tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2019 Facebook */
   3 #include <test_progs.h>
   4 #include <network_helpers.h>
   5 #include <bpf/btf.h>
   6 #include "bind4_prog.skel.h"
   7
   8 typedef int (*test_cb)(struct bpf_object *obj);
   9
  10 static int check_data_map(struct bpf_object *obj, int prog_cnt, bool reset)
  11 {
  12         struct bpf_map *data_map = NULL, *map;
  13         __u64 *result = NULL;
  14         const int zero = 0;
  15         __u32 duration = 0;
  16         int ret = -1, i;
  17
  18         result = malloc((prog_cnt + 32 /* spare */) * sizeof(__u64));
  19         if (CHECK(!result, "alloc_memory", "failed to alloc memory"))
  20                 return -ENOMEM;
  21
  22         bpf_object__for_each_map(map, obj)
  23                 if (bpf_map__is_internal(map)) {
  24                         data_map = map;
  25                         break;
  26                 }
  27         if (CHECK(!data_map, "find_data_map", "data map not found\n"))
  28                 goto out;
  29
  30         ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, result);
  31         if (CHECK(ret, "get_result",
  32                   "failed to get output data: %d\n", ret))
  33                 goto out;
  34
  35         for (i = 0; i < prog_cnt; i++) {
  36                 if (CHECK(result[i] != 1, "result",
  37                           "fexit_bpf2bpf result[%d] failed err %llu\n",
  38                           i, result[i]))
  39                         goto out;
  40                 result[i] = 0;
  41         }
  42         if (reset) {
  43                 ret = bpf_map_update_elem(bpf_map__fd(data_map), &zero, result, 0);
  44                 if (CHECK(ret, "reset_result", "failed to reset result\n"))
  45                         goto out;
  46         }
  47
  48         ret = 0;
  49 out:
  50         free(result);
  51         return ret;
  52 }
  53
  54 static void test_fexit_bpf2bpf_common(const char *obj_file,
  55                                       const char *target_obj_file,
  56                                       int prog_cnt,
  57                                       const char **prog_name,
  58                                       bool run_prog,
  59                                       test_cb cb)
  60 {
  61         struct bpf_object *obj = NULL, *tgt_obj;
  62         __u32 tgt_prog_id, info_len;
  63         struct bpf_prog_info prog_info = {};
  64         struct bpf_program **prog = NULL, *p;
  65         struct bpf_link **link = NULL;
  66         int err, tgt_fd, i;
  67         struct btf *btf;
  68         LIBBPF_OPTS(bpf_test_run_opts, topts,
  69                 .data_in = &pkt_v6,
  70                 .data_size_in = sizeof(pkt_v6),
  71                 .repeat = 1,
  72         );
  73
  74         err = bpf_prog_test_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
  75                             &tgt_obj, &tgt_fd);
  76         if (!ASSERT_OK(err, "tgt_prog_load"))
  77                 return;
  78
  79         info_len = sizeof(prog_info);
  80         err = bpf_obj_get_info_by_fd(tgt_fd, &prog_info, &info_len);
  81         if (!ASSERT_OK(err, "tgt_fd_get_info"))
  82                 goto close_prog;
  83
  84         tgt_prog_id = prog_info.id;
  85         btf = bpf_object__btf(tgt_obj);
  86
  87         link = calloc(sizeof(struct bpf_link *), prog_cnt);
  88         if (!ASSERT_OK_PTR(link, "link_ptr"))
  89                 goto close_prog;
  90
  91         prog = calloc(sizeof(struct bpf_program *), prog_cnt);
  92         if (!ASSERT_OK_PTR(prog, "prog_ptr"))
  93                 goto close_prog;
  94
  95         obj = bpf_object__open_file(obj_file, NULL);
  96         if (!ASSERT_OK_PTR(obj, "obj_open"))
  97                 goto close_prog;
  98
  99         bpf_object__for_each_program(p, obj) {
 100                 err = bpf_program__set_attach_target(p, tgt_fd, NULL);
 101                 ASSERT_OK(err, "set_attach_target");
 102         }
 103
 104         err = bpf_object__load(obj);
 105         if (!ASSERT_OK(err, "obj_load"))
 106                 goto close_prog;
 107
 108         for (i = 0; i < prog_cnt; i++) {
 109                 struct bpf_link_info link_info;
