[PATCH bpf-next v3 05/14] selftests/bpf: test_xdp_veth: Split network configuration

["Bastien Curutchet (eBPF Foundation)" <bastien.curutchet@bootlin.com>]

configure_network() does two things : it first creates the network
topology and then configures the BPF maps to fit the test needs. This
isn't convenient if we want to re-use the same network topology for
different test cases.

Rename configure_network() create_network().
Move the BPF configuration to the test itself.
Split the test description in two parts, first the description of the
network topology, then the description of the test case.
Remove the veth indexes from the ASCII art as dynamic ones are used

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
---
 .../selftests/bpf/prog_tests/test_xdp_veth.c       | 81 +++++++++++++---------
 1 file changed, 47 insertions(+), 34 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c
index 942c6e99e15ef69003c033e7bc1bfc9bc9777557..710136861bda7607dcaca6186b5acfe0082a870c 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_xdp_veth.c
@@ -3,17 +3,27 @@
 /* Create 3 namespaces with 3 veth peers, and forward packets in-between using
  * native XDP
  *
- *                      XDP_TX
- * NS1(veth11)        NS2(veth22)        NS3(veth33)
- *      |                  |                  |
- *      |                  |                  |
- *   (veth1,            (veth2,            (veth3,
- *   id:111)            id:122)            id:133)
- *     ^ |                ^ |                ^ |
- *     | |  XDP_REDIRECT  | |  XDP_REDIRECT  | |
- *     | ------------------ ------------------ |
- *     -----------------------------------------
- *                    XDP_REDIRECT
+ * Network topology:
+ *  ----------        ----------       ----------
+ *  |  NS1   |        |  NS2   |       |  NS3   |
+ *  | veth11 |        | veth22 |       | veth33 |
+ *  ----|-----        -----|----       -----|----
+ *      |                  |                |
+ *    veth1              veth2            veth3
+ *
+ * Test cases:
+ *  - [test_xdp_veth_redirect] : ping veth33 from veth11
+ *
+ *    veth11             veth22              veth33
+ *  (XDP_PASS)          (XDP_TX)           (XDP_PASS)
+ *       |                  |                  |
+ *       |                  |                  |
+ *     veth1             veth2              veth3
+ * (XDP_REDIRECT)     (XDP_REDIRECT)     (XDP_REDIRECT)
+ *      ^ |                ^ |                ^ |
+ *      | |                | |                | |
+ *      | ------------------ ------------------ |
+ *      -----------------------------------------
  */
 
 #define _GNU_SOURCE
@@ -119,12 +129,9 @@ static int attach_programs_to_veth_pair(struct skeletons *skeletons, int index)
 	return 0;
 }
 
-static int configure_network(struct skeletons *skeletons)
+static int create_network(void)
 {
-	int interface_id;
-	int map_fd;
-	int err;
-	int i = 0;
+	int i;
 
 	/* First create and configure all interfaces */
 	for (i = 0; i < VETH_PAIRS_COUNT; i++) {
@@ -139,27 +146,11 @@ static int configure_network(struct skeletons *skeletons)
 		    config[i].remote_veth);
 	}
 
-	/* Then configure the redirect map and attach programs to interfaces */
-	map_fd = bpf_map__fd(skeletons->xdp_redirect_maps->maps.tx_port);
-	if (!ASSERT_GE(map_fd, 0, "open redirect map"))
-		goto fail;
-	for (i = 0; i < VETH_PAIRS_COUNT; i++) {
-		int next_veth = config[i].next_veth;
-
-		interface_id = if_nametoindex(config[next_veth].local_veth);
-		if (!ASSERT_NEQ(interface_id, 0, "non zero interface index"))
-			goto fail;
-		err = bpf_map_update_elem(map_fd, &i, &interface_id, BPF_ANY);
-		if (!ASSERT_OK(err, "configure interface redirection through map"))
-			goto fail;
-		if (attach_programs_to_veth_pair(skeletons, i))
-			goto fail;
-	}
-
 	return 0;
 
 fail:
 	return -1;
+
 }
 
 static void cleanup_network(void)
@@ -175,6 +166,8 @@ static void cleanup_network(void)
 void test_xdp_veth_redirect(void)
 {
 	struct skeletons skeletons = {};
+	int map_fd;
+	int i;
 
 	skeletons.xdp_dummy = xdp_dummy__open_and_load();
 	if (!ASSERT_OK_PTR(skeletons.xdp_dummy, "xdp_dummy__open_and_load"))
@@ -188,9 +181,29 @@ void test_xdp_veth_redirect(void)
 	if (!ASSERT_OK_PTR(skeletons.xdp_redirect_maps, "xdp_redirect_map__open_and_load"))
 		goto destroy_xdp_tx;
 
-	if (configure_network(&skeletons))
+	if (!ASSERT_OK(create_network(), "create_network"))
 		goto destroy_xdp_redirect_map;
 
+	/* Then configure the redirect map and attach programs to interfaces */
+	map_fd = bpf_map__fd(skeletons.xdp_redirect_maps->maps.tx_port);
+	if (!ASSERT_OK_FD(map_fd, "open redirect map"))
+		goto destroy_xdp_redirect_map;
+
+	for (i = 0; i < VETH_PAIRS_COUNT; i++) {
+		int next_veth = config[i].next_veth;
+		int interface_id;
+		int err;
+
+		interface_id = if_nametoindex(config[next_veth].local_veth);
+		if (!ASSERT_NEQ(interface_id, 0, "non zero interface index"))
+			goto destroy_xdp_redirect_map;
+		err = bpf_map_update_elem(map_fd, &i, &interface_id, BPF_ANY);
+		if (!ASSERT_OK(err, "configure interface redirection through map"))
+			goto destroy_xdp_redirect_map;
+		if (attach_programs_to_veth_pair(&skeletons, i))
+			goto destroy_xdp_redirect_map;
+	}
+
 	/* Test: if all interfaces are properly configured, we must be able to ping
 	 * veth33 from veth11
 	 */

-- 
2.47.1