sys/netgraph7/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: src/sys/netgraph/ng_cisco.c,v 1.29 2007/11/30 23:27:39 julian Exp $
  41  * $DragonFly: src/sys/netgraph7/ng_cisco.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  42  * $Whistle: ng_cisco.c,v 1.25 1999/11/01 09:24:51 julian Exp $
  43  */
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/errno.h>
  48 #include <sys/kernel.h>
  49 #include <sys/socket.h>
  50 #include <sys/malloc.h>
  51 #include <sys/mbuf.h>
  52 #include <sys/syslog.h>
  53
  54 #include <net/if.h>
  55
  56 #include <netinet/in.h>
  57 #include <netinet/if_ether.h>
  58
  59 #include <netatalk/at.h>
  60
  61 #include <netipx/ipx.h>
  62 #include <netipx/ipx_if.h>
  63
  64 #include "ng_message.h"
  65 #include "netgraph.h"
  66 #include "ng_parse.h"
  67 #include "ng_cisco.h"
  68
  69 #define CISCO_MULTICAST         0x8f    /* Cisco multicast address */
  70 #define CISCO_UNICAST           0x0f    /* Cisco unicast address */
  71 #define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
  72 #define CISCO_ADDR_REQ          0       /* Cisco address request */
  73 #define CISCO_ADDR_REPLY        1       /* Cisco address reply */
  74 #define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */
  75
  76 #define KEEPALIVE_SECS          10
  77
  78 struct cisco_header {
  79         u_char  address;
  80         u_char  control;
  81         u_short protocol;
  82 };
  83
  84 #define CISCO_HEADER_LEN        sizeof (struct cisco_header)
  85
  86 struct cisco_packet {
  87         u_long  type;
  88         u_long  par1;
  89         u_long  par2;
  90         u_short rel;
  91         u_short time0;
  92         u_short time1;
  93 };
  94
  95 #define CISCO_PACKET_LEN (sizeof(struct cisco_packet))
  96
  97 struct protoent {
  98         hook_p  hook;           /* the hook for this proto */
  99         u_short af;             /* address family, -1 = downstream */
 100 };
 101
 102 struct cisco_priv {
 103         u_long  local_seq;
 104         u_long  remote_seq;
 105         u_long  seqRetries;     /* how many times we've been here throwing out
 106                                  * the same sequence number without ack */
 107         node_p  node;
 108         struct callout handle;
 109         struct protoent downstream;
 110         struct protoent inet;           /* IP information */
 111         struct in_addr localip;
 112         struct in_addr localmask;
 113         struct protoent inet6;          /* IPv6 information */
 114         struct protoent atalk;          /* AppleTalk information */
 115         struct protoent ipx;            /* IPX information */
 116 };
 117 typedef struct cisco_priv *sc_p;
 118
 119 /* Netgraph methods */
 120 static ng_constructor_t         cisco_constructor;
 121 static ng_rcvmsg_t              cisco_rcvmsg;
 122 static ng_shutdown_t            cisco_shutdown;
 123 static ng_newhook_t             cisco_newhook;
 124 static ng_rcvdata_t             cisco_rcvdata;
 125 static ng_disconnect_t          cisco_disconnect;
 126
 127 /* Other functions */
 128 static int      cisco_input(sc_p sc, item_p item);
 129 static void     cisco_keepalive(node_p node, hook_p hook, void *arg1, int arg2);
 130 static int      cisco_send(sc_p sc, int type, long par1, long par2);
 131 static void     cisco_notify(sc_p sc, uint32_t cmd);
 132
 133 /* Parse type for struct ng_cisco_ipaddr */
 134 static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
 135         = NG_CISCO_IPADDR_TYPE_INFO;
 136 static const struct ng_parse_type ng_cisco_ipaddr_type = {
 137         &ng_parse_struct_type,
 138         &ng_cisco_ipaddr_type_fields
 139 };
 140
 141 /* Parse type for struct ng_async_stat */
 142 static const struct ng_parse_struct_field ng_cisco_stats_type_fields[]
 143         = NG_CISCO_STATS_TYPE_INFO;
 144 static const struct ng_parse_type ng_cisco_stats_type = {
 145         &ng_parse_struct_type,
 146         &ng_cisco_stats_type_fields
 147 };
 148
 149 /* List of commands and how to convert arguments to/from ASCII */
 150 static const struct ng_cmdlist ng_cisco_cmdlist[] = {
 151         {
 152           NGM_CISCO_COOKIE,
 153           NGM_CISCO_SET_IPADDR,
 154           "setipaddr",
 155           &ng_cisco_ipaddr_type,
 156           NULL
 157         },
 158         {
 159           NGM_CISCO_COOKIE,
 160           NGM_CISCO_GET_IPADDR,
 161           "getipaddr",
 162           NULL,
 163           &ng_cisco_ipaddr_type
 164         },
 165         {
 166           NGM_CISCO_COOKIE,
 167           NGM_CISCO_GET_STATUS,
 168           "getstats",
 169           NULL,
 170           &ng_cisco_stats_type
 171         },
 172         { 0 }
 173 };
 174
 175 /* Node type */
 176 static struct ng_type typestruct = {
 177         .version =      NG_ABI_VERSION,
 178         .name =         NG_CISCO_NODE_TYPE,
 179         .constructor =  cisco_constructor,
 180         .rcvmsg =       cisco_rcvmsg,
 181         .shutdown =     cisco_shutdown,
 182         .newhook =      cisco_newhook,
 183         .rcvdata =      cisco_rcvdata,
 184         .disconnect =   cisco_disconnect,
 185         .cmdlist =      ng_cisco_cmdlist,
 186 };
 187 NETGRAPH_INIT(cisco, &typestruct);
 188
 189 /*
 190  * Node constructor
 191  */
 192 static int
 193 cisco_constructor(node_p node)
 194 {
 195         sc_p sc;
 196
 197         MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO);
 198         if (sc == NULL)
 199                 return (ENOMEM);
 200
 201         ng_callout_init(&sc->handle);
 202         NG_NODE_SET_PRIVATE(node, sc);
 203         sc->node = node;
 204
 205         /* Initialise the varous protocol hook holders */
 206         sc->downstream.af = 0xffff;
 207         sc->inet.af = AF_INET;
 208         sc->inet6.af = AF_INET6;
 209         sc->atalk.af = AF_APPLETALK;
 210         sc->ipx.af = AF_IPX;
 211         return (0);
 212 }
 213
 214 /*
 215  * Check new hook
 216  */
 217 static int
 218 cisco_newhook(node_p node, hook_p hook, const char *name)
 219 {
 220         const sc_p sc = NG_NODE_PRIVATE(node);
 221
 222         if (strcmp(name, NG_CISCO_HOOK_DOWNSTREAM) == 0) {
 223                 sc->downstream.hook = hook;
 224                 NG_HOOK_SET_PRIVATE(hook, &sc->downstream);
 225
 226                 /* Start keepalives */
 227                 ng_callout(&sc->handle, node, NULL, (hz * KEEPALIVE_SECS),
 228                     &cisco_keepalive, (void *)sc, 0);
 229         } else if (strcmp(name, NG_CISCO_HOOK_INET) == 0) {
 230                 sc->inet.hook = hook;
 231                 NG_HOOK_SET_PRIVATE(hook, &sc->inet);
 232         } else if (strcmp(name, NG_CISCO_HOOK_INET6) == 0) {
 233                 sc->inet6.hook = hook;
 234                 NG_HOOK_SET_PRIVATE(hook, &sc->inet6);
 235         } else if (strcmp(name, NG_CISCO_HOOK_APPLETALK) == 0) {
 236                 sc->atalk.hook = hook;
 237                 NG_HOOK_SET_PRIVATE(hook, &sc->atalk);
 238         } else if (strcmp(name, NG_CISCO_HOOK_IPX) == 0) {
 239                 sc->ipx.hook = hook;
 240                 NG_HOOK_SET_PRIVATE(hook, &sc->ipx);
 241         } else if (strcmp(name, NG_CISCO_HOOK_DEBUG) == 0) {
 242                 NG_HOOK_SET_PRIVATE(hook, NULL);        /* unimplemented */
 243         } else
 244                 return (EINVAL);
 245         return 0;
 246 }
 247
 248 /*
 249  * Receive control message.
 250  */
 251 static int
 252 cisco_rcvmsg(node_p node, item_p item, hook_p lasthook)
 253 {
 254         struct ng_mesg *msg;
 255         const sc_p sc = NG_NODE_PRIVATE(node);
 256         struct ng_mesg *resp = NULL;
 257         int error = 0;
 258
 259         NGI_GET_MSG(item, msg);
 260         switch (msg->header.typecookie) {
 261         case NGM_GENERIC_COOKIE:
 262                 switch (msg->header.cmd) {
 263                 case NGM_TEXT_STATUS:
 264                     {
 265                         char *arg;
 266                         int pos;
 267
 268                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_WAITOK | M_NULLOK);
 269                         if (resp == NULL) {
 270                                 error = ENOMEM;
 271                                 break;
 272                         }
 273                         arg = (char *) resp->data;
 274                         pos = sprintf(arg,
 275                           "keepalive period: %d sec; ", KEEPALIVE_SECS);
 276                         pos += sprintf(arg + pos,
 277                           "unacknowledged keepalives: %ld", sc->seqRetries);
 278                         resp->header.arglen = pos + 1;
 279                         break;
 280                     }
 281                 default:
 282                         error = EINVAL;
 283                         break;
 284                 }
 285                 break;
 286         case NGM_CISCO_COOKIE:
 287                 switch (msg->header.cmd) {
 288                 case NGM_CISCO_GET_IPADDR:      /* could be a late reply! */
 289                         if ((msg->header.flags & NGF_RESP) == 0) {
 290                                 struct in_addr *ips;
 291
 292                                 NG_MKRESPONSE(resp, msg,
 293                                     2 * sizeof(*ips), M_WAITOK | M_NULLOK);
 294                                 if (!resp) {
 295                                         error = ENOMEM;
 296                                         break;
 297                                 }
 298                                 ips = (struct in_addr *) resp->data;
 299                                 ips[0] = sc->localip;
 300                                 ips[1] = sc->localmask;
 301                                 break;
 302                         }
 303                         /* FALLTHROUGH */       /* ...if it's a reply */
 304                 case NGM_CISCO_SET_IPADDR:
 305                     {
 306                         struct in_addr *const ips = (struct in_addr *)msg->data;
 307
 308                         if (msg->header.arglen < 2 * sizeof(*ips)) {
 309                                 error = EINVAL;
 310                                 break;
 311                         }
 312                         sc->localip = ips[0];
 313                         sc->localmask = ips[1];
 314                         break;
 315                     }
 316                 case NGM_CISCO_GET_STATUS:
 317                     {
 318                         struct ng_cisco_stats *stat;
 319
 320                         NG_MKRESPONSE(resp, msg, sizeof(*stat), M_WAITOK | M_NULLOK);
 321                         if (!resp) {
 322                                 error = ENOMEM;
 323                                 break;
 324                         }
 325                         stat = (struct ng_cisco_stats *)resp->data;
 326                         stat->seqRetries = sc->seqRetries;
 327                         stat->keepAlivePeriod = KEEPALIVE_SECS;
 328                         break;
 329                     }
 330                 default:
 331                         error = EINVAL;
 332                         break;
 333                 }
 334                 break;
 335         default:
 336                 error = EINVAL;
 337                 break;
 338         }
 339         NG_RESPOND_MSG(error, node, item, resp);
 340         NG_FREE_MSG(msg);
 341         return (error);
 342 }
 343
 344 /*
 345  * Receive data
 346  */
 347 static int
 348 cisco_rcvdata(hook_p hook, item_p item)
 349 {
 350         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 351         struct protoent *pep;
 352         struct cisco_header *h;
 353         struct mbuf *m;
 354         int error = 0;
 355
 356         if ((pep = NG_HOOK_PRIVATE(hook)) == NULL)
 357                 goto out;
 358
 359         /* If it came from our downlink, deal with it separately */
 360         if (pep->af == 0xffff)
 361                 return (cisco_input(sc, item));
 362
 363         /* OK so it came from a protocol, heading out. Prepend general data
 364            packet header. For now, IP,IPX only  */
 365         m = NGI_M(item); /* still associated with item */
 366         M_PREPEND(m, CISCO_HEADER_LEN, MB_DONTWAIT);
 367         if (!m) {
 368                 error = ENOBUFS;
 369                 goto out;
 370         }
 371         h = mtod(m, struct cisco_header *);
 372         h->address = CISCO_UNICAST;
 373         h->control = 0;
 374
 375         switch (pep->af) {
 376         case AF_INET:           /* Internet Protocol */
 377                 h->protocol = htons(ETHERTYPE_IP);
 378                 break;
 379         case AF_INET6:
 380                 h->protocol = htons(ETHERTYPE_IPV6);
 381                 break;
 382         case AF_APPLETALK:      /* AppleTalk Protocol */
 383                 h->protocol = htons(ETHERTYPE_AT);
 384                 break;
 385         case AF_IPX:            /* Novell IPX Protocol */
 386                 h->protocol = htons(ETHERTYPE_IPX);
 387                 break;
 388         default:
 389                 error = EAFNOSUPPORT;
 390                 goto out;
 391         }
 392
 393         /* Send it */
