Commit Graph

1201 Commits

Author SHA1 Message Date
Richard Alpe
ba5aa84a2d tipc: split UDP nl address parsing
Split the UDP netlink parse function so that it only parses one
netlink attribute at the time. This makes the parse function more
generic and allow future UDP API functions to use it for parsing.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-26 21:38:40 -07:00
Wei Yongjun
a5de125dd4 tipc: fix the error handling in tipc_udp_enable()
Fix to return a negative error code in enable_mcast() error handling
case, and release udp socket when necessary.

Fixes: d0f91938be ("tipc: add ip/udp media type")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-25 16:32:34 -07:00
Wei Yongjun
5128b18522 tipc: use kfree_skb() instead of kfree()
Use kfree_skb() instead of kfree() to free sk_buff.

Fixes: 0d051bf93c ("tipc: make bearer packet filtering generic")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-23 23:08:25 -07:00
Richard Alpe
b34040227b tipc: add peer removal functionality
Add TIPC_NL_PEER_REMOVE netlink command. This command can remove
an offline peer node from the internal data structures.

This will be supported by the tipc user space tool in iproute2.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 23:36:07 -07:00
Jon Paul Maloy
5a0950c272 tipc: ensure that link congestion and wakeup use same criteria
When a link is attempted woken up after congestion, it uses a different,
more generous criteria than when it was originally declared congested.
This has the effect that the link, and the sending process, sometimes
will be woken up unnecessarily, just to immediately return to congestion
when it turns out there is not not enough space in its send queue to
host the pending message. This is a waste of CPU cycles.

We now change the function link_prepare_wakeup() to use exactly the same
criteria as tipc_link_xmit(). However, since we are now excluding the
window limit from the wakeup calculation, and the current backlog limit
for the lowest level is too small to house even a single maximum-size
message, we have to expand this limit. We do this by evaluating an
alternative, minimum value during the setting of the importance limits.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 21:14:37 -07:00
Jon Paul Maloy
0d051bf93c tipc: make bearer packet filtering generic
In commit 5b7066c3dd ("tipc: stricter filtering of packets in bearer
layer") we introduced a method of filtering out messages while a bearer
is being reset, to avoid that links may be re-created and come back in
working state while we are still in the process of shutting them down.

This solution works well, but is limited to only work with L2 media, which
is insufficient with the increasing use of UDP as carrier media.

We now replace this solution with a more generic one, by introducing a
new flag "up" in the generic struct tipc_bearer. This field will be set
and reset at the same locations as with the previous solution, while
the packet filtering is moved to the generic code for the sending side.
On the receiving side, the filtering is still done in media specific
code, but now including the UDP bearer.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18 21:14:36 -07:00
Vegard Nossum
d2fbdf76b8 tipc: fix NULL pointer dereference in shutdown()
tipc_msg_create() can return a NULL skb and if so, we shouldn't try to
call tipc_node_xmit_skb() on it.

    general protection fault: 0000 [#1] PREEMPT SMP KASAN
    CPU: 3 PID: 30298 Comm: trinity-c0 Not tainted 4.7.0-rc7+ #19
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    task: ffff8800baf09980 ti: ffff8800595b8000 task.ti: ffff8800595b8000
    RIP: 0010:[<ffffffff830bb46b>]  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
    RSP: 0018:ffff8800595bfce8  EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003023b0e0
    RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff83d12580
    RBP: ffff8800595bfd78 R08: ffffed000b2b7f32 R09: 0000000000000000
    R10: fffffbfff0759725 R11: 0000000000000000 R12: 1ffff1000b2b7f9f
    R13: ffff8800595bfd58 R14: ffffffff83d12580 R15: dffffc0000000000
    FS:  00007fcdde242700(0000) GS:ffff88011af80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fcddde1db10 CR3: 000000006874b000 CR4: 00000000000006e0
    DR0: 00007fcdde248000 DR1: 00007fcddd73d000 DR2: 00007fcdde248000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602
    Stack:
     0000000000000018 0000000000000018 0000000041b58ab3 ffffffff83954208
     ffffffff830bb400 ffff8800595bfd30 ffffffff8309d767 0000000000000018
     0000000000000018 ffff8800595bfd78 ffffffff8309da1a 00000000810ee611
    Call Trace:
     [<ffffffff830c84a3>] tipc_shutdown+0x553/0x880
     [<ffffffff825b4a3b>] SyS_shutdown+0x14b/0x170
     [<ffffffff8100334c>] do_syscall_64+0x19c/0x410
     [<ffffffff83295ca5>] entry_SYSCALL64_slow_path+0x25/0x25
    Code: 90 00 b4 0b 83 c7 00 f1 f1 f1 f1 4c 8d 6d e0 c7 40 04 00 00 00 f4 c7 40 08 f3 f3 f3 f3 48 89 d8 48 c1 e8 03 c7 45 b4 00 00 00 00 <80> 3c 30 00 75 78 48 8d 7b 08 49 8d 75 c0 48 b8 00 00 00 00 00
    RIP  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
     RSP <ffff8800595bfce8>
    ---[ end trace 57b0484e351e71f1 ]---

I feel like we should maybe return -ENOMEM or -ENOBUFS, but I'm not sure
userspace is equipped to handle that. Anyway, this is better than a GPF
and looks somewhat consistent with other tipc_msg_create() callers.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-15 13:55:36 -07:00
Parthasarathy Bhuvaragan
672ca65d9a tipc: fix variable dereference before NULL check
In commit cf6f7e1d51 ("tipc: dump monitor attributes"),
I dereferenced a pointer before checking if its valid.
This is reported by static check Smatch as:
net/tipc/monitor.c:733 tipc_nl_add_monitor_peer()
     warn: variable dereferenced before check 'mon' (see line 731)

In this commit, we check for a valid monitor before proceeding
with any other operation.

Fixes: cf6f7e1d51 ("tipc: dump monitor attributes")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-10 17:56:52 -07:00
Wei Yongjun
6b65bc2972 tipc: fix imbalance read_unlock_bh in __tipc_nl_add_monitor()
In the error handling case of nla_nest_start() failed read_unlock_bh()
is called  to unlock a lock that had not been taken yet. sparse warns
about the context imbalance as the following:

net/tipc/monitor.c:799:23: warning:
 context imbalance in '__tipc_nl_add_monitor' - different lock contexts for basic block

Fixes: cf6f7e1d51 ('tipc: dump monitor attributes')
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-30 20:38:22 -07:00
Parthasarathy Bhuvaragan
cf6f7e1d51 tipc: dump monitor attributes
In this commit, we dump the monitor attributes when queried.
The link monitor attributes are separated into two kinds:
1. general attributes per bearer
2. specific attributes per node/peer
This style resembles the socket attributes and the nametable
publications per socket.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:26:42 -07:00
Parthasarathy Bhuvaragan
ff0d3e78a6 tipc: add a function to get the bearer name
Introduce a new function to get the bearer name from
its id. This is used in subsequent commit.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:26:42 -07:00
Parthasarathy Bhuvaragan
bf1035b2ff tipc: get monitor threshold for the cluster
In this commit, we add support to fetch the configured
cluster monitoring threshold.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:26:42 -07:00
Parthasarathy Bhuvaragan
7b3f522964 tipc: make cluster size threshold for monitoring configurable
In this commit, we introduce support to configure the minimum
threshold to activate the new link monitoring algorithm.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:26:42 -07:00
Parthasarathy Bhuvaragan
9ff26e9fab tipc: introduce constants for tipc address validation
In this commit, we introduce defines for tipc address size,
offset and mask specification for Zone.Cluster.Node.
There is no functional change in this commit.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26 14:26:42 -07:00
David S. Miller
de0ba9a0d8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Just several instances of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-24 00:53:32 -04:00
Jon Paul Maloy
1fc07f3e15 tipc: reset all unicast links when broadcast send link fails
In test situations with many nodes and a heavily stressed system we have
observed that the transmission broadcast link may fail due to an
excessive number of retransmissions of the same packet. In such
situations we need to reset all unicast links to all peers, in order to
reset and re-synchronize the broadcast link.

In this commit, we add a new function tipc_bearer_reset_all() to be used
in such situations. The function scans across all bearers and resets all
their pertaining links.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11 22:42:12 -07:00
Jon Paul Maloy
a71eb72035 tipc: ensure correct broadcast send buffer release when peer is lost
After a new receiver peer has been added to the broadcast transmission
link, we allow immediate transmission of new broadcast packets, trusting
that the new peer will not accept the packets until it has received the
previously sent unicast broadcast initialiation message. In the same
way, the sender must not accept any acknowledges until it has itself
received the broadcast initialization from the peer, as well as
confirmation of the reception of its own initialization message.

Furthermore, when a receiver peer goes down, the sender has to produce
the missing acknowledges from the lost peer locally, in order ensure
correct release of the buffers that were expected to be acknowledged by
the said peer.

In a highly stressed system we have observed that contact with a peer
may come up and be lost before the above mentioned broadcast initial-
ization and confirmation have been received. This leads to the locally
produced acknowledges being rejected, and the non-acknowledged buffers
to linger in the broadcast link transmission queue until it fills up
and the link goes into permanent congestion.

In this commit, we remedy this by temporarily setting the corresponding
broadcast receive link state to ESTABLISHED and the 'bc_peer_is_up'
state to true before we issue the local acknowledges. This ensures that
those acknowledges will always be accepted. The mentioned state values
are restored immediately afterwards when the link is reset.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11 22:42:12 -07:00
Jon Paul Maloy
2d18ac4ba7 tipc: extend broadcast link initialization criteria
At first contact between two nodes, an endpoint might sometimes have
time to send out a LINK_PROTOCOL/STATE packet before it has received
the broadcast initialization packet from the peer, i.e., before it has
received a valid broadcast packet number to add to the 'bc_ack' field
of the protocol message.

