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2020-12-01net/tipc: fix all function Return: notationRandy Dunlap
Fix Return: kernel-doc notation in all net/tipc/ source files. Also keep ReST list notation intact for output formatting. Fix a few typos in comments. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-01net/tipc: fix link.c kernel-docRandy Dunlap
Fix link.c kernel-doc warnings in preparation for adding to the networking docbook. ../net/tipc/link.c:200: warning: Function parameter or member 'session' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'snd_nxt_state' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'rcv_nxt_state' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'in_session' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'active' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'if_name' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'rst_cnt' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'drop_point' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'failover_reasm_skb' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'failover_deferdq' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'transmq' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'backlog' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'snd_nxt' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'rcv_unacked' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'deferdq' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'window' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'min_win' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'ssthresh' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'max_win' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'cong_acks' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'checkpoint' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'reasm_tnlmsg' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'last_gap' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'last_ga' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'bc_rcvlink' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'bc_sndlink' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'nack_state' not described in 'tipc_link' ../net/tipc/link.c:200: warning: Function parameter or member 'bc_peer_is_up' not described in 'tipc_link' ../net/tipc/link.c:473: warning: Function parameter or member 'self' not described in 'tipc_link_create' ../net/tipc/link.c:473: warning: Function parameter or member 'peer_id' not described in 'tipc_link_create' ../net/tipc/link.c:473: warning: Excess function parameter 'ownnode' description in 'tipc_link_create' ../net/tipc/link.c:544: warning: Function parameter or member 'ownnode' not described in 'tipc_link_bc_create' ../net/tipc/link.c:544: warning: Function parameter or member 'peer' not described in 'tipc_link_bc_create' ../net/tipc/link.c:544: warning: Function parameter or member 'peer_id' not described in 'tipc_link_bc_create' ../net/tipc/link.c:544: warning: Function parameter or member 'peer_caps' not described in 'tipc_link_bc_create' ../net/tipc/link.c:544: warning: Function parameter or member 'bc_sndlink' not described in 'tipc_link_bc_create' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-02tipc: remove unneeded semicolonTom Rix
A semicolon is not needed after a switch statement. Signed-off-by: Tom Rix <trix@redhat.com> Link: https://lore.kernel.org/r/20201101155822.2294856-1-trix@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-18tipc: add automatic session key exchangeTuong Lien
With support from the master key option in the previous commit, it becomes easy to make frequent updates/exchanges of session keys between authenticated cluster nodes. Basically, there are two situations where the key exchange will take in place: - When a new node joins the cluster (with the master key), it will need to get its peer's TX key, so that be able to decrypt further messages from that peer. - When a new session key is generated (by either user manual setting or later automatic rekeying feature), the key will be distributed to all peer nodes in the cluster. A key to be exchanged is encapsulated in the data part of a 'MSG_CRYPTO /KEY_DISTR_MSG' TIPC v2 message, then xmit-ed as usual and encrypted by using the master key before sending out. Upon receipt of the message it will be decrypted in the same way as regular messages, then attached as the sender's RX key in the receiver node. In this way, the key exchange is reliable by the link layer, as well as security, integrity and authenticity by the crypto layer. Also, the forward security will be easily achieved by user changing the master key actively but this should not be required very frequently. The key exchange feature is independent on the presence of a master key Note however that the master key still is needed for new nodes to be able to join the cluster. It is also optional, and can be turned off/on via the sysfs: 'net/tipc/key_exchange_enabled' [default 1: enabled]. Backward compatibility is guaranteed because for nodes that do not have master key support, key exchange using master key ie. tx_key = 0 if any will be shortly discarded at the message validation step. In other words, the key exchange feature will be automatically disabled to those nodes. v2: fix the "implicit declaration of function 'tipc_crypto_key_flush'" error in node.c. The function only exists when built with the TIPC "CONFIG_TIPC_CRYPTO" option. v3: use 'info->extack' for a message emitted due to netlink operations instead (- David's comment). Reported-by: kernel test robot <lkp@intel.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-15net: tipc: kerneldoc fixesLu Wei
Fix parameter description of tipc_link_bc_create() Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 16ad3f4022bb ("tipc: introduce variable window congestion control") Signed-off-by: Lu Wei <luwei32@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-31tipc: Remove unused macro TIPC_NACK_INTVYueHaibing
There is no caller in tree any more. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-18net: tipc: Convert to use the preferred fallthrough macroMiaohe Lin
Convert the uses of fallthrough comments to fallthrough macro. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The UDP reuseport conflict was a little bit tricky. The net-next code, via bpf-next, extracted the reuseport handling into a helper so that the BPF sk lookup code could invoke it. At the same time, the logic for reuseport handling of unconnected sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace which changed the logic to carry on the reuseport result into the rest of the lookup loop if we do not return immediately. This requires moving the reuseport_has_conns() logic into the callers. While we are here, get rid of inline directives as they do not belong in foo.c files. The other changes were cases of more straightforward overlapping modifications. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20tipc: allow to build NACK message in link timeout functionTung Nguyen
Commit 02288248b051 ("tipc: eliminate gap indicator from ACK messages") eliminated sending of the 'gap' indicator in regular ACK messages and only allowed to build NACK message with enabled probe/probe_reply. However, necessary correction for building NACK message was missed in tipc_link_timeout() function. This leads to significant delay and link reset (due to retransmission failure) in lossy environment. This commit fixes it by setting the 'probe' flag to 'true' when the receive deferred queue is not empty. As a result, NACK message will be built to send back to another peer. Fixes: 02288248b051 ("tipc: eliminate gap indicator from ACK messages") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13net: tipc: kerneldoc fixesAndrew Lunn
Simple fixes which require no deep knowledge of the code. Cc: Jon Maloy <jmaloy@redhat.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
All conflicts seemed rather trivial, with some guidance from Saeed Mameed on the tc_ct.c one. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08tipc: fix retransmission on unicast linksHamish Martin
A scenario has been observed where a 'bc_init' message for a link is not retransmitted if it fails to be received by the peer. This leads to the peer never establishing the link fully and it discarding all other data received on the link. In this scenario the message is lost in transit to the peer. The issue is traced to the 'nxt_retr' field of the skb not being initialised for links that aren't a bc_sndlink. This leads to the comparison in tipc_link_advance_transmq() that gates whether to attempt retransmission of a message performing in an undesirable way. Depending on the relative value of 'jiffies', this comparison: time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr) may return true or false given that 'nxt_retr' remains at the uninitialised value of 0 for non bc_sndlinks. This is most noticeable shortly after boot when jiffies is initialised to a high value (to flush out rollover bugs) and we compare a jiffies of, say, 4294940189 to zero. In that case time_before returns 'true' leading to the skb not being retransmitted. The fix is to ensure that all skbs have a valid 'nxt_retr' time set for them and this is achieved by refactoring the setting of this value into a central function. With this fix, transmission losses of 'bc_init' messages do not stall the link establishment forever because the 'bc_init' message is retransmitted and the link eventually establishes correctly. Fixes: 382f598fb66b ("tipc: reduce duplicate packets for unicast traffic") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-19tipc: Use struct_size() helperGustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-17tipc: update a binding service via broadcastHoang Huu Le
Currently, updating binding table (add service binding to name table/withdraw a service binding) is being sent over replicast. However, if we are scaling up clusters to > 100 nodes/containers this method is less affection because of looping through nodes in a cluster one by one. It is worth to use broadcast to update a binding service. This way, the binding table can be updated on all peer nodes in one shot. Broadcast is used when all peer nodes, as indicated by a new capability flag TIPC_NAMED_BCAST, support reception of this message type. Four problems need to be considered when introducing this feature. 1) When establishing a link to a new peer node we still update this by a unicast 'bulk' update. This may lead to race conditions, where a later broadcast publication/withdrawal bypass the 'bulk', resulting in disordered publications, or even that a withdrawal may arrive before the corresponding publication. We solve this by adding an 'is_last_bulk' bit in the last bulk messages so that it can be distinguished from all other messages. Only when this message has arrived do we open up for reception of broadcast publications/withdrawals. 2) When a first legacy node is added to the cluster all distribution will switch over to use the legacy 'replicast' method, while the opposite happens when the last legacy node leaves the cluster. This entails another risk of message disordering that has to be handled. We solve this by adding a sequence number to the broadcast/replicast messages, so that disordering can be discovered and corrected. Note however that we don't need to consider potential message loss or duplication at this protocol level. 