sys/netgraph7/ng_one2many.c

   1 /*
   2  * ng_one2many.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 2000 Whistle Communications, Inc.
   7  * All rights reserved.
   8  *
   9  * Subject to the following obligations and disclaimer of warranty, use and
  10  * redistribution of this software, in source or object code forms, with or
  11  * without modifications are expressly permitted by Whistle Communications;
  12  * provided, however, that:
  13  * 1. Any and all reproductions of the source or object code must include the
  14  *    copyright notice above and the following disclaimer of warranties; and
  15  * 2. No rights are granted, in any manner or form, to use Whistle
  16  *    Communications, Inc. trademarks, including the mark "WHISTLE
  17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  18  *    such appears in the above copyright notice or in the software.
  19  *
  20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  36  * OF SUCH DAMAGE.
  37  *
  38  * Author: Archie Cobbs <archie@freebsd.org>
  39  *
  40  * $FreeBSD: src/sys/netgraph/ng_one2many.c,v 1.21 2005/03/11 10:29:38 glebius Exp $
  41  * $DragonFly: src/sys/netgraph7/ng_one2many.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  42  */
  43
  44 /*
  45  * ng_one2many(4) netgraph node type
  46  *
  47  * Packets received on the "one" hook are sent out each of the
  48  * "many" hooks accoring to an algorithm. Packets received on any
  49  * "many" hook are always delivered to the "one" hook.
  50  */
  51
  52 #include <sys/param.h>
  53 #include <sys/systm.h>
  54 #include <sys/kernel.h>
  55 #include <sys/malloc.h>
  56 #include <sys/ctype.h>
  57 #include <sys/mbuf.h>
  58 #include <sys/errno.h>
  59
  60 #include "ng_message.h"
  61 #include "netgraph.h"
  62 #include "ng_parse.h"
  63 #include "ng_one2many.h"
  64
  65 /* Per-link private data */
  66 struct ng_one2many_link {
  67         hook_p                          hook;   /* netgraph hook */
  68         struct ng_one2many_link_stats   stats;  /* link stats */
  69 };
  70
  71 /* Per-node private data */
  72 struct ng_one2many_private {
  73         node_p                          node;           /* link to node */
  74         struct ng_one2many_config       conf;           /* node configuration */
  75         struct ng_one2many_link         one;            /* "one" hook */
  76         struct ng_one2many_link         many[NG_ONE2MANY_MAX_LINKS];
  77         u_int16_t                       nextMany;       /* next round-robin */
  78         u_int16_t                       numActiveMany;  /* # active "many" */
  79         u_int16_t                       activeMany[NG_ONE2MANY_MAX_LINKS];
  80 };
  81 typedef struct ng_one2many_private *priv_p;
  82
  83 /* Netgraph node methods */
  84 static ng_constructor_t ng_one2many_constructor;
  85 static ng_rcvmsg_t      ng_one2many_rcvmsg;
  86 static ng_shutdown_t    ng_one2many_shutdown;
  87 static ng_newhook_t     ng_one2many_newhook;
  88 static ng_rcvdata_t     ng_one2many_rcvdata;
  89 static ng_disconnect_t  ng_one2many_disconnect;
  90
  91 /* Other functions */
  92 static void             ng_one2many_update_many(priv_p priv);
  93 static void             ng_one2many_notify(priv_p priv, uint32_t cmd);
  94
  95 /******************************************************************
  96                     NETGRAPH PARSE TYPES
  97 ******************************************************************/
  98
  99 /* Parse type for struct ng_one2many_config */
 100 static const struct ng_parse_fixedarray_info
 101     ng_one2many_enableLinks_array_type_info = {
 102         &ng_parse_uint8_type,
 103         NG_ONE2MANY_MAX_LINKS
 104 };
 105 static const struct ng_parse_type ng_one2many_enableLinks_array_type = {
 106         &ng_parse_fixedarray_type,
 107         &ng_one2many_enableLinks_array_type_info,
 108 };
 109 static const struct ng_parse_struct_field ng_one2many_config_type_fields[]
 110         = NG_ONE2MANY_CONFIG_TYPE_INFO(&ng_one2many_enableLinks_array_type);
 111 static const struct ng_parse_type ng_one2many_config_type = {
 112         &ng_parse_struct_type,
 113         &ng_one2many_config_type_fields
 114 };
 115
 116 /* Parse type for struct ng_one2many_link_stats */
 117 static const struct ng_parse_struct_field ng_one2many_link_stats_type_fields[]
 118         = NG_ONE2MANY_LINK_STATS_TYPE_INFO;
 119 static const struct ng_parse_type ng_one2many_link_stats_type = {
 120         &ng_parse_struct_type,
 121         &ng_one2many_link_stats_type_fields
 122 };
 123
 124 /* List of commands and how to convert arguments to/from ASCII */
 125 static const struct ng_cmdlist ng_one2many_cmdlist[] = {
 126         {
 127           NGM_ONE2MANY_COOKIE,
 128           NGM_ONE2MANY_SET_CONFIG,
 129           "setconfig",
 130           &ng_one2many_config_type,
 131           NULL
 132         },
 133         {
 134           NGM_ONE2MANY_COOKIE,
 135           NGM_ONE2MANY_GET_CONFIG,
 136           "getconfig",
 137           NULL,
 138           &ng_one2many_config_type
 139         },
 140         {
 141           NGM_ONE2MANY_COOKIE,
 142           NGM_ONE2MANY_GET_STATS,
 143           "getstats",
 144           &ng_parse_int32_type,
 145           &ng_one2many_link_stats_type
 146         },
 147         {
 148           NGM_ONE2MANY_COOKIE,
 149           NGM_ONE2MANY_CLR_STATS,
 150           "clrstats",
 151           &ng_parse_int32_type,
 152           NULL,
 153         },
 154         {
 155           NGM_ONE2MANY_COOKIE,
 156           NGM_ONE2MANY_GETCLR_STATS,
 157           "getclrstats",
 158           &ng_parse_int32_type,
 159           &ng_one2many_link_stats_type
 160         },
 161         { 0 }
 162 };
 163
 164 /* Node type descriptor */
 165 static struct ng_type ng_one2many_typestruct = {
 166         .version =      NG_ABI_VERSION,
 167         .name =         NG_ONE2MANY_NODE_TYPE,
 168         .constructor =  ng_one2many_constructor,
 169         .rcvmsg =       ng_one2many_rcvmsg,
 170         .shutdown =     ng_one2many_shutdown,
 171         .newhook =      ng_one2many_newhook,
 172         .rcvdata =      ng_one2many_rcvdata,
 173         .disconnect =   ng_one2many_disconnect,
 174         .cmdlist =      ng_one2many_cmdlist,
 175 };
 176 NETGRAPH_INIT(one2many, &ng_one2many_typestruct);
 177
 178 /******************************************************************
 179                     NETGRAPH NODE METHODS
 180 ******************************************************************/
 181
 182 /*
 183  * Node constructor
 184  */
 185 static int
 186 ng_one2many_constructor(node_p node)
 187 {
 188         priv_p priv;
 189
 190         /* Allocate and initialize private info */
 191         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO);
 192         if (priv == NULL)
 193                 return (ENOMEM);
 194         priv->conf.xmitAlg = NG_ONE2MANY_XMIT_ROUNDROBIN;
 195         priv->conf.failAlg = NG_ONE2MANY_FAIL_MANUAL;
 196
 197         /* cross reference */
 198         NG_NODE_SET_PRIVATE(node, priv);
 199         priv->node = node;
 200
 201         /* Done */
 202         return (0);
 203 }
 204
 205 /*
 206  * Method for attaching a new hook
 207  */
 208 static  int
 209 ng_one2many_newhook(node_p node, hook_p hook, const char *name)
 210 {
 211         const priv_p priv = NG_NODE_PRIVATE(node);
 212         struct ng_one2many_link *link;
 213         int linkNum;
 214         u_long i;
 215
 216         /* Which hook? */
 217         if (strncmp(name, NG_ONE2MANY_HOOK_MANY_PREFIX,
 218             strlen(NG_ONE2MANY_HOOK_MANY_PREFIX)) == 0) {
 219                 const char *cp;
 220                 char *eptr;
 221
 222                 cp = name + strlen(NG_ONE2MANY_HOOK_MANY_PREFIX);
 223                 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0'))
 224                         return (EINVAL);
 225                 i = strtoul(cp, &eptr, 10);
 226                 if (*eptr != '\0' || i < 0 || i >= NG_ONE2MANY_MAX_LINKS)
 227                         return (EINVAL);
 228                 linkNum = (int)i;
 229                 link = &priv->many[linkNum];
 230         } else if (strcmp(name, NG_ONE2MANY_HOOK_ONE) == 0) {
 231                 linkNum = NG_ONE2MANY_ONE_LINKNUM;
 232                 link = &priv->one;
 233         } else
