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2019-02-11tipc: fix link session and re-establish issuesTuong Lien1-5/+6
When a link endpoint is re-created (e.g. after a node reboot or interface reset), the link session number is varied by random, the peer endpoint will be synced with this new session number before the link is re-established. However, there is a shortcoming in this mechanism that can lead to the link never re-established or faced with a failure then. It happens when the peer endpoint is ready in ESTABLISHING state, the 'peer_session' as well as the 'in_session' flag have been set, but suddenly this link endpoint leaves. When it comes back with a random session number, there are two situations possible: 1/ If the random session number is larger than (or equal to) the previous one, the peer endpoint will be updated with this new session upon receipt of a RESET_MSG from this endpoint, and the link can be re- established as normal. Otherwise, all the RESET_MSGs from this endpoint will be rejected by the peer. In turn, when this link endpoint receives one ACTIVATE_MSG from the peer, it will move to ESTABLISHED and start to send STATE_MSGs, but again these messages will be dropped by the peer due to wrong session. The peer link endpoint can still become ESTABLISHED after receiving a traffic message from this endpoint (e.g. a BCAST_PROTOCOL or NAME_DISTRIBUTOR), but since all the STATE_MSGs are invalid, the link will be forced down sooner or later! Even in case the random session number is larger than the previous one, it can be that the ACTIVATE_MSG from the peer arrives first, and this link endpoint moves quickly to ESTABLISHED without sending out any RESET_MSG yet. Consequently, the peer link will not be updated with the new session number, and the same link failure scenario as above will happen. 2/ Another situation can be that, the peer link endpoint was reset due to any reasons in the meantime, its link state was set to RESET from ESTABLISHING but still in session, i.e. the 'in_session' flag is not reset... Now, if the random session number from this endpoint is less than the previous one, all the RESET_MSGs from this endpoint will be rejected by the peer. In the other direction, when this link endpoint receives a RESET_MSG from the peer, it moves to ESTABLISHING and starts to send ACTIVATE_MSGs, but all these messages will be rejected by the peer too. As a result, the link cannot be re-established but gets stuck with this link endpoint in state ESTABLISHING and the peer in RESET! Solution: =========== This link endpoint should not go directly to ESTABLISHED when getting ACTIVATE_MSG from the peer which may belong to the old session if the link was re-created. To ensure the session to be correct before the link is re-established, the peer endpoint in ESTABLISHING state will send back the last session number in ACTIVATE_MSG for a verification at this endpoint. Then, if needed, a new and more appropriate session number will be regenerated to force a re-synch first. In addition, when a link in ESTABLISHING state is reset, its state will move to RESET according to the link FSM, along with resetting the 'in_session' flag (and the other data) as a normal link reset, it will also be deleted if requested. The solution is backward compatible. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19tipc: add trace_events for tipc nodeTuong Lien1-0/+15
The commit adds the new trace_events for TIPC node object: trace_tipc_node_create() trace_tipc_node_delete() trace_tipc_node_lost_contact() trace_tipc_node_timeout() trace_tipc_node_link_up() trace_tipc_node_link_down() trace_tipc_node_reset_links() trace_tipc_node_fsm_evt() trace_tipc_node_check_state() Also, enables the traces for the following cases: - When a node is created/deleted; - When a node contact is lost; - When a node timer is timed out; - When a node link is up/down; - When all node links are reset; - When node state is changed; - When a skb comes and node state needs to be checked/updated. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19tipc: add trace_events for tipc linkTuong Lien1-1/+7
The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19tipc: enable tracepoints in tipcTuong Lien1-0/+63
As for the sake of debugging/tracing, the commit enables tracepoints in TIPC along with some general trace_events as shown below. It also defines some 'tipc_*_dump()' functions that allow to dump TIPC object data whenever needed, that is, for general debug purposes, ie. not just for the trace_events. The following trace_events are now available: - trace_tipc_skb_dump(): allows to trace and dump TIPC msg & skb data, e.g. message type, user, droppable, skb truesize, cloned skb, etc. - trace_tipc_list_dump(): allows to trace and dump any TIPC buffers or queues, e.g. TIPC link transmq, socket receive queue, etc. - trace_tipc_sk_dump(): allows to trace and dump TIPC socket data, e.g. sk state, sk type, connection type, rmem_alloc, socket queues, etc. - trace_tipc_link_dump(): allows to trace and dump TIPC link data, e.g. link state, silent_intv_cnt, gap, bc_gap, link queues, etc. - trace_tipc_node_dump(): allows to trace and dump TIPC node data, e.g. node state, active links, capabilities, link entries, etc. How to use: Put the trace functions at any places where we want to dump TIPC data or events. Note: a) The dump functions will generate raw data only, that is, to offload the trace event's processing, it can require a tool or script to parse the data but this should be simple. b) The trace_tipc_*_dump() should be reserved for a failure cases only (e.g. the retransmission failure case) or where we do not expect to happen too often, then we can consider enabling these events by default since they will almost not take any effects under normal conditions, but once the rare condition or failure occurs, we get the dumped data fully for post-analysis. For other trace purposes, we can reuse these trace classes as template but different events. c) A trace_event is only effective when we enable it. To enable the TIPC trace_events, echo 1 to 'enable' files in the events/tipc/ directory in the 'debugfs' file system. Normally, they are located at: /sys/kernel/debug/tracing/events/tipc/ For example: To enable the tipc_link_dump event: echo 1 > /sys/kernel/debug/tracing/events/tipc/tipc_link_dump/enable To enable all the TIPC trace_events: echo 1 > /sys/kernel/debug/tracing/events/tipc/enable To collect the trace data: cat trace or cat trace_pipe > /trace.out & To disable all the TIPC trace_events: echo 0 > /sys/kernel/debug/tracing/events/tipc/enable To clear the trace buffer: echo > trace d) Like the other trace_events, the feature like 'filter' or 'trigger' is also usable for the tipc trace_events. For more details, have a look at: Documentation/trace/ftrace.txt MAINTAINERS | add two new files 'trace.h' & 'trace.c' in tipc Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-18tipc: handle broadcast NAME_DISTRIBUTOR packet when receiving itZhenbo Gao1-0/+4
NAME_DISTRIBUTOR messages are transmitted through unicast link on TIPC 2.0, by contrast, the messages are delivered through broadcast link on TIPC 1.7. But at present, NAME_DISTRIBUTOR messages received by broadcast link cannot be handled in tipc_rcv() until an unicast message arrives, which may lead to a significant delay to update name table. To avoid this delay, we will also deal with broadcast NAME_DISTRIBUTOR message on broadcast receive path. Signed-off-by: Zhenbo Gao <zhenbo.gao@windriver.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05tipc: fix node keep alive interval calculationHoang Le1-0/+6
When setting LINK tolerance, node timer interval will be calculated base on the LINK with lowest tolerance. But when calculated, the old node timer interval only updated if current setting value (tolerance/4) less than old ones regardless of number of links as well as links' lowest tolerance value. This caused to two cases missing if tolerance changed as following: Case 1: 1.1/ There is one link (L1) available in the system 1.2/ Set L1's tolerance from 1500ms => lower (i.e 500ms) 1.3/ Then, fallback to default (1500ms) or higher (i.e 2000ms) Expected: node timer interval is 1500/4=375ms after 1.3 Result: node timer interval will not being updated after changing tolerance at 1.3 since its value 1500/4=375ms is not less than 500/4=125ms at 1.2. Case 2: 2.1/ There are two links (L1, L2) available in the system 2.2/ L1 and L2 tolerance value are 2000ms as initial 2.3/ Set L2's tolerance from 2000ms => lower 1500ms 2.4/ Disable link L2 (bring down its bearer) Expected: node timer interval is 2000ms/4=500ms after 2.4 Result: node timer interval will not being updated after disabling L2 since its value 2000ms/4=500ms is still not less than 1500/4=375ms at 2.3 although L2 is already not available in the system. To fix this, we start the node interval calculation by initializing it to a value larger than any conceivable calculated value. This way, the link with the lowest tolerance will always determine the calculated value. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27tipc: fix lockdep warning during node deleteJon Maloy1-2/+5
We see the following lockdep warning: [ 2284.078521] ====================================================== [ 2284.078604] WARNING: possible circular locking dependency detected [ 2284.078604] 4.19.0+ #42 Tainted: G E [ 2284.078604] ------------------------------------------------------ [ 2284.078604] rmmod/254 is trying to acquire lock: [ 2284.078604] 00000000acd94e28 ((&n->timer)#2){+.-.}, at: del_timer_sync+0x5/0xa0 [ 2284.078604] [ 2284.078604] but task is already holding lock: [ 2284.078604] 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x190 [tipc] [ 2284.078604] [ 2284.078604] which lock already depends on the new lock. [ 2284.078604] [ 2284.078604] [ 2284.078604] the existing dependency chain (in reverse order) is: [ 2284.078604] [ 2284.078604] -> #1 (&(&tn->node_list_lock)->rlock){+.-.}: [ 2284.078604] tipc_node_timeout+0x20a/0x330 [tipc] [ 2284.078604] call_timer_fn+0xa1/0x280 [ 2284.078604] run_timer_softirq+0x1f2/0x4d0 [ 2284.078604] __do_softirq+0xfc/0x413 [ 2284.078604] irq_exit+0xb5/0xc0 [ 2284.078604] smp_apic_timer_interrupt+0xac/0x210 [ 2284.078604] apic_timer_interrupt+0xf/0x20 [ 2284.078604] default_idle+0x1c/0x140 [ 2284.078604] do_idle+0x1bc/0x280 [ 2284.078604] cpu_startup_entry+0x19/0x20 [ 2284.078604] start_secondary+0x187/0x1c0 [ 2284.078604] secondary_startup_64+0xa4/0xb0 [ 2284.078604] [ 2284.078604] -> #0 ((&n->timer)#2){+.