xref: /csrg-svn/sys/net/if_loop.c (revision 6337)
1*6337Ssam /*	if_loop.c	4.8	82/03/28	*/
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"
115122Swnj #include "../net/in.h"
125122Swnj #include "../net/in_systm.h"
135122Swnj #include "../net/if.h"
145122Swnj #include "../net/ip.h"
155122Swnj #include "../net/ip_var.h"
165122Swnj #include "../h/mtpr.h"
175122Swnj 
185296Sroot #define	LONET	127
195207Swnj #define	LOMTU	(1024+512)
205122Swnj 
215122Swnj struct	ifnet loif;
225122Swnj int	looutput();
235122Swnj 
245122Swnj loattach()
255122Swnj {
265122Swnj 	register struct ifnet *ifp = &loif;
27*6337Ssam 	register struct sockaddr_in *sin;
285122Swnj 
295172Swnj 	ifp->if_name = "lo";
305122Swnj 	ifp->if_mtu = LOMTU;
315122Swnj 	ifp->if_net = LONET;
32*6337Ssam 	sin = (struct sockaddr_in *)&ifp->if_addr;
33*6337Ssam 	sin->sin_family = AF_INET;
34*6337Ssam 	sin->sin_addr = if_makeaddr(ifp->if_net, 0);
35*6337Ssam 	ifp->if_flags = IFF_UP;
365122Swnj 	ifp->if_output = looutput;
375161Swnj 	if_attach(ifp);
385122Swnj }
395122Swnj 
40*6337Ssam looutput(ifp, m0, dst)
415122Swnj 	struct ifnet *ifp;
425122Swnj 	struct mbuf *m0;
43*6337Ssam 	struct sockaddr *dst;
445122Swnj {
455122Swnj 	int s = splimp();
466209Swnj 	register struct ifqueue *ifq;
475122Swnj 
485172Swnj 	ifp->if_opackets++;
49*6337Ssam 	switch (dst->sa_family) {
505122Swnj 
515122Swnj #ifdef INET
52*6337Ssam 	case AF_INET:
536209Swnj 		ifq = &ipintrq;
546209Swnj 		if (IF_QFULL(ifq)) {
556209Swnj 			IF_DROP(ifq);
56*6337Ssam 			m_freem(m0);
576209Swnj 			splx(s);
586209Swnj 			return (0);
596209Swnj 		}
606209Swnj 		IF_ENQUEUE(ifq, m0);
616262Swnj 		schednetisr(NETISR_IP);
625122Swnj 		break;
635122Swnj #endif
645122Swnj 	default:
655122Swnj 		splx(s);
66*6337Ssam 		printf("lo%d: can't handle af%d\n", ifp->if_unit,
67*6337Ssam 			dst->sa_family);
68*6337Ssam 		m_freem(m0);
695122Swnj 		return (0);
705122Swnj 	}
715172Swnj 	ifp->if_ipackets++;
725122Swnj 	splx(s);
735122Swnj 	return (1);
745122Swnj }
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