[lwip-devel] Bypassing checksums

[Gisle Vanem]

While building lwIP on Windows and testing using e.g. Google Chrome
on the same Windows machine I build lwIP on, the lwIP application sense-fully
ignores incoming packets with wrong checksums.

AFAICS, since IP+UDP+TCP checksum routines are most often implemented in the
NIC driver, packets coming from 'WinPap' will have wrong (no?) checksums. Or
is there another reason?

Hence in my lwipopts.h I set these to 0 to ignore wrong checksums:
  #if (LWIP_DEBUG > 0)
    #define CHECKSUM_CHECK_IP       0
    #define CHECKSUM_CHECK_TCP      0
    #define CHECKSUM_CHECK_UDP      0
    #define CHECKSUM_CHECK_ICMP     0
    #define CHECKSUM_CHECK_ICMP6    0
    ...
  #endif

Without modifying the NIC-driver to NOT use this checksum
off-loading feature, is there a better way for my lwip test-app
to accept packets from my local machine?

Is there was a way to accept wrong checksums from a certain
source IP only? That would be perfect.

-- 
--gv