Commit Graph

1684 Commits

Author SHA1 Message Date
Tuong Lien
5e9eeccc58 tipc: fix NULL pointer dereference in streaming
syzbot found the following crash:

general protection fault, probably for non-canonical address 0xdffffc0000000019: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf]
CPU: 1 PID: 7060 Comm: syz-executor394 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__tipc_sendstream+0xbde/0x11f0 net/tipc/socket.c:1591
Code: 00 00 00 00 48 39 5c 24 28 48 0f 44 d8 e8 fa 3e db f9 48 b8 00 00 00 00 00 fc ff df 48 8d bb c8 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e2 04 00 00 48 8b 9b c8 00 00 00 48 b8 00 00 00
RSP: 0018:ffffc90003ef7818 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8797fd9d
RDX: 0000000000000019 RSI: ffffffff8797fde6 RDI: 00000000000000c8
RBP: ffff888099848040 R08: ffff88809a5f6440 R09: fffffbfff1860b4c
R10: ffffffff8c305a5f R11: fffffbfff1860b4b R12: ffff88809984857e
R13: 0000000000000000 R14: ffff888086aa4000 R15: 0000000000000000
FS:  00000000009b4880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 00000000a7fdf000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tipc_sendstream+0x4c/0x70 net/tipc/socket.c:1533
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x32f/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmmsg+0x195/0x480 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg net/socket.c:2522 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2522
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x440199
...

This bug was bisected to commit 0a3e060f34 ("tipc: add test for Nagle
algorithm effectiveness"). However, it is not the case, the trouble was
from the base in the case of zero data length message sending, we would
unexpectedly make an empty 'txq' queue after the 'tipc_msg_append()' in
Nagle mode.

A similar crash can be generated even without the bisected patch but at
the link layer when it accesses the empty queue.

We solve the issues by building at least one buffer to go with socket's
header and an optional data section that may be empty like what we had
with the 'tipc_msg_build()'.

Note: the previous commit 4c21daae3d ("tipc: Fix NULL pointer
dereference in __tipc_sendstream()") is obsoleted by this one since the
'txq' will be never empty and the check of 'skb != NULL' is unnecessary
but it is safe anyway.

Reported-by: syzbot+8eac6d030e7807c21d32@syzkaller.appspotmail.com
Fixes: c0bceb97db ("tipc: add smart nagle feature")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-04 15:37:59 -07:00
Tuong Lien
a275727b18 Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
This reverts commit 441870ee42.

Like the previous patch in this series, we revert the above commit that
causes similar issues with the 'aead' object.

Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-02 15:13:47 -07:00
Tuong Lien
049fa17f7a Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
This reverts commit de05842076.

There is no actual tipc_node refcnt leak as stated in the above commit.
The refcnt is hold carefully for the case of an asynchronous decryption
(i.e. -EINPROGRESS/-EBUSY and skb = NULL is returned), so that the node
object cannot be freed in the meantime. The counter will be re-balanced
when the operation's callback arrives with the decrypted buffer if any.
In other cases, e.g. a synchronous crypto the counter will be decreased
immediately when it is done.

Now with that commit, a kernel panic will occur when there is no node
found (i.e. n = NULL) in the 'tipc_rcv()' or a premature release of the
node object.

This commit solves the issues by reverting the said commit, but keeping
one valid case that the 'skb_linearize()' is failed.

Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Tested-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-02 15:13:46 -07:00
YueHaibing
4c21daae3d tipc: Fix NULL pointer dereference in __tipc_sendstream()
tipc_sendstream() may send zero length packet, then tipc_msg_append()
do not alloc skb, skb_peek_tail() will get NULL, msg_set_ack_required
will trigger NULL pointer dereference.

Reported-by: syzbot+8eac6d030e7807c21d32@syzkaller.appspotmail.com
Fixes: 0a3e060f34 ("tipc: add test for Nagle algorithm effectiveness")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-01 15:33:24 -07:00
YueHaibing
8298a419a0 tipc: remove set but not used variable 'prev'
Fixes gcc '-Wunused-but-set-variable' warning:

net/tipc/msg.c: In function 'tipc_msg_append':
net/tipc/msg.c:215:24: warning:
 variable 'prev' set but not used [-Wunused-but-set-variable]

commit 0a3e060f34 ("tipc: add test for Nagle algorithm effectiveness")
left behind this, remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-29 16:59:04 -07:00
Christoph Hellwig
095ae61253 tipc: call tsk_set_importance from tipc_topsrv_create_listener
Avoid using kernel_setsockopt for the TIPC_IMPORTANCE option when we can
just use the internal helper.  The only change needed is to pass a struct
sock instead of tipc_sock, which is private to socket.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28 11:11:46 -07:00
Tuong Lien
0a3e060f34 tipc: add test for Nagle algorithm effectiveness
When streaming in Nagle mode, we try to bundle small messages from user
as many as possible if there is one outstanding buffer, i.e. not ACK-ed
by the receiving side, which helps boost up the overall throughput. So,
the algorithm's effectiveness really depends on when Nagle ACK comes or
what the specific network latency (RTT) is, compared to the user's
message sending rate.

In a bad case, the user's sending rate is low or the network latency is
small, there will not be many bundles, so making a Nagle ACK or waiting
for it is not meaningful.
For example: a user sends its messages every 100ms and the RTT is 50ms,
then for each messages, we require one Nagle ACK but then there is only
one user message sent without any bundles.

In a better case, even if we have a few bundles (e.g. the RTT = 300ms),
but now the user sends messages in medium size, then there will not be
any difference at all, that says 3 x 1000-byte data messages if bundled
will still result in 3 bundles with MTU = 1500.

When Nagle is ineffective, the delay in user message sending is clearly
wasted instead of sending directly.

Besides, adding Nagle ACKs will consume some processor load on both the
sending and receiving sides.

This commit adds a test on the effectiveness of the Nagle algorithm for
an individual connection in the network on which it actually runs.
Particularly, upon receipt of a Nagle ACK we will compare the number of
bundles in the backlog queue to the number of user messages which would
be sent directly without Nagle. If the ratio is good (e.g. >= 2), Nagle
mode will be kept for further message sending. Otherwise, we will leave
Nagle and put a 'penalty' on the connection, so it will have to spend
more 'one-way' messages before being able to re-enter Nagle.

In addition, the 'ack-required' bit is only set when really needed that
the number of Nagle ACKs will be reduced during Nagle mode.

