2021-10-11 18:37:13 -03:00

174 lines
3.4 KiB
C

/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
* @(#)if_loop.c 1.1 94/10/31 SMI; from UCB 7.1 6/5/86
*/
/*
* Loopback interface driver for protocol testing and timing.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <net/if_arp.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_var.h>
struct ether_family *ether_families;
#endif
#ifdef vax
#include <vax/mtpr.h>
#endif
#define LOMTU (1024+512)
struct ifnet loif;
int looutput(), loioctl();
loattach()
{
register struct ifnet *ifp = &loif;
struct ifreq ifr;
ifp->if_name = "lo";
ifp->if_mtu = LOMTU;
ifp->if_flags = IFF_LOOPBACK;
ifp->if_ioctl = loioctl;
ifp->if_output = looutput;
if_attach(ifp);
#ifndef BERK
/*
* For "temporary" backward compatibility with older
* Sun releases we set an address and turn the loopback
* interface on automagically.
*/
bzero((caddr_t)&ifr, sizeof(ifr) );
IN_SET_LOOPBACK_ADDR((struct sockaddr_in*)&ifr.ifr_addr );
(void)in_control((struct socket *)0, SIOCSIFADDR, (caddr_t)&ifr, ifp);
ifp->if_flags |= IFF_UP;
#endif BERK
ifp->if_flags |= IFF_RUNNING;
}
looutput(ifp, m0, dst)
struct ifnet *ifp;
register struct mbuf *m0;
struct sockaddr *dst;
{
int s;
register struct ifqueue *ifq;
struct mbuf *m;
struct ether_family *efp;
/*
* 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_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);
(void) splx(s);
return (ENOBUFS);
}
IF_ENQUEUE(ifq, m0);
schednetisr(NETISR_IP);
break;
#endif
default:
/*
* If it was not one of our "native" address families,
* check the extended family table to see if anyone else
* wants it, and let them have it.
*/
for (efp = ether_families; efp != NULL; efp = efp->ef_next) {
if (efp->ef_family == dst->sa_family)
break;
}
if (efp != NULL && efp->ef_infunc != NULL) {
ifq = (*efp->ef_infunc)(ifp, m0);
if (ifq == NULL)
break;
if (efp->ef_netisr != NULL)
schednetisr(efp->ef_netisr);
if (IF_QFULL(ifq)) {
IF_DROP(ifq);
m_freem(m0);
}
else IF_ENQUEUE(ifq, m0);
break;
}
(void) 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++;
(void) 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);
}