hw/net/net_rx_pkt.c

   1 /*
   2  * QEMU RX packets abstractions
   3  *
   4  * Copyright (c) 2012 Ravello Systems LTD (http://ravellosystems.com)
   5  *
   6  * Developed by Daynix Computing LTD (http://www.daynix.com)
   7  *
   8  * Authors:
   9  * Dmitry Fleytman <dmitry@daynix.com>
  10  * Tamir Shomer <tamirs@daynix.com>
  11  * Yan Vugenfirer <yan@daynix.com>
  12  *
  13  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  14  * See the COPYING file in the top-level directory.
  15  *
  16  */
  17
  18 #include "qemu/osdep.h"
  19 #include "trace.h"
  20 #include "net_rx_pkt.h"
  21 #include "net/checksum.h"
  22 #include "net/tap.h"
  23
  24 struct NetRxPkt {
  25     struct virtio_net_hdr virt_hdr;
  26     uint8_t ehdr_buf[sizeof(struct eth_header)];
  27     struct iovec *vec;
  28     uint16_t vec_len_total;
  29     uint16_t vec_len;
  30     uint32_t tot_len;
  31     uint16_t tci;
  32     bool vlan_stripped;
  33     bool has_virt_hdr;
  34     eth_pkt_types_e packet_type;
  35
  36     /* Analysis results */
  37     bool isip4;
  38     bool isip6;
  39     bool isudp;
  40     bool istcp;
  41
  42     size_t l3hdr_off;
  43     size_t l4hdr_off;
  44     size_t l5hdr_off;
  45
  46     eth_ip6_hdr_info ip6hdr_info;
  47     eth_ip4_hdr_info ip4hdr_info;
  48     eth_l4_hdr_info  l4hdr_info;
  49 };
  50
  51 void net_rx_pkt_init(struct NetRxPkt **pkt, bool has_virt_hdr)
  52 {
  53     struct NetRxPkt *p = g_malloc0(sizeof *p);
  54     p->has_virt_hdr = has_virt_hdr;
  55     p->vec = NULL;
  56     p->vec_len_total = 0;
  57     *pkt = p;
  58 }
  59
  60 void net_rx_pkt_uninit(struct NetRxPkt *pkt)
  61 {
  62     if (pkt->vec_len_total != 0) {
  63         g_free(pkt->vec);
  64     }
  65
  66     g_free(pkt);
  67 }
  68
  69 struct virtio_net_hdr *net_rx_pkt_get_vhdr(struct NetRxPkt *pkt)
  70 {
  71     assert(pkt);
  72     return &pkt->virt_hdr;
  73 }
  74
  75 static inline void
  76 net_rx_pkt_iovec_realloc(struct NetRxPkt *pkt,
  77                             int new_iov_len)
  78 {
  79     if (pkt->vec_len_total < new_iov_len) {
  80         g_free(pkt->vec);
  81         pkt->vec = g_malloc(sizeof(*pkt->vec) * new_iov_len);
  82         pkt->vec_len_total = new_iov_len;
  83     }
  84 }
  85
  86 static void
  87 net_rx_pkt_pull_data(struct NetRxPkt *pkt,
  88                         const struct iovec *iov, int iovcnt,
  89                         size_t ploff)
  90 {
  91     if (pkt->vlan_stripped) {
  92         net_rx_pkt_iovec_realloc(pkt, iovcnt + 1);
  93
  94         pkt->vec[0].iov_base = pkt->ehdr_buf;
  95         pkt->vec[0].iov_len = sizeof(pkt->ehdr_buf);
  96
  97         pkt->tot_len =
  98             iov_size(iov, iovcnt) - ploff + sizeof(struct eth_header);
  99
 100         pkt->vec_len = iov_copy(pkt->vec + 1, pkt->vec_len_total - 1,
 101                                 iov, iovcnt, ploff, pkt->tot_len);
 102     } else {
 103         net_rx_pkt_iovec_realloc(pkt, iovcnt);
 104
 105         pkt->tot_len = iov_size(iov, iovcnt) - ploff;
 106         pkt->vec_len = iov_copy(pkt->vec, pkt->vec_len_total,
 107                                 iov, iovcnt, ploff, pkt->tot_len);
 108     }
 109
 110     eth_get_protocols(pkt->vec, pkt->vec_len, &pkt->isip4, &pkt->isip6,
 111                       &pkt->isudp, &pkt->istcp,
 112                       &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
 113                       &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
 114
 115     trace_net_rx_pkt_parsed(pkt->isip4, pkt->isip6, pkt->isudp, pkt->istcp,
 116                             pkt->l3hdr_off, pkt->l4hdr_off, pkt->l5hdr_off);
 117 }
 118
 119 void net_rx_pkt_attach_iovec(struct NetRxPkt *pkt,
