecessary.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:49 -07:00
Alex Elder
698aa6c46b net: qualcomm: rmnet: remove unneeded code
The previous patch makes rmnet_map_ipv4_dl_csum_trailer() return
early with an error if it is determined that the computed checksum
for the IP payload does not match what was expected.

If the computed checksum *does* match the expected value, the IP
payload (i.e., the transport message), can be considered good.
There is no need to do any further processing of the message.

This means a big block of code is unnecessary for validating the
transport checksum value, and can be removed.

Make comparable changes in rmnet_map_ipv6_dl_csum_trailer().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:48 -07:00
Alex Elder
fab01a6f3a net: qualcomm: rmnet: return earlier for bad checksum
In rmnet_map_ipv4_dl_csum_trailer(), if the sum of the trailer
checksum and the pseudo checksum is non-zero, checksum validation
has failed.  We can return an error as soon as we know that.

We can do the same thing in rmnet_map_ipv6_dl_csum_trailer().

Add some comments that explain where we're headed.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:48 -07:00
Alex Elder
9d0407bc4c net: qualcomm: rmnet: show that an intermediate sum is zero
This patch simply demonstrates that a checksum value computed when
verifying an offloaded transport checksum value for both IPv4 and
IPv6 is (normally) 0.  It can be squashed into the next patch.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:48 -07:00
Alex Elder
bbd45f10ed net: qualcomm: rmnet: rearrange some NOTs
With the ones' complement arithmetic, the sum of two negated values
is equal to the negation of the sum of the two original values [1].
Rearrange the calculation ip6_payload_sum using this property.

[1] https://tools.ietf.org/html/rfc1071

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:48 -07:00
Alex Elder
0e6af897fc net: qualcomm: rmnet: remove some local variables
In rmnet_map_ipv4_dl_csum_trailer(), remove the "csum_temp" and
"addend" local variables, and simplify a few lines of code.

Remove the "csum_temp", "csum_value", "ip6_hdr_csum", and "addend"
local variables in rmnet_map_ipv6_dl_csum_trailer(), and simplify a
few lines of code there as well.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-12 13:18:48 -07:00
Alex Elder
23a5708d4e net: qualcomm: rmnet: avoid unnecessary IPv6 byte-swapping
In the previous patch IPv4 download checksum offload code was
updated to avoid unnecessary byte swapping, based on properties of
the Internet checksum algorithm.  This patch makes comparable
changes to the IPv6 download checksum offload handling.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:50 -07:00
Alex Elder
a2918a169f net: qualcomm: rmnet: avoid unnecessary byte-swapping
Internet checksums are used for IPv4 header checksum, as well as TCP
segment and UDP datagram checksums.  Such a checksum represents the
negated sum of adjacent pairs of bytes, using ones' complement
arithmetic.

One property of the Internet checkum is byte order independence [1].
Specifically, the sum of byte-swapped pairs is equal to the result
of byte swapping the sum of those same pairs when not byte-swapped.

So for example if a, b, c, d, y, and z are hexadecimal digits, and
PLUS represents ones' complement addition:
    If:		ab PLUS cd = yz
    Then:	ba PLUS dc = zy

For this reason, there is no need to swap the order of bytes in the
checksum value held in a message header, nor the one in the QMAPv4
trailer, in order to operate on them.

In other words, we can determine whether the hardware-computed
checksum matches the one in the message header without any byte
swaps.

(This patch leaves in place all existing type casts.)

[1] https://tools.ietf.org/html/rfc1071

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
e5adbbdfa2 net: qualcomm: rmnet: clarify a bit of code
In rmnet_map_ipv6_dl_csum_trailer() there is an especially involved
line of code that determines the ones' complement sum of the IPv6
packet header (in host byte order).  Simplify that by storing the
result of computing just the header checksum in a local variable,
then using that in the original assignment.

Use the size of the IPv6 header structure as the number of bytes to
checksum, rather than computing the offset to the transport header.
And use ip_fast_csum() rather than ipa_compute_csum(), knowing that
the size of an IPv6 header (40 bytes) is a multiple of 4 bytes
greater than 16.

Add some comments to match rmnet_map_ipv4_dl_csum_trailer().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
16bf3d33c6 net: qualcomm: rmnet: IPv4 header has zero checksum
In rmnet_map_ipv4_dl_csum_trailer(), an illegal checksum subtraction
is done, subtracting hdr_csum (in host byte order) from csum_value (in
network byte order).  Despite being illegal, it generally works,
because it turns out the value subtracted is (or should be) always 0,
which has the same representation in either byte order.

Doing illegal operations is not good form though, so fix this by
verifying the IP header checksum early in that function.  If its
checksum is non-zero, the packet will be bad, so just return an
error.  This will cause the packet to passed to the IP layer where
it can be dropped.

Thereafter, there is no need subtract the IP header checksum from
the checksum value in the trailer because we know it is zero.
Add a comment explaining this.

