sys/netinet/tcp_lro.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2007, Myricom Inc.
   5  * Copyright (c) 2008, Intel Corporation.
   6  * Copyright (c) 2012 The FreeBSD Foundation
   7  * Copyright (c) 2016-2021 Mellanox Technologies.
   8  * All rights reserved.
   9  *
  10  * Portions of this software were developed by Bjoern Zeeb
  11  * under sponsorship from the FreeBSD Foundation.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/kernel.h>
  44 #include <sys/malloc.h>
  45 #include <sys/mbuf.h>
  46 #include <sys/socket.h>
  47 #include <sys/socketvar.h>
  48 #include <sys/sockbuf.h>
  49 #include <sys/sysctl.h>
  50
  51 #include <net/if.h>
  52 #include <net/if_var.h>
  53 #include <net/ethernet.h>
  54 #include <net/bpf.h>
  55 #include <net/vnet.h>
  56
  57 #include <netinet/in_systm.h>
  58 #include <netinet/in.h>
  59 #include <netinet/ip6.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/in_pcb.h>
  63 #include <netinet6/in6_pcb.h>
  64 #include <netinet/tcp.h>
  65 #include <netinet/tcp_seq.h>
  66 #include <netinet/tcp_lro.h>
  67 #include <netinet/tcp_var.h>
  68 #include <netinet/tcpip.h>
  69 #include <netinet/tcp_hpts.h>
  70 #include <netinet/tcp_log_buf.h>
  71 #include <netinet/udp.h>
  72 #include <netinet6/ip6_var.h>
  73
  74 #include <machine/in_cksum.h>
  75
  76 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
  77
  78 #define TCP_LRO_TS_OPTION \
  79     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
  80           (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
  81
  82 static void     tcp_lro_rx_done(struct lro_ctrl *lc);
  83 static int      tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m,
  84                     uint32_t csum, bool use_hash);
  85
  86 #ifdef TCPHPTS
  87 static bool     do_bpf_strip_and_compress(struct inpcb *, struct lro_ctrl *,
  88                 struct lro_entry *, struct mbuf **, struct mbuf **, struct mbuf **, bool *, bool);
  89
  90 #endif
  91
  92 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
  93     "TCP LRO");
  94
  95 static long tcplro_stacks_wanting_mbufq;
  96 counter_u64_t tcp_inp_lro_direct_queue;
  97 counter_u64_t tcp_inp_lro_wokeup_queue;
  98 counter_u64_t tcp_inp_lro_compressed;
  99 counter_u64_t tcp_inp_lro_locks_taken;
 100 counter_u64_t tcp_extra_mbuf;
 101 counter_u64_t tcp_would_have_but;
 102 counter_u64_t tcp_comp_total;
 103 counter_u64_t tcp_uncomp_total;
 104
 105 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
 106 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
 107     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
 108     "default number of LRO entries");
 109
 110 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
 111 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
 112     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
 113     "Number of interrups in a row on the same CPU that will make us declare an 'affinity' cpu?");
 114
 115 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
 116     &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
 117 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
 118     &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
 119 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
 120     &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
 121 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
 122     &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
 123 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
 124     &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
 125 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
 126     &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
 127 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
 128     &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
 129 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
 130     &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
 131
 132 void
 133 tcp_lro_reg_mbufq(void)
 134 {
 135         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
 136 }
 137
 138 void
 139 tcp_lro_dereg_mbufq(void)
 140 {
 141         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
 142 }
 143
 144 static __inline void
 145 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
 146     struct lro_entry *le)
 147 {
 148
 149         LIST_INSERT_HEAD(&lc->lro_active, le, next);
 150         LIST_INSERT_HEAD(bucket, le, hash_next);
 151 }
 152
 153 static __inline void
 154 tcp_lro_active_remove(struct lro_entry *le)
 155 {
 156
 157         LIST_REMOVE(le, next);          /* active list */
 158         LIST_REMOVE(le, hash_next);     /* hash bucket */
 159 }
 160
 161 int
 162 tcp_lro_init(struct lro_ctrl *lc)
 163 {
 164         return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
 165 }
 166
 167 int
 168 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
 169     unsigned lro_entries, unsigned lro_mbufs)
 170 {
 171         struct lro_entry *le;
 172         size_t size;
 173         unsigned i, elements;
 174
 175         lc->lro_bad_csum = 0;
 176         lc->lro_queued = 0;
 177         lc->lro_flushed = 0;
 178         lc->lro_mbuf_count = 0;
 179         lc->lro_mbuf_max = lro_mbufs;
 180         lc->lro_cnt = lro_entries;
 181         lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
 182         lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
 183         lc->ifp = ifp;
 184         LIST_INIT(&lc->lro_free);
 185         LIST_INIT(&lc->lro_active);
 186
 187         /* create hash table to accelerate entry lookup */
 188         if (lro_entries > lro_mbufs)
 189                 elements = lro_entries;
 190         else
 191                 elements = lro_mbufs;
 192         lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
 193             HASH_NOWAIT);
 194         if (lc->lro_hash == NULL) {
 195                 memset(lc, 0, sizeof(*lc));
 196                 return (ENOMEM);
 197         }
 198
 199         /* compute size to allocate */
 200         size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
 201             (lro_entries * sizeof(*le));
 202         lc->lro_mbuf_data = (struct lro_mbuf_sort *)
 203             malloc(size, M_LRO, M_NOWAIT | M_ZERO);
 204
 205         /* check for out of memory */
 206         if (lc->lro_mbuf_data == NULL) {
 207                 free(lc->lro_hash, M_LRO);
 208                 memset(lc, 0, sizeof(*lc));
 209                 return (ENOMEM);
 210         }
 211         /* compute offset for LRO entries */
 212         le = (struct lro_entry *)
 213             (lc->lro_mbuf_data + lro_mbufs);
 214
 215         /* setup linked list */
 216         for (i = 0; i != lro_entries; i++)
 217                 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
 218
 219         return (0);
 220 }
 221
 222 struct vxlan_header {
 223         uint32_t        vxlh_flags;
 224         uint32_t        vxlh_vni;
 225 };
 226
 227 static inline void *
 228 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan)
 229 {
 230         const struct ether_vlan_header *eh;
 231         void *old;
 232         uint16_t eth_type;
 233
 234         if (update_data)
 235                 memset(parser, 0, sizeof(*parser));
 236
 237         old = ptr;
 238
 239         if (is_vxlan) {
 240                 const struct vxlan_header *vxh;
 241                 vxh = ptr;
 242                 ptr = (uint8_t *)ptr + sizeof(*vxh);
 243                 if (update_data) {
 244                         parser->data.vxlan_vni =
 245                             vxh->vxlh_vni & htonl(0xffffff00);
 246                 }
 247         }
 248
 249         eh = ptr;
 250         if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
 251                 eth_type = eh->evl_proto;
 252                 if (update_data) {
 253                         /* strip priority and keep VLAN ID only */
 254                         parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
 255                 }
 256                 /* advance to next header */
 257                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
 258         } else {
 259                 eth_type = eh->evl_encap_proto;
 260                 /* advance to next header */
 261                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
 262         }
 263
 264         switch (eth_type) {
 265 #ifdef INET
 266         case htons(ETHERTYPE_IP):
 267                 parser->ip4 = ptr;
 268                 /* Ensure there are no IPv4 options. */
 269                 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
 270                         break;
 271                 /* .. and the packet is not fragmented. */
 272                 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
 273                         break;
 274                 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
 275                 if (update_data) {
 276                         parser->data.s_addr.v4 = parser->ip4->ip_src;
 277                         parser->data.d_addr.v4 = parser->ip4->ip_dst;
 278                 }
 279                 switch (parser->ip4->ip_p) {
 280                 case IPPROTO_UDP:
 281                         parser->udp = ptr;
 282                         if (update_data) {
 283                                 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
 284                                 parser->data.s_port = parser->udp->uh_sport;
 285                                 parser->data.d_port = parser->udp->uh_dport;
 286                         } else {
 287                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
 288                         }
 289                         ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
 290                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 291                         return (ptr);
