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sys/netinet/tcp_lro.c
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1 /*- 2 * Copyright (c) 2007, Myricom Inc. 3 * Copyright (c) 2008, Intel Corporation. 4 * Copyright (c) 2012 The FreeBSD Foundation 5 * Copyright (c) 2016 Mellanox Technologies. 6 * All rights reserved. 7 * 8 * Portions of this software were developed by Bjoern Zeeb 9 * under sponsorship from the FreeBSD Foundation. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD: releng/11.1/sys/netinet/tcp_lro.c 318772 2017-05-24 03:56:48Z np $"); 35 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/socket.h> 45 #include <sys/sysctl.h> 46 47 #include <net/if.h> 48 #include <net/if_var.h> 49 #include <net/ethernet.h> 50 #include <net/vnet.h> 51 52 #include <netinet/in_systm.h> 53 #include <netinet/in.h> 54 #include <netinet/ip6.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_var.h> 57 #include <netinet/tcp.h> 58 #include <netinet/tcp_lro.h> 59 #include <netinet/tcp_var.h> 60 61 #include <netinet6/ip6_var.h> 62 63 #include <machine/in_cksum.h> 64 65 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures"); 66 67 #define TCP_LRO_UPDATE_CSUM 1 68 #ifndef TCP_LRO_UPDATE_CSUM 69 #define TCP_LRO_INVALID_CSUM 0x0000 70 #endif 71 72 static void tcp_lro_rx_done(struct lro_ctrl *lc); 73 74 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 75 "TCP LRO"); 76 77 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES; 78 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries, 79 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0, 80 "default number of LRO entries"); 81 82 static __inline void 83 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_entry *le) 84 { 85 86 LIST_INSERT_HEAD(&lc->lro_active, le, next); 87 } 88 89 static __inline void 90 tcp_lro_active_remove(struct lro_entry *le) 91 { 92 93 LIST_REMOVE(le, next); 94 } 95 96 int 97 tcp_lro_init(struct lro_ctrl *lc) 98 { 99 return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0)); 100 } 101 102 int 103 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp, 104 unsigned lro_entries, unsigned lro_mbufs) 105 { 106 struct lro_entry *le; 107 size_t size; 108 unsigned i; 109 110 lc->lro_bad_csum = 0; 111 lc->lro_queued = 0; 112 lc->lro_flushed = 0; 113 lc->lro_mbuf_count = 0; 114 lc->lro_mbuf_max = lro_mbufs; 115 lc->lro_cnt = lro_entries; 116 lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX; 117 lc->lro_length_lim = TCP_LRO_LENGTH_MAX; 118 lc->ifp = ifp; 119 LIST_INIT(&lc->lro_free); 120 LIST_INIT(&lc->lro_active); 121 122 /* compute size to allocate */ 123 size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) + 124 (lro_entries * sizeof(*le)); 125 lc->lro_mbuf_data = (struct lro_mbuf_sort *) 126 malloc(size, M_LRO, M_NOWAIT | M_ZERO); 127 128 /* check for out of memory */ 129 if (lc->lro_mbuf_data == NULL) { 130 memset(lc, 0, sizeof(*lc)); 131 return (ENOMEM); 132 } 133 /* compute offset for LRO entries */ 134 le = (struct lro_entry *) 135 (lc->lro_mbuf_data + lro_mbufs); 136 137 /* setup linked list */ 138 for (i = 0; i != lro_entries; i++) 139 LIST_INSERT_HEAD(&lc->lro_free, le + i, next); 140 141 return (0); 142 } 143 144 