Rekeying is required for security since a key is less secure when using
for a long time. Also, key will be detached when its nonce value (or
seqno ...) is exhausted. We now make the rekeying process automatic and
configurable by user.
Basically, TIPC will at a specific interval generate a new key by using
the kernel 'Random Number Generator' cipher, then attach it as the node
TX key and securely distribute to others in the cluster as RX keys (-
the key exchange). The automatic key switching will then take over, and
make the new key active shortly. Afterwards, the traffic from this node
will be encrypted with the new session key. The same can happen in peer
nodes but not necessarily at the same time.
For simplicity, the automatically generated key will be initiated as a
per node key. It is not too hard to also support a cluster key rekeying
(e.g. a given node will generate a unique cluster key and update to the
others in the cluster...), but that doesn't bring much benefit, while a
per-node key is even more secure.
We also enable user to force a rekeying or change the rekeying interval
via netlink, the new 'set key' command option: 'TIPC_NLA_NODE_REKEYING'
is added for these purposes as follows:
- A value >= 1 will be set as the rekeying interval (in minutes);
- A value of 0 will disable the rekeying;
- A value of 'TIPC_REKEYING_NOW' (~0) will force an immediate rekeying;
The default rekeying interval is (60 * 24) minutes i.e. done every day.
There isn't any restriction for the value but user shouldn't set it too
small or too large which results in an "ineffective" rekeying (thats ok
for testing though).
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>
With support from the master key option in the previous commit, it
becomes easy to make frequent updates/exchanges of session keys between
authenticated cluster nodes.
Basically, there are two situations where the key exchange will take in
place:
- When a new node joins the cluster (with the master key), it will need
to get its peer's TX key, so that be able to decrypt further messages
from that peer.
- When a new session key is generated (by either user manual setting or
later automatic rekeying feature), the key will be distributed to all
peer nodes in the cluster.
A key to be exchanged is encapsulated in the data part of a 'MSG_CRYPTO
/KEY_DISTR_MSG' TIPC v2 message, then xmit-ed as usual and encrypted by
using the master key before sending out. Upon receipt of the message it
will be decrypted in the same way as regular messages, then attached as
the sender's RX key in the receiver node.
In this way, the key exchange is reliable by the link layer, as well as
security, integrity and authenticity by the crypto layer.
Also, the forward security will be easily achieved by user changing the
master key actively but this should not be required very frequently.
The key exchange feature is independent on the presence of a master key
Note however that the master key still is needed for new nodes to be
able to join the cluster. It is also optional, and can be turned off/on
via the sysfs: 'net/tipc/key_exchange_enabled' [default 1: enabled].
Backward compatibility is guaranteed because for nodes that do not have
master key support, key exchange using master key ie. tx_key = 0 if any
will be shortly discarded at the message validation step. In other
words, the key exchange feature will be automatically disabled to those
nodes.
v2: fix the "implicit declaration of function 'tipc_crypto_key_flush'"
error in node.c. The function only exists when built with the TIPC
"CONFIG_TIPC_CRYPTO" option.
v3: use 'info->extack' for a message emitted due to netlink operations
instead (- David's comment).
Reported-by: kernel test robot <lkp@intel.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>
In addition to the supported cluster & per-node encryption keys for the
en/decryption of TIPC messages, we now introduce one option for user to
set a cluster key as 'master key', which is simply a symmetric key like
the former but has a longer life cycle. It has two purposes:
- Authentication of new member nodes in the cluster. New nodes, having
no knowledge of current session keys in the cluster will still be
able to join the cluster as long as they know the master key. This is
because all neighbor discovery (LINK_CONFIG) messages must be
encrypted with this key.
- Encryption of session encryption keys during automatic exchange and
update of those.This is a feature we will introduce in a later commit
in this series.
We insert the new key into the currently unused slot 0 in the key array
and start using it immediately once the user has set it.
After joining, a node only knowing the master key should be fully
communicable to existing nodes in the cluster, although those nodes may
have their own session keys activated (i.e. not the master one). To
support this, we define a 'grace period', starting from the time a node
itself reports having no RX keys, so the existing nodes will use the
master key for encryption instead. The grace period can be extended but
will automatically stop after e.g. 5 seconds without a new report. This
is also the basis for later key exchanging feature as the new node will
be impossible to decrypt anything without the support from master key.
For user to set a master key, we define a new netlink flag -
'TIPC_NLA_NODE_KEY_MASTER', so it can be added to the current 'set key'
netlink command to specify the setting key to be a master key.
Above all, the traditional cluster/per-node key mechanism is guaranteed
to work when user comes not to use this master key option. This is also
compatible to legacy nodes without the feature supported.
Even this master key can be updated without any interruption of cluster
connectivity but is so is needed, this has to be coordinated and set by
the user.
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>
We reduce the lasting time for a pending TX key to be active as well as
for a passive RX key to be freed which generally helps speed up the key
switching. It is not expected to be too fast but should not be too slow
either. Also the key handling logic is simplified that a pending RX key
will be removed automatically if it is found not working after a number
of times; the probing for a pending TX key is now carried on a specific
message user ('LINK_PROTOCOL' or 'LINK_CONFIG') which is more efficient
than using a timer on broadcast messages, the timer is reserved for use
later as needed.
