net: WARN if skb_checksum_help() is called on skb requiring segmentation

skb_checksum_help() has never done anything useful with skbs that
require segmentation.  Setting skb->ip_summed = CHECKSUM_NONE makes
them invalid and provokes a later WARNing in skb_gso_segment().

Passing such an skb to skb_checksum_help() indicates a bug, so we
should warn about it immediately.  Move the warning from
skb_gso_segment() into a shared function, and add gso_type and
gso_size to it.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings 2012-01-17 07:57:56 +00:00 committed by David S. Miller
parent 4144cb2ade
commit 36c9247449

View file

@ -1887,6 +1887,22 @@ void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
EXPORT_SYMBOL(skb_set_dev);
#endif /* CONFIG_NET_NS */
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
const char *driver = "";
if (dev && dev->dev.parent)
driver = dev_driver_string(dev->dev.parent);
WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
"gso_type=%d ip_summed=%d\n",
driver, dev ? &dev->features : NULL,
skb->sk ? &skb->sk->sk_route_caps : NULL,
skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
skb_shinfo(skb)->gso_type, skb->ip_summed);
}
/*
* Invalidate hardware checksum when packet is to be mangled, and
* complete checksum manually on outgoing path.
@ -1900,8 +1916,8 @@ int skb_checksum_help(struct sk_buff *skb)
goto out_set_summed;
if (unlikely(skb_shinfo(skb)->gso_size)) {
/* Let GSO fix up the checksum. */
goto out_set_summed;
skb_warn_bad_offload(skb);
return -EINVAL;
}
offset = skb_checksum_start_offset(skb);
@ -1961,16 +1977,7 @@ struct sk_buff *skb_gso_segment(struct sk_buff *skb,
__skb_pull(skb, skb->mac_len);
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
struct net_device *dev = skb->dev;
const char *driver = "";
if (dev && dev->dev.parent)
driver = dev_driver_string(dev->dev.parent);
WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d ip_summed=%d\n",
driver, dev ? &dev->features : NULL,
skb->sk ? &skb->sk->sk_route_caps : NULL,
skb->len, skb->data_len, skb->ip_summed);
skb_warn_bad_offload(skb);
if (skb_header_cloned(skb) &&
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))