Ensure TIPC ignores an out-dated link reset message whose session
number predates the current session number. (Previously, TIPC only
ignored an out-date reset message whose session number was equal
to the current link session number.)

Out-dated link reset messages should not occur under normal circumstances;
however, they can be generated if a link endpoint is unable to send a
link reset message right away and queues it for later delivery, but the
queued message is not sent until after the link is established.

Thanks to Laser [gotolaser@gmail.com] for diagnosing the problem and
contributing a prototype patch.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Initializes the peer session number field of a newly created link
endpoint to an invalid value. This eliminates the remote possibility
that it will accidentally match the session number used by the peer
the first time the link is activated, and cause the link to ignore
a valid RESET message.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Sets the peer interface portion of the name of a newly created link
endpoint to "unknown". This ensures that state and statistics information
can be properly displayed during the time between the link endpoint's
creation and the time handshaking with its peer is completed.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Removes a test that ensures unicast link endpoints discard an incoming
message if it will not be consumed by the node itself and cannot be
forwarded to another node, since the preceding test already ensures that
the message is destined for this node and single-cluster TIPC no longer
performs message forwarding.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Eliminates code that increments and validates the re-route count field
of payload messages, since the elimination of multi-cluster support
means that it is no longer necessary for TIPC to forward incoming messages
to another node. (The obsolete code was incorrect anyway, since it
incorrectly incremented the re-route count field of messages that
originated on the node that forwarded the message.)
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simplifies the creation of connection protocol messages by eliminating
the passing of information that is no longer required, is constant,
or is contained within the port structure that is issuing the message.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the logic that creates a connection termination payload
message so that it no longer (mis)uses a routine that creates a
connection protocol message. The revised code is now more easily
understood, and avoids setting several fields that are either not
present in payload messages or were being set more than once.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Restructures the logic used in tipc_port_recv_proto_msg() to ensure
that incoming connection protocol messages are handled properly. The
routine now uses a two-stage process that first ensures the message
applies on an existing connection and then processes the request.
This corrects a loophole that allowed a connection probe request to
be processed if it was sent to an unconnected port that had no names
bound to it.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Speeds up the creation of the FIN message that terminates a TIPC
connection. The typical peer termination message is now created by
duplicating the terminating port's standard payload message header
and adjusting the message size, importance, and error code fields,
rather than building all fields of the message from scratch. A FIN
message that is directed to the port itself is created the same way.
but also requires swapping the origin and destination address fields.

In addition to reducing the work required to create FIN messages,
these changes eliminate several instances of duplicated code,
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Performs cosmetic cleanup of the symbolic names used to specify TIPC
payload message header sizes. The revised names now more accurately
reflect the payload messages in which they can appear. In addition,
several places where these payload message symbol names were being used
to create non-payload messages have been updated to use the proper
internal message symbolic name.

No functional changes are introduced by this rework.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Gets rid of code that allows tipc_msg_init() to create a short
payload message header. This optimization is possible because
there are no longer any callers who require this capability.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Eliminates a pair of #include statements for files that are brought in
automatically by including core.h.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Gets rid of counter that records the number of times a bearer has
resumed after congestion or blocking, since the value is never
referenced anywhere.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Fixes a minor error in the title of one of the message size profiling
values printed as part of TIPC's link statistics.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Gets rid of a pair of checks to see if a name sequence entry in
TIPC's name table has an empty zone list. These checks are pointless
since the zone list can never be empty (i.e. as soon as the list
becomes empty the associated name sequence entry is deleted).
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the main circular linked lists of publications used in TIPC's
name table to use the standard kernel linked list type. This change
simplifies the deletion of an existing publication by eliminating
the need to search up to three lists to locate the publication.
The use of standard list routines also helps improve the readability
of the name table code by make it clearer what each list operation
being performed is actually doing.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the name table array structure that contains the name
sequence instances for a given name type so that the publication
lists associated with a given instance are stored in a dynamically
allocated structure, rather than being embedded within the array
entry itself. This change is being done for several reasons:

1) It reduces the amount of data that needs to be copied whenever
a given array is expanded or contracted to accommodate the first
publication of a new name sequence or the removal of the last
publication of an existing name sequence.

2) It reduces the amount of memory associated with array entries that
are currently unused.

3) It facilitates the upcoming conversion of the publication lists
from TIPC-specific circular lists to standard kernel lists. (Standard
lists cannot be used with the former array structure because the
relocation of array entries during array expansion and contraction
would corrupt the lists.)

