Граф коммитов

499 Коммитов

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Paul Gortmaker 872f24dbc6 tipc: remove inline instances from C source files.
Untie gcc's hands and let it do what it wants within the
individual source files.  There are two files, node.c and
port.c -- only the latter effectively changes (gcc-4.5.2).
Objdump shows gcc deciding to not inline port_peernode().

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-24 00:41:03 -04:00
Eric Dumazet f545a38f74 net: add a limit parameter to sk_add_backlog()
sk_add_backlog() & sk_rcvqueues_full() hard coded sk_rcvbuf as the
memory limit. We need to make this limit a parameter for TCP use.

No functional change expected in this patch, all callers still using the
old sk_rcvbuf limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-23 22:28:28 -04:00
Allan Stephens 9d52ce4bd3 tipc: Ensure network address change doesn't impact configuration service
Enhances command validation done by TIPC's configuration service so
that it works properly even if the node's network address is changed in
mid-operation. The default node address of <0.0.0> is now recognized as an
alias for "this node" even after a new network address has been assigned.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:50 -04:00
Allan Stephens 630d920dca tipc: Ensure network address change doesn't impact rejected message
Revises handling of a rejected message to ensure that a locally
originated message is returned properly even if the node's network
address is changed in mid-operation. The routine now treats the
default node address of <0.0.0> as an alias for "this node" when
determining where to send a returned message.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:49 -04:00
Allan Stephens 8a55fe74b1 tipc: handle <0.0.0> as an alias for this node on outgoing msgs
Revises handling of send routines for payload messages to ensure that
they are processed properly even if the node's network address is
changed in mid-operation. The routines now treat the default node
address of <0.0.0> as an alias for "this node" when determining where
to send an outgoing message.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:48 -04:00
Allan Stephens b8f683d126 tipc: properly handle off-node send requests with invalid addr
There are two send routines that might conceivably be asked by an
application to send a message off-node when the node is still using
the default network address.  These now have an added check that
detects this and rejects the message gracefully.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:47 -04:00
Allan Stephens 974a5a864b tipc: take lock while updating node network address
The routine that changes the node's network address now takes TIPC's
network lock in write mode while the main address variable and associated
data structures are being changed; this is needed to ensure that the
link subsystem won't attempt to send a message off-node until the sending
port's message header template has been updated with the node's new
network address.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:46 -04:00
Allan Stephens f0712e86b7 tipc: Ensure network address change doesn't impact local connections
Revises routines that deal with connections between two ports on
the same node to ensure the connection is not impacted if the node's
network address is changed in mid-operation. The routines now treat
the default node address of <0.0.0> as an alias for "this node" in
the following situations:

1) Incoming messages destined to a connected port now handle the alias
properly when validating that the message was sent by the expected
peer port, ensuring that the message will be accepted regardless of
whether it specifies the node's old network address or it's current one.

2) The code which completes connection establishment now handles the
alias properly when determining if the peer port is on the same node
as the connected port.

An added benefit of addressing issue 1) is that some peer port
validation code has been relocated to TIPC's socket subsystem, which
means that validation is no longer done twice when a message is
sent to a non-socket port (such as TIPC's configuration service or
network topology service).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:45 -04:00
Allan Stephens d0e17fedc2 tipc: delete duplicate peerport/peernode helper functions
Prior to commit 23dd4cce38

