1 /* 2 * QEMU TX 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 "net_tx_pkt.h" 20 #include "net/eth.h" 21 #include "net/checksum.h" 22 #include "net/tap.h" 23 #include "net/net.h" 24 #include "hw/pci/pci_device.h" 25 26 enum { 27 NET_TX_PKT_VHDR_FRAG = 0, 28 NET_TX_PKT_L2HDR_FRAG, 29 NET_TX_PKT_L3HDR_FRAG, 30 NET_TX_PKT_PL_START_FRAG 31 }; 32 33 /* TX packet private context */ 34 struct NetTxPkt { 35 PCIDevice *pci_dev; 36 37 struct virtio_net_hdr virt_hdr; 38 39 struct iovec *raw; 40 uint32_t raw_frags; 41 uint32_t max_raw_frags; 42 43 struct iovec *vec; 44 45 uint8_t l2_hdr[ETH_MAX_L2_HDR_LEN]; 46 uint8_t l3_hdr[ETH_MAX_IP_DGRAM_LEN]; 47 48 uint32_t payload_len; 49 50 uint32_t payload_frags; 51 uint32_t max_payload_frags; 52 53 uint16_t hdr_len; 54 eth_pkt_types_e packet_type; 55 uint8_t l4proto; 56 }; 57 58 void net_tx_pkt_init(struct NetTxPkt **pkt, PCIDevice *pci_dev, 59 uint32_t max_frags) 60 { 61 struct NetTxPkt *p = g_malloc0(sizeof *p); 62 63 p->pci_dev = pci_dev; 64 65 p->vec = g_new(struct iovec, max_frags + NET_TX_PKT_PL_START_FRAG); 66 67 p->raw = g_new(struct iovec, max_frags); 68 69 p->max_payload_frags = max_frags; 70 p->max_raw_frags = max_frags; 71 p->vec[NET_TX_PKT_VHDR_FRAG].iov_base = &p->virt_hdr; 72 p->vec[NET_TX_PKT_VHDR_FRAG].iov_len = sizeof p->virt_hdr; 73 p->vec[NET_TX_PKT_L2HDR_FRAG].iov_base = &p->l2_hdr; 74 p->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = &p->l3_hdr; 75 76 *pkt = p; 77 } 78 79 void net_tx_pkt_uninit(struct NetTxPkt *pkt) 80 { 81 if (pkt) { 82 g_free(pkt->vec); 83 g_free(pkt->raw); 84 g_free(pkt); 85 } 86 } 87 88 void net_tx_pkt_update_ip_hdr_checksum(struct NetTxPkt *pkt) 89 { 90 uint16_t csum; 91 assert(pkt); 92 struct ip_header *ip_hdr; 93 ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base; 94 95 ip_hdr->ip_len = cpu_to_be16(pkt->payload_len + 96 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len); 97 98 ip_hdr->ip_sum = 0; 99 csum = net_raw_checksum((uint8_t *)ip_hdr, 100 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len); 101 ip_hdr->ip_sum = cpu_to_be16(csum); 102 } 103 104 void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt) 105 { 106 uint16_t csum; 107 uint32_t cntr, cso; 108 assert(pkt); 109 uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN; 110 void *ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base; 111 112 if (pkt->payload_len + pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len > 113 ETH_MAX_IP_DGRAM_LEN) { 114 return; 115 } 116 117 if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 || 118 gso_type == VIRTIO_NET_HDR_GSO_UDP) { 119 /* Calculate IP header checksum */ 120 net_tx_pkt_update_ip_hdr_checksum(pkt); 121 122 /* Calculate IP pseudo header checksum */ 123 cntr = eth_calc_ip4_pseudo_hdr_csum(ip_hdr, pkt->payload_len, &cso); 124 csum = cpu_to_be16(~net_checksum_finish(cntr)); 125 } else if (gso_type == VIRTIO_NET_HDR_GSO_TCPV6) { 