void 145 tcp_lro_free(struct lro_ctrl *lc) 146 { 147 struct lro_entry *le; 148 unsigned x; 149 150 /* reset LRO free list */ 151 LIST_INIT(&lc->lro_free); 152 153 /* free active mbufs, if any */ 154 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) { 155 tcp_lro_active_remove(le); 156 m_freem(le->m_head); 157 } 158 159 /* free mbuf array, if any */ 160 for (x = 0; x != lc->lro_mbuf_count; x++) 161 m_freem(lc->lro_mbuf_data[x].mb); 162 lc->lro_mbuf_count = 0; 163 164 /* free allocated memory, if any */ 165 free(lc->lro_mbuf_data, M_LRO); 166 lc->lro_mbuf_data = NULL; 167 } 168 169 #ifdef TCP_LRO_UPDATE_CSUM 170 static uint16_t 171 tcp_lro_csum_th(struct tcphdr *th) 172 { 173 uint32_t ch; 174 uint16_t *p, l; 175 176 ch = th->th_sum = 0x0000; 177 l = th->th_off; 178 p = (uint16_t *)th; 179 while (l > 0) { 180 ch += *p; 181 p++; 182 ch += *p; 183 p++; 184 l--; 185 } 186 while (ch > 0xffff) 187 ch = (ch >> 16) + (ch & 0xffff); 188 189 return (ch & 0xffff); 190 } 191 192 static uint16_t 193 tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th, 194 uint16_t tcp_data_len, uint16_t csum) 195 { 196 uint32_t c; 197 uint16_t cs; 198 199 c = csum; 200 201 /* Remove length from checksum. */ 202 switch (le->eh_type) { 203 #ifdef INET6 204 case ETHERTYPE_IPV6: 205 { 206 struct ip6_hdr *ip6; 207 208 ip6 = (struct ip6_hdr *)l3hdr; 209 if (le->append_cnt == 0) 210 cs = ip6->ip6_plen; 211 else { 212 uint32_t cx; 213 214 cx = ntohs(ip6->ip6_plen); 215 cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0); 216 } 217 break; 218 } 219 #endif 220 #ifdef INET 221 case ETHERTYPE_IP: 222 { 223 struct ip *ip4; 224 225 ip4 = (struct ip *)l3hdr; 226 if (le->append_cnt == 0) 227 cs = ip4->ip_len; 228 else { 229 cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4), 230 IPPROTO_TCP); 231 cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr, 232 htons(cs)); 233 } 234 break; 235 } 236 #endif 237 default: 238 cs = 0; /* Keep compiler happy. */ 239 } 240 241 cs = ~cs; 242 c += cs; 243 244 /* Remove TCP header csum. */ 245 cs = ~tcp_lro_csum_th(th); 246 c += cs; 247 while (c > 0xffff) 248 c = (c >> 16) + (c & 0xffff); 249 250 return (c & 0xffff); 251 } 252 #endif 253 254 static void 255 tcp_lro_rx_done(struct lro_ctrl *lc) 256 { 257 struct lro_entry *le; 258 259 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) { 260 tcp_lro_active_remove(le); 261 tcp_lro_flush(lc, le); 262 } 263 } 264 265 void 266 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout) 267 { 268 struct lro_entry *le, *le_tmp; 269 struct timeval tv; 270 271 if (LIST_EMPTY(&lc->lro_active)) 272 return; 273 274 getmicrotime(&tv); 275 timevalsub(&tv, timeout); 276 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) { 277 if (timevalcmp(&tv, &le->mtime, >=)) { 278 tcp_lro_active_remove(le); 279 tcp_lro_flush(lc, le); 280 } 281 } 282 } 283 284 void 285 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le) 286 { 287 288 if (le->append_cnt > 0) { 289 struct tcphdr *th; 290 uint16_t p_len; 291 292 p_len = htons(le->p_len); 293 switch (le->eh_type) { 294 #ifdef INET6 295 case ETHERTYPE_IPV6: 296 { 297 struct ip6_hdr *ip6; 298 299 ip6 = le->le_ip6; 300 ip6->ip6_plen = p_len; 