sys/netgraph/ng_cisco.c

   1 /*
   2  * ng_cisco.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 1996-1999 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: Julian Elischer <julian@freebsd.org>
  39  *
  40  * $FreeBSD$
  41  * $Whistle: ng_cisco.c,v 1.25 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 #include <sys/param.h>
  45 #include <sys/systm.h>
  46 #include <sys/errno.h>
  47 #include <sys/kernel.h>
  48 #include <sys/socket.h>
  49 #include <sys/malloc.h>
  50 #include <sys/mbuf.h>
  51 #include <sys/syslog.h>
  52
  53 #include <net/if.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/if_ether.h>
  57
  58 #include <netatalk/at.h>
  59
  60 #include <netipx/ipx.h>
  61 #include <netipx/ipx_if.h>
  62
  63 #include <netgraph/ng_message.h>
  64 #include <netgraph/netgraph.h>
  65 #include <netgraph/ng_parse.h>
  66 #include <netgraph/ng_cisco.h>
  67
  68 #define CISCO_MULTICAST         0x8f    /* Cisco multicast address */
  69 #define CISCO_UNICAST           0x0f    /* Cisco unicast address */
  70 #define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
  71 #define CISCO_ADDR_REQ          0       /* Cisco address request */
  72 #define CISCO_ADDR_REPLY        1       /* Cisco address reply */
  73 #define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */
  74
  75 #define KEEPALIVE_SECS          10
  76
  77 struct cisco_header {
  78         u_char  address;
  79         u_char  control;
  80         u_short protocol;
  81 };
  82
  83 #define CISCO_HEADER_LEN        sizeof (struct cisco_header)
  84
  85 struct cisco_packet {
  86         u_long  type;
  87         u_long  par1;
  88         u_long  par2;
  89         u_short rel;
  90         u_short time0;
  91         u_short time1;
  92 };
  93
  94 #define CISCO_PACKET_LEN (sizeof(struct cisco_packet))
  95
  96 struct protoent {
  97         hook_p  hook;           /* the hook for this proto */
  98         u_short af;             /* address family, -1 = downstream */
  99 };
 100
 101 struct cisco_priv {
 102         u_long  local_seq;
 103         u_long  remote_seq;
 104         u_long  seqRetries;     /* how many times we've been here throwing out
 105                                  * the same sequence number without ack */
 106         node_p  node;
 107         struct callout handle;
 108         struct protoent downstream;
 109         struct protoent inet;           /* IP information */
 110         struct in_addr localip;
 111         struct in_addr localmask;
 112         struct protoent inet6;          /* IPv6 information */
 113         struct protoent atalk;          /* AppleTalk information */
 114         struct protoent ipx;            /* IPX information */
 115 };
 116 typedef struct cisco_priv *sc_p;
 117
 118 /* Netgraph methods */
 119 static ng_constructor_t         cisco_constructor;
 120 static ng_rcvmsg_t              cisco_rcvmsg;
 121 static ng_shutdown_t            cisco_shutdown;
 122 static ng_newhook_t             cisco_newhook;
 123 static ng_rcvdata_t             cisco_rcvdata;
 124 static ng_disconnect_t          cisco_disconnect;
 125
 126 /* Other functions */
 127 static int      cisco_input(sc_p sc, item_p item);
 128 static void     cisco_keepalive(node_p node, hook_p hook, void *arg1, int arg2);
 129 static int      cisco_send(sc_p sc, int type, long par1, long par2);
 130 static void     cisco_notify(sc_p sc, uint32_t cmd);
 131
 132 /* Parse type for struct ng_cisco_ipaddr */
 133 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
 134         = NG_CISCO_IPADDR_TYPE_INFO;
 135 static const struct ng_parse_type ng_cisco_ipaddr_type = {
