kernel/linux.git/include/linux/rtnetlink.h, branch v6.6.132

rtnl: add helper to check if a notification is needed

2025-04-25T08:45:06+00:00

[ Upstream commit 8439109b76a3c405808383bf9dd532fc4b9c2dbd ] Building on the rtnl_has_listeners helper, add the rtnl_notify_needed helper to check if we can bail out early in the notification routines. Reviewed-by: Jiri Pirko Reviewed-by: Simon Horman Signed-off-by: Victor Nogueira Signed-off-by: Pedro Tammela Link: https://lore.kernel.org/r/20231208192847.714940-3-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski Stable-dep-of: 369609fc6272 ("tc: Ensure we have enough buffer space when sending filter netlink notifications") Signed-off-by: Sasha Levin

rtnl: add helper to check if rtnl group has listeners

2025-04-25T08:45:06+00:00

[ Upstream commit c5e2a973448d958feb7881e4d875eac59fdeff3d ] As of today, rtnl code creates a new skb and unconditionally fills and broadcasts it to the relevant group. For most operations this is okay and doesn't waste resources in general. When operations are done without the rtnl_lock, as in tc-flower, such skb allocation, message fill and no-op broadcasting can happen in all cores of the system, which contributes to system pressure and wastes precious cpu cycles when no one will receive the built message. Introduce this helper so rtnetlink operations can simply check if someone is listening and then proceed if necessary. Reviewed-by: Jiri Pirko Reviewed-by: Simon Horman Signed-off-by: Jamal Hadi Salim Signed-off-by: Victor Nogueira Signed-off-by: Pedro Tammela Link: https://lore.kernel.org/r/20231208192847.714940-2-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski Stable-dep-of: 369609fc6272 ("tc: Ensure we have enough buffer space when sending filter netlink notifications") Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-04-13T23:04:28+00:00

Conflicts: tools/testing/selftests/net/config 62199e3f1658 ("selftests: net: Add VXLAN MDB test") 3a0385be133e ("selftests: add the missing CONFIG_IP_SCTP in net config") Signed-off-by: Jakub Kicinski

rtnetlink: Restore RTM_NEW/DELLINK notification behavior

2023-04-13T03:47:58+00:00

The commits referenced below allows userspace to use the NLM_F_ECHO flag for RTM_NEW/DELLINK operations to receive unicast notifications for the affected link. Prior to these changes, applications may have relied on multicast notifications to learn the same information without specifying the NLM_F_ECHO flag. For such applications, the mentioned commits changed the behavior for requests not using NLM_F_ECHO. Multicast notifications are still received, but now use the portid of the requester and the sequence number of the request instead of zero values used previously. For the application, this message may be unexpected and likely handled as a response to the NLM_F_ACKed request, especially if it uses the same socket to handle requests and notifications. To fix existing applications relying on the old notification behavior, set the portid and sequence number in the notification only if the request included the NLM_F_ECHO flag. This restores the old behavior for applications not using it, but allows unicasted notifications for others. Fixes: f3a63cce1b4f ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link") Fixes: d88e136cab37 ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create") Signed-off-by: Martin Willi Acked-by: Guillaume Nault Acked-by: Hangbin Liu Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org Signed-off-by: Jakub Kicinski

net: remove rcu_dereference_bh_rtnl()

2023-03-22T04:32:18+00:00

This helper is no longer used in the tree. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

rtnetlink: pass netlink message header and portid to rtnl_configure_link()

2022-11-01T01:10:21+00:00

This patch pass netlink message header and portid to rtnl_configure_link() All the functions in this call chain need to add the parameters so we can use them in the last call rtnl_notify(), and notify the userspace about the new link info if NLM_F_ECHO flag is set. - rtnl_configure_link() - __dev_notify_flags() - rtmsg_ifinfo() - rtmsg_ifinfo_event() - rtmsg_ifinfo_build_skb() - rtmsg_ifinfo_send() - rtnl_notify() Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub suggested. Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski

net: sched: use queue_mapping to pick tx queue

2022-04-19T10:20:45+00:00

This patch fixes issue: * If we install tc filters with act_skbedit in clsact hook. It doesn't work, because netdev_core_pick_tx() overwrites queue_mapping. $ tc filter ... action skbedit queue_mapping 1 And this patch is useful: * We can use FQ + EDT to implement efficient policies. Tx queues are picked by xps, ndo_select_queue of netdev driver, or skb hash in netdev_core_pick_tx(). In fact, the netdev driver, and skb hash are _not_ under control. xps uses the CPUs map to select Tx queues, but we can't figure out which task_struct of pod/containter running on this cpu in most case. We can use clsact filters to classify one pod/container traffic to one Tx queue. Why ? In containter networking environment, there are two kinds of pod/ containter/net-namespace. One kind (e.g. P1, P2), the high throughput is key in these applications. But avoid running out of network resource, the outbound traffic of these pods is limited, using or sharing one dedicated Tx queues assigned HTB/TBF/FQ Qdisc. Other kind of pods (e.g. Pn), the low latency of data access is key. And the traffic is not limited. Pods use or share other dedicated Tx queues assigned FIFO Qdisc. This choice provides two benefits. First, contention on the HTB/FQ Qdisc lock is significantly reduced since fewer CPUs contend for the same queue. More importantly, Qdisc contention can be eliminated completely if each CPU has its own FIFO Qdisc for the second kind of pods. There must be a mechanism in place to support classifying traffic based on pods/container to different Tx queues. Note that clsact is outside of Qdisc while Qdisc can run a classifier to select a sub-queue under the lock. In general recording the decision in the skb seems a little heavy handed. This patch introduces a per-CPU variable, suggested by Eric. The xmit.skip_txqueue flag is firstly cleared in __dev_queue_xmit(). - Tx Qdisc may install that skbedit actions, then xmit.skip_txqueue flag is set in qdisc->enqueue() though tx queue has been selected in netdev_tx_queue_mapping() or netdev_core_pick_tx(). That flag is cleared firstly in __dev_queue_xmit(), is useful: - Avoid picking Tx queue with netdev_tx_queue_mapping() in next netdev in such case: eth0 macvlan - eth0.3 vlan - eth0 ixgbe-phy: For example, eth0, macvlan in pod, which root Qdisc install skbedit queue_mapping, send packets to eth0.3, vlan in host. In __dev_queue_xmit() of eth0.3, clear the flag, does not select tx queue according to skb->queue_mapping because there is no filters in clsact or tx Qdisc of this netdev. Same action taked in eth0, ixgbe in Host. - Avoid picking Tx queue for next packet. If we set xmit.skip_txqueue in tx Qdisc (qdisc->enqueue()), the proper way to clear it is clearing it in __dev_queue_xmit when processing next packets. For performance reasons, use the static key. If user does not config the NET_EGRESS, the patch will not be compiled. +----+ +----+ +----+ | P1 | | P2 | | Pn | +----+ +----+ +----+ | | | +-----------+-----------+ | | clsact/skbedit | MQ v +-----------+-----------+ | q0 | q1 | qn v v v HTB/FQ HTB/FQ ... FIFO Cc: Jamal Hadi Salim Cc: Cong Wang Cc: Jiri Pirko Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Jonathan Lemon Cc: Eric Dumazet Cc: Alexander Lobakin Cc: Paolo Abeni Cc: Talal Ahmad Cc: Kevin Hao Cc: Ilias Apalodimas Cc: Kees Cook Cc: Kumar Kartikeya Dwivedi Cc: Antoine Tenart Cc: Wei Wang Cc: Arnd Bergmann Suggested-by: Eric Dumazet Signed-off-by: Tonghao Zhang Acked-by: Jamal Hadi Salim Signed-off-by: Paolo Abeni

net: rtnetlink: Add UAPI toggle for IFLA_OFFLOAD_XSTATS_L3_STATS

2022-03-03T10:37:23+00:00

The offloaded HW stats are designed to allow per-netdevice enablement and disablement. Add an attribute, IFLA_STATS_SET_OFFLOAD_XSTATS_L3_STATS, which should be carried by the RTM_SETSTATS message, and expresses a desire to toggle L3 offload xstats on or off. As part of the above, add an exported function rtnl_offload_xstats_notify() that drivers can use when they have installed or deinstalled the counters backing the HW stats. At this point, it is possible to enable, disable and query L3 offload xstats on netdevices. (However there is no driver actually implementing these.) Signed-off-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

net: sched: extend Qdisc with rcu

2018-09-26T03:17:35+00:00

Currently, Qdisc API functions assume that users have rtnl lock taken. To implement rtnl unlocked classifiers update interface, Qdisc API must be extended with functions that do not require rtnl lock. Extend Qdisc structure with rcu. Implement special version of put function qdisc_put_unlocked() that is called without rtnl lock taken. This function only takes rtnl lock if Qdisc reference counter reached zero and is intended to be used as optimization. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net: core: netlink: add helper refcount dec and lock function

2018-09-26T03:17:35+00:00

Rtnl lock is encapsulated in netlink and cannot be accessed by other modules directly. This means that reference counted objects that rely on rtnl lock cannot use it with refcounter helper function that atomically releases decrements reference and obtains mutex. This patch implements simple wrapper function around refcount_dec_and_lock that obtains rtnl lock if reference counter value reached 0. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller