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 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 34 * $Id: if_loop.c,v 1.33 1998/06/12 03:48:09 julian Exp $ 35 */ 36 37 /* 38 * Loopback interface driver for protocol testing and timing. 39 */ 40 #include "loop.h" 41 #if NLOOP > 0 42 43 #include "opt_atalk.h" 44 #include "opt_inet.h" 45 #include "opt_ipx.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/mbuf.h> 51 #include <sys/socket.h> 52 #include <sys/sockio.h> 53 54 #include <net/if.h> 55 #include <net/if_types.h> 56 #include <net/netisr.h> 57 #include <net/route.h> 58 #include <net/bpf.h> 59 60 #ifdef INET 61 #include <netinet/in.h> 62 #include <netinet/in_var.h> 63 #endif 64 65 #ifdef IPX 66 #include <netipx/ipx.h> 67 #include <netipx/ipx_if.h> 68 #endif 69 70 #ifdef NS 71 #include <netns/ns.h> 72 #include <netns/ns_if.h> 73 #endif 74 75 #ifdef ISO 76 #include <netiso/iso.h> 77 #include <netiso/iso_var.h> 78 #endif 79 80 #ifdef NETATALK 81 #include <netatalk/at.h> 82 #include <netatalk/at_var.h> 83 #endif NETATALK 84 85 #include "bpfilter.h" 86 #if NBPFILTER > 0 87 #include <net/bpfdesc.h> 88 #endif 89 90 static int loioctl __P((struct ifnet *, u_long, caddr_t)); 91 static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 92 93 static void loopattach __P((void *)); 94 PSEUDO_SET(loopattach, if_loop); 95 96 static int looutput __P((struct ifnet *ifp, 97 struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)); 98 99 #ifdef TINY_LOMTU 100 #define LOMTU (1024+512) 101 #else 102 #define LOMTU 16384 103 #endif 104 105 struct ifnet loif[NLOOP]; 106 107 /* ARGSUSED */ 108 static void 109 loopattach(dummy) 110 void *dummy; 111 { 112 register struct ifnet *ifp; 113 register int i = 0; 114 115 for (ifp = loif; i < NLOOP; ifp++) { 116 ifp->if_name = "lo"; 117 ifp->if_unit = i++; 118 ifp->if_mtu = LOMTU; 119 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 120 ifp->if_ioctl = loioctl; 121 ifp->if_output = looutput; 122 ifp->if_type = IFT_LOOP; 123 if_attach(ifp); 124 #if NBPFILTER > 0 125 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 126 #endif 127 } 128 } 129 130 static int 131 looutput(ifp, m, dst, rt) 132 struct ifnet *ifp; 133 register struct mbuf *m; 134 struct sockaddr *dst; 135 register struct rtentry *rt; 136 { 137 if ((m->m_flags & M_PKTHDR) == 0) 138 panic("looutput no HDR"); 139 140 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 141 m_freem(m); 142 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 143 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 144 } 145 ifp->if_opackets++; 146 ifp->if_obytes += m->m_pkthdr.len; 147 return(if_simloop(ifp, m, dst, 0)); 148 } 149 150 /* 151 * if_simloop() 152 * 153 * This function is to support software emulation of hardware loopback, 154 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 155 * hear their own broadcasts, we create a copy of the packet that we 156 * would normally receive via a hardware loopback. 