Testing with benchmark showed that with the patch, there was not much
difference in throughput for small messages since the tool continuously
sends messages without a break, so Nagle would still take in effect.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 15:16:52 -07:00
Tuong Lien
03b6fefd9b tipc: add support for broadcast rcv stats dumping
This commit enables dumping the statistics of a broadcast-receiver link
like the traditional 'broadcast-link' one (which is for broadcast-
sender). The link dumping can be triggered via netlink (e.g. the
iproute2/tipc tool) by the link flag - 'TIPC_NLA_LINK_BROADCAST' as the
indicator.

The name of a broadcast-receiver link of a specific peer will be in the
format: 'broadcast-link:<peer-id>'.

For example:

Link <broadcast-link:1001002>
  Window:50 packets
  RX packets:7841 fragments:2408/440 bundles:0/0
  TX packets:0 fragments:0/0 bundles:0/0
  RX naks:0 defs:124 dups:0
  TX naks:21 acks:0 retrans:0
  Congestion link:0  Send queue max:0 avg:0

In addition, the broadcast-receiver link statistics can be reset in the
usual way via netlink by specifying that link name in command.

Note: the 'tipc_link_name_ext()' is removed because the link name can
now be retrieved simply via the 'l->name'.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 15:16:52 -07:00
Tuong Lien
a91d55d162 tipc: enable broadcast retrans via unicast
In some environment, broadcast traffic is suppressed at high rate (i.e.
a kind of bandwidth limit setting). When it is applied, TIPC broadcast
can still run successfully. However, when it comes to a high load, some
packets will be dropped first and TIPC tries to retransmit them but the
packet retransmission is intentionally broadcast too, so making things
worse and not helpful at all.

This commit enables the broadcast retransmission via unicast which only
retransmits packets to the specific peer that has really reported a gap
i.e. not broadcasting to all nodes in the cluster, so will prevent from
being suppressed, and also reduce some overheads on the other peers due
to duplicates, finally improve the overall TIPC broadcast performance.

Note: the functionality can be turned on/off via the sysctl file:

echo 1 > /proc/sys/net/tipc/bc_retruni
echo 0 > /proc/sys/net/tipc/bc_retruni

Default is '0', i.e. the broadcast retransmission still works as usual.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 15:16:52 -07:00
Tuong Lien
c6ed7a5cc2 tipc: add back link trace events
In the previous commit ("tipc: add Gap ACK blocks support for broadcast
link"), we have removed the following link trace events due to the code
changes:

- tipc_link_bc_ack
- tipc_link_retrans

This commit adds them back along with some minor changes to adapt to
the new code.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 15:16:52 -07:00
Tuong Lien
d7626b5acf tipc: introduce Gap ACK blocks for broadcast link
As achieved through commit 9195948fbf ("tipc: improve TIPC throughput
by Gap ACK blocks"), we apply the same mechanism for the broadcast link
as well. The 'Gap ACK blocks' data field in a 'PROTOCOL/STATE_MSG' will
consist of two parts built for both the broadcast and unicast types:

 31                       16 15                        0
+-------------+-------------+-------------+-------------+
|  bgack_cnt  |  ugack_cnt  |            len            |
+-------------+-------------+-------------+-------------+  -
|            gap            |            ack            |   |
+-------------+-------------+-------------+-------------+    > bc gacks
:                           :                           :   |
+-------------+-------------+-------------+-------------+  -
|            gap            |            ack            |   |
+-------------+-------------+-------------+-------------+    > uc gacks
:                           :                           :   |
+-------------+-------------+-------------+-------------+  -

which is "automatically" backward-compatible.

We also increase the max number of Gap ACK blocks to 128, allowing upto
64 blocks per type (total buffer size = 516 bytes).

Besides, the 'tipc_link_advance_transmq()' function is refactored which
is applicable for both the unicast and broadcast cases now, so some old
functions can be removed and the code is optimized.

With the patch, TIPC broadcast is more robust regardless of packet loss
or disorder, latency, ... in the underlying network. Its performance is
boost up significantly.
For example, experiment with a 5% packet loss rate results:

$ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000
real    0m 42.46s
user    0m 1.16s
sys     0m 17.67s

Without the patch:

$ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000
real    8m 27.94s
user    0m 0.55s
sys     0m 2.38s

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 15:16:52 -07:00
Eric Dumazet
1378817486 tipc: block BH before using dst_cache
dst_cache_get() documents it must be used with BH disabled.

sysbot reported :

BUG: using smp_processor_id() in preemptible [00000000] code: /21697
caller is dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68
CPU: 0 PID: 21697 Comm:  Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 check_preemption_disabled lib/smp_processor_id.c:47 [inline]
 debug_smp_processor_id.cold+0x88/0x9b lib/smp_processor_id.c:57
 dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68
 tipc_udp_xmit.isra.0+0xb9/0xad0 net/tipc/udp_media.c:164
 tipc_udp_send_msg+0x3e6/0x490 net/tipc/udp_media.c:244
 tipc_bearer_xmit_skb+0x1de/0x3f0 net/tipc/bearer.c:526
 tipc_enable_bearer+0xb2f/0xd60 net/tipc/bearer.c:331
 __tipc_nl_bearer_enable+0x2bf/0x390 net/tipc/bearer.c:995
 tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:1003
 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
 genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362
 ___sys_sendmsg+0x100/0x170 net/socket.c:2416
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29

Fixes: e9c1a79321 ("tipc: add dst_cache support for udp media")
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22 15:39:00 -07:00
Tuong Lien
88690b1079 tipc: fix failed service subscription deletion
When a service subscription is expired or canceled by user, it needs to
be deleted from the subscription list, so that new subscriptions can be
registered (max = 65535 per net). However, there are two issues in code
that can cause such an unused subscription to persist:

1) The 'tipc_conn_delete_sub()' has a loop on the subscription list but
it makes a break shortly when the 1st subscription differs from the one
specified, so the subscription will not be deleted.

2) In case a subscription is canceled, the code to remove the
'TIPC_SUB_CANCEL' flag from the subscription filter does not work if it
is a local subscription (i.e. the little endian isn't involved). So, it
will be no matches when looking for the subscription to delete later.

The subscription(s) will be removed eventually when the user terminates
its topology connection but that could be a long time later. Meanwhile,
the number of available subscriptions may be exhausted.

This commit fixes the two issues above, so as needed a subscription can
be deleted correctly.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-13 12:33:19 -07:00
Tuong Lien
0771d7df81 tipc: fix memory leak in service subscripting
Upon receipt of a service subscription request from user via a topology
connection, one 'sub' object will be allocated in kernel, so it will be
able to send an event of the service if any to the user correspondingly
then. Also, in case of any failure, the connection will be shutdown and
all the pertaining 'sub' objects will be freed.

