cvs commit: src/sys/dev/netif/nfe if_nfe.c if_nfereg.h

[Matthew Dillon]

:Please try testing with following patch:
:http://leaf.dragonflybsd.org/~sephe/nfe_csum.diff
:
:It should make turning on/off rxcsum/txcsum separately work.  And
:let's see which one generate wrong csum.
:
:Best Regards,
:sephe

    NFS client running on machine with NFE interface.

    txcsum works
    rxcsum does not

tcpdump -vvvvv -s 4096 -n -i nfe0 -l not port 22

						-Matt

	client sends readdir request.  Note that tcpdump is properly 
	reporting 'bad cksum' since when txcsum is turned on the packet
	checksum is left set to zero so hardware can calculate the correct
	checksum to insert.

10:41:42.521057 IP (tos 0x0, ttl  64, id 31776, offset 0, flags [none], proto: UDP (17), length: 168, bad cksum 0 (->fa0e)!) 216.240.41.28.1399809221 > 216.240.41.25.2049: 140 readdir fh Unknown/01CFA141D029474010000000B34F0200000000004BFA0C470000000000000000 8192 bytes @ 0 verf 0000000000000000

	client receives response.  This response packet appears to be getting
	thrown away.  Insofar as I can tell the received checksum is ok.

10:41:42.521592 IP (tos 0x0, ttl  64, id 16804, offset 0, flags [+], proto: UDP (17), length: 1500) 216.240.41.25.2049 > 216.240.41.28.1399809221: reply ok 1472 readdir POST: DIR 755 ids 0/0 sz 1024 verf 5e000000720392cc
10:41:42.521598 IP (tos 0x0, ttl  64, id 16804, offset 1480, flags [none], proto: UDP (17), length: 216) 216.240.41.25 > 216.240.41.28: udp

	--------

	Now I ifconfig nfe0 -rxcsum and I get (from the same NFS retry
	sequence):

10:48:10.346244 IP (tos 0x0, ttl  64, id 31959, offset 0, flags [none], proto: UDP (17), length: 168, bad cksum 0 (->f957)!) 216.240.41.28.1399809221 > 216.240.41.25.2049: 140 readdir fh Unknown/01CFA141D029474010000000B34F0200000000004BFA0C470000000000000000 8192 bytes @ 0 verf 0000000000000000
10:48:10.346729 IP (tos 0x0, ttl  64, id 4178, offset 0, flags [+], proto: UDP (17), length: 1500) 216.240.41.25.2049 > 216.240.41.28.1399809221: reply ok 1472 readdir POST: DIR 755 ids 0/0 sz 1024 nlink 22 rdev 194/589983 fsid 27407 fileid 24fb3 a/m/ctime 1173632815.000000 1186616261.000000 1186616261.000000 verf 5e000000720392cc
10:48:10.346736 IP (tos 0x0, ttl  64, id 4178, offset 1480, flags [none], proto: UDP (17), length: 216) 216.240.41.25 > 216.240.41.28: udp

	Note that tcpdump reports a more expanded received packet now, but
	I dont know if that means anything.  The received packet is processed
	by NFS and my ls of the NFS directory returns.

						-Matt