[PATCH bpf-next v7 21/24] selftests/bpf: Add a test for BPF_F_INSERT_HEAD

Benjamin Tissoires
2022-07-21T15:41:20Z

Insert 3 programs to check that we are doing the correct thing:
'2', '1', '3' are inserted, but '1' is supposed to be executed first.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

no changes in v7

changes in v6:
- fixed copy/paste in ASSERT_OK and test execution order

changes in v5:
- use the new API

not in v4

changes in v3:
- use the new hid_get_data API

new in v2
---
tools/testing/selftests/bpf/prog_tests/hid.c | 107 +++++++++++++++++++
tools/testing/selftests/bpf/progs/hid.c | 54 +++++++++-
2 files changed, 160 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/hid.c b/tools/testing/selftests/bpf/prog_tests/hid.c
index 9dc5f0038472..a86e16554e68 100644
--- a/tools/testing/selftests/bpf/prog_tests/hid.c
+++ b/tools/testing/selftests/bpf/prog_tests/hid.c
@@ -9,6 +9,7 @@
#include <dirent.h>
#include <poll.h>
#include <stdbool.h>
+#include <linux/hid_bpf.h>
#include <linux/hidraw.h>
#include <linux/uhid.h>

@@ -83,6 +84,7 @@ static u8 feature_data[] = { 1, 2 };
struct attach_prog_args {
int prog_fd;
unsigned int hid;
+ unsigned int flags;
int retval;
};

@@ -770,6 +772,109 @@ static int test_hid_user_raw_request_call(int uhid_fd, int dev_id)
return ret;
}

+/*
+ * Attach hid_insert{0,1,2} to the given uhid device,
+ * retrieve and open the matching hidraw node,
+ * inject one event in the uhid device,
+ * check that the programs have been inserted in the correct order.
+ */
+static int test_hid_attach_flags(int uhid_fd, int dev_id)
+{
+ struct hid *hid_skel = NULL;
+ u8 buf[64] = {0};
+ int hidraw_fd = -1;
+ int hid_id, attach_fd, err = -EINVAL;
+ struct attach_prog_args args = {
+ .retval = -1,
+ };
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr,
+ .ctx_in = &args,
+ .ctx_size_in = sizeof(args),
+ );
+
+ /* locate the uevent file of the created device */
+ hid_id = get_hid_id(dev_id);
+ if (!ASSERT_GE(hid_id, 0, "locate uhid device id"))
+ goto cleanup;
+
+ args.hid = hid_id;
+
+ hid_skel = hid__open();
+ if (!ASSERT_OK_PTR(hid_skel, "hid_skel_open"))
+ goto cleanup;
+
+ bpf_program__set_autoload(hid_skel->progs.hid_test_insert1, true);
+ bpf_program__set_autoload(hid_skel->progs.hid_test_insert2, true);
+ bpf_program__set_autoload(hid_skel->progs.hid_test_insert3, true);
+
+ err = hid__load(hid_skel);
+ if (!ASSERT_OK(err, "hid_skel_load"))
+ goto cleanup;
+
+ attach_fd = bpf_program__fd(hid_skel->progs.attach_prog);
+ if (!ASSERT_GE(attach_fd, 0, "locate attach_prog")) {
+ err = attach_fd;
+ goto cleanup;
+ }
+
+ /* attach hid_test_insert2 program */
+ args.prog_fd = bpf_program__fd(hid_skel->progs.hid_test_insert2);
+ args.flags = HID_BPF_FLAG_NONE;
+ args.retval = 1;
+ err = bpf_prog_test_run_opts(attach_fd, &tattr);
+ if (!ASSERT_EQ(args.retval, 0, "attach_hid_test_insert2"))
+ goto cleanup;
+
+ /* then attach hid_test_insert1 program before the previous*/
+ args.prog_fd = bpf_program__fd(hid_skel->progs.hid_test_insert1);
+ args.flags = HID_BPF_FLAG_INSERT_HEAD;
+ args.retval = 1;
+ err = bpf_prog_test_run_opts(attach_fd, &tattr);
+ if (!ASSERT_EQ(args.retval, 0, "attach_hid_test_insert1"))
+ goto cleanup;
+
+ /* finally attach hid_test_insert3 at the end */
+ args.prog_fd = bpf_program__fd(hid_skel->progs.hid_test_insert3);
+ args.flags = HID_BPF_FLAG_NONE;
+ args.retval = 1;
+ err = bpf_prog_test_run_opts(attach_fd, &tattr);
+ if (!ASSERT_EQ(args.retval, 0, "attach_hid_test_insert3"))
+ goto cleanup;
+
+ hidraw_fd = open_hidraw(dev_id);
+ if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw"))
+ goto cleanup;
+
+ /* inject one event */
+ buf[0] = 1;
+ send_event(uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[1], 1, "hid_test_insert1"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 2, "hid_test_insert2"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[3], 3, "hid_test_insert3"))
+ goto cleanup;
+
+ err = 0;
+
+ cleanup:
+ if (hidraw_fd >= 0)
+ close(hidraw_fd);
+
+ hid__destroy(hid_skel);
+
+ return err;
+}
+
/*
* Attach hid_rdesc_fixup to the given uhid device,
* retrieve and open the matching hidraw node,
@@ -866,6 +971,8 @@ void serial_test_hid_bpf(void)
ASSERT_OK(err, "hid_change_report");
err = test_hid_user_raw_request_call(uhid_fd, dev_id);
ASSERT_OK(err, "hid_user_raw_request");
+ err = test_hid_attach_flags(uhid_fd, dev_id);
+ ASSERT_OK(err, "hid_attach_flags");

