Commit Graph

249 Commits

Author SHA1 Message Date
Jon Paul Maloy 440d8963cd tipc: clean up link creation
We simplify the link creation function tipc_link_create() and the way
the link struct it is connected to the node struct. In particular, we
remove the duplicate initialization of some fields which are anyway set
in tipc_link_reset().

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:15 -07:00
Jon Paul Maloy 23d8335d78 tipc: remove implicit message delivery in node_unlock()
After the most recent changes, all access calls to a link which
may entail addition of messages to the link's input queue are
postpended by an explicit call to tipc_sk_rcv(), using a reference
to the correct queue.

This means that the potentially hazardous implicit delivery, using
tipc_node_unlock() in combination with a binary flag and a cached
queue pointer, now has become redundant.

This commit removes this implicit delivery mechanism both for regular
data messages and for binding table update messages.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy 598411d70f tipc: make resetting of links non-atomic
In order to facilitate future improvements to the locking structure, we
want to make resetting and establishing of links non-atomic. I.e., the
functions tipc_node_link_up() and tipc_node_link_down() should be called
from outside the node lock context, and grab/release the node lock
themselves. This requires that we can freeze the link state from the
moment it is set to RESETTING or PEER_RESET in one lock context until
it is set to RESET or ESTABLISHING in a later context. The recently
introduced link FSM makes this possible, so we are now ready to introduce
the above change.

This commit implements this.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy cf148816ac tipc: move received discovery data evaluation inside node.c
The node lock is currently grabbed and and released in the function
tipc_disc_rcv() in the file discover.c. As a preparation for the next
commits, we need to move this node lock handling, along with the code
area it is covering, to node.c.

This commit introduces this change.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy 662921cd0a tipc: merge link->exec_mode and link->state into one FSM
Until now, we have been handling link failover and synchronization
by using an additional link state variable, "exec_mode". This variable
is not independent of the link FSM state, something causing a risk of
inconsistencies, apart from the fact that it clutters the code.

The conditions are now in place to define a new link FSM that covers
all existing use cases, including failover and synchronization, and
eliminate the "exec_mode" field altogether. The FSM must also support
non-atomic resetting of links, which will be introduced later.

The new link FSM is shown below, with 7 states and 8 events.
Only events leading to state change are shown as edges.

+------------------------------------+
|RESET_EVT                           |
|                                    |
|                             +--------------+
|           +-----------------|   SYNCHING   |-----------------+
|           |FAILURE_EVT      +--------------+   PEER_RESET_EVT|
|           |                  A            |                  |
|           |                  |            |                  |
|           |                  |            |                  |
|           |                  |SYNCH_      |SYNCH_            |
|           |                  |BEGIN_EVT   |END_EVT           |
|           |                  |            |                  |
|           V                  |            V                  V
|    +-------------+          +--------------+          +------------+
|    |  RESETTING  |<---------|  ESTABLISHED |--------->| PEER_RESET |
|    +-------------+ FAILURE_ +--------------+ PEER_    +------------+
|           |        EVT        |    A         RESET_EVT       |
|           |                   |    |                         |
|           |                   |    |                         |
|           |    +--------------+    |                         |
|  RESET_EVT|    |RESET_EVT          |ESTABLISH_EVT            |
|           |    |                   |                         |
|           |    |                   |                         |
|           V    V                   |                         |
|    +-------------+          +--------------+        RESET_EVT|
+--->|    RESET    |--------->| ESTABLISHING |<----------------+
     +-------------+ PEER_    +--------------+
      |           A  RESET_EVT       |
      |           |                  |
      |           |                  |
      |FAILOVER_  |FAILOVER_         |FAILOVER_
      |BEGIN_EVT  |END_EVT           |BEGIN_EVT
      |           |                  |
      V           |                  |
     +-------------+                 |
     | FAILINGOVER |<----------------+
     +-------------+

These changes are fully backwards compatible.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy 5045f7b900 tipc: move protocol message sending away from link FSM
The implementation of the link FSM currently takes decisions about and
sends out link protocol messages. This is unnecessary, since such
actions are not the result of any link state change, and are even
decided based on non-FSM state information ("silent_intv_cnt").

We now move the sending of unicast link protocol messages to the
function tipc_link_timeout(), and the initial broadcast synchronization
message to tipc_node_link_up(). The latter is done because a link
instance should not need to know whether it is the first or second
link to a destination. Such information is now restricted to and
handled by the link aggregation layer in node.c

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy 6e498158a8 tipc: move link synch and failover to link aggregation level
Link failover and synchronization have until now been handled by the
links themselves, forcing them to have knowledge about and to access
parallel links in order to make the two algorithms work correctly.

In this commit, we move the control part of this functionality to the
link aggregation level in node.c, which is the right location for this.
As a result, the two algorithms become easier to follow, and the link
implementation becomes simpler.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:14 -07:00
Jon Paul Maloy 66996b6c47 tipc: extend node FSM
In the next commit, we will move link synch/failover orchestration to
the link aggregation level. In order to do this, we first need to extend
the node FSM with two more states, NODE_SYNCHING and NODE_FAILINGOVER,
plus four new events to enter and leave those states.

This commit introduces this change, without yet making use of it.
The node FSM now looks as follows:

                           +-----------------------------------------+
                           |                            PEER_DOWN_EVT|
                           |                                         |
  +------------------------+----------------+                        |
  |SELF_DOWN_EVT           |                |                        |
  |                        |                |                        |
  |              +-----------+          +-----------+                |
  |              |NODE_      |          |NODE_      |                |
  |   +----------|FAILINGOVER|<---------|SYNCHING   |------------+   |
  |   |SELF_     +-----------+ FAILOVER_+-----------+    PEER_   |   |
  |   |DOWN_EVT   |         A  BEGIN_EVT A         |     DOWN_EVT|   |
  |   |           |         |            |         |             |   |
  |   |           |         |            |         |             |   |
  |   |           |FAILOVER_|FAILOVER_   |SYNCH_   |SYNCH_       |   |
  |   |           |END_EVT  |BEGIN_EVT   |BEGIN_EVT|END_EVT      |   |
  |   |           |         |            |         |             |   |
  |   |           |         |            |         |             |   |
  |   |           |        +--------------+        |             |   |
  |   |           +------->|   SELF_UP_   |<-------+             |   |
  |   |   +----------------|   PEER_UP    |------------------+   |   |
  |   |   |SELF_DOWN_EVT   +--------------+     PEER_DOWN_EVT|   |   |
  |   |   |                   A          A                   |   |   |
  |   |   |                   |          |                   |   |   |
  |   |   |        PEER_UP_EVT|          |SELF_UP_EVT        |   |   |
  |   |   |                   |          |                   |   |   |
  V   V   V                   |          |                   V   V   V
+------------+       +-----------+    +-----------+       +------------+
|SELF_DOWN_  |       |SELF_UP_   |    |PEER_UP_   |       |PEER_DOWN   |
|PEER_LEAVING|<------|PEER_COMING|    |SELF_COMING|------>|SELF_LEAVING|
+------------+ SELF_ +-----------+    +-----------+ PEER_ +------------+
       |       DOWN_EVT       A          A          DOWN_EVT     |
       |                      |          |                       |
       |                      |          |                       |
       |           SELF_UP_EVT|          |PEER_UP_EVT            |
       |                      |          |                       |
       |                      |          |                       |
       |PEER_DOWN_EVT       +--------------+        SELF_DOWN_EVT|
       +------------------->|  SELF_DOWN_  |<--------------------+
                            |  PEER_DOWN   |
                            +--------------+

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:13 -07:00
Jon Paul Maloy 655fb243b8 tipc: reverse call order for link_reset()->node_link_down()
In many cases the call order when a link is reset goes as follows:
tipc_node_xx()->tipc_link_reset()->tipc_node_link_down()

This is not the right order if we want the node to be in control,
so in this commit we change the order to:
tipc_node_xx()->tipc_node_link_down()->tipc_link_reset()

The fact that tipc_link_reset() now is called from only one
location with a well-defined state will also facilitate later
simplifications of tipc_link_reset() and the link FSM.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:13 -07:00
Jon Paul Maloy 6144a996a6 tipc: move all link_reset() calls to link aggregation level
In line with our effort to let the node level have full control over
its links, we want to move all link reset calls from link.c to node.c.
Some of the calls can be moved by simply moving the calling function,
when this is the right thing to do. For the remaining calls we use
the now established technique of returning a TIPC_LINK_DOWN_EVT
flag from tipc_link_rcv(), whereafter we perform the reset call when
the call returns.

This change serves as a preparation for the coming commits.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:13 -07:00
Jon Paul Maloy cbeb83ca68 tipc: eliminate function tipc_link_activate()
The function tipc_link_activate() is redundant, since it mostly performs
settings that have already been done in a preceding tipc_link_reset().

There are three exceptions to this:
- The actual state change to TIPC_LINK_WORKING. This should anyway be done
  in the FSM, and not in a separate function.
- Registration of the link with the bearer. This should be done by the
  node, since we don't want the link to have any knowledge about its
  specific bearer.
- Call to tipc_node_link_up() for user access registration. With the new
  role distribution between link aggregation and link level this becomes
  the wrong call order; tipc_node_link_up() should instead be called
  directly as a result of a TIPC_LINK_UP event, hence by the node itself.

This commit implements those changes.

