1 files changed, 16 insertions, 0 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index ec4d28328652..065e9e67da5d 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -130,6 +130,8 @@ struct tipc_link {
         /* Management and link supervision data */
         u32 peer_session;
         u32 session;
+        u16 snd_nxt_state;
+        u16 rcv_nxt_state;
         u32 peer_bearer_id;
         u32 bearer_id;
         u32 tolerance;
@@ -339,6 +341,11 @@ char tipc_link_plane(struct tipc_link *l)
         return l->net_plane;
 }
 
+void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
+{
+        l->peer_caps = capabilities;
+}
+
 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
                            struct tipc_link *uc_l,
                            struct sk_buff_head *xmitq)
@@ -859,6 +866,8 @@ void tipc_link_reset(struct tipc_link *l)
         l->rcv_unacked = 0;
         l->snd_nxt = 1;
         l->rcv_nxt = 1;
+        l->snd_nxt_state = 1;
+        l->rcv_nxt_state = 1;
         l->acked = 0;
         l->silent_intv_cnt = 0;
         l->rst_cnt = 0;
@@ -1353,6 +1362,8 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
 
         if (mtyp == STATE_MSG) {
+                if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
+                        msg_set_seqno(hdr, l->snd_nxt_state++);
                 msg_set_seq_gap(hdr, rcvgap);
                 msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
                 msg_set_probe(hdr, probe);
@@ -1522,6 +1533,11 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 
         case STATE_MSG:
 
+                if (l->peer_caps & TIPC_LINK_PROTO_SEQNO &&
+                    less(msg_seqno(hdr), l->rcv_nxt_state))
+                        break;
+                l->rcv_nxt_state = msg_seqno(hdr) + 1;
+
                 /* Update own tolerance if peer indicates a non-zero value */
                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
                         l->tolerance = peers_tol;