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 #include "freplace_progmap.skel.h"
   8 #include "xdp_dummy.skel.h"
   9
  10 typedef int (*test_cb)(struct bpf_object *obj);
  11
  12 static int check_data_map(struct bpf_object *obj, int prog_cnt, bool reset)
  13 {
  14         struct bpf_map *data_map = NULL, *map;
  15         __u64 *result = NULL;
  16         const int zero = 0;
  17         __u32 duration = 0;
  18         int ret = -1, i;
  19
  20         result = malloc((prog_cnt + 32 /* spare */) * sizeof(__u64));
  21         if (CHECK(!result, "alloc_memory", "failed to alloc memory"))
  22                 return -ENOMEM;
  23
  24         bpf_object__for_each_map(map, obj)
  25                 if (bpf_map__is_internal(map)) {
  26                         data_map = map;
  27                         break;
  28                 }
  29         if (CHECK(!data_map, "find_data_map", "data map not found\n"))
  30                 goto out;
  31
  32         ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, result);
  33         if (CHECK(ret, "get_result",
  34                   "failed to get output data: %d\n", ret))
  35                 goto out;
  36
  37         for (i = 0; i < prog_cnt; i++) {
  38                 if (CHECK(result[i] != 1, "result",
  39                           "fexit_bpf2bpf result[%d] failed err %llu\n",
  40                           i, result[i]))
  41                         goto out;
  42                 result[i] = 0;
  43         }
  44         if (reset) {
  45                 ret = bpf_map_update_elem(bpf_map__fd(data_map), &zero, result, 0);
  46                 if (CHECK(ret, "reset_result", "failed to reset result\n"))
  47                         goto out;
  48         }
  49
  50         ret = 0;
  51 out:
  52         free(result);
  53         return ret;
  54 }
  55
  56 static void test_fexit_bpf2bpf_common(const char *obj_file,
  57                                       const char *target_obj_file,
  58                                       int prog_cnt,
  59                                       const char **prog_name,
  60                                       bool run_prog,
  61                                       test_cb cb)
  62 {
  63         struct bpf_object *obj = NULL, *tgt_obj;
  64         __u32 tgt_prog_id, info_len;
  65         struct bpf_prog_info prog_info = {};
  66         struct bpf_program **prog = NULL, *p;
  67         struct bpf_link **link = NULL;
  68         int err, tgt_fd, i;
  69         struct btf *btf;
  70         LIBBPF_OPTS(bpf_test_run_opts, topts,
  71                 .data_in = &pkt_v6,
  72                 .data_size_in = sizeof(pkt_v6),
  73                 .repeat = 1,
  74         );
  75
  76         err = bpf_prog_test_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
  77                             &tgt_obj, &tgt_fd);
  78         if (!ASSERT_OK(err, "tgt_prog_load"))
  79                 return;
  80
  81         info_len = sizeof(prog_info);
  82         err = bpf_obj_get_info_by_fd(tgt_fd, &prog_info, &info_len);
  83         if (!ASSERT_OK(err, "tgt_fd_get_info"))
  84                 goto close_prog;
  85
  86         tgt_prog_id = prog_info.id;
  87         btf = bpf_object__btf(tgt_obj);
  88
  89         link = calloc(sizeof(struct bpf_link *), prog_cnt);
  90         if (!ASSERT_OK_PTR(link, "link_ptr"))
  91                 goto close_prog;
  92
  93         prog = calloc(sizeof(struct bpf_program *), prog_cnt);
  94         if (!ASSERT_OK_PTR(prog, "prog_ptr"))
  95                 goto close_prog;
  96
  97         obj = bpf_object__open_file(obj_file, NULL);
  98         if (!ASSERT_OK_PTR(obj, "obj_open"))
  99                 goto close_prog;
 100
 101         bpf_object__for_each_program(p, obj) {
 102                 err = bpf_program__set_attach_target(p, tgt_fd, NULL);