This type of packet error is different from other types, so add a
new statistics counter to track this condition.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
874a333f74 net: qualcomm: rmnet: simplify rmnet_map_get_csum_field()
The checksum fields of the TCP and UDP header structures already
have type __sum16.  We don't support any other protocol headers, so
we can simplify rmnet_map_get_csum_field(), getting rid of the local
variable entirely and just returning the appropriate address.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
1d257f45ef net: qualcomm: rmnet: get rid of some local variables
The value passed as an argument to rmnet_map_ipv4_ul_csum_header()
is always an IPv4 header.  Rather than using a local variable, just
have the type of the argument reflect the proper type.

In rmnet_map_ipv6_ul_csum_header() things are defined a little
differently, but make the same basic change there.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
75db5b07f8 net: qualcomm: rmnet: eliminate some ifdefs
If IPV6 is not enabled in the kernel configuration, the RMNet
checksum code indicates a buffer containing an IPv6 packet is not
supported.  The same thing happens if a buffer contains something
other than an IPv4 or IPv6 packet.

We can rearrange things a bit in two functions so that some #ifdef
calls can simply be eliminated.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Alex Elder
e4517d8a7f net: qualcomm: rmnet: use ip_is_fragment()
In rmnet_map_ipv4_dl_csum_trailer() use ip_is_fragment() to
determine whether a socket buffer contains a packet fragment.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-11 13:37:49 -07:00
Nathan Chancellor
118de61067 net: ethernet: rmnet: Restructure if checks to avoid uninitialized warning
Clang warns that proto in rmnet_map_v5_checksum_uplink_packet() might be
used uninitialized:

drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:14: warning:
variable 'proto' is used uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
                } else if (skb->protocol == htons(ETH_P_IPV6)) {
                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:295:36: note:
uninitialized use occurs here
                check = rmnet_map_get_csum_field(proto, trans);
                                                 ^~~~~
drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:283:10: note:
remove the 'if' if its condition is always true
                } else if (skb->protocol == htons(ETH_P_IPV6)) {
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c:270:11: note:
initialize the variable 'proto' to silence this warning
                u8 proto;
                        ^
                         = '\0'
1 warning generated.

This is technically a false positive because there is an if statement
above this one that checks skb->protocol for not being either
ETH_P_IP{,V6}. However, it is more obvious to sink that into the if
statement as an else branch, which makes the code clearer and fixes the
warning.

At the same time, move the "IS_ENABLED(CONFIG_IPV6)" into the else if
condition so that the else branch of the preprocessor conditional can
be shared, since there is no build failure with CONFIG_IPV6 disabled.

Fixes: b6e5d27e32 ("net: ethernet: rmnet: Add support for MAPv5 egress packets")
Link: https://github.com/ClangBuiltLinux/linux/issues/1390
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-03 15:29:54 -07:00
Sharath Chandra Vurukala
b6e5d27e32 net: ethernet: rmnet: Add support for MAPv5 egress packets
Adding support for MAPv5 egress packets.

This involves adding the MAPv5 header and setting the csum_valid_required
in the checksum header to request HW compute the checksum.

Corresponding stats are incremented based on whether the checksum is
computed in software or HW.

New stat has been added which represents the count of packets whose
checksum is calculated by the HW.

Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-01 17:11:41 -07:00
Sharath Chandra Vurukala
e1d9a90a9b net: ethernet: rmnet: Support for ingress MAPv5 checksum offload
Adding support for processing of MAPv5 downlink packets.
It involves parsing the Mapv5 packet and checking the csum header
to know whether the hardware has validated the checksum and is
valid or not.

Based on the checksum valid bit the corresponding stats are
incremented and skb->ip_summed is marked either CHECKSUM_UNNECESSARY
or left as CHEKSUM_NONE to let network stack revalidate the checksum
and update the respective snmp stats.

Current MAPV1 header has been modified, the reserved field in the
Mapv1 header is now used for next header indication.

Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-01 17:11:41 -07:00
Alex Elder
86ca860e12 net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum header
Replace the use of C bit-fields in the rmnet_map_ul_csum_header
structure with a single two-byte (big endian) structure member,
and use masks to encode or get values within it.  The content of
these fields can be accessed using simple bitwise AND and OR
operations on the (host byte order) value of the new structure
member.

Previously rmnet_map_ipv4_ul_csum_header() would update C bit-field
values in host byte order, then forcibly fix their byte order using
a combination of byte swap operations and types.

Instead, just compute the value that needs to go into the new
structure member and save it with a simple byte-order conversion.

Make similar simplifications in rmnet_map_ipv6_ul_csum_header().

