[dpdk-dev] [RFC PATCH 0/5] add framework to load and execute BPF code

Konstantin Ananyev konstantin.ananyev at intel.com
Thu Mar 8 02:29:57 CET 2018


BPF is used quite intensively inside Linux (and BSD) kernels
for various different purposes and proved to be extremely useful.

In theory, BPF inside DPDK might also be used in a lot of places
for a lot of similar things.
 As an example to:
- packet filtering/tracing (aka tcpdump)
- packet classification
- statistics collection
- HW/PMD live-system debugging/prototyping - trace HW descriptors,
  internal PMD SW state, etc.   
 ...

All of that in a dynamic, user-defined and extensible manner.

So these series introduce new library - librte_bpf.
librte_bpf provides API to load and execute BPF bytecode within
user-space dpdk app.
It supported basic set of features from eBPF spec.
Also it introduces basic framework to load/unload BPF-based filters
on eth devices (right now via SW RX/TX callbacks).

How to try it:
===============

1) run testpmd as usual and start your favorite forwarding case.
2) build bpf program you'd like to load
(you'll need clang v3.7 or above):
$ cd test/bpf
$ clang -O2 -target bpf -c t1.c
   
3) load bpf program(s):
testpmd> bpf-load rx|tx <portid> <queueid> <load-flags> <bpf-prog-filename> 

<load-flags>:  [-][J][M]
J - use JIT generated native code, otherwise BPF interpreter will be used.
M - assume input parameter is a pointer to rte_mbuf, otherwise assume it is a pointer to
       first segment's data.

Few examples:

# to load (not JITed) dummy.o at TX queue 0, port 0:
testpmd> bpf-load tx 0 0 - ./dpdk.org/test/bpf/dummy.o

#to load (and JIT compile) t1.o at RX queue 0, port 1:
testpmd> bpf-load rx 1 0 J ./dpdk.org/test/bpf/t1.o

#to load and JIT t2.o (note that it expects mbuf as an input):
testpmd> bpf-load rx 2 0 JM ./dpdk.org/test/bpf/t2.o

4) observe changed traffic behavior
Let say with the examples above
  - dummy.o  does literally nothing, so no changes should be here,
    except some possible slowdown
 - t1.o - should force to drop all packets that doesn.t' match:
   'dst 1.2.3.4 && udp && dst port 5000' filter.    

5) unload some or all bpf programs:
testpmd> bpf-unload tx 0 0

6) continue with step 3) or exit

TODO list:
=========
- meson build
- UT for it
- implement proper validate()
- allow JIT to generate bulk version 

Not currently supported features:
=================================
- cBPF
- tail-pointer call
- eBPF MAP
- skb 

Konstantin Ananyev (5):
  bpf: add BPF loading and execution framework
  bpf: add JIT compilation for x86_64 ISA.
  bpf: introduce basic RX/TX BPF filters
  testpmd: new commands to load/unload BPF filters
  test: add few eBPF samples

 app/test-pmd/cmdline.c             |  144 +++++
 config/common_base                 |    5 +
 config/common_linuxapp             |    1 +
 lib/Makefile                       |    2 +
 lib/librte_bpf/Makefile            |   35 ++
 lib/librte_bpf/bpf.c               |   52 ++
 lib/librte_bpf/bpf_exec.c          |  453 ++++++++++++++
 lib/librte_bpf/bpf_impl.h          |   37 ++
 lib/librte_bpf/bpf_jit_x86.c       | 1155 ++++++++++++++++++++++++++++++++++++
 lib/librte_bpf/bpf_load.c          |  344 +++++++++++
 lib/librte_bpf/bpf_pkt.c           |  524 ++++++++++++++++
 lib/librte_bpf/bpf_validate.c      |   55 ++
 lib/librte_bpf/rte_bpf.h           |  154 +++++
 lib/librte_bpf/rte_bpf_ethdev.h    |   50 ++
 lib/librte_bpf/rte_bpf_version.map |   16 +
 mk/rte.app.mk                      |    2 +
 test/bpf/dummy.c                   |   20 +
 test/bpf/mbuf.h                    |  556 +++++++++++++++++
 test/bpf/t1.c                      |   54 ++
 test/bpf/t2.c                      |   31 +
 20 files changed, 3690 insertions(+)
 create mode 100644 lib/librte_bpf/Makefile
 create mode 100644 lib/librte_bpf/bpf.c
 create mode 100644 lib/librte_bpf/bpf_exec.c
 create mode 100644 lib/librte_bpf/bpf_impl.h
 create mode 100644 lib/librte_bpf/bpf_jit_x86.c
 create mode 100644 lib/librte_bpf/bpf_load.c
 create mode 100644 lib/librte_bpf/bpf_pkt.c
 create mode 100644 lib/librte_bpf/bpf_validate.c
 create mode 100644 lib/librte_bpf/rte_bpf.h
 create mode 100644 lib/librte_bpf/rte_bpf_ethdev.h
 create mode 100644 lib/librte_bpf/rte_bpf_version.map
 create mode 100644 test/bpf/dummy.c
 create mode 100644 test/bpf/mbuf.h
 create mode 100644 test/bpf/t1.c
 create mode 100644 test/bpf/t2.c

-- 
2.13.6



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