 103                 ASSERT_OK(err, "set_attach_target");
 104         }
 105
 106         err = bpf_object__load(obj);
 107         if (!ASSERT_OK(err, "obj_load"))
 108                 goto close_prog;
 109
 110         for (i = 0; i < prog_cnt; i++) {
 111                 struct bpf_link_info link_info;
 112                 struct bpf_program *pos;
 113                 const char *pos_sec_name;
 114                 char *tgt_name;
 115                 __s32 btf_id;
 116
 117                 tgt_name = strstr(prog_name[i], "/");
 118                 if (!ASSERT_OK_PTR(tgt_name, "tgt_name"))
 119                         goto close_prog;
 120                 btf_id = btf__find_by_name_kind(btf, tgt_name + 1, BTF_KIND_FUNC);
 121
 122                 prog[i] = NULL;
 123                 bpf_object__for_each_program(pos, obj) {
 124                         pos_sec_name = bpf_program__section_name(pos);
 125                         if (pos_sec_name && !strcmp(pos_sec_name, prog_name[i])) {
 126                                 prog[i] = pos;
 127                                 break;
 128                         }
 129                 }
 130                 if (!ASSERT_OK_PTR(prog[i], prog_name[i]))
 131                         goto close_prog;
 132
 133                 link[i] = bpf_program__attach_trace(prog[i]);
 134                 if (!ASSERT_OK_PTR(link[i], "attach_trace"))
 135                         goto close_prog;
 136
 137                 info_len = sizeof(link_info);
 138                 memset(&link_info, 0, sizeof(link_info));
 139                 err = bpf_obj_get_info_by_fd(bpf_link__fd(link[i]),
 140                                              &link_info, &info_len);
 141                 ASSERT_OK(err, "link_fd_get_info");
 142                 ASSERT_EQ(link_info.tracing.attach_type,
 143                           bpf_program__expected_attach_type(prog[i]),
 144                           "link_attach_type");
 145                 ASSERT_EQ(link_info.tracing.target_obj_id, tgt_prog_id, "link_tgt_obj_id");
 146                 ASSERT_EQ(link_info.tracing.target_btf_id, btf_id, "link_tgt_btf_id");
 147         }
 148
 149         if (cb) {
 150                 err = cb(obj);
 151                 if (err)
 152                         goto close_prog;
 153         }
 154
 155         if (!run_prog)
 156                 goto close_prog;
 157
 158         err = bpf_prog_test_run_opts(tgt_fd, &topts);
 159         ASSERT_OK(err, "prog_run");
 160         ASSERT_EQ(topts.retval, 0, "prog_run_ret");
 161
 162         if (check_data_map(obj, prog_cnt, false))
 163                 goto close_prog;
 164
 165 close_prog:
 166         for (i = 0; i < prog_cnt; i++)
 167                 bpf_link__destroy(link[i]);
 168         bpf_object__close(obj);
 169         bpf_object__close(tgt_obj);
 170         free(link);
 171         free(prog);
 172 }
 173
 174 static void test_target_no_callees(void)
 175 {
 176         const char *prog_name[] = {
 177                 "fexit/test_pkt_md_access",
 178         };
 179         test_fexit_bpf2bpf_common("./fexit_bpf2bpf_simple.bpf.o",
 180                                   "./test_pkt_md_access.bpf.o",
 181                                   ARRAY_SIZE(prog_name),
 182                                   prog_name, true, NULL);
 183 }
 184
 185 static void test_target_yes_callees(void)
 186 {
 187         const char *prog_name[] = {
 188                 "fexit/test_pkt_access",
 189                 "fexit/test_pkt_access_subprog1",
 190                 "fexit/test_pkt_access_subprog2",
 191                 "fexit/test_pkt_access_subprog3",
 192         };
 193         test_fexit_bpf2bpf_common("./fexit_bpf2bpf.bpf.o",
 194                                   "./test_pkt_access.bpf.o",
