linux-stable.git/net/tipc/discover.c, branch linux-4.8.y

tipc: honor msg2addr return value

2016-06-29T09:17:37+00:00

The UDP msg2addr function tipc_udp_msg2addr() can return -EINVAL which
prior to this patch was unhanded in the caller.

Signed-off-by: Richard Alpe 
Acked-by: Jon Maloy 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: eliminate buffer leak in bearer layer

2016-04-07T21:00:13+00:00

When enabling a bearer we create a 'neigbor discoverer' instance by
calling the function tipc_disc_create() before the bearer is actually
registered in the list of enabled bearers. Because of this, the very
first discovery broadcast message, created by the mentioned function,
is lost, since it cannot find any valid bearer to use. Furthermore,
the used send function, tipc_bearer_xmit_skb() does not free the given
buffer when it cannot find a  bearer, resulting in the leak of exactly
one send buffer each time a bearer is enabled.

This commit fixes this problem by introducing two changes:

1) Instead of attemting to send the discovery message directly, we let
   tipc_disc_create() return the discovery buffer to the calling
   function, tipc_enable_bearer(), so that the latter can send it
   when the enabling sequence is finished.

2) In tipc_bearer_xmit_skb(), as well as in the two other transmit
   functions at the bearer layer, we now free the indicated buffer or
   buffer chain when a valid bearer cannot be found.

Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: eliminate remnants of hungarian notation

2015-11-20T19:06:10+00:00

The number of variables with Hungarian notation (l_ptr, n_ptr etc.)
has been significantly reduced over the last couple of years.

We now root out the last traces of this practice.
There are no functional changes in this commit.

Reviewed-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: let neighbor discoverer tranmsit consumable buffers

2015-10-24T13:56:44+00:00

The neighbor discovery function currently uses the function
tipc_bearer_send() for transmitting packets, assuming that the
sent buffers are not consumed by the called function.

We want to change this, in order to avoid unnecessary buffer cloning
elswhere in the code.

This commit introduces a new function tipc_bearer_skb() which consumes
the sent buffers, and let the discoverer functions use this new call
instead. The discoverer does now itself perform the cloning when
that is necessary.

Signed-off-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: introduce capability bit for broadcast synchronization

2015-10-24T13:56:35+00:00

Until now, we have tried to support both the newer, dedicated broadcast
synchronization mechanism along with the older, less safe, RESET_MSG/
ACTIVATE_MSG based one. The latter method has turned out to be a hazard
in a highly dynamic cluster, so we find it safer to disable it completely
when we find that the former mechanism is supported by the peer node.

For this purpose, we now introduce a new capabability bit,
TIPC_BCAST_SYNCH, to inform any peer nodes that dedicated broadcast
syncronization is supported by the present node. The new bit is conveyed
between peers in the 'capabilities' field of neighbor discovery messages.

Signed-off-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: move received discovery data evaluation inside node.c

2015-07-31T00:25:14+00:00

The node lock is currently grabbed and and released in the function
tipc_disc_rcv() in the file discover.c. As a preparation for the next
commits, we need to move this node lock handling, along with the code
area it is covering, to node.c.

This commit introduces this change.

Tested-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: move link creation from neighbor discoverer to node

2015-07-21T03:41:14+00:00

As a step towards turning links into node internal entities, we move the
creation of links from the neighbor discovery logics to the node's link
control logics.

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

Reviewed-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: introduce link entry structure to struct tipc_node

2015-07-21T03:41:14+00:00

struct 'tipc_node' currently contains two arrays for link attributes,
one for the link pointers, and one for the usable link MTUs.

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

Reviewed-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: involve reference counter for node structure

2015-03-29T19:40:28+00:00

TIPC node hash node table is protected with rcu lock on read side.
tipc_node_find() is used to look for a node object with node address
through iterating the hash node table. As the entire process of what
tipc_node_find() traverses the table is guarded with rcu read lock,
it's safe for us. However, when callers use the node object returned
by tipc_node_find(), there is no rcu read lock applied. Therefore,
this is absolutely unsafe for callers of tipc_node_find().

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

Reviewed-by: Erik Hugne 
Reviewed-by: Jon Maloy 
Signed-off-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: add framework for node capabilities exchange

2015-03-14T18:38:32+00:00

The TIPC protocol spec has defined a 13 bit capability bitmap in
the neighbor discovery header, as a means to maintain compatibility
between different code and protocol generations. Until now this field
has been unused.

We now introduce the basic framework for exchanging capabilities
between nodes at first contact. After exchange, a peer node's
capabilities are stored as a 16 bit bitmap in struct tipc_node.

Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller