The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_pipe.c

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    1 /*-
    2  * Copyright (c) 2004-2010 University of Zagreb
    3  * Copyright (c) 2007-2008 FreeBSD Foundation
    4  *
    5  * This software was developed by the University of Zagreb and the
    6  * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
    7  * FreeBSD Foundation.
    8  *
    9  * Redistribution and use in source and binary forms, with or without
   10  * modification, are permitted provided that the following conditions
   11  * are met:
   12  * 1. Redistributions of source code must retain the above copyright
   13  *    notice, this list of conditions and the following disclaimer.
   14  * 2. Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in the
   16  *    documentation and/or other materials provided with the distribution.
   17  *
   18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   28  * SUCH DAMAGE.
   29  *
   30  * $FreeBSD: releng/8.4/sys/netgraph/ng_pipe.c 222347 2011-05-27 08:43:59Z zec $
   31  */
   32 
   33 /*
   34  * This node permits simple traffic shaping by emulating bandwidth
   35  * and delay, as well as random packet losses.
   36  * The node has two hooks, upper and lower. Traffic flowing from upper to
   37  * lower hook is referenced as downstream, and vice versa. Parameters for 
   38  * both directions can be set separately, except for delay.
   39  */
   40 
   41 
   42 #include <sys/param.h>
   43 #include <sys/errno.h>
   44 #include <sys/systm.h>
   45 #include <sys/kernel.h>
   46 #include <sys/malloc.h>
   47 #include <sys/mbuf.h>
   48 #include <sys/time.h>
   49 
   50 #include <vm/uma.h>
   51 
   52 #include <net/vnet.h>
   53 
   54 #include <netinet/in.h>
   55 #include <netinet/in_systm.h>
   56 #include <netinet/ip.h>
   57 
   58 #include <netgraph/ng_message.h>
   59 #include <netgraph/netgraph.h>
   60 #include <netgraph/ng_parse.h>
   61 #include <netgraph/ng_pipe.h>
   62 
   63 static MALLOC_DEFINE(M_NG_PIPE, "ng_pipe", "ng_pipe");
   64 
   65 /* Packet header struct */
   66 struct ngp_hdr {
   67         TAILQ_ENTRY(ngp_hdr)    ngp_link;       /* next pkt in queue */
   68         struct timeval          when;           /* this packet's due time */
   69         struct mbuf             *m;             /* ptr to the packet data */
   70 };
   71 TAILQ_HEAD(p_head, ngp_hdr);
   72 
   73 /* FIFO queue struct */
   74 struct ngp_fifo {
   75         TAILQ_ENTRY(ngp_fifo)   fifo_le;        /* list of active queues only */
   76         struct p_head           packet_head;    /* FIFO queue head */
   77         u_int32_t               hash;           /* flow signature */
   78         struct timeval          vtime;          /* virtual time, for WFQ */
   79         u_int32_t               rr_deficit;     /* for DRR */
   80         u_int32_t               packets;        /* # of packets in this queue */
   81 };
   82 
   83 /* Per hook info */
   84 struct hookinfo {
   85         hook_p                  hook;
   86         int                     noqueue;        /* bypass any processing */
   87         TAILQ_HEAD(, ngp_fifo)  fifo_head;      /* FIFO queues */
   88         TAILQ_HEAD(, ngp_hdr)   qout_head;      /* delay queue head */
   89         struct timeval          qin_utime;
   90         struct ng_pipe_hookcfg  cfg;
   91         struct ng_pipe_hookrun  run;
   92         struct ng_pipe_hookstat stats;
   93         uint64_t                *ber_p;         /* loss_p(BER,psize) map */
   94 };
   95 
   96 /* Per node info */
   97 struct node_priv {
   98         u_int64_t               delay;
   99         u_int32_t               overhead;
  100         u_int32_t               header_offset;
  101         struct hookinfo         lower;
  102         struct hookinfo         upper;
  103         struct callout          timer;
  104         int                     timer_scheduled;
  105 };
  106 typedef struct node_priv *priv_p;
  107 
  108 /* Macro for calculating the virtual time for packet dequeueing in WFQ */
  109 #define FIFO_VTIME_SORT(plen)                                           \
  110         if (hinfo->cfg.wfq && hinfo->cfg.bandwidth) {                   \
  111                 ngp_f->vtime.tv_usec = now->tv_usec + ((uint64_t) (plen) \
  112                         + priv->overhead ) * hinfo->run.fifo_queues *   \
  113                         8000000 / hinfo->cfg.bandwidth;                 \
  114                 ngp_f->vtime.tv_sec = now->tv_sec +                     \
  115                         ngp_f->vtime.tv_usec / 1000000;                 \
  116                 ngp_f->vtime.tv_usec = ngp_f->vtime.tv_usec % 1000000;  \
  117                 TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)       \
  118                         if (ngp_f1->vtime.tv_sec > ngp_f->vtime.tv_sec || \
  119                             (ngp_f1->vtime.tv_sec == ngp_f->vtime.tv_sec && \
  120                             ngp_f1->vtime.tv_usec > ngp_f->vtime.tv_usec)) \
  121                                 break;                                  \
  122                 if (ngp_f1 == NULL)                                     \
  123                         TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
  124                 else                                                    \
  125                         TAILQ_INSERT_BEFORE(ngp_f1, ngp_f, fifo_le);    \
  126         } else                                                          \
  127                 TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le);   \
  128 
  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_NOWAIT);
  257         if (priv == NULL)
  258                 return (ENOMEM);
  259         NG_NODE_SET_PRIVATE(node, priv);
  260 
  261         /* Mark node as single-threaded */
  262         NG_NODE_FORCE_WRITER(node);
  263 
  264         ng_callout_init(&priv->timer);
  265 
  266         return (0);
  267 }
  268 
  269 /* Add a hook */
  270 static int
  271 ngp_newhook(node_p node, hook_p hook, const char *name)
  272 {
  273         const priv_p priv = NG_NODE_PRIVATE(node);
  274         struct hookinfo *hinfo;
  275 
  276         if (strcmp(name, NG_PIPE_HOOK_UPPER) == 0) {
  277                 bzero(&priv->upper, sizeof(priv->upper));
  278                 priv->upper.hook = hook;
  279                 NG_HOOK_SET_PRIVATE(hook, &priv->upper);
  280         } else if (strcmp(name, NG_PIPE_HOOK_LOWER) == 0) {
  281                 bzero(&priv->lower, sizeof(priv->lower));
  282                 priv->lower.hook = hook;
  283                 NG_HOOK_SET_PRIVATE(hook, &priv->lower);
  284         } else
  285                 return (EINVAL);
  286 
  287         /* Load non-zero initial cfg values */
  288         hinfo = NG_HOOK_PRIVATE(hook);
  289         hinfo->cfg.qin_size_limit = 50;
  290         hinfo->cfg.fifo = 1;
  291         hinfo->cfg.droptail = 1;
  292         TAILQ_INIT(&hinfo->fifo_head);
  293         TAILQ_INIT(&hinfo->qout_head);
  294         return (0);
  295 }
  296 
  297 /* Receive a control message */
  298 static int
  299 ngp_rcvmsg(node_p node, item_p item, hook_p lasthook)
  300 {
  301         const priv_p priv = NG_NODE_PRIVATE(node);
  302         struct ng_mesg *resp = NULL;
  303         struct ng_mesg *msg, *flow_msg;
  304         struct ng_pipe_stats *stats;
  305         struct ng_pipe_run *run;
  306         struct ng_pipe_cfg *cfg;
  307         int error = 0;
  308         int prev_down, now_down, cmd;
  309 
  310         NGI_GET_MSG(item, msg);
  311         switch (msg->header.typecookie) {
  312         case NGM_PIPE_COOKIE:
  313                 switch (msg->header.cmd) {
  314                 case NGM_PIPE_GET_STATS:
  315                 case NGM_PIPE_CLR_STATS:
  316                 case NGM_PIPE_GETCLR_STATS:
  317                         if (msg->header.cmd != NGM_PIPE_CLR_STATS) {
  318                                 NG_MKRESPONSE(resp, msg,
  319                                     sizeof(*stats), M_NOWAIT);
  320                                 if (resp == NULL) {
  321                                         error = ENOMEM;
  322                                         break;
  323                                 }
  324                                 stats = (struct ng_pipe_stats *) resp->data;
  325                                 bcopy(&priv->upper.stats, &stats->downstream,
  326                                     sizeof(stats->downstream));
  327                                 bcopy(&priv->lower.stats, &stats->upstream,
  328                                     sizeof(stats->upstream));
  329                         }
  330                         if (msg->header.cmd != NGM_PIPE_GET_STATS) {
  331                                 bzero(&priv->upper.stats,
  332                                     sizeof(priv->upper.stats));
  333                                 bzero(&priv->lower.stats,
  334                                     sizeof(priv->lower.stats));
  335                         }
  336                         break;
  337                 case NGM_PIPE_GET_RUN:
  338                         NG_MKRESPONSE(resp, msg, sizeof(*run), M_NOWAIT);
  339                         if (resp == NULL) {
  340                                 error = ENOMEM;
  341                                 break;
  342                         }
  343                         run = (struct ng_pipe_run *) resp->data;
  344                         bcopy(&priv->upper.run, &run->downstream,
  345                                 sizeof(run->downstream));
  346                         bcopy(&priv->lower.run, &run->upstream,
  347                                 sizeof(run->upstream));
  348                         break;
  349                 case NGM_PIPE_GET_CFG:
  350                         NG_MKRESPONSE(resp, msg, sizeof(*cfg), M_NOWAIT);
  351                         if (resp == NULL) {
  352                                 error = ENOMEM;
