netfilter: nfnetlink_queue: add skb info attribute

Once we allow userspace to receive gso/gro packets, userspace
needs to be able to determine when checksums appear to be
broken, but are not.

NFQA_SKB_CSUMNOTREADY means 'checksums will be fixed in kernel
later, pretend they are ok'.

NFQA_SKB_GSO could be used for statistics, or to determine when
packet size exceeds mtu.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/uapi/linux/netfilter/nfnetlink_queue.h b/include/uapi/linux/netfilter/nfnetlink_queue.h
index 70ec8c2bc11a..0069da370464 100644
--- a/include/uapi/linux/netfilter/nfnetlink_queue.h
+++ b/include/uapi/linux/netfilter/nfnetlink_queue.h
@@ -45,6 +45,7 @@ enum nfqnl_attr_type {
         NFQA_CT,                        /* nf_conntrack_netlink.h */
         NFQA_CT_INFO,                   /* enum ip_conntrack_info */
         NFQA_CAP_LEN,                   /* __u32 length of captured packet */
+        NFQA_SKB_INFO,                  /* __u32 skb meta information */
 
         __NFQA_MAX
 };
@@ -98,4 +99,10 @@ enum nfqnl_attr_config {
 #define NFQA_CFG_F_CONNTRACK                    (1 << 1)
 #define NFQA_CFG_F_MAX                          (1 << 2)
 
+/* flags for NFQA_SKB_INFO */
+/* packet appears to have wrong checksums, but they are ok */
+#define NFQA_SKB_CSUMNOTREADY (1 << 0)
+/* packet is GSO (i.e., exceeds device mtu) */
+#define NFQA_SKB_GSO (1 << 1)
+
 #endif /* _NFNETLINK_QUEUE_H */