In commit d12d2e12 "tipc: send out join messages as soon as new
member is discovered") we added a call to the function tipc_group_join()
without considering the case that the preceding tipc_sk_publish() might
have failed, and the group item already deleted.

We fix this by returning from tipc_sk_join() directly after the
failed tipc_sk_publish.

Reported-by: syzbot+e3eeae78ea88b8d6d858@syzkaller.appspotmail.com
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current criteria for returning POLLOUT from a group member socket is
too simplistic. It basically returns POLLOUT as soon as the group has
external destinations, something obviously leading to a lot of spinning
during destination congestion situations. At the same time, the internal
congestion handling is unnecessarily complex.

We now change this as follows.

- We introduce an 'open' flag in  struct tipc_group. This flag is used
  only to help poll() get the setting of POLLOUT right, and *not* for
  congeston handling as such. This means that a user can choose to
  ignore an  EAGAIN for a destination and go on sending messages to
  other destinations in the group if he wants to.

- The flag is set to false every time we return EAGAIN on a send call.

- The flag is set to true every time any member, i.e., not necessarily
  the member that caused EAGAIN, is removed from the small_win list.

- We remove the group member 'usr_pending' flag. The size of the send
  window and presence in the 'small_win' list is sufficient criteria
  for recognizing congestion.

This solution seems to be a reasonable compromise between 'anycast',
which is normally not waiting for POLLOUT for a specific destination,
and the other three send modes, which are.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a member joins a group, it also indicates a binding scope. This
makes it possible to create both node local groups, invisible to other
nodes, as well as cluster global groups, visible everywhere.

In order to avoid that different members end up having permanently
differing views of group size and memberhip, we must inhibit locally
and globally bound members from joining the same group.

We do this by using the binding scope as an additional separator between
groups. I.e., a member must ignore all membership events from sockets
using a different scope than itself, and all lookups for message
destinations must require an exact match between the message's lookup
scope and the potential target's binding scope.

Apart from making it possible to create local groups using the same
identity on different nodes, a side effect of this is that it now also
becomes possible to create a cluster global group with the same identity
across the same nodes, without interfering with the local groups.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a socket is joining a group, we look up in the binding table to
find if there are already other members of the group present. This is
used for being able to return EAGAIN instead of EHOSTUNREACH if the
user proceeds directly to a send attempt.

However, the information in the binding table can be used to directly
set the created member in state MBR_PUBLISHED and send a JOIN message
to the peer, instead of waiting for a topology PUBLISH event to do this.
When there are many members in a group, the propagation time for such
events can be significant, and we can save time during the join
operation if we use the initial lookup result fully.

In this commit, we eliminate the member state MBR_DISCOVERED which has
been the result of the initial lookup, and do instead go directly to
MBR_PUBLISHED, which initiates the setup.

After this change, the tipc_member FSM looks as follows:

     +-----------+
---->| PUBLISHED |-----------------------------------------------+
PUB- +-----------+                                 LEAVE/WITHRAW |
LISH       |JOIN                                                 |
           |     +-------------------------------------------+   |
           |     |                            LEAVE/WITHDRAW |   |
           |     |                +------------+             |   |
           |     |   +----------->|  PENDING   |---------+   |   |
           |     |   |msg/maxactv +-+---+------+  LEAVE/ |   |   |
           |     |   |              |   |       WITHDRAW |   |   |
           |     |   |   +----------+   |                |   |   |
           |     |   |   |revert/maxactv|                |   |   |
           |     |   |   V              V                V   V   V
           |   +----------+  msg  +------------+       +-----------+
           +-->|  JOINED  |------>|   ACTIVE   |------>|  LEAVING  |--->
           |   +----------+       +--- -+------+ LEAVE/+-----------+DOWN
           |        A   A               |      WITHDRAW A   A    A   EVT
           |        |   |               |RECLAIM        |   |    |
           |        |   |REMIT          V               |   |    |
           |        |   |== adv   +------------+        |   |    |
           |        |   +---------| RECLAIMING |--------+   |    |
           |        |             +-----+------+  LEAVE/    |    |
           |        |                   |REMIT   WITHDRAW   |    |
           |        |                   |< adv              |    |
           |        |msg/               V            LEAVE/ |    |
           |        |adv==ADV_IDLE+------------+   WITHDRAW |    |
           |        +-------------|  REMITTED  |------------+    |
           |                      +------------+                 |
           |PUBLISH                                              |
JOIN +-----------+                                LEAVE/WITHDRAW |
---->|  JOINING  |-----------------------------------------------+
     +-----------+
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the current implementation, a group socket receiving topology
events about other members just converts the topology event message
into a group event message and stores it until it reaches the right
state to issue it to the user. This complicates the code unnecessarily,
and becomes impractical when we in the coming commits will need to
create and issue membership events independently.

In this commit, we change this so that we just notice the type and
origin of the incoming topology event, and then drop the buffer. Only
when it is time to actually send a group event to the user do we
explicitly create a new message and send it upwards.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 42b531de ("tipc: Fix missing connection request
handling"), we replaced unconditional wakeup() with condtional
wakeup for clients with flags POLLIN | POLLRDNORM | POLLRDBAND.

This breaks the applications which do a connect followed by poll
with POLLOUT flag. These applications are not woken when the
connection is ESTABLISHED and hence sleep forever.

In this commit, we fix it by including the POLLOUT event for
sockets in TIPC_CONNECTING state.

Fixes: 42b531de ("tipc: Fix missing connection request handling")
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the function tipc_sk_mcast_rcv() we call refcount_dec(&skb->users)
on received sk_buffers. Since the reference counter might hit zero at
this point, we have a potential memory leak.

We fix this by replacing refcount_dec() with kfree_skb().
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: tipc-discussion@lists.sourceforge.net
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tsk->group is set to grp earlier, but we forget to unset it
after grp is freed.

Fixes: 75da2163 ("tipc: introduce communication groups")
Reported-by: syzkaller bot
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function tipc_sk_timeout() is more complex than necessary, and
even seems to contain an undetected bug. At one of the occurences
where we renew the timer we just order it with (HZ / 20), instead
of (jiffies + HZ / 20);

In this commit we clean up the function.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit ae236fb2 ("tipc: receive group membership events via
member socket") we broke the tipc_poll() function by checking the
state of the receive queue before the call to poll_sock_wait(), while
relying that state afterwards, when it might have changed.

We restore this in this commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The following scenario is possible:
- A user joins a group, and immediately sends out a broadcast message
  to its members.
- The broadcast message, following a different data path than the
  initial JOIN message sent out during the joining procedure, arrives
  to a receiver before the latter..
- The receiver drops the message, since it is not ready to accept any
  messages until the JOIN has arrived.

We avoid this by treating group protocol JOIN messages like unicast
messages.
- We let them pass through the recipient's multicast input queue, just
  like ordinary unicasts.
- We force the first following broadacst to be sent as replicated
  unicast and being acknowledged by the recipient before accepting
  any more broadcast transmissions.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need a mechanism guaranteeing that group unicasts sent out from a
socket are not bypassed by later sent broadcasts from the same socket.
We do this as follows:

- Each time a unicast is sent, we set a the broadcast method for the
  socket to "replicast" and "mandatory". This forces the first
  subsequent broadcast message to follow the same network and data path
  as the preceding unicast to a destination, hence preventing it from
  overtaking the latter.

- In order to make the 'same data path' statement above true, we let
  group unicasts pass through the multicast link input queue, instead
  of as previously through the unicast link input queue.

- In the first broadcast following a unicast, we set a new header flag,
  requiring all recipients to immediately acknowledge its reception.

- During the period before all the expected acknowledges are received,
  the socket refuses to accept any more broadcast attempts, i.e., by
  blocking or returning EAGAIN. This period should typically not be
  longer than a few microseconds.

- When all acknowledges have been received, the sending socket will
  open up for subsequent broadcasts, this time giving the link layer
  freedom to itself select the best transmission method.

- The forced and/or abrupt transmission method changes described above
  may lead to broadcasts arriving out of order to the recipients. We
  remedy this by introducing code that checks and if necessary
  re-orders such messages at the receiving end.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Group unicast messages don't follow the same path as broadcast messages,
and there is a high risk that unicasts sent from a socket might bypass
previously sent broadcasts from the same socket.

We fix this by letting all unicast messages carry the sequence number of
the next sent broadcast from the same node, but without updating this
number at the receiver. This way, a receiver can check and if necessary
re-order such messages before they are added to the socket receive buffer.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The previously introduced message transport to all group members is
based on the tipc multicast service, but is logically a broadcast
service within the group, and that is what we call it.