 136         &ng_parse_struct_type,
 137         &ng_cisco_ipaddr_type_fields
 138 };
 139
 140 /* Parse type for struct ng_async_stat */
 141 static const struct ng_parse_struct_field ng_cisco_stats_type_fields[]
 142         = NG_CISCO_STATS_TYPE_INFO;
 143 static const struct ng_parse_type ng_cisco_stats_type = {
 144         &ng_parse_struct_type,
 145         &ng_cisco_stats_type_fields
 146 };
 147
 148 /* List of commands and how to convert arguments to/from ASCII */
 149 static const struct ng_cmdlist ng_cisco_cmdlist[] = {
 150         {
 151           NGM_CISCO_COOKIE,
 152           NGM_CISCO_SET_IPADDR,
 153           "setipaddr",
 154           &ng_cisco_ipaddr_type,
 155           NULL
 156         },
 157         {
 158           NGM_CISCO_COOKIE,
 159           NGM_CISCO_GET_IPADDR,
 160           "getipaddr",
 161           NULL,
 162           &ng_cisco_ipaddr_type
 163         },
 164         {
 165           NGM_CISCO_COOKIE,
 166           NGM_CISCO_GET_STATUS,
 167           "getstats",
 168           NULL,
 169           &ng_cisco_stats_type
 170         },
 171         { 0 }
 172 };
 173
 174 /* Node type */
 175 static struct ng_type typestruct = {
 176         .version =      NG_ABI_VERSION,
 177         .name =         NG_CISCO_NODE_TYPE,
 178         .constructor =  cisco_constructor,
 179         .rcvmsg =       cisco_rcvmsg,
 180         .shutdown =     cisco_shutdown,
 181         .newhook =      cisco_newhook,
 182         .rcvdata =      cisco_rcvdata,
 183         .disconnect =   cisco_disconnect,
 184         .cmdlist =      ng_cisco_cmdlist,
 185 };
 186 NETGRAPH_INIT(cisco, &typestruct);
 187
 188 /*
 189  * Node constructor
 190  */
 191 static int
 192 cisco_constructor(node_p node)
 193 {
 194         sc_p sc;
 195
 196         MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
 197         if (sc == NULL)
 198                 return (ENOMEM);
 199
 200         ng_callout_init(&sc->handle);
 201         NG_NODE_SET_PRIVATE(node, sc);
 202         sc->node = node;
 203
 204         /* Initialise the varous protocol hook holders */
 205         sc->downstream.af = 0xffff;
 206         sc->inet.af = AF_INET;
 207         sc->inet6.af = AF_INET6;
 208         sc->atalk.af = AF_APPLETALK;
 209         sc->ipx.af = AF_IPX;
 210         return (0);
 211 }
 212
 213 /*
 214  * Check new hook
 215  */
 216 static int
 217 cisco_newhook(node_p node, hook_p hook, const char *name)
 218 {
 219         const sc_p sc = NG_NODE_PRIVATE(node);
 220
 221         if (strcmp(name, NG_CISCO_HOOK_DOWNSTREAM) == 0) {
 222                 sc->downstream.hook = hook;
 223                 NG_HOOK_SET_PRIVATE(hook, &sc->downstream);
 224
 225                 /* Start keepalives */
 226                 ng_callout(&sc->handle, node, NULL, (hz * KEEPALIVE_SECS),
 227                     &cisco_keepalive, (void *)sc, 0);
 228         } else if (strcmp(name, NG_CISCO_HOOK_INET) == 0) {
 229                 sc->inet.hook = hook;
 230                 NG_HOOK_SET_PRIVATE(hook, &sc->inet);
 231         } else if (strcmp(name, NG_CISCO_HOOK_APPLETALK) == 0) {
 232                 sc->atalk.hook = hook;
 233                 NG_HOOK_SET_PRIVATE(hook, &sc->atalk);
 234         } else if (strcmp(name, NG_CISCO_HOOK_IPX) == 0) {
 235                 sc->ipx.hook = hook;
 236                 NG_HOOK_SET_PRIVATE(hook, &sc->ipx);
 237         } else if (strcmp(name, NG_CISCO_HOOK_DEBUG) == 0) {
 238                 NG_HOOK_SET_PRIVATE(hook, NULL);        /* unimplemented */
 239         } else
 240                 return (EINVAL);
 241         return 0;
 242 }
 243
 244 /*
 245  * Receive control message.
