gcc points out that the combined length of the fixed-length inputs to
l->name is larger than the destination buffer size:

net/tipc/link.c: In function 'tipc_link_create':
net/tipc/link.c:465:26: error: '%s' directive writing up to 32 bytes
into a region of size between 26 and 58 [-Werror=format-overflow=]
sprintf(l->name, "%s:%s-%s:unknown", self_str, if_name, peer_str);

net/tipc/link.c:465:2: note: 'sprintf' output 11 or more bytes
(assuming 75) into a destination of size 60
sprintf(l->name, "%s:%s-%s:unknown", self_str, if_name, peer_str);

A detailed analysis reveals that the theoretical maximum length of
a link name is:
max self_str + 1 + max if_name + 1 + max peer_str + 1 + max if_name =
16 + 1 + 15 + 1 + 16 + 1 + 15 = 65
Since we also need space for a trailing zero we now set MAX_LINK_NAME
to 68.

Just to be on the safe side we also replace the sprintf() call with
snprintf().

Fixes: 25b0b9c4 ("tipc: handle collisions of 32-bit node address
hash values")
Reported-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the new RB tree structure for service ranges it becomes possible to
solve an old problem; - we can now allow overlapping service ranges in
the table.

When inserting a new service range to the tree, we use 'lower' as primary
key, and when necessary 'upper' as secondary key.

Since there may now be multiple service ranges matching an indicated
'lower' value, we must also add the 'upper' value to the functions
used for removing publications, so that the correct, corresponding
range item can be found.

These changes guarantee that a well-formed publication/withdrawal item
from a peer node never will be rejected, and make it possible to
eliminate the problematic backlog functionality we currently have for
handling such cases.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function tipc_nametbl_translate() function is ugly and hard to
follow. This can be improved somewhat by introducing a stack variable
for holding the publication list to be used and re-ordering the if-
clauses for selection of algorithm.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current design of the binding table has an unnecessary memory
consuming and complex data structure. It aggregates the service range
items into an array, which is expanded by a factor two every time it
becomes too small to hold a new item. Furthermore, the arrays never
shrink when the number of ranges diminishes.

We now replace this array with an RB tree that is holding the range
items as tree nodes, each range directly holding a list of bindings.

This, along with a few name changes, improves both readability and
volume of the code, as well as reducing memory consumption and hopefully
improving cache hit rate.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes the following sparse warning:

net/tipc/node.c:336:18: warning:
 symbol 'tipc_node_create' was not declared. Should it be static?
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Release alloced resource before return from the error handling
case in tipc_udp_enable(), otherwise will cause memory leak.

Fixes: 52dfae5c ("tipc: obtain node identity from interface by default")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: 25b0b9c4 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Acked-by: Jon Maloy jon.maloy@ericsson.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Selecting and explicitly configuring a TIPC node identity may be
unwanted in some cases.

In this commit we introduce a default setting if the identity has not
been set at the moment the first bearer is enabled. We do this by
using a raw copy of a unique identifier from the used interface: MAC
address in the case of an L2 bearer, IPv4/IPv6 address in the case
of a UDP bearer.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a 32-bit node address is generated from a 128-bit identifier,
there is a risk of collisions which must be discovered and handled.

We do this as follows:
- We don't apply the generated address immediately to the node, but do
  instead initiate a 1 sec trial period to allow other cluster members
  to discover and handle such collisions.

- During the trial period the node periodically sends out a new type
  of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast,
  to all the other nodes in the cluster.

- When a node is receiving such a message, it must check that the
  presented 32-bit identifier either is unused, or was used by the very
  same peer in a previous session. In both cases it accepts the request
  by not responding to it.

- If it finds that the same node has been up before using a different
  address, it responds with a DSC_TRIAL_FAIL_MSG containing that
  address.

- If it finds that the address has already been taken by some other
  node, it generates a new, unused address and returns it to the
  requester.

