summaryrefslogtreecommitdiff
path: root/net/tipc/node.c
AgeCommit message (Collapse)Author
2018-03-23tipc: handle collisions of 32-bit node address hash valuesJon Maloy
When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23tipc: add 128-bit node identifierJon Maloy
We add a 128-bit node identity, as an alternative to the currently used 32-bit node address. For the sake of compatibility and to minimize message header changes we retain the existing 32-bit address field. When not set explicitly by the user, this field will be filled with a hash value generated from the much longer node identity, and be used as a shorthand value for the latter. We permit either the address or the identity to be set by configuration, but not both, so when the address value is set by a legacy user the corresponding 128-bit node identity is generated based on the that value. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23tipc: remove restrictions on node address valuesJon Maloy
Nominally, TIPC organizes network nodes into a three-level network hierarchy consisting of the levels 'zone', 'cluster' and 'node'. This hierarchy is reflected in the node address format, - it is sub-divided into an 8-bit zone id, and 12 bit cluster id, and a 12-bit node id. However, the 'zone' and 'cluster' levels have in reality never been fully implemented,and never will be. The result of this has been that the first 20 bits the node identity structure have been wasted, and the usable node identity range within a cluster has been limited to 12 bits. This is starting to become a problem. In the following commits, we will need to be able to connect between nodes which are using the whole 32-bit value space of the node address. We therefore remove the restrictions on which values can be assigned to node identity, -it is from now on only a 32-bit integer with no assumed internal structure. Isolation between clusters is now achieved only by setting different values for the 'network id' field used during neighbor discovery, in practice leading to the latter becoming the new cluster identity. The rules for accepting discovery requests/responses from neighboring nodes now become: - If the user is using legacy address format on both peers, reception of discovery messages is subject to the legacy lookup domain check in addition to the cluster id check. - Otherwise, the discovery request/response is always accepted, provided both peers have the same network id. This secures backwards compatibility for users who have been using zone or cluster identities as cluster separators, instead of the intended 'network id'. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-14tipc: apply bearer link tolerance on running linksJon Maloy
Currently, the default link tolerance set in struct tipc_bearer only has effect on links going up after that moment. I.e., a user has to reset all the node's links across that bearer to have the new value applied. This is too limiting and disturbing on a running cluster to be useful. We now change this so that also already existing links are updated dynamically, without any need for a reset, when the bearer value is changed. We leverage the already existing per-link functionality for this to achieve the wanted effect. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-15tipc: fix a memory leak in tipc_nl_node_get_link()Cong Wang
When tipc_node_find_by_name() fails, the nlmsg is not freed. While on it, switch to a goto label to properly free it. Fixes: be9c086715c ("tipc: narrow down exposure of struct tipc_node") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-16tipc: enforce valid ratio between skb truesize and contentsJon Maloy
The socket level flow control is based on the assumption that incoming buffers meet the condition (skb->truesize / roundup(skb->len) <= 4), where the latter value is rounded off upwards to the nearest 1k number. This does empirically hold true for the device drivers we know, but we cannot trust that it will always be so, e.g., in a system with jumbo frames and very small packets. We now introduce a check for this condition at packet arrival, and if we find it to be false, we copy the packet to a new, smaller buffer, where the condition will be true. We expect this to affect only a small fraction of all incoming packets, if at all. 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>
2017-11-01net: tipc: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: tipc-discussion@lists.sourceforge.net Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13tipc: add new function for sending multiple small messagesJon Maloy