301 th = (struct tcphdr *)(ip6 + 1); 302 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | 303 CSUM_PSEUDO_HDR; 304 le->p_len += ETHER_HDR_LEN + sizeof(*ip6); 305 break; 306 } 307 #endif 308 #ifdef INET 309 case ETHERTYPE_IP: 310 { 311 struct ip *ip4; 312 #ifdef TCP_LRO_UPDATE_CSUM 313 uint32_t cl; 314 uint16_t c; 315 #endif 316 317 ip4 = le->le_ip4; 318 #ifdef TCP_LRO_UPDATE_CSUM 319 /* Fix IP header checksum for new length. */ 320 c = ~ip4->ip_sum; 321 cl = c; 322 c = ~ip4->ip_len; 323 cl += c + p_len; 324 while (cl > 0xffff) 325 cl = (cl >> 16) + (cl & 0xffff); 326 c = cl; 327 ip4->ip_sum = ~c; 328 #else 329 ip4->ip_sum = TCP_LRO_INVALID_CSUM; 330 #endif 331 ip4->ip_len = p_len; 332 th = (struct tcphdr *)(ip4 + 1); 333 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | 334 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID; 335 le->p_len += ETHER_HDR_LEN; 336 break; 337 } 338 #endif 339 default: 340 th = NULL; /* Keep compiler happy. */ 341 } 342 le->m_head->m_pkthdr.csum_data = 0xffff; 343 le->m_head->m_pkthdr.len = le->p_len; 344 345 /* Incorporate the latest ACK into the TCP header. */ 346 th->th_ack = le->ack_seq; 347 th->th_win = le->window; 348 /* Incorporate latest timestamp into the TCP header. */ 349 if (le->timestamp != 0) { 350 uint32_t *ts_ptr; 351 352 ts_ptr = (uint32_t *)(th + 1); 353 ts_ptr[1] = htonl(le->tsval); 354 ts_ptr[2] = le->tsecr; 355 } 356 #ifdef TCP_LRO_UPDATE_CSUM 357 /* Update the TCP header checksum. */ 358 le->ulp_csum += p_len; 359 le->ulp_csum += tcp_lro_csum_th(th); 360 while (le->ulp_csum > 0xffff) 361 le->ulp_csum = (le->ulp_csum >> 16) + 362 (le->ulp_csum & 0xffff); 363 th->th_sum = (le->ulp_csum & 0xffff); 364 th->th_sum = ~th->th_sum; 365 #else 366 th->th_sum = TCP_LRO_INVALID_CSUM; 367 #endif 368 } 369 370 (*lc->ifp->if_input)(lc->ifp, le->m_head); 371 lc->lro_queued += le->append_cnt + 1; 372 lc->lro_flushed++; 373 bzero(le, sizeof(*le)); 374 LIST_INSERT_HEAD(&lc->lro_free, le, next); 375 } 376 377 #ifdef HAVE_INLINE_FLSLL 378 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1)) 379 #else 380 static inline uint64_t 381 tcp_lro_msb_64(uint64_t x) 382 { 383 x |= (x >> 1); 384 x |= (x >> 2); 385 x |= (x >> 4); 386 x |= (x >> 8); 387 x |= (x >> 16); 388 x |= (x >> 32); 389 return (x & ~(x >> 1)); 390 } 391 #endif 392 393 /* 394 * The tcp_lro_sort() routine is comparable to qsort(), except it has 395 * a worst case complexity limit of O(MIN(N,64)*N), where N is the 396 * number of elements to sort and 64 is the number of sequence bits 397 * available. The algorithm is bit-slicing the 64-bit sequence number, 398 * sorting one bit at a time from the most significant bit until the 399 * least significant one, skipping the constant bits. This is 400 * typically called a radix sort. 401 */ 402 static void 403 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size) 404 { 405 struct lro_mbuf_sort temp; 406 uint64_t ones; 407 uint64_t zeros; 408 uint32_t x; 409 uint32_t y; 410 411 repeat: 412 /* for small arrays insertion sort is faster */ 413 if (size <= 12) { 414 for (x = 1; x < size; x++) { 415 temp = parray[x]; 416 for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--) 417 parray[y] = parray[y - 1]; 418 parray[y] = temp; 419 } 420 return; 421 } 422 423 /* compute sequence bits which are constant */ 424 ones = 0; 425 zeros = 0; 426 for (x = 0; x != size; x++) { 427 ones |= parray[x].seq; 428 zeros |= ~parray[x].seq; 429 } 430 431 /* compute bits which are not constant into "ones" */ 432 ones &= zeros; 433 if (ones == 0) 434 return; 435 436 /* pick the most significant bit which is not constant */ 437 ones = tcp_lro_msb_64(ones); 438 439 /* 440 * Move entries having cleared sequence bits to the beginning 441 * of the array: 442 */ 443 for (x = y = 0; y != size; y++) { 444 /* skip set bits */ 445 if (parray[y].seq & ones) 446 continue; 447 /* swap entries */ 448 temp = parray[x]; 449 parray[x] = parray[y]; 450 parray[y] = temp; 451 x++; 452 } 453 454 KASSERT(x != 0 && x != size, ("Memory is corrupted\n")); 455 456 /* sort zeros */ 457 tcp_lro_sort(parray, x); 458 459 /* sort ones */ 460 parray += x; 461 size -= x; 462 goto repeat; 463 } 464 465 void 466 tcp_lro_flush_all(struct lro_ctrl *lc) 467 { 468 uint64_t seq; 469 uint64_t nseq; 470 unsigned x; 471 472 /* check if no mbufs to flush */ 473 if (lc->lro_mbuf_count == 0) 474 goto done; 475 476 /* sort all mbufs according to stream */ 477 tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count); 478 479 /* input data into LRO engine, stream by stream */ 480 seq = 0; 481 for (x = 0; x != lc->lro_mbuf_count; x++) { 482 struct mbuf *mb; 483 484 /* get mbuf */ 485 mb = lc->lro_mbuf_data[x].mb; 486 487 /* get sequence number, masking away the packet index */ 488 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24); 489 490 /* check for new stream */ 491 if (seq != nseq) { 492 seq = nseq; 493 494 /* flush active streams */ 495 tcp_lro_rx_done(lc); 496 } 497 498 /* add packet to LRO engine */ 499 if (tcp_lro_rx(lc, mb, 0) != 0) { 500 /* input packet to network layer */ 501 (*lc->ifp->if_input)(lc->ifp, mb); 502 lc->lro_queued++; 503 lc->lro_flushed++; 504 } 505 } 506 done: 507 /* flush active streams */ 508 tcp_lro_rx_done(lc); 509 510 lc->lro_mbuf_count = 0; 511 } 512 513 #ifdef INET6 514 static int 515 tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6, 516 struct tcphdr **th) 517 { 518 519 /* XXX-BZ we should check the flow-label. */ 520 521 /* XXX-BZ We do not yet support ext. hdrs. */ 522 if (ip6->ip6_nxt != IPPROTO_TCP) 523 return (TCP_LRO_NOT_SUPPORTED); 524 525 /* Find the TCP header. */ 526 *th = (struct tcphdr *)(ip6 + 1); 527 528 return (0); 529 } 530 #endif 531 532 #ifdef INET 533 static int 534 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4, 535 struct tcphdr **th) 536 { 537 int csum_flags; 538 uint16_t csum; 539 540 if (ip4->ip_p != IPPROTO_TCP) 541 return (TCP_LRO_NOT_SUPPORTED); 542 543 /* Ensure there are no options. */ 544 if ((ip4->ip_hl << 2) != sizeof (*ip4)) 545 return (TCP_LRO_CANNOT); 546 547 /* .. and the packet is not fragmented. */ 548 if (ip4->ip_off & htons(IP_MF|IP_OFFMASK)) 549 return (TCP_LRO_CANNOT); 550 551 /* Legacy IP has a header checksum that needs to be correct. */ 552 csum_flags = m->m_pkthdr.csum_flags; 553 if (csum_flags & CSUM_IP_CHECKED) { 554 if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) { 555 lc->lro_bad_csum++; 556 return (TCP_LRO_CANNOT); 557 } 558 } else { 559 csum = in_cksum_hdr(ip4); 560 if (__predict_false((csum) != 0)) { 561 lc->lro_bad_csum++; 562 return (TCP_LRO_CANNOT); 563 } 564 } 565 566 /* Find the TCP header (we assured there are no IP options). */ 567 *th = (struct tcphdr *)(ip4 + 1); 568 569 return (0); 570 } 571 #endif 572 573 int 574 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum) 575 { 576 struct lro_entry *le; 577 struct ether_header *eh; 578 #ifdef INET6 579 struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */ 580 #endif 581 #ifdef INET 582 struct ip *ip4 = NULL; /* Keep compiler happy. */ 583 #endif 584 struct tcphdr *th; 585 void *l3hdr = NULL; /* Keep compiler happy. */ 586 uint32_t *ts_ptr; 587 tcp_seq seq; 588 int error, ip_len, l; 589 uint16_t eh_type, tcp_data_len; 590 int force_flush = 0; 591 592 /* We expect a contiguous header [eh, ip, tcp]. */ 593 594 eh = mtod(m, struct ether_header *); 595 eh_type = ntohs(eh->ether_type); 596 switch (eh_type) { 597 #ifdef INET6 598 case ETHERTYPE_IPV6: 599 { 600 CURVNET_SET(lc->ifp->if_vnet); 601 if (V_ip6_forwarding != 0) { 602 /* XXX-BZ stats but changing lro_ctrl is a problem. */ 603 CURVNET_RESTORE(); 604 return (TCP_LRO_CANNOT); 605 } 606 CURVNET_RESTORE(); 607 l3hdr = ip6 = (struct ip6_hdr *)(eh + 1); 608 error = tcp_lro_rx_ipv6(lc, m, ip6, &th); 609 if (error != 0) 610 return (error); 611 tcp_data_len = ntohs(ip6->ip6_plen); 612 ip_len = sizeof(*ip6) + tcp_data_len; 613 break; 614 } 615 #endif 616 #ifdef INET 617 case ETHERTYPE_IP: 618 { 619 CURVNET_SET(lc->ifp->if_vnet); 620 if (V_ipforwarding != 0) { 621 /* XXX-BZ stats but changing lro_ctrl is a problem. */ 622 CURVNET_RESTORE(); 623 return (TCP_LRO_CANNOT); 624 } 625 CURVNET_RESTORE(); 626 l3hdr = ip4 = (struct ip *)(eh + 1); 627 error = tcp_lro_rx_ipv4(lc, m, ip4, &th); 628 if (error != 0) 629 return (error); 630 ip_len = ntohs(ip4->ip_len); 631 tcp_data_len = ip_len - sizeof(*ip4); 632 break; 633 } 634 #endif 635 /* XXX-BZ what happens in case of VLAN(s)? */ 636 default: 637 return (TCP_LRO_NOT_SUPPORTED); 638 } 639 640 /* 641 * If the frame is padded beyond the end of the IP packet, then we must 642 * trim the extra bytes off. 643 */ 644 l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len); 645 if (l != 0) { 646 if (l < 0) 647 /* Truncated packet. */ 648 return (TCP_LRO_CANNOT); 649 650 m_adj(m, -l); 651 } 652 653 /* 654 * Check TCP header constraints. 655 */ 656 /* Ensure no bits set besides ACK or PSH. */ 657 if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) { 658 if (th->th_flags & TH_SYN) 659 return (TCP_LRO_CANNOT); 660 /* 661 * Make sure that previously seen segements/ACKs are delivered 662 * before this segement, e.g. FIN. 663 */ 664 force_flush = 1; 665 } 666 667 /* XXX-BZ We lose a ACK|PUSH flag concatenating multiple segments. */ 668 /* XXX-BZ Ideally we'd flush on PUSH? */ 669 670 /* 671 * Check for timestamps. 672 * Since the only option we handle are timestamps, we only have to 673 * handle the simple case of aligned timestamps. 