user/sven/linux.git/net/tipc/addr.h, branch v4.20

tipc: add 128-bit node identifier

2018-03-23T17:12:18Z

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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: remove direct accesses to own_addr field in struct tipc_net

2018-03-23T17:12:18Z

As a preparation to changing the addressing structure of TIPC we replace all direct accesses to the tipc_net::own_addr field with the function dedicated for this, tipc_own_addr(). There are no changes to program logics in this commit. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: allow closest-first lookup algorithm when legacy address is configured

2018-03-23T17:12:18Z

The removal of an internal structure of the node address has an unwanted side effect. - Currently, if a user is sending an anycast message with destination domain 0, the tipc_namebl_translate() function will use the 'closest- first' algorithm to first look for a node local destination, and only when no such is found, will it resort to the cluster global 'round- robin' lookup algorithm. - Current users can get around this, and enforce unconditional use of global round-robin by indicating a destination as Z.0.0 or Z.C.0. - This option disappears when we make the node address flat, since the lookup algorithm has no way of recognizing this case. So, as long as there are node local destinations, the algorithm will always select one of those, and there is nothing the sender can do to change this. We solve this by eliminating the 'closest-first' option, which was never a good idea anyway, for non-legacy users, but only for those. To distinguish between legacy users and non-legacy users we introduce a new flag 'legacy_addr_format' in struct tipc_core, to be set when the user configures a legacy-style Z.C.N node address. Hence, when a legacy user indicates a zero lookup domain 'closest-first' is selected, and in all other cases we use 'round-robin'. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: remove restrictions on node address values

2018-03-23T17:12:18Z

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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: obsolete TIPC_ZONE_SCOPE

2018-03-17T21:11:46Z

Publications for TIPC_CLUSTER_SCOPE and TIPC_ZONE_SCOPE are in all aspects handled the same way, both on the publishing node and on the receiving nodes. Despite previous ambitions to the contrary, this is never going to change, so we take the conseqeunce of this and obsolete TIPC_ZONE_SCOPE and related macros/functions. Whenever a user is doing a bind() or a sendmsg() attempt using ZONE_SCOPE we translate this internally to CLUSTER_SCOPE, while we remain compatible with users and remote nodes still using ZONE_SCOPE. Furthermore, the non-formalized scope value 0 has always been permitted for use during lookup, with the same meaning as ZONE_SCOPE/CLUSTER_SCOPE. We now permit it even as binding scope, but for compatibility reasons we choose to not change the value of TIPC_CLUSTER_SCOPE. Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: introduce constants for tipc address validation

2016-07-26T21:26:42Z

In this commit, we introduce defines for tipc address size, offset and mask specification for Zone.Cluster.Node. There is no functional change in this commit. Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: add neighbor monitoring framework

2016-06-15T21:06:28Z

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 Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: simplify include dependencies

2015-05-14T16:24:45Z

When we try to add new inline functions in the code, we sometimes run into circular include dependencies. The main problem is that the file core.h, which really should be at the root of the dependency chain, instead is a leaf. I.e., core.h includes a number of header files that themselves should be allowed to include core.h. In reality this is unnecessary, because core.h does not need to know the full signature of any of the structs it refers to, only their type declaration. In this commit, we remove all dependencies from core.h towards any other tipc header file. As a consequence of this change, we can now move the function tipc_own_addr(net) from addr.c to addr.h, and make it inline. There are no functional changes in this commit. Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix two bugs in secondary destination lookup

2015-03-29T20:47:36Z

A message sent to a node after a successful name table lookup may still find that the destination socket has disappeared, because distribution of name table updates is non-atomic. If so, the message will be rejected back to the sender with error code TIPC_ERR_NO_PORT. If the source socket of the message has disappeared in the meantime, the message should be dropped. However, in the currrent code, the message will instead be subject to an unwanted tertiary lookup, because the function tipc_msg_lookup_dest() doesn't check if there is an error code present in the message before performing the lookup. In the worst case, the message may now find the old destination again, and be redirected once more, instead of being dropped directly as it should be. A second bug in this function is that the "prev_node" field in the message is not updated after successful lookup, something that may have unpredictable consequences. The problems arising from those bugs occur very infrequently. The third change in this function; the test on msg_reroute_msg_cnt() is purely cosmetic, reflecting that the returned value never can be negative. This commit corrects the two bugs described above. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: make tipc node address support net namespace

2015-01-12T21:24:33Z

If net namespace is supported in tipc, each namespace will be treated as a separate tipc node. Therefore, every namespace must own its private tipc node address. This means the "tipc_own_addr" global variable of node address must be moved to tipc_net structure to satisfy the requirement. It's turned out that users also can assign node address for every namespace. Signed-off-by: Ying Xue Tested-by: Tero Aho Reviewed-by: Jon Maloy Signed-off-by: David S. Miller