Due to the lacking of any credential, it's allowed to accept commands
requested from remote nodes to query the local node status, which is
prone to involve potential security risks. Instead, if we login to
a remote node with ssh command, this approach is not only more safe
than the remote management feature, but also it can give us more
permissions like changing the remote node configuration. So it's
reasonable for us to obsolete the remote management feature now.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a topology event subscription fails for any reason, such as out
of memory, max number reached or because we received an invalid
request the correct behavior is to terminate the subscribers
connection to the topology server. This is currently broken and
produces the following oops:

[27.953662] tipc: Subscription rejected, illegal request
[27.955329] BUG: spinlock recursion on CPU#1, kworker/u4:0/6
[27.957066]  lock: 0xffff88003c67f408, .magic: dead4ead, .owner: kworker/u4:0/6, .owner_cpu: 1
[27.958054] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.0-rc6+ #5
[27.960230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[27.960874] Workqueue: tipc_rcv tipc_recv_work [tipc]
[27.961430]  ffff88003c67f408 ffff88003de27c18 ffffffff815c0207 ffff88003de1c050
[27.962292]  ffff88003de27c38 ffffffff815beec5 ffff88003c67f408 ffffffff817f0a8a
[27.963152]  ffff88003de27c58 ffffffff815beeeb ffff88003c67f408 ffffffffa0013520
[27.964023] Call Trace:
[27.964292]  [<ffffffff815c0207>] dump_stack+0x45/0x56
[27.964874]  [<ffffffff815beec5>] spin_dump+0x8c/0x91
[27.965420]  [<ffffffff815beeeb>] spin_bug+0x21/0x26
[27.965995]  [<ffffffff81083df6>] do_raw_spin_lock+0x116/0x140
[27.966631]  [<ffffffff815c6215>] _raw_spin_lock_bh+0x15/0x20
[27.967256]  [<ffffffffa0008540>] subscr_conn_shutdown_event+0x20/0xa0 [tipc]
[27.968051]  [<ffffffffa000fde4>] tipc_close_conn+0xa4/0xb0 [tipc]
[27.968722]  [<ffffffffa00101ba>] tipc_conn_terminate+0x1a/0x30 [tipc]
[27.969436]  [<ffffffffa00089a2>] subscr_conn_msg_event+0x1f2/0x2f0 [tipc]
[27.970209]  [<ffffffffa0010000>] tipc_receive_from_sock+0x90/0xf0 [tipc]
[27.970972]  [<ffffffffa000fa79>] tipc_recv_work+0x29/0x50 [tipc]
[27.971633]  [<ffffffff8105dbf5>] process_one_work+0x165/0x3e0
[27.972267]  [<ffffffff8105e869>] worker_thread+0x119/0x3a0
[27.972896]  [<ffffffff8105e750>] ? manage_workers.isra.25+0x2a0/0x2a0
[27.973622]  [<ffffffff810648af>] kthread+0xdf/0x100
[27.974168]  [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0
[27.974893]  [<ffffffff815ce13c>] ret_from_fork+0x7c/0xb0
[27.975466]  [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0

The recursion occurs when subscr_terminate tries to grab the
subscriber lock, which is already taken by subscr_conn_msg_event.
We fix this by checking if the request to establish a new
subscription was successful, and if not we initiate termination of
the subscriber after we have released the subscriber lock.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As an artefact from the native interface, the message sending functions
in the port takes a port ref as first parameter, and then looks up in
the registry to find the corresponding port pointer. This despite the
fact that the only currently existing caller, tipc_sock, already knows
this pointer.

We change the signature of these functions to take a struct tipc_port*
argument, and remove the redundant lookups.

We also remove an unmotivated extra lookup in the function
socket.c:auto_connect(), and, as the lookup functions tipc_port_deref()
and ref_deref() now become unused, we remove these two functions.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The practice of naming variables in TIPC is inconistent, sometimes
even within the same file.

In this commit we align variable names and declarations within
socket.c, and function and macro names within socket.h. We also
reduce the number of conversion macros to two, in order to make
usage less obsure.

These changes are purely cosmetic.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The three functions tipc_portimportance(), tipc_portunreliable() and
tipc_portunreturnable() and their corresponding tipc_set* functions,
are all grabbing port_lock when accessing the targeted port. This is
unnecessary in the current code, since these calls only are made from
within socket downcalls, already protected by sock_lock.

