[TIPC]: Multicast link failure now resets all links to "nacking" node.

This fix prevents node from crashing.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 7 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 2c4ecbe50082..00691b7c35f8 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -49,13 +49,19 @@
 #include "name_table.h"
 #include "bcast.h"
 
-
 #define MAX_PKT_DEFAULT_MCAST 1500      /* bcast link max packet size (fixed) */
 
 #define BCLINK_WIN_DEFAULT 20           /* bcast link window size (default) */
 
 #define BCLINK_LOG_BUF_SIZE 0
 
+/*
+ * Loss rate for incoming broadcast frames; used to test retransmission code.
+ * Set to N to cause every N'th frame to be discarded; 0 => don't discard any.
+ */
+ 
+#define TIPC_BCAST_LOSS_RATE 0
+
 /**
  * struct bcbearer_pair - a pair of bearers used by broadcast link
  * @primary: pointer to primary bearer
@@ -165,21 +171,18 @@ static int bclink_ack_allowed(u32 n)
  * @after: sequence number of last packet to *not* retransmit
  * @to: sequence number of last packet to retransmit
  * 
- * Called with 'node' locked, bc_lock unlocked
+ * Called with bc_lock locked
  */
 
 static void bclink_retransmit_pkt(u32 after, u32 to)
 {
         struct sk_buff *buf;
 
-        spin_lock_bh(&bc_lock);
         buf = bcl->first_out;
         while (buf && less_eq(buf_seqno(buf), after)) {
                 buf = buf->next;                
         }
-        if (buf != NULL)
-                tipc_link_retransmit(bcl, buf, mod(to - after));
-        spin_unlock_bh(&bc_lock);              
+        tipc_link_retransmit(bcl, buf, mod(to - after));
 }
 
 /** 
@@ -399,7 +402,10 @@ int tipc_bclink_send_msg(struct sk_buff *buf)
  */
 
 void tipc_bclink_recv_pkt(struct sk_buff *buf)
-{        
+{
+#if (TIPC_BCAST_LOSS_RATE)
+        static int rx_count = 0;
+#endif
         struct tipc_msg *msg = buf_msg(buf);
         struct node* node = tipc_node_find(msg_prevnode(msg));
         u32 next_in;
@@ -420,9 +426,13 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
                         tipc_node_lock(node);
                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
                         tipc_node_unlock(node);
+                        spin_lock_bh(&bc_lock);
                         bcl->stats.recv_nacks++;
+                        bcl->owner->next = node;   /* remember requestor */
                         bclink_retransmit_pkt(msg_bcgap_after(msg),
                                               msg_bcgap_to(msg));
+                        bcl->owner->next = NULL;
+                        spin_unlock_bh(&bc_lock);              
                 } else {
                         tipc_bclink_peek_nack(msg_destnode(msg),
                                               msg_bcast_tag(msg),
@@ -433,6 +443,14 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf)
                 return;
         }
 
+#if (TIPC_BCAST_LOSS_RATE)
+        if (++rx_count == TIPC_BCAST_LOSS_RATE) {
+                rx_count = 0;
+                buf_discard(buf);
+                return;
+        }
+#endif
+
         tipc_node_lock(node);
 receive:
         deferred = node->bclink.deferred_head;