3) Bulk messages don't contain any sequence numbers, and will always arrive in order. Hence we must exempt those from the sequence number control and deliver them unconditionally. We solve this by adding a new 'is_bulk' bit in those messages so that they can be recognized. 4) Legacy messages, which don't contain any new bits or sequence numbers, but neither can arrive out of order, also need to be exempt from the initial synchronization and sequence number check, and delivered unconditionally. Therefore, we add another 'is_not_legacy' bit to all new messages so that those can be distinguished from legacy messages and the latter delivered directly. v1->v2: - fix warning issue reported by kbuild test robot <lkp@intel.com> - add santiy check to drop the publication message with a sequence number that is lower than the agreed synch point Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26tipc: add support for broadcast rcv stats dumpingTuong Lien
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:<peer-id>'. For example: Link <broadcast-link:1001002> 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 <ying.xue@windriver.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26tipc: enable broadcast retrans via unicastTuong Lien
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 <ying.xue@windriver.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26tipc: add back link trace eventsTuong Lien
In the previous commit ("tipc: add Gap ACK blocks support for broadcast link"), we have removed the following link trace events due to the code changes: - tipc_link_bc_ack - tipc_link_retrans This commit adds them back along with some minor changes to adapt to the new code. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26tipc: introduce Gap ACK blocks for broadcast linkTuong Lien
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 <ying.xue@windriver.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-15tipc: fix incorrect increasing of link windowTuong Lien
In commit 16ad3f4022bb ("tipc: introduce variable window congestion control"), we allow link window to change with the congestion avoidance algorithm. However, there is a bug that during the slow-start if packet retransmission occurs, the link will enter the fast-recovery phase, set its window to the 'ssthresh' which is never less than 300, so the link window suddenly increases to that limit instead of decreasing. Consequently, two issues have been observed: - For broadcast-link: it can leave a gap between the link queues that a new packet will be inserted and sent before the previous ones, i.e. not in-order. - For unicast: the algorithm does not work as expected, the link window jumps to the slow-start threshold whereas packet retransmission occurs. This commit fixes the issues by avoiding such the link window increase, but still decreasing if the 'ssthresh' is lowered. Fixes: 16ad3f4022bb ("tipc: introduce variable window congestion control") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17tipc: don't send gap blocks in ACK messagesJon Maloy
In the commit referred to below we eliminated sending of the 'gap' indicator in regular ACK messages, reserving this to explicit NACK ditto. Unfortunately we missed to also eliminate building of the 'gap block' area in ACK messages. This area is meant to report gaps in the received packet sequence following the initial gap, so that lost packets can be retransmitted earlier and received out-of-sequence packets can be released earlier. However, the interpretation of those blocks is dependent on a complete and correct sequence of gaps and acks. Hence, when the initial gap indicator is missing a single gap block will be interpreted as an acknowledgment of all preceding packets. This may lead to packets being released prematurely from the sender's transmit queue, with easily predicatble consequences. We now fix this by not building any gap block area if there is no initial gap to report. Fixes: commit 02288248b051 ("tipc: eliminate gap indicator from ACK messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-10tipc: introduce variable window congestion controlJon Maloy
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 <lucien.xin@gmail.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>
2019-12-10tipc: eliminate more unnecessary nacks and retransmissionsJon Maloy
When we increase the link tranmsit window we often observe the following scenario: 1) A STATE message bypasses a sequence of traffic packets and arrives far ahead of those to the receiver. STATE messages contain a 'peers_nxt_snt' field to indicate which was the last packet sent from the peer. This mechanism is intended as a last resort for the receiver to detect missing packets, e.g., during very low traffic when there is no packet flow to help early loss detection. 3) The receiving link compares the 'peer_nxt_snt' field to its own 'rcv_nxt', finds that there is a gap, and immediately sends a NACK message back to the peer. 4) When this NACKs arrives at the sender, all the requested retransmissions are performed, since it is a first-time request. Just like in the scenario described in the previous commit this leads to many redundant retransmissions, with decreased throughput as a consequence. We fix this by adding two more conditions before we send a NACK in this sitution. First, the deferred queue must be empty, so we cannot assume that the potential packet loss has already been detected by other means. Second, we check the 'peers_snd_nxt' field only in probe/ probe_reply messages, thus turning this into a true mechanism of last resort as it was really meant to be. 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>
2019-12-10tipc: eliminate gap indicator from ACK messagesJon Maloy
When we increase the link send window we sometimes observe the following scenario: 1) A packet #N arrives out of order far ahead of a sequence of older packets which are still under way. The packet is added to the deferred queue. 2) The missing packets arrive in sequence, and for each 16th of them an ACK is sent back to the receiver, as it should be. 3) When building those ACK messages, it is checked if there is a gap between the link's 'rcv_nxt' and the first packet in the deferred queue. This is always the case until packet number #N-1 arrives, and a 'gap' indicator is added, effectively turning them into NACK messages. 4) When those NACKs arrive at the sender, all the requested retransmissions are done, since it is a first-time request. This sometimes leads to a huge amount of redundant retransmissions, causing a drop in max throughput. This problem gets worse when we in a later commit introduce variable window congestion control, since it drops the link back to 'fast recovery' much more often than necessary. We now fix this by not sending any 'gap' indicator in regular ACK messages. We already have a mechanism for sending explicit NACKs in place, and this is sufficient to keep up the packet flow. 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>
2019-11-22tipc: update replicast capability for broadcast send linkHoang Le
When setting up a cluster with non-replicast/replicast capability supported. This capability will be disabled for broadcast send link in order to be backwards compatible. However, when these non-support nodes left and be removed out the cluster. We don't update this capability on broadcast send link. Then, some of features that based on this capability will also disabling as unexpected. In this commit, we make sure the broadcast send link capabilities will be re-calculated as soon as a node removed/rejoined a cluster. 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>
2019-11-08tipc: introduce TIPC encryption & authenticationTuong Lien
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 <ying.xue@windreiver.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>
2019-11-06tipc: eliminate the dummy packet in link synchingTuong Lien
When preparing tunnel packets for the link failover or synchronization, as for the safe algorithm, we added a dummy packet on the pair link but never sent it out. In the case of failover, the pair link will be reset anyway. But for link synching, it will always result in retransmission of the dummy packet after that. We have also observed that such the retransmission at the early stage when a new node comes in a large cluster will take some time and hard to be done, leading to the repeated retransmit failures and the link is reset. Since in commit 4929a932be33 ("tipc: optimize link synching mechanism") we have already built a dummy 'TUNNEL_PROTOCOL' message on the new link for the synchronization, there's no need for the dummy on the pair one, this commit will skip it when the new mechanism takes in place. In case nothing exists in the pair link's transmq, the link synching will just start and stop shortly on the peer side. The patch is backward compatible. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Tested-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06tipc: reduce sensitive to retransmit failuresHoang Le
With huge cluster (e.g >200nodes), the amount of that flow: gap -> retransmit packet -> acked will take time in case of STATE_MSG dropped/delayed because a lot of traffic. This lead to 1.5 sec tolerance value criteria made link easy failure around 2nd, 3rd of failed retransmission attempts. Instead of re-introduced criteria of 99 faled retransmissions to fix the issue, we increase failure detection timer to ten times tolerance value. Fixes: 77cf8edbc0e7 ("tipc: simplify stale link failure criteria") Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Acked-by: Jon Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-03tipc: improve message bundling algorithmTuong Lien
As mentioned in commit e95584a889e1 ("tipc: fix unlimited bundling of small messages"), the current message bundling algorithm is inefficient that can generate bundles of only one payload message, that causes unnecessary overheads for both the sender and receiver. This commit re-designs the 'tipc_msg_make_bundle()' function (now named as 'tipc_msg_try_bundle()'), so that when a message comes at the first place, we will just check & keep a reference to it if the message is suitable for bundling. The message buffer will be put into the link backlog queue and processed as normal. Later on, when another one comes we will make a bundle with the first message if possible and so on... This way, a bundle if really needed will always consist of at least two payload messages. Otherwise, we let the first buffer go its way without any need of bundling, so reduce the overheads to zero. Moreover, since now we have both the messages in hand, we can even optimize the 'tipc_msg_bundle()' function, make bundle of a very large (size ~ MSS) and small messages which is not with the current algorithm e.g. [1400-byte message] + [10-byte message] (MTU = 1500). Acked-by: Ying Xue <ying.xue@windreiver.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>
2019-10-28tipc: Spelling s/enpoint/endpoint/Geert Uytterhoeven
Fix misspelling of "endpoint". Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02tipc: fix unlimited bundling of small messagesTuong Lien