However, there is a race condition as follows resulting in memory leak:

       receive-work       connection        send-work
              |                |                |
        sub-1 |<------//-------|                |
        sub-2 |<------//-------|                |
              |                |<---------------| evt for sub-x
        sub-3 |<------//-------|                |
              :                :                :
              :                :                :
              |       /--------|                |
              |       |        * peer closed    |
              |       |        |                |
              |       |        |<-------X-------| evt for sub-y
              |       |        |<===============|
        sub-n |<------/        X    shutdown    |
    -> orphan |                                 |

That is, the 'receive-work' may get the last subscription request while
the 'send-work' is shutting down the connection due to peer close.

We had a 'lock' on the connection, so the two actions cannot be carried
out simultaneously. If the last subscription is allocated e.g. 'sub-n',
before the 'send-work' closes the connection, there will be no issue at
all, the 'sub' objects will be freed. In contrast the last subscription
will become orphan since the connection was closed, and we released all
references.

This commit fixes the issue by simply adding one test if the connection
remains in 'connected' state right after we obtain the connection lock,
then a subscription object can be created as usual, otherwise we ignore
it.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Reported-by: Thang Ngo <thang.h.ngo@dektech.com.au>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-13 12:33:18 -07:00
Tuong Lien
c726858945 tipc: fix large latency in smart Nagle streaming
Currently when a connection is in Nagle mode, we set the 'ack_required'
bit in the last sending buffer and wait for the corresponding ACK prior
to pushing more data. However, on the receiving side, the ACK is issued
only when application really  reads the whole data. Even if part of the
last buffer is received, we will not do the ACK as required. This might
cause an unnecessary delay since the receiver does not always fetch the
message as fast as the sender, resulting in a large latency in the user
message sending, which is: [one RTT + the receiver processing time].

The commit makes Nagle ACK as soon as possible i.e. when a message with
the 'ack_required' arrives in the receiving side's stack even before it
is processed or put in the socket receive queue...
This way, we can limit the streaming latency to one RTT as committed in
Nagle mode.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-13 12:33:18 -07:00
Tuong Lien
980d69276f tipc: fix partial topology connection closure
When an application connects to the TIPC topology server and subscribes
to some services, a new connection is created along with some objects -
'tipc_subscription' to store related data correspondingly...
However, there is one omission in the connection handling that when the
connection or application is orderly shutdown (e.g. via SIGQUIT, etc.),
the connection is not closed in kernel, the 'tipc_subscription' objects
are not freed too.
This results in:
- The maximum number of subscriptions (65535) will be reached soon, new
subscriptions will be rejected;
- TIPC module cannot be removed (unless the objects  are somehow forced
to release first);

The commit fixes the issue by closing the connection if the 'recvmsg()'
returns '0' i.e. when the peer is shutdown gracefully. It also includes
the other unexpected cases.

Acked-by: Jon Maloy <jmaloy@redhat.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:31:13 -07:00
Xiyu Yang
de05842076 tipc: Fix potential tipc_node refcnt leak in tipc_rcv
tipc_rcv() invokes tipc_node_find() twice, which returns a reference of
the specified tipc_node object to "n" with increased refcnt.

When tipc_rcv() returns or a new object is assigned to "n", the original
local reference of "n" becomes invalid, so the refcount should be
decreased to keep refcount balanced.

The issue happens in some paths of tipc_rcv(), which forget to decrease
the refcnt increased by tipc_node_find() and will cause a refcnt leak.

Fix this issue by calling tipc_node_put() before the original object
pointed by "n" becomes invalid.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-18 13:24:20 -07:00
Xiyu Yang
441870ee42 tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv
tipc_crypto_rcv() invokes tipc_aead_get(), which returns a reference of
the tipc_aead object to "aead" with increased refcnt.

When tipc_crypto_rcv() returns, the original local reference of "aead"
becomes invalid, so the refcount should be decreased to keep refcount
balanced.

The issue happens in one error path of tipc_crypto_rcv(). When TIPC
message decryption status is EINPROGRESS or EBUSY, the function forgets
to decrease the refcnt increased by tipc_aead_get() and causes a refcnt
leak.

Fix this issue by calling tipc_aead_put() on the error path when TIPC
message decryption status is EINPROGRESS or EBUSY.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-18 13:17:04 -07:00
Tuong Lien
edadedf1c5 tipc: fix incorrect increasing of link window
In commit 16ad3f4022 ("tipc: introduce variable window congestion
control"), we allow link window to change with the congestion avoidance
algorithm. However, there is a bug that during the slow-start if packet
retransmission occurs, the link will enter the fast-recovery phase, set
its window to the 'ssthresh' which is never less than 300, so the link
window suddenly increases to that limit instead of decreasing.

Consequently, two issues have been observed:

- For broadcast-link: it can leave a gap between the link queues that a
new packet will be inserted and sent before the previous ones, i.e. not
in-order.

- For unicast: the algorithm does not work as expected, the link window
jumps to the slow-start threshold whereas packet retransmission occurs.

This commit fixes the issues by avoiding such the link window increase,
but still decreasing if the 'ssthresh' is lowered.

Fixes: 16ad3f4022 ("tipc: introduce variable window congestion control")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-15 16:23:33 -07:00
Hoang Le
8b1e5b0a99 tipc: Add a missing case of TIPC_DIRECT_MSG type
In the commit f73b12812a
("tipc: improve throughput between nodes in netns"), we're missing a check
to handle TIPC_DIRECT_MSG type, it's still using old sending mechanism for
this message type. So, throughput improvement is not significant as
expected.

Besides that, when sending a large message with that type, we're also
handle wrong receiving queue, it should be enqueued in socket receiving
instead of multicast messages.

Fix this by adding the missing case for TIPC_DIRECT_MSG.

Fixes: f73b12812a ("tipc: improve throughput between nodes in netns")
Reported-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-26 11:21:02 -07:00
Hoang Le
746a1eda68 tipc: add NULL pointer check to prevent kernel oops
Calling:
tipc_node_link_down()->
   - tipc_node_write_unlock()->tipc_mon_peer_down()
   - tipc_mon_peer_down()
  just after disabling bearer could be caused kernel oops.

Fix this by adding a sanity check to make sure valid memory
access.

Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-15 00:07:00 -07:00
Hoang Le
e228c5c088 tipc: simplify trivial boolean return
Checking and returning 'true' boolean is useless as it will be
returning at end of function

Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-15 00:07:00 -07:00
Jakub Kicinski
213320a679 tipc: add missing attribute validation for MTU property
Add missing attribute validation for TIPC_NLA_PROP_MTU
to the netlink policy.