-.}: [ 2284.078604] del_timer_sync+0x34/0xa0 [ 2284.078604] tipc_node_delete+0x1a/0x40 [tipc] [ 2284.078604] tipc_node_stop+0xcb/0x190 [tipc] [ 2284.078604] tipc_net_stop+0x154/0x170 [tipc] [ 2284.078604] tipc_exit_net+0x16/0x30 [tipc] [ 2284.078604] ops_exit_list.isra.8+0x36/0x70 [ 2284.078604] unregister_pernet_operations+0x87/0xd0 [ 2284.078604] unregister_pernet_subsys+0x1d/0x30 [ 2284.078604] tipc_exit+0x11/0x6f2 [tipc] [ 2284.078604] __x64_sys_delete_module+0x1df/0x240 [ 2284.078604] do_syscall_64+0x66/0x460 [ 2284.078604] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 2284.078604] [ 2284.078604] other info that might help us debug this: [ 2284.078604] [ 2284.078604] Possible unsafe locking scenario: [ 2284.078604] [ 2284.078604] CPU0 CPU1 [ 2284.078604] ---- ---- [ 2284.078604] lock(&(&tn->node_list_lock)->rlock); [ 2284.078604] lock((&n->timer)#2); [ 2284.078604] lock(&(&tn->node_list_lock)->rlock); [ 2284.078604] lock((&n->timer)#2); [ 2284.078604] [ 2284.078604] *** DEADLOCK *** [ 2284.078604] [ 2284.078604] 3 locks held by rmmod/254: [ 2284.078604] #0: 000000003368be9b (pernet_ops_rwsem){+.+.}, at: unregister_pernet_subsys+0x15/0x30 [ 2284.078604] #1: 0000000046ed9c86 (rtnl_mutex){+.+.}, at: tipc_net_stop+0x144/0x170 [tipc] [ 2284.078604] #2: 00000000f997afc0 (&(&tn->node_list_lock)->rlock){+.-.}, at: tipc_node_stop+0xac/0x19 [...} The reason is that the node timer handler sometimes needs to delete a node which has been disconnected for too long. To do this, it grabs the lock 'node_list_lock', which may at the same time be held by the generic node cleanup function, tipc_node_stop(), during module removal. Since the latter is calling del_timer_sync() inside the same lock, we have a potential deadlock. We fix this letting the timer cleanup function use spin_trylock() instead of just spin_lock(), and when it fails to grab the lock it just returns so that the timer handler can terminate its execution. This is safe to do, since tipc_node_stop() anyway is about to delete both the timer and the node instance. Fixes: 6a939f365bdb ("tipc: Auto removal of peer down node instance") Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-01tipc: ignore STATE_MSG on wrong link sessionLUU Duc Canh1-2/+3
The initial session number when a link is created is based on a random value, taken from struct tipc_net->random. It is then incremented for each link reset to avoid mixing protocol messages from different link sessions. However, when a bearer is reset all its links are deleted, and will later be re-created using the same random value as the first time. This means that if the link never went down between creation and deletion we will still sometimes have two subsequent sessions with the same session number. In virtual environments with potentially long transmission times this has turned out to be a real problem. We now fix this by randomizing the session number each time a link is created. With a session number size of 16 bits this gives a risk of session collision of 1/64k. To reduce this further, we also introduce a sanity check on the very first STATE message arriving at a link. If this has an acknowledge value differing from 0, which is logically impossible, we ignore the message. The final risk for session collision is hence reduced to 1/4G, which should be sufficient. Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-29tipc: fix failover problemLUU Duc Canh1-0/+11
We see the following scenario: 1) Link endpoint B on node 1 discovers that its peer endpoint is gone. Since there is a second working link, failover procedure is started. 2) Link endpoint A on node 1 sends a FAILOVER message to peer endpoint A on node 2. The node item 1->2 goes to state FAILINGOVER. 3) Linke endpoint A/2 receives the failover, and is supposed to take down its parallell link endpoint B/2, while producing a FAILOVER message to send back to A/1. 4) However, B/2 has already been deleted, so no FAILOVER message can created. 5) Node 1->2 remains in state FAILINGOVER forever, refusing to receive any messages that can bring B/1 up again. We are left with a non- redundant link between node 1 and 2. We fix this with letting endpoint A/2 build a dummy FAILOVER message to send to back to A/1, so that the situation can be resolved. Signed-off-by: LUU Duc Canh <canh.d.luu@dektech.com.au> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linuxDavid S. Miller1-2/+5
All conflicts were trivial overlapping changes, so reasonably easy to resolve. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20tipc: make link capability update thread safeJon Maloy1-0/+4
The commit referred to below introduced an update of the link capabilities field that is not safe. Given the recently added feature to remove idle node and link items after 5 minutes, there is a small risk that the update will happen at the very moment the targeted link is being removed. To avoid this we have to perform the update inside the node item's write lock protection. Fixes: 9012de508956 ("tipc: add sequence number check for link STATE messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-11tipc: check session number before accepting link protocol messagesJon Maloy1-1/+4
