[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>

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 2c4ecbe50082aac52e58d0c20895497be6525c00..00691b7c35f854c12500ab8fcf28f6ebf603f4b1 100644 (file)
--- 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;

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 955b87d9b46c5003fc0008767b9102f2a1527139..ba7d3f19be12e4e5964e60d7cf1ad61ad1643fd6 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1604,40 +1604,121 @@ void tipc_link_push_queue(struct link *l_ptr)
                tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 }
 
+static void link_reset_all(unsigned long addr)
+{
+       struct node *n_ptr;
+       char addr_string[16];
+       u32 i;
+
+       read_lock_bh(&tipc_net_lock);
+       n_ptr = tipc_node_find((u32)addr);
+       if (!n_ptr) {
+               read_unlock_bh(&tipc_net_lock);
+               return; /* node no longer exists */
+       }
+
+       tipc_node_lock(n_ptr);
+
+       warn("Resetting all links to %s\n", 
+            addr_string_fill(addr_string, n_ptr->addr));
+
+       for (i = 0; i < MAX_BEARERS; i++) {
+               if (n_ptr->links[i]) {
+                       link_print(n_ptr->links[i], TIPC_OUTPUT, 
+                                  "Resetting link\n");
+                       tipc_link_reset(n_ptr->links[i]);
+               }
+       }
+
+       tipc_node_unlock(n_ptr);
+       read_unlock_bh(&tipc_net_lock);
+}
+
+static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
+{
+       struct tipc_msg *msg = buf_msg(buf);
+
+       warn("Retransmission failure on link <%s>\n", l_ptr->name);
+       tipc_msg_print(TIPC_OUTPUT, msg, ">RETR-FAIL>");
+
+       if (l_ptr->addr) {
+
+               /* Handle failure on standard link */
+
+               link_print(l_ptr, TIPC_OUTPUT, "Resetting link\n");
+               tipc_link_reset(l_ptr);
+
+       } else {
+
+               /* Handle failure on broadcast link */
+
+               struct node *n_ptr;
+               char addr_string[16];
+
+               tipc_printf(TIPC_OUTPUT, "Msg seq number: %u,  ", msg_seqno(msg));
+               tipc_printf(TIPC_OUTPUT, "Outstanding acks: %u\n", (u32)TIPC_SKB_CB(buf)->handle);
+               
+               n_ptr = l_ptr->owner->next;
+               tipc_node_lock(n_ptr);
+
+               addr_string_fill(addr_string, n_ptr->addr);
+               tipc_printf(TIPC_OUTPUT, "Multicast link info for %s\n", addr_string);
+               tipc_printf(TIPC_OUTPUT, "Supported: %d,  ", n_ptr->bclink.supported);
+               tipc_printf(TIPC_OUTPUT, "Acked: %u\n", n_ptr->bclink.acked);
+               tipc_printf(TIPC_OUTPUT, "Last in: %u,  ", n_ptr->bclink.last_in);
+               tipc_printf(TIPC_OUTPUT, "Gap after: %u,  ", n_ptr->bclink.gap_after);
+               tipc_printf(TIPC_OUTPUT, "Gap to: %u\n", n_ptr->bclink.gap_to);
+               tipc_printf(TIPC_OUTPUT, "Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
+
+               tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
+
+               tipc_node_unlock(n_ptr);
+
+               l_ptr->stale_count = 0;
+       }
+}
+
 void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf, 
                          u32 retransmits)
 {
        struct tipc_msg *msg;
 
+       if (!buf)
+               return;
+
+       msg = buf_msg(buf);
+       
        dbg("Retransmitting %u in link %x\n", retransmits, l_ptr);
 
-       if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr) && buf && !skb_cloned(buf)) {
-               msg_dbg(buf_msg(buf), ">NO_RETR->BCONG>");
-               dbg_print_link(l_ptr, "   ");
-               l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
-               l_ptr->retransm_queue_size = retransmits;
-               return;
+       if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
+               if (!skb_cloned(buf)) {
+                       msg_dbg(msg, ">NO_RETR->BCONG>");
+                       dbg_print_link(l_ptr, "   ");
+                       l_ptr->retransm_queue_head = msg_seqno(msg);
+                       l_ptr->retransm_queue_size = retransmits;
+                       return;
+               } else {
+                       /* Don't retransmit if driver already has the buffer */
+               }
+       } else {
+               /* Detect repeated retransmit failures on uncongested bearer */
+
+               if (l_ptr->last_retransmitted == msg_seqno(msg)) {
+                       if (++l_ptr->stale_count > 100) {
+                               link_retransmit_failure(l_ptr, buf);
+                               return;
+                       }
+               } else {
+                       l_ptr->last_retransmitted = msg_seqno(msg);
+                       l_ptr->stale_count = 1;
+               }
        }
+
        while (retransmits && (buf != l_ptr->next_out) && buf && !skb_cloned(buf)) {
                msg = buf_msg(buf);
                msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
                msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 
                if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
-                        /* Catch if retransmissions fail repeatedly: */
-                        if (l_ptr->last_retransmitted == msg_seqno(msg)) {
-                                if (++l_ptr->stale_count > 100) {
-                                        tipc_msg_print(TIPC_CONS, buf_msg(buf), ">RETR>");
-                                        info("...Retransmitted %u times\n",
-                                            l_ptr->stale_count);
-                                        link_print(l_ptr, TIPC_CONS, "Resetting Link\n");
-                                        tipc_link_reset(l_ptr);
-                                        break;
-                                }
-                        } else {
-                                l_ptr->stale_count = 0;
-                        }
-                        l_ptr->last_retransmitted = msg_seqno(msg);
-
                        msg_dbg(buf_msg(buf), ">RETR>");
                        buf = buf->next;
                        retransmits--;
@@ -1650,6 +1731,7 @@ void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
                        return;
                }
        }
+
        l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
 }