tools/testing/selftests/bpf/test_sock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2018 Facebook
   3
   4 #include <stdio.h>
   5 #include <unistd.h>
   6
   7 #include <arpa/inet.h>
   8 #include <sys/types.h>
   9 #include <sys/socket.h>
  10
  11 #include <linux/filter.h>
  12
  13 #include <bpf/bpf.h>
  14
  15 #include "cgroup_helpers.h"
  16
  17 #ifndef ARRAY_SIZE
  18 # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  19 #endif
  20
  21 #define CG_PATH         "/foo"
  22 #define MAX_INSNS       512
  23
  24 char bpf_log_buf[BPF_LOG_BUF_SIZE];
  25
  26 struct sock_test {
  27         const char *descr;
  28         /* BPF prog properties */
  29         struct bpf_insn insns[MAX_INSNS];
  30         enum bpf_attach_type expected_attach_type;
  31         enum bpf_attach_type attach_type;
  32         /* Socket properties */
  33         int domain;
  34         int type;
  35         /* Endpoint to bind() to */
  36         const char *ip;
  37         unsigned short port;
  38         /* Expected test result */
  39         enum {
  40                 LOAD_REJECT,
  41                 ATTACH_REJECT,
  42                 BIND_REJECT,
  43                 SUCCESS,
  44         } result;
  45 };
  46
  47 static struct sock_test tests[] = {
  48         {
  49                 "bind4 load with invalid access: src_ip6",
  50                 .insns = {
  51                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
  52                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
  53                                     offsetof(struct bpf_sock, src_ip6[0])),
  54                         BPF_MOV64_IMM(BPF_REG_0, 1),
  55                         BPF_EXIT_INSN(),
  56                 },
  57                 BPF_CGROUP_INET4_POST_BIND,
  58                 BPF_CGROUP_INET4_POST_BIND,
  59                 0,
  60                 0,
  61                 NULL,
  62                 0,
  63                 LOAD_REJECT,
  64         },
  65         {
  66                 "bind4 load with invalid access: mark",
  67                 .insns = {
  68                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
  69                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
  70                                     offsetof(struct bpf_sock, mark)),
  71                         BPF_MOV64_IMM(BPF_REG_0, 1),
  72                         BPF_EXIT_INSN(),
  73                 },
  74                 BPF_CGROUP_INET4_POST_BIND,
  75                 BPF_CGROUP_INET4_POST_BIND,
  76                 0,
  77                 0,
  78                 NULL,
  79                 0,
  80                 LOAD_REJECT,
  81         },
  82         {
  83                 "bind6 load with invalid access: src_ip4",
  84                 .insns = {
  85                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
  86                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
  87                                     offsetof(struct bpf_sock, src_ip4)),
  88                         BPF_MOV64_IMM(BPF_REG_0, 1),
  89                         BPF_EXIT_INSN(),
  90                 },
  91                 BPF_CGROUP_INET6_POST_BIND,
  92                 BPF_CGROUP_INET6_POST_BIND,
  93                 0,
  94                 0,
  95                 NULL,
  96                 0,
  97                 LOAD_REJECT,
  98         },
  99         {
 100                 "sock_create load with invalid access: src_port",
 101                 .insns = {
 102                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
 103                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 104                                     offsetof(struct bpf_sock, src_port)),
 105                         BPF_MOV64_IMM(BPF_REG_0, 1),
 106                         BPF_EXIT_INSN(),
 107                 },
 108                 BPF_CGROUP_INET_SOCK_CREATE,
 109                 BPF_CGROUP_INET_SOCK_CREATE,
 110                 0,
 111                 0,
 112                 NULL,
 113                 0,
 114                 LOAD_REJECT,
 115         },
 116         {
 117                 "sock_create load w/o expected_attach_type (compat mode)",
 118                 .insns = {
