[PATCH 4.17 202/324] tipc: correct discovery message handling during address trial period

Greg Kroah-Hartman
2018-08-23T08:58:46Z

From: Jon Maloy <jon.maloy@ericsson.com>

[ Upstream commit e415577f57f4452150642500364cbe5fa6112813 ]

With the duplicate address discovery protocol for tipc nodes addresses
we introduced a one second trial period before a node is allocated a
hash number to use as address.

Unfortunately, we miss to handle the case when a regular LINK REQUEST/
RESPONSE arrives from a cluster node during the trial period. Such
messages are not ignored as they should be, leading to links setup
attempts while the node still has no address.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/tipc/discover.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -133,6 +133,8 @@ static void disc_dupl_alert(struct tipc_
}

/* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer
+ * Returns true if message should be dropped by caller, i.e., if it is a
+ * trial message or we are inside trial period. Otherwise false.
*/
static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d,
struct tipc_media_addr *maddr,
@@ -168,8 +170,9 @@ static bool tipc_disc_addr_trial_msg(str
msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
}

+ /* Accept regular link requests/responses only after trial period */
if (mtyp != DSC_TRIAL_MSG)
- return false;
+ return trial;

sugg_addr = tipc_node_try_addr(net, peer_id, src);
if (sugg_addr)