The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>

sysbot/KMSAN reported an uninit-value in recvmsg() that
I tracked down to tipc_sk_set_orig_addr(), missing
srcaddr->member.scope initialization.

This patches moves srcaddr->sock.scope init to follow
fields order and ease future verifications.

BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline]
BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:226
CPU: 0 PID: 4549 Comm: syz-executor287 Not tainted 4.17.0-rc3+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 kmsan_internal_check_memory+0x135/0x1e0 mm/kmsan/kmsan.c:1157
 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199
 copy_to_user include/linux/uaccess.h:184 [inline]
 move_addr_to_user+0x32e/0x530 net/socket.c:226
 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2285
 __sys_recvmsg net/socket.c:2328 [inline]
 __do_sys_recvmsg net/socket.c:2338 [inline]
 __se_sys_recvmsg net/socket.c:2335 [inline]
 __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335
 do_syscall_64+0x154/0x220 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4455e9
RSP: 002b:00007fe3bd36ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004455e9
RDX: 0000000000002002 RSI: 0000000020000400 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff98ce4b6f R14: 00007fe3bd36e9c0 R15: 0000000000000003

Local variable description: ----addr@___sys_recvmsg
Variable was created at:
 ___sys_recvmsg+0xd5/0x810 net/socket.c:2246
 __sys_recvmsg net/socket.c:2328 [inline]
 __do_sys_recvmsg net/socket.c:2338 [inline]
 __se_sys_recvmsg net/socket.c:2335 [inline]
 __x64_sys_recvmsg+0x325/0x460 net/socket.c:2335

Byte 19 of 32 is uninitialized

Fixes: 31c82a2d ("tipc: add second source address to recvmsg()/recvfrom()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After the introduction of a 128-bit node identity it may be difficult
for a user to correlate between this identity and the generated node
hash address.

We now try to make this easier by introducing a new ioctl() call for
fetching a node identity by using the hash value as key. This will
be particularly useful when we extend some of the commands in the
'tipc' tool, but we also expect regular user applications to need
this feature.
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 stack variable 'dnode' in __tipc_sendmsg() may theoretically
end up tipc_node_get_mtu() as an unitilalized variable.

We fix this by intializing the variable at declaration. We also add
a default else clause to the two conditional ones already there, so
that we never end up in the named function if the given address
type is illegal.

Reported-by: syzbot+b0975ce9355b347c1546@syzkaller.appspotmail.com
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 4b2e6877 ("tipc: Fix namespace violation in tipc_sk_fill_sock_diag")
tried to fix the crash but failed, the crash is still 100% reproducible
with it.

In tipc_sk_fill_sock_diag(), skb is the diag dump we are filling, it is not
correct to retrieve its NETLINK_CB(), instead, like other protocol diag,
we should use NETLINK_CB(cb->skb).sk here.

Reported-by: <syzbot+326e587eff1074657718@syzkaller.appspotmail.com>
Fixes: 4b2e6877 ("tipc: Fix namespace violation in tipc_sk_fill_sock_diag")
Fixes: c30b70de (tipc: implement socket diagnostics for AF_TIPC)
Cc: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To fetch UID info for socket diagnostics, we determine the
namespace of user context using tipc socket instance. This
may cause namespace violation, as the kernel will remap based
on UID.

We fix this by fetching namespace info using the calling userspace
netlink socket.

Fixes: c30b70de (tipc: implement socket diagnostics for AF_TIPC)
Reported-by: syzbot+326e587eff1074657718@syzkaller.appspotmail.com
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NGhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@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>

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>

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>

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>

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>

Changes since v1:
Added changes in these files:
    drivers/infiniband/hw/usnic/usnic_transport.c
    drivers/staging/lustre/lnet/lnet/lib-socket.c
    drivers/target/iscsi/iscsi_target_login.c
    drivers/vhost/net.c
    fs/dlm/lowcomms.c
    fs/ocfs2/cluster/tcp.c
    security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

    text    data     bss      dec     hex filename
30108430 2633624  873672 33615726 200ef6e vmlinux.before.o
30108109 2633612  873672 33615393 200ee21 vmlinux.o
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Letting tipc_poll() dereference a socket's pointer to struct tipc_group
entails a race risk, as the group item may be deleted in a concurrent
tipc_sk_join() or tipc_sk_leave() thread.

