freebsd-dev/sys/netgraph/ng_iface.c
Alexander Motin 81a253a4ed Implement stack protection based on GET_STACK_USAGE() macro.
This fixes system panics possible with complicated netgraph setups
and allows to avoid unneded extra queueing for stack unwrapping.
2008-01-31 08:51:48 +00:00

818 lines
19 KiB
C

/*
* ng_iface.c
*/
/*-
* Copyright (c) 1996-1999 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Author: Archie Cobbs <archie@freebsd.org>
*
* $FreeBSD$
* $Whistle: ng_iface.c,v 1.33 1999/11/01 09:24:51 julian Exp $
*/
/*
* This node is also a system networking interface. It has
* a hook for each protocol (IP, AppleTalk, IPX, etc). Packets
* are simply relayed between the interface and the hooks.
*
* Interfaces are named ng0, ng1, etc. New nodes take the
* first available interface name.
*
* This node also includes Berkeley packet filter support.
*/
#include "opt_atalk.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipx.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/random.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/libkern.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/bpf.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_iface.h>
#include <netgraph/ng_cisco.h>
#ifdef NG_SEPARATE_MALLOC
MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node ");
#else
#define M_NETGRAPH_IFACE M_NETGRAPH
#endif
/* This struct describes one address family */
struct iffam {
sa_family_t family; /* Address family */
const char *hookname; /* Name for hook */
};
typedef const struct iffam *iffam_p;
/* List of address families supported by our interface */
const static struct iffam gFamilies[] = {
{ AF_INET, NG_IFACE_HOOK_INET },
{ AF_INET6, NG_IFACE_HOOK_INET6 },
{ AF_APPLETALK, NG_IFACE_HOOK_ATALK },
{ AF_IPX, NG_IFACE_HOOK_IPX },
{ AF_ATM, NG_IFACE_HOOK_ATM },
{ AF_NATM, NG_IFACE_HOOK_NATM },
};
#define NUM_FAMILIES (sizeof(gFamilies) / sizeof(*gFamilies))
/* Node private data */
struct ng_iface_private {
struct ifnet *ifp; /* Our interface */
int unit; /* Interface unit number */
node_p node; /* Our netgraph node */
hook_p hooks[NUM_FAMILIES]; /* Hook for each address family */
};
typedef struct ng_iface_private *priv_p;
/* Interface methods */
static void ng_iface_start(struct ifnet *ifp);
static int ng_iface_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data);
static int ng_iface_output(struct ifnet *ifp, struct mbuf *m0,
struct sockaddr *dst, struct rtentry *rt0);
static void ng_iface_bpftap(struct ifnet *ifp,
struct mbuf *m, sa_family_t family);
static int ng_iface_send(struct ifnet *ifp, struct mbuf *m,
sa_family_t sa);
#ifdef DEBUG
static void ng_iface_print_ioctl(struct ifnet *ifp, int cmd, caddr_t data);
#endif
/* Netgraph methods */
static int ng_iface_mod_event(module_t, int, void *);
static ng_constructor_t ng_iface_constructor;
static ng_rcvmsg_t ng_iface_rcvmsg;
static ng_shutdown_t ng_iface_shutdown;
static ng_newhook_t ng_iface_newhook;
static ng_rcvdata_t ng_iface_rcvdata;
static ng_disconnect_t ng_iface_disconnect;
/* Helper stuff */
static iffam_p get_iffam_from_af(sa_family_t family);
static iffam_p get_iffam_from_hook(priv_p priv, hook_p hook);
static iffam_p get_iffam_from_name(const char *name);
static hook_p *get_hook_from_iffam(priv_p priv, iffam_p iffam);
/* Parse type for struct ng_cisco_ipaddr */
static const struct ng_parse_struct_field ng_cisco_ipaddr_type_fields[]
= NG_CISCO_IPADDR_TYPE_INFO;
static const struct ng_parse_type ng_cisco_ipaddr_type = {
&ng_parse_struct_type,
&ng_cisco_ipaddr_type_fields
};