 195                                   ARRAY_SIZE(prog_name),
 196                                   prog_name, true, NULL);
 197 }
 198
 199 static void test_func_replace(void)
 200 {
 201         const char *prog_name[] = {
 202                 "fexit/test_pkt_access",
 203                 "fexit/test_pkt_access_subprog1",
 204                 "fexit/test_pkt_access_subprog2",
 205                 "fexit/test_pkt_access_subprog3",
 206                 "freplace/get_skb_len",
 207                 "freplace/get_skb_ifindex",
 208                 "freplace/get_constant",
 209                 "freplace/test_pkt_write_access_subprog",
 210         };
 211         test_fexit_bpf2bpf_common("./fexit_bpf2bpf.bpf.o",
 212                                   "./test_pkt_access.bpf.o",
 213                                   ARRAY_SIZE(prog_name),
 214                                   prog_name, true, NULL);
 215 }
 216
 217 static void test_func_replace_verify(void)
 218 {
 219         const char *prog_name[] = {
 220                 "freplace/do_bind",
 221         };
 222         test_fexit_bpf2bpf_common("./freplace_connect4.bpf.o",
 223                                   "./connect4_prog.bpf.o",
 224                                   ARRAY_SIZE(prog_name),
 225                                   prog_name, false, NULL);
 226 }
 227
 228 static int test_second_attach(struct bpf_object *obj)
 229 {
 230         const char *prog_name = "security_new_get_constant";
 231         const char *tgt_name = "get_constant";
 232         const char *tgt_obj_file = "./test_pkt_access.bpf.o";
 233         struct bpf_program *prog = NULL;
 234         struct bpf_object *tgt_obj;
 235         struct bpf_link *link;
 236         int err = 0, tgt_fd;
 237         LIBBPF_OPTS(bpf_test_run_opts, topts,
 238                 .data_in = &pkt_v6,
 239                 .data_size_in = sizeof(pkt_v6),
 240                 .repeat = 1,
 241         );
 242
 243         prog = bpf_object__find_program_by_name(obj, prog_name);
 244         if (!ASSERT_OK_PTR(prog, "find_prog"))
 245                 return -ENOENT;
 246
 247         err = bpf_prog_test_load(tgt_obj_file, BPF_PROG_TYPE_UNSPEC,
 248                             &tgt_obj, &tgt_fd);
 249         if (!ASSERT_OK(err, "second_prog_load"))
 250                 return err;
 251
 252         link = bpf_program__attach_freplace(prog, tgt_fd, tgt_name);
 253         if (!ASSERT_OK_PTR(link, "second_link"))
 254                 goto out;
 255
 256         err = bpf_prog_test_run_opts(tgt_fd, &topts);
 257         if (!ASSERT_OK(err, "ipv6 test_run"))
 258                 goto out;
 259         if (!ASSERT_OK(topts.retval, "ipv6 retval"))
 260                 goto out;
 261
 262         err = check_data_map(obj, 1, true);
 263         if (err)
 264                 goto out;
 265
 266 out:
 267         bpf_link__destroy(link);
 268         bpf_object__close(tgt_obj);
 269         return err;
 270 }
 271
 272 static void test_func_replace_multi(void)
 273 {
 274         const char *prog_name[] = {
 275                 "freplace/get_constant",
 276         };
 277         test_fexit_bpf2bpf_common("./freplace_get_constant.bpf.o",
 278                                   "./test_pkt_access.bpf.o",
 279                                   ARRAY_SIZE(prog_name),
 280                                   prog_name, true, test_second_attach);
 281 }
 282
 283 static void test_fmod_ret_freplace(void)
 284 {
 285         struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL;
 286         const char *freplace_name = "./freplace_get_constant.bpf.o";
 287         const char *fmod_ret_name = "./fmod_ret_freplace.bpf.o";
 288         DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
 289         const char *tgt_name = "./test_pkt_access.bpf.o";
 290         struct bpf_link *freplace_link = NULL;
