sys/netgraph/ng_pipe.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2004-2010 University of Zagreb
   5  * Copyright (c) 2007-2008 FreeBSD Foundation
   6  *
   7  * This software was developed by the University of Zagreb and the
   8  * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
   9  * FreeBSD Foundation.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD$
  33  */
  34
  35 /*
  36  * This node permits simple traffic shaping by emulating bandwidth
  37  * and delay, as well as random packet losses.
  38  * The node has two hooks, upper and lower. Traffic flowing from upper to
  39  * lower hook is referenced as downstream, and vice versa. Parameters for
  40  * both directions can be set separately, except for delay.
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/errno.h>
  45 #include <sys/systm.h>
  46 #include <sys/kernel.h>
  47 #include <sys/malloc.h>
  48 #include <sys/mbuf.h>
  49 #include <sys/time.h>
  50
  51 #include <vm/uma.h>
  52
  53 #include <net/vnet.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58
  59 #include <netgraph/ng_message.h>
  60 #include <netgraph/netgraph.h>
  61 #include <netgraph/ng_parse.h>
  62 #include <netgraph/ng_pipe.h>
  63
  64 static MALLOC_DEFINE(M_NG_PIPE, "ng_pipe", "ng_pipe");
  65
  66 /* Packet header struct */
  67 struct ngp_hdr {
  68         TAILQ_ENTRY(ngp_hdr)    ngp_link;       /* next pkt in queue */
  69         struct timeval          when;           /* this packet's due time */
  70         struct mbuf             *m;             /* ptr to the packet data */
  71 };
  72 TAILQ_HEAD(p_head, ngp_hdr);
  73
  74 /* FIFO queue struct */
  75 struct ngp_fifo {
  76         TAILQ_ENTRY(ngp_fifo)   fifo_le;        /* list of active queues only */
  77         struct p_head           packet_head;    /* FIFO queue head */
  78         u_int32_t               hash;           /* flow signature */
  79         struct timeval          vtime;          /* virtual time, for WFQ */
  80         u_int32_t               rr_deficit;     /* for DRR */
  81         u_int32_t               packets;        /* # of packets in this queue */
  82 };
  83
  84 /* Per hook info */
  85 struct hookinfo {
  86         hook_p                  hook;
  87         int                     noqueue;        /* bypass any processing */
  88         TAILQ_HEAD(, ngp_fifo)  fifo_head;      /* FIFO queues */
  89         TAILQ_HEAD(, ngp_hdr)   qout_head;      /* delay queue head */
  90         struct timeval          qin_utime;
  91         struct ng_pipe_hookcfg  cfg;
  92         struct ng_pipe_hookrun  run;
  93         struct ng_pipe_hookstat stats;
  94         uint64_t                *ber_p;         /* loss_p(BER,psize) map */
  95 };
  96
  97 /* Per node info */
  98 struct node_priv {
  99         u_int64_t               delay;
 100         u_int32_t               overhead;
 101         u_int32_t               header_offset;
 102         struct hookinfo         lower;
 103         struct hookinfo         upper;
 104         struct callout          timer;
 105         int                     timer_scheduled;
 106 };
 107 typedef struct node_priv *priv_p;
 108
 109 /* Macro for calculating the virtual time for packet dequeueing in WFQ */
 110 #define FIFO_VTIME_SORT(plen)                                           \
 111         if (hinfo->cfg.wfq && hinfo->cfg.bandwidth) {                   \
 112                 ngp_f->vtime.tv_usec = now->tv_usec + ((uint64_t) (plen) \
 113                         + priv->overhead ) * hinfo->run.fifo_queues *   \
 114                         8000000 / hinfo->cfg.bandwidth;                 \
 115                 ngp_f->vtime.tv_sec = now->tv_sec +                     \
 116                         ngp_f->vtime.tv_usec / 1000000;                 \
 117                 ngp_f->vtime.tv_usec = ngp_f->vtime.tv_usec % 1000000;  \
 118                 TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)       \
 119                         if (ngp_f1->vtime.tv_sec > ngp_f->vtime.tv_sec || \
 120                             (ngp_f1->vtime.tv_sec == ngp_f->vtime.tv_sec && \
 121                             ngp_f1->vtime.tv_usec > ngp_f->vtime.tv_usec)) \
 122                                 break;                                  \
 123                 if (ngp_f1 == NULL)                                     \
 124                         TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
 125                 else                                                    \
 126                         TAILQ_INSERT_BEFORE(ngp_f1, ngp_f, fifo_le);    \
 127         } else                                                          \
 128                 TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le);   \
 129
 130 static void     parse_cfg(struct ng_pipe_hookcfg *, struct ng_pipe_hookcfg *,
 131                         struct hookinfo *, priv_p);
 132 static void     pipe_dequeue(struct hookinfo *, struct timeval *);
 133 static void     ngp_callout(node_p, hook_p, void *, int);
 134 static int      ngp_modevent(module_t, int, void *);
 135
 136 /* zone for storing ngp_hdr-s */
 137 static uma_zone_t ngp_zone;
 138
