tools/testing/selftests/net/lib/csum.c

   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
  96 static bool cfg_bad_csum;
  97 static int cfg_family = PF_INET6;
  98 static int cfg_num_pkt = 4;
  99 static bool cfg_do_rx = true;
 100 static bool cfg_do_tx = true;
 101 static bool cfg_encap;
 102 static char *cfg_ifname = "eth0";
 103 static char *cfg_mac_dst;
 104 static char *cfg_mac_src;
 105 static int cfg_proto = IPPROTO_UDP;
 106 static int cfg_payload_char = 'a';
 107 static int cfg_payload_len = 100;
 108 static uint16_t cfg_port_dst = 34000;
 109 static uint16_t cfg_port_src = 33000;
 110 static uint16_t cfg_port_src_encap = 33001;
 111 static unsigned int cfg_random_seed;
 112 static int cfg_rcvbuf = 1 << 22;        /* be able to queue large cfg_num_pkt */
 113 static bool cfg_send_pfpacket;
 114 static bool cfg_send_udp;
 115 static int cfg_timeout_ms = 2000;
 116 static bool cfg_zero_disable; /* skip checksum: set to zero (udp only) */
 117 static bool cfg_zero_sum;     /* create packet that adds up to zero */
 118
 119 static struct sockaddr_in cfg_daddr4 = {.sin_family = AF_INET};
 120 static struct sockaddr_in cfg_saddr4 = {.sin_family = AF_INET};
 121 static struct sockaddr_in6 cfg_daddr6 = {.sin6_family = AF_INET6};
 122 static 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 */
 129 struct 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 */
 135 static void *iph_addr_p;
 136
 137 static 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
 145 static 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
 159 static 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
 169 static 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
 187 static 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
 207 static 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
 225 static 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
 256 static 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
 274 static 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
 295 static 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
 345 static 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
 374 static 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
 388 static 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
 399 static void eth_str_to_addr(const char *str, unsigned char *eth)
 400 {
 401         if (sscanf(str, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
 402                    &eth[0], &eth[1], &eth[2], &eth[3], &eth[4], &eth[5]) != 6)
 403                 error(1, 0, "cannot parse mac addr %s", str);
 404 }
 405
 406 static 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 = &eth;
 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
 467 static 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  */
 495 static 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
 515 static 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
 527 static 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
 546 static 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
 571 static 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
 590 static 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
 616 static 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
 626 static 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
 636 static 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
 653 static 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         uint16_t ip_len;
 658
 659         if (len < sizeof(*iph) || iph->protocol != proto)
 660                 return -1;
 661
 662         ip_len = ntohs(iph->tot_len);
 663         if (ip_len > len || ip_len < sizeof(*iph))
 664                 return -1;
 665
 666         len = ip_len;
 667         iph_addr_p = &iph->saddr;
 668         if (proto == IPPROTO_TCP)
 669                 return recv_verify_packet_tcp(iph + 1, len - sizeof(*iph));
 670         else
 671                 return recv_verify_packet_udp(iph + 1, len - sizeof(*iph));
 672 }
 673
 674 static int recv_verify_packet_ipv6(void *nh, int len)
 675 {
 676         struct ipv6hdr *ip6h = nh;
 677         uint16_t proto = cfg_encap ? IPPROTO_UDP : cfg_proto;
 678         uint16_t payload_len;
 679
 680         if (len < sizeof(*ip6h) || ip6h->nexthdr != proto)
 681                 return -1;
 682
 683         payload_len = ntohs(ip6h->payload_len);
 684         if (payload_len > len - sizeof(*ip6h))
 685                 return -1;
 686
 687         iph_addr_p = &ip6h->saddr;
 688         if (proto == IPPROTO_TCP)
 689                 return recv_verify_packet_tcp(ip6h + 1, payload_len);
 690         else
 691                 return recv_verify_packet_udp(ip6h + 1, payload_len);
 692 }
 693
 694 /* return whether auxdata includes TP_STATUS_CSUM_VALID */
 695 static uint32_t recv_get_packet_csum_status(struct msghdr *msg)
 696 {
 697         struct tpacket_auxdata *aux = NULL;
 698         struct cmsghdr *cm;
 699
 700         if (msg->msg_flags & MSG_CTRUNC)
 701                 error(1, 0, "cmsg: truncated");
 702
 703         for (cm = CMSG_FIRSTHDR(msg); cm; cm = CMSG_NXTHDR(msg, cm)) {
 704                 if (cm->cmsg_level != SOL_PACKET ||
 705                     cm->cmsg_type != PACKET_AUXDATA)
 706                         error(1, 0, "cmsg: level=%d type=%d\n",
 707                               cm->cmsg_level, cm->cmsg_type);
 708
 709                 if (cm->cmsg_len != CMSG_LEN(sizeof(struct tpacket_auxdata)))
 710                         error(1, 0, "cmsg: len=%lu expected=%lu",
 711                               cm->cmsg_len, CMSG_LEN(sizeof(struct tpacket_auxdata)));
 712
 713                 aux = (void *)CMSG_DATA(cm);
 714         }
 715
 716         if (!aux)
 717                 error(1, 0, "cmsg: no auxdata");
 718
 719         return aux->tp_status;
 720 }
 721
 722 static int recv_packet(int fd)
 723 {
 724         static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN];
 725         unsigned long total = 0, bad_csums = 0, bad_validations = 0;
 726         char ctrl[CMSG_SPACE(sizeof(struct tpacket_auxdata))];
 727         struct pkt *buf = (void *)_buf;
 728         struct msghdr msg = {0};
 729         uint32_t tp_status;
 730         struct iovec iov;
 731         int len, ret;
 732
 733         iov.iov_base = _buf;
 734         iov.iov_len = sizeof(_buf);
 735
 736         msg.msg_iov = &iov;
 737         msg.msg_iovlen = 1;
 738
 739         msg.msg_control = ctrl;
 740         msg.msg_controllen = sizeof(ctrl);
 741
 742         while (1) {
 743                 msg.msg_flags = 0;
 744
 745                 len = recvmsg(fd, &msg, MSG_DONTWAIT);
 746                 if (len == -1 && errno == EAGAIN)
 747                         break;
 748                 if (len == -1)
 749                         error(1, errno, "recv p");
 750
 751                 tp_status = recv_get_packet_csum_status(&msg);
 752
 753                 /* GRO might coalesce randomized packets. Such GSO packets are
 754                  * then reinitialized for csum offload (CHECKSUM_PARTIAL), with
 755                  * a pseudo csum. Do not try to validate these checksums.
 756                  */
 757                 if (tp_status & TP_STATUS_CSUMNOTREADY) {
 758                         fprintf(stderr, "cmsg: GSO packet has partial csum: skip\n");
 759                         continue;
 760                 }
 761
 762                 if (cfg_family == PF_INET6)
 763                         ret = recv_verify_packet_ipv6(buf, len);
 764                 else
 765                         ret = recv_verify_packet_ipv4(buf, len);
 766
 767                 if (ret == -1 /* skip: non-matching */)
 768                         continue;
 769
 770                 total++;
 771                 if (ret == 1)
 772                         bad_csums++;
 773
 774                 /* Fail if kernel returns valid for known bad csum.
 775                  * Do not fail if kernel does not validate a good csum:
 776                  * Absence of validation does not imply invalid.
