lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <20231229081409.1276386-1-menglong8.dong@gmail.com>
Date: Fri, 29 Dec 2023 16:14:07 +0800
From: Menglong Dong <menglong8.dong@...il.com>
To: andrii@...nel.org
Cc: ast@...nel.org,
	daniel@...earbox.net,
	martin.lau@...ux.dev,
	song@...nel.org,
	yonghong.song@...ux.dev,
	john.fastabend@...il.com,
	kpsingh@...nel.org,
	sdf@...gle.com,
	haoluo@...gle.com,
	jolsa@...nel.org,
	davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	mykolal@...com,
	shuah@...nel.org,
	horms@...nel.org,
	dhowells@...hat.com,
	linyunsheng@...wei.com,
	aleksander.lobakin@...el.com,
	joannelkoong@...il.com,
	laoar.shao@...il.com,
	kuifeng@...a.com,
	menglong8.dong@...il.com,
	bjorn@...osinc.com,
	linux-kernel@...r.kernel.org,
	bpf@...r.kernel.org,
	netdev@...r.kernel.org,
	linux-kselftest@...r.kernel.org
Subject: [PATCH bpf-next 0/2] bpf: add csum/ip_summed fields to __sk_buff

For now, we have to call some helpers when we need to update the csum,
such as bpf_l4_csum_replace, bpf_l3_csum_replace, etc. These helpers are
not inlined, which causes poor performance.

In fact, we can define our own csum update functions in BPF program
instead of bpf_l3_csum_replace, which is totally inlined and efficient.
However, we can't do this for bpf_l4_csum_replace for now, as we can't
update skb->csum, which can cause skb->csum invalid in the rx path with
CHECKSUM_COMPLETE mode.

What's more, we can't use the direct data access and have to use
skb_store_bytes() with the BPF_F_RECOMPUTE_CSUM flag in some case, such
as modifing the vni in the vxlan header and the underlay udp header has
no checksum.

In the first patch, we make skb->csum readable and writable, and we make
skb->ip_summed readable. For now, for tc only. With these 2 fields, we
don't need to call bpf helpers for csum update any more.

In the second patch, we add some testcases for the read/write testing for
skb->csum and skb->ip_summed.

If this series is acceptable, we can define the inlined functions for csum
update in libbpf in the next step.

Menglong Dong (2):
  bpf: add csum/ip_summed fields to __sk_buff
  testcases/bpf: add testcases for skb->csum to ctx_skb.c

 include/linux/skbuff.h                        |  2 +
 include/uapi/linux/bpf.h                      |  2 +
 net/core/filter.c                             | 22 ++++++++++
 tools/include/uapi/linux/bpf.h                |  2 +
 .../testing/selftests/bpf/verifier/ctx_skb.c  | 43 +++++++++++++++++++
 5 files changed, 71 insertions(+)

-- 
2.39.2


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