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) + sizeof(struct vlan_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     size_t ehdr_buf_len;
  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     uint32_t pllen = iov_size(iov, iovcnt) - ploff;
  92
  93     if (pkt->ehdr_buf_len) {
  94         net_rx_pkt_iovec_realloc(pkt, iovcnt + 1);
  95
  96         pkt->vec[0].iov_base = pkt->ehdr_buf;
  97         pkt->vec[0].iov_len = pkt->ehdr_buf_len;
  98
  99         pkt->tot_len = pllen + pkt->ehdr_buf_len;
 100         pkt->vec_len = iov_copy(pkt->vec + 1, pkt->vec_len_total - 1,
 101                                 iov, iovcnt, ploff, pllen) + 1;
 102     } else {
 103         net_rx_pkt_iovec_realloc(pkt, iovcnt);
 104
 105         pkt->tot_len = pllen;
 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
 127     if (strip_vlan) {
 128         pkt->ehdr_buf_len = eth_strip_vlan(iov, iovcnt, iovoff, pkt->ehdr_buf,
 129                                            &ploff, &tci);
 130     } else {
 131         pkt->ehdr_buf_len = 0;
 132     }
 133
 134     pkt->tci = tci;
 135
 136     net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 137 }
 138
 139 void net_rx_pkt_attach_iovec_ex(struct NetRxPkt *pkt,
 140                                 const struct iovec *iov, int iovcnt,
 141                                 size_t iovoff, bool strip_vlan,
 142                                 uint16_t vet)
 143 {
 144     uint16_t tci = 0;
 145     uint16_t ploff = iovoff;
 146     assert(pkt);
 147
 148     if (strip_vlan) {
 149         pkt->ehdr_buf_len = eth_strip_vlan_ex(iov, iovcnt, iovoff, vet,
 150                                               pkt->ehdr_buf,
 151                                               &ploff, &tci);
 152     } else {
 153         pkt->ehdr_buf_len = 0;
 154     }
 155
 156     pkt->tci = tci;
 157
 158     net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 159 }
 160
 161 void net_rx_pkt_dump(struct NetRxPkt *pkt)
 162 {
 163 #ifdef NET_RX_PKT_DEBUG
 164     assert(pkt);
 165
 166     printf("RX PKT: tot_len: %d, ehdr_buf_len: %lu, vlan_tag: %d\n",
 167               pkt->tot_len, pkt->ehdr_buf_len, pkt->tci);
 168 #endif
 169 }
 170
 171 void net_rx_pkt_set_packet_type(struct NetRxPkt *pkt,
 172     eth_pkt_types_e packet_type)
 173 {
 174     assert(pkt);
 175
 176     pkt->packet_type = packet_type;
 177
 178 }
 179
 180 eth_pkt_types_e net_rx_pkt_get_packet_type(struct NetRxPkt *pkt)
 181 {
 182     assert(pkt);
 183
 184     return pkt->packet_type;
 185 }
 186
 187 size_t net_rx_pkt_get_total_len(struct NetRxPkt *pkt)
 188 {
 189     assert(pkt);
 190
 191     return pkt->tot_len;
 192 }
 193
 194 void net_rx_pkt_set_protocols(struct NetRxPkt *pkt, const void *data,
 195                               size_t len)
 196 {
 197     const struct iovec iov = {
 198         .iov_base = (void *)data,
 199         .iov_len = len
 200     };
 201
 202     assert(pkt);
 203
 204     eth_get_protocols(&iov, 1, &pkt->isip4, &pkt->isip6,
 205                       &pkt->isudp, &pkt->istcp,
 206                       &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
 207                       &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
 208 }
 209
 210 void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
 211                               bool *isip4, bool *isip6,
 212                               bool *isudp, bool *istcp)
 213 {
 214     assert(pkt);
 215
 216     *isip4 = pkt->isip4;
 217     *isip6 = pkt->isip6;
 218     *isudp = pkt->isudp;
 219     *istcp = pkt->istcp;
 220 }
 221
 222 size_t net_rx_pkt_get_l3_hdr_offset(struct NetRxPkt *pkt)
 223 {
 224     assert(pkt);
 225     return pkt->l3hdr_off;
 226 }
 227
 228 size_t net_rx_pkt_get_l4_hdr_offset(struct NetRxPkt *pkt)
 229 {
 230     assert(pkt);
 231     return pkt->l4hdr_off;
 232 }
 233
