if_disc.c revision 53115
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 * $FreeBSD: head/sys/net/if_disc.c 53115 1999-11-12 19:30:08Z phk $ 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 "opt_inet.h" 55 56#ifdef TINY_DSMTU 57#define DSMTU (1024+512) 58#else 59#define DSMTU 65532 60#endif 61 62static void discattach __P((void *dummy)); 63PSEUDO_SET(discattach, if_disc); 64 65static struct ifnet discif; 66static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 67 struct rtentry *); 68static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa); 69static int discioctl(struct ifnet *, u_long, caddr_t); 70 71/* ARGSUSED */ 72static void 73discattach(dummy) 74 void *dummy; 75{ 76 register struct ifnet *ifp = &discif; 77 78 ifp->if_name = "ds"; 79 ifp->if_mtu = DSMTU; 80 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 81 ifp->if_ioctl = discioctl; 82 ifp->if_output = discoutput; 83 ifp->if_type = IFT_LOOP; 84 ifp->if_hdrlen = 0; 85 ifp->if_addrlen = 0; 86 ifp->if_snd.ifq_maxlen = 20; 87 if_attach(ifp); 88 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 89} 90 91static int 92discoutput(ifp, m, dst, rt) 93 struct ifnet *ifp; 94 register struct mbuf *m; 95 struct sockaddr *dst; 96 register struct rtentry *rt; 97{ 98 if ((m->m_flags & M_PKTHDR) == 0) 99 panic("discoutput no HDR"); 100 /* BPF write needs to be handled specially */ 101 if (dst->sa_family == AF_UNSPEC) { 102 dst->sa_family = *(mtod(m, int *)); 103 m->m_len -= sizeof(int); 104 m->m_pkthdr.len -= sizeof(int); 105 m->m_data += sizeof(int); 106 } 107 108 if (discif.if_bpf) { 109 /* 110 * We need to prepend the address family as 111 * a four byte field. Cons up a dummy header 112 * to pacify bpf. This is safe because bpf 113 * will only read from the mbuf (i.e., it won't 114 * try to free it or keep a pointer a to it). 115 */ 116 struct mbuf m0; 117 u_int af = dst->sa_family; 118 119 m0.m_next = m; 120 m0.m_len = 4; 121 m0.m_data = (char *)⁡ 122 123 bpf_mtap(&discif, &m0); 124 } 125 m->m_pkthdr.rcvif = ifp; 126 127 ifp->if_opackets++; 128 ifp->if_obytes += m->m_pkthdr.len; 129 130 m_freem(m); 131 return 0; 132} 133 134/* ARGSUSED */ 135static void 136discrtrequest(cmd, rt, sa) 137 int cmd; 138 struct rtentry *rt; 139 struct sockaddr *sa; 140{ 141 if (rt) 142 rt->rt_rmx.rmx_mtu = DSMTU; 143} 144 145/* 146 * Process an ioctl request. 147 */ 148/* ARGSUSED */ 149static int 150discioctl(ifp, cmd, data) 151 register struct ifnet *ifp; 152 u_long cmd; 153 caddr_t data; 154{ 155 register struct ifaddr *ifa; 156 register struct ifreq *ifr = (struct ifreq *)data; 157 register int error = 0; 158 159 switch (cmd) { 160 161 case SIOCSIFADDR: 162 ifp->if_flags |= IFF_UP; 163 ifa = (struct ifaddr *)data; 164 if (ifa != 0) 165 ifa->ifa_rtrequest = discrtrequest; 166 /* 167 * Everything else is done at a higher level. 168 */ 169 break; 170 171 case SIOCADDMULTI: 172 case SIOCDELMULTI: 173 if (ifr == 0) { 174 error = EAFNOSUPPORT; /* XXX */ 175 break; 176 } 177 switch (ifr->ifr_addr.sa_family) { 178 179#ifdef INET 180 case AF_INET: 181 break; 182#endif 183 184 default: 185 error = EAFNOSUPPORT; 186 break; 187 } 188 break; 189 190 case SIOCSIFMTU: 191 ifp->if_mtu = ifr->ifr_mtu; 192 break; 193 194 default: 195 error = EINVAL; 196 } 197 return (error); 198} 199