The kernel logs or 'pr***()' are now made as clear as possible to user.
Some prints are added, removed or changed to the debug-level. The
'TIPC_CRYPTO_DEBUG' definition is removed, and the 'pr_debug()' is used
instead which will be much helpful in runtime.
Besides we also optimize the code in some other places as a preparation
for later commits.
v2: silent more kernel logs, also use 'info->extack' for a message
emitted due to netlink operations instead (- David's comments).
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>
Simple fixes which require no deep knowledge of the code.
Cc: Jon Maloy <jmaloy@redhat.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, updating binding table (add service binding to
name table/withdraw a service binding) is being sent over replicast.
However, if we are scaling up clusters to > 100 nodes/containers this
method is less affection because of looping through nodes in a cluster one
by one.
It is worth to use broadcast to update a binding service. This way, the
binding table can be updated on all peer nodes in one shot.
Broadcast is used when all peer nodes, as indicated by a new capability
flag TIPC_NAMED_BCAST, support reception of this message type.
Four problems need to be considered when introducing this feature.
1) When establishing a link to a new peer node we still update this by a
unicast 'bulk' update. This may lead to race conditions, where a later
broadcast publication/withdrawal bypass the 'bulk', resulting in
disordered publications, or even that a withdrawal may arrive before the
corresponding publication. We solve this by adding an 'is_last_bulk' bit
in the last bulk messages so that it can be distinguished from all other
messages. Only when this message has arrived do we open up for reception
of broadcast publications/withdrawals.
2) When a first legacy node is added to the cluster all distribution
will switch over to use the legacy 'replicast' method, while the
opposite happens when the last legacy node leaves the cluster. This
entails another risk of message disordering that has to be handled. We
solve this by adding a sequence number to the broadcast/replicast
messages, so that disordering can be discovered and corrected. Note
however that we don't need to consider potential message loss or
duplication at this protocol level.
3) Bulk messages don't contain any sequence numbers, and will always
arrive in order. Hence we must exempt those from the sequence number
control and deliver them unconditionally. We solve this by adding a new
'is_bulk' bit in those messages so that they can be recognized.
4) Legacy messages, which don't contain any new bits or sequence
numbers, but neither can arrive out of order, also need to be exempt
from the initial synchronization and sequence number check, and
delivered unconditionally. Therefore, we add another 'is_not_legacy' bit
to all new messages so that those can be distinguished from legacy
messages and the latter delivered directly.
v1->v2:
- fix warning issue reported by kbuild test robot <lkp@intel.com>
- add santiy check to drop the publication message with a sequence
number that is lower than the agreed synch point
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
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>
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>
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>
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>
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>
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>
When setting up a cluster with non-replicast/replicast capability
supported. This capability will be disabled for broadcast send link
in order to be backwards compatible.
However, when these non-support nodes left and be removed out the cluster.
We don't update this capability on broadcast send link. Then, some of
features that based on this capability will also disabling as unexpected.
In this commit, we make sure the broadcast send link capabilities will
be re-calculated as soon as a node removed/rejoined a cluster.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit adds two netlink commands to TIPC in order for user to be
able to set or remove AEAD keys:
- TIPC_NL_KEY_SET
- TIPC_NL_KEY_FLUSH
When the 'KEY_SET' is given along with the key data, the key will be
initiated and attached to TIPC crypto. On the other hand, the
'KEY_FLUSH' command will remove all existing keys if any.
Acked-by: Ying Xue <ying.xue@windreiver.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>
This commit offers an option to encrypt and authenticate all messaging,
including the neighbor discovery messages. The currently most advanced
algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All
encryption/decryption is done at the bearer layer, just before leaving
or after entering TIPC.
Supported features:
- Encryption & authentication of all TIPC messages (header + data);
- Two symmetric-key modes: Cluster and Per-node;
- Automatic key switching;
- Key-expired revoking (sequence number wrapped);
- Lock-free encryption/decryption (RCU);
- Asynchronous crypto, Intel AES-NI supported;
- Multiple cipher transforms;
- Logs & statistics;
Two key modes:
- Cluster key mode: One single key is used for both TX & RX in all
nodes in the cluster.
- Per-node key mode: Each nodes in the cluster has one specific TX key.
For RX, a node requires its peers' TX key to be able to decrypt the
messages from those peers.
Key setting from user-space is performed via netlink by a user program
(e.g. the iproute2 'tipc' tool).