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_iface_cmds[] = {
{
NGM_IFACE_COOKIE,
NGM_IFACE_GET_IFNAME,
"getifname",
NULL,
&ng_parse_string_type
},
{
NGM_IFACE_COOKIE,
NGM_IFACE_POINT2POINT,
"point2point",
NULL,
NULL
},
{
NGM_IFACE_COOKIE,
NGM_IFACE_BROADCAST,
"broadcast",
NULL,
NULL
},
{
NGM_CISCO_COOKIE,
NGM_CISCO_GET_IPADDR,
"getipaddr",
NULL,
&ng_cisco_ipaddr_type
},
{
NGM_IFACE_COOKIE,
NGM_IFACE_GET_IFINDEX,
"getifindex",
NULL,
&ng_parse_uint32_type
},
{ 0 }
};
/* Node type descriptor */
static struct ng_type typestruct = {
.version = NG_ABI_VERSION,
.name = NG_IFACE_NODE_TYPE,
.mod_event = ng_iface_mod_event,
.constructor = ng_iface_constructor,
.rcvmsg = ng_iface_rcvmsg,
.shutdown = ng_iface_shutdown,
.newhook = ng_iface_newhook,
.rcvdata = ng_iface_rcvdata,
.disconnect = ng_iface_disconnect,
.cmdlist = ng_iface_cmds,
};
NETGRAPH_INIT(iface, &typestruct);
static struct unrhdr *ng_iface_unit;
/************************************************************************
HELPER STUFF
************************************************************************/
/*
* Get the family descriptor from the family ID
*/
static __inline iffam_p
get_iffam_from_af(sa_family_t family)
{
iffam_p iffam;
int k;
for (k = 0; k < NUM_FAMILIES; k++) {
iffam = &gFamilies[k];
if (iffam->family == family)
return (iffam);
}
return (NULL);
}
/*
* Get the family descriptor from the hook
*/
static __inline iffam_p
get_iffam_from_hook(priv_p priv, hook_p hook)
{
int k;
for (k = 0; k < NUM_FAMILIES; k++)
if (priv->hooks[k] == hook)
return (&gFamilies[k]);
return (NULL);
}
/*
* Get the hook from the iffam descriptor
*/
static __inline hook_p *
get_hook_from_iffam(priv_p priv, iffam_p iffam)
{
return (&priv->hooks[iffam - gFamilies]);
}
/*
* Get the iffam descriptor from the name
*/
static __inline iffam_p
get_iffam_from_name(const char *name)
{
iffam_p iffam;
int k;
for (k = 0; k < NUM_FAMILIES; k++) {
iffam = &gFamilies[k];
if (!strcmp(iffam->hookname, name))
return (iffam);
}
return (NULL);
}
/************************************************************************
INTERFACE STUFF
************************************************************************/
/*
* Process an ioctl for the virtual interface
*/
static int
ng_iface_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
{
struct ifreq *const ifr = (struct ifreq *) data;
int s, error = 0;
#ifdef DEBUG
ng_iface_print_ioctl(ifp, command, data);
#endif
s = splimp();
switch (command) {
/* These two are mostly handled at a higher layer */
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP;
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
break;
case SIOCGIFADDR:
break;
/* Set flags */
case SIOCSIFFLAGS:
/*
* If the interface is marked up and stopped, then start it.
* If it is marked down and running, then stop it.
*/
if (ifr->ifr_flags & IFF_UP) {
if (!(ifp->if_drv_flags & IFF_DRV_RUNNING)) {
ifp->if_drv_flags &= ~(IFF_DRV_OACTIVE);
ifp->if_drv_flags |= IFF_DRV_RUNNING;
}
} else {
if (ifp->if_drv_flags & IFF_DRV_RUNNING)
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING |
IFF_DRV_OACTIVE);
}
break;
/* Set the interface MTU */
case SIOCSIFMTU:
if (ifr->ifr_mtu > NG_IFACE_MTU_MAX
|| ifr->ifr_mtu < NG_IFACE_MTU_MIN)
error = EINVAL;
else
ifp->if_mtu = ifr->ifr_mtu;
break;
/* Stuff that's not supported */
case SIOCADDMULTI:
case SIOCDELMULTI:
error = 0;
break;
case SIOCSIFPHYS:
error = EOPNOTSUPP;
break;
default:
error = EINVAL;
break;
}
(void) splx(s);
return (error);
}
/*
* This routine is called to deliver a packet out the interface.