Finally, in rmnet_map_checksum_uplink_packet() a set of assignments
zeroes every field in the upload checksum header.  Replace that with
a single memset() operation.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-15 20:41:58 -07:00
Alex Elder
cc1b21ba62 net: qualcomm: rmnet: don't use C bit-fields in rmnet checksum trailer
Replace the use of C bit-fields in the rmnet_map_dl_csum_trailer
structure with a single one-byte field, using constant field masks
to encode or get at embedded values.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-15 20:41:58 -07:00
Alex Elder
16653c16d2 net: qualcomm: rmnet: use masks instead of C bit-fields
The actual layout of bits defined in C bit-fields (e.g. int foo : 3)
is implementation-defined.  Structures defined in <linux/if_rmnet.h>
address this by specifying all bit-fields twice, to cover two
possible layouts.

I think this pattern is repetitive and noisy, and I find the whole
notion of compiler "bitfield endianness" to be non-intuitive.

Stop using C bit-fields for the command/data flag and the pad length
fields in the rmnet_map structure, and define a single-byte flags
field instead.  Define a mask for the single-bit "command" flag,
and another mask for the encoded pad length.  The content of both
fields can be accessed using a simple bitwise AND operation.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-15 20:41:58 -07:00
Alex Elder
9d131d044f net: qualcomm: rmnet: kill RMNET_MAP_GET_*() accessor macros
The following macros, defined in "rmnet_map.h", assume a socket
buffer is provided as an argument without any real indication this
is the case.
    RMNET_MAP_GET_MUX_ID()
    RMNET_MAP_GET_CD_BIT()
    RMNET_MAP_GET_PAD()
    RMNET_MAP_GET_CMD_START()
    RMNET_MAP_GET_LENGTH()
What they hide is pretty trivial accessing of fields in a structure,
and it's much clearer to see this if we do these accesses directly.

So rather than using these accessor macros, assign a local
variable of the map header pointer type to the socket buffer data
pointer, and derereference that pointer variable.

In "rmnet_map_data.c", use sizeof(object) rather than sizeof(type)
in one spot.  Also, there's no need to byte swap 0; it's all zeros
irrespective of endianness.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-15 20:41:58 -07:00
Alex Elder
50c62a111c net: qualcomm: rmnet: simplify some byte order logic
In rmnet_map_ipv4_ul_csum_header() and rmnet_map_ipv6_ul_csum_header()
the offset within a packet at which checksumming should commence is
calculated.  This calculation involves byte swapping and a forced type
conversion that makes it hard to understand.

Simplify this by computing the offset in host byte order, then
converting the result when assigning it into the header field.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-15 20:41:58 -07:00
Subash Abhinov Kasiviswanathan
a7cf3d24ee net: qualcomm: rmnet: Fix incorrect UL checksum offload logic
The udp_ip4_ind bit is set only for IPv4 UDP non-fragmented packets
so that the hardware can flip the checksum to 0xFFFF if the computed
checksum is 0 per RFC768.

However, this bit had to be set for IPv6 UDP non fragmented packets
as well per hardware requirements. Otherwise, IPv6 UDP packets
with computed checksum as 0 were transmitted by hardware and were
dropped in the network.

In addition to setting this bit for IPv6 UDP, the field is also
appropriately renamed to udp_ind as part of this change.

Fixes: 5eb5f8608e ("net: qualcomm: rmnet: Add support for TX checksum offload")
Cc: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-26 14:20:06 -07:00
Thomas Gleixner
97fb5e8d9b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284
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 version 2 and
  only version 2 as published by the free software foundation this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Subash Abhinov Kasiviswanathan
bbde32d38b net: qualcomm: rmnet: Add support for ethtool private stats
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>
2018-05-16 14:23:04 -04:00
Subash Abhinov Kasiviswanathan
14452ca3b5 net: qualcomm: rmnet: Export mux_id and flags to netlink
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>
2018-03-22 15:00:44 -04:00
Subash Abhinov Kasiviswanathan
378e25357a net: qualcomm: rmnet: Remove unnecessary device assignment
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>
2018-03-22 15:00:44 -04:00
Subash Abhinov Kasiviswanathan
9dcaec0426 net: qualcomm: rmnet: Update copyright year to 2018
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22 15:00:44 -04:00
Subash Abhinov Kasiviswanathan
5eb5f8608e net: qualcomm: rmnet: Add support for TX checksum offload
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>
2018-01-08 13:58:49 -05:00
Subash Abhinov Kasiviswanathan
bbd21b247c net: qualcomm: rmnet: Add support for RX checksum offload
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>
2018-01-08 13:58:49 -05:00
Subash Abhinov Kasiviswanathan
4b5ba67745 net: qualcomm: rmnet: Remove redundant check when stamping map header
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>
2018-01-08 13:58:48 -05:00
Dan Carpenter
1f4f554a72 net: qualcomm: rmnet: Fix a double free
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>
2017-09-09 14:33:27 -07:00
Subash Abhinov Kasiviswanathan
b665f4f82d net: qualcomm: rmnet: Rename real_dev_info to port
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>
2017-09-03 21:27:18 -07:00
Subash Abhinov Kasiviswanathan
ceed73a2cf drivers: net: ethernet: qualcomm: rmnet: Initial implementation
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>
2017-08-30 11:41:13 -07:00