[PATCH] tipc: set addr_trail_end when using explicit node addresses

[PATCH] tipc: set addr_trail_end when using explicit node addresses

[Chris Packham]

When tipc uses auto-generated node addresses it goes through a duplicate
address detection phase to ensure the address is unique.

When using explicitly configured node names the DAD phase is skipped.
However addr_trail_end was being left set to 0 which causes parts of the
tipc state machine to assume that the address is not yet valid and
unnecessarily delays the discovery phase. By setting addr_trail_end to
jiffies when using explicit addresses we ensure that we move straight to
discovery.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
 net/tipc/discover.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index c138d68e8a69..f83bfe8c9443 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -361,6 +361,8 @@ int tipc_disc_create(struct net *net, struct tipc_bearer *b,
 	if (!tipc_own_addr(net)) {
 		tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
 		msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
+	} else {
+		tn->addr_trial_end = jiffies;
 	}
 	memcpy(&d->dest, dest, sizeof(*dest));
 	d->net = net;
-- 
2.22.0

RE: [PATCH] tipc: set addr_trail_end when using explicit node addresses

[Jon Maloy]

You should rather set this one unconditionally in tipc_set_node_addr().
The problems is not about the state machine, but that jiffies is close to the wrap-around time, so that it is perceived as being before the time "0".

BR
///jon


> -----Original Message-----
> From: netdev-owner@vger.kernel.org <netdev-owner@vger.kernel.org> On
> Behalf Of Chris Packham
> Sent: 7-Aug-19 00:56
> To: Jon Maloy <jon.maloy@ericsson.com>; ying.xue@windriver.com;
> davem@davemloft.net
> Cc: netdev@vger.kernel.org; tipc-discussion@lists.sourceforge.net; linux-
> kernel@vger.kernel.org; Chris Packham <chris.packham@alliedtelesis.co.nz>
> Subject: [PATCH] tipc: set addr_trail_end when using explicit node addresses
> 
> When tipc uses auto-generated node addresses it goes through a duplicate
> address detection phase to ensure the address is unique.
> 
> When using explicitly configured node names the DAD phase is skipped.
> However addr_trail_end was being left set to 0 which causes parts of the tipc
> state machine to assume that the address is not yet valid and unnecessarily
> delays the discovery phase. By setting addr_trail_end to jiffies when using
> explicit addresses we ensure that we move straight to discovery.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>  net/tipc/discover.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/tipc/discover.c b/net/tipc/discover.c index
> c138d68e8a69..f83bfe8c9443 100644
> --- a/net/tipc/discover.c
> +++ b/net/tipc/discover.c
> @@ -361,6 +361,8 @@ int tipc_disc_create(struct net *net, struct
> tipc_bearer *b,
>  	if (!tipc_own_addr(net)) {
>  		tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
>  		msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
> +	} else {
> +		tn->addr_trial_end = jiffies;
>  	}
>  	memcpy(&d->dest, dest, sizeof(*dest));
>  	d->net = net;
> --
> 2.22.0