/*
* this test should be run last because we disconnect/reconnect
diff --git a/tools/testing/selftests/bpf/progs/hid.c b/tools/testing/selftests/bpf/progs/hid.c
index 863c37ddf5ff..92cf57d2be3e 100644
--- a/tools/testing/selftests/bpf/progs/hid.c
+++ b/tools/testing/selftests/bpf/progs/hid.c
@@ -21,6 +21,7 @@ extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
struct attach_prog_args {
int prog_fd;
unsigned int hid;
+ unsigned int flags;
int retval;
};

@@ -60,7 +61,7 @@ int attach_prog(struct attach_prog_args *ctx)
{
ctx->retval = hid_bpf_attach_prog(ctx->hid,
ctx->prog_fd,
- 0);
+ ctx->flags);
return 0;
}

@@ -152,3 +153,54 @@ int BPF_PROG(hid_rdesc_fixup, struct hid_bpf_ctx *hid_ctx)

return sizeof(rdesc) + 73;
}
+
+SEC("?fmod_ret/hid_bpf_device_event")
+int BPF_PROG(hid_test_insert1, struct hid_bpf_ctx *hid_ctx)
+{
+ __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+ if (!data)
+ return 0; /* EPERM check */
+
+ /* we need to be run first */
+ if (data[2] || data[3])
+ return -1;
+
+ data[1] = 1;
+
+ return 0;
+}
+
+SEC("?fmod_ret/hid_bpf_device_event")
+int BPF_PROG(hid_test_insert2, struct hid_bpf_ctx *hid_ctx)
+{
+ __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+ if (!data)
+ return 0; /* EPERM check */
+
+ /* after insert0 and before insert2 */
+ if (!data[1] || data[3])
+ return -1;
+
+ data[2] = 2;
+
+ return 0;
+}
+
+SEC("?fmod_ret/hid_bpf_device_event")
+int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx)
+{
+ __u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);
+
+ if (!data)
+ return 0; /* EPERM check */
+
+ /* at the end */
+ if (!data[1] || !data[2])
+ return -1;
+
+ data[3] = 3;
+
+ return 0;
+}
--
2.36.1