When a message arrives in a node and finds no destination
socket, we may need to drop it, reject it, or forward it after
a secondary destination lookup. The latter two cases currently
results in a code path that is perceived as complex, because it
follows a deep call chain via obscure functions such as
net_route_named_msg() and net_route_msg().

We now introduce a function, tipc_msg_eval(), that takes the
decision about whether such a message should be rejected or
forwarded, but leaves it to the caller to actually perform
the indicated action.

If the decision is 'reject', it is still the task of the recently
introduced function tipc_msg_reverse() to take the final decision
about whether the message is rejectable or not. In the latter case
it drops the message.

As a result of this change, we can finally eliminate the function
net_route_named_msg(), and hence become independent of net_route_msg().
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 way we build and send rejected message is currenty perceived as
hard to follow, partly because we let the transmission go via deep
call chains through functions such as tipc_reject_msg() and
net_route_msg().

We want to remove those functions, and make the call sequences shallower
and simpler. For this purpose, we separate building and sending of
rejected messages. We build the reject message using the new function
tipc_msg_reverse(), and let the transmission go via the newly introduced
tipc_link_xmit2() function, as all transmission eventually will do. We
also ensure that all calls to tipc_link_xmit2() are made outside
port_lock/bh_lock_sock.

Finally, we replace all calls to tipc_reject_msg() with the two new
calls at all locations in the code that we want to keep. The remaining
calls are made from code that we are planning to remove, along with
tipc_reject_msg() itself.
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>

Fragmentation at message sending is currently performed in two
places in link.c, depending on whether data to be transmitted
is delivered in the form of an iovec or as a big sk_buff. Those
functions are also tightly entangled with the send functions
that are using them.

We now introduce a re-entrant, standalone function, tipc_msg_build2(),
that builds a packet chain directly from an iovec. Each fragment is
sized according to the MTU value given by the caller, and is prepended
with a correctly built fragment header, when needed. The function is
independent from who is calling and where the chain will be delivered,
as long as the caller is able to indicate a correct MTU.

The function is tested, but not called by anybody yet. Since it is
incompatible with the existing tipc_msg_build(), and we cannot yet
remove that function, we have given it a temporary name.
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>

Message fragmentation is currently performed at link level, inside
the protection of node_lock. This potentially binds up the sending
link structure for a long time, instead of letting it do other tasks,
such as handle reception of new packets.

In this commit, we make the MTUs of each active link become easily
accessible from the socket level, i.e., without taking any spinlock
or dereferencing the target link pointer. This way, we make it possible
to perform fragmentation in the sending socket, before sending the
whole fragment chain to the link for transport.
Signed-off-by: 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 current link implementation provides several different transmit
functions, depending on the characteristics of the message to be
sent: if it is an iovec or an sk_buff, if it needs fragmentation or
not, if the caller holds the node_lock or not. The permutation of
these options gives us an unwanted amount of unnecessarily complex
code.

As a first step towards simplifying the send path for all messages,
we introduce two new send functions at link level, tipc_link_xmit2()
and __tipc_link_xmit2(). The former looks up a link to the message
destination, and if one is found, it grabs the node lock and calls
the second function, which works exclusively inside the node lock
protection. If no link is found, and the destination is on the same
node, it delivers the message directly to the local destination
socket.

The new functions take a buffer chain where all packet headers are
already prepared, and the correct MTU has been used. These two
functions will later replace all other link-level transmit functions.

The functions are not backwards compatible, so we have added them
as new functions with temporary names. They are tested, but have no
users yet. Those will be added later in this series.
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 some places, TIPC functions returns positive integers as return
codes. This goes against standard Linux coding practice, and may
even cause problems in some cases.

We now change the return values of the functions filter_rcv()
and filter_connect() to become signed integers, and return
negative error codes when needed. The codes we use in these
particular cases are still TIPC specific, since they are both
part of the TIPC API and have no correspondence in errno.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 the function tipc_nodesub_notify() we call a function pointer
aggregated into the object to be notified, whereafter we set
the function pointer to NULL. However, in some cases the function
pointed to will free the struct containing the function pointer,
resulting in a write to already freed memory.

This bug seems to always have been there, without causing any
notable harm.

