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
  7static 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
 13static 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
 61out:
 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 */
 76void 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}