  353                                 break;
  354                         }
  355                         cfg = (struct ng_pipe_cfg *) resp->data;
  356                         bcopy(&priv->upper.cfg, &cfg->downstream,
  357                                 sizeof(cfg->downstream));
  358                         bcopy(&priv->lower.cfg, &cfg->upstream,
  359                                 sizeof(cfg->upstream));
  360                         cfg->delay = priv->delay;
  361                         cfg->overhead = priv->overhead;
  362                         cfg->header_offset = priv->header_offset;
  363                         if (cfg->upstream.bandwidth ==
  364                             cfg->downstream.bandwidth) {
  365                                 cfg->bandwidth = cfg->upstream.bandwidth;
  366                                 cfg->upstream.bandwidth = 0;
  367                                 cfg->downstream.bandwidth = 0;
  368                         } else
  369                                 cfg->bandwidth = 0;
  370                         break;
  371                 case NGM_PIPE_SET_CFG:
  372                         cfg = (struct ng_pipe_cfg *) msg->data;
  373                         if (msg->header.arglen != sizeof(*cfg)) {
  374                                 error = EINVAL;
  375                                 break;
  376                         }
  377 
  378                         if (cfg->delay == -1)
  379                                 priv->delay = 0;
  380                         else if (cfg->delay > 0 && cfg->delay < 10000000)
  381                                 priv->delay = cfg->delay;
  382 
  383                         if (cfg->bandwidth == -1) {
  384                                 priv->upper.cfg.bandwidth = 0;
  385                                 priv->lower.cfg.bandwidth = 0;
  386                                 priv->overhead = 0;
  387                         } else if (cfg->bandwidth >= 100 &&
  388                             cfg->bandwidth <= 1000000000) {
  389                                 priv->upper.cfg.bandwidth = cfg->bandwidth;
  390                                 priv->lower.cfg.bandwidth = cfg->bandwidth;
  391                                 if (cfg->bandwidth >= 10000000)
  392                                         priv->overhead = 8+4+12; /* Ethernet */
  393                                 else
  394                                         priv->overhead = 10; /* HDLC */
  395                         }
  396 
  397                         if (cfg->overhead == -1)
  398                                 priv->overhead = 0;
  399                         else if (cfg->overhead > 0 &&
  400                             cfg->overhead < MAX_OHSIZE)
  401                                 priv->overhead = cfg->overhead;
  402 
  403                         if (cfg->header_offset == -1)
  404                                 priv->header_offset = 0;
  405                         else if (cfg->header_offset > 0 &&
  406                             cfg->header_offset < 64)
  407                                 priv->header_offset = cfg->header_offset;
  408 
  409                         prev_down = priv->upper.cfg.ber == 1 ||
  410                             priv->lower.cfg.ber == 1;
  411                         parse_cfg(&priv->upper.cfg, &cfg->downstream,
  412                             &priv->upper, priv);
  413                         parse_cfg(&priv->lower.cfg, &cfg->upstream,
  414                             &priv->lower, priv);
  415                         now_down = priv->upper.cfg.ber == 1 ||
  416                             priv->lower.cfg.ber == 1;
  417 
  418                         if (prev_down != now_down) {
  419                                 if (now_down)
  420                                         cmd = NGM_LINK_IS_DOWN;
  421                                 else
  422                                         cmd = NGM_LINK_IS_UP;
  423 
  424                                 if (priv->lower.hook != NULL) {
  425                                         NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
  426                                             cmd, 0, M_NOWAIT);
  427                                         if (flow_msg != NULL)
  428                                                 NG_SEND_MSG_HOOK(error, node,
  429                                                     flow_msg, priv->lower.hook,
  430                                                     0);
  431                                 }
  432                                 if (priv->upper.hook != NULL) {
  433                                         NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
  434                                             cmd, 0, M_NOWAIT);
  435                                         if (flow_msg != NULL)
  436                                                 NG_SEND_MSG_HOOK(error, node,
  437                                                     flow_msg, priv->upper.hook,