Tested-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30 17:25:13 -07:00
Jon Paul Maloy d999297c3d tipc: reduce locking scope during packet reception
We convert packet/message reception according to the same principle
we have been using for message sending and timeout handling:

We move the function tipc_rcv() to node.c, hence handling the initial
packet reception at the link aggregation level. The function grabs
the node lock, selects the receiving link, and accesses it via a new
call tipc_link_rcv(). This function appends buffers to the input
queue for delivery upwards, but it may also append outgoing packets
to the xmit queue, just as we do during regular message sending. The
latter will happen when buffers are forwarded from the link backlog,
or when retransmission is requested.

Upon return of this function, and after having released the node lock,
tipc_rcv() delivers/tranmsits the contents of those queues, but it may
also perform actions such as link activation or reset, as indicated by
the return flags from the link.

This reduces the number of cpu cycles spent inside the node spinlock,
and reduces contention on that lock.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:16 -07:00
Jon Paul Maloy 1a20cc254e tipc: introduce node contact FSM
The logics for determining when a node is permitted to establish
and maintain contact with its peer node becomes non-trivial in the
presence of multiple parallel links that may come and go independently.

A known failure scenario is that one endpoint registers both its links
to the peer lost, cleans up it binding table, and prepares for a table
update once contact is re-establihed, while the other endpoint may
see its links reset and re-established one by one, hence seeing
no need to re-synchronize the binding table. To avoid this, a node
must not allow re-establishing contact until it has confirmation that
even the peer has lost both links.

Currently, the mechanism for handling this consists of setting and
resetting two state flags from different locations in the code. This
solution is hard to understand and maintain. A closer analysis even
reveals that it is not completely safe.

In this commit we do instead introduce an FSM that keeps track of
the conditions for when the node can establish and maintain links.
It has six states and four events, and is strictly based on explicit
knowledge about the own node's and the peer node's contact states.
Only events leading to state change are shown as edges in the figure
below.

                             +--------------+
                             | SELF_UP/     |
           +---------------->| PEER_COMING  |-----------------+
    SELF_  |                 +--------------+                 |PEER_
    ESTBL_ |                        |                         |ESTBL_
    CONTACT|      SELF_LOST_CONTACT |                         |CONTACT
           |                        v                         |
           |                 +--------------+                 |
           |      PEER_      | SELF_DOWN/   |     SELF_       |
           |      LOST_   +--| PEER_LEAVING |<--+ LOST_       v
+-------------+   CONTACT |  +--------------+   | CONTACT  +-----------+
| SELF_DOWN/  |<----------+                     +----------| SELF_UP/  |
| PEER_DOWN   |<----------+                     +----------| PEER_UP   |
+-------------+   SELF_   |  +--------------+   | PEER_    +-----------+
           |      LOST_   +--| SELF_LEAVING/|<--+ LOST_       A
           |      CONTACT    | PEER_DOWN    |     CONTACT     |
           |                 +--------------+                 |
           |                         A                        |
    PEER_  |       PEER_LOST_CONTACT |                        |SELF_
    ESTBL_ |                         |                        |ESTBL_
    CONTACT|                 +--------------+                 |CONTACT
           +---------------->| PEER_UP/     |-----------------+
                             | SELF_COMING  |
                             +--------------+

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:16 -07:00
Jon Paul Maloy 8a1577c96f tipc: move link supervision timer to node level
In our effort to move control of the links to the link aggregation
layer, we move the perodic link supervision timer to struct tipc_node.
The new timer is shared between all links belonging to the node, thus
saving resources, while still kicking the FSM on both its pertaining
links at each expiration.

The current link timer and corresponding functions are removed.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:16 -07:00
Jon Paul Maloy d3504c3449 tipc: clean up definitions and usage of link flags
The status flag LINK_STOPPED is not needed any more, since the
mechanism for delayed deletion of links has been removed.
Likewise, LINK_STARTED and LINK_START_EVT are unnecessary,
because we can just as well start the link timer directly from
inside tipc_link_create().

We eliminate these flags in this commit.

Instead of the above flags, we now introduce three new link modes,
TIPC_LINK_OPEN, TIPC_LINK_BLOCKED and TIPC_LINK_TUNNEL. The values
indicate whether, and in the case of TIPC_LINK_TUNNEL, which, messages
the link is allowed to receive in this state. TIPC_LINK_BLOCKED also
blocks timer-driven protocol messages to be sent out, and any change
to the link FSM. Since the modes are mutually exclusive, we convert
them to state values, and rename the 'flags' field in struct tipc_link
to 'exec_mode'.

Finally, we move the #defines for link FSM states and events from link.h
into enums inside the file link.c, which is the real usage scope of
these definitions.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:15 -07:00
Jon Paul Maloy af9b028e27 tipc: make media xmit call outside node spinlock context
Currently, message sending is performed through a deep call chain,
where the node spinlock is grabbed and held during a significant
part of the transmission time. This is clearly detrimental to
overall throughput performance; it would be better if we could send
the message after the spinlock has been released.

In this commit, we do instead let the call revert on the stack after
the buffer chain has been added to the transmission queue, whereafter
clones of the buffers are transmitted to the device layer outside the
spinlock scope.

As a further step in our effort to separate the roles of the node
and link entities we also move the function tipc_link_xmit() to
node.c, and rename it to tipc_node_xmit().

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:15 -07:00
Jon Paul Maloy 36e78a463b tipc: use bearer index when looking up active links
struct tipc_node currently holds two arrays of link pointers; one,
indexed by bearer identity, which contains all links irrespective of
current state, and one two-slot array for the currently active link
or links. The latter array contains direct pointers into the elements
of the former. This has the effect that we cannot know the bearer id of
a link when accessing it via the "active_links[]" array without actually
dereferencing the pointer, something we want to avoid in some cases.

In this commit, we do instead store the bearer identity in the
"active_links" array, and use this as an index to find the right element
in the overall link entry array. This change should be seen as a
preparation for the later commits in this series.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:14 -07:00
Jon Paul Maloy d39bbd445d tipc: move link input queue to tipc_node
At present, the link input queue and the name distributor receive
queues are fields aggregated in struct tipc_link. This is a hazard,
because a link might be deleted while a receiving socket still keeps
reference to one of the queues.

This commit fixes this bug. However, rather than adding yet another
reference counter to the critical data path, we move the two queues
to safe ground inside struct tipc_node, which is already protected, and
let the link code only handle references to the queues. This is also
in line with planned later changes in this area.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:14 -07:00
Jon Paul Maloy d3a43b907a tipc: move link creation from neighbor discoverer to node
As a step towards turning links into node internal entities, we move the
creation of links from the neighbor discovery logics to the node's link
control logics.

We also create an additional entry for the link's media address in the
newly introduced struct tipc_link_entry, since this is where it is
needed in the upcoming commits. The current copy in struct tipc_link
is kept for now, but will be removed later.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:14 -07:00
Jon Paul Maloy 9d13ec65ed tipc: introduce link entry structure to struct tipc_node
struct 'tipc_node' currently contains two arrays for link attributes,
one for the link pointers, and one for the usable link MTUs.

We now group those into a new struct 'tipc_link_entry', and intoduce
one single array consisting of such enties. Apart from being a cosmetic
improvement, this is a starting point for the strict master-slave
relation between node and link that we will introduce in the following
commits.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-20 20:41:14 -07:00
Jon Paul Maloy dd3f9e70f5 tipc: add packet sequence number at instant of transmission
Currently, the packet sequence number is updated and added to each
packet at the moment a packet is added to the link backlog queue.
This is wasteful, since it forces the code to traverse the send
packet list packet by packet when adding them to the backlog queue.
It would be better to just splice the whole packet list into the
backlog queue when that is the right action to do.

In this commit, we do this change. Also, since the sequence numbers
cannot now be assigned to the packets at the moment they are added
the backlog queue, we do instead calculate and add them at the moment
of transmission, when the backlog queue has to be traversed anyway.
We do this in the function tipc_link_push_packet().

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-14 12:24:46 -04:00
Jon Paul Maloy a6bf70f792 tipc: simplify include dependencies
When we try to add new inline functions in the code, we sometimes
run into circular include dependencies.

The main problem is that the file core.h, which really should be at
the root of the dependency chain, instead is a leaf. I.e., core.h
includes a number of header files that themselves should be allowed
to include core.h. In reality this is unnecessary, because core.h does
not need to know the full signature of any of the structs it refers to,
only their type declaration.

In this commit, we remove all dependencies from core.h towards any
other tipc header file.

As a consequence of this change, we can now move the function
tipc_own_addr(net) from addr.c to addr.h, and make it inline.

There are no functional changes in this commit.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-14 12:24:45 -04:00
Jon Paul Maloy ed193ece26 tipc: simplify link mtu negotiation
When a link is being established, the two endpoints advertise their
respective interface MTU in the transmitted RESET and ACTIVATE messages.
If there is any difference, the lower of the two MTUs will be selected
for use by both endpoints.

However, as a remnant of earlier attempts to introduce TIPC level
routing. there also exists an MTU discovery mechanism. If an intermediate
node has a lower MTU than the two endpoints, they will discover this
through a bisectional approach, and finally adopt this MTU for common use.

Since there is no TIPC level routing, and probably never will be,
this mechanism doesn't make any sense, and only serves to make the
link level protocol unecessarily complex.

In this commit, we eliminate the MTU discovery algorithm,and fall back
to the simple MTU advertising approach. This change is fully backwards
compatible.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-02 16:27:12 -04:00
Jon Paul Maloy dff29b1a88 tipc: eliminate delayed link deletion at link failover
When a bearer is disabled manually, all its links have to be reset
and deleted. However, if there is a remaining, parallel link ready
to take over a deleted link's traffic, we currently delay the delete
of the removed link until the failover procedure is finished. This
is because the remaining link needs to access state from the reset
link, such as the last received packet number, and any partially
reassembled buffer, in order to perform a successful failover.

In this commit, we do instead move the state data over to the new
link, so that it can fulfill the procedure autonomously, without
accessing any data on the old link. This means that we can now
proceed and delete all pertaining links immediately when a bearer
is disabled. This saves us from some unnecessary complexity in such
situations.

We also choose to change the confusing definitions CHANGEOVER_PROTOCOL,
ORIGINAL_MSG and DUPLICATE_MSG to the more descriptive TUNNEL_PROTOCOL,
FAILOVER_MSG and SYNCH_MSG respectively.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-02 16:27:12 -04:00
Ying Xue 8a0f6ebe84 tipc: involve reference counter for node structure
TIPC node hash node table is protected with rcu lock on read side.
tipc_node_find() is used to look for a node object with node address
through iterating the hash node table. As the entire process of what
tipc_node_find() traverses the table is guarded with rcu read lock,
it's safe for us. However, when callers use the node object returned
by tipc_node_find(), there is no rcu read lock applied. Therefore,
this is absolutely unsafe for callers of tipc_node_find().

Now we introduce a reference counter for node structure. Before
tipc_node_find() returns node object to its caller, it first increases
the reference counter. Accordingly, after its caller used it up,
it decreases the counter again. This can prevent a node being used by
one thread from being freed by another thread.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-29 12:40:28 -07:00
Ying Xue b952b2befb tipc: fix potential deadlock when all links are reset
[   60.988363] ======================================================
[   60.988754] [ INFO: possible circular locking dependency detected ]
[   60.989152] 3.19.0+ #194 Not tainted
[   60.989377] -------------------------------------------------------
[   60.989781] swapper/3/0 is trying to acquire lock:
[   60.990079]  (&(&n_ptr->lock)->rlock){+.-...}, at: [<ffffffffa0006dca>] tipc_link_retransmit+0x1aa/0x240 [tipc]
[   60.990743]
[   60.990743] but task is already holding lock:
[   60.991106]  (&(&bclink->lock)->rlock){+.-...}, at: [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc]
[   60.991738]
[   60.991738] which lock already depends on the new lock.
[   60.991738]
[   60.992174]
[   60.992174] the existing dependency chain (in reverse order) is:
[   60.992174]
-> #1 (&(&bclink->lock)->rlock){+.-...}:
[   60.992174]        [<ffffffff810a9c0c>] lock_acquire+0x9c/0x140
[   60.992174]        [<ffffffff8179c41f>] _raw_spin_lock_bh+0x3f/0x50
[   60.992174]        [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc]
[   60.992174]        [<ffffffffa0000f57>] tipc_bclink_add_node+0x97/0xf0 [tipc]
[   60.992174]        [<ffffffffa0011815>] tipc_node_link_up+0xf5/0x110 [tipc]
[   60.992174]        [<ffffffffa0007783>] link_state_event+0x2b3/0x4f0 [tipc]
[   60.992174]        [<ffffffffa00193c0>] tipc_link_proto_rcv+0x24c/0x418 [tipc]
[   60.992174]        [<ffffffffa0008857>] tipc_rcv+0x827/0xac0 [tipc]
[   60.992174]        [<ffffffffa0002ca3>] tipc_l2_rcv_msg+0x73/0xd0 [tipc]
[   60.992174]        [<ffffffff81646e66>] __netif_receive_skb_core+0x746/0x980
[   60.992174]        [<ffffffff816470c1>] __netif_receive_skb+0x21/0x70
[   60.992174]        [<ffffffff81647295>] netif_receive_skb_internal+0x35/0x130
[   60.992174]        [<ffffffff81648218>] napi_gro_receive+0x158/0x1d0
[   60.992174]        [<ffffffff81559e05>] e1000_clean_rx_irq+0x155/0x490
[   60.992174]        [<ffffffff8155c1b7>] e1000_clean+0x267/0x990
[   60.992174]        [<ffffffff81647b60>] net_rx_action+0x150/0x360
[   60.992174]        [<ffffffff8105ec43>] __do_softirq+0x123/0x360
[   60.992174]        [<ffffffff8105f12e>] irq_exit+0x8e/0xb0
[   60.992174]        [<ffffffff8179f9f5>] do_IRQ+0x65/0x110
[   60.992174]        [<ffffffff8179da6f>] ret_from_intr+0x0/0x13
[   60.992174]        [<ffffffff8100de9f>] arch_cpu_idle+0xf/0x20
[   60.992174]        [<ffffffff8109dfa6>] cpu_startup_entry+0x2f6/0x3f0
[   60.992174]        [<ffffffff81033cda>] start_secondary+0x13a/0x150
[   60.992174]
-> #0 (&(&n_ptr->lock)->rlock){+.-...}:
[   60.992174]        [<ffffffff810a8f7d>] __lock_acquire+0x163d/0x1ca0
[   60.992174]        [<ffffffff810a9c0c>] lock_acquire+0x9c/0x140
[   60.992174]        [<ffffffff8179c41f>] _raw_spin_lock_bh+0x3f/0x50
[   60.992174]        [<ffffffffa0006dca>] tipc_link_retransmit+0x1aa/0x240 [tipc]
[   60.992174]        [<ffffffffa0001e11>] tipc_bclink_rcv+0x611/0x640 [tipc]
[   60.992174]        [<ffffffffa0008646>] tipc_rcv+0x616/0xac0 [tipc]
[   60.992174]        [<ffffffffa0002ca3>] tipc_l2_rcv_msg+0x73/0xd0 [tipc]
[   60.992174]        [<ffffffff81646e66>] __netif_receive_skb_core+0x746/0x980
[   60.992174]        [<ffffffff816470c1>] __netif_receive_skb+0x21/0x70
[   60.992174]        [<ffffffff81647295>] netif_receive_skb_internal+0x35/0x130
[   60.992174]        [<ffffffff81648218>] napi_gro_receive+0x158/0x1d0
[   60.992174]        [<ffffffff81559e05>] e1000_clean_rx_irq+0x155/0x490
[   60.992174]        [<ffffffff8155c1b7>] e1000_clean+0x267/0x990
[   60.992174]        [<ffffffff81647b60>] net_rx_action+0x150/0x360
[   60.992174]        [<ffffffff8105ec43>] __do_softirq+0x123/0x360
[   60.992174]        [<ffffffff8105f12e>] irq_exit+0x8e/0xb0
[   60.992174]        [<ffffffff8179f9f5>] do_IRQ+0x65/0x110
[   60.992174]        [<ffffffff8179da6f>] ret_from_intr+0x0/0x13
[   60.992174]        [<ffffffff8100de9f>] arch_cpu_idle+0xf/0x20
[   60.992174]        [<ffffffff8109dfa6>] cpu_startup_entry+0x2f6/0x3f0
[   60.992174]        [<ffffffff81033cda>] start_secondary+0x13a/0x150
[   60.992174]
[   60.992174] other info that might help us debug this:
[   60.992174]
[   60.992174]  Possible unsafe locking scenario:
[   60.992174]
[   60.992174]        CPU0                    CPU1
[   60.992174]        ----                    ----
[   60.992174]   lock(&(&bclink->lock)->rlock);
[   60.992174]                                lock(&(&n_ptr->lock)->rlock);
[   60.992174]                                lock(&(&bclink->lock)->rlock);
[   60.992174]   lock(&(&n_ptr->lock)->rlock);
[   60.992174]
[   60.992174]  *** DEADLOCK ***
[   60.992174]
[   60.992174] 3 locks held by swapper/3/0:
[   60.992174]  #0:  (rcu_read_lock){......}, at: [<ffffffff81646791>] __netif_receive_skb_core+0x71/0x980
[   60.992174]  #1:  (rcu_read_lock){......}, at: [<ffffffffa0002c35>] tipc_l2_rcv_msg+0x5/0xd0 [tipc]
[   60.992174]  #2:  (&(&bclink->lock)->rlock){+.-...}, at: [<ffffffffa00004be>] tipc_bclink_lock+0x8e/0xa0 [tipc]
[   60.992174]

The correct the sequence of grabbing n_ptr->lock and bclink->lock
should be that the former is first held and the latter is then taken,
which exactly happened on CPU1. But especially when the retransmission
of broadcast link is failed, bclink->lock is first held in
tipc_bclink_rcv(), and n_ptr->lock is taken in link_retransmit_failure()
called by tipc_link_retransmit() subsequently, which is demonstrated on
CPU0. As a result, deadlock occurs.

If the order of holding the two locks happening on CPU0 is reversed, the
deadlock risk will be relieved. Therefore, the node lock taken in
link_retransmit_failure() originally is moved to tipc_bclink_rcv()
so that it's obtained before bclink lock. But the precondition of
the adjustment of node lock is that responding to bclink reset event
must be moved from tipc_bclink_unlock() to tipc_node_unlock().

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-29 12:40:27 -07:00
Jon Paul Maloy 05dcc5aa4d tipc: split link outqueue
struct tipc_link contains one single queue for outgoing packets,
where both transmitted and waiting packets are queued.

This infrastructure is hard to maintain, because we need
to keep a number of fields to keep track of which packets are
sent or unsent, and the number of packets in each category.

A lot of code becomes simpler if we split this queue into a transmission
queue, where sent/unacknowledged packets are kept, and a backlog queue,
where we keep the not yet sent packets.

In this commit we do this separation.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 14:38:32 -04:00
Richard Alpe 22ae7cff50 tipc: nl compat add noop and remove legacy nl framework
Add TIPC_CMD_NOOP to compat layer and remove the old framework.

