1 files changed, 51 insertions, 13 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2c6e1b9e024b..136316fb37ec 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -367,6 +367,18 @@ int tipc_link_bc_peers(struct tipc_link *l)
         return l->ackers;
 }
 
+u16 link_bc_rcv_gap(struct tipc_link *l)
+{
+        struct sk_buff *skb = skb_peek(&l->deferdq);
+        u16 gap = 0;
+
+        if (more(l->snd_nxt, l->rcv_nxt))
+                gap = l->snd_nxt - l->rcv_nxt;
+        if (skb)
+                gap = buf_seqno(skb) - l->rcv_nxt;
+        return gap;
+}
+
 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 {
         l->mtu = mtu;
@@ -1135,7 +1147,10 @@ int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
                 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
                         return 0;
                 l->rcv_unacked = 0;
-                return TIPC_LINK_SND_BC_ACK;
+
+                /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
+                l->snd_nxt = l->rcv_nxt;
+                return TIPC_LINK_SND_STATE;
         }
 
         /* Unicast ACK */
@@ -1236,7 +1251,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                         rc |= tipc_link_input(l, skb, l->inputq);
                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
                         rc |= tipc_link_build_state_msg(l, xmitq);
-                if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
+                if (unlikely(rc & ~TIPC_LINK_SND_STATE))
                         break;
         } while ((skb = __skb_dequeue(defq)));
 
@@ -1250,10 +1265,11 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                       u16 rcvgap, int tolerance, int priority,
                                       struct sk_buff_head *xmitq)
 {
+        struct tipc_link *bcl = l->bc_rcvlink;
         struct sk_buff *skb;
         struct tipc_msg *hdr;
         struct sk_buff_head *dfq = &l->deferdq;
-        bool node_up = link_is_up(l->bc_rcvlink);
+        bool node_up = link_is_up(bcl);
         struct tipc_mon_state *mstate = &l->mon_state;
         int dlen = 0;
         void *data;
@@ -1281,7 +1297,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
         msg_set_net_plane(hdr, l->net_plane);
         msg_set_next_sent(hdr, l->snd_nxt);
         msg_set_ack(hdr, l->rcv_nxt - 1);
-        msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
+        msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
         msg_set_link_tolerance(hdr, tolerance);
         msg_set_linkprio(hdr, priority);
@@ -1291,6 +1307,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 
         if (mtyp == STATE_MSG) {
                 msg_set_seq_gap(hdr, rcvgap);
+                msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
                 msg_set_probe(hdr, probe);
                 tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
                 msg_set_size(hdr, INT_H_SIZE + dlen);
@@ -1575,49 +1592,68 @@ void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
 
 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
  */
-void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
-                           struct sk_buff_head *xmitq)
+int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
+                          struct sk_buff_head *xmitq)
 {
         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
+        u16 from = msg_bcast_ack(hdr) + 1;
+        u16 to = from + msg_bc_gap(hdr) - 1;
+        int rc = 0;
 
         if (!link_is_up(l))
-                return;
+                return rc;
 
         if (!msg_peer_node_is_up(hdr))
-                return;
+                return rc;
 
         /* Open when peer ackowledges our bcast init msg (pkt #1) */
         if (msg_ack(hdr))
                 l->bc_peer_is_up = true;
 
         if (!l->bc_peer_is_up)
-                return;
+                return rc;
 
         /* Ignore if peers_snd_nxt goes beyond receive window */
         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
-                return;
+                return rc;
+
+        if (!less(to, from)) {
+                rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
+                l->stats.recv_nacks++;
+        }
+
+        l->snd_nxt = peers_snd_nxt;
+        if (link_bc_rcv_gap(l))
+                rc |= TIPC_LINK_SND_STATE;
+
+        /* Return now if sender supports nack via STATE messages */
+        if (l->peer_caps & TIPC_BCAST_STATE_NACK)
+                return rc;
+
+        /* Otherwise, be backwards compatible */
 
         if (!more(peers_snd_nxt, l->rcv_nxt)) {
                 l->nack_state = BC_NACK_SND_CONDITIONAL;
-                return;
+                return 0;
         }
 
         /* Don't NACK if one was recently sent or peeked */
         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
-                return;
+                return 0;
         }
 
         /* Conditionally delay NACK sending until next synch rcv */
         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
-                        return;
+                        return 0;
         }
 
         /* Send NACK now but suppress next one */
         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
         l->nack_state = BC_NACK_SND_SUPPRESS;
+        return 0;
 }
 
 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
@@ -1654,6 +1690,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
 }
 
 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
+ * This function is here for backwards compatibility, since
+ * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
  */
 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
                           struct sk_buff_head *xmitq)