Internal key state machine:
Attach Align(RX)
+-+ +-+
| V | V
+---------+ Attach +---------+
| IDLE |---------------->| PENDING |(user = 0)
+---------+ +---------+
A A Switch| A
| | | |
| | Free(switch/revoked) | |
(Free)| +----------------------+ | |Timeout
| (TX) | | |(RX)
| | | |
| | v |
+---------+ Switch +---------+
| PASSIVE |<----------------| ACTIVE |
+---------+ (RX) +---------+
(user = 1) (user >= 1)
The number of TFMs is 10 by default and can be changed via the procfs
'net/tipc/max_tfms'. At this moment, as for simplicity, this file is
also used to print the crypto statistics at runtime:
echo 0xfff1 > /proc/sys/net/tipc/max_tfms
The patch defines a new TIPC version (v7) for the encryption message (-
backward compatibility as well). The message is basically encapsulated
as follows:
+----------------------------------------------------------+
| TIPCv7 encryption | Original TIPCv2 | Authentication |
| header | packet (encrypted) | Tag |
+----------------------------------------------------------+
The throughput is about ~40% for small messages (compared with non-
encryption) and ~9% for large messages. With the support from hardware
crypto i.e. the Intel AES-NI CPU instructions, the throughput increases
upto ~85% for small messages and ~55% for large messages.
By default, the new feature is inactive (i.e. no encryption) until user
sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO"
in the kernel configuration to enable/disable the new code when needed.
MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc
Acked-by: Ying Xue <ying.xue@windreiver.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>
When user sets RX key for a peer not existing on the own node, a new
node entry is needed to which the RX key will be attached. However,
since the peer node address (& capabilities) is unknown at that moment,
only the node-ID is provided, this commit allows the creation of a node
with only the data that we call as “preliminary”.
A preliminary node is not the object of the “tipc_node_find()” but the
“tipc_node_find_by_id()”. Once the first message i.e. LINK_CONFIG comes
from that peer, and is successfully decrypted by the own node, the
actual peer node data will be properly updated and the node will
function as usual.
In addition, the node timer always starts when a node object is created
so if a preliminary node is not used, it will be cleaned up.
The later encryption functions will also use the node timer and be able
to create a preliminary node automatically when needed.
Acked-by: Ying Xue <ying.xue@windreiver.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>
Currently, we scan over all network namespaces at each received
discovery message in order to check if the sending peer might be
present in a host local namespaces.
This is unnecessary since we can assume that a peer will not change its
location during an established session.
We now improve the condition for this testing so that we don't perform
any redundant scans.
Fixes: f73b12812a ("tipc: improve throughput between nodes in netns")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are two improvements when re-calculate cluster capabilities:
- When deleting a specific down node, need to re-calculate.
- In tipc_node_cleanup(), do not need to re-calculate if node
is still existing in cluster.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Jon
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, TIPC transports intra-node user data messages directly
socket to socket, hence shortcutting all the lower layers of the
communication stack. This gives TIPC very good intra node performance,
both regarding throughput and latency.
We now introduce a similar mechanism for TIPC data traffic across
network namespaces located in the same kernel. On the send path, the
call chain is as always accompanied by the sending node's network name
space pointer. However, once we have reliably established that the
receiving node is represented by a namespace on the same host, we just
replace the namespace pointer with the receiving node/namespace's
ditto, and follow the regular socket receive patch though the receiving
node. This technique gives us a throughput similar to the node internal
throughput, several times larger than if we let the traffic go though
the full network stacks. As a comparison, max throughput for 64k
messages is four times larger than TCP throughput for the same type of
traffic.
To meet any security concerns, the following should be noted.
- All nodes joining a cluster are supposed to have been be certified
and authenticated by mechanisms outside TIPC. This is no different for
nodes/namespaces on the same host; they have to auto discover each
other using the attached interfaces, and establish links which are
supervised via the regular link monitoring mechanism. Hence, a kernel
local node has no other way to join a cluster than any other node, and
have to obey to policies set in the IP or device layers of the stack.
- Only when a sender has established with 100% certainty that the peer
node is located in a kernel local namespace does it choose to let user
data messages, and only those, take the crossover path to the receiving
node/namespace.
- If the receiving node/namespace is removed, its namespace pointer
is invalidated at all peer nodes, and their neighbor link monitoring
will eventually note that this node is gone.
- To ensure the "100% certainty" criteria, and prevent any possible
spoofing, received discovery messages must contain a proof that the
sender knows a common secret. We use the hash mix of the sending
node/namespace for this purpose, since it can be accessed directly by
all other namespaces in the kernel. Upon reception of a discovery
message, the receiver checks this proof against all the local
namespaces'hash_mix:es. If it finds a match, that, along with a
matching node id and cluster id, this is deemed sufficient proof that
the peer node in question is in a local namespace, and a wormhole can
be opened.
- We should also consider that TIPC is intended to be a cluster local
IPC mechanism (just like e.g. UNIX sockets) rather than a network
protocol, and hence we think it can justified to allow it to shortcut the
lower protocol layers.
Regarding traceability, we should notice that since commit 6c9081a391
("tipc: add loopback device tracking") it is possible to follow the node
internal packet flow by just activating tcpdump on the loopback
interface. This will be true even for this mechanism; by activating
tcpdump on the involved nodes' loopback interfaces their inter-name
space messaging can easily be tracked.
v2:
- update 'net' pointer when node left/rejoined
v3:
- grab read/write lock when using node ref obj
v4:
- clone traffics between netns to loopback
Suggested-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Benefit from the fact that the generic netlink code can parse the attrs
for dumpit op and avoid need to parse it in the op callback.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The policy for handling the skb list locks on the send and receive paths
is simple.