 292                 case IPPROTO_TCP:
 293                         parser->tcp = ptr;
 294                         if (update_data) {
 295                                 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
 296                                 parser->data.s_port = parser->tcp->th_sport;
 297                                 parser->data.d_port = parser->tcp->th_dport;
 298                         } else {
 299                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
 300                         }
 301                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
 302                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 303                         return (ptr);
 304                 default:
 305                         break;
 306                 }
 307                 break;
 308 #endif
 309 #ifdef INET6
 310         case htons(ETHERTYPE_IPV6):
 311                 parser->ip6 = ptr;
 312                 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
 313                 if (update_data) {
 314                         parser->data.s_addr.v6 = parser->ip6->ip6_src;
 315                         parser->data.d_addr.v6 = parser->ip6->ip6_dst;
 316                 }
 317                 switch (parser->ip6->ip6_nxt) {
 318                 case IPPROTO_UDP:
 319                         parser->udp = ptr;
 320                         if (update_data) {
 321                                 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
 322                                 parser->data.s_port = parser->udp->uh_sport;
 323                                 parser->data.d_port = parser->udp->uh_dport;
 324                         } else {
 325                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
 326                         }
 327                         ptr = (uint8_t *)ptr + sizeof(*parser->udp);
 328                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 329                         return (ptr);
 330                 case IPPROTO_TCP:
 331                         parser->tcp = ptr;
 332                         if (update_data) {
 333                                 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
 334                                 parser->data.s_port = parser->tcp->th_sport;
 335                                 parser->data.d_port = parser->tcp->th_dport;
 336                         } else {
 337                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
 338                         }
 339                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
 340                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 341                         return (ptr);
 342                 default:
 343                         break;
 344                 }
 345                 break;
 346 #endif
 347         default:
 348                 break;
 349         }
 350         /* Invalid packet - cannot parse */
 351         return (NULL);
 352 }
 353
 354 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
 355     CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
 356
 357 static inline struct lro_parser *
 358 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
 359 {
 360         void *data_ptr;
 361
 362         /* Try to parse outer headers first. */
 363         data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false);
 364         if (data_ptr == NULL || po->total_hdr_len > m->m_len)
 365                 return (NULL);
 366
 367         if (update_data) {
 368                 /* Store VLAN ID, if any. */
 369                 if (__predict_false(m->m_flags & M_VLANTAG)) {
 370                         po->data.vlan_id =
 371                             htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
 372                 }
 373         }
 374
 375         switch (po->data.lro_type) {
 376         case LRO_TYPE_IPV4_UDP:
 377         case LRO_TYPE_IPV6_UDP:
 378                 /* Check for VXLAN headers. */
 379                 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
 380                         break;
 381
 382                 /* Try to parse inner headers. */
 383                 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true);
 384                 if (data_ptr == NULL || pi->total_hdr_len > m->m_len)
 385                         break;
 386
 387                 /* Verify supported header types. */
 388                 switch (pi->data.lro_type) {
 389                 case LRO_TYPE_IPV4_TCP:
 390                 case LRO_TYPE_IPV6_TCP:
 391                         return (pi);
 392                 default:
 393                         break;
 394                 }
 395                 break;
 396         case LRO_TYPE_IPV4_TCP:
 397         case LRO_TYPE_IPV6_TCP:
 398                 if (update_data)
 399                         memset(pi, 0, sizeof(*pi));
 400                 return (po);
 401         default:
 402                 break;
 403         }
 404         return (NULL);
 405 }
 406
 407 static inline int
 408 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
 409 {
 410         int len;
 411
 412         switch (po->data.lro_type) {
 413 #ifdef INET
 414         case LRO_TYPE_IPV4_TCP:
 415                 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
 416                     ntohs(po->ip4->ip_len);
 417                 break;
 418 #endif
 419 #ifdef INET6
 420         case LRO_TYPE_IPV6_TCP:
 421                 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
 422                     ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
 423                 break;
 424 #endif
 425         default:
 426                 return (TCP_LRO_CANNOT);
 427         }
 428
 429         /*
 430          * If the frame is padded beyond the end of the IP packet,
 431          * then trim the extra bytes off:
 432          */
 433         if (__predict_true(m->m_pkthdr.len == len)) {
 434                 return (0);
 435         } else if (m->m_pkthdr.len > len) {
 436                 m_adj(m, len - m->m_pkthdr.len);
 437                 return (0);
 438         }
 439         return (TCP_LRO_CANNOT);
 440 }
 441
 442 static struct tcphdr *
 443 tcp_lro_get_th(struct mbuf *m)
 444 {
 445         return ((struct tcphdr *)((uint8_t *)m->m_data + m->m_pkthdr.lro_tcp_h_off));
 446 }
 447
 448 static void
 449 lro_free_mbuf_chain(struct mbuf *m)
 450 {
 451         struct mbuf *save;
 452
 453         while (m) {
 454                 save = m->m_nextpkt;
 455                 m->m_nextpkt = NULL;
 456                 m_freem(m);
 457                 m = save;
 458         }
 459 }
 460
 461 void
 462 tcp_lro_free(struct lro_ctrl *lc)
 463 {
 464         struct lro_entry *le;
 465         unsigned x;
 466
 467         /* reset LRO free list */
 468         LIST_INIT(&lc->lro_free);
 469
 470         /* free active mbufs, if any */
 471         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
 472                 tcp_lro_active_remove(le);
 473                 lro_free_mbuf_chain(le->m_head);
 474         }
 475
 476         /* free hash table */
 477         free(lc->lro_hash, M_LRO);
 478         lc->lro_hash = NULL;
 479         lc->lro_hashsz = 0;
 480
 481         /* free mbuf array, if any */
 482         for (x = 0; x != lc->lro_mbuf_count; x++)
 483                 m_freem(lc->lro_mbuf_data[x].mb);
 484         lc->lro_mbuf_count = 0;
 485
 486         /* free allocated memory, if any */
 487         free(lc->lro_mbuf_data, M_LRO);
 488         lc->lro_mbuf_data = NULL;
 489 }
 490
 491 static uint16_t
 492 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
 493 {
 494         const uint16_t *ptr;
 495         uint32_t csum;
 496         uint16_t len;
 497
 498         csum = -th->th_sum;     /* exclude checksum field */
 499         len = th->th_off;
 500         ptr = (const uint16_t *)th;
 501         while (len--) {
 502                 csum += *ptr;
 503                 ptr++;
 504                 csum += *ptr;
 505                 ptr++;
 506         }
 507         while (csum > 0xffff)
 508                 csum = (csum >> 16) + (csum & 0xffff);
 509
 510         return (csum);
 511 }
 512
 513 static uint16_t
 514 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
 515 {
 516         uint32_t c;
 517         uint16_t cs;
 518
 519         c = tcp_csum;
 520
 521         switch (pa->data.lro_type) {
 522 #ifdef INET6
 523         case LRO_TYPE_IPV6_TCP:
 524                 /* Compute full pseudo IPv6 header checksum. */
 525                 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
 526                 break;
 527 #endif
 528 #ifdef INET
 529         case LRO_TYPE_IPV4_TCP:
 530                 /* Compute full pseudo IPv4 header checsum. */
 531                 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
 532                 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
 533                 break;
 534 #endif
 535         default:
 536                 cs = 0;         /* Keep compiler happy. */
 537                 break;
 538         }
 539
 540         /* Complement checksum. */
 541         cs = ~cs;
 542         c += cs;
 543
 544         /* Remove TCP header checksum. */
 545         cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
 546         c += cs;
 547
 548         /* Compute checksum remainder. */
 549         while (c > 0xffff)
 550                 c = (c >> 16) + (c & 0xffff);
 551
 552         return (c);
 553 }
 554
 555 static void
 556 tcp_lro_rx_done(struct lro_ctrl *lc)
 557 {
 558         struct lro_entry *le;
 559
 560         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
 561                 tcp_lro_active_remove(le);
 562                 tcp_lro_flush(lc, le);
 563         }
 564 }
 565
 566 void
