net: Discard and warn about LRO'd skbs received for forwarding
Add skb_warn_if_lro() to test whether an skb was received with LRO and
warn if so.
Change br_forward(), ip_forward() and ip6_forward() to call it) and
discard the skb if it returns true.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 299ec4b..2220b9e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1702,6 +1702,20 @@
return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
}
+extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
+
+static inline bool skb_warn_if_lro(const struct sk_buff *skb)
+{
+ /* LRO sets gso_size but not gso_type, whereas if GSO is really
+ * wanted then gso_type will be set. */
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
+ __skb_warn_lro_forwarding(skb);
+ return true;
+ }
+ return false;
+}
+
static inline void skb_forward_csum(struct sk_buff *skb)
{
/* Unfortunately we don't support this one. Any brave souls? */
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 5126457..bdd9cce 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -89,7 +89,7 @@
/* called with rcu_read_lock */
void br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
{
- if (should_deliver(to, skb)) {
+ if (!skb_warn_if_lro(skb) && should_deliver(to, skb)) {
__br_forward(to, skb);
return;
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 3e18f85..2df012b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2583,6 +2583,13 @@
return true;
}
+void __skb_warn_lro_forwarding(const struct sk_buff *skb)
+{
+ if (net_ratelimit())
+ pr_warning("%s: received packets cannot be forwarded"
+ " while LRO is enabled\n", skb->dev->name);
+}
+
EXPORT_SYMBOL(___pskb_trim);
EXPORT_SYMBOL(__kfree_skb);
EXPORT_SYMBOL(kfree_skb);
@@ -2616,6 +2623,7 @@
EXPORT_SYMBOL(skb_abort_seq_read);
EXPORT_SYMBOL(skb_find_text);
EXPORT_SYMBOL(skb_append_datato_frags);
+EXPORT_SYMBOL(__skb_warn_lro_forwarding);
EXPORT_SYMBOL_GPL(skb_to_sgvec);
EXPORT_SYMBOL_GPL(skb_cow_data);
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 37d36a3..da14725 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -56,6 +56,9 @@
struct rtable *rt; /* Route we use */
struct ip_options * opt = &(IPCB(skb)->opt);
+ if (skb_warn_if_lro(skb))
+ goto drop;
+
if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb))
goto drop;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 40a2813..fd7cd1b 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -407,6 +407,9 @@
if (ipv6_devconf.forwarding == 0)
goto error;
+ if (skb_warn_if_lro(skb))
+ goto drop;
+
if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
goto drop;