1 /* $NetBSD: if_loop.c,v 1.13 1994/10/30 21:48:50 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 36 */ 37 38 /* 39 * Loopback interface driver for protocol testing and timing. 40 */ 41 42 #include "bpfilter.h" 43 #include "loop.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/mbuf.h> 49 #include <sys/socket.h> 50 #include <sys/errno.h> 51 #include <sys/ioctl.h> 52 #include <sys/time.h> 53 54 #include <machine/cpu.h> 55 56 #include <net/if.h> 57 #include <net/if_types.h> 58 #include <net/netisr.h> 59 #include <net/route.h> 60 61 #ifdef INET 62 #include <netinet/in.h> 63 #include <netinet/in_systm.h> 64 #include <netinet/in_var.h> 65 #include <netinet/ip.h> 66 #endif 67 68 #ifdef NS 69 #include <netns/ns.h> 70 #include <netns/ns_if.h> 71 #endif 72 73 #ifdef ISO 74 #include <netiso/iso.h> 75 #include <netiso/iso_var.h> 76 #endif 77 78 #if NBPFILTER > 0 79 #include <net/bpf.h> 80 #endif 81 82 #define LOMTU (32768) 83 84 struct ifnet loif[NLOOP]; 85 86 void 87 loopattach(n) 88 int n; 89 { 90 register int i; 91 register struct ifnet *ifp; 92 93 for (i = 0; i < NLOOP; i++) { 94 ifp = &loif[i]; 95 ifp->if_unit = i; 96 ifp->if_name = "lo"; 97 ifp->if_mtu = LOMTU; 98 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 99 ifp->if_ioctl = loioctl; 100 ifp->if_output = looutput; 101 ifp->if_type = IFT_LOOP; 102 ifp->if_hdrlen = 0; 103 ifp->if_addrlen = 0; 104 if_attach(ifp); 105 #if NBPFILTER > 0 106 bpfattach(&ifp->if_bpf, ifp, DLT_NULL, sizeof(u_int)); 107 #endif 108 } 109 } 110 111 int 112 looutput(ifp, m, dst, rt) 113 struct ifnet *ifp; 114 register struct mbuf *m; 115 struct sockaddr *dst; 116 register struct rtentry *rt; 117 { 118 int s, isr; 119 register struct ifqueue *ifq = 0; 120 121 if ((m->m_flags & M_PKTHDR) == 0) 122 panic("looutput no HDR"); 123 ifp->if_lastchange = time; 124 #if NBPFILTER > 0 125 if (ifp->if_bpf) { 126 /* 127 * We need to prepend the address family as 128 * a four byte field. Cons up a dummy header 129 * to pacify bpf. This is safe because bpf 130 * will only read from the mbuf (i.e., it won't 131 * try to free it or keep a pointer to it). 132 */ 133 struct mbuf m0; 134 u_int af = dst->sa_family; 135 136 m0.m_next = m; 137 m0.m_len = 4; 138 m0.m_data = (char *)⁡ 139 140 bpf_mtap(ifp->if_bpf, &m0); 141 } 142 #endif 143 m->m_pkthdr.rcvif = ifp; 144 145 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 146 m_freem(m); 147 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 148 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 149 } 150 ifp->if_opackets++; 151 ifp->if_obytes += m->m_pkthdr.len; 152 switch (dst->sa_family) { 153 154 #ifdef INET 155 case AF_INET: 156 ifq = &ipintrq; 157 isr = NETISR_IP; 158 break; 159 #endif 160 #ifdef NS 161 case AF_NS: 162 ifq = &nsintrq; 163 isr = NETISR_NS; 164 break; 165 #endif 166 #ifdef ISO 167 case AF_ISO: 168 ifq = &clnlintrq; 169 isr = NETISR_ISO; 170 break; 171 #endif 172 default: 173 printf("lo%d: can't handle af%d\n", ifp->if_unit, 174 dst->sa_family); 175 m_freem(m); 176 return (EAFNOSUPPORT); 177 } 178 s = splimp(); 179 if (IF_QFULL(ifq)) { 180 IF_DROP(ifq); 181 m_freem(m); 182 splx(s); 183 return (ENOBUFS); 184 } 185 IF_ENQUEUE(ifq, m); 186 schednetisr(isr); 187 ifp->if_ipackets++; 188 ifp->if_ibytes += m->m_pkthdr.len; 189 splx(s); 190 return (0); 191 } 192 193 /* ARGSUSED */ 194 void 195 lortrequest(cmd, rt, sa) 196 int cmd; 197 struct rtentry *rt; 198 struct sockaddr *sa; 199 { 200 201 if (rt) 202 rt->rt_rmx.rmx_mtu = LOMTU; 203 } 204 205 /* 206 * Process an ioctl request. 207 */ 208 /* ARGSUSED */ 209 int 210 loioctl(ifp, cmd, data) 211 register struct ifnet *ifp; 212 u_long cmd; 213 caddr_t data; 214 { 215 register struct ifaddr *ifa; 216 register struct ifreq *ifr; 217 register int error = 0; 218 219 switch (cmd) { 220 221 case SIOCSIFADDR: 222 ifp->if_flags |= IFF_UP; 223 ifa = (struct ifaddr *)data; 224 if (ifa != 0 && ifa->ifa_addr->sa_family == AF_ISO) 225 ifa->ifa_rtrequest = lortrequest; 226 /* 227 * Everything else is done at a higher level. 228 */ 229 break; 230 231 case SIOCADDMULTI: 232 case SIOCDELMULTI: 233 ifr = (struct ifreq *)data; 234 if (ifr == 0) { 235 error = EAFNOSUPPORT; /* XXX */ 236 break; 237 } 238 switch (ifr->ifr_addr.sa_family) { 239 240 #ifdef INET 241 case AF_INET: 242 break; 243 #endif 244 245 default: 246 error = EAFNOSUPPORT; 247 break; 248 } 249 break; 250 251 default: 252 error = EINVAL; 253 } 254 return (error); 255 } 256