sys/netgraph/ng_iface.c

   1 /*
   2  * ng_iface.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: Archie Cobbs <archie@freebsd.org>
  39  *
  40  * $FreeBSD$
  41  * $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 /*
  45  * This node is also a system networking interface. It has
  46  * a hook for each protocol (IP, AppleTalk, etc). Packets
  47  * are simply relayed between the interface and the hooks.
  48  *
  49  * Interfaces are named ng0, ng1, etc.  New nodes take the
  50  * first available interface name.
  51  *
  52  * This node also includes Berkeley packet filter support.
  53  */
  54
  55 #include "opt_inet.h"
  56 #include "opt_inet6.h"
  57
  58 #include <sys/param.h>
  59 #include <sys/systm.h>
  60 #include <sys/errno.h>
  61 #include <sys/kernel.h>
  62 #include <sys/lock.h>
  63 #include <sys/malloc.h>
  64 #include <sys/mbuf.h>
  65 #include <sys/errno.h>
  66 #include <sys/proc.h>
  67 #include <sys/random.h>
  68 #include <sys/rmlock.h>
  69 #include <sys/sockio.h>
  70 #include <sys/socket.h>
  71 #include <sys/sysctl.h>
  72 #include <sys/syslog.h>
  73 #include <sys/libkern.h>
  74
  75 #include <net/if.h>
  76 #include <net/if_var.h>
  77 #include <net/if_types.h>
  78 #include <net/bpf.h>
  79 #include <net/netisr.h>
  80 #include <net/route.h>
  81 #include <net/vnet.h>
  82
  83 #include <netinet/in.h>
  84
  85 #include <netgraph/ng_message.h>
  86 #include <netgraph/netgraph.h>
  87 #include <netgraph/ng_parse.h>
  88 #include <netgraph/ng_iface.h>
  89
  90 #ifdef NG_SEPARATE_MALLOC
  91 static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
  92 #else
  93 #define M_NETGRAPH_IFACE M_NETGRAPH
  94 #endif
  95
  96 static SYSCTL_NODE(_net_graph, OID_AUTO, iface, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
  97     "Point to point netgraph interface");
  98 VNET_DEFINE_STATIC(int, ng_iface_max_nest) = 2;
  99 #define V_ng_iface_max_nest     VNET(ng_iface_max_nest)
 100 SYSCTL_INT(_net_graph_iface, OID_AUTO, max_nesting, CTLFLAG_VNET | CTLFLAG_RW,
 101     &VNET_NAME(ng_iface_max_nest), 0, "Max nested tunnels");
 102
 103 /* This struct describes one address family */
 104 struct iffam {
 105         sa_family_t     family;         /* Address family */
 106         const char      *hookname;      /* Name for hook */
 107 };
 108 typedef const struct iffam *iffam_p;
 109
 110 /* List of address families supported by our interface */
 111 const static struct iffam gFamilies[] = {
 112         { AF_INET,      NG_IFACE_HOOK_INET      },
 113         { AF_INET6,     NG_IFACE_HOOK_INET6     },
 114 };
 115 #define NUM_FAMILIES            nitems(gFamilies)
 116
 117 /* Node private data */
 118 struct ng_iface_private {
 119         struct  ifnet *ifp;             /* Our interface */
 120         int     unit;                   /* Interface unit number */
 121         node_p  node;                   /* Our netgraph node */
 122         hook_p  hooks[NUM_FAMILIES];    /* Hook for each address family */
 123         struct rmlock   lock;           /* Protect private data changes */
 124 };
 125 typedef struct ng_iface_private *priv_p;
 126
 127 #define PRIV_RLOCK(priv, t)     rm_rlock(&priv->lock, t)
 128 #define PRIV_RUNLOCK(priv, t)   rm_runlock(&priv->lock, t)
 129 #define PRIV_WLOCK(priv)        rm_wlock(&priv->lock)
 130 #define PRIV_WUNLOCK(priv)      rm_wunlock(&priv->lock)
 131
 132 /* Interface methods */
 133 static void     ng_iface_start(struct ifnet *ifp);
 134 static int      ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
 135 static int      ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
 136                         const struct sockaddr *dst, struct route *ro);
 137 static void     ng_iface_bpftap(struct ifnet *ifp,
 138                         struct mbuf *m, sa_family_t family);
 139 static int      ng_iface_send(struct ifnet *ifp, struct mbuf *m,
 140                         sa_family_t sa);
 141 #ifdef DEBUG
 142 static void     ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
 143 #endif
 144
 145 /* Netgraph methods */
 146 static int              ng_iface_mod_event(module_t, int, void *);
 147 static ng_constructor_t ng_iface_constructor;
 148 static ng_rcvmsg_t      ng_iface_rcvmsg;
 149 static ng_shutdown_t    ng_iface_shutdown;
 150 static ng_newhook_t     ng_iface_newhook;
 151 static ng_rcvdata_t     ng_iface_rcvdata;
 152 static ng_disconnect_t  ng_iface_disconnect;
 153
 154 /* Helper stuff */
 155 static iffam_p  get_iffam_from_af(sa_family_t family);
 156 static iffam_p  get_iffam_from_hook(priv_p priv, hook_p hook);