  438                                                     0);
  439                                 }
  440                         }
  441                         break;
  442                 default:
  443                         error = EINVAL;
  444                         break;
  445                 }
  446                 break;
  447         default:
  448                 error = EINVAL;
  449                 break;
  450         }
  451         NG_RESPOND_MSG(error, node, item, resp);
  452         NG_FREE_MSG(msg);
  453 
  454         return (error);
  455 }
  456 
  457 static void
  458 parse_cfg(struct ng_pipe_hookcfg *current, struct ng_pipe_hookcfg *new,
  459         struct hookinfo *hinfo, priv_p priv)
  460 {
  461 
  462         if (new->ber == -1) {
  463                 current->ber = 0;
  464                 if (hinfo->ber_p) {
  465                         free(hinfo->ber_p, M_NG_PIPE);
  466                         hinfo->ber_p = NULL;
  467                 }
  468         } else if (new->ber >= 1 && new->ber <= 1000000000000) {
  469                 static const uint64_t one = 0x1000000000000; /* = 2^48 */
  470                 uint64_t p0, p;
  471                 uint32_t fsize, i;
  472 
  473                 if (hinfo->ber_p == NULL)
  474                         hinfo->ber_p =
  475                             malloc((MAX_FSIZE + MAX_OHSIZE) * sizeof(uint64_t),
  476                             M_NG_PIPE, M_NOWAIT);
  477                 current->ber = new->ber;
  478 
  479                 /*
  480                  * For given BER and each frame size N (in bytes) calculate
  481                  * the probability P_OK that the frame is clean:
  482                  *
  483                  * P_OK(BER,N) = (1 - 1/BER)^(N*8)
  484                  *
  485                  * We use a 64-bit fixed-point format with decimal point
  486                  * positioned between bits 47 and 48.
  487                  */
  488                 p0 = one - one / new->ber;
  489                 p = one;
  490                 for (fsize = 0; fsize < MAX_FSIZE + MAX_OHSIZE; fsize++) {
  491                         hinfo->ber_p[fsize] = p;
  492                         for (i = 0; i < 8; i++)
  493                                 p = (p * (p0 & 0xffff) >> 48) +
  494                                     (p * ((p0 >> 16) & 0xffff) >> 32) +
  495                                     (p * (p0 >> 32) >> 16);
  496                 }
  497         }
  498 
  499         if (new->qin_size_limit == -1)
  500                 current->qin_size_limit = 0;
  501         else if (new->qin_size_limit >= 5) 
  502                 current->qin_size_limit = new->qin_size_limit;
  503 
  504         if (new->qout_size_limit == -1)
  505                 current->qout_size_limit = 0;
  506         else if (new->qout_size_limit >= 5)
  507                 current->qout_size_limit = new->qout_size_limit;
  508 
  509         if (new->duplicate == -1)
  510                 current->duplicate = 0;
  511         else if (new->duplicate > 0 && new->duplicate <= 50)
  512                 current->duplicate = new->duplicate;
  513 
  514         if (new->fifo) {
  515                 current->fifo = 1;
  516                 current->wfq = 0;
  517                 current->drr = 0;
  518         }
  519 
  520         if (new->wfq) {
  521                 current->fifo = 0;
  522                 current->wfq = 1;
  523                 current->drr = 0;
  524         }
  525 
  526         if (new->drr) {
  527                 current->fifo = 0;
  528                 current->wfq = 0;
  529                 /* DRR quantum */
  530                 if (new->drr >= 32)
  531                         current->drr = new->drr;
  532                 else
  533                         current->drr = 2048;            /* default quantum */
  534         }
  535 
  536         if (new->droptail) {
  537                 current->droptail = 1;
  538                 current->drophead = 0;
  539         }
  540 
  541         if (new->drophead) {
  542                 current->droptail = 0;
  543                 current->drophead = 1;
  544         }
  545 
  546         if (new->bandwidth == -1) {
  547                 current->bandwidth = 0;
  548                 current->fifo = 1;
  549                 current->wfq = 0;
  550                 current->drr = 0;
  551         } else if (new->bandwidth >= 100 && new->bandwidth <= 1000000000)
  552                 current->bandwidth = new->bandwidth;
  553 
  554         if (current->bandwidth | priv->delay | 
  555             current->duplicate | current->ber)
  556                 hinfo->noqueue = 0;
  557         else
  558                 hinfo->noqueue = 1;
  559 }
  560 
  561 /*
  562  * Compute a hash signature for a packet. This function suffers from the
  563  * NIH sindrome, so probably it would be wise to look around what other
  564  * folks have found out to be a good and efficient IP hash function...