In some virtual environments we observe a significant higher number of packet reordering and delays than we have been used to traditionally. This makes it necessary with stricter checks on incoming link protocol messages' session number, which until now only has been validated for RESET messages. Since the other two message types, ACTIVATE and STATE messages also carry this number, it is easy to extend the validation check to those messages. We also introduce a flag indicating if a link has a valid peer session number or not. This eliminates the mixing of 32- and 16-bit arithmethics we are currently using to achieve this. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-11tipc: add sequence number check for link STATE messagesJon Maloy1-0/+7
Some switch infrastructures produce huge amounts of packet duplicates. This becomes a problem if those messages are STATE/NACK protocol messages, causing unnecessary retransmissions of already accepted packets. We now introduce a unique sequence number per STATE protocol message so that duplicates can be identified and ignored. This will also be useful when tracing such cases, and to avert replay attacks when TIPC is encrypted. For compatibility reasons we have to introduce a new capability flag TIPC_LINK_PROTO_SEQNO to handle this new feature. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07tipc: fix wrong return value from function tipc_node_try_addr()Jon Maloy1-2/+5
The function for checking if there is an node address conflict is supposed to return a suggestion for a new address if it finds a conflict, and zero otherwise. But in case the peer being checked is previously unknown it does instead return a "suggestion" for the checked address itself. This results in a DSC_TRIAL_FAIL_MSG being sent unecessarily to the peer, and sometimes makes the trial period starting over again. Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30tipc: Auto removal of peer down node instanceGhantaKrishnamurthy MohanKrishna1-11/+55
A peer node is considered down if there are no active links (or) lost contact to the node. In current implementation, a peer node instance is deleted either if a) TIPC module is removed (or) b) Application can use a netlink/iproute2 interface to delete a specific down node. Thus, a down node instance lives in the system forever, unless the application explicitly removes it. We fix this by deleting the nodes which are down for a specified amount of time (5 minutes). Existing node supervision timer is used to achieve this. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-30tipc: optimize function tipc_node_timeout()Tung Nguyen1-3/+5
In single-link usage, the function tipc_node_timeout() still iterates over the whole link array to handle each link. Given that the maximum number of bearers are 3, there are 2 redundant iterations with lock grab/release. Since this function is executing very frequently it makes sense to optimize it. This commit adds conditional checking to exit from the loop if the known number of configured links has already been accessed. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+13
The bpf syscall and selftests conflicts were trivial overlapping changes. The r8169 change involved moving the added mdelay from 'net' into a different function. A TLS close bug fix overlapped with the splitting of the TLS state into separate TX and RX parts. I just expanded the tests in the bug fix from "ctx->conf == X" into "ctx->tx_conf == X && ctx->rx_conf == X". Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-10tipc: eliminate KMSAN uninit-value in strcmp complaintYing Xue1-2/+13
When we get link properties through netlink interface with tipc_nl_node_get_link(), we don't validate TIPC_NLA_LINK_NAME attribute at all, instead we directly use it. As a consequence, KMSAN detected the TIPC_NLA_LINK_NAME attribute was an uninitialized value, and then posted the following complaint: ================================================================== BUG: KMSAN: uninit-value in strcmp+0xf7/0x160 lib/string.c:329 CPU: 1 PID: 4527 Comm: syz-executor655 Not tainted 4.16.0+ #87 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683 strcmp+0xf7/0x160 lib/string.c:329 tipc_nl_node_get_link+0x220/0x6f0 net/tipc/node.c:1881 genl_family_rcv_msg net/netlink/genetlink.c:599 [inline] genl_rcv_msg+0x1686/0x1810 net/netlink/genetlink.c:624 netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2447 genl_rcv+0x63/0x80 net/netlink/genetlink.c:635 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x166b/0x1740 net/netlink/af_netlink.c:1337 netlink_sendmsg+0x1048/0x1310 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmsg net/socket.c:2080 [inline] SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091 SyS_sendmsg+0x54/0x80 net/socket.c:2087 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x445589 RSP: 002b:00007fb7ee66cdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445589 RDX: 0000000000000000 RSI: 0000000020023000 RDI: 0000000000000003 RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa2bf3f3f R14: 00007fb7ee66d9c0 R15: 0000000000000001 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline] netlink_sendmsg+0x9a6/0x1310 net/netlink/af_netlink.c:1875 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] ___sys_sendmsg+0xec0/0x1310 net/socket.c:2046 __sys_sendmsg net/socket.c:2080 [inline] SYSC_sendmsg+0x2a3/0x3d0 net/socket.c:2091 SyS_sendmsg+0x54/0x80 net/socket.c:2087 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ================================================================== To quiet the complaint, TIPC_NLA_LINK_NAME attribute has been validated in tipc_nl_node_get_link() before it's used. Reported-by: syzbot+df0257c92ffd4fcc58cd@syzkaller.appspotmail.com Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+1
Overlapping changes in selftests Makefile. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27tipc: introduce ioctl for fetching node identityJon Maloy1-0/+21
After the introduction of a 128-bit node identity it may be difficult for a user to correlate between this identity and the generated node hash address. We now try to make this easier by introducing a new ioctl() call for fetching a node identity by using the hash value as key. This will be particularly useful when we extend some of the commands in the 'tipc' tool, but we also expect regular user applications to need this feature. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27tipc: fix bug in function tipc_nl_node_dump_monitorJon Maloy1-1/+1
Commit 36a50a989ee8 ("tipc: fix infinite loop when dumping link monitor summary") intended to fix a problem with user tool looping when max number of bearers are enabled. Unfortunately, the wrong version of the commit was posted, so the problem was not solved at all. This commit adds the missing part. Fixes: 36a50a989ee8 ("tipc: fix infinite loop when dumping link monitor summary") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-7/+4
Conflicts were simple overlapping changes in microchip driver. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-20tipc: confgiure and apply UDP bearer MTU on running linksGhantaKrishnamurthy MohanKrishna1-3/+9
Currently, we have option to configure MTU of UDP media. The configured MTU takes effect on the links going up after that moment. I.e, a user has to reset bearer to have new value applied across its links. This is confusing and disturbing on a running cluster. We now introduce the functionality to change the default UDP bearer MTU in struct tipc_bearer. Additionally, the links are updated dynamically, without any need for a reset, when bearer value is changed. We leverage the existing per-link functionality and the design being symetrical to the confguration of link tolerance. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: GhantaKrishnamurthy MohanKrishna <mohan.krishna.ghanta.krishnamurthy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-18tipc: fix infinite loop when dumping link monitor summaryTung Nguyen1-7/+4
When configuring the number of used bearers to MAX_BEARER and issuing command "tipc link monitor summary", the command enters infinite loop in user space. This issue happens because function tipc_nl_node_dump_monitor() returns the wrong 'prev_bearer' value when all potential monitors have been scanned. The correct behavior is to always try to scan all monitors until either the netlink message is full, in which case we return the bearer identity of the affected monitor, or we continue through the whole bearer array until we can return MAX_BEARERS. This solution also caters for the case where there may be gaps in the bearer array. Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31tipc: permit overlapping service ranges in name tableJon Maloy1-1/+1
With the new RB tree structure for service ranges it becomes possible to solve an old problem; - we can now allow overlapping service ranges in the table. When inserting a new service range to the tree, we use 'lower' as primary key, and when necessary 'upper' as secondary key. Since there may now be multiple service ranges matching an indicated 'lower' value, we must also add the 'upper' value to the functions used for removing publications, so that the correct, corresponding range item can be found. These changes guarantee that a well-formed publication/withdrawal item from a peer node never will be rejected, and make it possible to eliminate the problematic backlog functionality we currently have for handling such cases. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31tipc: replace name table service range array with rb treeJon Maloy1-2/+2
The current design of the binding table has an unnecessary memory consuming and complex data structure. It aggregates the service range items into an array, which is expanded by a factor two every time it becomes too small to hold a new item. Furthermore, the arrays never shrink when the number of ranges diminishes. We now replace this array with an RB tree that is holding the range items as tree nodes, each range directly holding a list of bindings. This, along with a few name changes, improves both readability and volume of the code, as well as reducing memory consumption and hopefully improving cache hit rate. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27tipc: tipc_node_create() can be staticWei Yongjun1-2/+2
