[PATCH v1 net-next] selftest: net: Use port outside of the default ip_local_ports in csum.c.

[Kuniyuki Iwashima <kuniyu@google.com>]

csum.c binds a socket on a fixed port in init_net to test
the csum offload feature between two machines.

In our testbed, the test sometimes fails with -EADDRINUSE.

  bind r: Address already in use
  bind dgram 6: Address already in use

The fixed ports (33000, 33001, 34000) are all within the default
ip_local_ports range (32768 ~ 60999), and other processes may
happen to be using them.

Let's use ports outside of the default ip_local_ports range to
deflake the test.

  # cat /etc/services | grep -E "(13000|13001|13002)" | echo no service
  no service
  # rpm -qf /etc/services
  setup-2.15.0-28.fc44.noarch

We could add an option to specify ports if needed.

Suggested-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 tools/testing/selftests/net/lib/csum.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/lib/csum.c b/tools/testing/selftests/net/lib/csum.c
index e28884ce3ab3..4e044689bc37 100644
--- a/tools/testing/selftests/net/lib/csum.c
+++ b/tools/testing/selftests/net/lib/csum.c
@@ -105,9 +105,9 @@ static char *cfg_mac_src;
 static int cfg_proto = IPPROTO_UDP;
 static int cfg_payload_char = 'a';
 static int cfg_payload_len = 100;
-static uint16_t cfg_port_dst = 34000;
-static uint16_t cfg_port_src = 33000;
-static uint16_t cfg_port_src_encap = 33001;
+static uint16_t cfg_port_dst = 13000;
+static uint16_t cfg_port_src = 13001;
+static uint16_t cfg_port_src_encap = 13002;
 static unsigned int cfg_random_seed;
 static int cfg_rcvbuf = 1 << 22;	/* be able to queue large cfg_num_pkt */
 static bool cfg_send_pfpacket;
-- 
2.53.0.1213.gd9a14994de-goog