netfilter: conntrack: add support for DCCP handshake sequence to ctnetlink

This patch adds CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ that exposes
the u64 handshake sequence number to user-space.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

3 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/netfilter/nfnetlink_conntrack.h b/include/linux/netfilter/nfnetlink_conntrack.h
index 1a865e48b8eb..ed4ef8d0b11b 100644
--- a/include/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/linux/netfilter/nfnetlink_conntrack.h
@@ -101,6 +101,7 @@ enum ctattr_protoinfo_dccp {
         CTA_PROTOINFO_DCCP_UNSPEC,
         CTA_PROTOINFO_DCCP_STATE,
         CTA_PROTOINFO_DCCP_ROLE,
+        CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ,
         __CTA_PROTOINFO_DCCP_MAX,
 };
 #define CTA_PROTOINFO_DCCP_MAX (__CTA_PROTOINFO_DCCP_MAX - 1)
diff --git a/include/net/netlink.h b/include/net/netlink.h
index eddb50289d6d..007bdb07dabb 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -940,6 +940,15 @@ static inline u64 nla_get_u64(const struct nlattr *nla)
 }
 
 /**
+ * nla_get_be64 - return payload of __be64 attribute
+ * @nla: __be64 netlink attribute
+ */
+static inline __be64 nla_get_be64(const struct nlattr *nla)
+{
+        return *(__be64 *) nla_data(nla);
+}
+
+/**
  * nla_get_flag - return payload of flag attribute
  * @nla: flag netlink attribute
  */
diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c
index 8e757dd53396..11801c43c8cf 100644
--- a/net/netfilter/nf_conntrack_proto_dccp.c
+++ b/net/netfilter/nf_conntrack_proto_dccp.c
@@ -635,6 +635,8 @@ static int dccp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
         NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_STATE, ct->proto.dccp.state);
         NLA_PUT_U8(skb, CTA_PROTOINFO_DCCP_ROLE,
                    ct->proto.dccp.role[IP_CT_DIR_ORIGINAL]);
+        NLA_PUT_BE64(skb, CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ,
+                     cpu_to_be64(ct->proto.dccp.handshake_seq));
         nla_nest_end(skb, nest_parms);
         read_unlock_bh(&dccp_lock);
         return 0;
@@ -647,6 +649,7 @@ nla_put_failure:
 static const struct nla_policy dccp_nla_policy[CTA_PROTOINFO_DCCP_MAX + 1] = {
         [CTA_PROTOINFO_DCCP_STATE]      = { .type = NLA_U8 },
         [CTA_PROTOINFO_DCCP_ROLE]       = { .type = NLA_U8 },
+        [CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ] = { .type = NLA_U64 },
 };
 
 static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
@@ -679,6 +682,10 @@ static int nlattr_to_dccp(struct nlattr *cda[], struct nf_conn *ct)
                 ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_SERVER;
                 ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_CLIENT;
         }
+        if (tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]) {
+                ct->proto.dccp.handshake_seq =
+                be64_to_cpu(nla_get_be64(tb[CTA_PROTOINFO_DCCP_HANDSHAKE_SEQ]));
+        }
         write_unlock_bh(&dccp_lock);
         return 0;
 }