kernel/linux.git/net/tipc/link.h, branch v6.12.80

tipc: Remove unused declaration tipc_link_build_bc_sync_msg()

2023-08-09T20:03:14+00:00

Commit 526669866140 ("tipc: let broadcast packet reception use new link receive function") declared but never implemented this. Signed-off-by: Yue Haibing Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230807142926.45752-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski

tipc: simplify the finalize work queue

2021-05-18T20:22:09+00:00

This patch is to use "struct work_struct" for the finalize work queue instead of "struct tipc_net_work", as it can get the "net" and "addr" from tipc_net's other members and there is no need to add extra net and addr in tipc_net by defining "struct tipc_net_work". Note that it's safe to get net from tn->bcl as bcl is always released after the finalize work queue is done. Signed-off-by: Xin Long Acked-by: Jon Maloy Signed-off-by: David S. Miller

tipc: add support for broadcast rcv stats dumping

2020-05-26T22:16:52+00:00

This commit enables dumping the statistics of a broadcast-receiver link like the traditional 'broadcast-link' one (which is for broadcast- sender). The link dumping can be triggered via netlink (e.g. the iproute2/tipc tool) by the link flag - 'TIPC_NLA_LINK_BROADCAST' as the indicator. The name of a broadcast-receiver link of a specific peer will be in the format: 'broadcast-link:'. For example: Link Window:50 packets RX packets:7841 fragments:2408/440 bundles:0/0 TX packets:0 fragments:0/0 bundles:0/0 RX naks:0 defs:124 dups:0 TX naks:21 acks:0 retrans:0 Congestion link:0 Send queue max:0 avg:0 In addition, the broadcast-receiver link statistics can be reset in the usual way via netlink by specifying that link name in command. Note: the 'tipc_link_name_ext()' is removed because the link name can now be retrieved simply via the 'l->name'. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: enable broadcast retrans via unicast

2020-05-26T22:16:52+00:00

In some environment, broadcast traffic is suppressed at high rate (i.e. a kind of bandwidth limit setting). When it is applied, TIPC broadcast can still run successfully. However, when it comes to a high load, some packets will be dropped first and TIPC tries to retransmit them but the packet retransmission is intentionally broadcast too, so making things worse and not helpful at all. This commit enables the broadcast retransmission via unicast which only retransmits packets to the specific peer that has really reported a gap i.e. not broadcasting to all nodes in the cluster, so will prevent from being suppressed, and also reduce some overheads on the other peers due to duplicates, finally improve the overall TIPC broadcast performance. Note: the functionality can be turned on/off via the sysctl file: echo 1 > /proc/sys/net/tipc/bc_retruni echo 0 > /proc/sys/net/tipc/bc_retruni Default is '0', i.e. the broadcast retransmission still works as usual. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: introduce Gap ACK blocks for broadcast link

2020-05-26T22:16:52+00:00

As achieved through commit 9195948fbf34 ("tipc: improve TIPC throughput by Gap ACK blocks"), we apply the same mechanism for the broadcast link as well. The 'Gap ACK blocks' data field in a 'PROTOCOL/STATE_MSG' will consist of two parts built for both the broadcast and unicast types: 31 16 15 0 +-------------+-------------+-------------+-------------+ | bgack_cnt | ugack_cnt | len | +-------------+-------------+-------------+-------------+ - | gap | ack | | +-------------+-------------+-------------+-------------+ > bc gacks : : : | +-------------+-------------+-------------+-------------+ - | gap | ack | | +-------------+-------------+-------------+-------------+ > uc gacks : : : | +-------------+-------------+-------------+-------------+ - which is "automatically" backward-compatible. We also increase the max number of Gap ACK blocks to 128, allowing upto 64 blocks per type (total buffer size = 516 bytes). Besides, the 'tipc_link_advance_transmq()' function is refactored which is applicable for both the unicast and broadcast cases now, so some old functions can be removed and the code is optimized. With the patch, TIPC broadcast is more robust regardless of packet loss or disorder, latency, ... in the underlying network. Its performance is boost up significantly. For example, experiment with a 5% packet loss rate results: $ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000 real 0m 42.46s user 0m 1.16s sys 0m 17.67s Without the patch: $ time tipc-pipe --mc --rdm --data_size 123 --data_num 1500000 real 8m 27.94s user 0m 0.55s sys 0m 2.38s Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: introduce variable window congestion control

2019-12-11T01:31:15+00:00

We introduce a simple variable window congestion control for links. The algorithm is inspired by the Reno algorithm, covering both 'slow start', 'congestion avoidance', and 'fast recovery' modes. - We introduce hard lower and upper window limits per link, still different and configurable per bearer type. - We introduce a 'slow start theshold' variable, initially set to the maximum window size. - We let a link start at the minimum congestion window, i.e. in slow start mode, and then let is grow rapidly (+1 per rceived ACK) until it reaches the slow start threshold and enters congestion avoidance mode. - In congestion avoidance mode we increment the congestion window for each window-size number of acked packets, up to a possible maximum equal to the configured maximum window. - For each non-duplicate NACK received, we drop back to fast recovery mode, by setting the both the slow start threshold to and the congestion window to (current_congestion_window / 2). - If the timeout handler finds that the transmit queue has not moved since the previous timeout, it drops the link back to slow start and forces a probe containing the last sent sequence number to the sent to the peer, so that this can discover the stale situation. This change does in reality have effect only on unicast ethernet transport, as we have seen that there is no room whatsoever for increasing the window max size for the UDP bearer. For now, we also choose to keep the limits for the broadcast link unchanged and equal. This algorithm seems to give a 50-100% throughput improvement for messages larger than MTU. Suggested-by: Xin Long Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: introduce TIPC encryption & authentication

2019-11-08T22:01:59+00:00

This commit offers an option to encrypt and authenticate all messaging, including the neighbor discovery messages. The currently most advanced algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All encryption/decryption is done at the bearer layer, just before leaving or after entering TIPC. Supported features: - Encryption & authentication of all TIPC messages (header + data); - Two symmetric-key modes: Cluster and Per-node; - Automatic key switching; - Key-expired revoking (sequence number wrapped); - Lock-free encryption/decryption (RCU); - Asynchronous crypto, Intel AES-NI supported; - Multiple cipher transforms; - Logs & statistics; Two key modes: - Cluster key mode: One single key is used for both TX & RX in all nodes in the cluster. - Per-node key mode: Each nodes in the cluster has one specific TX key. For RX, a node requires its peers' TX key to be able to decrypt the messages from those peers. Key setting from user-space is performed via netlink by a user program (e.g. the iproute2 'tipc' tool). Internal key state machine: Attach Align(RX) +-+ +-+ | V | V +---------+ Attach +---------+ | IDLE |---------------->| PENDING |(user = 0) +---------+ +---------+ A A Switch| A | | | | | | Free(switch/revoked) | | (Free)| +----------------------+ | |Timeout | (TX) | | |(RX) | | | | | | v | +---------+ Switch +---------+ | PASSIVE |<----------------| ACTIVE | +---------+ (RX) +---------+ (user = 1) (user >= 1) The number of TFMs is 10 by default and can be changed via the procfs 'net/tipc/max_tfms'. At this moment, as for simplicity, this file is also used to print the crypto statistics at runtime: echo 0xfff1 > /proc/sys/net/tipc/max_tfms The patch defines a new TIPC version (v7) for the encryption message (- backward compatibility as well). The message is basically encapsulated as follows: +----------------------------------------------------------+ | TIPCv7 encryption | Original TIPCv2 | Authentication | | header | packet (encrypted) | Tag | +----------------------------------------------------------+ The throughput is about ~40% for small messages (compared with non- encryption) and ~9% for large messages. With the support from hardware crypto i.e. the Intel AES-NI CPU instructions, the throughput increases upto ~85% for small messages and ~55% for large messages. By default, the new feature is inactive (i.e. no encryption) until user sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO" in the kernel configuration to enable/disable the new code when needed. MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: fix missing Name entries due to half-failover

2019-05-04T04:59:51+00:00

TIPC link can temporarily fall into "half-establish" that only one of the link endpoints is ESTABLISHED and starts to send traffic, PROTOCOL messages, whereas the other link endpoint is not up (e.g. immediately when the endpoint receives ACTIVATE_MSG, the network interface goes down...). This is a normal situation and will be settled because the link endpoint will be eventually brought down after the link tolerance time. However, the situation will become worse when the second link is established before the first link endpoint goes down, For example: 1. Both links <1A-2A>, <1B-2B> down 2. Link endpoint 2A up, but 1A still down (e.g. due to network disturbance, wrong session, etc.) 3. Link <1B-2B> up 4. Link endpoint 2A down (e.g. due to link tolerance timeout) 5. Node B starts failover onto link <1B-2B> ==> Node A does never start link failover. When the "half-failover" situation happens, two consequences have been observed: a) Peer link/node gets stuck in FAILINGOVER state; b) Traffic or user messages that peer node is trying to failover onto the second link can be partially or completely dropped by this node. The consequence a) was actually solved by commit c140eb166d68 ("tipc: fix failover problem"), but that commit didn't cover the b). It's due to the fact that the tunnel link endpoint has never been prepared for a failover, so the 'l->drop_point' (and the other data...) is not set correctly. When a TUNNEL_MSG from peer node arrives on the link, depending on the inner message's seqno and the current 'l->drop_point' value, the message can be dropped (- treated as a duplicate message) or processed. At this early stage, the traffic messages from peer are likely to be NAME_DISTRIBUTORs, this means some name table entries will be missed on the node forever! The commit resolves the issue by starting the FAILOVER process on this node as well. Another benefit from this solution is that we ensure the link will not be re-established until the failover ends. Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: add trace_events for tipc link

2018-12-19T19:49:24+00:00

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 Tested-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller

tipc: enable tracepoints in tipc

2018-12-19T19:49:24+00:00

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 Tested-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller