sys/netinet/tcp_ratelimit.c

   1 /*-
   2  *
   3  * SPDX-License-Identifier: BSD-3-Clause
   4  *
   5  * Copyright (c) 2018-2019
   6  *      Netflix Inc.
   7  *      All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31 /**
  32  * Author: Randall Stewart <rrs@netflix.com>
  33  */
  34
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37 #include "opt_inet.h"
  38 #include "opt_inet6.h"
  39 #include "opt_ipsec.h"
  40 #include "opt_tcpdebug.h"
  41 #include "opt_ratelimit.h"
  42 #include <sys/param.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 #ifdef KERN_TLS
  49 #include <sys/sockbuf_tls.h>
  50 #endif
  51 #include <sys/sysctl.h>
  52 #include <sys/eventhandler.h>
  53 #include <sys/mutex.h>
  54 #include <sys/ck.h>
  55 #define TCPSTATES               /* for logging */
  56 #include <netinet/in.h>
  57 #include <netinet/in_pcb.h>
  58 #include <netinet/tcp_var.h>
  59 #ifdef INET6
  60 #include <netinet6/tcp6_var.h>
  61 #endif
  62 #include <netinet/tcp_ratelimit.h>
  63 #ifndef USECS_IN_SECOND
  64 #define USECS_IN_SECOND 1000000
  65 #endif
  66 /*
  67  * For the purposes of each send, what is the size
  68  * of an ethernet frame.
  69  */
  70 #ifndef ETHERNET_SEGMENT_SIZE
  71 #define ETHERNET_SEGMENT_SIZE 1500
  72 #endif
  73 MALLOC_DEFINE(M_TCPPACE, "tcp_hwpace", "TCP Hardware pacing memory");
  74 #ifdef RATELIMIT
  75
  76 #define COMMON_RATE 180500
  77 uint64_t desired_rates[] = {
  78         62500,                  /* 500Kbps */
  79         180500,                 /* 1.44Mpbs */
  80         375000,                 /* 3Mbps */
  81         500000,                 /* 4Mbps */
  82         625000,                 /* 5Mbps */
  83         750000,                 /* 6Mbps */
  84         1000000,                /* 8Mbps */
  85         1250000,                /* 10Mbps */
  86         2500000,                /* 20Mbps */
  87         3750000,                /* 30Mbps */
  88         5000000,                /* 40Meg */
  89         6250000,                /* 50Mbps */
  90         12500000,               /* 100Mbps */
  91         25000000,               /* 200Mbps */
  92         50000000,               /* 400Mbps */
  93         100000000,              /* 800Mbps */
  94         12500,                  /* 100kbps */
  95         25000,                  /* 200kbps */
  96         875000,                 /* 7Mbps */
  97         1125000,                /* 9Mbps */
  98         1875000,                /* 15Mbps */
  99         3125000,                /* 25Mbps */
 100         8125000,                /* 65Mbps */
 101         10000000,               /* 80Mbps */
 102         18750000,               /* 150Mbps */
 103         20000000,               /* 250Mbps */
 104         37500000,               /* 350Mbps */
 105         62500000,               /* 500Mbps */
 106         78125000,               /* 625Mbps */
 107         125000000,              /* 1Gbps */
 108 };
 109 #define MAX_HDWR_RATES (sizeof(desired_rates)/sizeof(uint64_t))
 110 #define RS_ORDERED_COUNT 16     /*
 111                                  * Number that are in order
 112                                  * at the beginning of the table,
 113                                  * over this a sort is required.
 114                                  */
 115 #define RS_NEXT_ORDER_GROUP 16  /*
 116                                  * The point in our table where
 117                                  * we come fill in a second ordered
 118                                  * group (index wise means -1).
 119                                  */
 120 #define ALL_HARDWARE_RATES 1004 /*
 121                                  * 1Meg - 1Gig in 1 Meg steps
 122                                  * plus 100, 200k  and 500k and
 123                                  * 10Gig
 124                                  */
 125
 126 #define RS_ONE_MEGABIT_PERSEC 1000000
 127 #define RS_ONE_GIGABIT_PERSEC 1000000000
 128 #define RS_TEN_GIGABIT_PERSEC 10000000000
 129
 130 static struct head_tcp_rate_set int_rs;
 131 static struct mtx rs_mtx;
 132 uint32_t rs_number_alive;
 133 uint32_t rs_number_dead;
 134
 135 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, rl, CTLFLAG_RW, 0,
 136     "TCP Ratelimit stats");
 137 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, alive, CTLFLAG_RW,
 138     &rs_number_alive, 0,
 139     "Number of interfaces initialized for ratelimiting");
 140 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, dead, CTLFLAG_RW,
 141     &rs_number_dead, 0,
 142     "Number of interfaces departing from ratelimiting");
 143
 144 static void
 145 rl_add_syctl_entries(struct sysctl_oid *rl_sysctl_root, struct tcp_rate_set *rs)
 146 {
 147         /*
 148          * Add sysctl entries for thus interface.