 291         struct bpf_program *prog;
 292         __u32 duration = 0;
 293         int err, pkt_fd, attach_prog_fd;
 294
 295         err = bpf_prog_test_load(tgt_name, BPF_PROG_TYPE_UNSPEC,
 296                             &pkt_obj, &pkt_fd);
 297         /* the target prog should load fine */
 298         if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
 299                   tgt_name, err, errno))
 300                 return;
 301
 302         freplace_obj = bpf_object__open_file(freplace_name, NULL);
 303         if (!ASSERT_OK_PTR(freplace_obj, "freplace_obj_open"))
 304                 goto out;
 305
 306         prog = bpf_object__next_program(freplace_obj, NULL);
 307         err = bpf_program__set_attach_target(prog, pkt_fd, NULL);
 308         ASSERT_OK(err, "freplace__set_attach_target");
 309
 310         err = bpf_object__load(freplace_obj);
 311         if (CHECK(err, "freplace_obj_load", "err %d\n", err))
 312                 goto out;
 313
 314         freplace_link = bpf_program__attach_trace(prog);
 315         if (!ASSERT_OK_PTR(freplace_link, "freplace_attach_trace"))
 316                 goto out;
 317
 318         fmod_obj = bpf_object__open_file(fmod_ret_name, NULL);
 319         if (!ASSERT_OK_PTR(fmod_obj, "fmod_obj_open"))
 320                 goto out;
 321
 322         attach_prog_fd = bpf_program__fd(prog);
 323         prog = bpf_object__next_program(fmod_obj, NULL);
 324         err = bpf_program__set_attach_target(prog, attach_prog_fd, NULL);
 325         ASSERT_OK(err, "fmod_ret_set_attach_target");
 326
 327         err = bpf_object__load(fmod_obj);
 328         if (CHECK(!err, "fmod_obj_load", "loading fmod_ret should fail\n"))
 329                 goto out;
 330
 331 out:
 332         bpf_link__destroy(freplace_link);
 333         bpf_object__close(freplace_obj);
 334         bpf_object__close(fmod_obj);
 335         bpf_object__close(pkt_obj);
 336 }
 337
 338
 339 static void test_func_sockmap_update(void)
 340 {
 341         const char *prog_name[] = {
 342                 "freplace/cls_redirect",
 343         };
 344         test_fexit_bpf2bpf_common("./freplace_cls_redirect.bpf.o",
 345                                   "./test_cls_redirect.bpf.o",
 346                                   ARRAY_SIZE(prog_name),
 347                                   prog_name, false, NULL);
 348 }
 349
 350 static void test_obj_load_failure_common(const char *obj_file,
 351                                          const char *target_obj_file)
 352 {
 353         /*
 354          * standalone test that asserts failure to load freplace prog
 355          * because of invalid return code.
 356          */
 357         struct bpf_object *obj = NULL, *pkt_obj;
 358         struct bpf_program *prog;
 359         int err, pkt_fd;
 360         __u32 duration = 0;
 361
 362         err = bpf_prog_test_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
 363                             &pkt_obj, &pkt_fd);
 364         /* the target prog should load fine */
 365         if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
 366                   target_obj_file, err, errno))
 367                 return;
 368
 369         obj = bpf_object__open_file(obj_file, NULL);
 370         if (!ASSERT_OK_PTR(obj, "obj_open"))
 371                 goto close_prog;
 372
 373         prog = bpf_object__next_program(obj, NULL);
 374         err = bpf_program__set_attach_target(prog, pkt_fd, NULL);
 375         ASSERT_OK(err, "set_attach_target");
 376
 377         /* It should fail to load the program */
 378         err = bpf_object__load(obj);
 379         if (CHECK(!err, "bpf_obj_load should fail", "err %d\n", err))
 380                 goto close_prog;
 381
 382 close_prog:
 383         bpf_object__close(obj);
 384         bpf_object__close(pkt_obj);
 385 }
 386
