gro: Make GRO aware of lightweight tunnels.
GRO is currently not aware of tunnel metadata generated by lightweight
tunnels and stored in the dst. This leads to two possible problems:
* Incorrectly merging two frames that have different metadata.
* Leaking of allocated metadata from merged frames.
This avoids those problems by comparing the tunnel information before
merging, similar to how we handle other metadata (such as vlan tags),
and releasing any state when we are done.
Reported-by: John <john.phillips5@hpe.com>
Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: Jesse Gross <jesse@kernel.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h
index 6816f0f..30a56ab 100644
--- a/include/net/dst_metadata.h
+++ b/include/net/dst_metadata.h
@@ -44,6 +44,24 @@
return dst && !(dst->flags & DST_METADATA);
}
+static inline int skb_metadata_dst_cmp(const struct sk_buff *skb_a,
+ const struct sk_buff *skb_b)
+{
+ const struct metadata_dst *a, *b;
+
+ if (!(skb_a->_skb_refdst | skb_b->_skb_refdst))
+ return 0;
+
+ a = (const struct metadata_dst *) skb_dst(skb_a);
+ b = (const struct metadata_dst *) skb_dst(skb_b);
+
+ if (!a != !b || a->u.tun_info.options_len != b->u.tun_info.options_len)
+ return 1;
+
+ return memcmp(&a->u.tun_info, &b->u.tun_info,
+ sizeof(a->u.tun_info) + a->u.tun_info.options_len);
+}
+
struct metadata_dst *metadata_dst_alloc(u8 optslen, gfp_t flags);
struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags);
diff --git a/net/core/dev.c b/net/core/dev.c
index cc9e365..8cba3d8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4351,6 +4351,7 @@
diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
diffs |= p->vlan_tci ^ skb->vlan_tci;
+ diffs |= skb_metadata_dst_cmp(p, skb);
if (maclen == ETH_HLEN)
diffs |= compare_ether_header(skb_mac_header(p),
skb_mac_header(skb));
@@ -4548,10 +4549,12 @@
break;
case GRO_MERGED_FREE:
- if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
+ if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) {
+ skb_dst_drop(skb);
kmem_cache_free(skbuff_head_cache, skb);
- else
+ } else {
__kfree_skb(skb);
+ }
break;
case GRO_HELD: