1// SPDX-License-Identifier: GPL-2.0 2 3/* Test hardware checksum offload: Rx + Tx, IPv4 + IPv6, TCP + UDP. 4 * 5 * The test runs on two machines to exercise the NIC. For this reason it 6 * is not integrated in kselftests. 7 * 8 * CMD=$((./csum -[46] -[tu] -S $SADDR -D $DADDR -[RT] -r 1 $EXTRA_ARGS)) 9 * 10 * Rx: 11 * 12 * The sender sends packets with a known checksum field using PF_INET(6) 13 * SOCK_RAW sockets. 14 * 15 * good packet: $CMD [-t] 16 * bad packet: $CMD [-t] -E 17 * 18 * The receiver reads UDP packets with a UDP socket. This is not an 19 * option for TCP packets ('-t'). Optionally insert an iptables filter 20 * to avoid these entering the real protocol stack. 21 * 22 * The receiver also reads all packets with a PF_PACKET socket, to 23 * observe whether both good and bad packets arrive on the host. And to 24 * read the optional TP_STATUS_CSUM_VALID bit. This requires setting 25 * option PACKET_AUXDATA, and works only for CHECKSUM_UNNECESSARY. 26 * 27 * Tx: 28 * 29 * The sender needs to build CHECKSUM_PARTIAL packets to exercise tx 30 * checksum offload. 31 * 32 * The sender can sends packets with a UDP socket. 33 * 34 * Optionally crafts a packet that sums up to zero to verify that the 35 * device writes negative zero 0xFFFF in this case to distinguish from 36 * 0x0000 (checksum disabled), as required by RFC 768. Hit this case 37 * by choosing a specific source port. 38 * 39 * good packet: $CMD -U 40 * zero csum: $CMD -U -Z 41 * 42 * The sender can also build packets with PF_PACKET with PACKET_VNET_HDR, 43 * to cover more protocols. PF_PACKET requires passing src and dst mac 44 * addresses. 45 * 46 * good packet: $CMD -s $smac -d $dmac -p [-t] 47 * 48 * Argument '-z' sends UDP packets with a 0x000 checksum disabled field, 49 * to verify that the NIC passes these packets unmodified. 50 * 51 * Argument '-e' adds a transport mode encapsulation header between 52 * network and transport header. This will fail for devices that parse 53 * headers. Should work on devices that implement protocol agnostic tx 54 * checksum offload (NETIF_F_HW_CSUM). 55 * 56 * Argument '-r $SEED' optionally randomizes header, payload and length 57 * to increase coverage between packets sent. SEED 1 further chooses a 58 * different seed for each run (and logs this for reproducibility). It 59 * is advised to enable this for extra coverage in continuous testing. 60 */ 61 62#define _GNU_SOURCE 63 64#include <arpa/inet.h> 65#include <asm/byteorder.h> 66#include <errno.h> 67#include <error.h> 68#include <linux/filter.h> 69#include <linux/if_packet.h> 70#include <linux/ipv6.h> 71#include <linux/virtio_net.h> 72#include <net/ethernet.h> 73#include <net/if.h> 74#include <netinet/if_ether.h> 75#include <netinet/in.h> 76#include <netinet/ip.h> 77#include <netinet/ip6.h> 78#include <netinet/tcp.h> 79#include <netinet/udp.h> 80#include <poll.h> 81#include <sched.h> 82#include <stdbool.h> 83#include <stddef.h> 84#include <stdint.h> 85#include <stdio.h> 86#include <stdlib.h> 87#include <string.h> 88#include <sys/socket.h> 89#include <sys/stat.h> 90#include <sys/time.h> 91#include <sys/types.h> 92#include <unistd.h> 93 94#include "kselftest.h" 95 96static bool cfg_bad_csum; 97static int cfg_family = PF_INET6; 98static int cfg_num_pkt = 4; 99static bool cfg_do_rx = true; 100static bool cfg_do_tx = true; 101static bool cfg_encap; 102static char *cfg_ifname = "eth0"; 103static char *cfg_mac_dst; 104static char *cfg_mac_src; 105static int cfg_proto = IPPROTO_UDP; 106static int cfg_payload_char = 'a'; 107static int cfg_payload_len = 100; 108static uint16_t cfg_port_dst = 34000; 109static uint16_t cfg_port_src = 33000; 110static uint16_t cfg_port_src_encap = 33001; 111static unsigned int cfg_random_seed; 112static int cfg_rcvbuf = 1 << 22; /* be able to queue large cfg_num_pkt */ 113static bool cfg_send_pfpacket; 114static bool cfg_send_udp; 115static int cfg_timeout_ms = 2000; 116static bool cfg_zero_disable; /* skip checksum: set to zero (udp only) */ 117static bool cfg_zero_sum; /* create packet that adds up to zero */ 118 119static struct sockaddr_in cfg_daddr4 = {.sin_family = AF_INET}; 120static struct sockaddr_in cfg_saddr4 = {.sin_family = AF_INET}; 121static struct sockaddr_in6 cfg_daddr6 = {.sin6_family = AF_INET6}; 122static struct sockaddr_in6 cfg_saddr6 = {.sin6_family = AF_INET6}; 123 124#define ENC_HEADER_LEN (sizeof(struct udphdr) + sizeof(struct udp_encap_hdr)) 125#define MAX_HEADER_LEN (sizeof(struct ipv6hdr) + ENC_HEADER_LEN + sizeof(struct tcphdr)) 126#define MAX_PAYLOAD_LEN 1024 127 128/* Trivial demo encap. Stand-in for transport layer protocols like ESP or PSP */ 129struct udp_encap_hdr { 130 uint8_t nexthdr; 131 uint8_t padding[3]; 132}; 133 134/* Ipaddrs, for pseudo csum. Global var is ugly, pass through funcs was worse */ 135static void *iph_addr_p; 136 137static unsigned long gettimeofday_ms(void) 138{ 139 struct timeval tv; 140 141 gettimeofday(&tv, NULL); 142 return (tv.tv_sec * 1000UL) + (tv.tv_usec / 1000UL); 143} 144 145static uint32_t checksum_nofold(char *data, size_t len, uint32_t sum) 146{ 147 uint16_t *words = (uint16_t *)data; 148 int i; 149 150 for (i = 0; i < len / 2; i++) 151 sum += words[i]; 152 153 if (len & 1) 154 sum += ((unsigned char *)data)[len - 1]; 155 156 return sum; 157} 158 159static uint16_t checksum_fold(void *data, size_t len, uint32_t sum) 160{ 161 sum = checksum_nofold(data, len, sum); 162 163 while (sum > 0xFFFF) 164 sum = (sum & 0xFFFF) + (sum >> 16); 165 166 return ~sum; 167} 168 169static uint16_t checksum(void *th, uint16_t proto, size_t len) 170{ 171 uint32_t sum; 172 int alen; 173 174 alen = cfg_family == PF_INET6 ? 32 : 8; 175 176 sum = checksum_nofold(iph_addr_p, alen, 0); 177 sum += htons(proto); 178 sum += htons(len); 179 180 /* With CHECKSUM_PARTIAL kernel expects non-inverted pseudo csum */ 181 if (cfg_do_tx && cfg_send_pfpacket) 182 return ~checksum_fold(NULL, 0, sum); 183 else 184 return checksum_fold(th, len, sum); 185} 186 187static void *build_packet_ipv4(void *_iph, uint8_t proto, unsigned int len) 188{ 189 struct iphdr *iph = _iph; 190 191 memset(iph, 0, sizeof(*iph)); 192 193 iph->version = 4; 194 iph->ihl = 5; 195 iph->ttl = 8; 196 iph->protocol = proto; 197 iph->saddr = cfg_saddr4.sin_addr.s_addr; 198 iph->daddr = cfg_daddr4.sin_addr.s_addr; 199 iph->tot_len = htons(sizeof(*iph) + len); 200 iph->check = checksum_fold(iph, sizeof(*iph), 0); 201 202 iph_addr_p = &iph->saddr; 203 204 return iph + 1; 205} 206 207static void *build_packet_ipv6(void *_ip6h, uint8_t proto, unsigned int len) 208{ 209 struct ipv6hdr *ip6h = _ip6h; 210 211 memset(ip6h, 0, sizeof(*ip6h)); 212 213 ip6h->version = 6; 214 ip6h->payload_len = htons(len); 215 ip6h->nexthdr = proto; 216 ip6h->hop_limit = 64; 217 ip6h->saddr = cfg_saddr6.sin6_addr; 218 ip6h->daddr = cfg_daddr6.sin6_addr; 219 220 iph_addr_p = &ip6h->saddr; 221 222 return ip6h + 1; 223} 224 225static void *build_packet_udp(void *_uh) 226{ 227 struct udphdr *uh = _uh; 228 229 uh->source = htons(cfg_port_src); 230 uh->dest = htons(cfg_port_dst); 231 uh->len = htons(sizeof(*uh) + cfg_payload_len); 232 uh->check = 0; 233 234 /* choose source port so that uh->check adds up to zero */ 235 if (cfg_zero_sum) { 236 uh->source = 0; 237 uh->source = checksum(uh, IPPROTO_UDP, sizeof(*uh) + cfg_payload_len); 238 239 fprintf(stderr, "tx: changing sport: %hu -> %hu\n", 240 cfg_port_src, ntohs(uh->source)); 241 cfg_port_src = ntohs(uh->source); 242 } 243 244 if (cfg_zero_disable) 245 uh->check = 0; 246 else 247 uh->check = checksum(uh, IPPROTO_UDP, sizeof(*uh) + cfg_payload_len); 248 249 if (cfg_bad_csum) 250 uh->check = ~uh->check; 251 252 fprintf(stderr, "tx: sending checksum: 0x%x\n", uh->check); 253 return uh + 1; 254} 255 256static void *build_packet_tcp(void *_th) 257{ 258 struct tcphdr *th = _th; 259 260 th->source = htons(cfg_port_src); 261 th->dest = htons(cfg_port_dst); 262 th->doff = 5; 263 th->check = 0; 264 265 th->check = checksum(th, IPPROTO_TCP, sizeof(*th) + cfg_payload_len); 266 267 if (cfg_bad_csum) 268 th->check = ~th->check; 269 270 fprintf(stderr, "tx: sending checksum: 0x%x\n", th->check); 271 return th + 1; 272} 273 274static char *build_packet_udp_encap(void *_uh) 275{ 276 struct udphdr *uh = _uh; 277 struct udp_encap_hdr *eh = _uh + sizeof(*uh); 278 279 /* outer dst == inner dst, to simplify BPF filter 280 * outer src != inner src, to demultiplex on recv 281 */ 282 uh->dest = htons(cfg_port_dst); 283 uh->source = htons(cfg_port_src_encap); 284 uh->check = 0; 285 uh->len = htons(sizeof(*uh) + 286 sizeof(*eh) + 287 sizeof(struct tcphdr) + 288 cfg_payload_len); 289 290 eh->nexthdr = IPPROTO_TCP; 291 292 return build_packet_tcp(eh + 1); 293} 294 295static char *build_packet(char *buf, int max_len, int *len) 296{ 297 uint8_t proto; 298 char *off; 299 int tlen; 300 301 if (cfg_random_seed) { 302 int *buf32 = (void *)buf; 303 int i; 304 305 for (i = 0; i < (max_len / sizeof(int)); i++) 306 buf32[i] = rand(); 307 } else { 308 memset(buf, cfg_payload_char, max_len); 309 } 310 311 if (cfg_proto == IPPROTO_UDP) 312 tlen = sizeof(struct udphdr) + cfg_payload_len; 313 else 314 tlen = sizeof(struct tcphdr) + cfg_payload_len; 315 316 if (cfg_encap) { 317 proto = IPPROTO_UDP; 318 tlen += ENC_HEADER_LEN; 319 } else { 320 proto = cfg_proto; 321 } 322 323 if (cfg_family == PF_INET) 324 off = build_packet_ipv4(buf, proto, tlen); 325 else 326 off = build_packet_ipv6(buf, proto, tlen); 327 328 if (cfg_encap) 329 off = build_packet_udp_encap(off); 330 else if (cfg_proto == IPPROTO_UDP) 331 off = build_packet_udp(off); 332 else 333 off = build_packet_tcp(off); 334 335 /* only pass the payload, but still compute headers for cfg_zero_sum */ 336 if (cfg_send_udp) { 337 *len = cfg_payload_len; 338 return off; 339 } 340 341 *len = off - buf + cfg_payload_len; 342 return buf; 343} 344 345static int open_inet(int ipproto, int protocol) 346{ 347 int fd; 348 349 fd = socket(cfg_family, ipproto, protocol); 350 if (fd == -1) 351 error(1, errno, "socket inet"); 352 353 if (cfg_family == PF_INET6) { 354 /* may have been updated by cfg_zero_sum */ 355 cfg_saddr6.sin6_port = htons(cfg_port_src); 356 357 if (bind(fd, (void *)&cfg_saddr6, sizeof(cfg_saddr6))) 358 error(1, errno, "bind dgram 6"); 359 if (connect(fd, (void *)&cfg_daddr6, sizeof(cfg_daddr6))) 360 error(1, errno, "connect dgram 6"); 361 } else { 362 /* may have been updated by cfg_zero_sum */ 363 cfg_saddr4.sin_port = htons(cfg_port_src); 364 365 if (bind(fd, (void *)&cfg_saddr4, sizeof(cfg_saddr4))) 366 error(1, errno, "bind dgram 4"); 367 if (connect(fd, (void *)&cfg_daddr4, sizeof(cfg_daddr4))) 368 error(1, errno, "connect dgram 4"); 369 } 370 371 return fd; 372} 373 374static int open_packet(void) 375{ 376 int fd, one = 1; 377 378 fd = socket(PF_PACKET, SOCK_RAW, 0); 379 if (fd == -1) 380 error(1, errno, "socket packet"); 381 382 if (setsockopt(fd, SOL_PACKET, PACKET_VNET_HDR, &one, sizeof(one))) 383 error(1, errno, "setsockopt packet_vnet_ndr"); 384 385 return fd; 386} 387 388static void send_inet(int fd, const char *buf, int len) 389{ 390 int ret; 391 392 ret = write(fd, buf, len); 393 if (ret == -1) 394 error(1, errno, "write"); 395 if (ret != len) 396 error(1, 0, "write: %d", ret); 397} 398 399static void eth_str_to_addr(const char *str, unsigned char *eth) 400{ 401 if (sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx", 402 ð[0], ð[1], ð[2], ð[3], ð[4], ð[5]) != 6) 403 error(1, 0, "cannot parse mac addr %s", str); 404} 405 406static void send_packet(int fd, const char *buf, int len) 407{ 408 struct virtio_net_hdr vh = {0}; 409 struct sockaddr_ll addr = {0}; 410 struct msghdr msg = {0}; 411 struct ethhdr eth; 412 struct iovec iov[3]; 413 int ret; 414 415 addr.sll_family = AF_PACKET; 416 addr.sll_halen = ETH_ALEN; 417 addr.sll_ifindex = if_nametoindex(cfg_ifname); 418 if (!addr.sll_ifindex) 419 error(1, errno, "if_nametoindex %s", cfg_ifname); 420 421 vh.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 422 if (cfg_family == PF_INET6) { 423 vh.csum_start = sizeof(struct ethhdr) + sizeof(struct ipv6hdr); 424 addr.sll_protocol = htons(ETH_P_IPV6); 425 } else { 426 vh.csum_start = sizeof(struct ethhdr) + sizeof(struct iphdr); 427 addr.sll_protocol = htons(ETH_P_IP); 428 } 429 430 if (cfg_encap) 431 vh.csum_start += ENC_HEADER_LEN; 432 433 if (cfg_proto == IPPROTO_TCP) { 434 vh.csum_offset = __builtin_offsetof(struct tcphdr, check); 435 vh.hdr_len = vh.csum_start + sizeof(struct tcphdr); 436 } else { 437 vh.csum_offset = __builtin_offsetof(struct udphdr, check); 438 vh.hdr_len = vh.csum_start + sizeof(struct udphdr); 439 } 440 441 eth_str_to_addr(cfg_mac_src, eth.h_source); 442 eth_str_to_addr(cfg_mac_dst, eth.h_dest); 443 eth.h_proto = addr.sll_protocol; 444 445 iov[0].iov_base = &vh; 446 iov[0].iov_len = sizeof(vh); 447 448 iov[1].iov_base = ð 449 iov[1].iov_len = sizeof(eth); 450 451 iov[2].iov_base = (void *)buf; 452 iov[2].iov_len = len; 453 454 msg.msg_iov = iov; 455 msg.msg_iovlen = ARRAY_SIZE(iov); 456 457 msg.msg_name = &addr; 458 msg.msg_namelen = sizeof(addr); 459 460 ret = sendmsg(fd, &msg, 0); 461 if (ret == -1) 462 error(1, errno, "sendmsg packet"); 463 if (ret != sizeof(vh) + sizeof(eth) + len) 464 error(1, errno, "sendmsg packet: %u", ret); 465} 466 467static int recv_prepare_udp(void) 468{ 469 int fd; 470 471 fd = socket(cfg_family, SOCK_DGRAM, 0); 472 if (fd == -1) 473 error(1, errno, "socket r"); 474 475 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, 476 &cfg_rcvbuf, sizeof(cfg_rcvbuf))) 477 error(1, errno, "setsockopt SO_RCVBUF r"); 478 479 if (cfg_family == PF_INET6) { 480 if (bind(fd, (void *)&cfg_daddr6, sizeof(cfg_daddr6))) 481 error(1, errno, "bind r"); 482 } else { 483 if (bind(fd, (void *)&cfg_daddr4, sizeof(cfg_daddr4))) 484 error(1, errno, "bind r"); 485 } 486 487 return fd; 488} 489 490/* Filter out all traffic that is not cfg_proto with our destination port. 491 * 492 * Otherwise background noise may cause PF_PACKET receive queue overflow, 493 * dropping the expected packets and failing the test. 494 */ 495static void __recv_prepare_packet_filter(int fd, int off_nexthdr, int off_dport) 496{ 497 struct sock_filter filter[] = { 498 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, SKF_AD_OFF + SKF_AD_PKTTYPE), 499 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, PACKET_HOST, 0, 4), 500 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, off_nexthdr), 501 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_encap ? IPPROTO_UDP : cfg_proto, 0, 2), 502 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, off_dport), 503 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, cfg_port_dst, 1, 0), 504 BPF_STMT(BPF_RET + BPF_K, 0), 505 BPF_STMT(BPF_RET + BPF_K, 0xFFFF), 506 }; 507 struct sock_fprog prog = {}; 508 509 prog.filter = filter; 510 prog.len = ARRAY_SIZE(filter); 511 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog))) 512 error(1, errno, "setsockopt filter"); 513} 514 515static void recv_prepare_packet_filter(int fd) 516{ 517 const int off_dport = offsetof(struct tcphdr, dest); /* same for udp */ 518 519 if (cfg_family == AF_INET) 520 __recv_prepare_packet_filter(fd, offsetof(struct iphdr, protocol), 521 sizeof(struct iphdr) + off_dport); 522 else 523 __recv_prepare_packet_filter(fd, offsetof(struct ipv6hdr, nexthdr), 524 sizeof(struct ipv6hdr) + off_dport); 525} 526 527static void recv_prepare_packet_bind(int fd) 528{ 529 struct sockaddr_ll laddr = {0}; 530 531 laddr.sll_family = AF_PACKET; 532 533 if (cfg_family == PF_INET) 534 laddr.sll_protocol = htons(ETH_P_IP); 535 else 536 laddr.sll_protocol = htons(ETH_P_IPV6); 537 538 laddr.sll_ifindex = if_nametoindex(cfg_ifname); 539 if (!laddr.sll_ifindex) 540 error(1, 0, "if_nametoindex %s", cfg_ifname); 541 542 if (bind(fd, (void *)&laddr, sizeof(laddr))) 543 error(1, errno, "bind pf_packet"); 544} 545 546static int recv_prepare_packet(void) 547{ 548 int fd, one = 1; 549 550 fd = socket(PF_PACKET, SOCK_DGRAM, 0); 551 if (fd == -1) 552 error(1, errno, "socket p"); 553 554 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, 555 &cfg_rcvbuf, sizeof(cfg_rcvbuf))) 556 error(1, errno, "setsockopt SO_RCVBUF p"); 557 558 /* enable auxdata to recv checksum status (valid vs unknown) */ 559 if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one))) 560 error(1, errno, "setsockopt auxdata"); 561 562 /* install filter to restrict packet flow to match */ 563 recv_prepare_packet_filter(fd); 564 565 /* bind to address family to start packet flow */ 566 recv_prepare_packet_bind(fd); 567 568 return fd; 569} 570 571static int recv_udp(int fd) 572{ 573 static char buf[MAX_PAYLOAD_LEN]; 574 int ret, count = 0; 575 576 while (1) { 577 ret = recv(fd, buf, sizeof(buf), MSG_DONTWAIT); 578 if (ret == -1 && errno == EAGAIN) 579 break; 580 if (ret == -1) 581 error(1, errno, "recv r"); 582 583 fprintf(stderr, "rx: udp: len=%u\n", ret); 584 count++; 585 } 586 587 return count; 588} 589 590static int recv_verify_csum(void *th, int len, uint16_t sport, uint16_t csum_field) 591{ 592 uint16_t csum; 593 594 csum = checksum(th, cfg_proto, len); 595 596 fprintf(stderr, "rx: pkt: sport=%hu len=%u csum=0x%hx verify=0x%hx\n", 597 sport, len, csum_field, csum); 598 599 /* csum must be zero unless cfg_bad_csum indicates bad csum */ 600 if (csum && !cfg_bad_csum) { 601 fprintf(stderr, "pkt: bad csum\n"); 602 return 1; 603 } else if (cfg_bad_csum && !csum) { 604 fprintf(stderr, "pkt: good csum, while bad expected\n"); 605 return 1; 606 } 607 608 if (cfg_zero_sum && csum_field != 0xFFFF) { 609 fprintf(stderr, "pkt: zero csum: field should be 0xFFFF, is 0x%hx\n", csum_field); 610 return 1; 611 } 612 613 return 0; 614} 615 616static int recv_verify_packet_tcp(void *th, int len) 617{ 618 struct tcphdr *tcph = th; 619 620 if (len < sizeof(*tcph) || tcph->dest != htons(cfg_port_dst)) 621 return -1; 622 623 return recv_verify_csum(th, len, ntohs(tcph->source), tcph->check); 624} 625 626static int recv_verify_packet_udp_encap(void *th, int len) 627{ 628 struct udp_encap_hdr *eh = th; 629 630 if (len < sizeof(*eh) || eh->nexthdr != IPPROTO_TCP) 631 return -1; 632 633 return recv_verify_packet_tcp(eh + 1, len - sizeof(*eh)); 634} 635 636static int recv_verify_packet_udp(void *th, int len) 637{ 638 struct udphdr *udph = th; 639 640 if (len < sizeof(*udph)) 641 return -1; 642 643 if (udph->dest != htons(cfg_port_dst)) 644 return -1; 645 646 if (udph->source == htons(cfg_port_src_encap)) 647 return recv_verify_packet_udp_encap(udph + 1, 648 len - sizeof(*udph)); 649 650 return recv_verify_csum(th, len, ntohs(udph->source), udph->check); 651} 652 653static int recv_verify_packet_ipv4(void *nh, int len) 654{ 655 struct iphdr *iph = nh; 656 uint16_t proto = cfg_encap ? IPPROTO_UDP : cfg_proto; 657 658 if (len < sizeof(*iph) || iph->protocol != proto) 659 return -1; 660 661 iph_addr_p = &iph->saddr; 662 if (proto == IPPROTO_TCP) 663 return recv_verify_packet_tcp(iph + 1, len - sizeof(*iph)); 664 else 665 return recv_verify_packet_udp(iph + 1, len - sizeof(*iph)); 666} 667 668static int recv_verify_packet_ipv6(void *nh, int len) 669{ 670 struct ipv6hdr *ip6h = nh; 671 uint16_t proto = cfg_encap ? IPPROTO_UDP : cfg_proto; 672 673 if (len < sizeof(*ip6h) || ip6h->nexthdr != proto) 674 return -1; 675 676 iph_addr_p = &ip6h->saddr; 677 678 if (proto == IPPROTO_TCP) 679 return recv_verify_packet_tcp(ip6h + 1, len - sizeof(*ip6h)); 680 else 681 return recv_verify_packet_udp(ip6h + 1, len - sizeof(*ip6h)); 682} 683 684/* return whether auxdata includes TP_STATUS_CSUM_VALID */ 685static uint32_t recv_get_packet_csum_status(struct msghdr *msg) 686{ 687 struct tpacket_auxdata *aux = NULL; 688 struct cmsghdr *cm; 689 690 if (msg->msg_flags & MSG_CTRUNC) 691 error(1, 0, "cmsg: truncated"); 692 693 for (cm = CMSG_FIRSTHDR(msg); cm; cm = CMSG_NXTHDR(msg, cm)) { 694 if (cm->cmsg_level != SOL_PACKET || 695 cm->cmsg_type != PACKET_AUXDATA) 696 error(1, 0, "cmsg: level=%d type=%d\n", 697 cm->cmsg_level, cm->cmsg_type); 698 699 if (cm->cmsg_len != CMSG_LEN(sizeof(struct tpacket_auxdata))) 700 error(1, 0, "cmsg: len=%lu expected=%lu", 701 cm->cmsg_len, CMSG_LEN(sizeof(struct tpacket_auxdata))); 702 703 aux = (void *)CMSG_DATA(cm); 704 } 705 706 if (!aux) 707 error(1, 0, "cmsg: no auxdata"); 708 709 return aux->tp_status; 710} 711 712static int recv_packet(int fd) 713{ 714 static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN]; 715 unsigned long total = 0, bad_csums = 0, bad_validations = 0; 716 char ctrl[CMSG_SPACE(sizeof(struct tpacket_auxdata))]; 717 struct pkt *buf = (void *)_buf; 718 struct msghdr msg = {0}; 719 uint32_t tp_status; 720 struct iovec iov; 721 int len, ret; 722 723 iov.iov_base = _buf; 724 iov.iov_len = sizeof(_buf); 725 726 msg.msg_iov = &iov; 727 msg.msg_iovlen = 1; 728 729 msg.msg_control = ctrl; 730 msg.msg_controllen = sizeof(ctrl); 731 732 while (1) { 733 msg.msg_flags = 0; 734 735 len = recvmsg(fd, &msg, MSG_DONTWAIT); 736 if (len == -1 && errno == EAGAIN) 737 break; 738 if (len == -1) 739 error(1, errno, "recv p"); 740 741 tp_status = recv_get_packet_csum_status(&msg); 742 743 /* GRO might coalesce randomized packets. Such GSO packets are 744 * then reinitialized for csum offload (CHECKSUM_PARTIAL), with 745 * a pseudo csum. Do not try to validate these checksums. 746 */ 747 if (tp_status & TP_STATUS_CSUMNOTREADY) { 748 fprintf(stderr, "cmsg: GSO packet has partial csum: skip\n"); 749 continue; 750 } 751 752 if (cfg_family == PF_INET6) 753 ret = recv_verify_packet_ipv6(buf, len); 754 else 755 ret = recv_verify_packet_ipv4(buf, len); 756 757 if (ret == -1 /* skip: non-matching */) 758 continue; 759 760 total++; 761 if (ret == 1) 762 bad_csums++; 763 764 /* Fail if kernel returns valid for known bad csum. 765 * Do not fail if kernel does not validate a good csum: 766 * Absence of validation does not imply invalid. 767 */ 768 if (tp_status & TP_STATUS_CSUM_VALID && cfg_bad_csum) { 769 fprintf(stderr, "cmsg: expected bad csum, pf_packet returns valid\n"); 770 bad_validations++; 771 } 772 } 773 774 if (bad_csums || bad_validations) 775 error(1, 0, "rx: errors at pf_packet: total=%lu bad_csums=%lu bad_valids=%lu\n", 776 total, bad_csums, bad_validations); 777 778 return total; 779} 780 781static void parse_args(int argc, char *const argv[]) 782{ 783 const char *daddr = NULL, *saddr = NULL; 784 int c; 785 786 while ((c = getopt(argc, argv, "46d:D:eEi:l:L:n:r:PRs:S:tTuUzZ")) != -1) { 787 switch (c) { 788 case '4': 789 cfg_family = PF_INET; 790 break; 791 case '6': 792 cfg_family = PF_INET6; 793 break; 794 case 'd': 795 cfg_mac_dst = optarg; 796 break; 797 case 'D': 798 daddr = optarg; 799 break; 800 case 'e': 801 cfg_encap = true; 802 break; 803 case 'E': 804 cfg_bad_csum = true; 805 break; 806 case 'i': 807 cfg_ifname = optarg; 808 break; 809 case 'l': 810 cfg_payload_len = strtol(optarg, NULL, 0); 811 break; 812 case 'L': 813 cfg_timeout_ms = strtol(optarg, NULL, 0) * 1000; 814 break; 815 case 'n': 816 cfg_num_pkt = strtol(optarg, NULL, 0); 817 break; 818 case 'r': 819 cfg_random_seed = strtol(optarg, NULL, 0); 820 break; 821 case 'P': 822 cfg_send_pfpacket = true; 823 break; 824 case 'R': 825 /* only Rx: used with two machine tests */ 826 cfg_do_tx = false; 827 break; 828 case 's': 829 cfg_mac_src = optarg; 830 break; 831 case 'S': 832 saddr = optarg; 833 break; 834 case 't': 835 cfg_proto = IPPROTO_TCP; 836 break; 837 case 'T': 838 /* only Tx: used with two machine tests */ 839 cfg_do_rx = false; 840 break; 841 case 'u': 842 cfg_proto = IPPROTO_UDP; 843 break; 844 case 'U': 845 /* send using real udp socket, 846 * to exercise tx checksum offload 847 */ 848 cfg_send_udp = true; 849 break; 850 case 'z': 851 cfg_zero_disable = true; 852 break; 853 case 'Z': 854 cfg_zero_sum = true; 855 break; 856 default: 857 error(1, 0, "unknown arg %c", c); 858 } 859 } 860 861 if (!daddr || !saddr) 862 error(1, 0, "Must pass -D <daddr> and -S <saddr>"); 863 864 if (cfg_do_tx && cfg_send_pfpacket && (!cfg_mac_src || !cfg_mac_dst)) 865 error(1, 0, "Transmit with pf_packet requires mac addresses"); 866 867 if (cfg_payload_len > MAX_PAYLOAD_LEN) 868 error(1, 0, "Payload length exceeds max"); 869 870 if (cfg_proto != IPPROTO_UDP && (cfg_zero_sum || cfg_zero_disable)) 871 error(1, 0, "Only UDP supports zero csum"); 872 873 if (cfg_zero_sum && !cfg_send_udp) 874 error(1, 0, "Zero