 157 static iffam_p  get_iffam_from_name(const char *name);
 158 static hook_p  *get_hook_from_iffam(priv_p priv, iffam_p iffam);
 159
 160 /* List of commands and how to convert arguments to/from ASCII */
 161 static const struct ng_cmdlist ng_iface_cmds[] = {
 162         {
 163           NGM_IFACE_COOKIE,
 164           NGM_IFACE_GET_IFNAME,
 165           "getifname",
 166           NULL,
 167           &ng_parse_string_type
 168         },
 169         {
 170           NGM_IFACE_COOKIE,
 171           NGM_IFACE_POINT2POINT,
 172           "point2point",
 173           NULL,
 174           NULL
 175         },
 176         {
 177           NGM_IFACE_COOKIE,
 178           NGM_IFACE_BROADCAST,
 179           "broadcast",
 180           NULL,
 181           NULL
 182         },
 183         {
 184           NGM_IFACE_COOKIE,
 185           NGM_IFACE_GET_IFINDEX,
 186           "getifindex",
 187           NULL,
 188           &ng_parse_uint32_type
 189         },
 190         { 0 }
 191 };
 192
 193 /* Node type descriptor */
 194 static struct ng_type typestruct = {
 195         .version =      NG_ABI_VERSION,
 196         .name =         NG_IFACE_NODE_TYPE,
 197         .mod_event =    ng_iface_mod_event,
 198         .constructor =  ng_iface_constructor,
 199         .rcvmsg =       ng_iface_rcvmsg,
 200         .shutdown =     ng_iface_shutdown,
 201         .newhook =      ng_iface_newhook,
 202         .rcvdata =      ng_iface_rcvdata,
 203         .disconnect =   ng_iface_disconnect,
 204         .cmdlist =      ng_iface_cmds,
 205 };
 206 NETGRAPH_INIT(iface, &typestruct);
 207
 208 VNET_DEFINE_STATIC(struct unrhdr *, ng_iface_unit);
 209 #define V_ng_iface_unit                 VNET(ng_iface_unit)
 210
 211 /************************************************************************
 212                         HELPER STUFF
 213  ************************************************************************/
 214
 215 /*
 216  * Get the family descriptor from the family ID
 217  */
 218 static __inline iffam_p
 219 get_iffam_from_af(sa_family_t family)
 220 {
 221         iffam_p iffam;
 222         int k;
 223
 224         for (k = 0; k < NUM_FAMILIES; k++) {
 225                 iffam = &gFamilies[k];
 226                 if (iffam->family == family)
 227                         return (iffam);
 228         }
 229         return (NULL);
 230 }
 231
 232 /*
 233  * Get the family descriptor from the hook
 234  */
 235 static __inline iffam_p
 236 get_iffam_from_hook(priv_p priv, hook_p hook)
 237 {
 238         int k;
 239
 240         for (k = 0; k < NUM_FAMILIES; k++)
 241                 if (priv->hooks[k] == hook)
 242                         return (&gFamilies[k]);
 243         return (NULL);
 244 }
 245
 246 /*
 247  * Get the hook from the iffam descriptor
 248  */
 249
 250 static __inline hook_p *
 251 get_hook_from_iffam(priv_p priv, iffam_p iffam)
 252 {
 253         return (&priv->hooks[iffam - gFamilies]);
 254 }
 255
 256 /*
 257  * Get the iffam descriptor from the name
 258  */
 259 static __inline iffam_p
 260 get_iffam_from_name(const char *name)
 261 {
 262         iffam_p iffam;
 263         int k;
 264
 265         for (k = 0; k < NUM_FAMILIES; k++) {
 266                 iffam = &gFamilies[k];
 267                 if (!strcmp(iffam->hookname, name))
 268                         return (iffam);
 269         }
 270         return (NULL);
 271 }
 272
 273 /************************************************************************
 274                         INTERFACE STUFF
 275  ************************************************************************/
 276
 277 /*
 278  * Process an ioctl for the virtual interface
 279  */
 280 static int
 281 ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 282 {
 283         struct ifreq *const ifr = (struct ifreq *) data;
 284         int error = 0;
 285
 286 #ifdef DEBUG
 287         ng_iface_print_ioctl(ifp, command, data);
 288 #endif
 289         switch (command) {
 290         /* These two are mostly handled at a higher layer */
 291         case SIOCSIFADDR:
 292                 ifp->if_flags |= IFF_UP;
 293                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
 294                 ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
 295                 break;
 296         case SIOCGIFADDR:
 297                 break;
 298
 299         /* Set flags */
 300         case SIOCSIFFLAGS:
 301                 /*
 302                  * If the interface is marked up and stopped, then start it.