 777                  */
 778                 if (tp_status & TP_STATUS_CSUM_VALID && cfg_bad_csum) {
 779                         fprintf(stderr, "cmsg: expected bad csum, pf_packet returns valid\n");
 780                         bad_validations++;
 781                 }
 782         }
 783
 784         if (bad_csums || bad_validations)
 785                 error(1, 0, "rx: errors at pf_packet: total=%lu bad_csums=%lu bad_valids=%lu\n",
 786                       total, bad_csums, bad_validations);
 787
 788         return total;
 789 }
 790
 791 static void parse_args(int argc, char *const argv[])
 792 {
 793         const char *daddr = NULL, *saddr = NULL;
 794         int c;
 795
 796         while ((c = getopt(argc, argv, "46d:D:eEi:l:L:n:r:PRs:S:tTuUzZ")) != -1) {
 797                 switch (c) {
 798                 case '4':
 799                         cfg_family = PF_INET;
 800                         break;
 801                 case '6':
 802                         cfg_family = PF_INET6;
 803                         break;
 804                 case 'd':
 805                         cfg_mac_dst = optarg;
 806                         break;
 807                 case 'D':
 808                         daddr = optarg;
 809                         break;
 810                 case 'e':
 811                         cfg_encap = true;
 812                         break;
 813                 case 'E':
 814                         cfg_bad_csum = true;
 815                         break;
 816                 case 'i':
 817                         cfg_ifname = optarg;
 818                         break;
 819                 case 'l':
 820                         cfg_payload_len = strtol(optarg, NULL, 0);
 821                         break;
 822                 case 'L':
 823                         cfg_timeout_ms = strtol(optarg, NULL, 0) * 1000;
 824                         break;
 825                 case 'n':
 826                         cfg_num_pkt = strtol(optarg, NULL, 0);
 827                         break;
 828                 case 'r':
 829                         cfg_random_seed = strtol(optarg, NULL, 0);
 830                         break;
 831                 case 'P':
 832                         cfg_send_pfpacket = true;
 833                         break;
 834                 case 'R':
 835                         /* only Rx: used with two machine tests */
 836                         cfg_do_tx = false;
 837                         break;
 838                 case 's':
 839                         cfg_mac_src = optarg;
 840                         break;
 841                 case 'S':
 842                         saddr = optarg;
 843                         break;
 844                 case 't':
 845                         cfg_proto = IPPROTO_TCP;
 846                         break;
 847                 case 'T':
 848                         /* only Tx: used with two machine tests */
 849                         cfg_do_rx = false;
 850                         break;
 851                 case 'u':
 852                         cfg_proto = IPPROTO_UDP;
 853                         break;
 854                 case 'U':
 855                         /* send using real udp socket,
 856                          * to exercise tx checksum offload
 857                          */
 858                         cfg_send_udp = true;
 859                         break;
 860                 case 'z':
 861                         cfg_zero_disable = true;
 862                         break;
 863                 case 'Z':
 864                         cfg_zero_sum = true;
 865                         break;
 866                 default:
 867                         error(1, 0, "unknown arg %c", c);
 868                 }
 869         }
 870
 871         if (!daddr || !saddr)
 872                 error(1, 0, "Must pass -D <daddr> and -S <saddr>");
 873
 874         if (cfg_do_tx && cfg_send_pfpacket && (!cfg_mac_src || !cfg_mac_dst))
 875                 error(1, 0, "Transmit with pf_packet requires mac addresses");
 876
 877         if (cfg_payload_len > MAX_PAYLOAD_LEN)
 878                 error(1, 0, "Payload length exceeds max");
 879
 880         if (cfg_proto != IPPROTO_UDP && (cfg_zero_sum || cfg_zero_disable))
 881                 error(1, 0, "Only UDP supports zero csum");
 882
 883         if (cfg_zero_sum && !cfg_send_udp)
 884                 error(1, 0, "Zero checksum conversion requires -U for tx csum offload");
 885         if (cfg_zero_sum && cfg_bad_csum)
 886                 error(1, 0, "Cannot combine zero checksum conversion and invalid checksum");