674 */ 675 l = (th->th_off << 2); 676 tcp_data_len -= l; 677 l -= sizeof(*th); 678 ts_ptr = (uint32_t *)(th + 1); 679 if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) || 680 (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16| 681 TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) { 682 /* 683 * Make sure that previously seen segements/ACKs are delivered 684 * before this segement. 685 */ 686 force_flush = 1; 687 } 688 689 /* If the driver did not pass in the checksum, set it now. */ 690 if (csum == 0x0000) 691 csum = th->th_sum; 692 693 seq = ntohl(th->th_seq); 694 695 /* Try to find a matching previous segment. */ 696 LIST_FOREACH(le, &lc->lro_active, next) { 697 if (le->eh_type != eh_type) 698 continue; 699 if (le->source_port != th->th_sport || 700 le->dest_port != th->th_dport) 701 continue; 702 switch (eh_type) { 703 #ifdef INET6 704 case ETHERTYPE_IPV6: 705 if (bcmp(&le->source_ip6, &ip6->ip6_src, 706 sizeof(struct in6_addr)) != 0 || 707 bcmp(&le->dest_ip6, &ip6->ip6_dst, 708 sizeof(struct in6_addr)) != 0) 709 continue; 710 break; 711 #endif 712 #ifdef INET 713 case ETHERTYPE_IP: 714 if (le->source_ip4 != ip4->ip_src.s_addr || 715 le->dest_ip4 != ip4->ip_dst.s_addr) 716 continue; 717 break; 718 #endif 719 } 720 721 if (force_flush) { 722 /* Timestamps mismatch; this is a FIN, etc */ 723 tcp_lro_active_remove(le); 724 tcp_lro_flush(lc, le); 725 return (TCP_LRO_CANNOT); 726 } 727 728 /* Flush now if appending will result in overflow. */ 729 if (le->p_len > (lc->lro_length_lim - tcp_data_len)) { 730 tcp_lro_active_remove(le); 731 tcp_lro_flush(lc, le); 732 break; 733 } 734 735 /* Try to append the new segment. */ 736 if (__predict_false(seq != le->next_seq || 737 (tcp_data_len == 0 && le->ack_seq == th->th_ack))) { 738 /* Out of order packet or duplicate ACK. */ 739 tcp_lro_active_remove(le); 740 tcp_lro_flush(lc, le); 741 return (TCP_LRO_CANNOT); 742 } 743 744 if (l != 0) { 745 uint32_t tsval = ntohl(*(ts_ptr + 1)); 746 /* Make sure timestamp values are increasing. */ 747 /* XXX-BZ flip and use TSTMP_GEQ macro for this? */ 748 if (__predict_false(le->tsval > tsval || 749 *(ts_ptr + 2) == 0)) 750 return (TCP_LRO_CANNOT); 751 le->tsval = tsval; 752 le->tsecr = *(ts_ptr + 2); 753 } 754 755 le->next_seq += tcp_data_len; 756 le->ack_seq = th->th_ack; 757 le->window = th->th_win; 758 le->append_cnt++; 759 760 #ifdef TCP_LRO_UPDATE_CSUM 761 le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th, 762 tcp_data_len, ~csum); 763 #endif 764 765 if (tcp_data_len == 0) { 766 m_freem(m); 767 /* 768 * Flush this LRO entry, if this ACK should not 769 * be further delayed. 770 */ 771 if (le->append_cnt >= lc->lro_ackcnt_lim) { 772 tcp_lro_active_remove(le); 773 tcp_lro_flush(lc, le); 774 } 775 return (0); 776 } 777 778 le->p_len += tcp_data_len; 779 780 /* 781 * Adjust the mbuf so that m_data points to the first byte of 782 * the ULP payload. Adjust the mbuf to avoid complications and 783 * append new segment to existing mbuf chain. 