xen: netfront: handle incoming GSO SKBs which are not CHECKSUM_PARTIAL
The Linux network stack expects all GSO SKBs to have ip_summed == CHECKSUM_PARTIAL (which implies that the frame contains a partial checksum) and the Xen network ring protocol similarly expects an SKB which has GSO set to also have NETRX_csum_blank (which also implies a partial checksum). However there have been cases of buggy guests which mark a frame as GSO but do not set csum_blank. If we detect that we a receiving such a frame (which manifests as ip_summed != PARTIAL && skb_is_gso) then force the SKB to partial and recalculate the checksum, since we cannot rely on the peer having done so if they have not set csum_blank. Add an ethtool stat to track occurances of this event. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: David Miller <davem@davemloft.net> Cc: xen-devel@lists.xensource.com Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
389f2a18c6
commit
e0ce4af920
|
@ -120,6 +120,9 @@ struct netfront_info {
|
|||
unsigned long rx_pfn_array[NET_RX_RING_SIZE];
|
||||
struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
|
||||
struct mmu_update rx_mmu[NET_RX_RING_SIZE];
|
||||
|
||||
/* Statistics */
|
||||
int rx_gso_checksum_fixup;
|
||||
};
|
||||
|
||||
struct netfront_rx_info {
|
||||
|
@ -770,11 +773,29 @@ static RING_IDX xennet_fill_frags(struct netfront_info *np,
|
|||
return cons;
|
||||
}
|
||||
|
||||
static int skb_checksum_setup(struct sk_buff *skb)
|
||||
static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
|
||||
{
|
||||
struct iphdr *iph;
|
||||
unsigned char *th;
|
||||
int err = -EPROTO;
|
||||
int recalculate_partial_csum = 0;
|
||||
|
||||
/*
|
||||
* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
|
||||
* peers can fail to set NETRXF_csum_blank when sending a GSO
|
||||
* frame. In this case force the SKB to CHECKSUM_PARTIAL and
|
||||
* recalculate the partial checksum.
|
||||
*/
|
||||
if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
|
||||
struct netfront_info *np = netdev_priv(dev);
|
||||
np->rx_gso_checksum_fixup++;
|
||||
skb->ip_summed = CHECKSUM_PARTIAL;
|
||||
recalculate_partial_csum = 1;
|
||||
}
|
||||
|
||||
/* A non-CHECKSUM_PARTIAL SKB does not require setup. */
|
||||
if (skb->ip_summed != CHECKSUM_PARTIAL)
|
||||
return 0;
|
||||
|
||||
if (skb->protocol != htons(ETH_P_IP))
|
||||
goto out;
|
||||
|
@ -788,9 +809,23 @@ static int skb_checksum_setup(struct sk_buff *skb)
|
|||
switch (iph->protocol) {
|
||||
case IPPROTO_TCP:
|
||||
skb->csum_offset = offsetof(struct tcphdr, check);
|
||||
|
||||
if (recalculate_partial_csum) {
|
||||
struct tcphdr *tcph = (struct tcphdr *)th;
|
||||
tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
|
||||
skb->len - iph->ihl*4,
|
||||
IPPROTO_TCP, 0);
|
||||
}
|
||||
break;
|
||||
case IPPROTO_UDP:
|
||||
skb->csum_offset = offsetof(struct udphdr, check);
|
||||
|
||||
if (recalculate_partial_csum) {
|
||||
struct udphdr *udph = (struct udphdr *)th;
|
||||
udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
|
||||
skb->len - iph->ihl*4,
|
||||
IPPROTO_UDP, 0);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
if (net_ratelimit())
|
||||
|
@ -829,13 +864,11 @@ static int handle_incoming_queue(struct net_device *dev,
|
|||
/* Ethernet work: Delayed to here as it peeks the header. */
|
||||
skb->protocol = eth_type_trans(skb, dev);
|
||||
|
||||
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
||||
if (skb_checksum_setup(skb)) {
|
||||
kfree_skb(skb);
|
||||
packets_dropped++;
|
||||
dev->stats.rx_errors++;
|
||||
continue;
|
||||
}
|
||||
if (checksum_setup(dev, skb)) {
|
||||
kfree_skb(skb);
|
||||
packets_dropped++;
|
||||
dev->stats.rx_errors++;
|
||||
continue;
|
||||
}
|
||||
|
||||
dev->stats.rx_packets++;
|
||||
|
@ -1632,12 +1665,59 @@ static void netback_changed(struct xenbus_device *dev,
|
|||
}
|
||||
}
|
||||
|
||||
static const struct xennet_stat {
|
||||
char name[ETH_GSTRING_LEN];
|
||||
u16 offset;
|
||||
} xennet_stats[] = {
|
||||
{
|
||||
"rx_gso_checksum_fixup",
|
||||
offsetof(struct netfront_info, rx_gso_checksum_fixup)
|
||||
},
|
||||
};
|
||||
|
||||
static int xennet_get_sset_count(struct net_device *dev, int string_set)
|
||||
{
|
||||
switch (string_set) {
|
||||
case ETH_SS_STATS:
|
||||
return ARRAY_SIZE(xennet_stats);
|
||||
default:
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
static void xennet_get_ethtool_stats(struct net_device *dev,
|
||||
struct ethtool_stats *stats, u64 * data)
|
||||
{
|
||||
void *np = netdev_priv(dev);
|
||||
int i;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
|
||||
data[i] = *(int *)(np + xennet_stats[i].offset);
|
||||
}
|
||||
|
||||
static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
|
||||
{
|
||||
int i;
|
||||
|
||||
switch (stringset) {
|
||||
case ETH_SS_STATS:
|
||||
for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
|
||||
memcpy(data + i * ETH_GSTRING_LEN,
|
||||
xennet_stats[i].name, ETH_GSTRING_LEN);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
static const struct ethtool_ops xennet_ethtool_ops =
|
||||
{
|
||||
.set_tx_csum = ethtool_op_set_tx_csum,
|
||||
.set_sg = xennet_set_sg,
|
||||
.set_tso = xennet_set_tso,
|
||||
.get_link = ethtool_op_get_link,
|
||||
|
||||
.get_sset_count = xennet_get_sset_count,
|
||||
.get_ethtool_stats = xennet_get_ethtool_stats,
|
||||
.get_strings = xennet_get_strings,
|
||||
};
|
||||
|
||||
#ifdef CONFIG_SYSFS
|
||||
|
|
Loading…
Reference in a new issue