In this commit we fix the problem by inverting the order of the
zeroing and the function call.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are several instances where a pskb_copy or __pskb_copy is
immediately followed by an skb_clone.

Add a couple of new functions to allow the copy skb to be allocated
from the fclone cache and thus speed up subsequent skb_clone calls.

Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <antonio@meshcoding.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Arvid Brodin <arvid.brodin@alten.se>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 4f4482dc ("tipc: compensate
for double accounting in socket rcv buffer") we access 'truesize' of
a received buffer after it might have been released by the function
filter_rcv().

In this commit we correct this by reading the value of 'truesize' to
the stack before delivering the buffer to filter_rcv().
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it may then take longer than what the user specified using
setsockopt(SO_RCVTIMEO).
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to reduce complexity and save a call level during message
reception at port/socket level, we remove the function tipc_port_rcv()
and merge its functionality into tipc_sk_rcv().
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 function tipc_disc_rcv(), which is handling received neighbor
discovery messages, is perceived as messy, and it is hard to verify
its correctness by code inspection. The fact that the task it is set
to resolve is fairly complex does not make the situation better.

In this commit we try to take a more systematic approach to the
problem. We define a decision machine which takes three state flags
 as input, and produces three action flags as output. We then walk
through all permutations of the state flags, and for each of them we
describe verbally what is going on, plus that we set zero or more of
the action flags. The action flags indicate what should be done once
the decision machine has finished its job, while the last part of the
function deals with performing those actions.
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>

TIPC currently handles two media specific addresses: Ethernet MAC
addresses and InfiniBand addresses. Those are kept in three different
formats:

1) A "raw" format as obtained from the device. This format is known
   only by the media specific adapter code in eth_media.c and
   ib_media.c.
2) A "generic" internal format, in the form of struct tipc_media_addr,
   which can be referenced and passed around by the generic media-
   unaware code.
3) A serialized version of the latter, to be conveyed in neighbor
   discovery messages.

Conversion between the three formats can only be done by the media
specific code, so we have function pointers for this purpose in
struct tipc_media. Here, the media adapters can install their own
conversion functions at startup.

We now introduce a new such function, 'raw2addr()', whose purpose
is to convert from format 1 to format 2 above. We also try to as far
as possible uniform commenting, variable names and usage of these
functions, with the purpose of making them more comprehensible.

We can now also remove the function tipc_l2_media_addr_set(), whose
job is done better by the new function.

Finally, we expand the field for serialized addresses (format 3)
in discovery messages from 20 to 32 bytes. This is permitted
according to the spec, and reduces the risk of problems when we
add new media in the future.
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 function tipc_link_frag_rcv() is in reality a re-entrant generic
message reassemby function that has nothing in particular to do with
the link, where it is defined now. This becomes obvious when we see
the need to call the function from other places in the code.

In this commit rename it to tipc_buf_append() and move it to the file
msg.c. We also simplify its signature by moving the tail pointer to
the control block of the head buffer, hence making the head buffer
self-contained.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The message reassembly function does not update the 'len' and 'data_len'
fields of the head skbuff correctly when fragments are chained to it.
This may sometimes lead to obsure errors, such as fragment reordering
when we receive fragments which are cloned buffers.

This commit fixes this, by ensuring that the two fields are updated
correctly.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
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>

In the current code, all incoming LINK_PROTOCOL messages, irrespective
of type, nudge the "last message received" checkpoint, informing the
link state machine that a message was received from the peer since last
supervision timeout event. This inhibits the link from starting probing
the peer unnecessarily.

However, not only STATE messages are recorded as legitimate incoming
traffic this way, but even RESET and ACTIVATE messages, which in
reality are there to inform the link that the peer endpoint has been
reset. At the same time, some RESET messages may be dropped instead
of causing a link reset. This happens when the link endpoint thinks
it is fully up and working, and the session number of the RESET is
lower than or equal to the current link session. In such cases the
RESET is perceived as a delayed remnant from an earlier session, or
the current one, and dropped.

Now, if a TIPC module is removed and then immediately reinserted, e.g.
when using a script, RESET messages may arrive at the peer link endpoint
before this one has had time to discover the failure. The RESET may be
dropped because of the session number, but only after it has been
recorded as a legitimate traffic event. Hence, the receiving link will
not start probing, and not discover that the peer endpoint is down, at
the same time ignoring the periodic RESET messages coming from that
endpoint. We have ended up in a stale state where a failed link cannot
be re-established.

