File:  [DragonFly] / src / sys / netproto / natm / natm.c
Revision 1.15: download - view: text, annotated - select for diffs
Fri Apr 9 22:34:10 2004 UTC (10 years, 3 months ago) by hsu
Branches: MAIN
CVS tags: HEAD
Push the lwkt_replymsg() up one level from netisr_service_loop() to
the message handler so we can explicitly reply or not reply as appropriate.

/*	$NetBSD: natm.c,v 1.5 1996/11/09 03:26:26 chuck Exp $	*/
/* $FreeBSD: src/sys/netnatm/natm.c,v 1.12 2000/02/13 03:32:03 peter Exp $ */
/* $DragonFly: src/sys/netproto/natm/natm.c,v 1.15 2004/04/09 22:34:10 hsu Exp $ */

/*
 *
 * Copyright (c) 1996 Charles D. Cranor and Washington University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Charles D. Cranor and
 *      Washington University.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 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 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * natm.c: native mode ATM access (both aal0 and aal5).
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sockio.h>
#include <sys/protosw.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>

#include <sys/thread2.h>
#include <sys/msgport2.h>

#include <net/if.h>
#include <net/if_atm.h>
#include <net/netisr.h>

#include <netinet/in.h>

#include "natm.h"

static u_long natm5_sendspace = 16*1024;
static u_long natm5_recvspace = 16*1024;

static u_long natm0_sendspace = 16*1024;
static u_long natm0_recvspace = 16*1024;

/*
 * user requests
 */
#ifdef FREEBSD_USRREQS
/*
 * FreeBSD new usrreqs supersedes pr_usrreq.
 */
static int natm_usr_attach (struct socket *, int, struct pru_attach_info *);
static int natm_usr_detach (struct socket *);
static int natm_usr_connect (struct socket *, struct sockaddr *,
				 struct thread *);
static int natm_usr_disconnect (struct socket *);
static int natm_usr_shutdown (struct socket *);
static int natm_usr_send (struct socket *, int, struct mbuf *,
			      struct sockaddr *, struct mbuf *, 
			      struct thread *);
static int natm_usr_peeraddr (struct socket *, struct sockaddr **);
static int natm_usr_control (struct socket *, u_long, caddr_t,
				 struct ifnet *, struct thread *);
static int natm_usr_abort (struct socket *);
static int natm_usr_bind (struct socket *, struct sockaddr *, 
			      struct thread *);
static int natm_usr_sockaddr (struct socket *, struct sockaddr **);

static int
natm_usr_attach(struct socket *so, int proto, struct pru_attach_info *ai)
{
    struct natmpcb *npcb;
    int error = 0;
    int s = SPLSOFTNET();

    npcb = (struct natmpcb *) so->so_pcb;

    if (npcb) {
	error = EISCONN;
	goto out;
    }

    if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
	if (proto == PROTO_NATMAAL5) 
	    error = soreserve(so, natm5_sendspace, natm5_recvspace,
			      ai->sb_rlimit);
	else
	    error = soreserve(so, natm0_sendspace, natm0_recvspace,
			      ai->sb_rlimit);
        if (error)
          goto out;
    }

    so->so_pcb = (caddr_t) (npcb = npcb_alloc(M_WAITOK));
    npcb->npcb_socket = so;
 out:
    splx(s);
    return (error);
}

static int
natm_usr_detach(struct socket *so)
{
    struct natmpcb *npcb;
    int error = 0;
    int s = SPLSOFTNET();

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    /*
     * we turn on 'drain' *before* we sofree.
     */
    npcb_free(npcb, NPCB_DESTROY);	/* drain */
    so->so_pcb = NULL;
    sofree(so);
 out:
    splx(s);
    return (error);
}

static int
natm_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
    struct natmpcb *npcb;
    struct sockaddr_natm *snatm;
    struct atm_pseudoioctl api;
    struct ifnet *ifp;
    int error = 0;
    int s2, s = SPLSOFTNET();
    int proto = so->so_proto->pr_protocol;

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    /*
     * validate nam and npcb
     */

    snatm = (struct sockaddr_natm *)nam;
    if (snatm->snatm_len != sizeof(*snatm) ||
	(npcb->npcb_flags & NPCB_FREE) == 0) {
	error = EINVAL;
	goto out;
    }
    if (snatm->snatm_family != AF_NATM) {
	error = EAFNOSUPPORT;
	goto out;
    }

    snatm->snatm_if[IFNAMSIZ-1] = '\0';  /* XXX ensure null termination
					    since ifunit() uses strcmp */