* We simply look at the address family and relay the packet to
* the corresponding hook, if it exists and is connected.
*/
static int
ng_iface_output(struct ifnet *ifp, struct mbuf *m,
struct sockaddr *dst, struct rtentry *rt0)
{
uint32_t af;
int error;
/* Check interface flags */
if (!((ifp->if_flags & IFF_UP) &&
(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
m_freem(m);
return (ENETDOWN);
}
/* BPF writes need to be handled specially. */
if (dst->sa_family == AF_UNSPEC) {
bcopy(dst->sa_data, &af, sizeof(af));
dst->sa_family = af;
}
/* Berkeley packet filter */
ng_iface_bpftap(ifp, m, dst->sa_family);
if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
M_PREPEND(m, sizeof(sa_family_t), M_DONTWAIT);
if (m == NULL) {
IFQ_LOCK(&ifp->if_snd);
IFQ_INC_DROPS(&ifp->if_snd);
IFQ_UNLOCK(&ifp->if_snd);
ifp->if_oerrors++;
return (ENOBUFS);
}
*(sa_family_t *)m->m_data = dst->sa_family;
IFQ_HANDOFF(ifp, m, error);
} else
error = ng_iface_send(ifp, m, dst->sa_family);
return (error);
}
/*
* Start method is used only when ALTQ is enabled.
*/
static void
ng_iface_start(struct ifnet *ifp)
{
struct mbuf *m;
sa_family_t sa;
KASSERT(ALTQ_IS_ENABLED(&ifp->if_snd), ("%s without ALTQ", __func__));
for(;;) {
IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
if (m == NULL)
break;
sa = *mtod(m, sa_family_t *);
m_adj(m, sizeof(sa_family_t));
ng_iface_send(ifp, m, sa);
}
}
/*
* Flash a packet by the BPF (requires prepending 4 byte AF header)
* Note the phoney mbuf; this is OK because BPF treats it read-only.
*/
static void
ng_iface_bpftap(struct ifnet *ifp, struct mbuf *m, sa_family_t family)
{
KASSERT(family != AF_UNSPEC, ("%s: family=AF_UNSPEC", __func__));
if (bpf_peers_present(ifp->if_bpf)) {
int32_t family4 = (int32_t)family;
bpf_mtap2(ifp->if_bpf, &family4, sizeof(family4), m);
}
}
/*
* This routine does actual delivery of the packet into the
* netgraph(4). It is called from ng_iface_start() and
* ng_iface_output().
*/
static int
ng_iface_send(struct ifnet *ifp, struct mbuf *m, sa_family_t sa)
{
const priv_p priv = (priv_p) ifp->if_softc;
const iffam_p iffam = get_iffam_from_af(sa);
int error;
int len;
/* Check address family to determine hook (if known) */
if (iffam == NULL) {
m_freem(m);
log(LOG_WARNING, "%s: can't handle af%d\n", ifp->if_xname, sa);
return (EAFNOSUPPORT);
}
/* Copy length before the mbuf gets invalidated. */
len = m->m_pkthdr.len;
/* Send packet. If hook is not connected,
mbuf will get freed. */
NG_SEND_DATA_ONLY(error, *get_hook_from_iffam(priv, iffam), m);
/* Update stats. */
if (error == 0) {
ifp->if_obytes += len;
ifp->if_opackets++;
}
return (error);
}
#ifdef DEBUG
/*
* Display an ioctl to the virtual interface
*/
static void
ng_iface_print_ioctl(struct ifnet *ifp, int command, caddr_t data)
{
char *str;
switch (command & IOC_DIRMASK) {
case IOC_VOID:
str = "IO";
break;
case IOC_OUT:
str = "IOR";
break;
case IOC_IN:
str = "IOW";
break;
case IOC_INOUT:
str = "IORW";
break;
default:
str = "IO??";
}
log(LOG_DEBUG, "%s: %s('%c', %d, char[%d])\n",
ifp->if_xname,
str,
IOCGROUP(command),
command & 0xff,
IOCPARM_LEN(command));
}
#endif /* DEBUG */
/************************************************************************
