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