We see an increasing need to send multiple single-buffer messages of TIPC_SYSTEM_IMPORTANCE to different individual destination nodes. Instead of looping over the send queue and sending each buffer individually, as we do now, we add a new help function tipc_node_distr_xmit() to do this. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13tipc: add ability to obtain node availability status from other filesJon Maloy
In the coming commits, functions at the socket level will need the ability to read the availability status of a given node. We therefore introduce a new function for this purpose, while renaming the existing static function currently having the wanted name. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24tipc: context imbalance at node read unlockParthasarathy Bhuvaragan
If we fail to find a valid bearer in tipc_node_get_linkname(), node_read_unlock() is called without holding the node read lock. This commit fixes this error. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24tipc: perform skb_linearize() before parsing the inner headerParthasarathy Bhuvaragan
In tipc_rcv(), we linearize only the header and usually the packets are consumed as the nodes permit direct reception. However, if the skb contains tunnelled message due to fail over or synchronization we parse it in tipc_node_check_state() without performing linearization. This will cause link disturbances if the skb was non linear. In this commit, we perform linearization for the above messages. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21tipc: don't reset stale broadcast send linkJon Paul Maloy
When the broadcast send link after 100 attempts has failed to transfer a packet to all peers, we consider it stale, and reset it. Thereafter it needs to re-synchronize with the peers, something currently done by just resetting and re-establishing all links to all peers. This has turned out to be overkill, with potentially unwanted consequences for the remaining cluster. A closer analysis reveals that this can be done much simpler. When this kind of failure happens, for reasons that may lie outside the TIPC protocol, it is typically only one peer which is failing to receive and acknowledge packets. It is hence sufficient to identify and reset the links only to that peer to resolve the situation, without having to reset the broadcast link at all. This solution entails a much lower risk of negative consequences for the own node as well as for the overall cluster. We implement this change in this commit. Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.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>
2017-08-09tipc: remove premature ESTABLISH FSM event at link synchronizationJon Paul Maloy
When a link between two nodes come up, both endpoints will initially send out a STATE message to the peer, to increase the probability that the peer endpoint also is up when the first traffic message arrives. Thereafter, if the establishing link is the second link between two nodes, this first "traffic" message is a TUNNEL_PROTOCOL/SYNCH message, helping the peer to perform initial synchronization between the two links. However, the initial STATE message may be lost, in which case the SYNCH message will be the first one arriving at the peer. This should also work, as the SYNCH message itself will be used to take up the link endpoint before initializing synchronization. Unfortunately the code for this case is broken. Currently, the link is brought up through a tipc_link_fsm_evt(ESTABLISHED) when a SYNCH arrives, whereupon __tipc_node_link_up() is called to distribute the link slots and take the link into traffic. But, __tipc_node_link_up() is itself starting with a test for whether the link is up, and if true, returns without action. Clearly, the tipc_link_fsm_evt(ESTABLISHED) call is unnecessary, since tipc_node_link_up() is itself issuing such an event, but also harmful, since it inhibits tipc_node_link_up() to perform the test of its tasks, and the link endpoint in question hence is never taken into traffic. This problem has been exposed when we set up dual links between pre- and post-4.4 kernels, because the former ones don't send out the initial STATE message described above. We fix this by removing the unnecessary event call. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24tipc: check return value of nlmsg_newPan Bian
Function nlmsg_new() will return a NULL pointer if there is no enough memory, and its return value should be checked before it is used. However, in function tipc_nl_node_get_monitor(), the validation of the return value of function nlmsg_new() is missed. This patch fixes the bug. Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct where availableJohannes Berg
This is an add-on to the previous patch that passes the extended ACK structure where it's already available by existing genl_info or extack function arguments. This was done with this spatch (with some manual adjustment of indentation): @@ expression A, B, C, D, E; identifier fn, info; @@ fn(..., struct genl_info *info, ...) { ... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, info->extack) ... } @@ expression A, B, C, D, E; identifier fn, info; @@ fn(..., struct genl_info *info, ...) { <... -nla_parse_nested(A, B, C, D, NULL) +nla_parse_nested(A, B, C, D, info->extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_parse(A, B, C, D, E, NULL) +nla_parse(A, B, C, D, E, extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { ... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, extack) ... } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_parse_nested(A, B, C, D, NULL) +nla_parse_nested(A, B, C, D, extack) ...> } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nlmsg_validate(A, B, C, D, NULL) +nlmsg_validate(A, B, C, D, extack) ...> } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_validate(A, B, C, D, NULL) +nla_validate(A, B, C, D, extack) ...> } @@ expression A, B, C; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_validate_nested(A, B, C, NULL) +nla_validate_nested(A, B, C, extack) ...> } Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-24tipc: move premature initilalization of stack variablesJon Paul Maloy
In the function tipc_rcv() we initialize a couple of stack variables from the message header before that same header has been validated. In rare cases when the arriving header is non-linar, the validation function itself may linearize the buffer by calling skb_may_pull(), while the wrongly initialized stack fields are not updated accordingly. We fix this in this commit. Reported-by: Matthew Wong <mwong@sonusnet.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two trivial overlapping changes conflicts in MPLS and mlx5. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24tipc: fix nametbl_lock soft lockup at node/link eventsParthasarathy Bhuvaragan
We trigger a soft lockup as we grab nametbl_lock twice if the node has a pending node up/down or link up/down event while: - we process an incoming named message in tipc_named_rcv() and perform an tipc_update_nametbl(). - we have pending backlog items in the name distributor queue during a nametable update using tipc_nametbl_publish() or tipc_nametbl_withdraw(). The following are the call chain associated: tipc_named_rcv() Grabs nametbl_lock tipc_update_nametbl() (publish/withdraw) tipc_node_subscribe()/unsubscribe() tipc_node_write_unlock() << lockup occurs if an outstanding node/link event exits, as we grabs nametbl_lock again >> tipc_nametbl_withdraw() Grab nametbl_lock tipc_named_process_backlog() tipc_update_nametbl() << rest as above >> The function tipc_node_write_unlock(), in addition to releasing the lock processes the outstanding node/link up/down events. To do this, we need to grab the nametbl_lock again leading to the lockup. In this commit we fix the soft lockup by introducing a fast variant of node_unlock(), where we just release the lock. We adapt the node_subscribe()/node_unsubscribe() to use the fast variants. Reported-and-Tested-by: John Thompson <thompa.atl@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-20tipc: introduce replicast as transport option for multicastJon Paul Maloy
TIPC multicast messages are currently carried over a reliable 'broadcast link', making use of the underlying media's ability to transport packets as L2 broadcast or IP multicast to all nodes in the cluster. When the used bearer is lacking that ability, we can instead emulate the broadcast service by replicating and sending the packets over as many unicast links as needed to reach all identified destinations. We now introduce a new TIPC link-level 'replicast' service that does this. Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.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>
2017-01-03tipc: reduce risk of user starvation during link congestionJon Paul Maloy
The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29tipc: fix broadcast link synchronization problemJon Paul Maloy
In commit 2d18ac4ba745 ("tipc: extend broadcast link initialization criteria") we tried to fix a problem with the initial synchronization of broadcast link acknowledge values. Unfortunately that solution is not sufficient to solve the issue. We have seen it happen that LINK_PROTOCOL/STATE packets with a valid non-zero unicast acknowledge number may bypass BCAST_PROTOCOL initialization, NAME_DISTRIBUTOR and other STATE packets with invalid broadcast acknowledge numbers, leading to premature opening of the broadcast link. When the bypassed packets finally arrive, they are inadvertently accepted, and the already correctly initialized acknowledge number in the broadcast receive link is overwritten by the invalid (zero) value of the said packets. After this the broadcast link goes stale. We now fix this by marking the packets where we know the acknowledge value is or may be invalid, and then ignoring the acks from those. To this purpose, we claim an unused bit in the header to indicate that the value is invalid. We set the bit to 1 in the initial BCAST_PROTOCOL synchronization packet and all initial ("bulk") NAME_DISTRIBUTOR packets, plus those LINK_PROTOCOL packets sent out before the broadcast links are fully synchronized. This minor protocol update is fully backwards compatible. Reported-by: John Thompson <thompa.atl@gmail.com> Tested-by: John Thompson <thompa.atl@gmail.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-02tipc: transfer broadcast nacks in link state messagesJon Paul Maloy