 119                         BPF_MOV64_IMM(BPF_REG_0, 1),
 120                         BPF_EXIT_INSN(),
 121                 },
 122                 0,
 123                 BPF_CGROUP_INET_SOCK_CREATE,
 124                 AF_INET,
 125                 SOCK_STREAM,
 126                 "127.0.0.1",
 127                 8097,
 128                 SUCCESS,
 129         },
 130         {
 131                 "sock_create load w/ expected_attach_type",
 132                 .insns = {
 133                         BPF_MOV64_IMM(BPF_REG_0, 1),
 134                         BPF_EXIT_INSN(),
 135                 },
 136                 BPF_CGROUP_INET_SOCK_CREATE,
 137                 BPF_CGROUP_INET_SOCK_CREATE,
 138                 AF_INET,
 139                 SOCK_STREAM,
 140                 "127.0.0.1",
 141                 8097,
 142                 SUCCESS,
 143         },
 144         {
 145                 "attach type mismatch bind4 vs bind6",
 146                 .insns = {
 147                         BPF_MOV64_IMM(BPF_REG_0, 1),
 148                         BPF_EXIT_INSN(),
 149                 },
 150                 BPF_CGROUP_INET4_POST_BIND,
 151                 BPF_CGROUP_INET6_POST_BIND,
 152                 0,
 153                 0,
 154                 NULL,
 155                 0,
 156                 ATTACH_REJECT,
 157         },
 158         {
 159                 "attach type mismatch bind6 vs bind4",
 160                 .insns = {
 161                         BPF_MOV64_IMM(BPF_REG_0, 1),
 162                         BPF_EXIT_INSN(),
 163                 },
 164                 BPF_CGROUP_INET6_POST_BIND,
 165                 BPF_CGROUP_INET4_POST_BIND,
 166                 0,
 167                 0,
 168                 NULL,
 169                 0,
 170                 ATTACH_REJECT,
 171         },
 172         {
 173                 "attach type mismatch default vs bind4",
 174                 .insns = {
 175                         BPF_MOV64_IMM(BPF_REG_0, 1),
 176                         BPF_EXIT_INSN(),
 177                 },
 178                 0,
 179                 BPF_CGROUP_INET4_POST_BIND,
 180                 0,
 181                 0,
 182                 NULL,
 183                 0,
 184                 ATTACH_REJECT,
 185         },
 186         {
 187                 "attach type mismatch bind6 vs sock_create",
 188                 .insns = {
 189                         BPF_MOV64_IMM(BPF_REG_0, 1),
 190                         BPF_EXIT_INSN(),
 191                 },
 192                 BPF_CGROUP_INET6_POST_BIND,
 193                 BPF_CGROUP_INET_SOCK_CREATE,
 194                 0,
 195                 0,
 196                 NULL,
 197                 0,
 198                 ATTACH_REJECT,
 199         },
 200         {
 201                 "bind4 reject all",
 202                 .insns = {
 203                         BPF_MOV64_IMM(BPF_REG_0, 0),
 204                         BPF_EXIT_INSN(),
 205                 },
 206                 BPF_CGROUP_INET4_POST_BIND,
 207                 BPF_CGROUP_INET4_POST_BIND,
 208                 AF_INET,
 209                 SOCK_STREAM,
 210                 "0.0.0.0",
 211                 0,
 212                 BIND_REJECT,
 213         },
 214         {
 215                 "bind6 reject all",
 216                 .insns = {
 217                         BPF_MOV64_IMM(BPF_REG_0, 0),
 218                         BPF_EXIT_INSN(),
 219                 },
 220                 BPF_CGROUP_INET6_POST_BIND,
 221                 BPF_CGROUP_INET6_POST_BIND,
 222                 AF_INET6,
 223                 SOCK_STREAM,
 224                 "::",
 225                 0,
 226                 BIND_REJECT,
 227         },
 228         {
 229                 "bind6 deny specific IP & port",
 230                 .insns = {
 231                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
 232
 233                         /* if (ip == expected && port == expected) */
 234                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 235                                     offsetof(struct bpf_sock, src_ip6[3])),
 236                         BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x01000000, 4),
 237                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 238                                     offsetof(struct bpf_sock, src_port)),
 239                         BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
 240
 241                         /* return DENY; */
 242                         BPF_MOV64_IMM(BPF_REG_0, 0),
 243                         BPF_JMP_A(1),
 244
 245                         /* else return ALLOW; */
 246                         BPF_MOV64_IMM(BPF_REG_0, 1),
 247                         BPF_EXIT_INSN(),
 248                 },
 249                 BPF_CGROUP_INET6_POST_BIND,
 250                 BPF_CGROUP_INET6_POST_BIND,
 251                 AF_INET6,
 252                 SOCK_STREAM,
 253                 "::1",
 254                 8193,
 255                 BIND_REJECT,
 256         },
 257         {
 258                 "bind4 allow specific IP & port",
 259                 .insns = {
 260                         BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
 261
 262                         /* if (ip == expected && port == expected) */
 263                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 264                                     offsetof(struct bpf_sock, src_ip4)),
 265                         BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x0100007F, 4),
 266                         BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 267                                     offsetof(struct bpf_sock, src_port)),
 268                         BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),
 269
 270                         /* return ALLOW; */
 271                         BPF_MOV64_IMM(BPF_REG_0, 1),
 272                         BPF_JMP_A(1),
 273
 274                         /* else return DENY; */
 275                         BPF_MOV64_IMM(BPF_REG_0, 0),
 276                         BPF_EXIT_INSN(),
 277                 },
 278                 BPF_CGROUP_INET4_POST_BIND,
 279                 BPF_CGROUP_INET4_POST_BIND,
 280                 AF_INET,
 281                 SOCK_STREAM,
 282                 "127.0.0.1",
 283                 4098,
 284                 SUCCESS,
 285         },
 286         {
 287                 "bind4 allow all",
 288                 .insns = {
 289                         BPF_MOV64_IMM(BPF_REG_0, 1),
 290                         BPF_EXIT_INSN(),
 291                 },
 292                 BPF_CGROUP_INET4_POST_BIND,
 293                 BPF_CGROUP_INET4_POST_BIND,
 294                 AF_INET,
 295                 SOCK_STREAM,
 296                 "0.0.0.0",
 297                 0,
 298                 SUCCESS,
 299         },
 300         {
 301                 "bind6 allow all",
 302                 .insns = {
 303                         BPF_MOV64_IMM(BPF_REG_0, 1),
 304                         BPF_EXIT_INSN(),
 305                 },
 306                 BPF_CGROUP_INET6_POST_BIND,
 307                 BPF_CGROUP_INET6_POST_BIND,
 308                 AF_INET6,
 309                 SOCK_STREAM,
 310                 "::",
 311                 0,
 312                 SUCCESS,
 313         },
 314 };
 315
 316 static size_t probe_prog_length(const struct bpf_insn *fp)
 317 {
 318         size_t len;
 319
 320         for (len = MAX_INSNS - 1; len > 0; --len)
 321                 if (fp[len].code != 0 || fp[len].imm != 0)
 322                         break;
 323         return len + 1;
 324 }
 325
 326 static int load_sock_prog(const struct bpf_insn *prog,
 327                           enum bpf_attach_type attach_type)
 328 {
 329         struct bpf_load_program_attr attr;
 330
 331         memset(&attr, 0, sizeof(struct bpf_load_program_attr));
 332         attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
 333         attr.expected_attach_type = attach_type;
 334         attr.insns = prog;
 335         attr.insns_cnt = probe_prog_length(attr.insns);
 336         attr.license = "GPL";
 337
 338         return bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
 339 }
 340
 341 static int attach_sock_prog(int cgfd, int progfd,
 342                             enum bpf_attach_type attach_type)
 343 {
 344         return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE);
