[PATCH bpf-next v2 4/8] selftests/bpf: Export create_netns helper

[Geliang Tang <geliang@xxxxxxxxxx>]

From: Geliang Tang <tanggeliang@xxxxxxxxxx>

This patch moves create_netns() from mptcp.c into network_helpers.c, and
export it in network_helpers.h as a public helper.

The new helper accepts a string parameter, and uses SYS_NOFAIL() instead
of SYS() to execute the command, since SYS() deponds on test__fail()
which is defined in test_progs.c. SYS() is not suitable to be used in
network_helpers.c. Also using "ip netns del" command to delete netns
before runing "ip netns add" to add it, since the next tests run may fail
due to unable to create netns when last run tests interrupt.

Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
---
 tools/testing/selftests/bpf/network_helpers.c | 28 +++++++++++++++++++
 tools/testing/selftests/bpf/network_helpers.h |  1 +
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 14 ++--------
 3 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 919bb2a0c6a6..5555b109899f 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -498,6 +498,34 @@ void close_netns(struct nstoken *token)
 	free(token);
 }
 
+struct nstoken *create_netns(const char *name)
+{
+	struct nstoken *token = NULL;
+
+	SYS_NOFAIL("ip netns del %s", name);
+	if (SYS_NOFAIL("ip netns add %s", name)) {
+		log_err("add netns %s failed", name);
+		goto fail;
+	}
+
+	if (SYS_NOFAIL("ip -net %s link set dev lo up", name)) {
+		log_err("set dev lo up failed");
+		goto fail;
+	}
+
+	token = open_netns(name);
+	if (!token) {
+		log_err("open netns %s failed", name);
+		goto fail;
+	}
+
+	return token;
+
+fail:
+	SYS_NOFAIL("ip netns del %s", name);
+	return NULL;
+}
+
 int get_socket_local_port(int sock_fd)
 {
 	struct sockaddr_storage addr;
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index b087330f2861..5c0b082153fd 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -81,6 +81,7 @@ struct nstoken;
  */
 struct nstoken *open_netns(const char *name);
 void close_netns(struct nstoken *token);
+struct nstoken *create_netns(const char *name);
 int send_recv_data(int lfd, int fd, uint32_t total_bytes);
 int unshare_netns(void);
 
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 4472aa404da0..abb4372114b6 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -79,16 +79,6 @@ struct mptcp_storage {
 	char ca_name[TCP_CA_NAME_MAX];
 };
 
-static struct nstoken *create_netns(void)
-{
-	SYS(fail, "ip netns add %s", NS_TEST);
-	SYS(fail, "ip -net %s link set dev lo up", NS_TEST);
-
-	return open_netns(NS_TEST);
-fail:
-	return NULL;
-}
-
 static void cleanup_netns(struct nstoken *nstoken)
 {
 	if (nstoken)
@@ -228,7 +218,7 @@ static void test_base(void)
 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
 		return;
 
-	nstoken = create_netns();
+	nstoken = create_netns(NS_TEST);
 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
 		goto fail;
 
@@ -344,7 +334,7 @@ static void test_mptcpify(void)
 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
 		return;
 
-	nstoken = create_netns();
+	nstoken = create_netns(NS_TEST);
 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
 		goto fail;
 
-- 
2.43.0