784 */ 785 m_adj(m, m->m_pkthdr.len - tcp_data_len); 786 m_demote_pkthdr(m); 787 788 le->m_tail->m_next = m; 789 le->m_tail = m_last(m); 790 791 /* 792 * If a possible next full length packet would cause an 793 * overflow, pro-actively flush now. 794 */ 795 if (le->p_len > (lc->lro_length_lim - lc->ifp->if_mtu)) { 796 tcp_lro_active_remove(le); 797 tcp_lro_flush(lc, le); 798 } else 799 getmicrotime(&le->mtime); 800 801 return (0); 802 } 803 804 if (force_flush) { 805 /* 806 * Nothing to flush, but this segment can not be further 807 * aggregated/delayed. 808 */ 809 return (TCP_LRO_CANNOT); 810 } 811 812 /* Try to find an empty slot. */ 813 if (LIST_EMPTY(&lc->lro_free)) 814 return (TCP_LRO_NO_ENTRIES); 815 816 /* Start a new segment chain. */ 817 le = LIST_FIRST(&lc->lro_free); 818 LIST_REMOVE(le, next); 819 tcp_lro_active_insert(lc, le); 820 getmicrotime(&le->mtime); 821 822 /* Start filling in details. */ 823 switch (eh_type) { 824 #ifdef INET6 825 case ETHERTYPE_IPV6: 826 le->le_ip6 = ip6; 827 le->source_ip6 = ip6->ip6_src; 828 le->dest_ip6 = ip6->ip6_dst; 829 le->eh_type = eh_type; 830 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6); 831 break; 832 #endif 833 #ifdef INET 834 case ETHERTYPE_IP: 835 le->le_ip4 = ip4; 836 le->source_ip4 = ip4->ip_src.s_addr; 837 le->dest_ip4 = ip4->ip_dst.s_addr; 838 le->eh_type = eh_type; 839 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN; 840 break; 841 #endif 842 } 843 le->source_port = th->th_sport; 844 le->dest_port = th->th_dport; 845 846 le->next_seq = seq + tcp_data_len; 847 le->ack_seq = th->th_ack; 848 le->window = th->th_win; 849 if (l != 0) { 850 le->timestamp = 1; 851 le->tsval = ntohl(*(ts_ptr + 1)); 852 le->tsecr = *(ts_ptr + 2); 853 } 854 855 #ifdef TCP_LRO_UPDATE_CSUM 856 /* 857 * Do not touch the csum of the first packet. However save the 858 * "adjusted" checksum of just the source and destination addresses, 859 * the next header and the TCP payload. The length and TCP header 860 * parts may change, so we remove those from the saved checksum and 861 * re-add with final values on tcp_lro_flush() if needed. 862 */ 863 KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n", 864 __func__, le, le->ulp_csum)); 865 866 le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len, 867 ~csum); 868 th->th_sum = csum; /* Restore checksum on first packet. */ 869 #endif 870 871 le->m_head = m; 872 le->m_tail = m_last(m); 873 874 return (0); 875 } 876 877 void 878 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb) 879 { 880 /* sanity checks */ 881 if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL || 882 lc->lro_mbuf_max == 0)) { 883 /* packet drop */ 884 m_freem(mb); 885 return; 886 } 887 888 /* check if packet is not LRO capable */ 889 if (__predict_false(mb->m_pkthdr.csum_flags == 0 || 890 (lc->ifp->if_capenable & IFCAP_LRO) == 0)) { 891 892 /* input packet to network layer */ 893 (*lc->ifp->if_input) (lc->ifp, mb); 894 return; 895 } 896 897 /* create sequence number */ 898 lc->lro_mbuf_data[lc->lro_mbuf_count].seq = 899 (((uint64_t)M_HASHTYPE_GET(mb)) << 56) | 900 (((uint64_t)mb->m_pkthdr.flowid) << 24) | 901 ((uint64_t)lc->lro_mbuf_count); 902 903 /* enter mbuf */ 904 lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb; 905 906 /* flush if array is full */ 907 if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max)) 908 tcp_lro_flush_all(lc); 909 } 910 911 /* end */
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