Re: [PATCH bpf-next v3 2/3] selftests/bpf: make xdp_cpumap_attach keep redirect prog attached
From: Martin KaFai Lau
Date: Thu Oct 10 2024 - 21:23:48 EST
On 10/9/24 3:12 AM, Alexis Lothoré (eBPF Foundation) wrote:
Current test only checks attach/detach on cpu map type program, and so
does not check that it can be properly executed, neither that it
redirects correctly.
Update the existing test to extend its coverage:
- keep the redirected program loaded
- try to execute it through bpf_prog_test_run_opts with some dummy
context
While at it, bring the following minor improvements:
- isolate test interface in its own namespace
- replicate the test on a veth pair
Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@xxxxxxxxxxx>
---
This change is based on the similar update brought to xdp_devmap_attach
([1]) and then realigns xdp_cpumap_attach with it
[1] https://lore.kernel.org/bpf/20240911-devel-koalo-fix-ingress-ifindex-v4-2-5c643ae10258@xxxxxxxxxxxxx/
Changes in v3:
- new patch
---
.../selftests/bpf/prog_tests/xdp_cpumap_attach.c | 124 +++++++++++++++++++--
1 file changed, 117 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
index 481626a875d1c3db9c7bfe92c3cca6e967a6d45c..31c225f0239613f6b5adad36b5b0e6e85eeddd9a 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
@@ -2,35 +2,41 @@
#include <uapi/linux/bpf.h>
#include <linux/if_link.h>
#include <test_progs.h>
+#include <network_helpers.h>
#include "test_xdp_with_cpumap_frags_helpers.skel.h"
#include "test_xdp_with_cpumap_helpers.skel.h"
#define IFINDEX_LO 1
+#define TEST_NS "cpu_attach_ns"
static void test_xdp_with_cpumap_helpers(void)
{
- struct test_xdp_with_cpumap_helpers *skel;
+ struct test_xdp_with_cpumap_helpers *skel = NULL;
struct bpf_prog_info info = {};
__u32 len = sizeof(info);
struct bpf_cpumap_val val = {
.qsize = 192,
};
- int err, prog_fd, map_fd;
+ int err, prog_fd, prog_redir_fd, map_fd;
+ struct nstoken *nstoken = NULL;
__u32 idx = 0;
+ SYS(out_close, "ip netns add %s", TEST_NS);
+ nstoken = open_netns(TEST_NS);
+ if (!ASSERT_OK_PTR(nstoken, "open_netns"))
+ goto out_close;
+ SYS(out_close, "ip link set dev lo up");
There is easier helper netns_{new,free} to do all these:
netns_obj = netns_new(TEST_NS, true);
Only fyi for your future work.
+
skel = test_xdp_with_cpumap_helpers__open_and_load();
if (!ASSERT_OK_PTR(skel, "test_xdp_with_cpumap_helpers__open_and_load"))
return;
- prog_fd = bpf_program__fd(skel->progs.xdp_redir_prog);
- err = bpf_xdp_attach(IFINDEX_LO, prog_fd, XDP_FLAGS_SKB_MODE, NULL);
+ prog_redir_fd = bpf_program__fd(skel->progs.xdp_redir_prog);
+ err = bpf_xdp_attach(IFINDEX_LO, prog_redir_fd, XDP_FLAGS_SKB_MODE, NULL);
if (!ASSERT_OK(err, "Generic attach of program with 8-byte CPUMAP"))
goto out_close;
- err = bpf_xdp_detach(IFINDEX_LO, XDP_FLAGS_SKB_MODE, NULL);
- ASSERT_OK(err, "XDP program detach");
-
prog_fd = bpf_program__fd(skel->progs.xdp_dummy_cm);
map_fd = bpf_map__fd(skel->maps.cpu_map);
err = bpf_prog_get_info_by_fd(prog_fd, &info, &len);
@@ -45,6 +51,23 @@ static void test_xdp_with_cpumap_helpers(void)
ASSERT_OK(err, "Read cpumap entry");
ASSERT_EQ(info.id, val.bpf_prog.id, "Match program id to cpumap entry prog_id");
+ /* send a packet to trigger any potential bugs in there */
+ char data[10] = {};
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .data_in = &data,
+ .data_size_in = 10,
+ .flags = BPF_F_TEST_XDP_LIVE_FRAMES,
+ .repeat = 1,
+ );
+ err = bpf_prog_test_run_opts(prog_redir_fd, &opts);
+ ASSERT_OK(err, "XDP test run");
+
+ /* wait for the packets to be flushed */
+ kern_sync_rcu();
+
+ err = bpf_xdp_detach(IFINDEX_LO, XDP_FLAGS_SKB_MODE, NULL);
+ ASSERT_OK(err, "XDP program detach");
+
/* can not attach BPF_XDP_CPUMAP program to a device */
err = bpf_xdp_attach(IFINDEX_LO, prog_fd, XDP_FLAGS_SKB_MODE, NULL);
if (!ASSERT_NEQ(err, 0, "Attach of BPF_XDP_CPUMAP program"))
@@ -65,6 +88,8 @@ static void test_xdp_with_cpumap_helpers(void)
ASSERT_NEQ(err, 0, "Add BPF_XDP program with frags to cpumap entry");
out_close:
+ close_netns(nstoken);
+ SYS_NOFAIL("ip netns del %s", TEST_NS);
test_xdp_with_cpumap_helpers__destroy(skel);
}
@@ -111,6 +136,88 @@ static void test_xdp_with_cpumap_frags_helpers(void)
test_xdp_with_cpumap_frags_helpers__destroy(skel);
}
+static void test_xdp_with_cpumap_helpers_veth(void)
Unlike the devmap redirect, cpumap redirects pkt to another cpu instead of
another veth dev. veth test is not very useful here for cpumap, so I take the
veth test out.
