1 // SPDX-License-Identifier: GPL-2.0 2 3 #define _GNU_SOURCE 4 5 #include <stddef.h> 6 #include <arpa/inet.h> 7 #include <error.h> 8 #include <errno.h> 9 #include <net/if.h> 10 #include <linux/in.h> 11 #include <linux/netlink.h> 12 #include <linux/rtnetlink.h> 13 #include <netinet/if_ether.h> 14 #include <netinet/ip.h> 15 #include <netinet/ip6.h> 16 #include <netinet/udp.h> 17 #include <stdbool.h> 18 #include <stdlib.h> 19 #include <stdio.h> 20 #include <string.h> 21 #include <sys/ioctl.h> 22 #include <sys/socket.h> 23 #include <sys/stat.h> 24 #include <sys/time.h> 25 #include <sys/types.h> 26 #include <unistd.h> 27 28 #ifndef ETH_MAX_MTU 29 #define ETH_MAX_MTU 0xFFFFU 30 #endif 31 32 #ifndef UDP_SEGMENT 33 #define UDP_SEGMENT 103 34 #endif 35 36 #ifndef UDP_MAX_SEGMENTS 37 #define UDP_MAX_SEGMENTS (1 << 7UL) 38 #endif 39 40 #define CONST_MTU_TEST 1500 41 42 #define CONST_HDRLEN_V4 (sizeof(struct iphdr) + sizeof(struct udphdr)) 43 #define CONST_HDRLEN_V6 (sizeof(struct ip6_hdr) + sizeof(struct udphdr)) 44 45 #define CONST_MSS_V4 (CONST_MTU_TEST - CONST_HDRLEN_V4) 46 #define CONST_MSS_V6 (CONST_MTU_TEST - CONST_HDRLEN_V6) 47 48 #define CONST_MAX_SEGS_V4 (ETH_MAX_MTU / CONST_MSS_V4) 49 #define CONST_MAX_SEGS_V6 (ETH_MAX_MTU / CONST_MSS_V6) 50 51 static bool cfg_do_ipv4; 52 static bool cfg_do_ipv6; 53 static bool cfg_do_connected; 54 static bool cfg_do_connectionless; 55 static bool cfg_do_msgmore; 56 static bool cfg_do_recv = true; 57 static bool cfg_do_setsockopt; 58 static int cfg_specific_test_id = -1; 59 60 static unsigned short cfg_port = 9000; 61 62 static char buf[ETH_MAX_MTU]; 63 64 struct testcase { 65 int tlen; /* send() buffer size, may exceed mss */ 66 bool tfail; /* send() call is expected to fail */ 67 int gso_len; /* mss after applying gso */ 68 int r_num_mss; /* recv(): number of calls of full mss */ 69 int r_len_last; /* recv(): size of last non-mss dgram, if any */ 70 bool v6_ext_hdr; /* send() dgrams with IPv6 extension headers */ 71 }; 72 73 const struct in6_addr addr6 = { 74 { { 0xfd, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 } }, /* fd00::1 */ 75 }; 76 77 const struct in_addr addr4 = { 78 __constant_htonl(0x0a000001), /* 10.0.0.1 */ 79 }; 80 81 static const char ipv6_hopopts_pad1[8] = { 0 }; 82 83 struct testcase testcases_v4[] = { 84 { 85 /* no GSO: send a single byte */ 86 .tlen = 1, 87 .r_len_last = 1, 88 }, 89 { 90 /* no GSO: send a single MSS */ 91 .tlen = CONST_MSS_V4, 92 .r_num_mss = 1, 93 }, 94 { 95 /* no GSO: send a single MSS + 1B: fail */ 96 .tlen = CONST_MSS_V4 + 1, 97 .tfail = true, 98 }, 99 { 100 /* send a single MSS: will fall back to no GSO */ 101 .tlen = CONST_MSS_V4, 102 .gso_len = CONST_MSS_V4, 103 .r_num_mss = 1, 104 }, 105 { 106 /* send a single MSS + 1B */ 107 .tlen = CONST_MSS_V4 + 1, 108 .gso_len = CONST_MSS_V4, 109 .r_num_mss = 1, 110 .r_len_last = 1, 111 }, 112 { 113 /* send exactly 2 MSS */ 114 .tlen = CONST_MSS_V4 * 2, 115 .gso_len = CONST_MSS_V4, 116 .r_num_mss = 2, 117 }, 118 { 119 /* send 2 MSS + 1B */ 120 .tlen = (CONST_MSS_V4 * 2) + 1, 121 .gso_len = CONST_MSS_V4, 122 .r_num_mss = 2, 123 .r_len_last = 1, 124 }, 125 { 126 /* send MAX segs */ 127 .tlen = (ETH_MAX_MTU / CONST_MSS_V4) * CONST_MSS_V4, 128 .gso_len = CONST_MSS_V4, 129 .r_num_mss = (ETH_MAX_MTU / CONST_MSS_V4), 130 }, 131 132 { 133 /* send MAX bytes */ 134 .tlen = ETH_MAX_MTU - CONST_HDRLEN_V4, 135 .gso_len = CONST_MSS_V4, 136 .r_num_mss = CONST_MAX_SEGS_V4, 137 .r_len_last = ETH_MAX_MTU - CONST_HDRLEN_V4 - 138 (CONST_MAX_SEGS_V4 * CONST_MSS_V4), 139 }, 140 { 141 /* send MAX + 1: fail */ 142 .tlen = ETH_MAX_MTU - CONST_HDRLEN_V4 + 1, 143 .gso_len = CONST_MSS_V4, 144 .tfail = true, 145 }, 146 { 147 /* send a single 1B MSS: will fall back to no GSO */ 148 .tlen = 1, 149 .gso_len = 1, 150 .r_num_mss = 1, 151 }, 152 { 153 /* send 2 1B segments */ 154 .tlen = 2, 155 .gso_len = 1, 156 .r_num_mss = 2, 157 }, 158 { 159 /* send 2B + 2B + 1B segments */ 160 .tlen = 5, 161 .gso_len = 2, 162 .r_num_mss = 2, 163 .r_len_last = 1, 164 }, 165 { 166 /* send max number of min sized segments */ 167 .tlen = UDP_MAX_SEGMENTS, 168 .gso_len = 1, 169 .r_num_mss = UDP_MAX_SEGMENTS, 170 }, 171 { 172 /* send max number + 1 of min sized segments: fail */ 173 .tlen = UDP_MAX_SEGMENTS + 1, 174 .gso_len = 1, 175 .tfail = true, 176 }, 177 { 178 /* EOL */ 179 } 180 }; 181 182 #ifndef IP6_MAX_MTU 183 #define IP6_MAX_MTU (ETH_MAX_MTU + sizeof(struct ip6_hdr)) 184 #endif 185 186 struct testcase testcases_v6[] = { 187 { 188 /* no GSO: send a single byte */ 189 .tlen = 1, 190 .r_len_last = 1, 191 }, 192 { 193 /* no GSO: send a single MSS */ 194 .tlen = CONST_MSS_V6, 195 .r_num_mss = 1, 196 }, 197 { 198 /* no GSO: send a single MSS + 1B: fail */ 199 .tlen = CONST_MSS_V6 + 1, 200 .tfail = true, 201 }, 202 { 203 /* send a single MSS: will fall back to no GSO */ 204 .tlen = CONST_MSS_V6, 205 .gso_len = CONST_MSS_V6, 206 .r_num_mss = 1, 207 }, 208 { 209 /* send a single MSS + 1B */ 210 .tlen = CONST_MSS_V6 + 1, 211 .gso_len = CONST_MSS_V6, 212 .r_num_mss = 1, 213 .r_len_last = 1, 214 }, 215 { 216 /* send exactly 2 MSS */ 217 .tlen = CONST_MSS_V6 * 2, 218 .gso_len = CONST_MSS_V6, 219 .r_num_mss = 2, 220 }, 221 { 222 /* send 2 MSS + 1B */ 223 .tlen = (CONST_MSS_V6 * 2) + 1, 224 .gso_len = CONST_MSS_V6, 225 .r_num_mss = 2, 226 .r_len_last = 1, 227 }, 228 { 229 /* send MAX segs */ 230 .tlen = (IP6_MAX_MTU / CONST_MSS_V6) * CONST_MSS_V6, 231 .gso_len = CONST_MSS_V6, 232 .r_num_mss = (IP6_MAX_MTU / CONST_MSS_V6), 233 }, 234 235 { 236 /* send MAX bytes */ 237 .tlen = IP6_MAX_MTU - CONST_HDRLEN_V6, 238 .gso_len = CONST_MSS_V6, 239 .r_num_mss = CONST_MAX_SEGS_V6, 240 .r_len_last = IP6_MAX_MTU - CONST_HDRLEN_V6 - 241 (CONST_MAX_SEGS_V6 * CONST_MSS_V6), 242 }, 243 { 244 /* send MAX + 1: fail */ 245 .tlen = IP6_MAX_MTU - CONST_HDRLEN_V6 + 1, 246 .gso_len = CONST_MSS_V6, 247 .tfail = true, 248 }, 249 { 250 /* send a single 1B MSS: will fall back to no GSO */ 251 .tlen = 1, 252 .gso_len = 1, 253 .r_num_mss = 1, 254 }, 255 { 256 /* send 2 1B segments */ 257 .tlen = 2, 258 .gso_len = 1, 259 .r_num_mss = 2, 260 }, 261 { 262 /* send 2 1B segments with extension headers */ 263 .tlen = 2, 264 .gso_len = 1, 265 .r_num_mss = 2, 266 .v6_ext_hdr = true, 267 }, 268 { 269 /* send 2B + 2B + 1B segments */ 270 .tlen = 5, 271 .gso_len = 2, 272 .r_num_mss = 2, 273 .r_len_last = 1, 274 }, 275 { 276 /* send max number of min sized segments */ 277 .tlen = UDP_MAX_SEGMENTS, 278 .gso_len = 1, 279 .r_num_mss = UDP_MAX_SEGMENTS, 280 }, 281 { 282 /* send max number + 1 of min sized segments: fail */ 283 .tlen = UDP_MAX_SEGMENTS + 1, 284 .gso_len = 1, 285 .tfail = true, 286 }, 287 { 288 /* EOL */ 289 } 290 }; 291 292 static void set_pmtu_discover(int fd, bool is_ipv4) 293 { 294 int level, name, val; 295 296 if (is_ipv4) { 297 level = SOL_IP; 298 name = IP_MTU_DISCOVER; 299 val = IP_PMTUDISC_DO; 300 } else { 301 level = SOL_IPV6; 302 name = IPV6_MTU_DISCOVER; 303 val = IPV6_PMTUDISC_DO; 304 } 305 306 if (setsockopt(fd, level, name, &val, sizeof(val))) 307 error(1, errno, "setsockopt path mtu"); 308 } 309 310 static unsigned int get_path_mtu(int fd, bool is_ipv4) 311 { 312 socklen_t vallen; 313 unsigned int mtu; 314 int ret; 315 316 vallen = sizeof(mtu); 317 if (is_ipv4) 318 ret = getsockopt(fd, SOL_IP, IP_MTU, &mtu, &vallen); 319 else 320 ret = getsockopt(fd, SOL_IPV6, IPV6_MTU, &mtu, &vallen); 321 322 if (ret) 323 error(1, errno, "getsockopt mtu"); 324 325 326 fprintf(stderr, "path mtu (read): %u\n", mtu); 327 return mtu; 328 } 329 330 static bool __send_one(int fd, struct msghdr *msg, int flags) 331 { 332 int ret; 333 334 ret = sendmsg(fd, msg, flags); 335 if (ret == -1 && 336 (errno == EMSGSIZE || errno == ENOMEM || errno == EINVAL)) 337 return false; 338 if (ret == -1) 339 error(1, errno, "sendmsg"); 340 if (ret != msg->msg_iov->iov_len) 341 error(1, 0, "sendto: %d != %llu", ret, 342 (unsigned long long)msg->msg_iov->iov_len); 343 if (msg->msg_flags) 344 error(1, 0, "sendmsg: return flags 0x%x\n", msg->msg_flags); 345 346 return true; 347 } 348 349 static bool send_one(int fd, int len, int gso_len, 350 struct sockaddr *addr, socklen_t alen) 351 { 352 char control[CMSG_SPACE(sizeof(uint16_t))] = {0}; 353 struct msghdr msg = {0}; 354 struct iovec iov = {0}; 355 struct cmsghdr *cm; 356 357 iov.iov_base = buf; 358 iov.iov_len = len; 359 360 msg.msg_iov = &iov; 361 msg.msg_iovlen = 1; 362 363 msg.msg_name = addr; 364 msg.msg_namelen = alen; 365 366 if (gso_len && !cfg_do_setsockopt) { 367 msg.msg_control = control; 368 msg.msg_controllen = sizeof(control); 369 370 cm = CMSG_FIRSTHDR(&msg); 371 cm->cmsg_level = SOL_UDP; 372 cm->cmsg_type = UDP_SEGMENT; 373 cm->cmsg_len = CMSG_LEN(sizeof(uint16_t)); 374 *((uint16_t *) CMSG_DATA(cm)) = gso_len; 375 } 376 377 /* If MSG_MORE, send 1 byte followed by remainder */ 378 if (cfg_do_msgmore && len > 1) { 379 iov.iov_len = 1; 380 if (!