 394         NG_FWD_NEW_DATA(error, item,  sc->downstream.hook, m);
 395         return (error);
 396
 397 out:
 398         NG_FREE_ITEM(item);
 399         return (error);
 400 }
 401
 402 /*
 403  * Shutdown node
 404  */
 405 static int
 406 cisco_shutdown(node_p node)
 407 {
 408         const sc_p sc = NG_NODE_PRIVATE(node);
 409
 410         NG_NODE_SET_PRIVATE(node, NULL);
 411         NG_NODE_UNREF(sc->node);
 412         FREE(sc, M_NETGRAPH);
 413         return (0);
 414 }
 415
 416 /*
 417  * Disconnection of a hook
 418  *
 419  * For this type, removal of the last link destroys the node
 420  */
 421 static int
 422 cisco_disconnect(hook_p hook)
 423 {
 424         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 425         struct protoent *pep;
 426
 427         /* Check it's not the debug hook */
 428         if ((pep = NG_HOOK_PRIVATE(hook))) {
 429                 pep->hook = NULL;
 430                 if (pep->af == 0xffff)
 431                         /* If it is the downstream hook, stop the timers */
 432                         ng_uncallout(&sc->handle, NG_HOOK_NODE(hook));
 433         }
 434
 435         /* If no more hooks, remove the node */
 436         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 437         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 438                 ng_rmnode_self(NG_HOOK_NODE(hook));
 439         return (0);
 440 }
 441
 442 /*
 443  * Receive data
 444  */
 445 static int
 446 cisco_input(sc_p sc, item_p item)
 447 {
 448         const struct cisco_header *h;
 449         struct cisco_header hdrbuf;
 450         struct protoent *pep;
 451         struct mbuf *m;
 452         int error = 0;
 453
 454         /* Get data */
 455         m = NGI_M(item);
 456
 457         /* Sanity check header length */
 458         if (m->m_pkthdr.len < sizeof(*h)) {
 459                 error = EINVAL;
 460                 goto drop;
 461         }
 462
 463         /* Get cisco header */
 464         if (m->m_len >= sizeof(*h))                     /* the common case */
 465                 h = mtod(m, const struct cisco_header *);
 466         else {
 467                 m_copydata(m, 0, sizeof(*h), (caddr_t)&hdrbuf);
 468                 h = &hdrbuf;
 469         }
 470         m_adj(m, sizeof(*h));
 471
 472         /* Check header address */
 473         switch (h->address) {
 474         default:                /* Invalid Cisco packet. */
 475                 goto drop;
 476         case CISCO_UNICAST:
 477         case CISCO_MULTICAST:
 478                 /* Don't check the control field here (RFC 1547). */
 479                 switch (ntohs(h->protocol)) {
 480                 default:
 481                         goto drop;
 482                 case CISCO_KEEPALIVE:
 483                     {
 484                         const struct cisco_packet *p;
 485                         struct cisco_packet pktbuf;
 486
 487                         /* Sanity check packet length */
 488                         if (m->m_pkthdr.len < sizeof(*p)) {
 489                                 error = EINVAL;
 490                                 goto drop;
 491                         }
 492
 493                         /* Get cisco packet */
 494                         if (m->m_len >= sizeof(*p))     /* the common case */
 495                                 p = mtod(m, const struct cisco_packet *);
 496                         else {
 497                                 m_copydata(m, 0, sizeof(*p), (caddr_t)&pktbuf);
 498                                 p = &pktbuf;
 499                         }
 500
 501                         /* Check packet type */
 502                         switch (ntohl(p->type)) {
 503                         default:
 504                                 log(LOG_WARNING,
 505                                     "cisco: unknown cisco packet type: 0x%lx\n",
 506                                        (long)ntohl(p->type));
 507                                 break;
 508                         case CISCO_ADDR_REPLY:
 509                                 /* Reply on address request, ignore */
 510                                 break;
 511                         case CISCO_KEEPALIVE_REQ:
 512                                 sc->remote_seq = ntohl(p->par1);
 513                                 if (sc->local_seq == ntohl(p->par2)) {
 514                                         sc->local_seq++;
 515                                         if (sc->seqRetries > 1)
 516                                                 cisco_notify(sc, NGM_LINK_IS_UP);
 517                                         sc->seqRetries = 0;
 518                                 }
 519                                 break;
 520                         case CISCO_ADDR_REQ:
 521                             {
 522                                 struct ng_mesg *msg;
 523                                 int dummy_error = 0;
 524
 525                                 /* Ask inet peer for IP address information */
 526                                 if (sc->inet.hook == NULL)
 527                                         goto nomsg;
 528                                 NG_MKMESSAGE(msg, NGM_CISCO_COOKIE,
 529                                     NGM_CISCO_GET_IPADDR, 0, M_WAITOK | M_NULLOK);
 530                                 if (msg == NULL)
 531                                         goto nomsg;
 532                                 NG_SEND_MSG_HOOK(dummy_error,
 533                                     sc->node, msg, sc->inet.hook, 0);
 534                 /*
 535                  * XXX Now maybe we should set a flag telling
 536                  * our receiver to send this message when the response comes in
 537                  * instead of now when the data may be bad.