    /*
     * convert interface string to ifp, validate.
     */

    ifp = ifunit(snatm->snatm_if);
    if (ifp == NULL || (ifp->if_flags & IFF_RUNNING) == 0) {
	error = ENXIO;
	goto out;
    }
    if (ifp->if_output != atm_output) {
	error = EAFNOSUPPORT;
	goto out;
    }

    /*
     * register us with the NATM PCB layer
     */

    if (npcb_add(npcb, ifp, snatm->snatm_vci, snatm->snatm_vpi) != npcb) {
        error = EADDRINUSE;
        goto out;
    }

    /*
     * enable rx
     */

    ATM_PH_FLAGS(&api.aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
    ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
    ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
    api.rxhand = npcb;
    s2 = splimp();
    if (ifp->if_ioctl == NULL || 
	ifp->if_ioctl(ifp, SIOCATMENA, (caddr_t) &api,
		      td->td_proc->p_ucred) != 0) {
	splx(s2);
	npcb_free(npcb, NPCB_REMOVE);
        error = EIO;
	goto out;
    }
    splx(s2);

    soisconnected(so);

 out:
    splx(s);
    return (error);
}

static int
natm_usr_disconnect(struct socket *so)
{
    struct natmpcb *npcb;
    struct atm_pseudoioctl api;
    struct ifnet *ifp;
    int error = 0;
    int s2, s = SPLSOFTNET();

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    if ((npcb->npcb_flags & NPCB_CONNECTED) == 0) {
        printf("natm: disconnected check\n");
        error = EIO;
	goto out;
    }
    ifp = npcb->npcb_ifp;

    /*
     * disable rx
     */

    ATM_PH_FLAGS(&api.aph) = ATM_PH_AAL5;
    ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
    ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
    api.rxhand = npcb;
    s2 = splimp();
    if (ifp->if_ioctl != NULL)
	ifp->if_ioctl(ifp, SIOCATMDIS, (caddr_t) &api, (struct ucred *)NULL);
    splx(s2);

    npcb_free(npcb, NPCB_REMOVE);
    soisdisconnected(so);

 out:
    splx(s);
    return (error);
}

static int
natm_usr_shutdown(struct socket *so)
{
    socantsendmore(so);
    return 0;
}

static int
natm_usr_send(struct socket *so, int flags, struct mbuf *m, 
	      struct sockaddr *nam, struct mbuf *control, struct thread *td)
{
    struct natmpcb *npcb;
    struct atm_pseudohdr *aph;
    int error = 0;
    int s = SPLSOFTNET();
    int proto = so->so_proto->pr_protocol;

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    if (control && control->m_len) {
	m_freem(control);
	m_freem(m);
	error = EINVAL;
	goto out;
    }

    /*
     * send the data.   we must put an atm_pseudohdr on first
     */

    M_PREPEND(m, sizeof(*aph), M_WAITOK);
    if (m == NULL) {
        error = ENOBUFS;
	goto out;
    }
    aph = mtod(m, struct atm_pseudohdr *);
    ATM_PH_VPI(aph) = npcb->npcb_vpi;
    ATM_PH_SETVCI(aph, npcb->npcb_vci);
    ATM_PH_FLAGS(aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;

    error = atm_output(npcb->npcb_ifp, m, NULL, NULL);

 out:
    splx(s);
    return (error);
}

static int
natm_usr_peeraddr(struct socket *so, struct sockaddr **nam)
{
    struct natmpcb *npcb;
    struct sockaddr_natm *snatm, ssnatm;
    int error = 0;
    int s = SPLSOFTNET();

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    snatm = &ssnatm;
    bzero(snatm, sizeof(*snatm));
    snatm->snatm_len = sizeof(*snatm);
    snatm->snatm_family = AF_NATM;
    strlcpy(snatm->snatm_if, npcb->npcb_ifp->if_xname,
        sizeof(snatm->snatm_if));
    snatm->snatm_vci = npcb->npcb_vci;
    snatm->snatm_vpi = npcb->npcb_vpi;
    *nam = dup_sockaddr((struct sockaddr *)snatm, 0);

 out:
    splx(s);
    return (error);
}

static int
natm_usr_control(struct socket *so, u_long cmd, caddr_t arg,
		 struct ifnet *ifp, struct thread *td)
{
    struct natmpcb *npcb;
    struct atm_rawioctl ario;
    int error = 0;
    int s = SPLSOFTNET();

    npcb = (struct natmpcb *) so->so_pcb;
    if (npcb == NULL) {
	error = EINVAL;
	goto out;
    }

