text: // SPDX-License-Identifier: GPL-2.0
  /* Copyright (c) 2019 Facebook */
  #include <test_progs.h>
  
  static void test_fexit_bpf2bpf_common(const char *obj_file,
  				      const char *target_obj_file,
  				      int prog_cnt,
  				      const char **prog_name)
  {
  	struct bpf_object *obj = NULL, *pkt_obj;
  	int err, pkt_fd, i;
  	struct bpf_link **link = NULL;
  	struct bpf_program **prog = NULL;
  	__u32 duration = 0, retval;
  	struct bpf_map *data_map;
  	const int zero = 0;
  	u64 *result = NULL;
  
  	err = bpf_prog_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
  			    &pkt_obj, &pkt_fd);
  	if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
  		return;
  	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
  			    .attach_prog_fd = pkt_fd,
  			   );
  
  	link = calloc(sizeof(struct bpf_link *), prog_cnt);
  	prog = calloc(sizeof(struct bpf_program *), prog_cnt);
  	result = malloc((prog_cnt + 32 /* spare */) * sizeof(u64));
  	if (CHECK(!link || !prog || !result, "alloc_memory",
  		  "failed to alloc memory"))
  		goto close_prog;
  
  	obj = bpf_object__open_file(obj_file, &opts);
  	if (CHECK(IS_ERR_OR_NULL(obj), "obj_open",
  		  "failed to open fexit_bpf2bpf: %ld\n",
  		  PTR_ERR(obj)))
  		goto close_prog;
  
  	err = bpf_object__load(obj);
  	if (CHECK(err, "obj_load", "err %d\n", err))
  		goto close_prog;
  
  	for (i = 0; i < prog_cnt; i++) {
  		prog[i] = bpf_object__find_program_by_title(obj, prog_name[i]);
  		if (CHECK(!prog[i], "find_prog", "prog %s not found\n", prog_name[i]))
  			goto close_prog;
  		link[i] = bpf_program__attach_trace(prog[i]);
  		if (CHECK(IS_ERR(link[i]), "attach_trace", "failed to link\n"))
  			goto close_prog;
  	}
  	data_map = bpf_object__find_map_by_name(obj, "fexit_bp.bss");
  	if (CHECK(!data_map, "find_data_map", "data map not found\n"))
  		goto close_prog;
  
  	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v6, sizeof(pkt_v6),
  				NULL, NULL, &retval, &duration);
  	CHECK(err || retval, "ipv6",
  	      "err %d errno %d retval %d duration %d\n",
  	      err, errno, retval, duration);
  
  	err = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, result);
  	if (CHECK(err, "get_result",
  		  "failed to get output data: %d\n", err))
  		goto close_prog;
  
  	for (i = 0; i < prog_cnt; i++)
  		if (CHECK(result[i] != 1, "result", "fexit_bpf2bpf failed err %ld\n",
  			  result[i]))
  			goto close_prog;
  
  close_prog:
  	for (i = 0; i < prog_cnt; i++)
  		if (!IS_ERR_OR_NULL(link[i]))
  			bpf_link__destroy(link[i]);
  	if (!IS_ERR_OR_NULL(obj))
  		bpf_object__close(obj);
  	bpf_object__close(pkt_obj);
  	free(link);
  	free(prog);
  	free(result);
  }
  
  static void test_target_no_callees(void)
  {
  	const char *prog_name[] = {
  		"fexit/test_pkt_md_access",
  	};
  	test_fexit_bpf2bpf_common("./fexit_bpf2bpf_simple.o",
  				  "./test_pkt_md_access.o",
  				  ARRAY_SIZE(prog_name),
  				  prog_name);
  }
  
  static void test_target_yes_callees(void)
  {
  	const char *prog_name[] = {
  		"fexit/test_pkt_access",
  		"fexit/test_pkt_access_subprog1",
  		"fexit/test_pkt_access_subprog2",
  		"fexit/test_pkt_access_subprog3",
  	};
  	test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
  				  "./test_pkt_access.o",
  				  ARRAY_SIZE(prog_name),
  				  prog_name);
  }
  
  static void test_func_replace(void)
  {
  	const char *prog_name[] = {
  		"fexit/test_pkt_access",
  		"fexit/test_pkt_access_subprog1",
  		"fexit/test_pkt_access_subprog2",
  		"fexit/test_pkt_access_subprog3",
  		"freplace/get_skb_len",
  		"freplace/get_skb_ifindex",
  		"freplace/get_constant",
  	};
  	test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
  				  "./test_pkt_access.o",
  				  ARRAY_SIZE(prog_name),
  				  prog_name);
  }
  
  void test_fexit_bpf2bpf(void)
  {
  	test_target_no_callees();
  	test_target_yes_callees();
  	test_func_replace();
  }
  