When we send broadcasts in clusters of more 70-80 nodes, we sometimes see the broadcast link resetting because of an excessive number of retransmissions. This is caused by a combination of two factors: 1) A 'NACK crunch", where loss of broadcast packets is discovered and NACK'ed by several nodes simultaneously, leading to multiple redundant broadcast retransmissions. 2) The fact that the NACKS as such also are sent as broadcast, leading to excessive load and packet loss on the transmitting switch/bridge. This commit deals with the latter problem, by moving sending of broadcast nacks from the dedicated BCAST_PROTOCOL/NACK message type to regular unicast LINK_PROTOCOL/STATE messages. We allocate 10 unused bits in word 8 of the said message for this purpose, and introduce a new capability bit, TIPC_BCAST_STATE_NACK in order to keep the change backwards compatible. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-18tipc: add peer removal functionalityRichard Alpe
Add TIPC_NL_PEER_REMOVE netlink command. This command can remove an offline peer node from the internal data structures. This will be supported by the tipc user space tool in iproute2. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26tipc: dump monitor attributesParthasarathy Bhuvaragan
In this commit, we dump the monitor attributes when queried. The link monitor attributes are separated into two kinds: 1. general attributes per bearer 2. specific attributes per node/peer This style resembles the socket attributes and the nametable publications per socket. Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26tipc: get monitor threshold for the clusterParthasarathy Bhuvaragan
In this commit, we add support to fetch the configured cluster monitoring threshold. Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-26tipc: make cluster size threshold for monitoring configurableParthasarathy Bhuvaragan
In this commit, we introduce support to configure the minimum threshold to activate the new link monitoring algorithm. Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Just several instances of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11tipc: reset all unicast links when broadcast send link failsJon Paul Maloy
In test situations with many nodes and a heavily stressed system we have observed that the transmission broadcast link may fail due to an excessive number of retransmissions of the same packet. In such situations we need to reset all unicast links to all peers, in order to reset and re-synchronize the broadcast link. In this commit, we add a new function tipc_bearer_reset_all() to be used in such situations. The function scans across all bearers and resets all their pertaining links. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-15tipc: add neighbor monitoring frameworkJon Paul Maloy
TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08tipc: change node timer unit from jiffies to msJon Paul Maloy
The node keepalive interval is recalculated at each timer expiration to catch any changes in the link tolerance, and stored in a field in struct tipc_node. We use jiffies as unit for the stored value. This is suboptimal, because it makes the calculation unnecessary complex, including two unit conversions. The conversions also lead to a rounding error that causes the link "abort limit" to be 3 in the normal case, instead of 4, as intended. This again leads to unnecessary link resets when the network is pushed close to its limit, e.g., in an environment with hundreds of nodes or namesapces. In this commit, we do instead let the keepalive value be calculated and stored in milliseconds, so that there is only one conversion and the rounding error is eliminated. We also remove a redundant "keepalive" field in struct tipc_link. This is remnant from the previous implementation. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-08tipc: correct error in node fsmJon Paul Maloy
