linux/net/tipc/node.c, branch v4.7

tipc: reset all unicast links when broadcast send link fails

2016-07-12T05:42:12Z

In test situations with many nodes and a heavily stressed system we have observed that the transmission broadcast link may fail due to an excessive number of retransmissions of the same packet. In such situations we need to reset all unicast links to all peers, in order to reset and re-synchronize the broadcast link. In this commit, we add a new function tipc_bearer_reset_all() to be used in such situations. The function scans across all bearers and resets all their pertaining links. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: eliminate risk of double link_up events

2016-05-12T21:11:27Z

When an ACTIVATE or data packet is received in a link in state ESTABLISHING, the link does not immediately change state to ESTABLISHED, but does instead return a LINK_UP event to the caller, which will execute the state change in a different lock context. This non-atomic approach incurs a low risk that we may have two LINK_UP events pending simultaneously for the same link, resulting in the final part of the setup procedure being executed twice. The only potential harm caused by this it that we may see two LINK_UP events issued to subsribers of the topology server, something that may cause confusion. This commit eliminates this risk by checking if the link is already up before proceeding with the second half of the setup. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-05-04T04:52:29Z

Conflicts: net/ipv4/ip_gre.c Minor conflicts between tunnel bug fixes in net and ipv6 tunnel cleanups in net-next. Signed-off-by: David S. Miller

tipc: propagate peer node capabilities to socket layer

2016-05-03T19:51:15Z

During neighbor discovery, nodes advertise their capabilities as a bit map in a dedicated 16-bit field in the discovery message header. This bit map has so far only be stored in the node structure on the peer nodes, but we now see the need to keep a copy even in the socket structure. This commit adds this functionality. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: only process unicast on intended node

2016-05-02T01:03:30Z

We have observed complete lock up of broadcast-link transmission due to unacknowledged packets never being removed from the 'transmq' queue. This is traced to nodes having their ack field set beyond the sequence number of packets that have actually been transmitted to them. Consider an example where node 1 has sent 10 packets to node 2 on a link and node 3 has sent 20 packets to node 2 on another link. We see examples of an ack from node 2 destined for node 3 being treated as an ack from node 2 at node 1. This leads to the ack on the node 1 to node 2 link being increased to 20 even though we have only sent 10 packets. When node 1 does get around to sending further packets, none of the packets with sequence numbers less than 21 are actually removed from the transmq. To resolve this we reinstate some code lost in commit d999297c3dbb ("tipc: reduce locking scope during packet reception") which ensures that only messages destined for the receiving node are processed by that node. This prevents the sequence numbers from getting out of sync and resolves the packet leakage, thereby resolving the broadcast-link transmission lock-ups we observed. While we are aware that this change only patches over a root problem that we still haven't identified, this is a sanity test that it is always legitimate to do. It will remain in the code even after we identify and fix the real problem. Reviewed-by: Chris Packham Reviewed-by: John Thompson Signed-off-by: Hamish Martin Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: set 'active' state correctly for first established link

2016-05-01T23:40:22Z

When we are displaying statistics for the first link established between two peers, it will always be presented as STANDBY although it in reality is ACTIVE. This happens because we forget to set the 'active' flag in the link instance at the moment it is established. Although this is a bug, it only has impact on the presentation view of the link, not on its actual functionality. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: let first message on link be a state message

2016-04-15T20:09:06Z

According to the link FSM, a received traffic packet can take a link from state ESTABLISHING to ESTABLISHED, but the link can still not be fully set up in one atomic operation. This means that even if the the very first packet on the link is a traffic packet with sequence number 1 (one), it has to be dropped and retransmitted. This can be avoided if we let the mentioned packet be preceded by a LINK_PROTOCOL/STATE message, which takes up the endpoint before the arrival of the traffic. We add this small feature in this commit. This is a fully compatible change. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: ensure that first packets on link are sent in order

2016-04-15T20:09:06Z

In some link establishment scenarios we see that packet #2 may be sent out before packet #1, forcing the receiver to demand retransmission of the missing packet. This is harmless, but may cause confusion among people tracing the packet flow. Since this is extremely easy to fix, we do so by adding en extra send call to the bearer immediately after the link has come up. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: move netlink policies to netlink.c

2016-03-07T19:56:41Z

Make the c files less cluttered and enable netlink attributes to be shared between files. Signed-off-by: Richard Alpe Reviewed-by: Jon Maloy Acked-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: don't check link reset on non existing link

2016-03-07T03:54:56Z

Make sure we have a link before checking if it has been reset or not. Prior to this patch tipc_link_is_reset() could be called with a non existing link, resulting in a null pointer dereference. Signed-off-by: Richard Alpe Acked-by: Jon Maloy Reviewed-by: Erik Hugne Signed-off-by: David S. Miller