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 "hw/hw.h" 20 #include "net_tx_pkt.h" 21 #include "net/eth.h" 22 #include "qemu-common.h" 23 #include "qemu/iov.h" 24 #include "net/checksum.h" 25 #include "net/tap.h" 26 #include "net/net.h" 27 28 enum { 29 NET_TX_PKT_VHDR_FRAG = 0, 30 NET_TX_PKT_L2HDR_FRAG, 31 NET_TX_PKT_L3HDR_FRAG, 32 NET_TX_PKT_PL_START_FRAG 33 }; 34 35 /* TX packet private context */ 36 struct NetTxPkt { 37 struct virtio_net_hdr virt_hdr; 38 bool has_virt_hdr; 39 40 struct iovec *raw; 41 uint32_t raw_frags; 42 uint32_t max_raw_frags; 43 44 struct iovec *vec; 45 46 uint8_t l2_hdr[ETH_MAX_L2_HDR_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, uint32_t max_frags, 59 bool has_virt_hdr) 60 { 61 struct NetTxPkt *p = g_malloc0(sizeof *p); 62 63 p->vec = g_malloc((sizeof *p->vec) * 64 (max_frags + NET_TX_PKT_PL_START_FRAG)); 65 66 p->raw = g_malloc((sizeof *p->raw) * max_frags); 67 68 p->max_payload_frags = max_frags; 69 p->max_raw_frags = max_frags; 70 p->has_virt_hdr = has_virt_hdr; 71 p->vec[NET_TX_PKT_VHDR_FRAG].iov_base = &p->virt_hdr; 72 p->vec[NET_TX_PKT_VHDR_FRAG].iov_len = 73 p->has_virt_hdr ? sizeof p->virt_hdr : 0; 74 p->vec[NET_TX_PKT_L2HDR_FRAG].iov_base = &p->l2_hdr; 75 p->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = NULL; 76 p->vec[NET_TX_PKT_L3HDR_FRAG].iov_len = 0; 77 78 *pkt = p; 79 } 80 81 void net_tx_pkt_uninit(struct NetTxPkt *pkt) 82 { 83 if (pkt) { 84 g_free(pkt->vec); 85 g_free(pkt->raw); 86 g_free(pkt); 87 } 88 } 89 90 void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt) 91 { 92 uint16_t csum; 93 uint32_t ph_raw_csum; 94 assert(pkt); 95 uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN; 96 struct ip_header *ip_hdr; 97 98 if (VIRTIO_NET_HDR_GSO_TCPV4 != gso_type && 99 VIRTIO_NET_HDR_GSO_UDP != gso_type) { 100 return; 101 } 102 103 ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base; 104 105 if (pkt->payload_len + pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len > 106 ETH_MAX_IP_DGRAM_LEN) { 107 return; 108 } 109 110 ip_hdr->ip_len = cpu_to_be16(pkt->payload_len + 111 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len); 112 113 /* Calculate IP header checksum */ 114 ip_hdr->ip_sum = 0; 115 csum = net_raw_checksum((uint8_t *)ip_hdr, 116 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len); 117 ip_hdr->ip_sum = cpu_to_be16(csum); 118 119 /* Calculate IP pseudo header checksum */ 120 ph_raw_csum = eth_calc_pseudo_hdr_csum(ip_hdr, pkt->payload_len); 121 csum = cpu_to_be16(~net_checksum_finish(ph_raw_csum)); 122 iov_from_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags, 123 pkt->virt_hdr.csum_offset, &csum, sizeof(csum)); 124 } 125 126 static void net_tx_pkt_calculate_hdr_len(struct NetTxPkt *pkt) 127 { 128 pkt->hdr_len = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len + 129 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len; 130 } 131 132 static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt) 133 { 134 struct iovec *l2_hdr, *l3_hdr; 135 size_t bytes_read; 136 size_t full_ip6hdr_len; 137 uint16_t l3_proto; 138 139 assert(pkt); 140 