In commit c637c103 ("tipc: resolve race
problem at unicast message reception") we introduced a time limit
for how long the function tipc_sk_eneque() would be allowed to execute
its loop. Unfortunately, the test for when this limit is passed was put
in the wrong place, resulting in a lost message when the test is true.

We fix this by moving the test to before we dequeue the next buffer
from the input queue.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

The structure 'tipc_port_list' is used to collect port numbers
representing multicast destination socket on a receiving node.
The list is not based on a standard linked list, and is in reality
optimized for the uncommon case that there are more than one
multicast destinations per node. This makes the list handling
unecessarily complex, and as a consequence, even the socket
multicast reception becomes more complex.

In this commit, we replace 'tipc_port_list' with a new 'struct
tipc_plist', which is based on a standard list. We give the new
list stack (push/pop) semantics, someting that simplifies
the implementation of the function tipc_sk_mcast_rcv().
Reviewed-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>

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

The list for outgoing traffic buffers from a socket is currently
allocated on the stack. This forces us to initialize the queue for
each sent message, something costing extra CPU cycles in the most
critical data path. Later in this series we will introduce a new
safe input buffer queue, something that would force us to initialize
even the spinlock of the outgoing queue. A closer analysis reveals
that the queue always is filled and emptied within the same lock_sock()
session. It is therefore safe to use a queue aggregated in the socket
itself for this purpose. Since there already exists a queue for this
in struct sock, sk_write_queue, we introduce use of that queue in
this commit.
Reviewed-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>

The function tipc_msg_eval() is in reality doing two related, but
different tasks. First it tries to find a new destination for named
messages, in case there was no first lookup, or if the first lookup
failed. Second, it does what its name suggests, evaluating the validity
of the message and its destination, and returning an appropriate error
code depending on the result.

This is confusing, and in this commit we choose to break it up into two
functions. A new function, tipc_msg_lookup_dest(), first attempts to find
a new destination, if the message is of the right type. If this lookup
fails, or if the message should not be subject to a second lookup, the
already existing tipc_msg_reverse() is called. This function performs
prepares the message for rejection, if applicable.
Reviewed-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>

The code for enqueuing arriving buffers in the function tipc_sk_rcv()
contains long code lines and currently goes to two indentation levels.
As a cosmetic preparaton for the next commits, we break it out into
a separate function.
Reviewed-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>

Despite recent improvements, the handling of error codes and return
values at reception of messages in the socket layer is still confusing.

In this commit, we try to make it more comprehensible. First, we
separate between the return values coming from the functions called
by tipc_sk_rcv(), -those are TIPC specific error codes, and the
return values returned by tipc_sk_rcv() itself. Second, we don't
use the returned TIPC error code as indication for whether a buffer
should be forwarded/rejected or not; instead we use the buffer pointer
passed along with filter_msg(). This separation is necessary because
we sometimes want to forward messages even when there is no error
(i.e., protocol messages and successfully secondary looked up data
messages).
Reviewed-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>

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

This one needs to copy the same data from user potentially more than
once.  Sadly, MTU changes can trigger that ;-/

Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 07f6c4bc (tipc: convert tipc reference table to use generic
rhashtable) introduced a problem with port listing in the new netlink
API. It broke the resume functionality resulting in a never ending
loop. This was caused by starting with the first hash table every time
subsequently never returning an empty skb (terminating).

This patch fixes the resume mechanism by keeping a logical reference
to the last hash table along with a logical reference to the socket
(port) that didn't fit in the previous message.
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit f2f9800d "tipc: make tipc node table aware of net
namespace" has added a dereference of sock->sk before making sure it's
not NULL, which makes releasing a tipc socket NULL pointer dereference
for sockets that are not fully initialized.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the redundant timer defined in tipc_sock structure, instead we
can directly reuse the sk_timer defined in sock structure.
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>

TIPC establishes one subscriber server which allows users to subscribe
their interesting name service status. After tipc supports namespace,
one dedicated tipc stack instance is created for each namespace, and
each instance can be deemed as one independent TIPC node. As a result,
subscriber server must be built for each namespace.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Tested-by: NTero Aho <Tero.Aho@coriant.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