We now add functionality for sending messages to all group members
having a certain identity. Correspondingly, we call this feature 'group
multicast'. The service is using unicast when only one destination is
found, otherwise it will use the bearer broadcast service to transfer
the messages. In the latter case, the receiving members filter arriving
messages by looking at the intended destination instance. If there is
no match, the message will be dropped, while still being considered
received and read as seen by the flow control mechanism.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In this commit, we make it possible to send connectionless unicast
messages to any member corresponding to the given member identity,
when there is more than one such member. The sender must use a
TIPC_ADDR_NAME address to achieve this effect.

We also perform load balancing between the destinations, i.e., we
primarily select one which has advertised sufficient send window
to not cause a block/EAGAIN delay, if any. This mechanism is
overlayed on the always present round-robin selection.

Anycast messages are subject to the same start synchronization
and flow control mechanism as group broadcast messages.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We now make it possible to send connectionless unicast messages
within a communication group. To send a message, the sender can use
either a direct port address, aka port identity, or an indirect port
name to be looked up.

This type of messages are subject to the same start synchronization
and flow control mechanism as group broadcast messages.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We introduce an end-to-end flow control mechanism for group broadcast
messages. This ensures that no messages are ever lost because of
destination receive buffer overflow, with minimal impact on performance.
For now, the algorithm is based on the assumption that there is only one
active transmitter at any moment in time.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like with any other service, group members' availability can be
subscribed for by connecting to be topology server. However, because
the events arrive via a different socket than the member socket, there
is a real risk that membership events my arrive out of synch with the
actual JOIN/LEAVE action. I.e., it is possible to receive the first
messages from a new member before the corresponding JOIN event arrives,
just as it is possible to receive the last messages from a leaving
member after the LEAVE event has already been received.

Since each member socket is internally also subscribing for membership
events, we now fix this problem by passing those events on to the user
via the member socket. We leverage the already present member synch-
ronization protocol to guarantee correct message/event order. An event
is delivered to the user as an empty message where the two source
addresses identify the new/lost member. Furthermore, we set the MSG_OOB
bit in the message flags to mark it as an event. If the event is an
indication about a member loss we also set the MSG_EOR bit, so it can
be distinguished from a member addition event.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With group communication, it becomes important for a message receiver to
identify not only from which socket (identfied by a node:port tuple) the
message was sent, but also the logical identity (type:instance) of the
sending member.

We fix this by adding a second instance of struct sockaddr_tipc to the
source address area when a message is read. The extra address struct
is filled in with data found in the received message header (type,) and
in the local member representation struct (instance.)
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a preparation for introducing flow control for multicast and datagram
messaging we need a more strictly defined framework than we have now. A
socket must be able keep track of exactly how many and which other
sockets it is allowed to communicate with at any moment, and keep the
necessary state for those.

We therefore introduce a new concept we have named Communication Group.
Sockets can join a group via a new setsockopt() call TIPC_GROUP_JOIN.
The call takes four parameters: 'type' serves as group identifier,
'instance' serves as an logical member identifier, and 'scope' indicates
the visibility of the group (node/cluster/zone). Finally, 'flags' makes
it possible to set certain properties for the member. For now, there is
only one flag, indicating if the creator of the socket wants to receive
a copy of broadcast or multicast messages it is sending via the socket,
and if wants to be eligible as destination for its own anycasts.

A group is closed, i.e., sockets which have not joined a group will
not be able to send messages to or receive messages from members of
the group, and vice versa.

Any member of a group can send multicast ('group broadcast') messages
to all group members, optionally including itself, using the primitive
send(). The messages are received via the recvmsg() primitive. A socket
can only be member of one group at a time.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We often see a need for a linked list of destination identities,
sometimes containing a port number, sometimes a node identity, and
sometimes both. The currently defined struct u32_list is not generic
enough to cover all cases, so we extend it to contain two u32 integers
and rename it to struct tipc_dest_list.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We see an increasing need to send multiple single-buffer messages
of TIPC_SYSTEM_IMPORTANCE to different individual destination nodes.
Instead of looping over the send queue and sending each buffer
individually, as we do now, we add a new help function
tipc_node_distr_xmit() to do this.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the following commits we will need to handle multiple incoming and
rejected/returned buffers in the function socket.c::filter_rcv().
As a preparation for this, we generalize the function by handling
buffer queues instead of individual buffers. We also introduce a
help function tipc_skb_reject(), and rename filter_rcv() to
tipc_sk_filter_rcv() in line with other functions in socket.c.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The address given to tipc_connect() is not completely sanity checked,
under the assumption that this will be done later in the function
__tipc_sendmsg() when the address is used there.

