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sch_htb: Fail on unsupported parameters when offload is requested

PATCH Applied Maxim Mikityanskiy 2 participants 2 messages Jan 25, 2022 – Jan 26, 2022

Subsystems (3)
Networking Network drivers Traffic control (tc)
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Maxim Mikityanskiy

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#0 lore raw

PATCH 1/1 sch_htb: Fail on unsupported parameters when offload is requested

The current implementation of HTB offload doesn't support some parameters. Instead of ignoring them, actively return the EINVAL error when they are set to non-defaults.

As this patch goes to stable, the driver API is not changed here. If future drivers support more offload parameters, the checks can be moved to the driver side.

Note that the buffer and cbuffer parameters are also not supported, but the tc userspace tool assigns some default values derived from rate and ceil, and identifying these defaults in sch_htb would be unreliable, so they are still ignored.

Fixes d03b195b5aa0 ("sch_htb: Hierarchical QoS hardware offload")
Reported-by Jakub Kicinski <[email protected]>
Signed-off-by Maxim Mikityanskiy <[email protected]>
Reviewed-by Tariq Toukan <[email protected]>
---
 net/sched/sch_htb.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
net/sched/sch_htb.c +20 -0
index 9267922ea9c3..23a9d6242429 100644
@@ -1810,6 +1810,26 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 	if (!hopt->rate.rate || !hopt->ceil.rate)
 		goto failure;
 
+	if (q->offload) {
+		/* Options not supported by the offload. */
+		if (hopt->rate.overhead || hopt->ceil.overhead) {
+			NL_SET_ERR_MSG(extack, "HTB offload doesn't support the overhead parameter");
+			goto failure;
+		}
+		if (hopt->rate.mpu || hopt->ceil.mpu) {
+			NL_SET_ERR_MSG(extack, "HTB offload doesn't support the mpu parameter");
+			goto failure;
+		}
+		if (hopt->quantum) {
+			NL_SET_ERR_MSG(extack, "HTB offload doesn't support the quantum parameter");
+			goto failure;
+		}
+		if (hopt->prio) {
+			NL_SET_ERR_MSG(extack, "HTB offload doesn't support the prio parameter");
+			goto failure;
+		}
+	}
+
 	/* Keeping backward compatible with rate_table based iproute2 tc */
 	if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
 		qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB],
Signature · 1 line
2.25.1
CI Applied
#1 lore raw
This patch was applied to netdev/net.git (master) by Jakub Kicinski <[email protected]>:

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <[email protected]>:

Quoted 9 lines · On Tue, 25 Jan 2022 12:06:54 +0200 you wrote:

The current implementation of HTB offload doesn't support some parameters. Instead of ignoring them, actively return the EINVAL error when they are set to non-defaults.

As this patch goes to stable, the driver API is not changed here. If future drivers support more offload parameters, the checks can be moved to the driver side.

[...]

Here is the summary with links:
- [net] sch_htb: Fail on unsupported parameters when offload is requested

    https://git.kernel.org/netdev/net/c/429c3be8a5e2

You are awesome, thank you!

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