kernel/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c, branch linux-5.14.y

net: qualcomm: rmnet: fix two pointer math bugs

2021-06-21T19:19:19Z

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: 56a967c4f7e5 ("net: qualcomm: rmnet: Remove some unneeded casts") Signed-off-by: Dan Carpenter Reviewed-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller

net: qualcomm: rmnet: Remove some unneeded casts

2021-06-16T19:19:50Z

Remove the explicit casts in the checksum complement functions and pass the actual protocol specific headers instead. Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller

net: qualcomm: rmnet: always expose a few functions

2021-06-14T19:43:45Z

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 Fixes: 75db5b07f8c39 ("net: qualcomm: rmnet: eliminate some ifdefs") Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: qualcomm: rmnet: IPv6 payload length is simple

2021-06-12T20:18:49Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: drop some unary NOTs

2021-06-12T20:18:49Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: trailer value is a checksum

2021-06-12T20:18:49Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: remove unneeded code

2021-06-12T20:18:48Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: return earlier for bad checksum

2021-06-12T20:18:48Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: show that an intermediate sum is zero

2021-06-12T20:18:48Z

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 Signed-off-by: David S. Miller

net: qualcomm: rmnet: rearrange some NOTs

2021-06-12T20:18:48Z

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 Signed-off-by: David S. Miller