add LOOPBACK flag, interface metric

[unix-history] / usr / src / sys / net / if_loop.c

/*
* Copyright (c) 1982 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)if_loop.c   6.9 (Berkeley) %G%
*/

/*
* Loopback interface driver for protocol testing and timing.
*/

#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "socket.h"
#include "errno.h"
#include "ioctl.h"

#include "../net/if.h"
#include "../net/netisr.h"
#include "../net/route.h"

#ifdef  INET
#include "../netinet/in.h"
#include "../netinet/in_systm.h"
#include "../netinet/ip.h"
#include "../netinet/ip_var.h"
#endif

#ifdef vax
#include "../vax/mtpr.h"
#endif

#ifdef NS
#include "../netns/ns.h"
#include "../netns/ns_if.h"
#endif

#define LOMTU   (1024+512)

struct  ifnet loif;
int     looutput(), loioctl();

loattach()
{
       register struct ifnet *ifp = &loif;

       ifp->if_name = "lo";
       ifp->if_mtu = LOMTU;
       ifp->if_flags = IFF_LOOPBACK;
       ifp->if_ioctl = loioctl;
       ifp->if_output = looutput;
       if_attach(ifp);
}

looutput(ifp, m0, dst)
       struct ifnet *ifp;
       register struct mbuf *m0;
       struct sockaddr *dst;
{
       int s;
       register struct ifqueue *ifq;
       struct mbuf *m;

       /*
        * Place interface pointer before the data
        * for the receiving protocol.
        */
       if (m0->m_off <= MMAXOFF &&
           m0->m_off >= MMINOFF + sizeof(struct ifnet *)) {
               m0->m_off -= sizeof(struct ifnet *);
               m0->m_len += sizeof(struct ifnet *);
       } else {
               MGET(m, M_DONTWAIT, MT_HEADER);
               if (m == (struct mbuf *)0)
                       return (ENOBUFS);
               m->m_off = MMINOFF;
               m->m_len = sizeof(struct ifnet *);
               m->m_next = m0;
               m0 = m;
       }
       *(mtod(m0, struct ifnet **)) = ifp;
       s = splimp();
       ifp->if_opackets++;
       switch (dst->sa_family) {

#ifdef INET
       case AF_INET:
               ifq = &ipintrq;
               if (IF_QFULL(ifq)) {
                       IF_DROP(ifq);
                       m_freem(m0);
                       splx(s);
                       return (ENOBUFS);
               }
               IF_ENQUEUE(ifq, m0);
               schednetisr(NETISR_IP);
               break;
#endif
#ifdef NS
       case AF_NS:
               ifq = &nsintrq;
               if (IF_QFULL(ifq)) {
                       IF_DROP(ifq);
                       m_freem(m0);
                       splx(s);
                       return (ENOBUFS);
               }
               IF_ENQUEUE(ifq, m0);
               schednetisr(NETISR_NS);
               break;
#endif
       default:
               splx(s);
               printf("lo%d: can't handle af%d\n", ifp->if_unit,
                       dst->sa_family);
               m_freem(m0);
               return (EAFNOSUPPORT);
       }
       ifp->if_ipackets++;
       splx(s);
       return (0);
}

/*
* Process an ioctl request.
*/
/* ARGSUSED */
loioctl(ifp, cmd, data)
       register struct ifnet *ifp;
       int cmd;
       caddr_t data;
{
       int error = 0;

       switch (cmd) {

       case SIOCSIFADDR:
               ifp->if_flags |= IFF_UP;
               /*
                * Everything else is done at a higher level.
                */
               break;

       default:
               error = EINVAL;
       }
       return (error);
}