TIPC name table is used to store the mapping relationship between
TIPC service name and socket port ID. When tipc supports namespace,
it allows users to publish service names only owned by a certain
namespace. Therefore, every namespace must have its private name
table to prevent service names published to one namespace from being
contaminated by other service names in another namespace. Therefore,
The name table global variable (ie, nametbl) and its lock must be
moved to tipc_net structure, and a parameter of namespace must be
added for necessary functions so that they can obtain name table
variable defined in tipc_net structure.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Tested-by: NTero Aho <Tero.Aho@coriant.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now tipc socket table is statically allocated as a global variable.
Through it, we can look up one socket instance with port ID, insert
a new socket instance to the table, and delete a socket from the
table. But when tipc supports net namespace, each namespace must own
its specific socket table. So the global variable of socket table
must be redefined in tipc_net structure. As a concequence, a new
socket table will be allocated when a new namespace is created, and
a socket table will be deallocated when namespace is destroyed.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Tested-by: NTero Aho <Tero.Aho@coriant.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

In order to make tipc socket table aware of namespace, a networking
namespace instance must be passed to tipc_sk_lookup(), allowing it
to look up tipc socket instance with a given port ID from a concrete
socket table. However, as now tipc_sk_timeout() only has one port ID
parameter and is not namespace aware, it's unable to obtain a correct
socket instance through tipc_sk_lookup() just with a port ID,
especially after namespace is completely supported.

If port ID is replaced with socket instance as tipc_sk_timeout()'s
parameter, it's unnecessary to look up socket table. But as the timer
handler - tipc_sk_timeout() is run asynchronously, socket reference
must be held before its timer is launched, and must be carefully
checked to identify whether the socket reference needs to be put or
not when its timer is terminated.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Tested-by: NTero Aho <Tero.Aho@coriant.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Not only some wrapper function like k_term_timer() is empty, but also
some others including k_start_timer() and k_cancel_timer() don't return
back any value to its caller, what's more, there is no any component
in the kernel world to do such thing. Therefore, these timer interfaces
defined in tipc module should be purged.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Tested-by: NTero Aho <Tero.Aho@coriant.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As tipc reference table is statically allocated, its memory size
requested on stack initialization stage is quite big even if the
maximum port number is just restricted to 8191 currently, however,
the number already becomes insufficient in practice. But if the
maximum ports is allowed to its theory value - 2^32, its consumed
memory size will reach a ridiculously unacceptable value. Apart from
this, heavy tipc users spend a considerable amount of time in
tipc_sk_get() due to the read-lock on ref_table_lock.

If tipc reference table is converted with generic rhashtable, above
mentioned both disadvantages would be resolved respectively: making
use of the new resizable hash table can avoid locking on the lookup;
smaller memory size is required at initial stage, for example, 256
hash bucket slots are requested at the beginning phase instead of
allocating the entire 8191 slots in old mode. The hash table will
grow if entries exceeds 75% of table size up to a total table size
of 1M, and it will automatically shrink if usage falls below 30%,
but the minimum table size is allowed down to 256.

Also converts ref_table_lock to a separate mutex to protect hash table
mutations on write side. Lastly defers the release of the socket
reference using call_rcu() to allow using an RCU read-side protected
call to rhashtable_lookup().
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NErik Hugne <erik.hugne@ericsson.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Part of the old remote management feature is a piece of code
that checked permissions on the local system to see if a certain
operation was permitted, and if so pass the command to a remote
node. This serves no purpose after the removal of remote management
with commit 5902385a ("tipc: obsolete the remote management
feature") so we remove it.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use standard SKB list APIs associated with struct sk_buff_head to
manage socket outgoing packet chain and name table outgoing packet
chain, having relevant code simpler and more readable.
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>

Fix sparse warnings about non-static declaration of static functions
in the new tipc netlink API.
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add TIPC_NL_PUBL_GET command to the new tipc netlink API.

This command supports dumping of all publications for a specific
socket.

Netlink logical layout of request message:
    -> socket
        -> reference

Netlink logical layout of response message:
    -> publication
        -> type
        -> lower
        -> upper
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add TIPC_NL_SOCK_GET command to the new tipc netlink API.

This command supports dumping of all available sockets with their
associated connection or publication(s). It could be extended to reply
with a single socket if the NLM_F_DUMP isn't set.

The information about a socket includes reference, address, connection
information / publication information.