 387 static void test_func_replace_return_code(void)
 388 {
 389         /* test invalid return code in the replaced program */
 390         test_obj_load_failure_common("./freplace_connect_v4_prog.bpf.o",
 391                                      "./connect4_prog.bpf.o");
 392 }
 393
 394 static void test_func_map_prog_compatibility(void)
 395 {
 396         /* test with spin lock map value in the replaced program */
 397         test_obj_load_failure_common("./freplace_attach_probe.bpf.o",
 398                                      "./test_attach_probe.bpf.o");
 399 }
 400
 401 static void test_func_replace_global_func(void)
 402 {
 403         const char *prog_name[] = {
 404                 "freplace/test_pkt_access",
 405         };
 406
 407         test_fexit_bpf2bpf_common("./freplace_global_func.bpf.o",
 408                                   "./test_pkt_access.bpf.o",
 409                                   ARRAY_SIZE(prog_name),
 410                                   prog_name, false, NULL);
 411 }
 412
 413 static int find_prog_btf_id(const char *name, __u32 attach_prog_fd)
 414 {
 415         struct bpf_prog_info info = {};
 416         __u32 info_len = sizeof(info);
 417         struct btf *btf;
 418         int ret;
 419
 420         ret = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len);
 421         if (ret)
 422                 return ret;
 423
 424         if (!info.btf_id)
 425                 return -EINVAL;
 426
 427         btf = btf__load_from_kernel_by_id(info.btf_id);
 428         ret = libbpf_get_error(btf);
 429         if (ret)
 430                 return ret;
 431
 432         ret = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
 433         btf__free(btf);
 434         return ret;
 435 }
 436
 437 static int load_fentry(int attach_prog_fd, int attach_btf_id)
 438 {
 439         LIBBPF_OPTS(bpf_prog_load_opts, opts,
 440                     .expected_attach_type = BPF_TRACE_FENTRY,
 441                     .attach_prog_fd = attach_prog_fd,
 442                     .attach_btf_id = attach_btf_id,
 443         );
 444         struct bpf_insn insns[] = {
 445                 BPF_MOV64_IMM(BPF_REG_0, 0),
 446                 BPF_EXIT_INSN(),
 447         };
 448
 449         return bpf_prog_load(BPF_PROG_TYPE_TRACING,
 450                              "bind4_fentry",
 451                              "GPL",
 452                              insns,
 453                              ARRAY_SIZE(insns),
 454                              &opts);
 455 }
 456
 457 static void test_fentry_to_cgroup_bpf(void)
 458 {
 459         struct bind4_prog *skel = NULL;
 460         struct bpf_prog_info info = {};
 461         __u32 info_len = sizeof(info);
 462         int cgroup_fd = -1;
 463         int fentry_fd = -1;
 464         int btf_id;
 465
 466         cgroup_fd = test__join_cgroup("/fentry_to_cgroup_bpf");
 467         if (!ASSERT_GE(cgroup_fd, 0, "cgroup_fd"))
 468                 return;
 469
 470         skel = bind4_prog__open_and_load();
 471         if (!ASSERT_OK_PTR(skel, "skel"))
 472                 goto cleanup;
 473
 474         skel->links.bind_v4_prog = bpf_program__attach_cgroup(skel->progs.bind_v4_prog, cgroup_fd);
 475         if (!ASSERT_OK_PTR(skel->links.bind_v4_prog, "bpf_program__attach_cgroup"))
 476                 goto cleanup;
 477
 478         btf_id = find_prog_btf_id("bind_v4_prog", bpf_program__fd(skel->progs.bind_v4_prog));
 479         if (!ASSERT_GE(btf_id, 0, "find_prog_btf_id"))
 480                 goto cleanup;
 481
 482         fentry_fd = load_fentry(bpf_program__fd(skel->progs.bind_v4_prog), btf_id);
 483         if (!ASSERT_GE(fentry_fd, 0, "load_fentry"))
 484                 goto cleanup;
 485
 486         /* Make sure bpf_obj_get_info_by_fd works correctly when attaching
 487          * to another BPF program.
