[bpf-next,v2,2/2] selftests: bpf: validate CHECKSUM_COMPLETE option

Commit Message

Vadim Fedorenko May 24, 2024, 11:06 a.m. UTC

Adjust skb program test to run with checksum validation.

Signed-off-by: Vadim Fedorenko <[e-mail]>
---
 .../selftests/bpf/prog_tests/test_skb_pkt_end.c       |  1 +
 tools/testing/selftests/bpf/progs/skb_pkt_end.c       | 11 ++++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

Comments

Daniel Borkmann May 24, 2024, 4:18 p.m. UTC | #1

On 5/24/24 1:06 PM, Vadim Fedorenko wrote:
> Adjust skb program test to run with checksum validation.
> 
> Signed-off-by: Vadim Fedorenko <[e-mail]>

BPF CI complains :

   [...]
   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c:14:12: error: call to undeclared function 'BIT'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
      14 |                 .flags = BPF_F_TEST_SKB_CHECKSUM_COMPLETE,
         |                          ^
   /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:1429:42: note: expanded from macro 'BPF_F_TEST_SKB_CHECKSUM_COMPLETE'
    1429 | #define BPF_F_TEST_SKB_CHECKSUM_COMPLETE        BIT(2)
         |                                                 ^
   1 error generated.
   make: *** [Makefile:654: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/test_skb_pkt_end.test.o] Error 1
   make: *** Waiting for unfinished jobs....
   make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
   Error: Process completed with exit code 2.

Vadim Fedorenko May 24, 2024, 4:23 p.m. UTC | #2

On 24/05/2024 17:18, Daniel Borkmann wrote:
> On 5/24/24 1:06 PM, Vadim Fedorenko wrote:
>> Adjust skb program test to run with checksum validation.
>>
>> Signed-off-by: Vadim Fedorenko <[e-mail]>
> 
> BPF CI complains :
> 
>    [...]
>    
> /tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c:14:12: error: call to undeclared function 'BIT'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>       14 |                 .flags = BPF_F_TEST_SKB_CHECKSUM_COMPLETE,
>          |                          ^
>    /tmp/work/bpf/bpf/tools/include/uapi/linux/bpf.h:1429:42: note: 
> expanded from macro 'BPF_F_TEST_SKB_CHECKSUM_COMPLETE'
>     1429 | #define BPF_F_TEST_SKB_CHECKSUM_COMPLETE        BIT(2)
>          |                                                 ^
>    1 error generated.
>    make: *** [Makefile:654: 
> /tmp/work/bpf/bpf/tools/testing/selftests/bpf/test_skb_pkt_end.test.o] 
> Error 1
>    make: *** Waiting for unfinished jobs....
>    make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'
>    Error: Process completed with exit code 2.

Oops, looks like checkpatch.pl was too smart and replaced original
define with BIT() macro, but in one file only. I'll re-send it with
fixes.

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c b/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c
index ae93411fd582..09ca13bdf6ca 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_skb_pkt_end.c
@@ -11,6 +11,7 @@  static int sanity_run(struct bpf_program *prog)
 		.data_in = &pkt_v4,
 		.data_size_in = sizeof(pkt_v4),
 		.repeat = 1,
+		.flags = BPF_F_TEST_SKB_CHECKSUM_COMPLETE,
 	);
 
 	prog_fd = bpf_program__fd(prog);
diff --git a/tools/testing/selftests/bpf/progs/skb_pkt_end.c b/tools/testing/selftests/bpf/progs/skb_pkt_end.c
index db4abd2682fc..3bb4451524a1 100644
--- a/tools/testing/selftests/bpf/progs/skb_pkt_end.c
+++ b/tools/testing/selftests/bpf/progs/skb_pkt_end.c
@@ -33,6 +33,8 @@  int main_prog(struct __sk_buff *skb)
 	struct iphdr *ip = NULL;
 	struct tcphdr *tcp;
 	__u8 proto = 0;
+	int urg_ptr;
+	u32 offset;
 
 	if (!(ip = get_iphdr(skb)))
 		goto out;
@@ -48,7 +50,14 @@  int main_prog(struct __sk_buff *skb)
 	if (!tcp)
 		goto out;
 
-	return tcp->urg_ptr;
+	urg_ptr = tcp->urg_ptr;
+
+	/* Checksum validation part */
+	proto++;
+	offset = sizeof(struct ethhdr) + offsetof(struct iphdr, protocol);
+	bpf_skb_store_bytes(skb, offset, &proto, sizeof(proto), BPF_F_RECOMPUTE_CSUM);
+
+	return urg_ptr;
 out:
 	return -1;
 }