sys/netgraph/ng_car.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2005 Nuno Antunes <nuno.antunes@gmail.com>
   5  * Copyright (c) 2007 Alexander Motin <mav@freebsd.org>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  */
  31
  32 /*
  33  * ng_car - An implementation of committed access rate for netgraph
  34  *
  35  * TODO:
  36  *      - Sanitize input config values (impose some limits)
  37  *      - Implement internal packet painting (possibly using mbuf tags)
  38  *      - Implement color-aware mode
  39  *      - Implement DSCP marking for IPv4
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/errno.h>
  44 #include <sys/kernel.h>
  45 #include <sys/malloc.h>
  46 #include <sys/mbuf.h>
  47
  48 #include <netgraph/ng_message.h>
  49 #include <netgraph/ng_parse.h>
  50 #include <netgraph/netgraph.h>
  51 #include <netgraph/ng_car.h>
  52
  53 #define NG_CAR_QUEUE_SIZE       100     /* Maximum queue size for SHAPE mode */
  54 #define NG_CAR_QUEUE_MIN_TH     8       /* Minimum RED threshold for SHAPE mode */
  55
  56 /* Hook private info */
  57 struct hookinfo {
  58         hook_p          hook;           /* this (source) hook */
  59         hook_p          dest;           /* destination hook */
  60
  61         int64_t         tc;             /* committed token bucket counter */
  62         int64_t         te;             /* exceeded/peak token bucket counter */
  63         struct bintime  lastRefill;     /* last token refill time */
  64
  65         struct ng_car_hookconf conf;    /* hook configuration */
  66         struct ng_car_hookstats stats;  /* hook stats */
  67
  68         struct mbuf     *q[NG_CAR_QUEUE_SIZE];  /* circular packet queue */
  69         u_int           q_first;        /* first queue element */
  70         u_int           q_last;         /* last queue element */
  71         struct callout  q_callout;      /* periodic queue processing routine */
  72         struct mtx      q_mtx;          /* queue mutex */
  73 };
  74
  75 /* Private information for each node instance */
  76 struct privdata {
  77         node_p node;                            /* the node itself */
  78         struct hookinfo upper;                  /* hook to upper layers */
  79         struct hookinfo lower;                  /* hook to lower layers */
  80 };
  81 typedef struct privdata *priv_p;
  82
  83 static ng_constructor_t ng_car_constructor;
  84 static ng_rcvmsg_t      ng_car_rcvmsg;
  85 static ng_shutdown_t    ng_car_shutdown;
  86 static ng_newhook_t     ng_car_newhook;
  87 static ng_rcvdata_t     ng_car_rcvdata;
  88 static ng_disconnect_t  ng_car_disconnect;
  89
  90 static void     ng_car_refillhook(struct hookinfo *h);
  91 static void     ng_car_schedule(struct hookinfo *h);
  92 void            ng_car_q_event(node_p node, hook_p hook, void *arg, int arg2);
  93 static void     ng_car_enqueue(struct hookinfo *h, item_p item);
  94
  95 /* Parse type for struct ng_car_hookstats */
  96 static const struct ng_parse_struct_field ng_car_hookstats_type_fields[]
  97         = NG_CAR_HOOKSTATS;
  98 static const struct ng_parse_type ng_car_hookstats_type = {
  99         &ng_parse_struct_type,
 100         &ng_car_hookstats_type_fields
 101 };
 102
 103 /* Parse type for struct ng_car_bulkstats */
 104 static const struct ng_parse_struct_field ng_car_bulkstats_type_fields[]
 105         = NG_CAR_BULKSTATS(&ng_car_hookstats_type);
 106 static const struct ng_parse_type ng_car_bulkstats_type = {
 107         &ng_parse_struct_type,
 108         &ng_car_bulkstats_type_fields
 109 };
 110
 111 /* Parse type for struct ng_car_hookconf */
 112 static const struct ng_parse_struct_field ng_car_hookconf_type_fields[]
 113         = NG_CAR_HOOKCONF;
 114 static const struct ng_parse_type ng_car_hookconf_type = {
 115         &ng_parse_struct_type,
 116         &ng_car_hookconf_type_fields
 117 };
 118