- On the send path we never need to grab the lock on the 'xmitq' list
when the destination is an exernal node.
- On the receive path we always need to grab the lock on the 'inputq'
list, irrespective of source node.
However, when transmitting node local messages those will eventually
end up on the receive path of a local socket, meaning that the argument
'xmitq' in tipc_node_xmit() will become the 'ínputq' argument in the
function tipc_sk_rcv(). This has been handled by always initializing
the spinlock of the 'xmitq' list at message creation, just in case it
may end up on the receive path later, and despite knowing that the lock
in most cases never will be used.
This approach is inaccurate and confusing, and has also concealed the
fact that the stated 'no lock grabbing' policy for the send path is
violated in some cases.
We now clean up this by never initializing the lock at message creation,
instead doing this at the moment we find that the message actually will
enter the receive path. At the same time we fix the four locations
where we incorrectly access the spinlock on the send/error path.
This patch also reverts commit d12cffe932 ("tipc: ensure head->lock
is initialised") which has now become redundant.
CC: Eric Dumazet <edumazet@google.com>
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since node internal messages are passed directly to the socket, it is not
possible to observe those messages via tcpdump or wireshark.
We now remedy this by making it possible to clone such messages and send
the clones to the loopback interface. The clones are dropped at reception
and have no functional role except making the traffic visible.
The feature is enabled if network taps are active for the loopback device.
pcap filtering restrictions require the messages to be presented to the
receiving side of the loopback device.
v3 - Function dev_nit_active used to check for network taps.
- Procedure netif_rx_ni used to send cloned messages to loopback device.
Signed-off-by: John Rutherford <john.rutherford@dektech.com.au>
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>
This commit along with the next one are to resolve the issues with the
link changeover mechanism. See that commit for details.
Basically, for the link synching, from now on, we will send only one
single ("dummy") SYNCH message to peer. The SYNCH message does not
contain any data, just a header conveying the synch point to the peer.
A new node capability flag ("TIPC_TUNNEL_ENHANCED") is introduced for
backward compatible!
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Suggested-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>
The tipc_msg_validate() function leaves a boolean flag 'validated' in
the validated buffer's control block, to avoid performing this action
more than once. However, at reception of new packets, the position of
this field may already have been set by lower layer protocols, so
that the packet is erroneously perceived as already validated by TIPC.
We fix this by initializing the said field to 'false' before performing
the initial validation.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We rename the inline function msg_get_wrapped() to the more
comprehensible msg_inner_hdr().
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It appears that a FAILOVER_MSG can come from peer even when the failure
link is resetting (i.e. just after the 'node_write_unlock()'...). This
means the failover procedure on the node has not been started yet.
The situation is as follows:
node1 node2
linkb linka linka linkb
| | | |
| | x failure |
| | RESETTING |
| | | |
| x failure RESET |
| RESETTING FAILINGOVER |
| | (FAILOVER_MSG) | |
|<-------------------------------------------------|
| *FAILINGOVER | | |
| | (dummy FAILOVER_MSG) | |
|------------------------------------------------->|
| RESET | | FAILOVER_END
| FAILINGOVER RESET |
. . . .
. . . .
. . . .
Once this happens, the link failover procedure will be triggered
wrongly on the receiving node since the node isn't in FAILINGOVER state
but then another link failover will be carried out.
The consequences are:
1) A peer might get stuck in FAILINGOVER state because the 'sync_point'
was set, reset and set incorrectly, the criteria to end the failover
would not be met, it could keep waiting for a message that has already
received.
2) The early FAILOVER_MSG(s) could be queued in the link failover
deferdq but would be purged or not pulled out because the 'drop_point'
was not set correctly.
3) The early FAILOVER_MSG(s) could be dropped too.
4) The dummy FAILOVER_MSG could make the peer leaving FAILINGOVER state
shortly, but later on it would be restarted.
The same situation can also happen when the link is in PEER_RESET state
and a FAILOVER_MSG arrives.
The commit resolves the issues by forcing the link down immediately, so
the failover procedure will be started normally (which is the same as
when receiving a FAILOVER_MSG and the link is in up state).
Also, the function "tipc_node_link_failover()" is toughen to avoid such
a situation from happening.
Acked-by: Jon Maloy <jon.maloy@ericsson.se>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIPC link can temporarily fall into "half-establish" that only one of
the link endpoints is ESTABLISHED and starts to send traffic, PROTOCOL
messages, whereas the other link endpoint is not up (e.g. immediately
when the endpoint receives ACTIVATE_MSG, the network interface goes
down...).
This is a normal situation and will be settled because the link
endpoint will be eventually brought down after the link tolerance time.
However, the situation will become worse when the second link is
established before the first link endpoint goes down,
For example:
1. Both links <1A-2A>, <1B-2B> down
2. Link endpoint 2A up, but 1A still down (e.g. due to network
disturbance, wrong session, etc.)
3. Link <1B-2B> up
4. Link endpoint 2A down (e.g. due to link tolerance timeout)
5. Node B starts failover onto link <1B-2B>
==> Node A does never start link failover.