NETGRAPH NODE STUFF
************************************************************************/
/*
* Constructor for a node
*/
static int
ng_iface_constructor(node_p node)
{
struct ifnet *ifp;
priv_p priv;
/* Allocate node and interface private structures */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_IFACE, M_NOWAIT|M_ZERO);
if (priv == NULL)
return (ENOMEM);
ifp = if_alloc(IFT_PROPVIRTUAL);
if (ifp == NULL) {
FREE(priv, M_NETGRAPH_IFACE);
return (ENOMEM);
}
/* Link them together */
ifp->if_softc = priv;
priv->ifp = ifp;
/* Get an interface unit number */
priv->unit = alloc_unr(ng_iface_unit);
/* Link together node and private info */
NG_NODE_SET_PRIVATE(node, priv);
priv->node = node;
/* Initialize interface structure */
if_initname(ifp, NG_IFACE_IFACE_NAME, priv->unit);
ifp->if_output = ng_iface_output;
ifp->if_start = ng_iface_start;
ifp->if_ioctl = ng_iface_ioctl;
ifp->if_watchdog = NULL;
ifp->if_mtu = NG_IFACE_MTU_DEFAULT;
ifp->if_flags = (IFF_SIMPLEX|IFF_POINTOPOINT|IFF_NOARP|IFF_MULTICAST);
ifp->if_type = IFT_PROPVIRTUAL; /* XXX */
ifp->if_addrlen = 0; /* XXX */
ifp->if_hdrlen = 0; /* XXX */
ifp->if_baudrate = 64000; /* XXX */
IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN;
IFQ_SET_READY(&ifp->if_snd);
/* Give this node the same name as the interface (if possible) */
if (ng_name_node(node, ifp->if_xname) != 0)
log(LOG_WARNING, "%s: can't acquire netgraph name\n",
ifp->if_xname);
/* Attach the interface */
if_attach(ifp);
bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
/* Done */
return (0);
}
/*
* Give our ok for a hook to be added
*/
static int
ng_iface_newhook(node_p node, hook_p hook, const char *name)
{
const iffam_p iffam = get_iffam_from_name(name);
hook_p *hookptr;
if (iffam == NULL)
return (EPFNOSUPPORT);
hookptr = get_hook_from_iffam(NG_NODE_PRIVATE(node), iffam);
if (*hookptr != NULL)
return (EISCONN);
*hookptr = hook;
NG_HOOK_HI_STACK(hook);
return (0);
}
/*
* Receive a control message
*/
static int
ng_iface_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
const priv_p priv = NG_NODE_PRIVATE(node);
struct ifnet *const ifp = priv->ifp;
struct ng_mesg *resp = NULL;
int error = 0;
struct ng_mesg *msg;
NGI_GET_MSG(item, msg);
switch (msg->header.typecookie) {
case NGM_IFACE_COOKIE:
switch (msg->header.cmd) {
case NGM_IFACE_GET_IFNAME:
NG_MKRESPONSE(resp, msg, IFNAMSIZ, M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
strlcpy(resp->data, ifp->if_xname, IFNAMSIZ);
break;
case NGM_IFACE_POINT2POINT:
case NGM_IFACE_BROADCAST:
{
/* Deny request if interface is UP */
if ((ifp->if_flags & IFF_UP) != 0)
return (EBUSY);
/* Change flags */
switch (msg->header.cmd) {
case NGM_IFACE_POINT2POINT:
ifp->if_flags |= IFF_POINTOPOINT;
ifp->if_flags &= ~IFF_BROADCAST;
break;
case NGM_IFACE_BROADCAST:
ifp->if_flags &= ~IFF_POINTOPOINT;
ifp->if_flags |= IFF_BROADCAST;
break;
}
break;
}
case NGM_IFACE_GET_IFINDEX:
NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
*((uint32_t *)resp->data) = priv->ifp->if_index;
break;
default:
error = EINVAL;
break;
}
break;
case NGM_CISCO_COOKIE:
switch (msg->header.cmd) {
case NGM_CISCO_GET_IPADDR: /* we understand this too */
{
struct ifaddr *ifa;
/* Return the first configured IP address */
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct ng_cisco_ipaddr *ips;
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
NG_MKRESPONSE(resp, msg, sizeof(ips), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
ips = (struct ng_cisco_ipaddr *)resp->data;
ips->ipaddr = ((struct sockaddr_in *)
ifa->ifa_addr)->sin_addr;
ips->netmask = ((struct sockaddr_in *)
ifa->ifa_netmask)->sin_addr;
break;
}
/* No IP addresses on this interface? */
if (ifa == NULL)
error = EADDRNOTAVAIL;
break;
}
default:
error = EINVAL;
break;
}
break;
case NGM_FLOW_COOKIE:
switch (msg->header.cmd) {
case NGM_LINK_IS_UP:
ifp->if_drv_flags |= IFF_DRV_RUNNING;
break;
case NGM_LINK_IS_DOWN:
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
break;
default:
break;
}
break;
default:
error = EINVAL;
break;
}
NG_RESPOND_MSG(error, node, item, resp);
NG_FREE_MSG(msg);
return (error);
}
/*
* Recive data from a hook. Pass the packet to the correct input routine.
*/
static int
ng_iface_rcvdata(hook_p hook, item_p item)
{
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
const iffam_p iffam = get_iffam_from_hook(priv, hook);
struct ifnet *const ifp = priv->ifp;
struct mbuf *m;
int isr;
NGI_GET_M(item, m);
NG_FREE_ITEM(item);
/* Sanity checks */
KASSERT(iffam != NULL, ("%s: iffam", __func__));
M_ASSERTPKTHDR(m);
if ((ifp->if_flags & IFF_UP) == 0) {
NG_FREE_M(m);
return (ENETDOWN);
}
/* Update interface stats */
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
/* Note receiving interface */
m->m_pkthdr.rcvif = ifp;
/* Berkeley packet filter */
ng_iface_bpftap(ifp, m, iffam->family);
/* Send packet */
switch (iffam->family) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
isr = NETISR_IPV6;
break;
#endif
#ifdef IPX
case AF_IPX:
isr = NETISR_IPX;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
isr = NETISR_ATALK2;
break;
#endif
default:
m_freem(m);
return (EAFNOSUPPORT);
}
/* First chunk of an mbuf contains good junk */
if (harvest.point_to_point)
random_harvest(m, 16, 3, 0, RANDOM_NET);
netisr_dispatch(isr, m);
return (0);
}
/*
* Shutdown and remove the node and its associated interface.
*/
static int
ng_iface_shutdown(node_p node)
{
const priv_p priv = NG_NODE_PRIVATE(node);
bpfdetach(priv->ifp);
if_detach(priv->ifp);
if_free(priv->ifp);
priv->ifp = NULL;
free_unr(ng_iface_unit, priv->unit);
FREE(priv, M_NETGRAPH_IFACE);
NG_NODE_SET_PRIVATE(node, NULL);
NG_NODE_UNREF(node);
return (0);
}
/*
* Hook disconnection. Note that we do *not* shutdown when all
* hooks have been disconnected.
*/
static int
ng_iface_disconnect(hook_p hook)
{
const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
const iffam_p iffam = get_iffam_from_hook(priv, hook);
if (iffam == NULL)
panic(__func__);
*get_hook_from_iffam(priv, iffam) = NULL;
return (0);
}
/*
* Handle loading and unloading for this node type.
*/
static int
ng_iface_mod_event(module_t mod, int event, void *data)
{
int error = 0;
switch (event) {
case MOD_LOAD:
ng_iface_unit = new_unrhdr(0, 0xffff, NULL);
break;
case MOD_UNLOAD:
delete_unrhdr(ng_iface_unit);
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}