kernel_optimize_test/samples/bpf
Jesper Dangaard Brouer abcce733ad samples/bpf: xdp_fwd explain bpf_fib_lookup return codes
Make it clear that this XDP program depend on the network
stack to do the ARP resolution.  This is connected with the
BPF_FIB_LKUP_RET_NO_NEIGH return code from bpf_fib_lookup().

Another common mistake (seen via XDP-tutorial) is that users
don't realize that sysctl net.ipv{4,6}.conf.all.forwarding
setting is honored by bpf_fib_lookup.

Reported-by: Anton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-09 18:05:03 +02:00
..
.gitignore samples: bpf: add ibumad sample to .gitignore 2019-05-24 19:58:03 -07:00
asm_goto_workaround.h samples/bpf: fix build with new clang 2019-04-05 16:28:36 +02:00
bpf_insn.h selftests: bpf: functional and min/max reasoning unit tests for JMP32 2019-01-26 13:33:02 -08:00
bpf_load.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-17 20:20:36 -07:00
bpf_load.h samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
cookie_uid_helper_example.c samples: bpf: rename libbpf.h to bpf_insn.h 2018-05-14 22:52:10 -07:00
cpustat_kern.c samples/bpf: Add program for CPU state statistics 2018-02-26 10:54:02 +01:00
cpustat_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
do_hbm_test.sh bpf: Add support for fq's EDT to HBM 2019-07-03 15:03:00 +02:00
fds_example.c samples: bpf: refactor header include path 2019-06-18 00:28:36 +02:00
hash_func01.h samples/bpf: add Paul Hsieh's (LGPL 2.1) hash function SuperFastHash 2018-08-10 16:07:49 +02:00
hbm_edt_kern.c bpf: Add support for fq's EDT to HBM 2019-07-03 15:03:00 +02:00
hbm_kern.h bpf: Add support for fq's EDT to HBM 2019-07-03 15:03:00 +02:00
hbm_out_kern.c bpf: Add more stats to HBM 2019-05-31 16:41:29 -07:00
hbm.c bpf: Add support for fq's EDT to HBM 2019-07-03 15:03:00 +02:00
hbm.h bpf: Add more stats to HBM 2019-05-31 16:41:29 -07:00
ibumad_kern.c samples: bpf: Remove bpf_debug macro in favor of bpf_printk 2019-06-24 18:18:30 -07:00
ibumad_user.c samples: bpf: refactor header include path 2019-06-18 00:28:36 +02:00
lathist_kern.c
lathist_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
lwt_len_hist_kern.c
lwt_len_hist_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
lwt_len_hist.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile samples/bpf: build with -D__TARGET_ARCH_$(SRCARCH) 2019-07-15 23:13:17 +02:00
map_perf_test_kern.c
map_perf_test_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
offwaketime_kern.c
offwaketime_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
parse_ldabs.c
parse_simple.c
parse_varlen.c samples/bpf: add missing <linux/if_vlan.h> 2018-07-05 09:58:52 +02:00
README.rst
run_cookie_uid_helper_example.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sampleip_kern.c
sampleip_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
sock_example.c samples: bpf: force IPv4 in ping 2019-03-01 00:53:45 +01:00
sock_example.h samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
sock_flags_kern.c
sockex1_kern.c
sockex1_user.c samples: bpf: refactor header include path 2019-06-18 00:28:36 +02:00
sockex2_kern.c samples/bpf: fix compilation failure 2018-09-21 22:51:16 +02:00
sockex2_user.c samples: bpf: refactor header include path 2019-06-18 00:28:36 +02:00
sockex3_kern.c samples/bpf: fix compilation failure 2018-09-21 22:51:16 +02:00
sockex3_user.c samples: bpf: force IPv4 in ping 2019-03-01 00:53:45 +01:00
spintest_kern.c
spintest_user.c samples, selftests/bpf: add NULL check for ksym_search 2019-04-04 16:43:47 +02:00
syscall_nrs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
syscall_tp_kern.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
syscall_tp_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
task_fd_query_kern.c samples: bpf: fix: broken sample regarding removed function 2019-02-27 17:27:22 +01:00
task_fd_query_user.c samples, bpf: suppress compiler warning 2019-05-21 16:55:20 +02:00
tc_l2_redirect_kern.c
tc_l2_redirect_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
tc_l2_redirect.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcbpf1_kern.c
tcp_basertt_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_bpf.readme samples/bpf: fix tcp_bpf.readme detach command 2019-07-03 16:52:02 +02:00
tcp_bufs_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_clamp_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_cong_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_dumpstats_kern.c samples/bpf: add sample program that periodically dumps TCP stats 2019-07-03 16:52:02 +02:00
tcp_iw_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_rwnd_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_synrto_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
tcp_tos_reflect_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
test_cgrp2_array_pin.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
test_cgrp2_attach.c samples: bpf: rename libbpf.h to bpf_insn.h 2018-05-14 22:52:10 -07:00
test_cgrp2_sock.c samples: bpf: rename libbpf.h to bpf_insn.h 2018-05-14 22:52:10 -07:00
test_cgrp2_sock.sh samples/bpf: detach prog from cgroup 2018-03-02 00:16:36 +01:00
test_cgrp2_sock2.c samples/bpf: test_cgrp2_sock2: fix an off by one 2018-07-16 15:01:09 -07:00
test_cgrp2_sock2.sh samples/bpf: detach prog from cgroup 2018-03-02 00:16:36 +01:00
test_cgrp2_tc_kern.c
test_cgrp2_tc.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
test_cls_bpf.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
test_current_task_under_cgroup_kern.c
test_current_task_under_cgroup_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
test_ipip.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
test_lru_dist.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
test_lwt_bpf.c
test_lwt_bpf.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
test_map_in_map_kern.c
test_map_in_map_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
test_overhead_kprobe_kern.c
test_overhead_raw_tp_kern.c samples/bpf: raw tracepoint test 2018-03-28 22:55:19 +02:00
test_overhead_tp_kern.c
test_overhead_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
test_override_return.sh samples/bpf: add a test for bpf_override_return 2017-12-12 09:02:40 -08:00
test_probe_write_user_kern.c
test_probe_write_user_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
trace_event_kern.c samples/bpf: add example to test reading address 2018-03-08 02:22:34 +01:00
trace_event_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
trace_output_kern.c
trace_output_user.c samples/bpf: switch trace_output sample to perf_buffer API 2019-07-23 16:05:42 -07:00
tracex1_kern.c
tracex1_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
tracex2_kern.c
tracex2_user.c samples: bpf: force IPv4 in ping 2019-03-01 00:53:45 +01:00
tracex3_kern.c samples: bpf: fix: broken sample regarding removed function 2019-02-27 17:27:22 +01:00
tracex3_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
tracex4_kern.c
tracex4_user.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
tracex5_kern.c
tracex5_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
tracex6_kern.c bpf: add a test case for helper bpf_perf_event_read_value 2017-10-07 23:05:57 +01:00
tracex6_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
tracex7_kern.c samples/bpf: add a test for bpf_override_return 2017-12-12 09:02:40 -08:00
tracex7_user.c samples: bpf: include bpf/bpf.h instead of local libbpf.h 2018-05-14 22:52:10 -07:00
xdp_adjust_tail_kern.c bpf: add bpf_xdp_adjust_tail sample prog 2018-04-18 23:34:17 +02:00
xdp_adjust_tail_user.c samples: bpf: make the use of xdp samples consistent 2019-06-26 15:39:15 +02:00
xdp_fwd_kern.c samples/bpf: xdp_fwd explain bpf_fib_lookup return codes 2019-08-09 18:05:03 +02:00
xdp_fwd_user.c samples/bpf: make xdp_fwd more practically usable via devmap lookup 2019-08-09 18:05:03 +02:00
xdp_monitor_kern.c samples/bpf: xdp_monitor use err code from tracepoint xdp:xdp_devmap_xmit 2018-05-24 18:36:15 -07:00
xdp_monitor_user.c samples/bpf: xdp_monitor use err code from tracepoint xdp:xdp_devmap_xmit 2018-05-24 18:36:15 -07:00
xdp_redirect_cpu_kern.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-13 10:07:23 -07:00
xdp_redirect_cpu_user.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
xdp_redirect_kern.c
xdp_redirect_map_kern.c
xdp_redirect_map_user.c samples: bpf: make the use of xdp samples consistent 2019-06-26 15:39:15 +02:00
xdp_redirect_user.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
xdp_router_ipv4_kern.c xdp: Sample xdp program implementing ip forward 2017-11-08 10:39:41 +09:00
xdp_router_ipv4_user.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-06-20 00:06:27 -04:00
xdp_rxq_info_kern.c samples/bpf: xdp_rxq_info action XDP_TX must adjust MAC-addrs 2018-06-28 23:50:20 +02:00
xdp_rxq_info_user.c samples: bpf: refactor header include path 2019-06-18 00:28:36 +02:00
xdp_sample_pkts_kern.c samples: bpf: Do not define bpf_printk macro 2019-05-24 13:47:17 -07:00
xdp_sample_pkts_user.c samples/bpf: convert xdp_sample_pkts_user to perf_buffer API 2019-07-23 16:05:42 -07:00
xdp_tx_iptunnel_common.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
xdp_tx_iptunnel_kern.c
xdp_tx_iptunnel_user.c samples: bpf: make the use of xdp samples consistent 2019-06-26 15:39:15 +02:00
xdp1_kern.c
xdp1_user.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-06-20 00:06:27 -04:00
xdp2_kern.c
xdp2skb_meta_kern.c samples/bpf: xdp2skb_meta comment explain why pkt-data pointers are invalidated 2018-01-18 01:49:09 +01:00
xdp2skb_meta.sh samples/bpf: Fix tc and ip paths in xdp2skb_meta.sh 2018-07-10 09:19:01 +02:00
xdpsock_user.c xsk: Change the default frame size to 4096 and allow controlling it 2019-06-27 22:53:26 +02:00

