3 files changed, 34 insertions, 12 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index f0cf768a59f3..dfc738e5cff9 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -221,6 +221,7 @@ bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
         l->mtu = mtu;
         l->priority = priority;
         tipc_link_set_queue_limits(l, window);
+        l->ackers = 1;
         l->inputq = inputq;
         l->namedq = namedq;
         l->state = LINK_RESETTING;
@@ -647,6 +648,7 @@ void tipc_link_reset(struct tipc_link *l)
         l->rcv_unacked = 0;
         l->snd_nxt = 1;
         l->rcv_nxt = 1;
+        l->acked = 0;
         l->silent_intv_cnt = 0;
         l->stats.recv_info = 0;
         l->stale_count = 0;
@@ -769,6 +771,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
                         __skb_dequeue(list);
                         __skb_queue_tail(transmq, skb);
                         __skb_queue_tail(xmitq, _skb);
+                        TIPC_SKB_CB(skb)->ackers = l->ackers;
                         l->rcv_unacked = 0;
                         seqno++;
                         continue;
@@ -829,6 +832,7 @@ void tipc_link_push_packets(struct tipc_link *link)
                 skb = __skb_dequeue(&link->backlogq);
                 if (!skb)
                         break;
+                TIPC_SKB_CB(skb)->ackers = link->ackers;
                 msg = buf_msg(skb);
                 link->backlog[msg_importance(msg)].len--;
                 msg_set_ack(msg, ack);
@@ -862,6 +866,7 @@ void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
                 l->backlog[msg_importance(hdr)].len--;
                 __skb_queue_tail(&l->transmq, skb);
                 __skb_queue_tail(xmitq, _skb);
+                TIPC_SKB_CB(skb)->ackers = l->ackers;
                 msg_set_ack(hdr, ack);
                 msg_set_seqno(hdr, seqno);
                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
@@ -947,11 +952,13 @@ void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
         }
 }
 
-static int tipc_link_retransm(struct tipc_link *l, int retransm,
-                              struct sk_buff_head *xmitq)
+int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
+                      struct sk_buff_head *xmitq)
 {
         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
         struct tipc_msg *hdr;
+        u16 ack = l->rcv_nxt - 1;
+        u16 bc_ack = l->owner->bclink.last_in;
 
         if (!skb)
                 return 0;
@@ -964,19 +971,25 @@ static int tipc_link_retransm(struct tipc_link *l, int retransm,
                 link_retransmit_failure(l, skb);
                 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
         }
+
+        /* Move forward to where retransmission should start */
         skb_queue_walk(&l->transmq, skb) {
-                if (!retransm)
-                        return 0;
+                if (!less(buf_seqno(skb), from))
+                        break;
+        }
+
+        skb_queue_walk_from(&l->transmq, skb) {
+                if (more(buf_seqno(skb), to))
+                        break;
                 hdr = buf_msg(skb);
                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
                 if (!_skb)
                         return 0;
                 hdr = buf_msg(_skb);
-                msg_set_ack(hdr, l->rcv_nxt - 1);
-                msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
+                msg_set_ack(hdr, ack);
+                msg_set_bcast_ack(hdr, bc_ack);
                 _skb->priority = TC_PRIO_CONTROL;
                 __skb_queue_tail(xmitq, _skb);
-                retransm--;
                 l->stats.retransmitted++;
         }
         return 0;
@@ -1390,7 +1403,8 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 {
         struct tipc_msg *hdr = buf_msg(skb);
         u16 rcvgap = 0;
-        u16 nacked_gap = msg_seq_gap(hdr);
+        u16 ack = msg_ack(hdr);
+        u16 gap = msg_seq_gap(hdr);
         u16 peers_snd_nxt =  msg_next_sent(hdr);
         u16 peers_tol = msg_link_tolerance(hdr);
         u16 peers_prio = msg_linkprio(hdr);
@@ -1469,11 +1483,11 @@ static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
                 if (rcvgap || (msg_probe(hdr)))
                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
                                                   0, 0, xmitq);
-                tipc_link_release_pkts(l, msg_ack(hdr));
+                tipc_link_release_pkts(l, ack);
 
                 /* If NACK, retransmit will now start at right position */
-                if (nacked_gap) {
-                        rc = tipc_link_retransm(l, nacked_gap, xmitq);
+                if (gap) {
+                        rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
                         l->stats.recv_nacks++;
                 }
 
@@ -1550,7 +1564,7 @@ static void link_reset_statistics(struct tipc_link *l_ptr)
 static void link_print(struct tipc_link *l, const char *str)
 {
         struct sk_buff *hskb = skb_peek(&l->transmq);
-        u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt;
+        u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
         u16 tail = l->snd_nxt - 1;
 
         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
diff --git a/net/tipc/link.h b/net/tipc/link.h
index 9e4e3673da76..be24d1fd5132 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -134,6 +134,8 @@ struct tipc_stats {
  * @snt_nxt: next sequence number to use for outbound messages
  * @last_retransmitted: sequence number of most recently retransmitted message
  * @stale_count: # of identical retransmit requests made by peer
+ * @ackers: # of peers that needs to ack each packet before it can be released
+ * @acked: # last packet acked by a certain peer. Used for broadcast.
  * @rcv_nxt: next sequence number to expect for inbound messages
  * @deferred_queue: deferred queue saved OOS b'cast message received from node
  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
@@ -143,6 +145,7 @@ struct tipc_stats {
  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
  * @reasm_buf: head of partially reassembled inbound message fragments
+ * @bc_rcvr: marks that this is a broadcast receiver link
  * @stats: collects statistics regarding link activity
  */
 struct tipc_link {
@@ -201,6 +204,10 @@ struct tipc_link {
         /* Fragmentation/reassembly */
         struct sk_buff *reasm_buf;
 
+        /* Broadcast */
+        u16 ackers;
+        u16 acked;
+
         /* Statistics */
         struct tipc_stats stats;
 };
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index 9f0ef54be612..799782c47f6c 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -112,6 +112,7 @@ struct tipc_skb_cb {
         bool wakeup_pending;
         u16 chain_sz;
         u16 chain_imp;
+        u16 ackers;
 };
 
 #define TIPC_SKB_CB(__skb) ((struct tipc_skb_cb *)&((__skb)->cb[0]))