 345 }
 346
 347 static int bind_sock(int domain, int type, const char *ip, unsigned short port)
 348 {
 349         struct sockaddr_storage addr;
 350         struct sockaddr_in6 *addr6;
 351         struct sockaddr_in *addr4;
 352         int sockfd = -1;
 353         socklen_t len;
 354         int err = 0;
 355
 356         sockfd = socket(domain, type, 0);
 357         if (sockfd < 0)
 358                 goto err;
 359
 360         memset(&addr, 0, sizeof(addr));
 361
 362         if (domain == AF_INET) {
 363                 len = sizeof(struct sockaddr_in);
 364                 addr4 = (struct sockaddr_in *)&addr;
 365                 addr4->sin_family = domain;
 366                 addr4->sin_port = htons(port);
 367                 if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1)
 368                         goto err;
 369         } else if (domain == AF_INET6) {
 370                 len = sizeof(struct sockaddr_in6);
 371                 addr6 = (struct sockaddr_in6 *)&addr;
 372                 addr6->sin6_family = domain;
 373                 addr6->sin6_port = htons(port);
 374                 if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1)
 375                         goto err;
 376         } else {
 377                 goto err;
 378         }
 379
 380         if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1)
 381                 goto err;
 382
 383         goto out;
 384 err:
 385         err = -1;
 386 out:
 387         close(sockfd);
 388         return err;
 389 }
 390
 391 static int run_test_case(int cgfd, const struct sock_test *test)
 392 {
 393         int progfd = -1;
 394         int err = 0;
 395
 396         printf("Test case: %s .. ", test->descr);
 397         progfd = load_sock_prog(test->insns, test->expected_attach_type);
 398         if (progfd < 0) {
 399                 if (test->result == LOAD_REJECT)
 400                         goto out;
 401                 else
 402                         goto err;
 403         }
 404
 405         if (attach_sock_prog(cgfd, progfd, test->attach_type) == -1) {
 406                 if (test->result == ATTACH_REJECT)
 407                         goto out;
 408                 else
 409                         goto err;
 410         }
 411
 412         if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) {
 413                 /* sys_bind() may fail for different reasons, errno has to be
 414                  * checked to confirm that BPF program rejected it.
 415                  */
 416                 if (test->result == BIND_REJECT && errno == EPERM)
 417                         goto out;
 418                 else
 419                         goto err;
 420         }
 421
 422
 423         if (test->result != SUCCESS)
 424                 goto err;
 425
 426         goto out;
 427 err:
 428         err = -1;
 429 out:
 430         /* Detaching w/o checking return code: best effort attempt. */
 431         if (progfd != -1)
 432                 bpf_prog_detach(cgfd, test->attach_type);
 433         close(progfd);
 434         printf("[%s]\n", err ? "FAIL" : "PASS");
 435         return err;
 436 }
 437
 438 static int run_tests(int cgfd)
 439 {
 440         int passes = 0;
 441         int fails = 0;
 442         int i;
 443
 444         for (i = 0; i < ARRAY_SIZE(tests); ++i) {
 445                 if (run_test_case(cgfd, &tests[i]))
 446                         ++fails;
 447                 else
 448                         ++passes;
 449         }
 450         printf("Summary: %d PASSED, %d FAILED\n", passes, fails);
 451         return fails ? -1 : 0;
 452 }
 453
 454 int main(int argc, char **argv)
 455 {
 456         int cgfd = -1;
 457         int err = 0;
 458
 459         if (setup_cgroup_environment())
 460                 goto err;
 461
 462         cgfd = create_and_get_cgroup(CG_PATH);
 463         if (!cgfd)
 464                 goto err;
 465
 466         if (join_cgroup(CG_PATH))
 467                 goto err;
 468
 469         if (run_tests(cgfd))
 470                 goto err;
 471
 472         goto out;
 473 err:
 474         err = -1;
 475 out:
 476         close(cgfd);
 477         cleanup_cgroup_environment();
 478         return err;
 479 }