From: David Ahern Date: Tue, 30 Jan 2024 15:49:23 +0000 (+0000) Subject: Merge branch 'echo-tc-filter-actions' into next X-Git-Tag: v6.9.0~32^2~15 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=91e3be8fdf1b9c48c7bfc98516aac3d51858a9a5;p=thirdparty%2Fiproute2.git Merge branch 'echo-tc-filter-actions' into next Victor Nogueira says: ==================== Continuing on what Hangbin Liu started [1], this patch set adds support for the NLM_F_ECHO flag for tc actions and filters. For qdiscs it will require some kernel surgery, and we'll send it soon after this surgery is merged. When user space configures the kernel with netlink messages, it can set NLM_F_ECHO flag to request the kernel to send the applied configuration back to the caller. This allows user space to receive back configuration information that is populated by the kernel. Often because there are parameters that can only be set by the kernel which become visible with the echo, or because user space lets the kernel choose a default value. To illustrate a use case where the kernel will give us a default value, the example below shows the user not specifying the action index: tc -echo actions add action mirred egress mirror dev lo total acts 0 Added action action order 1: mirred (Egress Mirror to device lo) pipe index 1 ref 1 bind 0 not_in_hw Note that the echoed response indicates that the kernel gave us a value of index 1 [1] https://lore.kernel.org/netdev/20220916033428.400131-2-liuhangbin@gmail.com/ ==================== Signed-off-by: David Ahern --- 91e3be8fdf1b9c48c7bfc98516aac3d51858a9a5