This means that the peer endpoint will receive a protocol packet with an
invalid broadcast acknowledge value of 0. Under unlucky circumstances
this may lead to the original, already received acknowledge value being
overwritten, so that the whole broadcast link goes stale after a while.

We fix this by delaying the setting of the link field 'bc_peer_is_up'
until we know that the peer really has received our own broadcast
initialization message. The latter is always sent out as the first
unicast message on a link, and always with seqeunce number 1. Because
of this, we only need to look for a non-zero unicast acknowledge value
in the arriving STATE messages, and once that is confirmed we know we
are safe and can set the mentioned field. Before this moment, we must
ignore all broadcast acknowledges from the peer.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11 22:42:12 -07:00
David S. Miller
30d0844bdc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/mellanox/mlx5/core/en.h
	drivers/net/ethernet/mellanox/mlx5/core/en_main.c
	drivers/net/usb/r8152.c

All three conflicts were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-06 10:35:22 -07:00
Richard Alpe
55e77a3e82 tipc: fix nl compat regression for link statistics
Fix incorrect use of nla_strlcpy() where the first NLA_HDRLEN bytes
of the link name where left out.

Making the output of tipc-config -ls look something like:
Link statistics:
dcast-link
1:data0-1.1.2:data0
1:data0-1.1.3:data0

Also, for the record, the patch that introduce this regression
claims "Sending the whole object out can cause a leak". Which isn't
very likely as this is a compat layer, where the data we are parsing
is generated by us and we know the string to be NULL terminated. But
you can of course never be to secure.

Fixes: 5d2be1422e (tipc: fix an infoleak in tipc_nl_compat_link_dump)
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-01 16:47:38 -04:00
David S. Miller
ee58b57100 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several cases of overlapping changes, except the packet scheduler
conflicts which deal with the addition of the free list parameter
to qdisc_enqueue().

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-30 05:03:36 -04:00
Richard Alpe
bc3a334cc2 tipc: rename udp_port in struct udp_media_addr
Context implies that port in struct "udp_media_addr" is referring
to a UDP port.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-29 05:17:37 -04:00
Richard Alpe
e99429232e tipc: honor msg2addr return value
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 <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-29 05:17:37 -04:00
Amitoj Kaur Chawla
810bf11033 tipc: Use kmemdup instead of kmalloc and memcpy
Replace calls to kmalloc followed by a memcpy with a direct call to
kmemdup.

The Coccinelle semantic patch used to make this change is as follows:
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-27 09:56:58 -04:00
Jon Paul Maloy
27777daa8b tipc: unclone unbundled buffers before forwarding
When extracting an individual message from a received "bundle" buffer,
we just create a clone of the base buffer, and adjust it to point into
the right position of the linearized data area of the latter. This works
well for regular message reception, but during periods of extremely high
load it may happen that an extracted buffer, e.g, a connection probe, is
reversed and forwarded through an external interface while the preceding
extracted message is still unhandled. When this happens, the header or
data area of the preceding message will be partially overwritten by a
MAC header, leading to unpredicatable consequences, such as a link
reset.

We now fix this by ensuring that the msg_reverse() function never
returns a cloned buffer, and that the returned buffer always contains
sufficient valid head and tail room to be forwarded.

Reported-by: Erik Hugne <erik.hugne@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-22 16:33:35 -04:00
Jon Paul Maloy
f1d048f24e tipc: fix socket timer deadlock
We sometimes observe a 'deadly embrace' type deadlock occurring
between mutually connected sockets on the same node. This happens
when the one-hour peer supervision timers happen to expire
simultaneously in both sockets.

The scenario is as follows:

CPU 1:                          CPU 2:
--------                        --------
tipc_sk_timeout(sk1)            tipc_sk_timeout(sk2)
  lock(sk1.slock)                 lock(sk2.slock)
  msg_create(probe)               msg_create(probe)
  unlock(sk1.slock)               unlock(sk2.slock)
  tipc_node_xmit_skb()            tipc_node_xmit_skb()
    tipc_node_xmit()                tipc_node_xmit()
      tipc_sk_rcv(sk2)                tipc_sk_rcv(sk1)
        lock(sk2.slock)                 lock((sk1.slock)
        filter_rcv()                    filter_rcv()
          tipc_sk_proto_rcv()             tipc_sk_proto_rcv()
            msg_create(probe_rsp)           msg_create(probe_rsp)
            tipc_sk_respond()               tipc_sk_respond()
              tipc_node_xmit_skb()            tipc_node_xmit_skb()
                tipc_node_xmit()                tipc_node_xmit()
                  tipc_sk_rcv(sk1)                tipc_sk_rcv(sk2)
                    lock((sk1.slock)                lock((sk2.slock)
                    ===> DEADLOCK                   ===> DEADLOCK

Further analysis reveals that there are three different locations in the
socket code where tipc_sk_respond() is called within the context of the
socket lock, with ensuing risk of similar deadlocks.

We now solve this by passing a buffer queue along with all upcalls where
sk_lock.slock may potentially be held. Response or rejected message
buffers are accumulated into this queue instead of being sent out
directly, and only sent once we know we are safely outside the slock
context.

Reported-by: GUNA <gbalasun@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-17 21:38:10 -07:00
Dan Carpenter
0350cb48fb tipc: potential shift wrapping bug in map_set()
"up_map" is a u64 type but we're not using the high 32 bits.

Fixes: 35c55c9877 ('tipc: add neighbor monitoring framework')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-17 21:26:03 -07:00
Ying Xue
c91522f860 tipc: eliminate uninitialized variable warning
net/tipc/link.c: In function ‘tipc_link_timeout’:
net/tipc/link.c:744:28: warning: ‘mtyp’ may be used uninitialized in this function [-Wuninitialized]

Fixes: 42b18f605f ("tipc: refactor function tipc_link_timeout()")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 21:47:23 -07:00
Ying Xue
66d95b6705 tipc: fix suspicious RCU usage
When run tipcTS&tipcTC test suite, the following complaint appears:

[   56.926168] ===============================
[   56.926169] [ INFO: suspicious RCU usage. ]
[   56.926171] 4.7.0-rc1+ #160 Not tainted
[   56.926173] -------------------------------
[   56.926174] net/tipc/bearer.c:408 suspicious rcu_dereference_protected() usage!
[   56.926175]
[   56.926175] other info that might help us debug this:
[   56.926175]
[   56.926177]
[   56.926177] rcu_scheduler_active = 1, debug_locks = 1
[   56.926179] 3 locks held by swapper/4/0:
[   56.926180]  #0:  (((&req->timer))){+.-...}, at: [<ffffffff810e79b5>] call_timer_fn+0x5/0x340
[   56.926203]  #1:  (&(&req->lock)->rlock){+.-...}, at: [<ffffffffa000c29b>] disc_timeout+0x1b/0xd0 [tipc]
[   56.926212]  #2:  (rcu_read_lock){......}, at: [<ffffffffa00055e0>] tipc_bearer_xmit_skb+0xb0/0x2e0 [tipc]
[   56.926218]
[   56.926218] stack backtrace:
[   56.926221] CPU: 4 PID: 0 Comm: swapper/4 Not tainted 4.7.0-rc1+ #160
[   56.926222] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[   56.926224]  0000000000000000 ffff880016803d28 ffffffff813c4423 ffff8800154252c0
[   56.926227]  0000000000000001 ffff880016803d58 ffffffff810b7512 ffff8800124d8120
[   56.926230]  ffff880013f8a160 ffff8800132b5ccc ffff8800124d8120 ffff880016803d88
[   56.926234] Call Trace:
[   56.926235]  <IRQ>  [<ffffffff813c4423>] dump_stack+0x67/0x94
[   56.926250]  [<ffffffff810b7512>] lockdep_rcu_suspicious+0xe2/0x120
[   56.926256]  [<ffffffffa00051f1>] tipc_l2_send_msg+0x131/0x1c0 [tipc]
[   56.926261]  [<ffffffffa000567c>] tipc_bearer_xmit_skb+0x14c/0x2e0 [tipc]
[   56.926266]  [<ffffffffa00055e0>] ? tipc_bearer_xmit_skb+0xb0/0x2e0 [tipc]
[   56.926273]  [<ffffffffa000c280>] ? tipc_disc_init_msg+0x1f0/0x1f0 [tipc]
[   56.926278]  [<ffffffffa000c280>] ? tipc_disc_init_msg+0x1f0/0x1f0 [tipc]
[   56.926283]  [<ffffffffa000c2d6>] disc_timeout+0x56/0xd0 [tipc]
[   56.926288]  [<ffffffff810e7a68>] call_timer_fn+0xb8/0x340
[   56.926291]  [<ffffffff810e79b5>] ? call_timer_fn+0x5/0x340
[   56.926296]  [<ffffffffa000c280>] ? tipc_disc_init_msg+0x1f0/0x1f0 [tipc]
[   56.926300]  [<ffffffff810e8f4a>] run_timer_softirq+0x23a/0x390
[   56.926306]  [<ffffffff810f89ff>] ? clockevents_program_event+0x7f/0x130
[   56.926316]  [<ffffffff819727c3>] __do_softirq+0xc3/0x4a2
[   56.926323]  [<ffffffff8106ba5a>] irq_exit+0x8a/0xb0
[   56.926327]  [<ffffffff81972456>] smp_apic_timer_interrupt+0x46/0x60
[   56.926331]  [<ffffffff81970a49>] apic_timer_interrupt+0x89/0x90
[   56.926333]  <EOI>  [<ffffffff81027fda>] ? default_idle+0x2a/0x1a0
[   56.926340]  [<ffffffff81027fd8>] ? default_idle+0x28/0x1a0
[   56.926342]  [<ffffffff810289cf>] arch_cpu_idle+0xf/0x20
[   56.926345]  [<ffffffff810adf0f>] default_idle_call+0x2f/0x50
[   56.926347]  [<ffffffff810ae145>] cpu_startup_entry+0x215/0x3e0
[   56.926353]  [<ffffffff81040ad9>] start_secondary+0xf9/0x100

The warning appears as rtnl_dereference() is wrongly used in
tipc_l2_send_msg() under RCU read lock protection. Instead the proper
usage should be that rcu_dereference_rtnl() is called here.