In this commit, we remedy this by nudging the checkpoint only for
received STATE messages, not for RESET or ACTIVATE messages.
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 function net/core/sock.c::__release_sock() runs a tight loop
to move buffers from the socket backlog queue to the receive queue.

As a security measure, sk_backlog.len of the receiving socket
is not set to zero until after the loop is finished, i.e., until
the whole backlog queue has been transferred to the receive queue.
During this transfer, the data that has already been moved is counted
both in the backlog queue and the receive queue, hence giving an
incorrect picture of the available queue space for new arriving buffers.

This leads to unnecessary rejection of buffers by sk_add_backlog(),
which in TIPC leads to unnecessarily broken connections.

In this commit, we compensate for this double accounting by adding
a counter that keeps track of it. The function socket.c::backlog_rcv()
receives buffers one by one from __release_sock(), and adds them to the
socket receive queue. If the transfer is successful, it increases a new
atomic counter 'tipc_sock::dupl_rcvcnt' with 'truesize' of the
transferred buffer. If a new buffer arrives during this transfer and
finds the socket busy (owned), we attempt to add it to the backlog.
However, when sk_add_backlog() is called, we adjust the 'limit'
parameter with the value of the new counter, so that the risk of
inadvertent rejection is eliminated.

It should be noted that this change does not invalidate the original
purpose of zeroing 'sk_backlog.len' after the full transfer. We set an
upper limit for dupl_rcvcnt, so that if a 'wild' sender (i.e., one that
doesn't respect the send window) keeps pumping in buffers to
sk_add_backlog(), he will eventually reach an upper limit,
(2 x TIPC_CONN_OVERLOAD_LIMIT). After that, no messages can be added
to the backlog, and the connection will be broken. Ordinary, well-
behaved senders will never reach this buffer limit at all.
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>

Memory overhead when allocating big buffers for data transfer may
be quite significant. E.g., truesize of a 64 KB buffer turns out
to be 132 KB, 2 x the requested size.

This invalidates the "worst case" calculation we have been
using to determine the default socket receive buffer limit,
which is based on the assumption that 1024x64KB = 67MB buffers
may be queued up on a socket.

Since TIPC connections cannot survive hitting the buffer limit,
we have to compensate for this overhead.

We do that in this commit by dividing the fix connection flow
control window from 1024 (2*512) messages to 512 (2*256). Since
older version nodes send out acks at 512 message intervals,
compatibility with such nodes is guaranteed, although performance
may be non-optimal in such cases.
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>

Each node action flag should be set or cleared separately, instead
we now set the whole flags variable in one shot, and it's turned
out to be hard to see which other flags are affected. Therefore,
for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in
node_lost_contact().
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename node flags to action_flags as well as its enum names so
that they can reflect its real meanings.
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>

In the previous commits of this series, we removed all asynchronous
actions which were based on the tasklet handler - "tipc_k_signal()".

So the moment has now come when we can completely remove the tasklet
handler infrastructure. That is done with this commit.
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>

Postpone the actions of resetting all links until after bclink
lock is released, avoiding to asynchronously reset all links.
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>

Convert allocations of global variables associated with bclink from
static way to dynamical way for the convenience of bclink instance
initialisation. Meanwhile, this also helps TIPC support name space
in the future easily.
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>

As we are going to do more jobs when bc_lock is released, the two
operations of holding/releasing the lock should be encapsulated with
functions. In addition, we move bc_lock spin lock into tipc_bclink
structure avoiding to define the global variable.
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>

Postpone the actions of delivering name tables until after node
lock is released, avoiding to do it under asynchronous context.
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>

Since previously what all publications pertaining to the lost node
were removed from name table was finished in tasklet context
asynchronously, we need to TIPC_NAMES_GONE flag indicating whether
the node cleanup work is finished or not. But now as the cleanup work
has been finished when node lock is released, the flag becomes
meaningless for us.
Signed-off-by: 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>

Postpone the actions of notifying subscriptions until after node lock
is released, avoiding to asynchronously execute registered handlers
when node is lost.
Signed-off-by: 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>

