1 /*- 2 * Copyright (c) 2007, Myricom Inc. 3 * Copyright (c) 2008, Intel Corporation. 4 * Copyright (c) 2012 The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * Portions of this software were developed by Bjoern Zeeb 8 * under sponsorship from the FreeBSD Foundation. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/mbuf.h> 41 #include <sys/kernel.h> 42 #include <sys/socket.h> 43 44 #include <net/if.h> 45 #include <net/if_var.h> 46 #include <net/ethernet.h> 47 #include <net/vnet.h> 48 49 #include <netinet/in_systm.h> 50 #include <netinet/in.h> 51 #include <netinet/ip6.h> 52 #include <netinet/ip.h> 53 #include <netinet/ip_var.h> 54 #include <netinet/tcp.h> 55 #include <netinet/tcp_lro.h> 56 57 #include <netinet6/ip6_var.h> 58 59 #include <machine/in_cksum.h> 60 61 #ifndef LRO_ENTRIES 62 #define LRO_ENTRIES 8 /* # of LRO entries per RX queue. */ 63 #endif 64 65 #define TCP_LRO_UPDATE_CSUM 1 66 #ifndef TCP_LRO_UPDATE_CSUM 67 #define TCP_LRO_INVALID_CSUM 0x0000 68 #endif 69 70 int 71 tcp_lro_init(struct lro_ctrl *lc) 72 { 73 struct lro_entry *le; 74 int error, i; 75 76 lc->lro_bad_csum = 0; 77 lc->lro_queued = 0; 78 lc->lro_flushed = 0; 79 lc->lro_cnt = 0; 80 SLIST_INIT(&lc->lro_free); 81 SLIST_INIT(&lc->lro_active); 82 83 error = 0; 84 for (i = 0; i < LRO_ENTRIES; i++) { 85 le = (struct lro_entry *)malloc(sizeof(*le), M_DEVBUF, 86 M_NOWAIT | M_ZERO); 87 if (le == NULL) { 88 if (i == 0) 89 error = ENOMEM; 90 break; 91 } 92 lc->lro_cnt = i + 1; 93 SLIST_INSERT_HEAD(&lc->lro_free, le, next); 94 } 95 96 return (error); 97 } 98 99 void 100 tcp_lro_free(struct lro_ctrl *lc) 101 { 102 struct lro_entry *le; 103 104 while (!SLIST_EMPTY(&lc->lro_free)) { 105 le = SLIST_FIRST(&lc->lro_free); 106 SLIST_REMOVE_HEAD(&lc->lro_free, next); 107 free(le, M_DEVBUF); 108 } 109 } 110 111 #ifdef TCP_LRO_UPDATE_CSUM 112 static uint16_t 113 tcp_lro_csum_th(struct tcphdr *th) 114 { 115 uint32_t ch; 116 uint16_t *p, l; 117 118 ch = th->th_sum = 0x0000; 119 l = th->th_off; 120 p = (uint16_t *)th; 121 while (l > 0) { 122 ch += *p; 123 p++; 124 ch += *p; 125 p++; 126 l--; 127 } 128 while (ch > 0xffff) 129 ch = (ch >> 16) + (ch & 0xffff); 130 131 return (ch & 0xffff); 132 } 133 134 static uint16_t 135 tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th, 136 uint16_t tcp_data_len, uint16_t csum) 137 { 138 uint32_t c; 139 uint16_t cs; 140 141 c = csum; 142 143 /* Remove length from checksum. */ 144 switch (le->eh_type) { 145 #ifdef INET6 146 case ETHERTYPE_IPV6: 147 { 148 struct ip6_hdr *ip6; 149 150 ip6 = (struct ip6_hdr *)l3hdr; 151 if (le->append_cnt == 0) 152 cs = ip6->ip6_plen; 153 else { 154 uint32_t cx; 155 156 cx = ntohs(ip6->ip6_plen); 157 cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0); 158 } 159 break; 160 } 161 #endif 162 #ifdef INET 163 case ETHERTYPE_IP: 164 { 165 struct ip *ip4; 166 167 ip4 = (struct ip *)l3hdr; 168 if (le->append_cnt == 0) 169 cs = ip4->ip_len; 170 else { 171 cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4), 172 IPPROTO_TCP); 173 cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr, 174 htons(cs)); 175 } 176 break; 177 } 178 #endif 179 default: 180 cs = 0; /* Keep compiler happy. */ 181 } 182 183 cs = ~cs; 184 c += cs; 185 186 /* Remove TCP header csum. */ 187 cs = ~tcp_lro_csum_th(th); 188 c += cs; 189 while (c > 0xffff) 190 c = (c >> 16) + (c & 0xffff); 191 192 return (c & 0xffff); 193 } 194 #endif 195 196 void 197 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout) 198 { 199 struct lro_entry *le, *le_tmp; 200 struct timeval tv; 201 202 if (SLIST_EMPTY(&lc->lro_active)) 203 return; 204 205 getmicrotime(&tv); 206 timevalsub(&tv, timeout); 207 SLIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) { 208 if (timevalcmp(&tv, &le->mtime, >=)) { 209 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); 210 tcp_lro_flush(lc, le); 211 } 212 } 213 } 214 215 void 216 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le) 217 { 218 219 if (le->append_cnt > 0) { 220 struct tcphdr *th; 221 uint16_t p_len; 222 223 p_len = htons(le->p_len); 224 switch (le->eh_type) { 225 #ifdef INET6 226 case ETHERTYPE_IPV6: 227 { 228 struct ip6_hdr *ip6; 229 230 ip6 = le->le_ip6; 231 ip6->ip6_plen = p_len; 232 th = (struct tcphdr *)(ip6 + 1); 233 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | 234 CSUM_PSEUDO_HDR; 235 le->p_len += ETHER_HDR_LEN + sizeof(*ip6); 236 break; 237 } 238 #endif 239 #ifdef INET 240 case ETHERTYPE_IP: 241 { 242 struct ip *ip4; 243 #ifdef TCP_LRO_UPDATE_CSUM 244 uint32_t cl; 245 uint16_t c; 246 #endif 247 248 ip4 = le->le_ip4; 249 #ifdef TCP_LRO_UPDATE_CSUM 250 /* Fix IP header checksum for new length. */ 251 c = ~ip4->ip_sum; 252 cl = c; 253 c = ~ip4->ip_len; 254 cl += c + p_len; 255 while (cl > 0xffff) 256 cl = (cl >> 16) + (cl & 0xffff); 257 c = cl; 258 ip4->ip_sum = ~c; 259 #else 260 ip4->ip_sum = TCP_LRO_INVALID_CSUM; 261 #endif 262 ip4->ip_len = p_len; 263 th = (struct tcphdr *)(ip4 + 1); 264 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID | 265 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID; 266 le->p_len += ETHER_HDR_LEN; 267 break; 268 } 269 #endif 270 default: 271 th = NULL; /* Keep compiler happy. */ 272 } 273 le->m_head->m_pkthdr.csum_data = 0xffff; 274 le->m_head->m_pkthdr.len = le->p_len; 275 276 /* Incorporate the latest ACK into the TCP header. */ 277 th->th_ack = le->ack_seq; 278 th->th_win = le->window; 279 /* Incorporate latest timestamp into the TCP header. */ 280 if (le->timestamp != 0) { 281 uint32_t *ts_ptr; 282 283 ts_ptr = (uint32_t *)(th + 1); 284 ts_ptr[1] = htonl(le->tsval); 285 ts_ptr[2] = le->tsecr; 286 } 287 #ifdef TCP_LRO_UPDATE_CSUM 288 /* Update the TCP header checksum. */ 289 le->ulp_csum += p_len; 290 le->ulp_csum += tcp_lro_csum_th(th); 291 while (le->ulp_csum > 0xffff) 292 le->ulp_csum = (le->ulp_csum >> 16) + 293 (le->ulp_csum & 0xffff); 294 th->th_sum = (le->ulp_csum & 0xffff); 295 th->th_sum = ~th->th_sum; 296 #else 297 th->th_sum = TCP_LRO_INVALID_CSUM; 298 #endif 299 } 300 301 (*lc->ifp->if_input)(lc->ifp, le->m_head); 302 lc->lro_queued += le->append_cnt + 1; 303 lc->lro_flushed++; 304 bzero(le, sizeof(*le)); 305 SLIST_INSERT_HEAD(&lc->lro_free, le, next); 306 } 307 308 #ifdef INET6 309 static int 310 tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6, 311 struct tcphdr **th) 312 { 313 314 /* XXX-BZ we should check the flow-label. */ 315 316 /* XXX-BZ We do not yet support ext. hdrs. */ 317 if (ip6->ip6_nxt != IPPROTO_TCP) 318 return (TCP_LRO_NOT_SUPPORTED); 319 320 /* Find the TCP header. */ 321 *th = (struct tcphdr *)(ip6 + 1); 322 323 return (0); 324 } 325 #endif 326 327 #ifdef INET 328 static int 329 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4, 330 struct tcphdr **th) 331 { 332 int csum_flags; 333 uint16_t csum; 334 335 if (ip4->ip_p != IPPROTO_TCP) 336 return (TCP_LRO_NOT_SUPPORTED); 337 338 /* Ensure there are no options. */ 339 if ((ip4->ip_hl << 2) != sizeof (*ip4)) 340 return (TCP_LRO_CANNOT); 341 342 /* .. and the packet is not fragmented. */ 343 if (ip4->ip_off & htons(IP_MF|IP_OFFMASK)) 344 return (TCP_LRO_CANNOT); 345 346 /* Legacy IP has a header checksum that needs to be correct. */ 347 csum_flags = m->m_pkthdr.csum_flags; 348 if (csum_flags & CSUM_IP_CHECKED) { 349 if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) { 350 lc->lro_bad_csum++; 351 return (TCP_LRO_CANNOT); 352 } 353 } else { 354 csum = in_cksum_hdr(ip4); 355 if (__predict_false((csum) != 0)) { 356 lc->lro_bad_csum++; 357 return (TCP_LRO_CANNOT); 358 } 359 } 360 361 /* Find the TCP header (we assured there are no IP options). */ 362 *th = (struct tcphdr *)(ip4 + 1); 363 364 return (0); 365 } 366 #endif 367 368 int 369 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum) 370 { 371 struct lro_entry *le; 372 struct ether_header *eh; 373 #ifdef INET6 374 struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */ 375 #endif 376 #ifdef INET 377 struct ip *ip4 = NULL; /* Keep compiler happy. */ 378 #endif 379 struct tcphdr *th; 380 void *l3hdr = NULL; /* Keep compiler happy. */ 381 uint32_t *ts_ptr; 382 tcp_seq seq; 383 int error, ip_len, l; 384 uint16_t eh_type, tcp_data_len; 385 386 /* We expect a contiguous header [eh, ip, tcp]. */ 387 388 eh = mtod(m, struct ether_header *); 389 eh_type = ntohs(eh->ether_type); 390 switch (eh_type) { 391 #ifdef INET6 392 case ETHERTYPE_IPV6: 393 { 394 CURVNET_SET(lc->ifp->if_vnet); 395 if (V_ip6_forwarding != 0) { 396 /* XXX-BZ stats but changing lro_ctrl is a problem. */ 397 CURVNET_RESTORE(); 398 return (TCP_LRO_CANNOT); 399 } 400 CURVNET_RESTORE(); 401 l3hdr = ip6 = (struct ip6_hdr *)(eh + 1); 402 error = tcp_lro_rx_ipv6(lc, m, ip6, &th); 403 if (error != 0) 404 return (error); 405 tcp_data_len = ntohs(ip6->ip6_plen); 406 ip_len = sizeof(*ip6) + tcp_data_len; 407 break; 408 } 409 #endif 410 #ifdef INET 411 case ETHERTYPE_IP: 412 { 413 CURVNET_SET(lc->ifp->if_vnet); 414 if (V_ipforwarding != 0) { 415 /* XXX-BZ stats but changing lro_ctrl is a problem. */ 416 CURVNET_RESTORE(); 417 return (TCP_LRO_CANNOT); 418 } 419 CURVNET_RESTORE(); 420 l3hdr = ip4 = (struct ip *)(eh + 1); 421 error = tcp_lro_rx_ipv4(lc, m, ip4, &th); 422 if (error != 0) 423 return (error); 424 ip_len = ntohs(ip4->ip_len); 425 tcp_data_len = ip_len - sizeof(*ip4); 426 break; 427 } 428 #endif 429 /* XXX-BZ what happens in case of VLAN(s)? */ 430 default: 431 return (TCP_LRO_NOT_SUPPORTED); 432 } 433 434 /* 435 * If the frame is padded beyond the end of the IP packet, then we must 436 * trim the extra bytes off. 437 */ 438 l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len); 439 if (l != 0) { 440 if (l < 0) 441 /* Truncated packet. */ 442 return (TCP_LRO_CANNOT); 443 444 m_adj(m, -l); 445 } 446 447 /* 448 * Check TCP header constraints. 449 */ 450 /* Ensure no bits set besides ACK or PSH. */ 451 if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) 452 return (TCP_LRO_CANNOT); 453 454 /* XXX-BZ We lose a AKC|PUSH flag concatinating multiple segments. */ 455 /* XXX-BZ Ideally we'd flush on PUSH? */ 456 457 /* 458 * Check for timestamps. 459 * Since the only option we handle are timestamps, we only have to 460 * handle the simple case of aligned timestamps. 461 */ 462 l = (th->th_off << 2); 463 tcp_data_len -= l; 464 l -= sizeof(*th); 465 ts_ptr = (uint32_t *)(th + 1); 466 if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) || 467 (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16| 468 TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) 469 return (TCP_LRO_CANNOT); 470 471 /* If the driver did not pass in the checksum, set it now. */ 472 if (csum == 0x0000) 473 csum = th->th_sum; 474 475 seq = ntohl(th->th_seq); 476 477 /* Try to find a matching previous segment. */ 478 SLIST_FOREACH(le, &lc->lro_active, next) { 479 if (le->eh_type != eh_type) 480 continue; 481 if (le->source_port != th->th_sport || 482 le->dest_port != th->th_dport) 483 continue; 484 switch (eh_type) { 485 #ifdef INET6 486 case ETHERTYPE_IPV6: 487 if (bcmp(&le->source_ip6, &ip6->ip6_src, 488 sizeof(struct in6_addr)) != 0 || 489 bcmp(&le->dest_ip6, &ip6->ip6_dst, 490 sizeof(struct in6_addr)) != 0) 491 continue; 492 break; 493 #endif 494 #ifdef INET 495 case ETHERTYPE_IP: 496 if (le->source_ip4 != ip4->ip_src.s_addr || 497 le->dest_ip4 != ip4->ip_dst.s_addr) 498 continue; 499 break; 500 #endif 501 } 502 503 /* Flush now if appending will result in overflow. */ 504 if (le->p_len > (65535 - tcp_data_len)) { 505 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); 506 tcp_lro_flush(lc, le); 507 break; 508 } 509 510 /* Try to append the new segment. */ 511 if (__predict_false(seq != le->next_seq || 512 (tcp_data_len == 0 && le->ack_seq == th->th_ack))) { 513 /* Out of order packet or duplicate ACK. */ 514 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); 515 tcp_lro_flush(lc, le); 516 return (TCP_LRO_CANNOT); 517 } 518 519 if (l != 0) { 520 uint32_t tsval = ntohl(*(ts_ptr + 1)); 521 /* Make sure timestamp values are increasing. */ 522 /* XXX-BZ flip and use TSTMP_GEQ macro for this? */ 523 if (__predict_false(le->tsval > tsval || 524 *(ts_ptr + 2) == 0)) 525 return (TCP_LRO_CANNOT); 526 le->tsval = tsval; 527 le->tsecr = *(ts_ptr + 2); 528 } 529 530 le->next_seq += tcp_data_len; 531 le->ack_seq = th->th_ack; 532 le->window = th->th_win; 533 le->append_cnt++; 534 535 #ifdef TCP_LRO_UPDATE_CSUM 536 le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th, 537 tcp_data_len, ~csum); 538 #endif 539 540 if (tcp_data_len == 0) { 541 m_freem(m); 542 return (0); 543 } 544 545 le->p_len += tcp_data_len; 546 547 /* 548 * Adjust the mbuf so that m_data points to the first byte of 549 * the ULP payload. Adjust the mbuf to avoid complications and 550 * append new segment to existing mbuf chain. 551 */ 552 m_adj(m, m->m_pkthdr.len - tcp_data_len); 553 m->m_flags &= ~M_PKTHDR; 554 555 le->m_tail->m_next = m; 556 le->m_tail = m_last(m); 557 558 /* 559 * If a possible next full length packet would cause an 560 * overflow, pro-actively flush now. 561 */ 562 if (le->p_len > (65535 - lc->ifp->if_mtu)) { 563 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next); 564 tcp_lro_flush(lc, le); 565 } else 566 getmicrotime(&le->mtime); 567 568 return (0); 569 } 570 571 /* Try to find an empty slot. */ 572 if (SLIST_EMPTY(&lc->lro_free)) 573 return (TCP_LRO_CANNOT); 574 575 /* Start a new segment chain. */ 576 le = SLIST_FIRST(&lc->lro_free); 577 SLIST_REMOVE_HEAD(&lc->lro_free, next); 578 SLIST_INSERT_HEAD(&lc->lro_active, le, next); 579 getmicrotime(&le->mtime); 580 581 /* Start filling in details. */ 582 switch (eh_type) { 583 #ifdef INET6 584 case ETHERTYPE_IPV6: 585 le->le_ip6 = ip6; 586 le->source_ip6 = ip6->ip6_src; 587 le->dest_ip6 = ip6->ip6_dst; 588 le->eh_type = eh_type; 589 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6); 590 break; 591 #endif 592 #ifdef INET 593 case ETHERTYPE_IP: 594 le->le_ip4 = ip4; 595 le->source_ip4 = ip4->ip_src.s_addr; 596 le->dest_ip4 = ip4->ip_dst.s_addr; 597 le->eh_type = eh_type; 598 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN; 599 break; 600 #endif 601 } 602 le->source_port = th->th_sport; 603 le->dest_port = th->th_dport; 604 605 le->next_seq = seq + tcp_data_len; 606 le->ack_seq = th->th_ack; 607 le->window = th->th_win; 608 if (l != 0) { 609 le->timestamp = 1; 610 le->tsval = ntohl(*(ts_ptr + 1)); 611 le->tsecr = *(ts_ptr + 2); 612 } 613 614 #ifdef TCP_LRO_UPDATE_CSUM 615 /* 616 * Do not touch the csum of the first packet. However save the 617 * "adjusted" checksum of just the source and destination addresses, 618 * the next header and the TCP payload. The length and TCP header 619 * parts may change, so we remove those from the saved checksum and 620 * re-add with final values on tcp_lro_flush() if needed. 621 */ 622 KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n", 623 __func__, le, le->ulp_csum)); 624 625 le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len, 626 ~csum); 627 th->th_sum = csum; /* Restore checksum on first packet. */ 628 #endif 629 630 le->m_head = m; 631 le->m_tail = m_last(m); 632 633 return (0); 634 } 635 636 /* end */ 637