winsock: UDP-Rx without checksum

[Ezmeralda]

Hello,

I need to receive UDP Datagrams which do have no UDP-checksum, i. e.
UDP-checksum = 0x0000. My operating system is Windows 2000.
I tried with a normal socket


socket(PF_INET, SOCK_DGRAM, 0)


but obviously, I do not receive any datagram because of checksum.


Is it possible to disable checksum verification for RX-SOCK_DGRAM-
Sockets?
How?
Can you suggest a workaround if not?


Thanks!

[Ben Voigt [C++ MVP]]

Post by Ezmeralda
Hello,
I need to receive UDP Datagrams which do have no UDP-checksum, i. e.
UDP-checksum = 0x0000. My operating system is Windows 2000.
I tried with a normal socket
socket(PF_INET, SOCK_DGRAM, 0)

There's setsockopt(UDP_NOCHECKSUM) which disables transmit checksums...
nothing I saw for receive. But zero is supposed to be always accepted, it
isn't a wrong checksum, it is no checksum at all (the true checksum must be
non-zero).

Have you any sort of firewall that might be discarding what it perceives as
"invalid" packets?