On Tue, Sep 16, 2003 at 12:27:21PM +0100, Jamie Lokier wrote:
> Nick Patavalis wrote:
> > How should the kernel be notified if the calculation of a checksum
> > failed (checksum does not match). Reading the e100 source, I see that
> > if the checksums (any of the checksums, I presume) of a packet are
> > invalid, then the driver sets "skb->ip_summed" to CHECKSUM_NONE; but
>
> I'm reading the 2.6.0-test5 e100 source, and I don't see anywhere
> where it's set to CHECKSUM_NONE if the checksum is known to be
> invalid. I see CHECKSUM_UNNECESSARY in those cases.
>
Reading e100_main.c, from 2.6.0-test2 (the latest version I have
readily available), I see (sory for the ugly line-numbers):
2052 /* set the checksum info */
2053 if (bdp->flags & DF_CSUM_OFFLOAD) {
2054 if (bdp->rev_id >= D102_REV_ID) {
2055 skb->ip_summed = e100_D102_check_checksum(rfd);
2056 } else {
2057 skb->ip_summed = e100_D101M_checksum(bdp, skb);
2058 }
2059 } else {
2060 skb->ip_summed = CHECKSUM_NONE;
2061 }
2914 e100_D102_check_checksum(rfd_t *rfd)
2915 {
2916 if (((le16_to_cpu(rfd->rfd_header.cb_status)) & RFD_PARSE_BIT)
2917 && (((rfd->rcvparserstatus & CHECKSUM_PROTOCOL_MASK) ==
2918 RFD_TCP_PACKET)
2919 || ((rfd->rcvparserstatus & CHECKSUM_PROTOCOL_MASK) ==
2920 RFD_UDP_PACKET))
2921 && (rfd->checksumstatus & TCPUDP_CHECKSUM_BIT_VALID)
2922 && (rfd->checksumstatus & TCPUDP_CHECKSUM_VALID)) {
2923 return CHECKSUM_UNNECESSARY;
2924 }
2925 return CHECKSUM_NONE;
2926 }
the function "e100_D101M_checksum(bdp, skb)" is similar.
Am I wrong to interpret this as:
if HW checksuming supported, then
if checksum is valid
skb->ip_summed = CHECKSUM_UNNECESSARY
else
skb->ip_summed = CHECKSUM_NONE
else
skb->ip_summed = CHECKSUM_NONE
I don't know if sommething changed from test2 to test5
/npat
--
Perilous to us all are the devices of an art deeper than we possess
ourselves.
-- Gandalf, in J.R.R. Tolkien's The Lord of the Rings
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