selftest: tcp: Add v4-mapped-v6 cases in bind_wildcard.c.

We add these 8 test cases in bind_wildcard.c to check bind() conflicts.

  1st bind()          2nd bind()
  ---------           ---------
  0.0.0.0             ::FFFF:0.0.0.0
  ::FFFF:0.0.0.0      0.0.0.0
  0.0.0.0             ::FFFF:127.0.0.1
  ::FFFF:127.0.0.1    0.0.0.0
  127.0.0.1           ::FFFF:0.0.0.0
  ::FFFF:0.0.0.0      127.0.0.1
  127.0.0.1           ::FFFF:127.0.0.1
  ::FFFF:127.0.0.1    127.0.0.1

All test passed without bhash2 and with bhash2 and this series.

 Before bhash2:
  $ uname -r
  6.0.0-rc1-00393-g0bf73255
  $ ./bind_wildcard
  ...
  # PASSED: 16 / 16 tests passed.

 Just after bhash2:
  $ uname -r
  6.0.0-rc1-00394-g28044fc1
  $ ./bind_wildcard
  ...
  ok 15 bind_wildcard.v4_local_v6_v4mapped_local.v4_v6
  not ok 16 bind_wildcard.v4_local_v6_v4mapped_local.v6_v4
  # FAILED: 15 / 16 tests passed.

 On net.git:
  $ ./bind_wildcard
  ...
  not ok 14 bind_wildcard.v4_local_v6_v4mapped_any.v6_v4
  not ok 16 bind_wildcard.v4_local_v6_v4mapped_local.v6_v4
  # FAILED: 13 / 16 tests passed.

 With this series:
  $ ./bind_wildcard
  ...
  # PASSED: 16 / 16 tests passed.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/bind_wildcard.c

@@ -6,6 +6,24 @@
 
 #include "../kselftest_harness.h"
 
+struct in6_addr in6addr_v4mapped_any = {
+	.s6_addr = {
+		0, 0, 0, 0,
+		0, 0, 0, 0,
+		0, 0, 255, 255,
+		0, 0, 0, 0
+	}
+};
+
+struct in6_addr in6addr_v4mapped_loopback = {
+	.s6_addr = {
+		0, 0, 0, 0,
+		0, 0, 0, 0,
+		0, 0, 255, 255,
+		127, 0, 0, 1
+	}
+};
+
 FIXTURE(bind_wildcard)
 {
 	struct sockaddr_in addr4;
@@ -33,6 +51,20 @@ FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_local)
 	.expected_errno = 0,
 };
 
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_v4mapped_any)
+{
+	.addr4_const = INADDR_ANY,
+	.addr6_const = &in6addr_v4mapped_any,
+	.expected_errno = EADDRINUSE,
+};
+
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_any_v6_v4mapped_local)
+{
+	.addr4_const = INADDR_ANY,
+	.addr6_const = &in6addr_v4mapped_loopback,
+	.expected_errno = EADDRINUSE,
+};
+
 FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_any)
 {
 	.addr4_const = INADDR_LOOPBACK,
@@ -47,6 +79,20 @@ FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_local)
 	.expected_errno = 0,
 };
 
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_v4mapped_any)
+{
+	.addr4_const = INADDR_LOOPBACK,
+	.addr6_const = &in6addr_v4mapped_any,
+	.expected_errno = EADDRINUSE,
+};
+
+FIXTURE_VARIANT_ADD(bind_wildcard, v4_local_v6_v4mapped_local)
+{
+	.addr4_const = INADDR_LOOPBACK,
+	.addr6_const = &in6addr_v4mapped_loopback,
+	.expected_errno = EADDRINUSE,
+};
+
 FIXTURE_SETUP(bind_wildcard)
 {
 	self->addr4.sin_family = AF_INET;