bpf: obtain timestamps from controller via pkthdr if available

[jkim]

Summary

r325506 (3cf8254f1ea9666c9cd7bd55e56b4c8543505113) extended struct pkthdr to add packet timestamp in mbuf(9) chain. cxgbe(4) and mlx5en(4) seem to support this feature. Use the timestamp for bpf(4) if it is available. This patch was lightly tested on Chelsio T502-BT.

Test Plan

Check timestamp sanity with supported controllers via hwrxtstmp/-hwrxtstmp ifconfig parameters.

[kib]

Please upload patches with context.

sys/net/bpf.c

2279

Please use mbuf_tstmp2timespec(), somebody might add more precision to it one day.

[• hselasky]

I think you should use "1000000000ULL" to always get unsigned results, but I'm not an expert. Else code looks good.

[jkim]

sys/net/bpf.c

2279

Thanks, I didn't see that.

[• hselasky]

Looks good to me.

[jkim]

In D36868#836858, @hselasky wrote:

I think you should use "1000000000ULL" to always get unsigned results, but I'm not an expert. Else code looks good.

I used mbuf_tstmp2timespec() as @kib suggested. Note this function does not use ULL either.

[kib]

Please, upload patches with context. git show -U 9999999 or git diff -U 999999999

[jkim]

In D36868#836880, @kib wrote:

Please, upload patches with context. git show -U 9999999 or git diff -U 999999999

Sorry, done.