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* tipc: convert legacy nl node dump to nl compatRichard Alpe2015-02-091-2/+0
| | | | | | | | | | | Convert TIPC_CMD_GET_NODES to compat dumpit and remove global node counter solely used by the legacy API. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: convert legacy nl link dump to nl compatRichard Alpe2015-02-091-2/+0
| | | | | | | | | | | Convert TIPC_CMD_GET_LINKS to compat dumpit and remove global link counter solely used by the legacy API. Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: eliminate race condition at multicast receptionJon Paul Maloy2015-02-051-2/+5
| | | | | | | | | | | | | | | | | | | | In a previous commit in this series we resolved a race problem during unicast message reception. Here, we resolve the same problem at multicast reception. We apply the same technique: an input queue serializing the delivery of arriving buffers. The main difference is that here we do it in two steps. First, the broadcast link feeds arriving buffers into the tail of an arrival queue, which head is consumed at the socket level, and where destination lookup is performed. Second, if the lookup is successful, the resulting buffer clones are fed into a second queue, the input queue. This queue is consumed at reception in the socket just like in the unicast case. Both queues are protected by the same lock, -the one of the input queue. 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>
* tipc: resolve race problem at unicast message receptionJon Paul Maloy2015-02-051-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. 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>
* tipc: make tipc node table aware of net namespaceYing Xue2015-01-121-16/+19
| | | | | | | | | | | | | | | | | | | | | | | Global variables associated with node table are below: - node table list (node_htable) - node hash table list (tipc_node_list) - node table lock (node_list_lock) - node number counter (tipc_num_nodes) - node link number counter (tipc_num_links) To make node table support namespace, above global variables must be moved to tipc_net structure in order to keep secret for different namespaces. As a consequence, these variables are allocated and initialized when namespace is created, and deallocated when namespace is destroyed. After the change, functions associated with these variables have to utilize a namespace pointer to access them. So adding namespace pointer as a parameter of these functions is the major change made in the commit. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use generic SKB list APIs to manage deferred queue of linkYing Xue2014-11-261-5/+2
| | | | | | | | | Use standard SKB list APIs associated with struct sk_buff_head to manage link's deferred queue, simplifying relevant code. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove node subscription infrastructureYing Xue2014-11-261-3/+2
| | | | | | | | | | | | | | | The node subscribe infrastructure represents a virtual base class, so its users, such as struct tipc_port and struct publication, can derive its implemented functionalities. However, after the removal of struct tipc_port, struct publication is left as its only single user now. So defining an abstract infrastructure for one user becomes no longer reasonable. If corresponding new functions associated with the infrastructure are moved to name_table.c file, the node subscription infrastructure can be removed as well. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add node get/dump to new netlink apiRichard Alpe2014-11-211-1/+3
| | | | | | | | | | | | | | | | | | Add TIPC_NL_NODE_GET to the new tipc netlink API. This command can dump the address and node status of all nodes in the tipc cluster. Netlink logical layout of returned node/address data: -> node -> address -> up flag Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@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>
* tipc: fix a potential deadlockYing Xue2014-10-211-1/+6
| | | | | | | | | | | | | | | | | | | | | Locking dependency detected below possible unsafe locking scenario: CPU0 CPU1 T0: tipc_named_rcv() tipc_rcv() T1: [grab nametble write lock]* [grab node lock]* T2: tipc_update_nametbl() tipc_node_link_up() T3: tipc_nodesub_subscribe() tipc_nametbl_publish() T4: [grab node lock]* [grab nametble write lock]* The opposite order of holding nametbl write lock and node lock on above two different paths may result in a deadlock. If we move the the updating of the name table after link state named out of node lock, the reverse order of holding locks will be eliminated, and as a result, the deadlock risk. Signed-off-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>
* tipc: fix bug in multicast congestion handlingJon Maloy2014-10-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One aim of commit 50100a5e39461b2a61d6040e73c384766c29975d ("tipc: use pseudo message to wake up sockets after link congestion") was to handle link congestion abatement in a uniform way for both unicast and multicast transmit. However, the latter doesn't work correctly, and has been broken since the referenced commit was applied. If a user now sends a burst of multicast messages that is big enough to cause broadcast link congestion, it will be put to sleep, and not be waked up when the congestion abates as it should be. This has two reasons. First, the flag that is used, TIPC_WAKEUP_USERS, is set correctly, but in the wrong field. Instead of setting it in the 'action_flags' field of the arrival node struct, it is by mistake set in the dummy node struct that is owned by the broadcast link, where it will never tested for. Second, we cannot use the same flag for waking up unicast and multicast users, since the function tipc_node_unlock() needs to pick the wakeup pseudo messages to deliver from different queues. It must hence be able to distinguish between the two cases. This commit solves this problem by adding a new flag TIPC_WAKEUP_BCAST_USERS, and a new function tipc_bclink_wakeup_user(). The latter is to be called by tipc_node_unlock() when the named flag, now set in the correct field, is encountered. v2: using explicit 'unsigned int' declaration instead of 'uint', as per comment from David Miller. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use message to abort connections when losing contact to nodeJon Paul Maloy2014-08-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the current implementation, each 'struct tipc_node' instance keeps a linked list of those ports/sockets that are connected to the node represented by that struct. The purpose of this is to let the node object know which sockets to alert when it loses contact with its peer node, i.e., which sockets need to have their connections aborted. This entails an unwanted direct reference from the node structure back to the port/socket structure, and a need to grab port_lock when we have to make an upcall to the port. We want to get rid of this unecessary BH entry point into the socket, and also eliminate its use of port_lock. In this commit, we instead let the node struct keep list of "connected socket" structs, which each represents a connected socket, but is allocated independently by the node at the moment of connection. If the node loses contact with its peer node, the list is traversed, and a "connection abort" message is created for each entry in the list. The message is sent to it respective connected socket using the ordinary data path, and the receiving socket aborts its connections upon reception of the message. This enables us to get rid of the direct reference from 'struct node' to ´struct port', and another unwanted BH access point to the latter. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use pseudo message to wake up sockets after link congestionJon Paul Maloy2014-08-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current link implementation keeps a linked list of blocked ports/ sockets that is populated when there is link congestion. The purpose of this is to let the link know which users to wake up when the congestion abates. This adds unnecessary complexity to the data structure and the code, since it forces us to involve the link each time we want to delete a socket. It also forces us to grab the spinlock port_lock within the scope of node_lock. We want to get rid of this direct dependence, as well as the deadlock hazard resulting from the usage of port_lock. In this commit, we instead let the link keep list of a "wakeup" pseudo messages for use in such situations. Those messages are sent to the pending sockets via the ordinary message reception path, and wake up the socket's owner when they are received. This enables us to get rid of the 'waiting_ports' linked lists in struct tipc_port that manifest this direct reference. As a consequence, we can eliminate another BH entry into the socket, and hence the need to grab port_lock. This is a further step in our effort to remove port_lock altogether. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: make link mtu easily accessible from socketJon Paul Maloy2014-06-271-0/+17
| | | | | | | | | | | | | | | | | | Message fragmentation is currently performed at link level, inside the protection of node_lock. This potentially binds up the sending link structure for a long time, instead of letting it do other tasks, such as handle reception of new packets. In this commit, we make the MTUs of each active link become easily accessible from the socket level, i.e., without taking any spinlock or dereferencing the target link pointer. This way, we make it possible to perform fragmentation in the sending socket, before sending the whole fragment chain to the link for transport. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename and move message reassembly functionJon Paul Maloy2014-05-141-4/+2
| | | | | | | | | | | | | | | | The function tipc_link_frag_rcv() is in reality a re-entrant generic message reassemby function that has nothing in particular to do with the link, where it is defined now. This becomes obvious when we see the need to call the function from other places in the code. In this commit rename it to tipc_buf_append() and move it to the file msg.c. We also simplify its signature by moving the tail pointer to the control block of the head buffer, hence making the head buffer self-contained. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename enum names of node flagsYing Xue2014-05-091-16/+13
| | | | | | | | | Rename node flags to action_flags as well as its enum names so that they can reflect its real meanings. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: avoid to asynchronously deliver name tables to peer nodeYing Xue2014-05-051-2/+6
| | | | | | | | | | Postpone the actions of delivering name tables until after node lock is released, avoiding to do it under asynchronous context. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove TIPC_NAMES_GONE node flagYing Xue2014-05-051-5/+3
| | | | | | | | | | | | | | Since previously what all publications pertaining to the lost node were removed from name table was finished in tasklet context asynchronously, we need to TIPC_NAMES_GONE flag indicating whether the node cleanup work is finished or not. But now as the cleanup work has been finished when node lock is released, the flag becomes meaningless for us. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: avoid to asynchronously notify subscriptionsYing Xue2014-05-051-8/+7
| | | | | | | | | | | Postpone the actions of notifying subscriptions until after node lock is released, avoiding to asynchronously execute registered handlers when node is lost. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename setup_blocked variable of node struct to flagsYing Xue2014-05-051-6/+18
| | | | | | | | | | | Rename setup_blocked variable of node struct to a more common name called "flags", which will be used to represent kinds of node states. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: adjust order of variables in tipc_node structureYing Xue2014-05-051-29/+34
| | | | | | | | | | Move more frequently used variables up to the head of tipc_node structure, hopefully improving a bit performance. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: add ioctl to fetch link namesErik Hugne2014-04-261-0/+1
| | | | | | | | | | | | | We add a new ioctl for AF_TIPC that can be used to fetch the logical name for a link to a remote node on a given bearer. This should be used in combination with link state subscriptions. The logical name size limit definitions are moved to tipc.h, as they are now also needed by the new ioctl. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: tipc: convert node list and node hlist to RCU listsYing Xue2014-03-271-0/+2
| | | | | | | | | | | Convert tipc_node_list list and node_htable hash list to RCU lists. On read side, the two lists are protected with RCU read lock, and on update side, node_list_lock is applied to them. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename node create lock to protect node list and hlistYing Xue2014-03-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | When a node is created, tipc_net_lock read lock is first held and then node_create_lock is grabbed in order to prevent the same node from being created and inserted into both node list and hlist twice. But when we query node from the two node lists, we only hold tipc_net_lock read lock without grabbing node_create_lock. Obviously this locking policy is unable to guarantee that the two node lists are always synchronized especially when the operation of changing and accessing them occurs in different contexts like currently doing. Therefore, rename node_create_lock to node_list_lock to protect the two node lists, that is, whenever node is inserted into them or node is queried from them, the node_list_lock should be always held. As a result, tipc_net_lock read lock becomes redundant and then can be removed from the node query functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove 'has_redundant_link' flag from STATE link protocol messagesJon Paul Maloy2014-01-071-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The flag 'has_redundant_link' is defined only in RESET and ACTIVATE protocol messages. Due to an ambiguity in the protocol specification it is currently also transferred in STATE messages. Its value is used to initialize a link state variable, 'permit_changeover', which is used to inhibit futile link failover attempts when it is known that the peer node has no working links at the moment, although the local node may still think it has one. The fact that 'has_redundant_link' incorrectly is read from STATE messages has the effect that 'permit_changeover' sometimes gets a wrong value, and permanently blocks any links from being re-established. Such failures can only occur in in dual-link systems, and are extremely rare. This bug seems to have always been present in the code. Furthermore, since commit b4b5610223f17790419b03eaa962b0e3ecf930d7 ("tipc: Ensure both nodes recognize loss of contact between them"), the 'permit_changeover' field serves no purpose any more. The task of enforcing 'lost contact' cycles at both peer endpoints is now taken by a new mechanism, using the flags WAIT_NODE_DOWN and WAIT_PEER_DOWN in struct tipc_node to abort unnecessary failover attempts. We therefore remove the 'has_redundant_link' flag from STATE messages, as well as the now redundant 'permit_changeover' variable. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: remove unused codestephen hemminger2014-01-041-1/+0
| | | | | | | | | | | | Remove dead code; tipc_bearer_find_interface tipc_node_redundant_links This may break out of tree version of TIPC if there still is one. But that maybe a good thing :-) Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: message reassembly using fragment chainErik Hugne2013-11-071-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the first fragment of a long data data message is received on a link, a reassembly buffer large enough to hold the data from this and all subsequent fragments of the message is allocated. The payload of each new fragment is copied into this buffer upon arrival. When the last fragment is received, the reassembled message is delivered upwards to the port/socket layer. Not only is this an inefficient approach, but it may also cause bursts of reassembly failures in low memory situations. since we may fail to allocate the necessary large buffer in the first place. Furthermore, after 100 subsequent such failures the link will be reset, something that in reality aggravates the situation. To remedy this problem, this patch introduces a different approach. Instead of allocating a big reassembly buffer, we now append the arriving fragments to a reassembly chain on the link, and deliver the whole chain up to the socket layer once the last fragment has been received. This is safe because the retransmission layer of a TIPC link always delivers packets in strict uninterrupted order, to the reassembly layer as to all other upper layers. Hence there can never be more than one fragment chain pending reassembly at any given time in a link, and we can trust (but still verify) that the fragments will be chained up in the correct order. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: rename supported flag to recv_permittedYing Xue2012-11-221-2/+2
| | | | | | | | | | | | Rename the "supported" flag in bclink structure to "recv_permitted" to better reflect what it is used for. When this flag is set for a given node, we are permitted to receive and acknowledge broadcast messages from that node. Convert it to a bool at the same time, since it is not used to store any numerical values. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: remove supportable flag from bclink structureYing Xue2012-11-221-2/+0
| | | | | | | | | | | | | | The "supportable" flag in bclink structure is a compatibility flag indicating whether a peer node is capable of receiving TIPC broadcast messages. However, all TIPC versions since tipc-1.5, and after the inclusion in the upstream Linux kernel in 2006, support this capability. It is highly unlikely that anybody is still using such an old version of TIPC, let alone that they want to mix it with TIPC-2.0 nodes. Therefore, we now remove the "supportable" flag. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: compress out gratuitous extra carriage returnsPaul Gortmaker2012-04-301-2/+0
| | | | | | | | | | | | | | | Some of the comment blocks are floating in limbo between two functions, or between blocks of code. Delete the extra line feeds between any comment and its associated following block of code, to be consistent with the majority of the rest of the kernel. Also delete trailing newlines at EOF and fix a couple trivial typos in existing comments. This is a 100% cosmetic change with no runtime impact. We get rid of over 500 lines of non-code, and being blank line deletes, they won't even show up as noise in git blame. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Hide internal details of node table implementationAllan Stephens2012-02-241-12/+0
| | | | | | | | | | | | Relocates information about the size of TIPC's node table index and its associated hash function, since only node subsystem routines need to have access to this information. Note that these changes are essentially cosmetic in nature, and have no impact on the actual operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Introduce node signature field in neighbor discovery messageAllan Stephens2012-02-241-0/+7
| | | | | | | | | | | | | | | | | Adds support for the new "node signature" in neighbor discovery messages, which is a 16 bit identifier chosen randomly when TIPC is initialized. This field makes it possible for nodes receiving a neighbor discovery message to detect if multiple neighboring nodes are using the same network address (i.e. <Z.C.N>), even when the messages are arriving on different interfaces. This first phase of node signature support creates the signature, incorporates it into outgoing neighbor discovery messages, and tracks the signature used by valid neighbors. An upcoming patch builds on this foundation to implement the improved duplicate neighbor detection checking. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Remove obsolete broadcast tag capabilityAllan Stephens2012-02-061-2/+0
| | | | | | | | Eliminates support for the broadcast tag field, which is no longer used by broadcast link NACK messages. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Major redesign of broadcast link ACK/NACK algorithmsAllan Stephens2012-02-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Completely redesigns broadcast link ACK and NACK mechanisms to prevent spurious retransmit requests in dual LAN networks, and to prevent the broadcast link from stalling due to the failure of a receiving node to acknowledge receiving a broadcast message or request its retransmission. Note: These changes only impact the timing of when ACK and NACK messages are sent, and not the basic broadcast link protocol itself, so inter- operability with nodes using the "classic" algorithms is maintained. The revised algorithms are as follows: 1) An explicit ACK message is still sent after receiving 16 in-sequence messages, and implicit ACK information continues to be carried in other unicast link message headers (including link state messages). However, the timing of explicit ACKs is now based on the receiving node's absolute network address rather than its relative network address to ensure that the failure of another node does not delay the ACK beyond its 16 message target. 2) A NACK message is now typically sent only when a message gap persists for two consecutive incoming link state messages; this ensures that a suspected gap is not confirmed until both LANs in a dual LAN network have had an opportunity to deliver the message, thereby preventing spurious NACKs. A NACK message can also be generated by the arrival of a single link state message, if the deferred queue is so big that the current message gap cannot be the result of "normal" mis-ordering due to the use of dual LANs (or one LAN using a bonded interface). Since link state messages typically arrive at different nodes at different times the problem of multiple nodes issuing identical NACKs simultaneously is inherently avoided. 3) Nodes continue to "peek" at NACK messages sent by other nodes. If another node requests retransmission of a message gap suspected (but not yet confirmed) by the peeking node, the peeking node forgets about the gap and does not generate a duplicate retransmit request. (If the peeking node subsequently fails to receive the lost message, later link state messages will cause it to rediscover and confirm the gap and send another NACK.) 4) Message gap "equality" is now determined by the start of the gap only. This is sufficient to deal with the most common cases of message loss, and eliminates the need for complex end of gap computations. 5) A peeking node no longer tries to determine whether it should send a complementary NACK, since the most common cases of message loss don't require it to be sent. Consequently, the node no longer examines the "broadcast tag" field of a NACK message when peeking. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ensure broadcast link re-acquires node after link failureAllan Stephens2012-02-061-1/+3
| | | | | | | | | | | | | | | | | | | | | | | Fix a bug that can prevent TIPC from sending broadcast messages to a node if contact with the node is lost and then regained. The problem occurs if the broadcast link first clears the flag indicating the node is part of the link's distribution set (when it loses contact with the node), and later fails to restore the flag (when contact is regained); restoration fails if contact with the node is regained by implicit unicast link activation triggered by the arrival of a data message, rather than explicitly by the arrival of a link activation message. The broadcast link now uses separate fields to track whether a node is theoretically capable of receiving broadcast messages versus whether it is actually part of the link's distribution set. The former member is updated by the receipt of link protocol messages, which can occur at any time; the latter member is updated only when contact with the node is gained or lost. This change also permits the simplification of several conditional expressions since the broadcast link's "supported" field can now only be set if there are working links to the associated node. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: rename struct link* to struct tipc_link*Paul Gortmaker2011-12-291-6/+6
| | | | | | | | | | This converts the following: struct link -> struct tipc_link struct link_req -> struct tipc_link_req struct link_name -> struct tipc_link_name Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Ensure both nodes recognize loss of contact between themAllan Stephens2011-09-171-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enhances TIPC to ensure that a node that loses contact with a neighboring node does not allow contact to be re-established until it sees that its peer has also recognized the loss of contact. Previously, nodes that were connected by two or more links could encounter a situation in which node A would lose contact with node B on all of its links, purge its name table of names published by B, and then fail to repopulate those names once contact with B was restored. This would happen because B was able to re-establish one or more links so quickly that it never reached a point where it had no links to A -- meaning that B never saw a loss of contact with A, and consequently didn't re-publish its names to A. This problem is now prevented by enhancing the cleanup done by TIPC following a loss of contact with a neighboring node to ensure that node A ignores all messages sent by B until it receives a LINK_PROTOCOL message that indicates B has lost contact with A, thereby preventing the (re)establishment of links between the nodes. The loss of contact is recognized when a RESET or ACTIVATE message is received that has a "redundant link exists" field of 0, indicating that B's sending link endpoint is in a reset state and that B has no other working links. Additionally, TIPC now suppresses the sending of (most) link protocol messages to a neighboring node while it is cleaning up after an earlier loss of contact with that node. This stops the peer node from prematurely activating its link endpoint, which would prevent TIPC from later activating its own end. TIPC still allows outgoing RESET messages to occur during cleanup, to avoid problems if its own node recognizes the loss of contact first and tries to notify the peer of the situation. Finally, TIPC now recognizes an impending loss of contact with a peer node as soon as it receives a RESET message on a working link that is the peer's only link to the node, and ensures that the link protocol suppression mentioned above goes into effect right away -- that is, even before its own link endpoints have failed. This is necessary to ensure correct operation when there are redundant links between the nodes, since otherwise TIPC would send an ACTIVATE message upon receiving a RESET on its first link and only begin suppressing when a RESET on its second link was received, instead of initiating suppression with the first RESET message as it needs to. Note: The reworked cleanup code also eliminates a check that prevented a link endpoint's discovery object from responding to incoming messages while stale name table entries are being purged. This check is now unnecessary and would have slowed down re-establishment of communication between the nodes in some situations. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Optimizations to link creation codeAllan Stephens2011-03-131-1/+1
| | | | | | | | | | | | | | | | | Enhances link creation code as follows: 1) Detects illegal attempts to add a requested link earlier in the link creation process. This prevents TIPC from wasting time initializing a link object it then throws away, and also eliminates the code needed to do the throwing away. 2) Passes in the node object associated with the requested link. This allows TIPC to eliminate a search to locate the node object, as well as code that attempted to create the node if it doesn't exist. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: cosmetic - function names are not to be full sentencesPaul Gortmaker2011-03-131-2/+2
| | | | | | | | | | | Function names like "tipc_node_has_redundant_links" are unweildy and result in long lines even for simple lines. The "has" doesn't contribute any value add, so dropping that is a slight step in the right direction. This is a cosmetic change, basic result of: for i in `grep -l tipc_node_has_ *` ; do sed -i s/tipc_node_has_/tipc_node_/ $i ; done Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Convert node object array to a hash tableAllan Stephens2011-03-131-10/+20
| | | | | | | | | | | | | | | | | | | | Replaces the dynamically allocated array of pointers to the cluster's node objects with a static hash table. Hash collisions are resolved using chaining, with a typical hash chain having only a single node, to avoid degrading performance during processing of incoming packets. The conversion to a hash table reduces the memory requirements for TIPC's node table to approximately the same size it had prior to the previous commit. In addition to the hash table itself, TIPC now also maintains a linked list for the node objects, sorted by ascending network address. This list allows TIPC to continue sending responses to user space applications that request node and link information in sorted order. The list also improves performance when name table update messages are sent by making it easier to identify the nodes that must be notified. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Split up unified structure of network-related variablesAllan Stephens2011-03-131-1/+1
| | | | | | | | | | | | | | Converts the fields of the global "tipc_net" structure into individual variables. Since the struct was never referenced as a complete unit, its existence was pointless. This will facilitate upcoming changes to TIPC's node table and simpify upcoming relocation of the variables so they are only visible to the files that actually use them. This change is essentially cosmetic in nature, and doesn't affect the operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* tipc: Remove prototype code for supporting multiple clustersAllan Stephens2011-01-011-4/+3
| | | | | | | | | | | Eliminates routines, data structures, and files that were intended to allow TIPC to support a network containing multiple clusters. Currently, TIPC supports only networks consisting of a single cluster within a single zone, so this code is unnecessary. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Remove prototype code for supporting inter-cluster routingAllan Stephens2011-01-011-21/+0
| | | | | | | | | | | Eliminates routines and data structures that were intended to allow TIPC to route messages to other clusters. Currently, TIPC supports only networks consisting of a single cluster within a single zone, so this code is unnecessary. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Remove prototype code for supporting multiple zonesAllan Stephens2011-01-011-1/+0
| | | | | | | | | | | Eliminates routines, data structures, and files that were intended to allows TIPC to support a network containing multiple zones. Currently, TIPC supports only networks consisting of a single cluster within a single zone, so this code is unnecessary. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: cleanup function namespacestephen hemminger2010-10-161-1/+0
| | | | | | | | | | | | | | | | Do some cleanups of TIPC based on make namespacecheck 1. Don't export unused symbols 2. Eliminate dead code 3. Make functions and variables local 4. Rename buf_acquire to tipc_buf_acquire since it is used in several files Compile tested only. This make break out of tree kernel modules that depend on TIPC routines. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Prevent missing name table entries when link flip-flops rapidlyAllan Stephens2010-08-171-0/+2
| | | | | | | | | | | | | | Ensure that TIPC does not re-establish communication with a neighboring node until it has finished updating all data structures containing information about that node to reflect the earlier loss of contact. Previously, it was possible for TIPC to perform its purge of name table entries relating to the node once contact had already been re-established, resulting in the unwanted removal of valid name table entries. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Don't use structure names which easily globally conflict.David S. Miller2008-09-021-21/+21
| | | | | | | | | | | Andrew Morton reported a build failure on sparc32, because TIPC uses names like "struct node" and there is a like named data structure defined in linux/node.h This just regexp replaces "struct node*" to "struct tipc_node*" to avoid this and any future similar problems. Signed-off-by: David S. Miller <davem@davemloft.net>
* [NET] TIPC: Fix whitespace errors.YOSHIFUJI Hideaki2007-02-101-4/+4
| | | | | Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TIPC]: Fixed link switchover bugsAllan Stephens2006-06-251-0/+2
| | | | | | | | | | | Incorporates several related fixes: - switchover now occurs when switching from an active link to a standby link - failure of a standby link no longer initiates switchover - links now display correct # of received packtes following reactivation Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Per Liden <per.liden@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TIPC]: Fix simple sparse warningsSam Ravnborg2006-03-201-1/+1
| | | | | | | | | | | | | Tried to run the new tipc stack through sparse. Following patch fixes all cases where 0 was used as replacement of NULL. Use NULL to document this is a pointer and to silence sparse. This brough sparse warning count down with 127 to 24 warnings. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Per Liden <per.liden@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TIPC] Avoid polluting the global namespacePer Liden2006-01-181-25/+25
| | | | | | This patch adds a tipc_ prefix to all externally visible symbols. Signed-off-by: Per Liden <per.liden@ericsson.com>
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