 246  */
 247 static int
 248 cisco_rcvmsg(node_p node, item_p item, hook_p lasthook)
 249 {
 250         struct ng_mesg *msg;
 251         const sc_p sc = NG_NODE_PRIVATE(node);
 252         struct ng_mesg *resp = NULL;
 253         int error = 0;
 254
 255         NGI_GET_MSG(item, msg);
 256         switch (msg->header.typecookie) {
 257         case NGM_GENERIC_COOKIE:
 258                 switch (msg->header.cmd) {
 259                 case NGM_TEXT_STATUS:
 260                     {
 261                         char *arg;
 262                         int pos;
 263
 264                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
 265                         if (resp == NULL) {
 266                                 error = ENOMEM;
 267                                 break;
 268                         }
 269                         arg = (char *) resp->data;
 270                         pos = sprintf(arg,
 271                           "keepalive period: %d sec; ", KEEPALIVE_SECS);
 272                         pos += sprintf(arg + pos,
 273                           "unacknowledged keepalives: %ld", sc->seqRetries);
 274                         resp->header.arglen = pos + 1;
 275                         break;
 276                     }
 277                 default:
 278                         error = EINVAL;
 279                         break;
 280                 }
 281                 break;
 282         case NGM_CISCO_COOKIE:
 283                 switch (msg->header.cmd) {
 284                 case NGM_CISCO_GET_IPADDR:      /* could be a late reply! */
 285                         if ((msg->header.flags & NGF_RESP) == 0) {
 286                                 struct in_addr *ips;
 287
 288                                 NG_MKRESPONSE(resp, msg,
 289                                     2 * sizeof(*ips), M_NOWAIT);
 290                                 if (!resp) {
 291                                         error = ENOMEM;
 292                                         break;
 293                                 }
 294                                 ips = (struct in_addr *) resp->data;
 295                                 ips[0] = sc->localip;
 296                                 ips[1] = sc->localmask;
 297                                 break;
 298                         }
 299                         /* FALLTHROUGH */       /* ...if it's a reply */
 300                 case NGM_CISCO_SET_IPADDR:
 301                     {
 302                         struct in_addr *const ips = (struct in_addr *)msg->data;
 303
 304                         if (msg->header.arglen < 2 * sizeof(*ips)) {
 305                                 error = EINVAL;
 306                                 break;
 307                         }
 308                         sc->localip = ips[0];
 309                         sc->localmask = ips[1];
 310                         break;
 311                     }
 312                 case NGM_CISCO_GET_STATUS:
 313                     {
 314                         struct ng_cisco_stats *stat;
 315
 316                         NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
 317                         if (!resp) {
 318                                 error = ENOMEM;
 319                                 break;
 320                         }
 321                         stat = (struct ng_cisco_stats *)resp->data;
 322                         stat->seqRetries = sc->seqRetries;
 323                         stat->keepAlivePeriod = KEEPALIVE_SECS;
 324                         break;
 325                     }
 326                 default:
 327                         error = EINVAL;
 328                         break;
 329                 }
 330                 break;
 331         default:
 332                 error = EINVAL;
 333                 break;
 334         }
 335         NG_RESPOND_MSG(error, node, item, resp);
 336         NG_FREE_MSG(msg);
 337         return (error);
 338 }
 339
 340 /*
 341  * Receive data
 342  */
 343 static int
 344 cisco_rcvdata(hook_p hook, item_p item)
 345 {
 346         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 347         struct protoent *pep;
 348         struct cisco_header *h;
 349         struct mbuf *m;
 350         int error = 0;
 351
 352         if ((pep = NG_HOOK_PRIVATE(hook)) == NULL)
 353                 goto out;
 354
 355         /* If it came from our downlink, deal with it separately */
 356         if (pep->af == 0xffff)
 357                 return (cisco_input(sc, item));
 358
 359         /* OK so it came from a protocol, heading out. Prepend general data
 360            packet header. For now, IP,IPX only  */
 361         m = NGI_M(item); /* still associated with item */
 362         M_PREPEND(m, CISCO_HEADER_LEN, M_DONTWAIT);
 363         if (!m) {
 364                 error = ENOBUFS;
 365                 goto out;
 366         }
 367         h = mtod(m, struct cisco_header *);
 368         h->address = CISCO_UNICAST;
 369         h->control = 0;
 370
 371         switch (pep->af) {
 372         case AF_INET:           /* Internet Protocol */
 373                 h->protocol = htons(ETHERTYPE_IP);
 374                 break;
 375         case AF_INET6:
 376                 h->protocol = htons(ETHERTYPE_IPV6);
 377                 break;
 378         case AF_APPLETALK:      /* AppleTalk Protocol */
 379                 h->protocol = htons(ETHERTYPE_AT);
 380                 break;
 381         case AF_IPX:            /* Novell IPX Protocol */
 382                 h->protocol = htons(ETHERTYPE_IPX);
 383                 break;
 384         default:
 385                 error = EAFNOSUPPORT;
 386                 goto out;
 387         }
 388
 389         /* Send it */
 390         NG_FWD_NEW_DATA(error, item,  sc->downstream.hook, m);
 391         return (error);
 392
 393 out:
 394         NG_FREE_ITEM(item);
 395         return (error);
 396 }
 397
 398 /*
 399  * Shutdown node
 400  */
 401 static int
 402 cisco_shutdown(node_p node)
 403 {
 404         const sc_p sc = NG_NODE_PRIVATE(node);
 405
 406         NG_NODE_SET_PRIVATE(node, NULL);
 407         NG_NODE_UNREF(sc->node);
 408         FREE(sc, M_NETGRAPH);
 409         return (0);
 410 }
 411
 412 /*
 413  * Disconnection of a hook
 414  *
 415  * For this type, removal of the last link destroys the node
 416  */
 417 static int
 418 cisco_disconnect(hook_p hook)
 419 {
 420         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 421         struct protoent *pep;
 422
 423         /* Check it's not the debug hook */
 424         if ((pep = NG_HOOK_PRIVATE(hook))) {
 425                 pep->hook = NULL;
 426                 if (pep->af == 0xffff)
 427                         /* If it is the downstream hook, stop the timers */
 428                         ng_uncallout(&sc->handle, NG_HOOK_NODE(hook));
 429         }
 430
 431         /* If no more hooks, remove the node */
 432         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 433         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 434                 ng_rmnode_self(NG_HOOK_NODE(hook));
 435         return (0);
 436 }
 437
 438 /*
 439  * Receive data
 440  */
 441 static int
 442 cisco_input(sc_p sc, item_p item)
 443 {
 444         const struct cisco_header *h;
 445         struct cisco_header hdrbuf;
 446         struct protoent *pep;
 447         struct mbuf *m;
 448         int error = 0;
 449
 450         /* Get data */
 451         m = NGI_M(item);
 452
 453         /* Sanity check header length */
 454         if (m->m_pkthdr.len < sizeof(*h)) {
 455                 error = EINVAL;
 456                 goto drop;
 457         }
 458
 459         /* Get cisco header */
 460         if (m->m_len >= sizeof(*h))                     /* the common case */
 461                 h = mtod(m, const struct cisco_header *);
 462         else {
 463                 m_copydata(m, 0, sizeof(*h), (caddr_t)&hdrbuf);
 464                 h = &hdrbuf;
 465         }
 466         m_adj(m, sizeof(*h));
 467
 468         /* Check header address */
 469         switch (h->address) {
 470         default:                /* Invalid Cisco packet. */
 471                 goto drop;
 472         case CISCO_UNICAST:
 473         case CISCO_MULTICAST:
 474                 /* Don't check the control field here (RFC 1547). */
 475                 switch (ntohs(h->protocol)) {
 476                 default:
 477                         goto drop;
 478                 case CISCO_KEEPALIVE:
 479                     {
 480                         const struct cisco_packet *p;
 481                         struct cisco_packet pktbuf;
 482
 483                         /* Sanity check packet length */
 484                         if (m->m_pkthdr.len < sizeof(*p)) {
 485                                 error = EINVAL;
 486                                 goto drop;
 487                         }
 488
 489                         /* Get cisco packet */
 490                         if (m->m_len >= sizeof(*p))     /* the common case */
 491                                 p = mtod(m, const struct cisco_packet *);
 492                         else {
 493                                 m_copydata(m, 0, sizeof(*p), (caddr_t)&pktbuf);
 494                                 p = &pktbuf;
 495                         }
 496
 497                         /* Check packet type */
 498                         switch (ntohl(p->type)) {
 499                         default:
 500                                 log(LOG_WARNING,
 501                                     "cisco: unknown cisco packet type: 0x%lx\n",
 502                                        (long)ntohl(p->type));
 503                                 break;
 504                         case CISCO_ADDR_REPLY:
 505                                 /* Reply on address request, ignore */
 506                                 break;
 507                         case CISCO_KEEPALIVE_REQ:
 508                                 sc->remote_seq = ntohl(p->par1);
 509                                 if (sc->local_seq == ntohl(p->par2)) {
 510                                         sc->local_seq++;
 511                                         if (sc->seqRetries > 1)
 512                                                 cisco_notify(sc, NGM_LINK_IS_UP);
 513                                         sc->seqRetries = 0;
 514                                 }
 515                                 break;
 516                         case CISCO_ADDR_REQ:
 517                             {
 518                                 struct ng_mesg *msg;
 519                                 int dummy_error = 0;
 520
 521                                 /* Ask inet peer for IP address information */
 522                                 if (sc->inet.hook == NULL)
 523                                         goto nomsg;
 524                                 NG_MKMESSAGE(msg, NGM_CISCO_COOKIE,
 525                                     NGM_CISCO_GET_IPADDR, 0, M_NOWAIT);
 526                                 if (msg == NULL)
 527                                         goto nomsg;
 528                                 NG_SEND_MSG_HOOK(dummy_error,
 529                                     sc->node, msg, sc->inet.hook, 0);
 530                 /*
 531                  * XXX Now maybe we should set a flag telling
 532                  * our receiver to send this message when the response comes in
 533                  * instead of now when the data may be bad.