When the "half-failover" situation happens, two consequences have been
observed:
a) Peer link/node gets stuck in FAILINGOVER state;
b) Traffic or user messages that peer node is trying to failover onto
the second link can be partially or completely dropped by this node.
The consequence a) was actually solved by commit c140eb166d ("tipc:
fix failover problem"), but that commit didn't cover the b). It's due
to the fact that the tunnel link endpoint has never been prepared for a
failover, so the 'l->drop_point' (and the other data...) is not set
correctly. When a TUNNEL_MSG from peer node arrives on the link,
depending on the inner message's seqno and the current 'l->drop_point'
value, the message can be dropped (- treated as a duplicate message) or
processed.
At this early stage, the traffic messages from peer are likely to be
NAME_DISTRIBUTORs, this means some name table entries will be missed on
the node forever!
The commit resolves the issue by starting the FAILOVER process on this
node as well. Another benefit from this solution is that we ensure the
link will not be re-established until the failover ends.
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>
We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.
Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().
Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:
@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)
@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the function tipc_node_create() we protect the peer capability field
by using the node rw_lock. However, we access the lock directly instead
of using the dedicated functions for this, as we do everywhere else in
node.c. This cosmetic spot is fixed here.
Fixes: 40999f11ce ("tipc: make link capability update thread safe")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When checking the code with clang -Wsometimes-uninitialized we get the
following warning:
if (!tipc_link_is_establishing(l)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/node.c:847:46: note: uninitialized use occurs here
tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
net/tipc/node.c:831:2: note: remove the 'if' if its condition is always
true
if (!tipc_link_is_establishing(l)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/node.c:821:31: note: initialize the variable 'maddr' to silence
this warning
struct tipc_media_addr *maddr;
We fix this by initializing 'maddr' to NULL. For the matter of clarity,
we also test if 'xmitq' is non-empty before we use it and 'maddr'
further down in the function. It will never happen that 'xmitq' is non-
empty at the same time as 'maddr' is NULL, so this is a sufficient test.
Fixes: 598411d70f ("tipc: make resetting of links non-atomic")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As a preparation for introducing a smooth switching between replicast
and broadcast method for multicast message, We have to introduce a new
capability flag TIPC_MCAST_RBCTL to handle this new feature.
During a cluster upgrade a node can come back with this new capabilities
which also must be reflected in the cluster capabilities field.
The new feature is only applicable if all node in the cluster supports
this new capability.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a link endpoint is re-created (e.g. after a node reboot or
interface reset), the link session number is varied by random, the peer
endpoint will be synced with this new session number before the link is
re-established.
However, there is a shortcoming in this mechanism that can lead to the
link never re-established or faced with a failure then. It happens when
the peer endpoint is ready in ESTABLISHING state, the 'peer_session' as
well as the 'in_session' flag have been set, but suddenly this link
endpoint leaves. When it comes back with a random session number, there
are two situations possible:
1/ If the random session number is larger than (or equal to) the
previous one, the peer endpoint will be updated with this new session
upon receipt of a RESET_MSG from this endpoint, and the link can be re-
established as normal. Otherwise, all the RESET_MSGs from this endpoint
will be rejected by the peer. In turn, when this link endpoint receives
one ACTIVATE_MSG from the peer, it will move to ESTABLISHED and start
to send STATE_MSGs, but again these messages will be dropped by the
peer due to wrong session.
The peer link endpoint can still become ESTABLISHED after receiving a
traffic message from this endpoint (e.g. a BCAST_PROTOCOL or
NAME_DISTRIBUTOR), but since all the STATE_MSGs are invalid, the link
will be forced down sooner or later!
Even in case the random session number is larger than the previous one,
it can be that the ACTIVATE_MSG from the peer arrives first, and this
link endpoint moves quickly to ESTABLISHED without sending out any
RESET_MSG yet. Consequently, the peer link will not be updated with the
new session number, and the same link failure scenario as above will
happen.
2/ Another situation can be that, the peer link endpoint was reset due
to any reasons in the meantime, its link state was set to RESET from
ESTABLISHING but still in session, i.e. the 'in_session' flag is not
reset...
Now, if the random session number from this endpoint is less than the
previous one, all the RESET_MSGs from this endpoint will be rejected by
the peer. In the other direction, when this link endpoint receives a
RESET_MSG from the peer, it moves to ESTABLISHING and starts to send
ACTIVATE_MSGs, but all these messages will be rejected by the peer too.
As a result, the link cannot be re-established but gets stuck with this
link endpoint in state ESTABLISHING and the peer in RESET!
Solution:
===========
This link endpoint should not go directly to ESTABLISHED when getting
ACTIVATE_MSG from the peer which may belong to the old session if the
link was re-created. To ensure the session to be correct before the
link is re-established, the peer endpoint in ESTABLISHING state will
send back the last session number in ACTIVATE_MSG for a verification at
this endpoint. Then, if needed, a new and more appropriate session
number will be regenerated to force a re-synch first.
