Re: [PATCH bpf-next v2] selftests/bpf: Fix build errors if CONFIG_NF_CONNTRACK=m
From: Tiezhu Yang
Date: Mon Feb 06 2023 - 07:55:16 EST
On 02/04/2023 06:16 AM, Andrii Nakryiko wrote:
On Sat, Jan 28, 2023 at 10:25 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
On 01/24/2023 07:17 AM, Andrii Nakryiko wrote:
On Tue, Jan 17, 2023 at 11:57 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
If CONFIG_NF_CONNTRACK=m, there are no definitions of NF_NAT_MANIP_SRC
and NF_NAT_MANIP_DST in vmlinux.h, build test_bpf_nf.c failed.
$ make -C tools/testing/selftests/bpf/
CLNG-BPF [test_maps] test_bpf_nf.bpf.o
progs/test_bpf_nf.c:160:42: error: use of undeclared identifier 'NF_NAT_MANIP_SRC'
bpf_ct_set_nat_info(ct, &saddr, sport, NF_NAT_MANIP_SRC);
^
progs/test_bpf_nf.c:163:42: error: use of undeclared identifier 'NF_NAT_MANIP_DST'
bpf_ct_set_nat_info(ct, &daddr, dport, NF_NAT_MANIP_DST);
^
2 errors generated.
Copy the definitions in include/net/netfilter/nf_nat.h to test_bpf_nf.c,
in order to avoid redefinitions if CONFIG_NF_CONNTRACK=y, rename them with
___local suffix. This is similar with commit 1058b6a78db2 ("selftests/bpf:
Do not fail build if CONFIG_NF_CONNTRACK=m/n").
Fixes: b06b45e82b59 ("selftests/bpf: add tests for bpf_ct_set_nat_info kfunc")
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
tools/testing/selftests/bpf/progs/test_bpf_nf.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf.c b/tools/testing/selftests/bpf/progs/test_bpf_nf.c
index 227e85e..9fc603c 100644
--- a/tools/testing/selftests/bpf/progs/test_bpf_nf.c
+++ b/tools/testing/selftests/bpf/progs/test_bpf_nf.c
@@ -34,6 +34,11 @@ __be16 dport = 0;
int test_exist_lookup = -ENOENT;
u32 test_exist_lookup_mark = 0;
+enum nf_nat_manip_type___local {
+ NF_NAT_MANIP_SRC___local,
+ NF_NAT_MANIP_DST___local
+};
+
struct nf_conn;
struct bpf_ct_opts___local {
@@ -58,7 +63,7 @@ int bpf_ct_change_timeout(struct nf_conn *, u32) __ksym;
int bpf_ct_set_status(struct nf_conn *, u32) __ksym;
int bpf_ct_change_status(struct nf_conn *, u32) __ksym;
int bpf_ct_set_nat_info(struct nf_conn *, union nf_inet_addr *,
- int port, enum nf_nat_manip_type) __ksym;
+ int port, enum nf_nat_manip_type___local) __ksym;
static __always_inline void
nf_ct_test(struct nf_conn *(*lookup_fn)(void *, struct bpf_sock_tuple *, u32,
@@ -157,10 +162,10 @@ nf_ct_test(struct nf_conn *(*lookup_fn)(void *, struct bpf_sock_tuple *, u32,
/* snat */
saddr.ip = bpf_get_prandom_u32();
- bpf_ct_set_nat_info(ct, &saddr, sport, NF_NAT_MANIP_SRC);
+ bpf_ct_set_nat_info(ct, &saddr, sport, NF_NAT_MANIP_SRC___local);
/* dnat */
daddr.ip = bpf_get_prandom_u32();
- bpf_ct_set_nat_info(ct, &daddr, dport, NF_NAT_MANIP_DST);
+ bpf_ct_set_nat_info(ct, &daddr, dport, NF_NAT_MANIP_DST___local);
it would be a bit more reliable if you used `bpf_core_enum_value(enum
nf_nat_manip_type___local, NF_NAT_MANIP_DST___local)`. That would make
libbpf substitute correct absolute value, if actual enum
nf_nat_manip_type in kernel ever changed. Please consider a follow up
patch for this.
Sorry for the late reply, I tested the code as your suggestion, but it
failed.
failed to resolve CO-RE relocation <enumval_value> [101] enum
nf_nat_manip_type___local::NF_NAT_MANIP_SRC___local = 0
Was nf_conntrack kernel module loaded at the time when you ran the
test? If yes, what's the output of
Yes, nf_conntrack was loaded when ran the test.
[root@fedora bpf]# lsmod | grep -w nf_conntrack
nf_conntrack 188416 4
nf_nat,nft_ct,nf_conntrack_netbios_ns,nf_conntrack_broadcast
nf_defrag_ipv6 24576 1 nf_conntrack
nf_defrag_ipv4 16384 1 nf_conntrack
[root@fedora bpf]# ./test_progs -a bpf_nf
...
218: <invalid CO-RE relocation>
failed to resolve CO-RE relocation <enumval_value> [101] enum
nf_nat_manip_type___local::NF_NAT_MANIP_SRC___local = 0
processed 170 insns (limit 1000000) max_states_per_insn 0 total_states
12 peak_states 12 mark_read 2
-- END PROG LOAD LOG --
libbpf: prog 'nf_xdp_ct_test': failed to load: -22
libbpf: failed to load object 'test_bpf_nf'
libbpf: failed to load BPF skeleton 'test_bpf_nf': -22
test_bpf_nf_ct:FAIL:test_bpf_nf__open_and_load unexpected error: -22
#16/2 bpf_nf/tc-bpf-ct:FAIL
#16 bpf_nf:FAIL
Summary: 0/8 PASSED, 0 SKIPPED, 1 FAILED
bpftool btf dump file /sys/kernel/btf/nf_conntrack | grep nf_nat_manip_type
?
[root@fedora bpf]# ./bpftool btf dump file /sys/kernel/btf/nf_conntrack
| grep nf_nat_manip_type
[130070] ENUM 'nf_nat_manip_type' encoding=UNSIGNED size=4 vlen=2
[root@fedora bpf]# ./bpftool btf dump file /sys/kernel/btf/nf_conntrack
| grep NF_NAT_MANIP_SRC
'NF_NAT_MANIP_SRC' val=0
[root@fedora bpf]# ./bpftool btf dump file /sys/kernel/btf/nf_conntrack
| grep NF_NAT_MANIP_DST
'NF_NAT_MANIP_DST' val=1
Thanks,
Tiezhu
Is it necessary to send a follow patch now? Thank you.
Here are the test results.
(1) bpf_nf passed with the current code if CONFIG_NF_CONNTRACK=m:
[root@fedora bpf]# ./test_progs -a bpf_nf
#16/1 bpf_nf/xdp-ct:OK
#16/2 bpf_nf/tc-bpf-ct:OK
#16/3 bpf_nf/alloc_release:OK
#16/4 bpf_nf/insert_insert:OK
#16/5 bpf_nf/lookup_insert:OK
#16/6 bpf_nf/set_timeout_after_insert:OK
#16/7 bpf_nf/set_status_after_insert:OK
#16/8 bpf_nf/change_timeout_after_alloc:OK
#16/9 bpf_nf/change_status_after_alloc:OK
#16/10 bpf_nf/write_not_allowlisted_field:OK
#16 bpf_nf:OK
Summary: 1/10 PASSED, 0 SKIPPED, 0 FAILED
(2) bpf_nf failed with the following changes if CONFIG_NF_CONNTRACK=m:
[yangtiezhu@fedora bpf.git]$ git diff
diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf.c
b/tools/testing/selftests/bpf/progs/test_bpf_nf.c
index 9fc603c9d673..f56ba60ab809 100644
--- a/tools/testing/selftests/bpf/progs/test_bpf_nf.c
+++ b/tools/testing/selftests/bpf/progs/test_bpf_nf.c
@@ -2,6 +2,7 @@
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
+#include <bpf/bpf_core_read.h>
#define EAFNOSUPPORT 97
#define EPROTO 71
@@ -162,10 +163,14 @@ nf_ct_test(struct nf_conn *(*lookup_fn)(void *,
struct bpf_sock_tuple *, u32,
/* snat */
saddr.ip = bpf_get_prandom_u32();
- bpf_ct_set_nat_info(ct, &saddr, sport,
NF_NAT_MANIP_SRC___local);
+ bpf_ct_set_nat_info(ct, &saddr, sport,
+ bpf_core_enum_value(enum
nf_nat_manip_type___local,
+
NF_NAT_MANIP_SRC___local));
/* dnat */
daddr.ip = bpf_get_prandom_u32();
- bpf_ct_set_nat_info(ct, &daddr, dport,
NF_NAT_MANIP_DST___local);
+ bpf_ct_set_nat_info(ct, &daddr, dport,
+ bpf_core_enum_value(enum
nf_nat_manip_type___local,
+
NF_NAT_MANIP_DST___local));
ct_ins = bpf_ct_insert_entry(ct);
if (ct_ins) {
[root@fedora bpf]# ./test_progs -a bpf_nf
...
All error logs:
libbpf: prog 'nf_xdp_ct_test': BPF program load failed: Invalid argument
libbpf: prog 'nf_xdp_ct_test': -- BEGIN PROG LOAD LOG --
...
libbpf: failed to load object 'test_bpf_nf'
libbpf: failed to load BPF skeleton 'test_bpf_nf': -22
test_bpf_nf_ct:FAIL:test_bpf_nf__open_and_load unexpected error: -22
#16/1 bpf_nf/xdp-ct:FAIL
libbpf: prog 'nf_xdp_ct_test': BPF program load failed: Invalid argument
libbpf: prog 'nf_xdp_ct_test': -- BEGIN PROG LOAD LOG --
...
217: (bf) r1 = r7 ;
R1_w=ptr_nf_conn___init(ref_obj_id=18,off=0,imm=0)
R7=ptr_nf_conn___init(ref_obj_id=18,off=0,imm=0) refs=18
218: <invalid CO-RE relocation>
failed to resolve CO-RE relocation <enumval_value> [101] enum
nf_nat_manip_type___local::NF_NAT_MANIP_SRC___local = 0
processed 170 insns (limit 1000000) max_states_per_insn 0 total_states
12 peak_states 12 mark_read 2
-- END PROG LOAD LOG --
libbpf: prog 'nf_xdp_ct_test': failed to load: -22
libbpf: failed to load object 'test_bpf_nf'
libbpf: failed to load BPF skeleton 'test_bpf_nf': -22
test_bpf_nf_ct:FAIL:test_bpf_nf__open_and_load unexpected error: -22
#16/2 bpf_nf/tc-bpf-ct:FAIL
#16 bpf_nf:FAIL
Summary: 0/8 PASSED, 0 SKIPPED, 1 FAILED
Thanks,
Tiezhu