 234                 return (EINVAL);
 235
 236         /* Is hook already connected? (should never happen) */
 237         if (link->hook != NULL)
 238                 return (EISCONN);
 239
 240         /* Setup private info for this link */
 241         NG_HOOK_SET_PRIVATE(hook, (void *)(intptr_t)linkNum);
 242         link->hook = hook;
 243         bzero(&link->stats, sizeof(link->stats));
 244         if (linkNum != NG_ONE2MANY_ONE_LINKNUM) {
 245                 priv->conf.enabledLinks[linkNum] = 1;   /* auto-enable link */
 246                 ng_one2many_update_many(priv);
 247         }
 248
 249         /* Done */
 250         return (0);
 251 }
 252
 253 /*
 254  * Receive a control message
 255  */
 256 static int
 257 ng_one2many_rcvmsg(node_p node, item_p item, hook_p lasthook)
 258 {
 259         const priv_p priv = NG_NODE_PRIVATE(node);
 260         struct ng_mesg *resp = NULL;
 261         int error = 0;
 262         struct ng_mesg *msg;
 263
 264         NGI_GET_MSG(item, msg);
 265         switch (msg->header.typecookie) {
 266         case NGM_ONE2MANY_COOKIE:
 267                 switch (msg->header.cmd) {
 268                 case NGM_ONE2MANY_SET_CONFIG:
 269                     {
 270                         struct ng_one2many_config *conf;
 271                         int i;
 272
 273                         /* Check that new configuration is valid */
 274                         if (msg->header.arglen != sizeof(*conf)) {
 275                                 error = EINVAL;
 276                                 break;
 277                         }
 278                         conf = (struct ng_one2many_config *)msg->data;
 279                         switch (conf->xmitAlg) {
 280                         case NG_ONE2MANY_XMIT_ROUNDROBIN:
 281                         case NG_ONE2MANY_XMIT_ALL:
 282                                 break;
 283                         default:
 284                                 error = EINVAL;
 285                                 break;
 286                         }
 287                         switch (conf->failAlg) {
 288                         case NG_ONE2MANY_FAIL_MANUAL:
 289                         case NG_ONE2MANY_FAIL_NOTIFY:
 290                                 break;
 291                         default:
 292                                 error = EINVAL;
 293                                 break;
 294                         }
 295                         if (error != 0)
 296                                 break;
 297
 298                         /* Normalized many link enabled bits */
 299                         for (i = 0; i < NG_ONE2MANY_MAX_LINKS; i++)
 300                                 conf->enabledLinks[i] = !!conf->enabledLinks[i];
 301
 302                         /* Copy config and reset */
 303                         bcopy(conf, &priv->conf, sizeof(*conf));
 304                         ng_one2many_update_many(priv);
 305                         break;
 306                     }
 307                 case NGM_ONE2MANY_GET_CONFIG:
 308                     {
 309                         struct ng_one2many_config *conf;
 310
 311                         NG_MKRESPONSE(resp, msg, sizeof(*conf), M_WAITOK | M_NULLOK);
 312                         if (resp == NULL) {
 313                                 error = ENOMEM;
 314                                 break;
 315                         }
 316                         conf = (struct ng_one2many_config *)resp->data;
 317                         bcopy(&priv->conf, conf, sizeof(priv->conf));
 318                         break;
 319                     }
 320                 case NGM_ONE2MANY_GET_STATS:
 321                 case NGM_ONE2MANY_CLR_STATS:
 322                 case NGM_ONE2MANY_GETCLR_STATS:
 323                     {
 324                         struct ng_one2many_link *link;
 325                         int linkNum;
 326
 327                         /* Get link */
 328                         if (msg->header.arglen != sizeof(int32_t)) {
 329                                 error = EINVAL;
 330                                 break;
 331                         }