We remove the redundant locking. Also, since the functions now become
trivial one-liners, we move them to port.h and make them inline.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to the original one-to-many relation between port and user API
layers, upcalls to the API have been performed via function pointers,
installed in struct tipc_port at creation. Since this relation now
always is one-to-one, we can instead use ordinary function calls.

We remove the function pointers 'dispatcher' and ´wakeup' from
struct tipc_port, and replace them with calls to the renamed
functions tipc_sk_rcv() and tipc_sk_wakeup().

At the same time we change the name and signature of the functions
tipc_createport() and tipc_deleteport() to reflect their new role
as mere initialization/destruction functions.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the removal of the tipc native API the relation between
a tipc_port and its API types is strictly one-to-one, i.e, the
latter can now only be a socket API. There is therefore no need
to allocate struct tipc_port and struct sock independently.

In this commit, we aggregate struct tipc_port into struct tipc_sock,
hence saving both CPU cycles and structure complexity.

There are no functional changes in this commit, except for the
elimination of the separate allocation/freeing of tipc_port.
All other changes are just adaptatons to the new data structure.

This commit also opens up for further code simplifications and
code volume reduction, something we will do in later commits.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The field 'peer_name' in struct tipc_sock is redundant, since
this information already is available from tipc_port, to which
tipc_sock has a reference.

We remove the field, and ensure that peer node and peer port
info instead is fetched via the functions that already exist
for this purpose.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The lock for protecting the reference table is declared as an
RWLOCK, although it is only used in write mode, never in read
mode.

We redefine it to become a spinlock.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The use of __constant_<foo> has been unnecessary for quite awhile now.

Make these uses consistent with the rest of the kernel.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Failure to schedule a TIPC tasklet with tipc_k_signal because the
tasklet handler is disabled is not an error. It means TIPC is
currently in the process of shutting down. We remove the error
logging in this case.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the TIPC module is removed, the tasklet handler is disabled
before all other subsystems. This will cause lingering publications
in the name table because the node_down tasklets responsible to
clean up publications from an unreachable node will never run.
When the name table is shut down, these publications are detected
and an error message is logged:
tipc: nametbl_stop(): orphaned hash chain detected
This is actually a memory leak, introduced with commit
993b858e ("tipc: correct the order
of stopping services at rmmod")

Instead of just logging an error and leaking memory, we free
the orphaned entries during nametable shutdown.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a topology server subscriber is disconnected, the associated
connection id is set to zero. A check vs zero is then done in the
subscription timeout function to see if the subscriber have been
shut down. This is unnecessary, because all subscription timers
will be cancelled when a subscriber terminates. Setting the
connection id to zero is actually harmful because id zero is the
identity of the topology server listening socket, and can cause a
race that leads to this socket being closed instead.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When messages are received via tipc socket under non-block mode,
schedule_timeout() is called in tipc_wait_for_rcvmsg(), that is,
the process of receiving messages will be scheduled once although
timeout value passed to schedule_timeout() is 0. The same issue
exists in accept()/wait_for_accept(). To avoid this unnecessary
process switch, we only call schedule_timeout() if the timeout
value is non-zero.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When tipc_conn_sendmsg() calls tipc_conn_lookup() to query a
connection instance, its reference count value is increased if
it's found. But subsequently if it's found that the connection is
closed, the work of sending message is not queued into its server
send workqueue, and the connection reference count is not decreased.
This will cause a reference count leak. To reproduce this problem,
an application would need to open and closes topology server
connections with high intensity.

We fix this by immediately decrementing the connection reference
count if a send fails due to the connection being closed.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently connection shutdown callback function is called when
connection instance is released in tipc_conn_kref_release(), and
receiving packets and sending packets are running in different
threads. Even if connection is closed by the thread of receiving
packets, its shutdown callback may not be called immediately as
the connection reference count is non-zero at that moment. So,
although the connection is shut down by the thread of receiving
packets, the thread of sending packets doesn't know it. Before
its shutdown callback is invoked to tell the sending thread its
connection has been closed, the sending thread may deliver
messages by tipc_conn_sendmsg(), this is why the following error
information appears:

"Sending subscription event failed, no memory"