 538                  */
 539                 nomsg:
 540                                 /* Send reply to peer device */
 541                                 error = cisco_send(sc, CISCO_ADDR_REPLY,
 542                                             ntohl(sc->localip.s_addr),
 543                                             ntohl(sc->localmask.s_addr));
 544                                 break;
 545                             }
 546                         }
 547                         goto drop;
 548                     }
 549                 case ETHERTYPE_IP:
 550                         pep = &sc->inet;
 551                         break;
 552                 case ETHERTYPE_IPV6:
 553                         pep = &sc->inet6;
 554                         break;
 555                 case ETHERTYPE_AT:
 556                         pep = &sc->atalk;
 557                         break;
 558                 case ETHERTYPE_IPX:
 559                         pep = &sc->ipx;
 560                         break;
 561                 }
 562                 break;
 563         }
 564
 565         /* Drop if payload is empty */
 566         if (m->m_pkthdr.len == 0) {
 567                 error = EINVAL;
 568                 goto drop;
 569         }
 570
 571         /* Send it on */
 572         if (pep->hook == NULL)
 573                 goto drop;
 574         NG_FWD_NEW_DATA(error, item, pep->hook, m);
 575         return (error);
 576
 577 drop:
 578         NG_FREE_ITEM(item);
 579         return (error);
 580 }
 581
 582
 583 /*
 584  * Send keepalive packets, every 10 seconds.
 585  */
 586 static void
 587 cisco_keepalive(node_p node, hook_p hook, void *arg1, int arg2)
 588 {
 589         const sc_p sc = arg1;
 590
 591         cisco_send(sc, CISCO_KEEPALIVE_REQ, sc->local_seq, sc->remote_seq);
 592         if (sc->seqRetries++ > 1)
 593                 cisco_notify(sc, NGM_LINK_IS_DOWN);
 594         ng_callout(&sc->handle, node, NULL, (hz * KEEPALIVE_SECS),
 595             &cisco_keepalive, (void *)sc, 0);
 596 }
 597
 598 /*
 599  * Send Cisco keepalive packet.
 600  */
 601 static int
 602 cisco_send(sc_p sc, int type, long par1, long par2)
 603 {
 604         struct cisco_header *h;
 605         struct cisco_packet *ch;
 606         struct mbuf *m;
 607         struct timeval time;
 608         u_long  t;
 609         int     error = 0;
 610
 611         getmicrouptime(&time);
 612
 613         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 614         if (!m)
 615                 return (ENOBUFS);
 616
 617         t = time.tv_sec * 1000 + time.tv_usec / 1000;
 618         m->m_pkthdr.len = m->m_len = CISCO_HEADER_LEN + CISCO_PACKET_LEN;
 619         m->m_pkthdr.rcvif = 0;
 620
 621         h = mtod(m, struct cisco_header *);
 622         h->address = CISCO_MULTICAST;
 623         h->control = 0;
 624         h->protocol = htons(CISCO_KEEPALIVE);
 625
 626         ch = (struct cisco_packet *) (h + 1);
 627         ch->type = htonl(type);
 628         ch->par1 = htonl(par1);
 629         ch->par2 = htonl(par2);
 630         ch->rel = -1;
 631         ch->time0 = htons((u_short) (t >> 16));
 632         ch->time1 = htons((u_short) t);
 633
 634         NG_SEND_DATA_ONLY(error, sc->downstream.hook, m);
 635         return (error);
 636 }
 637
 638 /*
 639  * Send linkstate to upstream node.
 640  */
 641 static void
 642 cisco_notify(sc_p sc, uint32_t cmd)
 643 {
 644         struct ng_mesg *msg;
 645         int dummy_error = 0;
 646
 647         if (sc->inet.hook == NULL) /* nothing to notify */
 648                 return;
 649
 650         NG_MKMESSAGE(msg, NGM_FLOW_COOKIE, cmd, 0, M_WAITOK | M_NULLOK);
 651         if (msg != NULL)
 652                 NG_SEND_MSG_HOOK(dummy_error, sc->node, msg, sc->inet.hook, 0);
 653 }