xref: /csrg-svn/sys/net/if_loop.c (revision 10907)
1*10907Ssam /*	if_loop.c	4.16	83/02/11	*/
25122Swnj 
35122Swnj /*
45122Swnj  * Loopback interface driver for protocol testing and timing.
55122Swnj  */
65122Swnj 
75122Swnj #include "../h/param.h"
85122Swnj #include "../h/systm.h"
95122Swnj #include "../h/mbuf.h"
105122Swnj #include "../h/socket.h"
11*10907Ssam #include "../h/errno.h"
12*10907Ssam 
13*10907Ssam #include "../net/if.h"
14*10907Ssam #include "../net/netisr.h"
15*10907Ssam #include "../net/route.h"
16*10907Ssam 
178397Swnj #include "../netinet/in.h"
188397Swnj #include "../netinet/in_systm.h"
198397Swnj #include "../netinet/ip.h"
208397Swnj #include "../netinet/ip_var.h"
215122Swnj 
22*10907Ssam #include "../machine/mtpr.h"
23*10907Ssam 
245296Sroot #define	LONET	127
255207Swnj #define	LOMTU	(1024+512)
265122Swnj 
275122Swnj struct	ifnet loif;
285122Swnj int	looutput();
295122Swnj 
305122Swnj loattach()
315122Swnj {
325122Swnj 	register struct ifnet *ifp = &loif;
336337Ssam 	register struct sockaddr_in *sin;
345122Swnj 
355172Swnj 	ifp->if_name = "lo";
365122Swnj 	ifp->if_mtu = LOMTU;
375122Swnj 	ifp->if_net = LONET;
386337Ssam 	sin = (struct sockaddr_in *)&ifp->if_addr;
396337Ssam 	sin->sin_family = AF_INET;
406337Ssam 	sin->sin_addr = if_makeaddr(ifp->if_net, 0);
416337Ssam 	ifp->if_flags = IFF_UP;
425122Swnj 	ifp->if_output = looutput;
435161Swnj 	if_attach(ifp);
447154Swnj 	if_rtinit(ifp, RTF_UP);
455122Swnj }
465122Swnj 
476337Ssam looutput(ifp, m0, dst)
485122Swnj 	struct ifnet *ifp;
495122Swnj 	struct mbuf *m0;
506337Ssam 	struct sockaddr *dst;
515122Swnj {
525122Swnj 	int s = splimp();
536209Swnj 	register struct ifqueue *ifq;
545122Swnj 
555172Swnj 	ifp->if_opackets++;
566337Ssam 	switch (dst->sa_family) {
575122Swnj 
585122Swnj #ifdef INET
596337Ssam 	case AF_INET:
606209Swnj 		ifq = &ipintrq;
616209Swnj 		if (IF_QFULL(ifq)) {
626209Swnj 			IF_DROP(ifq);
636337Ssam 			m_freem(m0);
646209Swnj 			splx(s);
656544Sfeldman 			return (ENOBUFS);
666209Swnj 		}
676209Swnj 		IF_ENQUEUE(ifq, m0);
686262Swnj 		schednetisr(NETISR_IP);
695122Swnj 		break;
705122Swnj #endif
715122Swnj 	default:
725122Swnj 		splx(s);
736337Ssam 		printf("lo%d: can't handle af%d\n", ifp->if_unit,
746337Ssam 			dst->sa_family);
756337Ssam 		m_freem(m0);
766544Sfeldman 		return (EAFNOSUPPORT);
775122Swnj 	}
785172Swnj 	ifp->if_ipackets++;
795122Swnj 	splx(s);
806544Sfeldman 	return (0);
815122Swnj }
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