    /*
     * raw atm ioctl.   comes in as a SIOCRAWATM.   we convert it to
     * SIOCXRAWATM and pass it to the driver.
     */
    if (cmd == SIOCRAWATM) {
        if (npcb->npcb_ifp == NULL) {
	    error = ENOTCONN;
	    goto out;
        }
        ario.npcb = npcb;
        ario.rawvalue = *((int *)arg);
        error = npcb->npcb_ifp->if_ioctl(npcb->npcb_ifp, 
					 SIOCXRAWATM, (caddr_t) &ario,
					 td->td_proc->p_ucred);
	if (!error) {
	    if (ario.rawvalue) 
		npcb->npcb_flags |= NPCB_RAW;
	    else
		npcb->npcb_flags &= ~(NPCB_RAW);
	}
    }
    else
	error = EOPNOTSUPP;

 out:
    splx(s);
    return (error);
}

static int
natm_usr_abort(struct socket *so)
{
    return natm_usr_shutdown(so);
}

static int
natm_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
    return EOPNOTSUPP;
}

static int
natm_usr_sockaddr(struct socket *so, struct sockaddr **nam)
{
    return EOPNOTSUPP;
}

/* xxx - should be const */
struct pr_usrreqs natm_usrreqs = {
	natm_usr_abort, pru_accept_notsupp, natm_usr_attach, natm_usr_bind,
	natm_usr_connect, pru_connect2_notsupp, natm_usr_control,
	natm_usr_detach, natm_usr_disconnect, pru_listen_notsupp,
	natm_usr_peeraddr, pru_rcvd_notsupp, pru_rcvoob_notsupp,
	natm_usr_send, pru_sense_null, natm_usr_shutdown,
	natm_usr_sockaddr, sosend, soreceive, sopoll
};

#else  /* !FREEBSD_USRREQS */

#if defined(__NetBSD__) || defined(__OpenBSD__)
int natm_usrreq(so, req, m, nam, control, p)
#elif defined(__DragonFly__)
int natm_usrreq(so, req, m, nam, control)
#endif

struct socket *so;
int req;
struct mbuf *m, *nam, *control;
#if defined(__NetBSD__) || defined(__OpenBSD__)
struct proc *p;
#endif

{
  int error = 0, s, s2;
  struct natmpcb *npcb;
  struct sockaddr_natm *snatm;
  struct atm_pseudoioctl api;
  struct atm_pseudohdr *aph;
  struct atm_rawioctl ario;
  struct ifnet *ifp;
  int proto = so->so_proto->pr_protocol;

  s = SPLSOFTNET();

  npcb = (struct natmpcb *) so->so_pcb;

  if (npcb == NULL && req != PRU_ATTACH) {
    error = EINVAL;
    goto done;
  }
    

  switch (req) {
    case PRU_ATTACH:			/* attach protocol to up */

      if (npcb) {
	error = EISCONN;
	break;
      }

      if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
	if (proto == PROTO_NATMAAL5) 
          error = soreserve(so, natm5_sendspace, natm5_recvspace);
	else
          error = soreserve(so, natm0_sendspace, natm0_recvspace);
        if (error)
          break;
      }

      so->so_pcb = (caddr_t) (npcb = npcb_alloc(M_WAITOK));
      npcb->npcb_socket = so;

      break;

    case PRU_DETACH:			/* detach protocol from up */

      /*
       * we turn on 'drain' *before* we sofree.
       */

      npcb_free(npcb, NPCB_DESTROY);	/* drain */
      so->so_pcb = NULL;
      sofree(so);

      break;

    case PRU_CONNECT:			/* establish connection to peer */

      /*
       * validate nam and npcb
       */

      if (nam->m_len != sizeof(*snatm)) {
        error = EINVAL;
	break;
      }
      snatm = mtod(nam, struct sockaddr_natm *);
      if (snatm->snatm_len != sizeof(*snatm) ||
		(npcb->npcb_flags & NPCB_FREE) == 0) {
	error = EINVAL;
	break;
      }
      if (snatm->snatm_family != AF_NATM) {
	error = EAFNOSUPPORT;
	break;
      }

      snatm->snatm_if[IFNAMSIZ-1] = '\0';  /* XXX ensure null termination
						since ifunit() uses strcmp */

      /*
       * convert interface string to ifp, validate.
       */

      ifp = ifunit(snatm->snatm_if);
      if (ifp == NULL || (ifp->if_flags & IFF_RUNNING) == 0) {
	error = ENXIO;
	break;
      }
      if (ifp->if_output != atm_output) {
	error = EAFNOSUPPORT;
	break;
      }


      /*
       * register us with the NATM PCB layer
       */

      if (npcb_add(npcb, ifp, snatm->snatm_vci, snatm->snatm_vpi) != npcb) {
        error = EADDRINUSE;
        break;
      }

      /*
       * enable rx
       */

      ATM_PH_FLAGS(&api.aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
      ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
      ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
      api.rxhand = npcb;
      s2 = splimp();
      if (ifp->if_ioctl == NULL || 
	  ifp->if_ioctl(ifp, SIOCATMENA, (caddr_t) &api,
	  		(struct ucred *)NULL) != 0) {
	splx(s2);
	npcb_free(npcb, NPCB_REMOVE);
        error = EIO;
	break;
      }
      splx(s2);

      soisconnected(so);

      break;

    case PRU_DISCONNECT:		/* disconnect from peer */

      if ((npcb->npcb_flags & NPCB_CONNECTED) == 0) {
        printf("natm: disconnected check\n");
        error = EIO;
	break;
      }
      ifp = npcb->npcb_ifp;

      /*
       * disable rx
       */

      ATM_PH_FLAGS(&api.aph) = ATM_PH_AAL5;
      ATM_PH_VPI(&api.aph) = npcb->npcb_vpi;
      ATM_PH_SETVCI(&api.aph, npcb->npcb_vci);
      api.rxhand = npcb;
      s2 = splimp();
      if (ifp->if_ioctl != NULL)
	  ifp->if_ioctl(ifp, SIOCATMDIS, (caddr_t) &api, (struct ucred *)NULL);
      splx(s2);

      npcb_free(npcb, NPCB_REMOVE);
      soisdisconnected(so);

      break;

    case PRU_SHUTDOWN:			/* won't send any more data */
      socantsendmore(so);
      break;

    case PRU_SEND:			/* send this data */
      if (control && control->m_len) {
	m_freem(control);
	m_freem(m);
	error = EINVAL;
	break;
      }

      /*
       * send the data.   we must put an atm_pseudohdr on first
       */

      M_PREPEND(m, sizeof(*aph), M_WAITOK);
      if (m == NULL) {
        error = ENOBUFS;
	break;
      }
      aph = mtod(m, struct atm_pseudohdr *);
      ATM_PH_VPI(aph) = npcb->npcb_vpi;
      ATM_PH_SETVCI(aph, npcb->npcb_vci);
      ATM_PH_FLAGS(aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;

      error = atm_output(npcb->npcb_ifp, m, NULL, NULL);

      break;

    case PRU_SENSE:			/* return status into m */
      /* return zero? */
      break;

    case PRU_PEERADDR:			/* fetch peer's address */
      snatm = mtod(nam, struct sockaddr_natm *);
      bzero(snatm, sizeof(*snatm));
      nam->m_len = snatm->snatm_len = sizeof(*snatm);
      snatm->snatm_family = AF_NATM;
#if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
      bcopy(npcb->npcb_ifp->if_xname, snatm->snatm_if, sizeof(snatm->snatm_if));
#elif defined(__DragonFly__)
      snprintf(snatm->snatm_if, sizeof(snatm->snatm_if),
	"%s%d", npcb->npcb_ifp->if_name, npcb->npcb_ifp->if_unit);
#endif
      snatm->snatm_vci = npcb->npcb_vci;
      snatm->snatm_vpi = npcb->npcb_vpi;
      break;

    case PRU_CONTROL:			/* control operations on protocol */
      /*
       * raw atm ioctl.   comes in as a SIOCRAWATM.   we convert it to
       * SIOCXRAWATM and pass it to the driver.
       */
      if ((u_long)m == SIOCRAWATM) {
        if (npcb->npcb_ifp == NULL) {
          error = ENOTCONN;
          break;
        }
        ario.npcb = npcb;
        ario.rawvalue = *((int *)nam);
        error = npcb->npcb_ifp->if_ioctl(npcb->npcb_ifp, SIOCXRAWATM,
        				 (caddr_t) &ario, (struct ucred *)NULL);
	if (!error) {
          if (ario.rawvalue) 
	    npcb->npcb_flags |= NPCB_RAW;
	  else
	    npcb->npcb_flags &= ~(NPCB_RAW);
	}

        break;
      }

      error = EOPNOTSUPP;
      break;

    case PRU_BIND:			/* bind socket to address */
    case PRU_LISTEN:			/* listen for connection */
    case PRU_ACCEPT:			/* accept connection from peer */
    case PRU_CONNECT2:			/* connect two sockets */
    case PRU_ABORT:			/* abort (fast DISCONNECT, DETATCH) */
					/* (only happens if LISTEN socket) */
    case PRU_RCVD:			/* have taken data; more room now */
    case PRU_FASTTIMO:			/* 200ms timeout */
    case PRU_SLOWTIMO:			/* 500ms timeout */
    case PRU_RCVOOB:			/* retrieve out of band data */
    case PRU_SENDOOB:			/* send out of band data */
    case PRU_PROTORCV:			/* receive from below */
    case PRU_PROTOSEND:			/* send to below */
    case PRU_SOCKADDR:			/* fetch socket's address */
#ifdef DIAGNOSTIC
      printf("natm: PRU #%d unsupported\n", req);
#endif
      error = EOPNOTSUPP;
      break;
   
    default: panic("natm usrreq");
  }

done:
  splx(s);
  return(error);
}

#endif  /* !FREEBSD_USRREQS */

/* 
 * natm0_sysctl: not used, but here in case we want to add something
 * later...
 */

int natm0_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
    void *newp, size_t newlen)
{
  /* All sysctl names at this level are terminal. */
  if (namelen != 1)
    return (ENOTDIR);
  return (ENOPROTOOPT);
}

/* 
 * natm5_sysctl: not used, but here in case we want to add something
 * later...
 */

int natm5_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
    void *newp, size_t newlen)
{
  /* All sysctl names at this level are terminal. */
  if (namelen != 1)
    return (ENOTDIR);
  return (ENOPROTOOPT);
}

static void natmintr(struct netmsg *);

#if defined(__DragonFly__)
static void
netisr_natm_setup(void *dummy __unused)
{

	netisr_register(NETISR_NATM, cpu0_portfn, natmintr);
}
SYSINIT(natm_setup, SI_SUB_CPU, SI_ORDER_ANY, netisr_natm_setup, NULL);
#endif

void
natm_init()
{
  LIST_INIT(&natm_pcbs);

  netisr_register(NETISR_NATM, cpu0_portfn, natmintr);
}

/*
 * natmintr: splsoftnet interrupt
 *
 * note: we expect a socket pointer in rcvif rather than an interface
 * pointer.    we can get the interface pointer from the so's PCB if
 * we really need it.
 */
static void
natmintr(struct netmsg *msg)
{
  struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
  int s;
  struct socket *so;
  struct natmpcb *npcb;

#ifdef DIAGNOSTIC
  if ((m->m_flags & M_PKTHDR) == 0)
    panic("natmintr no HDR");
#endif

  npcb = (struct natmpcb *) m->m_pkthdr.rcvif; /* XXX: overloaded */
  so = npcb->npcb_socket;

  s = splimp();			/* could have atm devs @ different levels */
  npcb->npcb_inq--;
  splx(s);

  if (npcb->npcb_flags & NPCB_DRAIN) {
    m_freem(m);
    if (npcb->npcb_inq == 0)
      FREE(npcb, M_PCB);			/* done! */
    goto out;
  }

  if (npcb->npcb_flags & NPCB_FREE) {
    m_freem(m);					/* drop */
    goto out;
  }

#ifdef NEED_TO_RESTORE_IFP
  m->m_pkthdr.rcvif = npcb->npcb_ifp;
#else
#ifdef DIAGNOSTIC
m->m_pkthdr.rcvif = NULL;	/* null it out to be safe */
#endif
#endif

  if (sbspace(&so->so_rcv) > m->m_pkthdr.len ||
     ((npcb->npcb_flags & NPCB_RAW) != 0 && so->so_rcv.sb_cc < NPCB_RAWCC) ) {
#ifdef NATM_STAT
    natm_sookcnt++;
    natm_sookbytes += m->m_pkthdr.len;
#endif
    sbappendrecord(&so->so_rcv, m);
    sorwakeup(so);
  } else {
#ifdef NATM_STAT
    natm_sodropcnt++;
    natm_sodropbytes += m->m_pkthdr.len;
#endif
    m_freem(m);
  }
out:
  lwkt_replymsg(&msg->nm_lmsg, 0);
}