if_disc.c revision 13937
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 1.10 1995/12/03 19:08:55 bde 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/errno.h> 48#include <sys/ioctl.h> 49#include <sys/time.h> 50#include <machine/cpu.h> 51 52#include <net/if.h> 53#include <net/if_types.h> 54#include <net/netisr.h> 55#include <net/route.h> 56#include <net/bpf.h> 57 58#ifdef INET 59#include <netinet/in.h> 60#include <netinet/in_systm.h> 61#include <netinet/in_var.h> 62#include <netinet/ip.h> 63#endif 64 65#ifdef NS 66#include <netns/ns.h> 67#include <netns/ns_if.h> 68#endif 69 70#ifdef ISO 71#include <netiso/iso.h> 72#include <netiso/iso_var.h> 73#endif 74 75#include "bpfilter.h" 76 77#ifdef TINY_DSMTU 78#define DSMTU (1024+512) 79#else 80#define DSMTU 65532 81#endif 82 83static void discattach __P((void *dummy)); 84PSEUDO_SET(discattach, if_disc); 85 86static struct ifnet dsif; 87static int dsoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 88 struct rtentry *); 89static void dsrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa); 90static int dsioctl(struct ifnet *, int, caddr_t); 91 92/* ARGSUSED */ 93static void 94discattach(dummy) 95 void *dummy; 96{ 97 register struct ifnet *ifp = &dsif; 98 99 ifp->if_name = "ds"; 100 ifp->if_mtu = DSMTU; 101 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 102 ifp->if_ioctl = dsioctl; 103 ifp->if_output = dsoutput; 104 ifp->if_type = IFT_LOOP; 105 ifp->if_hdrlen = 0; 106 ifp->if_addrlen = 0; 107 if_attach(ifp); 108#if NBPFILTER > 0 109 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 110#endif 111} 112 113static int 114dsoutput(ifp, m, dst, rt) 115 struct ifnet *ifp; 116 register struct mbuf *m; 117 struct sockaddr *dst; 118 register struct rtentry *rt; 119{ 120 if ((m->m_flags & M_PKTHDR) == 0) 121 panic("dsoutput no HDR"); 122 ifp->if_lastchange = time; 123#if NBPFILTER > 0 124 /* BPF write needs to be handled specially */ 125 if (dst->sa_family == AF_UNSPEC) { 126 dst->sa_family = *(mtod(m, int *)); 127 m->m_len -= sizeof(int); 128 m->m_pkthdr.len -= sizeof(int); 129 m->m_data += sizeof(int); 130 } 131 132 if (dsif.if_bpf) { 133 /* 134 * We need to prepend the address family as 135 * a four byte field. Cons up a dummy header 136 * to pacify bpf. This is safe because bpf 137 * will only read from the mbuf (i.e., it won't 138 * try to free it or keep a pointer a to it). 139 */ 140 struct mbuf m0; 141 u_int af = dst->sa_family; 142 143 m0.m_next = m; 144 m0.m_len = 4; 145 m0.m_data = (char *)⁡ 146 147 bpf_mtap(&dsif, &m0); 148 } 149#endif 150 m->m_pkthdr.rcvif = ifp; 151 152 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 153 m_freem(m); 154 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 155 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 156 } 157 ifp->if_opackets++; 158 ifp->if_obytes += m->m_pkthdr.len; 159 160 m_freem(m); 161 return 0; 162} 163 164/* ARGSUSED */ 165static void 166dsrtrequest(cmd, rt, sa) 167 int cmd; 168 struct rtentry *rt; 169 struct sockaddr *sa; 170{ 171 if (rt) 172 rt->rt_rmx.rmx_mtu = DSMTU; 173} 174 175/* 176 * Process an ioctl request. 177 */ 178/* ARGSUSED */ 179static int 180dsioctl(ifp, cmd, data) 181 register struct ifnet *ifp; 182 int cmd; 183 caddr_t data; 184{ 185 register struct ifaddr *ifa; 186 register struct ifreq *ifr = (struct ifreq *)data; 187 register int error = 0; 188 189 switch (cmd) { 190 191 case SIOCSIFADDR: 192 ifp->if_flags |= IFF_UP; 193 ifa = (struct ifaddr *)data; 194 if (ifa != 0) 195 ifa->ifa_rtrequest = dsrtrequest; 196 /* 197 * Everything else is done at a higher level. 198 */ 199 break; 200 201 case SIOCADDMULTI: 202 case SIOCDELMULTI: 203 if (ifr == 0) { 204 error = EAFNOSUPPORT; /* XXX */ 205 break; 206 } 207 switch (ifr->ifr_addr.sa_family) { 208 209#ifdef INET 210 case AF_INET: 211 break; 212#endif 213 214 default: 215 error = EAFNOSUPPORT; 216 break; 217 } 218 break; 219 220 case SIOCSIFMTU: 221 ifp->if_mtu = ifr->ifr_mtu; 222 break; 223 224 default: 225 error = EINVAL; 226 } 227 return (error); 228} 229