In addition, when a link in ESTABLISHING state is reset, its state will
move to RESET according to the link FSM, along with resetting the
'in_session' flag (and the other data) as a normal link reset, it will
also be deleted if requested.
The solution is backward compatible.
Acked-by: Jon Maloy <jon.maloy@ericsson.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>
The commit adds the new trace_events for TIPC node object:
trace_tipc_node_create()
trace_tipc_node_delete()
trace_tipc_node_lost_contact()
trace_tipc_node_timeout()
trace_tipc_node_link_up()
trace_tipc_node_link_down()
trace_tipc_node_reset_links()
trace_tipc_node_fsm_evt()
trace_tipc_node_check_state()
Also, enables the traces for the following cases:
- When a node is created/deleted;
- When a node contact is lost;
- When a node timer is timed out;
- When a node link is up/down;
- When all node links are reset;
- When node state is changed;
- When a skb comes and node state needs to be checked/updated.
Acked-by: Ying Xue <ying.xue@windriver.com>
Tested-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>
The commit adds the new trace_events for TIPC link object:
trace_tipc_link_timeout()
trace_tipc_link_fsm()
trace_tipc_link_reset()
trace_tipc_link_too_silent()
trace_tipc_link_retrans()
trace_tipc_link_bc_ack()
trace_tipc_link_conges()
And the traces for PROTOCOL messages at building and receiving:
trace_tipc_proto_build()
trace_tipc_proto_rcv()
Note:
a) The 'tipc_link_too_silent' event will only happen when the
'silent_intv_cnt' is about to reach the 'abort_limit' value (and the
event is enabled). The benefit for this kind of event is that we can
get an early indication about TIPC link loss issue due to timeout, then
can do some necessary actions for troubleshooting.
For example: To trigger the 'tipc_proto_rcv' when the 'too_silent'
event occurs:
echo 'enable_event:tipc:tipc_proto_rcv' > \
events/tipc/tipc_link_too_silent/trigger
And disable it when TIPC link is reset:
echo 'disable_event:tipc:tipc_proto_rcv' > \
events/tipc/tipc_link_reset/trigger
b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to
trace TIPC retransmission issues.
In addition, the commit adds the 'trace_tipc_list/link_dump()' at the
'retransmission failure' case. Then, if the issue occurs, the link
'transmq' along with the link data can be dumped for post-analysis.
These dump events should be enabled by default since it will only take
effect when the failure happens.
The same approach is also applied for the faulty case that the
validation of protocol message is failed.
Acked-by: Ying Xue <ying.xue@windriver.com>
Tested-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>
As for the sake of debugging/tracing, the commit enables tracepoints in
TIPC along with some general trace_events as shown below. It also
defines some 'tipc_*_dump()' functions that allow to dump TIPC object
data whenever needed, that is, for general debug purposes, ie. not just
for the trace_events.
The following trace_events are now available:
- trace_tipc_skb_dump(): allows to trace and dump TIPC msg & skb data,
e.g. message type, user, droppable, skb truesize, cloned skb, etc.
- trace_tipc_list_dump(): allows to trace and dump any TIPC buffers or
queues, e.g. TIPC link transmq, socket receive queue, etc.
- trace_tipc_sk_dump(): allows to trace and dump TIPC socket data, e.g.
sk state, sk type, connection type, rmem_alloc, socket queues, etc.
- trace_tipc_link_dump(): allows to trace and dump TIPC link data, e.g.
link state, silent_intv_cnt, gap, bc_gap, link queues, etc.
- trace_tipc_node_dump(): allows to trace and dump TIPC node data, e.g.
node state, active links, capabilities, link entries, etc.
How to use:
Put the trace functions at any places where we want to dump TIPC data
or events.
Note:
a) The dump functions will generate raw data only, that is, to offload
the trace event's processing, it can require a tool or script to parse
the data but this should be simple.
b) The trace_tipc_*_dump() should be reserved for a failure cases only
(e.g. the retransmission failure case) or where we do not expect to
happen too often, then we can consider enabling these events by default
since they will almost not take any effects under normal conditions,
but once the rare condition or failure occurs, we get the dumped data
fully for post-analysis.
For other trace purposes, we can reuse these trace classes as template
but different events.
c) A trace_event is only effective when we enable it. To enable the
TIPC trace_events, echo 1 to 'enable' files in the events/tipc/
directory in the 'debugfs' file system. Normally, they are located at:
/sys/kernel/debug/tracing/events/tipc/
For example:
To enable the tipc_link_dump event:
echo 1 > /sys/kernel/debug/tracing/events/tipc/tipc_link_dump/enable
To enable all the TIPC trace_events:
echo 1 > /sys/kernel/debug/tracing/events/tipc/enable
To collect the trace data:
cat trace
or
cat trace_pipe > /trace.out &
To disable all the TIPC trace_events:
echo 0 > /sys/kernel/debug/tracing/events/tipc/enable
To clear the trace buffer:
echo > trace
d) Like the other trace_events, the feature like 'filter' or 'trigger'
is also usable for the tipc trace_events.