 120                                 const struct iovec *iov, int iovcnt,
 121                                 size_t iovoff, bool strip_vlan)
 122 {
 123     uint16_t tci = 0;
 124     uint16_t ploff = iovoff;
 125     assert(pkt);
 126     pkt->vlan_stripped = false;
 127
 128     if (strip_vlan) {
 129         pkt->vlan_stripped = eth_strip_vlan(iov, iovcnt, iovoff, pkt->ehdr_buf,
 130                                             &ploff, &tci);
 131     }
 132
 133     pkt->tci = tci;
 134
 135     net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 136 }
 137
 138 void net_rx_pkt_attach_iovec_ex(struct NetRxPkt *pkt,
 139                                 const struct iovec *iov, int iovcnt,
 140                                 size_t iovoff, bool strip_vlan,
 141                                 uint16_t vet)
 142 {
 143     uint16_t tci = 0;
 144     uint16_t ploff = iovoff;
 145     assert(pkt);
 146     pkt->vlan_stripped = false;
 147
 148     if (strip_vlan) {
 149         pkt->vlan_stripped = eth_strip_vlan_ex(iov, iovcnt, iovoff, vet,
 150                                                pkt->ehdr_buf,
 151                                                &ploff, &tci);
 152     }
 153
 154     pkt->tci = tci;
 155
 156     net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 157 }
 158
 159 void net_rx_pkt_dump(struct NetRxPkt *pkt)
 160 {
 161 #ifdef NET_RX_PKT_DEBUG
 162     NetRxPkt *pkt = (NetRxPkt *)pkt;
 163     assert(pkt);
 164
 165     printf("RX PKT: tot_len: %d, vlan_stripped: %d, vlan_tag: %d\n",
 166               pkt->tot_len, pkt->vlan_stripped, pkt->tci);
 167 #endif
 168 }
 169
 170 void net_rx_pkt_set_packet_type(struct NetRxPkt *pkt,
 171     eth_pkt_types_e packet_type)
 172 {
 173     assert(pkt);
 174
 175     pkt->packet_type = packet_type;
 176
 177 }
 178
 179 eth_pkt_types_e net_rx_pkt_get_packet_type(struct NetRxPkt *pkt)
 180 {
 181     assert(pkt);
 182
 183     return pkt->packet_type;
 184 }
 185
 186 size_t net_rx_pkt_get_total_len(struct NetRxPkt *pkt)
 187 {
 188     assert(pkt);
 189
 190     return pkt->tot_len;
 191 }
 192
 193 void net_rx_pkt_set_protocols(struct NetRxPkt *pkt, const void *data,
 194                               size_t len)
 195 {
 196     const struct iovec iov = {
 197         .iov_base = (void *)data,
 198         .iov_len = len
 199     };
 200
 201     assert(pkt);
 202
 203     eth_get_protocols(&iov, 1, &pkt->isip4, &pkt->isip6,
 204                       &pkt->isudp, &pkt->istcp,
 205                       &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
 206                       &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
 207 }
 208
 209 void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
 210                               bool *isip4, bool *isip6,
 211                               bool *isudp, bool *istcp)
 212 {
 213     assert(pkt);
 214
 215     *isip4 = pkt->isip4;
 216     *isip6 = pkt->isip6;
 217     *isudp = pkt->isudp;
 218     *istcp = pkt->istcp;
 219 }
 220
 221 size_t net_rx_pkt_get_l3_hdr_offset(struct NetRxPkt *pkt)
 222 {
 223     assert(pkt);
 224     return pkt->l3hdr_off;
 225 }
 226
 227 size_t net_rx_pkt_get_l4_hdr_offset(struct NetRxPkt *pkt)
 228 {
 229     assert(pkt);
 230     return pkt->l4hdr_off;
 231 }
 232
 233 size_t net_rx_pkt_get_l5_hdr_offset(struct NetRxPkt *pkt)
 234 {
 235     assert(pkt);
 236     return pkt->l5hdr_off;
 237 }
 238
 239 eth_ip6_hdr_info *net_rx_pkt_get_ip6_info(struct NetRxPkt *pkt)
 240 {
 241     return &pkt->ip6hdr_info;
 242 }
 243
 244 eth_ip4_hdr_info *net_rx_pkt_get_ip4_info(struct NetRxPkt *pkt)
 245 {
 246     return &pkt->ip4hdr_info;
 247 }
 248
 249 eth_l4_hdr_info *net_rx_pkt_get_l4_info(struct NetRxPkt *pkt)