Netlink logical layout of response message:
-> socket
    -> reference
    -> address
    [
    -> connection
        -> node
        -> socket
        [
        -> connected flag
        -> type
        -> instance
        ]
    ]
    [
    -> publication flag
    ]
Signed-off-by: NRichard Alpe <richard.alpe@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When running tipcTC&tipcTS test suite, below lockdep unsafe locking
scenario is reported:

[ 1109.997854]
[ 1109.997988] =================================
[ 1109.998290] [ INFO: inconsistent lock state ]
[ 1109.998575] 3.17.0-rc1+ #113 Not tainted
[ 1109.998762] ---------------------------------
[ 1109.998762] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 1109.998762] swapper/7/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 1109.998762]  (slock-AF_TIPC){+.?...}, at: [<ffffffffa0011969>] tipc_sk_rcv+0x49/0x2b0 [tipc]
[ 1109.998762] {SOFTIRQ-ON-W} state was registered at:
[ 1109.998762]   [<ffffffff810a4770>] __lock_acquire+0x6a0/0x1d80
[ 1109.998762]   [<ffffffff810a6555>] lock_acquire+0x95/0x1e0
[ 1109.998762]   [<ffffffff81a2d1ce>] _raw_spin_lock+0x3e/0x80
[ 1109.998762]   [<ffffffffa0011969>] tipc_sk_rcv+0x49/0x2b0 [tipc]
[ 1109.998762]   [<ffffffffa0004fe8>] tipc_link_xmit+0xa8/0xc0 [tipc]
[ 1109.998762]   [<ffffffffa000ec6f>] tipc_sendmsg+0x15f/0x550 [tipc]
[ 1109.998762]   [<ffffffffa000f165>] tipc_connect+0x105/0x140 [tipc]
[ 1109.998762]   [<ffffffff817676ee>] SYSC_connect+0xae/0xc0
[ 1109.998762]   [<ffffffff81767b7e>] SyS_connect+0xe/0x10
[ 1109.998762]   [<ffffffff817a9788>] compat_SyS_socketcall+0xb8/0x200
[ 1109.998762]   [<ffffffff81a306e5>] sysenter_dispatch+0x7/0x1f
[ 1109.998762] irq event stamp: 241060
[ 1109.998762] hardirqs last  enabled at (241060): [<ffffffff8105a4ad>] __local_bh_enable_ip+0x6d/0xd0
[ 1109.998762] hardirqs last disabled at (241059): [<ffffffff8105a46f>] __local_bh_enable_ip+0x2f/0xd0
[ 1109.998762] softirqs last  enabled at (241020): [<ffffffff81059a52>] _local_bh_enable+0x22/0x50
[ 1109.998762] softirqs last disabled at (241021): [<ffffffff8105a626>] irq_exit+0x96/0xc0
[ 1109.998762]
[ 1109.998762] other info that might help us debug this:
[ 1109.998762]  Possible unsafe locking scenario:
[ 1109.998762]
[ 1109.998762]        CPU0
[ 1109.998762]        ----
[ 1109.998762]   lock(slock-AF_TIPC);
[ 1109.998762]   <Interrupt>
[ 1109.998762]     lock(slock-AF_TIPC);
[ 1109.998762]
[ 1109.998762]  *** DEADLOCK ***
[ 1109.998762]
[ 1109.998762] 2 locks held by swapper/7/0:
[ 1109.998762]  #0:  (rcu_read_lock){......}, at: [<ffffffff81782dc9>] __netif_receive_skb_core+0x69/0xb70
[ 1109.998762]  #1:  (rcu_read_lock){......}, at: [<ffffffffa0001c90>] tipc_l2_rcv_msg+0x40/0x260 [tipc]
[ 1109.998762]
[ 1109.998762] stack backtrace:
[ 1109.998762] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 3.17.0-rc1+ #113
[ 1109.998762] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 1109.998762]  ffffffff82745830 ffff880016c03828 ffffffff81a209eb 0000000000000007
