openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

8139cp: Fix GSO MSS handling 

When fixing the TSO support I noticed we just mask ->gso_size with the
MSSMask value and don't care about the consequences.

Provide a .ndo_features_check() method which drops the NETIF_F_TSO
feature for any skb which would exceed the maximum, and thus forces it
to be segmented by software.

Then we can stop the masking in cp_start_xmit(), and just WARN if the
maximum is exceeded, which should now never happen.

Finally, Francois Romieu noticed that we didn't even have the right
value for MSSMask anyway; it should be 0x7ff (11 bits) not 0xfff.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Woodhouse 2015-09-24 11:38:22 +01:00 committed by David S. Miller
parent 5a58f22779
commit 8b7a704822
1 changed files with 18 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/net/ethernet/realtek/8139cp.c
View File

@ -175,7 +175,7 @@ enum {
LastFrag = (1 << 28), /* Final segment of a packet */
LargeSend = (1 << 27), /* TCP Large Send Offload (TSO) */
MSSShift = 16, /* MSS value position */
MSSMask = 0xfff, /* MSS value: 11 bits */
MSSMask = 0x7ff, /* MSS value: 11 bits */
TxError = (1 << 23), /* Tx error summary */
RxError = (1 << 20), /* Rx error summary */
IPCS = (1 << 18), /* Calculate IP checksum */
@ -754,10 +754,16 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb,
eor = (entry == (CP_TX_RING_SIZE - 1)) ? RingEnd : 0;
mss = skb_shinfo(skb)->gso_size;
if (mss > MSSMask) {
WARN_ONCE(1, "Net bug: GSO size %d too large for 8139CP\n",
mss);
goto out_dma_error;
}
opts2 = cpu_to_le32(cp_tx_vlan_tag(skb));
opts1 = DescOwn;
if (mss)
opts1 |= LargeSend | ((mss & MSSMask) << MSSShift);
opts1 |= LargeSend | (mss << MSSShift);
else if (skb->ip_summed == CHECKSUM_PARTIAL) {
const struct iphdr *ip = ip_hdr(skb);
if (ip->protocol == IPPROTO_TCP)
@ -1852,6 +1858,15 @@ static void cp_set_d3_state (struct cp_private *cp)
pci_set_power_state (cp->pdev, PCI_D3hot);
}
static netdev_features_t cp_features_check(struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
if (skb_shinfo(skb)->gso_size > MSSMask)
features &= ~NETIF_F_TSO;
return vlan_features_check(skb, features);
}
static const struct net_device_ops cp_netdev_ops = {
.ndo_open = cp_open,
.ndo_stop = cp_close,
@ -1864,6 +1879,7 @@ static const struct net_device_ops cp_netdev_ops = {
.ndo_tx_timeout = cp_tx_timeout,
.ndo_set_features = cp_set_features,
.ndo_change_mtu = cp_change_mtu,
.ndo_features_check = cp_features_check,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = cp_poll_controller,