 234 size_t net_rx_pkt_get_l5_hdr_offset(struct NetRxPkt *pkt)
 235 {
 236     assert(pkt);
 237     return pkt->l5hdr_off;
 238 }
 239
 240 eth_ip6_hdr_info *net_rx_pkt_get_ip6_info(struct NetRxPkt *pkt)
 241 {
 242     return &pkt->ip6hdr_info;
 243 }
 244
 245 eth_ip4_hdr_info *net_rx_pkt_get_ip4_info(struct NetRxPkt *pkt)
 246 {
 247     return &pkt->ip4hdr_info;
 248 }
 249
 250 eth_l4_hdr_info *net_rx_pkt_get_l4_info(struct NetRxPkt *pkt)
 251 {
 252     return &pkt->l4hdr_info;
 253 }
 254
 255 static inline void
 256 _net_rx_rss_add_chunk(uint8_t *rss_input, size_t *bytes_written,
 257                       void *ptr, size_t size)
 258 {
 259     memcpy(&rss_input[*bytes_written], ptr, size);
 260     trace_net_rx_pkt_rss_add_chunk(ptr, size, *bytes_written);
 261     *bytes_written += size;
 262 }
 263
 264 static inline void
 265 _net_rx_rss_prepare_ip4(uint8_t *rss_input,
 266                         struct NetRxPkt *pkt,
 267                         size_t *bytes_written)
 268 {
 269     struct ip_header *ip4_hdr = &pkt->ip4hdr_info.ip4_hdr;
 270
 271     _net_rx_rss_add_chunk(rss_input, bytes_written,
 272                           &ip4_hdr->ip_src, sizeof(uint32_t));
 273
 274     _net_rx_rss_add_chunk(rss_input, bytes_written,
 275                           &ip4_hdr->ip_dst, sizeof(uint32_t));
 276 }
 277
 278 static inline void
 279 _net_rx_rss_prepare_ip6(uint8_t *rss_input,
 280                         struct NetRxPkt *pkt,
 281                         bool ipv6ex, size_t *bytes_written)
 282 {
 283     eth_ip6_hdr_info *ip6info = &pkt->ip6hdr_info;
 284
 285     _net_rx_rss_add_chunk(rss_input, bytes_written,
 286            (ipv6ex && ip6info->rss_ex_src_valid) ? &ip6info->rss_ex_src
 287                                                  : &ip6info->ip6_hdr.ip6_src,
 288            sizeof(struct in6_address));
 289
 290     _net_rx_rss_add_chunk(rss_input, bytes_written,
 291            (ipv6ex && ip6info->rss_ex_dst_valid) ? &ip6info->rss_ex_dst
 292                                                  : &ip6info->ip6_hdr.ip6_dst,
 293            sizeof(struct in6_address));
 294 }
 295
 296 static inline void
 297 _net_rx_rss_prepare_tcp(uint8_t *rss_input,
 298                         struct NetRxPkt *pkt,
 299                         size_t *bytes_written)
 300 {
 301     struct tcp_header *tcphdr = &pkt->l4hdr_info.hdr.tcp;
 302
 303     _net_rx_rss_add_chunk(rss_input, bytes_written,
 304                           &tcphdr->th_sport, sizeof(uint16_t));
 305
 306     _net_rx_rss_add_chunk(rss_input, bytes_written,
 307                           &tcphdr->th_dport, sizeof(uint16_t));
 308 }
 309
 310 uint32_t
 311 net_rx_pkt_calc_rss_hash(struct NetRxPkt *pkt,
 312                          NetRxPktRssType type,
 313                          uint8_t *key)
 314 {
 315     uint8_t rss_input[36];
 316     size_t rss_length = 0;
 317     uint32_t rss_hash = 0;
 318     net_toeplitz_key key_data;
 319
 320     switch (type) {
 321     case NetPktRssIpV4:
 322         assert(pkt->isip4);
 323         trace_net_rx_pkt_rss_ip4();
 324         _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
 325         break;
 326     case NetPktRssIpV4Tcp:
 327         assert(pkt->isip4);
 328         assert(pkt->istcp);
 329         trace_net_rx_pkt_rss_ip4_tcp();
 330         _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
 331         _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
 332         break;
 333     case NetPktRssIpV6Tcp:
 334         assert(pkt->isip6);
 335         assert(pkt->istcp);
 336         trace_net_rx_pkt_rss_ip6_tcp();
 337         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
 338         _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
 339         break;
 340     case NetPktRssIpV6:
 341         assert(pkt->isip6);
 342         trace_net_rx_pkt_rss_ip6();
 343         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, false, &rss_length);
 344         break;
 345     case NetPktRssIpV6Ex:
 346         assert(pkt->isip6);
 347         trace_net_rx_pkt_rss_ip6_ex();
 348         _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
 349         break;
 350     default:
 351         assert(false);
 352         break;
 353     }
 354
 355     net_toeplitz_key_init(&key_data, key);
 356     net_toeplitz_add(&rss_hash, rss_input, rss_length, &key_data);
 357
 358     trace_net_rx_pkt_rss_hash(rss_length, rss_hash);
 359
 360     return rss_hash;
 361 }
 362
 363 uint16_t net_rx_pkt_get_ip_id(struct NetRxPkt *pkt)
 364 {
 365     assert(pkt);
 366
 367     if (pkt->isip4) {
 368         return be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_id);
 369     }
 370
 371     return 0;
 372 }
 373
 374 bool net_rx_pkt_is_tcp_ack(struct NetRxPkt *pkt)
 375 {
 376     assert(pkt);
 377
 378     if (pkt->istcp) {
 379         return TCP_HEADER_FLAGS(&pkt->l4hdr_info.hdr.tcp) & TCP_FLAG_ACK;
 380     }
 381
 382     return false;
 383 }
 384
 385 bool net_rx_pkt_has_tcp_data(struct NetRxPkt *pkt)
 386 {
 387     assert(pkt);
 388
 389     if (pkt->istcp) {
 390         return pkt->l4hdr_info.has_tcp_data;
 391     }
 392
 393     return false;
 394 }
 395
 396 struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
 397 {
 398     assert(pkt);
 399
 400     return pkt->vec;
 401 }
 402
 403 uint16_t net_rx_pkt_get_iovec_len(struct NetRxPkt *pkt)
 404 {
 405     assert(pkt);
 406
 407     return pkt->vec_len;
 408 }
 409
 410 void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
 411                             struct virtio_net_hdr *vhdr)
 412 {
 413     assert(pkt);
 414
 415     memcpy(&pkt->virt_hdr, vhdr, sizeof pkt->virt_hdr);
 416 }
 417
 418 void net_rx_pkt_set_vhdr_iovec(struct NetRxPkt *pkt,
 419     const struct iovec *iov, int iovcnt)
 420 {
 421     assert(pkt);
 422
 423     iov_to_buf(iov, iovcnt, 0, &pkt->virt_hdr, sizeof pkt->virt_hdr);
 424 }
 425
 426 bool net_rx_pkt_is_vlan_stripped(struct NetRxPkt *pkt)
 427 {
 428     assert(pkt);
 429
 430     return pkt->ehdr_buf_len ? true : false;
 431 }
 432
 433 bool net_rx_pkt_has_virt_hdr(struct NetRxPkt *pkt)
 434 {
 435     assert(pkt);
 436
 437     return pkt->has_virt_hdr;
 438 }
 439
 440 uint16_t net_rx_pkt_get_vlan_tag(struct NetRxPkt *pkt)
 441 {
 442     assert(pkt);
 443
 444     return pkt->tci;
 445 }
 446
 447 bool net_rx_pkt_validate_l3_csum(struct NetRxPkt *pkt, bool *csum_valid)
 448 {
 449     uint32_t cntr;
 450     uint16_t csum;
 451     uint32_t csl;
 452
 453     trace_net_rx_pkt_l3_csum_validate_entry();
 454
 455     if (!pkt->isip4) {
 456         trace_net_rx_pkt_l3_csum_validate_not_ip4();
 457         return false;
 458     }
 459
 460     csl = pkt->l4hdr_off - pkt->l3hdr_off;
 461
 462     cntr = net_checksum_add_iov(pkt->vec, pkt->vec_len,
 463                                 pkt->l3hdr_off,
 464                                 csl, 0);
 465
 466     csum = net_checksum_finish(cntr);
 467
 468     *csum_valid = (csum == 0);
 469
 470     trace_net_rx_pkt_l3_csum_validate_csum(pkt->l3hdr_off, csl,
 471                                            cntr, csum, *csum_valid);
 472
 473     return true;
 474 }
 475
 476 static uint16_t
 477 _net_rx_pkt_calc_l4_csum(struct NetRxPkt *pkt)
 478 {
 479     uint32_t cntr;
 480     uint16_t csum;
 481     uint16_t csl;
 482     uint32_t cso;
 483
 484     trace_net_rx_pkt_l4_csum_calc_entry();
 485
 486     if (pkt->isip4) {
 487         if (pkt->isudp) {
 488             csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
 489             trace_net_rx_pkt_l4_csum_calc_ip4_udp();
 490         } else {
 491             csl = be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_len) -
 492                   IP_HDR_GET_LEN(&pkt->ip4hdr_info.ip4_hdr);