Fixes: 901271e040 ("tipc: implement configuration of UDP media MTU")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-03 13:28:49 -08:00
Tuong Lien
5391a87751 tipc: fix successful connect() but timed out
In commit 9546a0b7ce ("tipc: fix wrong connect() return code"), we
fixed the issue with the 'connect()' that returns zero even though the
connecting has failed by waiting for the connection to be 'ESTABLISHED'
really. However, the approach has one drawback in conjunction with our
'lightweight' connection setup mechanism that the following scenario
can happen:

          (server)                        (client)

   +- accept()|                      |             wait_for_conn()
   |          |                      |connect() -------+
   |          |<-------[SYN]---------|                 > sleeping
   |          |                      *CONNECTING       |
   |--------->*ESTABLISHED           |                 |
              |--------[ACK]-------->*ESTABLISHED      > wakeup()
        send()|--------[DATA]------->|\                > wakeup()
        send()|--------[DATA]------->| |               > wakeup()
          .   .          .           . |-> recvq       .
          .   .          .           . |               .
        send()|--------[DATA]------->|/                > wakeup()
       close()|--------[FIN]-------->*DISCONNECTING    |
              *DISCONNECTING         |                 |
              |                      ~~~~~~~~~~~~~~~~~~> schedule()
                                                       | wait again
                                                       .
                                                       .
                                                       | ETIMEDOUT

Upon the receipt of the server 'ACK', the client becomes 'ESTABLISHED'
and the 'wait_for_conn()' process is woken up but not run. Meanwhile,
the server starts to send a number of data following by a 'close()'
shortly without waiting any response from the client, which then forces
the client socket to be 'DISCONNECTING' immediately. When the wait
process is switched to be running, it continues to wait until the timer
expires because of the unexpected socket state. The client 'connect()'
will finally get ‘-ETIMEDOUT’ and force to release the socket whereas
there remains the messages in its receive queue.

Obviously the issue would not happen if the server had some delay prior
to its 'close()' (or the number of 'DATA' messages is large enough),
but any kind of delay would make the connection setup/shutdown "heavy".
We solve this by simply allowing the 'connect()' returns zero in this
particular case. The socket is already 'DISCONNECTING', so any further
write will get '-EPIPE' but the socket is still able to read the
messages existing in its receive queue.

Note: This solution doesn't break the previous one as it deals with a
different situation that the socket state is 'DISCONNECTING' but has no
error (i.e. sk->sk_err = 0).

Fixes: 9546a0b7ce ("tipc: fix wrong connect() return code")
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-10 10:23:00 +01:00
Chen Wandun
2437fd7baf tipc: make three functions static
Fix the following sparse warning:

net/tipc/node.c:281:6: warning: symbol 'tipc_node_free' was not declared. Should it be static?
net/tipc/node.c:2801:5: warning: symbol '__tipc_nl_node_set_key' was not declared. Should it be static?
net/tipc/node.c:2878:5: warning: symbol '__tipc_nl_node_flush_key' was not declared. Should it be static?

Fixes: fc1b6d6de2 ("tipc: introduce TIPC encryption & authentication")
Fixes: e1f32190cf ("tipc: add support for AEAD key setting via netlink")

Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-10 10:23:00 +01:00
Linus Torvalds
bd2463ac7d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Add WireGuard

 2) Add HE and TWT support to ath11k driver, from John Crispin.

 3) Add ESP in TCP encapsulation support, from Sabrina Dubroca.

 4) Add variable window congestion control to TIPC, from Jon Maloy.

 5) Add BCM84881 PHY driver, from Russell King.

 6) Start adding netlink support for ethtool operations, from Michal
    Kubecek.

 7) Add XDP drop and TX action support to ena driver, from Sameeh
    Jubran.

 8) Add new ipv4 route notifications so that mlxsw driver does not have
    to handle identical routes itself. From Ido Schimmel.

 9) Add BPF dynamic program extensions, from Alexei Starovoitov.

10) Support RX and TX timestamping in igc, from Vinicius Costa Gomes.

11) Add support for macsec HW offloading, from Antoine Tenart.

12) Add initial support for MPTCP protocol, from Christoph Paasch,
    Matthieu Baerts, Florian Westphal, Peter Krystad, and many others.

13) Add Octeontx2 PF support, from Sunil Goutham, Geetha sowjanya, Linu
    Cherian, and others.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1469 commits)
  net: phy: add default ARCH_BCM_IPROC for MDIO_BCM_IPROC
  udp: segment looped gso packets correctly
  netem: change mailing list
  qed: FW 8.42.2.0 debug features
  qed: rt init valid initialization changed
  qed: Debug feature: ilt and mdump
  qed: FW 8.42.2.0 Add fw overlay feature
  qed: FW 8.42.2.0 HSI changes
  qed: FW 8.42.2.0 iscsi/fcoe changes
  qed: Add abstraction for different hsi values per chip
  qed: FW 8.42.2.0 Additional ll2 type
  qed: Use dmae to write to widebus registers in fw_funcs
  qed: FW 8.42.2.0 Parser offsets modified
  qed: FW 8.42.2.0 Queue Manager changes
  qed: FW 8.42.2.0 Expose new registers and change windows
  qed: FW 8.42.2.0 Internal ram offsets modifications
  MAINTAINERS: Add entry for Marvell OcteonTX2 Physical Function driver
  Documentation: net: octeontx2: Add RVU HW and drivers overview
  octeontx2-pf: ethtool RSS config support
  octeontx2-pf: Add basic ethtool support
  ...
2020-01-28 16:02:33 -08:00
Ingo Molnar
f8a4bb6bfa Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Expedited grace-period updates
 - kfree_rcu() updates
 - RCU list updates
 - Preemptible RCU updates
 - Torture-test updates
 - Miscellaneous fixes
 - Documentation updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-25 10:05:23 +01:00
David S. Miller
a2d6d7ae59 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The ungrafting from PRIO bug fixes in net, when merged into net-next,
merge cleanly but create a build failure.  The resolution used here is
from Petr Machata.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09 12:13:43 -08:00
Tuong Lien
9546a0b7ce tipc: fix wrong connect() return code
The current 'tipc_wait_for_connect()' function does a wait-loop for the
condition 'sk->sk_state != TIPC_CONNECTING' to conclude if the socket
connecting has done. However, when the condition is met, it returns '0'
even in the case the connecting is actually failed, the socket state is
set to 'TIPC_DISCONNECTING' (e.g. when the server socket has closed..).
This results in a wrong return code for the 'connect()' call from user,
making it believe that the connection is established and go ahead with
building, sending a message, etc. but finally failed e.g. '-EPIPE'.