+{
+ int err, cm_fd, cm_fd_redir, map_fd, ifindex_dst, ifindex_src;
+ struct test_xdp_with_cpumap_helpers *skel = NULL;
+ struct bpf_prog_info info = {};
+ struct bpf_cpumap_val val = {
+ .qsize = 192
+ };
+ struct nstoken *nstoken = NULL;
+ __u32 len = sizeof(info);
+ __u32 idx = 0;
+
+ SYS(out_close, "ip netns add %s", TEST_NS);
+ nstoken = open_netns(TEST_NS);
+ if (!ASSERT_OK_PTR(nstoken, "open_netns"))
+ goto out_close;
+
+ SYS(out_close, "ip link add veth_src type veth peer name veth_dst");
+ SYS(out_close, "ip link set dev veth_src up");
+ SYS(out_close, "ip link set dev veth_dst up");
+
+ ifindex_src = if_nametoindex("veth_src");
+ ifindex_dst = if_nametoindex("veth_dst");
+ if (!ASSERT_NEQ(ifindex_src, 0, "val.ifindex") ||
+ !ASSERT_NEQ(ifindex_dst, 0, "ifindex_dst"))
+ goto out_close;
+
+ skel = test_xdp_with_cpumap_helpers__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "test_xdp_with_cpumap_helpers__open_and_load"))
+ goto out_close;
+
+ cm_fd_redir = bpf_program__fd(skel->progs.xdp_redir_prog);
+ err = bpf_xdp_attach(ifindex_src, cm_fd_redir, XDP_FLAGS_DRV_MODE, NULL);
+ if (!ASSERT_OK(err, "Attach of program with 8-byte cpumap"))
+ goto out_close;
+
+ cm_fd = bpf_program__fd(skel->progs.xdp_dummy_cm);
+ map_fd = bpf_map__fd(skel->maps.cpu_map);
+ err = bpf_prog_get_info_by_fd(cm_fd, &info, &len);
+ if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd"))
+ goto out_close;
+
+ val.bpf_prog.fd = cm_fd;
+ err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+ ASSERT_OK(err, "Add program to cpumap entry");
+
+ err = bpf_map_lookup_elem(map_fd, &idx, &val);
+ ASSERT_OK(err, "Read cpumap entry");
+ ASSERT_EQ(info.id, val.bpf_prog.id, "Match program id to cpumap entry prog_id");
+
+ /* attach dummy to other side to enable reception */
+ cm_fd = bpf_program__fd(skel->progs.xdp_dummy_prog);
+ err = bpf_xdp_attach(ifindex_dst, cm_fd, XDP_FLAGS_DRV_MODE, NULL);
+ if (!ASSERT_OK(err, "Attach of dummy XDP"))
+ goto out_close;
+
+ /* send a packet to trigger any potential bugs in there */
+ char data[10] = {};
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
+ .data_in = &data,
+ .data_size_in = 10,
+ .flags = BPF_F_TEST_XDP_LIVE_FRAMES,
+ .repeat = 1,
+ );
+ err = bpf_prog_test_run_opts(cm_fd_redir, &opts);
+ ASSERT_OK(err, "XDP test run");
+
+ /* wait for the packets to be flushed */
+ kern_sync_rcu();
+
+ err = bpf_xdp_detach(ifindex_src, XDP_FLAGS_DRV_MODE, NULL);
+ ASSERT_OK(err, "XDP program detach");
+
+ err = bpf_xdp_detach(ifindex_dst, XDP_FLAGS_DRV_MODE, NULL);
+ ASSERT_OK(err, "XDP program detach");
+
+out_close:
+ close_netns(nstoken);
+ SYS_NOFAIL("ip netns del %s", TEST_NS);
+ test_xdp_with_cpumap_helpers__destroy(skel);
+}
+
void serial_test_xdp_cpumap_attach(void)
Thanks for improving the existing test by running in its netns, I also removed
the "serial_". Applied. Thanks.
{
if (test__start_subtest("CPUMAP with programs in entries"))
@@ -118,4 +225,7 @@ void serial_test_xdp_cpumap_attach(void)
if (test__start_subtest("CPUMAP with frags programs in entries"))
test_xdp_with_cpumap_frags_helpers();
+
+ if (test__start_subtest("CPUMAP attach with programs in entries on veth"))
+ test_xdp_with_cpumap_helpers_veth();
}