For more details, have a look at:
Documentation/trace/ftrace.txt
MAINTAINERS | add two new files 'trace.h' & 'trace.c' in tipc
Acked-by: Ying Xue <ying.xue@windriver.com>
Tested-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>
NAME_DISTRIBUTOR messages are transmitted through unicast link on TIPC
2.0, by contrast, the messages are delivered through broadcast link on
TIPC 1.7. But at present, NAME_DISTRIBUTOR messages received by
broadcast link cannot be handled in tipc_rcv() until an unicast message
arrives, which may lead to a significant delay to update name table.
To avoid this delay, we will also deal with broadcast NAME_DISTRIBUTOR
message on broadcast receive path.
Signed-off-by: Zhenbo Gao <zhenbo.gao@windriver.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When setting LINK tolerance, node timer interval will be calculated
base on the LINK with lowest tolerance.
But when calculated, the old node timer interval only updated if current
setting value (tolerance/4) less than old ones regardless of number of
links as well as links' lowest tolerance value.
This caused to two cases missing if tolerance changed as following:
Case 1:
1.1/ There is one link (L1) available in the system
1.2/ Set L1's tolerance from 1500ms => lower (i.e 500ms)
1.3/ Then, fallback to default (1500ms) or higher (i.e 2000ms)
Expected:
node timer interval is 1500/4=375ms after 1.3
Result:
node timer interval will not being updated after changing tolerance at 1.3
since its value 1500/4=375ms is not less than 500/4=125ms at 1.2.
Case 2:
2.1/ There are two links (L1, L2) available in the system
2.2/ L1 and L2 tolerance value are 2000ms as initial
2.3/ Set L2's tolerance from 2000ms => lower 1500ms
2.4/ Disable link L2 (bring down its bearer)
Expected:
node timer interval is 2000ms/4=500ms after 2.4
Result:
node timer interval will not being updated after disabling L2 since
its value 2000ms/4=500ms is still not less than 1500/4=375ms at 2.3
although L2 is already not available in the system.
To fix this, we start the node interval calculation by initializing it to
a value larger than any conceivable calculated value. This way, the link
with the lowest tolerance will always determine the calculated value.
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
We see the following lockdep warning:
[ 2284.078521] ======================================================
[ 2284.078604] WARNING: possible circular locking dependency detected
[ 2284.078604] 4.19.0+ #42 Tainted: G E
[ 2284.078604] ------------------------------------------------------
[ 2284.078604] rmmod/254 is trying to acquire lock:
[ 2284.078604] 00000000acd94e28 ((&n->timer)#2){+.-.}, at: del_timer_sync+0x5/0xa0
[ 2284.078604]
[ 2284.078604] but task is already holding lock:
[ 2284.078604] 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x190 [tipc]
[ 2284.078604]
[ 2284.078604] which lock already depends on the new lock.
[ 2284.078604]
[ 2284.078604]
[ 2284.078604] the existing dependency chain (in reverse order) is:
[ 2284.078604]
[ 2284.078604] -> #1 (&(&tn->node_list_lock)->rlock){+.-.}:
[ 2284.078604] tipc_node_timeout+0x20a/0x330 [tipc]
[ 2284.078604] call_timer_fn+0xa1/0x280
[ 2284.078604] run_timer_softirq+0x1f2/0x4d0
[ 2284.078604] __do_softirq+0xfc/0x413
[ 2284.078604] irq_exit+0xb5/0xc0
[ 2284.078604] smp_apic_timer_interrupt+0xac/0x210
[ 2284.078604] apic_timer_interrupt+0xf/0x20
[ 2284.078604] default_idle+0x1c/0x140
[ 2284.078604] do_idle+0x1bc/0x280
[ 2284.078604] cpu_startup_entry+0x19/0x20
[ 2284.078604] start_secondary+0x187/0x1c0
[ 2284.078604] secondary_startup_64+0xa4/0xb0
[ 2284.078604]
[ 2284.078604] -> #0 ((&n->timer)#2){+.-.}:
[ 2284.078604] del_timer_sync+0x34/0xa0
[ 2284.078604] tipc_node_delete+0x1a/0x40 [tipc]
[ 2284.078604] tipc_node_stop+0xcb/0x190 [tipc]
[ 2284.078604] tipc_net_stop+0x154/0x170 [tipc]
[ 2284.078604] tipc_exit_net+0x16/0x30 [tipc]
[ 2284.078604] ops_exit_list.isra.8+0x36/0x70
[ 2284.078604] unregister_pernet_operations+0x87/0xd0
[ 2284.078604] unregister_pernet_subsys+0x1d/0x30
[ 2284.078604] tipc_exit+0x11/0x6f2 [tipc]
[ 2284.078604] __x64_sys_delete_module+0x1df/0x240
[ 2284.078604] do_syscall_64+0x66/0x460
[ 2284.078604] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 2284.078604]
[ 2284.078604] other info that might help us debug this:
[ 2284.078604]
[ 2284.078604] Possible unsafe locking scenario:
[ 2284.078604]
[ 2284.078604] CPU0 CPU1
[ 2284.078604] ---- ----
[ 2284.078604] lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604] lock((&n->timer)#2);
[ 2284.078604] lock(&(&tn->node_list_lock)->rlock);
[ 2284.078604] lock((&n->timer)#2);
[ 2284.078604]
[ 2284.078604] *** DEADLOCK ***
[ 2284.078604]
[ 2284.078604] 3 locks held by rmmod/254:
[ 2284.078604] #0: 000000003368be9b (pernet_ops_rwsem){+.+.}, at: unregister_pernet_subsys+0x15/0x30
[ 2284.078604] #1: 0000000046ed9c86 (rtnl_mutex){+.+.}, at: tipc_net_stop+0x144/0x170 [tipc]
[ 2284.078604] #2: 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x19
[...}
The reason is that the node timer handler sometimes needs to delete a
node which has been disconnected for too long. To do this, it grabs
the lock 'node_list_lock', which may at the same time be held by the
generic node cleanup function, tipc_node_stop(), during module removal.