 110                 struct bpf_program *pos;
 111                 const char *pos_sec_name;
 112                 char *tgt_name;
 113                 __s32 btf_id;
 114
 115                 tgt_name = strstr(prog_name[i], "/");
 116                 if (!ASSERT_OK_PTR(tgt_name, "tgt_name"))
 117                         goto close_prog;
 118                 btf_id = btf__find_by_name_kind(btf, tgt_name + 1, BTF_KIND_FUNC);
 119
 120                 prog[i] = NULL;
 121                 bpf_object__for_each_program(pos, obj) {
 122                         pos_sec_name = bpf_program__section_name(pos);
 123                         if (pos_sec_name && !strcmp(pos_sec_name, prog_name[i])) {
 124                                 prog[i] = pos;
 125                                 break;
 126                         }
 127                 }
 128                 if (!ASSERT_OK_PTR(prog[i], prog_name[i]))
 129                         goto close_prog;
 130
 131                 link[i] = bpf_program__attach_trace(prog[i]);
 132                 if (!ASSERT_OK_PTR(link[i], "attach_trace"))
 133                         goto close_prog;
 134
 135                 info_len = sizeof(link_info);
 136                 memset(&link_info, 0, sizeof(link_info));
 137                 err = bpf_obj_get_info_by_fd(bpf_link__fd(link[i]),
 138                                              &link_info, &info_len);
 139                 ASSERT_OK(err, "link_fd_get_info");
 140                 ASSERT_EQ(link_info.tracing.attach_type,
 141                           bpf_program__expected_attach_type(prog[i]),
 142                           "link_attach_type");
 143                 ASSERT_EQ(link_info.tracing.target_obj_id, tgt_prog_id, "link_tgt_obj_id");
 144                 ASSERT_EQ(link_info.tracing.target_btf_id, btf_id, "link_tgt_btf_id");
 145         }
 146
 147         if (cb) {
 148                 err = cb(obj);
 149                 if (err)
 150                         goto close_prog;
 151         }
 152
 153         if (!run_prog)
 154                 goto close_prog;
 155
 156         err = bpf_prog_test_run_opts(tgt_fd, &topts);
 157         ASSERT_OK(err, "prog_run");
 158         ASSERT_EQ(topts.retval, 0, "prog_run_ret");
 159
 160         if (check_data_map(obj, prog_cnt, false))
 161                 goto close_prog;
 162
 163 close_prog:
 164         for (i = 0; i < prog_cnt; i++)
 165                 bpf_link__destroy(link[i]);
 166         bpf_object__close(obj);
 167         bpf_object__close(tgt_obj);
 168         free(link);
 169         free(prog);
 170 }
 171
 172 static void test_target_no_callees(void)
 173 {
 174         const char *prog_name[] = {
 175                 "fexit/test_pkt_md_access",
 176         };
 177         test_fexit_bpf2bpf_common("./fexit_bpf2bpf_simple.o",
 178                                   "./test_pkt_md_access.o",
 179                                   ARRAY_SIZE(prog_name),
 180                                   prog_name, true, NULL);
 181 }
 182
 183 static void test_target_yes_callees(void)
 184 {
 185         const char *prog_name[] = {
 186                 "fexit/test_pkt_access",
 187                 "fexit/test_pkt_access_subprog1",
 188                 "fexit/test_pkt_access_subprog2",
 189                 "fexit/test_pkt_access_subprog3",
 190         };
 191         test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
 192                                   "./test_pkt_access.o",
 193                                   ARRAY_SIZE(prog_name),
 194                                   prog_name, true, NULL);
 195 }
 196
 197 static void test_func_replace(void)
 198 {
 199         const char *prog_name[] = {
 200                 "fexit/test_pkt_access",
 201                 "fexit/test_pkt_access_subprog1",
 202                 "fexit/test_pkt_access_subprog2",
 203                 "fexit/test_pkt_access_subprog3",
 204                 "freplace/get_skb_len",
 205                 "freplace/get_skb_ifindex",
 206                 "freplace/get_constant",
 207                 "freplace/test_pkt_write_access_subprog",
 208         };
 209         test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
