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2013-11-07tipc: message reassembly using fragment chainErik Hugne
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>
2012-11-22tipc: rename supported flag to recv_permittedYing Xue
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>
2012-11-22tipc: remove supportable flag from bclink structureYing Xue
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>
2012-04-30tipc: compress out gratuitous extra carriage returnsPaul Gortmaker
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>
2012-02-24tipc: Hide internal details of node table implementationAllan Stephens
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>
2012-02-24tipc: Introduce node signature field in neighbor discovery messageAllan Stephens
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>
2012-02-06tipc: Remove obsolete broadcast tag capabilityAllan Stephens
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>
2012-02-06tipc: Major redesign of broadcast link ACK/NACK algorithmsAllan Stephens
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>
2012-02-06tipc: Ensure broadcast link re-acquires node after link failureAllan Stephens
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>
2011-12-29tipc: rename struct link* to struct tipc_link*Paul Gortmaker
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>
2011-09-17tipc: Ensure both nodes recognize loss of contact between themAllan Stephens
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>
2011-03-13tipc: Optimizations to link creation codeAllan Stephens
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>
2011-03-13tipc: cosmetic - function names are not to be full sentencesPaul Gortmaker
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>
2011-03-13tipc: Convert node object array to a hash tableAllan Stephens
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>
2011-03-13tipc: Split up unified structure of network-related variablesAllan Stephens
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>
2011-01-01tipc: Remove prototype code for supporting multiple clustersAllan Stephens
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>
2011-01-01tipc: Remove prototype code for supporting inter-cluster routingAllan Stephens
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>
2011-01-01tipc: Remove prototype code for supporting multiple zonesAllan Stephens
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>
2010-10-16tipc: cleanup function namespacestephen hemminger
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>
2010-08-17tipc: Prevent missing name table entries when link flip-flops rapidlyAllan Stephens
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>
2008-09-02tipc: Don't use structure names which easily globally conflict.David S. Miller
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>
2007-02-10[NET] TIPC: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-25[TIPC]: Fixed link switchover bugsAllan Stephens
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>
2006-03-20[TIPC]: Fix simple sparse warningsSam Ravnborg
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>
2006-01-18[TIPC] Avoid polluting the global namespacePer Liden
This patch adds a tipc_ prefix to all externally visible symbols. Signed-off-by: Per Liden <per.liden@ericsson.com>
2006-01-12[TIPC] More updates of file headersPer Liden
Updated copyright notice to include the year the file was actually created. Information about file creation dates was extracted from the files in the old CVS repository at tipc.sourceforge.net. Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12[TIPC] Update of file headersPer Liden
The copyright statements from different parts of Ericsson have been merged into one. Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12[TIPC] License header updatePer Liden
The license header in each file now more clearly state that this code is licensed under a dual BSD/GPL. Before this was only evident if you looked at the MODULE_LICENSE line in core.c. Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>
2006-01-12[TIPC] Initial mergePer Liden
TIPC (Transparent Inter Process Communication) is a protocol designed for intra cluster communication. For more information see http://tipc.sourceforge.net Signed-off-by: Per Liden <per.liden@nospam.ericsson.com>