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 * $FreeBSD$ 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 #include "opt_inet6.h" 56 57 #ifdef TINY_DSMTU 58 #define DSMTU (1024+512) 59 #else 60 #define DSMTU 65532 61 #endif 62 63 static void discattach __P((void *dummy)); 64 PSEUDO_SET(discattach, if_disc); 65 66 static struct ifnet discif; 67 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 68 struct rtentry *); 69 static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa); 70 static int discioctl(struct ifnet *, u_long, caddr_t); 71 72 /* ARGSUSED */ 73 static void 74 discattach(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 ifp->if_snd.ifq_maxlen = 20; 88 if_attach(ifp); 89 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 90 } 91 92 static int 93 discoutput(ifp, m, dst, rt) 94 struct ifnet *ifp; 95 register struct mbuf *m; 96 struct sockaddr *dst; 97 register struct rtentry *rt; 98 { 99 if ((m->m_flags & M_PKTHDR) == 0) 100 panic("discoutput no HDR"); 101 /* BPF write needs to be handled specially */ 102 if (dst->sa_family == AF_UNSPEC) { 103 dst->sa_family = *(mtod(m, int *)); 104 m->m_len -= sizeof(int); 105 m->m_pkthdr.len -= sizeof(int); 106 m->m_data += sizeof(int); 107 } 108 109 if (discif.if_bpf) { 110 /* 111 * We need to prepend the address family as 112 * a four byte field. Cons up a dummy header 113 * to pacify bpf. This is safe because bpf 114 * will only read from the mbuf (i.e., it won't 115 * try to free it or keep a pointer a to it). 116 */ 117 struct mbuf m0; 118 u_int af = dst->sa_family; 119 120 m0.m_next = m; 121 m0.m_len = 4; 122 m0.m_data = (char *)⁡ 123 124 bpf_mtap(&discif, &m0); 125 } 126 m->m_pkthdr.rcvif = ifp; 127 128 ifp->if_opackets++; 129 ifp->if_obytes += m->m_pkthdr.len; 130 131 m_freem(m); 132 return 0; 133 } 134 135 /* ARGSUSED */ 136 static void 137 discrtrequest(cmd, rt, sa) 138 int cmd; 139 struct rtentry *rt; 140 struct sockaddr *sa; 141 { 142 if (rt) 143 rt->rt_rmx.rmx_mtu = DSMTU; 144 } 145 146 /* 147 * Process an ioctl request. 148 */ 149 /* ARGSUSED */ 150 static int 151 discioctl(ifp, cmd, data) 152 register struct ifnet *ifp; 153 u_long cmd; 154 caddr_t data; 155 { 156 register struct ifaddr *ifa; 157 register struct ifreq *ifr = (struct ifreq *)data; 158 register int error = 0; 159 160 switch (cmd) { 161 162 case SIOCSIFADDR: 163 ifp->if_flags |= IFF_UP; 164 ifa = (struct ifaddr *)data; 165 if (ifa != 0) 166 ifa->ifa_rtrequest = discrtrequest; 167 /* 168 * Everything else is done at a higher level. 169 */ 170 break; 171 172 case SIOCADDMULTI: 173 case SIOCDELMULTI: 174 if (ifr == 0) { 175 error = EAFNOSUPPORT; /* XXX */ 176 break; 177 } 178 switch (ifr->ifr_addr.sa_family) { 179 180 #ifdef INET 181 case AF_INET: 182 break; 183 #endif 184 #ifdef INET6 185 case AF_INET6: 186 break; 187 #endif 188 189 default: 190 error = EAFNOSUPPORT; 191 break; 192 } 193 break; 194 195 case SIOCSIFMTU: 196 ifp->if_mtu = ifr->ifr_mtu; 197 break; 198 199 default: 200 error = EINVAL; 201 } 202 return (error); 203 } 204