Note that, aside from introducing a small amount of code to dynamically
allocate and free the structure that now holds publication list info,
this change is largely a simple renaming exercise that replaces
references to "sseq->LIST" with "sseq->info->LIST" (or "info->LIST").
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Gets rid of unnecessary masking in two routines that set TIPC message
header fields. (The msg_set_bits() routine already takes care of
masking the new value to the correct size.)
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Gets rid of a pair of routines that provide support for temporarily
caching the destination node for a message in the associated message
buffer's application handle, since this capability is no longer used.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Optimizes the creation of a returned payload message by duplicating
the original message and then updating the small number of fields
that need to be adjusted, rather than building the new message header
from scratch. In addition, certain operations that are not always
required are relocated so that they are only done if needed.

These optimizations also have the effect of addressing other issues
that were present previously:

1) Fixes a bug that caused the socket send routines to return the
size of the returned message, rather than the size of the sent
message, when a returnable payload message was sent to a non-existent
destination port.

2) The message header of the returned message now matches that of
the original message more closely. The header is now always the same
size as the original header, and some message header fields that
weren't being initialized in the returned message header are now
populated correctly -- namely the "d" and "s" bits, and the upper
bound of a multicast name instance (where present).
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Reduces the work involved in transmitting a returned payload message
by doing only the work necessary to route such a message directly to
the specified destination port, rather than invoking the code used
to route an arbitrary message to an arbitrary destination.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Introduces an internal sanity check to ensure that the only undeliverable
messages TIPC attempts to return to their origin are application payload
messages.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the routine that handles the rejection of payload messages
so that it has a single exit point that frees up the rejected message,
thereby eliminating some duplicated code.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Eliminates a TIPC-specific assert() macro that is no longer used.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the existing broadcast link sanity check that detects an
attempt to send a message off-node when there are no available
destinations so that it no longer causes a kernel panic; instead,
the check now issues a warning and stack trace and then returns
without sending the message anywhere.
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>

Create a helper routine to enqueue a chain of sk_buffs to a link's
transmit queue.  It improves readability and the new function is
anticipated to be used more than just once in the future as well.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Rework TIPC's message sending routines to take advantage of the total
amount of data value passed to it by the kernel socket infrastructure.
This change eliminates the need for TIPC to compute the size of outgoing
messages itself, as well as the check for an oversize message in
tipc_msg_build().  In addition, this change warrants an explanation:

   -     res = send_packet(NULL, sock, &my_msg, 0);
   +     res = send_packet(NULL, sock, &my_msg, bytes_to_send);

Previously, the final argument to send_packet() was ignored (since the
amount of data being sent was recalculated by a lower-level routine)
and we could just pass in a dummy value (0). Now that the
recalculation is being eliminated, the argument value being passed to
send_packet() is significant and we have to supply the actual amount
of data we want to send.
Signed-off-by: NAllan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Adds checks to TIPC's socket send routines to promptly detect and
abort attempts to send more than 66,000 bytes in a single TIPC
message or more than 2**31-1 bytes in a single TIPC byte stream request.
In addition, this ensures that the number of iovecs in a send request
does not exceed the limits of a standard integer variable.
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>

This allows them to be available for easy re-use in other places
and avoids trivial mistakes caused by  "count the f's and 0's".
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies a TIPC send routine that did not discard the outgoing sk_buff
if it was not transmitted because of link congestion; this eliminates
the potential for buffer leakage in the many callers who did not clean up
the unsent buffer. (The two routines that previously did discard the unsent
buffer have been updated to eliminate their now-redundant clean up.)
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Sets the destination node field of an incoming multicast message
to the receiving node's network address before handing off the message
to each receiving port. This ensures that, in the event the destination
port returns the message to the sender, the sender can identify which
node the destination port belonged to.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Set the destination node and destination port fields of an outgoing
multicast message header to zero; this is necessary to ensure that
the receiving node can route the message properly if it was packed
into a bundle due to link congestion. (Previously, there was a chance
that the receiving node would send the unbundled message to a random
node & port, rather than processing the message itself.)
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Ensures that all outgoing data messages have the "name lookup scope"
field of their header set correctly; that is, named multicast messages
now specify cluster-wide name lookup, while messages not using TIPC
naming zero out the lookup field.  (Previously, the lookup scope specified
for these types of messages was inherited from the last message sent
by the sending port.)
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Modifies the routine that fragments an existing message buffer to
use similar logic to that used when generating fragments from an iovec.
The routine now creates a complete chain of fragments and adds them to
the link transmit queue as a unit, so that the link sends all fragments
or none; this prevents the incomplete transmission of a fragmented
message that might otherwise result because of link congestion or
memory exhaustion. This change also ensures that the counter recording
the number of fragmented messages sent by the link is now incremented
only if the message is actually sent.
Signed-off-by: NAllan Stephens <allan.stephens@windriver.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>