 210                                   "./test_pkt_access.o",
 211                                   ARRAY_SIZE(prog_name),
 212                                   prog_name, true, NULL);
 213 }
 214
 215 static void test_func_replace_verify(void)
 216 {
 217         const char *prog_name[] = {
 218                 "freplace/do_bind",
 219         };
 220         test_fexit_bpf2bpf_common("./freplace_connect4.o",
 221                                   "./connect4_prog.o",
 222                                   ARRAY_SIZE(prog_name),
 223                                   prog_name, false, NULL);
 224 }
 225
 226 static int test_second_attach(struct bpf_object *obj)
 227 {
 228         const char *prog_name = "security_new_get_constant";
 229         const char *tgt_name = "get_constant";
 230         const char *tgt_obj_file = "./test_pkt_access.o";
 231         struct bpf_program *prog = NULL;
 232         struct bpf_object *tgt_obj;
 233         struct bpf_link *link;
 234         int err = 0, tgt_fd;
 235         LIBBPF_OPTS(bpf_test_run_opts, topts,
 236                 .data_in = &pkt_v6,
 237                 .data_size_in = sizeof(pkt_v6),
 238                 .repeat = 1,
 239         );
 240
 241         prog = bpf_object__find_program_by_name(obj, prog_name);
 242         if (!ASSERT_OK_PTR(prog, "find_prog"))
 243                 return -ENOENT;
 244
 245         err = bpf_prog_test_load(tgt_obj_file, BPF_PROG_TYPE_UNSPEC,
 246                             &tgt_obj, &tgt_fd);
 247         if (!ASSERT_OK(err, "second_prog_load"))
 248                 return err;
 249
 250         link = bpf_program__attach_freplace(prog, tgt_fd, tgt_name);
 251         if (!ASSERT_OK_PTR(link, "second_link"))
 252                 goto out;
 253
 254         err = bpf_prog_test_run_opts(tgt_fd, &topts);
 255         if (!ASSERT_OK(err, "ipv6 test_run"))
 256                 goto out;
 257         if (!ASSERT_OK(topts.retval, "ipv6 retval"))
 258                 goto out;
 259
 260         err = check_data_map(obj, 1, true);
 261         if (err)
 262                 goto out;
 263
 264 out:
 265         bpf_link__destroy(link);
 266         bpf_object__close(tgt_obj);
 267         return err;
 268 }
 269
 270 static void test_func_replace_multi(void)
 271 {
 272         const char *prog_name[] = {
 273                 "freplace/get_constant",
 274         };
 275         test_fexit_bpf2bpf_common("./freplace_get_constant.o",
 276                                   "./test_pkt_access.o",
 277                                   ARRAY_SIZE(prog_name),
 278                                   prog_name, true, test_second_attach);
 279 }
 280
 281 static void test_fmod_ret_freplace(void)
 282 {
 283         struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL;
 284         const char *freplace_name = "./freplace_get_constant.o";
 285         const char *fmod_ret_name = "./fmod_ret_freplace.o";
 286         DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
 287         const char *tgt_name = "./test_pkt_access.o";
 288         struct bpf_link *freplace_link = NULL;
 289         struct bpf_program *prog;
 290         __u32 duration = 0;
 291         int err, pkt_fd, attach_prog_fd;
 292
 293         err = bpf_prog_test_load(tgt_name, BPF_PROG_TYPE_UNSPEC,
 294                             &pkt_obj, &pkt_fd);
 295         /* the target prog should load fine */
 296         if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
 297                   tgt_name, err, errno))
 298                 return;
 299
 300         freplace_obj = bpf_object__open_file(freplace_name, NULL);
 301         if (!ASSERT_OK_PTR(freplace_obj, "freplace_obj_open"))
 302                 goto out;
 303
 304         prog = bpf_object__next_program(freplace_obj, NULL);
 305         err = bpf_program__set_attach_target(prog, pkt_fd, NULL);
 306         ASSERT_OK(err, "freplace__set_attach_target");
 307
 308         err = bpf_object__load(freplace_obj);
 309         if (CHECK(err, "freplace_obj_load", "err %d\n", err))
 310                 goto out;
 311
 312         freplace_link = bpf_program__attach_trace(prog);
 313         if (!ASSERT_OK_PTR(freplace_link, "freplace_attach_trace"))
