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 #include <net/if_dl.h>
  57 #include <net/if_media.h>
  58 #include <net/if_private.h>
  59 #include <net/if_types.h>
  60 #include <net/infiniband.h>
  61 #include <net/if_lagg.h>
  62
  63 #include <netinet/in_systm.h>
  64 #include <netinet/in.h>
  65 #include <netinet/ip6.h>
  66 #include <netinet/ip.h>
  67 #include <netinet/ip_var.h>
  68 #include <netinet/in_pcb.h>
  69 #include <netinet6/in6_pcb.h>
  70 #include <netinet/tcp.h>
  71 #include <netinet/tcp_seq.h>
  72 #include <netinet/tcp_lro.h>
  73 #include <netinet/tcp_var.h>
  74 #include <netinet/tcpip.h>
  75 #include <netinet/tcp_hpts.h>
  76 #include <netinet/tcp_log_buf.h>
  77 #include <netinet/tcp_fsm.h>
  78 #include <netinet/udp.h>
  79 #include <netinet6/ip6_var.h>
  80
  81 #include <machine/in_cksum.h>
  82
  83 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
  84
  85 #define TCP_LRO_TS_OPTION \
  86     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
  87           (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
  88
  89 static void     tcp_lro_rx_done(struct lro_ctrl *lc);
  90 static int      tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m,
  91                     uint32_t csum, bool use_hash);
  92
  93 #ifdef TCPHPTS
  94 static bool     do_bpf_strip_and_compress(struct inpcb *, struct lro_ctrl *,
  95                 struct lro_entry *, struct mbuf **, struct mbuf **, struct mbuf **,
  96                 bool *, bool, bool, struct ifnet *, bool);
  97
  98 #endif
  99
 100 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
 101     "TCP LRO");
 102
 103 static long tcplro_stacks_wanting_mbufq;
 104 counter_u64_t tcp_inp_lro_direct_queue;
 105 counter_u64_t tcp_inp_lro_wokeup_queue;
 106 counter_u64_t tcp_inp_lro_compressed;
 107 counter_u64_t tcp_inp_lro_locks_taken;
 108 counter_u64_t tcp_extra_mbuf;
 109 counter_u64_t tcp_would_have_but;
 110 counter_u64_t tcp_comp_total;
 111 counter_u64_t tcp_uncomp_total;
 112 counter_u64_t tcp_bad_csums;
 113
 114 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
 115 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
 116     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
 117     "default number of LRO entries");
 118
 119 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
 120 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
 121     CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
 122     "Number of interrupts in a row on the same CPU that will make us declare an 'affinity' cpu?");
 123
 124 static uint32_t tcp_less_accurate_lro_ts = 0;
 125 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_less_accurate,
 126     CTLFLAG_MPSAFE, &tcp_less_accurate_lro_ts, 0,
 127     "Do we trade off efficency by doing less timestamp operations for time accuracy?");
 128
 129 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
 130     &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
 131 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
 132     &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
 133 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
 134     &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
 135 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
 136     &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
 137 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
 138     &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
 139 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
 140     &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
 141 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
 142     &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
 143 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
 144     &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
 145 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lro_badcsum, CTLFLAG_RD,
 146     &tcp_bad_csums, "Number of packets that the common code saw with bad csums");
 147
 148 void
 149 tcp_lro_reg_mbufq(void)
 150 {
 151         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
 152 }
 153
 154 void
 155 tcp_lro_dereg_mbufq(void)
 156 {
 157         atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
 158 }
 159
 160 static __inline void
 161 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
 162     struct lro_entry *le)
 163 {
 164
 165         LIST_INSERT_HEAD(&lc->lro_active, le, next);
 166         LIST_INSERT_HEAD(bucket, le, hash_next);
 167 }
 168
 169 static __inline void
 170 tcp_lro_active_remove(struct lro_entry *le)
 171 {
 172
 173         LIST_REMOVE(le, next);          /* active list */
 174         LIST_REMOVE(le, hash_next);     /* hash bucket */
 175 }
 176
 177 int
 178 tcp_lro_init(struct lro_ctrl *lc)
 179 {
 180         return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
 181 }
 182
 183 int
 184 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
 185     unsigned lro_entries, unsigned lro_mbufs)
 186 {
 187         struct lro_entry *le;
 188         size_t size;
 189         unsigned i, elements;
 190
 191         lc->lro_bad_csum = 0;
 192         lc->lro_queued = 0;
 193         lc->lro_flushed = 0;
 194         lc->lro_mbuf_count = 0;
 195         lc->lro_mbuf_max = lro_mbufs;
 196         lc->lro_cnt = lro_entries;
 197         lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
 198         lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
 199         lc->ifp = ifp;
 200         LIST_INIT(&lc->lro_free);
 201         LIST_INIT(&lc->lro_active);
 202
 203         /* create hash table to accelerate entry lookup */
 204         if (lro_entries > lro_mbufs)
 205                 elements = lro_entries;
 206         else
 207                 elements = lro_mbufs;
 208         lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
 209             HASH_NOWAIT);
 210         if (lc->lro_hash == NULL) {
 211                 memset(lc, 0, sizeof(*lc));
 212                 return (ENOMEM);
 213         }
 214
 215         /* compute size to allocate */
 216         size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
 217             (lro_entries * sizeof(*le));
 218         lc->lro_mbuf_data = (struct lro_mbuf_sort *)
 219             malloc(size, M_LRO, M_NOWAIT | M_ZERO);
 220
 221         /* check for out of memory */
 222         if (lc->lro_mbuf_data == NULL) {
 223                 free(lc->lro_hash, M_LRO);
 224                 memset(lc, 0, sizeof(*lc));
 225                 return (ENOMEM);
 226         }
 227         /* compute offset for LRO entries */
 228         le = (struct lro_entry *)
 229             (lc->lro_mbuf_data + lro_mbufs);
 230
 231         /* setup linked list */
 232         for (i = 0; i != lro_entries; i++)
 233                 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
 234
 235         return (0);
 236 }
 237
 238 struct vxlan_header {
 239         uint32_t        vxlh_flags;
 240         uint32_t        vxlh_vni;
 241 };
 242
 243 static inline void *
 244 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan, int mlen)
 245 {
 246         const struct ether_vlan_header *eh;
 247         void *old;
 248         uint16_t eth_type;
 249
 250         if (update_data)
 251                 memset(parser, 0, sizeof(*parser));
 252
 253         old = ptr;
 254
 255         if (is_vxlan) {
 256                 const struct vxlan_header *vxh;
 257                 vxh = ptr;
 258                 ptr = (uint8_t *)ptr + sizeof(*vxh);
 259                 if (update_data) {
 260                         parser->data.vxlan_vni =
 261                             vxh->vxlh_vni & htonl(0xffffff00);
 262                 }
 263         }
 264
 265         eh = ptr;
 266         if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
 267                 eth_type = eh->evl_proto;
 268                 if (update_data) {
 269                         /* strip priority and keep VLAN ID only */
 270                         parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
 271                 }
 272                 /* advance to next header */
 273                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
 274                 mlen -= (ETHER_HDR_LEN  + ETHER_VLAN_ENCAP_LEN);
 275         } else {
 276                 eth_type = eh->evl_encap_proto;
 277                 /* advance to next header */
 278                 mlen -= ETHER_HDR_LEN;
 279                 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
 280         }
 281         if (__predict_false(mlen <= 0))
 282                 return (NULL);
 283         switch (eth_type) {
 284 #ifdef INET
 285         case htons(ETHERTYPE_IP):
 286                 parser->ip4 = ptr;
 287                 if (__predict_false(mlen < sizeof(struct ip)))
 288                         return (NULL);
 289                 /* Ensure there are no IPv4 options. */
 290                 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
 291                         break;
 292                 /* .. and the packet is not fragmented. */
 293                 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
 294                         break;
 295                 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
 296                 mlen -= sizeof(struct ip);
 297                 if (update_data) {
 298                         parser->data.s_addr.v4 = parser->ip4->ip_src;
 299                         parser->data.d_addr.v4 = parser->ip4->ip_dst;
 300                 }
 301                 switch (parser->ip4->ip_p) {
 302                 case IPPROTO_UDP:
 303                         if (__predict_false(mlen < sizeof(struct udphdr)))
 304                                 return (NULL);
 305                         parser->udp = ptr;
 306                         if (update_data) {
 307                                 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
 308                                 parser->data.s_port = parser->udp->uh_sport;
 309                                 parser->data.d_port = parser->udp->uh_dport;
 310                         } else {
 311                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
 312                         }
 313                         ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
 314                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 315                         return (ptr);
 316                 case IPPROTO_TCP:
 317                         parser->tcp = ptr;
 318                         if (__predict_false(mlen < sizeof(struct tcphdr)))
 319                                 return (NULL);
 320                         if (update_data) {
 321                                 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
 322                                 parser->data.s_port = parser->tcp->th_sport;
 323                                 parser->data.d_port = parser->tcp->th_dport;
 324                         } else {
 325                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