However, the latter functon will in the next commits serve as caller
to several other send functions, so we want to move the corresponding
sanity check there to the beginning of that function, before we possibly
need to grab the address stored by tipc_connect(). We must therefore
be able to trust that this address already has been thoroughly checked.

We do this in this commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As preparation for introducing communication groups, we add the ability
to issue topology subscriptions and receive topology events from kernel
space. This will make it possible for group member sockets to keep track
of other group members.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In 9dbbfb0a function tipc_sk_reinit
had additional logic added to loop in the event that function
rhashtable_walk_next() returned -EAGAIN. No worries.

However, if rhashtable_walk_start returns -EAGAIN, it does "continue",
and therefore skips the call to rhashtable_walk_stop(). That has
the effect of calling rcu_read_lock() without its paired call to
rcu_read_unlock(). Since rcu_read_lock() may be nested, the problem
may not be apparent for a while, especially since resize events may
be rare. But the comments to rhashtable_walk_start() state:

 * ...Note that we take the RCU lock in all
 * cases including when we return an error.  So you must always call
 * rhashtable_walk_stop to clean up.

This patch replaces the continue with a goto and label to ensure a
matching call to rhashtable_walk_stop().
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The macro tipc_wait_for_cond() is embedding the macro sk_wait_event()
to fulfil its task. The latter, in turn, is evaluating the stated
condition outside the socket lock context. This is problematic if
the condition is accessing non-trivial data structures which may be
altered by incoming interrupts, as is the case with the cong_links()
linked list, used by socket to keep track of the current set of
congested links. We sometimes see crashes when this list is accessed
by a condition function at the same time as a SOCK_WAKEUP interrupt
is removing an element from the list.

We fix this by expanding selected parts of sk_wait_event() into the
outer macro, while ensuring that all evaluations of a given condition
are performed under socket lock protection.

Fixes: commit 365ad353 ("tipc: reduce risk of user starvation during link congestion")
Reviewed-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We try to make this function more readable by improving variable names
and comments, using more stack variables, and doing some smaller changes
to the logics. We also rename the function to make it consistent with
naming conventions used elsewhere in the code.
Reviewed-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We try to make this function more readable by improving variable names
and comments, plus some minor changes to the logics.
Reviewed-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a socket is shutting down, we notify the peer node about the
connection termination by reusing an incoming message if possible.
If the last received message was a connection acknowledgment
message, we reverse this message and set the error code to
TIPC_ERR_NO_PORT and send it to peer.

In tipc_sk_proto_rcv(), we never check for message errors while
processing the connection acknowledgment or probe messages. Thus
this message performs the usual flow control accounting and leaves
the session hanging.

In this commit, we terminate the connection when we receive such
error messages.
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Until now, the checks for sockets in CONNECTING state was based on
the assumption that the incoming message was always from the
peer's accepted data socket.

However an application using a non-blocking socket sends an implicit
connect, this socket which is in CONNECTING state can receive error
messages from the peer's listening socket. As we discard these
messages, the application socket hangs as there due to inactivity.
In addition to this, there are other places where we process errors
but do not notify the user.

In this commit, we process such incoming error messages and notify
our users about them using sk_state_change().
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In filter_connect, we use waitqueue_active() to check for any
connections to wakeup. But waitqueue_active() is missing memory
barriers while accessing the critical sections, leading to
inconsistent results.

In this commit, we replace this with an SMP safe wq_has_sleeper()
using the generic socket callback sk_data_ready().
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Until now in tipc_recv_stream(), we update the received
unacknowledged bytes based on a stack variable and not based on the
actual message size.
If the user buffer passed at tipc_recv_stream() is smaller than the
received skb, the size variable in stack differs from the actual
message size in the skb. This leads to a flow control accounting
error causing permanent congestion.

In this commit, we fix this accounting error by always using the
size of the incoming message.

Fixes: 10724cc7 ("tipc: redesign connection-level flow control")
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Until now in tipc_send_stream(), we return -1 when the socket
encounters link congestion even if the socket had successfully
sent partial data. This is incorrect as the application resends
the same the partial data leading to data corruption at
receiver's end.

In this commit, we return the partially sent bytes as the return
value at link congestion.

Fixes: 10724cc7 ("tipc: redesign connection-level flow control")
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

for socketpairs using connectionless transport, we cache
the respective node local TIPC portid to use in subsequent
calls to send() in the socket's private data.
Signed-off-by: NErik Hugne <erik.hugne@gmail.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sockets A and B are connected back-to-back, similar to what
AF_UNIX does.
Signed-off-by: NErik Hugne <erik.hugne@gmail.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>