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: src/sys/net/if_disc.c,v 1.26.2.2 2001/12/20 10:30:16 ru 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/module.h> 46 #include <sys/mbuf.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 50 #include <net/if.h> 51 #include <net/if_types.h> 52 #include <net/route.h> 53 #include <net/bpf.h> 54 55 #include "opt_inet.h" 56 #include "opt_inet6.h" 57 58 #ifdef TINY_DSMTU 59 #define DSMTU (1024+512) 60 #else 61 #define DSMTU 65532 62 #endif 63 64 static void discattach __P((void)); 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 rt_addrinfo *info); 70 static int discioctl(struct ifnet *, u_long, caddr_t); 71 72 /* ARGSUSED */ 73 static void 74 discattach() 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 91 static int 92 disc_modevent(module_t mod, int type, void *data) 93 { 94 switch (type) { 95 case MOD_LOAD: 96 discattach(); 97 break; 98 case MOD_UNLOAD: 99 printf("if_disc module unload - not possible for this module type\n"); 100 return EINVAL; 101 } 102 return 0; 103 } 104 105 static moduledata_t disc_mod = { 106 "if_disc", 107 disc_modevent, 108 NULL 109 }; 110 111 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 112 113 static int 114 discoutput(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("discoutput no HDR"); 122 /* BPF write needs to be handled specially */ 123 if (dst->sa_family == AF_UNSPEC) { 124 dst->sa_family = *(mtod(m, int *)); 125 m->m_len -= sizeof(int); 126 m->m_pkthdr.len -= sizeof(int); 127 m->m_data += sizeof(int); 128 } 129 130 if (discif.if_bpf) { 131 /* 132 * We need to prepend the address family as 133 * a four byte field. Cons up a dummy header 134 * to pacify bpf. This is safe because bpf 135 * will only read from the mbuf (i.e., it won't 136 * try to free it or keep a pointer a to it). 137 */ 138 struct mbuf m0; 139 u_int af = dst->sa_family; 140 141 m0.m_next = m; 142 m0.m_len = 4; 143 m0.m_data = (char *)⁡ 144 145 bpf_mtap(&discif, &m0); 146 } 147 m->m_pkthdr.rcvif = ifp; 148 149 ifp->if_opackets++; 150 ifp->if_obytes += m->m_pkthdr.len; 151 152 m_freem(m); 153 return 0; 154 } 155 156 /* ARGSUSED */ 157 static void 158 discrtrequest(cmd, rt, info) 159 int cmd; 160 struct rtentry *rt; 161 struct rt_addrinfo *info; 162 { 163 if (rt) 164 rt->rt_rmx.rmx_mtu = DSMTU; 165 } 166 167 /* 168 * Process an ioctl request. 169 */ 170 /* ARGSUSED */ 171 static int 172 discioctl(ifp, cmd, data) 173 register struct ifnet *ifp; 174 u_long cmd; 175 caddr_t data; 176 { 177 register struct ifaddr *ifa; 178 register struct ifreq *ifr = (struct ifreq *)data; 179 register int error = 0; 180 181 switch (cmd) { 182 183 case SIOCSIFADDR: 184 ifp->if_flags |= IFF_UP; 185 ifa = (struct ifaddr *)data; 186 if (ifa != 0) 187 ifa->ifa_rtrequest = discrtrequest; 188 /* 189 * Everything else is done at a higher level. 190 */ 191 break; 192 193 case SIOCADDMULTI: 194 case SIOCDELMULTI: 195 if (ifr == 0) { 196 error = EAFNOSUPPORT; /* XXX */ 197 break; 198 } 199 switch (ifr->ifr_addr.sa_family) { 200 201 #ifdef INET 202 case AF_INET: 203 break; 204 #endif 205 #ifdef INET6 206 case AF_INET6: 207 break; 208 #endif 209 210 default: 211 error = EAFNOSUPPORT; 212 break; 213 } 214 break; 215 216 case SIOCSIFMTU: 217 ifp->if_mtu = ifr->ifr_mtu; 218 break; 219 220 default: 221 error = EINVAL; 222 } 223 return (error); 224 } 225