checksum conversion requires -U for tx csum offload"); 875 if (cfg_zero_sum && cfg_bad_csum) 876 error(1, 0, "Cannot combine zero checksum conversion and invalid checksum"); 877 if (cfg_zero_sum && cfg_random_seed) 878 error(1, 0, "Cannot combine zero checksum conversion with randomization"); 879 880 if (cfg_family == PF_INET6) { 881 cfg_saddr6.sin6_port = htons(cfg_port_src); 882 cfg_daddr6.sin6_port = htons(cfg_port_dst); 883 884 if (inet_pton(cfg_family, daddr, &cfg_daddr6.sin6_addr) != 1) 885 error(1, errno, "Cannot parse ipv6 -D"); 886 if (inet_pton(cfg_family, saddr, &cfg_saddr6.sin6_addr) != 1) 887 error(1, errno, "Cannot parse ipv6 -S"); 888 } else { 889 cfg_saddr4.sin_port = htons(cfg_port_src); 890 cfg_daddr4.sin_port = htons(cfg_port_dst); 891 892 if (inet_pton(cfg_family, daddr, &cfg_daddr4.sin_addr) != 1) 893 error(1, errno, "Cannot parse ipv4 -D"); 894 if (inet_pton(cfg_family, saddr, &cfg_saddr4.sin_addr) != 1) 895 error(1, errno, "Cannot parse ipv4 -S"); 896 } 897 898 if (cfg_do_tx && cfg_random_seed) { 899 /* special case: time-based seed */ 900 if (cfg_random_seed == 1) 901 cfg_random_seed = (unsigned int)gettimeofday_ms(); 902 srand(cfg_random_seed); 903 fprintf(stderr, "randomization seed: %u\n", cfg_random_seed); 904 } 905} 906 907static void do_tx(void) 908{ 909 static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN]; 910 char *buf; 911 int fd, len, i; 912 913 buf = build_packet(_buf, sizeof(_buf), &len); 914 915 if (cfg_send_pfpacket) 916 fd = open_packet(); 917 else if (cfg_send_udp) 918 fd = open_inet(SOCK_DGRAM, 0); 919 else 920 fd = open_inet(SOCK_RAW, IPPROTO_RAW); 921 922 for (i = 0; i < cfg_num_pkt; i++) { 923 if (cfg_send_pfpacket) 924 send_packet(fd, buf, len); 925 else 926 send_inet(fd, buf, len); 927 928 /* randomize each packet individually to increase coverage */ 929 if (cfg_random_seed) { 930 cfg_payload_len = rand() % MAX_PAYLOAD_LEN; 931 buf = build_packet(_buf, sizeof(_buf), &len); 932 } 933 } 934 935 if (close(fd)) 936 error(1, errno, "close tx"); 937} 938 939static void do_rx(int fdp, int fdr) 940{ 941 unsigned long count_udp = 0, count_pkt = 0; 942 long tleft, tstop; 943 struct pollfd pfd; 944 945 tstop = gettimeofday_ms() + cfg_timeout_ms; 946 tleft = cfg_timeout_ms; 947 948 do { 949 pfd.events = POLLIN; 950 pfd.fd = fdp; 951 if (poll(&pfd, 1, tleft) == -1) 952 error(1, errno, "poll"); 953 954 if (pfd.revents & POLLIN) 955 count_pkt += recv_packet(fdp); 956 957 if (cfg_proto == IPPROTO_UDP) 958 count_udp += recv_udp(fdr); 959 960 tleft = tstop - gettimeofday_ms(); 961 } while (tleft > 0); 962 963 if (close(fdr)) 964 error(1, errno, "close r"); 965 if (close(fdp)) 966 error(1, errno, "close p"); 967 968 if (count_pkt < cfg_num_pkt) 969 error(1, 0, "rx: missing packets at pf_packet: %lu < %u", 970 count_pkt, cfg_num_pkt); 971 972 if (cfg_proto == IPPROTO_UDP) { 973 if (cfg_bad_csum && count_udp) 974 error(1, 0, "rx: unexpected packets at udp"); 975 if (!cfg_bad_csum && !count_udp) 976 error(1, 0, "rx: missing packets at udp"); 977 } 978} 979 980int main(int argc, char *const argv[]) 981{ 982 int fdp = -1, fdr = -1; /* -1 to silence -Wmaybe-uninitialized */ 983 984 parse_args(argc, argv); 985 986 /* open receive sockets before transmitting */ 987 if (cfg_do_rx) { 988 fdp = recv_prepare_packet(); 989 fdr = recv_prepare_udp(); 990 } 991 992 if (cfg_do_tx) 993 do_tx(); 994 995 if (cfg_do_rx) 996 do_rx(fdp, fdr); 997 998 fprintf(stderr, "OK\n"); 999 return 0; 1000} 1001