- During the trial period the requesting node must always be prepared
  to accept a failure message, i.e., a message where a peer suggests a
  different (or equal)  address to the one tried. In those cases it
  must apply the suggested value as trial address and restart the trial
  period.

This algorithm ensures that in the vast majority of cases a node will
have the same address before and after a reboot. If a legacy user
configures the address explicitly, there will be no trial period and
messages, so this protocol addition is completely backwards compatible.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We add a 128-bit node identity, as an alternative to the currently used
32-bit node address.

For the sake of compatibility and to minimize message header changes
we retain the existing 32-bit address field. When not set explicitly by
the user, this field will be filled with a hash value generated from the
much longer node identity, and be used as a shorthand value for the
latter.

We permit either the address or the identity to be set by configuration,
but not both, so when the address value is set by a legacy user the
corresponding 128-bit node identity is generated based on the that value.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a preparation to changing the addressing structure of TIPC we replace
all direct accesses to the tipc_net::own_addr field with the function
dedicated for this, tipc_own_addr().

There are no changes to program logics in this commit.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The removal of an internal structure of the node address has an unwanted
side effect.
- Currently, if a user is sending an anycast message with destination
  domain 0, the tipc_namebl_translate() function will use the 'closest-
  first' algorithm to first look for a node local destination, and only
  when no such is found, will it resort to the cluster global 'round-
  robin' lookup algorithm.
- Current users can get around this, and enforce unconditional use of
  global round-robin by indicating a destination as Z.0.0 or Z.C.0.
- This option disappears when we make the node address flat, since the
  lookup algorithm has no way of recognizing this case. So, as long as
  there are node local destinations, the algorithm will always select
  one of those, and there is nothing the sender can do to change this.

We solve this by eliminating the 'closest-first' option, which was never
a good idea anyway, for non-legacy users, but only for those. To
distinguish between legacy users and non-legacy users we introduce a new
flag 'legacy_addr_format' in struct tipc_core, to be set when the user
configures a legacy-style Z.C.N node address. Hence, when a legacy user
indicates a zero lookup domain 'closest-first' is selected, and in all
other cases we use 'round-robin'.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Nominally, TIPC organizes network nodes into a three-level network
hierarchy consisting of the levels 'zone', 'cluster' and 'node'. This
hierarchy is reflected in the node address format, - it is sub-divided
into an 8-bit zone id, and 12 bit cluster id, and a 12-bit node id.

However, the 'zone' and 'cluster' levels have in reality never been
fully implemented,and never will be. The result of this has been
that the first 20 bits the node identity structure have been wasted,
and the usable node identity range within a cluster has been limited
to 12 bits. This is starting to become a problem.

In the following commits, we will need to be able to connect between
nodes which are using the whole 32-bit value space of the node address.
We therefore remove the restrictions on which values can be assigned
to node identity, -it is from now on only a 32-bit integer with no
assumed internal structure.

Isolation between clusters is now achieved only by setting different
values for the 'network id' field used during neighbor discovery, in
practice leading to the latter becoming the new cluster identity.

The rules for accepting discovery requests/responses from neighboring
nodes now become:

- If the user is using legacy address format on both peers, reception
  of discovery messages is subject to the legacy lookup domain check
  in addition to the cluster id check.

- Otherwise, the discovery request/response is always accepted, provided
  both peers have the same network id.

This secures backwards compatibility for users who have been using zone
or cluster identities as cluster separators, instead of the intended
'network id'.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To facilitate the coming changes in the neighbor discovery functionality
we make some renaming and refactoring of that code. The functional changes
in this commit are trivial, e.g., that we move the message sending call in
tipc_disc_timeout() outside the spinlock protected region.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a preparation for the next commits we try to reduce the footprint of
the function tipc_enable_bearer(), while hopefully making is simpler to
follow.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently when tipc is unable to queue a received message on a
socket, the message is rejected back to the sender with error
TIPC_ERR_OVERLOAD. However, the application on this socket
has no knowledge about these discards.