 149          */
 150         if (rs->rs_flags & RS_INTF_NO_SUP) {
 151                 SYSCTL_ADD_S32(&rs->sysctl_ctx,
 152                    SYSCTL_CHILDREN(rl_sysctl_root),
 153                    OID_AUTO, "disable", CTLFLAG_RD,
 154                    &rs->rs_disable, 0,
 155                    "Disable this interface from new hdwr limiting?");
 156         } else {
 157                 SYSCTL_ADD_S32(&rs->sysctl_ctx,
 158                    SYSCTL_CHILDREN(rl_sysctl_root),
 159                    OID_AUTO, "disable", CTLFLAG_RW,
 160                    &rs->rs_disable, 0,
 161                    "Disable this interface from new hdwr limiting?");
 162         }
 163         SYSCTL_ADD_S32(&rs->sysctl_ctx,
 164             SYSCTL_CHILDREN(rl_sysctl_root),
 165             OID_AUTO, "minseg", CTLFLAG_RW,
 166             &rs->rs_min_seg, 0,
 167             "What is the minimum we need to send on this interface?");
 168         SYSCTL_ADD_U64(&rs->sysctl_ctx,
 169             SYSCTL_CHILDREN(rl_sysctl_root),
 170             OID_AUTO, "flow_limit", CTLFLAG_RW,
 171             &rs->rs_flow_limit, 0,
 172             "What is the limit for number of flows (0=unlimited)?");
 173         SYSCTL_ADD_S32(&rs->sysctl_ctx,
 174             SYSCTL_CHILDREN(rl_sysctl_root),
 175             OID_AUTO, "highest", CTLFLAG_RD,
 176             &rs->rs_highest_valid, 0,
 177             "Highest valid rate");
 178         SYSCTL_ADD_S32(&rs->sysctl_ctx,
 179             SYSCTL_CHILDREN(rl_sysctl_root),
 180             OID_AUTO, "lowest", CTLFLAG_RD,
 181             &rs->rs_lowest_valid, 0,
 182             "Lowest valid rate");
 183         SYSCTL_ADD_S32(&rs->sysctl_ctx,
 184             SYSCTL_CHILDREN(rl_sysctl_root),
 185             OID_AUTO, "flags", CTLFLAG_RD,
 186             &rs->rs_flags, 0,
 187             "What lags are on the entry?");
 188         SYSCTL_ADD_S32(&rs->sysctl_ctx,
 189             SYSCTL_CHILDREN(rl_sysctl_root),
 190             OID_AUTO, "numrates", CTLFLAG_RD,
 191             &rs->rs_rate_cnt, 0,
 192             "How many rates re there?");
 193         SYSCTL_ADD_U64(&rs->sysctl_ctx,
 194             SYSCTL_CHILDREN(rl_sysctl_root),
 195             OID_AUTO, "flows_using", CTLFLAG_RD,
 196             &rs->rs_flows_using, 0,
 197             "How many flows are using this interface now?");
 198 #ifdef DETAILED_RATELIMIT_SYSCTL
 199         if (rs->rs_rlt && rs->rs_rate_cnt > 0) {
 200                 /*  Lets display the rates */
 201                 int i;
 202                 struct sysctl_oid *rl_rates;
 203                 struct sysctl_oid *rl_rate_num;
 204                 char rate_num[16];
 205                 rl_rates = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
 206                                             SYSCTL_CHILDREN(rl_sysctl_root),
 207                                             OID_AUTO,
 208                                             "rate",
 209                                             CTLFLAG_RW, 0,
 210                                             "Ratelist");
 211                 for( i = 0; i < rs->rs_rate_cnt; i++) {
 212                         sprintf(rate_num, "%d", i);
 213                         rl_rate_num = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
 214                                             SYSCTL_CHILDREN(rl_rates),
 215                                             OID_AUTO,
 216                                             rate_num,
 217                                             CTLFLAG_RW, 0,
 218                                             "Individual Rate");
 219                         SYSCTL_ADD_U32(&rs->sysctl_ctx,
 220                                        SYSCTL_CHILDREN(rl_rate_num),
 221                                        OID_AUTO, "flags", CTLFLAG_RD,
 222                                        &rs->rs_rlt[i].flags, 0,
 223                                        "Flags on this rate");
 224                         SYSCTL_ADD_U32(&rs->sysctl_ctx,
 225                                        SYSCTL_CHILDREN(rl_rate_num),
 226                                        OID_AUTO, "pacetime", CTLFLAG_RD,
 227                                        &rs->rs_rlt[i].time_between, 0,
 228                                        "Time hardware inserts between 1500 byte sends");
 229                         SYSCTL_ADD_U64(&rs->sysctl_ctx,
 230                                        SYSCTL_CHILDREN(rl_rate_num),
 231                                        OID_AUTO, "rate", CTLFLAG_RD,
 232                                        &rs->rs_rlt[i].rate, 0,
 233                                        "Rate in bytes per second");
 234                 }
 235         }
 236 #endif
 237 }
 238
 239 static void
 240 rs_destroy(epoch_context_t ctx)
 241 {
 242         struct tcp_rate_set *rs;
 243
 244         rs = __containerof(ctx, struct tcp_rate_set, rs_epoch_ctx);
 245         mtx_lock(&rs_mtx);
 246         rs->rs_flags &= ~RS_FUNERAL_SCHD;
 247         if (rs->rs_flows_using == 0) {
 248                 /*
 249                  * In theory its possible (but unlikely)
 250                  * that while the delete was occuring
 251                  * and we were applying the DEAD flag
 252                  * someone slipped in and found the
 253                  * interface in a lookup. While we
 254                  * decided rs_flows_using were 0 and
 255                  * scheduling the epoch_call, the other
 256                  * thread incremented rs_flow_using. This
 257                  * is because users have a pointer and
 258                  * we only use the rs_flows_using in an
 259                  * atomic fashion, i.e. the other entities
 260                  * are not protected. To assure this did
 261                  * not occur, we check rs_flows_using here
 262                  * before deleteing.
 263                  */
 264                 sysctl_ctx_free(&rs->sysctl_ctx);
 265                 free(rs->rs_rlt, M_TCPPACE);
 266                 free(rs, M_TCPPACE);
 267                 rs_number_dead--;
 268         }
 269         mtx_unlock(&rs_mtx);
 270
 271 }
 272
 273 extern counter_u64_t rate_limit_set_ok;
 274 extern counter_u64_t rate_limit_active;
 275 extern counter_u64_t rate_limit_alloc_fail;
 276
 277 static int
 278 rl_attach_txrtlmt(struct ifnet *ifp,
 279     uint32_t flowtype,
 280     int flowid,
 281     uint64_t cfg_rate,
 282     struct m_snd_tag **tag)
 283 {
 284         int error;
 285         union if_snd_tag_alloc_params params = {
 286                 .rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
 287                 .rate_limit.hdr.flowid = flowid,
 288                 .rate_limit.hdr.flowtype = flowtype,
 289                 .rate_limit.max_rate = cfg_rate,
 290                 .rate_limit.flags = M_NOWAIT,
 291         };
 292
 293         if (ifp->if_snd_tag_alloc == NULL) {
 294                 error = EOPNOTSUPP;
 295         } else {
 296                 error = ifp->if_snd_tag_alloc(ifp, &params, tag);
 297                 if (error == 0) {
 298                         if_ref((*tag)->ifp);
 299                         counter_u64_add(rate_limit_set_ok, 1);
 300                         counter_u64_add(rate_limit_active, 1);
 301                 } else
 302                         counter_u64_add(rate_limit_alloc_fail, 1);
 303         }
 304         return (error);
 305 }
 306
 307 static void
 308 populate_canned_table(struct tcp_rate_set *rs, const uint64_t *rate_table_act)
 309 {
 310         /*
 311          * The internal table is "special", it
 312          * is two seperate ordered tables that
 313          * must be merged. We get here when the
 314          * adapter specifies a number of rates that
 315          * covers both ranges in the table in some
 316          * form.