 303                  * If it is marked down and running, then stop it.
 304                  */
 305                 if (ifr->ifr_flags & IFF_UP) {
 306                         if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
 307                                 ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
 308                                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
 309                         }
 310                 } else {
 311                         if (ifp->if_drv_flags & IFF_DRV_RUNNING)
 312                                 ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
 313                                     IFF_DRV_OACTIVE);
 314                 }
 315                 break;
 316
 317         /* Set the interface MTU */
 318         case SIOCSIFMTU:
 319                 if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
 320                     || ifr->ifr_mtu < NG_IFACE_MTU_MIN)
 321                         error = EINVAL;
 322                 else
 323                         ifp->if_mtu = ifr->ifr_mtu;
 324                 break;
 325
 326         /* Stuff that's not supported */
 327         case SIOCADDMULTI:
 328         case SIOCDELMULTI:
 329                 error = 0;
 330                 break;
 331         case SIOCSIFPHYS:
 332                 error = EOPNOTSUPP;
 333                 break;
 334
 335         default:
 336                 error = EINVAL;
 337                 break;
 338         }
 339         return (error);
 340 }
 341
 342 /*
 343  * This routine is called to deliver a packet out the interface.
 344  * We simply look at the address family and relay the packet to
 345  * the corresponding hook, if it exists and is connected.
 346  */
 347
 348 static int
 349 ng_iface_output(struct ifnet *ifp, struct mbuf *m,
 350         const struct sockaddr *dst, struct route *ro)
 351 {
 352         uint32_t af;
 353         int error;
 354
 355         /* Check interface flags */
 356         if (!((ifp->if_flags & IFF_UP) &&
 357             (ifp->if_drv_flags & IFF_DRV_RUNNING))) {
 358                 m_freem(m);
 359                 return (ENETDOWN);
 360         }
 361
 362         /* Protect from deadly infinite recursion. */
 363         error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE,
 364             V_ng_iface_max_nest);
 365         if (error) {
 366                 m_freem(m);
 367                 return (error);
 368         }
 369
 370         /* BPF writes need to be handled specially. */
 371         if (dst->sa_family == AF_UNSPEC)
 372                 bcopy(dst->sa_data, &af, sizeof(af));
 373         else
 374                 af = dst->sa_family;
 375
 376         /* Berkeley packet filter */
 377         ng_iface_bpftap(ifp, m, af);
 378
 379         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 380                 M_PREPEND(m, sizeof(sa_family_t), M_NOWAIT);
 381                 if (m == NULL) {
 382                         if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
 383                         return (ENOBUFS);
 384                 }
 385                 *(sa_family_t *)m->m_data = af;
 386                 error = (ifp->if_transmit)(ifp, m);
 387         } else
 388                 error = ng_iface_send(ifp, m, af);
 389
 390         return (error);
 391 }
 392
 393 /*
 394  * Start method is used only when ALTQ is enabled.
 395  */
 396 static void
 397 ng_iface_start(struct ifnet *ifp)
 398 {
 399         struct mbuf *m;
 400         sa_family_t sa;
 401
 402         KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
 403
 404         for(;;) {
 405                 IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
 406                 if (m == NULL)
 407                         break;
 408                 sa = *mtod(m, sa_family_t *);
 409                 m_adj(m, sizeof(sa_family_t));
 410                 ng_iface_send(ifp, m, sa);
 411         }
 412 }
 413
 414 /*
 415  * Flash a packet by the BPF (requires prepending 4 byte AF header)
 416  * Note the phoney mbuf; this is OK because BPF treats it read-only.