__send_one(fd, &msg, MSG_MORE)) 381 error(1, 0, "send 1B failed"); 382 383 iov.iov_base++; 384 iov.iov_len = len - 1; 385 } 386 387 return __send_one(fd, &msg, 0); 388 } 389 390 static int recv_one(int fd, int flags) 391 { 392 int ret; 393 394 ret = recv(fd, buf, sizeof(buf), flags); 395 if (ret == -1 && errno == EAGAIN && (flags & MSG_DONTWAIT)) 396 return 0; 397 if (ret == -1) 398 error(1, errno, "recv"); 399 400 return ret; 401 } 402 403 static void run_one(struct testcase *test, int fdt, int fdr, 404 struct sockaddr *addr, socklen_t alen) 405 { 406 int i, ret, val, mss; 407 bool sent; 408 409 fprintf(stderr, "ipv%d tx:%d gso:%d %s%s\n", 410 addr->sa_family == AF_INET ? 4 : 6, 411 test->tlen, test->gso_len, 412 test->v6_ext_hdr ? "ext-hdr " : "", 413 test->tfail ? "(fail)" : ""); 414 415 if (test->v6_ext_hdr) { 416 if (setsockopt(fdt, IPPROTO_IPV6, IPV6_HOPOPTS, 417 ipv6_hopopts_pad1, sizeof(ipv6_hopopts_pad1))) 418 error(1, errno, "setsockopt ipv6 hopopts"); 419 } 420 421 val = test->gso_len; 422 if (cfg_do_setsockopt) { 423 if (setsockopt(fdt, SOL_UDP, UDP_SEGMENT, &val, sizeof(val))) 424 error(1, errno, "setsockopt udp segment"); 425 } 426 427 sent = send_one(fdt, test->tlen, test->gso_len, addr, alen); 428 if (sent && test->tfail) 429 error(1, 0, "send succeeded while expecting failure"); 430 if (!sent && !test->tfail) 431 error(1, 0, "send failed while expecting success"); 432 433 if (test->v6_ext_hdr) { 434 if (setsockopt(fdt, IPPROTO_IPV6, IPV6_HOPOPTS, NULL, 0)) 435 error(1, errno, "setsockopt ipv6 hopopts clear"); 436 } 437 438 if (!sent) 439 return; 440 441 if (!cfg_do_recv) 442 return; 443 444 if (test->gso_len) 445 mss = test->gso_len; 446 else 447 mss = addr->sa_family == AF_INET ? CONST_MSS_V4 : CONST_MSS_V6; 448 449 450 /* Recv all full MSS datagrams */ 451 for (i = 0; i < test->r_num_mss; i++) { 452 ret = recv_one(fdr, 0); 453 if (ret != mss) 454 error(1, 0, "recv.%d: %d != %d", i, ret, mss); 455 } 456 457 /* Recv the non-full last datagram, if tlen was not a multiple of mss */ 458 if (test->r_len_last) { 459 ret = recv_one(fdr, 0); 460 if (ret != test->r_len_last) 461 error(1, 0, "recv.