 326                         }
 327                         if (__predict_false(mlen < (parser->tcp->th_off << 2)))
 328                                 return (NULL);
 329                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
 330                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 331                         return (ptr);
 332                 default:
 333                         break;
 334                 }
 335                 break;
 336 #endif
 337 #ifdef INET6
 338         case htons(ETHERTYPE_IPV6):
 339                 parser->ip6 = ptr;
 340                 if (__predict_false(mlen < sizeof(struct ip6_hdr)))
 341                         return (NULL);
 342                 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
 343                 if (update_data) {
 344                         parser->data.s_addr.v6 = parser->ip6->ip6_src;
 345                         parser->data.d_addr.v6 = parser->ip6->ip6_dst;
 346                 }
 347                 mlen -= sizeof(struct ip6_hdr);
 348                 switch (parser->ip6->ip6_nxt) {
 349                 case IPPROTO_UDP:
 350                         if (__predict_false(mlen < sizeof(struct udphdr)))
 351                                 return (NULL);
 352                         parser->udp = ptr;
 353                         if (update_data) {
 354                                 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
 355                                 parser->data.s_port = parser->udp->uh_sport;
 356                                 parser->data.d_port = parser->udp->uh_dport;
 357                         } else {
 358                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
 359                         }
 360                         ptr = (uint8_t *)ptr + sizeof(*parser->udp);
 361                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 362                         return (ptr);
 363                 case IPPROTO_TCP:
 364                         if (__predict_false(mlen < sizeof(struct tcphdr)))
 365                                 return (NULL);
 366                         parser->tcp = ptr;
 367                         if (update_data) {
 368                                 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
 369                                 parser->data.s_port = parser->tcp->th_sport;
 370                                 parser->data.d_port = parser->tcp->th_dport;
 371                         } else {
 372                                 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
 373                         }
 374                         if (__predict_false(mlen < (parser->tcp->th_off << 2)))
 375                                 return (NULL);
 376                         ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
 377                         parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
 378                         return (ptr);
 379                 default:
 380                         break;
 381                 }
 382                 break;
 383 #endif
 384         default:
 385                 break;
 386         }
 387         /* Invalid packet - cannot parse */
 388         return (NULL);
 389 }
 390
 391 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
 392     CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
 393
 394 static inline struct lro_parser *
 395 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
 396 {
 397         void *data_ptr;
 398
 399         /* Try to parse outer headers first. */
 400         data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false, m->m_len);
 401         if (data_ptr == NULL || po->total_hdr_len > m->m_len)
 402                 return (NULL);
 403
 404         if (update_data) {
 405                 /* Store VLAN ID, if any. */
 406                 if (__predict_false(m->m_flags & M_VLANTAG)) {
 407                         po->data.vlan_id =
 408                             htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
 409                 }
 410                 /* Store decrypted flag, if any. */
 411                 if (__predict_false((m->m_pkthdr.csum_flags &
 412                     CSUM_TLS_MASK) == CSUM_TLS_DECRYPTED))
 413                         po->data.lro_flags |= LRO_FLAG_DECRYPTED;
 414         }
 415
 416         switch (po->data.lro_type) {
 417         case LRO_TYPE_IPV4_UDP:
 418         case LRO_TYPE_IPV6_UDP:
 419                 /* Check for VXLAN headers. */
 420                 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
 421                         break;
 422
 423                 /* Try to parse inner headers. */
 424                 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true,
 425                                                     (m->m_len - ((caddr_t)data_ptr - m->m_data)));
 426                 if (data_ptr == NULL || (pi->total_hdr_len + po->total_hdr_len) > m->m_len)
 427                         break;
 428
 429                 /* Verify supported header types. */
 430                 switch (pi->data.lro_type) {
 431                 case LRO_TYPE_IPV4_TCP:
 432                 case LRO_TYPE_IPV6_TCP:
 433                         return (pi);
 434                 default:
 435                         break;
 436                 }
 437                 break;
 438         case LRO_TYPE_IPV4_TCP:
 439         case LRO_TYPE_IPV6_TCP:
 440                 if (update_data)
 441                         memset(pi, 0, sizeof(*pi));
 442                 return (po);
 443         default:
 444                 break;
 445         }
 446         return (NULL);
 447 }
 448
 449 static inline int
 450 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
 451 {
 452         int len;
 453
 454         switch (po->data.lro_type) {
 455 #ifdef INET
 456         case LRO_TYPE_IPV4_TCP:
 457                 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
 458                     ntohs(po->ip4->ip_len);
 459                 break;
 460 #endif
 461 #ifdef INET6
 462         case LRO_TYPE_IPV6_TCP:
 463                 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
 464                     ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
 465                 break;
 466 #endif
 467         default:
 468                 return (TCP_LRO_CANNOT);
 469         }
 470
 471         /*
 472          * If the frame is padded beyond the end of the IP packet,
 473          * then trim the extra bytes off:
 474          */
 475         if (__predict_true(m->m_pkthdr.len == len)) {
 476                 return (0);
 477         } else if (m->m_pkthdr.len > len) {
 478                 m_adj(m, len - m->m_pkthdr.len);
 479                 return (0);
 480         }
 481         return (TCP_LRO_CANNOT);
 482 }
 483
 484 static struct tcphdr *
 485 tcp_lro_get_th(struct mbuf *m)
 486 {
 487         return ((struct tcphdr *)((uint8_t *)m->m_data + m->m_pkthdr.lro_tcp_h_off));
 488 }
 489
 490 static void
 491 lro_free_mbuf_chain(struct mbuf *m)
 492 {
 493         struct mbuf *save;
 494
 495         while (m) {
 496                 save = m->m_nextpkt;
 497                 m->m_nextpkt = NULL;
 498                 m_freem(m);
 499                 m = save;
 500         }
 501 }
 502
 503 void
 504 tcp_lro_free(struct lro_ctrl *lc)
 505 {
 506         struct lro_entry *le;
 507         unsigned x;
 508
 509         /* reset LRO free list */
 510         LIST_INIT(&lc->lro_free);
 511
 512         /* free active mbufs, if any */
 513         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
 514                 tcp_lro_active_remove(le);
 515                 lro_free_mbuf_chain(le->m_head);
 516         }
 517
 518         /* free hash table */
 519         free(lc->lro_hash, M_LRO);
 520         lc->lro_hash = NULL;
 521         lc->lro_hashsz = 0;
 522
 523         /* free mbuf array, if any */
 524         for (x = 0; x != lc->lro_mbuf_count; x++)
 525                 m_freem(lc->lro_mbuf_data[x].mb);
 526         lc->lro_mbuf_count = 0;
 527
 528         /* free allocated memory, if any */
 529         free(lc->lro_mbuf_data, M_LRO);
 530         lc->lro_mbuf_data = NULL;
 531 }
 532
 533 static uint16_t
 534 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
 535 {
 536         const uint16_t *ptr;
 537         uint32_t csum;
 538         uint16_t len;
 539
 540         csum = -th->th_sum;     /* exclude checksum field */
 541         len = th->th_off;
 542         ptr = (const uint16_t *)th;
 543         while (len--) {
 544                 csum += *ptr;
 545                 ptr++;
 546                 csum += *ptr;
 547                 ptr++;
 548         }
 549         while (csum > 0xffff)
 550                 csum = (csum >> 16) + (csum & 0xffff);
 551
 552         return (csum);
 553 }
 554
 555 static uint16_t
 556 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
 557 {
 558         uint32_t c;
 559         uint16_t cs;
 560
 561         c = tcp_csum;
 562
 563         switch (pa->data.lro_type) {
 564 #ifdef INET6
 565         case LRO_TYPE_IPV6_TCP:
 566                 /* Compute full pseudo IPv6 header checksum. */
 567                 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
 568                 break;
 569 #endif
 570 #ifdef INET
 571         case LRO_TYPE_IPV4_TCP:
 572                 /* Compute full pseudo IPv4 header checsum. */
 573                 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
 574                 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
 575                 break;
 576 #endif
 577         default:
 578                 cs = 0;         /* Keep compiler happy. */
 579                 break;
 580         }
 581
 582         /* Complement checksum. */
 583         cs = ~cs;
 584         c += cs;
 585
 586         /* Remove TCP header checksum. */
 587         cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
 588         c += cs;
 589
 590         /* Compute checksum remainder. */
 591         while (c > 0xffff)
 592                 c = (c >> 16) + (c & 0xffff);
 593
 594         return (c);
 595 }
 596
 597 static void
 598 tcp_lro_rx_done(struct lro_ctrl *lc)
 599 {
 600         struct lro_entry *le;
 601
 602         while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
 603                 tcp_lro_active_remove(le);
 604                 tcp_lro_flush(lc, le);
 605         }
 606 }
 607
 608 static void
 609 tcp_lro_flush_active(struct lro_ctrl *lc)
 610 {
 611         struct lro_entry *le;
 612
 613         /*
 614          * Walk through the list of le entries, and
 615          * any one that does have packets flush. This
 616          * is called because we have an inbound packet
 617          * (e.g. SYN) that has to have all others flushed
 618          * in front of it. Note we have to do the remove
 619          * because tcp_lro_flush() assumes that the entry
 620          * is being freed. This is ok it will just get
 621          * reallocated again like it was new.
