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