 139 /* Netgraph methods */
 140 static ng_constructor_t ngp_constructor;
 141 static ng_rcvmsg_t      ngp_rcvmsg;
 142 static ng_shutdown_t    ngp_shutdown;
 143 static ng_newhook_t     ngp_newhook;
 144 static ng_rcvdata_t     ngp_rcvdata;
 145 static ng_disconnect_t  ngp_disconnect;
 146
 147 /* Parse type for struct ng_pipe_hookstat */
 148 static const struct ng_parse_struct_field
 149         ng_pipe_hookstat_type_fields[] = NG_PIPE_HOOKSTAT_INFO;
 150 static const struct ng_parse_type ng_pipe_hookstat_type = {
 151         &ng_parse_struct_type,
 152         &ng_pipe_hookstat_type_fields
 153 };
 154
 155 /* Parse type for struct ng_pipe_stats */
 156 static const struct ng_parse_struct_field ng_pipe_stats_type_fields[] =
 157         NG_PIPE_STATS_INFO(&ng_pipe_hookstat_type);
 158 static const struct ng_parse_type ng_pipe_stats_type = {
 159         &ng_parse_struct_type,
 160         &ng_pipe_stats_type_fields
 161 };
 162
 163 /* Parse type for struct ng_pipe_hookrun */
 164 static const struct ng_parse_struct_field
 165         ng_pipe_hookrun_type_fields[] = NG_PIPE_HOOKRUN_INFO;
 166 static const struct ng_parse_type ng_pipe_hookrun_type = {
 167         &ng_parse_struct_type,
 168         &ng_pipe_hookrun_type_fields
 169 };
 170
 171 /* Parse type for struct ng_pipe_run */
 172 static const struct ng_parse_struct_field
 173         ng_pipe_run_type_fields[] = NG_PIPE_RUN_INFO(&ng_pipe_hookrun_type);
 174 static const struct ng_parse_type ng_pipe_run_type = {
 175         &ng_parse_struct_type,
 176         &ng_pipe_run_type_fields
 177 };
 178
 179 /* Parse type for struct ng_pipe_hookcfg */
 180 static const struct ng_parse_struct_field
 181         ng_pipe_hookcfg_type_fields[] = NG_PIPE_HOOKCFG_INFO;
 182 static const struct ng_parse_type ng_pipe_hookcfg_type = {
 183         &ng_parse_struct_type,
 184         &ng_pipe_hookcfg_type_fields
 185 };
 186
 187 /* Parse type for struct ng_pipe_cfg */
 188 static const struct ng_parse_struct_field
 189         ng_pipe_cfg_type_fields[] = NG_PIPE_CFG_INFO(&ng_pipe_hookcfg_type);
 190 static const struct ng_parse_type ng_pipe_cfg_type = {
 191         &ng_parse_struct_type,
 192         &ng_pipe_cfg_type_fields
 193 };
 194
 195 /* List of commands and how to convert arguments to/from ASCII */
 196 static const struct ng_cmdlist ngp_cmds[] = {
 197         {
 198                 .cookie =       NGM_PIPE_COOKIE,
 199                 .cmd =          NGM_PIPE_GET_STATS,
 200                 .name =         "getstats",
 201                 .respType =      &ng_pipe_stats_type
 202         },
 203         {
 204                 .cookie =       NGM_PIPE_COOKIE,
 205                 .cmd =          NGM_PIPE_CLR_STATS,
 206                 .name =         "clrstats"
 207         },
 208         {
 209                 .cookie =       NGM_PIPE_COOKIE,
 210                 .cmd =          NGM_PIPE_GETCLR_STATS,
 211                 .name =         "getclrstats",
 212                 .respType =     &ng_pipe_stats_type
 213         },
 214         {
 215                 .cookie =       NGM_PIPE_COOKIE,
 216                 .cmd =          NGM_PIPE_GET_RUN,
 217                 .name =         "getrun",
 218                 .respType =     &ng_pipe_run_type
 219         },
 220         {
 221                 .cookie =       NGM_PIPE_COOKIE,
 222                 .cmd =          NGM_PIPE_GET_CFG,
 223                 .name =         "getcfg",
 224                 .respType =     &ng_pipe_cfg_type
 225         },
 226         {
 227                 .cookie =       NGM_PIPE_COOKIE,
 228                 .cmd =          NGM_PIPE_SET_CFG,
 229                 .name =         "setcfg",
 230                 .mesgType =     &ng_pipe_cfg_type,
 231         },
 232         { 0 }
 233 };
 234
 235 /* Netgraph type descriptor */
 236 static struct ng_type ng_pipe_typestruct = {
 237         .version =      NG_ABI_VERSION,
 238         .name =         NG_PIPE_NODE_TYPE,
 239         .mod_event =    ngp_modevent,
 240         .constructor =  ngp_constructor,
 241         .shutdown =     ngp_shutdown,
 242         .rcvmsg =       ngp_rcvmsg,
 243         .newhook =      ngp_newhook,
 244         .rcvdata =      ngp_rcvdata,
 245         .disconnect =   ngp_disconnect,
 246         .cmdlist =      ngp_cmds
 247 };
 248 NETGRAPH_INIT(pipe, &ng_pipe_typestruct);
 249
 250 /* Node constructor */
 251 static int
 252 ngp_constructor(node_p node)
 253 {
 254         priv_p priv;
 255
 256         priv = malloc(sizeof(*priv), M_NG_PIPE, M_ZERO | M_WAITOK);
 257         NG_NODE_SET_PRIVATE(node, priv);
 258
 259         /* Mark node as single-threaded */
 260         NG_NODE_FORCE_WRITER(node);
 261
 262         ng_callout_init(&priv->timer);
 263
 264         return (0);
 265 }
 266
 267 /* Add a hook */
 268 static int
 269 ngp_newhook(node_p node, hook_p hook, const char *name)
 270 {
 271         const priv_p priv = NG_NODE_PRIVATE(node);
 272         struct hookinfo *hinfo;
 273
 274         if (strcmp(name, NG_PIPE_HOOK_UPPER) == 0) {
 275                 bzero(&priv->upper, sizeof(priv->upper));
 276                 priv->upper.hook = hook;
 277                 NG_HOOK_SET_PRIVATE(hook, &priv->upper);