Fixes: 5b7066c3dd ("tipc: stricter filtering of packets in bearer layer")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 21:47:23 -07:00
Jon Paul Maloy
35c55c9877 tipc: add neighbor monitoring framework
TIPC based clusters are by default set up with full-mesh link
connectivity between all nodes. Those links are expected to provide
a short failure detection time, by default set to 1500 ms. Because
of this, the background load for neighbor monitoring in an N-node
cluster increases with a factor N on each node, while the overall
monitoring traffic through the network infrastructure increases at
a ~(N * (N - 1)) rate. Experience has shown that such clusters don't
scale well beyond ~100 nodes unless we significantly increase failure
discovery tolerance.

This commit introduces a framework and an algorithm that drastically
reduces this background load, while basically maintaining the original
failure detection times across the whole cluster. Using this algorithm,
background load will now grow at a rate of ~(2 * sqrt(N)) per node, and
at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will
now have to actively monitor 38 neighbors in a 400-node cluster, instead
of as before 399.

This "Overlapping Ring Supervision Algorithm" is completely distributed
and employs no centralized or coordinated state. It goes as follows:

- Each node makes up a linearly ascending, circular list of all its N
  known neighbors, based on their TIPC node identity. This algorithm
  must be the same on all nodes.

- The node then selects the next M = sqrt(N) - 1 nodes downstream from
  itself in the list, and chooses to actively monitor those. This is
  called its "local monitoring domain".

- It creates a domain record describing the monitoring domain, and
  piggy-backs this in the data area of all neighbor monitoring messages
  (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in
  the cluster eventually (default within 400 ms) will learn about
  its monitoring domain.

- Whenever a node discovers a change in its local domain, e.g., a node
  has been added or has gone down, it creates and sends out a new
  version of its node record to inform all neighbors about the change.

- A node receiving a domain record from anybody outside its local domain
  matches this against its own list (which may not look the same), and
  chooses to not actively monitor those members of the received domain
  record that are also present in its own list. Instead, it relies on
  indications from the direct monitoring nodes if an indirectly
  monitored node has gone up or down. If a node is indicated lost, the
  receiving node temporarily activates its own direct monitoring towards
  that node in order to confirm, or not, that it is actually gone.

- Since each node is actively monitoring sqrt(N) downstream neighbors,
  each node is also actively monitored by the same number of upstream
  neighbors. This means that all non-direct monitoring nodes normally
  will receive sqrt(N) indications that a node is gone.

- A major drawback with ring monitoring is how it handles failures that
  cause massive network partitionings. If both a lost node and all its
  direct monitoring neighbors are inside the lost partition, the nodes in
  the remaining partition will never receive indications about the loss.
  To overcome this, each node also chooses to actively monitor some
  nodes outside its local domain. Those nodes are called remote domain
  "heads", and are selected in such a way that no node in the cluster
  will be more than two direct monitoring hops away. Because of this,
  each node, apart from monitoring the member of its local domain, will
  also typically monitor sqrt(N) remote head nodes.

- As an optimization, local list status, domain status and domain
  records are marked with a generation number. This saves senders from
  unnecessarily conveying  unaltered domain records, and receivers from
  performing unneeded re-adaptations of their node monitoring list, such
  as re-assigning domain heads.

- As a measure of caution we have added the possibility to disable the
  new algorithm through configuration. We do this by keeping a threshold
  value for the cluster size; a cluster that grows beyond this value
  will switch from full-mesh to ring monitoring, and vice versa when
  it shrinks below the value. This means that if the threshold is set to
  a value larger than any anticipated cluster size (default size is 32)
  the new algorithm is effectively disabled. A patch set for altering the
  threshold value and for listing the table contents will follow shortly.

- This change is fully backwards compatible.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15 14:06:28 -07:00
David S. Miller
1578b0a5e9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/sched/act_police.c
	net/sched/sch_drr.c
	net/sched/sch_hfsc.c
	net/sched/sch_prio.c
	net/sched/sch_red.c
	net/sched/sch_tbf.c

In net-next the drop methods of the packet schedulers got removed, so
the bug fixes to them in 'net' are irrelevant.

A packet action unload crash fix conflicts with the addition of the
new firstuse timestamp.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 11:52:24 -07:00
Jon Paul Maloy
5ca509fc0b tipc: change node timer unit from jiffies to ms
The node keepalive interval is recalculated at each timer expiration
to catch any changes in the link tolerance, and stored in a field in
struct tipc_node. We use jiffies as unit for the stored value.

This is suboptimal, because it makes the calculation unnecessary
complex, including two unit conversions. The conversions also lead to
a rounding error that causes the link "abort limit" to be 3 in the
normal case, instead of 4, as intended. This again leads to unnecessary
link resets when the network is pushed close to its limit, e.g., in an
environment with hundreds of nodes or namesapces.

In this commit, we do instead let the keepalive value be calculated and
stored in milliseconds, so that there is only one conversion and the
rounding error is eliminated.

We also remove a redundant "keepalive" field in struct tipc_link. This
is remnant from the previous implementation.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08 11:27:02 -07:00
Jon Paul Maloy
c4282ca76c tipc: correct error in node fsm
commit 88e8ac7000 ("tipc: reduce transmission rate of reset messages
when link is down") revealed a flaw in the node FSM, as defined in
the log of commit 66996b6c47 ("tipc: extend node FSM").

We see the following scenario:
1: Node B receives a RESET message from node A before its link endpoint
   is fully up, i.e., the node FSM is in state SELF_UP_PEER_COMING. This
   event will not change the node FSM state, but the (distinct) link FSM
   will move to state RESETTING.
2: As an effect of the previous event, the local endpoint on B will
   declare node A lost, and post the event SELF_DOWN to the its node
   FSM. This moves the FSM state to SELF_DOWN_PEER_LEAVING, meaning
   that no messages will be accepted from A until it receives another
   RESET message that confirms that A's endpoint has been reset. This
   is  wasteful, since we know this as a fact already from the first
   received RESET, but worse is that the link instance's FSM has not
   wasted this information, but instead moved on to state ESTABLISHING,
   meaning that it repeatedly sends out ACTIVATE messages to the reset
   peer A.
3: Node A will receive one of the ACTIVATE messages, move its link FSM
   to state ESTABLISHED, and start repeatedly sending out STATE messages
   to node B.
4: Node B will consistently drop these messages, since it can only accept
   accept a RESET according to its node FSM.
5: After four lost STATE messages node A will reset its link and start
   repeatedly sending out RESET messages to B.
6: Because of the reduced send rate for RESET messages, it is very
   likely that A will receive an ACTIVATE (which is sent out at a much
   higher frequency) before it gets the chance to send a RESET, and A
   may hence quickly move back to state ESTABLISHED and continue sending
   out STATE messages, which will again be dropped by B.
7: GOTO 5.
8: After having repeated the cycle 5-7 a number of times, node A will
   by chance get in between with sending a RESET, and the situation is
   resolved.

Unfortunately, we have seen that it may take a substantial amount of
time before this vicious loop is broken, sometimes in the order of
minutes.

We correct this by making a small correction to the node FSM: When a
node in state SELF_UP_PEER_COMING receives a SELF_DOWN event, it now
moves directly back to state SELF_DOWN_PEER_DOWN, instead of as now
SELF_DOWN_PEER_LEAVING. This is logically consistent, since we don't
need to wait for RESET confirmation from of an endpoint that we alread
know has been reset. It also means that node B in the scenario above
will not be dropping incoming STATE messages, and the link can come up
immediately.

Finally, a symmetry comparison reveals that the  FSM has a similar
error when receiving the event PEER_DOWN in state PEER_UP_SELF_COMING.
Instead of moving to PERR_DOWN_SELF_LEAVING, it should move directly
to SELF_DOWN_PEER_DOWN. Although we have never seen any negative effect
of this logical error, we choose fix this one, too.