commit 88e8ac7000dc ("tipc: reduce transmission rate of reset messages when link is down") revealed a flaw in the node FSM, as defined in the log of commit 66996b6c47ed ("tipc: extend node FSM"). We see the following scenario: 1: Node B receives a RESET message from node A before its link endpoint is fully up, i.e., the node FSM is in state SELF_UP_PEER_COMING. This event will not change the node FSM state, but the (distinct) link FSM will move to state RESETTING. 2: As an effect of the previous event, the local endpoint on B will declare node A lost, and post the event SELF_DOWN to the its node FSM. This moves the FSM state to SELF_DOWN_PEER_LEAVING, meaning that no messages will be accepted from A until it receives another RESET message that confirms that A's endpoint has been reset. This is wasteful, since we know this as a fact already from the first received RESET, but worse is that the link instance's FSM has not wasted this information, but instead moved on to state ESTABLISHING, meaning that it repeatedly sends out ACTIVATE messages to the reset peer A. 3: Node A will receive one of the ACTIVATE messages, move its link FSM to state ESTABLISHED, and start repeatedly sending out STATE messages to node B. 4: Node B will consistently drop these messages, since it can only accept accept a RESET according to its node FSM. 5: After four lost STATE messages node A will reset its link and start repeatedly sending out RESET messages to B. 6: Because of the reduced send rate for RESET messages, it is very likely that A will receive an ACTIVATE (which is sent out at a much higher frequency) before it gets the chance to send a RESET, and A may hence quickly move back to state ESTABLISHED and continue sending out STATE messages, which will again be dropped by B. 7: GOTO 5. 8: After having repeated the cycle 5-7 a number of times, node A will by chance get in between with sending a RESET, and the situation is resolved. Unfortunately, we have seen that it may take a substantial amount of time before this vicious loop is broken, sometimes in the order of minutes. We correct this by making a small correction to the node FSM: When a node in state SELF_UP_PEER_COMING receives a SELF_DOWN event, it now moves directly back to state SELF_DOWN_PEER_DOWN, instead of as now SELF_DOWN_PEER_LEAVING. This is logically consistent, since we don't need to wait for RESET confirmation from of an endpoint that we alread know has been reset. It also means that node B in the scenario above will not be dropping incoming STATE messages, and the link can come up immediately. Finally, a symmetry comparison reveals that the FSM has a similar error when receiving the event PEER_DOWN in state PEER_UP_SELF_COMING. Instead of moving to PERR_DOWN_SELF_LEAVING, it should move directly to SELF_DOWN_PEER_DOWN. Although we have never seen any negative effect of this logical error, we choose fix this one, too. The node FSM looks as follows after those changes: +----------------------------------------+ | PEER_DOWN_EVT| | | +------------------------+----------------+ | |SELF_DOWN_EVT | | | | | | | | +-----------+ +-----------+ | | |NODE_ | |NODE_ | | | +----------|FAILINGOVER|<---------|SYNCHING |-----------+ | | |SELF_ +-----------+ FAILOVER_+-----------+ PEER_ | | | |DOWN_EVT | A BEGIN_EVT A | DOWN_EVT| | | | | | | | | | | | | | | | | | | | |FAILOVER_ |FAILOVER_ |SYNCH_ |SYNCH_ | | | | |END_EVT |BEGIN_EVT |BEGIN_EVT|END_EVT | | | | | | | | | | | | | | | | | | | | | +--------------+ | | | | | +-------->| SELF_UP_ |<-------+ | | | | +-----------------| PEER_UP |----------------+ | | | | |SELF_DOWN_EVT +--------------+ PEER_DOWN_EVT| | | | | | A A | | | | | | | | | | | | | | PEER_UP_EVT| |SELF_UP_EVT | | | | | | | | | | | V V V | | V V V +------------+ +-----------+ +-----------+ +------------+ |SELF_DOWN_ | |SELF_UP_ | |PEER_UP_ | |PEER_DOWN | |PEER_LEAVING| |PEER_COMING| |SELF_COMING| |SELF_LEAVING| +------------+ +-----------+ +-----------+ +------------+ | | A A | | | | | | | | | SELF_ | |SELF_ |PEER_ |PEER_ | | DOWN_EVT| |UP_EVT |UP_EVT |DOWN_EVT | | | | | | | | | | | | | | | +--------------+ | | |PEER_DOWN_EVT +--->| SELF_DOWN_ |<---+ SELF_DOWN_EVT| +------------------->| PEER_DOWN |<--------------------+ +--------------+ Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-12tipc: eliminate risk of double link_up eventsJon Paul Maloy
When an ACTIVATE or data packet is received in a link in state ESTABLISHING, the link does not immediately change state to ESTABLISHED, but does instead return a LINK_UP event to the caller, which will execute the state change in a different lock context. This non-atomic approach incurs a low risk that we may have two LINK_UP events pending simultaneously for the same link, resulting in the final part of the setup procedure being executed twice. The only potential harm caused by this it that we may see two LINK_UP events issued to subsribers of the topology server, something that may cause confusion. This commit eliminates this risk by checking if the link is already up before proceeding with the second half of the setup. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/ipv4/ip_gre.c Minor conflicts between tunnel bug fixes in net and ipv6 tunnel cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03tipc: propagate peer node capabilities to socket layerJon Paul Maloy