 887         if (cfg_zero_sum && cfg_random_seed)
 888                 error(1, 0, "Cannot combine zero checksum conversion with randomization");
 889
 890         if (cfg_family == PF_INET6) {
 891                 cfg_saddr6.sin6_port = htons(cfg_port_src);
 892                 cfg_daddr6.sin6_port = htons(cfg_port_dst);
 893
 894                 if (inet_pton(cfg_family, daddr, &cfg_daddr6.sin6_addr) != 1)
 895                         error(1, errno, "Cannot parse ipv6 -D");
 896                 if (inet_pton(cfg_family, saddr, &cfg_saddr6.sin6_addr) != 1)
 897                         error(1, errno, "Cannot parse ipv6 -S");
 898         } else {
 899                 cfg_saddr4.sin_port = htons(cfg_port_src);
 900                 cfg_daddr4.sin_port = htons(cfg_port_dst);
 901
 902                 if (inet_pton(cfg_family, daddr, &cfg_daddr4.sin_addr) != 1)
 903                         error(1, errno, "Cannot parse ipv4 -D");
 904                 if (inet_pton(cfg_family, saddr, &cfg_saddr4.sin_addr) != 1)
 905                         error(1, errno, "Cannot parse ipv4 -S");
 906         }
 907
 908         if (cfg_do_tx && cfg_random_seed) {
 909                 /* special case: time-based seed */
 910                 if (cfg_random_seed == 1)
 911                         cfg_random_seed = (unsigned int)gettimeofday_ms();
 912                 srand(cfg_random_seed);
 913                 fprintf(stderr, "randomization seed: %u\n", cfg_random_seed);
 914         }
 915 }
 916
 917 static void do_tx(void)
 918 {
 919         static char _buf[MAX_HEADER_LEN + MAX_PAYLOAD_LEN];
 920         char *buf;
 921         int fd, len, i;
 922
 923         buf = build_packet(_buf, sizeof(_buf), &len);
 924
 925         if (cfg_send_pfpacket)
 926                 fd = open_packet();
 927         else if (cfg_send_udp)
 928                 fd = open_inet(SOCK_DGRAM, 0);
 929         else
 930                 fd = open_inet(SOCK_RAW, IPPROTO_RAW);
 931
 932         for (i = 0; i < cfg_num_pkt; i++) {
 933                 if (cfg_send_pfpacket)
 934                         send_packet(fd, buf, len);
 935                 else
 936                         send_inet(fd, buf, len);
 937
 938                 /* randomize each packet individually to increase coverage */
 939                 if (cfg_random_seed) {
 940                         cfg_payload_len = rand() % MAX_PAYLOAD_LEN;
 941                         buf = build_packet(_buf, sizeof(_buf), &len);
 942                 }
 943         }
 944
 945         if (close(fd))
 946                 error(1, errno, "close tx");
 947 }
 948
 949 static void do_rx(int fdp, int fdr)
 950 {
 951         unsigned long count_udp = 0, count_pkt = 0;
 952         long tleft, tstop;
 953         struct pollfd pfd;
 954
 955         tstop = gettimeofday_ms() + cfg_timeout_ms;
 956         tleft = cfg_timeout_ms;
 957
 958         do {
 959                 pfd.events = POLLIN;
 960                 pfd.fd = fdp;
 961                 if (poll(&pfd, 1, tleft) == -1)
 962                         error(1, errno, "poll");
 963
 964                 if (pfd.revents & POLLIN)
 965                         count_pkt += recv_packet(fdp);
 966
 967                 if (cfg_proto == IPPROTO_UDP)
 968                         count_udp += recv_udp(fdr);
 969
 970                 tleft = tstop - gettimeofday_ms();
 971         } while (tleft > 0);
 972
 973         if (close(fdr))
 974                 error(1, errno, "close r");
 975         if (close(fdp))
 976                 error(1, errno, "close p");
 977
 978         if (count_pkt < cfg_num_pkt)
 979                 error(1, 0, "rx: missing packets at pf_packet: %lu < %u",
 980                       count_pkt, cfg_num_pkt);
 981
 982         if (cfg_proto == IPPROTO_UDP) {
 983                 if (cfg_bad_csum && count_udp)
 984                         error(1, 0, "rx: unexpected packets at udp");
 985                 if (!cfg_bad_csum && !count_udp)
 986                         error(1, 0, "rx: missing packets at udp");
 987         }
 988 }
 989
 990 int main(int argc, char *const argv[])
 991 {
 992         int fdp = -1, fdr = -1;         /* -1 to silence -Wmaybe-uninitialized */
 993
 994         parse_args(argc, argv);
 995
 996         /* open receive sockets before transmitting */
 997         if (cfg_do_rx) {
 998                 fdp = recv_prepare_packet();
 999                 fdr = recv_prepare_udp();
1000         }
1001
1002         if (cfg_do_tx)
1003                 do_tx();
1004
1005         if (cfg_do_rx)
1006                 do_rx(fdp, fdr);
1007
1008         fprintf(stderr, "OK\n");
1009         return 0;
1010 }