Since the latter is calling del_timer_sync() inside the same lock, we
have a potential deadlock.
We fix this letting the timer cleanup function use spin_trylock()
instead of just spin_lock(), and when it fails to grab the lock it
just returns so that the timer handler can terminate its execution.
This is safe to do, since tipc_node_stop() anyway is about to
delete both the timer and the node instance.
Fixes: 6a939f365b ("tipc: Auto removal of peer down node instance")
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>
The initial session number when a link is created is based on a random
value, taken from struct tipc_net->random. It is then incremented for
each link reset to avoid mixing protocol messages from different link
sessions.
However, when a bearer is reset all its links are deleted, and will
later be re-created using the same random value as the first time.
This means that if the link never went down between creation and
deletion we will still sometimes have two subsequent sessions with
the same session number. In virtual environments with potentially
long transmission times this has turned out to be a real problem.
We now fix this by randomizing the session number each time a link
is created.
With a session number size of 16 bits this gives a risk of session
collision of 1/64k. To reduce this further, we also introduce a sanity
check on the very first STATE message arriving at a link. If this has
an acknowledge value differing from 0, which is logically impossible,
we ignore the message. The final risk for session collision is hence
reduced to 1/4G, which should be sufficient.
Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We see the following scenario:
1) Link endpoint B on node 1 discovers that its peer endpoint is gone.
Since there is a second working link, failover procedure is started.
2) Link endpoint A on node 1 sends a FAILOVER message to peer endpoint
A on node 2. The node item 1->2 goes to state FAILINGOVER.
3) Linke endpoint A/2 receives the failover, and is supposed to take
down its parallell link endpoint B/2, while producing a FAILOVER
message to send back to A/1.
4) However, B/2 has already been deleted, so no FAILOVER message can
created.
5) Node 1->2 remains in state FAILINGOVER forever, refusing to receive
any messages that can bring B/1 up again. We are left with a non-
redundant link between node 1 and 2.
We fix this with letting endpoint A/2 build a dummy FAILOVER message
to send to back to A/1, so that the situation can be resolved.
Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit referred to below introduced an update of the link
capabilities field that is not safe. Given the recently added
feature to remove idle node and link items after 5 minutes, there
is a small risk that the update will happen at the very moment the
targeted link is being removed. To avoid this we have to perform
the update inside the node item's write lock protection.
Fixes: 9012de5089 ("tipc: add sequence number check for link STATE messages")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In some virtual environments we observe a significant higher number of
packet reordering and delays than we have been used to traditionally.
This makes it necessary with stricter checks on incoming link protocol
messages' session number, which until now only has been validated for
RESET messages.
Since the other two message types, ACTIVATE and STATE messages also
carry this number, it is easy to extend the validation check to those
messages.
We also introduce a flag indicating if a link has a valid peer session
number or not. This eliminates the mixing of 32- and 16-bit arithmethics
we are currently using to achieve this.
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>
Some switch infrastructures produce huge amounts of packet duplicates.
This becomes a problem if those messages are STATE/NACK protocol
messages, causing unnecessary retransmissions of already accepted
packets.
We now introduce a unique sequence number per STATE protocol message
so that duplicates can be identified and ignored. This will also be
useful when tracing such cases, and to avert replay attacks when TIPC
is encrypted.
For compatibility reasons we have to introduce a new capability flag
TIPC_LINK_PROTO_SEQNO to handle this new feature.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function for checking if there is an node address conflict is
supposed to return a suggestion for a new address if it finds a
conflict, and zero otherwise. But in case the peer being checked
is previously unknown it does instead return a "suggestion" for
the checked address itself. This results in a DSC_TRIAL_FAIL_MSG
being sent unecessarily to the peer, and sometimes makes the trial
period starting over again.
Fixes: 25b0b9c4e8 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A peer node is considered down if there are no
active links (or) lost contact to the node. In current implementation,
a peer node instance is deleted either if
a) TIPC module is removed (or)
b) Application can use a netlink/iproute2 interface to delete a
specific down node.
Thus, a down node instance lives in the system forever, unless the
application explicitly removes it.
We fix this by deleting the nodes which are down for
a specified amount of time (5 minutes).
Existing node supervision timer is used to achieve this.
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tuong Lien