| Message ID | 1429043704-22552-4-git-send-email-tlfalcon@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Tue, 2015-04-14 at 15:35 -0500, Thomas Falcon wrote: > Enables receiving large packets from other LPARs. These packets > have a -1 IP header checksum, so we must recalculate to have > a valid checksum. > > Signed-off-by: Brian King <brking@linux.vnet.ibm.com> > Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com> > --- > drivers/net/ethernet/ibm/ibmveth.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c > index 08970c7..05eaca6a 100644 > --- a/drivers/net/ethernet/ibm/ibmveth.c > +++ b/drivers/net/ethernet/ibm/ibmveth.c > @@ -1092,6 +1092,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget) > struct net_device *netdev = adapter->netdev; > int frames_processed = 0; > unsigned long lpar_rc; > + struct iphdr *iph; > > restart_poll: > while (frames_processed < budget) { > @@ -1134,8 +1135,20 @@ restart_poll: > skb_put(skb, length); > skb->protocol = eth_type_trans(skb, netdev); > > - if (csum_good) > + if (csum_good) { > skb->ip_summed = CHECKSUM_UNNECESSARY; > + if (be16_to_cpu(skb->protocol) == ETH_P_IP) { > + skb_set_network_header(skb, 0); > + skb_set_transport_header(skb, sizeof(struct iphdr)); > + iph = ip_hdr(skb); > + > + /* If the IP checksum is not offloaded and if the packet > + * is large send, the checksum must be rebuilt. > + */ > + if (iph->check == 0xffff) > + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); How can this possibly work ? Normally you would have to set iph->check to 0 before calling ip_fast_csum(), as done in ip_send_check()
On 04/14/2015 05:00 PM, Eric Dumazet wrote: > On Tue, 2015-04-14 at 15:35 -0500, Thomas Falcon wrote: >> Enables receiving large packets from other LPARs. These packets >> have a -1 IP header checksum, so we must recalculate to have >> a valid checksum. >> >> Signed-off-by: Brian King <brking@linux.vnet.ibm.com> >> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com> >> --- >> drivers/net/ethernet/ibm/ibmveth.c | 15 ++++++++++++++- >> 1 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c >> index 08970c7..05eaca6a 100644 >> --- a/drivers/net/ethernet/ibm/ibmveth.c >> +++ b/drivers/net/ethernet/ibm/ibmveth.c >> @@ -1092,6 +1092,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget) >> struct net_device *netdev = adapter->netdev; >> int frames_processed = 0; >> unsigned long lpar_rc; >> + struct iphdr *iph; >> >> restart_poll: >> while (frames_processed < budget) { >> @@ -1134,8 +1135,20 @@ restart_poll: >> skb_put(skb, length); >> skb->protocol = eth_type_trans(skb, netdev); >> >> - if (csum_good) >> + if (csum_good) { >> skb->ip_summed = CHECKSUM_UNNECESSARY; >> + if (be16_to_cpu(skb->protocol) == ETH_P_IP) { >> + skb_set_network_header(skb, 0); >> + skb_set_transport_header(skb, sizeof(struct iphdr)); >> + iph = ip_hdr(skb); >> + >> + /* If the IP checksum is not offloaded and if the packet >> + * is large send, the checksum must be rebuilt. >> + */ >> + if (iph->check == 0xffff) >> + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); > > How can this possibly work ? > > Normally you would have to set iph->check to 0 before calling > ip_fast_csum(), as done in ip_send_check() I don't have an answer for why I weren't seeing any problems while testing this, but I'll go back and set iph->check to zero and retest. Thanks for noticing this. > > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c index 08970c7..05eaca6a 100644 --- a/drivers/net/ethernet/ibm/ibmveth.c +++ b/drivers/net/ethernet/ibm/ibmveth.c @@ -1092,6 +1092,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget) struct net_device *netdev = adapter->netdev; int frames_processed = 0; unsigned long lpar_rc; + struct iphdr *iph; restart_poll: while (frames_processed < budget) { @@ -1134,8 +1135,20 @@ restart_poll: skb_put(skb, length); skb->protocol = eth_type_trans(skb, netdev); - if (csum_good) + if (csum_good) { skb->ip_summed = CHECKSUM_UNNECESSARY; + if (be16_to_cpu(skb->protocol) == ETH_P_IP) { + skb_set_network_header(skb, 0); + skb_set_transport_header(skb, sizeof(struct iphdr)); + iph = ip_hdr(skb); + + /* If the IP checksum is not offloaded and if the packet + * is large send, the checksum must be rebuilt. + */ + if (iph->check == 0xffff) + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); + } + } napi_gro_receive(napi, skb); /* send it up */