Fixes the following sparse warning: net/tipc/node.c:336:18: warning: symbol 'tipc_node_create' was not declared. Should it be static? Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23tipc: handle collisions of 32-bit node address hash valuesJon Maloy1-7/+78
When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23tipc: add 128-bit node identifierJon Maloy1-6/+2
We add a 128-bit node identity, as an alternative to the currently used 32-bit node address. For the sake of compatibility and to minimize message header changes we retain the existing 32-bit address field. When not set explicitly by the user, this field will be filled with a hash value generated from the much longer node identity, and be used as a shorthand value for the latter. We permit either the address or the identity to be set by configuration, but not both, so when the address value is set by a legacy user the corresponding 128-bit node identity is generated based on the that value. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23tipc: remove restrictions on node address valuesJon Maloy1-6/+2
Nominally, TIPC organizes network nodes into a three-level network hierarchy consisting of the levels 'zone', 'cluster' and 'node'. This hierarchy is reflected in the node address format, - it is sub-divided into an 8-bit zone id, and 12 bit cluster id, and a 12-bit node id. However, the 'zone' and 'cluster' levels have in reality never been fully implemented,and never will be. The result of this has been that the first 20 bits the node identity structure have been wasted, and the usable node identity range within a cluster has been limited to 12 bits. This is starting to become a problem. In the following commits, we will need to be able to connect between nodes which are using the whole 32-bit value space of the node address. We therefore remove the restrictions on which values can be assigned to node identity, -it is from now on only a 32-bit integer with no assumed internal structure. Isolation between clusters is now achieved only by setting different values for the 'network id' field used during neighbor discovery, in practice leading to the latter becoming the new cluster identity. The rules for accepting discovery requests/responses from neighboring nodes now become: - If the user is using legacy address format on both peers, reception of discovery messages is subject to the legacy lookup domain check in addition to the cluster id check. - Otherwise, the discovery request/response is always accepted, provided both peers have the same network id. This secures backwards compatibility for users who have been using zone or cluster identities as cluster separators, instead of the intended 'network id'. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-14tipc: apply bearer link tolerance on running linksJon Maloy1-0/+24
Currently, the default link tolerance set in struct tipc_bearer only has effect on links going up after that moment. I.e., a user has to reset all the node's links across that bearer to have the new value applied. This is too limiting and disturbing on a running cluster to be useful. We now change this so that also already existing links are updated dynamically, without any need for a reset, when the bearer value is changed. We leverage the already existing per-link functionality for this to achieve the wanted effect. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-15tipc: fix a memory leak in tipc_nl_node_get_link()Cong Wang1-12/+14
When tipc_node_find_by_name() fails, the nlmsg is not freed. While on it, switch to a goto label to properly free it. Fixes: be9c086715c ("tipc: narrow down exposure of struct tipc_node") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-16tipc: enforce valid ratio between skb truesize and contentsJon Maloy1-1/+1
The socket level flow control is based on the assumption that incoming buffers meet the condition (skb->truesize / roundup(skb->len) <= 4), where the latter value is rounded off upwards to the nearest 1k number. This does empirically hold true for the device drivers we know, but we cannot trust that it will always be so, e.g., in a system with jumbo frames and very small packets. We now introduce a check for this condition at packet arrival, and if we find it to be false, we copy the packet to a new, smaller buffer, where the condition will be true. We expect this to affect only a small fraction of all incoming packets, if at all. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01net: tipc: Convert timers to use timer_setup()Kees Cook1-4/+4
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: tipc-discussion@lists.sourceforge.net Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13tipc: add new function for sending multiple small messagesJon Maloy1-0/+16
We see an increasing need to send multiple single-buffer messages of TIPC_SYSTEM_IMPORTANCE to different individual destination nodes. Instead of looping over the send queue and sending each buffer individually, as we do now, we add a new help function tipc_node_distr_xmit() to do this. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13tipc: add ability to obtain node availability status from other filesJon Maloy1-5/+21