We now move the 'open' flag in struct tipc_group to struct tipc_sock,
and let the former retain only a pointer to the moved field. This will
eliminate the race risk.

Reported-by: syzbot+799dafde0286795858ac@syzkaller.appspotmail.com
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 232d07b7 ("tipc: improve groupcast scope handling") we
inadvertently broke non-group multicast transmission when changing the
parameter 'domain' to 'scope' in the function
tipc_nametbl_lookup_dst_nodes(). We missed to make the corresponding
change in the calling function, with the result that the lookup always
fails.

A closer anaysis reveals that this parameter is not needed at all.
Non-group multicast is hard coded to use CLUSTER_SCOPE, and in the
current implementation this will be delivered to all matching
destinations except those which are published with NODE_SCOPE on other
nodes. Since such publications never will be visible on the sending node
anyway, it makes no sense to discriminate by scope at all.

We now remove this parameter altogether.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit d12d2e12 "tipc: send out join messages as soon as new
member is discovered") we added a call to the function tipc_group_join()
without considering the case that the preceding tipc_sk_publish() might
have failed, and the group item already deleted.

We fix this by returning from tipc_sk_join() directly after the
failed tipc_sk_publish.

Reported-by: syzbot+e3eeae78ea88b8d6d858@syzkaller.appspotmail.com
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current criteria for returning POLLOUT from a group member socket is
too simplistic. It basically returns POLLOUT as soon as the group has
external destinations, something obviously leading to a lot of spinning
during destination congestion situations. At the same time, the internal
congestion handling is unnecessarily complex.

We now change this as follows.

- We introduce an 'open' flag in  struct tipc_group. This flag is used
  only to help poll() get the setting of POLLOUT right, and *not* for
  congeston handling as such. This means that a user can choose to
  ignore an  EAGAIN for a destination and go on sending messages to
  other destinations in the group if he wants to.

- The flag is set to false every time we return EAGAIN on a send call.

- The flag is set to true every time any member, i.e., not necessarily
  the member that caused EAGAIN, is removed from the small_win list.

- We remove the group member 'usr_pending' flag. The size of the send
  window and presence in the 'small_win' list is sufficient criteria
  for recognizing congestion.

This solution seems to be a reasonable compromise between 'anycast',
which is normally not waiting for POLLOUT for a specific destination,
and the other three send modes, which are.
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 member joins a group, it also indicates a binding scope. This
makes it possible to create both node local groups, invisible to other
nodes, as well as cluster global groups, visible everywhere.

In order to avoid that different members end up having permanently
differing views of group size and memberhip, we must inhibit locally
and globally bound members from joining the same group.

We do this by using the binding scope as an additional separator between
groups. I.e., a member must ignore all membership events from sockets
using a different scope than itself, and all lookups for message
destinations must require an exact match between the message's lookup
scope and the potential target's binding scope.

Apart from making it possible to create local groups using the same
identity on different nodes, a side effect of this is that it now also
becomes possible to create a cluster global group with the same identity
across the same nodes, without interfering with the local groups.
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 socket is joining a group, we look up in the binding table to
find if there are already other members of the group present. This is
used for being able to return EAGAIN instead of EHOSTUNREACH if the
user proceeds directly to a send attempt.

However, the information in the binding table can be used to directly
set the created member in state MBR_PUBLISHED and send a JOIN message
to the peer, instead of waiting for a topology PUBLISH event to do this.
When there are many members in a group, the propagation time for such
events can be significant, and we can save time during the join
operation if we use the initial lookup result fully.

In this commit, we eliminate the member state MBR_DISCOVERED which has
been the result of the initial lookup, and do instead go directly to
MBR_PUBLISHED, which initiates the setup.

