Previously efx_filter_rfs() assumed that the headers it needed (802.1Q, IP)
would be present in the linear data area of the SKB.
When running with debugging I found that this is not always the case and
that in fact the data may all be paged.
So now use skb_header_pointer() to extract the data.
Also replace EFX_BUG_ON_PARANOID checks for insufficient data with checks
that return -EINVAL, as this case is possible if the received packet was
too short.
Signed-off-by: Edward Cree <ec...@solarflare.com>
---
drivers/net/ethernet/sfc/rx.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)
diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
index 8956995..52790f0 100644
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -842,25 +842,32 @@ int efx_filter_rfs(struct net_device *net_dev, const
struct sk_buff *skb,
struct efx_nic *efx = netdev_priv(net_dev);
struct efx_channel *channel;
struct efx_filter_spec spec;
+ /* 60 octets is the maximum length of an IPv4 header (all IPv6 headers
+ * are 40 octets), and we pull 4 more to get the port numbers
+ */
+ #define EFX_RFS_HEADER_LENGTH (sizeof(struct vlan_hdr) + 60 + 4)
+ unsigned char header[EFX_RFS_HEADER_LENGTH];
+ int headlen = min_t(int, EFX_RFS_HEADER_LENGTH, skb->len);
+ #undef EFX_RFS_HEADER_LENGTH
+ void *hptr;
const __be16 *ports;
__be16 ether_type;
int nhoff;
int rc;
- /* The core RPS/RFS code has already parsed and validated
- * VLAN, IP and transport headers. We assume they are in the
- * header area.
- */
+ hptr = skb_header_pointer(skb, 0, headlen, header);
+ if (!hptr)
+ return -EINVAL;
if (skb->protocol == htons(ETH_P_8021Q)) {
- const struct vlan_hdr *vh =
- (const struct vlan_hdr *)skb->data;
+ const struct vlan_hdr *vh = hptr;
/* We can't filter on the IP 5-tuple and the vlan
* together, so just strip the vlan header and filter
* on the IP part.
*/
- EFX_BUG_ON_PARANOID(skb_headlen(skb) < sizeof(*vh));
+ if (headlen < sizeof(*vh))
+ return -EINVAL;
ether_type = vh->h_vlan_encapsulated_proto;
nhoff = sizeof(struct vlan_hdr);
} else {
@@ -881,23 +888,23 @@ int efx_filter_rfs(struct net_device *net_dev, const
struct sk_buff *skb,
spec.ether_type = ether_type;
if (ether_type == htons(ETH_P_IP)) {
- const struct iphdr *ip =
- (const struct iphdr *)(skb->data + nhoff);
+ const struct iphdr *ip = hptr + nhoff;
- EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + sizeof(*ip));
+ if (headlen < nhoff + sizeof(*ip))
+ return -EINVAL;
if (ip_is_fragment(ip))
return -EPROTONOSUPPORT;
spec.ip_proto = ip->protocol;
spec.rem_host[0] = ip->saddr;
spec.loc_host[0] = ip->daddr;
- EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + 4 * ip->ihl + 4);
- ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
+ if (headlen < nhoff + 4 * ip->ihl + 4)
+ return -EINVAL;
+ ports = (const __be16 *)(hptr + nhoff + 4 * ip->ihl);
} else {
- const struct ipv6hdr *ip6 =
- (const struct ipv6hdr *)(skb->data + nhoff);
+ const struct ipv6hdr *ip6 = (hptr + nhoff);
- EFX_BUG_ON_PARANOID(skb_headlen(skb) <
- nhoff + sizeof(*ip6) + 4);
+ if (headlen < nhoff + sizeof(*ip6) + 4)
+ return -EINVAL;
spec.ip_proto = ip6->nexthdr;
memcpy(spec.rem_host, &ip6->saddr, sizeof(ip6->saddr));
memcpy(spec.loc_host, &ip6->daddr, sizeof(ip6->daddr));