In this commit, we try to step the sk_drops counter when tipc
is unable to queue a received message. Export sk_drops
using tipc socket diagnostics.
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NGhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit adds socket diagnostics capability for AF_TIPC in netlink
family NETLINK_SOCK_DIAG in a new kernel module (diag.ko).

The following are key design considerations:
- config TIPC_DIAG has default y, like INET_DIAG.
- only requests with flag NLM_F_DUMP is supported (dump all).
- tipc_sock_diag_req message is introduced to send filter parameters.
- the response attributes are of TLV, some nested.

To avoid exposing data structures between diag and tipc modules and
avoid code duplication, the following additions are required:
- export tipc_nl_sk_walk function to reuse socket iterator.
- export tipc_sk_fill_sock_diag to fill the tipc diag attributes.
- create a sock_diag response message in __tipc_add_sock_diag defined
  in diag.c and use the above exported tipc_sk_fill_sock_diag
  to fill response.
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NGhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current socket iterator function tipc_nl_sk_dump, handles socket
locks and calls __tipc_nl_add_sk for each socket.
To reuse this logic in sock_diag implementation, we do minor
modifications to make these functions generic as described below.

In this commit, we add a two new functions __tipc_nl_sk_walk,
__tipc_nl_add_sk_info and modify tipc_nl_sk_dump, __tipc_nl_add_sk
accordingly.

In __tipc_nl_sk_walk we:
1. acquire and release socket locks
2. for each socket, execute the specified callback function

In __tipc_nl_add_sk we:
- Move the netlink attribute insertion to __tipc_nl_add_sk_info.

tipc_nl_sk_dump calls tipc_nl_sk_walk with __tipc_nl_add_sk as argument.

sock_diag will use these generic functions in a later commit.

There is no functional change in this commit.
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NGhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We rename some lists and fields in struct publication both to make
the naming more consistent and to better reflect their roles. We
also update the descriptions of those lists.

node_list -> local_publ
cluster_list -> all_publ
pport_list -> binding_sock
ref -> port

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

The size of struct publication can be reduced further. Membership in
lists 'nodesub_list' and 'local_list' is mutually exlusive, in that
remote publications use the former and local publications the latter.
We replace the two lists with one single, named 'binding_node' which
reflects what it really is.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a further consequence of the previous commits, we can also remove
the member 'zone_list 'in struct name_info and struct publication.
Instead, we now let the member cluster_list take over the role a
container of all publications of a given <type,lower, upper>.
We also remove the counters for the size of those lists, since
they don't serve any purpose.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As a consequence of the previous commit we nan now eliminate zone scope
related lists in the name table. We start with name_table::publ_list[3],
which can now be replaced with two lists, one for node scope publications
and one for cluster scope publications.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Publications for TIPC_CLUSTER_SCOPE and TIPC_ZONE_SCOPE are in all
aspects handled the same way, both on the publishing node and on the
receiving nodes.

Despite previous ambitions to the contrary, this is never going to change,
so we take the conseqeunce of this and obsolete TIPC_ZONE_SCOPE and related
macros/functions. Whenever a user is doing a bind() or a sendmsg() attempt
using ZONE_SCOPE we translate this internally to CLUSTER_SCOPE, while we
remain compatible with users and remote nodes still using ZONE_SCOPE.

Furthermore, the non-formalized scope value 0 has always been permitted
for use during lookup, with the same meaning as ZONE_SCOPE/CLUSTER_SCOPE.
We now permit it even as binding scope, but for compatibility reasons we
choose to not change the value of TIPC_CLUSTER_SCOPE.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TIPC looks concentrated in itself, and other pernet_operations
seem not touching its entities.

tipc_net_ops look pernet-divided, and they should be safe to
be executed in parallel for several net the same time.
Signed-off-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Assign true or false to boolean variables instead of an integer value.

