On Tue, Jan 9, 2018 at 9:18 AM, David Miller <davem@xxxxxxxxxxxxx> wrote: > From: William Tu <u9012063@xxxxxxxxx> > Date: Tue, 9 Jan 2018 09:08:08 -0800 > >> But that means I should at lease see the first TCP SYN from my BPF >> program, and only the later retries get dropped. However, I didn't >> any. Maybe I still missing something? > > The first SYN will be a clone too. > > Every packet TCP might have to retransmit will be cloned. I see, thank you. Just to clarify, this test_xdp_redirect.sh won't work for TCP because it uses veth peer, so we receive a skb_cloned TCP packets. I assume the normal use case, which attaches non-veth device, the XDP generic can process the packet. Any reason XDP generic skips the skb_cloned packet? I search previous patches mention v4: - Do not perform generic XDP on reinjected packets (DaveM) but didn't see discussion. Thanks! William
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