%d: %d != %d (last)", 462 i, ret, test->r_len_last); 463 } 464 465 /* Verify received all data */ 466 ret = recv_one(fdr, MSG_DONTWAIT); 467 if (ret) 468 error(1, 0, "recv: unexpected datagram"); 469 } 470 471 static void run_all(int fdt, int fdr, struct sockaddr *addr, socklen_t alen) 472 { 473 struct testcase *tests, *test; 474 475 tests = addr->sa_family == AF_INET ? testcases_v4 : testcases_v6; 476 477 for (test = tests; test->tlen; test++) { 478 /* if a specific test is given, then skip all others */ 479 if (cfg_specific_test_id == -1 || 480 cfg_specific_test_id == test - tests) 481 run_one(test, fdt, fdr, addr, alen); 482 } 483 } 484 485 static void run_test(struct sockaddr *addr, socklen_t alen) 486 { 487 struct timeval tv = { .tv_usec = 100 * 1000 }; 488 int fdr, fdt, val; 489 490 fdr = socket(addr->sa_family, SOCK_DGRAM, 0); 491 if (fdr == -1) 492 error(1, errno, "socket r"); 493 494 if (cfg_do_recv) { 495 if (bind(fdr, addr, alen)) 496 error(1, errno, "bind"); 497 } 498 499 /* Have tests fail quickly instead of hang */ 500 if (setsockopt(fdr, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv))) 501 error(1, errno, "setsockopt rcv timeout"); 502 503 fdt = socket(addr->sa_family, SOCK_DGRAM, 0); 504 if (fdt == -1) 505 error(1, errno, "socket t"); 506 507 /* Do not fragment these datagrams: only succeed if GSO works */ 508 set_pmtu_discover(fdt, addr->sa_family == AF_INET); 509 510 if (cfg_do_connectionless) 511 run_all(fdt, fdr, addr, alen); 512 513 if (cfg_do_connected) { 514 if (connect(fdt, addr, alen)) 515 error(1, errno, "connect"); 516 517 val = get_path_mtu(fdt, addr->sa_family == AF_INET); 518 if (val != CONST_MTU_TEST) 519 error(1, 0, "bad path mtu %u\n", val); 520 521 run_all(fdt, fdr, addr, 0 /* use connected addr */); 522 } 523 524 if (close(fdt)) 525 error(1, errno, "close t"); 526 if (close(fdr)) 527 error(1, errno, "close r"); 528 } 529 530 static void run_test_v4(void) 531 { 532 struct sockaddr_in addr = {0}; 533 534 addr.sin_family = AF_INET; 535 addr.sin_port = htons(cfg_port); 536 addr.sin_addr = addr4; 537 538 run_test((void *)&addr, sizeof(addr)); 539 } 540 541 static void run_test_v6(void) 542 { 543 struct sockaddr_in6 addr = {0}; 544 545 addr.sin6_family = AF_INET6; 546 addr.sin6_port = htons(cfg_port); 547 addr.sin6_addr = addr6; 548 549 run_test((void *)&addr, sizeof(addr)); 550 } 551 552 static void parse_opts(int argc, char **argv) 553 { 554 int c; 555 556 while ((c = getopt(argc, argv, "46cCmRst:")) != -1) { 557 switch (c) { 558 case '4': 559 cfg_do_ipv4 = true; 560 break; 561 case '6': 562 cfg_do_ipv6 = true; 563 break; 564 case 'c': 565 cfg_do_connected = true; 566 break; 567 case 'C': 568 cfg_do_connectionless = true; 569 break; 570 case 'm': 571 cfg_do_msgmore = true; 572 break; 573 case 'R': 574 cfg_do_recv = false; 575 break; 576 case 's': 577 cfg_do_setsockopt = true; 578 break; 579 case 't': 580 cfg_specific_test_id = strtoul(optarg, NULL, 0); 581 break; 582 default: 583 error(1, 0, "%s: parse error", argv[0]); 584 } 585 } 586 } 587 588 int main(int argc, char **argv) 589 { 590 parse_opts(argc, argv); 591 592 if (cfg_do_ipv4) 593 run_test_v4(); 594 if (cfg_do_ipv6) 595 run_test_v6(); 596 597 fprintf(stderr, "OK\n"); 598 return 0; 599 } 600