[PATCH bpf-next 01/10] 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

Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
---
 .../selftests/bpf/prog_tests/test_xdp_veth.c       | 78 +++++++++++++---------
 1 file changed, 46 insertions(+), 32 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 8d75424fe6bc8b2d4eeabe3ec49b883284c834e9..8dc28274a6e8fc75b05781d827a04f01e03a6ebb 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
@@ -121,12 +131,9 @@ 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++) {
@@ -141,25 +148,11 @@ 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++) {
-		interface_id = if_nametoindex(config[i].next_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)
@@ -184,6 +177,8 @@ static int check_ping(struct skeletons *skeletons)
 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"))
@@ -197,9 +192,28 @@ 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 (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 interface_id;
+		int err;
+
+		interface_id = if_nametoindex(config[i].next_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;
+	}
+
 	ASSERT_OK(check_ping(&skeletons), "ping");
 
 destroy_xdp_redirect_map:

-- 
2.47.1