  565  */
  566 static int
  567 ip_hash(struct mbuf *m, int offset)
  568 {
  569         u_int64_t i;
  570         struct ip *ip = (struct ip *)(mtod(m, u_char *) + offset);
  571 
  572         if (m->m_len < sizeof(struct ip) + offset ||
  573             ip->ip_v != 4 || ip->ip_hl << 2 != sizeof(struct ip))
  574                 return 0;
  575 
  576         i = ((u_int64_t) ip->ip_src.s_addr ^
  577             ((u_int64_t) ip->ip_src.s_addr << 13) ^
  578             ((u_int64_t) ip->ip_dst.s_addr << 7) ^
  579             ((u_int64_t) ip->ip_dst.s_addr << 19));
  580         return (i ^ (i >> 32));
  581 }
  582 
  583 /*
  584  * Receive data on a hook - both in upstream and downstream direction.
  585  * We put the frame on the inbound queue, and try to initiate dequeuing
  586  * sequence immediately. If inbound queue is full, discard one frame
  587  * depending on dropping policy (from the head or from the tail of the
  588  * queue).
  589  */
  590 static int
  591 ngp_rcvdata(hook_p hook, item_p item)
  592 {
  593         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
  594         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  595         struct timeval uuptime;
  596         struct timeval *now = &uuptime;
  597         struct ngp_fifo *ngp_f = NULL, *ngp_f1;
  598         struct ngp_hdr *ngp_h = NULL;
  599         struct mbuf *m;
  600         int hash, plen;
  601         int error = 0;
  602 
  603         /*
  604          * Shortcut from inbound to outbound hook when neither of
  605          * bandwidth, delay, BER or duplication probability is
  606          * configured, nor we have queued frames to drain.
  607          */
  608         if (hinfo->run.qin_frames == 0 && hinfo->run.qout_frames == 0 &&
  609             hinfo->noqueue) {
  610                 struct hookinfo *dest;
  611                 if (hinfo == &priv->lower)
  612                         dest = &priv->upper;
  613                 else
  614                         dest = &priv->lower;
  615 
  616                 /* Send the frame. */
  617                 plen = NGI_M(item)->m_pkthdr.len;
  618                 NG_FWD_ITEM_HOOK(error, item, dest->hook);
  619 
  620                 /* Update stats. */
  621                 if (error) {
  622                         hinfo->stats.out_disc_frames++;
  623                         hinfo->stats.out_disc_octets += plen;
  624                 } else {
  625                         hinfo->stats.fwd_frames++;
  626                         hinfo->stats.fwd_octets += plen;
  627                 }
  628 
  629                 return (error);
  630         }
  631 
  632         microuptime(now);
  633 
  634         /*
  635          * If this was an empty queue, update service deadline time.
  636          */
  637         if (hinfo->run.qin_frames == 0) {
  638                 struct timeval *when = &hinfo->qin_utime;
  639                 if (when->tv_sec < now->tv_sec || (when->tv_sec == now->tv_sec
  640                     && when->tv_usec < now->tv_usec)) {
  641                         when->tv_sec = now->tv_sec;
  642                         when->tv_usec = now->tv_usec;
  643                 }
  644         }
  645 
  646         /* Populate the packet header */
  647         ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
  648         KASSERT((ngp_h != NULL), ("ngp_h zalloc failed (1)"));
  649         NGI_GET_M(item, m);
  650         KASSERT(m != NULL, ("NGI_GET_M failed"));
  651         ngp_h->m = m;
  652         NG_FREE_ITEM(item);
  653 
  654         if (hinfo->cfg.fifo)
  655                 hash = 0;       /* all packets go into a single FIFO queue */
  656         else
  657                 hash = ip_hash(m, priv->header_offset);
  658 
  659         /* Find the appropriate FIFO queue for the packet and enqueue it*/
  660         TAILQ_FOREACH(ngp_f, &hinfo->fifo_head, fifo_le)
  661                 if (hash == ngp_f->hash)
  662                         break;
  663         if (ngp_f == NULL) {
  664                 ngp_f = uma_zalloc(ngp_zone, M_NOWAIT);
  665                 KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (2)"));
  666                 TAILQ_INIT(&ngp_f->packet_head);
  667                 ngp_f->hash = hash;
  668                 ngp_f->packets = 1;
  669                 ngp_f->rr_deficit = hinfo->cfg.drr;     /* DRR quantum */
  670                 hinfo->run.fifo_queues++;
  671                 TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
  672                 FIFO_VTIME_SORT(m->m_pkthdr.len);
  673         } else {
  674                 TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
  675                 ngp_f->packets++;
  676         }
  677         hinfo->run.qin_frames++;
  678         hinfo->run.qin_octets += m->m_pkthdr.len;
  679 
  680         /* Discard a frame if inbound queue limit has been reached */
  681         if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
  682                 struct mbuf *m1;
  683                 int longest = 0;
  684 
  685                 /* Find the longest queue */
  686                 TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
  687                         if (ngp_f1->packets > longest) {
  688                                 longest = ngp_f1->packets;
  689                                 ngp_f = ngp_f1;
  690                         }
  691 
  692                 /* Drop a frame from the queue head/tail, depending on cfg */
  693                 if (hinfo->cfg.drophead) 
  694                         ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
  695                 else 
  696                         ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
  697                 TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
  698                 m1 = ngp_h->m;
  699                 uma_zfree(ngp_zone, ngp_h);
  700                 hinfo->run.qin_octets -= m1->m_pkthdr.len;
  701                 hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
  702                 m_freem(m1);
  703                 if (--(ngp_f->packets) == 0) {
  704                         TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  705                         uma_zfree(ngp_zone, ngp_f);
  706                         hinfo->run.fifo_queues--;
  707                 }
  708                 hinfo->run.qin_frames--;
  709                 hinfo->stats.in_disc_frames++;
  710         } else if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
  711                 struct mbuf *m1;
  712                 int longest = 0;
  713 
  714                 /* Find the longest queue */
  715                 TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
  716                         if (ngp_f1->packets > longest) {
  717                                 longest = ngp_f1->packets;
  718                                 ngp_f = ngp_f1;
  719                         }
  720 
  721                 /* Drop a frame from the queue head/tail, depending on cfg */
  722                 if (hinfo->cfg.drophead) 
  723                         ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
  724                 else 
  725                         ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
  726                 TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
  727                 m1 = ngp_h->m;
  728                 uma_zfree(ngp_zone, ngp_h);
  729                 hinfo->run.qin_octets -= m1->m_pkthdr.len;
  730                 hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
  731                 m_freem(m1);
  732                 if (--(ngp_f->packets) == 0) {
  733                         TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  734                         uma_zfree(ngp_zone, ngp_f);
  735                         hinfo->run.fifo_queues--;
  736                 }
  737                 hinfo->run.qin_frames--;
  738                 hinfo->stats.in_disc_frames++;
  739         }
  740 
  741         /*
  742          * Try to start the dequeuing process immediately.
  743          */
  744         pipe_dequeue(hinfo, now);
  745 
  746         return (0);
  747 }
  748 
  749 
  750 /*
  751  * Dequeueing sequence - we basically do the following:
  752  *  1) Try to extract the frame from the inbound (bandwidth) queue;
  753  *  2) In accordance to BER specified, discard the frame randomly;
  754  *  3) If the frame survives BER, prepend it with delay info and move it
  755  *     to outbound (delay) queue;
  756  *  4) Loop to 2) until bandwidth quota for this timeslice is reached, or
  757  *     inbound queue is flushed completely;
  758  *  5) Dequeue frames from the outbound queue and send them downstream until
  759  *     outbound queue is flushed completely, or the next frame in the queue
  760  *     is not due to be dequeued yet
  761  */
  762 static void
  763 pipe_dequeue(struct hookinfo *hinfo, struct timeval *now) {
  764         static uint64_t rand, oldrand;
  765         const node_p node = NG_HOOK_NODE(hinfo->hook);
  766         const priv_p priv = NG_NODE_PRIVATE(node);
  767         struct hookinfo *dest;
  768         struct ngp_fifo *ngp_f, *ngp_f1;
  769         struct ngp_hdr *ngp_h;
  770         struct timeval *when;
  771         struct mbuf *m;
  772         int plen, error = 0;
  773 
  774         /* Which one is the destination hook? */
  775         if (hinfo == &priv->lower)
  776                 dest = &priv->upper;
  777         else
  778                 dest = &priv->lower;
  779 
  780         /* Bandwidth queue processing */
  781         while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
  782                 when = &hinfo->qin_utime;
  783                 if (when->tv_sec > now->tv_sec || (when->tv_sec == now->tv_sec
  784                     && when->tv_usec > now->tv_usec))
  785                         break;
  786 
  787                 ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
  788                 m = ngp_h->m;
  789 
  790                 /* Deficit Round Robin (DRR) processing */
  791                 if (hinfo->cfg.drr) {
  792                         if (ngp_f->rr_deficit >= m->m_pkthdr.len) {
  793                                 ngp_f->rr_deficit -= m->m_pkthdr.len;
  794                         } else {
  795                                 ngp_f->rr_deficit += hinfo->cfg.drr;
  796                                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  797                                 TAILQ_INSERT_TAIL(&hinfo->fifo_head,
  798                                     ngp_f, fifo_le);
  799                                 continue;
  800                         }
  801                 }
  802 
  803                 /*
  804                  * Either create a duplicate and pass it on, or dequeue
  805                  * the original packet...