During neighbor discovery, nodes advertise their capabilities as a bit map in a dedicated 16-bit field in the discovery message header. This bit map has so far only be stored in the node structure on the peer nodes, but we now see the need to keep a copy even in the socket structure. This commit adds this functionality. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-01tipc: only process unicast on intended nodeHamish Martin
We have observed complete lock up of broadcast-link transmission due to unacknowledged packets never being removed from the 'transmq' queue. This is traced to nodes having their ack field set beyond the sequence number of packets that have actually been transmitted to them. Consider an example where node 1 has sent 10 packets to node 2 on a link and node 3 has sent 20 packets to node 2 on another link. We see examples of an ack from node 2 destined for node 3 being treated as an ack from node 2 at node 1. This leads to the ack on the node 1 to node 2 link being increased to 20 even though we have only sent 10 packets. When node 1 does get around to sending further packets, none of the packets with sequence numbers less than 21 are actually removed from the transmq. To resolve this we reinstate some code lost in commit d999297c3dbb ("tipc: reduce locking scope during packet reception") which ensures that only messages destined for the receiving node are processed by that node. This prevents the sequence numbers from getting out of sync and resolves the packet leakage, thereby resolving the broadcast-link transmission lock-ups we observed. While we are aware that this change only patches over a root problem that we still haven't identified, this is a sanity test that it is always legitimate to do. It will remain in the code even after we identify and fix the real problem. Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: John Thompson <john.thompson@alliedtelesis.co.nz> Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-01tipc: set 'active' state correctly for first established linkJon Paul Maloy
When we are displaying statistics for the first link established between two peers, it will always be presented as STANDBY although it in reality is ACTIVE. This happens because we forget to set the 'active' flag in the link instance at the moment it is established. Although this is a bug, it only has impact on the presentation view of the link, not on its actual functionality. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15tipc: let first message on link be a state messageJon Paul Maloy
According to the link FSM, a received traffic packet can take a link from state ESTABLISHING to ESTABLISHED, but the link can still not be fully set up in one atomic operation. This means that even if the the very first packet on the link is a traffic packet with sequence number 1 (one), it has to be dropped and retransmitted. This can be avoided if we let the mentioned packet be preceded by a LINK_PROTOCOL/STATE message, which takes up the endpoint before the arrival of the traffic. We add this small feature in this commit. This is a fully compatible change. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-15tipc: ensure that first packets on link are sent in orderJon Paul Maloy
In some link establishment scenarios we see that packet #2 may be sent out before packet #1, forcing the receiver to demand retransmission of the missing packet. This is harmless, but may cause confusion among people tracing the packet flow. Since this is extremely easy to fix, we do so by adding en extra send call to the bearer immediately after the link has come up. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-07tipc: move netlink policies to netlink.cRichard Alpe
Make the c files less cluttered and enable netlink attributes to be shared between files. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06tipc: don't check link reset on non existing linkRichard Alpe
Make sure we have a link before checking if it has been reset or not. Prior to this patch tipc_link_is_reset() could be called with a non existing link, resulting in a null pointer dereference. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-25tipc: fix crash during node removalJon Paul Maloy
When the TIPC module is unloaded, we have identified a race condition that allows a node reference counter to go to zero and the node instance being freed before the node timer is finished with accessing it. This leads to occasional crashes, especially in multi-namespace environments. The scenario goes as follows: CPU0:(node_stop) CPU1:(node_timeout) // ref == 2 1: if(!mod_timer()) 2: if (del_timer()) 3: tipc_node_put() // ref -> 1 4: tipc_node_put() // ref -> 0 5: kfree_rcu(node); 6: tipc_node_get(node) 7: // BOOM! We now clean up this functionality as follows: 1) We remove the node pointer from the node lookup table before we attempt deactivating the timer. This way, we reduce the risk that tipc_node_find() may obtain a valid pointer to an instance marked for deletion; a harmless but undesirable situation. 2) We use del_timer_sync() instead of del_timer() to safely deactivate the node timer without any risk that it might be reactivated by the timeout handler. There is no risk of deadlock here, since the two functions never touch the same spinlocks. 3: We remove a pointless tipc_node_get() + tipc_node_put() from the timeout handler. Reported-by: Zhijiang Hu <huzhijiang@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-25tipc: eliminate risk of finding to-be-deleted node instanceJon Paul Maloy
Although we have never seen it happen, we have identified the following problematic scenario when nodes are stopped and deleted: CPU0: CPU1: tipc_node_xxx() //ref == 1 tipc_node_put() //ref -> 0 tipc_node_find() // node still in table tipc_node_delete() list_del_rcu(n. list) tipc_node_get() //ref -> 1, bad kfree_rcu() tipc_node_put() //ref to 0 again. kfree_rcu() // BOOM! We fix this by introducing use of the conditional kref_get_if_not_zero() instead of kref_get() in the function tipc_node_find(). This eliminates any risk of post-mortem access. Reported-by: Zhijiang Hu <huzhijiang@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16tipc: refactor node xmit and fix memory leaksRichard Alpe
Refactor tipc_node_xmit() to fail fast and fail early. Fix several potential memory leaks in unexpected error paths. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16tipc: fix premature addition of node to lookup tableJon Paul Maloy
In commit 5266698661401a ("tipc: let broadcast packet reception use new link receive function") we introduced a new per-node broadcast reception link instance. This link is created at the moment the node itself is created. Unfortunately, the allocation is done after the node instance has already been added to the node lookup hash table. This creates a potential race condition, where arriving broadcast packets are able to find and access the node before it has been fully initialized, and before the above mentioned link has been created. The result is occasional crashes in the function tipc_bcast_rcv(), which is trying to access the not-yet existing link. We fix this by deferring the addition of the node instance until after it has been fully initialized in the function tipc_node_create(). Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix link attribute propagation bugRichard Alpe
Changing certain link attributes (link tolerance and link priority) from the TIPC management tool is supposed to automatically take effect at both endpoints of the affected link. Currently the media address is not instantiated for the link and is used uninstantiated when crafting protocol messages designated for the peer endpoint. This means that changing a link property currently results in the property being changed on the local machine but the protocol message designated for the peer gets lost. Resulting in property discrepancy between the endpoints. In this patch we resolve this by using the media address from the link entry and using the bearer transmit function to send it. Hence, we can now eliminate the redundant function tipc_link_prot_xmit() and the redundant field tipc_link::media_addr. Fixes: 2af5ae372a4b (tipc: clean up unused code and structures) Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reported-by: Jason Hu <huzhijiang@gmail.com> Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03tipc: fix node reference count bugJon Paul Maloy
Commit 5405ff6e15f40f2f ("tipc: convert node lock to rwlock") introduced a bug to the node reference counter handling. When a message is successfully sent in the function tipc_node_xmit(), we return directly after releasing the node lock, instead of continuing and decrementing the node reference counter as we should do. This commit fixes this bug. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-20tipc: eliminate remnants of hungarian notationJon Paul Maloy
The number of variables with Hungarian notation (l_ptr, n_ptr etc.) has been significantly reduced over the last couple of years. We now root out the last traces of this practice. There are no functional changes in this commit. Reviewed-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>