All legacy nl commands are now converted to the compat layer in
netlink_compat.c.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-09 13:20:49 -08:00
Richard Alpe 4b28cb581d tipc: convert legacy nl node dump to nl compat
Convert TIPC_CMD_GET_NODES to compat dumpit and remove global node
counter solely used by the legacy API.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-09 13:20:49 -08:00
Richard Alpe 357ebdbfca tipc: convert legacy nl link dump to nl compat
Convert TIPC_CMD_GET_LINKS to compat dumpit and remove global link
counter solely used by the legacy API.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-09 13:20:48 -08:00
Richard Alpe bfb3e5dd8d tipc: move and rename the legacy nl api to "nl compat"
The new netlink API is no longer "v2" but rather the standard API and
the legacy API is now "nl compat". We split them into separate
start/stop and put them in different files in order to further
distinguish them.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-09 13:20:47 -08:00
Jon Paul Maloy cb1b728096 tipc: eliminate race condition at multicast reception
In a previous commit in this series we resolved a race problem during
unicast message reception.

Here, we resolve the same problem at multicast reception. We apply the
same technique: an input queue serializing the delivery of arriving
buffers. The main difference is that here we do it in two steps.
First, the broadcast link feeds arriving buffers into the tail of an
arrival queue, which head is consumed at the socket level, and where
destination lookup is performed. Second, if the lookup is successful,
the resulting buffer clones are fed into a second queue, the input
queue. This queue is consumed at reception in the socket just like
in the unicast case. Both queues are protected by the same lock, -the
one of the input queue.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 16:00:03 -08:00
Jon Paul Maloy 708ac32cb5 tipc: simplify connection abort notifications when links break
The new input message queue in struct tipc_link can be used for
delivering connection abort messages to subscribing sockets. This
makes it possible to simplify the code for such cases.

This commit removes the temporary list in tipc_node_unlock()
used for transforming abort subscriptions to messages. Instead, the
abort messages are now created at the moment of lost contact, and
then added to the last failed link's generic input queue for delivery
to the sockets concerned.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 16:00:02 -08:00
Jon Paul Maloy c637c10355 tipc: resolve race problem at unicast message reception
TIPC handles message cardinality and sequencing at the link layer,
before passing messages upwards to the destination sockets. During the
upcall from link to socket no locks are held. It is therefore possible,
and we see it happen occasionally, that messages arriving in different
threads and delivered in sequence still bypass each other before they
reach the destination socket. This must not happen, since it violates
the sequentiality guarantee.

We solve this by adding a new input buffer queue to the link structure.
Arriving messages are added safely to the tail of that queue by the
link, while the head of the queue is consumed, also safely, by the
receiving socket. Sequentiality is secured per socket by only allowing
buffers to be dequeued inside the socket lock. Since there may be multiple
simultaneous readers of the queue, we use a 'filter' parameter to reduce
the risk that they peek the same buffer from the queue, hence also
reducing the risk of contention on the receiving socket locks.

This solves the sequentiality problem, and seems to cause no measurable
performance degradation.

A nice side effect of this change is that lock handling in the functions
tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that
will enable future simplifications of those functions.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 16:00:02 -08:00
Jon Paul Maloy c5898636c4 tipc: reduce usage of context info in socket and link
The most common usage of namespace information is when we fetch the
own node addess from the net structure. This leads to a lot of
passing around of a parameter of type 'struct net *' between
functions just to make them able to obtain this address.

However, in many cases this is unnecessary. The own node address
is readily available as a member of both struct tipc_sock and
tipc_link, and can be fetched from there instead.
The fact that the vast majority of functions in socket.c and link.c
anyway are maintaining a pointer to their respective base structures
makes this option even more compelling.

In this commit, we introduce the inline functions tsk_own_node()
and link_own_node() to make it easy for functions to fetch the node
address from those structs instead of having to pass along and
dereference the namespace struct.

In particular, we make calls to the msg_xx() functions in msg.{h,c}
context independent by directly passing them the own node address
as parameter when needed. Those functions should be regarded as
leaves in the code dependency tree, and it is hence desirable to
keep them namspace unaware.

Apart from a potential positive effect on cache behavior, these
changes make it easier to introduce the changes that will follow
later in this series.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 16:00:01 -08:00
Jon Paul Maloy b45db71b52 tipc: eliminate race during node creation
Instances of struct node are created in the function tipc_disc_rcv()
under the assumption that there is no race between received discovery
messages arriving from the same node. This assumption is wrong.
When we use more than one bearer, it is possible that discovery
messages from the same node arrive at the same moment, resulting in
creation of two instances of struct tipc_node. This may later cause
confusion during link establishment, and may result in one of the links
never becoming activated.

We fix this by making lookup and potential creation of nodes atomic.
Instead of first looking up the node, and in case of failure, create it,
we now start with looking up the node inside node_link_create(), and
return a reference to that one if found. Otherwise, we go ahead and
create the node as we did before.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-04 16:09:31 -08:00
Jon Paul Maloy 7d24dcdb3f tipc: avoid stale link after aborted failover
During link failover it may happen that the remaining link goes
down while it is still in the process of taking over traffic
from a previously failed link. When this happens, we currently
abort the failover procedure and reset the first failed link to
non-failover mode, so that it will be ready to re-establish
contact with its peer when it comes available.

However, if the first link goes down because its bearer was manually
disabled, it is not enough to reset it; it must also be deleted;
which is supposed to happen when the failover procedure is finished.
Otherwise it will remain a zombie link: attached to the owner node
structure, in mode LINK_STOPPED, and permanently blocking any re-
establishing of the link to the peer via the interface in question.

We fix this by amending the failover abort procedure. Apart from
resetting the link to non-failover state, we test if the link is
also in LINK_STOPPED mode. If so, we delete it, using the conditional
tipc_link_delete() function introduced in the previous commit.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-04 16:09:31 -08:00
Erik Hugne 3fa9cacd69 tipc: fix excessive network event logging
If a large number of namespaces is spawned on a node and TIPC is
enabled in each of these, the excessive printk tracing of network
events will cause the system to grind down to a near halt.
The traces are still of debug value, so instead of removing them
completely we fix it by changing the link state and node availability
logging debug traces.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-26 16:58:08 -08:00
Ying Xue 3474753954 tipc: make tipc node address support net namespace
If net namespace is supported in tipc, each namespace will be treated
as a separate tipc node. Therefore, every namespace must own its
private tipc node address. This means the "tipc_own_addr" global
variable of node address must be moved to tipc_net structure to
satisfy the requirement. It's turned out that users also can assign
node address for every namespace.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Tested-by: Tero Aho <Tero.Aho@coriant.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12 16:24:33 -05:00
Ying Xue 1da465683a tipc: make tipc broadcast link support net namespace
TIPC broadcast link is statically established and its relevant states
are maintained with the global variables: "bcbearer", "bclink" and
"bcl". Allowing different namespace to own different broadcast link
instances, these variables must be moved to tipc_net structure and
broadcast link instances would be allocated and initialized when
namespace is created.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Tested-by: Tero Aho <Tero.Aho@coriant.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12 16:24:33 -05:00
Ying Xue f2f9800d49 tipc: make tipc node table aware of net namespace
Global variables associated with node table are below:
- node table list (node_htable)
- node hash table list (tipc_node_list)
- node table lock (node_list_lock)
- node number counter (tipc_num_nodes)
- node link number counter (tipc_num_links)

To make node table support namespace, above global variables must be
moved to tipc_net structure in order to keep secret for different
namespaces. As a consequence, these variables are allocated and
initialized when namespace is created, and deallocated when namespace
is destroyed. After the change, functions associated with these
variables have to utilize a namespace pointer to access them. So
adding namespace pointer as a parameter of these functions is the
major change made in the commit.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Tested-by: Tero Aho <Tero.Aho@coriant.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12 16:24:32 -05:00
Richard Alpe 340b6e59fb tipc: fix broadcast wakeup contention after congestion
commit 908344cdda ("tipc: fix bug in multicast congestion handling")
introduced a race in the broadcast link wakeup functionality.

This patch eliminates this broadcast link wakeup race caused by
operation on the wakeup list without proper locking. If this race
hit and corrupted the list all subsequent wakeup messages would be
lost, resulting in a considerable memory leak.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-10 14:45:33 -05:00
Ying Xue bc6fecd409 tipc: use generic SKB list APIs to manage deferred queue of link
Use standard SKB list APIs associated with struct sk_buff_head to
manage link's deferred queue, simplifying relevant code.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-26 12:30:17 -05:00
Ying Xue a8f48af587 tipc: remove node subscription infrastructure
The node subscribe infrastructure represents a virtual base class, so
its users, such as struct tipc_port and struct publication, can derive
its implemented functionalities. However, after the removal of struct
tipc_port, struct publication is left as its only single user now. So
defining an abstract infrastructure for one user becomes no longer
reasonable. If corresponding new functions associated with the
infrastructure are moved to name_table.c file, the node subscription
infrastructure can be removed as well.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-26 12:30:16 -05:00
Richard Alpe d8182804cf tipc: fix sparse warnings in new nl api
Fix sparse warnings about non-static declaration of static functions
in the new tipc netlink API.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-24 16:10:23 -05:00
Richard Alpe 3e4b6ab58d tipc: add node get/dump to new netlink api
Add TIPC_NL_NODE_GET to the new tipc netlink API.

This command can dump the address and node status of all nodes in the
tipc cluster.