  806                  */
  807                 if (hinfo->cfg.duplicate &&
  808                     random() % 100 <= hinfo->cfg.duplicate) {
  809                         ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
  810                         KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (3)"));
  811                         m = m_dup(m, M_NOWAIT);
  812                         KASSERT(m != NULL, ("m_dup failed"));
  813                         ngp_h->m = m;
  814                 } else {
  815                         TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
  816                         hinfo->run.qin_frames--;
  817                         hinfo->run.qin_octets -= m->m_pkthdr.len;
  818                         ngp_f->packets--;
  819                 }
  820                 
  821                 /* Calculate the serialization delay */
  822                 if (hinfo->cfg.bandwidth) {
  823                         hinfo->qin_utime.tv_usec +=
  824                             ((uint64_t) m->m_pkthdr.len + priv->overhead ) *
  825                             8000000 / hinfo->cfg.bandwidth;
  826                         hinfo->qin_utime.tv_sec +=
  827                             hinfo->qin_utime.tv_usec / 1000000;
  828                         hinfo->qin_utime.tv_usec =
  829                             hinfo->qin_utime.tv_usec % 1000000;
  830                 }
  831                 when = &ngp_h->when;
  832                 when->tv_sec = hinfo->qin_utime.tv_sec;
  833                 when->tv_usec = hinfo->qin_utime.tv_usec;
  834 
  835                 /* Sort / rearrange inbound queues */
  836                 if (ngp_f->packets) {
  837                         if (hinfo->cfg.wfq) {
  838                                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  839                                 FIFO_VTIME_SORT(TAILQ_FIRST(
  840                                     &ngp_f->packet_head)->m->m_pkthdr.len)
  841                         }
  842                 } else {
  843                         TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  844                         uma_zfree(ngp_zone, ngp_f);
  845                         hinfo->run.fifo_queues--;
  846                 }
  847 
  848                 /* Randomly discard the frame, according to BER setting */
  849                 if (hinfo->cfg.ber) {
  850                         oldrand = rand;
  851                         rand = random();
  852                         if (((oldrand ^ rand) << 17) >=
  853                             hinfo->ber_p[priv->overhead + m->m_pkthdr.len]) {
  854                                 hinfo->stats.out_disc_frames++;
  855                                 hinfo->stats.out_disc_octets += m->m_pkthdr.len;
  856                                 uma_zfree(ngp_zone, ngp_h);
  857                                 m_freem(m);
  858                                 continue;
  859                         }
  860                 }
  861 
  862                 /* Discard frame if outbound queue size limit exceeded */
  863                 if (hinfo->cfg.qout_size_limit &&
  864                     hinfo->run.qout_frames>=hinfo->cfg.qout_size_limit) {
  865                         hinfo->stats.out_disc_frames++;
  866                         hinfo->stats.out_disc_octets += m->m_pkthdr.len;
  867                         uma_zfree(ngp_zone, ngp_h);
  868                         m_freem(m);
  869                         continue;
  870                 }
  871 
  872                 /* Calculate the propagation delay */
  873                 when->tv_usec += priv->delay;
  874                 when->tv_sec += when->tv_usec / 1000000;
  875                 when->tv_usec = when->tv_usec % 1000000;
  876 
  877                 /* Put the frame into the delay queue */
  878                 TAILQ_INSERT_TAIL(&hinfo->qout_head, ngp_h, ngp_link);
  879                 hinfo->run.qout_frames++;
  880                 hinfo->run.qout_octets += m->m_pkthdr.len;
  881         }
  882 
  883         /* Delay queue processing */
  884         while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
  885                 when = &ngp_h->when;
  886                 m = ngp_h->m;
  887                 if (when->tv_sec > now->tv_sec ||
  888                     (when->tv_sec == now->tv_sec &&
  889                     when->tv_usec > now->tv_usec))
  890                         break;
  891 
  892                 /* Update outbound queue stats */
  893                 plen = m->m_pkthdr.len;
  894                 hinfo->run.qout_frames--;
  895                 hinfo->run.qout_octets -= plen;
  896 
  897                 /* Dequeue the packet from qout */
  898                 TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
  899                 uma_zfree(ngp_zone, ngp_h);
  900 
  901                 NG_SEND_DATA(error, dest->hook, m, meta);
  902                 if (error) {
  903                         hinfo->stats.out_disc_frames++;
  904                         hinfo->stats.out_disc_octets += plen;
  905                 } else {
  906                         hinfo->stats.fwd_frames++;
  907                         hinfo->stats.fwd_octets += plen;
  908                 }
  909         }
  910 
  911         if ((hinfo->run.qin_frames != 0 || hinfo->run.qout_frames != 0) &&
  912             !priv->timer_scheduled) {
  913                 ng_callout(&priv->timer, node, NULL, 1, ngp_callout, NULL, 0);
  914                 priv->timer_scheduled = 1;
  915         }
  916 }
  917 
  918 /*
  919  * This routine is called on every clock tick.  We poll connected hooks
  920  * for queued frames by calling pipe_dequeue().