 488          */
 489
 490         ASSERT_OK(bpf_obj_get_info_by_fd(fentry_fd, &info, &info_len),
 491                   "bpf_obj_get_info_by_fd");
 492
 493         ASSERT_EQ(info.btf_id, 0, "info.btf_id");
 494         ASSERT_EQ(info.attach_btf_id, btf_id, "info.attach_btf_id");
 495         ASSERT_GT(info.attach_btf_obj_id, 0, "info.attach_btf_obj_id");
 496
 497 cleanup:
 498         if (cgroup_fd >= 0)
 499                 close(cgroup_fd);
 500         if (fentry_fd >= 0)
 501                 close(fentry_fd);
 502         bind4_prog__destroy(skel);
 503 }
 504
 505 static void test_func_replace_progmap(void)
 506 {
 507         struct bpf_cpumap_val value = { .qsize = 1 };
 508         struct freplace_progmap *skel = NULL;
 509         struct xdp_dummy *tgt_skel = NULL;
 510         __u32 key = 0;
 511         int err;
 512
 513         skel = freplace_progmap__open();
 514         if (!ASSERT_OK_PTR(skel, "prog_open"))
 515                 return;
 516
 517         tgt_skel = xdp_dummy__open_and_load();
 518         if (!ASSERT_OK_PTR(tgt_skel, "tgt_prog_load"))
 519                 goto out;
 520
 521         err = bpf_program__set_attach_target(skel->progs.xdp_cpumap_prog,
 522                                              bpf_program__fd(tgt_skel->progs.xdp_dummy_prog),
 523                                              "xdp_dummy_prog");
 524         if (!ASSERT_OK(err, "set_attach_target"))
 525                 goto out;
 526
 527         err = freplace_progmap__load(skel);
 528         if (!ASSERT_OK(err, "obj_load"))
 529                 goto out;
 530
 531         /* Prior to fixing the kernel, loading the PROG_TYPE_EXT 'redirect'
 532          * program above will cause the map owner type of 'cpumap' to be set to
 533          * PROG_TYPE_EXT. This in turn will cause the bpf_map_update_elem()
 534          * below to fail, because the program we are inserting into the map is
 535          * of PROG_TYPE_XDP. After fixing the kernel, the initial ownership will
 536          * be correctly resolved to the *target* of the PROG_TYPE_EXT program
 537          * (i.e., PROG_TYPE_XDP) and the map update will succeed.
 538          */
 539         value.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_drop_prog);
 540         err = bpf_map_update_elem(bpf_map__fd(skel->maps.cpu_map),
 541                                   &key, &value, 0);
 542         ASSERT_OK(err, "map_update");
 543
 544 out:
 545         xdp_dummy__destroy(tgt_skel);
 546         freplace_progmap__destroy(skel);
 547 }
 548
 549 /* NOTE: affect other tests, must run in serial mode */
 550 void serial_test_fexit_bpf2bpf(void)
 551 {
 552         if (test__start_subtest("target_no_callees"))
 553                 test_target_no_callees();
 554         if (test__start_subtest("target_yes_callees"))
 555                 test_target_yes_callees();
 556         if (test__start_subtest("func_replace"))
 557                 test_func_replace();
 558         if (test__start_subtest("func_replace_verify"))
 559                 test_func_replace_verify();
 560         if (test__start_subtest("func_sockmap_update"))
 561                 test_func_sockmap_update();
 562         if (test__start_subtest("func_replace_return_code"))
 563                 test_func_replace_return_code();
 564         if (test__start_subtest("func_map_prog_compatibility"))
 565                 test_func_map_prog_compatibility();
 566         if (test__start_subtest("func_replace_multi"))
 567                 test_func_replace_multi();
 568         if (test__start_subtest("fmod_ret_freplace"))
 569                 test_fmod_ret_freplace();
 570         if (test__start_subtest("func_replace_global_func"))
 571                 test_func_replace_global_func();
 572         if (test__start_subtest("fentry_to_cgroup_bpf"))
 573                 test_fentry_to_cgroup_bpf();
 574         if (test__start_subtest("func_replace_progmap"))
 575                 test_func_replace_progmap();
 576 }