 119 /* Parse type for struct ng_car_bulkconf */
 120 static const struct ng_parse_struct_field ng_car_bulkconf_type_fields[]
 121         = NG_CAR_BULKCONF(&ng_car_hookconf_type);
 122 static const struct ng_parse_type ng_car_bulkconf_type = {
 123         &ng_parse_struct_type,
 124         &ng_car_bulkconf_type_fields
 125 };
 126
 127 /* Command list */
 128 static struct ng_cmdlist ng_car_cmdlist[] = {
 129         {
 130           NGM_CAR_COOKIE,
 131           NGM_CAR_GET_STATS,
 132           "getstats",
 133           NULL,
 134           &ng_car_bulkstats_type,
 135         },
 136         {
 137           NGM_CAR_COOKIE,
 138           NGM_CAR_CLR_STATS,
 139           "clrstats",
 140           NULL,
 141           NULL,
 142         },
 143         {
 144           NGM_CAR_COOKIE,
 145           NGM_CAR_GETCLR_STATS,
 146           "getclrstats",
 147           NULL,
 148           &ng_car_bulkstats_type,
 149         },
 150
 151         {
 152           NGM_CAR_COOKIE,
 153           NGM_CAR_GET_CONF,
 154           "getconf",
 155           NULL,
 156           &ng_car_bulkconf_type,
 157         },
 158         {
 159           NGM_CAR_COOKIE,
 160           NGM_CAR_SET_CONF,
 161           "setconf",
 162           &ng_car_bulkconf_type,
 163           NULL,
 164         },
 165         { 0 }
 166 };
 167
 168 /* Netgraph node type descriptor */
 169 static struct ng_type ng_car_typestruct = {
 170         .version =      NG_ABI_VERSION,
 171         .name =         NG_CAR_NODE_TYPE,
 172         .constructor =  ng_car_constructor,
 173         .rcvmsg =       ng_car_rcvmsg,
 174         .shutdown =     ng_car_shutdown,
 175         .newhook =      ng_car_newhook,
 176         .rcvdata =      ng_car_rcvdata,
 177         .disconnect =   ng_car_disconnect,
 178         .cmdlist =      ng_car_cmdlist,
 179 };
 180 NETGRAPH_INIT(car, &ng_car_typestruct);
 181
 182 /*
 183  * Node constructor
 184  */
 185 static int
 186 ng_car_constructor(node_p node)
 187 {
 188         priv_p priv;
 189
 190         /* Initialize private descriptor. */
 191         priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 192
 193         NG_NODE_SET_PRIVATE(node, priv);
 194         priv->node = node;
 195
 196         /*
 197          * Arbitrary default values
 198          */
 199
 200         priv->upper.hook = NULL;
 201         priv->upper.dest = NULL;
 202         priv->upper.tc = priv->upper.conf.cbs = NG_CAR_CBS_MIN;
 203         priv->upper.te = priv->upper.conf.ebs = NG_CAR_EBS_MIN;
 204         priv->upper.conf.cir = NG_CAR_CIR_DFLT;
 205         priv->upper.conf.green_action = NG_CAR_ACTION_FORWARD;
 206         priv->upper.conf.yellow_action = NG_CAR_ACTION_FORWARD;
 207         priv->upper.conf.red_action = NG_CAR_ACTION_DROP;
 208         priv->upper.conf.mode = 0;
 209         getbinuptime(&priv->upper.lastRefill);
 210         priv->upper.q_first = 0;
 211         priv->upper.q_last = 0;
 212         ng_callout_init(&priv->upper.q_callout);
 213         mtx_init(&priv->upper.q_mtx, "ng_car_u", NULL, MTX_DEF);
 214
 215         priv->lower.hook = NULL;
 216         priv->lower.dest = NULL;
 217         priv->lower.tc = priv->lower.conf.cbs = NG_CAR_CBS_MIN;
 218         priv->lower.te = priv->lower.conf.ebs = NG_CAR_EBS_MIN;
 219         priv->lower.conf.cir = NG_CAR_CIR_DFLT;
 220         priv->lower.conf.green_action = NG_CAR_ACTION_FORWARD;
 221         priv->lower.conf.yellow_action = NG_CAR_ACTION_FORWARD;
 222         priv->lower.conf.red_action = NG_CAR_ACTION_DROP;
 223         priv->lower.conf.mode = 0;
 224         priv->lower.lastRefill = priv->upper.lastRefill;
 225         priv->lower.q_first = 0;
 226         priv->lower.q_last = 0;
 227         ng_callout_init(&priv->lower.q_callout);
 228         mtx_init(&priv->lower.q_mtx, "ng_car_l", NULL, MTX_DEF);
 229
 230         return (0);
 231 }
 232
 233 /*
 234  * Add a hook.
 235  */
 236 static int
 237 ng_car_newhook(node_p node, hook_p hook, const char *name)
 238 {
 239         const priv_p priv = NG_NODE_PRIVATE(node);
 240
 241         if (strcmp(name, NG_CAR_HOOK_LOWER) == 0) {
 242                 priv->lower.hook = hook;
 243                 priv->upper.dest = hook;
 244                 bzero(&priv->lower.stats, sizeof(priv->lower.stats));
 245                 NG_HOOK_SET_PRIVATE(hook, &priv->lower);
 246         } else if (strcmp(name, NG_CAR_HOOK_UPPER) == 0) {
 247                 priv->upper.hook = hook;
 248                 priv->lower.dest = hook;
 249                 bzero(&priv->upper.stats, sizeof(priv->upper.stats));
 250                 NG_HOOK_SET_PRIVATE(hook, &priv->upper);
 251         } else
 252                 return (EINVAL);
 253         return(0);
 254 }
 255
 256 /*
 257  * Data has arrived.
 258  */
 259 static int
 260 ng_car_rcvdata(hook_p hook, item_p item )
 261 {
 262         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 263         struct mbuf *m;
 264         int error = 0;
 265         u_int len;
 266
 267         /* If queue is not empty now then enqueue packet. */
 268         if (hinfo->q_first != hinfo->q_last) {
 269                 ng_car_enqueue(hinfo, item);
 270                 return (0);
 271         }
 272
 273         m = NGI_M(item);
 274
 275 #define NG_CAR_PERFORM_MATCH_ACTION(a)                  \
 276         do {                                            \
 277                 switch (a) {                            \
 278                 case NG_CAR_ACTION_FORWARD:             \
 279                         /* Do nothing. */               \
 280                         break;                          \
 281                 case NG_CAR_ACTION_MARK:                \
 282                         /* XXX find a way to mark packets (mbuf tag?) */ \
 283                         ++hinfo->stats.errors;          \
 284                         break;                          \
 285                 case NG_CAR_ACTION_DROP:                \
 286                 default:                                \
 287                         /* Drop packet and return. */   \
 288                         NG_FREE_ITEM(item);             \
 289                         ++hinfo->stats.dropped_pkts;    \
 290                         return (0);                     \
 291                 }                                       \
 292         } while (0)
 293
 294         /* Packet is counted as 128 tokens for better resolution */
 295         if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
 296                 len = 128;
 297         } else {
 298                 len = m->m_pkthdr.len;
 299         }
 300
 301         /* Check committed token bucket. */
 302         if (hinfo->tc - len >= 0) {
 303                 /* This packet is green. */
 304                 ++hinfo->stats.green_pkts;
 305                 hinfo->tc -= len;
 306                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.green_action);
 307         } else {
 308                 /* Refill only if not green without it. */
 309                 ng_car_refillhook(hinfo);
 310
 311                  /* Check committed token bucket again after refill. */
 312                 if (hinfo->tc - len >= 0) {
 313                         /* This packet is green */
 314                         ++hinfo->stats.green_pkts;
 315                         hinfo->tc -= len;
 316                         NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.green_action);
 317
 318                 /* If not green and mode is SHAPE, enqueue packet. */
 319                 } else if (hinfo->conf.mode == NG_CAR_SHAPE) {
 320                         ng_car_enqueue(hinfo, item);
 321                         return (0);
 322
 323                 /* If not green and mode is RED, calculate probability. */
 324                 } else if (hinfo->conf.mode == NG_CAR_RED) {
 325                         /* Is packet is bigger then extended burst? */
 326                         if (len - (hinfo->tc - len) > hinfo->conf.ebs) {
 327                                 /* This packet is definitely red. */
 328                                 ++hinfo->stats.red_pkts;
 329                                 hinfo->te = 0;
 330                                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
 331
 332                         /* Use token bucket to simulate RED-like drop
 333                            probability. */
 334                         } else if (hinfo->te + (len - hinfo->tc) <
 335                             hinfo->conf.ebs) {
 336                                 /* This packet is yellow */
 337                                 ++hinfo->stats.yellow_pkts;
 338                                 hinfo->te += len - hinfo->tc;
 339                                 /* Go to negative tokens. */
 340                                 hinfo->tc -= len;