Netlink logical layout of returned node/address data:
-> node
    -> address
    -> up flag

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-21 15:01:31 -05:00
Ying Xue 7b8613e0a1 tipc: fix a potential deadlock
Locking dependency detected below possible unsafe locking scenario:

           CPU0                          CPU1
T0:  tipc_named_rcv()                tipc_rcv()
T1:  [grab nametble write lock]*     [grab node lock]*
T2:  tipc_update_nametbl()           tipc_node_link_up()
T3:  tipc_nodesub_subscribe()        tipc_nametbl_publish()
T4:  [grab node lock]*               [grab nametble write lock]*

The opposite order of holding nametbl write lock and node lock on
above two different paths may result in a deadlock. If we move the
the updating of the name table after link state named out of node
lock, the reverse order of holding locks will be eliminated, and
as a result, the deadlock risk.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-21 15:28:15 -04:00
Jon Maloy 908344cdda tipc: fix bug in multicast congestion handling
One aim of commit 50100a5e39 ("tipc:
use pseudo message to wake up sockets after link congestion") was
to handle link congestion abatement in a uniform way for both unicast
and multicast transmit. However, the latter doesn't work correctly,
and has been broken since the referenced commit was applied.

If a user now sends a burst of multicast messages that is big
enough to cause broadcast link congestion, it will be put to sleep,
and not be waked up when the congestion abates as it should be.

This has two reasons. First, the flag that is used, TIPC_WAKEUP_USERS,
is set correctly, but in the wrong field. Instead of setting it in the
'action_flags' field of the arrival node struct, it is by mistake set
in the dummy node struct that is owned by the broadcast link, where it
will never tested for. Second, we cannot use the same flag for waking
up unicast and multicast users, since the function tipc_node_unlock()
needs to pick the wakeup pseudo messages to deliver from different
queues. It must hence be able to distinguish between the two cases.

This commit solves this problem by adding a new flag
TIPC_WAKEUP_BCAST_USERS, and a new function tipc_bclink_wakeup_user().
The latter is to be called by tipc_node_unlock() when the named flag,
now set in the correct field, is encountered.

v2: using explicit 'unsigned int' declaration instead of 'uint', as
per comment from David Miller.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 14:50:15 -04:00
Jon Paul Maloy 02be61a981 tipc: use message to abort connections when losing contact to node
In the current implementation, each 'struct tipc_node' instance keeps
a linked list of those ports/sockets that are connected to the node
represented by that struct. The purpose of this is to let the node
object know which sockets to alert when it loses contact with its peer
node, i.e., which sockets need to have their connections aborted.

This entails an unwanted direct reference from the node structure
back to the port/socket structure, and a need to grab port_lock
when we have to make an upcall to the port. We want to get rid of
this unecessary BH entry point into the socket, and also eliminate
its use of port_lock.

In this commit, we instead let the node struct keep list of "connected
socket" structs, which each represents a connected socket, but is
allocated independently by the node at the moment of connection. If
the node loses contact with its peer node, the list is traversed, and
a "connection abort" message is created for each entry in the list. The
message is sent to it respective connected socket using the ordinary
data path, and the receiving socket aborts its connections upon reception
of the message.

This enables us to get rid of the direct reference from 'struct node' to
´struct port', and another unwanted BH access point to the latter.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23 11:18:33 -07:00
Jon Paul Maloy 50100a5e39 tipc: use pseudo message to wake up sockets after link congestion
The current link implementation keeps a linked list of blocked ports/
sockets that is populated when there is link congestion. The purpose
of this is to let the link know which users to wake up when the
congestion abates.

This adds unnecessary complexity to the data structure and the code,
since it forces us to involve the link each time we want to delete
a socket. It also forces us to grab the spinlock port_lock within
the scope of node_lock. We want to get rid of this direct dependence,
as well as the deadlock hazard resulting from the usage of port_lock.

In this commit, we instead let the link keep list of a "wakeup" pseudo
messages for use in such situations. Those messages are sent to the
pending sockets via the ordinary message reception path, and wake up
the socket's owner when they are received.

This enables us to get rid of the 'waiting_ports' linked lists in struct
tipc_port that manifest this direct reference. As a consequence, we can
eliminate another BH entry into the socket, and hence the need to grab
port_lock. This is a further step in our effort to remove port_lock
altogether.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23 11:18:33 -07:00
Jon Paul Maloy dbdf6d24ad tipc: make name table distributor use new send function
In a previous commit series ("tipc: new unicast transmission code")
we introduced a new message sending function, tipc_link_xmit2(),
and moved the unicast data users over to use that function. We now
let the internal name table distributor do the same.

The interaction between the name distributor and the node/link
layer also becomes significantly simpler, so we can eliminate
the function tipc_link_names_xmit().

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16 21:38:18 -07:00
Jon Paul Maloy 16e166b88c tipc: make link mtu easily accessible from socket
Message fragmentation is currently performed at link level, inside
the protection of node_lock. This potentially binds up the sending
link structure for a long time, instead of letting it do other tasks,
such as handle reception of new packets.

In this commit, we make the MTUs of each active link become easily
accessible from the socket level, i.e., without taking any spinlock
or dereferencing the target link pointer. This way, we make it possible
to perform fragmentation in the sending socket, before sending the
whole fragment chain to the link for transport.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-27 12:50:55 -07:00
Jon Paul Maloy 37e22164a8 tipc: rename and move message reassembly function
The function tipc_link_frag_rcv() is in reality a re-entrant generic
message reassemby function that has nothing in particular to do with
the link, where it is defined now. This becomes obvious when we see
the need to call the function from other places in the code.

In this commit rename it to tipc_buf_append() and move it to the file
msg.c. We also simplify its signature by moving the tail pointer to
the control block of the head buffer, hence making the head buffer
self-contained.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-14 15:19:48 -04:00
Ying Xue ca9cf06a06 tipc: don't directly overwrite node action_flags
Each node action flag should be set or cleared separately, instead
we now set the whole flags variable in one shot, and it's turned
out to be hard to see which other flags are affected. Therefore,
for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in
node_lost_contact().

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-09 01:41:01 -04:00
Ying Xue aecb9bb89c tipc: rename enum names of node flags
Rename node flags to action_flags as well as its enum names so
that they can reflect its real meanings.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-09 01:41:01 -04:00
Ying Xue ca0c42732c tipc: avoid to asynchronously deliver name tables to peer node
Postpone the actions of delivering name tables until after node
lock is released, avoiding to do it under asynchronous context.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 17:26:44 -04:00
Ying Xue 9d56194968 tipc: remove TIPC_NAMES_GONE node flag
Since previously what all publications pertaining to the lost node
were removed from name table was finished in tasklet context
asynchronously, we need to TIPC_NAMES_GONE flag indicating whether
the node cleanup work is finished or not. But now as the cleanup work
has been finished when node lock is released, the flag becomes
meaningless for us.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 17:26:44 -04:00
Ying Xue 9db9fdd198 tipc: avoid to asynchronously notify subscriptions
Postpone the actions of notifying subscriptions until after node lock
is released, avoiding to asynchronously execute registered handlers
when node is lost.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 17:26:44 -04:00
Ying Xue 10f465c496 tipc: rename setup_blocked variable of node struct to flags
Rename setup_blocked variable of node struct to a more common
name called "flags", which will be used to represent kinds of
node states.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 17:26:44 -04:00
Erik Hugne d7bb74c38c tipc: fix out of bounds indexing
Commit 78acb1f9b8 ("tipc: add
ioctl to fetch link names") introduced a buffer overflow bug where
specially crafted ioctl requests could cause out-of-bounds indexing
of the node->links array. This was caused by an incorrect check vs
MAX_BEARERS, and the static code checker complaint is:
net/tipc/node.c:459 tipc_node_get_linkname() error: buffer overflow 'node->links' 2 <= 2

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-28 14:43:35 -04:00
Erik Hugne 78acb1f9b8 tipc: add ioctl to fetch link names
We add a new ioctl for AF_TIPC that can be used to fetch the
logical name for a link to a remote node on a given bearer. This
should be used in combination with link state subscriptions.
The logical name size limit definitions are moved to tipc.h, as
they are now also needed by the new ioctl.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:13:24 -04:00
Erik Hugne a89778d8ba tipc: add support for link state subscriptions
When links are established over a bearer plane, we create a node
local publication containing information about the peer node and
bearer plane. This allows TIPC applications to use the standard
TIPC topology server subscription mechanism to get notifications
when a link goes up or down.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:13:24 -04:00
Ying Xue 7216cd949c tipc: purge tipc_net_lock lock
Now tipc routing hierarchy comprises the structures 'node', 'link'and
'bearer'. The whole hierarchy is protected by a big read/write lock,
tipc_net_lock, to ensure that nothing is added or removed while code
is accessing any of these structures. Obviously the locking policy
makes node, link and bearer components closely bound together so that
their relationship becomes unnecessarily complex. In the worst case,
such locking policy not only has a negative influence on performance,
but also it's prone to lead to deadlock occasionally.

In order o decouple the complex relationship between bearer and node
as well as link, the locking policy is adjusted as follows:

- Bearer level
  RTNL lock is used on update side, and RCU is used on read side.
  Meanwhile, all bearer instances including broadcast bearer are
  saved into bearer_list array.

- Node and link level
  All node instances are saved into two tipc_node_list and node_htable
  lists. The two lists are protected by node_list_lock on write side,
  and they are guarded with RCU lock on read side. All members in node
  structure including link instances are protected by node spin lock.

- The relationship between bearer and node
  When link accesses bearer, it first needs to find the bearer with
  its bearer identity from the bearer_list array. When bearer accesses
  node, it can iterate the node_htable hash list with the node
  address to find the corresponding node.

In the new locking policy, every component has its private locking
solution and the relationship between bearer and node is very simple,
that is, they can find each other with node address or bearer identity
from node_htable hash list or bearer_list array.