    "tipc: Combine port structure with tipc_port structure"

there was a need for the two sets of helper functions.  But
now they are just duplicates.  Remove the globally visible
ones, and mark the remaining ones as inline.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:43 -04:00
Allan Stephens f21536d1e7 tipc: Ensure network address change doesn't impact new port
Re-orders port creation logic so that the initialization of a new
port's message header template occurs while the port list lock is
held. This ensures that a change to the node's network address that
occurs at the same time as the port is being created does not result
in the template identifying the sender using the former network
address. The new approach guarantees that the new port's template is
using the current network address or that it will be updated when
the address changes.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:42 -04:00
Allan Stephens 5eb0a291fb tipc: Optimize re-initialization of port message header templates
Removes an unnecessary check in the logic that updates the message
header template for existing ports when a node's network address is
first assigned. There is no longer any need to check to see if the
node's network address has actually changed since the calling routine
has already verified that this is so.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:41 -04:00
Allan Stephens d4f5c12cdf tipc: Ensure network address change doesn't impact name table updates
Revises routines that add and remove an entry from a node's name table
so that the publication scope lists are updated properly even if the
node's network address is changed in mid-operation. The routines now
recognize the default node address of <0.0.0> as an alias for "this node"
even after a new network address has been assigned.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:40 -04:00
Allan Stephens 336ebf5bf5 tipc: Add routines for safe checking of node's network address
Introduces routines that test whether a given network address is
equal to a node's own network address or if it lies within the node's
own network cluster, and which work properly regardless of whether
the node is using the default network address <0.0.0> or a non-zero
network address that is assigned later on. In essence, these routines
ensure that address <0.0.0> is treated as an alias for "this node",
regardless of which network address the node is actually using.

Old users of the pre-existing more strict match in_own_cluster()
have been accordingly redirected to what is now called
in_own_cluster_exact() --- which does not extend matching to <0,0,0>.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:39 -04:00
Allan Stephens fd6eced8a4 tipc: Don't record failed publication attempt as a success
No longer increments counter of number of publications by a node
if an attempt to add a new publication fails. This prevents TIPC from
incorrectly blocking future publications because the configured maximum
number of publications has been reached.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:37 -04:00
Allan Stephens 1110b8d33a tipc: Update node-scope publications when network address is assigned
Ensures that node-scope name publications that exist prior to the
configuration of a node's network address are properly re-initialized
with that address when it is assigned. TIPC's node-scope publications
are now tracked using a publications list like the lists used for
cluster-scope and zone-scope publications so they can be easily updated
when required.

The inclusion of node scope name publications in a conventional publication
list means that they must now also be withdrawn, just like cluster and zone
scope publications are currently withdrawn.  So some conditional tests on
scope ==/!= TIPC_NODE_SCOPE are inserted/removed accordingly.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:36 -04:00
Allan Stephens a909804f7c tipc: Separate cluster-scope and zone-scope names into distinct lists
Utilizes distinct lists to track zone-scope and cluster-scope names
published by a node. For now, TIPC continues to process the entries
in both lists in the same way; however, an upcoming patch will utilize
the existence of the lists to prevent the sending of cluster-scope names
to nodes that are not part of the local cluster.

To achieve this, an array of publication lists is introduced, so
that they can be iterated over and accessed via publ->scope as
an index where convenient.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:05 -04:00
Allan Stephens e11aa05971 tipc: Factor out name publication code to a separate function
This is done so that it can be reused with differing publication
lists, instead of being hard coded to the cluster publicaton list.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-18 09:36:02 -04:00
Allan Stephens 3f8375fee3 tipc: introduce publication lists struct
There is currently a single list that is containing both cluster-scope and
zone-scope publications, and the list count is a separate free floating
variable.  Create a struct to bind the count to the list, and to pave
the way for factoring out the publications into zone/cluster/node scope.

The current "publ_root" most matches what will be the cluster scope
list, so it is named accordingly in this commit.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-18 09:36:02 -04:00
Eric Dumazet 95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
Allan Stephens 9bbbc59dbd tipc: Optimize setting of immutable payload message header fields
Optimizes routines that send payload messages so that they no longer
update the "originating node" and "originating port" fields of the
outgoing message header template, since these fields are initialized
when the sending port is created and never change thereafter. Also
optimizes the routine which updates the message header template when
a connection to a port is established, for the same reason.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-29 11:45:35 -05:00
Allan Stephens e8ec1ae756 tipc: Eliminate obsolete code for re-sending a message
Removes code that updated the "previous node" field of an out-going
message over TIPC's links. Such updating is unnecessary since the
removal of the prototype multi-cluster capability means that all
outgoing messages are generated locally and already have this field
populated correctly.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-29 11:45:01 -05:00
Allan Stephens 9b641251ae tipc: Un-inline port routine for processing incoming messages
Converts a non-trivial routine from inline to non-inline form
to avoid bloating the TIPC code base with 6 copies of its body.

This change is essentially cosmetic, and doesn't change existing
TIPC behavior.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-29 11:44:32 -05:00
Allan Stephens b58343f9ea tipc: Eliminate support for tipc_mode global variable
Removes all references to the global variable that records whether
TIPC is running in "single node" mode or "network" mode, since this
information can be easily deduced from the global variable that
records TIPC's network address. (i.e. a non-zero network address
means that TIPC is running in network mode.)

The changes made update most existing mode-based checks to use the
network address global variable. A few checks that are no longer
needed are removed entirely, along with any associated code lying on
non-executable control paths.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:17 -05:00
Allan Stephens 077a26f029 tipc: Eliminate obsolete support for "not running" mode
Removes all references to TIPC's "not running" mode, since the
removal of support for the native API means that there is no longer
any way to interact with TIPC if it has not been initialized.

The changes made consist of removing mode-based checks that are no
longer needed, along with any associated code lying on non-executable
control paths.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:17 -05:00
Allan Stephens bc9f8143ec tipc: Revert name table translation optimization
Restores name table translation using a non-zero domain that is
"out of scope", which was broken by an earlier commit
(5d9c54c1e9). Comments have now been
added to the name table translation routine to make it clear that
there are actually three possible outcomes to a translation request
(found/not found/deferred), rather than just two (found/not found).

Note that a straightforward revert of the earlier commit is not
possible, as other changes to the name table translation logic
have occurred since the incorrect optimization was made.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:17 -05:00
Allan Stephens 75aba9af24 tipc: Minor optimization to broadcast link synchronization logic
Optimizes processing done when contact with a neighboring node is
established to avoid recording the current state of outgoing broadcast
messages if the neighboring node isn't a valid broadcast link destination,
since this state information isn't needed for such nodes.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:16 -05:00
Allan Stephens 1cc35df847 tipc: Remove obsolete comments about routing table updates
Eliminates a block of comments that describe how routing table updates
are to be handled. These comments no longer apply following the removal
of TIPC's prototype multi-cluster support.

Note that these changes are essentially cosmetic in nature, and have
no impact on the actual operation of TIPC.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:16 -05:00
Allan Stephens 5f6d9123f1 tipc: Eliminate trivial buffer manipulation helper routines
Gets rid of two inlined routines that simply call existing sk_buff
manipulation routines, since there is no longer any extra processing
done by the helper routines.

Note that these changes are essentially cosmetic in nature, and have
no impact on the actual operation of TIPC.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:16 -05:00
Allan Stephens a635b46bd8 tipc: Hide internal details of node table implementation
Relocates information about the size of TIPC's node table index and
its associated hash function, since only node subsystem routines need
to have access to this information.

Note that these changes are essentially cosmetic in nature, and have
no impact on the actual operation of TIPC.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:15 -05:00
Allan Stephens 9efde4a0bd tipc: Eliminate a test for negative unsigned quantities
Simplifies a comparison operation to eliminate a useless test that
checks if an unsigned value is less than zero.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:15 -05:00
Paul Gortmaker 732efba4d7 tipc: nuke the delimit static inline function.
This "shortform" is actually longer than typing out what it is really
trying to do, and just makes reading the code more difficult, so
lets simply shoot it in the head.