 250 {
 251     return &pkt->l4hdr_info;
 252 }
 253
 254 static inline void
 255 _net_rx_rss_add_chunk(uint8_t *rss_input, size_t *bytes_written,
 256                       void *ptr, size_t size)
 257 {
 258     memcpy(&rss_input[*bytes_written], ptr, size);
 259     trace_net_rx_pkt_rss_add_chunk(ptr, size, *bytes_written);
 260     *bytes_written += size;
 261 }
 262
 263 static inline void
 264 _net_rx_rss_prepare_ip4(uint8_t *rss_input,
 265                         struct NetRxPkt *pkt,
 266                         size_t *bytes_written)
 267 {
 268     struct ip_header *ip4_hdr = &pkt->ip4hdr_info.ip4_hdr;
 269
 270     _net_rx_rss_add_chunk(rss_input, bytes_written,
 271                           &ip4_hdr->ip_src, sizeof(uint32_t));
 272
 273     _net_rx_rss_add_chunk(rss_input, bytes_written,
 274                           &ip4_hdr->ip_dst, sizeof(uint32_t));
 275 }
 276
 277 static inline void
 278 _net_rx_rss_prepare_ip6(uint8_t *rss_input,
 279                         struct NetRxPkt *pkt,
 280                         bool ipv6ex, size_t *bytes_written)
 281 {
 282     eth_ip6_hdr_info *ip6info = &pkt->ip6hdr_info;
 283
 284     _net_rx_rss_add_chunk(rss_input, bytes_written,
 285            (ipv6ex && ip6info->rss_ex_src_valid) ? &ip6info->rss_ex_src
 286                                                  : &ip6info->ip6_hdr.ip6_src,
 287            sizeof(struct in6_address));
 288
 289     _net_rx_rss_add_chunk(rss_input, bytes_written,
 290            (ipv6ex && ip6info->rss_ex_dst_valid) ? &ip6info->rss_ex_dst
 291                                                  : &ip6info->ip6_hdr.ip6_dst,
 292            sizeof(struct in6_address));
 293 }
 294
 295 static inline void
 296 _net_rx_rss_prepare_tcp(uint8_t *rss_input,
 297                         struct NetRxPkt *pkt,
 298                         size_t *bytes_written)
 299 {
 300     struct tcp_header *tcphdr = &pkt->l4hdr_info.hdr.tcp;
 301
 302     _net_rx_rss_add_chunk(rss_input, bytes_written,
 303                           &tcphdr->th_sport, sizeof(uint16_t));
 304
 305     _net_rx_rss_add_chunk(rss_input, bytes_written,
 306                           &tcphdr->th_dport, sizeof(uint16_t));
 307 }
 308
 309 uint32_t
 310 net_rx_pkt_calc_rss_hash(struct NetRxPkt *pkt,
 311                          NetRxPktRssType type,
 312                          uint8_t *key)
 313 {
 314     uint8_t rss_input[36];
 315     size_t rss_length = 0;
 316     uint32_t rss_hash = 0;
 317     net_toeplitz_key key_data;
 318
 319     switch (type) {
 320     case NetPktRssIpV4:
 321         assert(pkt->isip4);
 322         trace_net_rx_pkt_rss_ip4();
 323         _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
 324         break;
 325     case NetPktRssIpV4Tcp:
 326         assert(pkt->isip4);
 327         assert(pkt->istcp);
 328         trace_net_rx_pkt_rss_ip4_tcp();
 329         _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
 330         _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
 331         break;
 332     case NetPktRssIpV6Tcp:
 333         assert(pkt->isip6);
 334         assert(pkt->istcp);
 335         trace_net_rx_pkt_rss_ip6_tcp();
 336         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
 337         _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
 338         break;
 339     case NetPktRssIpV6:
 340         assert(pkt->isip6);
 341         trace_net_rx_pkt_rss_ip6();
 342         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, false, &rss_length);
 343         break;
 344     case NetPktRssIpV6Ex:
 345         assert(pkt->isip6);
 346         trace_net_rx_pkt_rss_ip6_ex();
 347         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
 348         break;
 349     default:
 350         assert(false);
 351         break;
 352     }
 353
 354     net_toeplitz_key_init(&key_data, key);
 355     net_toeplitz_add(&rss_hash, rss_input, rss_length, &key_data);
 356
 357     trace_net_rx_pkt_rss_hash(rss_length, rss_hash);
 358
 359     return rss_hash;
 360 }
 361
 362 uint16_t net_rx_pkt_get_ip_id(struct NetRxPkt *pkt)
 363 {
 364     assert(pkt);
 365
 366     if (pkt->isip4) {
 367         return be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_id);
 368     }
 369
 370     return 0;
 371 }
 372
 373 bool net_rx_pkt_is_tcp_ack(struct NetRxPkt *pkt)
 374 {
 375     assert(pkt);
 376
 377     if (pkt->istcp) {
 378         return TCP_HEADER_FLAGS(&pkt->l4hdr_info.hdr.tcp) & TCP_FLAG_ACK;
 379     }
 380
 381     return false;
 382 }
 383
 384 bool net_rx_pkt_has_tcp_data(struct NetRxPkt *pkt)
 385 {
 386     assert(pkt);
 387
 388     if (pkt->istcp) {
 389         return pkt->l4hdr_info.has_tcp_data;
 390     }
 391
 392     return false;
 393 }
 394
 395 struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
 396 {
 397     assert(pkt);
 398
 399     return pkt->vec;
 400 }
 401
 402 uint16_t net_rx_pkt_get_iovec_len(struct NetRxPkt *pkt)
 403 {
 404     assert(pkt);
 405
 406     return pkt->vec_len;
 407 }
 408
 409 void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
 410                             struct virtio_net_hdr *vhdr)
 411 {
 412     assert(pkt);
 413
 414     memcpy(&pkt->virt_hdr, vhdr, sizeof pkt->virt_hdr);
 415 }
 416
 417 void net_rx_pkt_set_vhdr_iovec(struct NetRxPkt *pkt,
 418     const struct iovec *iov, int iovcnt)
 419 {
 420     assert(pkt);
 421
 422     iov_to_buf(iov, iovcnt, 0, &pkt->virt_hdr, sizeof pkt->virt_hdr);
 423 }
 424
 425 bool net_rx_pkt_is_vlan_stripped(struct NetRxPkt *pkt)
 426 {
 427     assert(pkt);
 428
 429     return pkt->vlan_stripped;
 430 }
 431
 432 bool net_rx_pkt_has_virt_hdr(struct NetRxPkt *pkt)
 433 {
 434     assert(pkt);
 435
 436     return pkt->has_virt_hdr;
 437 }
 438
 439 uint16_t net_rx_pkt_get_vlan_tag(struct NetRxPkt *pkt)
 440 {
 441     assert(pkt);
 442
 443     return pkt->tci;
 444 }
 445
 446 bool net_rx_pkt_validate_l3_csum(struct NetRxPkt *pkt, bool *csum_valid)
 447 {
 448     uint32_t cntr;
 449     uint16_t csum;
 450     uint32_t csl;
 451
 452     trace_net_rx_pkt_l3_csum_validate_entry();
 453
 454     if (!pkt->isip4) {
 455         trace_net_rx_pkt_l3_csum_validate_not_ip4();
 456         return false;
 457     }
 458
 459     csl = pkt->l4hdr_off - pkt->l3hdr_off;
 460
 461     cntr = net_checksum_add_iov(pkt->vec, pkt->vec_len,
 462                                 pkt->l3hdr_off,
 463                                 csl, 0);
 464
 465     csum = net_checksum_finish(cntr);
 466
 467     *csum_valid = (csum == 0);
 468
 469     trace_net_rx_pkt_l3_csum_validate_csum(pkt->l3hdr_off, csl,
 470                                            cntr, csum, *csum_valid);
 471
 472     return true;
 473 }
 474
 475 static uint16_t
 476 _net_rx_pkt_calc_l4_csum(struct NetRxPkt *pkt)
 477 {
 478     uint32_t cntr;
 479     uint16_t csum;
 480     uint16_t csl;
 481     uint32_t cso;
 482
 483     trace_net_rx_pkt_l4_csum_calc_entry();
 484
 485     if (pkt->isip4) {
 486         if (pkt->isudp) {
 487             csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
 488             trace_net_rx_pkt_l4_csum_calc_ip4_udp();
 489         } else {
 490             csl = be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_len) -
 491                   IP_HDR_GET_LEN(&pkt->ip4hdr_info.ip4_hdr);
 492             trace_net_rx_pkt_l4_csum_calc_ip4_tcp();
 493         }
 494
 495         cntr = eth_calc_ip4_pseudo_hdr_csum(&pkt->ip4hdr_info.ip4_hdr,