We have identified a problem with the "oversubscription" policy in the link transmission code. When small messages are transmitted, and the sending link has reached the transmit window limit, those messages will be bundled and put into the link backlog queue. However, bundles of data messages are counted at the 'CRITICAL' level, so that the counter for that level, instead of the counter for the real, bundled message's level is the one being increased. Subsequent, to-be-bundled data messages at non-CRITICAL levels continue to be tested against the unchanged counter for their own level, while contributing to an unrestrained increase at the CRITICAL backlog level. This leaves a gap in congestion control algorithm for small messages that can result in starvation for other users or a "real" CRITICAL user. Even that eventually can lead to buffer exhaustion & link reset. We fix this by keeping a 'target_bskb' buffer pointer at each levels, then when bundling, we only bundle messages at the same importance level only. This way, we know exactly how many slots a certain level have occupied in the queue, so can manage level congestion accurately. By bundling messages at the same level, we even have more benefits. Let consider this: - One socket sends 64-byte messages at the 'CRITICAL' level; - Another sends 4096-byte messages at the 'LOW' level; When a 64-byte message comes and is bundled the first time, we put the overhead of message bundle to it (+ 40-byte header, data copy, etc.) for later use, but the next message can be a 4096-byte one that cannot be bundled to the previous one. This means the last bundle carries only one payload message which is totally inefficient, as for the receiver also! Later on, another 64-byte message comes, now we make a new bundle and the same story repeats... With the new bundling algorithm, this will not happen, the 64-byte messages will be bundled together even when the 4096-byte message(s) comes in between. However, if the 4096-byte messages are sent at the same level i.e. 'CRITICAL', the bundling algorithm will again cause the same overhead. Also, the same will happen even with only one socket sending small messages at a rate close to the link transmit's one, so that, when one message is bundled, it's transmitted shortly. Then, another message comes, a new bundle is created and so on... We will solve this issue radically by another patch. Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion") Reported-by: Hoang Le <hoang.h.le@dektech.com.au> 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>
2019-08-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Merge conflict of mlx5 resolved using instructions in merge commit 9566e650bf7fdf58384bb06df634f7531ca3a97e. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-18tipc: clean up skb list lock handling on send pathJon Maloy
The policy for handling the skb list locks on the send and receive paths is simple. - On the send path we never need to grab the lock on the 'xmitq' list when the destination is an exernal node. - On the receive path we always need to grab the lock on the 'inputq' list, irrespective of source node. However, when transmitting node local messages those will eventually end up on the receive path of a local socket, meaning that the argument 'xmitq' in tipc_node_xmit() will become the 'ínputq' argument in the function tipc_sk_rcv(). This has been handled by always initializing the spinlock of the 'xmitq' list at message creation, just in case it may end up on the receive path later, and despite knowing that the lock in most cases never will be used. This approach is inaccurate and confusing, and has also concealed the fact that the stated 'no lock grabbing' policy for the send path is violated in some cases. We now clean up this by never initializing the lock at message creation, instead doing this at the moment we find that the message actually will enter the receive path. At the same time we fix the four locations where we incorrectly access the spinlock on the send/error path. This patch also reverts commit d12cffe9329f ("tipc: ensure head->lock is initialised") which has now become redundant. CC: Eric Dumazet <edumazet@google.com> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-16tipc: fix false detection of retransmit failuresTuong Lien
This commit eliminates the use of the link 'stale_limit' & 'prev_from' (besides the already removed - 'stale_cnt') variables in the detection of repeated retransmit failures as there is no proper way to initialize them to avoid a false detection, i.e. it is not really a retransmission failure but due to a garbage values in the variables. Instead, a jiffies variable will be added to individual skbs (like the way we restrict the skb retransmissions) in order to mark the first skb retransmit time. Later on, at the next retransmissions, the timestamp will be checked to see if the skb in the link transmq is "too stale", that is, the link tolerance time has passed, so that a link reset will be ordered. Note, just checking on the first skb in the queue is fine enough since it must be the oldest one. A counter is also added to keep track the actual skb retransmissions' number for later checking when the failure happens. The downside of this approach is that the skb->cb[] buffer is about to be exhausted, however it is always able to allocate another memory area and keep a reference to it when needed. Fixes: 77cf8edbc0e7 ("tipc: simplify stale link failure criteria") Reported-by: Hoang Le <hoang.h.le@dektech.com.au> Acked-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>
2019-08-01tipc: reduce risk of wakeup queue starvationJon Maloy