In the case of log.c - the comparison is on a u32, so we can drop the
check for < 0 at the same time.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:14 -05:00
Allan Stephens f80c24d996 tipc: Add check to prevent insertion of duplicate name table entries
Adds a new check to TIPC's name table logic to reject any attempt to
create a new name publication that is identical to an existing one.
(Such an attempt will never happen under normal circumstances, but
could arise if another network node malfunctions and issues a duplicate
name publication message.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:14 -05:00
Allan Stephens c422f1bdc3 tipc: Simplify enforcement of reserved name type prohibition
Streamlines the logic that prevents an application from binding a
reserved TIPC name type to a port by moving the check to the code
that handles a socket bind() operation. This allows internal TIPC
subsystems to bind a reserved name without having to set an atomic
flag to gain permission to use such a name. (This simplification is
now possible due to the elimination of support for TIPC's native API.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:14 -05:00
Allan Stephens c74a46110f tipc: Remove duplicate check of message destination node
Eliminates a check in the processing of TIPC messages arriving from
off node that ensures the message is destined for this node, since this
check duplicates an earlier check. (The check would be necessary if TIPC
needed to be able to route incoming messages to another node, but the
elimination of multi-cluster support means that this never happens and
all incoming messages are consumed by the receiving node.)

Note: This change involves the elimination of a single "if" statement
with a large "then" clause; consequently, a significant number of lines
end up getting re-indented. In addition, a simple message header access
routine that is no longer referenced is eliminated. However, the only
functional change is the elimination of the single check described above.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:14 -05:00
Allan Stephens 97878a405c tipc: Detect duplicate nodes using different network interfaces
Utilizes the new "node signature" field in neighbor discovery messages
to ensure that all links TIPC associates with a given <Z.C.N> network
address belong to the same neighboring node. (Previously, TIPC could not
tell if link setup requests arriving on different interfaces were from
the same node or from two different nodes that has mistakenly been assigned
the same network address.)

The revised algorithm for detecting a duplicate node considers both the
node signature and the network interface adddress specified in a request
message when deciding how to respond to a link setup request. This prevents
false alarms that might otherwise arise during normal network operation
under the following scenarios:

a) A neighboring node reboots. (The node's signature changes, but the
network interface address remains unchanged.)

b) A neighboring node's network interface is replaced. (The node's signature
remains unchanged, but the network interface address changes.)

c) A neighboring node is completely replaced. (The node's signature and
network interface address both change.)

The algorithm also handles cases in which a node reboots and re-establishes
its links to TIPC (or begins re-establishing those links) before TIPC
detects that it is using a new node signature. In such cases of "delayed
rediscovery" TIPC simply accepts the new signature without disrupting
communication that is already underway over the links.

Thanks to Laser [gotolaser@gmail.com] for his contributions to the
development of this enhancement.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:13 -05:00
Allan Stephens fc0eea691a tipc: Introduce node signature field in neighbor discovery message
Adds support for the new "node signature" in neighbor discovery messages,
which is a 16 bit identifier chosen randomly when TIPC is initialized.
This field makes it possible for nodes receiving a neighbor discovery
message to detect if multiple neighboring nodes are using the same network
address (i.e. <Z.C.N>), even when the messages are arriving on different
interfaces.

This first phase of node signature support creates the signature,
incorporates it into outgoing neighbor discovery messages, and tracks
the signature used by valid neighbors. An upcoming patch builds on this
foundation to implement the improved duplicate neighbor detection checking.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24 17:05:13 -05:00
Allan Stephens dff10e9e63 tipc: Minor optimization to rejection of connection-based messages
Modifies message rejection logic so that TIPC doesn't attempt to
send a FIN message to the rejecting port if it is known in advance
that there is no such message because the rejecting port doesn't exist.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:19 -05:00
Allan Stephens 3175bd9add tipc: Eliminate alteration of publication key during name table purging
Removes code that alters the publication key of a name table entry
that is being forcibly purged from TIPC's name table after contact
with the publishing node has been lost.

