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33 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.2 2001/12/20 10:30:16 ru Exp $
38 * Discard interface driver for protocol testing and timing.
39 * (Based on the loopback.)
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/module.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
51 #include <net/if_types.h>
52 #include <net/route.h>
56 #include "opt_inet6.h"
59 #define DSMTU (1024+512)
64 static void discattach (void);
66 static struct ifnet discif;
67 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
69 static void discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info);
70 static int discioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
76 struct ifnet *ifp = &discif;
78 if_initname(ifp, "ds", IF_DUNIT_NONE);
80 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
81 ifp->if_ioctl = discioctl;
82 ifp->if_output = discoutput;
83 ifp->if_type = IFT_LOOP;
86 ifp->if_snd.ifq_maxlen = 20;
88 bpfattach(ifp, DLT_NULL, sizeof(u_int));
92 disc_modevent(module_t mod, int type, void *data)
99 kprintf("if_disc module unload - not possible for this module type\n");
105 static moduledata_t disc_mod = {
111 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
114 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
117 if ((m->m_flags & M_PKTHDR) == 0)
118 panic("discoutput no HDR");
119 /* BPF write needs to be handled specially */
120 if (dst->sa_family == AF_UNSPEC) {
121 dst->sa_family = *(mtod(m, int *));
122 m->m_len -= sizeof(int);
123 m->m_pkthdr.len -= sizeof(int);
124 m->m_data += sizeof(int);
131 * We need to prepend the address family as
134 uint32_t af = dst->sa_family;
136 bpf_ptap(discif.if_bpf, m, &af, sizeof(af));
140 m->m_pkthdr.rcvif = ifp;
143 ifp->if_obytes += m->m_pkthdr.len;
151 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
154 rt->rt_rmx.rmx_mtu = DSMTU;
158 * Process an ioctl request.
162 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
165 struct ifreq *ifr = (struct ifreq *)data;
171 ifp->if_flags |= IFF_UP;
172 ifa = (struct ifaddr *)data;
174 ifa->ifa_rtrequest = discrtrequest;
176 * Everything else is done at a higher level.
183 error = EAFNOSUPPORT; /* XXX */
186 switch (ifr->ifr_addr.sa_family) {
198 error = EAFNOSUPPORT;
204 ifp->if_mtu = ifr->ifr_mtu;