 341                                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.yellow_action);
 342                         } else {
 343                                 /* This packet is probably red. */
 344                                 ++hinfo->stats.red_pkts;
 345                                 hinfo->te = 0;
 346                                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
 347                         }
 348                 /* If not green and mode is SINGLE/DOUBLE RATE. */
 349                 } else {
 350                         /* Check extended token bucket. */
 351                         if (hinfo->te - len >= 0) {
 352                                 /* This packet is yellow */
 353                                 ++hinfo->stats.yellow_pkts;
 354                                 hinfo->te -= len;
 355                                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.yellow_action);
 356                         } else {
 357                                 /* This packet is red */
 358                                 ++hinfo->stats.red_pkts;
 359                                 NG_CAR_PERFORM_MATCH_ACTION(hinfo->conf.red_action);
 360                         }
 361                 }
 362         }
 363
 364 #undef NG_CAR_PERFORM_MATCH_ACTION
 365
 366         NG_FWD_ITEM_HOOK(error, item, hinfo->dest);
 367         if (error != 0)
 368                 ++hinfo->stats.errors;
 369         ++hinfo->stats.passed_pkts;
 370
 371         return (error);
 372 }
 373
 374 /*
 375  * Receive a control message.
 376  */
 377 static int
 378 ng_car_rcvmsg(node_p node, item_p item, hook_p lasthook)
 379 {
 380         const priv_p priv = NG_NODE_PRIVATE(node);
 381         struct ng_mesg *resp = NULL;
 382         int error = 0;
 383         struct ng_mesg *msg;
 384
 385         NGI_GET_MSG(item, msg);
 386         switch (msg->header.typecookie) {
 387         case NGM_CAR_COOKIE:
 388                 switch (msg->header.cmd) {
 389                 case NGM_CAR_GET_STATS:
 390                 case NGM_CAR_GETCLR_STATS:
 391                         {
 392                                 struct ng_car_bulkstats *bstats;
 393
 394                                 NG_MKRESPONSE(resp, msg,
 395                                         sizeof(*bstats), M_NOWAIT);
 396                                 if (resp == NULL) {
 397                                         error = ENOMEM;
 398                                         break;
 399                                 }
 400                                 bstats = (struct ng_car_bulkstats *)resp->data;
 401
 402                                 bcopy(&priv->upper.stats, &bstats->downstream,
 403                                     sizeof(bstats->downstream));
 404                                 bcopy(&priv->lower.stats, &bstats->upstream,
 405                                     sizeof(bstats->upstream));
 406                         }
 407                         if (msg->header.cmd == NGM_CAR_GET_STATS)
 408                                 break;
 409                 case NGM_CAR_CLR_STATS:
 410                         bzero(&priv->upper.stats,
 411                                 sizeof(priv->upper.stats));
 412                         bzero(&priv->lower.stats,
 413                                 sizeof(priv->lower.stats));
 414                         break;
 415                 case NGM_CAR_GET_CONF:
 416                         {
 417                                 struct ng_car_bulkconf *bconf;
 418
 419                                 NG_MKRESPONSE(resp, msg,
 420                                         sizeof(*bconf), M_NOWAIT);
 421                                 if (resp == NULL) {
 422                                         error = ENOMEM;
 423                                         break;
 424                                 }
 425                                 bconf = (struct ng_car_bulkconf *)resp->data;
 426
 427                                 bcopy(&priv->upper.conf, &bconf->downstream,
 428                                     sizeof(bconf->downstream));
 429                                 bcopy(&priv->lower.conf, &bconf->upstream,
 430                                     sizeof(bconf->upstream));
 431                                 /* Convert internal 1/(8*128) of pps into pps */
 432                                 if (bconf->downstream.opt & NG_CAR_COUNT_PACKETS) {
 433                                     bconf->downstream.cir /= 1024;
 434                                     bconf->downstream.pir /= 1024;
 435                                     bconf->downstream.cbs /= 128;
 436                                     bconf->downstream.ebs /= 128;
 437                                 }
 438                                 if (bconf->upstream.opt & NG_CAR_COUNT_PACKETS) {
 439                                     bconf->upstream.cir /= 1024;
 440                                     bconf->upstream.pir /= 1024;