126 /* Calculate IP pseudo header checksum */ 127 cntr = eth_calc_ip6_pseudo_hdr_csum(ip_hdr, pkt->payload_len, 128 IP_PROTO_TCP, &cso); 129 csum = cpu_to_be16(~net_checksum_finish(cntr)); 130 } else { 131 return; 132 } 133 134 iov_from_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags, 135 pkt->virt_hdr.csum_offset, &csum, sizeof(csum)); 136 } 137 138 static void net_tx_pkt_calculate_hdr_len(struct NetTxPkt *pkt) 139 { 140 pkt->hdr_len = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len + 141 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len; 142 } 143 144 static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt) 145 { 146 struct iovec *l2_hdr, *l3_hdr; 147 size_t bytes_read; 148 size_t full_ip6hdr_len; 149 uint16_t l3_proto; 150 151 assert(pkt); 152 153 l2_hdr = &pkt->vec[NET_TX_PKT_L2HDR_FRAG]; 154 l3_hdr = &pkt->vec[NET_TX_PKT_L3HDR_FRAG]; 155 156 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, 0, l2_hdr->iov_base, 157 ETH_MAX_L2_HDR_LEN); 158 if (bytes_read < sizeof(struct eth_header)) { 159 l2_hdr->iov_len = 0; 160 return false; 161 } 162 163 l2_hdr->iov_len = sizeof(struct eth_header); 164 switch (be16_to_cpu(PKT_GET_ETH_HDR(l2_hdr->iov_base)->h_proto)) { 165 case ETH_P_VLAN: 166 l2_hdr->iov_len += sizeof(struct vlan_header); 167 break; 168 case ETH_P_DVLAN: 169 l2_hdr->iov_len += 2 * sizeof(struct vlan_header); 170 break; 171 } 172 173 if (bytes_read < l2_hdr->iov_len) { 174 l2_hdr->iov_len = 0; 175 l3_hdr->iov_len = 0; 176 pkt->packet_type = ETH_PKT_UCAST; 177 return false; 178 } else { 179 l2_hdr->iov_len = ETH_MAX_L2_HDR_LEN; 180 l2_hdr->iov_len = eth_get_l2_hdr_length(l2_hdr->iov_base); 181 pkt->packet_type = get_eth_packet_type(l2_hdr->iov_base); 182 } 183 184 l3_proto = eth_get_l3_proto(l2_hdr, 1, l2_hdr->iov_len); 185 186 switch (l3_proto) { 187 case ETH_P_IP: 188 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 189 l3_hdr->iov_base, sizeof(struct ip_header)); 190 191 if (bytes_read < sizeof(struct ip_header)) { 192 l3_hdr->iov_len = 0; 193 return false; 194 } 195 196 l3_hdr->iov_len = IP_HDR_GET_LEN(l3_hdr->iov_base); 197 198 if (l3_hdr->iov_len < sizeof(struct ip_header)) { 199 l3_hdr->iov_len = 0; 200 return false; 201 } 202 203 pkt->l4proto = IP_HDR_GET_P(l3_hdr->iov_base); 204 205 if (IP_HDR_GET_LEN(l3_hdr->iov_base) != sizeof(struct ip_header)) { 206 /* copy optional IPv4 header data if any*/ 207 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, 208 l2_hdr->iov_len + sizeof(struct ip_header), 209 l3_hdr->iov_base + sizeof(struct ip_header), 210 l3_hdr->iov_len - sizeof(struct ip_header)); 211 if (bytes_read < l3_hdr->iov_len - sizeof(struct ip_header)) { 212 l3_hdr->iov_len = 0; 213 return false; 214 } 215 } 216 217 break; 218 219 case ETH_P_IPV6: 220 { 221 eth_ip6_hdr_info hdrinfo; 222 223 if (!eth_parse_ipv6_hdr(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 224 &hdrinfo)) { 