 496                                             csl, &cso);
 497         trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
 498     } else {
 499         if (pkt->isudp) {
 500             csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
 501             trace_net_rx_pkt_l4_csum_calc_ip6_udp();
 502         } else {
 503             struct ip6_header *ip6hdr = &pkt->ip6hdr_info.ip6_hdr;
 504             size_t full_ip6hdr_len = pkt->l4hdr_off - pkt->l3hdr_off;
 505             size_t ip6opts_len = full_ip6hdr_len - sizeof(struct ip6_header);
 506
 507             csl = be16_to_cpu(ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen) -
 508                   ip6opts_len;
 509             trace_net_rx_pkt_l4_csum_calc_ip6_tcp();
 510         }
 511
 512         cntr = eth_calc_ip6_pseudo_hdr_csum(&pkt->ip6hdr_info.ip6_hdr, csl,
 513                                             pkt->ip6hdr_info.l4proto, &cso);
 514         trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
 515     }
 516
 517     cntr += net_checksum_add_iov(pkt->vec, pkt->vec_len,
 518                                  pkt->l4hdr_off, csl, cso);
 519
 520     csum = net_checksum_finish(cntr);
 521
 522     trace_net_rx_pkt_l4_csum_calc_csum(pkt->l4hdr_off, csl, cntr, csum);
 523
 524     return csum;
 525 }
 526
 527 bool net_rx_pkt_validate_l4_csum(struct NetRxPkt *pkt, bool *csum_valid)
 528 {
 529     uint16_t csum;
 530
 531     trace_net_rx_pkt_l4_csum_validate_entry();
 532
 533     if (!pkt->istcp && !pkt->isudp) {
 534         trace_net_rx_pkt_l4_csum_validate_not_xxp();
 535         return false;
 536     }
 537
 538     if (pkt->isudp && (pkt->l4hdr_info.hdr.udp.uh_sum == 0)) {
 539         trace_net_rx_pkt_l4_csum_validate_udp_with_no_checksum();
 540         return false;
 541     }
 542
 543     if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
 544         trace_net_rx_pkt_l4_csum_validate_ip4_fragment();
 545         return false;
 546     }
 547
 548     csum = _net_rx_pkt_calc_l4_csum(pkt);
 549
 550     *csum_valid = ((csum == 0) || (csum == 0xFFFF));
 551
 552     trace_net_rx_pkt_l4_csum_validate_csum(*csum_valid);
 553
 554     return true;
 555 }
 556
 557 bool net_rx_pkt_fix_l4_csum(struct NetRxPkt *pkt)
 558 {
 559     uint16_t csum = 0;
 560     uint32_t l4_cso;
 561
 562     trace_net_rx_pkt_l4_csum_fix_entry();
 563
 564     if (pkt->istcp) {
 565         l4_cso = offsetof(struct tcp_header, th_sum);
 566         trace_net_rx_pkt_l4_csum_fix_tcp(l4_cso);
 567     } else if (pkt->isudp) {
 568         if (pkt->l4hdr_info.hdr.udp.uh_sum == 0) {
 569             trace_net_rx_pkt_l4_csum_fix_udp_with_no_checksum();
 570             return false;
 571         }
 572         l4_cso = offsetof(struct udp_header, uh_sum);
 573         trace_net_rx_pkt_l4_csum_fix_udp(l4_cso);
 574     } else {
 575         trace_net_rx_pkt_l4_csum_fix_not_xxp();
 576         return false;
 577     }
 578
 579     if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
 580             trace_net_rx_pkt_l4_csum_fix_ip4_fragment();
 581             return false;
 582     }
 583
 584     /* Set zero to checksum word */
 585     iov_from_buf(pkt->vec, pkt->vec_len,
 586                  pkt->l4hdr_off + l4_cso,
 587                  &csum, sizeof(csum));
 588
 589     /* Calculate L4 checksum */
 590     csum = cpu_to_be16(_net_rx_pkt_calc_l4_csum(pkt));
 591
 592     /* Set calculated checksum to checksum word */
 593     iov_from_buf(pkt->vec, pkt->vec_len,
 594                  pkt->l4hdr_off + l4_cso,
 595                  &csum, sizeof(csum));
 596
 597     trace_net_rx_pkt_l4_csum_fix_csum(pkt->l4hdr_off + l4_cso, csum);
 598
 599     return true;
 600 }