After this change, the tipc_member FSM looks as follows:

     +-----------+
---->| PUBLISHED |-----------------------------------------------+
PUB- +-----------+                                 LEAVE/WITHRAW |
LISH       |JOIN                                                 |
           |     +-------------------------------------------+   |
           |     |                            LEAVE/WITHDRAW |   |
           |     |                +------------+             |   |
           |     |   +----------->|  PENDING   |---------+   |   |
           |     |   |msg/maxactv +-+---+------+  LEAVE/ |   |   |
           |     |   |              |   |       WITHDRAW |   |   |
           |     |   |   +----------+   |                |   |   |
           |     |   |   |revert/maxactv|                |   |   |
           |     |   |   V              V                V   V   V
           |   +----------+  msg  +------------+       +-----------+
           +-->|  JOINED  |------>|   ACTIVE   |------>|  LEAVING  |--->
           |   +----------+       +--- -+------+ LEAVE/+-----------+DOWN
           |        A   A               |      WITHDRAW A   A    A   EVT
           |        |   |               |RECLAIM        |   |    |
           |        |   |REMIT          V               |   |    |
           |        |   |== adv   +------------+        |   |    |
           |        |   +---------| RECLAIMING |--------+   |    |
           |        |             +-----+------+  LEAVE/    |    |
           |        |                   |REMIT   WITHDRAW   |    |
           |        |                   |< adv              |    |
           |        |msg/               V            LEAVE/ |    |
           |        |adv==ADV_IDLE+------------+   WITHDRAW |    |
           |        +-------------|  REMITTED  |------------+    |
           |                      +------------+                 |
           |PUBLISH                                              |
JOIN +-----------+                                LEAVE/WITHDRAW |
---->|  JOINING  |-----------------------------------------------+
     +-----------+
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 the current implementation, a group socket receiving topology
events about other members just converts the topology event message
into a group event message and stores it until it reaches the right
state to issue it to the user. This complicates the code unnecessarily,
and becomes impractical when we in the coming commits will need to
create and issue membership events independently.

In this commit, we change this so that we just notice the type and
origin of the incoming topology event, and then drop the buffer. Only
when it is time to actually send a group event to the user do we
explicitly create a new message and send it upwards.
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 commit 42b531de ("tipc: Fix missing connection request
handling"), we replaced unconditional wakeup() with condtional
wakeup for clients with flags POLLIN | POLLRDNORM | POLLRDBAND.

This breaks the applications which do a connect followed by poll
with POLLOUT flag. These applications are not woken when the
connection is ESTABLISHED and hence sleep forever.

In this commit, we fix it by including the POLLOUT event for
sockets in TIPC_CONNECTING state.

Fixes: 42b531de ("tipc: Fix missing connection request handling")
Acked-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the function tipc_sk_mcast_rcv() we call refcount_dec(&skb->users)
on received sk_buffers. Since the reference counter might hit zero at
this point, we have a potential memory leak.

We fix this by replacing refcount_dec() with kfree_skb().
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: tipc-discussion@lists.sourceforge.net
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tsk->group is set to grp earlier, but we forget to unset it
after grp is freed.

Fixes: 75da2163 ("tipc: introduce communication groups")
Reported-by: syzkaller bot
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function tipc_sk_timeout() is more complex than necessary, and
even seems to contain an undetected bug. At one of the occurences
where we renew the timer we just order it with (HZ / 20), instead
of (jiffies + HZ / 20);

In this commit we clean up the function.
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 commit ae236fb2 ("tipc: receive group membership events via
member socket") we broke the tipc_poll() function by checking the
state of the receive queue before the call to poll_sock_wait(), while
relying that state afterwards, when it might have changed.

We restore this in this commit.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The following scenario is possible:
- A user joins a group, and immediately sends out a broadcast message
  to its members.
- The broadcast message, following a different data path than the
  initial JOIN message sent out during the joining procedure, arrives
  to a receiver before the latter..
- The receiver drops the message, since it is not ready to accept any
  messages until the JOIN has arrived.