This commit fixes the issue by changing the wait condition to the
'tipc_sk_connected(sk)', so the function will return '0' only when the
connection is really established. Otherwise, either the socket 'sk_err'
if any or '-ETIMEDOUT'/'-EINTR' will be returned correspondingly.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 15:57:35 -08:00
Tuong Lien
49afb806cb tipc: fix link overflow issue at socket shutdown
When a socket is suddenly shutdown or released, it will reject all the
unreceived messages in its receive queue. This applies to a connected
socket too, whereas there is only one 'FIN' message required to be sent
back to its peer in this case.

In case there are many messages in the queue and/or some connections
with such messages are shutdown at the same time, the link layer will
easily get overflowed at the 'TIPC_SYSTEM_IMPORTANCE' backlog level
because of the message rejections. As a result, the link will be taken
down. Moreover, immediately when the link is re-established, the socket
layer can continue to reject the messages and the same issue happens...

The commit refactors the '__tipc_shutdown()' function to only send one
'FIN' in the situation mentioned above. For the connectionless case, it
is unavoidable but usually there is no rejections for such socket
messages because they are 'dest-droppable' by default.

In addition, the new code makes the other socket states clear
(e.g.'TIPC_LISTEN') and treats as a separate case to avoid misbehaving.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 15:57:07 -08:00
Masahiro Yamada
b969fee12b tipc: remove meaningless assignment in Makefile
There is no module named tipc_diag.

The assignment to tipc_diag-y has no effect.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 12:38:54 -08:00
Masahiro Yamada
ea04b445a2 tipc: do not add socket.o to tipc-y twice
net/tipc/Makefile adds socket.o twice.

tipc-y	+= addr.o bcast.o bearer.o \
           core.o link.o discover.o msg.o  \
           name_distr.o  subscr.o monitor.o name_table.o net.o  \
           netlink.o netlink_compat.o node.o socket.o eth_media.o \
                                             ^^^^^^^^
           topsrv.o socket.o group.o trace.o
                    ^^^^^^^^

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 12:38:54 -08:00
Ying Xue
a7869e5f91 tipc: eliminate KMSAN: uninit-value in __tipc_nl_compat_dumpit error
syzbot found the following crash on:
=====================================================
BUG: KMSAN: uninit-value in __nlmsg_parse include/net/netlink.h:661 [inline]
BUG: KMSAN: uninit-value in nlmsg_parse_deprecated
include/net/netlink.h:706 [inline]
BUG: KMSAN: uninit-value in __tipc_nl_compat_dumpit+0x553/0x11e0
net/tipc/netlink_compat.c:215
CPU: 0 PID: 12425 Comm: syz-executor062 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1c9/0x220 lib/dump_stack.c:118
  kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108
  __msan_warning+0x57/0xa0 mm/kmsan/kmsan_instr.c:245
  __nlmsg_parse include/net/netlink.h:661 [inline]
  nlmsg_parse_deprecated include/net/netlink.h:706 [inline]
  __tipc_nl_compat_dumpit+0x553/0x11e0 net/tipc/netlink_compat.c:215
  tipc_nl_compat_dumpit+0x761/0x910 net/tipc/netlink_compat.c:308
  tipc_nl_compat_handle net/tipc/netlink_compat.c:1252 [inline]
  tipc_nl_compat_recv+0x12e9/0x2870 net/tipc/netlink_compat.c:1311
  genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
  genl_family_rcv_msg net/netlink/genetlink.c:717 [inline]
  genl_rcv_msg+0x1dd0/0x23a0 net/netlink/genetlink.c:734
  netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477
  genl_rcv+0x63/0x80 net/netlink/genetlink.c:745
  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  netlink_unicast+0xfa0/0x1100 net/netlink/af_netlink.c:1328
  netlink_sendmsg+0x11f0/0x1480 net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec net/socket.c:639 [inline]
  sock_sendmsg net/socket.c:659 [inline]
  ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330
  ___sys_sendmsg net/socket.c:2384 [inline]
  __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417
  __do_sys_sendmsg net/socket.c:2426 [inline]
  __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424
  __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424
  do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:295
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x444179
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 1b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd2d6409c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444179
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401e20
R13: 0000000000401eb0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:149 [inline]
  kmsan_internal_poison_shadow+0x5c/0x110 mm/kmsan/kmsan.c:132
  kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:86
  slab_alloc_node mm/slub.c:2774 [inline]
  __kmalloc_node_track_caller+0xe47/0x11f0 mm/slub.c:4382
  __kmalloc_reserve net/core/skbuff.c:141 [inline]
  __alloc_skb+0x309/0xa50 net/core/skbuff.c:209
  alloc_skb include/linux/skbuff.h:1049 [inline]
  nlmsg_new include/net/netlink.h:888 [inline]
  tipc_nl_compat_dumpit+0x6e4/0x910 net/tipc/netlink_compat.c:301
  tipc_nl_compat_handle net/tipc/netlink_compat.c:1252 [inline]
  tipc_nl_compat_recv+0x12e9/0x2870 net/tipc/netlink_compat.c:1311
  genl_family_rcv_msg_doit net/netlink/genetlink.c:672 [inline]
  genl_family_rcv_msg net/netlink/genetlink.c:717 [inline]
  genl_rcv_msg+0x1dd0/0x23a0 net/netlink/genetlink.c:734
  netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2477
  genl_rcv+0x63/0x80 net/netlink/genetlink.c:745
  netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
  netlink_unicast+0xfa0/0x1100 net/netlink/af_netlink.c:1328
  netlink_sendmsg+0x11f0/0x1480 net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec net/socket.c:639 [inline]
  sock_sendmsg net/socket.c:659 [inline]
  ____sys_sendmsg+0x1362/0x13f0 net/socket.c:2330
  ___sys_sendmsg net/socket.c:2384 [inline]
  __sys_sendmsg+0x4f0/0x5e0 net/socket.c:2417
  __do_sys_sendmsg net/socket.c:2426 [inline]
  __se_sys_sendmsg+0x97/0xb0 net/socket.c:2424
  __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424
  do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:295
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
=====================================================

The complaint above occurred because the memory region pointed by attrbuf
variable was not initialized. To eliminate this warning, we use kcalloc()
rather than kmalloc_array() to allocate memory for attrbuf.