 622          */
 623         LIST_FOREACH(le, &lc->lro_active, next) {
 624                 if (le->m_head != NULL) {
 625                         tcp_lro_active_remove(le);
 626                         tcp_lro_flush(lc, le);
 627                 }
 628         }
 629 }
 630
 631 void
 632 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
 633 {
 634         struct lro_entry *le, *le_tmp;
 635         uint64_t now, tov;
 636         struct bintime bt;
 637
 638         NET_EPOCH_ASSERT();
 639         if (LIST_EMPTY(&lc->lro_active))
 640                 return;
 641
 642         /* get timeout time and current time in ns */
 643         binuptime(&bt);
 644         now = bintime2ns(&bt);
 645         tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
 646         LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
 647                 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
 648                         tcp_lro_active_remove(le);
 649                         tcp_lro_flush(lc, le);
 650                 }
 651         }
 652 }
 653
 654 #ifdef INET
 655 static int
 656 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
 657 {
 658         uint16_t csum;
 659
 660         /* Legacy IP has a header checksum that needs to be correct. */
 661         if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
 662                 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
 663                         lc->lro_bad_csum++;
 664                         return (TCP_LRO_CANNOT);
 665                 }
 666         } else {
 667                 csum = in_cksum_hdr(ip4);
 668                 if (__predict_false(csum != 0)) {
 669                         lc->lro_bad_csum++;
 670                         return (TCP_LRO_CANNOT);
 671                 }
 672         }
 673         return (0);
 674 }
 675 #endif
 676
 677 #ifdef TCPHPTS
 678 static void
 679 tcp_lro_log(struct tcpcb *tp, const struct lro_ctrl *lc,
 680     const struct lro_entry *le, const struct mbuf *m,
 681     int frm, int32_t tcp_data_len, uint32_t th_seq,
 682     uint32_t th_ack, uint16_t th_win)
 683 {
 684         if (tp->t_logstate != TCP_LOG_STATE_OFF) {
 685                 union tcp_log_stackspecific log;
 686                 struct timeval tv, btv;
 687                 uint32_t cts;
 688
 689                 cts = tcp_get_usecs(&tv);
 690                 memset(&log, 0, sizeof(union tcp_log_stackspecific));
 691                 log.u_bbr.flex8 = frm;
 692                 log.u_bbr.flex1 = tcp_data_len;
 693                 if (m)
 694                         log.u_bbr.flex2 = m->m_pkthdr.len;
 695                 else
 696                         log.u_bbr.flex2 = 0;
 697                 if (le->m_head) {
 698                         log.u_bbr.flex3 = le->m_head->m_pkthdr.lro_nsegs;
 699                         log.u_bbr.flex4 = le->m_head->m_pkthdr.lro_tcp_d_len;
 700                         log.u_bbr.flex5 = le->m_head->m_pkthdr.len;
 701                         log.u_bbr.delRate = le->m_head->m_flags;
 702                         log.u_bbr.rttProp = le->m_head->m_pkthdr.rcv_tstmp;
 703                 }
 704                 log.u_bbr.inflight = th_seq;
 705                 log.u_bbr.delivered = th_ack;
 706                 log.u_bbr.timeStamp = cts;
 707                 log.u_bbr.epoch = le->next_seq;
 708                 log.u_bbr.lt_epoch = le->ack_seq;
 709                 log.u_bbr.pacing_gain = th_win;
 710                 log.u_bbr.cwnd_gain = le->window;
 711                 log.u_bbr.lost = curcpu;
 712                 log.u_bbr.cur_del_rate = (uintptr_t)m;
 713                 log.u_bbr.bw_inuse = (uintptr_t)le->m_head;
 714                 bintime2timeval(&lc->lro_last_queue_time, &btv);
 715                 log.u_bbr.flex6 = tcp_tv_to_usectick(&btv);
 716                 log.u_bbr.flex7 = le->compressed;
 717                 log.u_bbr.pacing_gain = le->uncompressed;
 718                 if (in_epoch(net_epoch_preempt))
 719                         log.u_bbr.inhpts = 1;
 720                 else
 721                         log.u_bbr.inhpts = 0;
 722                 TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
 723                     &tptosocket(tp)->so_snd,
 724                     TCP_LOG_LRO, 0, 0, &log, false, &tv);
 725         }
 726 }
 727 #endif
 728
 729 static inline void
 730 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
 731 {
 732         uint32_t csum;
 733
 734         csum = 0xffff - *ptr + value;
 735         while (csum > 0xffff)
 736                 csum = (csum >> 16) + (csum & 0xffff);
 737         *ptr = value;
 738         *psum = csum;
 739 }
 740
 741 static uint16_t
 742 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
 743     uint16_t payload_len, uint16_t delta_sum)
 744 {
 745         uint32_t csum;
 746         uint16_t tlen;
 747         uint16_t temp[5] = {};
 748
 749         switch (pa->data.lro_type) {
 750         case LRO_TYPE_IPV4_TCP:
 751                 /* Compute new IPv4 length. */
 752                 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
 753                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
 754
 755                 /* Subtract delta from current IPv4 checksum. */
 756                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
 757                 while (csum > 0xffff)
 758                         csum = (csum >> 16) + (csum & 0xffff);
 759                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
 760                 goto update_tcp_header;
 761
 762         case LRO_TYPE_IPV6_TCP:
 763                 /* Compute new IPv6 length. */
 764                 tlen = (pa->tcp->th_off << 2) + payload_len;
 765                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
 766                 goto update_tcp_header;
 767
 768         case LRO_TYPE_IPV4_UDP:
 769                 /* Compute new IPv4 length. */
 770                 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
 771                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
 772
 773                 /* Subtract delta from current IPv4 checksum. */
 774                 csum = pa->ip4->ip_sum + 0xffff - temp[0];
 775                 while (csum > 0xffff)
 776                         csum = (csum >> 16) + (csum & 0xffff);
 777                 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
 778                 goto update_udp_header;
 779
 780         case LRO_TYPE_IPV6_UDP:
 781                 /* Compute new IPv6 length. */
 782                 tlen = sizeof(*pa->udp) + payload_len;
 783                 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
 784                 goto update_udp_header;
 785
 786         default:
 787                 return (0);
 788         }
 789
 790 update_tcp_header:
 791         /* Compute current TCP header checksum. */
 792         temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
 793
 794         /* Incorporate the latest ACK into the TCP header. */
 795         pa->tcp->th_ack = le->ack_seq;
 796         pa->tcp->th_win = le->window;
 797
 798         /* Incorporate latest timestamp into the TCP header. */
 799         if (le->timestamp != 0) {
 800                 uint32_t *ts_ptr;
 801
 802                 ts_ptr = (uint32_t *)(pa->tcp + 1);
 803                 ts_ptr[1] = htonl(le->tsval);
 804                 ts_ptr[2] = le->tsecr;
 805         }
 806
 807         /* Compute new TCP header checksum. */
 808         temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
 809
 810         /* Compute new TCP checksum. */
 811         csum = pa->tcp->th_sum + 0xffff - delta_sum +
 812             0xffff - temp[0] + 0xffff - temp[3] + temp[2];
 813         while (csum > 0xffff)
 814                 csum = (csum >> 16) + (csum & 0xffff);
 815
 816         /* Assign new TCP checksum. */
 817         tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
 818
 819         /* Compute all modififications affecting next checksum. */
 820         csum = temp[0] + temp[1] + 0xffff - temp[2] +
 821             temp[3] + temp[4] + delta_sum;
 822         while (csum > 0xffff)
 823                 csum = (csum >> 16) + (csum & 0xffff);
 824
 825         /* Return delta checksum to next stage, if any. */
 826         return (csum);
 827
 828 update_udp_header:
 829         tlen = sizeof(*pa->udp) + payload_len;
 830         /* Assign new UDP length and compute checksum delta. */
 831         tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
 832
 833         /* Check if there is a UDP checksum. */
 834         if (__predict_false(pa->udp->uh_sum != 0)) {
 835                 /* Compute new UDP checksum. */
 836                 csum = pa->udp->uh_sum + 0xffff - delta_sum +
 837                     0xffff - temp[0] + 0xffff - temp[2];
 838                 while (csum > 0xffff)
 839                         csum = (csum >> 16) + (csum & 0xffff);
 840                 /* Assign new UDP checksum. */
 841                 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
 842         }
 843
 844         /* Compute all modififications affecting next checksum. */
 845         csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
 846         while (csum > 0xffff)
 847                 csum = (csum >> 16) + (csum & 0xffff);
 848
 849         /* Return delta checksum to next stage, if any. */
 850         return (csum);
 851 }
 852
 853 static void
 854 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
 855 {
 856         /* Check if we need to recompute any checksums. */
 857         if (le->needs_merge) {
 858                 uint16_t csum;
 859
 860                 switch (le->inner.data.lro_type) {
 861                 case LRO_TYPE_IPV4_TCP:
 862                         csum = tcp_lro_update_checksum(&le->inner, le,
 863                             le->m_head->m_pkthdr.lro_tcp_d_len,
 864                             le->m_head->m_pkthdr.lro_tcp_d_csum);
 865                         csum = tcp_lro_update_checksum(&le->outer, NULL,
 866                             le->m_head->m_pkthdr.lro_tcp_d_len +
 867                             le->inner.total_hdr_len, csum);
 868                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 869                             CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
 870                         le->m_head->m_pkthdr.csum_data = 0xffff;