To eliminate it, allow connection shutdown callback function to
be called before connection id is removed in tipc_close_conn(),
which makes the sending thread know the truth in time that its
socket is closed so that it doesn't send message to it. We also
remove the "Sending XXX failed..." error reporting for topology
and config services.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Accidentally a side effect is involved by commit 6e967adf(tipc:
relocate common functions from media to bearer). Now tipc stack
handler of receiving packets from netdevices as well as netdevice
notification handler are registered when bearer is enabled rather
than tipc module initialization stage, but the two handlers are
both unregistered in tipc module exit phase. If tipc module is
inserted and then immediately removed, the following warning
message will appear:

"dev_remove_pack: ffffffffa0380940 not found"

This is because in module insertion stage tipc stack packet handler
is not registered at all, but in module exit phase dev_remove_pack()
needs to remove it. Of course, dev_remove_pack() cannot find tipc
protocol handler from the kernel protocol handler list so that the
warning message is printed out.

But if registering the two handlers is adjusted from enabling bearer
phase into inserting module stage, the warning message will be
eliminated. Due to this change, tipc_core_start_net() and
tipc_core_stop_net() can be deleted as well.
Reported-by: NWang Weidong <wangweidong1@huawei.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When tipc module is inserted, many tipc components are initialized
one by one. During the initialization period, if one of them is
failed, tipc_core_stop() will be called to stop all components
whatever corresponding components are created or not. To avoid to
release uncreated ones, relevant components have to add necessary
enabled flags indicating whether they are created or not.

But in the initialization stage, if one component is unsuccessfully
created, we will just destroy successfully created components before
the failed component instead of all components. All enabled flags
defined in components, in turn, become redundant. Additionally it's
also unnecessary to identify whether table.types is NULL in
tipc_nametbl_stop() because name stable has been definitely created
successfully when tipc_nametbl_stop() is called.

Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a message could not be sent out because the destination node
or link could not be found, the full message size is returned from
sendmsg() as if it had been sent successfully. An application will
then get a false indication that it's making forward progress. This
problem has existed since the initial commit in 2.6.16.

We change this to return -ENETUNREACH if the message cannot be
delivered due to the destination node/link being unavailable. We
also get rid of the redundant tipc_reject_msg call since freeing
the buffer and doing a tipc_port_iovec_reject accomplishes exactly
the same thing.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I commit e099e86c
("tipc: add node_lock protection to link lookup function")
we are calling spin_lock(&node->lock) directly instead of indirectly
via the tipc_node_lock(node) function. However, tipc_node_lock() is
using spin_lock_bh(), not spin_lock(), something leading to
unbalanced usage in one place, and a smatch warning.

We fix this by consistently using tipc_node_lock()/unlock() in
in the places touched by the mentioned commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 7d33939f
("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: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In an earlier commit, ("tipc: remove links list from bearer struct")
we described three issues that need to be pre-emptively resolved before
we can remove tipc_net_lock. Here we resolve issue a) described in that
commit:

"a) In access method #2, we access the link before taking the
    protecting node_lock. This will not work once net_lock is gone,
    so we will have to change the access order. We will deal with
    this in a later commit in this series."

Here, we change that access order, by ensuring that the function
link_find_link() returns only a safe reference for finding
the link, i.e., a node pointer and an index into its 'links' array,
not the link pointer itself. We also change all callers of this
function to first take the node lock before they can check if there
still is a valid link pointer at the returned index. Since the
function now returns a node pointer rather than a link pointer,
we rename it to the more appropriate 'tipc_link_find_owner().
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the earlier commits ("tipc: remove 'links' list from
tipc_bearer struct") and ("tipc: introduce new spinlock to protect
struct link_req"), there is no longer any need to protect struct
link_req or or any link list by use of bearer_lock. Furthermore,
we have eliminated the need for using bearer_lock during downcalls
(send) from the link to the bearer, since we have ensured that
bearers always have a longer life cycle that their associated links,
and always contain valid data.

So, the only need now for a lock protecting bearers is for guaranteeing
consistency of the bearer list itself. For this, it is sufficient, at
least for the time being, to continue applying 'net_lock´ in write mode.

By removing bearer_lock we also pre-empt introduction of issue b) descibed
in the previous commit "tipc: remove 'links' list from tipc_bearer struct":

"b) When the outer protection from net_lock is gone, taking
    bearer_lock and node_lock in opposite order of method 1) and 2)
    will become an obvious deadlock hazard".