 534                  */
 535                 nomsg:
 536                                 /* Send reply to peer device */
 537                                 error = cisco_send(sc, CISCO_ADDR_REPLY,
 538                                             ntohl(sc->localip.s_addr),
 539                                             ntohl(sc->localmask.s_addr));
 540                                 break;
 541                             }
 542                         }
 543                         goto drop;
 544                     }
 545                 case ETHERTYPE_IP:
 546                         pep = &sc->inet;
 547                         break;
 548                 case ETHERTYPE_IPV6:
 549                         pep = &sc->inet6;
 550                         break;
 551                 case ETHERTYPE_AT:
 552                         pep = &sc->atalk;
 553                         break;
 554                 case ETHERTYPE_IPX:
 555                         pep = &sc->ipx;
 556                         break;
 557                 }
 558                 break;
 559         }
 560
 561         /* Drop if payload is empty */
 562         if (m->m_pkthdr.len == 0) {
 563                 error = EINVAL;
 564                 goto drop;
 565         }
 566
 567         /* Send it on */
 568         if (pep->hook == NULL)
 569                 goto drop;
 570         NG_FWD_NEW_DATA(error, item, pep->hook, m);
 571         return (error);
 572
 573 drop:
 574         NG_FREE_ITEM(item);
 575         return (error);
 576 }
 577
 578
 579 /*
 580  * Send keepalive packets, every 10 seconds.
 581  */
 582 static void
 583 cisco_keepalive(node_p node, hook_p hook, void *arg1, int arg2)
 584 {
 585         const sc_p sc = arg1;
 586
 587         cisco_send(sc, CISCO_KEEPALIVE_REQ, sc->local_seq, sc->remote_seq);
 588         if (sc->seqRetries++ > 1)
 589                 cisco_notify(sc, NGM_LINK_IS_DOWN);
 590         ng_callout(&sc->handle, node, NULL, (hz * KEEPALIVE_SECS),
 591             &cisco_keepalive, (void *)sc, 0);
 592 }
 593
 594 /*
 595  * Send Cisco keepalive packet.
 596  */
 597 static int
 598 cisco_send(sc_p sc, int type, long par1, long par2)
 599 {
 600         struct cisco_header *h;
 601         struct cisco_packet *ch;
 602         struct mbuf *m;
 603         struct timeval time;
 604         u_long  t;
 605         int     error = 0;
 606
 607         getmicrouptime(&time);
 608
 609         MGETHDR(m, M_DONTWAIT, MT_DATA);
 610         if (!m)
 611                 return (ENOBUFS);
 612
 613         t = time.tv_sec * 1000 + time.tv_usec / 1000;
 614         m->m_pkthdr.len = m->m_len = CISCO_HEADER_LEN + CISCO_PACKET_LEN;
 615         m->m_pkthdr.rcvif = 0;
 616
 617         h = mtod(m, struct cisco_header *);
 618         h->address = CISCO_MULTICAST;
 619         h->control = 0;
 620         h->protocol = htons(CISCO_KEEPALIVE);
 621
 622         ch = (struct cisco_packet *) (h + 1);
 623         ch->type = htonl(type);
 624         ch->par1 = htonl(par1);
 625         ch->par2 = htonl(par2);
 626         ch->rel = -1;
 627         ch->time0 = htons((u_short) (t >> 16));
 628         ch->time1 = htons((u_short) t);
 629
 630         NG_SEND_DATA_ONLY(error, sc->downstream.hook, m);
 631         return (error);
 632 }
 633
 634 /*
 635  * Send linkstate to upstream node.
 636  */
 637 static void
 638 cisco_notify(sc_p sc, uint32_t cmd)
 639 {
 640         struct ng_mesg *msg;
 641         int dummy_error = 0;
 642
 643         if (sc->inet.hook == NULL) /* nothing to notify */
 644                 return;
 645
 646         NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_NOWAIT);
 647         if (msg != NULL)
 648                 NG_SEND_MSG_HOOK(dummy_error, sc->node, msg, sc->inet.hook, 0);
 649 }