Reported-by: syzbot+b1fd2bf2c89d8407e15f@syzkaller.appspotmail.com
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 13:24:31 -08:00
David S. Miller
ac80010fc9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-22 15:15:05 -08:00
John Rutherford
e1b5e598e5 tipc: make legacy address flag readable over netlink
To enable iproute2/tipc to generate backwards compatible
printouts and validate command parameters for nodes using a
<z.c.n> node address, it needs to be able to read the legacy
address flag from the kernel.  The legacy address flag records
the way in which the node identity was originally specified.

The legacy address flag is requested by the netlink message
TIPC_NL_ADDR_LEGACY_GET.  If the flag is set the attribute
TIPC_NLA_NET_ADDR_LEGACY is set in the return message.

Signed-off-by: John Rutherford <john.rutherford@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-20 21:18:42 -08:00
Jon Maloy
b7ffa045e7 tipc: don't send gap blocks in ACK messages
In the commit referred to below we eliminated sending of the 'gap'
indicator in regular ACK messages, reserving this to explicit NACK
ditto.

Unfortunately we missed to also eliminate building of the 'gap block'
area in ACK messages. This area is meant to report gaps in the
received packet sequence following the initial gap, so that lost
packets can be retransmitted earlier and received out-of-sequence
packets can be released earlier. However, the interpretation of those
blocks is dependent on a complete and correct sequence of gaps and
acks. Hence, when the initial gap indicator is missing a single gap
block will be interpreted as an acknowledgment of all preceding
packets. This may lead to packets being released prematurely from the
sender's transmit queue, with easily predicatble consequences.

We now fix this by not building any gap block area if there is no
initial gap to report.

Fixes: commit 02288248b0 ("tipc: eliminate gap indicator from ACK messages")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 14:16:56 -08:00
Paul E. McKenney
1a271ebbfe net/tipc: Replace rcu_swap_protected() with rcu_replace_pointer()
This commit replaces the use of rcu_swap_protected() with the more
intuitively appealing rcu_replace_pointer() as a step towards removing
rcu_swap_protected().

Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@mail.gmail.com/
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Updated based on Ying Xue and Tuong Lien Tong feedback. ]
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Cc: <tipc-discussion@lists.sourceforge.net>
2019-12-12 10:19:40 -08:00
Tuong Lien
31e4ccc99e tipc: fix use-after-free in tipc_disc_rcv()
In the function 'tipc_disc_rcv()', the 'msg_peer_net_hash()' is called
to read the header data field but after the message skb has been freed,
that might result in a garbage value...

This commit fixes it by defining a new local variable to store the data
first, just like the other header fields' handling.

Fixes: f73b12812a ("tipc: improve throughput between nodes in netns")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10 17:45:04 -08:00
Tuong Lien
abc9b4e054 tipc: fix retrans failure due to wrong destination
When a user message is sent, TIPC will check if the socket has faced a
congestion at link layer. If that happens, it will make a sleep to wait
for the congestion to disappear. This leaves a gap for other users to
take over the socket (e.g. multi threads) since the socket is released
as well. Also, in case of connectionless (e.g. SOCK_RDM), user is free
to send messages to various destinations (e.g. via 'sendto()'), then
the socket's preformatted header has to be updated correspondingly
prior to the actual payload message building.

Unfortunately, the latter action is done before the first action which
causes a condition issue that the destination of a certain message can
be modified incorrectly in the middle, leading to wrong destination
when that message is built. Consequently, when the message is sent to
the link layer, it gets stuck there forever because the peer node will
simply reject it. After a number of retransmission attempts, the link
is eventually taken down and the retransmission failure is reported.

This commit fixes the problem by rearranging the order of actions to
prevent the race condition from occurring, so the message building is
'atomic' and its header will not be modified by anyone.

Fixes: 365ad353c2 ("tipc: reduce risk of user starvation during link congestion")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10 17:45:04 -08:00
Tuong Lien
dca4a17d24 tipc: fix potential hanging after b/rcast changing
In commit c55c8edafa ("tipc: smooth change between replicast and
broadcast"), we allow instant switching between replicast and broadcast
by sending a dummy 'SYN' packet on the last used link to synchronize
packets on the links. The 'SYN' message is an object of link congestion
also, so if that happens, a 'SOCK_WAKEUP' will be scheduled to be sent
back to the socket...
However, in that commit, we simply use the same socket 'cong_link_cnt'
counter for both the 'SYN' & normal payload message sending. Therefore,
if both the replicast & broadcast links are congested, the counter will
be not updated correctly but overwritten by the latter congestion.
Later on, when the 'SOCK_WAKEUP' messages are processed, the counter is
reduced one by one and eventually overflowed. Consequently, further
activities on the socket will only wait for the false congestion signal
to disappear but never been met.

Because sending the 'SYN' message is vital for the mechanism, it should
be done anyway. This commit fixes the issue by marking the message with
an error code e.g. 'TIPC_ERR_NO_PORT', so its sending should not face a
link congestion, there is no need to touch the socket 'cong_link_cnt'
either. In addition, in the event of any error (e.g. -ENOBUFS), we will
purge the entire payload message queue and make a return immediately.

Fixes: c55c8edafa ("tipc: smooth change between replicast and broadcast")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10 17:45:04 -08:00
Tuong Lien
d5162f341e tipc: fix name table rbtree issues
The current rbtree for service ranges in the name table is built based
on the 'lower' & 'upper' range values resulting in a flaw in the rbtree
searching. Some issues have been observed in case of range overlapping:

Case #1: unable to withdraw a name entry:
After some name services are bound, all of them are withdrawn by user
but one remains in the name table forever. This corrupts the table and
that service becomes dummy i.e. no real port.
E.g.

                /
           {22, 22}
              /
             /
   --->  {10, 50}
           /  \
          /    \
    {10, 30}  {20, 60}

The node {10, 30} cannot be removed since the rbtree searching stops at
the node's ancestor i.e. {10, 50}, so starting from it will never reach
the finding node.

Case #2: failed to send data in some cases:
E.g. Two service ranges: {20, 60}, {10, 50} are bound. The rbtree for
this service will be one of the two cases below depending on the order
of the bindings:

        {20, 60}             {10, 50} <--
          /  \                 /  \
         /    \               /    \
    {10, 50}  NIL <--       NIL  {20, 60}

          (a)                    (b)

Now, try to send some data to service {30}, there will be two results:
(a): Failed, no route to host.
(b): Ok.

The reason is that the rbtree searching will stop at the pointing node
as shown above.

Case #3: Same as case #2b above but if the data sending's scope is
local and the {10, 50} is published by a peer node, then it will result
in 'no route to host' even though the other {20, 60} is for example on
the local node which should be able to get the data.