157 * 158 * This function expects the packet to include the media header of length hlen. 159 */ 160 161 int 162 if_simloop(ifp, m, dst, hlen) 163 struct ifnet *ifp; 164 register struct mbuf *m; 165 struct sockaddr *dst; 166 int hlen; 167 { 168 int s, isr; 169 register struct ifqueue *ifq = 0; 170 171 if ((m->m_flags & M_PKTHDR) == 0) 172 panic("if_simloop: no HDR"); 173 m->m_pkthdr.rcvif = ifp; 174 #if NBPFILTER > 0 175 /* BPF write needs to be handled specially */ 176 if (dst->sa_family == AF_UNSPEC) { 177 dst->sa_family = *(mtod(m, int *)); 178 m->m_len -= sizeof(int); 179 m->m_pkthdr.len -= sizeof(int); 180 m->m_data += sizeof(int); 181 } 182 183 if (ifp->if_bpf) { 184 struct mbuf m0, *n = m; 185 u_int af = dst->sa_family; 186 187 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 188 /* 189 * We need to prepend the address family as 190 * a four byte field. Cons up a dummy header 191 * to pacify bpf. This is safe because bpf 192 * will only read from the mbuf (i.e., it won't 193 * try to free it or keep a pointer a to it). 194 */ 195 m0.m_next = m; 196 m0.m_len = 4; 197 m0.m_data = (char *)⁡ 198 n = &m0; 199 } 200 bpf_mtap(ifp, n); 201 } 202 #endif 203 204 /* Strip away media header */ 205 if (hlen > 0) 206 m_adj(m, hlen); 207 208 switch (dst->sa_family) { 209 #ifdef INET 210 case AF_INET: 211 ifq = &ipintrq; 212 isr = NETISR_IP; 213 break; 214 #endif 215 #ifdef IPX 216 case AF_IPX: 217 ifq = &ipxintrq; 218 isr = NETISR_IPX; 219 break; 220 #endif 221 #ifdef NS 222 case AF_NS: 223 ifq = &nsintrq; 224 isr = NETISR_NS; 225 break; 226 #endif 227 #ifdef ISO 228 case AF_ISO: 229 ifq = &clnlintrq; 230 isr = NETISR_ISO; 231 break; 232 #endif 233 #ifdef NETATALK 234 case AF_APPLETALK: 235 ifq = &atintrq2; 236 isr = NETISR_ATALK; 237 break; 238 #endif NETATALK 239 default: 240 printf("if_simloop: can't handle af=%d\n", dst->sa_family); 241 m_freem(m); 242 return (EAFNOSUPPORT); 243 } 244 s = splimp(); 245 if (IF_QFULL(ifq)) { 246 IF_DROP(ifq); 247 m_freem(m); 248 splx(s); 249 return (ENOBUFS); 250 } 251 IF_ENQUEUE(ifq, m); 252 schednetisr(isr); 253 ifp->if_ipackets++; 254 ifp->if_ibytes += m->m_pkthdr.len; 255 splx(s); 256 return (0); 257 } 258 259 /* ARGSUSED */ 260 static void 261 lortrequest(cmd, rt, sa) 262 int cmd; 263 struct rtentry *rt; 264 struct sockaddr *sa; 265 { 266 if (rt) { 267 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 268 /* 269 * For optimal performance, the send and receive buffers 270 * should be at least twice the MTU plus a little more for 271 * overhead. 272 */ 273 rt->rt_rmx.rmx_recvpipe = 274 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 275 } 276 } 277 278 /* 279 * Process an ioctl request. 280 */ 281 /* ARGSUSED */ 282 static int 283 loioctl(ifp, cmd, data) 284 register struct ifnet *ifp; 285 u_long cmd; 286 caddr_t data; 287 { 288 register struct ifaddr *ifa; 289 register struct ifreq *ifr = (struct ifreq *)data; 290 register int error = 0; 291 292 switch (cmd) { 293 294 case SIOCSIFADDR: 295 ifp->if_flags |= IFF_UP | IFF_RUNNING; 296 ifa = (struct ifaddr *)data; 297 ifa->ifa_rtrequest = lortrequest; 298 /* 299 * Everything else is done at a higher level. 300 */ 301 break; 302 303 case SIOCADDMULTI: 304 case SIOCDELMULTI: 305 if (ifr == 0) { 306 error = EAFNOSUPPORT; /* XXX */ 307 break; 308 } 309 switch (ifr->ifr_addr.sa_family) { 310 311 #ifdef INET 312 case AF_INET: 313 break; 314 #endif 315 316 default: 317 error = EAFNOSUPPORT; 318 break; 319 } 320 break; 321 322 case SIOCSIFMTU: 323 ifp->if_mtu = ifr->ifr_mtu; 324 break; 325 326 case SIOCSIFFLAGS: 327 break; 328 329 default: 330 error = EINVAL; 331 } 332 return (error); 333 } 334 #endif /* NLOOP > 0 */ 335