 278         } else if (strcmp(name, NG_PIPE_HOOK_LOWER) == 0) {
 279                 bzero(&priv->lower, sizeof(priv->lower));
 280                 priv->lower.hook = hook;
 281                 NG_HOOK_SET_PRIVATE(hook, &priv->lower);
 282         } else
 283                 return (EINVAL);
 284
 285         /* Load non-zero initial cfg values */
 286         hinfo = NG_HOOK_PRIVATE(hook);
 287         hinfo->cfg.qin_size_limit = 50;
 288         hinfo->cfg.fifo = 1;
 289         hinfo->cfg.droptail = 1;
 290         TAILQ_INIT(&hinfo->fifo_head);
 291         TAILQ_INIT(&hinfo->qout_head);
 292         return (0);
 293 }
 294
 295 /* Receive a control message */
 296 static int
 297 ngp_rcvmsg(node_p node, item_p item, hook_p lasthook)
 298 {
 299         const priv_p priv = NG_NODE_PRIVATE(node);
 300         struct ng_mesg *resp = NULL;
 301         struct ng_mesg *msg, *flow_msg;
 302         struct ng_pipe_stats *stats;
 303         struct ng_pipe_run *run;
 304         struct ng_pipe_cfg *cfg;
 305         int error = 0;
 306         int prev_down, now_down, cmd;
 307
 308         NGI_GET_MSG(item, msg);
 309         switch (msg->header.typecookie) {
 310         case NGM_PIPE_COOKIE:
 311                 switch (msg->header.cmd) {
 312                 case NGM_PIPE_GET_STATS:
 313                 case NGM_PIPE_CLR_STATS:
 314                 case NGM_PIPE_GETCLR_STATS:
 315                         if (msg->header.cmd != NGM_PIPE_CLR_STATS) {
 316                                 NG_MKRESPONSE(resp, msg,
 317                                     sizeof(*stats), M_NOWAIT);
 318                                 if (resp == NULL) {
 319                                         error = ENOMEM;
 320                                         break;
 321                                 }
 322                                 stats = (struct ng_pipe_stats *) resp->data;
 323                                 bcopy(&priv->upper.stats, &stats->downstream,
 324                                     sizeof(stats->downstream));
 325                                 bcopy(&priv->lower.stats, &stats->upstream,
 326                                     sizeof(stats->upstream));
 327                         }
 328                         if (msg->header.cmd != NGM_PIPE_GET_STATS) {
 329                                 bzero(&priv->upper.stats,
 330                                     sizeof(priv->upper.stats));
 331                                 bzero(&priv->lower.stats,
 332                                     sizeof(priv->lower.stats));
 333                         }
 334                         break;
 335                 case NGM_PIPE_GET_RUN:
 336                         NG_MKRESPONSE(resp, msg, sizeof(*run), M_NOWAIT);
 337                         if (resp == NULL) {
 338                                 error = ENOMEM;
 339                                 break;
 340                         }
 341                         run = (struct ng_pipe_run *) resp->data;
 342                         bcopy(&priv->upper.run, &run->downstream,
 343                                 sizeof(run->downstream));
 344                         bcopy(&priv->lower.run, &run->upstream,
 345                                 sizeof(run->upstream));
 346                         break;
 347                 case NGM_PIPE_GET_CFG:
 348                         NG_MKRESPONSE(resp, msg, sizeof(*cfg), M_NOWAIT);
 349                         if (resp == NULL) {
 350                                 error = ENOMEM;
 351                                 break;
 352                         }
 353                         cfg = (struct ng_pipe_cfg *) resp->data;
 354                         bcopy(&priv->upper.cfg, &cfg->downstream,
 355                                 sizeof(cfg->downstream));
 356                         bcopy(&priv->lower.cfg, &cfg->upstream,
 357                                 sizeof(cfg->upstream));
 358                         cfg->delay = priv->delay;
 359                         cfg->overhead = priv->overhead;
 360                         cfg->header_offset = priv->header_offset;
 361                         if (cfg->upstream.bandwidth ==
 362                             cfg->downstream.bandwidth) {
 363                                 cfg->bandwidth = cfg->upstream.bandwidth;
 364                                 cfg->upstream.bandwidth = 0;
 365                                 cfg->downstream.bandwidth = 0;
 366                         } else
 367                                 cfg->bandwidth = 0;
 368                         break;
 369                 case NGM_PIPE_SET_CFG:
 370                         cfg = (struct ng_pipe_cfg *) msg->data;
 371                         if (msg->header.arglen != sizeof(*cfg)) {
 372                                 error = EINVAL;
 373                                 break;
 374                         }
 375
 376                         if (cfg->delay == -1)
 377                                 priv->delay = 0;
 378                         else if (cfg->delay > 0 && cfg->delay < 10000000)
 379                                 priv->delay = cfg->delay;
 380
 381                         if (cfg->bandwidth == -1) {
 382                                 priv->upper.cfg.bandwidth = 0;
 383                                 priv->lower.cfg.bandwidth = 0;
 384                                 priv->overhead = 0;
 385                         } else if (cfg->bandwidth >= 100 &&
 386                             cfg->bandwidth <= 1000000000) {
 387                                 priv->upper.cfg.bandwidth = cfg->bandwidth;
 388                                 priv->lower.cfg.bandwidth = cfg->bandwidth;
 389                                 if (cfg->bandwidth >= 10000000)
 390                                         priv->overhead = 8+4+12; /* Ethernet */
 391                                 else
 392                                         priv->overhead = 10; /* HDLC */
 393                         }
 394
 395                         if (cfg->overhead == -1)
 396                                 priv->overhead = 0;
 397                         else if (cfg->overhead > 0 &&
 398                             cfg->overhead < MAX_OHSIZE)
 399                                 priv->overhead = cfg->overhead;
 400
 401                         if (cfg->header_offset == -1)
 402                                 priv->header_offset = 0;
 403                         else if (cfg->header_offset > 0 &&
 404                             cfg->header_offset < 64)
 405                                 priv->header_offset = cfg->header_offset;
 406
 407                         prev_down = priv->upper.cfg.ber == 1 ||
 408                             priv->lower.cfg.ber == 1;
 409                         parse_cfg(&priv->upper.cfg, &cfg->downstream,
 410                             &priv->upper, priv);
 411                         parse_cfg(&priv->lower.cfg, &cfg->upstream,
 412                             &priv->lower, priv);
 413                         now_down = priv->upper.cfg.ber == 1 ||
 414                             priv->lower.cfg.ber == 1;
 415
 416                         if (prev_down != now_down) {
 417                                 if (now_down)
 418                                         cmd = NGM_LINK_IS_DOWN;
 419                                 else
 420                                         cmd = NGM_LINK_IS_UP;
 421
 422                                 if (priv->lower.hook != NULL) {
 423                                         NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
 424                                             cmd, 0, M_NOWAIT);
 425                                         if (flow_msg != NULL)
 426                                                 NG_SEND_MSG_HOOK(error, node,
 427                                                     flow_msg, priv->lower.hook,
 428                                                     0);
 429                                 }
 430                                 if (priv->upper.hook != NULL) {
 431                                         NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
 432                                             cmd, 0, M_NOWAIT);
 433                                         if (flow_msg != NULL)
 434                                                 NG_SEND_MSG_HOOK(error, node,
 435                                                     flow_msg, priv->upper.hook,
 436                                                     0);
 437                                 }
 438                         }
 439                         break;
 440                 default:
 441                         error = EINVAL;
 442                         break;
 443                 }
 444                 break;
 445         default:
 446                 error = EINVAL;
 447                 break;
 448         }
 449         NG_RESPOND_MSG(error, node, item, resp);
 450         NG_FREE_MSG(msg);
 451
 452         return (error);
 453 }
 454
 455 static void
 456 parse_cfg(struct ng_pipe_hookcfg *current, struct ng_pipe_hookcfg *new,
 457         struct hookinfo *hinfo, priv_p priv)
 458 {
 459
 460         if (new->ber == -1) {
 461                 current->ber = 0;
 462                 if (hinfo->ber_p) {
 463                         free(hinfo->ber_p, M_NG_PIPE);
 464                         hinfo->ber_p = NULL;
 465                 }
 466         } else if (new->ber >= 1 && new->ber <= 1000000000000) {
 467                 static const uint64_t one = 0x1000000000000; /* = 2^48 */
 468                 uint64_t p0, p;
 469                 uint32_t fsize, i;
 470
 471                 if (hinfo->ber_p == NULL)
 472                         hinfo->ber_p =
 473                             malloc((MAX_FSIZE + MAX_OHSIZE) * sizeof(uint64_t),
 474                             M_NG_PIPE, M_WAITOK);
 475                 current->ber = new->ber;
 476
 477                 /*
 478                  * For given BER and each frame size N (in bytes) calculate
 479                  * the probability P_OK that the frame is clean:
 480                  *
 481                  * P_OK(BER,N) = (1 - 1/BER)^(N*8)
 482                  *
 483                  * We use a 64-bit fixed-point format with decimal point
 484                  * positioned between bits 47 and 48.