In commit 365ad353c256 ("tipc: reduce risk of user starvation during link congestion") we allowed senders to add exactly one list of extra buffers to the link backlog queues during link congestion (aka "oversubscription"). However, the criteria for when to stop adding wakeup messages to the input queue when the overload abates is inaccurate, and may cause starvation problems during very high load. Currently, we stop adding wakeup messages after 10 total failed attempts where we find that there is no space left in the backlog queue for a certain importance level. The counter for this is accumulated across all levels, which may lead the algorithm to leave the loop prematurely, although there may still be plenty of space available at some levels. The result is sometimes that messages near the wakeup queue tail are not added to the input queue as they should be. We now introduce a more exact algorithm, where we keep adding wakeup messages to a level as long as the backlog queue has free slots for the corresponding level, and stop at the moment there are no more such slots or when there are no more wakeup messages to dequeue. Fixes: 365ad35 ("tipc: reduce risk of user starvation during link congestion") Reported-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> 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>
2019-07-25tipc: fix changeover issues due to large packetTuong Lien
In conjunction with changing the interfaces' MTU (e.g. especially in the case of a bonding) where the TIPC links are brought up and down in a short time, a couple of issues were detected with the current link changeover mechanism: 1) When one link is up but immediately forced down again, the failover procedure will be carried out in order to failover all the messages in the link's transmq queue onto the other working link. The link and node state is also set to FAILINGOVER as part of the process. The message will be transmited in form of a FAILOVER_MSG, so its size is plus of 40 bytes (= the message header size). There is no problem if the original message size is not larger than the link's MTU - 40, and indeed this is the max size of a normal payload messages. However, in the situation above, because the link has just been up, the messages in the link's transmq are almost SYNCH_MSGs which had been generated by the link synching procedure, then their size might reach the max value already! When the FAILOVER_MSG is built on the top of such a SYNCH_MSG, its size will exceed the link's MTU. As a result, the messages are dropped silently and the failover procedure will never end up, the link will not be able to exit the FAILINGOVER state, so cannot be re-established. 2) The same scenario above can happen more easily in case the MTU of the links is set differently or when changing. In that case, as long as a large message in the failure link's transmq queue was built and fragmented with its link's MTU > the other link's one, the issue will happen (there is no need of a link synching in advance). 3) The link synching procedure also faces with the same issue but since the link synching is only started upon receipt of a SYNCH_MSG, dropping the message will not result in a state deadlock, but it is not expected as design. The 1) & 3) issues are resolved by the last commit that only a dummy SYNCH_MSG (i.e. without data) is generated at the link synching, so the size of a FAILOVER_MSG if any then will never exceed the link's MTU. For the 2) issue, the only solution is trying to fragment the messages in the failure link's transmq queue according to the working link's MTU so they can be failovered then. A new function is made to accomplish this, it will still be a TUNNEL PROTOCOL/FAILOVER MSG but if the original message size is too large, it will be fragmented & reassembled at the receiving side. Acked-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>
2019-07-25tipc: optimize link synching mechanismTuong Lien
This commit along with the next one are to resolve the issues with the link changeover mechanism. See that commit for details. Basically, for the link synching, from now on, we will send only one single ("dummy") SYNCH message to peer. The SYNCH message does not contain any data, just a header conveying the synch point to the peer. A new node capability flag ("TIPC_TUNNEL_ENHANCED") is introduced for backward compatible! Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Suggested-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>
2019-07-01tipc: embed jiffies in macro TIPC_BC_RETR_LIMJon Maloy
The macro TIPC_BC_RETR_LIM is always used in combination with 'jiffies', so we can just as well perform the addition in the macro itself. This way, we get a few shorter code lines and one less line break. 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>
2019-06-25tipc: rename function msg_get_wrapped() to msg_inner_hdr()Jon Maloy
We rename the inline function msg_get_wrapped() to the more comprehensible msg_inner_hdr(). Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-25tipc: eliminate unnecessary skb expansion during retransmissionJon Maloy
We increase the allocated headroom for the buffer copies to be retransmitted. This eliminates the need for the lower stack levels (UDP/IP/L2) to expand the headroom in order to add their own headers. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-25tipc: simplify stale link failure criteriaJon Maloy
In commit a4dc70d46cf1 ("tipc: extend link reset criteria for stale packet retransmission") we made link retransmission failure events dependent on the link tolerance, and not only of the number of failed retransmission attempts, as we did earlier. This works well. However, keeping the original, additional criteria of 99 failed retransmissions is now redundant, and may in some cases lead to failure detection times in the order of minutes instead of the expected 1.5 sec link tolerance value. We now remove this criteria altogether. 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>
2019-06-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Minor SPDX change conflict. Signed-off-by: David S. Miller <davem@davemloft.ne