Rename setup_blocked variable of node struct to a more common
name called "flags", which will be used to represent kinds of
node states.
Signed-off-by: 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>

Move more frequently used variables up to the head of tipc_node
structure, hopefully improving a bit performance.
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>

Although we obtain node lock with tipc_node_lock() in most time, there
are still places where we directly use native spin lock interface
to grab node lock. But as we will do more jobs in the future when node
lock is released, we should ensure that tipc_node_lock() is always
called when node lock is taken.
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>

Commit 1bb8dce5 ("tipc: fix memory
leak during module removal") introduced a memory leak issue: when
name table is stopped, it's forgotten that publication instances are
freed properly. Additionally the useless "continue" statement in
tipc_nametbl_stop() is removed as well.
Reported-by: NJason <huzhijiang@gmail.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Acked-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit a89778d8 ("tipc: add support
for link state subscriptions") introduced below possible deadlock
scenario:

       CPU0                          CPU1
T0:   tipc_publish()                 link_timeout()
T1:   tipc_nametbl_publish()         [grab node lock]*
T2:   [grab nametbl write lock]*     link_state_event()
T3:   named_cluster_distribute()     link_activate()
T4:   [grab node lock]*              tipc_node_link_up()
T5:                                  tipc_nametbl_publish()
T6:                                  [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 delivery of named messages via link out of name nametbl lock,
the reverse order of holding locks will be eliminated, as a result,
the deadlock will be killed as well.
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>

Commit 78acb1f9 ("tipc: add
ioctl to fetch link names") introduced a buffer overflow bug where
specially crafted ioctl requests could cause out-of-bounds indexing
of the node->links array. This was caused by an incorrect check vs
MAX_BEARERS, and the static code checker complaint is:
net/tipc/node.c:459 tipc_node_get_linkname() error: buffer overflow 'node->links' 2 <= 2
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The commit a8b9b96e ("tipc: fix race
in disc create/delete") leads to the following static checker warning:

	net/tipc/discover.c:352 tipc_disc_create()
		warn: possible memory leak of 'req'

The risk of memory leak really exists in practice. Especially when
it's failed to allocate memory for "req->buf", tipc_disc_create()
doesn't free its allocated memory, instead just directly returns
with ENOMEM error code. In this situation, memory leak, of course,
happens.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We add a new ioctl for AF_TIPC that can be used to fetch the
logical name for a link to a remote node on a given bearer. This
should be used in combination with link state subscriptions.
The logical name size limit definitions are moved to tipc.h, as
they are now also needed by the new ioctl.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-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 links are established over a bearer plane, we create a node
local publication containing information about the peer node and
bearer plane. This allows TIPC applications to use the standard
TIPC topology server subscription mechanism to get notifications
when a link goes up or down.
Signed-off-by: NErik Hugne <erik.hugne@ericsson.com>
Reviewed-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit a21a584d (tipc: fix neighbor
detection problem after hw address change) introduces a race condition
involving tipc_disc_delete() and tipc_disc_add/remove_dest that can
cause TIPC to dereference the pointer to the bearer discovery request
structure after it has been freed since a stray pointer is left in the
bearer structure.

In order to fix the issue, the process of resetting the discovery
request handler is optimized: the discovery request handler and request
buffer are just reset instead of being freed, allocated and initialized.
As the request point is always valid and the request's lock is taken
while the request handler is reset, the race doesn't happen any more.
Reported-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Tested-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The node map variable - 'nodes' in bearer structure is only used by
bclink. When bclink accesses it, bc_lock is held. But when change it,
for instance, in tipc_bearer_add_dest() or tipc_bearer_remove_dest()
the bc_lock is not taken at all. To avoid any inconsistent data, we
should always grab bc_lock while accessing node map variable.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Tested-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As bearer pointer is known in tipc_l2_device_event(), it's unnecessary
to search it again in tipc_disable_bearer(). If tipc_disable_bearer()
is replaced with bearer_disable() in tipc_l2_device_event(), this will
help us save a bit time when bearer is disabled.
Signed-off-by: NYing Xue <ying.xue@windriver.com>
Reviewed-by: NJon Maloy <jon.maloy@ericsson.com>
Reviewed-by: NErik Hugne <erik.hugne@ericsson.com>
Tested-by: NErik Hugne <erik.hugne@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>