eBPF sample programs
====================

This directory contains a test stubs, verifier test-suite and examples
for using eBPF. The examples use libbpf from tools/lib/bpf.

Build dependencies
==================

Compiling requires having installed:
 * clang >= version 3.4.0
 * llvm >= version 3.7.1

Note that LLVM's tool 'llc' must support target 'bpf', list version
and supported targets with command: ``llc --version``

Kernel headers
--------------

There are usually dependencies to header files of the current kernel.
To avoid installing devel kernel headers system wide, as a normal
user, simply call::

 make headers_install

This will creates a local "usr/include" directory in the git/build top
level directory, that the make system automatically pickup first.

Compiling
=========

For building the BPF samples, issue the below command from the kernel
top level directory::

 make samples/bpf/

Do notice the "/" slash after the directory name.

It is also possible to call make from this directory.  This will just
hide the the invocation of make as above with the appended "/".

Manually compiling LLVM with 'bpf' support
------------------------------------------

Since version 3.7.0, LLVM adds a proper LLVM backend target for the
BPF bytecode architecture.

By default llvm will build all non-experimental backends including bpf.
To generate a smaller llc binary one can use::

 -DLLVM_TARGETS_TO_BUILD="BPF"

Quick sniplet for manually compiling LLVM and clang
(build dependencies are cmake and gcc-c++)::

 $ git clone http://llvm.org/git/llvm.git
 $ cd llvm/tools
 $ git clone --depth 1 http://llvm.org/git/clang.git
 $ cd ..; mkdir build; cd build
 $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
 $ make -j $(getconf _NPROCESSORS_ONLN)

It is also possible to point make to the newly compiled 'llc' or
'clang' command via redefining LLC or CLANG on the make command line::

 make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang

Cross compiling samples
-----------------------
In order to cross-compile, say for arm64 targets, export CROSS_COMPILE and ARCH
environment variables before calling make. This will direct make to build
samples for the cross target.

export ARCH=arm64
export CROSS_COMPILE="aarch64-linux-gnu-"
make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang