From 94d69cc07f3af9178bd9be9c8f971554f63e1d93 Mon Sep 17 00:00:00 2001 From: Shmulik Ladkani Date: Sun, 21 Aug 2022 14:35:17 +0300 Subject: [PATCH] bpf, flow_dissector: Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode for bpf progs Currently, attaching BPF_PROG_TYPE_FLOW_DISSECTOR programs completely replaces the flow-dissector logic with custom dissection logic. This forces implementors to write programs that handle dissection for any flows expected in the namespace. It makes sense for flow-dissector BPF programs to just augment the dissector with custom logic (e.g. dissecting certain flows or custom protocols), while enjoying the broad capabilities of the standard dissector for any other traffic. Introduce BPF_FLOW_DISSECTOR_CONTINUE retcode. Flow-dissector BPF programs may return this to indicate no dissection was made, and fallback to the standard dissector is requested. Signed-off-by: Shmulik Ladkani Signed-off-by: Daniel Borkmann Reviewed-by: Stanislav Fomichev Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20220821113519.116765-3-shmulik.ladkani@gmail.com --- include/uapi/linux/bpf.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1d6085e..f38814f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5861,6 +5861,11 @@ enum bpf_ret_code { * represented by BPF_REDIRECT above). */ BPF_LWT_REROUTE = 128, + /* BPF_FLOW_DISSECTOR_CONTINUE: used by BPF_PROG_TYPE_FLOW_DISSECTOR + * to indicate that no custom dissection was performed, and + * fallback to standard dissector is requested. + */ + BPF_FLOW_DISSECTOR_CONTINUE = 129, }; struct bpf_sock {