tools/testing/selftests/bpf/prog_tests/changes_pkt_data.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "bpf/libbpf.h"
   3 #include "changes_pkt_data_freplace.skel.h"
   4 #include "changes_pkt_data.skel.h"
   5 #include <test_progs.h>
   6
   7 static void print_verifier_log(const char *log)
   8 {
   9         if (env.verbosity >= VERBOSE_VERY)
  10                 fprintf(stdout, "VERIFIER LOG:\n=============\n%s=============\n", log);
  11 }
  12
  13 static void test_aux(const char *main_prog_name,
  14                      const char *to_be_replaced,
  15                      const char *replacement,
  16                      bool expect_load)
  17 {
  18         struct changes_pkt_data_freplace *freplace = NULL;
  19         struct bpf_program *freplace_prog = NULL;
  20         struct bpf_program *main_prog = NULL;
  21         LIBBPF_OPTS(bpf_object_open_opts, opts);
  22         struct changes_pkt_data *main = NULL;
  23         char log[16*1024];
  24         int err;
  25
  26         opts.kernel_log_buf = log;
  27         opts.kernel_log_size = sizeof(log);
  28         if (env.verbosity >= VERBOSE_SUPER)
  29                 opts.kernel_log_level = 1 | 2 | 4;
  30         main = changes_pkt_data__open_opts(&opts);
  31         if (!ASSERT_OK_PTR(main, "changes_pkt_data__open"))
  32                 goto out;
  33         main_prog = bpf_object__find_program_by_name(main->obj, main_prog_name);
  34         if (!ASSERT_OK_PTR(main_prog, "main_prog"))
  35                 goto out;
  36         bpf_program__set_autoload(main_prog, true);
  37         err = changes_pkt_data__load(main);
  38         print_verifier_log(log);
  39         if (!ASSERT_OK(err, "changes_pkt_data__load"))
  40                 goto out;
  41         freplace = changes_pkt_data_freplace__open_opts(&opts);
  42         if (!ASSERT_OK_PTR(freplace, "changes_pkt_data_freplace__open"))
  43                 goto out;
  44         freplace_prog = bpf_object__find_program_by_name(freplace->obj, replacement);
  45         if (!ASSERT_OK_PTR(freplace_prog, "freplace_prog"))
  46                 goto out;
  47         bpf_program__set_autoload(freplace_prog, true);
  48         bpf_program__set_autoattach(freplace_prog, true);
  49         bpf_program__set_attach_target(freplace_prog,
  50                                        bpf_program__fd(main_prog),
  51                                        to_be_replaced);
  52         err = changes_pkt_data_freplace__load(freplace);
  53         print_verifier_log(log);
  54         if (expect_load) {
  55                 ASSERT_OK(err, "changes_pkt_data_freplace__load");
  56         } else {
  57                 ASSERT_ERR(err, "changes_pkt_data_freplace__load");
  58                 ASSERT_HAS_SUBSTR(log, "Extension program changes packet data", "error log");
  59         }
  60
  61 out:
  62         changes_pkt_data_freplace__destroy(freplace);
  63         changes_pkt_data__destroy(main);
  64 }
  65
  66 /* There are two global subprograms in both changes_pkt_data.skel.h:
  67  * - one changes packet data;
  68  * - another does not.
  69  * It is ok to freplace subprograms that change packet data with those
  70  * that either do or do not. It is only ok to freplace subprograms
  71  * that do not change packet data with those that do not as well.
  72  * The below tests check outcomes for each combination of such freplace.
  73  * Also test a case when main subprogram itself is replaced and is a single
  74  * subprogram in a program.
  75  */
  76 void test_changes_pkt_data_freplace(void)
  77 {
  78         struct {
  79                 const char *main;
  80                 const char *to_be_replaced;
  81                 bool changes;
  82         } mains[] = {
  83                 { "main_with_subprogs",   "changes_pkt_data",         true },
  84                 { "main_with_subprogs",   "does_not_change_pkt_data", false },
  85                 { "main_changes",         "main_changes",             true },
  86                 { "main_does_not_change", "main_does_not_change",     false },
  87         };
  88         struct {
  89                 const char *func;
  90                 bool changes;
  91         } replacements[] = {
  92                 { "changes_pkt_data",         true },
  93                 { "does_not_change_pkt_data", false }
  94         };
  95         char buf[64];
  96
  97         for (int i = 0; i < ARRAY_SIZE(mains); ++i) {
  98                 for (int j = 0; j < ARRAY_SIZE(replacements); ++j) {
  99                         snprintf(buf, sizeof(buf), "%s_with_%s",
 100                                  mains[i].to_be_replaced, replacements[j].func);
 101                         if (!test__start_subtest(buf))
 102                                 continue;
 103                         test_aux(mains[i].main, mains[i].to_be_replaced, replacements[j].func,
 104                                  mains[i].changes || !replacements[j].changes);
 105                 }
 106         }
 107 }