[ 1109.998762]  ffff880017b3cac0 ffff880016c03888 ffffffff81a1c5ef 0000000000000001
[ 1109.998762]  ffff880000000001 ffff880000000000 ffffffff81012d4f 0000000000000000
[ 1109.998762] Call Trace:
[ 1109.998762]  <IRQ>  [<ffffffff81a209eb>] dump_stack+0x4e/0x68
[ 1109.998762]  [<ffffffff81a1c5ef>] print_usage_bug+0x1f1/0x202
[ 1109.998762]  [<ffffffff81012d4f>] ? save_stack_trace+0x2f/0x50
[ 1109.998762]  [<ffffffff810a406c>] mark_lock+0x28c/0x2f0
[ 1109.998762]  [<ffffffff810a3440>] ? print_irq_inversion_bug.part.46+0x1f0/0x1f0
[ 1109.998762]  [<ffffffff810a467d>] __lock_acquire+0x5ad/0x1d80
[ 1109.998762]  [<ffffffff810a70dd>] ? trace_hardirqs_on+0xd/0x10
[ 1109.998762]  [<ffffffff8108ace8>] ? sched_clock_cpu+0x98/0xc0
[ 1109.998762]  [<ffffffff8108ad2b>] ? local_clock+0x1b/0x30
[ 1109.998762]  [<ffffffff810a10dc>] ? lock_release_holdtime.part.29+0x1c/0x1a0
[ 1109.998762]  [<ffffffff8108aa05>] ? sched_clock_local+0x25/0x90
[ 1109.998762]  [<ffffffffa000dec0>] ? tipc_sk_get+0x60/0x80 [tipc]
[ 1109.998762]  [<ffffffff810a6555>] lock_acquire+0x95/0x1e0
[ 1109.998762]  [<ffffffffa0011969>] ? tipc_sk_rcv+0x49/0x2b0 [tipc]
[ 1109.998762]  [<ffffffff810a6fb6>] ? trace_hardirqs_on_caller+0xa6/0x1c0
[ 1109.998762]  [<ffffffff81a2d1ce>] _raw_spin_lock+0x3e/0x80
[ 1109.998762]  [<ffffffffa0011969>] ? tipc_sk_rcv+0x49/0x2b0 [tipc]
[ 1109.998762]  [<ffffffffa000dec0>] ? tipc_sk_get+0x60/0x80 [tipc]
[ 1109.998762]  [<ffffffffa0011969>] tipc_sk_rcv+0x49/0x2b0 [tipc]
[ 1109.998762]  [<ffffffffa00076bd>] tipc_rcv+0x5ed/0x960 [tipc]
[ 1109.998762]  [<ffffffffa0001d1c>] tipc_l2_rcv_msg+0xcc/0x260 [tipc]
[ 1109.998762]  [<ffffffffa0001c90>] ? tipc_l2_rcv_msg+0x40/0x260 [tipc]
[ 1109.998762]  [<ffffffff81783345>] __netif_receive_skb_core+0x5e5/0xb70
[ 1109.998762]  [<ffffffff81782dc9>] ? __netif_receive_skb_core+0x69/0xb70
[ 1109.998762]  [<ffffffff81784eb9>] ? dev_gro_receive+0x259/0x4e0
[ 1109.998762]  [<ffffffff817838f6>] __netif_receive_skb+0x26/0x70
[ 1109.998762]  [<ffffffff81783acd>] netif_receive_skb_internal+0x2d/0x1f0
[ 1109.998762]  [<ffffffff81785518>] napi_gro_receive+0xd8/0x240
[ 1109.998762]  [<ffffffff815bf854>] e1000_clean_rx_irq+0x2c4/0x530
[ 1109.998762]  [<ffffffff815c1a46>] e1000_clean+0x266/0x9c0
[ 1109.998762]  [<ffffffff8108ad2b>] ? local_clock+0x1b/0x30
[ 1109.998762]  [<ffffffff8108aa05>] ? sched_clock_local+0x25/0x90
[ 1109.998762]  [<ffffffff817842b1>] net_rx_action+0x141/0x310
[ 1109.998762]  [<ffffffff810bd710>] ? handle_fasteoi_irq+0xe0/0x150
[ 1109.998762]  [<ffffffff81059fa6>] __do_softirq+0x116/0x4d0
[ 1109.998762]  [<ffffffff8105a626>] irq_exit+0x96/0xc0
[ 1109.998762]  [<ffffffff81a30d07>] do_IRQ+0x67/0x110
[ 1109.998762]  [<ffffffff81a2ee2f>] common_interrupt+0x6f/0x6f
[ 1109.998762]  <EOI>  [<ffffffff8100d2b7>] ? default_idle+0x37/0x250
[ 1109.998762]  [<ffffffff8100d2b5>] ? default_idle+0x35/0x250
[ 1109.998762]  [<ffffffff8100dd1f>] arch_cpu_idle+0xf/0x20
[ 1109.998762]  [<ffffffff810999fd>] cpu_startup_entry+0x27d/0x4d0
[ 1109.998762]  [<ffffffff81034c78>] start_secondary+0x188/0x1f0