The node FSM looks as follows after those changes:

                           +----------------------------------------+
                           |                           PEER_DOWN_EVT|
                           |                                        |
  +------------------------+----------------+                       |
  |SELF_DOWN_EVT           |                |                       |
  |                        |                |                       |
  |              +-----------+          +-----------+               |
  |              |NODE_      |          |NODE_      |               |
  |   +----------|FAILINGOVER|<---------|SYNCHING   |-----------+   |
  |   |SELF_     +-----------+ FAILOVER_+-----------+   PEER_   |   |
  |   |DOWN_EVT   |          A BEGIN_EVT  A         |   DOWN_EVT|   |
  |   |           |          |            |         |           |   |
  |   |           |          |            |         |           |   |
  |   |           |FAILOVER_ |FAILOVER_   |SYNCH_   |SYNCH_     |   |
  |   |           |END_EVT   |BEGIN_EVT   |BEGIN_EVT|END_EVT    |   |
  |   |           |          |            |         |           |   |
  |   |           |          |            |         |           |   |
  |   |           |         +--------------+        |           |   |
  |   |           +-------->|   SELF_UP_   |<-------+           |   |
  |   |   +-----------------|   PEER_UP    |----------------+   |   |
  |   |   |SELF_DOWN_EVT    +--------------+   PEER_DOWN_EVT|   |   |
  |   |   |                    A        A                   |   |   |
  |   |   |                    |        |                   |   |   |
  |   |   |         PEER_UP_EVT|        |SELF_UP_EVT        |   |   |
  |   |   |                    |        |                   |   |   |
  V   V   V                    |        |                   V   V   V
+------------+       +-----------+    +-----------+       +------------+
|SELF_DOWN_  |       |SELF_UP_   |    |PEER_UP_   |       |PEER_DOWN   |
|PEER_LEAVING|       |PEER_COMING|    |SELF_COMING|       |SELF_LEAVING|
+------------+       +-----------+    +-----------+       +------------+
       |               |       A        A       |                |
       |               |       |        |       |                |
       |       SELF_   |       |SELF_   |PEER_  |PEER_           |
       |       DOWN_EVT|       |UP_EVT  |UP_EVT |DOWN_EVT        |
       |               |       |        |       |                |
       |               |       |        |       |                |
       |               |    +--------------+    |                |
       |PEER_DOWN_EVT  +--->|  SELF_DOWN_  |<---+   SELF_DOWN_EVT|
       +------------------->|  PEER_DOWN   |<--------------------+
                            +--------------+

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08 11:27:01 -07:00
Kangjie Lu
5d2be1422e tipc: fix an infoleak in tipc_nl_compat_link_dump
link_info.str is a char array of size 60. Memory after the NULL
byte is not initialized. Sending the whole object out can cause
a leak.

Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-02 21:32:37 -07:00
Baozeng Ding
297f7d2cce tipc: fix potential null pointer dereferences in some compat functions
Before calling the nla_parse_nested function, make sure the pointer to the
attribute is not null. This patch fixes several potential null pointer
dereference vulnerabilities in the tipc netlink functions.

Signed-off-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-25 12:33:52 -07:00
Eric Dumazet
b91083a45e tipc: block BH in TCP callbacks
TCP stack can now run from process context.

Use read_lock_bh(&sk->sk_callback_lock) variant to restore previous
assumption.

Fixes: 5413d1babe ("net: do not block BH while processing socket backlog")
Fixes: d41a69f1d3 ("tcp: make tcp_sendmsg() aware of socket backlog")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-19 11:36:49 -07:00
Linus Torvalds
16bf834805 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (21 commits)
  gitignore: fix wording
  mfd: ab8500-debugfs: fix "between" in printk
  memstick: trivial fix of spelling mistake on management
  cpupowerutils: bench: fix "average"
  treewide: Fix typos in printk
  IB/mlx4: printk fix
  pinctrl: sirf/atlas7: fix printk spelling
  serial: mctrl_gpio: Grammar s/lines GPIOs/line GPIOs/, /sets/set/
  w1: comment spelling s/minmum/minimum/
  Blackfin: comment spelling s/divsor/divisor/
  metag: Fix misspellings in comments.
  ia64: Fix misspellings in comments.
  hexagon: Fix misspellings in comments.
  tools/perf: Fix misspellings in comments.
  cris: Fix misspellings in comments.
  c6x: Fix misspellings in comments.
  blackfin: Fix misspelling of 'register' in comment.
  avr32: Fix misspelling of 'definitions' in comment.
  treewide: Fix typos in printk
  Doc: treewide : Fix typos in DocBook/filesystem.xml
  ...
2016-05-17 17:05:30 -07:00
Richard Alpe
03aaaa9b94 tipc: fix nametable publication field in nl compat
The publication field of the old netlink API should contain the
publication key and not the publication reference.

Fixes: 44a8ae94fd (tipc: convert legacy nl name table dump to nl compat)
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-17 12:34:02 -04:00
Richard Alpe
45e093ae28 tipc: check nl sock before parsing nested attributes
Make sure the socket for which the user is listing publication exists
before parsing the socket netlink attributes.

Prior to this patch a call without any socket caused a NULL pointer
dereference in tipc_nl_publ_dump().

Tested-and-reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.cm>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-16 21:58:54 -04:00
Jon Paul Maloy
e7142c341c tipc: eliminate risk of double link_up events
When an ACTIVATE or data packet is received in a link in state
ESTABLISHING, the link does not immediately change state to
ESTABLISHED, but does instead return a LINK_UP event to the caller,
which will execute the state change in a different lock context.

This non-atomic approach incurs a low risk that we may have two
LINK_UP events pending simultaneously for the same link, resulting
in the final part of the setup procedure being executed twice. The
only potential harm caused by this it that we may see two LINK_UP
events issued to subsribers of the topology server, something that
may cause confusion.

This commit eliminates this risk by checking if the link is already
up before proceeding with the second half of the setup.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-12 17:11:27 -04:00
David S. Miller
cba6532100 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv4/ip_gre.c

Minor conflicts between tunnel bug fixes in net and
ipv6 tunnel cleanups in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-04 00:52:29 -04:00
Jon Paul Maloy
10724cc7bb tipc: redesign connection-level flow control
There are two flow control mechanisms in TIPC; one at link level that
handles network congestion, burst control, and retransmission, and one
at connection level which' only remaining task is to prevent overflow
in the receiving socket buffer. In TIPC, the latter task has to be
solved end-to-end because messages can not be thrown away once they
have been accepted and delivered upwards from the link layer, i.e, we
can never permit the receive buffer to overflow.

Currently, this algorithm is message based. A counter in the receiving
socket keeps track of number of consumed messages, and sends a dedicated
acknowledge message back to the sender for each 256 consumed message.
A counter at the sending end keeps track of the sent, not yet
acknowledged messages, and blocks the sender if this number ever reaches
512 unacknowledged messages. When the missing acknowledge arrives, the
socket is then woken up for renewed transmission. This works well for
keeping the message flow running, as it almost never happens that a
sender socket is blocked this way.

A problem with the current mechanism is that it potentially is very
memory consuming. Since we don't distinguish between small and large
messages, we have to dimension the socket receive buffer according
to a worst-case of both. I.e., the window size must be chosen large
enough to sustain a reasonable throughput even for the smallest
messages, while we must still consider a scenario where all messages
are of maximum size. Hence, the current fix window size of 512 messages
and a maximum message size of 66k results in a receive buffer of 66 MB
when truesize(66k) = 131k is taken into account. It is possible to do
much better.

This commit introduces an algorithm where we instead use 1024-byte
blocks as base unit. This unit, always rounded upwards from the
actual message size, is used when we advertise windows as well as when
we count and acknowledge transmitted data. The advertised window is
based on the configured receive buffer size in such a way that even
the worst-case truesize/msgsize ratio always is covered. Since the
smallest possible message size (from a flow control viewpoint) now is
1024 bytes, we can safely assume this ratio to be less than four, which
is the value we are now using.

This way, we have been able to reduce the default receive buffer size
from 66 MB to 2 MB with maintained performance.

In order to keep this solution backwards compatible, we introduce a
new capability bit in the discovery protocol, and use this throughout
the message sending/reception path to always select the right unit.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03 15:51:16 -04:00
Jon Paul Maloy
60020e1857 tipc: propagate peer node capabilities to socket layer
During neighbor discovery, nodes advertise their capabilities as a bit
map in a dedicated 16-bit field in the discovery message header. This
bit map has so far only be stored in the node structure on the peer
nodes, but we now see the need to keep a copy even in the socket
structure.

This commit adds this functionality.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03 15:51:15 -04:00
Jon Paul Maloy
7c8bcfb125 tipc: re-enable compensation for socket receive buffer double counting
In the refactoring commit d570d86497 ("tipc: enqueue arrived buffers
in socket in separate function") we did by accident replace the test

if (sk->sk_backlog.len == 0)
     atomic_set(&tsk->dupl_rcvcnt, 0);

with

if (sk->sk_backlog.len)
     atomic_set(&tsk->dupl_rcvcnt, 0);

This effectively disables the compensation we have for the double
receive buffer accounting that occurs temporarily when buffers are
moved from the backlog to the socket receive queue. Until now, this
has gone unnoticed because of the large receive buffer limits we are
applying, but becomes indispensable when we reduce this buffer limit
later in this series.

We now fix this by inverting the mentioned condition.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03 15:51:14 -04:00
Hamish Martin
efe790502b tipc: only process unicast on intended node
We have observed complete lock up of broadcast-link transmission due to
unacknowledged packets never being removed from the 'transmq' queue. This
is traced to nodes having their ack field set beyond the sequence number
of packets that have actually been transmitted to them.
Consider an example where node 1 has sent 10 packets to node 2 on a
link and node 3 has sent 20 packets to node 2 on another link. We
see examples of an ack from node 2 destined for node 3 being treated as
an ack from node 2 at node 1. This leads to the ack on the node 1 to node
2 link being increased to 20 even though we have only sent 10 packets.
When node 1 does get around to sending further packets, none of the
packets with sequence numbers less than 21 are actually removed from the
transmq.
To resolve this we reinstate some code lost in commit d999297c3d ("tipc:
reduce locking scope during packet reception") which ensures that only
messages destined for the receiving node are processed by that node. This
prevents the sequence numbers from getting out of sync and resolves the
packet leakage, thereby resolving the broadcast-link transmission
lock-ups we observed.

While we are aware that this change only patches over a root problem that
we still haven't identified, this is a sanity test that it is always
legitimate to do. It will remain in the code even after we identify and
fix the real problem.

Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: John Thompson <john.thompson@alliedtelesis.co.nz>
Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-01 21:03:30 -04:00
Jon Paul Maloy
def22c47d7 tipc: set 'active' state correctly for first established link
When we are displaying statistics for the first link established between
two peers, it will always be presented as STANDBY although it in reality
is ACTIVE.

