bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest

Introduce kernel selftest for new bpf_xdp_{load,store}_bytes helpers.
and bpf_xdp_pointer/bpf_xdp_copy_buf utility routines.

Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/2c99ae663a5dcfbd9240b1d0489ad55dea4f4601.1642758637.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
new file mode 100644 (file)
index 0000000..31c1886
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_frags.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <network_helpers.h>
+
+void test_xdp_update_frags(void)
+{
+       const char *file = "./test_xdp_update_frags.o";
+       __u32 duration, retval, size;
+       struct bpf_program *prog;
+       struct bpf_object *obj;
+       int err, prog_fd;
+       __u32 *offset;
+       __u8 *buf;
+
+       obj = bpf_object__open(file);
+       if (libbpf_get_error(obj))
+               return;
+
+       prog = bpf_object__next_program(obj, NULL);
+       if (bpf_object__load(obj))
+               return;
+
+       prog_fd = bpf_program__fd(prog);
+
+       buf = malloc(128);
+       if (!ASSERT_OK_PTR(buf, "alloc buf 128b"))
+               goto out;
+
+       memset(buf, 0, 128);
+       offset = (__u32 *)buf;
+       *offset = 16;
+       buf[*offset] = 0xaa;            /* marker at offset 16 (head) */
+       buf[*offset + 15] = 0xaa;       /* marker at offset 31 (head) */
+
+       err = bpf_prog_test_run(prog_fd, 1, buf, 128,
+                               buf, &size, &retval, &duration);
+
+       /* test_xdp_update_frags: buf[16,31]: 0xaa -> 0xbb */
+       ASSERT_OK(err, "xdp_update_frag");
+       ASSERT_EQ(retval, XDP_PASS, "xdp_update_frag retval");
+       ASSERT_EQ(buf[16], 0xbb, "xdp_update_frag buf[16]");
+       ASSERT_EQ(buf[31], 0xbb, "xdp_update_frag buf[31]");
+
+       free(buf);
+
+       buf = malloc(9000);
+       if (!ASSERT_OK_PTR(buf, "alloc buf 9Kb"))
+               goto out;
+
+       memset(buf, 0, 9000);
+       offset = (__u32 *)buf;
+       *offset = 5000;
+       buf[*offset] = 0xaa;            /* marker at offset 5000 (frag0) */
+       buf[*offset + 15] = 0xaa;       /* marker at offset 5015 (frag0) */
+
+       err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+                               buf, &size, &retval, &duration);
+
+       /* test_xdp_update_frags: buf[5000,5015]: 0xaa -> 0xbb */
+       ASSERT_OK(err, "xdp_update_frag");
+       ASSERT_EQ(retval, XDP_PASS, "xdp_update_frag retval");
+       ASSERT_EQ(buf[5000], 0xbb, "xdp_update_frag buf[5000]");
+       ASSERT_EQ(buf[5015], 0xbb, "xdp_update_frag buf[5015]");
+
+       memset(buf, 0, 9000);
+       offset = (__u32 *)buf;
+       *offset = 3510;
+       buf[*offset] = 0xaa;            /* marker at offset 3510 (head) */
+       buf[*offset + 15] = 0xaa;       /* marker at offset 3525 (frag0) */
+
+       err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+                               buf, &size, &retval, &duration);
+
+       /* test_xdp_update_frags: buf[3510,3525]: 0xaa -> 0xbb */
+       ASSERT_OK(err, "xdp_update_frag");
+       ASSERT_EQ(retval, XDP_PASS, "xdp_update_frag retval");
+       ASSERT_EQ(buf[3510], 0xbb, "xdp_update_frag buf[3510]");
+       ASSERT_EQ(buf[3525], 0xbb, "xdp_update_frag buf[3525]");
+
+       memset(buf, 0, 9000);
+       offset = (__u32 *)buf;
+       *offset = 7606;
+       buf[*offset] = 0xaa;            /* marker at offset 7606 (frag0) */
+       buf[*offset + 15] = 0xaa;       /* marker at offset 7621 (frag1) */
+
+       err = bpf_prog_test_run(prog_fd, 1, buf, 9000,
+                               buf, &size, &retval, &duration);
+
+       /* test_xdp_update_frags: buf[7606,7621]: 0xaa -> 0xbb */
+       ASSERT_OK(err, "xdp_update_frag");
+       ASSERT_EQ(retval, XDP_PASS, "xdp_update_frag retval");
+       ASSERT_EQ(buf[7606], 0xbb, "xdp_update_frag buf[7606]");
+       ASSERT_EQ(buf[7621], 0xbb, "xdp_update_frag buf[7621]");
+
+       free(buf);
+out:
+       bpf_object__close(obj);
+}
+
+void test_xdp_adjust_frags(void)
+{
+       if (test__start_subtest("xdp_adjust_frags"))
+               test_xdp_update_frags();
+}

diff --git a/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
new file mode 100644 (file)
index 0000000..2a3496d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_xdp_update_frags.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <bpf/bpf_helpers.h>
+
+int _version SEC("version") = 1;
+
+SEC("xdp.frags")
+int xdp_adjust_frags(struct xdp_md *xdp)
+{
+       __u8 *data_end = (void *)(long)xdp->data_end;
+       __u8 *data = (void *)(long)xdp->data;
+       __u8 val[16] = {};
+       __u32 offset;
+       int err;
+
+       if (data + sizeof(__u32) > data_end)
+               return XDP_DROP;
+
+       offset = *(__u32 *)data;
+       err = bpf_xdp_load_bytes(xdp, offset, val, sizeof(val));
+       if (err < 0)
+               return XDP_DROP;
+
+       if (val[0] != 0xaa || val[15] != 0xaa) /* marker */
+               return XDP_DROP;
+
+       val[0] = 0xbb; /* update the marker */
+       val[15] = 0xbb;
+       err = bpf_xdp_store_bytes(xdp, offset, val, sizeof(val));
+       if (err < 0)
+               return XDP_DROP;
+
+       return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";