141 l2_hdr = &pkt->vec[NET_TX_PKT_L2HDR_FRAG]; 142 l3_hdr = &pkt->vec[NET_TX_PKT_L3HDR_FRAG]; 143 144 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, 0, l2_hdr->iov_base, 145 ETH_MAX_L2_HDR_LEN); 146 if (bytes_read < sizeof(struct eth_header)) { 147 l2_hdr->iov_len = 0; 148 return false; 149 } 150 151 l2_hdr->iov_len = sizeof(struct eth_header); 152 switch (be16_to_cpu(PKT_GET_ETH_HDR(l2_hdr->iov_base)->h_proto)) { 153 case ETH_P_VLAN: 154 l2_hdr->iov_len += sizeof(struct vlan_header); 155 break; 156 case ETH_P_DVLAN: 157 l2_hdr->iov_len += 2 * sizeof(struct vlan_header); 158 break; 159 } 160 161 if (bytes_read < l2_hdr->iov_len) { 162 l2_hdr->iov_len = 0; 163 return false; 164 } 165 166 l3_proto = eth_get_l3_proto(l2_hdr->iov_base, l2_hdr->iov_len); 167 168 switch (l3_proto) { 169 case ETH_P_IP: 170 l3_hdr->iov_base = g_malloc(ETH_MAX_IP4_HDR_LEN); 171 172 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 173 l3_hdr->iov_base, sizeof(struct ip_header)); 174 175 if (bytes_read < sizeof(struct ip_header)) { 176 l3_hdr->iov_len = 0; 177 return false; 178 } 179 180 l3_hdr->iov_len = IP_HDR_GET_LEN(l3_hdr->iov_base); 181 pkt->l4proto = ((struct ip_header *) l3_hdr->iov_base)->ip_p; 182 183 /* copy optional IPv4 header data */ 184 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, 185 l2_hdr->iov_len + sizeof(struct ip_header), 186 l3_hdr->iov_base + sizeof(struct ip_header), 187 l3_hdr->iov_len - sizeof(struct ip_header)); 188 if (bytes_read < l3_hdr->iov_len - sizeof(struct ip_header)) { 189 l3_hdr->iov_len = 0; 190 return false; 191 } 192 break; 193 194 case ETH_P_IPV6: 195 if (!eth_parse_ipv6_hdr(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 196 &pkt->l4proto, &full_ip6hdr_len)) { 197 l3_hdr->iov_len = 0; 198 return false; 199 } 200 201 l3_hdr->iov_base = g_malloc(full_ip6hdr_len); 202 203 bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len, 204 l3_hdr->iov_base, full_ip6hdr_len); 205 206 if (bytes_read < full_ip6hdr_len) { 207 l3_hdr->iov_len = 0; 208 return false; 209 } else { 210 l3_hdr->iov_len = full_ip6hdr_len; 211 } 212 break; 213 214 default: 215 l3_hdr->iov_len = 0; 216 break; 217 } 218 219 net_tx_pkt_calculate_hdr_len(pkt); 220 pkt->packet_type = get_eth_packet_type(l2_hdr->iov_base); 221 return true; 222 } 223 224 static bool net_tx_pkt_rebuild_payload(struct NetTxPkt *pkt) 225 { 226 size_t payload_len = iov_size(pkt->raw, pkt->raw_frags) - pkt->hdr_len; 227 228 pkt->payload_frags = iov_copy(&pkt->vec[NET_TX_PKT_PL_START_FRAG], 229 pkt->max_payload_frags, 230 pkt->raw, pkt->raw_frags, 231 pkt->hdr_len, payload_len); 232 233 if (pkt->payload_frags != (uint32_t) -1) { 234 pkt->payload_len = payload_len; 235 return true; 236 } else { 237 return false; 238 } 239 } 240 241 bool net_tx_pkt_parse(struct NetTxPkt *pkt) 242 { 243 return net_tx_pkt_parse_headers(pkt) && 244 net_tx_pkt_rebuild_payload(pkt); 245 } 246 247 struct virtio_net_hdr *net_tx_pkt_get_vhdr(struct NetTxPkt *pkt) 248 { 249 assert(pkt); 250 return &pkt->virt_hdr; 251 } 252 253 static uint8_t net_tx_pkt_get_gso_type(struct NetTxPkt *pkt, 254 bool tso_enable) 255 { 256 uint8_t rc = VIRTIO_NET_HDR_GSO_NONE; 257 uint16_t l3_proto; 258 259 l3_proto = eth_get_l3_proto(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base, 260 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len); 261 262 if (!tso_enable) { 263 goto func_exit; 264 } 265 266 rc = eth_get_gso_type(l3_proto, pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base, 267 pkt->l4proto); 268 269 func_exit: 270 return rc; 271 } 272 273 void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable, 274 bool csum_enable, uint32_t gso_size) 275 { 276 struct tcp_hdr l4hdr; 277 assert(pkt); 278 279 /* csum has to be enabled if tso is. */ 280 assert(csum_enable || !tso_enable); 281 282 pkt->virt_hdr.gso_type = net_tx_pkt_get_gso_type(pkt, tso_enable); 283 284 switch (pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { 285 case VIRTIO_NET_HDR_GSO_NONE: 286 pkt->virt_hdr.hdr_len = 0; 287 pkt->virt_hdr.gso_size = 0; 288 break; 289 290 case VIRTIO_NET_HDR_GSO_UDP: 291 pkt->virt_hdr.gso_size = IP_FRAG_ALIGN_SIZE(gso_size); 292 pkt->virt_hdr.hdr_len = pkt->hdr_len + sizeof(struct udp_header); 293 break; 294 295 case VIRTIO_NET_HDR_GSO_TCPV4: 296 case VIRTIO_NET_HDR_GSO_TCPV6: 297 iov_to_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags, 298 0, &l4hdr, sizeof(l4hdr)); 299 pkt->virt_hdr.hdr_len = pkt->hdr_len + l4hdr.th_off * sizeof(uint32_t); 300 pkt->virt_hdr.gso_size = IP_FRAG_ALIGN_SIZE(gso_size); 301 break; 302 303 default: 304 g_assert_not_reached(); 305 } 306 307 if (csum_enable) { 308 switch (pkt->l4proto) { 309 case IP_PROTO_TCP: 310 pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 311 pkt->virt_hdr.csum_start = pkt->hdr_len; 312 pkt->virt_hdr.csum_offset = offsetof(struct tcp_hdr, th_sum); 313 break; 314 case IP_PROTO_UDP: 315 pkt->virt_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; 316 pkt->virt_hdr.csum_start = pkt->hdr_len; 317 pkt->virt_hdr.csum_offset = offsetof(struct udp_hdr, uh_sum); 318 break; 319 default: 320 break; 321 } 322 } 323 } 324 325 void net_tx_pkt_setup_vlan_header(struct NetTxPkt *pkt, uint16_t vlan) 326 { 327 bool is_new; 328 assert(pkt); 329 330 eth_setup_vlan_headers(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base, 331 vlan, &is_new); 332 333 /* update l2hdrlen */ 334 if (is_new) { 335 pkt->hdr_len += sizeof(struct vlan_header); 336 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len += 337 sizeof(struct vlan_header); 338 } 339 } 340 341 bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa, 342 size_t len) 343 { 344 hwaddr mapped_len = 0; 345 struct iovec *ventry; 346 assert(pkt); 347 assert(pkt->max_raw_frags > pkt->raw_frags); 348 349 if (!len) { 350 return true; 351 } 352 353 ventry = &pkt->raw[pkt->raw_frags]; 354 mapped_len = len; 355 356 ventry->iov_base = cpu_physical_memory_map(pa, &mapped_len, false); 357 ventry->iov_len = mapped_len; 358 pkt->raw_frags += !!ventry->iov_base; 359 360 if ((ventry->iov_base == NULL) || (len != mapped_len)) { 361 return false; 362 } 363 364 return true; 365 } 366 367 eth_pkt_types_e net_tx_pkt_get_packet_type(struct NetTxPkt *pkt) 368 { 369 assert(pkt); 370 371 return pkt->packet_type; 372 } 373 374 size_t net_tx_pkt_get_total_len(struct NetTxPkt *pkt) 375 { 376 assert(pkt); 377 378 return pkt->hdr_len + pkt->payload_len; 379 } 380 381 void net_tx_pkt_dump(struct NetTxPkt *pkt) 382 { 383 #ifdef NET_TX_PKT_DEBUG 384 assert(pkt); 385 386 printf("TX PKT: hdr_len: %d, pkt_type: 0x%X, l2hdr_len: %lu, " 387 "l3hdr_len: %lu, payload_len: %u\n", pkt->hdr_len, pkt->packet_type, 388 pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len, 389 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len, pkt->payload_len); 390 #endif 391 } 392 393 void net_tx_pkt_reset(struct NetTxPkt *pkt) 394 { 395 int i; 396 397 /* no assert, as reset can be called before tx_pkt_init */ 398 if (!pkt) { 399 return; 400 } 401 402 memset(&pkt->virt_hdr, 0, sizeof(pkt->virt_hdr)); 403 404 g_free(pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base); 405 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = NULL; 406 407 assert(pkt->vec); 408 for (i = NET_TX_PKT_L2HDR_FRAG; 409 i < pkt->payload_frags + NET_TX_PKT_PL_START_FRAG; i++) { 410 pkt->vec[i].iov_len = 0; 411 } 412 pkt->payload_len = 0; 413 pkt->payload_frags = 0; 414 415 assert(pkt->raw); 416 for (i = 0; i < pkt->raw_frags; i++) { 417 assert(pkt->raw[i].iov_base); 418 cpu_physical_memory_unmap(pkt->raw[i].iov_base, pkt->raw[i].iov_len, 419 false, pkt->raw[i].iov_len); 420 pkt->raw[i].iov_len = 0; 421 } 422 pkt->raw_frags = 0; 423 424 pkt->hdr_len = 0; 425 pkt->packet_type = 0; 426 pkt->l4proto = 0; 427 } 428 429 static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt) 430 { 431 struct iovec *iov = &pkt->vec[NET_TX_PKT_L2HDR_FRAG]; 432 uint32_t csum_cntr; 433 uint16_t csum = 0; 434 /* num of iovec without vhdr */ 435 uint32_t iov_len = pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1; 436 uint16_t csl; 437 struct ip_header *iphdr; 438 size_t csum_offset = pkt->virt_hdr.csum_start + pkt->virt_hdr.csum_offset; 439 440 /* Put zero to checksum field */ 441 iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum); 442 443 /* Calculate L4 TCP/UDP checksum */ 444 csl = pkt->payload_len; 445 446 /* data checksum */ 447 csum_cntr = 448 net_checksum_add_iov(iov, iov_len, pkt->virt_hdr.csum_start, csl); 449 /* add pseudo header to csum */ 450 iphdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base; 451 csum_cntr += eth_calc_pseudo_hdr_csum(iphdr, csl); 452 453 /* Put the checksum obtained into the packet */ 454 csum = cpu_to_be16(net_checksum_finish(csum_cntr)); 455 iov_from_buf(iov, iov_len, csum_offset, &csum, sizeof csum); 456 } 457 458 enum { 459 NET_TX_PKT_FRAGMENT_L2_HDR_POS = 0, 460 NET_TX_PKT_FRAGMENT_L3_HDR_POS, 461 NET_TX_PKT_FRAGMENT_HEADER_NUM 462 }; 463 464 #define NET_MAX_FRAG_SG_LIST (64) 465 466 static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt, 467 int *src_idx, size_t *src_offset, struct iovec *dst, int *dst_idx) 468 { 469 size_t fetched = 0; 470 struct iovec *src = pkt->vec; 471 472 *dst_idx = NET_TX_PKT_FRAGMENT_HEADER_NUM; 473 474 while (fetched < pkt->virt_hdr.gso_size) { 475 476 /* no more place in fragment iov */ 477 if (*dst_idx == NET_MAX_FRAG_SG_LIST) { 478 break; 479 } 480 481 /* no more data in iovec */ 482 if (*src_idx == (pkt->payload_frags + NET_TX_PKT_PL_START_FRAG)) { 483 break; 484 } 485 486 487 dst[*dst_idx].iov_base = src[*src_idx].iov_base + *src_offset; 488 dst[*dst_idx].iov_len = MIN(src[*src_idx].iov_len - *src_offset, 489 pkt->virt_hdr.gso_size - fetched); 490 491 *src_offset += dst[*dst_idx].iov_len; 492 fetched += dst[*dst_idx].iov_len; 493 494 if (*src_offset == src[*src_idx].iov_len) { 495 *src_offset = 0; 496 (*src_idx)++; 497 } 498 499 (*dst_idx)++; 500 } 501 502 return fetched; 503 } 504 505 static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt, 506 NetClientState *nc) 507 { 508 struct iovec fragment[NET_MAX_FRAG_SG_LIST]; 509 size_t fragment_len = 0; 510 bool more_frags = false; 511 512 /* some pointers for shorter code */ 513 void *l2_iov_base, *l3_iov_base; 514 size_t l2_iov_len, l3_iov_len; 515 int src_idx = NET_TX_PKT_PL_START_FRAG, dst_idx; 516 size_t src_offset = 0; 517 size_t fragment_offset = 0; 518 519 l2_iov_base = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base; 520 l2_iov_len = pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len; 521 l3_iov_base = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base; 522 l3_iov_len = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len; 523 524 /* Copy headers */ 525 fragment[NET_TX_PKT_FRAGMENT_L2_HDR_POS].iov_base = l2_iov_base; 526 fragment[NET_TX_PKT_FRAGMENT_L2_HDR_POS].iov_len = l2_iov_len; 527 fragment[NET_TX_PKT_FRAGMENT_L3_HDR_POS].iov_base = l3_iov_base; 528 fragment[NET_TX_PKT_FRAGMENT_L3_HDR_POS].iov_len = l3_iov_len; 529 530 531 /* Put as much data as possible and send */ 532 do { 533 fragment_len = net_tx_pkt_fetch_fragment(pkt, &src_idx, &src_offset, 534 fragment, &dst_idx); 535 536 more_frags = (fragment_offset + fragment_len < pkt->payload_len); 537 538 eth_setup_ip4_fragmentation(l2_iov_base, l2_iov_len, l3_iov_base, 539 l3_iov_len, fragment_len, fragment_offset, more_frags); 540 541 eth_fix_ip4_checksum(l3_iov_base, l3_iov_len); 542 543 qemu_sendv_packet(nc, fragment, dst_idx); 544 545 fragment_offset += fragment_len; 546 547 } while (more_frags); 548 549 return true; 550 } 551 552 bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc) 553 { 554 assert(pkt); 555 556 if (!pkt->has_virt_hdr && 557 pkt->virt_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { 558 net_tx_pkt_do_sw_csum(pkt); 559 } 560 561 /* 562 * Since underlying infrastructure does not support IP datagrams longer 563 * than 64K we should drop such packets and don't even try to send 564 */ 565 if (VIRTIO_NET_HDR_GSO_NONE != pkt->virt_hdr.gso_type) { 566 if (pkt->payload_len > 567 ETH_MAX_IP_DGRAM_LEN - 568 pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len) { 569 return false; 570 } 571 } 572 573 if (pkt->has_virt_hdr || 574 pkt->virt_hdr.gso_type == VIRTIO_NET_HDR_GSO_NONE) { 575 qemu_sendv_packet(nc, pkt->vec, 576 pkt->payload_frags + NET_TX_PKT_PL_START_FRAG); 577 return true; 578 } 579 580 return net_tx_pkt_do_sw_fragmentation(pkt, nc); 581 } 582