Until now above all changes have been done, so tipc_net_lock can be
removed safely.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:17:53 -04:00
Ying Xue 7a2f7d18e7 tipc: decouple the relationship between bearer and link
Currently on both paths of message transmission and reception, the
read lock of tipc_net_lock must be held before bearer is accessed,
while the write lock of tipc_net_lock has to be taken before bearer
is configured. Although it can ensure that bearer is always valid on
the two data paths, link and bearer is closely bound together.

So as the part of effort of removing tipc_net_lock, the locking
policy of bearer protection will be adjusted as below: on the two
data paths, RCU is used, and on the configuration path of bearer,
RTNL lock is applied.

Now RCU just covers the path of message reception. To make it possible
to protect the path of message transmission with RCU, link should not
use its stored bearer pointer to access bearer, but it should use the
bearer identity of its attached bearer as index to get bearer instance
from bearer_list array, which can help us decouple the relationship
between bearer and link. As a result, bearer on the path of message
transmission can be safely protected by RCU when we access bearer_list
array within RCU lock protection.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:17:53 -04:00
Ying Xue dde2026608 tipc: use node list lock to protect tipc_num_links variable
Without properly implicit or explicit read memory barrier, it's
unsafe to read an atomic variable with atomic_read() from another
thread which is different with the thread of changing the atomic
variable with atomic_inc() or atomic_dec(). So a stale tipc_num_links
may be got with atomic_read() in tipc_node_get_links(). If the
tipc_num_links variable type is converted from atomic to unsigned
integer and node list lock is used to protect it, the issue would
be avoided.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 13:08:38 -04:00
Ying Xue 2220646a53 tipc: use node_list_lock to protect tipc_num_nodes variable
As tipc_node_list is protected by rcu read lock on read side, it's
unnecessary to hold node_list_lock to protect tipc_node_list in
tipc_node_get_links(). Instead, node_list_lock should just protects
tipc_num_nodes in the function.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 13:08:37 -04:00
Ying Xue 6c7a762e70 tipc: tipc: convert node list and node hlist to RCU lists
Convert tipc_node_list list and node_htable hash list to RCU lists.
On read side, the two lists are protected with RCU read lock, and
on update side, node_list_lock is applied to them.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 13:08:37 -04:00
Ying Xue 46651c59c4 tipc: rename node create lock to protect node list and hlist
When a node is created, tipc_net_lock read lock is first held and
then node_create_lock is grabbed in order to prevent the same node
from being created and inserted into both node list and hlist twice.
But when we query node from the two node lists, we only hold
tipc_net_lock read lock without grabbing node_create_lock. Obviously
this locking policy is unable to guarantee that the two node lists
are always synchronized especially when the operation of changing
and accessing them occurs in different contexts like currently doing.

Therefore, rename node_create_lock to node_list_lock to protect the
two node lists, that is, whenever node is inserted into them or node
is queried from them, the node_list_lock should be always held. As a
result, tipc_net_lock read lock becomes redundant and then can be
removed from the node query functions.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 13:08:37 -04:00
Ying Xue 76d7882420 tipc: remove unnecessary checking for node object
tipc_node_create routine doesn't need to check whether a node
object specified with a node address exists or not because its
caller(ie, tipc_disc_recv_msg routine) has checked this before
calling it.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 13:08:36 -04:00
Ying Xue 247f0f3c31 tipc: align tipc function names with common naming practice in the network
Rename the following functions, which are shorter and more in line
with common naming practice in the network subsystem.

tipc_bclink_send_msg->tipc_bclink_xmit
tipc_bclink_recv_pkt->tipc_bclink_rcv
tipc_disc_recv_msg->tipc_disc_rcv
tipc_link_send_proto_msg->tipc_link_proto_xmit
link_recv_proto_msg->tipc_link_proto_rcv
link_send_sections_long->tipc_link_iovec_long_xmit
tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast
tipc_link_send_sync->tipc_link_sync_xmit
tipc_link_recv_sync->tipc_link_sync_rcv
tipc_link_send_buf->__tipc_link_xmit
tipc_link_send->tipc_link_xmit
tipc_link_send_names->tipc_link_names_xmit
tipc_named_recv->tipc_named_rcv
tipc_link_recv_bundle->tipc_link_bundle_rcv
tipc_link_dup_send_queue->tipc_link_dup_queue_xmit
link_send_long_buf->tipc_link_frag_xmit

tipc_multicast->tipc_port_mcast_xmit
tipc_port_recv_mcast->tipc_port_mcast_rcv
tipc_port_reject_sections->tipc_port_iovec_reject
tipc_port_recv_proto_msg->tipc_port_proto_rcv
tipc_connect->tipc_port_connect
__tipc_connect->__tipc_port_connect
__tipc_disconnect->__tipc_port_disconnect
tipc_disconnect->tipc_port_disconnect
tipc_shutdown->tipc_port_shutdown
tipc_port_recv_msg->tipc_port_rcv
tipc_port_recv_sections->tipc_port_iovec_rcv

release->tipc_release
accept->tipc_accept
bind->tipc_bind
get_name->tipc_getname
poll->tipc_poll
send_msg->tipc_sendmsg
send_packet->tipc_send_packet
send_stream->tipc_send_stream
recv_msg->tipc_recvmsg
recv_stream->tipc_recv_stream
connect->tipc_connect
listen->tipc_listen
shutdown->tipc_shutdown
setsockopt->tipc_setsockopt
getsockopt->tipc_getsockopt

Above changes have no impact on current users of the functions.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-18 17:31:59 -05:00
Jon Paul Maloy 074bb43e9e tipc: fix a loop style problem
In commit 7d33939f47
("tipc: delay delete of link when failover is needed") we
introduced a loop for finding and removing a link pointer
in an array. The removal is done after we have left the loop,
giving the impression that one may remove the wrong pointer
if no matching element is found.

This is not really a bug, since we know that there will always
be a matching element, but it looks wrong, and causes a smatch
warning.

We fix this loop with this commit.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-17 00:26:26 -05:00
Jon Paul Maloy 7d33939f47 tipc: delay delete of link when failover is needed
When a bearer is disabled, all its attached links are deleted.
Ideally, we should do link failover to redundant links on other bearers,
if there are any, in such cases. This would be consistent with current
behavior when a link is reset, but not deleted. However, due to the
complexity involved, and the (wrongly) perceived low demand for this
feature, it was never implemented until now.

We mark the doomed link for deletion with a new flag, but wait until the
failover process is finished before we actually delete it. With the
improved link tunnelling/failover code introduced earlier in this commit
series, it is now easy to identify a spot in the code where the failover
is finished and it is safe to delete the marked link. Moreover, the test
for the flag and the deletion can be done synchronously, and outside the
most time critical data path.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13 17:57:07 -05:00
Jon Paul Maloy 170b3927b4 tipc: rename functions related to link failover and improve comments
The functionality related to link addition and failover is unnecessarily
hard to understand and maintain. We try to improve this by renaming
some of the functions, at the same time adding or improving the
explanatory comments around them. Names such as "tipc_rcv()" etc. also
align better with what is used in other networking components.

The changes in this commit are purely cosmetic, no functional changes
are made.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-07 18:44:25 -05:00
stephen hemminger eec73f1c96 tipc: remove unused code
Remove dead code;
       tipc_bearer_find_interface
       tipc_node_redundant_links

This may break out of tree version of TIPC if there still is one.
But that maybe a good thing :-)

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-04 20:18:50 -05:00
Ying Xue d77b3831f7 tipc: eliminate redundant code with kfree_skb_list routine
sk_buff lists are currently relased by looping over the list and
explicitly releasing each buffer.

We replace all occurrences of this loop with a call to kfree_skb_list().

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-11 00:17:42 -05:00
Erik Hugne 40ba3cdf54 tipc: message reassembly using fragment chain
When the first fragment of a long data data message is received on a link, a
reassembly buffer large enough to hold the data from this and all subsequent
fragments of the message is allocated. The payload of each new fragment is
copied into this buffer upon arrival. When the last fragment is received, the
reassembled message is delivered upwards to the port/socket layer.

Not only is this an inefficient approach, but it may also cause bursts of
reassembly failures in low memory situations. since we may fail to allocate
the necessary large buffer in the first place. Furthermore, after 100 subsequent
such failures the link will be reset, something that in reality aggravates the
situation.

To remedy this problem, this patch introduces a different approach. Instead of
allocating a big reassembly buffer, we now append the arriving fragments
to a reassembly chain on the link, and deliver the whole chain up to the
socket layer once the last fragment has been received. This is safe because
the retransmission layer of a TIPC link always delivers packets in strict
uninterrupted order, to the reassembly layer as to all other upper layers.
Hence there can never be more than one fragment chain pending reassembly at
any given time in a link, and we can trust (but still verify) that the
fragments will be chained up in the correct order.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-07 18:30:11 -05:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Jon Maloy c64f7a6a1f tipc: introduce message to synchronize broadcast link
Upon establishing a first link between two nodes, there is
currently a risk that the two endpoints will disagree on exactly
which sequence number reception and acknowleding of broadcast
packets should start.

The following scenarios may happen:

1: Node A sends an ACTIVATE message to B, telling it to start acking
   packets from sequence number N.
2: Node A sends out broadcast N, but does not expect an acknowledge
   from B, since B is not yet in its broadcast receiver's list.
3: Node A receives ACK for N from all nodes except B, and releases
   packet N.
4: Node B receives the ACTIVATE, activates its link endpoint, and
   stores the value N as sequence number of first expected packet.
5: Node B sends a NAME_DISTR message to A.
6: Node A receives the NAME_DISTR message, and activates its endpoint.
   At this moment B is added to A's broadcast receiver's set.
   Node A also sets sequence number 0 as the first broadcast packet
   to be received from B.
7: Node A sends broadcast N+1.
8: B receives N+1, determines there is a gap in the sequence, since
   it is expecting N, and sends a NACK for N back to A.
9: Node A has already released N, so no retransmission is possible.
   The broadcast link in direction A->B is stale.

In addition to, or instead of, 7-9 above, the following may happen:

10: Node B sends broadcast M > 0 to A.
11: Node A receives M, falsely decides there must be a gap, since
    it is expecting packet 0, and asks for retransmission of packets
    [0,M-1].
12: Node B has already released these packets, so the broadcast
    link is stale in direction B->A.

We solve this problem by introducing a new unicast message type,
BCAST_PROTOCOL/STATE, to convey the sequence number of the next
sent broadcast packet to the other endpoint, at exactly the moment
that endpoint is added to the own node's broadcast receivers list,
and before any other unicast messages are permitted to be sent.

Furthermore, we don't allow any node to start receiving and
processing broadcast packets until this new synchronization
message has been received.

To maintain backwards compatibility, we still open up for
broadcast reception if we receive a NAME_DISTR message without
any preceding broadcast sync message. In this case, we must
assume that the other end has an older code version, and will
never send out the new synchronization message. Hence, for mixed
old and new nodes, the issue arising in 7-12 of the above may
happen with the same probability as before.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-22 14:33:21 -05:00
Ying Xue 389dd9bcf6 tipc: rename supported flag to recv_permitted
Rename the "supported" flag in bclink structure to "recv_permitted"
to better reflect what it is used for. When this flag is set for a
given node, we are permitted to receive and acknowledge broadcast
messages from that node.  Convert it to a bool at the same time,
since it is not used to store any numerical values.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-22 07:50:51 -05:00
Ying Xue 818f4da526 tipc: remove supportable flag from bclink structure
The "supportable" flag in bclink structure is a compatibility flag
indicating whether a peer node is capable of receiving TIPC broadcast
messages. However, all TIPC versions since tipc-1.5, and after the
inclusion in the upstream Linux kernel in 2006, support this capability.
It is highly unlikely that anybody is still using such an old
version of TIPC, let alone that they want to mix it with TIPC-2.0
nodes. Therefore, we now remove the "supportable" flag.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-11-22 07:50:50 -05:00
Erik Hugne 2cf8aa19fe tipc: use standard printk shortcut macros (pr_err etc.)
All messages should go directly to the kernel log.  The TIPC
specific error, warning, info and debug trace macro's are
removed and all references replaced with pr_err, pr_warn,
pr_info and pr_debug.

Commonly used sub-strings are explicitly declared as a const
char to reduce .text size.

Note that this means the debug messages (changed to pr_debug),
are now enabled through dynamic debugging, instead of a TIPC
specific Kconfig option (TIPC_DEBUG).  The latter will be
phased out completely

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
[PG: use pr_fmt as suggested by Joe Perches <joe@perches.com>]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-07-13 19:24:44 -04:00
Paul Gortmaker 617d3c7a50 tipc: compress out gratuitous extra carriage returns
Some of the comment blocks are floating in limbo between two
functions, or between blocks of code.  Delete the extra line
feeds between any comment and its associated following block
of code, to be consistent with the majority of the rest of
the kernel.  Also delete trailing newlines at EOF and fix
a couple trivial typos in existing comments.

This is a 100% cosmetic change with no runtime impact.  We get
rid of over 500 lines of non-code, and being blank line deletes,
they won't even show up as noise in git blame.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-30 15:53:56 -04:00
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
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 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 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 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 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 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
Paul Gortmaker a18c4bc3ea tipc: rename struct link* to struct tipc_link*
This converts the following:

	struct link		->	struct tipc_link
	struct link_req		->	struct tipc_link_req
	struct link_name	->	struct tipc_link_name

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-29 21:53:30 -05:00
Allan Stephens 3655959143 tipc: Ignore broadcast acknowledgements that are out-of-range
Adds checks to TIPC's broadcast link so that it ignores any
acknowledgement message containing a sequence number that does not
correspond to an unacknowledged message currently in the broadcast
link's transmit queue.

This change prevents the broadcast link from becoming stalled if a
newly booted node receives stale broadcast link acknowledgement
information from another node that has not yet fully synchronized
its end of the broadcast link to reflect the current state of the
new node's end.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-27 11:33:53 -05:00
Allan Stephens cd3decdfd1 tipc: Ensure broadcast link spinlock is held when updating node map
Fixes oversight that allowed broadcast link node map to be updated without
first taking the broadcast link spinlock that protects the map. As part
of this fix the node map has been incorporated into the broadcast link
structure to make the need for such protection more evident.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-27 11:33:48 -05:00
Allan Stephens b4b5610223 tipc: Ensure both nodes recognize loss of contact between them
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: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-09-17 22:55:03 -04:00
Allan Stephens 169073db44 tipc: Prevent broadcast link stalling when another node fails
Ensure that broadcast link messages that have not been acknowledged
by a newly failed node do not get an implied acknowledgement until the
failed node is removed from the broadcast link's map of reachable nodes.

Previously, a race condition allowed a new broadcast link message to be
sent after the implicit acknowledgement processing was completed, but
before the map of reachable nodes was updated, resulting in the message
having an expected acknowledgement count that required the failed node
to explicitly acknowledge the message. Since this would never occur
the new message would remain in the broadcast link's transmit queue
forever, eventually causing the link to become congested and "stall".
Delaying the implicit acknowledgement processing until after the update
of the map of reachable nodes eliminates this race condition and prevents
stalling.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-09-01 11:16:36 -04:00
Allan Stephens c5bd4d85d3 tipc: Enhance cleanup of broadcast link when contact with node is lost
Enhances cleanup of broadcast link-related information when contact
with a node is lost.

1) All broadcast link-related cleanup now occurs only if the lost node
   was capable of communicating over the broadcast link.

2) Following cleanup, the lost node is marked as no longer supporting
   the broadcast link, ensuring that any remaining broadcast messages
   received from that node prior to the re-establishment of a normal
   communication link are ignored.

Thanks to Surya [Suryanarayana.Garlapati@emerson.com] for contributing
a prototype version of this patch.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-09-01 11:16:36 -04:00
Allan Stephens 37b9c08a88 tipc: Optimizations to link creation code
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 <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:18 -04:00
Paul Gortmaker 8f19afb2db tipc: cosmetic - function names are not to be full sentences
Function names like "tipc_node_has_redundant_links" are unweildy
and result in long lines even for simple lines.  The "has" doesn't
contribute any value add, so dropping that is a slight step in the
right direction.   This is a cosmetic change, basic result of:

for i in `grep -l tipc_node_has_ *` ; do sed -i s/tipc_node_has_/tipc_node_/ $i ; done

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:17 -04:00
Allan Stephens 34e46258cb tipc: manually inline net_start/stop, make assoc. vars static
Relocates network-related variables into the subsystem files where
they are now primarily used (following the recent rework of TIPC's
node table), and converts globals into locals where possible. Changes
the initialization of tipc_num_links from run-time to compile-time,
and eliminates the net_start routine that becomes empty as a result.
Also eliminates the corresponding net_stop routine by moving its
(trivial) content into the one location that called the routine.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:17 -04:00
Allan Stephens 672d99e19a tipc: Convert node object array to a hash table
Replaces the dynamically allocated array of pointers to the cluster's
node objects with a static hash table. Hash collisions are resolved
using chaining, with a typical hash chain having only a single node,
to avoid degrading performance during processing of incoming packets.
The conversion to a hash table reduces the memory requirements for
TIPC's node table to approximately the same size it had prior to
the previous commit.

In addition to the hash table itself, TIPC now also maintains a
linked list for the node objects, sorted by ascending network address.
This list allows TIPC to continue sending responses to user space
applications that request node and link information in sorted order.
The list also improves performance when name table update messages are
sent by making it easier to identify the nodes that must be notified.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:17 -04:00
Allan Stephens d1bcb11544 tipc: Split up unified structure of network-related variables
Converts the fields of the global "tipc_net" structure into individual
variables.  Since the struct was never referenced as a complete unit,
its existence was pointless.  This will facilitate upcoming changes to
TIPC's node table and simpify upcoming relocation of the variables so
they are only visible to the files that actually use them.

This change is essentially cosmetic in nature, and doesn't affect the
operation of TIPC.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:17 -04:00
Allan Stephens 9df3b7eb6e tipc: Fix problem with missing link in "tipc-config -l" output
Removes a race condition that could cause TIPC's internal counter
of the number of links it has to neighboring nodes to have the
incorrect value if two independent threads of control simultaneously
create new link endpoints connecting to two different nodes using two
different bearers. Such under counting would result in TIPC failing to
list the final link(s) in its response to a configuration request to
list all of the node's links. The counter is now updated atomically
to ensure that simultaneous increments do not interfere with each
other.

Thanks go to Peter Butler <pbutler@pt.com> for his assistance in
diagnosing and fixing this problem.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:16 -04:00
Allan Stephens f137917332 tipc: Cosmetic changes to node subscription code
Relocates the code that notifies users of node subscriptions so that
it is adjacent to the rest of the routines that implement TIPC's node
subscription capability. Renames the name table routine that is
invoked by a node subscription to better reflect its purpose and to
be consistent with other, similar name table routines.