 417  */
 418 static void
 419 ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
 420 {
 421         KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
 422         if (bpf_peers_present(ifp->if_bpf)) {
 423                 int32_t family4 = (int32_t)family;
 424                 bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
 425         }
 426 }
 427
 428 /*
 429  * This routine does actual delivery of the packet into the
 430  * netgraph(4). It is called from ng_iface_start() and
 431  * ng_iface_output().
 432  */
 433 static int
 434 ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
 435 {
 436         struct rm_priotracker priv_tracker;
 437         const priv_p priv = (priv_p) ifp->if_softc;
 438         const iffam_p iffam = get_iffam_from_af(sa);
 439         hook_p hook;
 440         int error;
 441         int len;
 442
 443         /* Check address family to determine hook (if known) */
 444         if (iffam == NULL) {
 445                 m_freem(m);
 446                 log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
 447                 return (EAFNOSUPPORT);
 448         }
 449
 450         /* Copy length before the mbuf gets invalidated. */
 451         len = m->m_pkthdr.len;
 452
 453         PRIV_RLOCK(priv, &priv_tracker);
 454         hook = *get_hook_from_iffam(priv, iffam);
 455         if (hook == NULL) {
 456                 NG_FREE_M(m);
 457                 PRIV_RUNLOCK(priv, &priv_tracker);
 458                 return ENETDOWN;
 459         }
 460         NG_HOOK_REF(hook);
 461         PRIV_RUNLOCK(priv, &priv_tracker);
 462
 463         NG_OUTBOUND_THREAD_REF();
 464         NG_SEND_DATA_ONLY(error, hook, m);
 465         NG_OUTBOUND_THREAD_UNREF();
 466         NG_HOOK_UNREF(hook);
 467
 468         /* Update stats. */
 469         if (error == 0) {
 470                 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
 471                 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
 472         }
 473
 474         return (error);
 475 }
 476
 477 #ifdef DEBUG
 478 /*
 479  * Display an ioctl to the virtual interface
 480  */
 481
 482 static void
 483 ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
 484 {
 485         char   *str;
 486
 487         switch (command & IOC_DIRMASK) {
 488         case IOC_VOID:
 489                 str = "IO";
 490                 break;
 491         case IOC_OUT:
 492                 str = "IOR";
 493                 break;
 494         case IOC_IN:
 495                 str = "IOW";
 496                 break;
 497         case IOC_INOUT:
 498                 str = "IORW";
 499                 break;
 500         default:
 501                 str = "IO??";
 502         }
 503         log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
 504                ifp->if_xname,
 505                str,
 506                IOCGROUP(command),
 507                command & 0xff,
 508                IOCPARM_LEN(command));
 509 }
 510 #endif /* DEBUG */
 511
 512 /************************************************************************
 513                         NETGRAPH NODE STUFF
 514  ************************************************************************/
 515
 516 /*
 517  * Constructor for a node
 518  */
 519 static int
 520 ng_iface_constructor(node_p node)
 521 {
 522         struct ifnet *ifp;
 523         priv_p priv;
 524
 525         /* Allocate node and interface private structures */
 526         priv = malloc(sizeof(*priv), M_NETGRAPH_IFACE, M_WAITOK | M_ZERO);
 527         ifp = if_alloc(IFT_PROPVIRTUAL);
 528         if (ifp == NULL) {
 529                 free(priv, M_NETGRAPH_IFACE);
 530                 return (ENOMEM);
 531         }
 532
 533         rm_init(&priv->lock, "ng_iface private rmlock");
 534
 535         /* Link them together */
 536         ifp->if_softc = priv;
 537         priv->ifp = ifp;
 538
 539         /* Get an interface unit number */
 540         priv->unit = alloc_unr(V_ng_iface_unit);
 541
 542         /* Link together node and private info */
 543         NG_NODE_SET_PRIVATE(node, priv);
 544         priv->node = node;
 545
 546         /* Initialize interface structure */
 547         if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
 548         ifp->if_output = ng_iface_output;
 549         ifp->if_start = ng_iface_start;
 550         ifp->if_ioctl = ng_iface_ioctl;
 551         ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
 552         ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
 553         ifp->if_type = IFT_PROPVIRTUAL;         /* XXX */
 554         ifp->if_addrlen = 0;                    /* XXX */
 555         ifp->if_hdrlen = 0;                     /* XXX */
 556         ifp->if_baudrate = 64000;               /* XXX */
 557         IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
 558         ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
 559         IFQ_SET_READY(&ifp->if_snd);
 560
 561         /* Give this node the same name as the interface (if possible) */
 562         if (ng_name_node(node, ifp->if_xname) != 0)
 563                 log(LOG_WARNING, "%s: can't acquire netgraph name\n",
 564                     ifp->if_xname);
 565
 566         /* Attach the interface */
 567         if_attach(ifp);
 568         bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
 569
 570         /* Done */
 571         return (0);
 572 }
 573
 574 /*
 575  * Give our ok for a hook to be added
 576  */
 577 static int
 578 ng_iface_newhook(node_p node, hook_p hook, const char *name)
 579 {
 580         const iffam_p iffam = get_iffam_from_name(name);
 581         const priv_p priv = NG_NODE_PRIVATE(node);
 582         hook_p *hookptr;
 583
 584         if (iffam == NULL)
 585                 return (EPFNOSUPPORT);
 586         PRIV_WLOCK(priv);
 587         hookptr = get_hook_from_iffam(priv, iffam);
 588         if (*hookptr != NULL) {
 589                 PRIV_WUNLOCK(priv);
 590                 return (EISCONN);
 591         }
 592         *hookptr = hook;
 593         NG_HOOK_HI_STACK(hook);
 594         NG_HOOK_SET_TO_INBOUND(hook);
 595         PRIV_WUNLOCK(priv);
 596         return (0);
 597 }
 598
 599 /*
 600  * Receive a control message
 601  */
 602 static int
 603 ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
 604 {
 605         const priv_p priv = NG_NODE_PRIVATE(node);
 606         struct ifnet *const ifp = priv->ifp;
 607         struct ng_mesg *resp = NULL;
 608         int error = 0;
 609         struct ng_mesg *msg;
 610
 611         NGI_GET_MSG(item, msg);
 612         switch (msg->header.typecookie) {
 613         case NGM_IFACE_COOKIE:
 614                 switch (msg->header.cmd) {
 615                 case NGM_IFACE_GET_IFNAME:
 616                         NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
 617                         if (resp == NULL) {
 618                                 error = ENOMEM;
 619                                 break;
 620                         }
 621                         strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
 622                         break;
 623
 624                 case NGM_IFACE_POINT2POINT:
 625                 case NGM_IFACE_BROADCAST:
 626                     {
 627                         /* Deny request if interface is UP */
 628                         if ((ifp->if_flags & IFF_UP) != 0)
 629                                 return (EBUSY);
 630
 631                         /* Change flags */
 632                         switch (msg->header.cmd) {
 633                         case NGM_IFACE_POINT2POINT:
 634                                 ifp->if_flags |= IFF_POINTOPOINT;
 635                                 ifp->if_flags &= ~IFF_BROADCAST;
 636                                 break;
 637                         case NGM_IFACE_BROADCAST:
 638                                 ifp->if_flags &= ~IFF_POINTOPOINT;
 639                                 ifp->if_flags |= IFF_BROADCAST;
 640                                 break;
 641                         }
 642                         break;
 643                     }
 644
 645                 case NGM_IFACE_GET_IFINDEX:
 646                         NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
 647                         if (resp == NULL) {
 648                                 error = ENOMEM;
 649                                 break;
 650                         }
 651                         *((uint32_t *)resp->data) = priv->ifp->if_index;
 652                         break;
 653
 654                 default:
 655                         error = EINVAL;
 656                         break;
 657                 }
 658                 break;
 659         case NGM_FLOW_COOKIE:
 660                 switch (msg->header.cmd) {
 661                 case NGM_LINK_IS_UP:
 662                         if_link_state_change(ifp, LINK_STATE_UP);
 663                         break;
 664                 case NGM_LINK_IS_DOWN:
 665                         if_link_state_change(ifp, LINK_STATE_DOWN);
 666                         break;
 667                 default:
 668                         break;
 669                 }
 670                 break;
 671         default:
 672                 error = EINVAL;
 673                 break;
 674         }
 675         NG_RESPOND_MSG(error, node, item, resp);
 676         NG_FREE_MSG(msg);
 677         return (error);
 678 }
 679
 680 /*
 681  * Recive data from a hook. Pass the packet to the correct input routine.
 682  */
 683 static int
 684 ng_iface_rcvdata(hook_p hook, item_p item)
 685 {
 686         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 687         const iffam_p iffam = get_iffam_from_hook(priv, hook);
 688         struct ifnet *const ifp = priv->ifp;
 689         struct epoch_tracker et;
 690         struct mbuf *m;
 691         int isr;
 692
 693         NGI_GET_M(item, m);
 694         NG_FREE_ITEM(item);
 695         /* Sanity checks */
 696         KASSERT(iffam != NULL, ("%s: iffam", __func__));
 697         M_ASSERTPKTHDR(m);
 698         if ((ifp->if_flags & IFF_UP) == 0) {
 699                 NG_FREE_M(m);
 700                 return (ENETDOWN);
 701         }
 702
 703         /* Update interface stats */
 704         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
 705         if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
 706
 707         /* Note receiving interface */
 708         m->m_pkthdr.rcvif = ifp;
 709
 710         /* Berkeley packet filter */
 711         ng_iface_bpftap(ifp, m, iffam->family);
 712
 713         /* Send packet */
 714         switch (iffam->family) {
 715 #ifdef INET
 716         case AF_INET:
 717                 isr = NETISR_IP;
 718                 break;
 719 #endif
 720 #ifdef INET6
 721         case AF_INET6:
 722                 isr = NETISR_IPV6;
 723                 break;
 724 #endif
 725         default:
 726                 m_freem(m);
 727                 return (EAFNOSUPPORT);
 728         }
 729         random_harvest_queue(m, sizeof(*m), RANDOM_NET_NG);
 730         M_SETFIB(m, ifp->if_fib);
 731         CURVNET_SET(ifp->if_vnet);
 732         NET_EPOCH_ENTER(et);
 733         netisr_dispatch(isr, m);
 734         NET_EPOCH_EXIT(et);
 735         CURVNET_RESTORE();
 736         return (0);
 737 }
 738
 739 /*
 740  * Shutdown and remove the node and its associated interface.
 741  */
 742 static int
 743 ng_iface_shutdown(node_p node)
 744 {
 745         const priv_p priv = NG_NODE_PRIVATE(node);
 746
 747         /*
 748          * The ifnet may be in a different vnet than the netgraph node,
 749          * hence we have to change the current vnet context here.
 750          */
 751         CURVNET_SET_QUIET(priv->ifp->if_vnet);
 752         bpfdetach(priv->ifp);
 753         if_detach(priv->ifp);
 754         if_free(priv->ifp);
 755         CURVNET_RESTORE();
 756         priv->ifp = NULL;
 757         free_unr(V_ng_iface_unit, priv->unit);
 758         rm_destroy(&priv->lock);
 759         free(priv, M_NETGRAPH_IFACE);
 760         NG_NODE_SET_PRIVATE(node, NULL);
 761         NG_NODE_UNREF(node);
 762         return (0);
 763 }
 764
 765 /*
 766  * Hook disconnection. Note that we do *not* shutdown when all
 767  * hooks have been disconnected.
 768  */
 769 static int
 770 ng_iface_disconnect(hook_p hook)
 771 {
 772         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 773         const iffam_p iffam = get_iffam_from_hook(priv, hook);
 774
 775         if (iffam == NULL)
 776                 panic("%s", __func__);
 777         PRIV_WLOCK(priv);
 778         *get_hook_from_iffam(priv, iffam) = NULL;
 779         PRIV_WUNLOCK(priv);
 780         return (0);
 781 }
 782
 783 /*
 784  * Handle loading and unloading for this node type.
 785  */
 786 static int
 787 ng_iface_mod_event(module_t mod, int event, void *data)
 788 {
 789         int error = 0;
 790
 791         switch (event) {
 792         case MOD_LOAD:
 793         case MOD_UNLOAD:
 794                 break;
 795         default:
 796                 error = EOPNOTSUPP;
 797                 break;
 798         }
 799         return (error);
 800 }
 801
 802 static void
 803 vnet_ng_iface_init(const void *unused)
 804 {
 805
 806         V_ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
 807 }
 808 VNET_SYSINIT(vnet_ng_iface_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
 809     vnet_ng_iface_init, NULL);
 810
 811 static void
 812 vnet_ng_iface_uninit(const void *unused)
 813 {
 814
 815         delete_unrhdr(V_ng_iface_unit);
 816 }
 817 VNET_SYSUNINIT(vnet_ng_iface_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
 818     vnet_ng_iface_uninit, NULL);