The issues are actually due to the way we built the rbtree. This commit
fixes it by introducing an additional field to each node - named 'max',
which is the largest 'upper' of that node subtree. The 'max' value for
each subtrees will be propagated correctly whenever a node is inserted/
removed or the tree is rebalanced by the augmented rbtree callbacks.

By this way, we can change the rbtree searching appoarch to solve the
issues above. Another benefit from this is that we can now improve the
searching for a next range matching e.g. in case of multicast, so get
rid of the unneeded looping over all nodes in the tree.

Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10 17:45:04 -08:00
Jon Maloy
16ad3f4022 tipc: introduce variable window congestion control
We introduce a simple variable window congestion control for links.
The algorithm is inspired by the Reno algorithm, covering both 'slow
start', 'congestion avoidance', and 'fast recovery' modes.

- We introduce hard lower and upper window limits per link, still
  different and configurable per bearer type.

- We introduce a 'slow start theshold' variable, initially set to
  the maximum window size.

- We let a link start at the minimum congestion window, i.e. in slow
  start mode, and then let is grow rapidly (+1 per rceived ACK) until
  it reaches the slow start threshold and enters congestion avoidance
  mode.

- In congestion avoidance mode we increment the congestion window for
  each window-size number of acked packets, up to a possible maximum
  equal to the configured maximum window.

- For each non-duplicate NACK received, we drop back to fast recovery
  mode, by setting the both the slow start threshold to and the
  congestion window to (current_congestion_window / 2).

- If the timeout handler finds that the transmit queue has not moved
  since the previous timeout, it drops the link back to slow start
  and forces a probe containing the last sent sequence number to the
  sent to the peer, so that this can discover the stale situation.

This change does in reality have effect only on unicast ethernet
transport, as we have seen that there is no room whatsoever for
increasing the window max size for the UDP bearer.
For now, we also choose to keep the limits for the broadcast link
unchanged and equal.

This algorithm seems to give a 50-100% throughput improvement for
messages larger than MTU.

Suggested-by: Xin Long <lucien.xin@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>
2019-12-10 17:31:15 -08:00
Jon Maloy
d3b09995ab tipc: eliminate more unnecessary nacks and retransmissions
When we increase the link tranmsit window we often observe the following
scenario:

1) A STATE message bypasses a sequence of traffic packets and arrives
   far ahead of those to the receiver. STATE messages contain a
   'peers_nxt_snt' field to indicate which was the last packet sent
   from the peer. This mechanism is intended as a last resort for the
   receiver to detect missing packets, e.g., during very low traffic
   when there is no packet flow to help early loss detection.
3) The receiving link compares the 'peer_nxt_snt' field to its own
   'rcv_nxt', finds that there is a gap, and immediately sends a
   NACK message back to the peer.
4) When this NACKs arrives at the sender, all the requested
   retransmissions are performed, since it is a first-time request.

Just like in the scenario described in the previous commit this leads
to many redundant retransmissions, with decreased throughput as a
consequence.

We fix this by adding two more conditions before we send a NACK in
this sitution. First, the deferred queue must be empty, so we cannot
assume that the potential packet loss has already been detected by
other means. Second, we check the 'peers_snd_nxt' field only in probe/
probe_reply messages, thus turning this into a true mechanism of last
resort as it was really meant to be.

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>
2019-12-10 17:31:15 -08:00
Jon Maloy
02288248b0 tipc: eliminate gap indicator from ACK messages
When we increase the link send window we sometimes observe the
following scenario:

1) A packet #N arrives out of order far ahead of a sequence of older
   packets which are still under way. The packet is added to the
   deferred queue.
2) The missing packets arrive in sequence, and for each 16th of them
   an ACK is sent back to the receiver, as it should be.
3) When building those ACK messages, it is checked if there is a gap
   between the link's 'rcv_nxt' and the first packet in the deferred
   queue. This is always the case until packet number #N-1 arrives, and
   a 'gap' indicator is added, effectively turning them into NACK
   messages.
4) When those NACKs arrive at the sender, all the requested
   retransmissions are done, since it is a first-time request.

This sometimes leads to a huge amount of redundant retransmissions,
causing a drop in max throughput. This problem gets worse when we
in a later commit introduce variable window congestion control,
since it drops the link back to 'fast recovery' much more often
than necessary.

We now fix this by not sending any 'gap' indicator in regular ACK
messages. We already have a mechanism for sending explicit NACKs
in place, and this is sufficient to keep up the packet flow.

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>
2019-12-10 17:31:15 -08:00
Taehee Yoo
9cf1cd8ee3 tipc: fix ordering of tipc module init and exit routine
In order to set/get/dump, the tipc uses the generic netlink
infrastructure. So, when tipc module is inserted, init function
calls genl_register_family().
After genl_register_family(), set/get/dump commands are immediately
allowed and these callbacks internally use the net_generic.
net_generic is allocated by register_pernet_device() but this
is called after genl_register_family() in the __init function.
So, these callbacks would use un-initialized net_generic.

Test commands:
    #SHELL1
    while :
    do
        modprobe tipc
        modprobe -rv tipc
    done

