Re: AF_XDP socket TX path interact with TC?
Konrad Zemek <[email protected]>
| Newsgroups | org.kernel.vger.xdp-newbies |
|---|---|
| Message-ID | <oM1Y-n6UaYUi_6m-lAXmxeqxarfyIBRoZcEpq5WObujvHCCFRZZNwjrBIn0ycTo5oevKJvw6JtlR2UeE2qqzwtKV_QNrpxHBfFgJ_EQLdfQ=@zemek.io> |
On Monday, October 25th, 2021 at 8:26 PM, Jun Hu <[email protected]> wrote: > On Mon, Oct 25, 2021 at 3:48 AM Toke Høiland-Jørgensen [email protected] wrote: > > > Jun Hu [email protected] writes: > > > > > Hi, > > > > > > I want to put a timestamp in the egress packets, and I want to use > > > > > > AF_XDP socket for both sending and receiving packets; since a XDP > > > > > > kernel program only work in ingress direction, I wonder if I could use > > > > > > a tc kernel program to change a packet sent out via an AF_XDP socket? > > > > > > I searched around, but couldn't find any direct answer... > > > > Nope, AF_XDP bypasses the stack completely, so TC won't see the packet > > > > on egress... > > > > -Toke > > Ok, thanks for the clarification, I guess I have to wait for the XDP > > egress support ... You can also directly modify the packet that you send out through an AF_XDP socket, before putting it on the outgoing queue. Is there anything specific that you would want to do in an egress-attached BPF program that you would not be able to do in the userspace program that manages your AF_XDP socket? Konrad