[PATCH v7 bpf-next 9/9] selftest: add tests for XDP programs in CPUMAP entries

Lorenzo Bianconi
2020-07-14T13:57:38Z

Similar to what have been done for DEVMAP, introduce tests to verify
ability to add a XDP program to an entry in a CPUMAP.
Verify CPUMAP programs can not be attached to devices as a normal
XDP program, and only programs with BPF_XDP_CPUMAP attach type can
be loaded in a CPUMAP.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
.../bpf/prog_tests/xdp_cpumap_attach.c | 70 +++++++++++++++++++
.../bpf/progs/test_xdp_with_cpumap_helpers.c | 36 ++++++++++
2 files changed, 106 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
create mode 100644 tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
new file mode 100644
index 000000000000..0176573fe4e7
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_cpumap_attach.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <uapi/linux/bpf.h>
+#include <linux/if_link.h>
+#include <test_progs.h>
+
+#include "test_xdp_with_cpumap_helpers.skel.h"
+
+#define IFINDEX_LO 1
+
+void test_xdp_with_cpumap_helpers(void)
+{
+ struct test_xdp_with_cpumap_helpers *skel;
+ struct bpf_prog_info info = {};
+ struct bpf_cpumap_val val = {
+ .qsize = 192,
+ };
+ __u32 duration = 0, idx = 0;
+ __u32 len = sizeof(info);
+ int err, prog_fd, map_fd;
+
+ skel = test_xdp_with_cpumap_helpers__open_and_load();
+ if (CHECK_FAIL(!skel)) {
+ perror("test_xdp_with_cpumap_helpers__open_and_load");
+ return;
+ }
+
+ /* can not attach program with cpumaps that allow programs
+ * as xdp generic
+ */
+ prog_fd = bpf_program__fd(skel->progs.xdp_redir_prog);
+ err = bpf_set_link_xdp_fd(IFINDEX_LO, prog_fd, XDP_FLAGS_SKB_MODE);
+ CHECK(err == 0, "Generic attach of program with 8-byte CPUMAP",
+ "should have failed\n");
+
+ prog_fd = bpf_program__fd(skel->progs.xdp_dummy_cm);
+ map_fd = bpf_map__fd(skel->maps.cpu_map);
+ err = bpf_obj_get_info_by_fd(prog_fd, &info, &len);
+ if (CHECK_FAIL(err))
+ goto out_close;
+
+ val.bpf_prog.fd = prog_fd;
+ err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+ CHECK(err, "Add program to cpumap entry", "err %d errno %d\n",
+ err, errno);
+
+ err = bpf_map_lookup_elem(map_fd, &idx, &val);
+ CHECK(err, "Read cpumap entry", "err %d errno %d\n", err, errno);
+ CHECK(info.id != val.bpf_prog.id, "Expected program id in cpumap entry",
+ "expected %u read %u\n", info.id, val.bpf_prog.id);
+
+ /* can not attach BPF_XDP_CPUMAP program to a device */
+ err = bpf_set_link_xdp_fd(IFINDEX_LO, prog_fd, XDP_FLAGS_SKB_MODE);
+ CHECK(err == 0, "Attach of BPF_XDP_CPUMAP program",
+ "should have failed\n");
+
+ val.qsize = 192;
+ val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_dummy_prog);
+ err = bpf_map_update_elem(map_fd, &idx, &val, 0);
+ CHECK(err == 0, "Add non-BPF_XDP_CPUMAP program to cpumap entry",
+ "should have failed\n");
+
+out_close:
+ test_xdp_with_cpumap_helpers__destroy(skel);
+}
+
+void test_xdp_cpumap_attach(void)
+{
+ if (test__start_subtest("cpumap_with_progs"))
+ test_xdp_with_cpumap_helpers();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
new file mode 100644
index 000000000000..59ee4f182ff8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_with_cpumap_helpers.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define IFINDEX_LO 1
+
+struct {
+ __uint(type, BPF_MAP_TYPE_CPUMAP);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(struct bpf_cpumap_val));
+ __uint(max_entries, 4);
+} cpu_map SEC(".maps");
+
+SEC("xdp_redir")
+int xdp_redir_prog(struct xdp_md *ctx)
+{
+ return bpf_redirect_map(&cpu_map, 1, 0);
+}
+
+SEC("xdp_dummy")
+int xdp_dummy_prog(struct xdp_md *ctx)
+{
+ return XDP_PASS;
+}
+
+SEC("xdp_cpumap/dummy_cm")
+int xdp_dummy_cm(struct xdp_md *ctx)
+{
+ if (ctx->ingress_ifindex == IFINDEX_LO)
+ return XDP_DROP;
+
+ return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.26.2