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linux/tools/testing/selftests/bpf/prog_tests/xdp_attach.c
Joanne Koong cfa7b01189 selftests/bpf: tests for using dynptrs to parse skb and xdp buffers
Test skb and xdp dynptr functionality in the following ways:

1) progs/test_cls_redirect_dynptr.c
   * Rewrite "progs/test_cls_redirect.c" test to use dynptrs to parse
     skb data

   * This is a great example of how dynptrs can be used to simplify a
     lot of the parsing logic for non-statically known values.

     When measuring the user + system time between the original version
     vs. using dynptrs, and averaging the time for 10 runs (using
     "time ./test_progs -t cls_redirect"):
         original version: 0.092 sec
         with dynptrs: 0.078 sec

2) progs/test_xdp_dynptr.c
   * Rewrite "progs/test_xdp.c" test to use dynptrs to parse xdp data

     When measuring the user + system time between the original version
     vs. using dynptrs, and averaging the time for 10 runs (using
     "time ./test_progs -t xdp_attach"):
         original version: 0.118 sec
         with dynptrs: 0.094 sec

3) progs/test_l4lb_noinline_dynptr.c
   * Rewrite "progs/test_l4lb_noinline.c" test to use dynptrs to parse
     skb data

     When measuring the user + system time between the original version
     vs. using dynptrs, and averaging the time for 10 runs (using
     "time ./test_progs -t l4lb_all"):
         original version: 0.062 sec
         with dynptrs: 0.081 sec

     For number of processed verifier instructions:
         original version: 6268 insns
         with dynptrs: 2588 insns

4) progs/test_parse_tcp_hdr_opt_dynptr.c
   * Add sample code for parsing tcp hdr opt lookup using dynptrs.
     This logic is lifted from a real-world use case of packet parsing
     in katran [0], a layer 4 load balancer. The original version
     "progs/test_parse_tcp_hdr_opt.c" (not using dynptrs) is included
     here as well, for comparison.

     When measuring the user + system time between the original version
     vs. using dynptrs, and averaging the time for 10 runs (using
     "time ./test_progs -t parse_tcp_hdr_opt"):
         original version: 0.031 sec
         with dynptrs: 0.045 sec

5) progs/dynptr_success.c
   * Add test case "test_skb_readonly" for testing attempts at writes
     on a prog type with read-only skb ctx.
   * Add "test_dynptr_skb_data" for testing that bpf_dynptr_data isn't
     supported for skb progs.

6) progs/dynptr_fail.c
   * Add test cases "skb_invalid_data_slice{1,2,3,4}" and
     "xdp_invalid_data_slice{1,2}" for testing that helpers that modify the
     underlying packet buffer automatically invalidate the associated
     data slice.
   * Add test cases "skb_invalid_ctx" and "xdp_invalid_ctx" for testing
     that prog types that do not support bpf_dynptr_from_skb/xdp don't
     have access to the API.
   * Add test case "dynptr_slice_var_len{1,2}" for testing that
     variable-sized len can't be passed in to bpf_dynptr_slice
   * Add test case "skb_invalid_slice_write" for testing that writes to a
     read-only data slice are rejected by the verifier.
   * Add test case "data_slice_out_of_bounds_skb" for testing that
     writes to an area outside the slice are rejected.
   * Add test case "invalid_slice_rdwr_rdonly" for testing that prog
     types that don't allow writes to packet data don't accept any calls
     to bpf_dynptr_slice_rdwr.

[0] https://github.com/facebookincubator/katran/blob/main/katran/lib/bpf/pckt_parsing.h

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230301154953.641654-11-joannelkoong@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-01 10:05:19 -08:00

94 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#define IFINDEX_LO 1
#define XDP_FLAGS_REPLACE (1U << 4)
static void test_xdp_attach(const char *file)
{
__u32 duration = 0, id1, id2, id0 = 0, len;
struct bpf_object *obj1, *obj2, *obj3;
struct bpf_prog_info info = {};
int err, fd1, fd2, fd3;
LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
len = sizeof(info);
err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj1, &fd1);
if (CHECK_FAIL(err))
return;
err = bpf_prog_get_info_by_fd(fd1, &info, &len);
if (CHECK_FAIL(err))
goto out_1;
id1 = info.id;
err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj2, &fd2);
if (CHECK_FAIL(err))
goto out_1;
memset(&info, 0, sizeof(info));
err = bpf_prog_get_info_by_fd(fd2, &info, &len);
if (CHECK_FAIL(err))
goto out_2;
id2 = info.id;
err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj3, &fd3);
if (CHECK_FAIL(err))
goto out_2;
err = bpf_xdp_attach(IFINDEX_LO, fd1, XDP_FLAGS_REPLACE, &opts);
if (CHECK(err, "load_ok", "initial load failed"))
goto out_close;
err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
if (CHECK(err || id0 != id1, "id1_check",
"loaded prog id %u != id1 %u, err %d", id0, id1, err))
goto out_close;
err = bpf_xdp_attach(IFINDEX_LO, fd2, XDP_FLAGS_REPLACE, &opts);
if (CHECK(!err, "load_fail", "load with expected id didn't fail"))
goto out;
opts.old_prog_fd = fd1;
err = bpf_xdp_attach(IFINDEX_LO, fd2, 0, &opts);
if (CHECK(err, "replace_ok", "replace valid old_fd failed"))
goto out;
err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
if (CHECK(err || id0 != id2, "id2_check",
"loaded prog id %u != id2 %u, err %d", id0, id2, err))
goto out_close;
err = bpf_xdp_attach(IFINDEX_LO, fd3, 0, &opts);
if (CHECK(!err, "replace_fail", "replace invalid old_fd didn't fail"))
goto out;
err = bpf_xdp_detach(IFINDEX_LO, 0, &opts);
if (CHECK(!err, "remove_fail", "remove invalid old_fd didn't fail"))
goto out;
opts.old_prog_fd = fd2;
err = bpf_xdp_detach(IFINDEX_LO, 0, &opts);
if (CHECK(err, "remove_ok", "remove valid old_fd failed"))
goto out;
err = bpf_xdp_query_id(IFINDEX_LO, 0, &id0);
if (CHECK(err || id0 != 0, "unload_check",
"loaded prog id %u != 0, err %d", id0, err))
goto out_close;
out:
bpf_xdp_detach(IFINDEX_LO, 0, NULL);
out_close:
bpf_object__close(obj3);
out_2:
bpf_object__close(obj2);
out_1:
bpf_object__close(obj1);
}
void serial_test_xdp_attach(void)
{
if (test__start_subtest("xdp_attach"))
test_xdp_attach("./test_xdp.bpf.o");
if (test__start_subtest("xdp_attach_dynptr"))
test_xdp_attach("./test_xdp_dynptr.bpf.o");
}