From 05421aecd4ed65da0dc17b0c3c13779ef334e9e5 Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Wed, 1 Mar 2023 07:49:51 -0800 Subject: bpf: Add xdp dynptrs Add xdp dynptrs, which are dynptrs whose underlying pointer points to a xdp_buff. The dynptr acts on xdp data. xdp dynptrs have two main benefits. One is that they allow operations on sizes that are not statically known at compile-time (eg variable-sized accesses). Another is that parsing the packet data through dynptrs (instead of through direct access of xdp->data and xdp->data_end) can be more ergonomic and less brittle (eg does not need manual if checking for being within bounds of data_end). For reads and writes on the dynptr, this includes reading/writing from/to and across fragments. Data slices through the bpf_dynptr_data API are not supported; instead bpf_dynptr_slice() and bpf_dynptr_slice_rdwr() should be used. For examples of how xdp dynptrs can be used, please see the attached selftests. Signed-off-by: Joanne Koong Link: https://lore.kernel.org/r/20230301154953.641654-9-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/include/uapi/linux') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index d0351d30e551..faa304c926cf 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5344,7 +5344,7 @@ union bpf_attr { * *len* must be a statically known value. The returned data slice * is invalidated whenever the dynptr is invalidated. * - * skb type dynptrs may not use bpf_dynptr_data. They should + * skb and xdp type dynptrs may not use bpf_dynptr_data. They should * instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr. * Return * Pointer to the underlying dynptr data, NULL if the dynptr is -- cgit v1.2.3