Therefore, we now eliminate the bearer_lock spinlock.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We change the order of checking for destination users when processing
incoming packets. By placing the checks for users that may potentially
replace the processed buffer, i.e., CHANGEOVER_PROTOCOL and
MSG_FRAGMENTER, in a separate step before we check for the true end
users, we get rid of a label and a 'goto', at the same time making the
code more comprehensible and easy to follow.

This commit does not change any functionality, it is just a cosmetic
code reshuffle.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the previous redesign of the tunnel reception algorithm and
functions, we finalize it by renaming a couple of stack variables
in tipc_tunnel_rcv(). This makes it more consistent with the naming
scheme elsewhere in this part of the code.

This change is purely cosmetic, with no functional changes.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We simplify and slim down the code in function tipc_tunnel_rcv()
No impact on the users of this function.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the earlier commits in this series related to the function
tipc_link_tunnel_rcv(), we can now go further and simplify its
signature.

The function now consumes all DUPLICATE packets, and only returns such
ORIGINAL packets that are ready for immediate delivery, i.e., no
more link level protocol processing needs to be done by the caller.
As a consequence, the the caller, tipc_rcv(), does not access the link
pointer after call return, and it becomes unnecessary to pass a link
pointer reference in the call. Instead, we now only pass it the tunnel
link's owner node, which is sufficient to find the destination link for
the tunnelled packet.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a link is reset, and there is a redundant link available, all
sender sockets will steer their subsequent traffic through the
remaining link. In order to guarantee preserved packet order and
cardinality during the transition, we tunnel the failing link's send
queue through the remaining link before we allow any sockets to use it.

In this commit, we change the algorithm for receiving failover
("ORIGINAL_MSG") packets in tipc_link_tunnel_rcv(), at the same time
delegating it to a new subfuncton, tipc_link_failover_rcv(). Instead
of directly returning an extracted inner packet to the packet reception
loop in tipc_rcv(), we first check if it is a message fragment, in which
case we append it to the reset link's fragment chain. If the fragment
chain is complete, we return the whole chain instead of the individual
buffer, eliminating any need for the tipc_rcv() loop to do reassembly of
tunneled packets.

This change makes it possible to further simplify tipc_link_tunnel_rcv(),
as well as the calling tipc_rcv() loop. We will do that in later
commits. It also makes it possible to identify a single spot in the code
where we can tell that a failover procedure is finished, something that
is useful when we are deleting links after a failover. This will also
be done in a later commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a second link to a destination comes up, some sender sockets will
steer their subsequent traffic through the new link. In order to
guarantee preserved packet order and cardinality for those sockets, we
tunnel a duplicate of the old link's send queue through the new link
before we open it for regular traffic. The last arriving packet copy,
on whichever link, will be dropped at the receiving end based on the
original sequence number, to ensure that only one copy is delivered to
the end receiver.

In this commit, we change the algorithm for receiving DUPLICATE_MSG
packets, at the same time delegating it to a new subfunction,
tipc_link_dup_rcv(). Instead of returning an extracted inner packet to
the packet reception loop in tipc_rcv(), we just add it to the receiving
(new) link's deferred packet queue. The packet will then be processed by
that link when it receives its first non-tunneled packet, i.e., at
latest when the changeover procedure is finished.

Because tipc_link_tunnel_rcv()/tipc_link_dup_rcv() now is consuming all
packets of type DUPLICATE_MSG, the calling tipc_rcv() function can omit
testing for this. This in turn means that the current conditional jump
to the label 'protocol_check' becomes redundant, and we can remove that
label.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In our ongoing effort to simplify the TIPC locking structure,
we see a need to remove the linked list for tipc_links
in the bearer. This can be explained as follows.

Currently, we have three different ways to access a link,
via three different lists/tables:

1: Via a node hash table:
   Used by the time-critical outgoing/incoming data paths.
   (e.g. link_send_sections_fast() and tipc_recv_msg() ):

grab net_lock(read)
   find node from node hash table
   grab node_lock
       select link
       grab bearer_lock
          send_msg()
       release bearer_lock
   release node lock
release net_lock

2: Via a global linked list for nodes:
   Used by configuration commands (link_cmd_set_value())

grab net_lock(read)
   find node and link from global node list (using link name)
   grab node_lock
       update link
   release node lock
release net_lock

(Same locking order as above. No problem.)