 314                 goto out;
 315
 316         fmod_obj = bpf_object__open_file(fmod_ret_name, NULL);
 317         if (!ASSERT_OK_PTR(fmod_obj, "fmod_obj_open"))
 318                 goto out;
 319
 320         attach_prog_fd = bpf_program__fd(prog);
 321         prog = bpf_object__next_program(fmod_obj, NULL);
 322         err = bpf_program__set_attach_target(prog, attach_prog_fd, NULL);
 323         ASSERT_OK(err, "fmod_ret_set_attach_target");
 324
 325         err = bpf_object__load(fmod_obj);
 326         if (CHECK(!err, "fmod_obj_load", "loading fmod_ret should fail\n"))
 327                 goto out;
 328
 329 out:
 330         bpf_link__destroy(freplace_link);
 331         bpf_object__close(freplace_obj);
 332         bpf_object__close(fmod_obj);
 333         bpf_object__close(pkt_obj);
 334 }
 335
 336
 337 static void test_func_sockmap_update(void)
 338 {
 339         const char *prog_name[] = {
 340                 "freplace/cls_redirect",
 341         };
 342         test_fexit_bpf2bpf_common("./freplace_cls_redirect.o",
 343                                   "./test_cls_redirect.o",
 344                                   ARRAY_SIZE(prog_name),
 345                                   prog_name, false, NULL);
 346 }
 347
 348 static void test_obj_load_failure_common(const char *obj_file,
 349                                          const char *target_obj_file)
 350 {
 351         /*
 352          * standalone test that asserts failure to load freplace prog
 353          * because of invalid return code.
 354          */
 355         struct bpf_object *obj = NULL, *pkt_obj;
 356         struct bpf_program *prog;
 357         int err, pkt_fd;
 358         __u32 duration = 0;
 359
 360         err = bpf_prog_test_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
 361                             &pkt_obj, &pkt_fd);
 362         /* the target prog should load fine */
 363         if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
 364                   target_obj_file, err, errno))
 365                 return;
 366
 367         obj = bpf_object__open_file(obj_file, NULL);
 368         if (!ASSERT_OK_PTR(obj, "obj_open"))
 369                 goto close_prog;
 370
 371         prog = bpf_object__next_program(obj, NULL);
 372         err = bpf_program__set_attach_target(prog, pkt_fd, NULL);
 373         ASSERT_OK(err, "set_attach_target");
 374
 375         /* It should fail to load the program */
 376         err = bpf_object__load(obj);
 377         if (CHECK(!err, "bpf_obj_load should fail", "err %d\n", err))
 378                 goto close_prog;
 379
 380 close_prog:
 381         bpf_object__close(obj);
 382         bpf_object__close(pkt_obj);
 383 }
 384
 385 static void test_func_replace_return_code(void)
 386 {
 387         /* test invalid return code in the replaced program */
 388         test_obj_load_failure_common("./freplace_connect_v4_prog.o",
 389                                      "./connect4_prog.o");
 390 }
 391
 392 static void test_func_map_prog_compatibility(void)
 393 {
 394         /* test with spin lock map value in the replaced program */
 395         test_obj_load_failure_common("./freplace_attach_probe.o",
 396                                      "./test_attach_probe.o");
 397 }
 398
 399 static void test_func_replace_global_func(void)
 400 {
 401         const char *prog_name[] = {
 402                 "freplace/test_pkt_access",
 403         };
 404
 405         test_fexit_bpf2bpf_common("./freplace_global_func.o",
 406                                   "./test_pkt_access.o",
 407                                   ARRAY_SIZE(prog_name),
 408                                   prog_name, false, NULL);
 409 }
 410
 411 static int find_prog_btf_id(const char *name, __u32 attach_prog_fd)
 412 {
 413         struct bpf_prog_info info = {};
 414         __u32 info_len = sizeof(info);
 415         struct btf *btf;
 416         int ret;
 417
 418         ret = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len);
 419         if (ret)
 420                 return ret;
 421
 422         if (!info.btf_id)
 423                 return -EINVAL;
 424
 425         btf = btf__load_from_kernel_by_id(info.btf_id);