 567 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
 568 {
 569         struct lro_entry *le, *le_tmp;
 570         uint64_t now, tov;
 571         struct bintime bt;
 572
 573         if (LIST_EMPTY(&lc->lro_active))
 574                 return;
 575
 576         /* get timeout time and current time in ns */
 577         binuptime(&bt);
 578         now = bintime2ns(&bt);
 579         tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
 580         LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
 581                 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
 582                         tcp_lro_active_remove(le);
 583                         tcp_lro_flush(lc, le);
 584                 }
 585         }
 586 }
 587
 588 #ifdef INET
 589 static int
 590 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
 591 {
 592         uint16_t csum;
 593
 594         /* Legacy IP has a header checksum that needs to be correct. */
 595         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
 596                 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
 597                         lc->lro_bad_csum++;
 598                         return (TCP_LRO_CANNOT);
 599                 }
 600         } else {
 601                 csum = in_cksum_hdr(ip4);
 602                 if (__predict_false(csum != 0)) {
 603                         lc->lro_bad_csum++;
 604                         return (TCP_LRO_CANNOT);
 605                 }
 606         }
 607         return (0);
 608 }
 609 #endif
 610
 611 #ifdef TCPHPTS
 612 static void
 613 tcp_lro_log(struct tcpcb *tp, const struct lro_ctrl *lc,
 614     const struct lro_entry *le, const struct mbuf *m,
 615     int frm, int32_t tcp_data_len, uint32_t th_seq,
 616     uint32_t th_ack, uint16_t th_win)
 617 {
 618         if (tp->t_logstate != TCP_LOG_STATE_OFF) {
 619                 union tcp_log_stackspecific log;
 620                 struct timeval tv, btv;
 621                 uint32_t cts;
 622
 623                 cts = tcp_get_usecs(&tv);
 624                 memset(&log, 0, sizeof(union tcp_log_stackspecific));
 625                 log.u_bbr.flex8 = frm;
 626                 log.u_bbr.flex1 = tcp_data_len;
 627                 if (m)
 628                         log.u_bbr.flex2 = m->m_pkthdr.len;
 629                 else
 630                         log.u_bbr.flex2 = 0;
 631                 log.u_bbr.flex3 = le->m_head->m_pkthdr.lro_nsegs;
 632                 log.u_bbr.flex4 = le->m_head->m_pkthdr.lro_tcp_d_len;
 633                 if (le->m_head) {
 634                         log.u_bbr.flex5 = le->m_head->m_pkthdr.len;
 635                         log.u_bbr.delRate = le->m_head->m_flags;
 636                         log.u_bbr.rttProp = le->m_head->m_pkthdr.rcv_tstmp;
 637                 }
 638                 log.u_bbr.inflight = th_seq;
 639                 log.u_bbr.delivered = th_ack;
 640                 log.u_bbr.timeStamp = cts;
 641                 log.u_bbr.epoch = le->next_seq;
 642                 log.u_bbr.lt_epoch = le->ack_seq;
 643                 log.u_bbr.pacing_gain = th_win;
 644                 log.u_bbr.cwnd_gain = le->window;
 645                 log.u_bbr.lost = curcpu;
 646                 log.u_bbr.cur_del_rate = (uintptr_t)m;
 647                 log.u_bbr.bw_inuse = (uintptr_t)le->m_head;
 648                 bintime2timeval(&lc->lro_last_queue_time, &btv);
 649                 log.u_bbr.flex6 = tcp_tv_to_usectick(&btv);
 650                 log.u_bbr.flex7 = le->compressed;
 651                 log.u_bbr.pacing_gain = le->uncompressed;
 652                 if (in_epoch(net_epoch_preempt))
 653                         log.u_bbr.inhpts = 1;
 654                 else
 655                         log.u_bbr.inhpts = 0;
 656                 TCP_LOG_EVENTP(tp, NULL,
 657                                &tp->t_inpcb->inp_socket->so_rcv,
 658                                &tp->t_inpcb->inp_socket->so_snd,
 659                                TCP_LOG_LRO, 0,
 660                                0, &log, false, &tv);
 661         }
 662 }
 663 #endif
 664
 665 static inline void
 666 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
 667 {
 668         uint32_t csum;
 669
 670         csum = 0xffff - *ptr + value;
 671         while (csum > 0xffff)
 672                 csum = (csum >> 16) + (csum & 0xffff);
 673         *ptr = value;
 674         *psum = csum;
 675 }
 676
 677 static uint16_t
 678 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
 679     uint16_t payload_len, uint16_t delta_sum)
 680 {
 681         uint32_t csum;
 682         uint16_t tlen;
 683         uint16_t temp[5] = {};
 684
 685         switch (pa->data.lro_type) {
 686         case LRO_TYPE_IPV4_TCP:
 687                 /* Compute new IPv4 length. */
 688                 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
 689                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
 690
 691                 /* Subtract delta from current IPv4 checksum. */
 692                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
 693                 while (csum > 0xffff)
 694                         csum = (csum >> 16) + (csum & 0xffff);
 695                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
 696                 goto update_tcp_header;
 697
 698         case LRO_TYPE_IPV6_TCP:
 699                 /* Compute new IPv6 length. */
 700                 tlen = (pa->tcp->th_off << 2) + payload_len;
 701                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
 702                 goto update_tcp_header;
 703
 704         case LRO_TYPE_IPV4_UDP:
 705                 /* Compute new IPv4 length. */
 706                 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
 707                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
 708
 709                 /* Subtract delta from current IPv4 checksum. */
 710                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
 711                 while (csum > 0xffff)
 712                         csum = (csum >> 16) + (csum & 0xffff);
 713                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
 714                 goto update_udp_header;
 715
 716         case LRO_TYPE_IPV6_UDP:
 717                 /* Compute new IPv6 length. */
 718                 tlen = sizeof(*pa->udp) + payload_len;
 719                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
 720                 goto update_udp_header;
 721
 722         default:
 723                 return (0);
 724         }
 725
 726 update_tcp_header:
 727         /* Compute current TCP header checksum. */
 728         temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
 729
 730         /* Incorporate the latest ACK into the TCP header. */
 731         pa->tcp->th_ack = le->ack_seq;
 732         pa->tcp->th_win = le->window;
 733
 734         /* Incorporate latest timestamp into the TCP header. */
 735         if (le->timestamp != 0) {
 736                 uint32_t *ts_ptr;
 737
 738                 ts_ptr = (uint32_t *)(pa->tcp + 1);
 739                 ts_ptr[1] = htonl(le->tsval);
 740                 ts_ptr[2] = le->tsecr;
 741         }
 742
 743         /* Compute new TCP header checksum. */
 744         temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
 745
 746         /* Compute new TCP checksum. */
 747         csum = pa->tcp->th_sum + 0xffff - delta_sum +
 748             0xffff - temp[0] + 0xffff - temp[3] + temp[2];
 749         while (csum > 0xffff)
 750                 csum = (csum >> 16) + (csum & 0xffff);
 751
 752         /* Assign new TCP checksum. */
 753         tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
 754
 755         /* Compute all modififications affecting next checksum. */
 756         csum = temp[0] + temp[1] + 0xffff - temp[2] +
 757             temp[3] + temp[4] + delta_sum;
 758         while (csum > 0xffff)
 759                 csum = (csum >> 16) + (csum & 0xffff);
 760
 761         /* Return delta checksum to next stage, if any. */
 762         return (csum);
 763
 764 update_udp_header:
 765         tlen = sizeof(*pa->udp) + payload_len;
 766         /* Assign new UDP length and compute checksum delta. */
 767         tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
 768
 769         /* Check if there is a UDP checksum. */
 770         if (__predict_false(pa->udp->uh_sum != 0)) {
 771                 /* Compute new UDP checksum. */
 772                 csum = pa->udp->uh_sum + 0xffff - delta_sum +
 773                     0xffff - temp[0] + 0xffff - temp[2];
 774                 while (csum > 0xffff)
 775                         csum = (csum >> 16) + (csum & 0xffff);
 776                 /* Assign new UDP checksum. */
 777                 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
 778         }
 779
 780         /* Compute all modififications affecting next checksum. */
 781         csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
 782         while (csum > 0xffff)
 783                 csum = (csum >> 16) + (csum & 0xffff);
 784
 785         /* Return delta checksum to next stage, if any. */
 786         return (csum);
 787 }
 788
 789 static void
 790 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
 791 {
 792         /* Check if we need to recompute any checksums. */
 793         if (le->m_head->m_pkthdr.lro_nsegs > 1) {
 794                 uint16_t csum;
 795
 796                 switch (le->inner.data.lro_type) {
 797                 case LRO_TYPE_IPV4_TCP:
 798                         csum = tcp_lro_update_checksum(&le->inner, le,
 799                             le->m_head->m_pkthdr.lro_tcp_d_len,
 800                             le->m_head->m_pkthdr.lro_tcp_d_csum);
 801                         csum = tcp_lro_update_checksum(&le->outer, NULL,
 802                             le->m_head->m_pkthdr.lro_tcp_d_len +