225 l3_hdr->iov_len = 0; 226 return false; 227 } 228 229 pkt->l4proto = hdrinfo.l4proto; 230 full_ip6hdr_len = hdrinfo.full_hdr_len; 231 232 if (full_ip6hdr_len > ETH_MAX_IP_DGRAM_LEN) { 233 l3_hdr->iov_len = 0; 234 return false; 235 } 236 237 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 238 l3_hdr->iov_base, full_ip6hdr_len); 239 240 if (bytes_read < full_ip6hdr_len) { 241 l3_hdr->iov_len = 0; 242 return false; 243 } else { 244 l3_hdr->iov_len = full_ip6hdr_len; 245 } 246 break; 247 } 248 default: 249 l3_hdr->iov_len = 0; 250 break; 251 } 252 253 net_tx_pkt_calculate_hdr_len(pkt); 254 return true; 255 } 256 257 static void net_tx_pkt_rebuild_payload(struct NetTxPkt *pkt) 258 { 259 pkt->payload_len = iov_size(pkt->raw, pkt->raw_frags) - pkt->hdr_len; 260 pkt->payload_frags = iov_copy(&pkt->vec[NET_TX_PKT_PL_START_FRAG], 261 pkt->max_payload_frags, 262 pkt->raw, pkt->raw_frags, 263 pkt->hdr_len, pkt->payload_len); 264 } 265 266 bool net_tx_pkt_parse(struct NetTxPkt *pkt) 267 { 268 if (net_tx_pkt_parse_headers(pkt)) { 269 net_tx_pkt_rebuild_payload(pkt); 270 return true; 271 } else { 272 return false; 273 } 274 } 275 276 struct virtio_net_hdr *net_tx_pkt_get_vhdr(struct NetTxPkt *pkt) 277 { 278 assert(pkt); 279 return &pkt->virt_hdr; 280 } 281 282 static uint8_t net_tx_pkt_get_gso_type(struct NetTxPkt *pkt, 283 bool tso_enable) 284 { 285 uint8_t rc = VIRTIO_NET_HDR_GSO_NONE; 286 uint16_t l3_proto; 287 288 l3_proto = eth_get_l3_proto(&pkt->vec[NET_TX_PKT_L2HDR_FRAG], 1, 289 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len); 290 291 if (!tso_enable) { 292 goto func_exit; 293 } 294 295 rc = eth_get_gso_type(l3_proto, pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base, 296 pkt->l4proto); 297 298 func_exit: 299 return rc; 300 } 301 302 bool net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable, 303 bool csum_enable, uint32_t gso_size) 304 { 305 struct tcp_hdr l4hdr; 306 size_t bytes_read; 307 assert(pkt); 308 309 /* csum has to be enabled if tso is. */ 310 assert(csum_enable || !tso_enable); 311 312 pkt->virt_hdr.gso_type = net_tx_pkt_get_gso_type(pkt, tso_enable); 313 314 switch (pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 315 case VIRTIO_NET_HDR_GSO_NONE: 316 pkt->virt_hdr.hdr_len = 0; 317 pkt->virt_hdr.gso_size = 0; 318 break; 319 320 case VIRTIO_NET_HDR_GSO_UDP: 321 pkt->virt_hdr.gso_size = gso_size; 322 pkt->virt_hdr.hdr_len = pkt->hdr_len + sizeof(struct udp_header); 323 break; 324 325 case VIRTIO_NET_HDR_GSO_TCPV4: 326 case VIRTIO_NET_HDR_GSO_TCPV6: 327 bytes_read = iov_to_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], 328 pkt->payload_frags, 0, &l4hdr, sizeof(l4hdr)); 329 if (bytes_read < sizeof(l4hdr) || 330 l4hdr.th_off * sizeof(uint32_t) < sizeof(l4hdr)) { 331 return false; 332 } 333 334 pkt->virt_hdr.hdr_len = pkt->hdr_len + l4hdr.th_off * sizeof(uint32_t); 335 pkt->virt_hdr.gso_size = gso_size; 336 break; 337 338 default: 339 g_assert_not_reached(); 340 } 341 342 if (csum_enable) { 343 switch (pkt->l4proto) { 344 case IP_PROTO_TCP: 345 pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 346 pkt->virt_hdr.csum_start = pkt->hdr_len; 347 pkt->virt_hdr.csum_offset = offsetof(struct tcp_hdr, th_sum); 348 break; 349 case IP_PROTO_UDP: 350 pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 351 pkt->virt_hdr.csum_start = pkt->hdr_len; 352 pkt->virt_hdr.csum_offset = offsetof(struct udp_hdr, uh_sum); 353 break; 354 default: 355 break; 356 } 357 } 358 359 return true; 360 } 361 362 void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt, 363 uint16_t vlan, uint16_t vlan_ethtype) 364 { 365 bool is_new; 366 assert(pkt); 367 368 eth_setup_vlan_headers_ex(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base, 369 vlan, vlan_ethtype, &is_new); 370 371 /* update l2hdrlen */ 372 if (is_new) { 373 pkt->hdr_len += sizeof(struct vlan_header); 374 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len += 375 sizeof(struct vlan_header); 376 } 377 } 378 379 bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa, 380 size_t len) 381 { 382 hwaddr mapped_len = 0; 383 struct iovec *ventry; 384 assert(pkt); 385 386 if (pkt->raw_frags >= pkt->max_raw_frags) { 387 return false; 388 } 389 390 if (!len) { 391 return true; 392 } 393 394 ventry = &pkt->raw[pkt->raw_frags]; 395 mapped_len = len; 396 397 ventry->iov_base = pci_dma_map(pkt->pci_dev, pa, 398 &mapped_len, DMA_DIRECTION_TO_DEVICE); 399 400 if ((ventry->iov_base != NULL) && (len == mapped_len)) { 401 ventry->iov_len = mapped_len; 402 pkt->raw_frags++; 403 return true; 404 } else { 405 return false; 406 } 407 } 408 409 bool net_tx_pkt_has_fragments(struct NetTxPkt *pkt) 410 { 411 return pkt->raw_frags > 0; 412 } 413 414 eth_pkt_types_e net_tx_pkt_get_packet_type(struct NetTxPkt *pkt) 415 { 416 assert(pkt); 417 418 return pkt->packet_type; 419 } 420 421 size_t net_tx_pkt_get_total_len(struct NetTxPkt *pkt) 422 { 423 assert(pkt); 424 425 return pkt->hdr_len + pkt->payload_len; 426 } 427 428 void net_tx_pkt_dump(struct NetTxPkt *pkt) 429 { 430 #ifdef NET_TX_PKT_DEBUG 431 assert(pkt); 432 433 printf("TX PKT: hdr_len: %d, pkt_type: 0x%X, l2hdr_len: %lu, " 434 "l3hdr_len: %lu, payload_len: %u\n", pkt->hdr_len, pkt->packet_type, 435 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len, 436 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len, pkt->payload_len); 437 #endif 438 } 439 440 void net_tx_pkt_reset(struct NetTxPkt *pkt) 441 { 442 int i; 443 444 /* no assert, as reset can be called before tx_pkt_init */ 445 if (!pkt) { 446 return; 447 } 448 449 memset(&pkt->virt_hdr, 0, sizeof(pkt->virt_hdr)); 450 451 assert(pkt->vec); 452 453 pkt->payload_len = 0; 454 pkt->payload_frags = 0; 455 456 if (pkt->max_raw_frags > 0) { 457 assert(pkt->raw); 458 for (i = 0; i < pkt->raw_frags; i++) { 459 assert(pkt->raw[i].iov_base); 460 pci_dma_unmap(pkt->pci_dev, pkt->raw[i].iov_base, 461 pkt->raw[i].iov_len, DMA_DIRECTION_TO_DEVICE, 0); 462 } 463 } 464 pkt->raw_frags = 0; 465 466 pkt->hdr_len = 0; 467 pkt->l4proto = 0; 468 } 469 470 static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt, 471 struct iovec *iov, uint32_t iov_len, 472 uint16_t csl) 473 { 474 uint32_t csum_cntr; 475 uint16_t csum = 0; 476 uint32_t cso; 477 /* num of iovec without vhdr */ 478 size_t csum_offset = pkt->virt_hdr.csum_start + pkt->virt_hdr.csum_offset; 479 uint16_t l3_proto = eth_get_l3_proto(iov, 1, iov->iov_len); 480 481 /* Put zero to checksum field */ 482 iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum); 483 484 /* Calculate L4 TCP/UDP checksum */ 485 csum_cntr = 0; 486 cso = 0; 487 /* add pseudo header to csum */ 488 if (l3_proto == ETH_P_IP) { 489 csum_cntr = eth_calc_ip4_pseudo_hdr_csum( 490 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base, 491 csl, &cso); 492 } else if (l3_proto == ETH_P_IPV6) { 493 csum_cntr = eth_calc_ip6_pseudo_hdr_csum( 494 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base, 495 csl, pkt->l4proto, &cso); 496 } 497 498 /* data checksum */ 499 csum_cntr += 500 net_checksum_add_iov(iov, iov_len, pkt->virt_hdr.csum_start, csl, cso); 501 502 /* Put the checksum obtained into the packet */ 503 csum = cpu_to_be16(net_checksum_finish_nozero(csum_cntr)); 504 iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum); 505 } 506 507 #define NET_MAX_FRAG_SG_LIST (64) 508 509 static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt, 510 int *src_idx, size_t *src_offset, size_t src_len, 511 struct iovec *dst, int *dst_idx) 512 { 513 size_t fetched = 0; 514 struct iovec *src = pkt->vec; 515 516 while (fetched < src_len) { 517 518 /* no more place in fragment iov */ 519 if (*dst_idx == NET_MAX_FRAG_SG_LIST) { 520 break; 521 } 522 523 /* no more data in iovec */ 524 if (*src_idx == (pkt->payload_frags + NET_TX_PKT_PL_START_FRAG)) { 525 break; 526 } 527 528 529 dst[*dst_idx].iov_base = src[*src_idx].iov_base + *src_offset; 530 dst[*dst_idx].iov_len = MIN(src[*src_idx].iov_len - *src_offset, 531 src_len - fetched); 532 533 *src_offset += dst[*dst_idx].iov_len; 534 fetched += dst[*dst_idx].iov_len; 535 536 if (*src_offset == src[*src_idx].iov_len) { 537 *src_offset = 0; 538 (*src_idx)++; 539 } 540 541 (*dst_idx)++; 542 } 543 544 return fetched; 545 } 546 547 static void net_tx_pkt_sendv( 548 void *opaque, const struct iovec *iov, int iov_cnt, 549 const struct iovec *virt_iov, int virt_iov_cnt) 550 { 551 NetClientState *nc = opaque; 552 553 if (qemu_get_using_vnet_hdr(nc->peer)) { 554 qemu_sendv_packet(nc, virt_iov, virt_iov_cnt); 555 } else { 556 qemu_sendv_packet(nc, iov, iov_cnt); 557 } 558 } 559 560 static bool net_tx_pkt_tcp_fragment_init(struct NetTxPkt *pkt, 561 struct iovec *fragment, 562 int *pl_idx, 563 size_t *l4hdr_len, 564 