 317          */
 318         int i, at_low, at_high;
 319         uint8_t low_disabled = 0, high_disabled = 0;
 320
 321         for(i = 0, at_low = 0, at_high = RS_NEXT_ORDER_GROUP; i < rs->rs_rate_cnt; i++) {
 322                 rs->rs_rlt[i].flags = 0;
 323                 rs->rs_rlt[i].time_between = 0;
 324                 if ((low_disabled == 0) &&
 325                     (high_disabled ||
 326                      (rate_table_act[at_low] < rate_table_act[at_high]))) {
 327                         rs->rs_rlt[i].rate = rate_table_act[at_low];
 328                         at_low++;
 329                         if (at_low == RS_NEXT_ORDER_GROUP)
 330                                 low_disabled = 1;
 331                 } else if (high_disabled == 0) {
 332                         rs->rs_rlt[i].rate = rate_table_act[at_high];
 333                         at_high++;
 334                         if (at_high == MAX_HDWR_RATES)
 335                                 high_disabled = 1;
 336                 }
 337         }
 338 }
 339
 340 static struct tcp_rate_set *
 341 rt_setup_new_rs(struct ifnet *ifp, int *error)
 342 {
 343         struct tcp_rate_set *rs;
 344         const uint64_t *rate_table_act;
 345         uint64_t lentim, res;
 346         size_t sz;
 347         uint32_t hash_type;
 348         int i;
 349         struct if_ratelimit_query_results rl;
 350         struct sysctl_oid *rl_sysctl_root;
 351         /*
 352          * We expect to enter with the
 353          * mutex locked.
 354          */
 355
 356         if (ifp->if_ratelimit_query == NULL) {
 357                 /*
 358                  * We can do nothing if we cannot
 359                  * get a query back from the driver.
 360                  */
 361                 return (NULL);
 362         }
 363         rs = malloc(sizeof(struct tcp_rate_set), M_TCPPACE, M_NOWAIT | M_ZERO);
 364         if (rs == NULL) {
 365                 if (error)
 366                         *error = ENOMEM;
 367                 return (NULL);
 368         }
 369         rl.flags = RT_NOSUPPORT;
 370         ifp->if_ratelimit_query(ifp, &rl);
 371         if (rl.flags & RT_IS_UNUSABLE) {
 372                 /*
 373                  * The interface does not really support
 374                  * the rate-limiting.
 375                  */
 376                 memset(rs, 0, sizeof(struct tcp_rate_set));
 377                 rs->rs_ifp = ifp;
 378                 rs->rs_if_dunit = ifp->if_dunit;
 379                 rs->rs_flags = RS_INTF_NO_SUP;
 380                 rs->rs_disable = 1;
 381                 rs_number_alive++;
 382                 sysctl_ctx_init(&rs->sysctl_ctx);
 383                 rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
 384                     SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
 385                     OID_AUTO,
 386                     rs->rs_ifp->if_xname,
 387                     CTLFLAG_RW, 0,
 388                     "");
 389                 CK_LIST_INSERT_HEAD(&int_rs, rs, next);
 390                 /* Unlock to allow the sysctl stuff to allocate */
 391                 mtx_unlock(&rs_mtx);
 392                 rl_add_syctl_entries(rl_sysctl_root, rs);
 393                 /* re-lock for our caller */
 394                 mtx_lock(&rs_mtx);
 395                 return (rs);
 396         } else if ((rl.flags & RT_IS_INDIRECT) == RT_IS_INDIRECT) {
 397                 memset(rs, 0, sizeof(struct tcp_rate_set));
 398                 rs->rs_ifp = ifp;
 399                 rs->rs_if_dunit = ifp->if_dunit;
 400                 rs->rs_flags = RS_IS_DEFF;
 401                 rs_number_alive++;
 402                 sysctl_ctx_init(&rs->sysctl_ctx);
 403                 rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
 404                     SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
 405                     OID_AUTO,
 406                     rs->rs_ifp->if_xname,
 407                     CTLFLAG_RW, 0,
 408                     "");
 409                 CK_LIST_INSERT_HEAD(&int_rs, rs, next);
 410                 /* Unlock to allow the sysctl stuff to allocate */
 411                 mtx_unlock(&rs_mtx);
 412                 rl_add_syctl_entries(rl_sysctl_root, rs);
 413                 /* re-lock for our caller */
 414                 mtx_lock(&rs_mtx);
 415                 return (rs);
 416         } else if ((rl.flags & RT_IS_FIXED_TABLE) == RT_IS_FIXED_TABLE) {
 417                 /* Mellanox most likely */
 418                 rs->rs_ifp = ifp;
 419                 rs->rs_if_dunit = ifp->if_dunit;
 420                 rs->rs_rate_cnt = rl.number_of_rates;
 421                 rs->rs_min_seg = rl.min_segment_burst;
 422                 rs->rs_highest_valid = 0;
 423                 rs->rs_flow_limit = rl.max_flows;
 424                 rs->rs_flags = RS_IS_INTF | RS_NO_PRE;
 425                 rs->rs_disable = 0;
 426                 rate_table_act = rl.rate_table;
 427         } else if ((rl.flags & RT_IS_SELECTABLE) == RT_IS_SELECTABLE) {
 428                 /* Chelsio */
 429                 rs->rs_ifp = ifp;
 430                 rs->rs_if_dunit = ifp->if_dunit;
 431                 rs->rs_rate_cnt = rl.number_of_rates;
 432                 rs->rs_min_seg = rl.min_segment_burst;
 433                 rs->rs_disable = 0;
 434                 rs->rs_flow_limit = rl.max_flows;
 435                 rate_table_act = desired_rates;
 436                 if ((rs->rs_rate_cnt > MAX_HDWR_RATES) &&
 437                     (rs->rs_rate_cnt < ALL_HARDWARE_RATES)) {
 438                         /*
 439                          * Our desired table is not big
 440                          * enough, do what we can.
 441                          */
 442                         rs->rs_rate_cnt = MAX_HDWR_RATES;
 443                  }
 444                 if (rs->rs_rate_cnt <= RS_ORDERED_COUNT)
 445                         rs->rs_flags = RS_IS_INTF;
 446                 else
 447                         rs->rs_flags = RS_IS_INTF | RS_INT_TBL;
 448                 if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES)
 449                         rs->rs_rate_cnt = ALL_HARDWARE_RATES;
 450         } else {
 451                 printf("Interface:%s unit:%d not one known to have rate-limits\n",
 452                     ifp->if_dname,
 453                     ifp->if_dunit);
 454                 free(rs, M_TCPPACE);
 455                 return (NULL);
 456         }
 457         sz = sizeof(struct tcp_hwrate_limit_table) * rs->rs_rate_cnt;
 458         rs->rs_rlt = malloc(sz, M_TCPPACE, M_NOWAIT);
 459         if (rs->rs_rlt == NULL) {
 460                 if (error)
 461                         *error = ENOMEM;
 462 bail:
 463                 free(rs, M_TCPPACE);
 464                 return (NULL);
 465         }
 466         if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES) {
 467                 /*
 468                  * The interface supports all
 469                  * the rates we could possibly want.
 470                  */
 471                 uint64_t rat;
 472
 473                 rs->rs_rlt[0].rate = 12500;     /* 100k */
 474                 rs->rs_rlt[1].rate = 25000;     /* 200k */
 475                 rs->rs_rlt[2].rate = 62500;     /* 500k */
 476                 /* Note 125000 == 1Megabit
 477                  * populate 1Meg - 1000meg.
 478                  */
 479                 for(i = 3, rat = 125000; i< (ALL_HARDWARE_RATES-1); i++) {
 480                         rs->rs_rlt[i].rate = rat;
 481                         rat += 125000;
 482                 }
 483                 rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate = 1250000000;
 484         } else if (rs->rs_flags & RS_INT_TBL) {
 485                 /* We populate this in a special way */
 486                 populate_canned_table(rs, rate_table_act);
 487         } else {
 488                 /*
 489                  * Just copy in the rates from
 490                  * the table, it is in order.
 491                  */
 492                 for (i=0; i<rs->rs_rate_cnt; i++) {
 493                         rs->rs_rlt[i].rate = rate_table_act[i];
 494                         rs->rs_rlt[i].time_between = 0;
 495                         rs->rs_rlt[i].flags = 0;
 496                 }
 497         }
 498         for (i = (rs->rs_rate_cnt - 1); i >= 0; i--) {
 499                 /*
 500                  * We go backwards through the list so that if we can't get
 501                  * a rate and fail to init one, we have at least a chance of
 502                  * getting the highest one.
 503                  */
 504                 rs->rs_rlt[i].ptbl = rs;
 505                 rs->rs_rlt[i].tag = NULL;
 506                 /*
 507                  * Calculate the time between.
 508                  */
 509                 lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND;
 510                 res = lentim / rs->rs_rlt[i].rate;
 511                 if (res > 0)
 512                         rs->rs_rlt[i].time_between = res;
 513                 else
 514                         rs->rs_rlt[i].time_between = 1;
 515                 if (rs->rs_flags & RS_NO_PRE) {
 516                         rs->rs_rlt[i].flags = HDWRPACE_INITED;
 517                         rs->rs_lowest_valid = i;
 518                 } else {
 519                         int err;
 520 #ifdef RSS
 521                         hash_type = M_HASHTYPE_RSS_TCP_IPV4;
 522 #else
 523                         hash_type = M_HASHTYPE_OPAQUE_HASH;
 524 #endif
 525                         err = rl_attach_txrtlmt(ifp,
 526                             hash_type,
 527                             (i + 1),
 528                             rs->rs_rlt[i].rate,
 529                             &rs->rs_rlt[i].tag);
 530                         if (err) {
 531                                 if (i == (rs->rs_rate_cnt - 1)) {
 532                                         /*
 533                                          * Huh - first rate and we can't get
 534                                          * it?
 535                                          */
 536                                         free(rs->rs_rlt, M_TCPPACE);
 537                                         if (error)
 538                                                 *error = err;
 539                                         goto bail;
 540                                 } else {
 541                                         if (error)
 542                                                 *error = err;
 543                                 }
 544                                 break;
 545                         } else {
 546                                 rs->rs_rlt[i].flags = HDWRPACE_INITED | HDWRPACE_TAGPRESENT;
 547                                 rs->rs_lowest_valid = i;
 548                         }
 549                 }
 550         }
 551         /* Did we get at least 1 rate? */
 552         if (rs->rs_rlt[(rs->rs_rate_cnt - 1)].flags & HDWRPACE_INITED)
 553                 rs->rs_highest_valid = rs->rs_rate_cnt - 1;
 554         else {
 555                 free(rs->rs_rlt, M_TCPPACE);
 556                 goto bail;
 557         }
 558         rs_number_alive++;
 559         CK_LIST_INSERT_HEAD(&int_rs, rs, next);
 560         sysctl_ctx_init(&rs->sysctl_ctx);
 561         rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
 562             SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
 563             OID_AUTO,
 564             rs->rs_ifp->if_xname,
 565             CTLFLAG_RW, 0,
 566             "");
 567         /* Unlock to allow the sysctl stuff to allocate */
 568         mtx_unlock(&rs_mtx);
 569         rl_add_syctl_entries(rl_sysctl_root, rs);
 570         /* re-lock for our caller */
 571         mtx_lock(&rs_mtx);
 572         return (rs);
 573 }
 574
 575 static const struct tcp_hwrate_limit_table *
 576 tcp_int_find_suitable_rate(const struct tcp_rate_set *rs,
 577     uint64_t bytes_per_sec, uint32_t flags)
 578 {
 579         struct tcp_hwrate_limit_table *arte = NULL, *rte = NULL;
 580         uint64_t mbits_per_sec, ind_calc;
 581         int i;
 582
 583         mbits_per_sec = (bytes_per_sec * 8);
 584         if (flags & RS_PACING_LT) {
 585                 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
 586                     (rs->rs_lowest_valid <= 2)){
 587                         /*
 588                          * Smaller than 1Meg, only
 589                          * 3 entries can match it.
 590                          */
 591                         for(i = rs->rs_lowest_valid; i < 3; i++) {
 592                                 if (bytes_per_sec <= rs->rs_rlt[i].rate) {
 593                                         rte = &rs->rs_rlt[i];
 594                                         break;
 595                                 } else if (rs->rs_rlt[i].flags & HDWRPACE_INITED) {
 596                                         arte = &rs->rs_rlt[i];
 597                                 }
 598                         }
 599                         goto done;
 600                 } else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
 601                            (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
 602                         /*
 603                          * Larger than 1G (the majority of
 604                          * our table.
 605                          */
 606                         if (mbits_per_sec < RS_TEN_GIGABIT_PERSEC)
 607                                 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 608                         else
 609                                 arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 610                         goto done;
 611                 }
 612                 /*
 613                  * If we reach here its in our table (between 1Meg - 1000Meg),
 614                  * just take the rounded down mbits per second, and add
 615                  * 1Megabit to it, from this we can calculate
 616                  * the index in the table.
 617                  */
 618                 ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
 619                 if ((ind_calc * RS_ONE_MEGABIT_PERSEC) != mbits_per_sec)
 620                         ind_calc++;
 621                 /* our table is offset by 3, we add 2 */
 622                 ind_calc += 2;
 623                 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
 624                         /* This should not happen */
 625                         ind_calc = ALL_HARDWARE_RATES-1;
 626                 }
 627                 if ((ind_calc >= rs->rs_lowest_valid) &&
 628                     (ind_calc <= rs->rs_highest_valid))
 629                 rte = &rs->rs_rlt[ind_calc];
 630         } else if (flags & RS_PACING_EXACT_MATCH) {
 631                 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
 632                     (rs->rs_lowest_valid <= 2)){
 633                         for(i = rs->rs_lowest_valid; i < 3; i++) {
 634                                 if (bytes_per_sec == rs->rs_rlt[i].rate) {
 635                                         rte = &rs->rs_rlt[i];
 636                                         break;
 637                                 }
 638                         }
 639                 } else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
 640                            (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
 641                         /* > 1Gbps only one rate */
 642                         if (bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) {
 643                                 /* Its 10G wow */
 644                                 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 645                         }
 646                 } else {
 647                         /* Ok it must be a exact meg (its between 1G and 1Meg) */
 648                         ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
 649                         if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
 650                                 /* its an exact Mbps */
 651                                 ind_calc += 2;
 652                                 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
 653                                         /* This should not happen */
 654                                         ind_calc = ALL_HARDWARE_RATES-1;
 655                                 }
 656                                 if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED)
 657                                         rte = &rs->rs_rlt[ind_calc];
 658                         }
 659                 }
 660         } else {
 661                 /* we want greater than the requested rate */
 662                 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
 663                     (rs->rs_lowest_valid <= 2)){
 664                         arte = &rs->rs_rlt[3]; /* set alternate to 1Meg */
 665                         for (i=2; i>=rs->rs_lowest_valid; i--) {
 666                                 if (bytes_per_sec < rs->rs_rlt[i].rate) {
 667                                         rte = &rs->rs_rlt[i];
 668                                         break;
 669                                 } else if ((flags & RS_PACING_GEQ) &&
 670                                            (bytes_per_sec == rs->rs_rlt[i].rate)) {
 671                                         rte = &rs->rs_rlt[i];
 672                                         break;
 673                                 } else {
 674                                         arte = &rs->rs_rlt[i]; /* new alternate */
 675                                 }
 676                         }
 677                 } else if (mbits_per_sec > RS_ONE_GIGABIT_PERSEC) {
 678                         if ((bytes_per_sec < rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
 679                             (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
 680                                 /* Our top rate is larger than the request */
 681                                 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 682                         } else if ((flags & RS_PACING_GEQ) &&
 683                                    (bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
 684                                    (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
 685                                 /* It matches our top rate */
 686                                 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 687                         } else if (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED) {
 688                                 /* The top rate is an alternative */
 689                                 arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
 690                         }
 691                 } else {
 692                         /* Its in our range 1Meg - 1Gig */
 693                         if (flags & RS_PACING_GEQ) {
 694                                 ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
 695                                 if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
 696                                         if (ind_calc > (ALL_HARDWARE_RATES-1)) {
 697                                                 /* This should not happen */
 698                                                 ind_calc = (ALL_HARDWARE_RATES-1);
 699                                         }
 700                                         rte = &rs->rs_rlt[ind_calc];
 701                                 }
 702                                 goto done;
 703                         }
 704                         ind_calc = (mbits_per_sec + (RS_ONE_MEGABIT_PERSEC-1))/RS_ONE_MEGABIT_PERSEC;
 705                         ind_calc += 2;
 706                         if (ind_calc > (ALL_HARDWARE_RATES-1)) {
 707                                 /* This should not happen */
 708                                 ind_calc = ALL_HARDWARE_RATES-1;
 709                         }
 710                         if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED)
 711                                 rte = &rs->rs_rlt[ind_calc];
 712                 }
 713         }
 714 done:
 715         if ((rte == NULL) &&
 716             (arte != NULL) &&
 717             (flags & RS_PACING_SUB_OK)) {
 718                 /* We can use the substitute */
 719                 rte = arte;
 720         }
 721         return (rte);
 722 }
 723
 724 static const struct tcp_hwrate_limit_table *
 725 tcp_find_suitable_rate(const struct tcp_rate_set *rs, uint64_t bytes_per_sec, uint32_t flags)
 726 {
 727         /**
 728          * Hunt the rate table with the restrictions in flags and find a
 729          * suitable rate if possible.
 730          * RS_PACING_EXACT_MATCH - look for an exact match to rate.
 731          * RS_PACING_GT     - must be greater than.
 732          * RS_PACING_GEQ    - must be greater than or equal.
 733          * RS_PACING_LT     - must be less than.
 734          * RS_PACING_SUB_OK - If we don't meet criteria a
 735          *                    substitute is ok.
 736          */
 737         int i, matched;
 738         struct tcp_hwrate_limit_table *rte = NULL;
 739
 740
 741         if ((rs->rs_flags & RS_INT_TBL) &&
 742             (rs->rs_rate_cnt >= ALL_HARDWARE_RATES)) {
 743                 /*
 744                  * Here we don't want to paw thru
 745                  * a big table, we have everything
 746                  * from 1Meg - 1000Meg in 1Meg increments.
 747                  * Use an alternate method to "lookup".
 748                  */
 749                 return (tcp_int_find_suitable_rate(rs, bytes_per_sec, flags));
 750         }
 751         if ((flags & RS_PACING_LT) ||
 752             (flags & RS_PACING_EXACT_MATCH)) {
 753                 /*
 754                  * For exact and less than we go forward through the table.
 755                  * This way when we find one larger we stop (exact was a
 756                  * toss up).
 757                  */
 758                 for (i = rs->rs_lowest_valid, matched = 0; i <= rs->rs_highest_valid; i++) {
 759                         if ((flags & RS_PACING_EXACT_MATCH) &&
 760                             (bytes_per_sec == rs->rs_rlt[i].rate)) {
 761                                 rte = &rs->rs_rlt[i];
 762                                 matched = 1;
 763                                 break;
 764                         } else if ((flags & RS_PACING_LT) &&
 765                             (bytes_per_sec <= rs->rs_rlt[i].rate)) {
 766                                 rte = &rs->rs_rlt[i];
 767                                 matched = 1;
 768                                 break;
 769                         }
 770                         if (bytes_per_sec > rs->rs_rlt[i].rate)
 771                                 break;
 772                 }
 773                 if ((matched == 0) &&
 774                     (flags & RS_PACING_LT) &&
 775                     (flags & RS_PACING_SUB_OK)) {
 776                         /* Kick in a substitute (the lowest) */
 777                         rte = &rs->rs_rlt[rs->rs_lowest_valid];
 778                 }
 779         } else {
 780                 /*
 781                  * Here we go backward through the table so that we can find
 782                  * the one greater in theory faster (but its probably a
 783                  * wash).
 784                  */
 785                 for (i = rs->rs_highest_valid, matched = 0; i >= rs->rs_lowest_valid; i--) {
 786                         if (rs->rs_rlt[i].rate > bytes_per_sec) {
 787                                 /* A possible candidate */
 788                                 rte = &rs->rs_rlt[i];
 789                         }
 790                         if ((flags & RS_PACING_GEQ) &&
 791                             (bytes_per_sec == rs->rs_rlt[i].rate)) {
 792                                 /* An exact match and we want equal */
 793                                 matched = 1;
 794                                 rte = &rs->rs_rlt[i];
 795                                 break;
 796                         } else if (rte) {
 797                                 /*
 798                                  * Found one that is larger than but don't
 799                                  * stop, there may be a more closer match.
 800                                  */
 801                                 matched = 1;
 802                         }
 803                         if (rs->rs_rlt[i].rate < bytes_per_sec) {
 804                                 /*
 805                                  * We found a table entry that is smaller,
 806                                  * stop there will be none greater or equal.
 807                                  */
 808                                 break;
 809                         }
 810                 }
 811                 if ((matched == 0) &&
 812                     (flags & RS_PACING_SUB_OK)) {
 813                         /* Kick in a substitute (the highest) */
 814                         rte = &rs->rs_rlt[rs->rs_highest_valid];
 815                 }
 816         }
 817         return (rte);
 818 }
 819
 820 static struct ifnet *
 821 rt_find_real_interface(struct ifnet *ifp, struct inpcb *inp, int *error)
 822 {
 823         struct ifnet *tifp;
 824         struct m_snd_tag *tag;
 825         union if_snd_tag_alloc_params params = {
 826                 .rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
 827                 .rate_limit.hdr.flowid = 1,
 828                 .rate_limit.max_rate = COMMON_RATE,
 829                 .rate_limit.flags = M_NOWAIT,
 830         };
 831         int err;
 832 #ifdef RSS
 833         params.rate_limit.hdr.flowtype = ((inp->inp_vflag & INP_IPV6) ?
 834             M_HASHTYPE_RSS_TCP_IPV6 : M_HASHTYPE_RSS_TCP_IPV4);
 835 #else
 836         params.rate_limit.hdr.flowtype = M_HASHTYPE_OPAQUE_HASH;
 837 #endif
 838         tag = NULL;
 839         if (ifp->if_snd_tag_alloc) {
 840                 if (error)
 841                         *error = ENODEV;
 842                 return (NULL);
 843         }
 844         err = ifp->if_snd_tag_alloc(ifp, &params, &tag);
 845         if (err) {
 846                 /* Failed to setup a tag? */
 847                 if (error)
 848                         *error = err;
 849                 return (NULL);
 850         }
 851         tifp = tag->ifp;
 852         tifp->if_snd_tag_free(tag);
 853         return (tifp);
 854 }
 855
 856 static const struct tcp_hwrate_limit_table *
 857 rt_setup_rate(struct inpcb *inp, struct ifnet *ifp, uint64_t bytes_per_sec,
 858     uint32_t flags, int *error)
 859 {
 860         /* First lets find the interface if it exists */
 861         const struct tcp_hwrate_limit_table *rte;
 862         struct tcp_rate_set *rs;
 863         struct epoch_tracker et;
 864         int err;
 865
 866         epoch_enter_preempt(net_epoch_preempt, &et);
 867 use_real_interface:
 868         CK_LIST_FOREACH(rs, &int_rs, next) {
 869                 /*
 870                  * Note we don't look with the lock since we either see a
 871                  * new entry or will get one when we try to add it.
 872                  */
 873                 if (rs->rs_flags & RS_IS_DEAD) {
 874                         /* The dead are not looked at */
 875                         continue;
 876                 }
 877                 if ((rs->rs_ifp == ifp) &&
 878                     (rs->rs_if_dunit == ifp->if_dunit)) {
 879                         /* Ok we found it */
 880                         break;
 881                 }
 882         }
 883         if ((rs == NULL) ||
 884             (rs->rs_flags & RS_INTF_NO_SUP) ||
 885             (rs->rs_flags & RS_IS_DEAD)) {
 886                 /*
 887                  * This means we got a packet *before*
 888                  * the IF-UP was processed below, <or>
 889                  * while or after we already received an interface
 890                  * departed event. In either case we really don't
 891                  * want to do anything with pacing, in
 892                  * the departing case the packet is not
 893                  * going to go very far. The new case
 894                  * might be arguable, but its impossible
 895                  * to tell from the departing case.
 896                  */
 897                 if (rs->rs_disable && error)
 898                         *error = ENODEV;
 899                 epoch_exit_preempt(net_epoch_preempt, &et);
 900                 return (NULL);
 901         }
 902
 903         if ((rs == NULL) || (rs->rs_disable != 0)) {
 904                 if (rs->rs_disable && error)
 905                         *error = ENOSPC;
 906                 epoch_exit_preempt(net_epoch_preempt, &et);
 907                 return (NULL);
 908         }
 909         if (rs->rs_flags & RS_IS_DEFF) {
 910                 /* We need to find the real interface */
 911                 struct ifnet *tifp;
 912
 913                 tifp = rt_find_real_interface(ifp, inp, error);
 914                 if (tifp == NULL) {
 915                         if (rs->rs_disable && error)
 916                                 *error = ENOTSUP;
 917                         epoch_exit_preempt(net_epoch_preempt, &et);
 918                         return (NULL);
 919                 }
 920                 goto use_real_interface;
 921         }
 922         if (rs->rs_flow_limit &&
 923             ((rs->rs_flows_using + 1) > rs->rs_flow_limit)) {
 924                 if (error)
 925                         *error = ENOSPC;
 926                 epoch_exit_preempt(net_epoch_preempt, &et);
 927                 return (NULL);
 928         }
 929         rte = tcp_find_suitable_rate(rs, bytes_per_sec, flags);
 930         if (rte) {
 931                 err = in_pcbattach_txrtlmt(inp, rs->rs_ifp,
 932                     inp->inp_flowtype,
 933                     inp->inp_flowid,
 934                     rte->rate,
 935                     &inp->inp_snd_tag);
 936                 if (err) {
 937                         /* Failed to attach */
 938                         if (error)
 939                                 *error = err;
 940                         rte = NULL;
 941                 }
 942         }
 943         if (rte) {
 944                 /*
 945                  * We use an atomic here for accounting so we don't have to
 946                  * use locks when freeing.
 947                  */
 948                 atomic_add_64(&rs->rs_flows_using, 1);
 949         }
 950         epoch_exit_preempt(net_epoch_preempt, &et);
 951         return (rte);
 952 }
 953
 954 static void
 955 tcp_rl_ifnet_link(void *arg __unused, struct ifnet *ifp, int link_state)
 956 {
 957         int error;
 958         struct tcp_rate_set *rs;
 959
 960         if (((ifp->if_capabilities & IFCAP_TXRTLMT) == 0) ||
 961             (link_state != LINK_STATE_UP)) {
 962                 /*
 963                  * We only care on an interface going up that is rate-limit
 964                  * capable.
 965                  */
 966                 return;
 967         }
 968         mtx_lock(&rs_mtx);
 969         CK_LIST_FOREACH(rs, &int_rs, next) {
 970                 if ((rs->rs_ifp == ifp) &&
 971                     (rs->rs_if_dunit == ifp->if_dunit)) {
 972                         /* We already have initialized this guy */
 973                         mtx_unlock(&rs_mtx);
 974                         return;
 975                 }
 976         }
 977         rt_setup_new_rs(ifp, &error);
 978         mtx_unlock(&rs_mtx);
 979 }
 980
 981 static void
 982 tcp_rl_ifnet_departure(void *arg __unused, struct ifnet *ifp)
 983 {
 984         struct tcp_rate_set *rs, *nrs;
 985         struct ifnet *tifp;
 986         int i;
 987
 988         mtx_lock(&rs_mtx);
 989         CK_LIST_FOREACH_SAFE(rs, &int_rs, next, nrs) {
 990                 if ((rs->rs_ifp == ifp) &&
 991                     (rs->rs_if_dunit == ifp->if_dunit)) {
 992                         CK_LIST_REMOVE(rs, next);
 993                         rs_number_alive--;
 994                         rs_number_dead++;
 995                         rs->rs_flags |= RS_IS_DEAD;
 996                         for (i = 0; i < rs->rs_rate_cnt; i++) {
 997                                 if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
 998                                         tifp = rs->rs_rlt[i].tag->ifp;
 999                                         in_pcbdetach_tag(tifp, rs->rs_rlt[i].tag);
1000                                         rs->rs_rlt[i].tag = NULL;
1001                                 }
1002                                 rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
1003                         }
1004                         if (rs->rs_flows_using == 0) {
1005                                 /*
1006                                  * No references left, so we can schedule the
1007                                  * destruction after the epoch (with a caveat).
1008                                  */
1009                                 rs->rs_flags |= RS_FUNERAL_SCHD;
1010                                 epoch_call(net_epoch, &rs->rs_epoch_ctx, rs_destroy);
1011                         }
1012                         break;
1013                 }
1014         }
1015         mtx_unlock(&rs_mtx);
1016 }
1017
1018 static void
1019 tcp_rl_shutdown(void *arg __unused, int howto __unused)
1020 {
1021         struct tcp_rate_set *rs, *nrs;
1022         struct ifnet *tifp;
1023         int i;
1024
1025         mtx_lock(&rs_mtx);
1026         CK_LIST_FOREACH_SAFE(rs, &int_rs, next, nrs) {
1027                 CK_LIST_REMOVE(rs, next);
1028                 rs_number_alive--;
1029                 rs_number_dead++;
1030                 rs->rs_flags |= RS_IS_DEAD;
1031                 for (i = 0; i < rs->rs_rate_cnt; i++) {
1032                         if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
1033                                 tifp = rs->rs_rlt[i].tag->ifp;
1034                                 in_pcbdetach_tag(tifp, rs->rs_rlt[i].tag);
1035                                 rs->rs_rlt[i].tag = NULL;
1036                         }
1037                         rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
1038                 }
1039                 if (rs->rs_flows_using != 0) {
1040                         /*
1041                          * We dont hold a reference
1042                          * so we have nothing left to
1043                          * do.
1044                          */
1045                 } else {
1046                         /*
1047                          * No references left, so we can destroy it
1048                          * after the epoch.
1049                          */
1050                         rs->rs_flags |= RS_FUNERAL_SCHD;
1051                         epoch_call(net_epoch, &rs->rs_epoch_ctx, rs_destroy);
1052                 }
1053         }
1054         mtx_unlock(&rs_mtx);
1055 }
1056
1057 const struct tcp_hwrate_limit_table *
1058 tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
1059     uint64_t bytes_per_sec, int flags, int *error)
1060 {
1061         const struct tcp_hwrate_limit_table *rte;
1062
1063         if (tp->t_inpcb->inp_snd_tag == NULL) {
1064                 /*
1065                  * We are setting up a rate for the first time.
1066                  */
1067                 if ((ifp->if_capabilities & IFCAP_TXRTLMT) == 0) {
1068                         /* Not supported by the egress */
1069                         if (error)
1070                                 *error = ENODEV;
1071                         return (NULL);
1072                 }
1073 #ifdef KERN_TLS
1074                 if (tp->t_inpcb->inp_socket->so_snd.sb_tls_flags & SB_TLS_IFNET) {
1075                         /*
1076                          * We currently can't do both TLS and hardware
1077                          * pacing
1078                          */
1079                         if (error)
1080                                 *error = EINVAL;
1081                         return (NULL);
1082                 }
1083 #endif
1084                 rte = rt_setup_rate(tp->t_inpcb, ifp, bytes_per_sec, flags, error);
1085         } else {
1086                 /*
1087                  * We are modifying a rate, wrong interface?
1088                  */
1089                 if (error)
1090                         *error = EINVAL;
1091                 rte = NULL;
1092         }
1093         return (rte);
1094 }
1095
1096 const struct tcp_hwrate_limit_table *
1097 tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
1098     struct tcpcb *tp, struct ifnet *ifp,
1099     uint64_t bytes_per_sec, int flags, int *error)
1100 {
1101         const struct tcp_hwrate_limit_table *nrte;
1102         const struct tcp_rate_set *rs;
1103         int is_indirect = 0;
1104         int err;
1105
1106
1107         if ((tp->t_inpcb->inp_snd_tag == NULL) ||
1108             (crte == NULL)) {
1109                 /* Wrong interface */
1110                 if (error)
1111                         *error = EINVAL;
1112                 return (NULL);
1113         }
1114         rs = crte->ptbl;
1115         if ((rs->rs_flags & RS_IS_DEAD) ||
1116             (crte->flags & HDWRPACE_IFPDEPARTED)) {
1117                 /* Release the rate, and try anew */
1118 re_rate:
1119                 tcp_rel_pacing_rate(crte, tp);
1120                 nrte = tcp_set_pacing_rate(tp, ifp,
1121                     bytes_per_sec, flags, error);
1122                 return (nrte);
1123         }
1124         if ((rs->rs_flags & RT_IS_INDIRECT ) == RT_IS_INDIRECT)
1125                 is_indirect = 1;
1126         else
1127                 is_indirect = 0;
1128         if ((is_indirect == 0) &&
1129             ((ifp != rs->rs_ifp) ||
1130             (ifp->if_dunit != rs->rs_if_dunit))) {
1131                 /*
1132                  * Something changed, the user is not pointing to the same
1133                  * ifp? Maybe a route updated on this guy?
1134                  */
1135                 goto re_rate;
1136         } else if (is_indirect) {
1137                 /*
1138                  * For indirect we have to dig in and find the real interface.
1139                  */
1140                 struct ifnet *rifp;
1141
1142                 rifp = rt_find_real_interface(ifp, tp->t_inpcb, error);
1143                 if (rifp == NULL) {
1144                         /* Can't find it? */
1145                         goto re_rate;
1146                 }
1147                 if ((rifp != rs->rs_ifp) ||
1148                     (ifp->if_dunit != rs->rs_if_dunit)) {
1149                         goto re_rate;
1150                 }
1151         }
1152         nrte = tcp_find_suitable_rate(rs, bytes_per_sec, flags);
1153         if (nrte == crte) {
1154                 /* No change */
1155                 if (error)
1156                         *error = 0;
1157                 return (crte);
1158         }
1159         if (nrte == NULL) {
1160                 /* Release the old rate */
1161                 tcp_rel_pacing_rate(crte, tp);
1162                 return (NULL);
1163         }
1164         /* Change rates to our new entry */
1165         err = in_pcbmodify_txrtlmt(tp->t_inpcb, nrte->rate);
1166         if (err) {
1167                 if (error)
1168                         *error = err;
1169                 return (NULL);
1170         }
1171         if (error)
1172                 *error = 0;
1173         return (nrte);
1174 }
1175
1176 void
1177 tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte, struct tcpcb *tp)
1178 {
1179         const struct tcp_rate_set *crs;
1180         struct tcp_rate_set *rs;
1181         uint64_t pre;
1182
1183         crs = crte->ptbl;
1184         /*
1185          * Now we must break the const
1186          * in order to release our refcount.
1187          */
1188         rs = __DECONST(struct tcp_rate_set *, crs);
1189         pre = atomic_fetchadd_64(&rs->rs_flows_using, -1);
1190         if (pre == 1) {
1191                 mtx_lock(&rs_mtx);
1192                 /*
1193                  * Is it dead?
1194                  */
1195                 if ((rs->rs_flags & RS_IS_DEAD) &&
1196                     ((rs->rs_flags & RS_FUNERAL_SCHD) == 0)){
1197                         /*
1198                          * We were the last,
1199                          * and a funeral is not pending, so
1200                          * we must schedule it.
1201                          */
1202                         rs->rs_flags |= RS_FUNERAL_SCHD;
1203                         epoch_call(net_epoch, &rs->rs_epoch_ctx, rs_destroy);
1204                 }
1205                 mtx_unlock(&rs_mtx);
1206         }
1207         in_pcbdetach_txrtlmt(tp->t_inpcb);
1208 }
1209
1210 static eventhandler_tag rl_ifnet_departs;
1211 static eventhandler_tag rl_ifnet_arrives;
1212 static eventhandler_tag rl_shutdown_start;
1213
1214 static void
1215 tcp_rs_init(void *st __unused)
1216 {
1217         CK_LIST_INIT(&int_rs);
1218         rs_number_alive = 0;
1219         rs_number_dead = 0;;
1220         mtx_init(&rs_mtx, "tcp_rs_mtx", "rsmtx", MTX_DEF);
1221         rl_ifnet_departs = EVENTHANDLER_REGISTER(ifnet_departure_event,
1222             tcp_rl_ifnet_departure,
1223             NULL, EVENTHANDLER_PRI_ANY);
1224         rl_ifnet_arrives = EVENTHANDLER_REGISTER(ifnet_link_event,
1225             tcp_rl_ifnet_link,
1226             NULL, EVENTHANDLER_PRI_ANY);
1227         rl_shutdown_start = EVENTHANDLER_REGISTER(shutdown_pre_sync,
1228             tcp_rl_shutdown, NULL,
1229             SHUTDOWN_PRI_FIRST);
1230         printf("TCP_ratelimit: Is now initialized\n");
1231 }
1232
1233 SYSINIT(tcp_rl_init, SI_SUB_SMP + 1, SI_ORDER_ANY, tcp_rs_init, NULL);
1234 #endif