 803                             le->inner.total_hdr_len, csum);
 804                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 805                             CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
 806                         le->m_head->m_pkthdr.csum_data = 0xffff;
 807                         break;
 808                 case LRO_TYPE_IPV6_TCP:
 809                         csum = tcp_lro_update_checksum(&le->inner, le,
 810                             le->m_head->m_pkthdr.lro_tcp_d_len,
 811                             le->m_head->m_pkthdr.lro_tcp_d_csum);
 812                         csum = tcp_lro_update_checksum(&le->outer, NULL,
 813                             le->m_head->m_pkthdr.lro_tcp_d_len +
 814                             le->inner.total_hdr_len, csum);
 815                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 816                             CSUM_PSEUDO_HDR;
 817                         le->m_head->m_pkthdr.csum_data = 0xffff;
 818                         break;
 819                 case LRO_TYPE_NONE:
 820                         switch (le->outer.data.lro_type) {
 821                         case LRO_TYPE_IPV4_TCP:
 822                                 csum = tcp_lro_update_checksum(&le->outer, le,
 823                                     le->m_head->m_pkthdr.lro_tcp_d_len,
 824                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
 825                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 826                                     CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
 827                                 le->m_head->m_pkthdr.csum_data = 0xffff;
 828                                 break;
 829                         case LRO_TYPE_IPV6_TCP:
 830                                 csum = tcp_lro_update_checksum(&le->outer, le,
 831                                     le->m_head->m_pkthdr.lro_tcp_d_len,
 832                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
 833                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 834                                     CSUM_PSEUDO_HDR;
 835                                 le->m_head->m_pkthdr.csum_data = 0xffff;
 836                                 break;
 837                         default:
 838                                 break;
 839                         }
 840                         break;
 841                 default:
 842                         break;
 843                 }
 844         }
 845
 846         /*
 847          * Break any chain, this is not set to NULL on the singleton
 848          * case m_nextpkt points to m_head. Other case set them
 849          * m_nextpkt to NULL in push_and_replace.
 850          */
 851         le->m_head->m_nextpkt = NULL;
 852         lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
 853         (*lc->ifp->if_input)(lc->ifp, le->m_head);
 854 }
 855
 856 static void
 857 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
 858     struct mbuf *m, struct tcphdr *th)
 859 {
 860         uint32_t *ts_ptr;
 861         uint16_t tcp_data_len;
 862         uint16_t tcp_opt_len;
 863
 864         ts_ptr = (uint32_t *)(th + 1);
 865         tcp_opt_len = (th->th_off << 2);
 866         tcp_opt_len -= sizeof(*th);
 867
 868         /* Check if there is a timestamp option. */
 869         if (tcp_opt_len == 0 ||
 870             __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
 871             *ts_ptr != TCP_LRO_TS_OPTION)) {
 872                 /* We failed to find the timestamp option. */
 873                 le->timestamp = 0;
 874         } else {
 875                 le->timestamp = 1;
 876                 le->tsval = ntohl(*(ts_ptr + 1));
 877                 le->tsecr = *(ts_ptr + 2);
 878         }
 879
 880         tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
 881
 882         /* Pull out TCP sequence numbers and window size. */
 883         le->next_seq = ntohl(th->th_seq) + tcp_data_len;
 884         le->ack_seq = th->th_ack;
 885         le->window = th->th_win;
 886
 887         /* Setup new data pointers. */
 888         le->m_head = m;
 889         le->m_tail = m_last(m);
 890 }
 891
 892 static void
 893 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
 894 {
 895         struct lro_parser *pa;
 896
 897         /*
 898          * Push up the stack of the current entry
 899          * and replace it with "m".
 900          */
 901         struct mbuf *msave;
 902
 903         /* Grab off the next and save it */
 904         msave = le->m_head->m_nextpkt;
 905         le->m_head->m_nextpkt = NULL;
 906
 907         /* Now push out the old entry */
 908         tcp_flush_out_entry(lc, le);
 909
 910         /* Re-parse new header, should not fail. */
 911         pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
 912         KASSERT(pa != NULL,
 913             ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
 914
 915         /*
 916          * Now to replace the data properly in the entry
 917          * we have to reset the TCP header and
 918          * other fields.
 919          */
 920         tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
 921
 922         /* Restore the next list */
 923         m->m_nextpkt = msave;
 924 }
 925
 926 static void
 927 tcp_lro_mbuf_append_pkthdr(struct mbuf *m, const struct mbuf *p)
 928 {
 929         uint32_t csum;
 930
 931         if (m->m_pkthdr.lro_nsegs == 1) {
 932                 /* Compute relative checksum. */
 933                 csum = p->m_pkthdr.lro_tcp_d_csum;
 934         } else {
 935                 /* Merge TCP data checksums. */
 936                 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
 937                     (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
 938                 while (csum > 0xffff)
 939                         csum = (csum >> 16) + (csum & 0xffff);
 940         }
 941
 942         /* Update various counters. */
 943         m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
 944         m->m_pkthdr.lro_tcp_d_csum = csum;
 945         m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
 946         m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
 947 }
 948
 949 static void
 950 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
 951 {
 952         /*
 953          * Walk through the mbuf chain we
 954          * have on tap and compress/condense
 955          * as required.
 956          */
 957         uint32_t *ts_ptr;
 958         struct mbuf *m;
 959         struct tcphdr *th;
 960         uint32_t tcp_data_len_total;
 961         uint32_t tcp_data_seg_total;
 962         uint16_t tcp_data_len;
 963         uint16_t tcp_opt_len;
 964
 965         /*
 966          * First we must check the lead (m_head)
 967          * we must make sure that it is *not*
 968          * something that should be sent up
 969          * right away (sack etc).
 970          */
 971 again:
 972         m = le->m_head->m_nextpkt;
 973         if (m == NULL) {
 974                 /* Just one left. */
 975                 return;
 976         }
 977
 978         th = tcp_lro_get_th(m);
 979         tcp_opt_len = (th->th_off << 2);
 980         tcp_opt_len -= sizeof(*th);
 981         ts_ptr = (uint32_t *)(th + 1);
 982
 983         if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
 984             *ts_ptr != TCP_LRO_TS_OPTION)) {
 985                 /*
 986                  * Its not the timestamp. We can't
 987                  * use this guy as the head.
 988                  */
 989                 le->m_head->m_nextpkt = m->m_nextpkt;
 990                 tcp_push_and_replace(lc, le, m);
 991                 goto again;
 992         }
 993         if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
 994                 /*
 995                  * Make sure that previously seen segements/ACKs are delivered
 996                  * before this segment, e.g. FIN.
 997                  */
 998                 le->m_head->m_nextpkt = m->m_nextpkt;
 999                 tcp_push_and_replace(lc, le, m);
1000                 goto again;
1001         }
1002         while((m = le->m_head->m_nextpkt) != NULL) {
1003                 /*
1004                  * condense m into le, first
1005                  * pull m out of the list.
1006                  */
1007                 le->m_head->m_nextpkt = m->m_nextpkt;
1008                 m->m_nextpkt = NULL;
1009                 /* Setup my data */
1010                 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1011                 th = tcp_lro_get_th(m);
1012                 ts_ptr = (uint32_t *)(th + 1);
1013                 tcp_opt_len = (th->th_off << 2);
1014                 tcp_opt_len -= sizeof(*th);
1015                 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1016                 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1017
1018                 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1019                     tcp_data_len_total >= lc->lro_length_lim) {
1020                         /* Flush now if appending will result in overflow. */
1021                         tcp_push_and_replace(lc, le, m);
1022                         goto again;
1023                 }
1024                 if (tcp_opt_len != 0 &&
1025                     __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1026                     *ts_ptr != TCP_LRO_TS_OPTION)) {
1027                         /*
1028                          * Maybe a sack in the new one? We need to
1029                          * start all over after flushing the
1030                          * current le. We will go up to the beginning
1031                          * and flush it (calling the replace again possibly
1032                          * or just returning).
1033                          */
1034                         tcp_push_and_replace(lc, le, m);
1035                         goto again;
1036                 }
1037                 if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
1038                         tcp_push_and_replace(lc, le, m);
1039                         goto again;
1040                 }
1041                 if (tcp_opt_len != 0) {
1042                         uint32_t tsval = ntohl(*(ts_ptr + 1));
1043                         /* Make sure timestamp values are increasing. */
1044                         if (TSTMP_GT(le->tsval, tsval))  {
1045                                 tcp_push_and_replace(lc, le, m);
1046                                 goto again;
1047                         }
1048                         le->tsval = tsval;
1049                         le->tsecr = *(ts_ptr + 2);
1050                 }
1051                 /* Try to append the new segment. */
1052                 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1053                                     (tcp_data_len == 0 &&
1054                                      le->ack_seq == th->th_ack &&
1055                                      le->window == th->th_win))) {
1056                         /* Out of order packet or duplicate ACK. */
1057                         tcp_push_and_replace(lc, le, m);
1058                         goto again;
1059                 }
1060                 if (tcp_data_len != 0 ||
1061                     SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1062                         le->next_seq += tcp_data_len;
1063                         le->ack_seq = th->th_ack;
1064                         le->window = th->th_win;
1065                 } else if (th->th_ack == le->ack_seq) {
1066                         le->window = WIN_MAX(le->window, th->th_win);
1067                 }
1068
1069                 if (tcp_data_len == 0) {
1070                         m_freem(m);
1071                         continue;
1072                 }
1073
1074                 /* Merge TCP data checksum and length to head mbuf. */
1075                 tcp_lro_mbuf_append_pkthdr(le->m_head, m);
1076
1077                 /*
1078                  * Adjust the mbuf so that m_data points to the first byte of
1079                  * the ULP payload.  Adjust the mbuf to avoid complications and
1080                  * append new segment to existing mbuf chain.
1081                  */
1082                 m_adj(m, m->m_pkthdr.len - tcp_data_len);
1083                 m_demote_pkthdr(m);
1084                 le->m_tail->m_next = m;
1085                 le->m_tail = m_last(m);
1086         }
1087 }
1088
1089 #ifdef TCPHPTS
1090 static void
1091 tcp_queue_pkts(struct inpcb *inp, struct tcpcb *tp, struct lro_entry *le)
1092 {
1093         INP_WLOCK_ASSERT(inp);
1094         if (tp->t_in_pkt == NULL) {
1095                 /* Nothing yet there */
1096                 tp->t_in_pkt = le->m_head;
1097                 tp->t_tail_pkt = le->m_last_mbuf;
1098         } else {
1099                 /* Already some there */
1100                 tp->t_tail_pkt->m_nextpkt = le->m_head;
1101                 tp->t_tail_pkt = le->m_last_mbuf;
1102         }
1103         le->m_head = NULL;
1104         le->m_last_mbuf = NULL;
1105 }
1106
1107 static struct mbuf *
1108 tcp_lro_get_last_if_ackcmp(struct lro_ctrl *lc, struct lro_entry *le,
1109     struct inpcb *inp, int32_t *new_m)
1110 {
1111         struct tcpcb *tp;
1112         struct mbuf *m;
1113
1114         tp = intotcpcb(inp);
1115         if (__predict_false(tp == NULL))
1116                 return (NULL);
1117
1118         /* Look at the last mbuf if any in queue */
1119         m = tp->t_tail_pkt;
1120         if (m != NULL && (m->m_flags & M_ACKCMP) != 0) {
1121                 if (M_TRAILINGSPACE(m) >= sizeof(struct tcp_ackent)) {
1122                         tcp_lro_log(tp, lc, le, NULL, 23, 0, 0, 0, 0);
1123                         *new_m = 0;
1124                         counter_u64_add(tcp_extra_mbuf, 1);
1125                         return (m);
1126                 } else {
1127                         /* Mark we ran out of space */
1128                         inp->inp_flags2 |= INP_MBUF_L_ACKS;
1129                 }
1130         }
1131         /* Decide mbuf size. */
1132         if (inp->inp_flags2 & INP_MBUF_L_ACKS)
1133                 m = m_getcl(M_NOWAIT, MT_DATA, M_ACKCMP | M_PKTHDR);
1134         else
1135                 m = m_gethdr(M_NOWAIT, MT_DATA);
1136
1137         if (__predict_false(m == NULL)) {
1138                 counter_u64_add(tcp_would_have_but, 1);
1139                 return (NULL);
1140         }
1141         counter_u64_add(tcp_comp_total, 1);
1142         m->m_flags |= M_ACKCMP;
1143         *new_m = 1;
1144         return (m);
1145 }
1146
1147 static struct inpcb *
1148 tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
1149 {
1150         struct inpcb *inp;
1151
1152         NET_EPOCH_ASSERT();
1153
1154         switch (pa->data.lro_type) {
1155 #ifdef INET6
1156         case LRO_TYPE_IPV6_TCP:
1157                 inp = in6_pcblookup(&V_tcbinfo,
1158                     &pa->data.s_addr.v6,
1159                     pa->data.s_port,
1160                     &pa->data.d_addr.v6,
1161                     pa->data.d_port,
1162                     INPLOOKUP_WLOCKPCB,
1163                     ifp);
1164                 break;
1165 #endif
1166 #ifdef INET
1167         case LRO_TYPE_IPV4_TCP:
1168                 inp = in_pcblookup(&V_tcbinfo,
1169                     pa->data.s_addr.v4,
1170                     pa->data.s_port,
1171                     pa->data.d_addr.v4,
1172                     pa->data.d_port,
1173                     INPLOOKUP_WLOCKPCB,
1174                     ifp);
1175                 break;
1176 #endif
1177         default:
1178                 inp = NULL;
1179                 break;
1180         }
1181         return (inp);
1182 }
1183
1184 static inline bool
1185 tcp_lro_ack_valid(struct mbuf *m, struct tcphdr *th, uint32_t **ppts, bool *other_opts)
1186 {
1187         /*
1188          * This function returns two bits of valuable information.
1189          * a) Is what is present capable of being ack-compressed,
1190          *    we can ack-compress if there is no options or just
1191          *    a timestamp option, and of course the th_flags must
1192          *    be correct as well.
1193          * b) Our other options present such as SACK. This is
1194          *    used to determine if we want to wakeup or not.
1195          */
1196         bool ret = true;
1197
1198         switch (th->th_off << 2) {
1199         case (sizeof(*th) + TCPOLEN_TSTAMP_APPA):
1200                 *ppts = (uint32_t *)(th + 1);
1201                 /* Check if we have only one timestamp option. */
1202                 if (**ppts == TCP_LRO_TS_OPTION)
1203                         *other_opts = false;
1204                 else {
1205                         *other_opts = true;
1206                         ret = false;
1207                 }
1208                 break;
1209         case (sizeof(*th)):
1210                 /* No options. */
1211                 *ppts = NULL;
1212                 *other_opts = false;
1213                 break;
1214         default:
1215                 *ppts = NULL;
1216                 *other_opts = true;
1217                 ret = false;
1218                 break;
1219         }
1220         /* For ACKCMP we only accept ACK, PUSH, ECE and CWR. */
1221         if ((th->th_flags & ~(TH_ACK | TH_PUSH | TH_ECE | TH_CWR)) != 0)
1222                 ret = false;
1223         /* If it has data on it we cannot compress it */
1224         if (m->m_pkthdr.lro_tcp_d_len)
1225                 ret = false;
1226
1227         /* ACK flag must be set. */
1228         if (!(th->th_flags & TH_ACK))
1229                 ret = false;
1230         return (ret);
1231 }
1232
1233 static int
1234 tcp_lro_flush_tcphpts(struct lro_ctrl *lc, struct lro_entry *le)
1235 {
1236         struct inpcb *inp;
1237         struct tcpcb *tp;
1238         struct mbuf **pp, *cmp, *mv_to;
1239         bool bpf_req, should_wake;
1240
1241         /* Check if packet doesn't belongs to our network interface. */
1242         if ((tcplro_stacks_wanting_mbufq == 0) ||
1243             (le->outer.data.vlan_id != 0) ||
1244             (le->inner.data.lro_type != LRO_TYPE_NONE))
1245                 return (TCP_LRO_CANNOT);
1246
1247 #ifdef INET6
1248         /*
1249          * Be proactive about unspecified IPv6 address in source. As
1250          * we use all-zero to indicate unbounded/unconnected pcb,
1251          * unspecified IPv6 address can be used to confuse us.
1252          *
1253          * Note that packets with unspecified IPv6 destination is
1254          * already dropped in ip6_input.
1255          */
1256         if (__predict_false(le->outer.data.lro_type == LRO_TYPE_IPV6_TCP &&
1257             IN6_IS_ADDR_UNSPECIFIED(&le->outer.data.s_addr.v6)))
1258                 return (TCP_LRO_CANNOT);
1259
1260         if (__predict_false(le->inner.data.lro_type == LRO_TYPE_IPV6_TCP &&
1261             IN6_IS_ADDR_UNSPECIFIED(&le->inner.data.s_addr.v6)))
1262                 return (TCP_LRO_CANNOT);
1263 #endif
1264         /* Lookup inp, if any. */
1265         inp = tcp_lro_lookup(lc->ifp,
1266             (le->inner.data.lro_type == LRO_TYPE_NONE) ? &le->outer : &le->inner);
1267         if (inp == NULL)
1268                 return (TCP_LRO_CANNOT);
1269
1270         counter_u64_add(tcp_inp_lro_locks_taken, 1);
1271
1272         /* Get TCP control structure. */
1273         tp = intotcpcb(inp);
1274
1275         /* Check if the inp is dead, Jim. */
1276         if (tp == NULL ||
1277             (inp->inp_flags & (INP_DROPPED | INP_TIMEWAIT)) ||
1278             (inp->inp_flags2 & INP_FREED)) {
1279                 INP_WUNLOCK(inp);
1280                 return (TCP_LRO_CANNOT);
1281         }
1282         if ((inp->inp_irq_cpu_set == 0)  && (lc->lro_cpu_is_set == 1)) {
1283                 inp->inp_irq_cpu = lc->lro_last_cpu;
1284                 inp->inp_irq_cpu_set = 1;
1285         }
1286         /* Check if the transport doesn't support the needed optimizations. */
1287         if ((inp->inp_flags2 & (INP_SUPPORTS_MBUFQ | INP_MBUF_ACKCMP)) == 0) {
1288                 INP_WUNLOCK(inp);
1289                 return (TCP_LRO_CANNOT);
1290         }
1291
1292         if (inp->inp_flags2 & INP_MBUF_QUEUE_READY)
1293                 should_wake = false;
1294         else
1295                 should_wake = true;
1296         /* Check if packets should be tapped to BPF. */
1297         bpf_req = bpf_peers_present(lc->ifp->if_bpf);
1298
1299         /* Strip and compress all the incoming packets. */
1300         cmp = NULL;
1301         for (pp = &le->m_head; *pp != NULL; ) {
1302                 mv_to = NULL;
1303                 if (do_bpf_strip_and_compress(inp, lc, le, pp,
1304                          &cmp, &mv_to, &should_wake, bpf_req ) == false) {
1305                         /* Advance to next mbuf. */
1306                         pp = &(*pp)->m_nextpkt;
1307                 } else if (mv_to != NULL) {
1308                         /* We are asked to move pp up */
1309                         pp = &mv_to->m_nextpkt;
1310                 }
1311         }
1312         /* Update "m_last_mbuf", if any. */
1313         if (pp == &le->m_head)
1314                 le->m_last_mbuf = *pp;
1315         else
1316                 le->m_last_mbuf = __containerof(pp, struct mbuf, m_nextpkt);
1317
1318         /* Check if any data mbufs left. */
1319         if (le->m_head != NULL) {
1320                 counter_u64_add(tcp_inp_lro_direct_queue, 1);
1321                 tcp_lro_log(tp, lc, le, NULL, 22, 1,
1322                             inp->inp_flags2, inp->inp_in_input, 1);
1323                 tcp_queue_pkts(inp, tp, le);
1324         }
1325         if (should_wake) {
1326                 /* Wakeup */
1327                 counter_u64_add(tcp_inp_lro_wokeup_queue, 1);
1328                 if ((*tp->t_fb->tfb_do_queued_segments)(inp->inp_socket, tp, 0))
1329                         inp = NULL;
1330         }
1331         if (inp != NULL)
1332                 INP_WUNLOCK(inp);
1333         return (0);     /* Success. */
1334 }
1335 #endif
1336
1337 void
1338 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1339 {
1340         /* Only optimise if there are multiple packets waiting. */
1341 #ifdef TCPHPTS
1342         int error;
1343
1344         CURVNET_SET(lc->ifp->if_vnet);
1345         error = tcp_lro_flush_tcphpts(lc, le);
1346         CURVNET_RESTORE();
1347         if (error != 0) {
1348 #endif
1349                 tcp_lro_condense(lc, le);
1350                 tcp_flush_out_entry(lc, le);
1351 #ifdef TCPHPTS
1352         }
1353 #endif
1354         lc->lro_flushed++;
1355         bzero(le, sizeof(*le));
1356         LIST_INSERT_HEAD(&lc->lro_free, le, next);
1357 }
1358
1359 #ifdef HAVE_INLINE_FLSLL
1360 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1361 #else
1362 static inline uint64_t
1363 tcp_lro_msb_64(uint64_t x)
1364 {
1365         x |= (x >> 1);
1366         x |= (x >> 2);
1367         x |= (x >> 4);
1368         x |= (x >> 8);
1369         x |= (x >> 16);
1370         x |= (x >> 32);
1371         return (x & ~(x >> 1));
1372 }
1373 #endif
1374
1375 /*
1376  * The tcp_lro_sort() routine is comparable to qsort(), except it has
1377  * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1378  * number of elements to sort and 64 is the number of sequence bits
1379  * available. The algorithm is bit-slicing the 64-bit sequence number,
1380  * sorting one bit at a time from the most significant bit until the
1381  * least significant one, skipping the constant bits. This is
1382  * typically called a radix sort.
