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authorLUU Duc Canh <canh.d.luu@dektech.com.au>2018-09-26 21:00:54 +0200
committerDavid S. Miller <davem@davemloft.net>2018-09-29 11:45:14 -0700
commitc140eb166d681f66bd7e99fb121357db1a503e7f (patch)
tree9eda87117d15507035fd046a9f9c3d610f0013fc /net/tipc/link.c
parent418b9a353a821f5d1787fd310d2af31232e9ff32 (diff)
downloadlinux-c140eb166d681f66bd7e99fb121357db1a503e7f.tar.bz2
tipc: fix failover problem
We see the following scenario: 1) Link endpoint B on node 1 discovers that its peer endpoint is gone. Since there is a second working link, failover procedure is started. 2) Link endpoint A on node 1 sends a FAILOVER message to peer endpoint A on node 2. The node item 1->2 goes to state FAILINGOVER. 3) Linke endpoint A/2 receives the failover, and is supposed to take down its parallell link endpoint B/2, while producing a FAILOVER message to send back to A/1. 4) However, B/2 has already been deleted, so no FAILOVER message can created. 5) Node 1->2 remains in state FAILINGOVER forever, refusing to receive any messages that can bring B/1 up again. We are left with a non- redundant link between node 1 and 2. We fix this with letting endpoint A/2 build a dummy FAILOVER message to send to back to A/1, so that the situation can be resolved. Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/link.c')
-rw-r--r--net/tipc/link.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 26cc033ee167..4ed650ce6e61 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -410,6 +410,11 @@ char *tipc_link_name(struct tipc_link *l)
return l->name;
}
+u32 tipc_link_state(struct tipc_link *l)
+{
+ return l->state;
+}
+
/**
* tipc_link_create - create a new link
* @n: pointer to associated node
@@ -1385,6 +1390,36 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
__skb_queue_tail(xmitq, skb);
}
+void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
+ struct sk_buff_head *xmitq)
+{
+ u32 onode = tipc_own_addr(l->net);
+ struct tipc_msg *hdr, *ihdr;
+ struct sk_buff_head tnlq;
+ struct sk_buff *skb;
+ u32 dnode = l->addr;
+
+ skb_queue_head_init(&tnlq);
+ skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
+ INT_H_SIZE, BASIC_H_SIZE,
+ dnode, onode, 0, 0, 0);
+ if (!skb) {
+ pr_warn("%sunable to create tunnel packet\n", link_co_err);
+ return;
+ }
+
+ hdr = buf_msg(skb);
+ msg_set_msgcnt(hdr, 1);
+ msg_set_bearer_id(hdr, l->peer_bearer_id);
+
+ ihdr = (struct tipc_msg *)msg_data(hdr);
+ tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
+ BASIC_H_SIZE, dnode);
+ msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
+ __skb_queue_tail(&tnlq, skb);
+ tipc_link_xmit(l, &tnlq, xmitq);
+}
+
/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
* with contents of the link's transmit and backlog queues.
*/