    #SHELL2
    while :
    do
        tipc link list
    done

Splat looks like:
[   59.616322][ T2788] kasan: CONFIG_KASAN_INLINE enabled
[   59.617234][ T2788] kasan: GPF could be caused by NULL-ptr deref or user memory access
[   59.618398][ T2788] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[   59.619389][ T2788] CPU: 3 PID: 2788 Comm: tipc Not tainted 5.4.0+ #194
[   59.620231][ T2788] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   59.621428][ T2788] RIP: 0010:tipc_bcast_get_broadcast_mode+0x131/0x310 [tipc]
[   59.622379][ T2788] Code: c7 c6 ef 8b 38 c0 65 ff 0d 84 83 c9 3f e8 d7 a5 f2 e3 48 8d bb 38 11 00 00 48 b8 00 00 00 00
[   59.622550][ T2780] NET: Registered protocol family 30
[   59.624627][ T2788] RSP: 0018:ffff88804b09f578 EFLAGS: 00010202
[   59.624630][ T2788] RAX: dffffc0000000000 RBX: 0000000000000011 RCX: 000000008bc66907
[   59.624631][ T2788] RDX: 0000000000000229 RSI: 000000004b3cf4cc RDI: 0000000000001149
[   59.624633][ T2788] RBP: ffff88804b09f588 R08: 0000000000000003 R09: fffffbfff4fb3df1
[   59.624635][ T2788] R10: fffffbfff50318f8 R11: ffff888066cadc18 R12: ffffffffa6cc2f40
[   59.624637][ T2788] R13: 1ffff11009613eba R14: ffff8880662e9328 R15: ffff8880662e9328
[   59.624639][ T2788] FS:  00007f57d8f7b740(0000) GS:ffff88806cc00000(0000) knlGS:0000000000000000
[   59.624645][ T2788] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.625875][ T2780] tipc: Started in single node mode
[   59.626128][ T2788] CR2: 00007f57d887a8c0 CR3: 000000004b140002 CR4: 00000000000606e0
[   59.633991][ T2788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   59.635195][ T2788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   59.636478][ T2788] Call Trace:
[   59.637025][ T2788]  tipc_nl_add_bc_link+0x179/0x1470 [tipc]
[   59.638219][ T2788]  ? lock_downgrade+0x6e0/0x6e0
[   59.638923][ T2788]  ? __tipc_nl_add_link+0xf90/0xf90 [tipc]
[   59.639533][ T2788]  ? tipc_nl_node_dump_link+0x318/0xa50 [tipc]
[   59.640160][ T2788]  ? mutex_lock_io_nested+0x1380/0x1380
[   59.640746][ T2788]  tipc_nl_node_dump_link+0x4fd/0xa50 [tipc]
[   59.641356][ T2788]  ? tipc_nl_node_reset_link_stats+0x340/0x340 [tipc]
[   59.642088][ T2788]  ? __skb_ext_del+0x270/0x270
[   59.642594][ T2788]  genl_lock_dumpit+0x85/0xb0
[   59.643050][ T2788]  netlink_dump+0x49c/0xed0
[   59.643529][ T2788]  ? __netlink_sendskb+0xc0/0xc0
[   59.644044][ T2788]  ? __netlink_dump_start+0x190/0x800
[   59.644617][ T2788]  ? __mutex_unlock_slowpath+0xd0/0x670
[   59.645177][ T2788]  __netlink_dump_start+0x5a0/0x800
[   59.645692][ T2788]  genl_rcv_msg+0xa75/0xe90
[   59.646144][ T2788]  ? __lock_acquire+0xdfe/0x3de0
[   59.646692][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.647340][ T2788]  ? genl_lock_dumpit+0xb0/0xb0
[   59.647821][ T2788]  ? genl_unlock+0x20/0x20
[   59.648290][ T2788]  ? genl_parallel_done+0xe0/0xe0
[   59.648787][ T2788]  ? find_held_lock+0x39/0x1d0
[   59.649276][ T2788]  ? genl_rcv+0x15/0x40
[   59.649722][ T2788]  ? lock_contended+0xcd0/0xcd0
[   59.650296][ T2788]  netlink_rcv_skb+0x121/0x350
[   59.650828][ T2788]  ? genl_family_rcv_msg_attrs_parse+0x320/0x320
[   59.651491][ T2788]  ? netlink_ack+0x940/0x940
[   59.651953][ T2788]  ? lock_acquire+0x164/0x3b0
[   59.652449][ T2788]  genl_rcv+0x24/0x40
[   59.652841][ T2788]  netlink_unicast+0x421/0x600
[ ... ]

Fixes: 7e43690578 ("tipc: fix a slab object leak")
Fixes: a62fbccecd ("tipc: make subscriber server support net namespace")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-06 12:01:09 -08:00
Sabrina Dubroca
6c8991f415 net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup
ipv6_stub uses the ip6_dst_lookup function to allow other modules to
perform IPv6 lookups. However, this function skips the XFRM layer
entirely.

All users of ipv6_stub->ip6_dst_lookup use ip_route_output_flow (via the
ip_route_output_key and ip_route_output helpers) for their IPv4 lookups,
which calls xfrm_lookup_route(). This patch fixes this inconsistent
behavior by switching the stub to ip6_dst_lookup_flow, which also calls
xfrm_lookup_route().

This requires some changes in all the callers, as these two functions
take different arguments and have different return types.

Fixes: 5f81bd2e5d ("ipv6: export a stub for IPv6 symbols used by vxlan")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-04 12:27:13 -08:00
Tung Nguyen
d34910e175 tipc: fix duplicate SYN messages under link congestion
Scenario:
1. A client socket initiates a SYN message to a listening socket.
2. The send link is congested, the SYN message is put in the
send link and a wakeup message is put in wakeup queue.
3. The congestion situation is abated, the wakeup message is
pulled out of the wakeup queue. Function tipc_sk_push_backlog()
is called to send out delayed messages by Nagle. However,
the client socket is still in CONNECTING state. So, it sends
the SYN message in the socket write queue to the listening socket
again.
4. The listening socket receives the first SYN message and creates
first server socket. The client socket receives ACK- and establishes
a connection to the first server socket. The client socket closes
its connection with the first server socket.
5. The listening socket receives the second SYN message and creates
second server socket. The second server socket sends ACK- to the
client socket, but it has been closed. It results in connection
reset error when reading from the server socket in user space.

Solution: return from function tipc_sk_push_backlog() immediately
if there is pending SYN message in the socket write queue.

Fixes: c0bceb97db ("tipc: add smart nagle feature")
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-28 23:09:15 -08:00
Tung Nguyen
12db3c8083 tipc: fix wrong timeout input for tipc_wait_for_cond()
In function __tipc_shutdown(), the timeout value passed to
tipc_wait_for_cond() is not jiffies.

This commit fixes it by converting that value from milliseconds
to jiffies.

Fixes: 365ad353c2 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-28 23:09:14 -08:00
Tung Nguyen
91a4a3eb43 tipc: fix wrong socket reference counter after tipc_sk_timeout() returns
When tipc_sk_timeout() is executed but user space is grabbing
ownership, this function rearms itself and returns. However, the
socket reference counter is not reduced. This causes potential
unexpected behavior.

This commit fixes it by calling sock_put() before tipc_sk_timeout()
returns in the above-mentioned case.

Fixes: afe8792fec ("tipc: refactor function tipc_sk_timeout()")
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
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>
2019-11-28 23:09:14 -08:00
Tung Nguyen
2fe97a578d tipc: fix potential memory leak in __tipc_sendmsg()
When initiating a connection message to a server side, the connection
message is cloned and added to the socket write queue. However, if the
cloning is failed, only the socket write queue is purged. It causes
memory leak because the original connection message is not freed.

This commit fixes it by purging the list of connection message when
it cannot be cloned.

Fixes: 6787927475 ("tipc: buffer overflow handling in listener socket")
Reported-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
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>
2019-11-28 23:09:14 -08:00