 871                         if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
 872                                 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
 873                         break;
 874                 case LRO_TYPE_IPV6_TCP:
 875                         csum = tcp_lro_update_checksum(&le->inner, le,
 876                             le->m_head->m_pkthdr.lro_tcp_d_len,
 877                             le->m_head->m_pkthdr.lro_tcp_d_csum);
 878                         csum = tcp_lro_update_checksum(&le->outer, NULL,
 879                             le->m_head->m_pkthdr.lro_tcp_d_len +
 880                             le->inner.total_hdr_len, csum);
 881                         le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 882                             CSUM_PSEUDO_HDR;
 883                         le->m_head->m_pkthdr.csum_data = 0xffff;
 884                         if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
 885                                 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
 886                         break;
 887                 case LRO_TYPE_NONE:
 888                         switch (le->outer.data.lro_type) {
 889                         case LRO_TYPE_IPV4_TCP:
 890                                 csum = tcp_lro_update_checksum(&le->outer, le,
 891                                     le->m_head->m_pkthdr.lro_tcp_d_len,
 892                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
 893                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 894                                     CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
 895                                 le->m_head->m_pkthdr.csum_data = 0xffff;
 896                                 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
 897                                         le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
 898                                 break;
 899                         case LRO_TYPE_IPV6_TCP:
 900                                 csum = tcp_lro_update_checksum(&le->outer, le,
 901                                     le->m_head->m_pkthdr.lro_tcp_d_len,
 902                                     le->m_head->m_pkthdr.lro_tcp_d_csum);
 903                                 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
 904                                     CSUM_PSEUDO_HDR;
 905                                 le->m_head->m_pkthdr.csum_data = 0xffff;
 906                                 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
 907                                         le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
 908                                 break;
 909                         default:
 910                                 break;
 911                         }
 912                         break;
 913                 default:
 914                         break;
 915                 }
 916         }
 917
 918         /*
 919          * Break any chain, this is not set to NULL on the singleton
 920          * case m_nextpkt points to m_head. Other case set them
 921          * m_nextpkt to NULL in push_and_replace.
 922          */
 923         le->m_head->m_nextpkt = NULL;
 924         lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
 925         (*lc->ifp->if_input)(lc->ifp, le->m_head);
 926 }
 927
 928 static void
 929 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
 930     struct mbuf *m, struct tcphdr *th)
 931 {
 932         uint32_t *ts_ptr;
 933         uint16_t tcp_data_len;
 934         uint16_t tcp_opt_len;
 935
 936         ts_ptr = (uint32_t *)(th + 1);
 937         tcp_opt_len = (th->th_off << 2);
 938         tcp_opt_len -= sizeof(*th);
 939
 940         /* Check if there is a timestamp option. */
 941         if (tcp_opt_len == 0 ||
 942             __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
 943             *ts_ptr != TCP_LRO_TS_OPTION)) {
 944                 /* We failed to find the timestamp option. */
 945                 le->timestamp = 0;
 946         } else {
 947                 le->timestamp = 1;
 948                 le->tsval = ntohl(*(ts_ptr + 1));
 949                 le->tsecr = *(ts_ptr + 2);
 950         }
 951
 952         tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
 953
 954         /* Pull out TCP sequence numbers and window size. */
 955         le->next_seq = ntohl(th->th_seq) + tcp_data_len;
 956         le->ack_seq = th->th_ack;
 957         le->window = th->th_win;
 958         le->flags = tcp_get_flags(th);
 959         le->needs_merge = 0;
 960
 961         /* Setup new data pointers. */
 962         le->m_head = m;
 963         le->m_tail = m_last(m);
 964 }
 965
 966 static void
 967 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
 968 {
 969         struct lro_parser *pa;
 970
 971         /*
 972          * Push up the stack of the current entry
 973          * and replace it with "m".
 974          */
 975         struct mbuf *msave;
 976
 977         /* Grab off the next and save it */
 978         msave = le->m_head->m_nextpkt;
 979         le->m_head->m_nextpkt = NULL;
 980
 981         /* Now push out the old entry */
 982         tcp_flush_out_entry(lc, le);
 983
 984         /* Re-parse new header, should not fail. */
 985         pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
 986         KASSERT(pa != NULL,
 987             ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
 988
 989         /*
 990          * Now to replace the data properly in the entry
 991          * we have to reset the TCP header and
 992          * other fields.
 993          */
 994         tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
 995
 996         /* Restore the next list */
 997         m->m_nextpkt = msave;
 998 }
 999
1000 static void
1001 tcp_lro_mbuf_append_pkthdr(struct lro_entry *le, const struct mbuf *p)
1002 {
1003         struct mbuf *m;
1004         uint32_t csum;
1005
1006         m = le->m_head;
1007         if (m->m_pkthdr.lro_nsegs == 1) {
1008                 /* Compute relative checksum. */
1009                 csum = p->m_pkthdr.lro_tcp_d_csum;
1010         } else {
1011                 /* Merge TCP data checksums. */
1012                 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
1013                     (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
1014                 while (csum > 0xffff)
1015                         csum = (csum >> 16) + (csum & 0xffff);
1016         }
1017
1018         /* Update various counters. */
1019         m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
1020         m->m_pkthdr.lro_tcp_d_csum = csum;
1021         m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
1022         m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
1023         le->needs_merge = 1;
1024 }
1025
1026 static void
1027 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
1028 {
1029         /*
1030          * Walk through the mbuf chain we
1031          * have on tap and compress/condense
1032          * as required.
1033          */
1034         uint32_t *ts_ptr;
1035         struct mbuf *m;
1036         struct tcphdr *th;
1037         uint32_t tcp_data_len_total;
1038         uint32_t tcp_data_seg_total;
1039         uint16_t tcp_data_len;
1040         uint16_t tcp_opt_len;
1041
1042         /*
1043          * First we must check the lead (m_head)
1044          * we must make sure that it is *not*
1045          * something that should be sent up
1046          * right away (sack etc).
1047          */
1048 again:
1049         m = le->m_head->m_nextpkt;
1050         if (m == NULL) {
1051                 /* Just one left. */
1052                 return;
1053         }
1054
1055         th = tcp_lro_get_th(m);
1056         tcp_opt_len = (th->th_off << 2);
1057         tcp_opt_len -= sizeof(*th);
1058         ts_ptr = (uint32_t *)(th + 1);
1059
1060         if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1061             *ts_ptr != TCP_LRO_TS_OPTION)) {
1062                 /*
1063                  * Its not the timestamp. We can't
1064                  * use this guy as the head.
1065                  */
1066                 le->m_head->m_nextpkt = m->m_nextpkt;
1067                 tcp_push_and_replace(lc, le, m);
1068                 goto again;
1069         }
1070         if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1071                 /*
1072                  * Make sure that previously seen segments/ACKs are delivered
1073                  * before this segment, e.g. FIN.
1074                  */
1075                 le->m_head->m_nextpkt = m->m_nextpkt;
1076                 tcp_push_and_replace(lc, le, m);
1077                 goto again;
1078         }
1079         while((m = le->m_head->m_nextpkt) != NULL) {
1080                 /*
1081                  * condense m into le, first
1082                  * pull m out of the list.
1083                  */
1084                 le->m_head->m_nextpkt = m->m_nextpkt;
1085                 m->m_nextpkt = NULL;
1086                 /* Setup my data */
1087                 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1088                 th = tcp_lro_get_th(m);
1089                 ts_ptr = (uint32_t *)(th + 1);
1090                 tcp_opt_len = (th->th_off << 2);
1091                 tcp_opt_len -= sizeof(*th);
1092                 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1093                 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1094
1095                 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1096                     tcp_data_len_total >= lc->lro_length_lim) {
1097                         /* Flush now if appending will result in overflow. */
1098                         tcp_push_and_replace(lc, le, m);
1099                         goto again;
1100                 }
1101                 if (tcp_opt_len != 0 &&
1102                     __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1103                     *ts_ptr != TCP_LRO_TS_OPTION)) {
1104                         /*
1105                          * Maybe a sack in the new one? We need to
1106                          * start all over after flushing the
1107                          * current le. We will go up to the beginning
1108                          * and flush it (calling the replace again possibly
1109                          * or just returning).
1110                          */
1111                         tcp_push_and_replace(lc, le, m);
1112                         goto again;
1113                 }
1114                 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1115                         tcp_push_and_replace(lc, le, m);
1116                         goto again;
1117                 }
1118                 if (tcp_opt_len != 0) {
1119                         uint32_t tsval = ntohl(*(ts_ptr + 1));
1120                         /* Make sure timestamp values are increasing. */
1121                         if (TSTMP_GT(le->tsval, tsval))  {
1122                                 tcp_push_and_replace(lc, le, m);
1123                                 goto again;
1124                         }
1125                         le->tsval = tsval;
1126                         le->tsecr = *(ts_ptr + 2);
1127                 }
1128                 /* Try to append the new segment. */
1129                 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1130                                     ((tcp_get_flags(th) & TH_ACK) !=
1131                                       (le->flags & TH_ACK)) ||
1132                                     (tcp_data_len == 0 &&
1133                                      le->ack_seq == th->th_ack &&
1134                                      le->window == th->th_win))) {
1135                         /* Out of order packet, non-ACK + ACK or dup ACK. */
1136                         tcp_push_and_replace(lc, le, m);
1137                         goto again;
1138                 }
1139                 if (tcp_data_len != 0 ||
1140                     SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1141                         le->next_seq += tcp_data_len;
1142                         le->ack_seq = th->th_ack;
1143                         le->window = th->th_win;
1144                         le->needs_merge = 1;
1145                 } else if (th->th_ack == le->ack_seq) {
1146                         if (WIN_GT(th->th_win, le->window)) {
1147                                 le->window = th->th_win;
1148                                 le->needs_merge = 1;
1149                         }
1150                 }
1151
1152                 if (tcp_data_len == 0) {
1153                         m_freem(m);
1154                         continue;
1155                 }
1156
1157                 /* Merge TCP data checksum and length to head mbuf. */
1158                 tcp_lro_mbuf_append_pkthdr(le, m);
1159
1160                 /*
1161                  * Adjust the mbuf so that m_data points to the first byte of
1162                  * the ULP payload.  Adjust the mbuf to avoid complications and
1163                  * append new segment to existing mbuf chain.
1164                  */
1165                 m_adj(m, m->m_pkthdr.len - tcp_data_len);
1166                 m_demote_pkthdr(m);
1167                 le->m_tail->m_next = m;
1168                 le->m_tail = m_last(m);
1169         }
1170 }
1171
1172 #ifdef TCPHPTS
1173 static void
1174 tcp_queue_pkts(struct inpcb *inp, struct tcpcb *tp, struct lro_entry *le)
1175 {
1176         INP_WLOCK_ASSERT(inp);
1177         if (tp->t_in_pkt == NULL) {
1178                 /* Nothing yet there */
1179                 tp->t_in_pkt = le->m_head;
1180                 tp->t_tail_pkt = le->m_last_mbuf;
1181         } else {
1182                 /* Already some there */
1183                 tp->t_tail_pkt->m_nextpkt = le->m_head;
1184                 tp->t_tail_pkt = le->m_last_mbuf;
1185         }
1186         le->m_head = NULL;
1187         le->m_last_mbuf = NULL;
1188 }
1189
1190 static struct mbuf *
1191 tcp_lro_get_last_if_ackcmp(struct lro_ctrl *lc, struct lro_entry *le,
1192     struct inpcb *inp, int32_t *new_m, bool can_append_old_cmp)
1193 {
1194         struct tcpcb *tp;
1195         struct mbuf *m;
1196
1197         tp = intotcpcb(inp);
1198         if (__predict_false(tp == NULL))
1199                 return (NULL);
1200
1201         /* Look at the last mbuf if any in queue */
1202         if (can_append_old_cmp) {
1203                 m = tp->t_tail_pkt;
1204                 if (m != NULL && (m->m_flags & M_ACKCMP) != 0) {
1205                         if (M_TRAILINGSPACE(m) >= sizeof(struct tcp_ackent)) {
1206                                 tcp_lro_log(tp, lc, le, NULL, 23, 0, 0, 0, 0);
1207                                 *new_m = 0;
1208                                 counter_u64_add(tcp_extra_mbuf, 1);
1209                                 return (m);
1210                         } else {
1211                                 /* Mark we ran out of space */
1212                                 inp->inp_flags2 |= INP_MBUF_L_ACKS;
1213                         }
1214                 }
1215         }
1216         /* Decide mbuf size. */
1217         tcp_lro_log(tp, lc, le, NULL, 21, 0, 0, 0, 0);
1218         if (inp->inp_flags2 & INP_MBUF_L_ACKS)
1219                 m = m_getcl(M_NOWAIT, MT_DATA, M_ACKCMP | M_PKTHDR);
1220         else
1221                 m = m_gethdr(M_NOWAIT, MT_DATA);
1222
1223         if (__predict_false(m == NULL)) {
1224                 counter_u64_add(tcp_would_have_but, 1);
1225                 return (NULL);
1226         }
1227         counter_u64_add(tcp_comp_total, 1);
1228         m->m_pkthdr.rcvif = lc->ifp;
1229         m->m_flags |= M_ACKCMP;
1230         *new_m = 1;
1231         return (m);
1232 }
1233
1234 static struct inpcb *
1235 tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
1236 {
1237         struct inpcb *inp;
1238
1239         switch (pa->data.lro_type) {
1240 #ifdef INET6
1241         case LRO_TYPE_IPV6_TCP:
1242                 inp = in6_pcblookup(&V_tcbinfo,
1243                     &pa->data.s_addr.v6,
1244                     pa->data.s_port,
1245                     &pa->data.d_addr.v6,
1246                     pa->data.d_port,
1247                     INPLOOKUP_WLOCKPCB,
1248                     ifp);
1249                 break;
1250 #endif
1251 #ifdef INET
1252         case LRO_TYPE_IPV4_TCP:
1253                 inp = in_pcblookup(&V_tcbinfo,
1254                     pa->data.s_addr.v4,
1255                     pa->data.s_port,
1256                     pa->data.d_addr.v4,
1257                     pa->data.d_port,
1258                     INPLOOKUP_WLOCKPCB,
1259                     ifp);
1260                 break;
1261 #endif
1262         default:
1263                 inp = NULL;
1264                 break;
1265         }
1266         return (inp);
1267 }
1268
1269 static inline bool
1270 tcp_lro_ack_valid(struct mbuf *m, struct tcphdr *th, uint32_t **ppts, bool *other_opts)
1271 {
1272         /*
1273          * This function returns two bits of valuable information.
1274          * a) Is what is present capable of being ack-compressed,
1275          *    we can ack-compress if there is no options or just
1276          *    a timestamp option, and of course the th_flags must
1277          *    be correct as well.
1278          * b) Our other options present such as SACK. This is
1279          *    used to determine if we want to wakeup or not.
1280          */
1281         bool ret = true;
1282
1283         switch (th->th_off << 2) {
1284         case (sizeof(*th) + TCPOLEN_TSTAMP_APPA):
1285                 *ppts = (uint32_t *)(th + 1);
1286                 /* Check if we have only one timestamp option. */
1287                 if (**ppts == TCP_LRO_TS_OPTION)
1288                         *other_opts = false;
1289                 else {
1290                         *other_opts = true;
1291                         ret = false;
1292                 }
1293                 break;
1294         case (sizeof(*th)):
1295                 /* No options. */
1296                 *ppts = NULL;
1297                 *other_opts = false;
1298                 break;
1299         default:
1300                 *ppts = NULL;
1301                 *other_opts = true;
1302                 ret = false;
1303                 break;
1304         }
1305         /* For ACKCMP we only accept ACK, PUSH, ECE and CWR. */
1306         if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH | TH_ECE | TH_CWR)) != 0)
1307                 ret = false;
1308         /* If it has data on it we cannot compress it */
1309         if (m->m_pkthdr.lro_tcp_d_len)
1310                 ret = false;
1311
1312         /* ACK flag must be set. */
1313         if (!(tcp_get_flags(th) & TH_ACK))
1314                 ret = false;
1315         return (ret);
1316 }
1317
1318 static int
1319 tcp_lro_flush_tcphpts(struct lro_ctrl *lc, struct lro_entry *le)
1320 {
1321         struct inpcb *inp;
1322         struct tcpcb *tp;
1323         struct mbuf **pp, *cmp, *mv_to;
1324         struct ifnet *lagg_ifp;
1325         bool bpf_req, lagg_bpf_req, should_wake, can_append_old_cmp;
1326
1327         /* Check if packet doesn't belongs to our network interface. */
1328         if ((tcplro_stacks_wanting_mbufq == 0) ||
1329             (le->outer.data.vlan_id != 0) ||
1330             (le->inner.data.lro_type != LRO_TYPE_NONE))
1331                 return (TCP_LRO_CANNOT);
1332
1333 #ifdef INET6
1334         /*
1335          * Be proactive about unspecified IPv6 address in source. As
1336          * we use all-zero to indicate unbounded/unconnected pcb,
1337          * unspecified IPv6 address can be used to confuse us.
1338          *
1339          * Note that packets with unspecified IPv6 destination is
1340          * already dropped in ip6_input.
1341          */
1342         if (__predict_false(le->outer.data.lro_type == LRO_TYPE_IPV6_TCP &&
1343             IN6_IS_ADDR_UNSPECIFIED(&le->outer.data.s_addr.v6)))
1344                 return (TCP_LRO_CANNOT);
1345
1346         if (__predict_false(le->inner.data.lro_type == LRO_TYPE_IPV6_TCP &&
1347             IN6_IS_ADDR_UNSPECIFIED(&le->inner.data.s_addr.v6)))
1348                 return (TCP_LRO_CANNOT);
1349 #endif
1350         /* Lookup inp, if any. */
1351         inp = tcp_lro_lookup(lc->ifp,
1352             (le->inner.data.lro_type == LRO_TYPE_NONE) ? &le->outer : &le->inner);
1353         if (inp == NULL)
1354                 return (TCP_LRO_CANNOT);
1355
1356         counter_u64_add(tcp_inp_lro_locks_taken, 1);
1357
1358         /* Get TCP control structure. */
1359         tp = intotcpcb(inp);
1360
1361         /* Check if the inp is dead, Jim. */
1362         if (tp->t_state == TCPS_TIME_WAIT) {
1363                 INP_WUNLOCK(inp);
1364                 return (TCP_LRO_CANNOT);
1365         }
1366         if ((inp->inp_irq_cpu_set == 0)  && (lc->lro_cpu_is_set == 1)) {
1367                 inp->inp_irq_cpu = lc->lro_last_cpu;
1368                 inp->inp_irq_cpu_set = 1;
1369         }
1370         /* Check if the transport doesn't support the needed optimizations. */
1371         if ((inp->inp_flags2 & (INP_SUPPORTS_MBUFQ | INP_MBUF_ACKCMP)) == 0) {
1372                 INP_WUNLOCK(inp);
1373                 return (TCP_LRO_CANNOT);
1374         }
1375
1376         if (inp->inp_flags2 & INP_MBUF_QUEUE_READY)
1377                 should_wake = false;
1378         else
1379                 should_wake = true;
1380         /* Check if packets should be tapped to BPF. */
1381         bpf_req = bpf_peers_present(lc->ifp->if_bpf);
1382         lagg_bpf_req = false;
1383         lagg_ifp = NULL;
1384         if (lc->ifp->if_type == IFT_IEEE8023ADLAG ||
1385             lc->ifp->if_type == IFT_INFINIBANDLAG) {
1386                 struct lagg_port *lp = lc->ifp->if_lagg;
1387                 struct lagg_softc *sc = lp->lp_softc;
1388
1389                 lagg_ifp = sc->sc_ifp;
1390                 if (lagg_ifp != NULL)
1391                         lagg_bpf_req = bpf_peers_present(lagg_ifp->if_bpf);
1392         }
1393
1394         /* Strip and compress all the incoming packets. */
1395         can_append_old_cmp = true;
1396         cmp = NULL;
1397         for (pp = &le->m_head; *pp != NULL; ) {
1398                 mv_to = NULL;
1399                 if (do_bpf_strip_and_compress(inp, lc, le, pp,
1400                         &cmp, &mv_to, &should_wake, bpf_req,
1401                         lagg_bpf_req, lagg_ifp, can_append_old_cmp) == false) {
1402                         /* Advance to next mbuf. */
1403                         pp = &(*pp)->m_nextpkt;
1404                         /*
1405                          * Once we have appended we can't look in the pending
1406                          * inbound packets for a compressed ack to append to.
1407                          */
1408                         can_append_old_cmp = false;
1409                         /*
1410                          * Once we append we also need to stop adding to any
1411                          * compressed ack we were remembering. A new cmp
1412                          * ack will be required.
1413                          */
1414                         cmp = NULL;
1415                         tcp_lro_log(tp, lc, le, NULL, 25, 0, 0, 0, 0);
1416                 } else if (mv_to != NULL) {
1417                         /* We are asked to move pp up */
1418                         pp = &mv_to->m_nextpkt;
1419                         tcp_lro_log(tp, lc, le, NULL, 24, 0, 0, 0, 0);
1420                 } else
1421                         tcp_lro_log(tp, lc, le, NULL, 26, 0, 0, 0, 0);
1422         }
1423         /* Update "m_last_mbuf", if any. */
1424         if (pp == &le->m_head)
1425                 le->m_last_mbuf = *pp;
1426         else
1427                 le->m_last_mbuf = __containerof(pp, struct mbuf, m_nextpkt);
1428
1429         /* Check if any data mbufs left. */
1430         if (le->m_head != NULL) {
1431                 counter_u64_add(tcp_inp_lro_direct_queue, 1);
1432                 tcp_lro_log(tp, lc, le, NULL, 22, 1, inp->inp_flags2, 0, 1);
1433                 tcp_queue_pkts(inp, tp, le);
1434         }
1435         if (should_wake) {
1436                 /* Wakeup */
1437                 counter_u64_add(tcp_inp_lro_wokeup_queue, 1);
1438                 if ((*tp->t_fb->tfb_do_queued_segments)(inp->inp_socket, tp, 0))
1439                         inp = NULL;
1440         }
1441         if (inp != NULL)
1442                 INP_WUNLOCK(inp);
1443         return (0);     /* Success. */
1444 }
1445 #endif
1446
1447 void
1448 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1449 {
1450         /* Only optimise if there are multiple packets waiting. */
1451 #ifdef TCPHPTS
1452         int error;
1453 #endif
1454
1455         NET_EPOCH_ASSERT();
1456 #ifdef TCPHPTS
1457         CURVNET_SET(lc->ifp->if_vnet);
1458         error = tcp_lro_flush_tcphpts(lc, le);
1459         CURVNET_RESTORE();
1460         if (error != 0) {
1461 #endif
1462                 tcp_lro_condense(lc, le);
1463                 tcp_flush_out_entry(lc, le);
1464 #ifdef TCPHPTS
1465         }
1466 #endif
1467         lc->lro_flushed++;
1468         bzero(le, sizeof(*le));
1469         LIST_INSERT_HEAD(&lc->lro_free, le, next);
1470 }
1471
1472 #ifdef HAVE_INLINE_FLSLL
1473 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1474 #else
1475 static inline uint64_t
1476 tcp_lro_msb_64(uint64_t x)
1477 {
1478         x |= (x >> 1);
1479         x |= (x >> 2);
1480         x |= (x >> 4);
1481         x |= (x >> 8);
1482         x |= (x >> 16);
1483         x |= (x >> 32);
1484         return (x & ~(x >> 1));
1485 }
1486 #endif
1487
1488 /*
1489  * The tcp_lro_sort() routine is comparable to qsort(), except it has
1490  * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1491  * number of elements to sort and 64 is the number of sequence bits
1492  * available. The algorithm is bit-slicing the 64-bit sequence number,
1493  * sorting one bit at a time from the most significant bit until the
1494  * least significant one, skipping the constant bits. This is
1495  * typically called a radix sort.
1496  */
1497 static void
1498 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1499 {
1500         struct lro_mbuf_sort temp;
1501         uint64_t ones;
1502         uint64_t zeros;
1503         uint32_t x;
1504         uint32_t y;
1505
1506 repeat:
1507         /* for small arrays insertion sort is faster */
1508         if (size <= 12) {
1509                 for (x = 1; x < size; x++) {
1510                         temp = parray[x];
1511                         for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1512                                 parray[y] = parray[y - 1];
1513                         parray[y] = temp;
1514                 }
1515                 return;
1516         }
1517
1518         /* compute sequence bits which are constant */
1519         ones = 0;
1520         zeros = 0;
1521         for (x = 0; x != size; x++) {
1522                 ones |= parray[x].seq;
1523                 zeros |= ~parray[x].seq;
1524         }
1525
1526         /* compute bits which are not constant into "ones" */
1527         ones &= zeros;
1528         if (ones == 0)
1529                 return;
1530
1531         /* pick the most significant bit which is not constant */
1532         ones = tcp_lro_msb_64(ones);
1533
1534         /*
1535          * Move entries having cleared sequence bits to the beginning
1536          * of the array:
1537          */
1538         for (x = y = 0; y != size; y++) {
1539                 /* skip set bits */
1540                 if (parray[y].seq & ones)
1541                         continue;
1542                 /* swap entries */
1543                 temp = parray[x];
1544                 parray[x] = parray[y];
1545                 parray[y] = temp;
1546                 x++;
1547         }
1548
1549         KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1550
1551         /* sort zeros */
1552         tcp_lro_sort(parray, x);
1553
1554         /* sort ones */
1555         parray += x;
1556         size -= x;
1557         goto repeat;
1558 }
1559
1560 void
1561 tcp_lro_flush_all(struct lro_ctrl *lc)
1562 {
1563         uint64_t seq;
1564         uint64_t nseq;
1565         unsigned x;
1566
1567         NET_EPOCH_ASSERT();
1568         /* check if no mbufs to flush */
1569         if (lc->lro_mbuf_count == 0)
1570                 goto done;
1571         if (lc->lro_cpu_is_set == 0) {
1572                 if (lc->lro_last_cpu == curcpu) {
1573                         lc->lro_cnt_of_same_cpu++;
1574                         /* Have we reached the threshold to declare a cpu? */
1575                         if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1576                                 lc->lro_cpu_is_set = 1;
1577                 } else {
1578                         lc->lro_last_cpu = curcpu;
1579                         lc->lro_cnt_of_same_cpu = 0;
1580                 }
1581         }
1582         CURVNET_SET(lc->ifp->if_vnet);
1583
1584         /* get current time */
1585         binuptime(&lc->lro_last_queue_time);
1586
1587         /* sort all mbufs according to stream */
1588         tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1589
1590         /* input data into LRO engine, stream by stream */
1591         seq = 0;
1592         for (x = 0; x != lc->lro_mbuf_count; x++) {
1593                 struct mbuf *mb;
1594
1595                 /* get mbuf */
1596                 mb = lc->lro_mbuf_data[x].mb;
1597
1598                 /* get sequence number, masking away the packet index */
1599                 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1600
1601                 /* check for new stream */
1602                 if (seq != nseq) {
1603                         seq = nseq;
1604
1605                         /* flush active streams */
1606                         tcp_lro_rx_done(lc);
1607                 }
1608
1609                 /* add packet to LRO engine */
1610                 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1611                         /* Flush anything we have acummulated */
1612                         tcp_lro_flush_active(lc);
1613                         /* input packet to network layer */
1614                         (*lc->ifp->if_input)(lc->ifp, mb);
1615                         lc->lro_queued++;
1616                         lc->lro_flushed++;
1617                 }
1618         }
1619         CURVNET_RESTORE();
1620 done:
1621         /* flush active streams */
1622         tcp_lro_rx_done(lc);
1623
1624 #ifdef TCPHPTS
1625         tcp_run_hpts();
1626 #endif
1627         lc->lro_mbuf_count = 0;
1628 }
1629
1630 #ifdef TCPHPTS
1631 static void
1632 build_ack_entry(struct tcp_ackent *ae, struct tcphdr *th, struct mbuf *m,
1633     uint32_t *ts_ptr, uint16_t iptos)
1634 {
1635         /*
1636          * Given a TCP ACK, summarize it down into the small TCP ACK
1637          * entry.
1638          */
1639         ae->timestamp = m->m_pkthdr.rcv_tstmp;
1640         ae->flags = 0;
1641         if (m->m_flags & M_TSTMP_LRO)
1642                 ae->flags |= TSTMP_LRO;
1643         else if (m->m_flags & M_TSTMP)
1644                 ae->flags |= TSTMP_HDWR;
1645         ae->seq = ntohl(th->th_seq);
1646         ae->ack = ntohl(th->th_ack);
1647         ae->flags |= tcp_get_flags(th);
1648         if (ts_ptr != NULL) {
1649                 ae->ts_value = ntohl(ts_ptr[1]);
1650                 ae->ts_echo = ntohl(ts_ptr[2]);
1651                 ae->flags |= HAS_TSTMP;
1652         }
1653         ae->win = ntohs(th->th_win);
1654         ae->codepoint = iptos;
1655 }
1656
1657 /*
1658  * Do BPF tap for either ACK_CMP packets or MBUF QUEUE type packets
1659  * and strip all, but the IPv4/IPv6 header.
1660  */
1661 static bool
1662 do_bpf_strip_and_compress(struct inpcb *inp, struct lro_ctrl *lc,
1663     struct lro_entry *le, struct mbuf **pp, struct mbuf **cmp, struct mbuf **mv_to,
1664     bool *should_wake, bool bpf_req, bool lagg_bpf_req, struct ifnet *lagg_ifp, bool can_append_old_cmp)
1665 {
1666         union {
1667                 void *ptr;
1668                 struct ip *ip4;
1669                 struct ip6_hdr *ip6;
1670         } l3;
1671         struct mbuf *m;
1672         struct mbuf *nm;
1673         struct tcphdr *th;
1674         struct tcp_ackent *ack_ent;
1675         uint32_t *ts_ptr;
1676         int32_t n_mbuf;
1677         bool other_opts, can_compress;
1678         uint8_t lro_type;
1679         uint16_t iptos;
1680         int tcp_hdr_offset;
1681         int idx;
1682
1683         /* Get current mbuf. */
1684         m = *pp;
1685
1686         /* Let the BPF see the packet */
1687         if (__predict_false(bpf_req))
1688                 ETHER_BPF_MTAP(lc->ifp, m);
1689
1690         if (__predict_false(lagg_bpf_req))
1691                 ETHER_BPF_MTAP(lagg_ifp, m);
1692
1693         tcp_hdr_offset = m->m_pkthdr.lro_tcp_h_off;
1694         lro_type = le->inner.data.lro_type;
1695         switch (lro_type) {
1696         case LRO_TYPE_NONE:
1697                 lro_type = le->outer.data.lro_type;
1698                 switch (lro_type) {
1699                 case LRO_TYPE_IPV4_TCP:
1700                         tcp_hdr_offset -= sizeof(*le->outer.ip4);
1701                         m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1702                         break;
1703                 case LRO_TYPE_IPV6_TCP:
1704                         tcp_hdr_offset -= sizeof(*le->outer.ip6);
1705                         m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1706                         break;
1707                 default:
1708                         goto compressed;
1709                 }
1710                 break;
1711         case LRO_TYPE_IPV4_TCP:
1712                 tcp_hdr_offset -= sizeof(*le->outer.ip4);
1713                 m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1714                 break;
1715         case LRO_TYPE_IPV6_TCP:
1716                 tcp_hdr_offset -= sizeof(*le->outer.ip6);
1717                 m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1718                 break;
1719         default:
1720                 goto compressed;
1721         }
1722
1723         MPASS(tcp_hdr_offset >= 0);
1724
1725         m_adj(m, tcp_hdr_offset);
1726         m->m_flags |= M_LRO_EHDRSTRP;
1727         m->m_flags &= ~M_ACKCMP;
1728         m->m_pkthdr.lro_tcp_h_off -= tcp_hdr_offset;
1729
1730         th = tcp_lro_get_th(m);
1731
1732         th->th_sum = 0;         /* TCP checksum is valid. */
1733
1734         /* Check if ACK can be compressed */
1735         can_compress = tcp_lro_ack_valid(m, th, &ts_ptr, &other_opts);
1736
1737         /* Now lets look at the should wake states */
1738         if ((other_opts == true) &&
1739             ((inp->inp_flags2 & INP_DONT_SACK_QUEUE) == 0)) {
1740                 /*
1741                  * If there are other options (SACK?) and the
1742                  * tcp endpoint has not expressly told us it does
1743                  * not care about SACKS, then we should wake up.
1744                  */
1745                 *should_wake = true;
1746         }
1747         /* Is the ack compressable? */
1748         if (can_compress == false)
1749                 goto done;
1750         /* Does the TCP endpoint support ACK compression? */
1751         if ((inp->inp_flags2 & INP_MBUF_ACKCMP) == 0)
1752                 goto done;
1753
1754         /* Lets get the TOS/traffic class field */
1755         l3.ptr = mtod(m, void *);
1756         switch (lro_type) {
1757         case LRO_TYPE_IPV4_TCP:
1758                 iptos = l3.ip4->ip_tos;
1759                 break;
1760         case LRO_TYPE_IPV6_TCP:
1761                 iptos = IPV6_TRAFFIC_CLASS(l3.ip6);
1762                 break;
1763         default:
1764                 iptos = 0;      /* Keep compiler happy. */
1765                 break;
1766         }
1767         /* Now lets get space if we don't have some already */
1768         if (*cmp == NULL) {
1769 new_one:
1770                 nm = tcp_lro_get_last_if_ackcmp(lc, le, inp, &n_mbuf, can_append_old_cmp);
1771                 if (__predict_false(nm == NULL))
1772                         goto done;
1773                 *cmp = nm;
1774                 if (n_mbuf) {
1775                         /*
1776                          *  Link in the new cmp ack to our in-order place,
1777                          * first set our cmp ack's next to where we are.
1778                          */
1779                         nm->m_nextpkt = m;
1780                         (*pp) = nm;
1781                         /*
1782                          * Set it up so mv_to is advanced to our
1783                          * compressed ack. This way the caller can
1784                          * advance pp to the right place.
1785                          */
1786                         *mv_to = nm;
1787                         /*
1788                          * Advance it here locally as well.
1789                          */
1790                         pp = &nm->m_nextpkt;
1791                 }
1792         } else {
1793                 /* We have one already we are working on */
1794                 nm = *cmp;
1795                 if (M_TRAILINGSPACE(nm) < sizeof(struct tcp_ackent)) {
1796                         /* We ran out of space */
1797                         inp->inp_flags2 |= INP_MBUF_L_ACKS;
1798                         goto new_one;
1799                 }
1800         }
1801         MPASS(M_TRAILINGSPACE(nm) >= sizeof(struct tcp_ackent));
1802         counter_u64_add(tcp_inp_lro_compressed, 1);
1803         le->compressed++;
1804         /* We can add in to the one on the tail */
1805         ack_ent = mtod(nm, struct tcp_ackent *);
1806         idx = (nm->m_len / sizeof(struct tcp_ackent));
1807         build_ack_entry(&ack_ent[idx], th, m, ts_ptr, iptos);
1808
1809         /* Bump the size of both pkt-hdr and len */
1810         nm->m_len += sizeof(struct tcp_ackent);
1811         nm->m_pkthdr.len += sizeof(struct tcp_ackent);
1812 compressed:
1813         /* Advance to next mbuf before freeing. */
1814         *pp = m->m_nextpkt;
1815         m->m_nextpkt = NULL;
1816         m_freem(m);
1817         return (true);
1818 done:
1819         counter_u64_add(tcp_uncomp_total, 1);
1820         le->uncompressed++;
1821         return (false);
1822 }
1823 #endif
1824
1825 static struct lro_head *
1826 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1827 {
1828         u_long hash;
1829
1830         if (M_HASHTYPE_ISHASH(m)) {
1831                 hash = m->m_pkthdr.flowid;
1832         } else {
1833                 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1834                         hash += parser->data.raw[i];
1835         }
1836         return (&lc->lro_hash[hash % lc->lro_hashsz]);
1837 }
1838
1839 static int
1840 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1841 {
1842         struct lro_parser pi;   /* inner address data */
1843         struct lro_parser po;   /* outer address data */
1844         struct lro_parser *pa;  /* current parser for TCP stream */
1845         struct lro_entry *le;
1846         struct lro_head *bucket;
1847         struct tcphdr *th;
1848         int tcp_data_len;
1849         int tcp_opt_len;
1850         int error;
1851         uint16_t tcp_data_sum;
1852
1853 #ifdef INET
1854         /* Quickly decide if packet cannot be LRO'ed */
1855         if (__predict_false(V_ipforwarding != 0))
1856                 return (TCP_LRO_CANNOT);
1857 #endif
1858 #ifdef INET6
1859         /* Quickly decide if packet cannot be LRO'ed */
1860         if (__predict_false(V_ip6_forwarding != 0))
1861                 return (TCP_LRO_CANNOT);
1862 #endif
1863         if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1864              ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1865             (m->m_pkthdr.csum_data != 0xffff)) {
1866                 /*
1867                  * The checksum either did not have hardware offload
1868                  * or it was a bad checksum. We can't LRO such
1869                  * a packet.
1870                  */
1871                 counter_u64_add(tcp_bad_csums, 1);
1872                 return (TCP_LRO_CANNOT);
1873         }
1874         /* We expect a contiguous header [eh, ip, tcp]. */
1875         pa = tcp_lro_parser(m, &po, &pi, true);
1876         if (__predict_false(pa == NULL))
1877                 return (TCP_LRO_NOT_SUPPORTED);
1878
1879         /* We don't expect any padding. */
1880         error = tcp_lro_trim_mbuf_chain(m, pa);
1881         if (__predict_false(error != 0))
1882                 return (error);
1883
1884 #ifdef INET
1885         switch (pa->data.lro_type) {
1886         case LRO_TYPE_IPV4_TCP:
1887                 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1888                 if (__predict_false(error != 0))
1889                         return (error);
1890                 break;
1891         default:
1892                 break;
1893         }
1894 #endif
1895         /* If no hardware or arrival stamp on the packet add timestamp */
1896         if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1897                 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1898                 m->m_flags |= M_TSTMP_LRO;
1899         }
1900
1901         /* Get pointer to TCP header. */
1902         th = pa->tcp;
1903
1904         /* Don't process SYN packets. */
1905         if (__predict_false(tcp_get_flags(th) & TH_SYN))
1906                 return (TCP_LRO_CANNOT);
1907
1908         /* Get total TCP header length and compute payload length. */
1909         tcp_opt_len = (th->th_off << 2);
1910         tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1911             (uint8_t *)m->m_data) - tcp_opt_len;
1912         tcp_opt_len -= sizeof(*th);
1913
1914         /* Don't process invalid TCP headers. */
1915         if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1916                 return (TCP_LRO_CANNOT);
1917
1918         /* Compute TCP data only checksum. */
1919         if (tcp_data_len == 0)
1920                 tcp_data_sum = 0;       /* no data, no checksum */
1921         else if (__predict_false(csum != 0))
1922                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1923         else
1924                 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1925
1926         /* Save TCP info in mbuf. */
1927         m->m_nextpkt = NULL;
1928         m->m_pkthdr.rcvif = lc->ifp;
1929         m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1930         m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1931         m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1932         m->m_pkthdr.lro_nsegs = 1;
1933
1934         /* Get hash bucket. */
1935         if (!use_hash) {
1936                 bucket = &lc->lro_hash[0];
1937         } else {
1938                 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1939         }
1940
1941         /* Try to find a matching previous segment. */
1942         LIST_FOREACH(le, bucket, hash_next) {
1943                 /* Compare addresses and ports. */
1944                 if (lro_address_compare(&po.data, &le->outer.data) == false ||
1945                     lro_address_compare(&pi.data, &le->inner.data) == false)
1946                         continue;
1947
1948                 /* Check if no data and old ACK. */
1949                 if (tcp_data_len == 0 &&
1950                     SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1951                         m_freem(m);
1952                         return (0);
1953                 }
1954
1955                 /* Mark "m" in the last spot. */
1956                 le->m_last_mbuf->m_nextpkt = m;
1957                 /* Now set the tail to "m". */
1958                 le->m_last_mbuf = m;
1959                 return (0);
1960         }
1961
1962         /* Try to find an empty slot. */
1963         if (LIST_EMPTY(&lc->lro_free))
1964                 return (TCP_LRO_NO_ENTRIES);
1965
1966         /* Start a new segment chain. */
1967         le = LIST_FIRST(&lc->lro_free);
1968         LIST_REMOVE(le, next);
1969         tcp_lro_active_insert(lc, bucket, le);
1970
1971         /* Make sure the headers are set. */
1972         le->inner = pi;
1973         le->outer = po;
1974
1975         /* Store time this entry was allocated. */
1976         le->alloc_time = lc->lro_last_queue_time;
1977
1978         tcp_set_entry_to_mbuf(lc, le, m, th);
1979
1980         /* Now set the tail to "m". */
1981         le->m_last_mbuf = m;
1982
1983         return (0);
1984 }
1985
1986 int
1987 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1988 {
1989         int error;
1990
1991         if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1992              ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1993             (m->m_pkthdr.csum_data != 0xffff)) {
1994                 /*
1995                  * The checksum either did not have hardware offload
1996                  * or it was a bad checksum. We can't LRO such
1997                  * a packet.
1998                  */
1999                 counter_u64_add(tcp_bad_csums, 1);
2000                 return (TCP_LRO_CANNOT);
2001         }
2002         /* get current time */
2003         binuptime(&lc->lro_last_queue_time);
2004         CURVNET_SET(lc->ifp->if_vnet);
2005         error = tcp_lro_rx_common(lc, m, csum, true);
2006         if (__predict_false(error != 0)) {
2007                 /*
2008                  * Flush anything we have acummulated
2009                  * ahead of this packet that can't
2010                  * be LRO'd. This preserves order.
2011                  */
2012                 tcp_lro_flush_active(lc);
2013         }
2014         CURVNET_RESTORE();
2015
2016         return (error);
2017 }
2018
2019 void
2020 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
2021 {
2022         NET_EPOCH_ASSERT();
2023         /* sanity checks */
2024         if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
2025             lc->lro_mbuf_max == 0)) {
2026                 /* packet drop */
2027                 m_freem(mb);
2028                 return;
2029         }
2030
2031         /* check if packet is not LRO capable */
2032         if (__predict_false((lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
2033                 /* input packet to network layer */
2034                 (*lc->ifp->if_input) (lc->ifp, mb);
2035                 return;
2036         }
2037
2038         /* If no hardware or arrival stamp on the packet add timestamp */
2039         if ((tcplro_stacks_wanting_mbufq > 0) &&
2040             (tcp_less_accurate_lro_ts == 0) &&
2041             ((mb->m_flags & M_TSTMP) == 0)) {
2042                 /* Add in an LRO time since no hardware */
2043                 binuptime(&lc->lro_last_queue_time);
2044                 mb->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
2045                 mb->m_flags |= M_TSTMP_LRO;
2046         }
2047
2048         /* create sequence number */
2049         lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
2050             (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
2051             (((uint64_t)mb->m_pkthdr.flowid) << 24) |
2052             ((uint64_t)lc->lro_mbuf_count);
2053
2054         /* enter mbuf */
2055         lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
2056
2057         /* flush if array is full */
2058         if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
2059                 tcp_lro_flush_all(lc);
2060 }
2061
2062 /* end */