  921  */
  922 static void
  923 ngp_callout(node_p node, hook_p hook, void *arg1, int arg2)
  924 {
  925         const priv_p priv = NG_NODE_PRIVATE(node);
  926         struct timeval now;
  927 
  928         priv->timer_scheduled = 0;
  929         microuptime(&now);
  930         if (priv->upper.hook != NULL)
  931                 pipe_dequeue(&priv->upper, &now);
  932         if (priv->lower.hook != NULL)
  933                 pipe_dequeue(&priv->lower, &now);
  934 }
  935 
  936 /*
  937  * Shutdown processing
  938  *
  939  * This is tricky. If we have both a lower and upper hook, then we
  940  * probably want to extricate ourselves and leave the two peers
  941  * still linked to each other. Otherwise we should just shut down as
  942  * a normal node would.
  943  */
  944 static int
  945 ngp_shutdown(node_p node)
  946 {
  947         const priv_p priv = NG_NODE_PRIVATE(node);
  948 
  949         if (priv->timer_scheduled)
  950                 ng_uncallout(&priv->timer, node);
  951         if (priv->lower.hook && priv->upper.hook)
  952                 ng_bypass(priv->lower.hook, priv->upper.hook);
  953         else {
  954                 if (priv->upper.hook != NULL)
  955                         ng_rmhook_self(priv->upper.hook);
  956                 if (priv->lower.hook != NULL)
  957                         ng_rmhook_self(priv->lower.hook);
  958         }
  959         NG_NODE_UNREF(node);
  960         free(priv, M_NG_PIPE);
  961         return (0);
  962 }
  963 
  964 
  965 /*
  966  * Hook disconnection
  967  */
  968 static int
  969 ngp_disconnect(hook_p hook)
  970 {
  971         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
  972         struct ngp_fifo *ngp_f;
  973         struct ngp_hdr *ngp_h;
  974 
  975         KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
  976         hinfo->hook = NULL;
  977 
  978         /* Flush all fifo queues associated with the hook */
  979         while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
  980                 while ((ngp_h = TAILQ_FIRST(&ngp_f->packet_head))) {
  981                         TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
  982                         m_freem(ngp_h->m);
  983                         uma_zfree(ngp_zone, ngp_h);
  984                 }
  985                 TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
  986                 uma_zfree(ngp_zone, ngp_f);
  987         }
  988 
  989         /* Flush the delay queue */
  990         while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
  991                 TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
  992                 m_freem(ngp_h->m);
  993                 uma_zfree(ngp_zone, ngp_h);
  994         }
  995 
  996         /* Release the packet loss probability table (BER) */
  997         if (hinfo->ber_p)
  998                 free(hinfo->ber_p, M_NG_PIPE);
  999 
 1000         return (0);
 1001 }
 1002 
 1003 static int
 1004 ngp_modevent(module_t mod, int type, void *unused)
 1005 {
 1006         int error = 0;
 1007 
 1008         switch (type) {
 1009         case MOD_LOAD:
 1010                 ngp_zone = uma_zcreate("ng_pipe", max(sizeof(struct ngp_hdr),
 1011                     sizeof (struct ngp_fifo)), NULL, NULL, NULL, NULL,
 1012                     UMA_ALIGN_PTR, 0);
 1013                 if (ngp_zone == NULL)
 1014                         panic("ng_pipe: couldn't allocate descriptor zone");
 1015                 break;
 1016         case MOD_UNLOAD:
 1017                 uma_zdestroy(ngp_zone);
 1018                 break;
 1019         default:
 1020                 error = EOPNOTSUPP;
 1021                 break;
 1022         }
 1023 
 1024         return (error);
 1025 }

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