samples: bpf: add skb->field examples and tests

- modify sockex1 example to count number of bytes in outgoing packets
- modify sockex2 example to count number of bytes and packets per flow
- add 4 stress tests that exercise 'skb->field' code path of verifier

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 3 deletions

diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
index d2d5f5a..29a276d 100644
--- a/samples/bpf/sockex2_user.c
+++ b/samples/bpf/sockex2_user.c
@@ -6,6 +6,11 @@
 #include <unistd.h>
 #include <arpa/inet.h>
 
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
 int main(int ac, char **argv)
 {
 	char filename[256];
@@ -29,13 +34,13 @@ int main(int ac, char **argv)
 
 	for (i = 0; i < 5; i++) {
 		int key = 0, next_key;
-		long long value;
+		struct pair value;
 
 		while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
 			bpf_lookup_elem(map_fd[0], &next_key, &value);
-			printf("ip %s count %lld\n",
+			printf("ip %s bytes %lld packets %lld\n",
 			       inet_ntoa((struct in_addr){htonl(next_key)}),
-			       value);
+			       value.bytes, value.packets);
 			key = next_key;
 		}
 		sleep(1);