This issue was detected with the help of Coccinelle.
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 60c25306 ("tipc: fix race between poll() and
setsockopt()") we introduced a pointer from struct tipc_group to the
'group_is_connected' flag in struct tipc_sock, so that this field can
be checked without dereferencing the group pointer of the latter struct.

The initial value for this flag is correctly set to 'false' when a
group is created, but we miss the case when no group is created at
all, in which case the initial value should be 'true'. This has the
effect that SOCK_RDM/DGRAM sockets sending datagrams never receive
POLLOUT if they request so.

This commit corrects this bug.

Fixes: 60c25306 ("tipc: fix race between poll() and setsockopt()")
Reported-by: NHoang Le <hoang.h.le@dektek.com.au>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported a scheduling while atomic issue at netns
destruction time:

BUG: sleeping function called from invalid context at net/core/sock.c:2769
in_atomic(): 1, irqs_disabled(): 0, pid: 85, name: kworker/u4:3
5 locks held by kworker/u4:3/85:
  #0:  ((wq_completion)"%s""netns"){+.+.}, at: [<00000000c9792deb>]
process_one_work+0xaaf/0x1af0 kernel/workqueue.c:2084
  #1:  (net_cleanup_work){+.+.}, at: [<00000000adc12e2a>]
process_one_work+0xb01/0x1af0 kernel/workqueue.c:2088
  #2:  (net_sem){++++}, at: [<000000009ccb5669>] cleanup_net+0x23f/0xd20
net/core/net_namespace.c:494
  #3:  (net_mutex){+.+.}, at: [<00000000a92767d9>] cleanup_net+0xa7d/0xd20
net/core/net_namespace.c:496
  #4:  (&(&srv->idr_lock)->rlock){+...}, at: [<000000001343e568>]
spin_lock_bh include/linux/spinlock.h:315 [inline]
  #4:  (&(&srv->idr_lock)->rlock){+...}, at: [<000000001343e568>]
tipc_topsrv_stop+0x231/0x610 net/tipc/topsrv.c:685
CPU: 0 PID: 85 Comm: kworker/u4:3 Not tainted 4.16.0-rc1+ #230
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6128
  __might_sleep+0x95/0x190 kernel/sched/core.c:6081
  lock_sock_nested+0x37/0x110 net/core/sock.c:2769
  lock_sock include/net/sock.h:1463 [inline]
  tipc_release+0x103/0xff0 net/tipc/socket.c:572
  sock_release+0x8d/0x1e0 net/socket.c:594
  tipc_topsrv_stop+0x3c0/0x610 net/tipc/topsrv.c:696
  tipc_exit_net+0x15/0x40 net/tipc/core.c:96
  ops_exit_list.isra.6+0xae/0x150 net/core/net_namespace.c:148
  cleanup_net+0x6ba/0xd20 net/core/net_namespace.c:529
  process_one_work+0xbbf/0x1af0 kernel/workqueue.c:2113
  worker_thread+0x223/0x1990 kernel/workqueue.c:2247
  kthread+0x33c/0x400 kernel/kthread.c:238
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:429

This is caused by tipc_topsrv_stop() releasing the listener socket
with the idr lock held. This changeset addresses the issue moving
the release operation outside such lock.

Reported-and-tested-by: syzbot+749d9d87c294c00ca856@syzkaller.appspotmail.com
Fixes: 0ef897be ("tipc: separate topology server listener socket from subcsriber sockets")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by:  ///jon
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit cc1ea9ffadf7 ("tipc: eliminate struct tipc_subscriber") we
re-introduced an old bug on the error path in the function
tipc_topsrv_kern_subscr(). We now re-introduce the correction too.

Reported-by: syzbot+f62e0f2a0ef578703946@syzkaller.appspotmail.com
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We rename struct tipc_server to struct tipc_topsrv. This reflect its now
specialized role as topology server. Accoringly, we change or add function
prefixes to make it clearer which functionality those belong to.