In the coming commits, functions at the socket level will need the ability to read the availability status of a given node. We therefore introduce a new function for this purpose, while renaming the existing static function currently having the wanted name. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+3
Three cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24tipc: context imbalance at node read unlockParthasarathy Bhuvaragan1-1/+1
If we fail to find a valid bearer in tipc_node_get_linkname(), node_read_unlock() is called without holding the node read lock. This commit fixes this error. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-24tipc: perform skb_linearize() before parsing the inner headerParthasarathy Bhuvaragan1-0/+2
In tipc_rcv(), we linearize only the header and usually the packets are consumed as the nodes permit direct reception. However, if the skb contains tunnelled message due to fail over or synchronization we parse it in tipc_node_check_state() without performing linearization. This will cause link disturbances if the skb was non linear. In this commit, we perform linearization for the above messages. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-21tipc: don't reset stale broadcast send linkJon Paul Maloy1-10/+4
When the broadcast send link after 100 attempts has failed to transfer a packet to all peers, we consider it stale, and reset it. Thereafter it needs to re-synchronize with the peers, something currently done by just resetting and re-establishing all links to all peers. This has turned out to be overkill, with potentially unwanted consequences for the remaining cluster. A closer analysis reveals that this can be done much simpler. When this kind of failure happens, for reasons that may lie outside the TIPC protocol, it is typically only one peer which is failing to receive and acknowledge packets. It is hence sufficient to identify and reset the links only to that peer to resolve the situation, without having to reset the broadcast link at all. This solution entails a much lower risk of negative consequences for the own node as well as for the overall cluster. We implement this change in this commit. Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-09tipc: remove premature ESTABLISH FSM event at link synchronizationJon Paul Maloy1-3/+1
When a link between two nodes come up, both endpoints will initially send out a STATE message to the peer, to increase the probability that the peer endpoint also is up when the first traffic message arrives. Thereafter, if the establishing link is the second link between two nodes, this first "traffic" message is a TUNNEL_PROTOCOL/SYNCH message, helping the peer to perform initial synchronization between the two links. However, the initial STATE message may be lost, in which case the SYNCH message will be the first one arriving at the peer. This should also work, as the SYNCH message itself will be used to take up the link endpoint before initializing synchronization. Unfortunately the code for this case is broken. Currently, the link is brought up through a tipc_link_fsm_evt(ESTABLISHED) when a SYNCH arrives, whereupon __tipc_node_link_up() is called to distribute the link slots and take the link into traffic. But, __tipc_node_link_up() is itself starting with a test for whether the link is up, and if true, returns without action. Clearly, the tipc_link_fsm_evt(ESTABLISHED) call is unnecessary, since tipc_node_link_up() is itself issuing such an event, but also harmful, since it inhibits tipc_node_link_up() to perform the test of its tasks, and the link endpoint in question hence is never taken into traffic. This problem has been exposed when we set up dual links between pre- and post-4.4 kernels, because the former ones don't send out the initial STATE message described above. We fix this by removing the unnecessary event call. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24tipc: check return value of nlmsg_newPan Bian1-0/+2
Function nlmsg_new() will return a NULL pointer if there is no enough memory, and its return value should be checked before it is used. However, in function tipc_nl_node_get_monitor(), the validation of the return value of function nlmsg_new() is missed. This patch fixes the bug. Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct where availableJohannes Berg1-4/+4