 493             trace_net_rx_pkt_l4_csum_calc_ip4_tcp();
 494         }
 495
 496         cntr = eth_calc_ip4_pseudo_hdr_csum(&pkt->ip4hdr_info.ip4_hdr,
 497                                             csl, &cso);
 498         trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
 499     } else {
 500         if (pkt->isudp) {
 501             csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
 502             trace_net_rx_pkt_l4_csum_calc_ip6_udp();
 503         } else {
 504             struct ip6_header *ip6hdr = &pkt->ip6hdr_info.ip6_hdr;
 505             size_t full_ip6hdr_len = pkt->l4hdr_off - pkt->l3hdr_off;
 506             size_t ip6opts_len = full_ip6hdr_len - sizeof(struct ip6_header);
 507
 508             csl = be16_to_cpu(ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen) -
 509                   ip6opts_len;
 510             trace_net_rx_pkt_l4_csum_calc_ip6_tcp();
 511         }
 512
 513         cntr = eth_calc_ip6_pseudo_hdr_csum(&pkt->ip6hdr_info.ip6_hdr, csl,
 514                                             pkt->ip6hdr_info.l4proto, &cso);
 515         trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
 516     }
 517
 518     cntr += net_checksum_add_iov(pkt->vec, pkt->vec_len,
 519                                  pkt->l4hdr_off, csl, cso);
 520
 521     csum = net_checksum_finish(cntr);
 522
 523     trace_net_rx_pkt_l4_csum_calc_csum(pkt->l4hdr_off, csl, cntr, csum);
 524
 525     return csum;
 526 }
 527
 528 bool net_rx_pkt_validate_l4_csum(struct NetRxPkt *pkt, bool *csum_valid)
 529 {
 530     uint16_t csum;
 531
 532     trace_net_rx_pkt_l4_csum_validate_entry();
 533
 534     if (!pkt->istcp && !pkt->isudp) {
 535         trace_net_rx_pkt_l4_csum_validate_not_xxp();
 536         return false;
 537     }
 538
 539     if (pkt->isudp && (pkt->l4hdr_info.hdr.udp.uh_sum == 0)) {
 540         trace_net_rx_pkt_l4_csum_validate_udp_with_no_checksum();
 541         return false;
 542     }
 543
 544     if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
 545         trace_net_rx_pkt_l4_csum_validate_ip4_fragment();
 546         return false;
 547     }
 548
 549     csum = _net_rx_pkt_calc_l4_csum(pkt);
 550
 551     *csum_valid = ((csum == 0) || (csum == 0xFFFF));
 552
 553     trace_net_rx_pkt_l4_csum_validate_csum(*csum_valid);
 554
 555     return true;
 556 }
 557
 558 bool net_rx_pkt_fix_l4_csum(struct NetRxPkt *pkt)
 559 {
 560     uint16_t csum = 0;
 561     uint32_t l4_cso;
 562
 563     trace_net_rx_pkt_l4_csum_fix_entry();
 564
 565     if (pkt->istcp) {
 566         l4_cso = offsetof(struct tcp_header, th_sum);
 567         trace_net_rx_pkt_l4_csum_fix_tcp(l4_cso);
 568     } else if (pkt->isudp) {
 569         if (pkt->l4hdr_info.hdr.udp.uh_sum == 0) {
 570             trace_net_rx_pkt_l4_csum_fix_udp_with_no_checksum();
 571             return false;
 572         }
 573         l4_cso = offsetof(struct udp_header, uh_sum);
 574         trace_net_rx_pkt_l4_csum_fix_udp(l4_cso);
 575     } else {
 576         trace_net_rx_pkt_l4_csum_fix_not_xxp();
 577         return false;
 578     }
 579
 580     if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
 581             trace_net_rx_pkt_l4_csum_fix_ip4_fragment();
 582             return false;
 583     }
 584
 585     /* Set zero to checksum word */
 586     iov_from_buf(pkt->vec, pkt->vec_len,
 587                  pkt->l4hdr_off + l4_cso,
 588                  &csum, sizeof(csum));
 589
 590     /* Calculate L4 checksum */
 591     csum = cpu_to_be16(_net_rx_pkt_calc_l4_csum(pkt));
 592
 593     /* Set calculated checksum to checksum word */
 594     iov_from_buf(pkt->vec, pkt->vec_len,
 595                  pkt->l4hdr_off + l4_cso,
 596                  &csum, sizeof(csum));
 597
 598     trace_net_rx_pkt_l4_csum_fix_csum(pkt->l4hdr_off + l4_cso, csum);
 599
 600     return true;
 601 }