tools: selftests: psock_tpacket: skip un-supported tpacket_v3 test

[Orson Zhai]

The TPACKET_V3 test of PACKET_TX_RING will fail with kernel version
lower than v4.11. Supported code of tx ring was add with commit id
<7f953ab2ba46: af_packet: TX_RING support for TPACKET_V3> at Jan. 3
of 2017.

So skip this item test instead of reporting failing for old kernels.

Signed-off-by: Orson Zhai <orson.z...@linaro.org>
---
 tools/testing/selftests/net/psock_tpacket.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/psock_tpacket.c 
b/tools/testing/selftests/net/psock_tpacket.c
index 7f6cd9fdacf3..f0cfc18c3726 100644
--- a/tools/testing/selftests/net/psock_tpacket.c
+++ b/tools/testing/selftests/net/psock_tpacket.c
@@ -57,6 +57,7 @@
 #include <net/if.h>
 #include <inttypes.h>
 #include <poll.h>
+#include <errno.h>
 
 #include "psock_lib.h"
 
@@ -676,7 +677,7 @@ static void __v3_fill(struct ring *ring, unsigned int 
blocks, int type)
        ring->flen = ring->req3.tp_block_size;
 }
 
-static void setup_ring(int sock, struct ring *ring, int version, int type)
+static int setup_ring(int sock, struct ring *ring, int version, int type)
 {
        int ret = 0;
        unsigned int blocks = 256;
@@ -703,7 +704,11 @@ static void setup_ring(int sock, struct ring *ring, int 
version, int type)
 
        if (ret == -1) {
                perror("setsockopt");
-               exit(1);
+               if (errno == EINVAL) {
+                       printf("[SKIP] This type seems un-supported in current 
kernel, skipped.\n");
+                       return -1;
+               } else
+                       exit(1);
        }
 
        ring->rd_len = ring->rd_num * sizeof(*ring->rd);
@@ -715,6 +720,7 @@ static void setup_ring(int sock, struct ring *ring, int 
version, int type)
 
        total_packets = 0;
        total_bytes = 0;
+       return 0;
 }
 
 static void mmap_ring(int sock, struct ring *ring)
@@ -830,7 +836,12 @@ static int test_tpacket(int version, int type)
 
        sock = pfsocket(version);
        memset(&ring, 0, sizeof(ring));
-       setup_ring(sock, &ring, version, type);
+       if(setup_ring(sock, &ring, version, type)) {
+               /* skip test when error of invalid argument */
+               close(sock);
+               return 0;
+       }
+
        mmap_ring(sock, &ring);
        bind_ring(sock, &ring);
        walk_ring(sock, &ring);
-- 
2.12.2