This happens because we forget to set the 'active' flag in the link
instance at the moment it is established. Although this is a bug, it only
has impact on the presentation view of the link, not on its actual
functionality.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-01 19:40:22 -04:00
Dan Carpenter
b43586576e tipc: remove an unnecessary NULL check
This is never called with a NULL "buf" and anyway, we dereference 's' on
the lines before so it would Oops before we reach the check.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28 16:54:12 -04:00
Parthasarathy Bhuvaragan
8cee83dd29 tipc: fix stale links after re-enabling bearer
Commit 42b18f605f ("tipc: refactor function tipc_link_timeout()"),
introduced a bug which prevents sending of probe messages during
link synchronization phase. This leads to hanging links, if the
bearer is disabled/enabled after links are up.

In this commit, we send the probe messages correctly.

Fixes: 42b18f605f ("tipc: refactor function tipc_link_timeout()")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-24 14:35:07 -04:00
David S. Miller
1602f49b58 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts were two cases of simple overlapping changes,
nothing serious.

In the UDP case, we need to add a hlist_add_tail_rcu()
to linux/rculist.h, because we've moved UDP socket handling
away from using nulls lists.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-23 18:51:33 -04:00
Masanari Iida
c19ca6cb4c treewide: Fix typos in printk
This patch fix spelling typos found in printk
within various part of the kernel sources.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-04-18 11:23:24 +02:00
Jon Paul Maloy
34b9cd64c8 tipc: let first message on link be a state message
According to the link FSM, a received traffic packet can take a link
from state ESTABLISHING to ESTABLISHED, but the link can still not be
fully set up in one atomic operation. This means that even if the the
very first packet on the link is a traffic packet with sequence number
1 (one), it has to be dropped and retransmitted.

This can be avoided if we let the mentioned packet be preceded by a
LINK_PROTOCOL/STATE message, which takes up the endpoint before the
arrival of the traffic.

We add this small feature in this commit.

This is a fully compatible change.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15 16:09:06 -04:00
Jon Paul Maloy
de7e07f9ee tipc: ensure that first packets on link are sent in order
In some link establishment scenarios we see that packet #2 may be sent
out before packet #1, forcing the receiver to demand retransmission of
the missing packet. This is harmless, but may cause confusion among
people tracing the packet flow.

Since this is extremely easy to fix, we do so by adding en extra send
call to the bearer immediately after the link has come up.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15 16:09:06 -04:00
Jon Paul Maloy
42b18f605f tipc: refactor function tipc_link_timeout()
The function tipc_link_timeout() is unnecessary complex, and can
easily be made more readable.

We do that with this commit. The only functional change is that we
remove a redundant test for whether the broadcast link is up or not.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15 16:09:06 -04:00
Jon Paul Maloy
88e8ac7000 tipc: reduce transmission rate of reset messages when link is down
When a link is down, it will continuously try to re-establish contact
with the peer by sending out a RESET or an ACTIVATE message at each
timeout interval. The default value for this interval is currently
375 ms. This is wasteful, and may become a problem in very large
clusters with dozens or hundreds of nodes being down simultaneously.

We now introduce a simple backoff algorithm for these cases. The
first five messages are sent at default rate; thereafter a message
is sent only each 16th timer interval.

This will cover the vast majority of link recycling cases, since the
endpoint starting last will transmit at the higher speed, and the link
should normally be established well be before the rate needs to be
reduced.

The only case where we will see a degradation of link re-establishment
times is when the endpoints remain intact, and a glitch in the
transmission media is causing the link reset. We will then experience
a worst-case re-establishing time of 6 seconds, something we deem
acceptable.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15 16:09:05 -04:00
Jon Paul Maloy
634696b197 tipc: guarantee peer bearer id exchange after reboot
When a link endpoint is going down locally, e.g., because its interface
is being stopped, it will spontaneously send out a RESET message to
its peer, informing it about this fact. This saves the peer from
detecting the failure via probing, and hence gives both speedier and
less resource consuming failure detection on the peer side.

According to the link FSM, a receiver of a RESET message, ignoring the
reason for it, must now consider the sender ready to come back up, and
starts periodically sending out ACTIVATE messages to the peer in order
to re-establish the link. Also, according to the FSM, the receiver of
an ACTIVATE message can now go directly to state ESTABLISHED and start
sending regular traffic packets. This is a well-proven and robust FSM.

However, in the case of a reboot, there is a small possibilty that link
endpoint on the rebooted node may have been re-created with a new bearer
identity between the moment it sent its (pre-boot) RESET and the moment
it receives the ACTIVATE from the peer. The new bearer identity cannot
be known by the peer according to this scenario, since traffic headers
don't convey such information. This is a problem, because both endpoints
need to know the correct value of the peer's bearer id at any moment in
time in order to be able to produce correct link events for their users.

The only way to guarantee this is to enforce a full setup message
exchange (RESET + ACTIVATE) even after the reboot, since those messages
carry the bearer idientity in their header.

In this commit we do this by introducing and setting a "stopping" bit in
the header of the spontaneously generated RESET messages, informing the
peer that the sender will not be immediately ready to re-establish the
link. A receiver seeing this bit must act as if this were a locally
detected connectivity failure, and hence has to go through a full two-
way setup message exchange before any link can be re-established.

Although never reported, this problem seems to have always been around.

This protocol addition is fully backwards compatible.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15 16:09:05 -04:00
Parthasarathy Bhuvaragan
333f796235 tipc: fix a race condition leading to subscriber refcnt bug
Until now, the requests sent to topology server are queued
to a workqueue by the generic server framework.
These messages are processed by worker threads and trigger the
registered callbacks.
To reduce latency on uniprocessor systems, explicit rescheduling
is performed using cond_resched() after MAX_RECV_MSG_COUNT(25)
messages.

This implementation on SMP systems leads to an subscriber refcnt
error as described below:
When a worker thread yields by calling cond_resched() in a SMP
system, a new worker is created on another CPU to process the
pending workitem. Sometimes the sleeping thread wakes up before
the new thread finishes execution.
This breaks the assumption on ordering and being single threaded.
The fault is more frequent when MAX_RECV_MSG_COUNT is lowered.

If the first thread was processing subscription create and the
second thread processing close(), the close request will free
the subscriber and the create request oops as follows:

[31.224137] WARNING: CPU: 2 PID: 266 at include/linux/kref.h:46 tipc_subscrb_rcv_cb+0x317/0x380         [tipc]
[31.228143] CPU: 2 PID: 266 Comm: kworker/u8:1 Not tainted 4.5.0+ #97
[31.228377] Workqueue: tipc_rcv tipc_recv_work [tipc]
[...]
[31.228377] Call Trace:
[31.228377]  [<ffffffff812fbb6b>] dump_stack+0x4d/0x72
[31.228377]  [<ffffffff8105a311>] __warn+0xd1/0xf0
[31.228377]  [<ffffffff8105a3fd>] warn_slowpath_null+0x1d/0x20
[31.228377]  [<ffffffffa0098067>] tipc_subscrb_rcv_cb+0x317/0x380 [tipc]
[31.228377]  [<ffffffffa00a4984>] tipc_receive_from_sock+0xd4/0x130 [tipc]
[31.228377]  [<ffffffffa00a439b>] tipc_recv_work+0x2b/0x50 [tipc]
[31.228377]  [<ffffffff81071925>] process_one_work+0x145/0x3d0
[31.246554] ---[ end trace c3882c9baa05a4fd ]---
[31.248327] BUG: spinlock bad magic on CPU#2, kworker/u8:1/266
[31.249119] BUG: unable to handle kernel NULL pointer dereference at 0000000000000428
[31.249323] IP: [<ffffffff81099d0c>] spin_dump+0x5c/0xe0
[31.249323] PGD 0
[31.249323] Oops: 0000 [#1] SMP

In this commit, we
- rename tipc_conn_shutdown() to tipc_conn_release().
- move connection release callback execution from tipc_close_conn()
  to a new function tipc_sock_release(), which is executed before
  we free the connection.
Thus we release the subscriber during connection release procedure
rather than connection shutdown procedure.

Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14 16:46:46 -04:00
Jon Paul Maloy
7d45a04cbc tipc: remove remnants of old broadcast code
We remove a couple of leftover fields in struct tipc_bearer. Those
were used by the old broadcast implementation, and are not needed
any longer. There is no functional changes in this commit.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-13 17:49:11 -04:00
Erik Hugne
ddb1d33969 tipc: purge deferred updates from dead nodes
If a peer node becomes unavailable, in addition to removing the
nametable entries from this node we also need to purge all deferred
updates associated with this node.

Signed-off-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:22:20 -04:00
Erik Hugne
541726abe7 tipc: make dist queue pernet
Nametable updates received from the network that cannot be applied
immediately are placed on a defer queue. This queue is global to the
TIPC module, which might cause problems when using TIPC in containers.
To prevent nametable updates from escaping into the wrong namespace,
we make the queue pernet instead.

Signed-off-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:22:20 -04:00
Jon Paul Maloy
5b7066c3dd tipc: stricter filtering of packets in bearer layer
Resetting a bearer/interface, with the consequence of resetting all its
pertaining links, is not an atomic action. This becomes particularly
evident in very large clusters, where a lot of traffic may happen on the
remaining links while we are busy shutting them down. In extreme cases,
we may even see links being re-created and re-established before we are
finished with the job.

To solve this, we now introduce a solution where we temporarily detach
the bearer from the interface when the bearer is reset. This inhibits
all packet reception, while sending still is possible. For the latter,
we use the fact that the device's user pointer now is zero to filter out
which packets can be sent during this situation; i.e., outgoing RESET
messages only.  This filtering serves to speed up the neighbors'
detection of the loss event, and saves us from unnecessary probing.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 17:00:13 -04:00
Jon Paul Maloy
4e801fa14f tipc: eliminate buffer leak in bearer layer
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 <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 17:00:13 -04:00
Richard Alpe
9bd160bfa2 tipc: make sure IPv6 header fits in skb headroom
Expand headroom further in order to be able to fit the larger IPv6
header. Prior to this patch this caused a skb under panic for certain
tipc packets when using IPv6 UDP bearer(s).

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-14 12:23:12 -04:00
Daniel Borkmann
134611446d ip_tunnel: add support for setting flow label via collect metadata
This patch extends udp_tunnel6_xmit_skb() to pass in the IPv6 flow label
from call sites. Currently, there's no such option and it's always set to
zero when writing ip6_flow_hdr(). Add a label member to ip_tunnel_key, so
that flow-based tunnels via collect metadata frontends can make use of it.
vxlan and geneve will be converted to add flow label support separately.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-11 15:14:26 -05:00
David S. Miller
810813c47a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several cases of overlapping changes, as well as one instance
(vxlan) of a bug fix in 'net' overlapping with code movement
in 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 12:34:12 -05:00
Richard Alpe
49cc66eaee tipc: move netlink policies to netlink.c
Make the c files less cluttered and enable netlink attributes to be
shared between files.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-07 14:56:41 -05:00
Jon Paul Maloy
e74a386d70 tipc: remove pre-allocated message header in link struct
Until now, we have kept a pre-allocated protocol message header
aggregated into struct tipc_link. Apart from adding unnecessary
footprint to the link instances, this requires extra code both to
initialize and re-initialize it.

We now remove this sub-optimization. This change also makes it
possible to clean up the function tipc_build_proto_msg() and remove
a couple of small functions that were accessing the mentioned header.
In particular, we can replace all occurrences of the local function
call link_own_addr(link) with the generic tipc_own_addr(net).

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 23:01:20 -05:00
Parthasarathy Bhuvaragan
4de13d7ed6 tipc: fix nullptr crash during subscription cancel
commit 4d5cfcba2f ('tipc: fix connection abort during subscription
cancel'), removes the check for a valid subscription before calling
tipc_nametbl_subscribe().

This will lead to a nullptr exception when we process a
subscription cancel request. For a cancel request, a null
subscription is passed to tipc_nametbl_subscribe() resulting
in exception.

In this commit, we call tipc_nametbl_subscribe() only for
a valid subscription.

Fixes: 4d5cfcba2f ('tipc: fix connection abort during subscription cancel')
Reported-by: Anders Widell <anders.widell@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 23:00:08 -05:00
Richard Alpe
34f65dbb6c tipc: make sure required IPv6 addresses are scoped
Make sure the user has provided a scope for multicast and link local
addresses used locally by a UDP bearer.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 22:54:57 -05:00
Richard Alpe
ddb3712552 tipc: safely copy UDP netlink data from user
The netlink policy for TIPC_NLA_UDP_LOCAL and TIPC_NLA_UDP_REMOTE
is of type binary with a defined length. This causes the policy
framework to threat the defined length as maximum length.

There is however no protection against a user sending a smaller
amount of data. Prior to this patch this wasn't handled which could
result in a partially incomplete sockaddr_storage struct containing
uninitialized data.

In this patch we use nla_memcpy() when copying the user data. This
ensures a potential gap at the end is cleared out properly.

This was found by Julia with Coccinelle tool.

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 22:54:57 -05:00
Richard Alpe
2837f39c7c tipc: don't check link reset on non existing link
Make sure we have a link before checking if it has been reset or not.

Prior to this patch tipc_link_is_reset() could be called with a non
existing link, resulting in a null pointer dereference.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 22:54:56 -05:00
Richard Alpe
9b3009604b tipc: add net device to skb before UDP xmit
Prior to this patch enabling a IPv4 UDP bearer caused a null pointer
dereference in iptunnel_xmit_stats(), when it tried to dereference the
net device from the skb. To resolve this we now point the skb device
to the net device resolved from the routing table.

Fixes: 039f50629b (ip_tunnel: Move stats update to iptunnel_xmit())
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06 22:54:56 -05:00
Parthasarathy Bhuvaragan
f214fc4029 tipc: Revert "tipc: use existing sk_write_queue for outgoing packet chain"
reverts commit 94153e36e7 ("tipc: use existing sk_write_queue for
outgoing packet chain")

In Commit 94153e36e7, we assume that we fill & empty the socket's
sk_write_queue within the same lock_sock() session.

This is not true if the link is congested. During congestion, the
socket lock is released while we wait for the congestion to cease.
This implementation causes a nullptr exception, if the user space
program has several threads accessing the same socket descriptor.

Consider two threads of the same program performing the following:
     Thread1                                  Thread2
--------------------                    ----------------------
Enter tipc_sendmsg()                    Enter tipc_sendmsg()
lock_sock()                             lock_sock()
Enter tipc_link_xmit(), ret=ELINKCONG   spin on socket lock..
sk_wait_event()                             :
release_sock()                          grab socket lock
    :                                   Enter tipc_link_xmit(), ret=0
    :                                   release_sock()
Wakeup after congestion
lock_sock()
skb = skb_peek(pktchain);
!! TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong;

In this case, the second thread transmits the buffers belonging to
both thread1 and thread2 successfully. When the first thread wakeup
after the congestion it assumes that the pktchain is intact and
operates on the skb's in it, which leads to the following exception:

[2102.439969] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0
[2102.440074] IP: [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc]
[2102.440074] PGD 3fa3f067 PUD 3fa6b067 PMD 0
[2102.440074] Oops: 0000 [#1] SMP
[2102.440074] CPU: 2 PID: 244 Comm: sender Not tainted 3.12.28 #1
[2102.440074] RIP: 0010:[<ffffffffa005f330>]  [<ffffffffa005f330>] __tipc_link_xmit+0x2b0/0x4d0 [tipc]
[...]
[2102.440074] Call Trace:
[2102.440074]  [<ffffffff8163f0b9>] ? schedule+0x29/0x70
[2102.440074]  [<ffffffffa006a756>] ? tipc_node_unlock+0x46/0x170 [tipc]
[2102.440074]  [<ffffffffa005f761>] tipc_link_xmit+0x51/0xf0 [tipc]
[2102.440074]  [<ffffffffa006d8ae>] tipc_send_stream+0x11e/0x4f0 [tipc]
[2102.440074]  [<ffffffff8106b150>] ? __wake_up_sync+0x20/0x20
[2102.440074]  [<ffffffffa006dc9c>] tipc_send_packet+0x1c/0x20 [tipc]
[2102.440074]  [<ffffffff81502478>] sock_sendmsg+0xa8/0xd0
[2102.440074]  [<ffffffff81507895>] ? release_sock+0x145/0x170
[2102.440074]  [<ffffffff815030d8>] ___sys_sendmsg+0x3d8/0x3e0
[2102.440074]  [<ffffffff816426ae>] ? _raw_spin_unlock+0xe/0x10
[2102.440074]  [<ffffffff81115c2a>] ? handle_mm_fault+0x6ca/0x9d0
[2102.440074]  [<ffffffff8107dd65>] ? set_next_entity+0x85/0xa0
[2102.440074]  [<ffffffff816426de>] ? _raw_spin_unlock_irq+0xe/0x20
[2102.440074]  [<ffffffff8107463c>] ? finish_task_switch+0x5c/0xc0
[2102.440074]  [<ffffffff8163ea8c>] ? __schedule+0x34c/0x950
[2102.440074]  [<ffffffff81504e12>] __sys_sendmsg+0x42/0x80
[2102.440074]  [<ffffffff81504e62>] SyS_sendmsg+0x12/0x20
[2102.440074]  [<ffffffff8164aed2>] system_call_fastpath+0x16/0x1b

In this commit, we maintain the skb list always in the stack.

Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-03 16:30:29 -05:00
Florian Westphal
619b17452a tipc: fix null deref crash in compat config path
msg.dst_sk needs to be set up with a valid socket because some callbacks
later derive the netns from it.

Fixes: 263ea09084d172d ("Revert "genl: Add genlmsg_new_unicast() for unicast message allocation")
Reported-by: Jon Maloy <maloy@donjonn.com>
Bisected-by: Jon Maloy <maloy@donjonn.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-25 17:04:48 -05:00
Jon Paul Maloy
d25a01257e tipc: fix crash during node removal
When the TIPC module is unloaded, we have identified a race condition
that allows a node reference counter to go to zero and the node instance
being freed before the node timer is finished with accessing it. This
leads to occasional crashes, especially in multi-namespace environments.

The scenario goes as follows:

CPU0:(node_stop)                       CPU1:(node_timeout)  // ref == 2

1:                                          if(!mod_timer())
2: if (del_timer())
3:   tipc_node_put()                                        // ref -> 1
4: tipc_node_put()                                          // ref -> 0
5:   kfree_rcu(node);
6:                                               tipc_node_get(node)
7:                                               // BOOM!

We now clean up this functionality as follows:

1) We remove the node pointer from the node lookup table before we
   attempt deactivating the timer. This way, we reduce the risk that
   tipc_node_find() may obtain a valid pointer to an instance marked
   for deletion; a harmless but undesirable situation.

2) We use del_timer_sync() instead of del_timer() to safely deactivate
   the node timer without any risk that it might be reactivated by the
   timeout handler. There is no risk of deadlock here, since the two
   functions never touch the same spinlocks.

3: We remove a pointless tipc_node_get() + tipc_node_put() from the
   timeout handler.

Reported-by: Zhijiang Hu <huzhijiang@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-25 17:04:48 -05:00
Jon Paul Maloy
b170997ace tipc: eliminate risk of finding to-be-deleted node instance
Although we have never seen it happen, we have identified the
following problematic scenario when nodes are stopped and deleted:

CPU0:                            CPU1:

tipc_node_xxx()                                   //ref == 1
   tipc_node_put()                                //ref -> 0
                                 tipc_node_find() // node still in table
       tipc_node_delete()
         list_del_rcu(n. list)
                                 tipc_node_get()  //ref -> 1, bad
         kfree_rcu()

                                 tipc_node_put() //ref to 0 again.
                                 kfree_rcu()     // BOOM!

We fix this by introducing use of the conditional kref_get_if_not_zero()
instead of kref_get() in the function tipc_node_find(). This eliminates
any risk of post-mortem access.

Reported-by: Zhijiang Hu <huzhijiang@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-25 17:04:48 -05:00
David S. Miller
b633353115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23 00:09:14 -05:00
Insu Yun
b53ce3e7d4 tipc: unlock in error path
tipc_bcast_unlock need to be unlocked in error path.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-19 15:38:44 -05:00
Florian Westphal
263ea09084 Revert "genl: Add genlmsg_new_unicast() for unicast message allocation"
This reverts commit bb9b18fb55 ("genl: Add genlmsg_new_unicast() for
unicast message allocation")'.

Nothing wrong with it; its no longer needed since this was only for
mmapped netlink support.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:42:19 -05:00
Richard Alpe
4952cd3e7b tipc: refactor node xmit and fix memory leaks
Refactor tipc_node_xmit() to fail fast and fail early. Fix several
potential memory leaks in unexpected error paths.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 15:58:40 -05:00
Jon Paul Maloy
d5c91fb72f tipc: fix premature addition of node to lookup table
In commit 5266698661 ("tipc: let broadcast packet reception
use new link receive function") we introduced a new per-node
broadcast reception link instance. This link is created at the
moment the node itself is created. Unfortunately, the allocation
is done after the node instance has already been added to the node
lookup hash table. This creates a potential race condition, where
arriving broadcast packets are able to find and access the node
before it has been fully initialized, and before the above mentioned
link has been created. The result is occasional crashes in the function
tipc_bcast_rcv(), which is trying to access the not-yet existing link.

We fix this by deferring the addition of the node instance until after
it has been fully initialized in the function tipc_node_create().

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 15:57:11 -05:00
Parthasarathy Bhuvaragan
06c8581f85 tipc: use alloc_ordered_workqueue() instead of WQ_UNBOUND w/ max_active = 1
Until now, tipc_rcv and tipc_send workqueues in server are allocated
with parameters WQ_UNBOUND & max_active = 1.
This parameters passed to this function makes it equivalent to
alloc_ordered_workqueue(). The later form is more explicit and
can inherit future ordered_workqueue changes.

In this commit we replace alloc_workqueue() with more readable
alloc_ordered_workqueue().

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
ae245557f8 tipc: donot create timers if subscription timeout = TIPC_WAIT_FOREVER
Until now, we create timers even for the subscription requests
with timeout = TIPC_WAIT_FOREVER.
This can be improved by avoiding timer creation when the timeout
is set to TIPC_WAIT_FOREVER.

In this commit, we introduce a check to creates timers only
when timeout != TIPC_WAIT_FOREVER.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
f3ad288c56 tipc: protect tipc_subscrb_get() with subscriber spin lock
Until now, during subscription creation the mod_time() &
tipc_subscrb_get() are called after releasing the subscriber
spin lock.

In a SMP system when performing a subscription creation, if the
subscription timeout occurs simultaneously (the timer is
scheduled to run on another CPU) then the timer thread
might decrement the subscribers refcount before the create
thread increments the refcount.

This can be simulated by creating subscription with timeout=0 and
sometimes the timeout occurs before the create request is complete.
This leads to the following message:
[30.702949] BUG: spinlock bad magic on CPU#1, kworker/u8:3/87
[30.703834] general protection fault: 0000 [#1] SMP
[30.704826] CPU: 1 PID: 87 Comm: kworker/u8:3 Not tainted 4.4.0-rc8+ #18
[30.704826] Workqueue: tipc_rcv tipc_recv_work [tipc]
[30.704826] task: ffff88003f878600 ti: ffff88003fae0000 task.ti: ffff88003fae0000
[30.704826] RIP: 0010:[<ffffffff8109196c>]  [<ffffffff8109196c>] spin_dump+0x5c/0xe0
[...]
[30.704826] Call Trace:
[30.704826]  [<ffffffff81091a16>] spin_bug+0x26/0x30
[30.704826]  [<ffffffff81091b75>] do_raw_spin_lock+0xe5/0x120
[30.704826]  [<ffffffff81684439>] _raw_spin_lock_bh+0x19/0x20
[30.704826]  [<ffffffffa0096f10>] tipc_subscrb_rcv_cb+0x1d0/0x330 [tipc]
[30.704826]  [<ffffffffa00a37b1>] tipc_receive_from_sock+0xc1/0x150 [tipc]
[30.704826]  [<ffffffffa00a31df>] tipc_recv_work+0x3f/0x80 [tipc]
[30.704826]  [<ffffffff8106a739>] process_one_work+0x149/0x3c0
[30.704826]  [<ffffffff8106aa16>] worker_thread+0x66/0x460
[30.704826]  [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0
[30.704826]  [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0
[30.704826]  [<ffffffff8107029d>] kthread+0xed/0x110
[30.704826]  [<ffffffff810701b0>] ? kthread_create_on_node+0x190/0x190
[30.704826]  [<ffffffff81684bdf>] ret_from_fork+0x3f/0x70

In this commit,
1. we remove the check for the return code for mod_timer()
2. we protect tipc_subscrb_get() using the subscriber spin lock.
   We increment the subscriber's refcount as soon as we add the
   subscription to subscriber's subscription list.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
d4091899c9 tipc: hold subscriber->lock for tipc_nametbl_subscribe()
Until now, while creating a subscription the subscriber lock
protects only the subscribers subscription list and not the
nametable. The call to tipc_nametbl_subscribe() is outside
the lock. However, at subscription timeout and cancel both
the subscribers subscription list and the nametable are
protected by the subscriber lock.

This asymmetric locking mechanism leads to the following problem:
In a SMP system, the timer can be fire on another core before
the create request is complete.
When the timer thread calls tipc_nametbl_unsubscribe() before create
thread calls tipc_nametbl_subscribe(), we get a nullptr exception.

This can be simulated by creating subscription with timeout=0 and
sometimes the timeout occurs before the create request is complete.

The following is the oops:
[57.569661] BUG: unable to handle kernel NULL pointer dereference at (null)
[57.577498] IP: [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/0x120 [tipc]
[57.584820] PGD 0
[57.586834] Oops: 0002 [#1] SMP
[57.685506] CPU: 14 PID: 10077 Comm: kworker/u40:1 Tainted: P OENX 3.12.48-52.27.1.     9688.1.PTF-default #1
[57.703637] Workqueue: tipc_rcv tipc_recv_work [tipc]
[57.708697] task: ffff88064c7f00c0 ti: ffff880629ef4000 task.ti: ffff880629ef4000
[57.716181] RIP: 0010:[<ffffffffa02135aa>]  [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/   0x120 [tipc]
[...]
[57.812327] Call Trace:
[57.814806]  [<ffffffffa0211c77>] tipc_subscrp_delete+0x37/0x90 [tipc]
[57.821357]  [<ffffffffa0211e2f>] tipc_subscrp_timeout+0x3f/0x70 [tipc]
[57.827982]  [<ffffffff810618c1>] call_timer_fn+0x31/0x100
[57.833490]  [<ffffffff81062709>] run_timer_softirq+0x1f9/0x2b0
[57.839414]  [<ffffffff8105a795>] __do_softirq+0xe5/0x230
[57.844827]  [<ffffffff81520d1c>] call_softirq+0x1c/0x30
[57.850150]  [<ffffffff81004665>] do_softirq+0x55/0x90
[57.855285]  [<ffffffff8105aa35>] irq_exit+0x95/0xa0
[57.860290]  [<ffffffff815215b5>] smp_apic_timer_interrupt+0x45/0x60
[57.866644]  [<ffffffff8152005d>] apic_timer_interrupt+0x6d/0x80
[57.872686]  [<ffffffffa02121c5>] tipc_subscrb_rcv_cb+0x2a5/0x3f0 [tipc]
[57.879425]  [<ffffffffa021c65f>] tipc_receive_from_sock+0x9f/0x100 [tipc]
[57.886324]  [<ffffffffa021c826>] tipc_recv_work+0x26/0x60 [tipc]
[57.892463]  [<ffffffff8106fb22>] process_one_work+0x172/0x420
[57.898309]  [<ffffffff8107079a>] worker_thread+0x11a/0x3c0
[57.903871]  [<ffffffff81077114>] kthread+0xb4/0xc0
[57.908751]  [<ffffffff8151f318>] ret_from_fork+0x58/0x90

In this commit, we do the following at subscription creation:
1. set the subscription's subscriber pointer before performing
   tipc_nametbl_subscribe(), as this value is required further in
   the call chain ex: by tipc_subscrp_send_event().
2. move tipc_nametbl_subscribe() under the scope of subscriber lock

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
cb01c7c870 tipc: fix connection abort when receiving invalid cancel request
Until now, the subscribers endianness for a subscription
create/cancel request is determined as:
    swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE))
The checks are performed only for port/service subscriptions.