 426         ret = libbpf_get_error(btf);
 427         if (ret)
 428                 return ret;
 429
 430         ret = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
 431         btf__free(btf);
 432         return ret;
 433 }
 434
 435 static int load_fentry(int attach_prog_fd, int attach_btf_id)
 436 {
 437         LIBBPF_OPTS(bpf_prog_load_opts, opts,
 438                     .expected_attach_type = BPF_TRACE_FENTRY,
 439                     .attach_prog_fd = attach_prog_fd,
 440                     .attach_btf_id = attach_btf_id,
 441         );
 442         struct bpf_insn insns[] = {
 443                 BPF_MOV64_IMM(BPF_REG_0, 0),
 444                 BPF_EXIT_INSN(),
 445         };
 446
 447         return bpf_prog_load(BPF_PROG_TYPE_TRACING,
 448                              "bind4_fentry",
 449                              "GPL",
 450                              insns,
 451                              ARRAY_SIZE(insns),
 452                              &opts);
 453 }
 454
 455 static void test_fentry_to_cgroup_bpf(void)
 456 {
 457         struct bind4_prog *skel = NULL;
 458         struct bpf_prog_info info = {};
 459         __u32 info_len = sizeof(info);
 460         int cgroup_fd = -1;
 461         int fentry_fd = -1;
 462         int btf_id;
 463
 464         cgroup_fd = test__join_cgroup("/fentry_to_cgroup_bpf");
 465         if (!ASSERT_GE(cgroup_fd, 0, "cgroup_fd"))
 466                 return;
 467
 468         skel = bind4_prog__open_and_load();
 469         if (!ASSERT_OK_PTR(skel, "skel"))
 470                 goto cleanup;
 471
 472         skel->links.bind_v4_prog = bpf_program__attach_cgroup(skel->progs.bind_v4_prog, cgroup_fd);
 473         if (!ASSERT_OK_PTR(skel->links.bind_v4_prog, "bpf_program__attach_cgroup"))
 474                 goto cleanup;
 475
 476         btf_id = find_prog_btf_id("bind_v4_prog", bpf_program__fd(skel->progs.bind_v4_prog));
 477         if (!ASSERT_GE(btf_id, 0, "find_prog_btf_id"))
 478                 goto cleanup;
 479
 480         fentry_fd = load_fentry(bpf_program__fd(skel->progs.bind_v4_prog), btf_id);
 481         if (!ASSERT_GE(fentry_fd, 0, "load_fentry"))
 482                 goto cleanup;
 483
 484         /* Make sure bpf_obj_get_info_by_fd works correctly when attaching
 485          * to another BPF program.
 486          */
 487
 488         ASSERT_OK(bpf_obj_get_info_by_fd(fentry_fd, &info, &info_len),
 489                   "bpf_obj_get_info_by_fd");
 490
 491         ASSERT_EQ(info.btf_id, 0, "info.btf_id");
 492         ASSERT_EQ(info.attach_btf_id, btf_id, "info.attach_btf_id");
 493         ASSERT_GT(info.attach_btf_obj_id, 0, "info.attach_btf_obj_id");
 494
 495 cleanup:
 496         if (cgroup_fd >= 0)
 497                 close(cgroup_fd);
 498         if (fentry_fd >= 0)
 499                 close(fentry_fd);
 500         bind4_prog__destroy(skel);
 501 }
 502
 503 /* NOTE: affect other tests, must run in serial mode */
 504 void serial_test_fexit_bpf2bpf(void)
 505 {
 506         if (test__start_subtest("target_no_callees"))
 507                 test_target_no_callees();
 508         if (test__start_subtest("target_yes_callees"))
 509                 test_target_yes_callees();
 510         if (test__start_subtest("func_replace"))
 511                 test_func_replace();
 512         if (test__start_subtest("func_replace_verify"))
 513                 test_func_replace_verify();
 514         if (test__start_subtest("func_sockmap_update"))
 515                 test_func_sockmap_update();
 516         if (test__start_subtest("func_replace_return_code"))
 517                 test_func_replace_return_code();
 518         if (test__start_subtest("func_map_prog_compatibility"))
 519                 test_func_map_prog_compatibility();
 520         if (test__start_subtest("func_replace_multi"))
 521                 test_func_replace_multi();
 522         if (test__start_subtest("fmod_ret_freplace"))
 523                 test_fmod_ret_freplace();
 524         if (test__start_subtest("func_replace_global_func"))
 525                 test_func_replace_global_func();
 526         if (test__start_subtest("fentry_to_cgroup_bpf"))
 527                 test_fentry_to_cgroup_bpf();
 528 }