When intra-node messages are delivered from one process to another
process, tipc_link_xmit() doesn't disable BH before it directly calls
tipc_sk_rcv() on process context to forward messages to destination
socket. Meanwhile, if messages delivered by remote node arrive at the
node and their destinations are also the same socket, tipc_sk_rcv()
running on process context might be preempted by tipc_sk_rcv() running
BH context. As a result, the latter cannot obtain the socket lock as
the lock was obtained by the former, however, the former has no chance
to be run as the latter is owning the CPU now, so headlock happens. To
avoid it, BH should be always disabled in tipc_sk_rcv().
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>

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

Commit 6c9808ce ("tipc: remove port_lock") accidentally involves
a potential bug: when tipc socket instance(tsk) is not got with given
reference number in tipc_sk_get(), tsk is set to NULL. Subsequently
we jump to exit label where to decrease socket reference counter
pointed by tsk pointer in tipc_sk_put(). However, As now tsk is NULL,
oops may happen because of touching a NULL pointer.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NErik Hugne <erik.hugne@ericsson.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We complete the merging of the port and socket layer by aggregating
the fields of struct tipc_port directly into struct tipc_sock, and
moving the combined structure into socket.c.

We also move all functions and macros that are not any longer
exposed to the rest of the stack into socket.c, and rename them
accordingly.

Despite the size of this commit, there are no functional changes.
We have only made such changes that are necessary due of the removal
of struct tipc_port.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The reference table is now 'socket aware' instead of being generic,
and has in reality become a socket internal table. In order to be
able to minimize the API exposed by the socket layer towards the rest
of the stack, we now move the reference table definitions and functions
into the file socket.c, and rename the functions accordingly.

There are no functional changes in this commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We move the inline functions in the file port.h to socket.c, and modify
their names accordingly.

We move struct tipc_port and some macros to socket.h.

Finally, we remove the file port.h.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In this commit, we move the remaining functions in port.c to
socket.c, and give them new names that correspond to their new
location. We then remove the file port.c.

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

In previous commits we have reduced usage of port_lock to a minimum,
and complemented it with usage of bh_lock_sock() at the remaining
locations. The purpose has been to remove this lock altogether, since
it largely duplicates the role of bh_lock_sock. We are now ready to do
this.

However, we still need to protect the BH callers from inadvertent
release of the socket while they hold a reference to it. We do this by
replacing port_lock by a combination of a rw-lock protecting the
reference table as such, and updating the socket reference counter while
the socket is referenced from BH. This technique is more standard and
comprehensible than the previous approach, and turns out to have a
positive effect on overall performance.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to make tipc_sock the only entity referencable from other
parts of the stack, we add a tipc_sock pointer instead of a tipc_port
pointer to the registry. As a consequence, we also let the function
tipc_port_lock() return a pointer to a tipc_sock instead  of a tipc_port.
We keep the function's name for now, since the lock still is owned by
the port.

This is another step in the direction of eliminating port_lock, replacing
its usage with lock_sock() and bh_lock_sock().
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The functions tipc_port_get_ports() and tipc_port_reinit() scan over
all sockets/ports to access each of them. This is done by using a
dedicated linked list, 'tipc_socks' where all sockets are members. The
list is in turn protected by a spinlock, 'port_list_lock', while each
socket is locked by using port_lock at the moment of access.

In order to reduce complexity and risk of deadlock, we want to get
rid of the linked list and the accompanying spinlock.

This is what we do in this commit. Instead of the linked list, we use
the port registry to scan across the sockets. We also add usage of
bh_lock_sock() inside the scope of port_lock in both functions, as a
preparation for the complete removal of port_lock.

Finally, we move the functions from port.c to socket.c, and rename them
to tipc_sk_sock_show() and tipc_sk_reinit() repectively.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>