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* tipc: merge port message reception into socket reception functionJon Paul Maloy2014-05-14
| | | | | | | | | | In order to reduce complexity and save a call level during message reception at port/socket level, we remove the function tipc_port_rcv() and merge its functionality into tipc_sk_rcv(). 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: clean up neigbor discovery message receptionJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | | | | | The function tipc_disc_rcv(), which is handling received neighbor discovery messages, is perceived as messy, and it is hard to verify its correctness by code inspection. The fact that the task it is set to resolve is fairly complex does not make the situation better. In this commit we try to take a more systematic approach to the problem. We define a decision machine which takes three state flags as input, and produces three action flags as output. We then walk through all permutations of the state flags, and for each of them we describe verbally what is going on, plus that we set zero or more of the action flags. The action flags indicate what should be done once the decision machine has finished its job, while the last part of the function deals with performing those actions. 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: improve and extend media address conversion functionsJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TIPC currently handles two media specific addresses: Ethernet MAC addresses and InfiniBand addresses. Those are kept in three different formats: 1) A "raw" format as obtained from the device. This format is known only by the media specific adapter code in eth_media.c and ib_media.c. 2) A "generic" internal format, in the form of struct tipc_media_addr, which can be referenced and passed around by the generic media- unaware code. 3) A serialized version of the latter, to be conveyed in neighbor discovery messages. Conversion between the three formats can only be done by the media specific code, so we have function pointers for this purpose in struct tipc_media. Here, the media adapters can install their own conversion functions at startup. We now introduce a new such function, 'raw2addr()', whose purpose is to convert from format 1 to format 2 above. We also try to as far as possible uniform commenting, variable names and usage of these functions, with the purpose of making them more comprehensible. We can now also remove the function tipc_l2_media_addr_set(), whose job is done better by the new function. Finally, we expand the field for serialized addresses (format 3) in discovery messages from 20 to 32 bytes. This is permitted according to the spec, and reduces the risk of problems when we add new media in the future. 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 and move message reassembly functionJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | 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: mark head of reassembly buffer as non-linearJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | The message reassembly function does not update the 'len' and 'data_len' fields of the head skbuff correctly when fragments are chained to it. This may sometimes lead to obsure errors, such as fragment reordering when we receive fragments which are cloned buffers. This commit fixes this, by ensuring that the two fields are updated correctly. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> 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: don't record link RESET or ACTIVATE messages as trafficJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the current code, all incoming LINK_PROTOCOL messages, irrespective of type, nudge the "last message received" checkpoint, informing the link state machine that a message was received from the peer since last supervision timeout event. This inhibits the link from starting probing the peer unnecessarily. However, not only STATE messages are recorded as legitimate incoming traffic this way, but even RESET and ACTIVATE messages, which in reality are there to inform the link that the peer endpoint has been reset. At the same time, some RESET messages may be dropped instead of causing a link reset. This happens when the link endpoint thinks it is fully up and working, and the session number of the RESET is lower than or equal to the current link session. In such cases the RESET is perceived as a delayed remnant from an earlier session, or the current one, and dropped. Now, if a TIPC module is removed and then immediately reinserted, e.g. when using a script, RESET messages may arrive at the peer link endpoint before this one has had time to discover the failure. The RESET may be dropped because of the session number, but only after it has been recorded as a legitimate traffic event. Hence, the receiving link will not start probing, and not discover that the peer endpoint is down, at the same time ignoring the periodic RESET messages coming from that endpoint. We have ended up in a stale state where a failed link cannot be re-established. In this commit, we remedy this by nudging the checkpoint only for received STATE messages, not for RESET or ACTIVATE messages. 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: compensate for double accounting in socket rcv bufferJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function net/core/sock.c::__release_sock() runs a tight loop to move buffers from the socket backlog queue to the receive queue. As a security measure, sk_backlog.len of the receiving socket is not set to zero until after the loop is finished, i.e., until the whole backlog queue has been transferred to the receive queue. During this transfer, the data that has already been moved is counted both in the backlog queue and the receive queue, hence giving an incorrect picture of the available queue space for new arriving buffers. This leads to unnecessary rejection of buffers by sk_add_backlog(), which in TIPC leads to unnecessarily broken connections. In this commit, we compensate for this double accounting by adding a counter that keeps track of it. The function socket.c::backlog_rcv() receives buffers one by one from __release_sock(), and adds them to the socket receive queue. If the transfer is successful, it increases a new atomic counter 'tipc_sock::dupl_rcvcnt' with 'truesize' of the transferred buffer. If a new buffer arrives during this transfer and finds the socket busy (owned), we attempt to add it to the backlog. However, when sk_add_backlog() is called, we adjust the 'limit' parameter with the value of the new counter, so that the risk of inadvertent rejection is eliminated. It should be noted that this change does not invalidate the original purpose of zeroing 'sk_backlog.len' after the full transfer. We set an upper limit for dupl_rcvcnt, so that if a 'wild' sender (i.e., one that doesn't respect the send window) keeps pumping in buffers to sk_add_backlog(), he will eventually reach an upper limit, (2 x TIPC_CONN_OVERLOAD_LIMIT). After that, no messages can be added to the backlog, and the connection will be broken. Ordinary, well- behaved senders will never reach this buffer limit at all. 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: decrease connection flow control windowJon Paul Maloy2014-05-14
| | | | | | | | | | | | | | | | | | | | | | | | Memory overhead when allocating big buffers for data transfer may be quite significant. E.g., truesize of a 64 KB buffer turns out to be 132 KB, 2 x the requested size. This invalidates the "worst case" calculation we have been using to determine the default socket receive buffer limit, which is based on the assumption that 1024x64KB = 67MB buffers may be queued up on a socket. Since TIPC connections cannot survive hitting the buffer limit, we have to compensate for this overhead. We do that in this commit by dividing the fix connection flow control window from 1024 (2*512) messages to 512 (2*256). Since older version nodes send out acks at 512 message intervals, compatibility with such nodes is guaranteed, although performance may be non-optimal in such cases. 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-05-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/ethernet/altera/altera_sgdma.c net/netlink/af_netlink.c net/sched/cls_api.c net/sched/sch_api.c The netlink conflict dealt with moving to netlink_capable() and netlink_ns_capable() in the 'net' tree vs. supporting 'tc' operations in non-init namespaces. These were simple transformations from netlink_capable to netlink_ns_capable. The Altera driver conflict was simply code removal overlapping some void pointer cast cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Use netlink_ns_capable to verify the permisions of netlink messagesEric W. Biederman2014-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is possible by passing a netlink socket to a more privileged executable and then to fool that executable into writing to the socket data that happens to be valid netlink message to do something that privileged executable did not intend to do. To keep this from happening replace bare capable and ns_capable calls with netlink_capable, netlink_net_calls and netlink_ns_capable calls. Which act the same as the previous calls except they verify that the opener of the socket had the desired permissions as well. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: don't directly overwrite node action_flagsYing Xue2014-05-09
| | | | | | | | | | | | | | | | | | | | | | | | Each node action flag should be set or cleared separately, instead we now set the whole flags variable in one shot, and it's turned out to be hard to see which other flags are affected. Therefore, for instance, we explicitly clear TIPC_WAIT_OWN_LINKS_DOWN bit in node_lost_contact(). 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: rename enum names of node flagsYing Xue2014-05-09
| | | | | | | | | | | | | | | | | | 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: purge signal handler infrastructureYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | | | | | In the previous commits of this series, we removed all asynchronous actions which were based on the tasklet handler - "tipc_k_signal()". So the moment has now come when we can completely remove the tasklet handler infrastructure. That is done with this commit. 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 reset all linksYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | Postpone the actions of resetting all links until after bclink lock is released, avoiding to asynchronously reset all links. 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: convert allocations of global variables associated with bclinkYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | | | Convert allocations of global variables associated with bclink from static way to dynamical way for the convenience of bclink instance initialisation. Meanwhile, this also helps TIPC support name space in the future easily. 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: define new functions to operate bc_lockYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | | | As we are going to do more jobs when bc_lock is released, the two operations of holding/releasing the lock should be encapsulated with functions. In addition, we move bc_lock spin lock into tipc_bclink structure avoiding to define the global variable. 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 deliver name tables to peer nodeYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | 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 Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | 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 Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | 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 Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | 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: always use tipc_node_lock() to hold node lockYing Xue2014-05-05
| | | | | | | | | | | | | | | | | | | | | | | | | | Although we obtain node lock with tipc_node_lock() in most time, there are still places where we directly use native spin lock interface to grab node lock. But as we will do more jobs in the future when node lock is released, we should ensure that tipc_node_lock() is always called when node lock is taken. 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: fix memory leak of publicationsYing Xue2014-04-30
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 1bb8dce57f4d15233688c68990852a10eb1cd79f ("tipc: fix memory leak during module removal") introduced a memory leak issue: when name table is stopped, it's forgotten that publication instances are freed properly. Additionally the useless "continue" statement in tipc_nametbl_stop() is removed as well. Reported-by: Jason <huzhijiang@gmail.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: move the delivery of named messages out of nametbl lockYing Xue2014-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a89778d8baf19cd7e728d81121a294a06cedaad1 ("tipc: add support for link state subscriptions") introduced below possible deadlock scenario: CPU0 CPU1 T0: tipc_publish() link_timeout() T1: tipc_nametbl_publish() [grab node lock]* T2: [grab nametbl write lock]* link_state_event() T3: named_cluster_distribute() link_activate() T4: [grab node lock]* tipc_node_link_up() T5: tipc_nametbl_publish() T6: [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 delivery of named messages via link out of name nametbl lock, the reverse order of holding locks will be eliminated, as a result, the deadlock will be killed as well. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: fix out of bounds indexingErik Hugne2014-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 78acb1f9b898e85fa2c1e28e700b54b66b288e8d ("tipc: add ioctl to fetch link names") introduced a buffer overflow bug where specially crafted ioctl requests could cause out-of-bounds indexing of the node->links array. This was caused by an incorrect check vs MAX_BEARERS, and the static code checker complaint is: net/tipc/node.c:459 tipc_node_get_linkname() error: buffer overflow 'node->links' 2 <= 2 Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: fix a possible memory leakYing Xue2014-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit a8b9b96e959f3c035af20b1bd2ba67b0b7269b19 ("tipc: fix race in disc create/delete") leads to the following static checker warning: net/tipc/discover.c:352 tipc_disc_create() warn: possible memory leak of 'req' The risk of memory leak really exists in practice. Especially when it's failed to allocate memory for "req->buf", tipc_disc_create() doesn't free its allocated memory, instead just directly returns with ENOMEM error code. In this situation, memory leak, of course, happens. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: add ioctl to fetch link namesErik Hugne2014-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | 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: add support for link state subscriptionsErik Hugne2014-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | When links are established over a bearer plane, we create a node local publication containing information about the peer node and bearer plane. This allows TIPC applications to use the standard TIPC topology server subscription mechanism to get notifications when a link goes up or down. 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: fix race in disc create/deleteYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a21a584d6720ce349b05795b9bcfab3de8e58419 (tipc: fix neighbor detection problem after hw address change) introduces a race condition involving tipc_disc_delete() and tipc_disc_add/remove_dest that can cause TIPC to dereference the pointer to the bearer discovery request structure after it has been freed since a stray pointer is left in the bearer structure. In order to fix the issue, the process of resetting the discovery request handler is optimized: the discovery request handler and request buffer are just reset instead of being freed, allocated and initialized. As the request point is always valid and the request's lock is taken while the request handler is reset, the race doesn't happen any more. Reported-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: use bc_lock to protect node map in bearer structureYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The node map variable - 'nodes' in bearer structure is only used by bclink. When bclink accesses it, bc_lock is held. But when change it, for instance, in tipc_bearer_add_dest() or tipc_bearer_remove_dest() the bc_lock is not taken at all. To avoid any inconsistent data, we should always grab bc_lock while accessing node map variable. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: use bearer_disable to disable bearer in tipc_l2_device_eventYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | As bearer pointer is known in tipc_l2_device_event(), it's unnecessary to search it again in tipc_disable_bearer(). If tipc_disable_bearer() is replaced with bearer_disable() in tipc_l2_device_event(), this will help us save a bit time when bearer is disabled. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: make media_ptr pointed netdevice validYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | The 'media_ptr' pointer in bearer structure which points to network device, is protected by RCU. So, before netdevice is released, synchronize_net() should be involved to prevent no any user of the netdevice on read side from accessing it after it is freed. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: purge tipc_net_lock lockYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now tipc routing hierarchy comprises the structures 'node', 'link'and 'bearer'. The whole hierarchy is protected by a big read/write lock, tipc_net_lock, to ensure that nothing is added or removed while code is accessing any of these structures. Obviously the locking policy makes node, link and bearer components closely bound together so that their relationship becomes unnecessarily complex. In the worst case, such locking policy not only has a negative influence on performance, but also it's prone to lead to deadlock occasionally. In order o decouple the complex relationship between bearer and node as well as link, the locking policy is adjusted as follows: - Bearer level RTNL lock is used on update side, and RCU is used on read side. Meanwhile, all bearer instances including broadcast bearer are saved into bearer_list array. - Node and link level All node instances are saved into two tipc_node_list and node_htable lists. The two lists are protected by node_list_lock on write side, and they are guarded with RCU lock on read side. All members in node structure including link instances are protected by node spin lock. - The relationship between bearer and node When link accesses bearer, it first needs to find the bearer with its bearer identity from the bearer_list array. When bearer accesses node, it can iterate the node_htable hash list with the node address to find the corresponding node. In the new locking policy, every component has its private locking solution and the relationship between bearer and node is very simple, that is, they can find each other with node address or bearer identity from node_htable hash list or bearer_list array. Until now above all changes have been done, so tipc_net_lock can be removed safely. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: use RCU to protect media_ptr pointerYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Now the media_ptr pointer is protected with tipc_net_lock write lock on write side; tipc_net_lock read lock is used to read side. As the part of effort of eliminating tipc_net_lock, we decide to adjust the locking policy of media_ptr pointer protection: on write side, RTNL lock is use while on read side RCU read lock is applied. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: decouple the relationship between bearer and linkYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently on both paths of message transmission and reception, the read lock of tipc_net_lock must be held before bearer is accessed, while the write lock of tipc_net_lock has to be taken before bearer is configured. Although it can ensure that bearer is always valid on the two data paths, link and bearer is closely bound together. So as the part of effort of removing tipc_net_lock, the locking policy of bearer protection will be adjusted as below: on the two data paths, RCU is used, and on the configuration path of bearer, RTNL lock is applied. Now RCU just covers the path of message reception. To make it possible to protect the path of message transmission with RCU, link should not use its stored bearer pointer to access bearer, but it should use the bearer identity of its attached bearer as index to get bearer instance from bearer_list array, which can help us decouple the relationship between bearer and link. As a result, bearer on the path of message transmission can be safely protected by RCU when we access bearer_list array within RCU lock protection. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: convert bearer_list to RCU listYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | Convert bearer_list to RCU list. It's protected by RTNL lock on update side, and RCU read lock is applied to read side. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: use RTNL lock to protect tipc_net_stop routineYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | As the tipc network initialization(ie, tipc_net_start routine) is under RTNL protection, its corresponding deinitialization part(ie, tipc_net_stop routine) should be protected by RTNL too. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: adjust locking policy of protecting tipc_ptr pointer of net_deviceYing Xue2014-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the 'tipc_ptr' pointer is protected by tipc_net_lock write lock on write side, and RCU read lock is applied to read side. In addition, there have two paths on write side where we may change variables pointed by the 'tipc_ptr' pointer: one is to configure bearer by tipc-config tool and another one is that bearer status is changed by notification events of its attached interface. But on the latter path, we improperly deem that accessing 'tipc_ptr' pointer happens on read side with rcu_read_lock() although some variables pointed by the 'tipc_ptr' pointer are changed possibly. Moreover, as now the both paths are guarded by RTNL lock, it's better to adjust the locking policy of 'tipc_ptr' pointer protection, allowing RTNL instead of tipc_net_lock write lock to protect it on write side, which will help us purge tipc_net_lock in the future. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tipc: replace config_mutex lock with RTNL lockYing Xue2014-04-22
|/ | | | | | | | | | | | | | | | | | There have two paths where we can configure or change bearer status: one is that bearer is configured from user space with tipc-config tool; another one is that bearer is changed by notification events from its attached interface. On the first path, one dedicated config_mutex lock is guarded; on the latter path, RTNL lock has been placed to serialize the process of dealing with interface events. So, if RTNL lock is also used to protect the first path, this will not only extremely help us simplify current locking policy, but also config_mutex lock can be deleted as well. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Fix use after free by removing length arg from sk_data_ready callbacks.David S. Miller2014-04-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Several spots in the kernel perform a sequence like: skb_queue_tail(&sk->s_receive_queue, skb); sk->sk_data_ready(sk, skb->len); But at the moment we place the SKB onto the socket receive queue it can be consumed and freed up. So this skb->len access is potentially to freed up memory. Furthermore, the skb->len can be modified by the consumer so it is possible that the value isn't accurate. And finally, no actual implementation of this callback actually uses the length argument. And since nobody actually cared about it's value, lots of call sites pass arbitrary values in such as '0' and even '1'. So just remove the length argument from the callback, that way there is no confusion whatsoever and all of these use-after-free cases get fixed as a side effect. Based upon a patch by Eric Dumazet and his suggestion to audit this issue tree-wide. Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: Let tipc_release() return 0Geert Uytterhoeven2014-04-07
| | | | | | | | | | | | | | net/tipc/socket.c: In function ‘tipc_release’: net/tipc/socket.c:352: warning: ‘res’ is used uninitialized in this function Introduced by commit 24be34b5a0c9114541891d29dff1152bb1a8df34 ("tipc: eliminate upcall function pointers between port and socket"), which removed the sole initializer of "res". Just return 0 to fix it. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: fix regression bug where node events are not being generatedErik Hugne2014-04-03
| | | | | | | | | | | | | | | | | Commit 5902385a2440a55f005b266c93e0bb9398e5a62b ("tipc: obsolete the remote management feature") introduces a regression where node topology events are not being generated because the publication that triggers this: {0, <z.c.n>, <z.c.n>} is no longer available. This will break applications that rely on node events to discover when nodes join/leave a cluster. We fix this by advertising the node publication when TIPC enters networking mode, and withdraws it upon shutdown. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-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: make discovery domain a bearer attributeErik Hugne2014-03-28
| | | | | | | | | | | | | | The node discovery domain is assigned when a bearer is enabled. In the previous commit we reflect this attribute directly in the bearer structure since it's needed to reinitialize the node discovery mechanism after a hardware address change. There's no need to replicate this attribute anywhere else, so we remove it from the tipc_link_req structure. Signed-off-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: fix neighbor detection problem after hw address changeErik Hugne2014-03-28
| | | | | | | | | | | | | | | | If the hardware address of a underlying netdevice is changed, it is not enough to simply reset the bearer/links over this device. We also need to reflect this change in the TIPC bearer and node discovery structures aswell. This patch adds the necessary reinitialization of the node disovery mechanism following a hardware address change so that the correct originating media address is advertised in the discovery messages. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reported-by: Dong Liu <dliu.cn@gmail.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tipc: use node list lock to protect tipc_num_links variableYing Xue2014-03-27
| | | | | | | | | | | | | | | | Without properly implicit or explicit read memory barrier, it's unsafe to read an atomic variable with atomic_read() from another thread which is different with the thread of changing the atomic variable with atomic_inc() or atomic_dec(). So a stale tipc_num_links may be got with atomic_read() in tipc_node_get_links(). If the tipc_num_links variable type is converted from atomic to unsigned integer and node list lock is used to protect it, the issue would be avoided. 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: use node_list_lock to protect tipc_num_nodes variableYing Xue2014-03-27
| | | | | | | | | | | | As tipc_node_list is protected by rcu read lock on read side, it's unnecessary to hold node_list_lock to protect tipc_node_list in tipc_node_get_links(). Instead, node_list_lock should just protects tipc_num_nodes in the function. 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: tipc: convert node list and node hlist to RCU listsYing Xue2014-03-27
| | | | | | | | | | | 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 Xue2014-03-27
| | | | | | | | | | | | | | | | | | | | | | 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: make broadcast bearer store in bearer_list arrayYing Xue2014-03-27
| | | | | | | | | | | | | | | | | | Now unicast bearer is dynamically allocated and placed into its identity specified slot of bearer_list array. When we search bearer_list array with a bearer identity, the corresponding bearer instance can be found. But broadcast bearer is statically allocated and it is not located in the bearer_list array yet. So we decide to enlarge bearer_list array into MAX_BEARERS + 1 slots, and its last slot stores the broadcast bearer so that the broadcast bearer can be found from bearer_list array with MAX_BEARERS as index. The change will help us reduce the complex relationship between bearer and link in the future. 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 active flag from tipc_bearer structureYing Xue2014-03-27
| | | | | | | | | | | | | After the allocation of tipc_bearer structure instance is converted from statical way to dynamical way, we identify whether a certain tipc_bearer structure pointer is valid by checking whether the pointer is NULL or not. So the active flag in tipc_bearer structure becomes redundant. 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>