 485                  */
 486                 p0 = one - one / new->ber;
 487                 p = one;
 488                 for (fsize = 0; fsize < MAX_FSIZE + MAX_OHSIZE; fsize++) {
 489                         hinfo->ber_p[fsize] = p;
 490                         for (i = 0; i < 8; i++)
 491                                 p = (p * (p0 & 0xffff) >> 48) +
 492                                     (p * ((p0 >> 16) & 0xffff) >> 32) +
 493                                     (p * (p0 >> 32) >> 16);
 494                 }
 495         }
 496
 497         if (new->qin_size_limit == -1)
 498                 current->qin_size_limit = 0;
 499         else if (new->qin_size_limit >= 5)
 500                 current->qin_size_limit = new->qin_size_limit;
 501
 502         if (new->qout_size_limit == -1)
 503                 current->qout_size_limit = 0;
 504         else if (new->qout_size_limit >= 5)
 505                 current->qout_size_limit = new->qout_size_limit;
 506
 507         if (new->duplicate == -1)
 508                 current->duplicate = 0;
 509         else if (new->duplicate > 0 && new->duplicate <= 50)
 510                 current->duplicate = new->duplicate;
 511
 512         if (new->fifo) {
 513                 current->fifo = 1;
 514                 current->wfq = 0;
 515                 current->drr = 0;
 516         }
 517
 518         if (new->wfq) {
 519                 current->fifo = 0;
 520                 current->wfq = 1;
 521                 current->drr = 0;
 522         }
 523
 524         if (new->drr) {
 525                 current->fifo = 0;
 526                 current->wfq = 0;
 527                 /* DRR quantum */
 528                 if (new->drr >= 32)
 529                         current->drr = new->drr;
 530                 else
 531                         current->drr = 2048;            /* default quantum */
 532         }
 533
 534         if (new->droptail) {
 535                 current->droptail = 1;
 536                 current->drophead = 0;
 537         }
 538
 539         if (new->drophead) {
 540                 current->droptail = 0;
 541                 current->drophead = 1;
 542         }
 543
 544         if (new->bandwidth == -1) {
 545                 current->bandwidth = 0;
 546                 current->fifo = 1;
 547                 current->wfq = 0;
 548                 current->drr = 0;
 549         } else if (new->bandwidth >= 100 && new->bandwidth <= 1000000000)
 550                 current->bandwidth = new->bandwidth;
 551
 552         if (current->bandwidth | priv->delay |
 553             current->duplicate | current->ber)
 554                 hinfo->noqueue = 0;
 555         else
 556                 hinfo->noqueue = 1;
 557 }
 558
 559 /*
 560  * Compute a hash signature for a packet. This function suffers from the
 561  * NIH sindrome, so probably it would be wise to look around what other
 562  * folks have found out to be a good and efficient IP hash function...
 563  */
 564 static int
 565 ip_hash(struct mbuf *m, int offset)
 566 {
 567         u_int64_t i;
 568         struct ip *ip = (struct ip *)(mtod(m, u_char *) + offset);
 569
 570         if (m->m_len < sizeof(struct ip) + offset ||
 571             ip->ip_v != 4 || ip->ip_hl << 2 != sizeof(struct ip))
 572                 return 0;
 573
 574         i = ((u_int64_t) ip->ip_src.s_addr ^
 575             ((u_int64_t) ip->ip_src.s_addr << 13) ^
 576             ((u_int64_t) ip->ip_dst.s_addr << 7) ^
 577             ((u_int64_t) ip->ip_dst.s_addr << 19));
 578         return (i ^ (i >> 32));
 579 }
 580
 581 /*
 582  * Receive data on a hook - both in upstream and downstream direction.
 583  * We put the frame on the inbound queue, and try to initiate dequeuing
 584  * sequence immediately. If inbound queue is full, discard one frame
 585  * depending on dropping policy (from the head or from the tail of the
 586  * queue).
 587  */
 588 static int
 589 ngp_rcvdata(hook_p hook, item_p item)
 590 {
 591         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 592         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 593         struct timeval uuptime;
 594         struct timeval *now = &uuptime;
 595         struct ngp_fifo *ngp_f = NULL, *ngp_f1;
 596         struct ngp_hdr *ngp_h = NULL;
 597         struct mbuf *m;
 598         int hash, plen;
 599         int error = 0;
 600
 601         /*
 602          * Shortcut from inbound to outbound hook when neither of
 603          * bandwidth, delay, BER or duplication probability is
 604          * configured, nor we have queued frames to drain.
