sys/netgraph/ng_car.c

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