Current TIPC ensures that all defunct names are purged before
re-establishing contact with a failed node.  There used to be a risk
that the publication might be accidentally deleted because it might be
re-added to the name table before the purge operation was completed.
But now there is no longer a need to ensure that the new key is different
than the old one.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:19 -05:00
Allan Stephens 63e7f1ac28 tipc: Prevent loss of fragmented messages over broadcast link
Modifies broadcast link so that an incoming fragmented message is not
lost if reassembly cannot begin because there currently is no buffer
big enough to hold the entire reassembled message. The broadcast link
now ignores the first fragment completely, which causes the sending node
to retransmit the first fragment so that reassembly can be re-attempted.

Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.

To do this cleanly without duplicaton, a new bclink_accept_pkt()
function is introduced.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:19 -05:00
Allan Stephens b76b27cad5 tipc: Prevent loss of fragmented messages over unicast links
Modifies unicast link endpoint logic so an incoming fragmented message
is not lost if reassembly cannot begin because there is no buffer big
enough to hold the entire reassembled message. The link endpoint now
ignores the first fragment completely, which causes the sending node to
retransmit the first fragment so that reassembly can be re-attempted.

Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
2012-02-06 16:59:19 -05:00
Allan Stephens 1ec2bb0840 tipc: Remove obsolete broadcast tag capability
Eliminates support for the broadcast tag field, which is no longer
used by broadcast link NACK messages.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:18 -05:00
Allan Stephens 7a54d4a99d tipc: Major redesign of broadcast link ACK/NACK algorithms
Completely redesigns broadcast link ACK and NACK mechanisms to prevent
spurious retransmit requests in dual LAN networks, and to prevent the
broadcast link from stalling due to the failure of a receiving node to
acknowledge receiving a broadcast message or request its retransmission.

Note: These changes only impact the timing of when ACK and NACK messages
are sent, and not the basic broadcast link protocol itself, so inter-
operability with nodes using the "classic" algorithms is maintained.

The revised algorithms are as follows:

1) An explicit ACK message is still sent after receiving 16 in-sequence
messages, and implicit ACK information continues to be carried in other
unicast link message headers (including link state messages).  However,
the timing of explicit ACKs is now based on the receiving node's absolute
network address rather than its relative network address to ensure that
the failure of another node does not delay the ACK beyond its 16 message
target.

2) A NACK message is now typically sent only when a message gap persists
for two consecutive incoming link state messages; this ensures that a
suspected gap is not confirmed until both LANs in a dual LAN network have
had an opportunity to deliver the message, thereby preventing spurious NACKs.
A NACK message can also be generated by the arrival of a single link state
message, if the deferred queue is so big that the current message gap
cannot be the result of "normal" mis-ordering due to the use of dual LANs
(or one LAN using a bonded interface). Since link state messages typically
arrive at different nodes at different times the problem of multiple nodes
issuing identical NACKs simultaneously is inherently avoided.

3) Nodes continue to "peek" at NACK messages sent by other nodes. If
another node requests retransmission of a message gap suspected (but not
yet confirmed) by the peeking node, the peeking node forgets about the
gap and does not generate a duplicate retransmit request. (If the peeking
node subsequently fails to receive the lost message, later link state
messages will cause it to rediscover and confirm the gap and send another
NACK.)

4) Message gap "equality" is now determined by the start of the gap only.
This is sufficient to deal with the most common cases of message loss,
and eliminates the need for complex end of gap computations.

5) A peeking node no longer tries to determine whether it should send a
complementary NACK, since the most common cases of message loss don't
require it to be sent. Consequently, the node no longer examines the
"broadcast tag" field of a NACK message when peeking.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:18 -05:00
Allan Stephens b98158e3b3 tipc: Add missing locks in broadcast link statistics accumulation
Ensures that all attempts to update broadcast link statistics are done
only while holding the lock that protects the link's main data structures,
to prevent interference by simultaneous updates caused by messages
arriving on other interfaces.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:18 -05:00
Allan Stephens 0232c5a566 tipc: Fix bug in broadcast link duplicate message statistics
Modifies broadcast link so that it increments the "received duplicate
message" count if an incoming message cannot be added to the deferred
message queue because it is already present in the queue. (The aligns
broadcast link behavior with that of TIPC's unicast links.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:17 -05:00
Allan Stephens 8a275a6a30 tipc: Fix node lock reclamation issues in broadcast link reception
Fixes a pair of problems in broadcast link message reception code
relating to the reclamation of the node lock after consuming an
in-sequence message.

1) Now retests to see if the sending node is still up after reclaiming
   the node lock, and bails out if it is non-operational.

2) Now manipulates the node's deferred message queue only after
   reclaiming the node lock, rather than using queue head pointer
   information that was cached previously.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:17 -05:00
Allan Stephens 57732560d1 tipc: Add missing broadcast link lock when sending NACK
Ensures that any attempt to send a NACK message over TIPC's broadcast
link has exclusive access to the link's main data structures, to prevent
interference with a simultaneous attempt to send other broadcast link
traffic (such as application-generated multicast messages).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:17 -05:00
Allan Stephens 47361c87c5 tipc: Fix problem with broadcast link synchronization between nodes
Corrects a problem in which a link endpoint that activates as the
result of receiving a RESET/STATE sequence of link protocol messages
fails to properly record the broadcast link status information about
the node to which it is now communicating with. (The problem does
not occur with the more common RESET/ACTIVATE sequence of messages.)
The fix ensures that the broadcast link status info is updated after
the RESET message resets the link endpoint, rather than before, thereby
preventing new information from being overwritten by the reset operation.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:16 -05:00
Allan Stephens 9349931371 tipc: Ensure broadcast link re-acquires node after link failure
Fix a bug that can prevent TIPC from sending broadcast messages to a node
if contact with the node is lost and then regained. The problem occurs if
the broadcast link first clears the flag indicating the node is part of the
link's distribution set (when it loses contact with the node), and later
fails to restore the flag (when contact is regained); restoration fails
if contact with the node is regained by implicit unicast link activation
triggered by the arrival of a data message, rather than explicitly by the
arrival of a link activation message.

The broadcast link now uses separate fields to track whether a node is
theoretically capable of receiving broadcast messages versus whether it is
actually part of the link's distribution set. The former member is updated
by the receipt of link protocol messages, which can occur at any time; the
latter member is updated only when contact with the node is gained or lost.
This change also permits the simplification of several conditional
expressions since the broadcast link's "supported" field can now only be
set if there are working links to the associated node.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:16 -05:00
Allan Stephens 4d75313ce9 tipc: Prevent broadcast link stalling in dual LAN environments
Ensure that sequence number information about incoming broadcast link
messages is initialized only by the activation of the first link to a
given cluster node.  Previously, a race condition allowed reset and/or
activation messages for a second link to re-initialize this sequence
number information with obsolete values. This could trigger TIPC to
request the retransmission of previously acknowledged broadcast link
messages from that node, resulting in broadcast link processing becoming
stalled if the node had already released one or more of those messages
and was unable to perform the required retransmission.

Thanks to Laser <gotolaser@gmail.com> for identifying this problem
and assisting in the development of this fix.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:16 -05:00
Allan Stephens 92d2c905b4 tipc: Prevent transmission of outdated link protocol messages
Ensures that a link endpoint discards any previously deferred link
protocol message whenever it attempts to send a new one.

Previously, it was possible for a link protocol message that was unsent
due to congestion to be transmitted after newer protocol messages had
been sent. The stale link protocol message might then cause the receiving
link endpoint to malfunction because of its outdated conent.

Thanks to Osamu Kaminuma [okaminum@avaya.com] for diagnosing the problem
and contributing a prototype patch.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-06 16:59:15 -05:00