 332                         linkNum = *((int32_t *)msg->data);
 333                         if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
 334                                 link = &priv->one;
 335                         else if (linkNum >= 0
 336                             && linkNum < NG_ONE2MANY_MAX_LINKS) {
 337                                 link = &priv->many[linkNum];
 338                         } else {
 339                                 error = EINVAL;
 340                                 break;
 341                         }
 342
 343                         /* Get/clear stats */
 344                         if (msg->header.cmd != NGM_ONE2MANY_CLR_STATS) {
 345                                 NG_MKRESPONSE(resp, msg,
 346                                     sizeof(link->stats), M_WAITOK | M_NULLOK);
 347                                 if (resp == NULL) {
 348                                         error = ENOMEM;
 349                                         break;
 350                                 }
 351                                 bcopy(&link->stats,
 352                                     resp->data, sizeof(link->stats));
 353                         }
 354                         if (msg->header.cmd != NGM_ONE2MANY_GET_STATS)
 355                                 bzero(&link->stats, sizeof(link->stats));
 356                         break;
 357                     }
 358                 default:
 359                         error = EINVAL;
 360                         break;
 361                 }
 362                 break;
 363         /*
 364          * One of our downstreams notifies us of link change. If we are
 365          * configured to listen to these message, then we remove/add
 366          * this hook from array of active hooks.
 367          */
 368         case NGM_FLOW_COOKIE:
 369             {
 370                 int linkNum;
 371
 372                 if (priv->conf.failAlg != NG_ONE2MANY_FAIL_NOTIFY)
 373                         break;
 374
 375                 if (lasthook == NULL)
 376                         break;
 377
 378                 linkNum = (intptr_t)NG_HOOK_PRIVATE(lasthook);
 379                 if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
 380                         break;
 381
 382                 KASSERT((linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
 383                     ("%s: linkNum=%d", __func__, linkNum));
 384
 385                 switch (msg->header.cmd) {
 386                 case NGM_LINK_IS_UP:
 387                         priv->conf.enabledLinks[linkNum] = 1;
 388                         ng_one2many_update_many(priv);
 389                         break;
 390                 case NGM_LINK_IS_DOWN:
 391                         priv->conf.enabledLinks[linkNum] = 0;
 392                         ng_one2many_update_many(priv);
 393                         break;
 394                 default:
 395                         break;
 396                 }
 397                 break;
 398             }
 399         default:
 400                 error = EINVAL;
 401                 break;
 402         }
 403
 404         /* Done */
 405         NG_RESPOND_MSG(error, node, item, resp);
 406         NG_FREE_MSG(msg);
 407         return (error);
 408 }
 409
 410 /*
 411  * Receive data on a hook
 412  */
 413 static int
 414 ng_one2many_rcvdata(hook_p hook, item_p item)
 415 {
 416         const node_p node = NG_HOOK_NODE(hook);
 417         const priv_p priv = NG_NODE_PRIVATE(node);
 418         struct ng_one2many_link *src;
 419         struct ng_one2many_link *dst = NULL;
 420         int error = 0;
 421         int linkNum;
 422         int i;
 423         struct mbuf *m;
 424
 425         m = NGI_M(item); /* just peaking, mbuf still owned by item */
 426         /* Get link number */
 427         linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
 428         KASSERT(linkNum == NG_ONE2MANY_ONE_LINKNUM
 429             || (linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
 430             ("%s: linkNum=%d", __func__, linkNum));
 431
 432         /* Figure out source link */
 433         src = (linkNum == NG_ONE2MANY_ONE_LINKNUM) ?