 441                                     bconf->upstream.cbs /= 128;
 442                                     bconf->upstream.ebs /= 128;
 443                                 }
 444                         }
 445                         break;
 446                 case NGM_CAR_SET_CONF:
 447                         {
 448                                 struct ng_car_bulkconf *const bconf =
 449                                 (struct ng_car_bulkconf *)msg->data;
 450
 451                                 /* Check for invalid or illegal config. */
 452                                 if (msg->header.arglen != sizeof(*bconf)) {
 453                                         error = EINVAL;
 454                                         break;
 455                                 }
 456                                 /* Convert pps into internal 1/(8*128) of pps */
 457                                 if (bconf->downstream.opt & NG_CAR_COUNT_PACKETS) {
 458                                     bconf->downstream.cir *= 1024;
 459                                     bconf->downstream.pir *= 1024;
 460                                     bconf->downstream.cbs *= 125;
 461                                     bconf->downstream.ebs *= 125;
 462                                 }
 463                                 if (bconf->upstream.opt & NG_CAR_COUNT_PACKETS) {
 464                                     bconf->upstream.cir *= 1024;
 465                                     bconf->upstream.pir *= 1024;
 466                                     bconf->upstream.cbs *= 125;
 467                                     bconf->upstream.ebs *= 125;
 468                                 }
 469                                 if ((bconf->downstream.cir > 1000000000) ||
 470                                     (bconf->downstream.pir > 1000000000) ||
 471                                     (bconf->upstream.cir > 1000000000) ||
 472                                     (bconf->upstream.pir > 1000000000) ||
 473                                     (bconf->downstream.cbs == 0 &&
 474                                         bconf->downstream.ebs == 0) ||
 475                                     (bconf->upstream.cbs == 0 &&
 476                                         bconf->upstream.ebs == 0))
 477                                 {
 478                                         error = EINVAL;
 479                                         break;
 480                                 }
 481                                 if ((bconf->upstream.mode == NG_CAR_SHAPE) &&
 482                                     (bconf->upstream.cir == 0)) {
 483                                         error = EINVAL;
 484                                         break;
 485                                 }
 486                                 if ((bconf->downstream.mode == NG_CAR_SHAPE) &&
 487                                     (bconf->downstream.cir == 0)) {
 488                                         error = EINVAL;
 489                                         break;
 490                                 }
 491
 492                                 /* Copy downstream config. */
 493                                 bcopy(&bconf->downstream, &priv->upper.conf,
 494                                     sizeof(priv->upper.conf));
 495                                 priv->upper.tc = priv->upper.conf.cbs;
 496                                 if (priv->upper.conf.mode == NG_CAR_RED ||
 497                                     priv->upper.conf.mode == NG_CAR_SHAPE) {
 498                                         priv->upper.te = 0;
 499                                 } else {
 500                                         priv->upper.te = priv->upper.conf.ebs;
 501                                 }
 502
 503                                 /* Copy upstream config. */
 504                                 bcopy(&bconf->upstream, &priv->lower.conf,
 505                                     sizeof(priv->lower.conf));
 506                                 priv->lower.tc = priv->lower.conf.cbs;
 507                                 if (priv->lower.conf.mode == NG_CAR_RED ||
 508                                     priv->lower.conf.mode == NG_CAR_SHAPE) {
 509                                         priv->lower.te = 0;
 510                                 } else {
 511                                         priv->lower.te = priv->lower.conf.ebs;
 512                                 }
 513                         }
 514                         break;
 515                 default:
 516                         error = EINVAL;
 517                         break;
 518                 }
 519                 break;
 520         default:
 521                 error = EINVAL;
 522                 break;
 523         }
 524         NG_RESPOND_MSG(error, node, item, resp);
 525         NG_FREE_MSG(msg);
 526         return (error);
 527 }
 528
 529 /*
 530  * Do local shutdown processing.
 531  */
 532 static int
 533 ng_car_shutdown(node_p node)
 534 {
 535         const priv_p priv = NG_NODE_PRIVATE(node);
 536
 537         ng_uncallout(&priv->upper.q_callout, node);
 538         ng_uncallout(&priv->lower.q_callout, node);
 539         mtx_destroy(&priv->upper.q_mtx);
 540         mtx_destroy(&priv->lower.q_mtx);
 541         NG_NODE_UNREF(priv->node);
 542         free(priv, M_NETGRAPH);
 543         return (0);
 544 }
 545
 546 /*
 547  * Hook disconnection.
 548  *
 549  * For this type, removal of the last link destroys the node.
 550  */
 551 static int
 552 ng_car_disconnect(hook_p hook)
 553 {
 554         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 555         const node_p node = NG_HOOK_NODE(hook);
 556         const priv_p priv = NG_NODE_PRIVATE(node);
 557
 558         if (hinfo) {
 559                 /* Purge queue if not empty. */
 560                 while (hinfo->q_first != hinfo->q_last) {
 561                         NG_FREE_M(hinfo->q[hinfo->q_first]);
 562                         hinfo->q_first++;
 563                         if (hinfo->q_first >= NG_CAR_QUEUE_SIZE)
 564                                 hinfo->q_first = 0;
 565                 }
 566                 /* Remove hook refs. */
 567                 if (hinfo->hook == priv->upper.hook)
 568                         priv->lower.dest = NULL;
 569                 else
 570                         priv->upper.dest = NULL;
 571                 hinfo->hook = NULL;
 572         }
 573         /* Already shutting down? */
 574         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 575             && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 576                 ng_rmnode_self(NG_HOOK_NODE(hook));
 577         return (0);
 578 }
 579
 580 /*
 581  * Hook's token buckets refillment.
 582  */
 583 static void
 584 ng_car_refillhook(struct hookinfo *h)
 585 {
 586         struct bintime newt, deltat;
 587         unsigned int deltat_us;
 588
 589         /* Get current time. */
 590         getbinuptime(&newt);
 591
 592         /* Get time delta since last refill. */
 593         deltat = newt;
 594         bintime_sub(&deltat, &h->lastRefill);
 595
 596         /* Time must go forward. */
 597         if (deltat.sec < 0) {
 598             h->lastRefill = newt;
 599             return;
 600         }
 601
 602         /* But not too far forward. */
 603         if (deltat.sec >= 1000) {
 604             deltat_us = (1000 << 20);
 605         } else {
 606             /* convert bintime to the 1/(2^20) of sec */
 607             deltat_us = (deltat.sec << 20) + (deltat.frac >> 44);
 608         }
 609
 610         if (h->conf.mode == NG_CAR_SINGLE_RATE) {
 611                 int64_t delta;
 612                 /* Refill committed token bucket. */
 613                 h->tc += (h->conf.cir * deltat_us) >> 23;
 614                 delta = h->tc - h->conf.cbs;
 615                 if (delta > 0) {
 616                         h->tc = h->conf.cbs;
 617
 618                         /* Refill exceeded token bucket. */
 619                         h->te += delta;
 620                         if (h->te > ((int64_t)h->conf.ebs))
 621                                 h->te = h->conf.ebs;
 622                 }
 623
 624         } else if (h->conf.mode == NG_CAR_DOUBLE_RATE) {
 625                 /* Refill committed token bucket. */
 626                 h->tc += (h->conf.cir * deltat_us) >> 23;
 627                 if (h->tc > ((int64_t)h->conf.cbs))
 628                         h->tc = h->conf.cbs;
 629
 630                 /* Refill peak token bucket. */
 631                 h->te += (h->conf.pir * deltat_us) >> 23;
 632                 if (h->te > ((int64_t)h->conf.ebs))
 633                         h->te = h->conf.ebs;
 634
 635         } else { /* RED or SHAPE mode. */
 636                 /* Refill committed token bucket. */
 637                 h->tc += (h->conf.cir * deltat_us) >> 23;
 638                 if (h->tc > ((int64_t)h->conf.cbs))
 639                         h->tc = h->conf.cbs;
 640         }
 641
 642         /* Remember this moment. */
 643         h->lastRefill = newt;
 644 }
 645
 646 /*
 647  * Schedule callout when we will have required tokens.