The swap calculation is incorrect if the filter in the subscription
cancellation request is set to TIPC_SUB_CANCEL (it's a malformed
cancel request, as the corresponding subscription create filter
is missing).
Thus, the check if the request is for cancellation fails and the
request is treated as a subscription create request. The
subscription creation fails as the request is illegal, which
terminates this connection.

In this commit we determine the endianness by including
TIPC_SUB_CANCEL, which will set swap correctly and the
request is processed as a cancellation request.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
c8beccc67c tipc: fix connection abort during subscription cancellation
In 'commit 7fe8097cef ("tipc: fix nullpointer bug when subscribing
to events")', we terminate the connection if the subscription
creation fails.
In the same commit, the subscription creation result was based on
the value of subscription pointer (set in the function) instead of
the return code.

Unfortunately, the same function also handles subscription
cancellation request. For a subscription cancellation request,
the subscription pointer cannot be set. Thus the connection is
terminated during cancellation request.

In this commit, we move the subcription cancel check outside
of tipc_subscrp_create(). Hence,
- tipc_subscrp_create() will create a subscripton
- tipc_subscrb_rcv_cb() will subscribe or cancel a subscription.

Fixes: 'commit 7fe8097cef ("tipc: fix nullpointer bug when subscribing to events")'

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:58 -05:00
Parthasarathy Bhuvaragan
7c13c62241 tipc: introduce tipc_subscrb_subscribe() routine
In this commit, we split tipc_subscrp_create() into two:
1. tipc_subscrp_create() creates a subscription
2. A new function tipc_subscrp_subscribe() adds the
   subscription to the subscriber subscription list,
   activates the subscription timer and subscribes to
   the nametable updates.

In future commits, the purpose of tipc_subscrb_rcv_cb() will
be to either subscribe or cancel a subscription.

There is no functional change in this commit.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:41:57 -05:00
Parthasarathy Bhuvaragan
a4273c73eb tipc: remove struct tipc_name_seq from struct tipc_subscription
Until now, struct tipc_subscriber has duplicate fields for
type, upper and lower (as member of struct tipc_name_seq) at:
1. as member seq in struct tipc_subscription
2. as member seq in struct tipc_subscr, which is contained
   in struct tipc_event
The former structure contains the type, upper and lower
values in network byte order and the later contains the
intact copy of the request.
The struct tipc_subscription contains a field swap to
determine if request needs network byte order conversion.
Thus by using swap, we can convert the request when
required instead of duplicating it.

In this commit,
1. we remove the references to these elements as members of
   struct tipc_subscription and replace them with elements
   from struct tipc_subscr.
2. provide new functions to convert the user request into
   network byte order.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:40:43 -05:00
Parthasarathy Bhuvaragan
3086523149 tipc: remove filter and timeout elements from struct tipc_subscription
Until now, struct tipc_subscription has duplicate timeout and filter
attributes present:
1. directly as members of struct tipc_subscription
2. in struct tipc_subscr, which is contained in struct tipc_event

In this commit, we remove the references to these elements as
members of struct tipc_subscription and replace them with elements
from struct tipc_subscr.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:40:43 -05:00
Parthasarathy Bhuvaragan
4f61d4ef70 tipc: remove incorrect check for subscription timeout value
Until now, during subscription creation we set sub->timeout by
converting the timeout request value in milliseconds to jiffies.
This is followed by setting the timeout value in the timer if
sub->timeout != TIPC_WAIT_FOREVER.

For a subscription create request with a timeout value of
TIPC_WAIT_FOREVER, msecs_to_jiffies(TIPC_WAIT_FOREVER)
returns MAX_JIFFY_OFFSET (0xfffffffe). This is not equal to
TIPC_WAIT_FOREVER (0xffffffff).

In this commit, we remove this check.

Acked-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 03:40:43 -05:00
Richard Alpe
817298102b tipc: fix link priority propagation
Currently link priority changes isn't handled for active links. In
this patch we resolve this by changing our priority if the peer passes
a valid priority in a state message.

Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 02:45:38 -05:00
Richard Alpe
d01332f1ac tipc: fix link attribute propagation bug
Changing certain link attributes (link tolerance and link priority)
from the TIPC management tool is supposed to automatically take
effect at both endpoints of the affected link.

Currently the media address is not instantiated for the link and is
used uninstantiated when crafting protocol messages designated for the
peer endpoint. This means that changing a link property currently
results in the property being changed on the local machine but the
protocol message designated for the peer gets lost. Resulting in
property discrepancy between the endpoints.

In this patch we resolve this by using the media address from the
link entry and using the bearer transmit function to send it. Hence,
we can now eliminate the redundant function tipc_link_prot_xmit() and
the redundant field tipc_link::media_addr.

Fixes: 2af5ae372a (tipc: clean up unused code and structures)
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reported-by: Jason Hu <huzhijiang@gmail.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06 02:45:27 -05:00
Parthasarathy Bhuvaragan
4d5cfcba2f tipc: fix connection abort during subscription cancel
In 'commit 7fe8097cef ("tipc: fix nullpointer bug when subscribing
to events")', we terminate the connection if the subscription
creation fails.
In the same commit, the subscription creation result was based on
the value of the subscription pointer (set in the function) instead
of the return code.

Unfortunately, the same function tipc_subscrp_create() handles
subscription cancel request. For a subscription cancellation request,
the subscription pointer cannot be set. Thus if a subscriber has
several subscriptions and cancels any of them, the connection is
terminated.

In this commit, we terminate the connection based on the return value
of tipc_subscrp_create().
Fixes: commit 7fe8097cef ("tipc: fix nullpointer bug when subscribing to events")

Reviewed-by:  Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-29 15:14:21 -05:00
Pravin B Shelar
039f50629b ip_tunnel: Move stats update to iptunnel_xmit()
By moving stats update into iptunnel_xmit(), we can simplify
iptunnel_xmit() usage. With this change there is no need to
call another function (iptunnel_xmit_stats()) to update stats
in tunnel xmit code path.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-25 23:32:23 -05:00
David S. Miller
f188b951f3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/renesas/ravb_main.c
	kernel/bpf/syscall.c
	net/ipv4/ipmr.c

All three conflicts were cases of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 21:09:12 -05:00
Jon Paul Maloy
dc8d1eb305 tipc: fix node reference count bug
Commit 5405ff6e15 ("tipc: convert node lock to rwlock")
introduced a bug to the node reference counter handling. When a
message is successfully sent in the function tipc_node_xmit(),
we return directly after releasing the node lock, instead of
continuing and decrementing the node reference counter as we
should do.

This commit fixes this bug.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 15:19:40 -05:00
Herbert Xu
1ce0bf50ae net: Generalise wq_has_sleeper helper
The memory barrier in the helper wq_has_sleeper is needed by just
about every user of waitqueue_active.  This patch generalises it
by making it take a wait_queue_head_t directly.  The existing
helper is renamed to skwq_has_sleeper.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-30 14:47:33 -05:00
Ying Xue
7098356bac tipc: fix error handling of expanding buffer headroom
Coverity says:

*** CID 1338065:  Error handling issues  (CHECKED_RETURN)
/net/tipc/udp_media.c: 162 in tipc_udp_send_msg()
156     	struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
157     	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
158     	struct sk_buff *clone;
159     	struct rtable *rt;
160
161     	if (skb_headroom(skb) < UDP_MIN_HEADROOM)
>>>     CID 1338065:  Error handling issues  (CHECKED_RETURN)
>>>     Calling "pskb_expand_head" without checking return value (as is done elsewhere 51 out of 56 times).
162     		pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
163
164     	clone = skb_clone(skb, GFP_ATOMIC);
165     	skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
166     	ub = rcu_dereference_rtnl(b->media_ptr);
167     	if (!ub) {

When expanding buffer headroom over udp tunnel with pskb_expand_head(),
it's unfortunate that we don't check its return value. As a result, if
the function returns an error code due to the lack of memory, it may
cause unpredictable consequence as we unconditionally consider that
it's always successful.

Fixes: e53567948f ("tipc: conditionally expand buffer headroom over udp tunnel")
Reported-by: <scan-admin@coverity.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-24 11:26:19 -05:00
Ying Xue
f4195d1eac tipc: avoid packets leaking on socket receive queue
Even if we drain receive queue thoroughly in tipc_release() after tipc
socket is removed from rhashtable, it is possible that some packets
are in flight because some CPU runs receiver and did rhashtable lookup
before we removed socket. They will achieve receive queue, but nobody
delete them at all. To avoid this leak, we register a private socket
destructor to purge receive queue, meaning releasing packets pending
on receive queue will be delayed until the last reference of tipc
socket will be released.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-23 23:45:15 -05:00
Jon Paul Maloy
9a65083827 tipc: correct settings of broadcast link state
Since commit 5266698661 ("tipc: let broadcast packet
reception use new link receive function") the broadcast send
link state was meant to always be set to LINK_ESTABLISHED, since
we don't need this link to follow the regular link FSM rules. It
was also the intention that this state anyway shouldn't impact
the run-time working state of the link, since the latter in
reality is controlled by the number of registered peers.

We have now discovered that this assumption is not quite correct.
If the broadcast link is reset because of too many retransmissions,
its state will inadvertently go to LINK_RESETTING, and never go
back to LINK_ESTABLISHED, because the LINK_FAILURE event was not
anticipated. This will work well once, but if it happens a second
time, the reset on a link in LINK_RESETTING has has no effect, and
neither the broadcast link nor the unicast links will go down as
they should.

Furthermore, it is confusing that the management tool shows that
this link is in UP state when that obviously isn't the case.

We now ensure that this state strictly follows the true working
state of the link. The state is set to LINK_ESTABLISHED when
the number of peers is non-zero, and to LINK_RESET otherwise.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-20 14:08:51 -05:00