linux-toradex.git/net/tipc/discover.c, branch v3.0.95

tipc: Revise timings used when sending link request messages

2011-05-10T20:04:02+00:00

Revises the algorithm governing the sending of link request messages
to take into account the number of nodes each bearer is currently in
contact with, and to ensure more rapid rediscovery of neighboring nodes
if a bearer fails and then recovers.

The discovery object now sends requests at least once a second if it
is not in contact with any other nodes, and at least once a minute if
it has at least one neighbor; if contact with the only neighbor is
lost, the object immediately reverts to its initial rapid-fire search
timing to accelerate the rediscovery process.

In addition, the discovery object now stops issuing link request
messages if it is in contact with the only neighboring node it is
configured to communicate with, since further searching is unnecessary.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Add monitoring of number of nodes discovered by bearer

2011-05-10T20:04:01+00:00

Augments TIPC's discovery object to track the number of neighboring nodes
having an active link to the associated bearer.

This means tipc_disc_update_link_req() becomes either one of:

       tipc_disc_add_dest()
or:
       tipc_disc_remove_dest()

depending on the code flow direction of things.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Enhance sending of discovery object link request messages

2011-05-10T20:04:00+00:00

Augments TIPC's discovery object to send its initial neighbor discovery
request message as soon as the associated bearer is created, rather than
waiting for its first periodic timeout to occur, thereby speeding up the
discovery process. Also adds a check to suppress the initial request or
subsequent requests if the bearer is blocked at the time the request is
scheduled for transmission.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Enhance handling of discovery object creation failures

2011-05-10T20:03:59+00:00

Modifies bearer creation and deletion code to improve handling of
scenarios when a neighbor discovery object cannot be created. The
creation routine now aborts the creation of a bearer if its discovery
object cannot be created, and deletes the newly created bearer, rather
than failing quietly and leaving an unusable bearer hanging around.

Since the exit via the goto label really isn't a definitive failure
in all cases, relabel it appropriately.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Strengthen checks for neighboring node discovery

2011-05-10T20:03:55+00:00

Enhances existing checks on the discovery domain associated with a TIPC
bearer. A bearer can no longer be configured to accept links from itself
only (which would be pointless), or to nodes outside its own cluster
(since multi-cluster support has now been removed from TIPC). Also, the
neighbor discovery routine now validates link setup requests against the
configured discovery domain for the bearer, rather than simply ensuring
the requesting node belongs to the node's own cluster.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Don't respond to neighbor discovery request on blocked bearer

2011-03-13T20:35:19+00:00

Adds a check to prevent TIPC from trying to respond to an incoming
LINK_CONFIG request message if the associated bearer is currently
prohibited from sending messages.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Eliminate unnecessary constant for neighbor discovery msg size

2011-03-13T20:35:18+00:00

Eliminates an unnecessary constant that defines the size of a LINK_CONFIG
message, and uses one of the existing standard message size symbols in
its place. (The defunct constant was located in the wrong place anyway,
since it was grouped with other constants that define message users instead
of message sizes.)

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Optimizations to link creation code

2011-03-13T20:35:18+00:00

Enhances link creation code as follows:

1) Detects illegal attempts to add a requested link earlier in the
   link creation process. This prevents TIPC from wasting time
   initializing a link object it then throws away, and also eliminates
   the code needed to do the throwing away.

2) Passes in the node object associated with the requested link.
   This allows TIPC to eliminate a search to locate the node object,
   as well as code that attempted to create the node if it doesn't
   exist.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Give Tx of discovery responses priority over link messages

2011-03-13T20:35:18+00:00

Delay releasing the node lock when processing a neighbor discovery
message until after the optional discovery response message has been
sent. This helps ensure that any link protocol messages sent by a
link endpoint created as a result of a neighbor discovery request
are received after the discovery response is received, thereby
giving the receiving node a chance to create a peer link endpoint to
consume those link protocol messages, if one does not already exist.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker

tipc: Cosmetic changes to neighbor discovery logic

2011-03-13T20:35:18+00:00

Reworks the appearance of the routine that processes incoming
LINK_CONFIG messages to keep the main logic flow at a consistent level
of indentation, and to add comments outlining the various phases involved
in processing each message. This rework is being done to allow upcoming
enhancements to this routine to be integrated more cleanly.

The diff isn't really readable, so know that it was a case of the
old code being like:

	tipc_disc_recv_msg(..)
	{
		if (in_own_cluster(orig)) {
			...
			lines and lines of stuff
			...
		}
	}

which is now replaced with the more sane:

	tipc_disc_recv_msg(..)
	{
		if (!in_own_cluster(orig))
			return;
		...
		lines and lines of stuff
		...
	}

Instances of spin locking within the reindented block were replaced with
the identical tipc_node_[un]lock() abstractions.  Note that all these
changes are cosmetic in nature, and do not change the way LINK_CONFIG
messages are processed.

Signed-off-by: Allan Stephens 
Signed-off-by: Paul Gortmaker