 605          */
 606         if (hinfo->run.qin_frames == 0 && hinfo->run.qout_frames == 0 &&
 607             hinfo->noqueue) {
 608                 struct hookinfo *dest;
 609                 if (hinfo == &priv->lower)
 610                         dest = &priv->upper;
 611                 else
 612                         dest = &priv->lower;
 613
 614                 /* Send the frame. */
 615                 plen = NGI_M(item)->m_pkthdr.len;
 616                 NG_FWD_ITEM_HOOK(error, item, dest->hook);
 617
 618                 /* Update stats. */
 619                 if (error) {
 620                         hinfo->stats.out_disc_frames++;
 621                         hinfo->stats.out_disc_octets += plen;
 622                 } else {
 623                         hinfo->stats.fwd_frames++;
 624                         hinfo->stats.fwd_octets += plen;
 625                 }
 626
 627                 return (error);
 628         }
 629
 630         microuptime(now);
 631
 632         /*
 633          * If this was an empty queue, update service deadline time.
 634          */
 635         if (hinfo->run.qin_frames == 0) {
 636                 struct timeval *when = &hinfo->qin_utime;
 637                 if (when->tv_sec < now->tv_sec || (when->tv_sec == now->tv_sec
 638                     && when->tv_usec < now->tv_usec)) {
 639                         when->tv_sec = now->tv_sec;
 640                         when->tv_usec = now->tv_usec;
 641                 }
 642         }
 643
 644         /* Populate the packet header */
 645         ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
 646         KASSERT((ngp_h != NULL), ("ngp_h zalloc failed (1)"));
 647         NGI_GET_M(item, m);
 648         KASSERT(m != NULL, ("NGI_GET_M failed"));
 649         ngp_h->m = m;
 650         NG_FREE_ITEM(item);
 651
 652         if (hinfo->cfg.fifo)
 653                 hash = 0;       /* all packets go into a single FIFO queue */
 654         else
 655                 hash = ip_hash(m, priv->header_offset);
 656
 657         /* Find the appropriate FIFO queue for the packet and enqueue it*/
 658         TAILQ_FOREACH(ngp_f, &hinfo->fifo_head, fifo_le)
 659                 if (hash == ngp_f->hash)
 660                         break;
 661         if (ngp_f == NULL) {
 662                 ngp_f = uma_zalloc(ngp_zone, M_NOWAIT);
 663                 KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (2)"));
 664                 TAILQ_INIT(&ngp_f->packet_head);
 665                 ngp_f->hash = hash;
 666                 ngp_f->packets = 1;
 667                 ngp_f->rr_deficit = hinfo->cfg.drr;     /* DRR quantum */
 668                 hinfo->run.fifo_queues++;
 669                 TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
 670                 FIFO_VTIME_SORT(m->m_pkthdr.len);
 671         } else {
 672                 TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
 673                 ngp_f->packets++;
 674         }
 675         hinfo->run.qin_frames++;
 676         hinfo->run.qin_octets += m->m_pkthdr.len;
 677
 678         /* Discard a frame if inbound queue limit has been reached */
 679         if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
 680                 struct mbuf *m1;
 681                 int longest = 0;
 682
 683                 /* Find the longest queue */
 684                 TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
 685                         if (ngp_f1->packets > longest) {
 686                                 longest = ngp_f1->packets;
 687                                 ngp_f = ngp_f1;
 688                         }
 689
 690                 /* Drop a frame from the queue head/tail, depending on cfg */
 691                 if (hinfo->cfg.drophead)
 692                         ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
 693                 else
 694                         ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
 695                 TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
 696                 m1 = ngp_h->m;
 697                 uma_zfree(ngp_zone, ngp_h);
 698                 hinfo->run.qin_octets -= m1->m_pkthdr.len;
 699                 hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
 700                 m_freem(m1);
 701                 if (--(ngp_f->packets) == 0) {
 702                         TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
 703                         uma_zfree(ngp_zone, ngp_f);
 704                         hinfo->run.fifo_queues--;
 705                 }
 706                 hinfo->run.qin_frames--;
 707                 hinfo->stats.in_disc_frames++;
 708         }
 709
 710         /*
 711          * Try to start the dequeuing process immediately.