This is an add-on to the previous patch that passes the extended ACK structure where it's already available by existing genl_info or extack function arguments. This was done with this spatch (with some manual adjustment of indentation): @@ expression A, B, C, D, E; identifier fn, info; @@ fn(..., struct genl_info *info, ...) { ... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, info->extack) ... } @@ expression A, B, C, D, E; identifier fn, info; @@ fn(..., struct genl_info *info, ...) { <... -nla_parse_nested(A, B, C, D, NULL) +nla_parse_nested(A, B, C, D, info->extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_parse(A, B, C, D, E, NULL) +nla_parse(A, B, C, D, E, extack) ...> } @@ expression A, B, C, D, E; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { ... -nlmsg_parse(A, B, C, D, E, NULL) +nlmsg_parse(A, B, C, D, E, extack) ... } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_parse_nested(A, B, C, D, NULL) +nla_parse_nested(A, B, C, D, extack) ...> } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nlmsg_validate(A, B, C, D, NULL) +nlmsg_validate(A, B, C, D, extack) ...> } @@ expression A, B, C, D; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_validate(A, B, C, D, NULL) +nla_validate(A, B, C, D, extack) ...> } @@ expression A, B, C; identifier fn, extack; @@ fn(..., struct netlink_ext_ack *extack, ...) { <... -nla_validate_nested(A, B, C, NULL) +nla_validate_nested(A, B, C, extack) ...> } Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-6/+6
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-24tipc: move premature initilalization of stack variablesJon Paul Maloy1-5/+7
In the function tipc_rcv() we initialize a couple of stack variables from the message header before that same header has been validated. In rare cases when the arriving header is non-linar, the validation function itself may linearize the buffer by calling skb_may_pull(), while the wrongly initialized stack fields are not updated accordingly. We fix this in this commit. Reported-by: Matthew Wong <mwong@sonusnet.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+7
Two trivial overlapping changes conflicts in MPLS and mlx5. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24tipc: fix nametbl_lock soft lockup at node/link eventsParthasarathy Bhuvaragan1-2/+7
We trigger a soft lockup as we grab nametbl_lock twice if the node has a pending node up/down or link up/down event while: - we process an incoming named message in tipc_named_rcv() and perform an tipc_update_nametbl(). - we have pending backlog items in the name distributor queue during a nametable update using tipc_nametbl_publish() or tipc_nametbl_withdraw(). The following are the call chain associated: tipc_named_rcv() Grabs nametbl_lock tipc_update_nametbl() (publish/withdraw) tipc_node_subscribe()/unsubscribe() tipc_node_write_unlock() << lockup occurs if an outstanding node/link event exits, as we grabs nametbl_lock again >> tipc_nametbl_withdraw() Grab nametbl_lock tipc_named_process_backlog() tipc_update_nametbl() << rest as above >> The function tipc_node_write_unlock(), in addition to releasing the lock processes the outstanding node/link up/down events. To do this, we need to grab the nametbl_lock again leading to the lockup. In this commit we fix the soft lockup by introducing a fast variant of node_unlock(), where we just release the lock. We adapt the node_subscribe()/node_unsubscribe() to use the fast variants. Reported-and-Tested-by: John Thompson <thompa.atl@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-20tipc: introduce replicast as transport option for multicastJon Paul Maloy1-9/+18
TIPC multicast messages are currently carried over a reliable 'broadcast link', making use of the underlying media's ability to transport packets as L2 broadcast or IP multicast to all nodes in the cluster. When the used bearer is lacking that ability, we can instead emulate the broadcast service by replicating and sending the packets over as many unicast links as needed to reach all identified destinations. We now introduce a new TIPC link-level 'replicast' service that does this. Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03tipc: reduce risk of user starvation during link congestionJon Paul Maloy1-10/+5
The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29tipc: fix broadcast link synchronization problemJon Paul Maloy1-1/+1
In commit 2d18ac4ba745 ("tipc: extend broadcast link initialization criteria") we tried to fix a problem with the initial synchronization of broadcast link acknowledge values. Unfortunately that solution is not sufficient to solve the issue. We have seen it happen that LINK_PROTOCOL/STATE packets with a valid non-zero unicast acknowledge number may bypass BCAST_PROTOCOL initialization, NAME_DISTRIBUTOR and other STATE packets with invalid broadcast acknowledge numbers, leading to premature opening of the broadcast link. When the bypassed packets finally arrive, they are inadvertently accepted, and the already correctly initialized acknowledge number in the broadcast receive link is overwritten by the invalid (zero) value of the said packets. After this the broadcast link goes stale. We now fix this by marking the packets where we know the acknowledge value is or may be invalid, and then ignoring the acks from those. To this purpose, we claim an unused bit in the header to indicate that the value is invalid. We set the bit to 1 in the initial BCAST_PROTOCOL synchronization packet and all initial ("bulk") NAME_DISTRIBUTOR packets, plus those LINK_PROTOCOL packets sent out before the broadcast links are fully synchronized. This minor protocol update is fully backwards compatible. Reported-by: John Thompson <thompa.atl@gmail.com> Tested-by: John Thompson <thompa.atl@gmail.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>