1383  */
1384 static void
1385 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1386 {
1387         struct lro_mbuf_sort temp;
1388         uint64_t ones;
1389         uint64_t zeros;
1390         uint32_t x;
1391         uint32_t y;
1392
1393 repeat:
1394         /* for small arrays insertion sort is faster */
1395         if (size <= 12) {
1396                 for (x = 1; x < size; x++) {
1397                         temp = parray[x];
1398                         for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1399                                 parray[y] = parray[y - 1];
1400                         parray[y] = temp;
1401                 }
1402                 return;
1403         }
1404
1405         /* compute sequence bits which are constant */
1406         ones = 0;
1407         zeros = 0;
1408         for (x = 0; x != size; x++) {
1409                 ones |= parray[x].seq;
1410                 zeros |= ~parray[x].seq;
1411         }
1412
1413         /* compute bits which are not constant into "ones" */
1414         ones &= zeros;
1415         if (ones == 0)
1416                 return;
1417
1418         /* pick the most significant bit which is not constant */
1419         ones = tcp_lro_msb_64(ones);
1420
1421         /*
1422          * Move entries having cleared sequence bits to the beginning
1423          * of the array:
1424          */
1425         for (x = y = 0; y != size; y++) {
1426                 /* skip set bits */
1427                 if (parray[y].seq & ones)
1428                         continue;
1429                 /* swap entries */
1430                 temp = parray[x];
1431                 parray[x] = parray[y];
1432                 parray[y] = temp;
1433                 x++;
1434         }
1435
1436         KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1437
1438         /* sort zeros */
1439         tcp_lro_sort(parray, x);
1440
1441         /* sort ones */
1442         parray += x;
1443         size -= x;
1444         goto repeat;
1445 }
1446
1447 void
1448 tcp_lro_flush_all(struct lro_ctrl *lc)
1449 {
1450         uint64_t seq;
1451         uint64_t nseq;
1452         unsigned x;
1453
1454         /* check if no mbufs to flush */
1455         if (lc->lro_mbuf_count == 0)
1456                 goto done;
1457         if (lc->lro_cpu_is_set == 0) {
1458                 if (lc->lro_last_cpu == curcpu) {
1459                         lc->lro_cnt_of_same_cpu++;
1460                         /* Have we reached the threshold to declare a cpu? */
1461                         if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1462                                 lc->lro_cpu_is_set = 1;
1463                 } else {
1464                         lc->lro_last_cpu = curcpu;
1465                         lc->lro_cnt_of_same_cpu = 0;
1466                 }
1467         }
1468         CURVNET_SET(lc->ifp->if_vnet);
1469
1470         /* get current time */
1471         binuptime(&lc->lro_last_queue_time);
1472
1473         /* sort all mbufs according to stream */
1474         tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1475
1476         /* input data into LRO engine, stream by stream */
1477         seq = 0;
1478         for (x = 0; x != lc->lro_mbuf_count; x++) {
1479                 struct mbuf *mb;
1480
1481                 /* get mbuf */
1482                 mb = lc->lro_mbuf_data[x].mb;
1483
1484                 /* get sequence number, masking away the packet index */
1485                 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1486
1487                 /* check for new stream */
1488                 if (seq != nseq) {
1489                         seq = nseq;
1490
1491                         /* flush active streams */
1492                         tcp_lro_rx_done(lc);
1493                 }
1494
1495                 /* add packet to LRO engine */
1496                 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1497                         /* input packet to network layer */
1498                         (*lc->ifp->if_input)(lc->ifp, mb);
1499                         lc->lro_queued++;
1500                         lc->lro_flushed++;
1501                 }
1502         }
1503         CURVNET_RESTORE();
1504 done:
1505         /* flush active streams */
1506         tcp_lro_rx_done(lc);
1507
1508 #ifdef TCPHPTS
1509         tcp_run_hpts();
1510 #endif
1511         lc->lro_mbuf_count = 0;
1512 }
1513
1514 #ifdef TCPHPTS
1515 static void
1516 build_ack_entry(struct tcp_ackent *ae, struct tcphdr *th, struct mbuf *m,
1517     uint32_t *ts_ptr, uint16_t iptos)
1518 {
1519         /*
1520          * Given a TCP ACK, summarize it down into the small TCP ACK
1521          * entry.
1522          */
1523         ae->timestamp = m->m_pkthdr.rcv_tstmp;
1524         if (m->m_flags & M_TSTMP_LRO)
1525                 ae->flags = TSTMP_LRO;
1526         else if (m->m_flags & M_TSTMP)
1527                 ae->flags = TSTMP_HDWR;
1528         ae->seq = ntohl(th->th_seq);
1529         ae->ack = ntohl(th->th_ack);
1530         ae->flags |= th->th_flags;
1531         if (ts_ptr != NULL) {
1532                 ae->ts_value = ntohl(ts_ptr[1]);
1533                 ae->ts_echo = ntohl(ts_ptr[2]);
1534                 ae->flags |= HAS_TSTMP;
1535         }
1536         ae->win = ntohs(th->th_win);
1537         ae->codepoint = iptos;
1538 }
1539
1540 /*
1541  * Do BPF tap for either ACK_CMP packets or MBUF QUEUE type packets
1542  * and strip all, but the IPv4/IPv6 header.
1543  */
1544 static bool
1545 do_bpf_strip_and_compress(struct inpcb *inp, struct lro_ctrl *lc,
1546     struct lro_entry *le, struct mbuf **pp, struct mbuf **cmp, struct mbuf **mv_to,
1547     bool *should_wake, bool bpf_req)
1548 {
1549         union {
1550                 void *ptr;
1551                 struct ip *ip4;
1552                 struct ip6_hdr *ip6;
1553         } l3;
1554         struct mbuf *m;
1555         struct mbuf *nm;
1556         struct tcphdr *th;
1557         struct tcp_ackent *ack_ent;
1558         uint32_t *ts_ptr;
1559         int32_t n_mbuf;
1560         bool other_opts, can_compress;
1561         uint16_t lro_type;
1562         uint16_t iptos;
1563         int tcp_hdr_offset;
1564         int idx;
1565
1566         /* Get current mbuf. */
1567         m = *pp;
1568
1569         /* Let the BPF see the packet */
1570         if (__predict_false(bpf_req))
1571                 ETHER_BPF_MTAP(lc->ifp, m);
1572
1573         tcp_hdr_offset = m->m_pkthdr.lro_tcp_h_off;
1574         lro_type = le->inner.data.lro_type;
1575         switch (lro_type) {
1576         case LRO_TYPE_NONE:
1577                 lro_type = le->outer.data.lro_type;
1578                 switch (lro_type) {
1579                 case LRO_TYPE_IPV4_TCP:
1580                         tcp_hdr_offset -= sizeof(*le->outer.ip4);
1581                         m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1582                         break;
1583                 case LRO_TYPE_IPV6_TCP:
1584                         tcp_hdr_offset -= sizeof(*le->outer.ip6);
1585                         m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1586                         break;
1587                 default:
1588                         goto compressed;
1589                 }
1590                 break;
1591         case LRO_TYPE_IPV4_TCP:
1592                 tcp_hdr_offset -= sizeof(*le->outer.ip4);
1593                 m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1594                 break;
1595         case LRO_TYPE_IPV6_TCP:
1596                 tcp_hdr_offset -= sizeof(*le->outer.ip6);
1597                 m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1598                 break;
1599         default:
1600                 goto compressed;
1601         }
1602
1603         MPASS(tcp_hdr_offset >= 0);
1604
1605         m_adj(m, tcp_hdr_offset);
1606         m->m_flags |= M_LRO_EHDRSTRP;
1607         m->m_flags &= ~M_ACKCMP;
1608         m->m_pkthdr.lro_tcp_h_off -= tcp_hdr_offset;
1609
1610         th = tcp_lro_get_th(m);
1611
1612         th->th_sum = 0;         /* TCP checksum is valid. */
1613
1614         /* Check if ACK can be compressed */
1615         can_compress = tcp_lro_ack_valid(m, th, &ts_ptr, &other_opts);
1616
1617         /* Now lets look at the should wake states */
1618         if ((other_opts == true) &&
1619             ((inp->inp_flags2 & INP_DONT_SACK_QUEUE) == 0)) {
1620                 /*
1621                  * If there are other options (SACK?) and the
1622                  * tcp endpoint has not expressly told us it does
1623                  * not care about SACKS, then we should wake up.
1624                  */
1625                 *should_wake = true;
1626         }
1627         /* Is the ack compressable? */
1628         if (can_compress == false)
1629                 goto done;
1630         /* Does the TCP endpoint support ACK compression? */
1631         if ((inp->inp_flags2 & INP_MBUF_ACKCMP) == 0)
1632                 goto done;
1633
1634         /* Lets get the TOS/traffic class field */
1635         l3.ptr = mtod(m, void *);
1636         switch (lro_type) {
1637         case LRO_TYPE_IPV4_TCP:
1638                 iptos = l3.ip4->ip_tos;
1639                 break;
1640         case LRO_TYPE_IPV6_TCP:
1641                 iptos = IPV6_TRAFFIC_CLASS(l3.ip6);
1642                 break;
1643         default:
1644                 iptos = 0;      /* Keep compiler happy. */
1645                 break;
1646         }
1647         /* Now lets get space if we don't have some already */
1648         if (*cmp == NULL) {
1649 new_one:
1650                 nm = tcp_lro_get_last_if_ackcmp(lc, le, inp, &n_mbuf);
1651                 if (__predict_false(nm == NULL))
1652                         goto done;
1653                 *cmp = nm;
1654                 if (n_mbuf) {
1655                         /*
1656                          *  Link in the new cmp ack to our in-order place,
1657                          * first set our cmp ack's next to where we are.
1658                          */
1659                         nm->m_nextpkt = m;
1660                         (*pp) = nm;
1661                         /*
1662                          * Set it up so mv_to is advanced to our
1663                          * compressed ack. This way the caller can
1664                          * advance pp to the right place.
1665                          */
1666                         *mv_to = nm;
1667                         /*
1668                          * Advance it here locally as well.
1669                          */
1670                         pp = &nm->m_nextpkt;
1671                 }
1672         } else {
1673                 /* We have one already we are working on */
1674                 nm = *cmp;
1675                 if (M_TRAILINGSPACE(nm) < sizeof(struct tcp_ackent)) {
1676                         /* We ran out of space */
1677                         inp->inp_flags2 |= INP_MBUF_L_ACKS;
1678                         goto new_one;
1679                 }
1680         }
1681         MPASS(M_TRAILINGSPACE(nm) >= sizeof(struct tcp_ackent));
1682         counter_u64_add(tcp_inp_lro_compressed, 1);
1683         le->compressed++;
1684         /* We can add in to the one on the tail */
1685         ack_ent = mtod(nm, struct tcp_ackent *);
1686         idx = (nm->m_len / sizeof(struct tcp_ackent));
1687         build_ack_entry(&ack_ent[idx], th, m, ts_ptr, iptos);
1688
1689         /* Bump the size of both pkt-hdr and len */
1690         nm->m_len += sizeof(struct tcp_ackent);
1691         nm->m_pkthdr.len += sizeof(struct tcp_ackent);
1692 compressed:
1693         /* Advance to next mbuf before freeing. */
1694         *pp = m->m_nextpkt;
1695         m->m_nextpkt = NULL;
1696         m_freem(m);
1697         return (true);
1698 done:
1699         counter_u64_add(tcp_uncomp_total, 1);
1700         le->uncompressed++;
1701         return (false);
1702 }
1703 #endif
1704
1705 static struct lro_head *
1706 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1707 {
1708         u_long hash;
1709
1710         if (M_HASHTYPE_ISHASH(m)) {
1711                 hash = m->m_pkthdr.flowid;
1712         } else {
1713                 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1714                         hash += parser->data.raw[i];
1715         }
1716         return (&lc->lro_hash[hash % lc->lro_hashsz]);
1717 }
1718
1719 static int
1720 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1721 {
1722         struct lro_parser pi;   /* inner address data */
1723         struct lro_parser po;   /* outer address data */
1724         struct lro_parser *pa;  /* current parser for TCP stream */
1725         struct lro_entry *le;
1726         struct lro_head *bucket;
1727         struct tcphdr *th;
1728         int tcp_data_len;
1729         int tcp_opt_len;
1730         int error;
1731         uint16_t tcp_data_sum;
1732
1733 #ifdef INET
1734         /* Quickly decide if packet cannot be LRO'ed */
1735         if (__predict_false(V_ipforwarding != 0))
1736                 return (TCP_LRO_CANNOT);
1737 #endif
1738 #ifdef INET6
1739         /* Quickly decide if packet cannot be LRO'ed */
1740         if (__predict_false(V_ip6_forwarding != 0))
1741                 return (TCP_LRO_CANNOT);
1742 #endif
1743
1744         /* We expect a contiguous header [eh, ip, tcp]. */
1745         pa = tcp_lro_parser(m, &po, &pi, true);
1746         if (__predict_false(pa == NULL))
1747                 return (TCP_LRO_NOT_SUPPORTED);
1748
1749         /* We don't expect any padding. */
1750         error = tcp_lro_trim_mbuf_chain(m, pa);
1751         if (__predict_false(error != 0))
1752                 return (error);
1753
1754 #ifdef INET
1755         switch (pa->data.lro_type) {
1756         case LRO_TYPE_IPV4_TCP:
1757                 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1758                 if (__predict_false(error != 0))
1759                         return (error);
1760                 break;
1761         default:
1762                 break;
1763         }
1764 #endif
1765         /* If no hardware or arrival stamp on the packet add timestamp */
1766         if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1767                 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1768                 m->m_flags |= M_TSTMP_LRO;
1769         }
1770
1771         /* Get pointer to TCP header. */
1772         th = pa->tcp;
1773
1774         /* Don't process SYN packets. */
1775         if (__predict_false(th->th_flags & TH_SYN))
1776                 return (TCP_LRO_CANNOT);
1777
1778         /* Get total TCP header length and compute payload length. */
1779         tcp_opt_len = (th->th_off << 2);
1780         tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1781             (uint8_t *)m->m_data) - tcp_opt_len;
1782         tcp_opt_len -= sizeof(*th);
1783
1784         /* Don't process invalid TCP headers. */
1785         if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1786                 return (TCP_LRO_CANNOT);
1787
1788         /* Compute TCP data only checksum. */
1789         if (tcp_data_len == 0)
1790                 tcp_data_sum = 0;       /* no data, no checksum */
1791         else if (__predict_false(csum != 0))
1792                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1793         else
1794                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1795
1796         /* Save TCP info in mbuf. */
1797         m->m_nextpkt = NULL;
1798         m->m_pkthdr.rcvif = lc->ifp;
1799         m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1800         m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1801         m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1802         m->m_pkthdr.lro_nsegs = 1;
1803
1804         /* Get hash bucket. */
1805         if (!use_hash) {
1806                 bucket = &lc->lro_hash[0];
1807         } else {
1808                 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1809         }
1810
1811         /* Try to find a matching previous segment. */
1812         LIST_FOREACH(le, bucket, hash_next) {
1813                 /* Compare addresses and ports. */
1814                 if (lro_address_compare(&po.data, &le->outer.data) == false ||
1815                     lro_address_compare(&pi.data, &le->inner.data) == false)
1816                         continue;
1817
1818                 /* Check if no data and old ACK. */
1819                 if (tcp_data_len == 0 &&
1820                     SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1821                         m_freem(m);
1822                         return (0);
1823                 }
1824
1825                 /* Mark "m" in the last spot. */
1826                 le->m_last_mbuf->m_nextpkt = m;
1827                 /* Now set the tail to "m". */
1828                 le->m_last_mbuf = m;
1829                 return (0);
1830         }
1831
1832         /* Try to find an empty slot. */
1833         if (LIST_EMPTY(&lc->lro_free))
1834                 return (TCP_LRO_NO_ENTRIES);
1835
1836         /* Start a new segment chain. */
1837         le = LIST_FIRST(&lc->lro_free);
1838         LIST_REMOVE(le, next);
1839         tcp_lro_active_insert(lc, bucket, le);
1840
1841         /* Make sure the headers are set. */
1842         le->inner = pi;
1843         le->outer = po;
1844
1845         /* Store time this entry was allocated. */
1846         le->alloc_time = lc->lro_last_queue_time;
1847
1848         tcp_set_entry_to_mbuf(lc, le, m, th);
1849
1850         /* Now set the tail to "m". */
1851         le->m_last_mbuf = m;
1852
1853         return (0);
1854 }
1855
1856 int
1857 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1858 {
1859         int error;
1860
1861         /* get current time */
1862         binuptime(&lc->lro_last_queue_time);
1863
1864         CURVNET_SET(lc->ifp->if_vnet);
1865         error = tcp_lro_rx_common(lc, m, csum, true);
1866         CURVNET_RESTORE();
1867
1868         return (error);
1869 }
1870
1871 void
1872 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
1873 {
1874         /* sanity checks */
1875         if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
1876             lc->lro_mbuf_max == 0)) {
1877                 /* packet drop */
1878                 m_freem(mb);
1879                 return;
1880         }
1881
1882         /* check if packet is not LRO capable */
1883         if (__predict_false(mb->m_pkthdr.csum_flags == 0 ||
1884             (lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
1885                 /* input packet to network layer */
1886                 (*lc->ifp->if_input) (lc->ifp, mb);
1887                 return;
1888         }
1889
1890         /* create sequence number */
1891         lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
1892             (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
1893             (((uint64_t)mb->m_pkthdr.flowid) << 24) |
1894             ((uint64_t)lc->lro_mbuf_count);
1895
1896         /* enter mbuf */
1897         lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
1898
1899         /* flush if array is full */
1900         if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
1901                 tcp_lro_flush_all(lc);
1902 }
1903
1904 /* end */