 712          */
 713         pipe_dequeue(hinfo, now);
 714
 715         return (0);
 716 }
 717
 718 /*
 719  * Dequeueing sequence - we basically do the following:
 720  *  1) Try to extract the frame from the inbound (bandwidth) queue;
 721  *  2) In accordance to BER specified, discard the frame randomly;
 722  *  3) If the frame survives BER, prepend it with delay info and move it
 723  *     to outbound (delay) queue;
 724  *  4) Loop to 2) until bandwidth quota for this timeslice is reached, or
 725  *     inbound queue is flushed completely;
 726  *  5) Dequeue frames from the outbound queue and send them downstream until
 727  *     outbound queue is flushed completely, or the next frame in the queue
 728  *     is not due to be dequeued yet
 729  */
 730 static void
 731 pipe_dequeue(struct hookinfo *hinfo, struct timeval *now) {
 732         static uint64_t rand, oldrand;
 733         const node_p node = NG_HOOK_NODE(hinfo->hook);
 734         const priv_p priv = NG_NODE_PRIVATE(node);
 735         struct hookinfo *dest;
 736         struct ngp_fifo *ngp_f, *ngp_f1;
 737         struct ngp_hdr *ngp_h;
 738         struct timeval *when;
 739         struct mbuf *m;
 740         int plen, error = 0;
 741
 742         /* Which one is the destination hook? */
 743         if (hinfo == &priv->lower)
 744                 dest = &priv->upper;
 745         else
 746                 dest = &priv->lower;
 747
 748         /* Bandwidth queue processing */
 749         while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
 750                 when = &hinfo->qin_utime;
 751                 if (when->tv_sec > now->tv_sec || (when->tv_sec == now->tv_sec
 752                     && when->tv_usec > now->tv_usec))
 753                         break;
 754
 755                 ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
 756                 m = ngp_h->m;
 757
 758                 /* Deficit Round Robin (DRR) processing */
 759                 if (hinfo->cfg.drr) {
 760                         if (ngp_f->rr_deficit >= m->m_pkthdr.len) {
 761                                 ngp_f->rr_deficit -= m->m_pkthdr.len;
 762                         } else {
 763                                 ngp_f->rr_deficit += hinfo->cfg.drr;
 764                                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
 765                                 TAILQ_INSERT_TAIL(&hinfo->fifo_head,
 766                                     ngp_f, fifo_le);
 767                                 continue;
 768                         }
 769                 }
 770
 771                 /*
 772                  * Either create a duplicate and pass it on, or dequeue
 773                  * the original packet...
 774                  */
 775                 if (hinfo->cfg.duplicate &&
 776                     random() % 100 <= hinfo->cfg.duplicate) {
 777                         ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
 778                         KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (3)"));
 779                         m = m_dup(m, M_NOWAIT);
 780                         KASSERT(m != NULL, ("m_dup failed"));
 781                         ngp_h->m = m;
 782                 } else {
 783                         TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
 784                         hinfo->run.qin_frames--;
 785                         hinfo->run.qin_octets -= m->m_pkthdr.len;
 786                         ngp_f->packets--;
 787                 }
 788
 789                 /* Calculate the serialization delay */
 790                 if (hinfo->cfg.bandwidth) {
 791                         hinfo->qin_utime.tv_usec +=
 792                             ((uint64_t) m->m_pkthdr.len + priv->overhead ) *
 793                             8000000 / hinfo->cfg.bandwidth;
 794                         hinfo->qin_utime.tv_sec +=
 795                             hinfo->qin_utime.tv_usec / 1000000;
 796                         hinfo->qin_utime.tv_usec =
 797                             hinfo->qin_utime.tv_usec % 1000000;
 798                 }
 799                 when = &ngp_h->when;
 800                 when->tv_sec = hinfo->qin_utime.tv_sec;
 801                 when->tv_usec = hinfo->qin_utime.tv_usec;
 802
 803                 /* Sort / rearrange inbound queues */
 804                 if (ngp_f->packets) {
 805                         if (hinfo->cfg.wfq) {
 806                                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
 807                                 FIFO_VTIME_SORT(TAILQ_FIRST(
 808                                     &ngp_f->packet_head)->m->m_pkthdr.len)
 809                         }
 810                 } else {
 811                         TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
 812                         uma_zfree(ngp_zone, ngp_f);
 813                         hinfo->run.fifo_queues--;
 814                 }
 815
 816                 /* Randomly discard the frame, according to BER setting */
 817                 if (hinfo->cfg.ber) {
 818                         oldrand = rand;
 819                         rand = random();
 820                         if (((oldrand ^ rand) << 17) >=
 821                             hinfo->ber_p[priv->overhead + m->m_pkthdr.len]) {
 822                                 hinfo->stats.out_disc_frames++;
 823                                 hinfo->stats.out_disc_octets += m->m_pkthdr.len;
 824                                 uma_zfree(ngp_zone, ngp_h);
 825                                 m_freem(m);
 826                                 continue;
 827                         }
 828                 }
 829
 830                 /* Discard frame if outbound queue size limit exceeded */
 831                 if (hinfo->cfg.qout_size_limit &&
 832                     hinfo->run.qout_frames>=hinfo->cfg.qout_size_limit) {
 833                         hinfo->stats.out_disc_frames++;
 834                         hinfo->stats.out_disc_octets += m->m_pkthdr.len;
 835                         uma_zfree(ngp_zone, ngp_h);
 836                         m_freem(m);
 837                         continue;
 838                 }
 839
 840                 /* Calculate the propagation delay */
 841                 when->tv_usec += priv->delay;
 842                 when->tv_sec += when->tv_usec / 1000000;
 843                 when->tv_usec = when->tv_usec % 1000000;
 844
 845                 /* Put the frame into the delay queue */
 846                 TAILQ_INSERT_TAIL(&hinfo->qout_head, ngp_h, ngp_link);
 847                 hinfo->run.qout_frames++;
 848                 hinfo->run.qout_octets += m->m_pkthdr.len;
 849         }
 850
 851         /* Delay queue processing */
 852         while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
 853                 when = &ngp_h->when;
 854                 m = ngp_h->m;
 855                 if (when->tv_sec > now->tv_sec ||
 856                     (when->tv_sec == now->tv_sec &&
 857                     when->tv_usec > now->tv_usec))
 858                         break;
 859
 860                 /* Update outbound queue stats */
 861                 plen = m->m_pkthdr.len;
 862                 hinfo->run.qout_frames--;
 863                 hinfo->run.qout_octets -= plen;
 864
 865                 /* Dequeue the packet from qout */
 866                 TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
 867                 uma_zfree(ngp_zone, ngp_h);
 868
 869                 NG_SEND_DATA(error, dest->hook, m, meta);
 870                 if (error) {
 871                         hinfo->stats.out_disc_frames++;
 872                         hinfo->stats.out_disc_octets += plen;
 873                 } else {
 874                         hinfo->stats.fwd_frames++;
 875                         hinfo->stats.fwd_octets += plen;
 876                 }
 877         }
 878
 879         if ((hinfo->run.qin_frames != 0 || hinfo->run.qout_frames != 0) &&
 880             !priv->timer_scheduled) {
 881                 ng_callout(&priv->timer, node, NULL, 1, ngp_callout, NULL, 0);
 882                 priv->timer_scheduled = 1;
 883         }
 884 }
 885
 886 /*
 887  * This routine is called on every clock tick.  We poll connected hooks
 888  * for queued frames by calling pipe_dequeue().