3: Via the bearer's linked link list:
   Used by notifications from interface (e.g. tipc_disable_bearer() )

grab net_lock(write)
   grab bearer_lock
      get link ptr from bearer's link list
      get node from link
      grab node_lock
         delete link
      release node lock
   release bearer_lock
release net_lock

(Different order from above, but works because we grab the
outer net_lock in write mode first, excluding all other access.)

The first major goal in our simplification effort is to get rid
of the "big" net_lock, replacing it with rcu-locks when accessing
the node list and node hash array. This will come in a later patch
series.

But to get there we first need to rewrite access methods ##2 and 3,
since removal of net_lock would introduce three major problems:

a) In access method #2, we access the link before taking the
   protecting node_lock. This will not work once net_lock is gone,
   so we will have to change the access order. We will deal with
   this in a later commit in this series, "tipc: add node lock
   protection to link found by link_find_link()".

b) When the outer protection from net_lock is gone, taking
   bearer_lock and node_lock in opposite order of method 1) and 2)
   will become an obvious deadlock hazard. This is fixed in the
   commit ("tipc: remove bearer_lock from tipc_bearer struct")
   later in this series.

c) Similar to what is described in problem a), access method #3
   starts with using a link pointer that is unprotected by node_lock,
   in order to via that pointer find the correct node struct and
   lock it. Before we remove net_lock, this access order must be
   altered. This is what we do with this commit.

We can avoid introducing problem problem c) by even here using the
global node list to find the node, before accessing its links. When
we loop though the node list we use the own bearer identity as search
criteria, thus easily finding the links that are associated to the
resetting/disabling bearer. It should be noted that although this
method is somewhat slower than the current list traversal, it is in
no way time critical. This is only about resetting or deleting links,
something that must be considered relatively infrequent events.

As a bonus, we can get rid of the mutual pointers between links and
bearers. After this commit, pointer dependency go in one direction
only: from the link to the bearer.

This commit pre-empts introduction of problem c) as described above.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, the 'started' field in struct tipc_link represents only a
binary state, 'started' or 'not started'. We need it to represent
more link execution states in the coming commits in this series.
Hence, we rename the field to 'flags', and define the current
started/non-started state to be represented by the LSB bit of
that field.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We break out the code for deleting attached links in the
function bearer_disable(), and define a new function named
tipc_link_delete_list() to do this job.

This commit incurs no functional changes, but makes the code of
function bearer_disable() cleaner. It is also a preparation
for a more important change to the bearer code, in a subsequent
commit in this series.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We break out the code for resetting attached links in the
function tipc_reset_bearer(), and define a new function named
tipc_link_reset_list() to do this job.

This commit incurs no functional changes, but makes the code
of function tipc_reset_bearer() cleaner. It is also a preparation
for a more important change to the bearer code, in a subsequent
commit in this series.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function tipc_link_recv_fragment(struct sk_buff **buf) currently
leaves the value of the input buffer pointer undefined when it returns,
except when the return code indicates that the reassembly is complete.
This despite the fact that it always consumes the input buffer.

Here, we enforce a stricter behavior by this function, ensuring that
the returned buffer pointer is non-NULL if and only if the reassembly
is complete. This makes it possible to test for the buffer pointer as
criteria for successful reassembly.

We also rename the function to tipc_link_frag_rcv(), which is both
shorter and more in line with common naming practice in the network
subsystem.

Apart from the new name, these changes have no impact on current
users of the function, but makes it more practical for use in some
planned future commits.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The inline functions in addr.h uses tipc_own_addr which is exported by
core.h, but addr.h never actually includes it. It works because it is
explicitly included where this is used, but it looks a bit strange.

Include core.h in addr.h explicitly to make the dependency clearer.
Signed-off-by: NAndreas Bofjäll <andreas.bofjall@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a packet received on a link is out-of-sequence, it will be
placed on a deferred queue and later reinserted in the receive
path once the preceding packets have been processed. The problem
with this is that it will be subject to the buffer adjustment from
link_recv_buf_validate twice. The second adjustment for 20 bytes
header space will corrupt the packet.

We solve this by tagging the deferred packets and bail out from
receive buffer validation for packets that have already been
subjected to this.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is a follow-up patch to f3d33426 ("net: rework recvmsg
handler msg_name and msg_namelen logic").

DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.
Signed-off-by: NSteffen Hurrle <steffen@hurrle.net>
Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>