DPDK patches and discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: Konstantin Ananyev <konstantin.ananyev@intel.com>
Cc: dev@dpdk.org
Subject: [dpdk-dev] BUG: eBPF missing BPF_ABS
Date: Tue, 4 Feb 2020 06:52:29 -0800	[thread overview]
Message-ID: <20200204065229.0e8a85f7@shemminger-XPS-13-9360> (raw)

As I mentioned in my FOSDEM talk the current DPDK eBPF handling is
not usable for packet filters. I have ported the classic BPF to eBPF code
and the generated code is not usable by DPDK.

The problem is that DPDK eBPF does not implement all the opcodes.
BPF_ABS is not implemented and must be. It is in the Linux kernel.

PCAP filter string: ip dst fosdem.org
cBPF program (6 insns):
 L0:	28 00 00 00 0c 00 00 00 ldh [12]
 L1:	15 00 00 03 00 08 00 00 jeq #0x800, L2, L5
 L2:	20 00 00 00 1e 00 00 00 ld [30]
 L3:	15 00 00 01 8c 16 16 1f jeq #0x1f16168c, L4, L5
 L4:	06 00 00 00 ff ff ff ff ret #0xffffffff
 L5:	06 00 00 00 00 00 00 00 ret #0x0
eBPF program (11 insns):
 L0:	af 00 00 00 00 00 00 00 xor r0, r0
 L1:	af 77 00 00 00 00 00 00 xor r7, r7
 L2:	bf 16 00 00 00 00 00 00 mov r6, r1
 L3:	28 70 00 00 0c 00 00 00 ldh r0, [12]
 L4:	55 00 04 00 00 08 00 00 jne r0, #0x800, L9
 L5:	20 70 00 00 1e 00 00 00 ldw r0, [30]
 L6:	55 00 02 00 8c 16 16 1f jne r0, #0x1f16168c, L9
 L7:	b4 00 00 00 01 00 00 00 mov32 r0, #0x1
 L8:	95 00 00 00 00 00 00 00 exit
 L9:	b4 00 00 00 02 00 00 00 mov32 r0, #0x2
 L10:	95 00 00 00 00 00 00 00 exit
validate: invalid opcode at pc: 3
validate: invalid opcode at pc: 5
rte_bpf_load failed: Invalid argument

             reply	other threads:[~2020-02-04 14:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-04 14:52 Stephen Hemminger [this message]
2020-02-05 21:16 ` Ananyev, Konstantin
2020-02-06  4:22   ` Jerin Jacob
2020-02-06  8:54   ` Morten Brørup
2020-02-06  9:11     ` Stephen Hemminger
2020-02-06 10:16       ` Ananyev, Konstantin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200204065229.0e8a85f7@shemminger-XPS-13-9360 \
    --to=stephen@networkplumber.org \
    --cc=dev@dpdk.org \
    --cc=konstantin.ananyev@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).