int *src_idx, 565 size_t *src_offset, 566 size_t *src_len) 567 { 568 struct iovec *l4 = fragment + NET_TX_PKT_PL_START_FRAG; 569 size_t bytes_read = 0; 570 struct tcp_hdr *th; 571 572 if (!pkt->payload_frags) { 573 return false; 574 } 575 576 l4->iov_len = pkt->virt_hdr.hdr_len - pkt->hdr_len; 577 l4->iov_base = g_malloc(l4->iov_len); 578 579 *src_idx = NET_TX_PKT_PL_START_FRAG; 580 while (pkt->vec[*src_idx].iov_len < l4->iov_len - bytes_read) { 581 memcpy((char *)l4->iov_base + bytes_read, pkt->vec[*src_idx].iov_base, 582 pkt->vec[*src_idx].iov_len); 583 584 bytes_read += pkt->vec[*src_idx].iov_len; 585 586 (*src_idx)++; 587 if (*src_idx >= pkt->payload_frags + NET_TX_PKT_PL_START_FRAG) { 588 g_free(l4->iov_base); 589 return false; 590 } 591 } 592 593 *src_offset = l4->iov_len - bytes_read; 594 memcpy((char *)l4->iov_base + bytes_read, pkt->vec[*src_idx].iov_base, 595 *src_offset); 596 597 th = l4->iov_base; 598 th->th_flags &= ~(TH_FIN | TH_PUSH); 599 600 *pl_idx = NET_TX_PKT_PL_START_FRAG + 1; 601 *l4hdr_len = l4->iov_len; 602 *src_len = pkt->virt_hdr.gso_size; 603 604 return true; 605 } 606 607 static void net_tx_pkt_tcp_fragment_deinit(struct iovec *fragment) 608 { 609 g_free(fragment[NET_TX_PKT_PL_START_FRAG].iov_base); 610 } 611 612 static void net_tx_pkt_tcp_fragment_fix(struct NetTxPkt *pkt, 613 struct iovec *fragment, 614 size_t fragment_len, 615 uint8_t gso_type) 616 { 617 struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG; 618 struct iovec *l4hdr = fragment + NET_TX_PKT_PL_START_FRAG; 619 struct ip_header *ip = l3hdr->iov_base; 620 struct ip6_header *ip6 = l3hdr->iov_base; 621 size_t len = l3hdr->iov_len + l4hdr->iov_len + fragment_len; 622 623 switch (gso_type) { 624 case VIRTIO_NET_HDR_GSO_TCPV4: 625 ip->ip_len = cpu_to_be16(len); 626 eth_fix_ip4_checksum(l3hdr->iov_base, l3hdr->iov_len); 627 break; 628 629 case VIRTIO_NET_HDR_GSO_TCPV6: 630 len -= sizeof(struct ip6_header); 631 ip6->ip6_ctlun.ip6_un1.ip6_un1_plen = cpu_to_be16(len); 632 break; 633 } 634 } 635 636 static void net_tx_pkt_tcp_fragment_advance(struct NetTxPkt *pkt, 637 struct iovec *fragment, 638 size_t fragment_len, 639 uint8_t gso_type) 640 { 641 struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG; 642 struct iovec *l4hdr = fragment + NET_TX_PKT_PL_START_FRAG; 643 struct ip_header *ip = l3hdr->iov_base; 644 struct tcp_hdr *th = l4hdr->iov_base; 645 646 if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4) { 647 ip->ip_id = cpu_to_be16(be16_to_cpu(ip->ip_id) + 1); 648 } 649 650 th->th_seq = cpu_to_be32(be32_to_cpu(th->th_seq) + fragment_len); 651 th->th_flags &= ~TH_CWR; 652 } 653 654 static void net_tx_pkt_udp_fragment_init(struct NetTxPkt *pkt, 655 int *pl_idx, 656 size_t *l4hdr_len, 657 int *src_idx, size_t *src_offset, 658 size_t *src_len) 659 { 660 *pl_idx = NET_TX_PKT_PL_START_FRAG; 661 *l4hdr_len = 0; 662 *src_idx = NET_TX_PKT_PL_START_FRAG; 663 *src_offset = 0; 664 *src_len = IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size); 665 } 666 667 static void net_tx_pkt_udp_fragment_fix(struct NetTxPkt *pkt, 668 struct iovec *fragment, 669 size_t fragment_offset, 670 size_t fragment_len) 671 { 672 bool more_frags = fragment_offset + fragment_len < pkt->payload_len; 673 uint16_t orig_flags; 674 struct iovec *l3hdr = fragment + NET_TX_PKT_L3HDR_FRAG; 675 struct ip_header *ip = l3hdr->iov_base; 676 uint16_t frag_off_units = fragment_offset / IP_FRAG_UNIT_SIZE; 677 uint16_t new_ip_off; 678 679 assert(fragment_offset % IP_FRAG_UNIT_SIZE == 0); 680 assert((frag_off_units & ~IP_OFFMASK) == 0); 681 682 orig_flags = be16_to_cpu(ip->ip_off) & ~(IP_OFFMASK | IP_MF); 683 new_ip_off = frag_off_units | orig_flags | (more_frags ? IP_MF : 0); 684 ip->ip_off = cpu_to_be16(new_ip_off); 685 ip->ip_len = cpu_to_be16(l3hdr->iov_len + fragment_len); 686 687 eth_fix_ip4_checksum(l3hdr->iov_base, l3hdr->iov_len); 688 } 689 690 static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt, 691 NetTxPktCallback callback, 692 void *context) 693 { 694 uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN; 695 696 struct iovec fragment[NET_MAX_FRAG_SG_LIST]; 697 size_t fragment_len; 698 size_t l4hdr_len; 699 size_t src_len; 700 701 int src_idx, dst_idx, pl_idx; 702 size_t src_offset; 703 size_t fragment_offset = 0; 704 struct virtio_net_hdr virt_hdr = { 705 .flags = pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM ? 706 VIRTIO_NET_HDR_F_DATA_VALID : 0 707 }; 708 709 /* Copy headers */ 710 fragment[NET_TX_PKT_VHDR_FRAG].iov_base = &virt_hdr; 711 fragment[NET_TX_PKT_VHDR_FRAG].iov_len = sizeof(virt_hdr); 712 fragment[NET_TX_PKT_L2HDR_FRAG] = pkt->vec[NET_TX_PKT_L2HDR_FRAG]; 713 fragment[NET_TX_PKT_L3HDR_FRAG] = pkt->vec[NET_TX_PKT_L3HDR_FRAG]; 714 715 switch (gso_type) { 716 case VIRTIO_NET_HDR_GSO_TCPV4: 717 case VIRTIO_NET_HDR_GSO_TCPV6: 718 if (!net_tx_pkt_tcp_fragment_init(pkt, fragment, &pl_idx, &l4hdr_len, 719 &src_idx, &src_offset, &src_len)) { 720 return false; 721 } 722 break; 723 724 case VIRTIO_NET_HDR_GSO_UDP: 725 net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG], 726 pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1, 727 pkt->payload_len); 728 net_tx_pkt_udp_fragment_init(pkt, &pl_idx, &l4hdr_len, 729 &src_idx, &src_offset, &src_len); 730 break; 731 732 default: 733 abort(); 734 } 735 736 /* Put as much data as possible and send */ 737 while (true) { 738 dst_idx = pl_idx; 739 fragment_len = net_tx_pkt_fetch_fragment(pkt, 740 &src_idx, &src_offset, src_len, fragment, &dst_idx); 741 if (!fragment_len) { 742 break; 743 } 744 745 switch (gso_type) { 746 case VIRTIO_NET_HDR_GSO_TCPV4: 747 case VIRTIO_NET_HDR_GSO_TCPV6: 748 net_tx_pkt_tcp_fragment_fix(pkt, fragment, fragment_len, gso_type); 749 net_tx_pkt_do_sw_csum(pkt, fragment + NET_TX_PKT_L2HDR_FRAG, 750 dst_idx - NET_TX_PKT_L2HDR_FRAG, 751 l4hdr_len + fragment_len); 752 break; 753 754 case VIRTIO_NET_HDR_GSO_UDP: 755 net_tx_pkt_udp_fragment_fix(pkt, fragment, fragment_offset, 756 fragment_len); 757 break; 758 } 759 760 callback(context, 761 fragment + NET_TX_PKT_L2HDR_FRAG, dst_idx - NET_TX_PKT_L2HDR_FRAG, 762 fragment + NET_TX_PKT_VHDR_FRAG, dst_idx - NET_TX_PKT_VHDR_FRAG); 763 764 if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 || 765 gso_type == VIRTIO_NET_HDR_GSO_TCPV6) { 766 net_tx_pkt_tcp_fragment_advance(pkt, fragment, fragment_len, 767 gso_type); 768 } 769 770 fragment_offset += fragment_len; 771 } 772 773 if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 || 774 gso_type == VIRTIO_NET_HDR_GSO_TCPV6) { 775 net_tx_pkt_tcp_fragment_deinit(fragment); 776 } 777 778 return true; 779 } 780 781 bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc) 782 { 783 bool offload = qemu_get_using_vnet_hdr(nc->peer); 784 return net_tx_pkt_send_custom(pkt, offload, net_tx_pkt_sendv, nc); 785 } 786 787 bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload, 788 NetTxPktCallback callback, void *context) 789 { 790 assert(pkt); 791 792 /* 793 * Since underlying infrastructure does not support IP datagrams longer 794 * than 64K we should drop such packets and don't even try to send 795 */ 796 if (VIRTIO_NET_HDR_GSO_NONE != pkt->virt_hdr.gso_type) { 797 if (pkt->payload_len > 798 ETH_MAX_IP_DGRAM_LEN - 799 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len) { 800 return false; 801 } 802 } 803 804 if (offload || pkt->virt_hdr.gso_type == VIRTIO_NET_HDR_GSO_NONE) { 805 if (!offload && pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 806 net_tx_pkt_do_sw_csum(pkt, &pkt->vec[NET_TX_PKT_L2HDR_FRAG], 807 pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1, 808 pkt->payload_len); 809 } 810 811 net_tx_pkt_fix_ip6_payload_len(pkt); 812 callback(context, pkt->vec + NET_TX_PKT_L2HDR_FRAG, 813 pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - NET_TX_PKT_L2HDR_FRAG, 814 pkt->vec + NET_TX_PKT_VHDR_FRAG, 815 pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - NET_TX_PKT_VHDR_FRAG); 816 return true; 817 } 818 819 return net_tx_pkt_do_sw_fragmentation(pkt, callback, context); 820 } 821 822 void net_tx_pkt_fix_ip6_payload_len(struct NetTxPkt *pkt) 823 { 824 struct iovec *l2 = &pkt->vec[NET_TX_PKT_L2HDR_FRAG]; 825 if (eth_get_l3_proto(l2, 1, l2->iov_len) == ETH_P_IPV6) { 826 struct ip6_header *ip6 = (struct ip6_header *) pkt->l3_hdr; 827 /* 828 * TODO: if qemu would support >64K packets - add jumbo option check 829 * something like that: 830 * 'if (ip6->ip6_plen == 0 && !has_jumbo_option(ip6)) {' 831 */ 832 if (ip6->ip6_plen == 0) { 833 if (pkt->payload_len <= ETH_MAX_IP_DGRAM_LEN) { 834 ip6->ip6_plen = htons(pkt->payload_len); 835 } 836 /* 837 * TODO: if qemu would support >64K packets 838 * add jumbo option for packets greater then 65,535 bytes 839 */ 840 } 841 } 842 } 843