These changes are cosmetic in nature, and do not alter the behavior
of TIPC.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:16 -04:00
Allan Stephens 431697eb60 tipc: Prevent null pointer error when removing a node subscription
Prevents a null pointer dereference from occurring if a node subscription
is triggered at the same time that the subscribing port or publication is
terminating the subscription. The problem arises if the triggering routine
asynchronously activates and deregisters the node subscription while
deregistration is already underway -- the deregistration routine may find
that the pointer it has just verified to be non-NULL is now NULL.
To avoid this race condition the triggering routine now simply marks the
node subscription as defunct (to prevent it from re-activating)
instead of deregistering it. The subscription is now both deregistered
and destroyed only when the subscribing port or publication code terminates
the node subscription.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:16 -04:00
Allan Stephens a3796f895f tipc: Add network address mask helper routines
Introduces a pair of helper routines that convert the network address
for a TIPC node into the network address for its cluster or zone.

This is a cosmetic change designed to avoid future errors caused by
the incorrect use of address bitmasks, and does not alter the existing
operation of TIPC.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:16 -04:00
Allan Stephens aa84729484 tipc: Correct broadcast link peer info when displaying links
Fixes a typo in the calculation of the network address of a node's own
cluster when generating a response to the configuration command that
lists all of the node's links. The correct mask value for a <Z.C.N>
network address uses 1's for the 8-bit zone and 12-bit cluster parts
and 0's for the 12-bit node part.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-03-13 16:35:16 -04:00
Allan Stephens 2d627b92fd tipc: Combine bearer structure with tipc_bearer structure
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: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-02-23 18:05:05 -05:00
Allan Stephens e3ec9c7d5e tipc: remove zeroing assignments to static global variables
Cleans up TIPC's source code to eliminate the needless initialization
of static variables to zero.

These changes are purely cosmetic and do not alter the operation of TIPC
in any way.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:57 -08:00
Allan Stephens 0e65967e33 tipc: cleanup various cosmetic whitespace issues
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: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:56 -08:00
Allan Stephens 886ef52a8c tipc: remove redundant #includes
Eliminates a number of #include statements that no longer serve any
useful purpose.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:54 -08:00
Allan Stephens b29f142849 tipc: remove calls to dbg() and msg_dbg()
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: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:52 -08:00
Allan Stephens 5af5479296 tipc: Remove internal linked list of node objects
Eliminates a sorted list TIPC uses to keep track of the neighboring
nodes it has links to, since this duplicates information already present
in the internal array of node object pointers.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:51 -08:00
Allan Stephens 8f92df6ad4 tipc: Remove prototype code for supporting multiple clusters
Eliminates routines, data structures, and files that were intended
to allow TIPC to support a network containing multiple clusters.
Currently, TIPC supports only networks consisting of a single cluster
within a single zone, so this code is unnecessary.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:49 -08:00
Allan Stephens 51a8e4dee7 tipc: Remove prototype code for supporting inter-cluster routing
Eliminates routines and data structures that were intended to allow
TIPC to route messages to other clusters. Currently, TIPC supports only
networks consisting of a single cluster within a single zone, so this
code is unnecessary.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:48 -08:00
Allan Stephens 08c80e9a03 tipc: Remove prototype code for supporting slave nodes
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: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:48 -08:00
Allan Stephens 51f98a8d70 tipc: Remove prototype code for supporting multiple zones
Eliminates routines, data structures, and files that were intended
to allows TIPC to support a network containing multiple zones.
Currently, TIPC supports only networks consisting of a single cluster
within a single zone, so this code is unnecessary.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01 13:57:47 -08:00
Allan Stephens 528c771e87 tipc: Delete useless function prototypes
Removes several function declarations that aren't used anywhere,
either because they reference routines that no longer exist or
because all users of the function reference it after it has already
been defined.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-02 13:34:03 -08:00
Allan Stephens c802628297 tipc: Remove obsolete inclusions of header files
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: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-02 13:34:02 -08:00
stephen hemminger 31e3c3f6f1 tipc: cleanup function namespace
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: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-16 11:13:24 -07:00
Paul Gortmaker 7368ddf144 tipc: clean out all instances of #if 0'd unused code
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: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-13 14:27:34 -07:00
Eric Dumazet a02cec2155 net: return operator cleanup
Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-23 14:33:39 -07:00
Allan Stephens 5a68d5ee00 tipc: Prevent missing name table entries when link flip-flops rapidly
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: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-17 17:32:00 -07:00
Allan Stephens 76ae0d71d8 tipc: Optimize tipc_node_has_active_links()
Eliminate unnecessary checking for null node pointer and redundant
check of second active link array entry.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-17 17:31:57 -07:00
Allan Stephens c68ca7b720 tipc: add tipc_ prefix to fcns targeted for un-inlining
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: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-12 23:02:25 -07:00
Frans Pop a570f095ea tipc: remove trailing space in messages
Signed-off-by: Frans Pop <elendil@planet.nl>
Cc: Per Liden <per.liden@ericsson.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-24 14:01:54 -07:00
Stephen Hemminger 4b704d59d6 tipc: fix non-const printf format arguments
Fix warnings from current gcc about using non-const strings as printf
args in TIPC. Compile tested only (not a TIPC user).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-18 19:11:29 -07:00
David S. Miller 6c00055a81 tipc: Don't use structure names which easily globally conflict.
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: David S. Miller <davem@davemloft.net>
2008-09-02 23:38:32 -07:00
Allan Stephens 1aad72d6cd tipc: Add missing locks when inspecting node list & link list
This patch ensures that TIPC configuration commands that display info
about neighboring nodes and their links take the spinlocks that
protect the node list and link lists from changing while the lists
are being traversed.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-14 22:44:58 -07:00
Allan Stephens 2ecb0924d7 tipc: Prevent node object duplication due to simultaneous discovery
This patch ensures that the simultaneous discovery of the same
neighboring node by multiple interfaces does not cause TIPC to add
the node into its internal data structures more than once.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-05-21 14:53:00 -07:00
Florian Westphal d788d8056f [TIPC]: Fix two minor sparse warnings.
fix two warnings generated by sparse:

link.c:2386 symbol 'msgcount' shadows an earlier one
node.c:244 symbol 'addr_string' shadows an earlier one

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-02 19:42:31 -07:00
YOSHIFUJI Hideaki c430728526 [NET] TIPC: Fix whitespace errors.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:20:15 -08:00
Arnaldo Carvalho de Melo 2710b57ff9 [TIPC]: Use kzalloc where appropriate
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02 21:30:21 -08:00
Al Viro 3e6c8cd566 [TIPC]: endianness annotations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:08 -08:00
Allan Stephens fc144deec6 [TIPC]: Can now list multicast link on an isolated network node
This patch fixes a minor bug that prevents "tipc-config -l" from
displaying the multicast link if a TIPC node has never successfully
established at least one unicast link.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-18 19:55:21 -07:00
Allan Stephens ea13847b24 [TIPC]: Improve response to requests for node/link information
Now allocates reply space for "get links" request based on number of actual
links, not number of potential links.  Also, limits reply to "get links" and
"get nodes" requests to 32KB to match capabilities of tipc-config utility
that issued request.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
2006-06-29 17:08:15 -07:00
Ingo Molnar 34af946a22 [PATCH] spin/rwlock init cleanups
locking init cleanups:

 - convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
 - convert rwlocks in a similar manner

this patch was generated automatically.

Motivation:

 - cleanliness
 - lockdep needs control of lock initialization, which the open-coded
   variants do not give
 - it's also useful for -rt and for lock debugging in general

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:39 -07:00
Allan Stephens 5392d64688 [TIPC]: Fixed link switchover bugs
Incorporates several related fixes:
- switchover now occurs when switching from an active link to a standby link
- failure of a standby link no longer initiates switchover
- links now display correct # of received packtes following reactivation

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-25 23:52:50 -07:00
Allan Stephens a10bd924a4 [TIPC]: Enhanced & cleaned up system messages; fixed 2 obscure memory leaks.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-25 23:52:17 -07:00
Allan Stephens f131072c3d [TIPC]: First phase of assert() cleanup
This also contains enhancements to simplify comparisons in name table
publication removal algorithm and to simplify name table sanity checking
when shutting down TIPC.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-25 23:51:37 -07:00
Adrian Bunk 988f088a8e [TIPC]: Cleanups
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: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 22:37:52 -08:00
Sam Ravnborg 1fc54d8f49 [TIPC]: Fix simple sparse warnings
Tried to run the new tipc stack through sparse.
Following patch fixes all cases where 0 was used
as replacement of NULL.
Use NULL to document this is a pointer and to silence sparse.

This brough sparse warning count down with 127 to 24 warnings.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 22:36:47 -08:00
Per Liden 4323add677 [TIPC] Avoid polluting the global namespace
This patch adds a tipc_ prefix to all externally visible symbols.

Signed-off-by: Per Liden <per.liden@ericsson.com>
2006-01-18 00:45:16 +01:00
Per Liden 593a5f22d8 [TIPC] More updates of file headers
Updated copyright notice to include the year the file was
actually created. Information about file creation dates
was extracted from the files in the old CVS repository
at tipc.sourceforge.net.

Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12 14:06:39 -08:00
Per Liden 9da1c8b694 [TIPC] Update of file headers
The copyright statements from different parts of Ericsson
have been merged into one.

Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12 14:06:38 -08:00
Per Liden 9ea1fd3c1a [TIPC] License header update
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: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12 14:06:36 -08:00
Per Liden b97bf3fd8f [TIPC] Initial merge
TIPC (Transparent Inter Process Communication) is a protocol designed for
intra cluster communication. For more information see
http://tipc.sourceforge.net

Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12 14:06:31 -08:00