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

We move the listener socket to struct tipc_server and give it its own
work item. This makes it easier to follow the code, and entails some
simplifications in the reception code in subscriber sockets.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to narrow the interface and dependencies between the topology
server and the subscription/binding table functionality we move struct
tipc_server inside the file server.c. This requires some code
adaptations in other files, but those are mostly minor.

The most important change is that we have to move the start/stop
functions for the topology server to server.c, where they logically
belong anyway.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since we now have removed struct tipc_subscriber from the code, and
only struct tipc_subscription remains, there is no longer need for long
and awkward prefixes to distinguish between their pertaining functions.

We now change all tipc_subscrp_* prefixes to tipc_sub_*. This is
a purely cosmetic change.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the previous changes it becomes logical to collapse the two-level
creation of subscription instances into one. We do that here.

We also rename the creation and deletion functions for more consistency.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Because of the requirement for total distribution transparency, users
send subscriptions and receive topology events in their own host format.
It is up to the topology server to determine this format and do the
correct conversions to and from its own host format when needed.

Until now, this has been handled in a rather non-transparent way inside
the topology server and subscriber code, leading to unnecessary
complexity when creating subscriptions and issuing events.

We now improve this situation by adding two new macros, tipc_sub_read()
and tipc_evt_write(). Both those functions calculate the need for
conversion internally before performing their respective operations.
Hence, all handling of such conversions become transparent to the rest
of the code.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The message transmission and reception in the topology server is more
generic than is currently necessary. By basing the funtionality on the
fact that we only send items of type struct tipc_event and always
receive items of struct tipc_subcr we can make several simplifications,
and also get rid of some unnecessary dynamic memory allocations.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is unnecessary to keep two structures, struct tipc_conn and struct
tipc_subscriber, with a one-to-one relationship and still with different
life cycles. The fact that the two often run in different contexts, and
still may access each other via direct pointers constitutes an additional
hazard, something we have experienced at several occasions, and still
see happening.

We have identified at least two remaining problems that are easier to
fix if we simplify the topology server data structure somewhat.

- When there is a race between a subscription up/down event and a
  timeout event, it is fully possible that the former might be delivered
  after the latter, leading to confusion for the receiver.

- The function tipc_subcrp_timeout() is executing in interrupt context,
  while the following call chain is at least theoretically possible:
  tipc_subscrp_timeout()
    tipc_subscrp_send_event()
      tipc_conn_sendmsg()
        conn_put()
          tipc_conn_kref_release()
            sock_release(sock)

I.e., we end up calling a function that might try to sleep in
interrupt context. To eliminate this, we need to ensure that the
tipc_conn structure and the socket, as well as the subscription
instances, only are deleted in work queue context, i.e., after the
timeout event really has been sent out.

We now remove this unnecessary complexity, by merging data and
functionality of the subscriber structure into struct tipc_conn
and the associated file server.c. We thereafter add a spinlock and
a new 'inactive' state to the subscription structure. Using those,
both problems described above can be easily solved.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Interaction between the functionality in server.c and subscr.c is
done via function pointers installed in struct server. This makes
the code harder to follow, and doesn't serve any obvious purpose.

Here, we replace the function pointers with direct function calls.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The socket handling in the topology server is unnecessarily generic.
It is prepared to handle both SOCK_RDM, SOCK_DGRAM and SOCK_STREAM
type sockets, as well as the only socket type which is really used,
SOCK_SEQPACKET.

We now remove this redundant code to make the code more readable.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, the default link tolerance set in struct tipc_bearer only
has effect on links going up after that moment. I.e., a user has to
reset all the node's links across that bearer to have the new value
applied. This is too limiting and disturbing on a running cluster to
be useful.

We now change this so that also already existing links are updated
dynamically, without any need for a reset, when the bearer value is
changed. We leverage the already existing per-link functionality
for this to achieve the wanted effect.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>