Enhances TIPC to ensure that a node that loses contact with a
neighboring node does not allow contact to be re-established until
it sees that its peer has also recognized the loss of contact.

Previously, nodes that were connected by two or more links could
encounter a situation in which node A would lose contact with node B
on all of its links, purge its name table of names published by B,
and then fail to repopulate those names once contact with B was restored.
This would happen because B was able to re-establish one or more links
so quickly that it never reached a point where it had no links to A --
meaning that B never saw a loss of contact with A, and consequently
didn't re-publish its names to A.

This problem is now prevented by enhancing the cleanup done by TIPC
following a loss of contact with a neighboring node to ensure that
node A ignores all messages sent by B until it receives a LINK_PROTOCOL
message that indicates B has lost contact with A, thereby preventing
the (re)establishment of links between the nodes. The loss of contact
is recognized when a RESET or ACTIVATE message is received that has
a "redundant link exists" field of 0, indicating that B's sending link
endpoint is in a reset state and that B has no other working links.

Additionally, TIPC now suppresses the sending of (most) link protocol
messages to a neighboring node while it is cleaning up after an earlier
loss of contact with that node. This stops the peer node from prematurely
activating its link endpoint, which would prevent TIPC from later
activating its own end. TIPC still allows outgoing RESET messages to
occur during cleanup, to avoid problems if its own node recognizes
the loss of contact first and tries to notify the peer of the situation.

Finally, TIPC now recognizes an impending loss of contact with a peer node
as soon as it receives a RESET message on a working link that is the
peer's only link to the node, and ensures that the link protocol
suppression mentioned above goes into effect right away -- that is,
even before its own link endpoints have failed. This is necessary to
ensure correct operation when there are redundant links between the nodes,
since otherwise TIPC would send an ACTIVATE message upon receiving a RESET
on its first link and only begin suppressing when a RESET on its second
link was received, instead of initiating suppression with the first RESET
message as it needs to.

Note: The reworked cleanup code also eliminates a check that prevented
a link endpoint's discovery object from responding to incoming messages
while stale name table entries are being purged. This check is now
unnecessary and would have slowed down re-establishment of communication
between the nodes in some situations.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Eliminates support for the "number of requested links" field in a neighbor
discovery message. This field was never used and has been removed from
the TIPC 2.0 protocol specification.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Combines two distinct structures containing information about a TIPC bearer
into a single structure. The structures were previously kept separate so
that public information about a bearer could be made available to plug-in
media types using TIPC's native API, while the remaining information was
kept private for use by TIPC itself. However, now that the native API has
been removed there is no longer any need for this arrangement.

Since one of the structures was already embedded within the other, the
change largely involves replacing instances of "publ.foo" with "foo".
The changes do not otherwise alter the operation of TIPC bearers.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Cleans up TIPC's source code to eliminate deviations from generally
accepted coding conventions relating to leading/trailing white space
and white space around commas, braces, cases, and sizeof.

These changes are purely cosmetic and do not alter the operation of TIPC
in any way.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eliminates a number of #include statements that no longer serve any
useful purpose.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eliminates obsolete calls to two of TIPC's main debugging macros, as well
as a pair of associated debugging routines that are no longer required.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simplifies routines and data structures that were intended to allow
TIPC to support slave nodes (i.e. nodes that did not have links to
all of the other nodes in its cluster, forcing TIPC to route messages
that it could not deliver directly through a non-slave node).

Currently, TIPC supports only networks containing non-slave nodes,
so this code is unnecessary.

Note: The latest edition of the TIPC 2.0 Specification has eliminated
the concept of slave nodes entirely.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Gets rid of #include statements that are no longer required as a
result of the merging of obsolete native API header file content
into other TIPC include files.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do some cleanups of TIPC based on make namespacecheck
  1. Don't export unused symbols
  2. Eliminate dead code
  3. Make functions and variables local
  4. Rename buf_acquire to tipc_buf_acquire since it is used in several files

Compile tested only.
This make break out of tree kernel modules that depend on TIPC routines.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove all instances of legacy, or as yet to be implemented code
that is currently living within an #if 0 ... #endif block.
In the rare instance that some of it be needed in the future,
it can still be dragged out of history, but there is no need
for it to sit in mainline.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ensure that TIPC does not re-establish communication with a
neighboring node until it has finished updating all data structures
containing information about that node to reflect the earlier loss of
contact.  Previously, it was possible for TIPC to perform its purge of
name table entries relating to the node once contact had already been
re-established, resulting in the unwanted removal of valid name table
entries.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These functions have enough code in them such that they
seem like sensible targets for un-inlining.  Prior to doing
that, this adds the tipc_ prefix to the functions, so that
in the event of a panic dump or similar, the subsystem from
which the functions come from is immediately clear.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than live in link.c where they can only be used in that file alone,
these helper routines are better served by being in link.h

Relocated are the following:

	link_working_working
	link_working_unknown
	link_reset_unknown
	link_reset_reset
	link_blocked
	link_congested
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Andrew Morton reported a build failure on sparc32, because TIPC
uses names like "struct node" and there is a like named data
structure defined in linux/node.h

This just regexp replaces "struct node*" to "struct tipc_node*"
to avoid this and any future similar problems.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch defines a few new message header manipulation routines,
and generalizes the usefulness of another, in preparation for upcoming
rework of TIPC's message rejection code.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch eliminates the rarely-used "error code" argument
when initializing a TIPC message header, since the default
value of zero is the desired result in most cases; the few
exceptional cases now set the error code explicitly.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch enhances TIPC's handler for incoming messages in two
ways:
- the trivial, single-use routine for processing non-sequenced
  messages has been merged into the main handler
- the interface that received a message is now identified without
  having to access and/or modify the associated sk_buff
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch optimizes TIPC neighbor discovery code to avoid testing for
a null node pointer when the pointer is already known to be non-null.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch corrects an issue wherein a previouly failed node could
not reestablish a links to a non-failing node in the TIPC network
until the latter node detected the link failure itself (which might
be configured to take up to 30 seconds).  The non-failing node now
responds to link setup requests from a previously failed node in at
most 1 second, allowing it to detect the link failure more quickly.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPer Liden <per.liden@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TIPC now rejects and logs link setup requests from node <Z.C.N> if the
receiving node already has a functional link to that node on the associated
interface, or if the requestor is using the same <Z.C.N> as the receiver.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPer Liden <per.liden@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removing useless casts
Signed-off-by: NPanagiotis Issaris <takis@issaris.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPer Liden <per.liden@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPer Liden <per.liden@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch contains the following possible cleanups:
- make needlessly global code static
- #if 0 the following unused global functions:
  - name_table.c: tipc_nametbl_print()
  - name_table.c: tipc_nametbl_dump()
  - net.c: tipc_net_next_node()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NPer Liden <per.liden@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a tipc_ prefix to all externally visible symbols.
Signed-off-by: NPer Liden <per.liden@ericsson.com>

The copyright statements from different parts of Ericsson
have been merged into one.
Signed-off-by: NPer Liden <per.liden@nospam.ericsson.com>

The license header in each file now more clearly state that this
code is licensed under a dual BSD/GPL. Before this was only
evident if you looked at the MODULE_LICENSE line in core.c.
Signed-off-by: NPer Liden <per.liden@nospam.ericsson.com>

Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>

TIPC (Transparent Inter Process Communication) is a protocol designed for
intra cluster communication. For more information see
http://tipc.sourceforge.netSigned-off-by: NPer Liden <per.liden@nospam.ericsson.com>