if_disc.c revision 41757
1/* 2 * Copyright (c) 1982, 1986, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93 34 * $Id: if_disc.c,v 1.20 1998/06/07 17:12:03 dfr Exp $ 35 */ 36 37/* 38 * Discard interface driver for protocol testing and timing. 39 * (Based on the loopback.) 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/kernel.h> 45#include <sys/mbuf.h> 46#include <sys/socket.h> 47#include <sys/sockio.h> 48 49#include <net/if.h> 50#include <net/if_types.h> 51#include <net/route.h> 52#include <net/bpf.h> 53 54#include "bpfilter.h" 55#include "opt_inet.h" 56 57#ifdef TINY_DSMTU 58#define DSMTU (1024+512) 59#else 60#define DSMTU 65532 61#endif 62 63static void discattach __P((void *dummy)); 64PSEUDO_SET(discattach, if_disc); 65 66static struct ifnet discif; 67static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 68 struct rtentry *); 69static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa); 70static int discioctl(struct ifnet *, u_long, caddr_t); 71 72/* ARGSUSED */ 73static void 74discattach(dummy) 75 void *dummy; 76{ 77 register struct ifnet *ifp = &discif; 78 79 ifp->if_name = "ds"; 80 ifp->if_mtu = DSMTU; 81 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 82 ifp->if_ioctl = discioctl; 83 ifp->if_output = discoutput; 84 ifp->if_type = IFT_LOOP; 85 ifp->if_hdrlen = 0; 86 ifp->if_addrlen = 0; 87 if_attach(ifp); 88#if NBPFILTER > 0 89 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 90#endif 91} 92 93static int 94discoutput(ifp, m, dst, rt) 95 struct ifnet *ifp; 96 register struct mbuf *m; 97 struct sockaddr *dst; 98 register struct rtentry *rt; 99{ 100 if ((m->m_flags & M_PKTHDR) == 0) 101 panic("discoutput no HDR"); 102#if NBPFILTER > 0 103 /* BPF write needs to be handled specially */ 104 if (dst->sa_family == AF_UNSPEC) { 105 dst->sa_family = *(mtod(m, int *)); 106 m->m_len -= sizeof(int); 107 m->m_pkthdr.len -= sizeof(int); 108 m->m_data += sizeof(int); 109 } 110 111 if (discif.if_bpf) { 112 /* 113 * We need to prepend the address family as 114 * a four byte field. Cons up a dummy header 115 * to pacify bpf. This is safe because bpf 116 * will only read from the mbuf (i.e., it won't 117 * try to free it or keep a pointer a to it). 118 */ 119 struct mbuf m0; 120 u_int af = dst->sa_family; 121 122 m0.m_next = m; 123 m0.m_len = 4; 124 m0.m_data = (char *)⁡ 125 126 bpf_mtap(&discif, &m0); 127 } 128#endif 129 m->m_pkthdr.rcvif = ifp; 130 131 ifp->if_opackets++; 132 ifp->if_obytes += m->m_pkthdr.len; 133 134 m_freem(m); 135 return 0; 136} 137 138/* ARGSUSED */ 139static void 140discrtrequest(cmd, rt, sa) 141 int cmd; 142 struct rtentry *rt; 143 struct sockaddr *sa; 144{ 145 if (rt) 146 rt->rt_rmx.rmx_mtu = DSMTU; 147} 148 149/* 150 * Process an ioctl request. 151 */ 152/* ARGSUSED */ 153static int 154discioctl(ifp, cmd, data) 155 register struct ifnet *ifp; 156 u_long cmd; 157 caddr_t data; 158{ 159 register struct ifaddr *ifa; 160 register struct ifreq *ifr = (struct ifreq *)data; 161 register int error = 0; 162 163 switch (cmd) { 164 165 case SIOCSIFADDR: 166 ifp->if_flags |= IFF_UP; 167 ifa = (struct ifaddr *)data; 168 if (ifa != 0) 169 ifa->ifa_rtrequest = discrtrequest; 170 /* 171 * Everything else is done at a higher level. 172 */ 173 break; 174 175 case SIOCADDMULTI: 176 case SIOCDELMULTI: 177 if (ifr == 0) { 178 error = EAFNOSUPPORT; /* XXX */ 179 break; 180 } 181 switch (ifr->ifr_addr.sa_family) { 182 183#ifdef INET 184 case AF_INET: 185 break; 186#endif 187 188 default: 189 error = EAFNOSUPPORT; 190 break; 191 } 192 break; 193 194 case SIOCSIFMTU: 195 ifp->if_mtu = ifr->ifr_mtu; 196 break; 197 198 default: 199 error = EINVAL; 200 } 201 return (error); 202} 203