 889  */
 890 static void
 891 ngp_callout(node_p node, hook_p hook, void *arg1, int arg2)
 892 {
 893         const priv_p priv = NG_NODE_PRIVATE(node);
 894         struct timeval now;
 895
 896         priv->timer_scheduled = 0;
 897         microuptime(&now);
 898         if (priv->upper.hook != NULL)
 899                 pipe_dequeue(&priv->upper, &now);
 900         if (priv->lower.hook != NULL)
 901                 pipe_dequeue(&priv->lower, &now);
 902 }
 903
 904 /*
 905  * Shutdown processing
 906  *
 907  * This is tricky. If we have both a lower and upper hook, then we
 908  * probably want to extricate ourselves and leave the two peers
 909  * still linked to each other. Otherwise we should just shut down as
 910  * a normal node would.
 911  */
 912 static int
 913 ngp_shutdown(node_p node)
 914 {
 915         const priv_p priv = NG_NODE_PRIVATE(node);
 916
 917         if (priv->timer_scheduled)
 918                 ng_uncallout(&priv->timer, node);
 919         if (priv->lower.hook && priv->upper.hook)
 920                 ng_bypass(priv->lower.hook, priv->upper.hook);
 921         else {
 922                 if (priv->upper.hook != NULL)
 923                         ng_rmhook_self(priv->upper.hook);
 924                 if (priv->lower.hook != NULL)
 925                         ng_rmhook_self(priv->lower.hook);
 926         }
 927         NG_NODE_UNREF(node);
 928         free(priv, M_NG_PIPE);
 929         return (0);
 930 }
 931
 932 /*
 933  * Hook disconnection
 934  */
 935 static int
 936 ngp_disconnect(hook_p hook)
 937 {
 938         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 939         struct ngp_fifo *ngp_f;
 940         struct ngp_hdr *ngp_h;
 941
 942         KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
 943         hinfo->hook = NULL;
 944
 945         /* Flush all fifo queues associated with the hook */
 946         while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
 947                 while ((ngp_h = TAILQ_FIRST(&ngp_f->packet_head))) {
 948                         TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
 949                         m_freem(ngp_h->m);
 950                         uma_zfree(ngp_zone, ngp_h);
 951                 }
 952                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
 953                 uma_zfree(ngp_zone, ngp_f);
 954         }
 955
 956         /* Flush the delay queue */
 957         while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
 958                 TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
 959                 m_freem(ngp_h->m);
 960                 uma_zfree(ngp_zone, ngp_h);
 961         }
 962
 963         /* Release the packet loss probability table (BER) */
 964         if (hinfo->ber_p)
 965                 free(hinfo->ber_p, M_NG_PIPE);
 966
 967         return (0);
 968 }
 969
 970 static int
 971 ngp_modevent(module_t mod, int type, void *unused)
 972 {
 973         int error = 0;
 974
 975         switch (type) {
 976         case MOD_LOAD:
 977                 ngp_zone = uma_zcreate("ng_pipe", max(sizeof(struct ngp_hdr),
 978                     sizeof (struct ngp_fifo)), NULL, NULL, NULL, NULL,
 979                     UMA_ALIGN_PTR, 0);
 980                 if (ngp_zone == NULL)
 981                         panic("ng_pipe: couldn't allocate descriptor zone");
 982                 break;
 983         case MOD_UNLOAD:
 984                 uma_zdestroy(ngp_zone);
 985                 break;
 986         default:
 987                 error = EOPNOTSUPP;
 988                 break;
 989         }
 990
 991         return (error);
 992 }