We avoid this by treating group protocol JOIN messages like unicast
messages.
- We let them pass through the recipient's multicast input queue, just
  like ordinary unicasts.
- We force the first following broadacst to be sent as replicated
  unicast and being acknowledged by the recipient before accepting
  any more broadcast transmissions.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We need a mechanism guaranteeing that group unicasts sent out from a
socket are not bypassed by later sent broadcasts from the same socket.
We do this as follows:

- Each time a unicast is sent, we set a the broadcast method for the
  socket to "replicast" and "mandatory". This forces the first
  subsequent broadcast message to follow the same network and data path
  as the preceding unicast to a destination, hence preventing it from
  overtaking the latter.

- In order to make the 'same data path' statement above true, we let
  group unicasts pass through the multicast link input queue, instead
  of as previously through the unicast link input queue.

- In the first broadcast following a unicast, we set a new header flag,
  requiring all recipients to immediately acknowledge its reception.

- During the period before all the expected acknowledges are received,
  the socket refuses to accept any more broadcast attempts, i.e., by
  blocking or returning EAGAIN. This period should typically not be
  longer than a few microseconds.

- When all acknowledges have been received, the sending socket will
  open up for subsequent broadcasts, this time giving the link layer
  freedom to itself select the best transmission method.

- The forced and/or abrupt transmission method changes described above
  may lead to broadcasts arriving out of order to the recipients. We
  remedy this by introducing code that checks and if necessary
  re-orders such messages at the receiving end.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Group unicast messages don't follow the same path as broadcast messages,
and there is a high risk that unicasts sent from a socket might bypass
previously sent broadcasts from the same socket.

We fix this by letting all unicast messages carry the sequence number of
the next sent broadcast from the same node, but without updating this
number at the receiver. This way, a receiver can check and if necessary
re-order such messages before they are added to the socket receive buffer.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The previously introduced message transport to all group members is
based on the tipc multicast service, but is logically a broadcast
service within the group, and that is what we call it.

We now add functionality for sending messages to all group members
having a certain identity. Correspondingly, we call this feature 'group
multicast'. The service is using unicast when only one destination is
found, otherwise it will use the bearer broadcast service to transfer
the messages. In the latter case, the receiving members filter arriving
messages by looking at the intended destination instance. If there is
no match, the message will be dropped, while still being considered
received and read as seen by the flow control mechanism.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In this commit, we make it possible to send connectionless unicast
messages to any member corresponding to the given member identity,
when there is more than one such member. The sender must use a
TIPC_ADDR_NAME address to achieve this effect.

We also perform load balancing between the destinations, i.e., we
primarily select one which has advertised sufficient send window
to not cause a block/EAGAIN delay, if any. This mechanism is
overlayed on the always present round-robin selection.

Anycast messages are subject to the same start synchronization
and flow control mechanism as group broadcast messages.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We now make it possible to send connectionless unicast messages
within a communication group. To send a message, the sender can use
either a direct port address, aka port identity, or an indirect port
name to be looked up.

This type of messages are subject to the same start synchronization
and flow control mechanism as group broadcast messages.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We introduce an end-to-end flow control mechanism for group broadcast
messages. This ensures that no messages are ever lost because of
destination receive buffer overflow, with minimal impact on performance.
For now, the algorithm is based on the assumption that there is only one
active transmitter at any moment in time.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like with any other service, group members' availability can be
subscribed for by connecting to be topology server. However, because
the events arrive via a different socket than the member socket, there
is a real risk that membership events my arrive out of synch with the
actual JOIN/LEAVE action. I.e., it is possible to receive the first
messages from a new member before the corresponding JOIN event arrives,
just as it is possible to receive the last messages from a leaving
member after the LEAVE event has already been received.

Since each member socket is internally also subscribing for membership
events, we now fix this problem by passing those events on to the user
via the member socket. We leverage the already present member synch-
ronization protocol to guarantee correct message/event order. An event
is delivered to the user as an empty message where the two source
addresses identify the new/lost member. Furthermore, we set the MSG_OOB
bit in the message flags to mark it as an event. If the event is an
indication about a member loss we also set the MSG_EOR bit, so it can
be distinguished from a member addition event.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>