 434             &priv->one : &priv->many[linkNum];
 435         KASSERT(src->hook != NULL, ("%s: no src%d", __func__, linkNum));
 436
 437         /* Update receive stats */
 438         src->stats.recvPackets++;
 439         src->stats.recvOctets += m->m_pkthdr.len;
 440
 441         /* Figure out destination link */
 442         if (linkNum == NG_ONE2MANY_ONE_LINKNUM) {
 443                 if (priv->numActiveMany == 0) {
 444                         NG_FREE_ITEM(item);
 445                         return (ENOTCONN);
 446                 }
 447                 switch(priv->conf.xmitAlg) {
 448                 case NG_ONE2MANY_XMIT_ROUNDROBIN:
 449                         dst = &priv->many[priv->activeMany[priv->nextMany]];
 450                         priv->nextMany = (priv->nextMany + 1) % priv->numActiveMany;
 451                         break;
 452                 case NG_ONE2MANY_XMIT_ALL:
 453                         /* no need to copy data for the 1st one */
 454                         dst = &priv->many[priv->activeMany[0]];
 455
 456                         /* make copies of data and send for all links
 457                          * except the first one, which we'll do last
 458                          */
 459                         for (i = 1; i < priv->numActiveMany; i++) {
 460                                 struct mbuf *m2;
 461                                 struct ng_one2many_link *mdst;
 462
 463                                 mdst = &priv->many[priv->activeMany[i]];
 464                                 m2 = m_dup(m, MB_DONTWAIT);        /* XXX m_copypacket() */
 465                                 if (m2 == NULL) {
 466                                         mdst->stats.memoryFailures++;
 467                                         NG_FREE_ITEM(item);
 468                                         NG_FREE_M(m);
 469                                         return (ENOBUFS);
 470                                 }
 471                                 /* Update transmit stats */
 472                                 mdst->stats.xmitPackets++;
 473                                 mdst->stats.xmitOctets += m->m_pkthdr.len;
 474                                 NG_SEND_DATA_ONLY(error, mdst->hook, m2);
 475                         }
 476                         break;
 477 #ifdef INVARIANTS
 478                 default:
 479                         panic("%s: invalid xmitAlg", __func__);
 480 #endif
 481                 }
 482         } else {
 483                 dst = &priv->one;
 484         }
 485
 486         /* Update transmit stats */
 487         dst->stats.xmitPackets++;
 488         dst->stats.xmitOctets += m->m_pkthdr.len;
 489
 490         /* Deliver packet */
 491         NG_FWD_ITEM_HOOK(error, item, dst->hook);
 492         return (error);
 493 }
 494
 495 /*
 496  * Shutdown node
 497  */
 498 static int
 499 ng_one2many_shutdown(node_p node)
 500 {
 501         const priv_p priv = NG_NODE_PRIVATE(node);
 502
 503         KASSERT(priv->numActiveMany == 0,
 504             ("%s: numActiveMany=%d", __func__, priv->numActiveMany));
 505         FREE(priv, M_NETGRAPH);
 506         NG_NODE_SET_PRIVATE(node, NULL);
 507         NG_NODE_UNREF(node);
 508         return (0);
 509 }
 510
 511 /*
 512  * Hook disconnection.
 513  */
 514 static int
 515 ng_one2many_disconnect(hook_p hook)
 516 {
 517         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 518         int linkNum;
 519
 520         /* Get link number */
 521         linkNum = (intptr_t)NG_HOOK_PRIVATE(hook);
 522         KASSERT(linkNum == NG_ONE2MANY_ONE_LINKNUM
 523             || (linkNum >= 0 && linkNum < NG_ONE2MANY_MAX_LINKS),
 524             ("%s: linkNum=%d", __func__, linkNum));
 525
 526         /* Nuke the link */
 527         if (linkNum == NG_ONE2MANY_ONE_LINKNUM)
 528                 priv->one.hook = NULL;
 529         else {
 530                 priv->many[linkNum].hook = NULL;
 531                 priv->conf.enabledLinks[linkNum] = 0;
 532                 ng_one2many_update_many(priv);
 533         }
 534
 535         /* If no hooks left, go away */
 536         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 537         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 538                 ng_rmnode_self(NG_HOOK_NODE(hook));
 539         return (0);
 540 }
 541
 542 /******************************************************************
 543                         OTHER FUNCTIONS
 544 ******************************************************************/
 545
 546 /*
 547  * Update internal state after the addition or removal of a "many" link
 548  */
 549 static void
 550 ng_one2many_update_many(priv_p priv)
 551 {
 552         uint16_t saveActive = priv->numActiveMany;
 553         int linkNum;
 554
 555         /* Update list of which "many" links are up */
 556         priv->numActiveMany = 0;
 557         for (linkNum = 0; linkNum < NG_ONE2MANY_MAX_LINKS; linkNum++) {
 558                 switch (priv->conf.failAlg) {
 559                 case NG_ONE2MANY_FAIL_MANUAL:
 560                 case NG_ONE2MANY_FAIL_NOTIFY:
 561                         if (priv->many[linkNum].hook != NULL
 562                             && priv->conf.enabledLinks[linkNum]) {
 563                                 priv->activeMany[priv->numActiveMany] = linkNum;
 564                                 priv->numActiveMany++;
 565                         }
 566                         break;
 567 #ifdef INVARIANTS
 568                 default:
 569                         panic("%s: invalid failAlg", __func__);
 570 #endif
 571                 }
 572         }
 573
 574         if (priv->numActiveMany == 0 && saveActive > 0)
 575                 ng_one2many_notify(priv, NGM_LINK_IS_DOWN);
 576
 577         if (saveActive == 0 && priv->numActiveMany > 0)
 578                 ng_one2many_notify(priv, NGM_LINK_IS_UP);
 579
 580         /* Update transmit algorithm state */
 581         switch (priv->conf.xmitAlg) {
 582         case NG_ONE2MANY_XMIT_ROUNDROBIN:
 583                 if (priv->numActiveMany > 0)
 584                         priv->nextMany %= priv->numActiveMany;
 585                 break;
 586         case NG_ONE2MANY_XMIT_ALL:
 587                 break;
 588 #ifdef INVARIANTS
 589         default:
 590                 panic("%s: invalid xmitAlg", __func__);
 591 #endif
 592         }
 593 }
 594
 595 /*
 596  * Notify upstream if we are out of links, or we have at least one link.
 597  */
 598 static void
 599 ng_one2many_notify(priv_p priv, uint32_t cmd)
 600 {
 601         struct ng_mesg *msg;
 602         int dummy_error = 0;
 603
 604         if (priv->one.hook == NULL)
 605                 return;
 606
 607         NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_WAITOK | M_NULLOK);
 608         if (msg != NULL)
 609                 NG_SEND_MSG_HOOK(dummy_error, priv->node, msg, priv->one.hook, 0);
 610 }