 648  */
 649 static void
 650 ng_car_schedule(struct hookinfo *hinfo)
 651 {
 652         int     delay;
 653
 654         delay = (-(hinfo->tc)) * hz * 8 / hinfo->conf.cir + 1;
 655
 656         ng_callout(&hinfo->q_callout, NG_HOOK_NODE(hinfo->hook), hinfo->hook,
 657             delay, &ng_car_q_event, NULL, 0);
 658 }
 659
 660 /*
 661  * Queue processing callout handler.
 662  */
 663 void
 664 ng_car_q_event(node_p node, hook_p hook, void *arg, int arg2)
 665 {
 666         struct hookinfo *hinfo = NG_HOOK_PRIVATE(hook);
 667         struct mbuf     *m;
 668         int             error;
 669
 670         /* Refill tokens for time we have slept. */
 671         ng_car_refillhook(hinfo);
 672
 673         /* If we have some tokens */
 674         while (hinfo->tc >= 0) {
 675                 /* Send packet. */
 676                 m = hinfo->q[hinfo->q_first];
 677                 NG_SEND_DATA_ONLY(error, hinfo->dest, m);
 678                 if (error != 0)
 679                         ++hinfo->stats.errors;
 680                 ++hinfo->stats.passed_pkts;
 681
 682                 /* Get next one. */
 683                 hinfo->q_first++;
 684                 if (hinfo->q_first >= NG_CAR_QUEUE_SIZE)
 685                         hinfo->q_first = 0;
 686
 687                 /* Stop if none left. */
 688                 if (hinfo->q_first == hinfo->q_last)
 689                         break;
 690
 691                 /* If we have more packet, try it. */
 692                 m = hinfo->q[hinfo->q_first];
 693                 if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
 694                         hinfo->tc -= 128;
 695                 } else {
 696                         hinfo->tc -= m->m_pkthdr.len;
 697                 }
 698         }
 699
 700         /* If something left */
 701         if (hinfo->q_first != hinfo->q_last)
 702                 /* Schedule queue processing. */
 703                 ng_car_schedule(hinfo);
 704 }
 705
 706 /*
 707  * Enqueue packet.
 708  */
 709 static void
 710 ng_car_enqueue(struct hookinfo *hinfo, item_p item)
 711 {
 712         struct mbuf     *m;
 713         int             len;
 714
 715         NGI_GET_M(item, m);
 716         NG_FREE_ITEM(item);
 717
 718         /* Lock queue mutex. */
 719         mtx_lock(&hinfo->q_mtx);
 720
 721         /* Calculate used queue length. */
 722         len = hinfo->q_last - hinfo->q_first;
 723         if (len < 0)
 724                 len += NG_CAR_QUEUE_SIZE;
 725
 726         /* If queue is overflowed or we have no RED tokens. */
 727         if ((len >= (NG_CAR_QUEUE_SIZE - 1)) ||
 728             (hinfo->te + len >= NG_CAR_QUEUE_SIZE)) {
 729                 /* Drop packet. */
 730                 ++hinfo->stats.red_pkts;
 731                 ++hinfo->stats.dropped_pkts;
 732                 NG_FREE_M(m);
 733
 734                 hinfo->te = 0;
 735         } else {
 736                 /* This packet is yellow. */
 737                 ++hinfo->stats.yellow_pkts;
 738
 739                 /* Enqueue packet. */
 740                 hinfo->q[hinfo->q_last] = m;
 741                 hinfo->q_last++;
 742                 if (hinfo->q_last >= NG_CAR_QUEUE_SIZE)
 743                         hinfo->q_last = 0;
 744
 745                 /* Use RED tokens. */
 746                 if (len > NG_CAR_QUEUE_MIN_TH)
 747                         hinfo->te += len - NG_CAR_QUEUE_MIN_TH;
 748
 749                 /* If this is a first packet in the queue. */
 750                 if (len == 0) {
 751                         if (hinfo->conf.opt & NG_CAR_COUNT_PACKETS) {
 752                                 hinfo->tc -= 128;
 753                         } else {
 754                                 hinfo->tc -= m->m_pkthdr.len;
 755                         }
 756
 757                         /* Schedule queue processing. */
 758                         ng_car_schedule(hinfo);
 759                 }
 760         }
 761
 762         /* Unlock queue mutex. */
 763         mtx_unlock(&hinfo->q_mtx);
 764 }